From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/dccp/Kconfig | 46 + net/dccp/Makefile | 30 + net/dccp/ackvec.c | 407 +++++++++ net/dccp/ackvec.h | 136 +++ net/dccp/ccid.c | 219 +++++ net/dccp/ccid.h | 262 ++++++ net/dccp/ccids/Kconfig | 55 ++ net/dccp/ccids/ccid2.c | 793 ++++++++++++++++++ net/dccp/ccids/ccid2.h | 121 +++ net/dccp/ccids/ccid3.c | 866 +++++++++++++++++++ net/dccp/ccids/ccid3.h | 148 ++++ net/dccp/ccids/lib/loss_interval.c | 184 ++++ net/dccp/ccids/lib/loss_interval.h | 69 ++ net/dccp/ccids/lib/packet_history.c | 439 ++++++++++ net/dccp/ccids/lib/packet_history.h | 142 ++++ net/dccp/ccids/lib/tfrc.c | 46 + net/dccp/ccids/lib/tfrc.h | 73 ++ net/dccp/ccids/lib/tfrc_equation.c | 702 ++++++++++++++++ net/dccp/dccp.h | 483 +++++++++++ net/dccp/diag.c | 84 ++ net/dccp/feat.c | 1577 +++++++++++++++++++++++++++++++++++ net/dccp/feat.h | 134 +++ net/dccp/input.c | 739 ++++++++++++++++ net/dccp/ipv4.c | 1100 ++++++++++++++++++++++++ net/dccp/ipv6.c | 1181 ++++++++++++++++++++++++++ net/dccp/ipv6.h | 31 + net/dccp/minisocks.c | 272 ++++++ net/dccp/options.c | 609 ++++++++++++++ net/dccp/output.c | 709 ++++++++++++++++ net/dccp/proto.c | 1290 ++++++++++++++++++++++++++++ net/dccp/qpolicy.c | 136 +++ net/dccp/sysctl.c | 113 +++ net/dccp/timer.c | 272 ++++++ net/dccp/trace.h | 82 ++ 34 files changed, 13550 insertions(+) create mode 100644 net/dccp/Kconfig create mode 100644 net/dccp/Makefile create mode 100644 net/dccp/ackvec.c create mode 100644 net/dccp/ackvec.h create mode 100644 net/dccp/ccid.c create mode 100644 net/dccp/ccid.h create mode 100644 net/dccp/ccids/Kconfig create mode 100644 net/dccp/ccids/ccid2.c create mode 100644 net/dccp/ccids/ccid2.h create mode 100644 net/dccp/ccids/ccid3.c create mode 100644 net/dccp/ccids/ccid3.h create mode 100644 net/dccp/ccids/lib/loss_interval.c create mode 100644 net/dccp/ccids/lib/loss_interval.h create mode 100644 net/dccp/ccids/lib/packet_history.c create mode 100644 net/dccp/ccids/lib/packet_history.h create mode 100644 net/dccp/ccids/lib/tfrc.c create mode 100644 net/dccp/ccids/lib/tfrc.h create mode 100644 net/dccp/ccids/lib/tfrc_equation.c create mode 100644 net/dccp/dccp.h create mode 100644 net/dccp/diag.c create mode 100644 net/dccp/feat.c create mode 100644 net/dccp/feat.h create mode 100644 net/dccp/input.c create mode 100644 net/dccp/ipv4.c create mode 100644 net/dccp/ipv6.c create mode 100644 net/dccp/ipv6.h create mode 100644 net/dccp/minisocks.c create mode 100644 net/dccp/options.c create mode 100644 net/dccp/output.c create mode 100644 net/dccp/proto.c create mode 100644 net/dccp/qpolicy.c create mode 100644 net/dccp/sysctl.c create mode 100644 net/dccp/timer.c create mode 100644 net/dccp/trace.h (limited to 'net/dccp') diff --git a/net/dccp/Kconfig b/net/dccp/Kconfig new file mode 100644 index 000000000..0c7d2f66b --- /dev/null +++ b/net/dccp/Kconfig @@ -0,0 +1,46 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig IP_DCCP + tristate "The DCCP Protocol" + depends on INET + help + Datagram Congestion Control Protocol (RFC 4340) + + From https://www.ietf.org/rfc/rfc4340.txt: + + The Datagram Congestion Control Protocol (DCCP) is a transport + protocol that implements bidirectional, unicast connections of + congestion-controlled, unreliable datagrams. It should be suitable + for use by applications such as streaming media, Internet telephony, + and on-line games. + + To compile this protocol support as a module, choose M here: the + module will be called dccp. + + If in doubt, say N. + +if IP_DCCP + +config INET_DCCP_DIAG + depends on INET_DIAG + def_tristate y if (IP_DCCP = y && INET_DIAG = y) + def_tristate m + +source "net/dccp/ccids/Kconfig" + +menu "DCCP Kernel Hacking" + depends on DEBUG_KERNEL=y + +config IP_DCCP_DEBUG + bool "DCCP debug messages" + help + Only use this if you're hacking DCCP. + + When compiling DCCP as a module, this debugging output can be toggled + by setting the parameter dccp_debug of the `dccp' module to 0 or 1. + + Just say N. + + +endmenu + +endif # IP_DDCP diff --git a/net/dccp/Makefile b/net/dccp/Makefile new file mode 100644 index 000000000..5b4ff37bc --- /dev/null +++ b/net/dccp/Makefile @@ -0,0 +1,30 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_IP_DCCP) += dccp.o dccp_ipv4.o + +dccp-y := ccid.o feat.o input.o minisocks.o options.o output.o proto.o timer.o \ + qpolicy.o +# +# CCID algorithms to be used by dccp.ko +# +# CCID-2 is default (RFC 4340, p. 77) and has Ack Vectors as dependency +dccp-y += ccids/ccid2.o ackvec.o +dccp-$(CONFIG_IP_DCCP_CCID3) += ccids/ccid3.o +dccp-$(CONFIG_IP_DCCP_TFRC_LIB) += ccids/lib/tfrc.o \ + ccids/lib/tfrc_equation.o \ + ccids/lib/packet_history.o \ + ccids/lib/loss_interval.o + +dccp_ipv4-y := ipv4.o + +# build dccp_ipv6 as module whenever either IPv6 or DCCP is a module +obj-$(subst y,$(CONFIG_IP_DCCP),$(CONFIG_IPV6)) += dccp_ipv6.o +dccp_ipv6-y := ipv6.o + +obj-$(CONFIG_INET_DCCP_DIAG) += dccp_diag.o + +dccp-$(CONFIG_SYSCTL) += sysctl.o + +dccp_diag-y := diag.o + +# build with local directory for trace.h +CFLAGS_proto.o := -I$(src) diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c new file mode 100644 index 000000000..c4bbac997 --- /dev/null +++ b/net/dccp/ackvec.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/ackvec.c + * + * An implementation of Ack Vectors for the DCCP protocol + * Copyright (c) 2007 University of Aberdeen, Scotland, UK + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ +#include "dccp.h" +#include +#include +#include + +static struct kmem_cache *dccp_ackvec_slab; +static struct kmem_cache *dccp_ackvec_record_slab; + +struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority) +{ + struct dccp_ackvec *av = kmem_cache_zalloc(dccp_ackvec_slab, priority); + + if (av != NULL) { + av->av_buf_head = av->av_buf_tail = DCCPAV_MAX_ACKVEC_LEN - 1; + INIT_LIST_HEAD(&av->av_records); + } + return av; +} + +static void dccp_ackvec_purge_records(struct dccp_ackvec *av) +{ + struct dccp_ackvec_record *cur, *next; + + list_for_each_entry_safe(cur, next, &av->av_records, avr_node) + kmem_cache_free(dccp_ackvec_record_slab, cur); + INIT_LIST_HEAD(&av->av_records); +} + +void dccp_ackvec_free(struct dccp_ackvec *av) +{ + if (likely(av != NULL)) { + dccp_ackvec_purge_records(av); + kmem_cache_free(dccp_ackvec_slab, av); + } +} + +/** + * dccp_ackvec_update_records - Record information about sent Ack Vectors + * @av: Ack Vector records to update + * @seqno: Sequence number of the packet carrying the Ack Vector just sent + * @nonce_sum: The sum of all buffer nonces contained in the Ack Vector + */ +int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seqno, u8 nonce_sum) +{ + struct dccp_ackvec_record *avr; + + avr = kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC); + if (avr == NULL) + return -ENOBUFS; + + avr->avr_ack_seqno = seqno; + avr->avr_ack_ptr = av->av_buf_head; + avr->avr_ack_ackno = av->av_buf_ackno; + avr->avr_ack_nonce = nonce_sum; + avr->avr_ack_runlen = dccp_ackvec_runlen(av->av_buf + av->av_buf_head); + /* + * When the buffer overflows, we keep no more than one record. This is + * the simplest way of disambiguating sender-Acks dating from before the + * overflow from sender-Acks which refer to after the overflow; a simple + * solution is preferable here since we are handling an exception. + */ + if (av->av_overflow) + dccp_ackvec_purge_records(av); + /* + * Since GSS is incremented for each packet, the list is automatically + * arranged in descending order of @ack_seqno. + */ + list_add(&avr->avr_node, &av->av_records); + + dccp_pr_debug("Added Vector, ack_seqno=%llu, ack_ackno=%llu (rl=%u)\n", + (unsigned long long)avr->avr_ack_seqno, + (unsigned long long)avr->avr_ack_ackno, + avr->avr_ack_runlen); + return 0; +} + +static struct dccp_ackvec_record *dccp_ackvec_lookup(struct list_head *av_list, + const u64 ackno) +{ + struct dccp_ackvec_record *avr; + /* + * Exploit that records are inserted in descending order of sequence + * number, start with the oldest record first. If @ackno is `before' + * the earliest ack_ackno, the packet is too old to be considered. + */ + list_for_each_entry_reverse(avr, av_list, avr_node) { + if (avr->avr_ack_seqno == ackno) + return avr; + if (before48(ackno, avr->avr_ack_seqno)) + break; + } + return NULL; +} + +/* + * Buffer index and length computation using modulo-buffersize arithmetic. + * Note that, as pointers move from right to left, head is `before' tail. + */ +static inline u16 __ackvec_idx_add(const u16 a, const u16 b) +{ + return (a + b) % DCCPAV_MAX_ACKVEC_LEN; +} + +static inline u16 __ackvec_idx_sub(const u16 a, const u16 b) +{ + return __ackvec_idx_add(a, DCCPAV_MAX_ACKVEC_LEN - b); +} + +u16 dccp_ackvec_buflen(const struct dccp_ackvec *av) +{ + if (unlikely(av->av_overflow)) + return DCCPAV_MAX_ACKVEC_LEN; + return __ackvec_idx_sub(av->av_buf_tail, av->av_buf_head); +} + +/** + * dccp_ackvec_update_old - Update previous state as per RFC 4340, 11.4.1 + * @av: non-empty buffer to update + * @distance: negative or zero distance of @seqno from buf_ackno downward + * @seqno: the (old) sequence number whose record is to be updated + * @state: state in which packet carrying @seqno was received + */ +static void dccp_ackvec_update_old(struct dccp_ackvec *av, s64 distance, + u64 seqno, enum dccp_ackvec_states state) +{ + u16 ptr = av->av_buf_head; + + BUG_ON(distance > 0); + if (unlikely(dccp_ackvec_is_empty(av))) + return; + + do { + u8 runlen = dccp_ackvec_runlen(av->av_buf + ptr); + + if (distance + runlen >= 0) { + /* + * Only update the state if packet has not been received + * yet. This is OK as per the second table in RFC 4340, + * 11.4.1; i.e. here we are using the following table: + * RECEIVED + * 0 1 3 + * S +---+---+---+ + * T 0 | 0 | 0 | 0 | + * O +---+---+---+ + * R 1 | 1 | 1 | 1 | + * E +---+---+---+ + * D 3 | 0 | 1 | 3 | + * +---+---+---+ + * The "Not Received" state was set by reserve_seats(). + */ + if (av->av_buf[ptr] == DCCPAV_NOT_RECEIVED) + av->av_buf[ptr] = state; + else + dccp_pr_debug("Not changing %llu state to %u\n", + (unsigned long long)seqno, state); + break; + } + + distance += runlen + 1; + ptr = __ackvec_idx_add(ptr, 1); + + } while (ptr != av->av_buf_tail); +} + +/* Mark @num entries after buf_head as "Not yet received". */ +static void dccp_ackvec_reserve_seats(struct dccp_ackvec *av, u16 num) +{ + u16 start = __ackvec_idx_add(av->av_buf_head, 1), + len = DCCPAV_MAX_ACKVEC_LEN - start; + + /* check for buffer wrap-around */ + if (num > len) { + memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, len); + start = 0; + num -= len; + } + if (num) + memset(av->av_buf + start, DCCPAV_NOT_RECEIVED, num); +} + +/** + * dccp_ackvec_add_new - Record one or more new entries in Ack Vector buffer + * @av: container of buffer to update (can be empty or non-empty) + * @num_packets: number of packets to register (must be >= 1) + * @seqno: sequence number of the first packet in @num_packets + * @state: state in which packet carrying @seqno was received + */ +static void dccp_ackvec_add_new(struct dccp_ackvec *av, u32 num_packets, + u64 seqno, enum dccp_ackvec_states state) +{ + u32 num_cells = num_packets; + + if (num_packets > DCCPAV_BURST_THRESH) { + u32 lost_packets = num_packets - 1; + + DCCP_WARN("Warning: large burst loss (%u)\n", lost_packets); + /* + * We received 1 packet and have a loss of size "num_packets-1" + * which we squeeze into num_cells-1 rather than reserving an + * entire byte for each lost packet. + * The reason is that the vector grows in O(burst_length); when + * it grows too large there will no room left for the payload. + * This is a trade-off: if a few packets out of the burst show + * up later, their state will not be changed; it is simply too + * costly to reshuffle/reallocate/copy the buffer each time. + * Should such problems persist, we will need to switch to a + * different underlying data structure. + */ + for (num_packets = num_cells = 1; lost_packets; ++num_cells) { + u8 len = min_t(u32, lost_packets, DCCPAV_MAX_RUNLEN); + + av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, 1); + av->av_buf[av->av_buf_head] = DCCPAV_NOT_RECEIVED | len; + + lost_packets -= len; + } + } + + if (num_cells + dccp_ackvec_buflen(av) >= DCCPAV_MAX_ACKVEC_LEN) { + DCCP_CRIT("Ack Vector buffer overflow: dropping old entries"); + av->av_overflow = true; + } + + av->av_buf_head = __ackvec_idx_sub(av->av_buf_head, num_packets); + if (av->av_overflow) + av->av_buf_tail = av->av_buf_head; + + av->av_buf[av->av_buf_head] = state; + av->av_buf_ackno = seqno; + + if (num_packets > 1) + dccp_ackvec_reserve_seats(av, num_packets - 1); +} + +/** + * dccp_ackvec_input - Register incoming packet in the buffer + * @av: Ack Vector to register packet to + * @skb: Packet to register + */ +void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb) +{ + u64 seqno = DCCP_SKB_CB(skb)->dccpd_seq; + enum dccp_ackvec_states state = DCCPAV_RECEIVED; + + if (dccp_ackvec_is_empty(av)) { + dccp_ackvec_add_new(av, 1, seqno, state); + av->av_tail_ackno = seqno; + + } else { + s64 num_packets = dccp_delta_seqno(av->av_buf_ackno, seqno); + u8 *current_head = av->av_buf + av->av_buf_head; + + if (num_packets == 1 && + dccp_ackvec_state(current_head) == state && + dccp_ackvec_runlen(current_head) < DCCPAV_MAX_RUNLEN) { + + *current_head += 1; + av->av_buf_ackno = seqno; + + } else if (num_packets > 0) { + dccp_ackvec_add_new(av, num_packets, seqno, state); + } else { + dccp_ackvec_update_old(av, num_packets, seqno, state); + } + } +} + +/** + * dccp_ackvec_clear_state - Perform house-keeping / garbage-collection + * @av: Ack Vector record to clean + * @ackno: last Ack Vector which has been acknowledged + * + * This routine is called when the peer acknowledges the receipt of Ack Vectors + * up to and including @ackno. While based on section A.3 of RFC 4340, here + * are additional precautions to prevent corrupted buffer state. In particular, + * we use tail_ackno to identify outdated records; it always marks the earliest + * packet of group (2) in 11.4.2. + */ +void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno) +{ + struct dccp_ackvec_record *avr, *next; + u8 runlen_now, eff_runlen; + s64 delta; + + avr = dccp_ackvec_lookup(&av->av_records, ackno); + if (avr == NULL) + return; + /* + * Deal with outdated acknowledgments: this arises when e.g. there are + * several old records and the acks from the peer come in slowly. In + * that case we may still have records that pre-date tail_ackno. + */ + delta = dccp_delta_seqno(av->av_tail_ackno, avr->avr_ack_ackno); + if (delta < 0) + goto free_records; + /* + * Deal with overlapping Ack Vectors: don't subtract more than the + * number of packets between tail_ackno and ack_ackno. + */ + eff_runlen = delta < avr->avr_ack_runlen ? delta : avr->avr_ack_runlen; + + runlen_now = dccp_ackvec_runlen(av->av_buf + avr->avr_ack_ptr); + /* + * The run length of Ack Vector cells does not decrease over time. If + * the run length is the same as at the time the Ack Vector was sent, we + * free the ack_ptr cell. That cell can however not be freed if the run + * length has increased: in this case we need to move the tail pointer + * backwards (towards higher indices), to its next-oldest neighbour. + */ + if (runlen_now > eff_runlen) { + + av->av_buf[avr->avr_ack_ptr] -= eff_runlen + 1; + av->av_buf_tail = __ackvec_idx_add(avr->avr_ack_ptr, 1); + + /* This move may not have cleared the overflow flag. */ + if (av->av_overflow) + av->av_overflow = (av->av_buf_head == av->av_buf_tail); + } else { + av->av_buf_tail = avr->avr_ack_ptr; + /* + * We have made sure that avr points to a valid cell within the + * buffer. This cell is either older than head, or equals head + * (empty buffer): in both cases we no longer have any overflow. + */ + av->av_overflow = 0; + } + + /* + * The peer has acknowledged up to and including ack_ackno. Hence the + * first packet in group (2) of 11.4.2 is the successor of ack_ackno. + */ + av->av_tail_ackno = ADD48(avr->avr_ack_ackno, 1); + +free_records: + list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) { + list_del(&avr->avr_node); + kmem_cache_free(dccp_ackvec_record_slab, avr); + } +} + +/* + * Routines to keep track of Ack Vectors received in an skb + */ +int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce) +{ + struct dccp_ackvec_parsed *new = kmalloc(sizeof(*new), GFP_ATOMIC); + + if (new == NULL) + return -ENOBUFS; + new->vec = vec; + new->len = len; + new->nonce = nonce; + + list_add_tail(&new->node, head); + return 0; +} +EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_add); + +void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks) +{ + struct dccp_ackvec_parsed *cur, *next; + + list_for_each_entry_safe(cur, next, parsed_chunks, node) + kfree(cur); + INIT_LIST_HEAD(parsed_chunks); +} +EXPORT_SYMBOL_GPL(dccp_ackvec_parsed_cleanup); + +int __init dccp_ackvec_init(void) +{ + dccp_ackvec_slab = kmem_cache_create("dccp_ackvec", + sizeof(struct dccp_ackvec), 0, + SLAB_HWCACHE_ALIGN, NULL); + if (dccp_ackvec_slab == NULL) + goto out_err; + + dccp_ackvec_record_slab = kmem_cache_create("dccp_ackvec_record", + sizeof(struct dccp_ackvec_record), + 0, SLAB_HWCACHE_ALIGN, NULL); + if (dccp_ackvec_record_slab == NULL) + goto out_destroy_slab; + + return 0; + +out_destroy_slab: + kmem_cache_destroy(dccp_ackvec_slab); + dccp_ackvec_slab = NULL; +out_err: + DCCP_CRIT("Unable to create Ack Vector slab cache"); + return -ENOBUFS; +} + +void dccp_ackvec_exit(void) +{ + kmem_cache_destroy(dccp_ackvec_slab); + dccp_ackvec_slab = NULL; + kmem_cache_destroy(dccp_ackvec_record_slab); + dccp_ackvec_record_slab = NULL; +} diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h new file mode 100644 index 000000000..d2c4220fb --- /dev/null +++ b/net/dccp/ackvec.h @@ -0,0 +1,136 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _ACKVEC_H +#define _ACKVEC_H +/* + * net/dccp/ackvec.h + * + * An implementation of Ack Vectors for the DCCP protocol + * Copyright (c) 2007 University of Aberdeen, Scotland, UK + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include + +/* + * Ack Vector buffer space is static, in multiples of %DCCP_SINGLE_OPT_MAXLEN, + * the maximum size of a single Ack Vector. Setting %DCCPAV_NUM_ACKVECS to 1 + * will be sufficient for most cases of low Ack Ratios, using a value of 2 gives + * more headroom if Ack Ratio is higher or when the sender acknowledges slowly. + * The maximum value is bounded by the u16 types for indices and functions. + */ +#define DCCPAV_NUM_ACKVECS 2 +#define DCCPAV_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * DCCPAV_NUM_ACKVECS) + +/* Estimated minimum average Ack Vector length - used for updating MPS */ +#define DCCPAV_MIN_OPTLEN 16 + +/* Threshold for coping with large bursts of losses */ +#define DCCPAV_BURST_THRESH (DCCPAV_MAX_ACKVEC_LEN / 8) + +enum dccp_ackvec_states { + DCCPAV_RECEIVED = 0x00, + DCCPAV_ECN_MARKED = 0x40, + DCCPAV_RESERVED = 0x80, + DCCPAV_NOT_RECEIVED = 0xC0 +}; +#define DCCPAV_MAX_RUNLEN 0x3F + +static inline u8 dccp_ackvec_runlen(const u8 *cell) +{ + return *cell & DCCPAV_MAX_RUNLEN; +} + +static inline u8 dccp_ackvec_state(const u8 *cell) +{ + return *cell & ~DCCPAV_MAX_RUNLEN; +} + +/** + * struct dccp_ackvec - Ack Vector main data structure + * + * This implements a fixed-size circular buffer within an array and is largely + * based on Appendix A of RFC 4340. + * + * @av_buf: circular buffer storage area + * @av_buf_head: head index; begin of live portion in @av_buf + * @av_buf_tail: tail index; first index _after_ the live portion in @av_buf + * @av_buf_ackno: highest seqno of acknowledgeable packet recorded in @av_buf + * @av_tail_ackno: lowest seqno of acknowledgeable packet recorded in @av_buf + * @av_buf_nonce: ECN nonce sums, each covering subsequent segments of up to + * %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf + * @av_overflow: if 1 then buf_head == buf_tail indicates buffer wraparound + * @av_records: list of %dccp_ackvec_record (Ack Vectors sent previously) + */ +struct dccp_ackvec { + u8 av_buf[DCCPAV_MAX_ACKVEC_LEN]; + u16 av_buf_head; + u16 av_buf_tail; + u64 av_buf_ackno:48; + u64 av_tail_ackno:48; + bool av_buf_nonce[DCCPAV_NUM_ACKVECS]; + u8 av_overflow:1; + struct list_head av_records; +}; + +/** + * struct dccp_ackvec_record - Records information about sent Ack Vectors + * + * These list entries define the additional information which the HC-Receiver + * keeps about recently-sent Ack Vectors; again refer to RFC 4340, Appendix A. + * + * @avr_node: the list node in @av_records + * @avr_ack_seqno: sequence number of the packet the Ack Vector was sent on + * @avr_ack_ackno: the Ack number that this record/Ack Vector refers to + * @avr_ack_ptr: pointer into @av_buf where this record starts + * @avr_ack_runlen: run length of @avr_ack_ptr at the time of sending + * @avr_ack_nonce: the sum of @av_buf_nonce's at the time this record was sent + * + * The list as a whole is sorted in descending order by @avr_ack_seqno. + */ +struct dccp_ackvec_record { + struct list_head avr_node; + u64 avr_ack_seqno:48; + u64 avr_ack_ackno:48; + u16 avr_ack_ptr; + u8 avr_ack_runlen; + u8 avr_ack_nonce:1; +}; + +int dccp_ackvec_init(void); +void dccp_ackvec_exit(void); + +struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority); +void dccp_ackvec_free(struct dccp_ackvec *av); + +void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb); +int dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum); +void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno); +u16 dccp_ackvec_buflen(const struct dccp_ackvec *av); + +static inline bool dccp_ackvec_is_empty(const struct dccp_ackvec *av) +{ + return av->av_overflow == 0 && av->av_buf_head == av->av_buf_tail; +} + +/** + * struct dccp_ackvec_parsed - Record offsets of Ack Vectors in skb + * @vec: start of vector (offset into skb) + * @len: length of @vec + * @nonce: whether @vec had an ECN nonce of 0 or 1 + * @node: FIFO - arranged in descending order of ack_ackno + * + * This structure is used by CCIDs to access Ack Vectors in a received skb. + */ +struct dccp_ackvec_parsed { + u8 *vec, + len, + nonce:1; + struct list_head node; +}; + +int dccp_ackvec_parsed_add(struct list_head *head, u8 *vec, u8 len, u8 nonce); +void dccp_ackvec_parsed_cleanup(struct list_head *parsed_chunks); +#endif /* _ACKVEC_H */ diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c new file mode 100644 index 000000000..6beac5d34 --- /dev/null +++ b/net/dccp/ccid.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/ccid.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + * + * CCID infrastructure + */ + +#include + +#include "ccid.h" +#include "ccids/lib/tfrc.h" + +static struct ccid_operations *ccids[] = { + &ccid2_ops, +#ifdef CONFIG_IP_DCCP_CCID3 + &ccid3_ops, +#endif +}; + +static struct ccid_operations *ccid_by_number(const u8 id) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ccids); i++) + if (ccids[i]->ccid_id == id) + return ccids[i]; + return NULL; +} + +/* check that up to @array_len members in @ccid_array are supported */ +bool ccid_support_check(u8 const *ccid_array, u8 array_len) +{ + while (array_len > 0) + if (ccid_by_number(ccid_array[--array_len]) == NULL) + return false; + return true; +} + +/** + * ccid_get_builtin_ccids - Populate a list of built-in CCIDs + * @ccid_array: pointer to copy into + * @array_len: value to return length into + * + * This function allocates memory - caller must see that it is freed after use. + */ +int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len) +{ + *ccid_array = kmalloc(ARRAY_SIZE(ccids), gfp_any()); + if (*ccid_array == NULL) + return -ENOBUFS; + + for (*array_len = 0; *array_len < ARRAY_SIZE(ccids); *array_len += 1) + (*ccid_array)[*array_len] = ccids[*array_len]->ccid_id; + return 0; +} + +int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, + char __user *optval, int __user *optlen) +{ + u8 *ccid_array, array_len; + int err = 0; + + if (ccid_get_builtin_ccids(&ccid_array, &array_len)) + return -ENOBUFS; + + if (put_user(array_len, optlen)) + err = -EFAULT; + else if (len > 0 && copy_to_user(optval, ccid_array, + len > array_len ? array_len : len)) + err = -EFAULT; + + kfree(ccid_array); + return err; +} + +static __printf(3, 4) struct kmem_cache *ccid_kmem_cache_create(int obj_size, char *slab_name_fmt, const char *fmt,...) +{ + struct kmem_cache *slab; + va_list args; + + va_start(args, fmt); + vsnprintf(slab_name_fmt, CCID_SLAB_NAME_LENGTH, fmt, args); + va_end(args); + + slab = kmem_cache_create(slab_name_fmt, sizeof(struct ccid) + obj_size, 0, + SLAB_HWCACHE_ALIGN, NULL); + return slab; +} + +static void ccid_kmem_cache_destroy(struct kmem_cache *slab) +{ + kmem_cache_destroy(slab); +} + +static int __init ccid_activate(struct ccid_operations *ccid_ops) +{ + int err = -ENOBUFS; + + ccid_ops->ccid_hc_rx_slab = + ccid_kmem_cache_create(ccid_ops->ccid_hc_rx_obj_size, + ccid_ops->ccid_hc_rx_slab_name, + "ccid%u_hc_rx_sock", + ccid_ops->ccid_id); + if (ccid_ops->ccid_hc_rx_slab == NULL) + goto out; + + ccid_ops->ccid_hc_tx_slab = + ccid_kmem_cache_create(ccid_ops->ccid_hc_tx_obj_size, + ccid_ops->ccid_hc_tx_slab_name, + "ccid%u_hc_tx_sock", + ccid_ops->ccid_id); + if (ccid_ops->ccid_hc_tx_slab == NULL) + goto out_free_rx_slab; + + pr_info("DCCP: Activated CCID %d (%s)\n", + ccid_ops->ccid_id, ccid_ops->ccid_name); + err = 0; +out: + return err; +out_free_rx_slab: + ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); + ccid_ops->ccid_hc_rx_slab = NULL; + goto out; +} + +static void ccid_deactivate(struct ccid_operations *ccid_ops) +{ + ccid_kmem_cache_destroy(ccid_ops->ccid_hc_tx_slab); + ccid_ops->ccid_hc_tx_slab = NULL; + ccid_kmem_cache_destroy(ccid_ops->ccid_hc_rx_slab); + ccid_ops->ccid_hc_rx_slab = NULL; + + pr_info("DCCP: Deactivated CCID %d (%s)\n", + ccid_ops->ccid_id, ccid_ops->ccid_name); +} + +struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx) +{ + struct ccid_operations *ccid_ops = ccid_by_number(id); + struct ccid *ccid = NULL; + + if (ccid_ops == NULL) + goto out; + + ccid = kmem_cache_alloc(rx ? ccid_ops->ccid_hc_rx_slab : + ccid_ops->ccid_hc_tx_slab, gfp_any()); + if (ccid == NULL) + goto out; + ccid->ccid_ops = ccid_ops; + if (rx) { + memset(ccid + 1, 0, ccid_ops->ccid_hc_rx_obj_size); + if (ccid->ccid_ops->ccid_hc_rx_init != NULL && + ccid->ccid_ops->ccid_hc_rx_init(ccid, sk) != 0) + goto out_free_ccid; + } else { + memset(ccid + 1, 0, ccid_ops->ccid_hc_tx_obj_size); + if (ccid->ccid_ops->ccid_hc_tx_init != NULL && + ccid->ccid_ops->ccid_hc_tx_init(ccid, sk) != 0) + goto out_free_ccid; + } +out: + return ccid; +out_free_ccid: + kmem_cache_free(rx ? ccid_ops->ccid_hc_rx_slab : + ccid_ops->ccid_hc_tx_slab, ccid); + ccid = NULL; + goto out; +} + +void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk) +{ + if (ccid != NULL) { + if (ccid->ccid_ops->ccid_hc_rx_exit != NULL) + ccid->ccid_ops->ccid_hc_rx_exit(sk); + kmem_cache_free(ccid->ccid_ops->ccid_hc_rx_slab, ccid); + } +} + +void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk) +{ + if (ccid != NULL) { + if (ccid->ccid_ops->ccid_hc_tx_exit != NULL) + ccid->ccid_ops->ccid_hc_tx_exit(sk); + kmem_cache_free(ccid->ccid_ops->ccid_hc_tx_slab, ccid); + } +} + +int __init ccid_initialize_builtins(void) +{ + int i, err = tfrc_lib_init(); + + if (err) + return err; + + for (i = 0; i < ARRAY_SIZE(ccids); i++) { + err = ccid_activate(ccids[i]); + if (err) + goto unwind_registrations; + } + return 0; + +unwind_registrations: + while(--i >= 0) + ccid_deactivate(ccids[i]); + tfrc_lib_exit(); + return err; +} + +void ccid_cleanup_builtins(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(ccids); i++) + ccid_deactivate(ccids[i]); + tfrc_lib_exit(); +} diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h new file mode 100644 index 000000000..105f3734d --- /dev/null +++ b/net/dccp/ccid.h @@ -0,0 +1,262 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _CCID_H +#define _CCID_H +/* + * net/dccp/ccid.h + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + * + * CCID infrastructure + */ + +#include +#include +#include +#include +#include + +/* maximum value for a CCID (RFC 4340, 19.5) */ +#define CCID_MAX 255 +#define CCID_SLAB_NAME_LENGTH 32 + +struct tcp_info; + +/** + * struct ccid_operations - Interface to Congestion-Control Infrastructure + * + * @ccid_id: numerical CCID ID (up to %CCID_MAX, cf. table 5 in RFC 4340, 10.) + * @ccid_ccmps: the CCMPS including network/transport headers (0 when disabled) + * @ccid_name: alphabetical identifier string for @ccid_id + * @ccid_hc_{r,t}x_slab: memory pool for the receiver/sender half-connection + * @ccid_hc_{r,t}x_obj_size: size of the receiver/sender half-connection socket + * + * @ccid_hc_{r,t}x_init: CCID-specific initialisation routine (before startup) + * @ccid_hc_{r,t}x_exit: CCID-specific cleanup routine (before destruction) + * @ccid_hc_rx_packet_recv: implements the HC-receiver side + * @ccid_hc_{r,t}x_parse_options: parsing routine for CCID/HC-specific options + * @ccid_hc_{r,t}x_insert_options: insert routine for CCID/HC-specific options + * @ccid_hc_tx_packet_recv: implements feedback processing for the HC-sender + * @ccid_hc_tx_send_packet: implements the sending part of the HC-sender + * @ccid_hc_tx_packet_sent: does accounting for packets in flight by HC-sender + * @ccid_hc_{r,t}x_get_info: INET_DIAG information for HC-receiver/sender + * @ccid_hc_{r,t}x_getsockopt: socket options specific to HC-receiver/sender + */ +struct ccid_operations { + unsigned char ccid_id; + __u32 ccid_ccmps; + const char *ccid_name; + struct kmem_cache *ccid_hc_rx_slab, + *ccid_hc_tx_slab; + char ccid_hc_rx_slab_name[CCID_SLAB_NAME_LENGTH]; + char ccid_hc_tx_slab_name[CCID_SLAB_NAME_LENGTH]; + __u32 ccid_hc_rx_obj_size, + ccid_hc_tx_obj_size; + /* Interface Routines */ + int (*ccid_hc_rx_init)(struct ccid *ccid, struct sock *sk); + int (*ccid_hc_tx_init)(struct ccid *ccid, struct sock *sk); + void (*ccid_hc_rx_exit)(struct sock *sk); + void (*ccid_hc_tx_exit)(struct sock *sk); + void (*ccid_hc_rx_packet_recv)(struct sock *sk, + struct sk_buff *skb); + int (*ccid_hc_rx_parse_options)(struct sock *sk, u8 pkt, + u8 opt, u8 *val, u8 len); + int (*ccid_hc_rx_insert_options)(struct sock *sk, + struct sk_buff *skb); + void (*ccid_hc_tx_packet_recv)(struct sock *sk, + struct sk_buff *skb); + int (*ccid_hc_tx_parse_options)(struct sock *sk, u8 pkt, + u8 opt, u8 *val, u8 len); + int (*ccid_hc_tx_send_packet)(struct sock *sk, + struct sk_buff *skb); + void (*ccid_hc_tx_packet_sent)(struct sock *sk, + unsigned int len); + void (*ccid_hc_rx_get_info)(struct sock *sk, + struct tcp_info *info); + void (*ccid_hc_tx_get_info)(struct sock *sk, + struct tcp_info *info); + int (*ccid_hc_rx_getsockopt)(struct sock *sk, + const int optname, int len, + u32 __user *optval, + int __user *optlen); + int (*ccid_hc_tx_getsockopt)(struct sock *sk, + const int optname, int len, + u32 __user *optval, + int __user *optlen); +}; + +extern struct ccid_operations ccid2_ops; +#ifdef CONFIG_IP_DCCP_CCID3 +extern struct ccid_operations ccid3_ops; +#endif + +int ccid_initialize_builtins(void); +void ccid_cleanup_builtins(void); + +struct ccid { + struct ccid_operations *ccid_ops; + char ccid_priv[]; +}; + +static inline void *ccid_priv(const struct ccid *ccid) +{ + return (void *)ccid->ccid_priv; +} + +bool ccid_support_check(u8 const *ccid_array, u8 array_len); +int ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len); +int ccid_getsockopt_builtin_ccids(struct sock *sk, int len, + char __user *, int __user *); + +struct ccid *ccid_new(const u8 id, struct sock *sk, bool rx); + +static inline int ccid_get_current_rx_ccid(struct dccp_sock *dp) +{ + struct ccid *ccid = dp->dccps_hc_rx_ccid; + + if (ccid == NULL || ccid->ccid_ops == NULL) + return -1; + return ccid->ccid_ops->ccid_id; +} + +static inline int ccid_get_current_tx_ccid(struct dccp_sock *dp) +{ + struct ccid *ccid = dp->dccps_hc_tx_ccid; + + if (ccid == NULL || ccid->ccid_ops == NULL) + return -1; + return ccid->ccid_ops->ccid_id; +} + +void ccid_hc_rx_delete(struct ccid *ccid, struct sock *sk); +void ccid_hc_tx_delete(struct ccid *ccid, struct sock *sk); + +/* + * Congestion control of queued data packets via CCID decision. + * + * The TX CCID performs its congestion-control by indicating whether and when a + * queued packet may be sent, using the return code of ccid_hc_tx_send_packet(). + * The following modes are supported via the symbolic constants below: + * - timer-based pacing (CCID returns a delay value in milliseconds); + * - autonomous dequeueing (CCID internally schedules dccps_xmitlet). + */ + +enum ccid_dequeueing_decision { + CCID_PACKET_SEND_AT_ONCE = 0x00000, /* "green light": no delay */ + CCID_PACKET_DELAY_MAX = 0x0FFFF, /* maximum delay in msecs */ + CCID_PACKET_DELAY = 0x10000, /* CCID msec-delay mode */ + CCID_PACKET_WILL_DEQUEUE_LATER = 0x20000, /* CCID autonomous mode */ + CCID_PACKET_ERR = 0xF0000, /* error condition */ +}; + +static inline int ccid_packet_dequeue_eval(const int return_code) +{ + if (return_code < 0) + return CCID_PACKET_ERR; + if (return_code == 0) + return CCID_PACKET_SEND_AT_ONCE; + if (return_code <= CCID_PACKET_DELAY_MAX) + return CCID_PACKET_DELAY; + return return_code; +} + +static inline int ccid_hc_tx_send_packet(struct ccid *ccid, struct sock *sk, + struct sk_buff *skb) +{ + if (ccid->ccid_ops->ccid_hc_tx_send_packet != NULL) + return ccid->ccid_ops->ccid_hc_tx_send_packet(sk, skb); + return CCID_PACKET_SEND_AT_ONCE; +} + +static inline void ccid_hc_tx_packet_sent(struct ccid *ccid, struct sock *sk, + unsigned int len) +{ + if (ccid->ccid_ops->ccid_hc_tx_packet_sent != NULL) + ccid->ccid_ops->ccid_hc_tx_packet_sent(sk, len); +} + +static inline void ccid_hc_rx_packet_recv(struct ccid *ccid, struct sock *sk, + struct sk_buff *skb) +{ + if (ccid->ccid_ops->ccid_hc_rx_packet_recv != NULL) + ccid->ccid_ops->ccid_hc_rx_packet_recv(sk, skb); +} + +static inline void ccid_hc_tx_packet_recv(struct ccid *ccid, struct sock *sk, + struct sk_buff *skb) +{ + if (ccid->ccid_ops->ccid_hc_tx_packet_recv != NULL) + ccid->ccid_ops->ccid_hc_tx_packet_recv(sk, skb); +} + +/** + * ccid_hc_tx_parse_options - Parse CCID-specific options sent by the receiver + * @pkt: type of packet that @opt appears on (RFC 4340, 5.1) + * @opt: the CCID-specific option type (RFC 4340, 5.8 and 10.3) + * @val: value of @opt + * @len: length of @val in bytes + */ +static inline int ccid_hc_tx_parse_options(struct ccid *ccid, struct sock *sk, + u8 pkt, u8 opt, u8 *val, u8 len) +{ + if (!ccid || !ccid->ccid_ops->ccid_hc_tx_parse_options) + return 0; + return ccid->ccid_ops->ccid_hc_tx_parse_options(sk, pkt, opt, val, len); +} + +/** + * ccid_hc_rx_parse_options - Parse CCID-specific options sent by the sender + * Arguments are analogous to ccid_hc_tx_parse_options() + */ +static inline int ccid_hc_rx_parse_options(struct ccid *ccid, struct sock *sk, + u8 pkt, u8 opt, u8 *val, u8 len) +{ + if (!ccid || !ccid->ccid_ops->ccid_hc_rx_parse_options) + return 0; + return ccid->ccid_ops->ccid_hc_rx_parse_options(sk, pkt, opt, val, len); +} + +static inline int ccid_hc_rx_insert_options(struct ccid *ccid, struct sock *sk, + struct sk_buff *skb) +{ + if (ccid->ccid_ops->ccid_hc_rx_insert_options != NULL) + return ccid->ccid_ops->ccid_hc_rx_insert_options(sk, skb); + return 0; +} + +static inline void ccid_hc_rx_get_info(struct ccid *ccid, struct sock *sk, + struct tcp_info *info) +{ + if (ccid->ccid_ops->ccid_hc_rx_get_info != NULL) + ccid->ccid_ops->ccid_hc_rx_get_info(sk, info); +} + +static inline void ccid_hc_tx_get_info(struct ccid *ccid, struct sock *sk, + struct tcp_info *info) +{ + if (ccid->ccid_ops->ccid_hc_tx_get_info != NULL) + ccid->ccid_ops->ccid_hc_tx_get_info(sk, info); +} + +static inline int ccid_hc_rx_getsockopt(struct ccid *ccid, struct sock *sk, + const int optname, int len, + u32 __user *optval, int __user *optlen) +{ + int rc = -ENOPROTOOPT; + if (ccid != NULL && ccid->ccid_ops->ccid_hc_rx_getsockopt != NULL) + rc = ccid->ccid_ops->ccid_hc_rx_getsockopt(sk, optname, len, + optval, optlen); + return rc; +} + +static inline int ccid_hc_tx_getsockopt(struct ccid *ccid, struct sock *sk, + const int optname, int len, + u32 __user *optval, int __user *optlen) +{ + int rc = -ENOPROTOOPT; + if (ccid != NULL && ccid->ccid_ops->ccid_hc_tx_getsockopt != NULL) + rc = ccid->ccid_ops->ccid_hc_tx_getsockopt(sk, optname, len, + optval, optlen); + return rc; +} +#endif /* _CCID_H */ diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig new file mode 100644 index 000000000..a3eeb84d1 --- /dev/null +++ b/net/dccp/ccids/Kconfig @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "DCCP CCIDs Configuration" + +config IP_DCCP_CCID2_DEBUG + bool "CCID-2 debugging messages" + help + Enable CCID-2 specific debugging messages. + + The debugging output can additionally be toggled by setting the + ccid2_debug parameter to 0 or 1. + + If in doubt, say N. + +config IP_DCCP_CCID3 + bool "CCID-3 (TCP-Friendly)" + def_bool y if (IP_DCCP = y || IP_DCCP = m) + help + CCID-3 denotes TCP-Friendly Rate Control (TFRC), an equation-based + rate-controlled congestion control mechanism. TFRC is designed to + be reasonably fair when competing for bandwidth with TCP-like flows, + where a flow is "reasonably fair" if its sending rate is generally + within a factor of two of the sending rate of a TCP flow under the + same conditions. However, TFRC has a much lower variation of + throughput over time compared with TCP, which makes CCID-3 more + suitable than CCID-2 for applications such streaming media where a + relatively smooth sending rate is of importance. + + CCID-3 is further described in RFC 4342, + https://www.ietf.org/rfc/rfc4342.txt + + The TFRC congestion control algorithms were initially described in + RFC 5348. + + This text was extracted from RFC 4340 (sec. 10.2), + https://www.ietf.org/rfc/rfc4340.txt + + If in doubt, say N. + +config IP_DCCP_CCID3_DEBUG + bool "CCID-3 debugging messages" + depends on IP_DCCP_CCID3 + help + Enable CCID-3 specific debugging messages. + + The debugging output can additionally be toggled by setting the + ccid3_debug parameter to 0 or 1. + + If in doubt, say N. + +config IP_DCCP_TFRC_LIB + def_bool y if IP_DCCP_CCID3 + +config IP_DCCP_TFRC_DEBUG + def_bool y if IP_DCCP_CCID3_DEBUG +endmenu diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c new file mode 100644 index 000000000..4d9823d6d --- /dev/null +++ b/net/dccp/ccids/ccid2.c @@ -0,0 +1,793 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2005, 2006 Andrea Bittau + * + * Changes to meet Linux coding standards, and DCCP infrastructure fixes. + * + * Copyright (c) 2006 Arnaldo Carvalho de Melo + */ + +/* + * This implementation should follow RFC 4341 + */ +#include +#include "../feat.h" +#include "ccid2.h" + + +#ifdef CONFIG_IP_DCCP_CCID2_DEBUG +static bool ccid2_debug; +#define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) +#else +#define ccid2_pr_debug(format, a...) +#endif + +static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hc) +{ + struct ccid2_seq *seqp; + int i; + + /* check if we have space to preserve the pointer to the buffer */ + if (hc->tx_seqbufc >= (sizeof(hc->tx_seqbuf) / + sizeof(struct ccid2_seq *))) + return -ENOMEM; + + /* allocate buffer and initialize linked list */ + seqp = kmalloc_array(CCID2_SEQBUF_LEN, sizeof(struct ccid2_seq), + gfp_any()); + if (seqp == NULL) + return -ENOMEM; + + for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) { + seqp[i].ccid2s_next = &seqp[i + 1]; + seqp[i + 1].ccid2s_prev = &seqp[i]; + } + seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp; + seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; + + /* This is the first allocation. Initiate the head and tail. */ + if (hc->tx_seqbufc == 0) + hc->tx_seqh = hc->tx_seqt = seqp; + else { + /* link the existing list with the one we just created */ + hc->tx_seqh->ccid2s_next = seqp; + seqp->ccid2s_prev = hc->tx_seqh; + + hc->tx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; + seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hc->tx_seqt; + } + + /* store the original pointer to the buffer so we can free it */ + hc->tx_seqbuf[hc->tx_seqbufc] = seqp; + hc->tx_seqbufc++; + + return 0; +} + +static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) +{ + if (ccid2_cwnd_network_limited(ccid2_hc_tx_sk(sk))) + return CCID_PACKET_WILL_DEQUEUE_LATER; + return CCID_PACKET_SEND_AT_ONCE; +} + +static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) +{ + u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->tx_cwnd, 2); + + /* + * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from + * RFC 4341, 6.1.2. We ignore the statement that Ack Ratio 2 is always + * acceptable since this causes starvation/deadlock whenever cwnd < 2. + * The same problem arises when Ack Ratio is 0 (ie. Ack Ratio disabled). + */ + if (val == 0 || val > max_ratio) { + DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio); + val = max_ratio; + } + dccp_feat_signal_nn_change(sk, DCCPF_ACK_RATIO, + min_t(u32, val, DCCPF_ACK_RATIO_MAX)); +} + +static void ccid2_check_l_ack_ratio(struct sock *sk) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + + /* + * After a loss, idle period, application limited period, or RTO we + * need to check that the ack ratio is still less than the congestion + * window. Otherwise, we will send an entire congestion window of + * packets and got no response because we haven't sent ack ratio + * packets yet. + * If the ack ratio does need to be reduced, we reduce it to half of + * the congestion window (or 1 if that's zero) instead of to the + * congestion window. This prevents problems if one ack is lost. + */ + if (dccp_feat_nn_get(sk, DCCPF_ACK_RATIO) > hc->tx_cwnd) + ccid2_change_l_ack_ratio(sk, hc->tx_cwnd/2 ? : 1U); +} + +static void ccid2_change_l_seq_window(struct sock *sk, u64 val) +{ + dccp_feat_signal_nn_change(sk, DCCPF_SEQUENCE_WINDOW, + clamp_val(val, DCCPF_SEQ_WMIN, + DCCPF_SEQ_WMAX)); +} + +static void dccp_tasklet_schedule(struct sock *sk) +{ + struct tasklet_struct *t = &dccp_sk(sk)->dccps_xmitlet; + + if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) { + sock_hold(sk); + __tasklet_schedule(t); + } +} + +static void ccid2_hc_tx_rto_expire(struct timer_list *t) +{ + struct ccid2_hc_tx_sock *hc = from_timer(hc, t, tx_rtotimer); + struct sock *sk = hc->sk; + const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + HZ / 5); + goto out; + } + + ccid2_pr_debug("RTO_EXPIRE\n"); + + if (sk->sk_state == DCCP_CLOSED) + goto out; + + /* back-off timer */ + hc->tx_rto <<= 1; + if (hc->tx_rto > DCCP_RTO_MAX) + hc->tx_rto = DCCP_RTO_MAX; + + /* adjust pipe, cwnd etc */ + hc->tx_ssthresh = hc->tx_cwnd / 2; + if (hc->tx_ssthresh < 2) + hc->tx_ssthresh = 2; + hc->tx_cwnd = 1; + hc->tx_pipe = 0; + + /* clear state about stuff we sent */ + hc->tx_seqt = hc->tx_seqh; + hc->tx_packets_acked = 0; + + /* clear ack ratio state. */ + hc->tx_rpseq = 0; + hc->tx_rpdupack = -1; + ccid2_change_l_ack_ratio(sk, 1); + + /* if we were blocked before, we may now send cwnd=1 packet */ + if (sender_was_blocked) + dccp_tasklet_schedule(sk); + /* restart backed-off timer */ + sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); +out: + bh_unlock_sock(sk); + sock_put(sk); +} + +/* + * Congestion window validation (RFC 2861). + */ +static bool ccid2_do_cwv = true; +module_param(ccid2_do_cwv, bool, 0644); +MODULE_PARM_DESC(ccid2_do_cwv, "Perform RFC2861 Congestion Window Validation"); + +/** + * ccid2_update_used_window - Track how much of cwnd is actually used + * @hc: socket to update window + * @new_wnd: new window values to add into the filter + * + * This is done in addition to CWV. The sender needs to have an idea of how many + * packets may be in flight, to set the local Sequence Window value accordingly + * (RFC 4340, 7.5.2). The CWV mechanism is exploited to keep track of the + * maximum-used window. We use an EWMA low-pass filter to filter out noise. + */ +static void ccid2_update_used_window(struct ccid2_hc_tx_sock *hc, u32 new_wnd) +{ + hc->tx_expected_wnd = (3 * hc->tx_expected_wnd + new_wnd) / 4; +} + +/* This borrows the code of tcp_cwnd_application_limited() */ +static void ccid2_cwnd_application_limited(struct sock *sk, const u32 now) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + /* don't reduce cwnd below the initial window (IW) */ + u32 init_win = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache), + win_used = max(hc->tx_cwnd_used, init_win); + + if (win_used < hc->tx_cwnd) { + hc->tx_ssthresh = max(hc->tx_ssthresh, + (hc->tx_cwnd >> 1) + (hc->tx_cwnd >> 2)); + hc->tx_cwnd = (hc->tx_cwnd + win_used) >> 1; + } + hc->tx_cwnd_used = 0; + hc->tx_cwnd_stamp = now; + + ccid2_check_l_ack_ratio(sk); +} + +/* This borrows the code of tcp_cwnd_restart() */ +static void ccid2_cwnd_restart(struct sock *sk, const u32 now) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + u32 cwnd = hc->tx_cwnd, restart_cwnd, + iwnd = rfc3390_bytes_to_packets(dccp_sk(sk)->dccps_mss_cache); + s32 delta = now - hc->tx_lsndtime; + + hc->tx_ssthresh = max(hc->tx_ssthresh, (cwnd >> 1) + (cwnd >> 2)); + + /* don't reduce cwnd below the initial window (IW) */ + restart_cwnd = min(cwnd, iwnd); + + while ((delta -= hc->tx_rto) >= 0 && cwnd > restart_cwnd) + cwnd >>= 1; + hc->tx_cwnd = max(cwnd, restart_cwnd); + hc->tx_cwnd_stamp = now; + hc->tx_cwnd_used = 0; + + ccid2_check_l_ack_ratio(sk); +} + +static void ccid2_hc_tx_packet_sent(struct sock *sk, unsigned int len) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + const u32 now = ccid2_jiffies32; + struct ccid2_seq *next; + + /* slow-start after idle periods (RFC 2581, RFC 2861) */ + if (ccid2_do_cwv && !hc->tx_pipe && + (s32)(now - hc->tx_lsndtime) >= hc->tx_rto) + ccid2_cwnd_restart(sk, now); + + hc->tx_lsndtime = now; + hc->tx_pipe += 1; + + /* see whether cwnd was fully used (RFC 2861), update expected window */ + if (ccid2_cwnd_network_limited(hc)) { + ccid2_update_used_window(hc, hc->tx_cwnd); + hc->tx_cwnd_used = 0; + hc->tx_cwnd_stamp = now; + } else { + if (hc->tx_pipe > hc->tx_cwnd_used) + hc->tx_cwnd_used = hc->tx_pipe; + + ccid2_update_used_window(hc, hc->tx_cwnd_used); + + if (ccid2_do_cwv && (s32)(now - hc->tx_cwnd_stamp) >= hc->tx_rto) + ccid2_cwnd_application_limited(sk, now); + } + + hc->tx_seqh->ccid2s_seq = dp->dccps_gss; + hc->tx_seqh->ccid2s_acked = 0; + hc->tx_seqh->ccid2s_sent = now; + + next = hc->tx_seqh->ccid2s_next; + /* check if we need to alloc more space */ + if (next == hc->tx_seqt) { + if (ccid2_hc_tx_alloc_seq(hc)) { + DCCP_CRIT("packet history - out of memory!"); + /* FIXME: find a more graceful way to bail out */ + return; + } + next = hc->tx_seqh->ccid2s_next; + BUG_ON(next == hc->tx_seqt); + } + hc->tx_seqh = next; + + ccid2_pr_debug("cwnd=%d pipe=%d\n", hc->tx_cwnd, hc->tx_pipe); + + /* + * FIXME: The code below is broken and the variables have been removed + * from the socket struct. The `ackloss' variable was always set to 0, + * and with arsent there are several problems: + * (i) it doesn't just count the number of Acks, but all sent packets; + * (ii) it is expressed in # of packets, not # of windows, so the + * comparison below uses the wrong formula: Appendix A of RFC 4341 + * comes up with the number K = cwnd / (R^2 - R) of consecutive windows + * of data with no lost or marked Ack packets. If arsent were the # of + * consecutive Acks received without loss, then Ack Ratio needs to be + * decreased by 1 when + * arsent >= K * cwnd / R = cwnd^2 / (R^3 - R^2) + * where cwnd / R is the number of Acks received per window of data + * (cf. RFC 4341, App. A). The problems are that + * - arsent counts other packets as well; + * - the comparison uses a formula different from RFC 4341; + * - computing a cubic/quadratic equation each time is too complicated. + * Hence a different algorithm is needed. + */ +#if 0 + /* Ack Ratio. Need to maintain a concept of how many windows we sent */ + hc->tx_arsent++; + /* We had an ack loss in this window... */ + if (hc->tx_ackloss) { + if (hc->tx_arsent >= hc->tx_cwnd) { + hc->tx_arsent = 0; + hc->tx_ackloss = 0; + } + } else { + /* No acks lost up to now... */ + /* decrease ack ratio if enough packets were sent */ + if (dp->dccps_l_ack_ratio > 1) { + /* XXX don't calculate denominator each time */ + int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - + dp->dccps_l_ack_ratio; + + denom = hc->tx_cwnd * hc->tx_cwnd / denom; + + if (hc->tx_arsent >= denom) { + ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); + hc->tx_arsent = 0; + } + } else { + /* we can't increase ack ratio further [1] */ + hc->tx_arsent = 0; /* or maybe set it to cwnd*/ + } + } +#endif + + sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); + +#ifdef CONFIG_IP_DCCP_CCID2_DEBUG + do { + struct ccid2_seq *seqp = hc->tx_seqt; + + while (seqp != hc->tx_seqh) { + ccid2_pr_debug("out seq=%llu acked=%d time=%u\n", + (unsigned long long)seqp->ccid2s_seq, + seqp->ccid2s_acked, seqp->ccid2s_sent); + seqp = seqp->ccid2s_next; + } + } while (0); + ccid2_pr_debug("=========\n"); +#endif +} + +/** + * ccid2_rtt_estimator - Sample RTT and compute RTO using RFC2988 algorithm + * @sk: socket to perform estimator on + * + * This code is almost identical with TCP's tcp_rtt_estimator(), since + * - it has a higher sampling frequency (recommended by RFC 1323), + * - the RTO does not collapse into RTT due to RTTVAR going towards zero, + * - it is simple (cf. more complex proposals such as Eifel timer or research + * which suggests that the gain should be set according to window size), + * - in tests it was found to work well with CCID2 [gerrit]. + */ +static void ccid2_rtt_estimator(struct sock *sk, const long mrtt) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + long m = mrtt ? : 1; + + if (hc->tx_srtt == 0) { + /* First measurement m */ + hc->tx_srtt = m << 3; + hc->tx_mdev = m << 1; + + hc->tx_mdev_max = max(hc->tx_mdev, tcp_rto_min(sk)); + hc->tx_rttvar = hc->tx_mdev_max; + + hc->tx_rtt_seq = dccp_sk(sk)->dccps_gss; + } else { + /* Update scaled SRTT as SRTT += 1/8 * (m - SRTT) */ + m -= (hc->tx_srtt >> 3); + hc->tx_srtt += m; + + /* Similarly, update scaled mdev with regard to |m| */ + if (m < 0) { + m = -m; + m -= (hc->tx_mdev >> 2); + /* + * This neutralises RTO increase when RTT < SRTT - mdev + * (see P. Sarolahti, A. Kuznetsov,"Congestion Control + * in Linux TCP", USENIX 2002, pp. 49-62). + */ + if (m > 0) + m >>= 3; + } else { + m -= (hc->tx_mdev >> 2); + } + hc->tx_mdev += m; + + if (hc->tx_mdev > hc->tx_mdev_max) { + hc->tx_mdev_max = hc->tx_mdev; + if (hc->tx_mdev_max > hc->tx_rttvar) + hc->tx_rttvar = hc->tx_mdev_max; + } + + /* + * Decay RTTVAR at most once per flight, exploiting that + * 1) pipe <= cwnd <= Sequence_Window = W (RFC 4340, 7.5.2) + * 2) AWL = GSS-W+1 <= GAR <= GSS (RFC 4340, 7.5.1) + * GAR is a useful bound for FlightSize = pipe. + * AWL is probably too low here, as it over-estimates pipe. + */ + if (after48(dccp_sk(sk)->dccps_gar, hc->tx_rtt_seq)) { + if (hc->tx_mdev_max < hc->tx_rttvar) + hc->tx_rttvar -= (hc->tx_rttvar - + hc->tx_mdev_max) >> 2; + hc->tx_rtt_seq = dccp_sk(sk)->dccps_gss; + hc->tx_mdev_max = tcp_rto_min(sk); + } + } + + /* + * Set RTO from SRTT and RTTVAR + * As in TCP, 4 * RTTVAR >= TCP_RTO_MIN, giving a minimum RTO of 200 ms. + * This agrees with RFC 4341, 5: + * "Because DCCP does not retransmit data, DCCP does not require + * TCP's recommended minimum timeout of one second". + */ + hc->tx_rto = (hc->tx_srtt >> 3) + hc->tx_rttvar; + + if (hc->tx_rto > DCCP_RTO_MAX) + hc->tx_rto = DCCP_RTO_MAX; +} + +static void ccid2_new_ack(struct sock *sk, struct ccid2_seq *seqp, + unsigned int *maxincr) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + int r_seq_used = hc->tx_cwnd / dp->dccps_l_ack_ratio; + + if (hc->tx_cwnd < dp->dccps_l_seq_win && + r_seq_used < dp->dccps_r_seq_win) { + if (hc->tx_cwnd < hc->tx_ssthresh) { + if (*maxincr > 0 && ++hc->tx_packets_acked >= 2) { + hc->tx_cwnd += 1; + *maxincr -= 1; + hc->tx_packets_acked = 0; + } + } else if (++hc->tx_packets_acked >= hc->tx_cwnd) { + hc->tx_cwnd += 1; + hc->tx_packets_acked = 0; + } + } + + /* + * Adjust the local sequence window and the ack ratio to allow about + * 5 times the number of packets in the network (RFC 4340 7.5.2) + */ + if (r_seq_used * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_r_seq_win) + ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio * 2); + else if (r_seq_used * CCID2_WIN_CHANGE_FACTOR < dp->dccps_r_seq_win/2) + ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio / 2 ? : 1U); + + if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR >= dp->dccps_l_seq_win) + ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win * 2); + else if (hc->tx_cwnd * CCID2_WIN_CHANGE_FACTOR < dp->dccps_l_seq_win/2) + ccid2_change_l_seq_window(sk, dp->dccps_l_seq_win / 2); + + /* + * FIXME: RTT is sampled several times per acknowledgment (for each + * entry in the Ack Vector), instead of once per Ack (as in TCP SACK). + * This causes the RTT to be over-estimated, since the older entries + * in the Ack Vector have earlier sending times. + * The cleanest solution is to not use the ccid2s_sent field at all + * and instead use DCCP timestamps: requires changes in other places. + */ + ccid2_rtt_estimator(sk, ccid2_jiffies32 - seqp->ccid2s_sent); +} + +static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + + if ((s32)(seqp->ccid2s_sent - hc->tx_last_cong) < 0) { + ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); + return; + } + + hc->tx_last_cong = ccid2_jiffies32; + + hc->tx_cwnd = hc->tx_cwnd / 2 ? : 1U; + hc->tx_ssthresh = max(hc->tx_cwnd, 2U); + + ccid2_check_l_ack_ratio(sk); +} + +static int ccid2_hc_tx_parse_options(struct sock *sk, u8 packet_type, + u8 option, u8 *optval, u8 optlen) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + + switch (option) { + case DCCPO_ACK_VECTOR_0: + case DCCPO_ACK_VECTOR_1: + return dccp_ackvec_parsed_add(&hc->tx_av_chunks, optval, optlen, + option - DCCPO_ACK_VECTOR_0); + } + return 0; +} + +static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + const bool sender_was_blocked = ccid2_cwnd_network_limited(hc); + struct dccp_ackvec_parsed *avp; + u64 ackno, seqno; + struct ccid2_seq *seqp; + int done = 0; + unsigned int maxincr = 0; + + /* check reverse path congestion */ + seqno = DCCP_SKB_CB(skb)->dccpd_seq; + + /* XXX this whole "algorithm" is broken. Need to fix it to keep track + * of the seqnos of the dupacks so that rpseq and rpdupack are correct + * -sorbo. + */ + /* need to bootstrap */ + if (hc->tx_rpdupack == -1) { + hc->tx_rpdupack = 0; + hc->tx_rpseq = seqno; + } else { + /* check if packet is consecutive */ + if (dccp_delta_seqno(hc->tx_rpseq, seqno) == 1) + hc->tx_rpseq = seqno; + /* it's a later packet */ + else if (after48(seqno, hc->tx_rpseq)) { + hc->tx_rpdupack++; + + /* check if we got enough dupacks */ + if (hc->tx_rpdupack >= NUMDUPACK) { + hc->tx_rpdupack = -1; /* XXX lame */ + hc->tx_rpseq = 0; +#ifdef __CCID2_COPES_GRACEFULLY_WITH_ACK_CONGESTION_CONTROL__ + /* + * FIXME: Ack Congestion Control is broken; in + * the current state instabilities occurred with + * Ack Ratios greater than 1; causing hang-ups + * and long RTO timeouts. This needs to be fixed + * before opening up dynamic changes. -- gerrit + */ + ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio); +#endif + } + } + } + + /* check forward path congestion */ + if (dccp_packet_without_ack(skb)) + return; + + /* still didn't send out new data packets */ + if (hc->tx_seqh == hc->tx_seqt) + goto done; + + ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; + if (after48(ackno, hc->tx_high_ack)) + hc->tx_high_ack = ackno; + + seqp = hc->tx_seqt; + while (before48(seqp->ccid2s_seq, ackno)) { + seqp = seqp->ccid2s_next; + if (seqp == hc->tx_seqh) { + seqp = hc->tx_seqh->ccid2s_prev; + break; + } + } + + /* + * In slow-start, cwnd can increase up to a maximum of Ack Ratio/2 + * packets per acknowledgement. Rounding up avoids that cwnd is not + * advanced when Ack Ratio is 1 and gives a slight edge otherwise. + */ + if (hc->tx_cwnd < hc->tx_ssthresh) + maxincr = DIV_ROUND_UP(dp->dccps_l_ack_ratio, 2); + + /* go through all ack vectors */ + list_for_each_entry(avp, &hc->tx_av_chunks, node) { + /* go through this ack vector */ + for (; avp->len--; avp->vec++) { + u64 ackno_end_rl = SUB48(ackno, + dccp_ackvec_runlen(avp->vec)); + + ccid2_pr_debug("ackvec %llu |%u,%u|\n", + (unsigned long long)ackno, + dccp_ackvec_state(avp->vec) >> 6, + dccp_ackvec_runlen(avp->vec)); + /* if the seqno we are analyzing is larger than the + * current ackno, then move towards the tail of our + * seqnos. + */ + while (after48(seqp->ccid2s_seq, ackno)) { + if (seqp == hc->tx_seqt) { + done = 1; + break; + } + seqp = seqp->ccid2s_prev; + } + if (done) + break; + + /* check all seqnos in the range of the vector + * run length + */ + while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { + const u8 state = dccp_ackvec_state(avp->vec); + + /* new packet received or marked */ + if (state != DCCPAV_NOT_RECEIVED && + !seqp->ccid2s_acked) { + if (state == DCCPAV_ECN_MARKED) + ccid2_congestion_event(sk, + seqp); + else + ccid2_new_ack(sk, seqp, + &maxincr); + + seqp->ccid2s_acked = 1; + ccid2_pr_debug("Got ack for %llu\n", + (unsigned long long)seqp->ccid2s_seq); + hc->tx_pipe--; + } + if (seqp == hc->tx_seqt) { + done = 1; + break; + } + seqp = seqp->ccid2s_prev; + } + if (done) + break; + + ackno = SUB48(ackno_end_rl, 1); + } + if (done) + break; + } + + /* The state about what is acked should be correct now + * Check for NUMDUPACK + */ + seqp = hc->tx_seqt; + while (before48(seqp->ccid2s_seq, hc->tx_high_ack)) { + seqp = seqp->ccid2s_next; + if (seqp == hc->tx_seqh) { + seqp = hc->tx_seqh->ccid2s_prev; + break; + } + } + done = 0; + while (1) { + if (seqp->ccid2s_acked) { + done++; + if (done == NUMDUPACK) + break; + } + if (seqp == hc->tx_seqt) + break; + seqp = seqp->ccid2s_prev; + } + + /* If there are at least 3 acknowledgements, anything unacknowledged + * below the last sequence number is considered lost + */ + if (done == NUMDUPACK) { + struct ccid2_seq *last_acked = seqp; + + /* check for lost packets */ + while (1) { + if (!seqp->ccid2s_acked) { + ccid2_pr_debug("Packet lost: %llu\n", + (unsigned long long)seqp->ccid2s_seq); + /* XXX need to traverse from tail -> head in + * order to detect multiple congestion events in + * one ack vector. + */ + ccid2_congestion_event(sk, seqp); + hc->tx_pipe--; + } + if (seqp == hc->tx_seqt) + break; + seqp = seqp->ccid2s_prev; + } + + hc->tx_seqt = last_acked; + } + + /* trim acked packets in tail */ + while (hc->tx_seqt != hc->tx_seqh) { + if (!hc->tx_seqt->ccid2s_acked) + break; + + hc->tx_seqt = hc->tx_seqt->ccid2s_next; + } + + /* restart RTO timer if not all outstanding data has been acked */ + if (hc->tx_pipe == 0) + sk_stop_timer(sk, &hc->tx_rtotimer); + else + sk_reset_timer(sk, &hc->tx_rtotimer, jiffies + hc->tx_rto); +done: + /* check if incoming Acks allow pending packets to be sent */ + if (sender_was_blocked && !ccid2_cwnd_network_limited(hc)) + dccp_tasklet_schedule(sk); + dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); +} + +static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) +{ + struct ccid2_hc_tx_sock *hc = ccid_priv(ccid); + struct dccp_sock *dp = dccp_sk(sk); + u32 max_ratio; + + /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ + hc->tx_ssthresh = ~0U; + + /* Use larger initial windows (RFC 4341, section 5). */ + hc->tx_cwnd = rfc3390_bytes_to_packets(dp->dccps_mss_cache); + hc->tx_expected_wnd = hc->tx_cwnd; + + /* Make sure that Ack Ratio is enabled and within bounds. */ + max_ratio = DIV_ROUND_UP(hc->tx_cwnd, 2); + if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio) + dp->dccps_l_ack_ratio = max_ratio; + + /* XXX init ~ to window size... */ + if (ccid2_hc_tx_alloc_seq(hc)) + return -ENOMEM; + + hc->tx_rto = DCCP_TIMEOUT_INIT; + hc->tx_rpdupack = -1; + hc->tx_last_cong = hc->tx_lsndtime = hc->tx_cwnd_stamp = ccid2_jiffies32; + hc->tx_cwnd_used = 0; + hc->sk = sk; + timer_setup(&hc->tx_rtotimer, ccid2_hc_tx_rto_expire, 0); + INIT_LIST_HEAD(&hc->tx_av_chunks); + return 0; +} + +static void ccid2_hc_tx_exit(struct sock *sk) +{ + struct ccid2_hc_tx_sock *hc = ccid2_hc_tx_sk(sk); + int i; + + sk_stop_timer(sk, &hc->tx_rtotimer); + + for (i = 0; i < hc->tx_seqbufc; i++) + kfree(hc->tx_seqbuf[i]); + hc->tx_seqbufc = 0; + dccp_ackvec_parsed_cleanup(&hc->tx_av_chunks); +} + +static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) +{ + struct ccid2_hc_rx_sock *hc = ccid2_hc_rx_sk(sk); + + if (!dccp_data_packet(skb)) + return; + + if (++hc->rx_num_data_pkts >= dccp_sk(sk)->dccps_r_ack_ratio) { + dccp_send_ack(sk); + hc->rx_num_data_pkts = 0; + } +} + +struct ccid_operations ccid2_ops = { + .ccid_id = DCCPC_CCID2, + .ccid_name = "TCP-like", + .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), + .ccid_hc_tx_init = ccid2_hc_tx_init, + .ccid_hc_tx_exit = ccid2_hc_tx_exit, + .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, + .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, + .ccid_hc_tx_parse_options = ccid2_hc_tx_parse_options, + .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, + .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), + .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, +}; + +#ifdef CONFIG_IP_DCCP_CCID2_DEBUG +module_param(ccid2_debug, bool, 0644); +MODULE_PARM_DESC(ccid2_debug, "Enable CCID-2 debug messages"); +#endif diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h new file mode 100644 index 000000000..330c7b4ec --- /dev/null +++ b/net/dccp/ccids/ccid2.h @@ -0,0 +1,121 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2005 Andrea Bittau + */ +#ifndef _DCCP_CCID2_H_ +#define _DCCP_CCID2_H_ + +#include +#include +#include "../ccid.h" +#include "../dccp.h" + +/* + * CCID-2 timestamping faces the same issues as TCP timestamping. + * Hence we reuse/share as much of the code as possible. + */ +#define ccid2_jiffies32 ((u32)jiffies) + +/* NUMDUPACK parameter from RFC 4341, p. 6 */ +#define NUMDUPACK 3 + +struct ccid2_seq { + u64 ccid2s_seq; + u32 ccid2s_sent; + int ccid2s_acked; + struct ccid2_seq *ccid2s_prev; + struct ccid2_seq *ccid2s_next; +}; + +#define CCID2_SEQBUF_LEN 1024 +#define CCID2_SEQBUF_MAX 128 + +/* + * Multiple of congestion window to keep the sequence window at + * (RFC 4340 7.5.2) + */ +#define CCID2_WIN_CHANGE_FACTOR 5 + +/** + * struct ccid2_hc_tx_sock - CCID2 TX half connection + * @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 + * @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465) + * @tx_srtt: smoothed RTT estimate, scaled by 2^3 + * @tx_mdev: smoothed RTT variation, scaled by 2^2 + * @tx_mdev_max: maximum of @mdev during one flight + * @tx_rttvar: moving average/maximum of @mdev_max + * @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) + * @tx_rtt_seq: to decay RTTVAR at most once per flight + * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861 + * @tx_expected_wnd: moving average of @tx_cwnd_used + * @tx_cwnd_stamp: to track idle periods in CWV + * @tx_lsndtime: last time (in jiffies) a data packet was sent + * @tx_rpseq: last consecutive seqno + * @tx_rpdupack: dupacks since rpseq + * @tx_av_chunks: list of Ack Vectors received on current skb + */ +struct ccid2_hc_tx_sock { + u32 tx_cwnd; + u32 tx_ssthresh; + u32 tx_pipe; + u32 tx_packets_acked; + struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX]; + int tx_seqbufc; + struct ccid2_seq *tx_seqh; + struct ccid2_seq *tx_seqt; + + /* RTT measurement: variables/principles are the same as in TCP */ + u32 tx_srtt, + tx_mdev, + tx_mdev_max, + tx_rttvar, + tx_rto; + u64 tx_rtt_seq:48; + struct timer_list tx_rtotimer; + struct sock *sk; + + /* Congestion Window validation (optional, RFC 2861) */ + u32 tx_cwnd_used, + tx_expected_wnd, + tx_cwnd_stamp, + tx_lsndtime; + + u64 tx_rpseq; + int tx_rpdupack; + u32 tx_last_cong; + u64 tx_high_ack; + struct list_head tx_av_chunks; +}; + +static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) +{ + return hc->tx_pipe >= hc->tx_cwnd; +} + +/* + * Convert RFC 3390 larger initial window into an equivalent number of packets. + * This is based on the numbers specified in RFC 5681, 3.1. + */ +static inline u32 rfc3390_bytes_to_packets(const u32 smss) +{ + return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); +} + +/** + * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection + * @rx_num_data_pkts: number of data packets received since last feedback + */ +struct ccid2_hc_rx_sock { + u32 rx_num_data_pkts; +}; + +static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) +{ + return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); +} + +static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk) +{ + return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); +} +#endif /* _DCCP_CCID2_H_ */ diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c new file mode 100644 index 000000000..ca8670f78 --- /dev/null +++ b/net/dccp/ccids/ccid3.c @@ -0,0 +1,866 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005-7 Ian McDonald + * + * An implementation of the DCCP protocol + * + * This code has been developed by the University of Waikato WAND + * research group. For further information please see https://www.wand.net.nz/ + * + * This code also uses code from Lulea University, rereleased as GPL by its + * authors: + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * Changes to meet Linux coding standards, to make it meet latest ccid3 draft + * and to make it work as a loadable module in the DCCP stack written by + * Arnaldo Carvalho de Melo . + * + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ +#include "../dccp.h" +#include "ccid3.h" + +#include + +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static bool ccid3_debug; +#define ccid3_pr_debug(format, a...) DCCP_PR_DEBUG(ccid3_debug, format, ##a) +#else +#define ccid3_pr_debug(format, a...) +#endif + +/* + * Transmitter Half-Connection Routines + */ +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static const char *ccid3_tx_state_name(enum ccid3_hc_tx_states state) +{ + static const char *const ccid3_state_names[] = { + [TFRC_SSTATE_NO_SENT] = "NO_SENT", + [TFRC_SSTATE_NO_FBACK] = "NO_FBACK", + [TFRC_SSTATE_FBACK] = "FBACK", + }; + + return ccid3_state_names[state]; +} +#endif + +static void ccid3_hc_tx_set_state(struct sock *sk, + enum ccid3_hc_tx_states state) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + enum ccid3_hc_tx_states oldstate = hc->tx_state; + + ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", + dccp_role(sk), sk, ccid3_tx_state_name(oldstate), + ccid3_tx_state_name(state)); + WARN_ON(state == oldstate); + hc->tx_state = state; +} + +/* + * Compute the initial sending rate X_init in the manner of RFC 3390: + * + * X_init = min(4 * s, max(2 * s, 4380 bytes)) / RTT + * + * Note that RFC 3390 uses MSS, RFC 4342 refers to RFC 3390, and rfc3448bis + * (rev-02) clarifies the use of RFC 3390 with regard to the above formula. + * For consistency with other parts of the code, X_init is scaled by 2^6. + */ +static inline u64 rfc3390_initial_rate(struct sock *sk) +{ + const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + const __u32 w_init = clamp_t(__u32, 4380U, 2 * hc->tx_s, 4 * hc->tx_s); + + return scaled_div(w_init << 6, hc->tx_rtt); +} + +/** + * ccid3_update_send_interval - Calculate new t_ipi = s / X_inst + * @hc: socket to have the send interval updated + * + * This respects the granularity of X_inst (64 * bytes/second). + */ +static void ccid3_update_send_interval(struct ccid3_hc_tx_sock *hc) +{ + hc->tx_t_ipi = scaled_div32(((u64)hc->tx_s) << 6, hc->tx_x); + + DCCP_BUG_ON(hc->tx_t_ipi == 0); + ccid3_pr_debug("t_ipi=%u, s=%u, X=%u\n", hc->tx_t_ipi, + hc->tx_s, (unsigned int)(hc->tx_x >> 6)); +} + +static u32 ccid3_hc_tx_idle_rtt(struct ccid3_hc_tx_sock *hc, ktime_t now) +{ + u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count); + + return delta / hc->tx_rtt; +} + +/** + * ccid3_hc_tx_update_x - Update allowed sending rate X + * @sk: socket to be updated + * @stamp: most recent time if available - can be left NULL. + * + * This function tracks draft rfc3448bis, check there for latest details. + * + * Note: X and X_recv are both stored in units of 64 * bytes/second, to support + * fine-grained resolution of sending rates. This requires scaling by 2^6 + * throughout the code. Only X_calc is unscaled (in bytes/second). + * + */ +static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + __u64 min_rate = 2 * hc->tx_x_recv; + const __u64 old_x = hc->tx_x; + ktime_t now = stamp ? *stamp : ktime_get_real(); + + /* + * Handle IDLE periods: do not reduce below RFC3390 initial sending rate + * when idling [RFC 4342, 5.1]. Definition of idling is from rfc3448bis: + * a sender is idle if it has not sent anything over a 2-RTT-period. + * For consistency with X and X_recv, min_rate is also scaled by 2^6. + */ + if (ccid3_hc_tx_idle_rtt(hc, now) >= 2) { + min_rate = rfc3390_initial_rate(sk); + min_rate = max(min_rate, 2 * hc->tx_x_recv); + } + + if (hc->tx_p > 0) { + + hc->tx_x = min(((__u64)hc->tx_x_calc) << 6, min_rate); + hc->tx_x = max(hc->tx_x, (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); + + } else if (ktime_us_delta(now, hc->tx_t_ld) - (s64)hc->tx_rtt >= 0) { + + hc->tx_x = min(2 * hc->tx_x, min_rate); + hc->tx_x = max(hc->tx_x, + scaled_div(((__u64)hc->tx_s) << 6, hc->tx_rtt)); + hc->tx_t_ld = now; + } + + if (hc->tx_x != old_x) { + ccid3_pr_debug("X_prev=%u, X_now=%u, X_calc=%u, " + "X_recv=%u\n", (unsigned int)(old_x >> 6), + (unsigned int)(hc->tx_x >> 6), hc->tx_x_calc, + (unsigned int)(hc->tx_x_recv >> 6)); + + ccid3_update_send_interval(hc); + } +} + +/** + * ccid3_hc_tx_update_s - Track the mean packet size `s' + * @hc: socket to be updated + * @len: DCCP packet payload size in bytes + * + * cf. RFC 4342, 5.3 and RFC 3448, 4.1 + */ +static inline void ccid3_hc_tx_update_s(struct ccid3_hc_tx_sock *hc, int len) +{ + const u16 old_s = hc->tx_s; + + hc->tx_s = tfrc_ewma(hc->tx_s, len, 9); + + if (hc->tx_s != old_s) + ccid3_update_send_interval(hc); +} + +/* + * Update Window Counter using the algorithm from [RFC 4342, 8.1]. + * As elsewhere, RTT > 0 is assumed by using dccp_sample_rtt(). + */ +static inline void ccid3_hc_tx_update_win_count(struct ccid3_hc_tx_sock *hc, + ktime_t now) +{ + u32 delta = ktime_us_delta(now, hc->tx_t_last_win_count), + quarter_rtts = (4 * delta) / hc->tx_rtt; + + if (quarter_rtts > 0) { + hc->tx_t_last_win_count = now; + hc->tx_last_win_count += min(quarter_rtts, 5U); + hc->tx_last_win_count &= 0xF; /* mod 16 */ + } +} + +static void ccid3_hc_tx_no_feedback_timer(struct timer_list *t) +{ + struct ccid3_hc_tx_sock *hc = from_timer(hc, t, tx_no_feedback_timer); + struct sock *sk = hc->sk; + unsigned long t_nfb = USEC_PER_SEC / 5; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + /* Try again later. */ + /* XXX: set some sensible MIB */ + goto restart_timer; + } + + ccid3_pr_debug("%s(%p, state=%s) - entry\n", dccp_role(sk), sk, + ccid3_tx_state_name(hc->tx_state)); + + /* Ignore and do not restart after leaving the established state */ + if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) + goto out; + + /* Reset feedback state to "no feedback received" */ + if (hc->tx_state == TFRC_SSTATE_FBACK) + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + + /* + * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4 + * RTO is 0 if and only if no feedback has been received yet. + */ + if (hc->tx_t_rto == 0 || hc->tx_p == 0) { + + /* halve send rate directly */ + hc->tx_x = max(hc->tx_x / 2, + (((__u64)hc->tx_s) << 6) / TFRC_T_MBI); + ccid3_update_send_interval(hc); + } else { + /* + * Modify the cached value of X_recv + * + * If (X_calc > 2 * X_recv) + * X_recv = max(X_recv / 2, s / (2 * t_mbi)); + * Else + * X_recv = X_calc / 4; + * + * Note that X_recv is scaled by 2^6 while X_calc is not + */ + if (hc->tx_x_calc > (hc->tx_x_recv >> 5)) + hc->tx_x_recv = + max(hc->tx_x_recv / 2, + (((__u64)hc->tx_s) << 6) / (2*TFRC_T_MBI)); + else { + hc->tx_x_recv = hc->tx_x_calc; + hc->tx_x_recv <<= 4; + } + ccid3_hc_tx_update_x(sk, NULL); + } + ccid3_pr_debug("Reduced X to %llu/64 bytes/sec\n", + (unsigned long long)hc->tx_x); + + /* + * Set new timeout for the nofeedback timer. + * See comments in packet_recv() regarding the value of t_RTO. + */ + if (unlikely(hc->tx_t_rto == 0)) /* no feedback received yet */ + t_nfb = TFRC_INITIAL_TIMEOUT; + else + t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); + +restart_timer: + sk_reset_timer(sk, &hc->tx_no_feedback_timer, + jiffies + usecs_to_jiffies(t_nfb)); +out: + bh_unlock_sock(sk); + sock_put(sk); +} + +/** + * ccid3_hc_tx_send_packet - Delay-based dequeueing of TX packets + * @sk: socket to send packet from + * @skb: next packet candidate to send on @sk + * + * This function uses the convention of ccid_packet_dequeue_eval() and + * returns a millisecond-delay value between 0 and t_mbi = 64000 msec. + */ +static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + ktime_t now = ktime_get_real(); + s64 delay; + + /* + * This function is called only for Data and DataAck packets. Sending + * zero-sized Data(Ack)s is theoretically possible, but for congestion + * control this case is pathological - ignore it. + */ + if (unlikely(skb->len == 0)) + return -EBADMSG; + + if (hc->tx_state == TFRC_SSTATE_NO_SENT) { + sk_reset_timer(sk, &hc->tx_no_feedback_timer, (jiffies + + usecs_to_jiffies(TFRC_INITIAL_TIMEOUT))); + hc->tx_last_win_count = 0; + hc->tx_t_last_win_count = now; + + /* Set t_0 for initial packet */ + hc->tx_t_nom = now; + + hc->tx_s = skb->len; + + /* + * Use initial RTT sample when available: recommended by erratum + * to RFC 4342. This implements the initialisation procedure of + * draft rfc3448bis, section 4.2. Remember, X is scaled by 2^6. + */ + if (dp->dccps_syn_rtt) { + ccid3_pr_debug("SYN RTT = %uus\n", dp->dccps_syn_rtt); + hc->tx_rtt = dp->dccps_syn_rtt; + hc->tx_x = rfc3390_initial_rate(sk); + hc->tx_t_ld = now; + } else { + /* + * Sender does not have RTT sample: + * - set fallback RTT (RFC 4340, 3.4) since a RTT value + * is needed in several parts (e.g. window counter); + * - set sending rate X_pps = 1pps as per RFC 3448, 4.2. + */ + hc->tx_rtt = DCCP_FALLBACK_RTT; + hc->tx_x = hc->tx_s; + hc->tx_x <<= 6; + } + ccid3_update_send_interval(hc); + + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_NO_FBACK); + + } else { + delay = ktime_us_delta(hc->tx_t_nom, now); + ccid3_pr_debug("delay=%ld\n", (long)delay); + /* + * Scheduling of packet transmissions (RFC 5348, 8.3) + * + * if (t_now > t_nom - delta) + * // send the packet now + * else + * // send the packet in (t_nom - t_now) milliseconds. + */ + if (delay >= TFRC_T_DELTA) + return (u32)delay / USEC_PER_MSEC; + + ccid3_hc_tx_update_win_count(hc, now); + } + + /* prepare to send now (add options etc.) */ + dp->dccps_hc_tx_insert_options = 1; + DCCP_SKB_CB(skb)->dccpd_ccval = hc->tx_last_win_count; + + /* set the nominal send time for the next following packet */ + hc->tx_t_nom = ktime_add_us(hc->tx_t_nom, hc->tx_t_ipi); + return CCID_PACKET_SEND_AT_ONCE; +} + +static void ccid3_hc_tx_packet_sent(struct sock *sk, unsigned int len) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + + ccid3_hc_tx_update_s(hc, len); + + if (tfrc_tx_hist_add(&hc->tx_hist, dccp_sk(sk)->dccps_gss)) + DCCP_CRIT("packet history - out of memory!"); +} + +static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + struct tfrc_tx_hist_entry *acked; + ktime_t now; + unsigned long t_nfb; + u32 r_sample; + + /* we are only interested in ACKs */ + if (!(DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_ACK || + DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_DATAACK)) + return; + /* + * Locate the acknowledged packet in the TX history. + * + * Returning "entry not found" here can for instance happen when + * - the host has not sent out anything (e.g. a passive server), + * - the Ack is outdated (packet with higher Ack number was received), + * - it is a bogus Ack (for a packet not sent on this connection). + */ + acked = tfrc_tx_hist_find_entry(hc->tx_hist, dccp_hdr_ack_seq(skb)); + if (acked == NULL) + return; + /* For the sake of RTT sampling, ignore/remove all older entries */ + tfrc_tx_hist_purge(&acked->next); + + /* Update the moving average for the RTT estimate (RFC 3448, 4.3) */ + now = ktime_get_real(); + r_sample = dccp_sample_rtt(sk, ktime_us_delta(now, acked->stamp)); + hc->tx_rtt = tfrc_ewma(hc->tx_rtt, r_sample, 9); + + /* + * Update allowed sending rate X as per draft rfc3448bis-00, 4.2/3 + */ + if (hc->tx_state == TFRC_SSTATE_NO_FBACK) { + ccid3_hc_tx_set_state(sk, TFRC_SSTATE_FBACK); + + if (hc->tx_t_rto == 0) { + /* + * Initial feedback packet: Larger Initial Windows (4.2) + */ + hc->tx_x = rfc3390_initial_rate(sk); + hc->tx_t_ld = now; + + ccid3_update_send_interval(hc); + + goto done_computing_x; + } else if (hc->tx_p == 0) { + /* + * First feedback after nofeedback timer expiry (4.3) + */ + goto done_computing_x; + } + } + + /* Update sending rate (step 4 of [RFC 3448, 4.3]) */ + if (hc->tx_p > 0) + hc->tx_x_calc = tfrc_calc_x(hc->tx_s, hc->tx_rtt, hc->tx_p); + ccid3_hc_tx_update_x(sk, &now); + +done_computing_x: + ccid3_pr_debug("%s(%p), RTT=%uus (sample=%uus), s=%u, " + "p=%u, X_calc=%u, X_recv=%u, X=%u\n", + dccp_role(sk), sk, hc->tx_rtt, r_sample, + hc->tx_s, hc->tx_p, hc->tx_x_calc, + (unsigned int)(hc->tx_x_recv >> 6), + (unsigned int)(hc->tx_x >> 6)); + + /* unschedule no feedback timer */ + sk_stop_timer(sk, &hc->tx_no_feedback_timer); + + /* + * As we have calculated new ipi, delta, t_nom it is possible + * that we now can send a packet, so wake up dccp_wait_for_ccid + */ + sk->sk_write_space(sk); + + /* + * Update timeout interval for the nofeedback timer. In order to control + * rate halving on networks with very low RTTs (<= 1 ms), use per-route + * tunable RTAX_RTO_MIN value as the lower bound. + */ + hc->tx_t_rto = max_t(u32, 4 * hc->tx_rtt, + USEC_PER_SEC/HZ * tcp_rto_min(sk)); + /* + * Schedule no feedback timer to expire in + * max(t_RTO, 2 * s/X) = max(t_RTO, 2 * t_ipi) + */ + t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi); + + ccid3_pr_debug("%s(%p), Scheduled no feedback timer to " + "expire in %lu jiffies (%luus)\n", + dccp_role(sk), sk, usecs_to_jiffies(t_nfb), t_nfb); + + sk_reset_timer(sk, &hc->tx_no_feedback_timer, + jiffies + usecs_to_jiffies(t_nfb)); +} + +static int ccid3_hc_tx_parse_options(struct sock *sk, u8 packet_type, + u8 option, u8 *optval, u8 optlen) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + __be32 opt_val; + + switch (option) { + case TFRC_OPT_RECEIVE_RATE: + case TFRC_OPT_LOSS_EVENT_RATE: + /* Must be ignored on Data packets, cf. RFC 4342 8.3 and 8.5 */ + if (packet_type == DCCP_PKT_DATA) + break; + if (unlikely(optlen != 4)) { + DCCP_WARN("%s(%p), invalid len %d for %u\n", + dccp_role(sk), sk, optlen, option); + return -EINVAL; + } + opt_val = ntohl(get_unaligned((__be32 *)optval)); + + if (option == TFRC_OPT_RECEIVE_RATE) { + /* Receive Rate is kept in units of 64 bytes/second */ + hc->tx_x_recv = opt_val; + hc->tx_x_recv <<= 6; + + ccid3_pr_debug("%s(%p), RECEIVE_RATE=%u\n", + dccp_role(sk), sk, opt_val); + } else { + /* Update the fixpoint Loss Event Rate fraction */ + hc->tx_p = tfrc_invert_loss_event_rate(opt_val); + + ccid3_pr_debug("%s(%p), LOSS_EVENT_RATE=%u\n", + dccp_role(sk), sk, opt_val); + } + } + return 0; +} + +static int ccid3_hc_tx_init(struct ccid *ccid, struct sock *sk) +{ + struct ccid3_hc_tx_sock *hc = ccid_priv(ccid); + + hc->tx_state = TFRC_SSTATE_NO_SENT; + hc->tx_hist = NULL; + hc->sk = sk; + timer_setup(&hc->tx_no_feedback_timer, + ccid3_hc_tx_no_feedback_timer, 0); + return 0; +} + +static void ccid3_hc_tx_exit(struct sock *sk) +{ + struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + + sk_stop_timer(sk, &hc->tx_no_feedback_timer); + tfrc_tx_hist_purge(&hc->tx_hist); +} + +static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info) +{ + info->tcpi_rto = ccid3_hc_tx_sk(sk)->tx_t_rto; + info->tcpi_rtt = ccid3_hc_tx_sk(sk)->tx_rtt; +} + +static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len, + u32 __user *optval, int __user *optlen) +{ + const struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk); + struct tfrc_tx_info tfrc; + const void *val; + + switch (optname) { + case DCCP_SOCKOPT_CCID_TX_INFO: + if (len < sizeof(tfrc)) + return -EINVAL; + memset(&tfrc, 0, sizeof(tfrc)); + tfrc.tfrctx_x = hc->tx_x; + tfrc.tfrctx_x_recv = hc->tx_x_recv; + tfrc.tfrctx_x_calc = hc->tx_x_calc; + tfrc.tfrctx_rtt = hc->tx_rtt; + tfrc.tfrctx_p = hc->tx_p; + tfrc.tfrctx_rto = hc->tx_t_rto; + tfrc.tfrctx_ipi = hc->tx_t_ipi; + len = sizeof(tfrc); + val = &tfrc; + break; + default: + return -ENOPROTOOPT; + } + + if (put_user(len, optlen) || copy_to_user(optval, val, len)) + return -EFAULT; + + return 0; +} + +/* + * Receiver Half-Connection Routines + */ + +/* CCID3 feedback types */ +enum ccid3_fback_type { + CCID3_FBACK_NONE = 0, + CCID3_FBACK_INITIAL, + CCID3_FBACK_PERIODIC, + CCID3_FBACK_PARAM_CHANGE +}; + +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +static const char *ccid3_rx_state_name(enum ccid3_hc_rx_states state) +{ + static const char *const ccid3_rx_state_names[] = { + [TFRC_RSTATE_NO_DATA] = "NO_DATA", + [TFRC_RSTATE_DATA] = "DATA", + }; + + return ccid3_rx_state_names[state]; +} +#endif + +static void ccid3_hc_rx_set_state(struct sock *sk, + enum ccid3_hc_rx_states state) +{ + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + enum ccid3_hc_rx_states oldstate = hc->rx_state; + + ccid3_pr_debug("%s(%p) %-8.8s -> %s\n", + dccp_role(sk), sk, ccid3_rx_state_name(oldstate), + ccid3_rx_state_name(state)); + WARN_ON(state == oldstate); + hc->rx_state = state; +} + +static void ccid3_hc_rx_send_feedback(struct sock *sk, + const struct sk_buff *skb, + enum ccid3_fback_type fbtype) +{ + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + ktime_t now = ktime_get(); + s64 delta = 0; + + switch (fbtype) { + case CCID3_FBACK_INITIAL: + hc->rx_x_recv = 0; + hc->rx_pinv = ~0U; /* see RFC 4342, 8.5 */ + break; + case CCID3_FBACK_PARAM_CHANGE: + /* + * When parameters change (new loss or p > p_prev), we do not + * have a reliable estimate for R_m of [RFC 3448, 6.2] and so + * need to reuse the previous value of X_recv. However, when + * X_recv was 0 (due to early loss), this would kill X down to + * s/t_mbi (i.e. one packet in 64 seconds). + * To avoid such drastic reduction, we approximate X_recv as + * the number of bytes since last feedback. + * This is a safe fallback, since X is bounded above by X_calc. + */ + if (hc->rx_x_recv > 0) + break; + fallthrough; + case CCID3_FBACK_PERIODIC: + delta = ktime_us_delta(now, hc->rx_tstamp_last_feedback); + if (delta <= 0) + delta = 1; + hc->rx_x_recv = scaled_div32(hc->rx_bytes_recv, delta); + break; + default: + return; + } + + ccid3_pr_debug("Interval %lldusec, X_recv=%u, 1/p=%u\n", delta, + hc->rx_x_recv, hc->rx_pinv); + + hc->rx_tstamp_last_feedback = now; + hc->rx_last_counter = dccp_hdr(skb)->dccph_ccval; + hc->rx_bytes_recv = 0; + + dp->dccps_hc_rx_insert_options = 1; + dccp_send_ack(sk); +} + +static int ccid3_hc_rx_insert_options(struct sock *sk, struct sk_buff *skb) +{ + const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + __be32 x_recv, pinv; + + if (!(sk->sk_state == DCCP_OPEN || sk->sk_state == DCCP_PARTOPEN)) + return 0; + + if (dccp_packet_without_ack(skb)) + return 0; + + x_recv = htonl(hc->rx_x_recv); + pinv = htonl(hc->rx_pinv); + + if (dccp_insert_option(skb, TFRC_OPT_LOSS_EVENT_RATE, + &pinv, sizeof(pinv)) || + dccp_insert_option(skb, TFRC_OPT_RECEIVE_RATE, + &x_recv, sizeof(x_recv))) + return -1; + + return 0; +} + +/** + * ccid3_first_li - Implements [RFC 5348, 6.3.1] + * @sk: socket to calculate loss interval for + * + * Determine the length of the first loss interval via inverse lookup. + * Assume that X_recv can be computed by the throughput equation + * s + * X_recv = -------- + * R * fval + * Find some p such that f(p) = fval; return 1/p (scaled). + */ +static u32 ccid3_first_li(struct sock *sk) +{ + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + u32 x_recv, p; + s64 delta; + u64 fval; + + if (hc->rx_rtt == 0) { + DCCP_WARN("No RTT estimate available, using fallback RTT\n"); + hc->rx_rtt = DCCP_FALLBACK_RTT; + } + + delta = ktime_us_delta(ktime_get(), hc->rx_tstamp_last_feedback); + if (delta <= 0) + delta = 1; + x_recv = scaled_div32(hc->rx_bytes_recv, delta); + if (x_recv == 0) { /* would also trigger divide-by-zero */ + DCCP_WARN("X_recv==0\n"); + if (hc->rx_x_recv == 0) { + DCCP_BUG("stored value of X_recv is zero"); + return ~0U; + } + x_recv = hc->rx_x_recv; + } + + fval = scaled_div(hc->rx_s, hc->rx_rtt); + fval = scaled_div32(fval, x_recv); + p = tfrc_calc_x_reverse_lookup(fval); + + ccid3_pr_debug("%s(%p), receive rate=%u bytes/s, implied " + "loss rate=%u\n", dccp_role(sk), sk, x_recv, p); + + return p == 0 ? ~0U : scaled_div(1, p); +} + +static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) +{ + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; + const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; + const bool is_data_packet = dccp_data_packet(skb); + + if (unlikely(hc->rx_state == TFRC_RSTATE_NO_DATA)) { + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + do_feedback = CCID3_FBACK_INITIAL; + ccid3_hc_rx_set_state(sk, TFRC_RSTATE_DATA); + hc->rx_s = payload; + /* + * Not necessary to update rx_bytes_recv here, + * since X_recv = 0 for the first feedback packet (cf. + * RFC 3448, 6.3) -- gerrit + */ + } + goto update_records; + } + + if (tfrc_rx_hist_duplicate(&hc->rx_hist, skb)) + return; /* done receiving */ + + if (is_data_packet) { + const u32 payload = skb->len - dccp_hdr(skb)->dccph_doff * 4; + /* + * Update moving-average of s and the sum of received payload bytes + */ + hc->rx_s = tfrc_ewma(hc->rx_s, payload, 9); + hc->rx_bytes_recv += payload; + } + + /* + * Perform loss detection and handle pending losses + */ + if (tfrc_rx_handle_loss(&hc->rx_hist, &hc->rx_li_hist, + skb, ndp, ccid3_first_li, sk)) { + do_feedback = CCID3_FBACK_PARAM_CHANGE; + goto done_receiving; + } + + if (tfrc_rx_hist_loss_pending(&hc->rx_hist)) + return; /* done receiving */ + + /* + * Handle data packets: RTT sampling and monitoring p + */ + if (unlikely(!is_data_packet)) + goto update_records; + + if (!tfrc_lh_is_initialised(&hc->rx_li_hist)) { + const u32 sample = tfrc_rx_hist_sample_rtt(&hc->rx_hist, skb); + /* + * Empty loss history: no loss so far, hence p stays 0. + * Sample RTT values, since an RTT estimate is required for the + * computation of p when the first loss occurs; RFC 3448, 6.3.1. + */ + if (sample != 0) + hc->rx_rtt = tfrc_ewma(hc->rx_rtt, sample, 9); + + } else if (tfrc_lh_update_i_mean(&hc->rx_li_hist, skb)) { + /* + * Step (3) of [RFC 3448, 6.1]: Recompute I_mean and, if I_mean + * has decreased (resp. p has increased), send feedback now. + */ + do_feedback = CCID3_FBACK_PARAM_CHANGE; + } + + /* + * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 + */ + if (SUB16(dccp_hdr(skb)->dccph_ccval, hc->rx_last_counter) > 3) + do_feedback = CCID3_FBACK_PERIODIC; + +update_records: + tfrc_rx_hist_add_packet(&hc->rx_hist, skb, ndp); + +done_receiving: + if (do_feedback) + ccid3_hc_rx_send_feedback(sk, skb, do_feedback); +} + +static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) +{ + struct ccid3_hc_rx_sock *hc = ccid_priv(ccid); + + hc->rx_state = TFRC_RSTATE_NO_DATA; + tfrc_lh_init(&hc->rx_li_hist); + return tfrc_rx_hist_alloc(&hc->rx_hist); +} + +static void ccid3_hc_rx_exit(struct sock *sk) +{ + struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + + tfrc_rx_hist_purge(&hc->rx_hist); + tfrc_lh_cleanup(&hc->rx_li_hist); +} + +static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info) +{ + info->tcpi_ca_state = ccid3_hc_rx_sk(sk)->rx_state; + info->tcpi_options |= TCPI_OPT_TIMESTAMPS; + info->tcpi_rcv_rtt = ccid3_hc_rx_sk(sk)->rx_rtt; +} + +static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len, + u32 __user *optval, int __user *optlen) +{ + const struct ccid3_hc_rx_sock *hc = ccid3_hc_rx_sk(sk); + struct tfrc_rx_info rx_info; + const void *val; + + switch (optname) { + case DCCP_SOCKOPT_CCID_RX_INFO: + if (len < sizeof(rx_info)) + return -EINVAL; + rx_info.tfrcrx_x_recv = hc->rx_x_recv; + rx_info.tfrcrx_rtt = hc->rx_rtt; + rx_info.tfrcrx_p = tfrc_invert_loss_event_rate(hc->rx_pinv); + len = sizeof(rx_info); + val = &rx_info; + break; + default: + return -ENOPROTOOPT; + } + + if (put_user(len, optlen) || copy_to_user(optval, val, len)) + return -EFAULT; + + return 0; +} + +struct ccid_operations ccid3_ops = { + .ccid_id = DCCPC_CCID3, + .ccid_name = "TCP-Friendly Rate Control", + .ccid_hc_tx_obj_size = sizeof(struct ccid3_hc_tx_sock), + .ccid_hc_tx_init = ccid3_hc_tx_init, + .ccid_hc_tx_exit = ccid3_hc_tx_exit, + .ccid_hc_tx_send_packet = ccid3_hc_tx_send_packet, + .ccid_hc_tx_packet_sent = ccid3_hc_tx_packet_sent, + .ccid_hc_tx_packet_recv = ccid3_hc_tx_packet_recv, + .ccid_hc_tx_parse_options = ccid3_hc_tx_parse_options, + .ccid_hc_rx_obj_size = sizeof(struct ccid3_hc_rx_sock), + .ccid_hc_rx_init = ccid3_hc_rx_init, + .ccid_hc_rx_exit = ccid3_hc_rx_exit, + .ccid_hc_rx_insert_options = ccid3_hc_rx_insert_options, + .ccid_hc_rx_packet_recv = ccid3_hc_rx_packet_recv, + .ccid_hc_rx_get_info = ccid3_hc_rx_get_info, + .ccid_hc_tx_get_info = ccid3_hc_tx_get_info, + .ccid_hc_rx_getsockopt = ccid3_hc_rx_getsockopt, + .ccid_hc_tx_getsockopt = ccid3_hc_tx_getsockopt, +}; + +#ifdef CONFIG_IP_DCCP_CCID3_DEBUG +module_param(ccid3_debug, bool, 0644); +MODULE_PARM_DESC(ccid3_debug, "Enable CCID-3 debug messages"); +#endif diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h new file mode 100644 index 000000000..02e0fc9f6 --- /dev/null +++ b/net/dccp/ccids/ccid3.h @@ -0,0 +1,148 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * + * An implementation of the DCCP protocol + * + * This code has been developed by the University of Waikato WAND + * research group. For further information please see https://www.wand.net.nz/ + * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz + * + * This code also uses code from Lulea University, rereleased as GPL by its + * authors: + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * Changes to meet Linux coding standards, to make it meet latest ccid3 draft + * and to make it work as a loadable module in the DCCP stack written by + * Arnaldo Carvalho de Melo . + * + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ +#ifndef _DCCP_CCID3_H_ +#define _DCCP_CCID3_H_ + +#include +#include +#include +#include +#include "lib/tfrc.h" +#include "../ccid.h" + +/* Two seconds as per RFC 5348, 4.2 */ +#define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC) + +/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */ +#define TFRC_T_MBI 64 + +/* + * The t_delta parameter (RFC 5348, 8.3): delays of less than %USEC_PER_MSEC are + * rounded down to 0, since sk_reset_timer() here uses millisecond granularity. + * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse + * resolution of HZ < 500 means that the error is below one timer tick (t_gran) + * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ). + */ +#if (HZ >= 500) +# define TFRC_T_DELTA USEC_PER_MSEC +#else +# define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ)) +#endif + +enum ccid3_options { + TFRC_OPT_LOSS_EVENT_RATE = 192, + TFRC_OPT_LOSS_INTERVALS = 193, + TFRC_OPT_RECEIVE_RATE = 194, +}; + +/* TFRC sender states */ +enum ccid3_hc_tx_states { + TFRC_SSTATE_NO_SENT = 1, + TFRC_SSTATE_NO_FBACK, + TFRC_SSTATE_FBACK, +}; + +/** + * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket + * @tx_x: Current sending rate in 64 * bytes per second + * @tx_x_recv: Receive rate in 64 * bytes per second + * @tx_x_calc: Calculated rate in bytes per second + * @tx_rtt: Estimate of current round trip time in usecs + * @tx_p: Current loss event rate (0-1) scaled by 1000000 + * @tx_s: Packet size in bytes + * @tx_t_rto: Nofeedback Timer setting in usecs + * @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs + * @tx_state: Sender state, one of %ccid3_hc_tx_states + * @tx_last_win_count: Last window counter sent + * @tx_t_last_win_count: Timestamp of earliest packet + * with last_win_count value sent + * @tx_no_feedback_timer: Handle to no feedback timer + * @tx_t_ld: Time last doubled during slow start + * @tx_t_nom: Nominal send time of next packet + * @tx_hist: Packet history + */ +struct ccid3_hc_tx_sock { + u64 tx_x; + u64 tx_x_recv; + u32 tx_x_calc; + u32 tx_rtt; + u32 tx_p; + u32 tx_t_rto; + u32 tx_t_ipi; + u16 tx_s; + enum ccid3_hc_tx_states tx_state:8; + u8 tx_last_win_count; + ktime_t tx_t_last_win_count; + struct timer_list tx_no_feedback_timer; + struct sock *sk; + ktime_t tx_t_ld; + ktime_t tx_t_nom; + struct tfrc_tx_hist_entry *tx_hist; +}; + +static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) +{ + struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); + BUG_ON(hctx == NULL); + return hctx; +} + +/* TFRC receiver states */ +enum ccid3_hc_rx_states { + TFRC_RSTATE_NO_DATA = 1, + TFRC_RSTATE_DATA, +}; + +/** + * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket + * @rx_last_counter: Tracks window counter (RFC 4342, 8.1) + * @rx_state: Receiver state, one of %ccid3_hc_rx_states + * @rx_bytes_recv: Total sum of DCCP payload bytes + * @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3) + * @rx_rtt: Receiver estimate of RTT + * @rx_tstamp_last_feedback: Time at which last feedback was sent + * @rx_hist: Packet history (loss detection + RTT sampling) + * @rx_li_hist: Loss Interval database + * @rx_s: Received packet size in bytes + * @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5) + */ +struct ccid3_hc_rx_sock { + u8 rx_last_counter:4; + enum ccid3_hc_rx_states rx_state:8; + u32 rx_bytes_recv; + u32 rx_x_recv; + u32 rx_rtt; + ktime_t rx_tstamp_last_feedback; + struct tfrc_rx_hist rx_hist; + struct tfrc_loss_hist rx_li_hist; + u16 rx_s; +#define rx_pinv rx_li_hist.i_mean +}; + +static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk) +{ + struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); + BUG_ON(hcrx == NULL); + return hcrx; +} + +#endif /* _DCCP_CCID3_H_ */ diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c new file mode 100644 index 000000000..da9531984 --- /dev/null +++ b/net/dccp/ccids/lib/loss_interval.c @@ -0,0 +1,184 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005-7 Ian McDonald + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ +#include +#include "tfrc.h" + +static struct kmem_cache *tfrc_lh_slab __read_mostly; +/* Loss Interval weights from [RFC 3448, 5.4], scaled by 10 */ +static const int tfrc_lh_weights[NINTERVAL] = { 10, 10, 10, 10, 8, 6, 4, 2 }; + +/* implements LIFO semantics on the array */ +static inline u8 LIH_INDEX(const u8 ctr) +{ + return LIH_SIZE - 1 - (ctr % LIH_SIZE); +} + +/* the `counter' index always points at the next entry to be populated */ +static inline struct tfrc_loss_interval *tfrc_lh_peek(struct tfrc_loss_hist *lh) +{ + return lh->counter ? lh->ring[LIH_INDEX(lh->counter - 1)] : NULL; +} + +/* given i with 0 <= i <= k, return I_i as per the rfc3448bis notation */ +static inline u32 tfrc_lh_get_interval(struct tfrc_loss_hist *lh, const u8 i) +{ + BUG_ON(i >= lh->counter); + return lh->ring[LIH_INDEX(lh->counter - i - 1)]->li_length; +} + +/* + * On-demand allocation and de-allocation of entries + */ +static struct tfrc_loss_interval *tfrc_lh_demand_next(struct tfrc_loss_hist *lh) +{ + if (lh->ring[LIH_INDEX(lh->counter)] == NULL) + lh->ring[LIH_INDEX(lh->counter)] = kmem_cache_alloc(tfrc_lh_slab, + GFP_ATOMIC); + return lh->ring[LIH_INDEX(lh->counter)]; +} + +void tfrc_lh_cleanup(struct tfrc_loss_hist *lh) +{ + if (!tfrc_lh_is_initialised(lh)) + return; + + for (lh->counter = 0; lh->counter < LIH_SIZE; lh->counter++) + if (lh->ring[LIH_INDEX(lh->counter)] != NULL) { + kmem_cache_free(tfrc_lh_slab, + lh->ring[LIH_INDEX(lh->counter)]); + lh->ring[LIH_INDEX(lh->counter)] = NULL; + } +} + +static void tfrc_lh_calc_i_mean(struct tfrc_loss_hist *lh) +{ + u32 i_i, i_tot0 = 0, i_tot1 = 0, w_tot = 0; + int i, k = tfrc_lh_length(lh) - 1; /* k is as in rfc3448bis, 5.4 */ + + if (k <= 0) + return; + + for (i = 0; i <= k; i++) { + i_i = tfrc_lh_get_interval(lh, i); + + if (i < k) { + i_tot0 += i_i * tfrc_lh_weights[i]; + w_tot += tfrc_lh_weights[i]; + } + if (i > 0) + i_tot1 += i_i * tfrc_lh_weights[i-1]; + } + + lh->i_mean = max(i_tot0, i_tot1) / w_tot; +} + +/** + * tfrc_lh_update_i_mean - Update the `open' loss interval I_0 + * @lh: histogram to update + * @skb: received socket triggering loss interval update + * + * For recomputing p: returns `true' if p > p_prev <=> 1/p < 1/p_prev + */ +u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb) +{ + struct tfrc_loss_interval *cur = tfrc_lh_peek(lh); + u32 old_i_mean = lh->i_mean; + s64 len; + + if (cur == NULL) /* not initialised */ + return 0; + + len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1; + + if (len - (s64)cur->li_length <= 0) /* duplicate or reordered */ + return 0; + + if (SUB16(dccp_hdr(skb)->dccph_ccval, cur->li_ccval) > 4) + /* + * Implements RFC 4342, 10.2: + * If a packet S (skb) exists whose seqno comes `after' the one + * starting the current loss interval (cur) and if the modulo-16 + * distance from C(cur) to C(S) is greater than 4, consider all + * subsequent packets as belonging to a new loss interval. This + * test is necessary since CCVal may wrap between intervals. + */ + cur->li_is_closed = 1; + + if (tfrc_lh_length(lh) == 1) /* due to RFC 3448, 6.3.1 */ + return 0; + + cur->li_length = len; + tfrc_lh_calc_i_mean(lh); + + return lh->i_mean < old_i_mean; +} + +/* Determine if `new_loss' does begin a new loss interval [RFC 4342, 10.2] */ +static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur, + struct tfrc_rx_hist_entry *new_loss) +{ + return dccp_delta_seqno(cur->li_seqno, new_loss->tfrchrx_seqno) > 0 && + (cur->li_is_closed || SUB16(new_loss->tfrchrx_ccval, cur->li_ccval) > 4); +} + +/** + * tfrc_lh_interval_add - Insert new record into the Loss Interval database + * @lh: Loss Interval database + * @rh: Receive history containing a fresh loss event + * @calc_first_li: Caller-dependent routine to compute length of first interval + * @sk: Used by @calc_first_li in caller-specific way (subtyping) + * + * Updates I_mean and returns 1 if a new interval has in fact been added to @lh. + */ +int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, + u32 (*calc_first_li)(struct sock *), struct sock *sk) +{ + struct tfrc_loss_interval *cur = tfrc_lh_peek(lh), *new; + + if (cur != NULL && !tfrc_lh_is_new_loss(cur, tfrc_rx_hist_loss_prev(rh))) + return 0; + + new = tfrc_lh_demand_next(lh); + if (unlikely(new == NULL)) { + DCCP_CRIT("Cannot allocate/add loss record."); + return 0; + } + + new->li_seqno = tfrc_rx_hist_loss_prev(rh)->tfrchrx_seqno; + new->li_ccval = tfrc_rx_hist_loss_prev(rh)->tfrchrx_ccval; + new->li_is_closed = 0; + + if (++lh->counter == 1) + lh->i_mean = new->li_length = (*calc_first_li)(sk); + else { + cur->li_length = dccp_delta_seqno(cur->li_seqno, new->li_seqno); + new->li_length = dccp_delta_seqno(new->li_seqno, + tfrc_rx_hist_last_rcv(rh)->tfrchrx_seqno) + 1; + if (lh->counter > (2*LIH_SIZE)) + lh->counter -= LIH_SIZE; + + tfrc_lh_calc_i_mean(lh); + } + return 1; +} + +int __init tfrc_li_init(void) +{ + tfrc_lh_slab = kmem_cache_create("tfrc_li_hist", + sizeof(struct tfrc_loss_interval), 0, + SLAB_HWCACHE_ALIGN, NULL); + return tfrc_lh_slab == NULL ? -ENOBUFS : 0; +} + +void tfrc_li_exit(void) +{ + if (tfrc_lh_slab != NULL) { + kmem_cache_destroy(tfrc_lh_slab); + tfrc_lh_slab = NULL; + } +} diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h new file mode 100644 index 000000000..c3d95f85e --- /dev/null +++ b/net/dccp/ccids/lib/loss_interval.h @@ -0,0 +1,69 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _DCCP_LI_HIST_ +#define _DCCP_LI_HIST_ +/* + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005-7 Ian McDonald + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ +#include +#include +#include + +/* + * Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than + * NINTERVAL, since the `open' interval I_0 is always stored as the first entry. + */ +#define NINTERVAL 8 +#define LIH_SIZE (NINTERVAL + 1) + +/** + * tfrc_loss_interval - Loss history record for TFRC-based protocols + * @li_seqno: Highest received seqno before the start of loss + * @li_ccval: The CCVal belonging to @li_seqno + * @li_is_closed: Whether @li_seqno is older than 1 RTT + * @li_length: Loss interval sequence length + */ +struct tfrc_loss_interval { + u64 li_seqno:48, + li_ccval:4, + li_is_closed:1; + u32 li_length; +}; + +/** + * tfrc_loss_hist - Loss record database + * @ring: Circular queue managed in LIFO manner + * @counter: Current count of entries (can be more than %LIH_SIZE) + * @i_mean: Current Average Loss Interval [RFC 3448, 5.4] + */ +struct tfrc_loss_hist { + struct tfrc_loss_interval *ring[LIH_SIZE]; + u8 counter; + u32 i_mean; +}; + +static inline void tfrc_lh_init(struct tfrc_loss_hist *lh) +{ + memset(lh, 0, sizeof(struct tfrc_loss_hist)); +} + +static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh) +{ + return lh->counter > 0; +} + +static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh) +{ + return min(lh->counter, (u8)LIH_SIZE); +} + +struct tfrc_rx_hist; + +int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, + u32 (*first_li)(struct sock *), struct sock *); +u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); +void tfrc_lh_cleanup(struct tfrc_loss_hist *lh); + +#endif /* _DCCP_LI_HIST_ */ diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c new file mode 100644 index 000000000..0cdda3c66 --- /dev/null +++ b/net/dccp/ccids/lib/packet_history.c @@ -0,0 +1,439 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. + * + * An implementation of the DCCP protocol + * + * This code has been developed by the University of Waikato WAND + * research group. For further information please see https://www.wand.net.nz/ + * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz + * + * This code also uses code from Lulea University, rereleased as GPL by its + * authors: + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * Changes to meet Linux coding standards, to make it meet latest ccid3 draft + * and to make it work as a loadable module in the DCCP stack written by + * Arnaldo Carvalho de Melo . + * + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ + +#include +#include +#include "packet_history.h" +#include "../../dccp.h" + +/* + * Transmitter History Routines + */ +static struct kmem_cache *tfrc_tx_hist_slab; + +int __init tfrc_tx_packet_history_init(void) +{ + tfrc_tx_hist_slab = kmem_cache_create("tfrc_tx_hist", + sizeof(struct tfrc_tx_hist_entry), + 0, SLAB_HWCACHE_ALIGN, NULL); + return tfrc_tx_hist_slab == NULL ? -ENOBUFS : 0; +} + +void tfrc_tx_packet_history_exit(void) +{ + if (tfrc_tx_hist_slab != NULL) { + kmem_cache_destroy(tfrc_tx_hist_slab); + tfrc_tx_hist_slab = NULL; + } +} + +int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno) +{ + struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist_slab, gfp_any()); + + if (entry == NULL) + return -ENOBUFS; + entry->seqno = seqno; + entry->stamp = ktime_get_real(); + entry->next = *headp; + *headp = entry; + return 0; +} + +void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp) +{ + struct tfrc_tx_hist_entry *head = *headp; + + while (head != NULL) { + struct tfrc_tx_hist_entry *next = head->next; + + kmem_cache_free(tfrc_tx_hist_slab, head); + head = next; + } + + *headp = NULL; +} + +/* + * Receiver History Routines + */ +static struct kmem_cache *tfrc_rx_hist_slab; + +int __init tfrc_rx_packet_history_init(void) +{ + tfrc_rx_hist_slab = kmem_cache_create("tfrc_rxh_cache", + sizeof(struct tfrc_rx_hist_entry), + 0, SLAB_HWCACHE_ALIGN, NULL); + return tfrc_rx_hist_slab == NULL ? -ENOBUFS : 0; +} + +void tfrc_rx_packet_history_exit(void) +{ + if (tfrc_rx_hist_slab != NULL) { + kmem_cache_destroy(tfrc_rx_hist_slab); + tfrc_rx_hist_slab = NULL; + } +} + +static inline void tfrc_rx_hist_entry_from_skb(struct tfrc_rx_hist_entry *entry, + const struct sk_buff *skb, + const u64 ndp) +{ + const struct dccp_hdr *dh = dccp_hdr(skb); + + entry->tfrchrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq; + entry->tfrchrx_ccval = dh->dccph_ccval; + entry->tfrchrx_type = dh->dccph_type; + entry->tfrchrx_ndp = ndp; + entry->tfrchrx_tstamp = ktime_get_real(); +} + +void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, + const struct sk_buff *skb, + const u64 ndp) +{ + struct tfrc_rx_hist_entry *entry = tfrc_rx_hist_last_rcv(h); + + tfrc_rx_hist_entry_from_skb(entry, skb, ndp); +} + +/* has the packet contained in skb been seen before? */ +int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb) +{ + const u64 seq = DCCP_SKB_CB(skb)->dccpd_seq; + int i; + + if (dccp_delta_seqno(tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, seq) <= 0) + return 1; + + for (i = 1; i <= h->loss_count; i++) + if (tfrc_rx_hist_entry(h, i)->tfrchrx_seqno == seq) + return 1; + + return 0; +} + +static void tfrc_rx_hist_swap(struct tfrc_rx_hist *h, const u8 a, const u8 b) +{ + const u8 idx_a = tfrc_rx_hist_index(h, a), + idx_b = tfrc_rx_hist_index(h, b); + + swap(h->ring[idx_a], h->ring[idx_b]); +} + +/* + * Private helper functions for loss detection. + * + * In the descriptions, `Si' refers to the sequence number of entry number i, + * whose NDP count is `Ni' (lower case is used for variables). + * Note: All __xxx_loss functions expect that a test against duplicates has been + * performed already: the seqno of the skb must not be less than the seqno + * of loss_prev; and it must not equal that of any valid history entry. + */ +static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1) +{ + u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, + s1 = DCCP_SKB_CB(skb)->dccpd_seq; + + if (!dccp_loss_free(s0, s1, n1)) { /* gap between S0 and S1 */ + h->loss_count = 1; + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1); + } +} + +static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) +{ + u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, + s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, + s2 = DCCP_SKB_CB(skb)->dccpd_seq; + + if (likely(dccp_delta_seqno(s1, s2) > 0)) { /* S1 < S2 */ + h->loss_count = 2; + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n2); + return; + } + + /* S0 < S2 < S1 */ + + if (dccp_loss_free(s0, s2, n2)) { + u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; + + if (dccp_loss_free(s2, s1, n1)) { + /* hole is filled: S0, S2, and S1 are consecutive */ + h->loss_count = 0; + h->loss_start = tfrc_rx_hist_index(h, 1); + } else + /* gap between S2 and S1: just update loss_prev */ + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2); + + } else { /* gap between S0 and S2 */ + /* + * Reorder history to insert S2 between S0 and S1 + */ + tfrc_rx_hist_swap(h, 0, 3); + h->loss_start = tfrc_rx_hist_index(h, 3); + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n2); + h->loss_count = 2; + } +} + +/* return 1 if a new loss event has been identified */ +static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3) +{ + u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, + s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, + s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, + s3 = DCCP_SKB_CB(skb)->dccpd_seq; + + if (likely(dccp_delta_seqno(s2, s3) > 0)) { /* S2 < S3 */ + h->loss_count = 3; + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 3), skb, n3); + return 1; + } + + /* S3 < S2 */ + + if (dccp_delta_seqno(s1, s3) > 0) { /* S1 < S3 < S2 */ + /* + * Reorder history to insert S3 between S1 and S2 + */ + tfrc_rx_hist_swap(h, 2, 3); + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n3); + h->loss_count = 3; + return 1; + } + + /* S0 < S3 < S1 */ + + if (dccp_loss_free(s0, s3, n3)) { + u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp; + + if (dccp_loss_free(s3, s1, n1)) { + /* hole between S0 and S1 filled by S3 */ + u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp; + + if (dccp_loss_free(s1, s2, n2)) { + /* entire hole filled by S0, S3, S1, S2 */ + h->loss_start = tfrc_rx_hist_index(h, 2); + h->loss_count = 0; + } else { + /* gap remains between S1 and S2 */ + h->loss_start = tfrc_rx_hist_index(h, 1); + h->loss_count = 1; + } + + } else /* gap exists between S3 and S1, loss_count stays at 2 */ + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n3); + + return 0; + } + + /* + * The remaining case: S0 < S3 < S1 < S2; gap between S0 and S3 + * Reorder history to insert S3 between S0 and S1. + */ + tfrc_rx_hist_swap(h, 0, 3); + h->loss_start = tfrc_rx_hist_index(h, 3); + tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n3); + h->loss_count = 3; + + return 1; +} + +/* recycle RX history records to continue loss detection if necessary */ +static void __three_after_loss(struct tfrc_rx_hist *h) +{ + /* + * At this stage we know already that there is a gap between S0 and S1 + * (since S0 was the highest sequence number received before detecting + * the loss). To recycle the loss record, it is thus only necessary to + * check for other possible gaps between S1/S2 and between S2/S3. + */ + u64 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno, + s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno, + s3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_seqno; + u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp, + n3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_ndp; + + if (dccp_loss_free(s1, s2, n2)) { + + if (dccp_loss_free(s2, s3, n3)) { + /* no gap between S2 and S3: entire hole is filled */ + h->loss_start = tfrc_rx_hist_index(h, 3); + h->loss_count = 0; + } else { + /* gap between S2 and S3 */ + h->loss_start = tfrc_rx_hist_index(h, 2); + h->loss_count = 1; + } + + } else { /* gap between S1 and S2 */ + h->loss_start = tfrc_rx_hist_index(h, 1); + h->loss_count = 2; + } +} + +/** + * tfrc_rx_handle_loss - Loss detection and further processing + * @h: The non-empty RX history object + * @lh: Loss Intervals database to update + * @skb: Currently received packet + * @ndp: The NDP count belonging to @skb + * @calc_first_li: Caller-dependent computation of first loss interval in @lh + * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) + * + * Chooses action according to pending loss, updates LI database when a new + * loss was detected, and does required post-processing. Returns 1 when caller + * should send feedback, 0 otherwise. + * Since it also takes care of reordering during loss detection and updates the + * records accordingly, the caller should not perform any more RX history + * operations when loss_count is greater than 0 after calling this function. + */ +int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, + struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*calc_first_li)(struct sock *), struct sock *sk) +{ + int is_new_loss = 0; + + if (h->loss_count == 0) { + __do_track_loss(h, skb, ndp); + } else if (h->loss_count == 1) { + __one_after_loss(h, skb, ndp); + } else if (h->loss_count != 2) { + DCCP_BUG("invalid loss_count %d", h->loss_count); + } else if (__two_after_loss(h, skb, ndp)) { + /* + * Update Loss Interval database and recycle RX records + */ + is_new_loss = tfrc_lh_interval_add(lh, h, calc_first_li, sk); + __three_after_loss(h); + } + return is_new_loss; +} + +int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h) +{ + int i; + + for (i = 0; i <= TFRC_NDUPACK; i++) { + h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC); + if (h->ring[i] == NULL) + goto out_free; + } + + h->loss_count = h->loss_start = 0; + return 0; + +out_free: + while (i-- != 0) { + kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]); + h->ring[i] = NULL; + } + return -ENOBUFS; +} + +void tfrc_rx_hist_purge(struct tfrc_rx_hist *h) +{ + int i; + + for (i = 0; i <= TFRC_NDUPACK; ++i) + if (h->ring[i] != NULL) { + kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]); + h->ring[i] = NULL; + } +} + +/** + * tfrc_rx_hist_rtt_last_s - reference entry to compute RTT samples against + * @h: The non-empty RX history object + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_rtt_last_s(const struct tfrc_rx_hist *h) +{ + return h->ring[0]; +} + +/** + * tfrc_rx_hist_rtt_prev_s - previously suitable (wrt rtt_last_s) RTT-sampling entry + * @h: The non-empty RX history object + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_rtt_prev_s(const struct tfrc_rx_hist *h) +{ + return h->ring[h->rtt_sample_prev]; +} + +/** + * tfrc_rx_hist_sample_rtt - Sample RTT from timestamp / CCVal + * @h: receive histogram + * @skb: packet containing timestamp. + * + * Based on ideas presented in RFC 4342, 8.1. Returns 0 if it was not able + * to compute a sample with given data - calling function should check this. + */ +u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb) +{ + u32 sample = 0, + delta_v = SUB16(dccp_hdr(skb)->dccph_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + + if (delta_v < 1 || delta_v > 4) { /* unsuitable CCVal delta */ + if (h->rtt_sample_prev == 2) { /* previous candidate stored */ + sample = SUB16(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + if (sample) + sample = 4 / sample * + ktime_us_delta(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_tstamp, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp); + else /* + * FIXME: This condition is in principle not + * possible but occurs when CCID is used for + * two-way data traffic. I have tried to trace + * it, but the cause does not seem to be here. + */ + DCCP_BUG("please report to dccp@vger.kernel.org" + " => prev = %u, last = %u", + tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval, + tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval); + } else if (delta_v < 1) { + h->rtt_sample_prev = 1; + goto keep_ref_for_next_time; + } + + } else if (delta_v == 4) /* optimal match */ + sample = ktime_to_us(net_timedelta(tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp)); + else { /* suboptimal match */ + h->rtt_sample_prev = 2; + goto keep_ref_for_next_time; + } + + if (unlikely(sample > DCCP_SANE_RTT_MAX)) { + DCCP_WARN("RTT sample %u too large, using max\n", sample); + sample = DCCP_SANE_RTT_MAX; + } + + h->rtt_sample_prev = 0; /* use current entry as next reference */ +keep_ref_for_next_time: + + return sample; +} diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h new file mode 100644 index 000000000..159cc9326 --- /dev/null +++ b/net/dccp/ccids/lib/packet_history.h @@ -0,0 +1,142 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Packet RX/TX history data structures and routines for TFRC-based protocols. + * + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. + * + * This code has been developed by the University of Waikato WAND + * research group. For further information please see https://www.wand.net.nz/ + * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz + * + * This code also uses code from Lulea University, rereleased as GPL by its + * authors: + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + * + * Changes to meet Linux coding standards, to make it meet latest ccid3 draft + * and to make it work as a loadable module in the DCCP stack written by + * Arnaldo Carvalho de Melo . + * + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ + +#ifndef _DCCP_PKT_HIST_ +#define _DCCP_PKT_HIST_ + +#include +#include +#include "tfrc.h" + +/** + * tfrc_tx_hist_entry - Simple singly-linked TX history list + * @next: next oldest entry (LIFO order) + * @seqno: sequence number of this entry + * @stamp: send time of packet with sequence number @seqno + */ +struct tfrc_tx_hist_entry { + struct tfrc_tx_hist_entry *next; + u64 seqno; + ktime_t stamp; +}; + +static inline struct tfrc_tx_hist_entry * + tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno) +{ + while (head != NULL && head->seqno != seqno) + head = head->next; + return head; +} + +int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno); +void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp); + +/* Subtraction a-b modulo-16, respects circular wrap-around */ +#define SUB16(a, b) (((a) + 16 - (b)) & 0xF) + +/* Number of packets to wait after a missing packet (RFC 4342, 6.1) */ +#define TFRC_NDUPACK 3 + +/** + * tfrc_rx_hist_entry - Store information about a single received packet + * @tfrchrx_seqno: DCCP packet sequence number + * @tfrchrx_ccval: window counter value of packet (RFC 4342, 8.1) + * @tfrchrx_ndp: the NDP count (if any) of the packet + * @tfrchrx_tstamp: actual receive time of packet + */ +struct tfrc_rx_hist_entry { + u64 tfrchrx_seqno:48, + tfrchrx_ccval:4, + tfrchrx_type:4; + u64 tfrchrx_ndp:48; + ktime_t tfrchrx_tstamp; +}; + +/** + * tfrc_rx_hist - RX history structure for TFRC-based protocols + * @ring: Packet history for RTT sampling and loss detection + * @loss_count: Number of entries in circular history + * @loss_start: Movable index (for loss detection) + * @rtt_sample_prev: Used during RTT sampling, points to candidate entry + */ +struct tfrc_rx_hist { + struct tfrc_rx_hist_entry *ring[TFRC_NDUPACK + 1]; + u8 loss_count:2, + loss_start:2; +#define rtt_sample_prev loss_start +}; + +/** + * tfrc_rx_hist_index - index to reach n-th entry after loss_start + */ +static inline u8 tfrc_rx_hist_index(const struct tfrc_rx_hist *h, const u8 n) +{ + return (h->loss_start + n) & TFRC_NDUPACK; +} + +/** + * tfrc_rx_hist_last_rcv - entry with highest-received-seqno so far + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_last_rcv(const struct tfrc_rx_hist *h) +{ + return h->ring[tfrc_rx_hist_index(h, h->loss_count)]; +} + +/** + * tfrc_rx_hist_entry - return the n-th history entry after loss_start + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_entry(const struct tfrc_rx_hist *h, const u8 n) +{ + return h->ring[tfrc_rx_hist_index(h, n)]; +} + +/** + * tfrc_rx_hist_loss_prev - entry with highest-received-seqno before loss was detected + */ +static inline struct tfrc_rx_hist_entry * + tfrc_rx_hist_loss_prev(const struct tfrc_rx_hist *h) +{ + return h->ring[h->loss_start]; +} + +/* indicate whether previously a packet was detected missing */ +static inline bool tfrc_rx_hist_loss_pending(const struct tfrc_rx_hist *h) +{ + return h->loss_count > 0; +} + +void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, const struct sk_buff *skb, + const u64 ndp); + +int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb); + +struct tfrc_loss_hist; +int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*first_li)(struct sock *sk), struct sock *sk); +u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb); +int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h); +void tfrc_rx_hist_purge(struct tfrc_rx_hist *h); + +#endif /* _DCCP_PKT_HIST_ */ diff --git a/net/dccp/ccids/lib/tfrc.c b/net/dccp/ccids/lib/tfrc.c new file mode 100644 index 000000000..d7f265e1f --- /dev/null +++ b/net/dccp/ccids/lib/tfrc.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TFRC library initialisation + * + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2007 Arnaldo Carvalho de Melo + */ +#include +#include "tfrc.h" + +#ifdef CONFIG_IP_DCCP_TFRC_DEBUG +bool tfrc_debug; +module_param(tfrc_debug, bool, 0644); +MODULE_PARM_DESC(tfrc_debug, "Enable TFRC debug messages"); +#endif + +int __init tfrc_lib_init(void) +{ + int rc = tfrc_li_init(); + + if (rc) + goto out; + + rc = tfrc_tx_packet_history_init(); + if (rc) + goto out_free_loss_intervals; + + rc = tfrc_rx_packet_history_init(); + if (rc) + goto out_free_tx_history; + return 0; + +out_free_tx_history: + tfrc_tx_packet_history_exit(); +out_free_loss_intervals: + tfrc_li_exit(); +out: + return rc; +} + +void tfrc_lib_exit(void) +{ + tfrc_rx_packet_history_exit(); + tfrc_tx_packet_history_exit(); + tfrc_li_exit(); +} diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h new file mode 100644 index 000000000..0a63e8750 --- /dev/null +++ b/net/dccp/ccids/lib/tfrc.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _TFRC_H_ +#define _TFRC_H_ +/* + * Copyright (c) 2007 The University of Aberdeen, Scotland, UK + * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005-6 Ian McDonald + * Copyright (c) 2005 Arnaldo Carvalho de Melo + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + */ +#include +#include +#include "../../dccp.h" + +/* internal includes that this library exports: */ +#include "loss_interval.h" +#include "packet_history.h" + +#ifdef CONFIG_IP_DCCP_TFRC_DEBUG +extern bool tfrc_debug; +#define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) +#else +#define tfrc_pr_debug(format, a...) +#endif + +/* integer-arithmetic divisions of type (a * 1000000)/b */ +static inline u64 scaled_div(u64 a, u64 b) +{ + BUG_ON(b == 0); + return div64_u64(a * 1000000, b); +} + +static inline u32 scaled_div32(u64 a, u64 b) +{ + u64 result = scaled_div(a, b); + + if (result > UINT_MAX) { + DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", + (unsigned long long)a, (unsigned long long)b); + return UINT_MAX; + } + return result; +} + +/** + * tfrc_ewma - Exponentially weighted moving average + * @weight: Weight to be used as damping factor, in units of 1/10 + */ +static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) +{ + return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; +} + +u32 tfrc_calc_x(u16 s, u32 R, u32 p); +u32 tfrc_calc_x_reverse_lookup(u32 fvalue); +u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); + +int tfrc_tx_packet_history_init(void); +void tfrc_tx_packet_history_exit(void); +int tfrc_rx_packet_history_init(void); +void tfrc_rx_packet_history_exit(void); + +int tfrc_li_init(void); +void tfrc_li_exit(void); + +#ifdef CONFIG_IP_DCCP_TFRC_LIB +int tfrc_lib_init(void); +void tfrc_lib_exit(void); +#else +#define tfrc_lib_init() (0) +#define tfrc_lib_exit() +#endif +#endif /* _TFRC_H_ */ diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c new file mode 100644 index 000000000..92a8c6bea --- /dev/null +++ b/net/dccp/ccids/lib/tfrc_equation.c @@ -0,0 +1,702 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. + * Copyright (c) 2005 Ian McDonald + * Copyright (c) 2005 Arnaldo Carvalho de Melo + * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon + */ + +#include +#include "../../dccp.h" +#include "tfrc.h" + +#define TFRC_CALC_X_ARRSIZE 500 +#define TFRC_CALC_X_SPLIT 50000 /* 0.05 * 1000000, details below */ +#define TFRC_SMALLEST_P (TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE) + +/* + TFRC TCP Reno Throughput Equation Lookup Table for f(p) + + The following two-column lookup table implements a part of the TCP throughput + equation from [RFC 3448, sec. 3.1]: + + s + X_calc = -------------------------------------------------------------- + R * sqrt(2*b*p/3) + (3 * t_RTO * sqrt(3*b*p/8) * (p + 32*p^3)) + + Where: + X is the transmit rate in bytes/second + s is the packet size in bytes + R is the round trip time in seconds + p is the loss event rate, between 0 and 1.0, of the number of loss + events as a fraction of the number of packets transmitted + t_RTO is the TCP retransmission timeout value in seconds + b is the number of packets acknowledged by a single TCP ACK + + We can assume that b = 1 and t_RTO is 4 * R. The equation now becomes: + + s + X_calc = ------------------------------------------------------- + R * sqrt(p*2/3) + (12 * R * sqrt(p*3/8) * (p + 32*p^3)) + + which we can break down into: + + s + X_calc = --------- + R * f(p) + + where f(p) is given for 0 < p <= 1 by: + + f(p) = sqrt(2*p/3) + 12 * sqrt(3*p/8) * (p + 32*p^3) + + Since this is kernel code, floating-point arithmetic is avoided in favour of + integer arithmetic. This means that nearly all fractional parameters are + scaled by 1000000: + * the parameters p and R + * the return result f(p) + The lookup table therefore actually tabulates the following function g(q): + + g(q) = 1000000 * f(q/1000000) + + Hence, when p <= 1, q must be less than or equal to 1000000. To achieve finer + granularity for the practically more relevant case of small values of p (up to + 5%), the second column is used; the first one ranges up to 100%. This split + corresponds to the value of q = TFRC_CALC_X_SPLIT. At the same time this also + determines the smallest resolution possible with this lookup table: + + TFRC_SMALLEST_P = TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE + + The entire table is generated by: + for(i=0; i < TFRC_CALC_X_ARRSIZE; i++) { + lookup[i][0] = g((i+1) * 1000000/TFRC_CALC_X_ARRSIZE); + lookup[i][1] = g((i+1) * TFRC_CALC_X_SPLIT/TFRC_CALC_X_ARRSIZE); + } + + With the given configuration, we have, with M = TFRC_CALC_X_ARRSIZE-1, + lookup[0][0] = g(1000000/(M+1)) = 1000000 * f(0.2%) + lookup[M][0] = g(1000000) = 1000000 * f(100%) + lookup[0][1] = g(TFRC_SMALLEST_P) = 1000000 * f(0.01%) + lookup[M][1] = g(TFRC_CALC_X_SPLIT) = 1000000 * f(5%) + + In summary, the two columns represent f(p) for the following ranges: + * The first column is for 0.002 <= p <= 1.0 + * The second column is for 0.0001 <= p <= 0.05 + Where the columns overlap, the second (finer-grained) is given preference, + i.e. the first column is used only for p >= 0.05. + */ +static const u32 tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE][2] = { + { 37172, 8172 }, + { 53499, 11567 }, + { 66664, 14180 }, + { 78298, 16388 }, + { 89021, 18339 }, + { 99147, 20108 }, + { 108858, 21738 }, + { 118273, 23260 }, + { 127474, 24693 }, + { 136520, 26052 }, + { 145456, 27348 }, + { 154316, 28589 }, + { 163130, 29783 }, + { 171919, 30935 }, + { 180704, 32049 }, + { 189502, 33130 }, + { 198328, 34180 }, + { 207194, 35202 }, + { 216114, 36198 }, + { 225097, 37172 }, + { 234153, 38123 }, + { 243294, 39055 }, + { 252527, 39968 }, + { 261861, 40864 }, + { 271305, 41743 }, + { 280866, 42607 }, + { 290553, 43457 }, + { 300372, 44293 }, + { 310333, 45117 }, + { 320441, 45929 }, + { 330705, 46729 }, + { 341131, 47518 }, + { 351728, 48297 }, + { 362501, 49066 }, + { 373460, 49826 }, + { 384609, 50577 }, + { 395958, 51320 }, + { 407513, 52054 }, + { 419281, 52780 }, + { 431270, 53499 }, + { 443487, 54211 }, + { 455940, 54916 }, + { 468635, 55614 }, + { 481581, 56306 }, + { 494785, 56991 }, + { 508254, 57671 }, + { 521996, 58345 }, + { 536019, 59014 }, + { 550331, 59677 }, + { 564939, 60335 }, + { 579851, 60988 }, + { 595075, 61636 }, + { 610619, 62279 }, + { 626491, 62918 }, + { 642700, 63553 }, + { 659253, 64183 }, + { 676158, 64809 }, + { 693424, 65431 }, + { 711060, 66050 }, + { 729073, 66664 }, + { 747472, 67275 }, + { 766266, 67882 }, + { 785464, 68486 }, + { 805073, 69087 }, + { 825103, 69684 }, + { 845562, 70278 }, + { 866460, 70868 }, + { 887805, 71456 }, + { 909606, 72041 }, + { 931873, 72623 }, + { 954614, 73202 }, + { 977839, 73778 }, + { 1001557, 74352 }, + { 1025777, 74923 }, + { 1050508, 75492 }, + { 1075761, 76058 }, + { 1101544, 76621 }, + { 1127867, 77183 }, + { 1154739, 77741 }, + { 1182172, 78298 }, + { 1210173, 78852 }, + { 1238753, 79405 }, + { 1267922, 79955 }, + { 1297689, 80503 }, + { 1328066, 81049 }, + { 1359060, 81593 }, + { 1390684, 82135 }, + { 1422947, 82675 }, + { 1455859, 83213 }, + { 1489430, 83750 }, + { 1523671, 84284 }, + { 1558593, 84817 }, + { 1594205, 85348 }, + { 1630518, 85878 }, + { 1667543, 86406 }, + { 1705290, 86932 }, + { 1743770, 87457 }, + { 1782994, 87980 }, + { 1822973, 88501 }, + { 1863717, 89021 }, + { 1905237, 89540 }, + { 1947545, 90057 }, + { 1990650, 90573 }, + { 2034566, 91087 }, + { 2079301, 91600 }, + { 2124869, 92111 }, + { 2171279, 92622 }, + { 2218543, 93131 }, + { 2266673, 93639 }, + { 2315680, 94145 }, + { 2365575, 94650 }, + { 2416371, 95154 }, + { 2468077, 95657 }, + { 2520707, 96159 }, + { 2574271, 96660 }, + { 2628782, 97159 }, + { 2684250, 97658 }, + { 2740689, 98155 }, + { 2798110, 98651 }, + { 2856524, 99147 }, + { 2915944, 99641 }, + { 2976382, 100134 }, + { 3037850, 100626 }, + { 3100360, 101117 }, + { 3163924, 101608 }, + { 3228554, 102097 }, + { 3294263, 102586 }, + { 3361063, 103073 }, + { 3428966, 103560 }, + { 3497984, 104045 }, + { 3568131, 104530 }, + { 3639419, 105014 }, + { 3711860, 105498 }, + { 3785467, 105980 }, + { 3860253, 106462 }, + { 3936229, 106942 }, + { 4013410, 107422 }, + { 4091808, 107902 }, + { 4171435, 108380 }, + { 4252306, 108858 }, + { 4334431, 109335 }, + { 4417825, 109811 }, + { 4502501, 110287 }, + { 4588472, 110762 }, + { 4675750, 111236 }, + { 4764349, 111709 }, + { 4854283, 112182 }, + { 4945564, 112654 }, + { 5038206, 113126 }, + { 5132223, 113597 }, + { 5227627, 114067 }, + { 5324432, 114537 }, + { 5422652, 115006 }, + { 5522299, 115474 }, + { 5623389, 115942 }, + { 5725934, 116409 }, + { 5829948, 116876 }, + { 5935446, 117342 }, + { 6042439, 117808 }, + { 6150943, 118273 }, + { 6260972, 118738 }, + { 6372538, 119202 }, + { 6485657, 119665 }, + { 6600342, 120128 }, + { 6716607, 120591 }, + { 6834467, 121053 }, + { 6953935, 121514 }, + { 7075025, 121976 }, + { 7197752, 122436 }, + { 7322131, 122896 }, + { 7448175, 123356 }, + { 7575898, 123815 }, + { 7705316, 124274 }, + { 7836442, 124733 }, + { 7969291, 125191 }, + { 8103877, 125648 }, + { 8240216, 126105 }, + { 8378321, 126562 }, + { 8518208, 127018 }, + { 8659890, 127474 }, + { 8803384, 127930 }, + { 8948702, 128385 }, + { 9095861, 128840 }, + { 9244875, 129294 }, + { 9395760, 129748 }, + { 9548529, 130202 }, + { 9703198, 130655 }, + { 9859782, 131108 }, + { 10018296, 131561 }, + { 10178755, 132014 }, + { 10341174, 132466 }, + { 10505569, 132917 }, + { 10671954, 133369 }, + { 10840345, 133820 }, + { 11010757, 134271 }, + { 11183206, 134721 }, + { 11357706, 135171 }, + { 11534274, 135621 }, + { 11712924, 136071 }, + { 11893673, 136520 }, + { 12076536, 136969 }, + { 12261527, 137418 }, + { 12448664, 137867 }, + { 12637961, 138315 }, + { 12829435, 138763 }, + { 13023101, 139211 }, + { 13218974, 139658 }, + { 13417071, 140106 }, + { 13617407, 140553 }, + { 13819999, 140999 }, + { 14024862, 141446 }, + { 14232012, 141892 }, + { 14441465, 142339 }, + { 14653238, 142785 }, + { 14867346, 143230 }, + { 15083805, 143676 }, + { 15302632, 144121 }, + { 15523842, 144566 }, + { 15747453, 145011 }, + { 15973479, 145456 }, + { 16201939, 145900 }, + { 16432847, 146345 }, + { 16666221, 146789 }, + { 16902076, 147233 }, + { 17140429, 147677 }, + { 17381297, 148121 }, + { 17624696, 148564 }, + { 17870643, 149007 }, + { 18119154, 149451 }, + { 18370247, 149894 }, + { 18623936, 150336 }, + { 18880241, 150779 }, + { 19139176, 151222 }, + { 19400759, 151664 }, + { 19665007, 152107 }, + { 19931936, 152549 }, + { 20201564, 152991 }, + { 20473907, 153433 }, + { 20748982, 153875 }, + { 21026807, 154316 }, + { 21307399, 154758 }, + { 21590773, 155199 }, + { 21876949, 155641 }, + { 22165941, 156082 }, + { 22457769, 156523 }, + { 22752449, 156964 }, + { 23049999, 157405 }, + { 23350435, 157846 }, + { 23653774, 158287 }, + { 23960036, 158727 }, + { 24269236, 159168 }, + { 24581392, 159608 }, + { 24896521, 160049 }, + { 25214642, 160489 }, + { 25535772, 160929 }, + { 25859927, 161370 }, + { 26187127, 161810 }, + { 26517388, 162250 }, + { 26850728, 162690 }, + { 27187165, 163130 }, + { 27526716, 163569 }, + { 27869400, 164009 }, + { 28215234, 164449 }, + { 28564236, 164889 }, + { 28916423, 165328 }, + { 29271815, 165768 }, + { 29630428, 166208 }, + { 29992281, 166647 }, + { 30357392, 167087 }, + { 30725779, 167526 }, + { 31097459, 167965 }, + { 31472452, 168405 }, + { 31850774, 168844 }, + { 32232445, 169283 }, + { 32617482, 169723 }, + { 33005904, 170162 }, + { 33397730, 170601 }, + { 33792976, 171041 }, + { 34191663, 171480 }, + { 34593807, 171919 }, + { 34999428, 172358 }, + { 35408544, 172797 }, + { 35821174, 173237 }, + { 36237335, 173676 }, + { 36657047, 174115 }, + { 37080329, 174554 }, + { 37507197, 174993 }, + { 37937673, 175433 }, + { 38371773, 175872 }, + { 38809517, 176311 }, + { 39250924, 176750 }, + { 39696012, 177190 }, + { 40144800, 177629 }, + { 40597308, 178068 }, + { 41053553, 178507 }, + { 41513554, 178947 }, + { 41977332, 179386 }, + { 42444904, 179825 }, + { 42916290, 180265 }, + { 43391509, 180704 }, + { 43870579, 181144 }, + { 44353520, 181583 }, + { 44840352, 182023 }, + { 45331092, 182462 }, + { 45825761, 182902 }, + { 46324378, 183342 }, + { 46826961, 183781 }, + { 47333531, 184221 }, + { 47844106, 184661 }, + { 48358706, 185101 }, + { 48877350, 185541 }, + { 49400058, 185981 }, + { 49926849, 186421 }, + { 50457743, 186861 }, + { 50992759, 187301 }, + { 51531916, 187741 }, + { 52075235, 188181 }, + { 52622735, 188622 }, + { 53174435, 189062 }, + { 53730355, 189502 }, + { 54290515, 189943 }, + { 54854935, 190383 }, + { 55423634, 190824 }, + { 55996633, 191265 }, + { 56573950, 191706 }, + { 57155606, 192146 }, + { 57741621, 192587 }, + { 58332014, 193028 }, + { 58926806, 193470 }, + { 59526017, 193911 }, + { 60129666, 194352 }, + { 60737774, 194793 }, + { 61350361, 195235 }, + { 61967446, 195677 }, + { 62589050, 196118 }, + { 63215194, 196560 }, + { 63845897, 197002 }, + { 64481179, 197444 }, + { 65121061, 197886 }, + { 65765563, 198328 }, + { 66414705, 198770 }, + { 67068508, 199213 }, + { 67726992, 199655 }, + { 68390177, 200098 }, + { 69058085, 200540 }, + { 69730735, 200983 }, + { 70408147, 201426 }, + { 71090343, 201869 }, + { 71777343, 202312 }, + { 72469168, 202755 }, + { 73165837, 203199 }, + { 73867373, 203642 }, + { 74573795, 204086 }, + { 75285124, 204529 }, + { 76001380, 204973 }, + { 76722586, 205417 }, + { 77448761, 205861 }, + { 78179926, 206306 }, + { 78916102, 206750 }, + { 79657310, 207194 }, + { 80403571, 207639 }, + { 81154906, 208084 }, + { 81911335, 208529 }, + { 82672880, 208974 }, + { 83439562, 209419 }, + { 84211402, 209864 }, + { 84988421, 210309 }, + { 85770640, 210755 }, + { 86558080, 211201 }, + { 87350762, 211647 }, + { 88148708, 212093 }, + { 88951938, 212539 }, + { 89760475, 212985 }, + { 90574339, 213432 }, + { 91393551, 213878 }, + { 92218133, 214325 }, + { 93048107, 214772 }, + { 93883493, 215219 }, + { 94724314, 215666 }, + { 95570590, 216114 }, + { 96422343, 216561 }, + { 97279594, 217009 }, + { 98142366, 217457 }, + { 99010679, 217905 }, + { 99884556, 218353 }, + { 100764018, 218801 }, + { 101649086, 219250 }, + { 102539782, 219698 }, + { 103436128, 220147 }, + { 104338146, 220596 }, + { 105245857, 221046 }, + { 106159284, 221495 }, + { 107078448, 221945 }, + { 108003370, 222394 }, + { 108934074, 222844 }, + { 109870580, 223294 }, + { 110812910, 223745 }, + { 111761087, 224195 }, + { 112715133, 224646 }, + { 113675069, 225097 }, + { 114640918, 225548 }, + { 115612702, 225999 }, + { 116590442, 226450 }, + { 117574162, 226902 }, + { 118563882, 227353 }, + { 119559626, 227805 }, + { 120561415, 228258 }, + { 121569272, 228710 }, + { 122583219, 229162 }, + { 123603278, 229615 }, + { 124629471, 230068 }, + { 125661822, 230521 }, + { 126700352, 230974 }, + { 127745083, 231428 }, + { 128796039, 231882 }, + { 129853241, 232336 }, + { 130916713, 232790 }, + { 131986475, 233244 }, + { 133062553, 233699 }, + { 134144966, 234153 }, + { 135233739, 234608 }, + { 136328894, 235064 }, + { 137430453, 235519 }, + { 138538440, 235975 }, + { 139652876, 236430 }, + { 140773786, 236886 }, + { 141901190, 237343 }, + { 143035113, 237799 }, + { 144175576, 238256 }, + { 145322604, 238713 }, + { 146476218, 239170 }, + { 147636442, 239627 }, + { 148803298, 240085 }, + { 149976809, 240542 }, + { 151156999, 241000 }, + { 152343890, 241459 }, + { 153537506, 241917 }, + { 154737869, 242376 }, + { 155945002, 242835 }, + { 157158929, 243294 }, + { 158379673, 243753 }, + { 159607257, 244213 }, + { 160841704, 244673 }, + { 162083037, 245133 }, + { 163331279, 245593 }, + { 164586455, 246054 }, + { 165848586, 246514 }, + { 167117696, 246975 }, + { 168393810, 247437 }, + { 169676949, 247898 }, + { 170967138, 248360 }, + { 172264399, 248822 }, + { 173568757, 249284 }, + { 174880235, 249747 }, + { 176198856, 250209 }, + { 177524643, 250672 }, + { 178857621, 251136 }, + { 180197813, 251599 }, + { 181545242, 252063 }, + { 182899933, 252527 }, + { 184261908, 252991 }, + { 185631191, 253456 }, + { 187007807, 253920 }, + { 188391778, 254385 }, + { 189783129, 254851 }, + { 191181884, 255316 }, + { 192588065, 255782 }, + { 194001698, 256248 }, + { 195422805, 256714 }, + { 196851411, 257181 }, + { 198287540, 257648 }, + { 199731215, 258115 }, + { 201182461, 258582 }, + { 202641302, 259050 }, + { 204107760, 259518 }, + { 205581862, 259986 }, + { 207063630, 260454 }, + { 208553088, 260923 }, + { 210050262, 261392 }, + { 211555174, 261861 }, + { 213067849, 262331 }, + { 214588312, 262800 }, + { 216116586, 263270 }, + { 217652696, 263741 }, + { 219196666, 264211 }, + { 220748520, 264682 }, + { 222308282, 265153 }, + { 223875978, 265625 }, + { 225451630, 266097 }, + { 227035265, 266569 }, + { 228626905, 267041 }, + { 230226576, 267514 }, + { 231834302, 267986 }, + { 233450107, 268460 }, + { 235074016, 268933 }, + { 236706054, 269407 }, + { 238346244, 269881 }, + { 239994613, 270355 }, + { 241651183, 270830 }, + { 243315981, 271305 } +}; + +/* return largest index i such that fval <= lookup[i][small] */ +static inline u32 tfrc_binsearch(u32 fval, u8 small) +{ + u32 try, low = 0, high = TFRC_CALC_X_ARRSIZE - 1; + + while (low < high) { + try = (low + high) / 2; + if (fval <= tfrc_calc_x_lookup[try][small]) + high = try; + else + low = try + 1; + } + return high; +} + +/** + * tfrc_calc_x - Calculate the send rate as per section 3.1 of RFC3448 + * @s: packet size in bytes + * @R: RTT scaled by 1000000 (i.e., microseconds) + * @p: loss ratio estimate scaled by 1000000 + * + * Returns X_calc in bytes per second (not scaled). + */ +u32 tfrc_calc_x(u16 s, u32 R, u32 p) +{ + u16 index; + u32 f; + u64 result; + + /* check against invalid parameters and divide-by-zero */ + BUG_ON(p > 1000000); /* p must not exceed 100% */ + BUG_ON(p == 0); /* f(0) = 0, divide by zero */ + if (R == 0) { /* possible divide by zero */ + DCCP_CRIT("WARNING: RTT is 0, returning maximum X_calc."); + return ~0U; + } + + if (p <= TFRC_CALC_X_SPLIT) { /* 0.0000 < p <= 0.05 */ + if (p < TFRC_SMALLEST_P) { /* 0.0000 < p < 0.0001 */ + DCCP_WARN("Value of p (%d) below resolution. " + "Substituting %d\n", p, TFRC_SMALLEST_P); + index = 0; + } else /* 0.0001 <= p <= 0.05 */ + index = p/TFRC_SMALLEST_P - 1; + + f = tfrc_calc_x_lookup[index][1]; + + } else { /* 0.05 < p <= 1.00 */ + index = p/(1000000/TFRC_CALC_X_ARRSIZE) - 1; + + f = tfrc_calc_x_lookup[index][0]; + } + + /* + * Compute X = s/(R*f(p)) in bytes per second. + * Since f(p) and R are both scaled by 1000000, we need to multiply by + * 1000000^2. To avoid overflow, the result is computed in two stages. + * This works under almost all reasonable operational conditions, for a + * wide range of parameters. Yet, should some strange combination of + * parameters result in overflow, the use of scaled_div32 will catch + * this and return UINT_MAX - which is a logically adequate consequence. + */ + result = scaled_div(s, R); + return scaled_div32(result, f); +} + +/** + * tfrc_calc_x_reverse_lookup - try to find p given f(p) + * @fvalue: function value to match, scaled by 1000000 + * + * Returns closest match for p, also scaled by 1000000 + */ +u32 tfrc_calc_x_reverse_lookup(u32 fvalue) +{ + int index; + + if (fvalue == 0) /* f(p) = 0 whenever p = 0 */ + return 0; + + /* Error cases. */ + if (fvalue < tfrc_calc_x_lookup[0][1]) { + DCCP_WARN("fvalue %u smaller than resolution\n", fvalue); + return TFRC_SMALLEST_P; + } + if (fvalue > tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][0]) { + DCCP_WARN("fvalue %u exceeds bounds!\n", fvalue); + return 1000000; + } + + if (fvalue <= tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][1]) { + index = tfrc_binsearch(fvalue, 1); + return (index + 1) * TFRC_CALC_X_SPLIT / TFRC_CALC_X_ARRSIZE; + } + + /* else ... it must be in the coarse-grained column */ + index = tfrc_binsearch(fvalue, 0); + return (index + 1) * 1000000 / TFRC_CALC_X_ARRSIZE; +} + +/** + * tfrc_invert_loss_event_rate - Compute p so that 10^6 corresponds to 100% + * @loss_event_rate: loss event rate to invert + * When @loss_event_rate is large, there is a chance that p is truncated to 0. + * To avoid re-entering slow-start in that case, we set p = TFRC_SMALLEST_P > 0. + */ +u32 tfrc_invert_loss_event_rate(u32 loss_event_rate) +{ + if (loss_event_rate == UINT_MAX) /* see RFC 4342, 8.5 */ + return 0; + if (unlikely(loss_event_rate == 0)) /* map 1/0 into 100% */ + return 1000000; + return max_t(u32, scaled_div(1, loss_event_rate), TFRC_SMALLEST_P); +} diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h new file mode 100644 index 000000000..9ddc3a9e8 --- /dev/null +++ b/net/dccp/dccp.h @@ -0,0 +1,483 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DCCP_H +#define _DCCP_H +/* + * net/dccp/dccp.h + * + * An implementation of the DCCP protocol + * Copyright (c) 2005 Arnaldo Carvalho de Melo + * Copyright (c) 2005-6 Ian McDonald + */ + +#include +#include +#include +#include +#include +#include "ackvec.h" + +/* + * DCCP - specific warning and debugging macros. + */ +#define DCCP_WARN(fmt, ...) \ + net_warn_ratelimited("%s: " fmt, __func__, ##__VA_ARGS__) +#define DCCP_CRIT(fmt, a...) printk(KERN_CRIT fmt " at %s:%d/%s()\n", ##a, \ + __FILE__, __LINE__, __func__) +#define DCCP_BUG(a...) do { DCCP_CRIT("BUG: " a); dump_stack(); } while(0) +#define DCCP_BUG_ON(cond) do { if (unlikely((cond) != 0)) \ + DCCP_BUG("\"%s\" holds (exception!)", \ + __stringify(cond)); \ + } while (0) + +#define DCCP_PRINTK(enable, fmt, args...) do { if (enable) \ + printk(fmt, ##args); \ + } while(0) +#define DCCP_PR_DEBUG(enable, fmt, a...) DCCP_PRINTK(enable, KERN_DEBUG \ + "%s: " fmt, __func__, ##a) + +#ifdef CONFIG_IP_DCCP_DEBUG +extern bool dccp_debug; +#define dccp_pr_debug(format, a...) DCCP_PR_DEBUG(dccp_debug, format, ##a) +#define dccp_pr_debug_cat(format, a...) DCCP_PRINTK(dccp_debug, format, ##a) +#define dccp_debug(fmt, a...) dccp_pr_debug_cat(KERN_DEBUG fmt, ##a) +#else +#define dccp_pr_debug(format, a...) do {} while (0) +#define dccp_pr_debug_cat(format, a...) do {} while (0) +#define dccp_debug(format, a...) do {} while (0) +#endif + +extern struct inet_hashinfo dccp_hashinfo; + +DECLARE_PER_CPU(unsigned int, dccp_orphan_count); + +void dccp_time_wait(struct sock *sk, int state, int timeo); + +/* + * Set safe upper bounds for header and option length. Since Data Offset is 8 + * bits (RFC 4340, sec. 5.1), the total header length can never be more than + * 4 * 255 = 1020 bytes. The largest possible header length is 28 bytes (X=1): + * - DCCP-Response with ACK Subheader and 4 bytes of Service code OR + * - DCCP-Reset with ACK Subheader and 4 bytes of Reset Code fields + * Hence a safe upper bound for the maximum option length is 1020-28 = 992 + */ +#define MAX_DCCP_SPECIFIC_HEADER (255 * sizeof(uint32_t)) +#define DCCP_MAX_PACKET_HDR 28 +#define DCCP_MAX_OPT_LEN (MAX_DCCP_SPECIFIC_HEADER - DCCP_MAX_PACKET_HDR) +#define MAX_DCCP_HEADER (MAX_DCCP_SPECIFIC_HEADER + MAX_HEADER) + +/* Upper bound for initial feature-negotiation overhead (padded to 32 bits) */ +#define DCCP_FEATNEG_OVERHEAD (32 * sizeof(uint32_t)) + +#define DCCP_TIMEWAIT_LEN (60 * HZ) /* how long to wait to destroy TIME-WAIT + * state, about 60 seconds */ + +/* RFC 1122, 4.2.3.1 initial RTO value */ +#define DCCP_TIMEOUT_INIT ((unsigned int)(3 * HZ)) + +/* + * The maximum back-off value for retransmissions. This is needed for + * - retransmitting client-Requests (sec. 8.1.1), + * - retransmitting Close/CloseReq when closing (sec. 8.3), + * - feature-negotiation retransmission (sec. 6.6.3), + * - Acks in client-PARTOPEN state (sec. 8.1.5). + */ +#define DCCP_RTO_MAX ((unsigned int)(64 * HZ)) + +/* + * RTT sampling: sanity bounds and fallback RTT value from RFC 4340, section 3.4 + */ +#define DCCP_SANE_RTT_MIN 100 +#define DCCP_FALLBACK_RTT (USEC_PER_SEC / 5) +#define DCCP_SANE_RTT_MAX (3 * USEC_PER_SEC) + +/* sysctl variables for DCCP */ +extern int sysctl_dccp_request_retries; +extern int sysctl_dccp_retries1; +extern int sysctl_dccp_retries2; +extern int sysctl_dccp_tx_qlen; +extern int sysctl_dccp_sync_ratelimit; + +/* + * 48-bit sequence number arithmetic (signed and unsigned) + */ +#define INT48_MIN 0x800000000000LL /* 2^47 */ +#define UINT48_MAX 0xFFFFFFFFFFFFLL /* 2^48 - 1 */ +#define COMPLEMENT48(x) (0x1000000000000LL - (x)) /* 2^48 - x */ +#define TO_SIGNED48(x) (((x) < INT48_MIN)? (x) : -COMPLEMENT48( (x))) +#define TO_UNSIGNED48(x) (((x) >= 0)? (x) : COMPLEMENT48(-(x))) +#define ADD48(a, b) (((a) + (b)) & UINT48_MAX) +#define SUB48(a, b) ADD48((a), COMPLEMENT48(b)) + +static inline void dccp_inc_seqno(u64 *seqno) +{ + *seqno = ADD48(*seqno, 1); +} + +/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */ +static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2) +{ + u64 delta = SUB48(seqno2, seqno1); + + return TO_SIGNED48(delta); +} + +/* is seq1 < seq2 ? */ +static inline int before48(const u64 seq1, const u64 seq2) +{ + return (s64)((seq2 << 16) - (seq1 << 16)) > 0; +} + +/* is seq1 > seq2 ? */ +#define after48(seq1, seq2) before48(seq2, seq1) + +/* is seq2 <= seq1 <= seq3 ? */ +static inline int between48(const u64 seq1, const u64 seq2, const u64 seq3) +{ + return (seq3 << 16) - (seq2 << 16) >= (seq1 << 16) - (seq2 << 16); +} + +/** + * dccp_loss_count - Approximate the number of lost data packets in a burst loss + * @s1: last known sequence number before the loss ('hole') + * @s2: first sequence number seen after the 'hole' + * @ndp: NDP count on packet with sequence number @s2 + */ +static inline u64 dccp_loss_count(const u64 s1, const u64 s2, const u64 ndp) +{ + s64 delta = dccp_delta_seqno(s1, s2); + + WARN_ON(delta < 0); + delta -= ndp + 1; + + return delta > 0 ? delta : 0; +} + +/** + * dccp_loss_free - Evaluate condition for data loss from RFC 4340, 7.7.1 + */ +static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) +{ + return dccp_loss_count(s1, s2, ndp) == 0; +} + +enum { + DCCP_MIB_NUM = 0, + DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */ + DCCP_MIB_ESTABRESETS, /* EstabResets */ + DCCP_MIB_CURRESTAB, /* CurrEstab */ + DCCP_MIB_OUTSEGS, /* OutSegs */ + DCCP_MIB_OUTRSTS, + DCCP_MIB_ABORTONTIMEOUT, + DCCP_MIB_TIMEOUTS, + DCCP_MIB_ABORTFAILED, + DCCP_MIB_PASSIVEOPENS, + DCCP_MIB_ATTEMPTFAILS, + DCCP_MIB_OUTDATAGRAMS, + DCCP_MIB_INERRS, + DCCP_MIB_OPTMANDATORYERROR, + DCCP_MIB_INVALIDOPT, + __DCCP_MIB_MAX +}; + +#define DCCP_MIB_MAX __DCCP_MIB_MAX +struct dccp_mib { + unsigned long mibs[DCCP_MIB_MAX]; +}; + +DECLARE_SNMP_STAT(struct dccp_mib, dccp_statistics); +#define DCCP_INC_STATS(field) SNMP_INC_STATS(dccp_statistics, field) +#define __DCCP_INC_STATS(field) __SNMP_INC_STATS(dccp_statistics, field) +#define DCCP_DEC_STATS(field) SNMP_DEC_STATS(dccp_statistics, field) + +/* + * Checksumming routines + */ +static inline unsigned int dccp_csum_coverage(const struct sk_buff *skb) +{ + const struct dccp_hdr* dh = dccp_hdr(skb); + + if (dh->dccph_cscov == 0) + return skb->len; + return (dh->dccph_doff + dh->dccph_cscov - 1) * sizeof(u32); +} + +static inline void dccp_csum_outgoing(struct sk_buff *skb) +{ + unsigned int cov = dccp_csum_coverage(skb); + + if (cov >= skb->len) + dccp_hdr(skb)->dccph_cscov = 0; + + skb->csum = skb_checksum(skb, 0, (cov > skb->len)? skb->len : cov, 0); +} + +void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb); + +int dccp_retransmit_skb(struct sock *sk); + +void dccp_send_ack(struct sock *sk); +void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, + struct request_sock *rsk); + +void dccp_send_sync(struct sock *sk, const u64 seq, + const enum dccp_pkt_type pkt_type); + +/* + * TX Packet Dequeueing Interface + */ +void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb); +bool dccp_qpolicy_full(struct sock *sk); +void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb); +struct sk_buff *dccp_qpolicy_top(struct sock *sk); +struct sk_buff *dccp_qpolicy_pop(struct sock *sk); +bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param); + +/* + * TX Packet Output and TX Timers + */ +void dccp_write_xmit(struct sock *sk); +void dccp_write_space(struct sock *sk); +void dccp_flush_write_queue(struct sock *sk, long *time_budget); + +void dccp_init_xmit_timers(struct sock *sk); +static inline void dccp_clear_xmit_timers(struct sock *sk) +{ + inet_csk_clear_xmit_timers(sk); +} + +unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu); + +const char *dccp_packet_name(const int type); + +void dccp_set_state(struct sock *sk, const int state); +void dccp_done(struct sock *sk); + +int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp, + struct sk_buff const *skb); + +int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb); + +struct sock *dccp_create_openreq_child(const struct sock *sk, + const struct request_sock *req, + const struct sk_buff *skb); + +int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); + +struct sock *dccp_v4_request_recv_sock(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req); +struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, + struct request_sock *req); + +int dccp_child_process(struct sock *parent, struct sock *child, + struct sk_buff *skb); +int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, + struct dccp_hdr *dh, unsigned int len); +int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, + const struct dccp_hdr *dh, const unsigned int len); + +void dccp_destruct_common(struct sock *sk); +int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized); +void dccp_destroy_sock(struct sock *sk); + +void dccp_close(struct sock *sk, long timeout); +struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst, + struct request_sock *req); + +int dccp_connect(struct sock *sk); +int dccp_disconnect(struct sock *sk, int flags); +int dccp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen); +int dccp_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen); +int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg); +int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); +int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, + int *addr_len); +void dccp_shutdown(struct sock *sk, int how); +int inet_dccp_listen(struct socket *sock, int backlog); +__poll_t dccp_poll(struct file *file, struct socket *sock, + poll_table *wait); +int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); +void dccp_req_err(struct sock *sk, u64 seq); + +struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *skb); +int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); +void dccp_send_close(struct sock *sk, const int active); +int dccp_invalid_packet(struct sk_buff *skb); +u32 dccp_sample_rtt(struct sock *sk, long delta); + +static inline bool dccp_bad_service_code(const struct sock *sk, + const __be32 service) +{ + const struct dccp_sock *dp = dccp_sk(sk); + + if (dp->dccps_service == service) + return false; + return !dccp_list_has_service(dp->dccps_service_list, service); +} + +/** + * dccp_skb_cb - DCCP per-packet control information + * @dccpd_type: one of %dccp_pkt_type (or unknown) + * @dccpd_ccval: CCVal field (5.1), see e.g. RFC 4342, 8.1 + * @dccpd_reset_code: one of %dccp_reset_codes + * @dccpd_reset_data: Data1..3 fields (depend on @dccpd_reset_code) + * @dccpd_opt_len: total length of all options (5.8) in the packet + * @dccpd_seq: sequence number + * @dccpd_ack_seq: acknowledgment number subheader field value + * + * This is used for transmission as well as for reception. + */ +struct dccp_skb_cb { + union { + struct inet_skb_parm h4; +#if IS_ENABLED(CONFIG_IPV6) + struct inet6_skb_parm h6; +#endif + } header; + __u8 dccpd_type:4; + __u8 dccpd_ccval:4; + __u8 dccpd_reset_code, + dccpd_reset_data[3]; + __u16 dccpd_opt_len; + __u64 dccpd_seq; + __u64 dccpd_ack_seq; +}; + +#define DCCP_SKB_CB(__skb) ((struct dccp_skb_cb *)&((__skb)->cb[0])) + +/* RFC 4340, sec. 7.7 */ +static inline int dccp_non_data_packet(const struct sk_buff *skb) +{ + const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; + + return type == DCCP_PKT_ACK || + type == DCCP_PKT_CLOSE || + type == DCCP_PKT_CLOSEREQ || + type == DCCP_PKT_RESET || + type == DCCP_PKT_SYNC || + type == DCCP_PKT_SYNCACK; +} + +/* RFC 4340, sec. 7.7 */ +static inline int dccp_data_packet(const struct sk_buff *skb) +{ + const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; + + return type == DCCP_PKT_DATA || + type == DCCP_PKT_DATAACK || + type == DCCP_PKT_REQUEST || + type == DCCP_PKT_RESPONSE; +} + +static inline int dccp_packet_without_ack(const struct sk_buff *skb) +{ + const __u8 type = DCCP_SKB_CB(skb)->dccpd_type; + + return type == DCCP_PKT_DATA || type == DCCP_PKT_REQUEST; +} + +#define DCCP_PKT_WITHOUT_ACK_SEQ (UINT48_MAX << 2) + +static inline void dccp_hdr_set_seq(struct dccp_hdr *dh, const u64 gss) +{ + struct dccp_hdr_ext *dhx = (struct dccp_hdr_ext *)((void *)dh + + sizeof(*dh)); + dh->dccph_seq2 = 0; + dh->dccph_seq = htons((gss >> 32) & 0xfffff); + dhx->dccph_seq_low = htonl(gss & 0xffffffff); +} + +static inline void dccp_hdr_set_ack(struct dccp_hdr_ack_bits *dhack, + const u64 gsr) +{ + dhack->dccph_reserved1 = 0; + dhack->dccph_ack_nr_high = htons(gsr >> 32); + dhack->dccph_ack_nr_low = htonl(gsr & 0xffffffff); +} + +static inline void dccp_update_gsr(struct sock *sk, u64 seq) +{ + struct dccp_sock *dp = dccp_sk(sk); + + if (after48(seq, dp->dccps_gsr)) + dp->dccps_gsr = seq; + /* Sequence validity window depends on remote Sequence Window (7.5.1) */ + dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4); + /* + * Adjust SWL so that it is not below ISR. In contrast to RFC 4340, + * 7.5.1 we perform this check beyond the initial handshake: W/W' are + * always > 32, so for the first W/W' packets in the lifetime of a + * connection we always have to adjust SWL. + * A second reason why we are doing this is that the window depends on + * the feature-remote value of Sequence Window: nothing stops the peer + * from updating this value while we are busy adjusting SWL for the + * first W packets (we would have to count from scratch again then). + * Therefore it is safer to always make sure that the Sequence Window + * is not artificially extended by a peer who grows SWL downwards by + * continually updating the feature-remote Sequence-Window. + * If sequence numbers wrap it is bad luck. But that will take a while + * (48 bit), and this measure prevents Sequence-number attacks. + */ + if (before48(dp->dccps_swl, dp->dccps_isr)) + dp->dccps_swl = dp->dccps_isr; + dp->dccps_swh = ADD48(dp->dccps_gsr, (3 * dp->dccps_r_seq_win) / 4); +} + +static inline void dccp_update_gss(struct sock *sk, u64 seq) +{ + struct dccp_sock *dp = dccp_sk(sk); + + dp->dccps_gss = seq; + /* Ack validity window depends on local Sequence Window value (7.5.1) */ + dp->dccps_awl = SUB48(ADD48(dp->dccps_gss, 1), dp->dccps_l_seq_win); + /* Adjust AWL so that it is not below ISS - see comment above for SWL */ + if (before48(dp->dccps_awl, dp->dccps_iss)) + dp->dccps_awl = dp->dccps_iss; + dp->dccps_awh = dp->dccps_gss; +} + +static inline int dccp_ackvec_pending(const struct sock *sk) +{ + return dccp_sk(sk)->dccps_hc_rx_ackvec != NULL && + !dccp_ackvec_is_empty(dccp_sk(sk)->dccps_hc_rx_ackvec); +} + +static inline int dccp_ack_pending(const struct sock *sk) +{ + return dccp_ackvec_pending(sk) || inet_csk_ack_scheduled(sk); +} + +int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val); +int dccp_feat_finalise_settings(struct dccp_sock *dp); +int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq); +int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*, + struct sk_buff *skb); +int dccp_feat_activate_values(struct sock *sk, struct list_head *fn); +void dccp_feat_list_purge(struct list_head *fn_list); + +int dccp_insert_options(struct sock *sk, struct sk_buff *skb); +int dccp_insert_options_rsk(struct dccp_request_sock *, struct sk_buff *); +u32 dccp_timestamp(void); +void dccp_timestamping_init(void); +int dccp_insert_option(struct sk_buff *skb, unsigned char option, + const void *value, unsigned char len); + +#ifdef CONFIG_SYSCTL +int dccp_sysctl_init(void); +void dccp_sysctl_exit(void); +#else +static inline int dccp_sysctl_init(void) +{ + return 0; +} + +static inline void dccp_sysctl_exit(void) +{ +} +#endif + +#endif /* _DCCP_H */ diff --git a/net/dccp/diag.c b/net/dccp/diag.c new file mode 100644 index 000000000..8a82c5a2c --- /dev/null +++ b/net/dccp/diag.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/diag.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + + +#include +#include + +#include "ccid.h" +#include "dccp.h" + +static void dccp_get_info(struct sock *sk, struct tcp_info *info) +{ + struct dccp_sock *dp = dccp_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + + memset(info, 0, sizeof(*info)); + + info->tcpi_state = sk->sk_state; + info->tcpi_retransmits = icsk->icsk_retransmits; + info->tcpi_probes = icsk->icsk_probes_out; + info->tcpi_backoff = icsk->icsk_backoff; + info->tcpi_pmtu = icsk->icsk_pmtu_cookie; + + if (dp->dccps_hc_rx_ackvec != NULL) + info->tcpi_options |= TCPI_OPT_SACK; + + if (dp->dccps_hc_rx_ccid != NULL) + ccid_hc_rx_get_info(dp->dccps_hc_rx_ccid, sk, info); + + if (dp->dccps_hc_tx_ccid != NULL) + ccid_hc_tx_get_info(dp->dccps_hc_tx_ccid, sk, info); +} + +static void dccp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, + void *_info) +{ + r->idiag_rqueue = r->idiag_wqueue = 0; + + if (_info != NULL) + dccp_get_info(sk, _info); +} + +static void dccp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, + const struct inet_diag_req_v2 *r) +{ + inet_diag_dump_icsk(&dccp_hashinfo, skb, cb, r); +} + +static int dccp_diag_dump_one(struct netlink_callback *cb, + const struct inet_diag_req_v2 *req) +{ + return inet_diag_dump_one_icsk(&dccp_hashinfo, cb, req); +} + +static const struct inet_diag_handler dccp_diag_handler = { + .dump = dccp_diag_dump, + .dump_one = dccp_diag_dump_one, + .idiag_get_info = dccp_diag_get_info, + .idiag_type = IPPROTO_DCCP, + .idiag_info_size = sizeof(struct tcp_info), +}; + +static int __init dccp_diag_init(void) +{ + return inet_diag_register(&dccp_diag_handler); +} + +static void __exit dccp_diag_fini(void) +{ + inet_diag_unregister(&dccp_diag_handler); +} + +module_init(dccp_diag_init); +module_exit(dccp_diag_fini); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arnaldo Carvalho de Melo "); +MODULE_DESCRIPTION("DCCP inet_diag handler"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-33 /* AF_INET - IPPROTO_DCCP */); diff --git a/net/dccp/feat.c b/net/dccp/feat.c new file mode 100644 index 000000000..54086bb05 --- /dev/null +++ b/net/dccp/feat.c @@ -0,0 +1,1577 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/feat.c + * + * Feature negotiation for the DCCP protocol (RFC 4340, section 6) + * + * Copyright (c) 2008 Gerrit Renker + * Rewrote from scratch, some bits from earlier code by + * Copyright (c) 2005 Andrea Bittau + * + * ASSUMPTIONS + * ----------- + * o Feature negotiation is coordinated with connection setup (as in TCP), wild + * changes of parameters of an established connection are not supported. + * o Changing non-negotiable (NN) values is supported in state OPEN/PARTOPEN. + * o All currently known SP features have 1-byte quantities. If in the future + * extensions of RFCs 4340..42 define features with item lengths larger than + * one byte, a feature-specific extension of the code will be required. + */ +#include +#include +#include "ccid.h" +#include "feat.h" + +/* feature-specific sysctls - initialised to the defaults from RFC 4340, 6.4 */ +unsigned long sysctl_dccp_sequence_window __read_mostly = 100; +int sysctl_dccp_rx_ccid __read_mostly = 2, + sysctl_dccp_tx_ccid __read_mostly = 2; + +/* + * Feature activation handlers. + * + * These all use an u64 argument, to provide enough room for NN/SP features. At + * this stage the negotiated values have been checked to be within their range. + */ +static int dccp_hdlr_ccid(struct sock *sk, u64 ccid, bool rx) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct ccid *new_ccid = ccid_new(ccid, sk, rx); + + if (new_ccid == NULL) + return -ENOMEM; + + if (rx) { + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + dp->dccps_hc_rx_ccid = new_ccid; + } else { + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + dp->dccps_hc_tx_ccid = new_ccid; + } + return 0; +} + +static int dccp_hdlr_seq_win(struct sock *sk, u64 seq_win, bool rx) +{ + struct dccp_sock *dp = dccp_sk(sk); + + if (rx) { + dp->dccps_r_seq_win = seq_win; + /* propagate changes to update SWL/SWH */ + dccp_update_gsr(sk, dp->dccps_gsr); + } else { + dp->dccps_l_seq_win = seq_win; + /* propagate changes to update AWL */ + dccp_update_gss(sk, dp->dccps_gss); + } + return 0; +} + +static int dccp_hdlr_ack_ratio(struct sock *sk, u64 ratio, bool rx) +{ + if (rx) + dccp_sk(sk)->dccps_r_ack_ratio = ratio; + else + dccp_sk(sk)->dccps_l_ack_ratio = ratio; + return 0; +} + +static int dccp_hdlr_ackvec(struct sock *sk, u64 enable, bool rx) +{ + struct dccp_sock *dp = dccp_sk(sk); + + if (rx) { + if (enable && dp->dccps_hc_rx_ackvec == NULL) { + dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(gfp_any()); + if (dp->dccps_hc_rx_ackvec == NULL) + return -ENOMEM; + } else if (!enable) { + dccp_ackvec_free(dp->dccps_hc_rx_ackvec); + dp->dccps_hc_rx_ackvec = NULL; + } + } + return 0; +} + +static int dccp_hdlr_ndp(struct sock *sk, u64 enable, bool rx) +{ + if (!rx) + dccp_sk(sk)->dccps_send_ndp_count = (enable > 0); + return 0; +} + +/* + * Minimum Checksum Coverage is located at the RX side (9.2.1). This means that + * `rx' holds when the sending peer informs about his partial coverage via a + * ChangeR() option. In the other case, we are the sender and the receiver + * announces its coverage via ChangeL() options. The policy here is to honour + * such communication by enabling the corresponding partial coverage - but only + * if it has not been set manually before; the warning here means that all + * packets will be dropped. + */ +static int dccp_hdlr_min_cscov(struct sock *sk, u64 cscov, bool rx) +{ + struct dccp_sock *dp = dccp_sk(sk); + + if (rx) + dp->dccps_pcrlen = cscov; + else { + if (dp->dccps_pcslen == 0) + dp->dccps_pcslen = cscov; + else if (cscov > dp->dccps_pcslen) + DCCP_WARN("CsCov %u too small, peer requires >= %u\n", + dp->dccps_pcslen, (u8)cscov); + } + return 0; +} + +static const struct { + u8 feat_num; /* DCCPF_xxx */ + enum dccp_feat_type rxtx; /* RX or TX */ + enum dccp_feat_type reconciliation; /* SP or NN */ + u8 default_value; /* as in 6.4 */ + int (*activation_hdlr)(struct sock *sk, u64 val, bool rx); +/* + * Lookup table for location and type of features (from RFC 4340/4342) + * +--------------------------+----+-----+----+----+---------+-----------+ + * | Feature | Location | Reconc. | Initial | Section | + * | | RX | TX | SP | NN | Value | Reference | + * +--------------------------+----+-----+----+----+---------+-----------+ + * | DCCPF_CCID | | X | X | | 2 | 10 | + * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 | + * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 | + * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 | + * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 | + * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 | + * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 | + * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 | + * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 | + * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 | + * +--------------------------+----+-----+----+----+---------+-----------+ + */ +} dccp_feat_table[] = { + { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2, dccp_hdlr_ccid }, + { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0, NULL }, + { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100, dccp_hdlr_seq_win }, + { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0, NULL }, + { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2, dccp_hdlr_ack_ratio}, + { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_ackvec }, + { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0, dccp_hdlr_ndp }, + { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0, dccp_hdlr_min_cscov}, + { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0, NULL }, + { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0, NULL }, +}; +#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table) + +/** + * dccp_feat_index - Hash function to map feature number into array position + * @feat_num: feature to hash, one of %dccp_feature_numbers + * + * Returns consecutive array index or -1 if the feature is not understood. + */ +static int dccp_feat_index(u8 feat_num) +{ + /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */ + if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM) + return feat_num - 1; + + /* + * Other features: add cases for new feature types here after adding + * them to the above table. + */ + switch (feat_num) { + case DCCPF_SEND_LEV_RATE: + return DCCP_FEAT_SUPPORTED_MAX - 1; + } + return -1; +} + +static u8 dccp_feat_type(u8 feat_num) +{ + int idx = dccp_feat_index(feat_num); + + if (idx < 0) + return FEAT_UNKNOWN; + return dccp_feat_table[idx].reconciliation; +} + +static int dccp_feat_default_value(u8 feat_num) +{ + int idx = dccp_feat_index(feat_num); + /* + * There are no default values for unknown features, so encountering a + * negative index here indicates a serious problem somewhere else. + */ + DCCP_BUG_ON(idx < 0); + + return idx < 0 ? 0 : dccp_feat_table[idx].default_value; +} + +/* + * Debugging and verbose-printing section + */ +static const char *dccp_feat_fname(const u8 feat) +{ + static const char *const feature_names[] = { + [DCCPF_RESERVED] = "Reserved", + [DCCPF_CCID] = "CCID", + [DCCPF_SHORT_SEQNOS] = "Allow Short Seqnos", + [DCCPF_SEQUENCE_WINDOW] = "Sequence Window", + [DCCPF_ECN_INCAPABLE] = "ECN Incapable", + [DCCPF_ACK_RATIO] = "Ack Ratio", + [DCCPF_SEND_ACK_VECTOR] = "Send ACK Vector", + [DCCPF_SEND_NDP_COUNT] = "Send NDP Count", + [DCCPF_MIN_CSUM_COVER] = "Min. Csum Coverage", + [DCCPF_DATA_CHECKSUM] = "Send Data Checksum", + }; + if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC) + return feature_names[DCCPF_RESERVED]; + + if (feat == DCCPF_SEND_LEV_RATE) + return "Send Loss Event Rate"; + if (feat >= DCCPF_MIN_CCID_SPECIFIC) + return "CCID-specific"; + + return feature_names[feat]; +} + +static const char *const dccp_feat_sname[] = { + "DEFAULT", "INITIALISING", "CHANGING", "UNSTABLE", "STABLE", +}; + +#ifdef CONFIG_IP_DCCP_DEBUG +static const char *dccp_feat_oname(const u8 opt) +{ + switch (opt) { + case DCCPO_CHANGE_L: return "Change_L"; + case DCCPO_CONFIRM_L: return "Confirm_L"; + case DCCPO_CHANGE_R: return "Change_R"; + case DCCPO_CONFIRM_R: return "Confirm_R"; + } + return NULL; +} + +static void dccp_feat_printval(u8 feat_num, dccp_feat_val const *val) +{ + u8 i, type = dccp_feat_type(feat_num); + + if (val == NULL || (type == FEAT_SP && val->sp.vec == NULL)) + dccp_pr_debug_cat("(NULL)"); + else if (type == FEAT_SP) + for (i = 0; i < val->sp.len; i++) + dccp_pr_debug_cat("%s%u", i ? " " : "", val->sp.vec[i]); + else if (type == FEAT_NN) + dccp_pr_debug_cat("%llu", (unsigned long long)val->nn); + else + dccp_pr_debug_cat("unknown type %u", type); +} + +static void dccp_feat_printvals(u8 feat_num, u8 *list, u8 len) +{ + u8 type = dccp_feat_type(feat_num); + dccp_feat_val fval = { .sp.vec = list, .sp.len = len }; + + if (type == FEAT_NN) + fval.nn = dccp_decode_value_var(list, len); + dccp_feat_printval(feat_num, &fval); +} + +static void dccp_feat_print_entry(struct dccp_feat_entry const *entry) +{ + dccp_debug(" * %s %s = ", entry->is_local ? "local" : "remote", + dccp_feat_fname(entry->feat_num)); + dccp_feat_printval(entry->feat_num, &entry->val); + dccp_pr_debug_cat(", state=%s %s\n", dccp_feat_sname[entry->state], + entry->needs_confirm ? "(Confirm pending)" : ""); +} + +#define dccp_feat_print_opt(opt, feat, val, len, mandatory) do { \ + dccp_pr_debug("%s(%s, ", dccp_feat_oname(opt), dccp_feat_fname(feat));\ + dccp_feat_printvals(feat, val, len); \ + dccp_pr_debug_cat(") %s\n", mandatory ? "!" : ""); } while (0) + +#define dccp_feat_print_fnlist(fn_list) { \ + const struct dccp_feat_entry *___entry; \ + \ + dccp_pr_debug("List Dump:\n"); \ + list_for_each_entry(___entry, fn_list, node) \ + dccp_feat_print_entry(___entry); \ +} +#else /* ! CONFIG_IP_DCCP_DEBUG */ +#define dccp_feat_print_opt(opt, feat, val, len, mandatory) +#define dccp_feat_print_fnlist(fn_list) +#endif + +static int __dccp_feat_activate(struct sock *sk, const int idx, + const bool is_local, dccp_feat_val const *fval) +{ + bool rx; + u64 val; + + if (idx < 0 || idx >= DCCP_FEAT_SUPPORTED_MAX) + return -1; + if (dccp_feat_table[idx].activation_hdlr == NULL) + return 0; + + if (fval == NULL) { + val = dccp_feat_table[idx].default_value; + } else if (dccp_feat_table[idx].reconciliation == FEAT_SP) { + if (fval->sp.vec == NULL) { + /* + * This can happen when an empty Confirm is sent + * for an SP (i.e. known) feature. In this case + * we would be using the default anyway. + */ + DCCP_CRIT("Feature #%d undefined: using default", idx); + val = dccp_feat_table[idx].default_value; + } else { + val = fval->sp.vec[0]; + } + } else { + val = fval->nn; + } + + /* Location is RX if this is a local-RX or remote-TX feature */ + rx = (is_local == (dccp_feat_table[idx].rxtx == FEAT_AT_RX)); + + dccp_debug(" -> activating %s %s, %sval=%llu\n", rx ? "RX" : "TX", + dccp_feat_fname(dccp_feat_table[idx].feat_num), + fval ? "" : "default ", (unsigned long long)val); + + return dccp_feat_table[idx].activation_hdlr(sk, val, rx); +} + +/** + * dccp_feat_activate - Activate feature value on socket + * @sk: fully connected DCCP socket (after handshake is complete) + * @feat_num: feature to activate, one of %dccp_feature_numbers + * @local: whether local (1) or remote (0) @feat_num is meant + * @fval: the value (SP or NN) to activate, or NULL to use the default value + * + * For general use this function is preferable over __dccp_feat_activate(). + */ +static int dccp_feat_activate(struct sock *sk, u8 feat_num, bool local, + dccp_feat_val const *fval) +{ + return __dccp_feat_activate(sk, dccp_feat_index(feat_num), local, fval); +} + +/* Test for "Req'd" feature (RFC 4340, 6.4) */ +static inline int dccp_feat_must_be_understood(u8 feat_num) +{ + return feat_num == DCCPF_CCID || feat_num == DCCPF_SHORT_SEQNOS || + feat_num == DCCPF_SEQUENCE_WINDOW; +} + +/* copy constructor, fval must not already contain allocated memory */ +static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len) +{ + fval->sp.len = len; + if (fval->sp.len > 0) { + fval->sp.vec = kmemdup(val, len, gfp_any()); + if (fval->sp.vec == NULL) { + fval->sp.len = 0; + return -ENOMEM; + } + } + return 0; +} + +static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val) +{ + if (unlikely(val == NULL)) + return; + if (dccp_feat_type(feat_num) == FEAT_SP) + kfree(val->sp.vec); + memset(val, 0, sizeof(*val)); +} + +static struct dccp_feat_entry * + dccp_feat_clone_entry(struct dccp_feat_entry const *original) +{ + struct dccp_feat_entry *new; + u8 type = dccp_feat_type(original->feat_num); + + if (type == FEAT_UNKNOWN) + return NULL; + + new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any()); + if (new == NULL) + return NULL; + + if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val, + original->val.sp.vec, + original->val.sp.len)) { + kfree(new); + return NULL; + } + return new; +} + +static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry) +{ + if (entry != NULL) { + dccp_feat_val_destructor(entry->feat_num, &entry->val); + kfree(entry); + } +} + +/* + * List management functions + * + * Feature negotiation lists rely on and maintain the following invariants: + * - each feat_num in the list is known, i.e. we know its type and default value + * - each feat_num/is_local combination is unique (old entries are overwritten) + * - SP values are always freshly allocated + * - list is sorted in increasing order of feature number (faster lookup) + */ +static struct dccp_feat_entry *dccp_feat_list_lookup(struct list_head *fn_list, + u8 feat_num, bool is_local) +{ + struct dccp_feat_entry *entry; + + list_for_each_entry(entry, fn_list, node) { + if (entry->feat_num == feat_num && entry->is_local == is_local) + return entry; + else if (entry->feat_num > feat_num) + break; + } + return NULL; +} + +/** + * dccp_feat_entry_new - Central list update routine (called by all others) + * @head: list to add to + * @feat: feature number + * @local: whether the local (1) or remote feature with number @feat is meant + * + * This is the only constructor and serves to ensure the above invariants. + */ +static struct dccp_feat_entry * + dccp_feat_entry_new(struct list_head *head, u8 feat, bool local) +{ + struct dccp_feat_entry *entry; + + list_for_each_entry(entry, head, node) + if (entry->feat_num == feat && entry->is_local == local) { + dccp_feat_val_destructor(entry->feat_num, &entry->val); + return entry; + } else if (entry->feat_num > feat) { + head = &entry->node; + break; + } + + entry = kmalloc(sizeof(*entry), gfp_any()); + if (entry != NULL) { + entry->feat_num = feat; + entry->is_local = local; + list_add_tail(&entry->node, head); + } + return entry; +} + +/** + * dccp_feat_push_change - Add/overwrite a Change option in the list + * @fn_list: feature-negotiation list to update + * @feat: one of %dccp_feature_numbers + * @local: whether local (1) or remote (0) @feat_num is meant + * @mandatory: whether to use Mandatory feature negotiation options + * @fval: pointer to NN/SP value to be inserted (will be copied) + */ +static int dccp_feat_push_change(struct list_head *fn_list, u8 feat, u8 local, + u8 mandatory, dccp_feat_val *fval) +{ + struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local); + + if (new == NULL) + return -ENOMEM; + + new->feat_num = feat; + new->is_local = local; + new->state = FEAT_INITIALISING; + new->needs_confirm = false; + new->empty_confirm = false; + new->val = *fval; + new->needs_mandatory = mandatory; + + return 0; +} + +/** + * dccp_feat_push_confirm - Add a Confirm entry to the FN list + * @fn_list: feature-negotiation list to add to + * @feat: one of %dccp_feature_numbers + * @local: whether local (1) or remote (0) @feat_num is being confirmed + * @fval: pointer to NN/SP value to be inserted or NULL + * + * Returns 0 on success, a Reset code for further processing otherwise. + */ +static int dccp_feat_push_confirm(struct list_head *fn_list, u8 feat, u8 local, + dccp_feat_val *fval) +{ + struct dccp_feat_entry *new = dccp_feat_entry_new(fn_list, feat, local); + + if (new == NULL) + return DCCP_RESET_CODE_TOO_BUSY; + + new->feat_num = feat; + new->is_local = local; + new->state = FEAT_STABLE; /* transition in 6.6.2 */ + new->needs_confirm = true; + new->empty_confirm = (fval == NULL); + new->val.nn = 0; /* zeroes the whole structure */ + if (!new->empty_confirm) + new->val = *fval; + new->needs_mandatory = false; + + return 0; +} + +static int dccp_push_empty_confirm(struct list_head *fn_list, u8 feat, u8 local) +{ + return dccp_feat_push_confirm(fn_list, feat, local, NULL); +} + +static inline void dccp_feat_list_pop(struct dccp_feat_entry *entry) +{ + list_del(&entry->node); + dccp_feat_entry_destructor(entry); +} + +void dccp_feat_list_purge(struct list_head *fn_list) +{ + struct dccp_feat_entry *entry, *next; + + list_for_each_entry_safe(entry, next, fn_list, node) + dccp_feat_entry_destructor(entry); + INIT_LIST_HEAD(fn_list); +} +EXPORT_SYMBOL_GPL(dccp_feat_list_purge); + +/* generate @to as full clone of @from - @to must not contain any nodes */ +int dccp_feat_clone_list(struct list_head const *from, struct list_head *to) +{ + struct dccp_feat_entry *entry, *new; + + INIT_LIST_HEAD(to); + list_for_each_entry(entry, from, node) { + new = dccp_feat_clone_entry(entry); + if (new == NULL) + goto cloning_failed; + list_add_tail(&new->node, to); + } + return 0; + +cloning_failed: + dccp_feat_list_purge(to); + return -ENOMEM; +} + +/** + * dccp_feat_valid_nn_length - Enforce length constraints on NN options + * @feat_num: feature to return length of, one of %dccp_feature_numbers + * + * Length is between 0 and %DCCP_OPTVAL_MAXLEN. Used for outgoing packets only, + * incoming options are accepted as long as their values are valid. + */ +static u8 dccp_feat_valid_nn_length(u8 feat_num) +{ + if (feat_num == DCCPF_ACK_RATIO) /* RFC 4340, 11.3 and 6.6.8 */ + return 2; + if (feat_num == DCCPF_SEQUENCE_WINDOW) /* RFC 4340, 7.5.2 and 6.5 */ + return 6; + return 0; +} + +static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val) +{ + switch (feat_num) { + case DCCPF_ACK_RATIO: + return val <= DCCPF_ACK_RATIO_MAX; + case DCCPF_SEQUENCE_WINDOW: + return val >= DCCPF_SEQ_WMIN && val <= DCCPF_SEQ_WMAX; + } + return 0; /* feature unknown - so we can't tell */ +} + +/* check that SP values are within the ranges defined in RFC 4340 */ +static u8 dccp_feat_is_valid_sp_val(u8 feat_num, u8 val) +{ + switch (feat_num) { + case DCCPF_CCID: + return val == DCCPC_CCID2 || val == DCCPC_CCID3; + /* Type-check Boolean feature values: */ + case DCCPF_SHORT_SEQNOS: + case DCCPF_ECN_INCAPABLE: + case DCCPF_SEND_ACK_VECTOR: + case DCCPF_SEND_NDP_COUNT: + case DCCPF_DATA_CHECKSUM: + case DCCPF_SEND_LEV_RATE: + return val < 2; + case DCCPF_MIN_CSUM_COVER: + return val < 16; + } + return 0; /* feature unknown */ +} + +static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len) +{ + if (sp_list == NULL || sp_len < 1) + return 0; + while (sp_len--) + if (!dccp_feat_is_valid_sp_val(feat_num, *sp_list++)) + return 0; + return 1; +} + +/** + * dccp_feat_insert_opts - Generate FN options from current list state + * @skb: next sk_buff to be sent to the peer + * @dp: for client during handshake and general negotiation + * @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND) + */ +int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq, + struct sk_buff *skb) +{ + struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; + struct dccp_feat_entry *pos, *next; + u8 opt, type, len, *ptr, nn_in_nbo[DCCP_OPTVAL_MAXLEN]; + bool rpt; + + /* put entries into @skb in the order they appear in the list */ + list_for_each_entry_safe_reverse(pos, next, fn, node) { + opt = dccp_feat_genopt(pos); + type = dccp_feat_type(pos->feat_num); + rpt = false; + + if (pos->empty_confirm) { + len = 0; + ptr = NULL; + } else { + if (type == FEAT_SP) { + len = pos->val.sp.len; + ptr = pos->val.sp.vec; + rpt = pos->needs_confirm; + } else if (type == FEAT_NN) { + len = dccp_feat_valid_nn_length(pos->feat_num); + ptr = nn_in_nbo; + dccp_encode_value_var(pos->val.nn, ptr, len); + } else { + DCCP_BUG("unknown feature %u", pos->feat_num); + return -1; + } + } + dccp_feat_print_opt(opt, pos->feat_num, ptr, len, 0); + + if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt)) + return -1; + if (pos->needs_mandatory && dccp_insert_option_mandatory(skb)) + return -1; + + if (skb->sk->sk_state == DCCP_OPEN && + (opt == DCCPO_CONFIRM_R || opt == DCCPO_CONFIRM_L)) { + /* + * Confirms don't get retransmitted (6.6.3) once the + * connection is in state OPEN + */ + dccp_feat_list_pop(pos); + } else { + /* + * Enter CHANGING after transmitting the Change + * option (6.6.2). + */ + if (pos->state == FEAT_INITIALISING) + pos->state = FEAT_CHANGING; + } + } + return 0; +} + +/** + * __feat_register_nn - Register new NN value on socket + * @fn: feature-negotiation list to register with + * @feat: an NN feature from %dccp_feature_numbers + * @mandatory: use Mandatory option if 1 + * @nn_val: value to register (restricted to 4 bytes) + * + * Note that NN features are local by definition (RFC 4340, 6.3.2). + */ +static int __feat_register_nn(struct list_head *fn, u8 feat, + u8 mandatory, u64 nn_val) +{ + dccp_feat_val fval = { .nn = nn_val }; + + if (dccp_feat_type(feat) != FEAT_NN || + !dccp_feat_is_valid_nn_val(feat, nn_val)) + return -EINVAL; + + /* Don't bother with default values, they will be activated anyway. */ + if (nn_val - (u64)dccp_feat_default_value(feat) == 0) + return 0; + + return dccp_feat_push_change(fn, feat, 1, mandatory, &fval); +} + +/** + * __feat_register_sp - Register new SP value/list on socket + * @fn: feature-negotiation list to register with + * @feat: an SP feature from %dccp_feature_numbers + * @is_local: whether the local (1) or the remote (0) @feat is meant + * @mandatory: use Mandatory option if 1 + * @sp_val: SP value followed by optional preference list + * @sp_len: length of @sp_val in bytes + */ +static int __feat_register_sp(struct list_head *fn, u8 feat, u8 is_local, + u8 mandatory, u8 const *sp_val, u8 sp_len) +{ + dccp_feat_val fval; + + if (dccp_feat_type(feat) != FEAT_SP || + !dccp_feat_sp_list_ok(feat, sp_val, sp_len)) + return -EINVAL; + + /* Avoid negotiating alien CCIDs by only advertising supported ones */ + if (feat == DCCPF_CCID && !ccid_support_check(sp_val, sp_len)) + return -EOPNOTSUPP; + + if (dccp_feat_clone_sp_val(&fval, sp_val, sp_len)) + return -ENOMEM; + + if (dccp_feat_push_change(fn, feat, is_local, mandatory, &fval)) { + kfree(fval.sp.vec); + return -ENOMEM; + } + + return 0; +} + +/** + * dccp_feat_register_sp - Register requests to change SP feature values + * @sk: client or listening socket + * @feat: one of %dccp_feature_numbers + * @is_local: whether the local (1) or remote (0) @feat is meant + * @list: array of preferred values, in descending order of preference + * @len: length of @list in bytes + */ +int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, + u8 const *list, u8 len) +{ /* any changes must be registered before establishing the connection */ + if (sk->sk_state != DCCP_CLOSED) + return -EISCONN; + if (dccp_feat_type(feat) != FEAT_SP) + return -EINVAL; + return __feat_register_sp(&dccp_sk(sk)->dccps_featneg, feat, is_local, + 0, list, len); +} + +/** + * dccp_feat_nn_get - Query current/pending value of NN feature + * @sk: DCCP socket of an established connection + * @feat: NN feature number from %dccp_feature_numbers + * + * For a known NN feature, returns value currently being negotiated, or + * current (confirmed) value if no negotiation is going on. + */ +u64 dccp_feat_nn_get(struct sock *sk, u8 feat) +{ + if (dccp_feat_type(feat) == FEAT_NN) { + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_feat_entry *entry; + + entry = dccp_feat_list_lookup(&dp->dccps_featneg, feat, 1); + if (entry != NULL) + return entry->val.nn; + + switch (feat) { + case DCCPF_ACK_RATIO: + return dp->dccps_l_ack_ratio; + case DCCPF_SEQUENCE_WINDOW: + return dp->dccps_l_seq_win; + } + } + DCCP_BUG("attempt to look up unsupported feature %u", feat); + return 0; +} +EXPORT_SYMBOL_GPL(dccp_feat_nn_get); + +/** + * dccp_feat_signal_nn_change - Update NN values for an established connection + * @sk: DCCP socket of an established connection + * @feat: NN feature number from %dccp_feature_numbers + * @nn_val: the new value to use + * + * This function is used to communicate NN updates out-of-band. + */ +int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val) +{ + struct list_head *fn = &dccp_sk(sk)->dccps_featneg; + dccp_feat_val fval = { .nn = nn_val }; + struct dccp_feat_entry *entry; + + if (sk->sk_state != DCCP_OPEN && sk->sk_state != DCCP_PARTOPEN) + return 0; + + if (dccp_feat_type(feat) != FEAT_NN || + !dccp_feat_is_valid_nn_val(feat, nn_val)) + return -EINVAL; + + if (nn_val == dccp_feat_nn_get(sk, feat)) + return 0; /* already set or negotiation under way */ + + entry = dccp_feat_list_lookup(fn, feat, 1); + if (entry != NULL) { + dccp_pr_debug("Clobbering existing NN entry %llu -> %llu\n", + (unsigned long long)entry->val.nn, + (unsigned long long)nn_val); + dccp_feat_list_pop(entry); + } + + inet_csk_schedule_ack(sk); + return dccp_feat_push_change(fn, feat, 1, 0, &fval); +} +EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_change); + +/* + * Tracking features whose value depend on the choice of CCID + * + * This is designed with an extension in mind so that a list walk could be done + * before activating any features. However, the existing framework was found to + * work satisfactorily up until now, the automatic verification is left open. + * When adding new CCIDs, add a corresponding dependency table here. + */ +static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local) +{ + static const struct ccid_dependency ccid2_dependencies[2][2] = { + /* + * CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX + * feature and Send Ack Vector is an RX feature, `is_local' + * needs to be reversed. + */ + { /* Dependencies of the receiver-side (remote) CCID2 */ + { + .dependent_feat = DCCPF_SEND_ACK_VECTOR, + .is_local = true, + .is_mandatory = true, + .val = 1 + }, + { 0, 0, 0, 0 } + }, + { /* Dependencies of the sender-side (local) CCID2 */ + { + .dependent_feat = DCCPF_SEND_ACK_VECTOR, + .is_local = false, + .is_mandatory = true, + .val = 1 + }, + { 0, 0, 0, 0 } + } + }; + static const struct ccid_dependency ccid3_dependencies[2][5] = { + { /* + * Dependencies of the receiver-side CCID3 + */ + { /* locally disable Ack Vectors */ + .dependent_feat = DCCPF_SEND_ACK_VECTOR, + .is_local = true, + .is_mandatory = false, + .val = 0 + }, + { /* see below why Send Loss Event Rate is on */ + .dependent_feat = DCCPF_SEND_LEV_RATE, + .is_local = true, + .is_mandatory = true, + .val = 1 + }, + { /* NDP Count is needed as per RFC 4342, 6.1.1 */ + .dependent_feat = DCCPF_SEND_NDP_COUNT, + .is_local = false, + .is_mandatory = true, + .val = 1 + }, + { 0, 0, 0, 0 }, + }, + { /* + * CCID3 at the TX side: we request that the HC-receiver + * will not send Ack Vectors (they will be ignored, so + * Mandatory is not set); we enable Send Loss Event Rate + * (Mandatory since the implementation does not support + * the Loss Intervals option of RFC 4342, 8.6). + * The last two options are for peer's information only. + */ + { + .dependent_feat = DCCPF_SEND_ACK_VECTOR, + .is_local = false, + .is_mandatory = false, + .val = 0 + }, + { + .dependent_feat = DCCPF_SEND_LEV_RATE, + .is_local = false, + .is_mandatory = true, + .val = 1 + }, + { /* this CCID does not support Ack Ratio */ + .dependent_feat = DCCPF_ACK_RATIO, + .is_local = true, + .is_mandatory = false, + .val = 0 + }, + { /* tell receiver we are sending NDP counts */ + .dependent_feat = DCCPF_SEND_NDP_COUNT, + .is_local = true, + .is_mandatory = false, + .val = 1 + }, + { 0, 0, 0, 0 } + } + }; + switch (ccid) { + case DCCPC_CCID2: + return ccid2_dependencies[is_local]; + case DCCPC_CCID3: + return ccid3_dependencies[is_local]; + default: + return NULL; + } +} + +/** + * dccp_feat_propagate_ccid - Resolve dependencies of features on choice of CCID + * @fn: feature-negotiation list to update + * @id: CCID number to track + * @is_local: whether TX CCID (1) or RX CCID (0) is meant + * + * This function needs to be called after registering all other features. + */ +static int dccp_feat_propagate_ccid(struct list_head *fn, u8 id, bool is_local) +{ + const struct ccid_dependency *table = dccp_feat_ccid_deps(id, is_local); + int i, rc = (table == NULL); + + for (i = 0; rc == 0 && table[i].dependent_feat != DCCPF_RESERVED; i++) + if (dccp_feat_type(table[i].dependent_feat) == FEAT_SP) + rc = __feat_register_sp(fn, table[i].dependent_feat, + table[i].is_local, + table[i].is_mandatory, + &table[i].val, 1); + else + rc = __feat_register_nn(fn, table[i].dependent_feat, + table[i].is_mandatory, + table[i].val); + return rc; +} + +/** + * dccp_feat_finalise_settings - Finalise settings before starting negotiation + * @dp: client or listening socket (settings will be inherited) + * + * This is called after all registrations (socket initialisation, sysctls, and + * sockopt calls), and before sending the first packet containing Change options + * (ie. client-Request or server-Response), to ensure internal consistency. + */ +int dccp_feat_finalise_settings(struct dccp_sock *dp) +{ + struct list_head *fn = &dp->dccps_featneg; + struct dccp_feat_entry *entry; + int i = 2, ccids[2] = { -1, -1 }; + + /* + * Propagating CCIDs: + * 1) not useful to propagate CCID settings if this host advertises more + * than one CCID: the choice of CCID may still change - if this is + * the client, or if this is the server and the client sends + * singleton CCID values. + * 2) since is that propagate_ccid changes the list, we defer changing + * the sorted list until after the traversal. + */ + list_for_each_entry(entry, fn, node) + if (entry->feat_num == DCCPF_CCID && entry->val.sp.len == 1) + ccids[entry->is_local] = entry->val.sp.vec[0]; + while (i--) + if (ccids[i] > 0 && dccp_feat_propagate_ccid(fn, ccids[i], i)) + return -1; + dccp_feat_print_fnlist(fn); + return 0; +} + +/** + * dccp_feat_server_ccid_dependencies - Resolve CCID-dependent features + * @dreq: server socket to resolve + * + * It is the server which resolves the dependencies once the CCID has been + * fully negotiated. If no CCID has been negotiated, it uses the default CCID. + */ +int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq) +{ + struct list_head *fn = &dreq->dreq_featneg; + struct dccp_feat_entry *entry; + u8 is_local, ccid; + + for (is_local = 0; is_local <= 1; is_local++) { + entry = dccp_feat_list_lookup(fn, DCCPF_CCID, is_local); + + if (entry != NULL && !entry->empty_confirm) + ccid = entry->val.sp.vec[0]; + else + ccid = dccp_feat_default_value(DCCPF_CCID); + + if (dccp_feat_propagate_ccid(fn, ccid, is_local)) + return -1; + } + return 0; +} + +/* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */ +static int dccp_feat_preflist_match(u8 *servlist, u8 slen, u8 *clilist, u8 clen) +{ + u8 c, s; + + for (s = 0; s < slen; s++) + for (c = 0; c < clen; c++) + if (servlist[s] == clilist[c]) + return servlist[s]; + return -1; +} + +/** + * dccp_feat_prefer - Move preferred entry to the start of array + * @preferred_value: entry to move to start of array + * @array: array of preferred entries + * @array_len: size of the array + * + * Reorder the @array_len elements in @array so that @preferred_value comes + * first. Returns >0 to indicate that @preferred_value does occur in @array. + */ +static u8 dccp_feat_prefer(u8 preferred_value, u8 *array, u8 array_len) +{ + u8 i, does_occur = 0; + + if (array != NULL) { + for (i = 0; i < array_len; i++) + if (array[i] == preferred_value) { + array[i] = array[0]; + does_occur++; + } + if (does_occur) + array[0] = preferred_value; + } + return does_occur; +} + +/** + * dccp_feat_reconcile - Reconcile SP preference lists + * @fv: SP list to reconcile into + * @arr: received SP preference list + * @len: length of @arr in bytes + * @is_server: whether this side is the server (and @fv is the server's list) + * @reorder: whether to reorder the list in @fv after reconciling with @arr + * When successful, > 0 is returned and the reconciled list is in @fval. + * A value of 0 means that negotiation failed (no shared entry). + */ +static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len, + bool is_server, bool reorder) +{ + int rc; + + if (!fv->sp.vec || !arr) { + DCCP_CRIT("NULL feature value or array"); + return 0; + } + + if (is_server) + rc = dccp_feat_preflist_match(fv->sp.vec, fv->sp.len, arr, len); + else + rc = dccp_feat_preflist_match(arr, len, fv->sp.vec, fv->sp.len); + + if (!reorder) + return rc; + if (rc < 0) + return 0; + + /* + * Reorder list: used for activating features and in dccp_insert_fn_opt. + */ + return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len); +} + +/** + * dccp_feat_change_recv - Process incoming ChangeL/R options + * @fn: feature-negotiation list to update + * @is_mandatory: whether the Change was preceded by a Mandatory option + * @opt: %DCCPO_CHANGE_L or %DCCPO_CHANGE_R + * @feat: one of %dccp_feature_numbers + * @val: NN value or SP value/preference list + * @len: length of @val in bytes + * @server: whether this node is the server (1) or the client (0) + */ +static u8 dccp_feat_change_recv(struct list_head *fn, u8 is_mandatory, u8 opt, + u8 feat, u8 *val, u8 len, const bool server) +{ + u8 defval, type = dccp_feat_type(feat); + const bool local = (opt == DCCPO_CHANGE_R); + struct dccp_feat_entry *entry; + dccp_feat_val fval; + + if (len == 0 || type == FEAT_UNKNOWN) /* 6.1 and 6.6.8 */ + goto unknown_feature_or_value; + + dccp_feat_print_opt(opt, feat, val, len, is_mandatory); + + /* + * Negotiation of NN features: Change R is invalid, so there is no + * simultaneous negotiation; hence we do not look up in the list. + */ + if (type == FEAT_NN) { + if (local || len > sizeof(fval.nn)) + goto unknown_feature_or_value; + + /* 6.3.2: "The feature remote MUST accept any valid value..." */ + fval.nn = dccp_decode_value_var(val, len); + if (!dccp_feat_is_valid_nn_val(feat, fval.nn)) + goto unknown_feature_or_value; + + return dccp_feat_push_confirm(fn, feat, local, &fval); + } + + /* + * Unidirectional/simultaneous negotiation of SP features (6.3.1) + */ + entry = dccp_feat_list_lookup(fn, feat, local); + if (entry == NULL) { + /* + * No particular preferences have been registered. We deal with + * this situation by assuming that all valid values are equally + * acceptable, and apply the following checks: + * - if the peer's list is a singleton, we accept a valid value; + * - if we are the server, we first try to see if the peer (the + * client) advertises the default value. If yes, we use it, + * otherwise we accept the preferred value; + * - else if we are the client, we use the first list element. + */ + if (dccp_feat_clone_sp_val(&fval, val, 1)) + return DCCP_RESET_CODE_TOO_BUSY; + + if (len > 1 && server) { + defval = dccp_feat_default_value(feat); + if (dccp_feat_preflist_match(&defval, 1, val, len) > -1) + fval.sp.vec[0] = defval; + } else if (!dccp_feat_is_valid_sp_val(feat, fval.sp.vec[0])) { + kfree(fval.sp.vec); + goto unknown_feature_or_value; + } + + /* Treat unsupported CCIDs like invalid values */ + if (feat == DCCPF_CCID && !ccid_support_check(fval.sp.vec, 1)) { + kfree(fval.sp.vec); + goto not_valid_or_not_known; + } + + return dccp_feat_push_confirm(fn, feat, local, &fval); + + } else if (entry->state == FEAT_UNSTABLE) { /* 6.6.2 */ + return 0; + } + + if (dccp_feat_reconcile(&entry->val, val, len, server, true)) { + entry->empty_confirm = false; + } else if (is_mandatory) { + return DCCP_RESET_CODE_MANDATORY_ERROR; + } else if (entry->state == FEAT_INITIALISING) { + /* + * Failed simultaneous negotiation (server only): try to `save' + * the connection by checking whether entry contains the default + * value for @feat. If yes, send an empty Confirm to signal that + * the received Change was not understood - which implies using + * the default value. + * If this also fails, we use Reset as the last resort. + */ + WARN_ON(!server); + defval = dccp_feat_default_value(feat); + if (!dccp_feat_reconcile(&entry->val, &defval, 1, server, true)) + return DCCP_RESET_CODE_OPTION_ERROR; + entry->empty_confirm = true; + } + entry->needs_confirm = true; + entry->needs_mandatory = false; + entry->state = FEAT_STABLE; + return 0; + +unknown_feature_or_value: + if (!is_mandatory) + return dccp_push_empty_confirm(fn, feat, local); + +not_valid_or_not_known: + return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR + : DCCP_RESET_CODE_OPTION_ERROR; +} + +/** + * dccp_feat_confirm_recv - Process received Confirm options + * @fn: feature-negotiation list to update + * @is_mandatory: whether @opt was preceded by a Mandatory option + * @opt: %DCCPO_CONFIRM_L or %DCCPO_CONFIRM_R + * @feat: one of %dccp_feature_numbers + * @val: NN value or SP value/preference list + * @len: length of @val in bytes + * @server: whether this node is server (1) or client (0) + */ +static u8 dccp_feat_confirm_recv(struct list_head *fn, u8 is_mandatory, u8 opt, + u8 feat, u8 *val, u8 len, const bool server) +{ + u8 *plist, plen, type = dccp_feat_type(feat); + const bool local = (opt == DCCPO_CONFIRM_R); + struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local); + + dccp_feat_print_opt(opt, feat, val, len, is_mandatory); + + if (entry == NULL) { /* nothing queued: ignore or handle error */ + if (is_mandatory && type == FEAT_UNKNOWN) + return DCCP_RESET_CODE_MANDATORY_ERROR; + + if (!local && type == FEAT_NN) /* 6.3.2 */ + goto confirmation_failed; + return 0; + } + + if (entry->state != FEAT_CHANGING) /* 6.6.2 */ + return 0; + + if (len == 0) { + if (dccp_feat_must_be_understood(feat)) /* 6.6.7 */ + goto confirmation_failed; + /* + * Empty Confirm during connection setup: this means reverting + * to the `old' value, which in this case is the default. Since + * we handle default values automatically when no other values + * have been set, we revert to the old value by removing this + * entry from the list. + */ + dccp_feat_list_pop(entry); + return 0; + } + + if (type == FEAT_NN) { + if (len > sizeof(entry->val.nn)) + goto confirmation_failed; + + if (entry->val.nn == dccp_decode_value_var(val, len)) + goto confirmation_succeeded; + + DCCP_WARN("Bogus Confirm for non-existing value\n"); + goto confirmation_failed; + } + + /* + * Parsing SP Confirms: the first element of @val is the preferred + * SP value which the peer confirms, the remainder depends on @len. + * Note that only the confirmed value need to be a valid SP value. + */ + if (!dccp_feat_is_valid_sp_val(feat, *val)) + goto confirmation_failed; + + if (len == 1) { /* peer didn't supply a preference list */ + plist = val; + plen = len; + } else { /* preferred value + preference list */ + plist = val + 1; + plen = len - 1; + } + + /* Check whether the peer got the reconciliation right (6.6.8) */ + if (dccp_feat_reconcile(&entry->val, plist, plen, server, 0) != *val) { + DCCP_WARN("Confirm selected the wrong value %u\n", *val); + return DCCP_RESET_CODE_OPTION_ERROR; + } + entry->val.sp.vec[0] = *val; + +confirmation_succeeded: + entry->state = FEAT_STABLE; + return 0; + +confirmation_failed: + DCCP_WARN("Confirmation failed\n"); + return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR + : DCCP_RESET_CODE_OPTION_ERROR; +} + +/** + * dccp_feat_handle_nn_established - Fast-path reception of NN options + * @sk: socket of an established DCCP connection + * @mandatory: whether @opt was preceded by a Mandatory option + * @opt: %DCCPO_CHANGE_L | %DCCPO_CONFIRM_R (NN only) + * @feat: NN number, one of %dccp_feature_numbers + * @val: NN value + * @len: length of @val in bytes + * + * This function combines the functionality of change_recv/confirm_recv, with + * the following differences (reset codes are the same): + * - cleanup after receiving the Confirm; + * - values are directly activated after successful parsing; + * - deliberately restricted to NN features. + * The restriction to NN features is essential since SP features can have non- + * predictable outcomes (depending on the remote configuration), and are inter- + * dependent (CCIDs for instance cause further dependencies). + */ +static u8 dccp_feat_handle_nn_established(struct sock *sk, u8 mandatory, u8 opt, + u8 feat, u8 *val, u8 len) +{ + struct list_head *fn = &dccp_sk(sk)->dccps_featneg; + const bool local = (opt == DCCPO_CONFIRM_R); + struct dccp_feat_entry *entry; + u8 type = dccp_feat_type(feat); + dccp_feat_val fval; + + dccp_feat_print_opt(opt, feat, val, len, mandatory); + + /* Ignore non-mandatory unknown and non-NN features */ + if (type == FEAT_UNKNOWN) { + if (local && !mandatory) + return 0; + goto fast_path_unknown; + } else if (type != FEAT_NN) { + return 0; + } + + /* + * We don't accept empty Confirms, since in fast-path feature + * negotiation the values are enabled immediately after sending + * the Change option. + * Empty Changes on the other hand are invalid (RFC 4340, 6.1). + */ + if (len == 0 || len > sizeof(fval.nn)) + goto fast_path_unknown; + + if (opt == DCCPO_CHANGE_L) { + fval.nn = dccp_decode_value_var(val, len); + if (!dccp_feat_is_valid_nn_val(feat, fval.nn)) + goto fast_path_unknown; + + if (dccp_feat_push_confirm(fn, feat, local, &fval) || + dccp_feat_activate(sk, feat, local, &fval)) + return DCCP_RESET_CODE_TOO_BUSY; + + /* set the `Ack Pending' flag to piggyback a Confirm */ + inet_csk_schedule_ack(sk); + + } else if (opt == DCCPO_CONFIRM_R) { + entry = dccp_feat_list_lookup(fn, feat, local); + if (entry == NULL || entry->state != FEAT_CHANGING) + return 0; + + fval.nn = dccp_decode_value_var(val, len); + /* + * Just ignore a value that doesn't match our current value. + * If the option changes twice within two RTTs, then at least + * one CONFIRM will be received for the old value after a + * new CHANGE was sent. + */ + if (fval.nn != entry->val.nn) + return 0; + + /* Only activate after receiving the Confirm option (6.6.1). */ + dccp_feat_activate(sk, feat, local, &fval); + + /* It has been confirmed - so remove the entry */ + dccp_feat_list_pop(entry); + + } else { + DCCP_WARN("Received illegal option %u\n", opt); + goto fast_path_failed; + } + return 0; + +fast_path_unknown: + if (!mandatory) + return dccp_push_empty_confirm(fn, feat, local); + +fast_path_failed: + return mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR + : DCCP_RESET_CODE_OPTION_ERROR; +} + +/** + * dccp_feat_parse_options - Process Feature-Negotiation Options + * @sk: for general use and used by the client during connection setup + * @dreq: used by the server during connection setup + * @mandatory: whether @opt was preceded by a Mandatory option + * @opt: %DCCPO_CHANGE_L | %DCCPO_CHANGE_R | %DCCPO_CONFIRM_L | %DCCPO_CONFIRM_R + * @feat: one of %dccp_feature_numbers + * @val: value contents of @opt + * @len: length of @val in bytes + * + * Returns 0 on success, a Reset code for ending the connection otherwise. + */ +int dccp_feat_parse_options(struct sock *sk, struct dccp_request_sock *dreq, + u8 mandatory, u8 opt, u8 feat, u8 *val, u8 len) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg; + bool server = false; + + switch (sk->sk_state) { + /* + * Negotiation during connection setup + */ + case DCCP_LISTEN: + server = true; + fallthrough; + case DCCP_REQUESTING: + switch (opt) { + case DCCPO_CHANGE_L: + case DCCPO_CHANGE_R: + return dccp_feat_change_recv(fn, mandatory, opt, feat, + val, len, server); + case DCCPO_CONFIRM_R: + case DCCPO_CONFIRM_L: + return dccp_feat_confirm_recv(fn, mandatory, opt, feat, + val, len, server); + } + break; + /* + * Support for exchanging NN options on an established connection. + */ + case DCCP_OPEN: + case DCCP_PARTOPEN: + return dccp_feat_handle_nn_established(sk, mandatory, opt, feat, + val, len); + } + return 0; /* ignore FN options in all other states */ +} + +/** + * dccp_feat_init - Seed feature negotiation with host-specific defaults + * @sk: Socket to initialize. + * + * This initialises global defaults, depending on the value of the sysctls. + * These can later be overridden by registering changes via setsockopt calls. + * The last link in the chain is finalise_settings, to make sure that between + * here and the start of actual feature negotiation no inconsistencies enter. + * + * All features not appearing below use either defaults or are otherwise + * later adjusted through dccp_feat_finalise_settings(). + */ +int dccp_feat_init(struct sock *sk) +{ + struct list_head *fn = &dccp_sk(sk)->dccps_featneg; + u8 on = 1, off = 0; + int rc; + struct { + u8 *val; + u8 len; + } tx, rx; + + /* Non-negotiable (NN) features */ + rc = __feat_register_nn(fn, DCCPF_SEQUENCE_WINDOW, 0, + sysctl_dccp_sequence_window); + if (rc) + return rc; + + /* Server-priority (SP) features */ + + /* Advertise that short seqnos are not supported (7.6.1) */ + rc = __feat_register_sp(fn, DCCPF_SHORT_SEQNOS, true, true, &off, 1); + if (rc) + return rc; + + /* RFC 4340 12.1: "If a DCCP is not ECN capable, ..." */ + rc = __feat_register_sp(fn, DCCPF_ECN_INCAPABLE, true, true, &on, 1); + if (rc) + return rc; + + /* + * We advertise the available list of CCIDs and reorder according to + * preferences, to avoid failure resulting from negotiating different + * singleton values (which always leads to failure). + * These settings can still (later) be overridden via sockopts. + */ + if (ccid_get_builtin_ccids(&tx.val, &tx.len)) + return -ENOBUFS; + if (ccid_get_builtin_ccids(&rx.val, &rx.len)) { + kfree(tx.val); + return -ENOBUFS; + } + + if (!dccp_feat_prefer(sysctl_dccp_tx_ccid, tx.val, tx.len) || + !dccp_feat_prefer(sysctl_dccp_rx_ccid, rx.val, rx.len)) + goto free_ccid_lists; + + rc = __feat_register_sp(fn, DCCPF_CCID, true, false, tx.val, tx.len); + if (rc) + goto free_ccid_lists; + + rc = __feat_register_sp(fn, DCCPF_CCID, false, false, rx.val, rx.len); + +free_ccid_lists: + kfree(tx.val); + kfree(rx.val); + return rc; +} + +int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_feat_entry *cur, *next; + int idx; + dccp_feat_val *fvals[DCCP_FEAT_SUPPORTED_MAX][2] = { + [0 ... DCCP_FEAT_SUPPORTED_MAX-1] = { NULL, NULL } + }; + + list_for_each_entry(cur, fn_list, node) { + /* + * An empty Confirm means that either an unknown feature type + * or an invalid value was present. In the first case there is + * nothing to activate, in the other the default value is used. + */ + if (cur->empty_confirm) + continue; + + idx = dccp_feat_index(cur->feat_num); + if (idx < 0) { + DCCP_BUG("Unknown feature %u", cur->feat_num); + goto activation_failed; + } + if (cur->state != FEAT_STABLE) { + DCCP_CRIT("Negotiation of %s %s failed in state %s", + cur->is_local ? "local" : "remote", + dccp_feat_fname(cur->feat_num), + dccp_feat_sname[cur->state]); + goto activation_failed; + } + fvals[idx][cur->is_local] = &cur->val; + } + + /* + * Activate in decreasing order of index, so that the CCIDs are always + * activated as the last feature. This avoids the case where a CCID + * relies on the initialisation of one or more features that it depends + * on (e.g. Send NDP Count, Send Ack Vector, and Ack Ratio features). + */ + for (idx = DCCP_FEAT_SUPPORTED_MAX; --idx >= 0;) + if (__dccp_feat_activate(sk, idx, 0, fvals[idx][0]) || + __dccp_feat_activate(sk, idx, 1, fvals[idx][1])) { + DCCP_CRIT("Could not activate %d", idx); + goto activation_failed; + } + + /* Clean up Change options which have been confirmed already */ + list_for_each_entry_safe(cur, next, fn_list, node) + if (!cur->needs_confirm) + dccp_feat_list_pop(cur); + + dccp_pr_debug("Activation OK\n"); + return 0; + +activation_failed: + /* + * We clean up everything that may have been allocated, since + * it is difficult to track at which stage negotiation failed. + * This is ok, since all allocation functions below are robust + * against NULL arguments. + */ + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL; + dccp_ackvec_free(dp->dccps_hc_rx_ackvec); + dp->dccps_hc_rx_ackvec = NULL; + return -1; +} diff --git a/net/dccp/feat.h b/net/dccp/feat.h new file mode 100644 index 000000000..d76c9be5b --- /dev/null +++ b/net/dccp/feat.h @@ -0,0 +1,134 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DCCP_FEAT_H +#define _DCCP_FEAT_H +/* + * net/dccp/feat.h + * + * Feature negotiation for the DCCP protocol (RFC 4340, section 6) + * Copyright (c) 2008 Gerrit Renker + * Copyright (c) 2005 Andrea Bittau + */ +#include +#include "dccp.h" + +/* + * Known limit values + */ +/* Ack Ratio takes 2-byte integer values (11.3) */ +#define DCCPF_ACK_RATIO_MAX 0xFFFF +/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */ +#define DCCPF_SEQ_WMIN 32 +#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull +/* Maximum number of SP values that fit in a single (Confirm) option */ +#define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2) + +enum dccp_feat_type { + FEAT_AT_RX = 1, /* located at RX side of half-connection */ + FEAT_AT_TX = 2, /* located at TX side of half-connection */ + FEAT_SP = 4, /* server-priority reconciliation (6.3.1) */ + FEAT_NN = 8, /* non-negotiable reconciliation (6.3.2) */ + FEAT_UNKNOWN = 0xFF /* not understood or invalid feature */ +}; + +enum dccp_feat_state { + FEAT_DEFAULT = 0, /* using default values from 6.4 */ + FEAT_INITIALISING, /* feature is being initialised */ + FEAT_CHANGING, /* Change sent but not confirmed yet */ + FEAT_UNSTABLE, /* local modification in state CHANGING */ + FEAT_STABLE /* both ends (think they) agree */ +}; + +/** + * dccp_feat_val - Container for SP or NN feature values + * @nn: single NN value + * @sp.vec: single SP value plus optional preference list + * @sp.len: length of @sp.vec in bytes + */ +typedef union { + u64 nn; + struct { + u8 *vec; + u8 len; + } sp; +} dccp_feat_val; + +/** + * struct feat_entry - Data structure to perform feature negotiation + * @val: feature's current value (SP features may have preference list) + * @state: feature's current state + * @feat_num: one of %dccp_feature_numbers + * @needs_mandatory: whether Mandatory options should be sent + * @needs_confirm: whether to send a Confirm instead of a Change + * @empty_confirm: whether to send an empty Confirm (depends on @needs_confirm) + * @is_local: feature location (1) or feature-remote (0) + * @node: list pointers, entries arranged in FIFO order + */ +struct dccp_feat_entry { + dccp_feat_val val; + enum dccp_feat_state state:8; + u8 feat_num; + + bool needs_mandatory, + needs_confirm, + empty_confirm, + is_local; + + struct list_head node; +}; + +static inline u8 dccp_feat_genopt(struct dccp_feat_entry *entry) +{ + if (entry->needs_confirm) + return entry->is_local ? DCCPO_CONFIRM_L : DCCPO_CONFIRM_R; + return entry->is_local ? DCCPO_CHANGE_L : DCCPO_CHANGE_R; +} + +/** + * struct ccid_dependency - Track changes resulting from choosing a CCID + * @dependent_feat: one of %dccp_feature_numbers + * @is_local: local (1) or remote (0) @dependent_feat + * @is_mandatory: whether presence of @dependent_feat is mission-critical or not + * @val: corresponding default value for @dependent_feat (u8 is sufficient here) + */ +struct ccid_dependency { + u8 dependent_feat; + bool is_local:1, + is_mandatory:1; + u8 val; +}; + +/* + * Sysctls to seed defaults for feature negotiation + */ +extern unsigned long sysctl_dccp_sequence_window; +extern int sysctl_dccp_rx_ccid; +extern int sysctl_dccp_tx_ccid; + +int dccp_feat_init(struct sock *sk); +void dccp_feat_initialise_sysctls(void); +int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, + u8 const *list, u8 len); +int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *, + u8 mand, u8 opt, u8 feat, u8 *val, u8 len); +int dccp_feat_clone_list(struct list_head const *, struct list_head *); + +/* + * Encoding variable-length options and their maximum length. + * + * This affects NN options (SP options are all u8) and other variable-length + * options (see table 3 in RFC 4340). The limit is currently given the Sequence + * Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other + * options consume less than 6 bytes (timestamps are 4 bytes). + * When updating this constant (e.g. due to new internet drafts / RFCs), make + * sure that you also update all code which refers to it. + */ +#define DCCP_OPTVAL_MAXLEN 6 + +void dccp_encode_value_var(const u64 value, u8 *to, const u8 len); +u64 dccp_decode_value_var(const u8 *bf, const u8 len); +u64 dccp_feat_nn_get(struct sock *sk, u8 feat); + +int dccp_insert_option_mandatory(struct sk_buff *skb); +int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, u8 *val, u8 len, + bool repeat_first); +#endif /* _DCCP_FEAT_H */ diff --git a/net/dccp/input.c b/net/dccp/input.c new file mode 100644 index 000000000..2cbb757a8 --- /dev/null +++ b/net/dccp/input.c @@ -0,0 +1,739 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/input.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include + +#include + +#include "ackvec.h" +#include "ccid.h" +#include "dccp.h" + +/* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */ +int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8; + +static void dccp_enqueue_skb(struct sock *sk, struct sk_buff *skb) +{ + __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4); + __skb_queue_tail(&sk->sk_receive_queue, skb); + skb_set_owner_r(skb, sk); + sk->sk_data_ready(sk); +} + +static void dccp_fin(struct sock *sk, struct sk_buff *skb) +{ + /* + * On receiving Close/CloseReq, both RD/WR shutdown are performed. + * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after + * receiving the closing segment, but there is no guarantee that such + * data will be processed at all. + */ + sk->sk_shutdown = SHUTDOWN_MASK; + sock_set_flag(sk, SOCK_DONE); + dccp_enqueue_skb(sk, skb); +} + +static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb) +{ + int queued = 0; + + switch (sk->sk_state) { + /* + * We ignore Close when received in one of the following states: + * - CLOSED (may be a late or duplicate packet) + * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier) + * - RESPOND (already handled by dccp_check_req) + */ + case DCCP_CLOSING: + /* + * Simultaneous-close: receiving a Close after sending one. This + * can happen if both client and server perform active-close and + * will result in an endless ping-pong of crossing and retrans- + * mitted Close packets, which only terminates when one of the + * nodes times out (min. 64 seconds). Quicker convergence can be + * achieved when one of the nodes acts as tie-breaker. + * This is ok as both ends are done with data transfer and each + * end is just waiting for the other to acknowledge termination. + */ + if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) + break; + fallthrough; + case DCCP_REQUESTING: + case DCCP_ACTIVE_CLOSEREQ: + dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); + dccp_done(sk); + break; + case DCCP_OPEN: + case DCCP_PARTOPEN: + /* Give waiting application a chance to read pending data */ + queued = 1; + dccp_fin(sk, skb); + dccp_set_state(sk, DCCP_PASSIVE_CLOSE); + fallthrough; + case DCCP_PASSIVE_CLOSE: + /* + * Retransmitted Close: we have already enqueued the first one. + */ + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + } + return queued; +} + +static int dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) +{ + int queued = 0; + + /* + * Step 7: Check for unexpected packet types + * If (S.is_server and P.type == CloseReq) + * Send Sync packet acknowledging P.seqno + * Drop packet and return + */ + if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) { + dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); + return queued; + } + + /* Step 13: process relevant Client states < CLOSEREQ */ + switch (sk->sk_state) { + case DCCP_REQUESTING: + dccp_send_close(sk, 0); + dccp_set_state(sk, DCCP_CLOSING); + break; + case DCCP_OPEN: + case DCCP_PARTOPEN: + /* Give waiting application a chance to read pending data */ + queued = 1; + dccp_fin(sk, skb); + dccp_set_state(sk, DCCP_PASSIVE_CLOSEREQ); + fallthrough; + case DCCP_PASSIVE_CLOSEREQ: + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); + } + return queued; +} + +static u16 dccp_reset_code_convert(const u8 code) +{ + static const u16 error_code[] = { + [DCCP_RESET_CODE_CLOSED] = 0, /* normal termination */ + [DCCP_RESET_CODE_UNSPECIFIED] = 0, /* nothing known */ + [DCCP_RESET_CODE_ABORTED] = ECONNRESET, + + [DCCP_RESET_CODE_NO_CONNECTION] = ECONNREFUSED, + [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED, + [DCCP_RESET_CODE_TOO_BUSY] = EUSERS, + [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT, + + [DCCP_RESET_CODE_PACKET_ERROR] = ENOMSG, + [DCCP_RESET_CODE_BAD_INIT_COOKIE] = EBADR, + [DCCP_RESET_CODE_BAD_SERVICE_CODE] = EBADRQC, + [DCCP_RESET_CODE_OPTION_ERROR] = EILSEQ, + [DCCP_RESET_CODE_MANDATORY_ERROR] = EOPNOTSUPP, + }; + + return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code]; +} + +static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb) +{ + u16 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code); + + sk->sk_err = err; + + /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */ + dccp_fin(sk, skb); + + if (err && !sock_flag(sk, SOCK_DEAD)) + sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR); + dccp_time_wait(sk, DCCP_TIME_WAIT, 0); +} + +static void dccp_handle_ackvec_processing(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_ackvec *av = dccp_sk(sk)->dccps_hc_rx_ackvec; + + if (av == NULL) + return; + if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) + dccp_ackvec_clear_state(av, DCCP_SKB_CB(skb)->dccpd_ack_seq); + dccp_ackvec_input(av, skb); +} + +static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb) +{ + const struct dccp_sock *dp = dccp_sk(sk); + + /* Don't deliver to RX CCID when node has shut down read end. */ + if (!(sk->sk_shutdown & RCV_SHUTDOWN)) + ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); + /* + * Until the TX queue has been drained, we can not honour SHUT_WR, since + * we need received feedback as input to adjust congestion control. + */ + if (sk->sk_write_queue.qlen > 0 || !(sk->sk_shutdown & SEND_SHUTDOWN)) + ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); +} + +static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) +{ + const struct dccp_hdr *dh = dccp_hdr(skb); + struct dccp_sock *dp = dccp_sk(sk); + u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq, + ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; + + /* + * Step 5: Prepare sequence numbers for Sync + * If P.type == Sync or P.type == SyncAck, + * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL, + * / * P is valid, so update sequence number variables + * accordingly. After this update, P will pass the tests + * in Step 6. A SyncAck is generated if necessary in + * Step 15 * / + * Update S.GSR, S.SWL, S.SWH + * Otherwise, + * Drop packet and return + */ + if (dh->dccph_type == DCCP_PKT_SYNC || + dh->dccph_type == DCCP_PKT_SYNCACK) { + if (between48(ackno, dp->dccps_awl, dp->dccps_awh) && + dccp_delta_seqno(dp->dccps_swl, seqno) >= 0) + dccp_update_gsr(sk, seqno); + else + return -1; + } + + /* + * Step 6: Check sequence numbers + * Let LSWL = S.SWL and LAWL = S.AWL + * If P.type == CloseReq or P.type == Close or P.type == Reset, + * LSWL := S.GSR + 1, LAWL := S.GAR + * If LSWL <= P.seqno <= S.SWH + * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH), + * Update S.GSR, S.SWL, S.SWH + * If P.type != Sync, + * Update S.GAR + */ + lswl = dp->dccps_swl; + lawl = dp->dccps_awl; + + if (dh->dccph_type == DCCP_PKT_CLOSEREQ || + dh->dccph_type == DCCP_PKT_CLOSE || + dh->dccph_type == DCCP_PKT_RESET) { + lswl = ADD48(dp->dccps_gsr, 1); + lawl = dp->dccps_gar; + } + + if (between48(seqno, lswl, dp->dccps_swh) && + (ackno == DCCP_PKT_WITHOUT_ACK_SEQ || + between48(ackno, lawl, dp->dccps_awh))) { + dccp_update_gsr(sk, seqno); + + if (dh->dccph_type != DCCP_PKT_SYNC && + ackno != DCCP_PKT_WITHOUT_ACK_SEQ && + after48(ackno, dp->dccps_gar)) + dp->dccps_gar = ackno; + } else { + unsigned long now = jiffies; + /* + * Step 6: Check sequence numbers + * Otherwise, + * If P.type == Reset, + * Send Sync packet acknowledging S.GSR + * Otherwise, + * Send Sync packet acknowledging P.seqno + * Drop packet and return + * + * These Syncs are rate-limited as per RFC 4340, 7.5.4: + * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second. + */ + if (time_before(now, (dp->dccps_rate_last + + sysctl_dccp_sync_ratelimit))) + return -1; + + DCCP_WARN("Step 6 failed for %s packet, " + "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " + "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), " + "sending SYNC...\n", dccp_packet_name(dh->dccph_type), + (unsigned long long) lswl, (unsigned long long) seqno, + (unsigned long long) dp->dccps_swh, + (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" + : "exists", + (unsigned long long) lawl, (unsigned long long) ackno, + (unsigned long long) dp->dccps_awh); + + dp->dccps_rate_last = now; + + if (dh->dccph_type == DCCP_PKT_RESET) + seqno = dp->dccps_gsr; + dccp_send_sync(sk, seqno, DCCP_PKT_SYNC); + return -1; + } + + return 0; +} + +static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, + const struct dccp_hdr *dh, const unsigned int len) +{ + struct dccp_sock *dp = dccp_sk(sk); + + switch (dccp_hdr(skb)->dccph_type) { + case DCCP_PKT_DATAACK: + case DCCP_PKT_DATA: + /* + * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when + * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening" + * - sk_receive_queue is full, use Code 2, "Receive Buffer" + */ + dccp_enqueue_skb(sk, skb); + return 0; + case DCCP_PKT_ACK: + goto discard; + case DCCP_PKT_RESET: + /* + * Step 9: Process Reset + * If P.type == Reset, + * Tear down connection + * S.state := TIMEWAIT + * Set TIMEWAIT timer + * Drop packet and return + */ + dccp_rcv_reset(sk, skb); + return 0; + case DCCP_PKT_CLOSEREQ: + if (dccp_rcv_closereq(sk, skb)) + return 0; + goto discard; + case DCCP_PKT_CLOSE: + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; + case DCCP_PKT_REQUEST: + /* Step 7 + * or (S.is_server and P.type == Response) + * or (S.is_client and P.type == Request) + * or (S.state >= OPEN and P.type == Request + * and P.seqno >= S.OSR) + * or (S.state >= OPEN and P.type == Response + * and P.seqno >= S.OSR) + * or (S.state == RESPOND and P.type == Data), + * Send Sync packet acknowledging P.seqno + * Drop packet and return + */ + if (dp->dccps_role != DCCP_ROLE_LISTEN) + goto send_sync; + goto check_seq; + case DCCP_PKT_RESPONSE: + if (dp->dccps_role != DCCP_ROLE_CLIENT) + goto send_sync; +check_seq: + if (dccp_delta_seqno(dp->dccps_osr, + DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { +send_sync: + dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, + DCCP_PKT_SYNC); + } + break; + case DCCP_PKT_SYNC: + dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, + DCCP_PKT_SYNCACK); + /* + * From RFC 4340, sec. 5.7 + * + * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets + * MAY have non-zero-length application data areas, whose + * contents receivers MUST ignore. + */ + goto discard; + } + + DCCP_INC_STATS(DCCP_MIB_INERRS); +discard: + __kfree_skb(skb); + return 0; +} + +int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, + const struct dccp_hdr *dh, const unsigned int len) +{ + if (dccp_check_seqno(sk, skb)) + goto discard; + + if (dccp_parse_options(sk, NULL, skb)) + return 1; + + dccp_handle_ackvec_processing(sk, skb); + dccp_deliver_input_to_ccids(sk, skb); + + return __dccp_rcv_established(sk, skb, dh, len); +discard: + __kfree_skb(skb); + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_rcv_established); + +static int dccp_rcv_request_sent_state_process(struct sock *sk, + struct sk_buff *skb, + const struct dccp_hdr *dh, + const unsigned int len) +{ + /* + * Step 4: Prepare sequence numbers in REQUEST + * If S.state == REQUEST, + * If (P.type == Response or P.type == Reset) + * and S.AWL <= P.ackno <= S.AWH, + * / * Set sequence number variables corresponding to the + * other endpoint, so P will pass the tests in Step 6 * / + * Set S.GSR, S.ISR, S.SWL, S.SWH + * / * Response processing continues in Step 10; Reset + * processing continues in Step 9 * / + */ + if (dh->dccph_type == DCCP_PKT_RESPONSE) { + const struct inet_connection_sock *icsk = inet_csk(sk); + struct dccp_sock *dp = dccp_sk(sk); + long tstamp = dccp_timestamp(); + + if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, + dp->dccps_awl, dp->dccps_awh)) { + dccp_pr_debug("invalid ackno: S.AWL=%llu, " + "P.ackno=%llu, S.AWH=%llu\n", + (unsigned long long)dp->dccps_awl, + (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, + (unsigned long long)dp->dccps_awh); + goto out_invalid_packet; + } + + /* + * If option processing (Step 8) failed, return 1 here so that + * dccp_v4_do_rcv() sends a Reset. The Reset code depends on + * the option type and is set in dccp_parse_options(). + */ + if (dccp_parse_options(sk, NULL, skb)) + return 1; + + /* Obtain usec RTT sample from SYN exchange (used by TFRC). */ + if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) + dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - + dp->dccps_options_received.dccpor_timestamp_echo)); + + /* Stop the REQUEST timer */ + inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); + WARN_ON(sk->sk_send_head == NULL); + kfree_skb(sk->sk_send_head); + sk->sk_send_head = NULL; + + /* + * Set ISR, GSR from packet. ISS was set in dccp_v{4,6}_connect + * and GSS in dccp_transmit_skb(). Setting AWL/AWH and SWL/SWH + * is done as part of activating the feature values below, since + * these settings depend on the local/remote Sequence Window + * features, which were undefined or not confirmed until now. + */ + dp->dccps_gsr = dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; + + dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); + + /* + * Step 10: Process REQUEST state (second part) + * If S.state == REQUEST, + * / * If we get here, P is a valid Response from the + * server (see Step 4), and we should move to + * PARTOPEN state. PARTOPEN means send an Ack, + * don't send Data packets, retransmit Acks + * periodically, and always include any Init Cookie + * from the Response * / + * S.state := PARTOPEN + * Set PARTOPEN timer + * Continue with S.state == PARTOPEN + * / * Step 12 will send the Ack completing the + * three-way handshake * / + */ + dccp_set_state(sk, DCCP_PARTOPEN); + + /* + * If feature negotiation was successful, activate features now; + * an activation failure means that this host could not activate + * one ore more features (e.g. insufficient memory), which would + * leave at least one feature in an undefined state. + */ + if (dccp_feat_activate_values(sk, &dp->dccps_featneg)) + goto unable_to_proceed; + + /* Make sure socket is routed, for correct metrics. */ + icsk->icsk_af_ops->rebuild_header(sk); + + if (!sock_flag(sk, SOCK_DEAD)) { + sk->sk_state_change(sk); + sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT); + } + + if (sk->sk_write_pending || inet_csk_in_pingpong_mode(sk) || + icsk->icsk_accept_queue.rskq_defer_accept) { + /* Save one ACK. Data will be ready after + * several ticks, if write_pending is set. + * + * It may be deleted, but with this feature tcpdumps + * look so _wonderfully_ clever, that I was not able + * to stand against the temptation 8) --ANK + */ + /* + * OK, in DCCP we can as well do a similar trick, its + * even in the draft, but there is no need for us to + * schedule an ack here, as dccp_sendmsg does this for + * us, also stated in the draft. -acme + */ + __kfree_skb(skb); + return 0; + } + dccp_send_ack(sk); + return -1; + } + +out_invalid_packet: + /* dccp_v4_do_rcv will send a reset */ + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; + return 1; + +unable_to_proceed: + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_ABORTED; + /* + * We mark this socket as no longer usable, so that the loop in + * dccp_sendmsg() terminates and the application gets notified. + */ + dccp_set_state(sk, DCCP_CLOSED); + sk->sk_err = ECOMM; + return 1; +} + +static int dccp_rcv_respond_partopen_state_process(struct sock *sk, + struct sk_buff *skb, + const struct dccp_hdr *dh, + const unsigned int len) +{ + struct dccp_sock *dp = dccp_sk(sk); + u32 sample = dp->dccps_options_received.dccpor_timestamp_echo; + int queued = 0; + + switch (dh->dccph_type) { + case DCCP_PKT_RESET: + inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); + break; + case DCCP_PKT_DATA: + if (sk->sk_state == DCCP_RESPOND) + break; + fallthrough; + case DCCP_PKT_DATAACK: + case DCCP_PKT_ACK: + /* + * FIXME: we should be resetting the PARTOPEN (DELACK) timer + * here but only if we haven't used the DELACK timer for + * something else, like sending a delayed ack for a TIMESTAMP + * echo, etc, for now were not clearing it, sending an extra + * ACK when there is nothing else to do in DELACK is not a big + * deal after all. + */ + + /* Stop the PARTOPEN timer */ + if (sk->sk_state == DCCP_PARTOPEN) + inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); + + /* Obtain usec RTT sample from SYN exchange (used by TFRC). */ + if (likely(sample)) { + long delta = dccp_timestamp() - sample; + + dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * delta); + } + + dp->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq; + dccp_set_state(sk, DCCP_OPEN); + + if (dh->dccph_type == DCCP_PKT_DATAACK || + dh->dccph_type == DCCP_PKT_DATA) { + __dccp_rcv_established(sk, skb, dh, len); + queued = 1; /* packet was queued + (by __dccp_rcv_established) */ + } + break; + } + + return queued; +} + +int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, + struct dccp_hdr *dh, unsigned int len) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + const int old_state = sk->sk_state; + bool acceptable; + int queued = 0; + + /* + * Step 3: Process LISTEN state + * + * If S.state == LISTEN, + * If P.type == Request or P contains a valid Init Cookie option, + * (* Must scan the packet's options to check for Init + * Cookies. Only Init Cookies are processed here, + * however; other options are processed in Step 8. This + * scan need only be performed if the endpoint uses Init + * Cookies *) + * (* Generate a new socket and switch to that socket *) + * Set S := new socket for this port pair + * S.state = RESPOND + * Choose S.ISS (initial seqno) or set from Init Cookies + * Initialize S.GAR := S.ISS + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init + * Cookies Continue with S.state == RESPOND + * (* A Response packet will be generated in Step 11 *) + * Otherwise, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (sk->sk_state == DCCP_LISTEN) { + if (dh->dccph_type == DCCP_PKT_REQUEST) { + /* It is possible that we process SYN packets from backlog, + * so we need to make sure to disable BH and RCU right there. + */ + rcu_read_lock(); + local_bh_disable(); + acceptable = inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) >= 0; + local_bh_enable(); + rcu_read_unlock(); + if (!acceptable) + return 1; + consume_skb(skb); + return 0; + } + if (dh->dccph_type == DCCP_PKT_RESET) + goto discard; + + /* Caller (dccp_v4_do_rcv) will send Reset */ + dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; + return 1; + } else if (sk->sk_state == DCCP_CLOSED) { + dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; + return 1; + } + + /* Step 6: Check sequence numbers (omitted in LISTEN/REQUEST state) */ + if (sk->sk_state != DCCP_REQUESTING && dccp_check_seqno(sk, skb)) + goto discard; + + /* + * Step 7: Check for unexpected packet types + * If (S.is_server and P.type == Response) + * or (S.is_client and P.type == Request) + * or (S.state == RESPOND and P.type == Data), + * Send Sync packet acknowledging P.seqno + * Drop packet and return + */ + if ((dp->dccps_role != DCCP_ROLE_CLIENT && + dh->dccph_type == DCCP_PKT_RESPONSE) || + (dp->dccps_role == DCCP_ROLE_CLIENT && + dh->dccph_type == DCCP_PKT_REQUEST) || + (sk->sk_state == DCCP_RESPOND && dh->dccph_type == DCCP_PKT_DATA)) { + dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); + goto discard; + } + + /* Step 8: Process options */ + if (dccp_parse_options(sk, NULL, skb)) + return 1; + + /* + * Step 9: Process Reset + * If P.type == Reset, + * Tear down connection + * S.state := TIMEWAIT + * Set TIMEWAIT timer + * Drop packet and return + */ + if (dh->dccph_type == DCCP_PKT_RESET) { + dccp_rcv_reset(sk, skb); + return 0; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ + if (dccp_rcv_closereq(sk, skb)) + return 0; + goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ + if (dccp_rcv_close(sk, skb)) + return 0; + goto discard; + } + + switch (sk->sk_state) { + case DCCP_REQUESTING: + queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); + if (queued >= 0) + return queued; + + __kfree_skb(skb); + return 0; + + case DCCP_PARTOPEN: + /* Step 8: if using Ack Vectors, mark packet acknowledgeable */ + dccp_handle_ackvec_processing(sk, skb); + dccp_deliver_input_to_ccids(sk, skb); + fallthrough; + case DCCP_RESPOND: + queued = dccp_rcv_respond_partopen_state_process(sk, skb, + dh, len); + break; + } + + if (dh->dccph_type == DCCP_PKT_ACK || + dh->dccph_type == DCCP_PKT_DATAACK) { + switch (old_state) { + case DCCP_PARTOPEN: + sk->sk_state_change(sk); + sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT); + break; + } + } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { + dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); + goto discard; + } + + if (!queued) { +discard: + __kfree_skb(skb); + } + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_rcv_state_process); + +/** + * dccp_sample_rtt - Validate and finalise computation of RTT sample + * @sk: socket structure + * @delta: number of microseconds between packet and acknowledgment + * + * The routine is kept generic to work in different contexts. It should be + * called immediately when the ACK used for the RTT sample arrives. + */ +u32 dccp_sample_rtt(struct sock *sk, long delta) +{ + /* dccpor_elapsed_time is either zeroed out or set and > 0 */ + delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; + + if (unlikely(delta <= 0)) { + DCCP_WARN("unusable RTT sample %ld, using min\n", delta); + return DCCP_SANE_RTT_MIN; + } + if (unlikely(delta > DCCP_SANE_RTT_MAX)) { + DCCP_WARN("RTT sample %ld too large, using max\n", delta); + return DCCP_SANE_RTT_MAX; + } + + return delta; +} diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c new file mode 100644 index 000000000..9fe6d9679 --- /dev/null +++ b/net/dccp/ipv4.c @@ -0,0 +1,1100 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/ipv4.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ackvec.h" +#include "ccid.h" +#include "dccp.h" +#include "feat.h" + +struct dccp_v4_pernet { + struct sock *v4_ctl_sk; +}; + +static unsigned int dccp_v4_pernet_id __read_mostly; + +/* + * The per-net v4_ctl_sk socket is used for responding to + * the Out-of-the-blue (OOTB) packets. A control sock will be created + * for this socket at the initialization time. + */ + +int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + const struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; + struct inet_sock *inet = inet_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + __be16 orig_sport, orig_dport; + __be32 daddr, nexthop; + struct flowi4 *fl4; + struct rtable *rt; + int err; + struct ip_options_rcu *inet_opt; + + dp->dccps_role = DCCP_ROLE_CLIENT; + + if (addr_len < sizeof(struct sockaddr_in)) + return -EINVAL; + + if (usin->sin_family != AF_INET) + return -EAFNOSUPPORT; + + nexthop = daddr = usin->sin_addr.s_addr; + + inet_opt = rcu_dereference_protected(inet->inet_opt, + lockdep_sock_is_held(sk)); + if (inet_opt != NULL && inet_opt->opt.srr) { + if (daddr == 0) + return -EINVAL; + nexthop = inet_opt->opt.faddr; + } + + orig_sport = inet->inet_sport; + orig_dport = usin->sin_port; + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, + sk->sk_bound_dev_if, IPPROTO_DCCP, orig_sport, + orig_dport, sk); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { + ip_rt_put(rt); + return -ENETUNREACH; + } + + if (inet_opt == NULL || !inet_opt->opt.srr) + daddr = fl4->daddr; + + if (inet->inet_saddr == 0) { + err = inet_bhash2_update_saddr(sk, &fl4->saddr, AF_INET); + if (err) { + ip_rt_put(rt); + return err; + } + } else { + sk_rcv_saddr_set(sk, inet->inet_saddr); + } + + inet->inet_dport = usin->sin_port; + sk_daddr_set(sk, daddr); + + inet_csk(sk)->icsk_ext_hdr_len = 0; + if (inet_opt) + inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; + /* + * Socket identity is still unknown (sport may be zero). + * However we set state to DCCP_REQUESTING and not releasing socket + * lock select source port, enter ourselves into the hash tables and + * complete initialization after this. + */ + dccp_set_state(sk, DCCP_REQUESTING); + err = inet_hash_connect(&dccp_death_row, sk); + if (err != 0) + goto failure; + + rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, + inet->inet_sport, inet->inet_dport, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + goto failure; + } + /* OK, now commit destination to socket. */ + sk_setup_caps(sk, &rt->dst); + + dp->dccps_iss = secure_dccp_sequence_number(inet->inet_saddr, + inet->inet_daddr, + inet->inet_sport, + inet->inet_dport); + atomic_set(&inet->inet_id, get_random_u16()); + + err = dccp_connect(sk); + rt = NULL; + if (err != 0) + goto failure; +out: + return err; +failure: + /* + * This unhashes the socket and releases the local port, if necessary. + */ + dccp_set_state(sk, DCCP_CLOSED); + inet_bhash2_reset_saddr(sk); + ip_rt_put(rt); + sk->sk_route_caps = 0; + inet->inet_dport = 0; + goto out; +} +EXPORT_SYMBOL_GPL(dccp_v4_connect); + +/* + * This routine does path mtu discovery as defined in RFC1191. + */ +static inline void dccp_do_pmtu_discovery(struct sock *sk, + const struct iphdr *iph, + u32 mtu) +{ + struct dst_entry *dst; + const struct inet_sock *inet = inet_sk(sk); + const struct dccp_sock *dp = dccp_sk(sk); + + /* We are not interested in DCCP_LISTEN and request_socks (RESPONSEs + * send out by Linux are always < 576bytes so they should go through + * unfragmented). + */ + if (sk->sk_state == DCCP_LISTEN) + return; + + dst = inet_csk_update_pmtu(sk, mtu); + if (!dst) + return; + + /* Something is about to be wrong... Remember soft error + * for the case, if this connection will not able to recover. + */ + if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) + sk->sk_err_soft = EMSGSIZE; + + mtu = dst_mtu(dst); + + if (inet->pmtudisc != IP_PMTUDISC_DONT && + ip_sk_accept_pmtu(sk) && + inet_csk(sk)->icsk_pmtu_cookie > mtu) { + dccp_sync_mss(sk, mtu); + + /* + * From RFC 4340, sec. 14.1: + * + * DCCP-Sync packets are the best choice for upward + * probing, since DCCP-Sync probes do not risk application + * data loss. + */ + dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); + } /* else let the usual retransmit timer handle it */ +} + +static void dccp_do_redirect(struct sk_buff *skb, struct sock *sk) +{ + struct dst_entry *dst = __sk_dst_check(sk, 0); + + if (dst) + dst->ops->redirect(dst, sk, skb); +} + +void dccp_req_err(struct sock *sk, u64 seq) + { + struct request_sock *req = inet_reqsk(sk); + struct net *net = sock_net(sk); + + /* + * ICMPs are not backlogged, hence we cannot get an established + * socket here. + */ + if (!between48(seq, dccp_rsk(req)->dreq_iss, dccp_rsk(req)->dreq_gss)) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + } else { + /* + * Still in RESPOND, just remove it silently. + * There is no good way to pass the error to the newly + * created socket, and POSIX does not want network + * errors returned from accept(). + */ + inet_csk_reqsk_queue_drop(req->rsk_listener, req); + } + reqsk_put(req); +} +EXPORT_SYMBOL(dccp_req_err); + +/* + * This routine is called by the ICMP module when it gets some sort of error + * condition. If err < 0 then the socket should be closed and the error + * returned to the user. If err > 0 it's just the icmp type << 8 | icmp code. + * After adjustment header points to the first 8 bytes of the tcp header. We + * need to find the appropriate port. + * + * The locking strategy used here is very "optimistic". When someone else + * accesses the socket the ICMP is just dropped and for some paths there is no + * check at all. A more general error queue to queue errors for later handling + * is probably better. + */ +static int dccp_v4_err(struct sk_buff *skb, u32 info) +{ + const struct iphdr *iph = (struct iphdr *)skb->data; + const u8 offset = iph->ihl << 2; + const struct dccp_hdr *dh; + struct dccp_sock *dp; + struct inet_sock *inet; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct sock *sk; + __u64 seq; + int err; + struct net *net = dev_net(skb->dev); + + if (!pskb_may_pull(skb, offset + sizeof(*dh))) + return -EINVAL; + dh = (struct dccp_hdr *)(skb->data + offset); + if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh))) + return -EINVAL; + iph = (struct iphdr *)skb->data; + dh = (struct dccp_hdr *)(skb->data + offset); + + sk = __inet_lookup_established(net, &dccp_hashinfo, + iph->daddr, dh->dccph_dport, + iph->saddr, ntohs(dh->dccph_sport), + inet_iif(skb), 0); + if (!sk) { + __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); + return -ENOENT; + } + + if (sk->sk_state == DCCP_TIME_WAIT) { + inet_twsk_put(inet_twsk(sk)); + return 0; + } + seq = dccp_hdr_seq(dh); + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + dccp_req_err(sk, seq); + return 0; + } + + bh_lock_sock(sk); + /* If too many ICMPs get dropped on busy + * servers this needs to be solved differently. + */ + if (sock_owned_by_user(sk)) + __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); + + if (sk->sk_state == DCCP_CLOSED) + goto out; + + dp = dccp_sk(sk); + if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) && + !between48(seq, dp->dccps_awl, dp->dccps_awh)) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + goto out; + } + + switch (type) { + case ICMP_REDIRECT: + if (!sock_owned_by_user(sk)) + dccp_do_redirect(skb, sk); + goto out; + case ICMP_SOURCE_QUENCH: + /* Just silently ignore these. */ + goto out; + case ICMP_PARAMETERPROB: + err = EPROTO; + break; + case ICMP_DEST_UNREACH: + if (code > NR_ICMP_UNREACH) + goto out; + + if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ + if (!sock_owned_by_user(sk)) + dccp_do_pmtu_discovery(sk, iph, info); + goto out; + } + + err = icmp_err_convert[code].errno; + break; + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + default: + goto out; + } + + switch (sk->sk_state) { + case DCCP_REQUESTING: + case DCCP_RESPOND: + if (!sock_owned_by_user(sk)) { + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + sk->sk_err = err; + + sk_error_report(sk); + + dccp_done(sk); + } else + sk->sk_err_soft = err; + goto out; + } + + /* If we've already connected we will keep trying + * until we time out, or the user gives up. + * + * rfc1122 4.2.3.9 allows to consider as hard errors + * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, + * but it is obsoleted by pmtu discovery). + * + * Note, that in modern internet, where routing is unreliable + * and in each dark corner broken firewalls sit, sending random + * errors ordered by their masters even this two messages finally lose + * their original sense (even Linux sends invalid PORT_UNREACHs) + * + * Now we are in compliance with RFCs. + * --ANK (980905) + */ + + inet = inet_sk(sk); + if (!sock_owned_by_user(sk) && inet->recverr) { + sk->sk_err = err; + sk_error_report(sk); + } else /* Only an error on timeout */ + sk->sk_err_soft = err; +out: + bh_unlock_sock(sk); + sock_put(sk); + return 0; +} + +static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb, + __be32 src, __be32 dst) +{ + return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum); +} + +void dccp_v4_send_check(struct sock *sk, struct sk_buff *skb) +{ + const struct inet_sock *inet = inet_sk(sk); + struct dccp_hdr *dh = dccp_hdr(skb); + + dccp_csum_outgoing(skb); + dh->dccph_checksum = dccp_v4_csum_finish(skb, + inet->inet_saddr, + inet->inet_daddr); +} +EXPORT_SYMBOL_GPL(dccp_v4_send_check); + +static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb) +{ + return secure_dccp_sequence_number(ip_hdr(skb)->daddr, + ip_hdr(skb)->saddr, + dccp_hdr(skb)->dccph_dport, + dccp_hdr(skb)->dccph_sport); +} + +/* + * The three way handshake has completed - we got a valid ACK or DATAACK - + * now create the new socket. + * + * This is the equivalent of TCP's tcp_v4_syn_recv_sock + */ +struct sock *dccp_v4_request_recv_sock(const struct sock *sk, + struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req) +{ + struct inet_request_sock *ireq; + struct inet_sock *newinet; + struct sock *newsk; + + if (sk_acceptq_is_full(sk)) + goto exit_overflow; + + newsk = dccp_create_openreq_child(sk, req, skb); + if (newsk == NULL) + goto exit_nonewsk; + + newinet = inet_sk(newsk); + ireq = inet_rsk(req); + sk_daddr_set(newsk, ireq->ir_rmt_addr); + sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); + newinet->inet_saddr = ireq->ir_loc_addr; + RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt)); + newinet->mc_index = inet_iif(skb); + newinet->mc_ttl = ip_hdr(skb)->ttl; + atomic_set(&newinet->inet_id, get_random_u16()); + + if (dst == NULL && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL) + goto put_and_exit; + + sk_setup_caps(newsk, dst); + + dccp_sync_mss(newsk, dst_mtu(dst)); + + if (__inet_inherit_port(sk, newsk) < 0) + goto put_and_exit; + *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL); + if (*own_req) + ireq->ireq_opt = NULL; + else + newinet->inet_opt = NULL; + return newsk; + +exit_overflow: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +exit_nonewsk: + dst_release(dst); +exit: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); + return NULL; +put_and_exit: + newinet->inet_opt = NULL; + inet_csk_prepare_forced_close(newsk); + dccp_done(newsk); + goto exit; +} +EXPORT_SYMBOL_GPL(dccp_v4_request_recv_sock); + +static struct dst_entry* dccp_v4_route_skb(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + struct rtable *rt; + const struct iphdr *iph = ip_hdr(skb); + struct flowi4 fl4 = { + .flowi4_oif = inet_iif(skb), + .daddr = iph->saddr, + .saddr = iph->daddr, + .flowi4_tos = RT_CONN_FLAGS(sk), + .flowi4_proto = sk->sk_protocol, + .fl4_sport = dccp_hdr(skb)->dccph_dport, + .fl4_dport = dccp_hdr(skb)->dccph_sport, + }; + + security_skb_classify_flow(skb, flowi4_to_flowi_common(&fl4)); + rt = ip_route_output_flow(net, &fl4, sk); + if (IS_ERR(rt)) { + IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); + return NULL; + } + + return &rt->dst; +} + +static int dccp_v4_send_response(const struct sock *sk, struct request_sock *req) +{ + int err = -1; + struct sk_buff *skb; + struct dst_entry *dst; + struct flowi4 fl4; + + dst = inet_csk_route_req(sk, &fl4, req); + if (dst == NULL) + goto out; + + skb = dccp_make_response(sk, dst, req); + if (skb != NULL) { + const struct inet_request_sock *ireq = inet_rsk(req); + struct dccp_hdr *dh = dccp_hdr(skb); + + dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->ir_loc_addr, + ireq->ir_rmt_addr); + rcu_read_lock(); + err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, + ireq->ir_rmt_addr, + rcu_dereference(ireq->ireq_opt), + inet_sk(sk)->tos); + rcu_read_unlock(); + err = net_xmit_eval(err); + } + +out: + dst_release(dst); + return err; +} + +static void dccp_v4_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb) +{ + int err; + const struct iphdr *rxiph; + struct sk_buff *skb; + struct dst_entry *dst; + struct net *net = dev_net(skb_dst(rxskb)->dev); + struct dccp_v4_pernet *pn; + struct sock *ctl_sk; + + /* Never send a reset in response to a reset. */ + if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) + return; + + if (skb_rtable(rxskb)->rt_type != RTN_LOCAL) + return; + + pn = net_generic(net, dccp_v4_pernet_id); + ctl_sk = pn->v4_ctl_sk; + dst = dccp_v4_route_skb(net, ctl_sk, rxskb); + if (dst == NULL) + return; + + skb = dccp_ctl_make_reset(ctl_sk, rxskb); + if (skb == NULL) + goto out; + + rxiph = ip_hdr(rxskb); + dccp_hdr(skb)->dccph_checksum = dccp_v4_csum_finish(skb, rxiph->saddr, + rxiph->daddr); + skb_dst_set(skb, dst_clone(dst)); + + local_bh_disable(); + bh_lock_sock(ctl_sk); + err = ip_build_and_send_pkt(skb, ctl_sk, + rxiph->daddr, rxiph->saddr, NULL, + inet_sk(ctl_sk)->tos); + bh_unlock_sock(ctl_sk); + + if (net_xmit_eval(err) == 0) { + __DCCP_INC_STATS(DCCP_MIB_OUTSEGS); + __DCCP_INC_STATS(DCCP_MIB_OUTRSTS); + } + local_bh_enable(); +out: + dst_release(dst); +} + +static void dccp_v4_reqsk_destructor(struct request_sock *req) +{ + dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); + kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); +} + +void dccp_syn_ack_timeout(const struct request_sock *req) +{ +} +EXPORT_SYMBOL(dccp_syn_ack_timeout); + +static struct request_sock_ops dccp_request_sock_ops __read_mostly = { + .family = PF_INET, + .obj_size = sizeof(struct dccp_request_sock), + .rtx_syn_ack = dccp_v4_send_response, + .send_ack = dccp_reqsk_send_ack, + .destructor = dccp_v4_reqsk_destructor, + .send_reset = dccp_v4_ctl_send_reset, + .syn_ack_timeout = dccp_syn_ack_timeout, +}; + +int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb) +{ + struct inet_request_sock *ireq; + struct request_sock *req; + struct dccp_request_sock *dreq; + const __be32 service = dccp_hdr_request(skb)->dccph_req_service; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + + /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */ + if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) + return 0; /* discard, don't send a reset here */ + + if (dccp_bad_service_code(sk, service)) { + dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; + goto drop; + } + /* + * TW buckets are converted to open requests without + * limitations, they conserve resources and peer is + * evidently real one. + */ + dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; + if (inet_csk_reqsk_queue_is_full(sk)) + goto drop; + + if (sk_acceptq_is_full(sk)) + goto drop; + + req = inet_reqsk_alloc(&dccp_request_sock_ops, sk, true); + if (req == NULL) + goto drop; + + if (dccp_reqsk_init(req, dccp_sk(sk), skb)) + goto drop_and_free; + + dreq = dccp_rsk(req); + if (dccp_parse_options(sk, dreq, skb)) + goto drop_and_free; + + ireq = inet_rsk(req); + sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); + sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); + ireq->ir_mark = inet_request_mark(sk, skb); + ireq->ireq_family = AF_INET; + ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if); + + if (security_inet_conn_request(sk, skb, req)) + goto drop_and_free; + + /* + * Step 3: Process LISTEN state + * + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie + * + * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). + */ + dreq->dreq_isr = dcb->dccpd_seq; + dreq->dreq_gsr = dreq->dreq_isr; + dreq->dreq_iss = dccp_v4_init_sequence(skb); + dreq->dreq_gss = dreq->dreq_iss; + dreq->dreq_service = service; + + if (dccp_v4_send_response(sk, req)) + goto drop_and_free; + + inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); + reqsk_put(req); + return 0; + +drop_and_free: + reqsk_free(req); +drop: + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + return -1; +} +EXPORT_SYMBOL_GPL(dccp_v4_conn_request); + +int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_hdr *dh = dccp_hdr(skb); + + if (sk->sk_state == DCCP_OPEN) { /* Fast path */ + if (dccp_rcv_established(sk, skb, dh, skb->len)) + goto reset; + return 0; + } + + /* + * Step 3: Process LISTEN state + * If P.type == Request or P contains a valid Init Cookie option, + * (* Must scan the packet's options to check for Init + * Cookies. Only Init Cookies are processed here, + * however; other options are processed in Step 8. This + * scan need only be performed if the endpoint uses Init + * Cookies *) + * (* Generate a new socket and switch to that socket *) + * Set S := new socket for this port pair + * S.state = RESPOND + * Choose S.ISS (initial seqno) or set from Init Cookies + * Initialize S.GAR := S.ISS + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies + * Continue with S.state == RESPOND + * (* A Response packet will be generated in Step 11 *) + * Otherwise, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + * + * NOTE: the check for the packet types is done in + * dccp_rcv_state_process + */ + + if (dccp_rcv_state_process(sk, skb, dh, skb->len)) + goto reset; + return 0; + +reset: + dccp_v4_ctl_send_reset(sk, skb); + kfree_skb(skb); + return 0; +} +EXPORT_SYMBOL_GPL(dccp_v4_do_rcv); + +/** + * dccp_invalid_packet - check for malformed packets + * @skb: Packet to validate + * + * Implements RFC 4340, 8.5: Step 1: Check header basics + * Packets that fail these checks are ignored and do not receive Resets. + */ +int dccp_invalid_packet(struct sk_buff *skb) +{ + const struct dccp_hdr *dh; + unsigned int cscov; + u8 dccph_doff; + + if (skb->pkt_type != PACKET_HOST) + return 1; + + /* If the packet is shorter than 12 bytes, drop packet and return */ + if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) { + DCCP_WARN("pskb_may_pull failed\n"); + return 1; + } + + dh = dccp_hdr(skb); + + /* If P.type is not understood, drop packet and return */ + if (dh->dccph_type >= DCCP_PKT_INVALID) { + DCCP_WARN("invalid packet type\n"); + return 1; + } + + /* + * If P.Data Offset is too small for packet type, drop packet and return + */ + dccph_doff = dh->dccph_doff; + if (dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) { + DCCP_WARN("P.Data Offset(%u) too small\n", dccph_doff); + return 1; + } + /* + * If P.Data Offset is too large for packet, drop packet and return + */ + if (!pskb_may_pull(skb, dccph_doff * sizeof(u32))) { + DCCP_WARN("P.Data Offset(%u) too large\n", dccph_doff); + return 1; + } + dh = dccp_hdr(skb); + /* + * If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet + * has short sequence numbers), drop packet and return + */ + if ((dh->dccph_type < DCCP_PKT_DATA || + dh->dccph_type > DCCP_PKT_DATAACK) && dh->dccph_x == 0) { + DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n", + dccp_packet_name(dh->dccph_type)); + return 1; + } + + /* + * If P.CsCov is too large for the packet size, drop packet and return. + * This must come _before_ checksumming (not as RFC 4340 suggests). + */ + cscov = dccp_csum_coverage(skb); + if (cscov > skb->len) { + DCCP_WARN("P.CsCov %u exceeds packet length %d\n", + dh->dccph_cscov, skb->len); + return 1; + } + + /* If header checksum is incorrect, drop packet and return. + * (This step is completed in the AF-dependent functions.) */ + skb->csum = skb_checksum(skb, 0, cscov, 0); + + return 0; +} +EXPORT_SYMBOL_GPL(dccp_invalid_packet); + +/* this is called when real data arrives */ +static int dccp_v4_rcv(struct sk_buff *skb) +{ + const struct dccp_hdr *dh; + const struct iphdr *iph; + bool refcounted; + struct sock *sk; + int min_cov; + + /* Step 1: Check header basics */ + + if (dccp_invalid_packet(skb)) + goto discard_it; + + iph = ip_hdr(skb); + /* Step 1: If header checksum is incorrect, drop packet and return */ + if (dccp_v4_csum_finish(skb, iph->saddr, iph->daddr)) { + DCCP_WARN("dropped packet with invalid checksum\n"); + goto discard_it; + } + + dh = dccp_hdr(skb); + + DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); + DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; + + dccp_pr_debug("%8.8s src=%pI4@%-5d dst=%pI4@%-5d seq=%llu", + dccp_packet_name(dh->dccph_type), + &iph->saddr, ntohs(dh->dccph_sport), + &iph->daddr, ntohs(dh->dccph_dport), + (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); + + if (dccp_packet_without_ack(skb)) { + DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; + dccp_pr_debug_cat("\n"); + } else { + DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); + dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long) + DCCP_SKB_CB(skb)->dccpd_ack_seq); + } + +lookup: + sk = __inet_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), + dh->dccph_sport, dh->dccph_dport, 0, &refcounted); + if (!sk) { + dccp_pr_debug("failed to look up flow ID in table and " + "get corresponding socket\n"); + goto no_dccp_socket; + } + + /* + * Step 2: + * ... or S.state == TIMEWAIT, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (sk->sk_state == DCCP_TIME_WAIT) { + dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); + inet_twsk_put(inet_twsk(sk)); + goto no_dccp_socket; + } + + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + struct request_sock *req = inet_reqsk(sk); + struct sock *nsk; + + sk = req->rsk_listener; + if (unlikely(sk->sk_state != DCCP_LISTEN)) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + sock_hold(sk); + refcounted = true; + nsk = dccp_check_req(sk, skb, req); + if (!nsk) { + reqsk_put(req); + goto discard_and_relse; + } + if (nsk == sk) { + reqsk_put(req); + } else if (dccp_child_process(sk, nsk, skb)) { + dccp_v4_ctl_send_reset(sk, skb); + goto discard_and_relse; + } else { + sock_put(sk); + return 0; + } + } + /* + * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage + * o if MinCsCov = 0, only packets with CsCov = 0 are accepted + * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov + */ + min_cov = dccp_sk(sk)->dccps_pcrlen; + if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { + dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", + dh->dccph_cscov, min_cov); + /* FIXME: "Such packets SHOULD be reported using Data Dropped + * options (Section 11.7) with Drop Code 0, Protocol + * Constraints." */ + goto discard_and_relse; + } + + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_and_relse; + nf_reset_ct(skb); + + return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4, refcounted); + +no_dccp_socket: + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto discard_it; + /* + * Step 2: + * If no socket ... + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (dh->dccph_type != DCCP_PKT_RESET) { + DCCP_SKB_CB(skb)->dccpd_reset_code = + DCCP_RESET_CODE_NO_CONNECTION; + dccp_v4_ctl_send_reset(sk, skb); + } + +discard_it: + kfree_skb(skb); + return 0; + +discard_and_relse: + if (refcounted) + sock_put(sk); + goto discard_it; +} + +static const struct inet_connection_sock_af_ops dccp_ipv4_af_ops = { + .queue_xmit = ip_queue_xmit, + .send_check = dccp_v4_send_check, + .rebuild_header = inet_sk_rebuild_header, + .conn_request = dccp_v4_conn_request, + .syn_recv_sock = dccp_v4_request_recv_sock, + .net_header_len = sizeof(struct iphdr), + .setsockopt = ip_setsockopt, + .getsockopt = ip_getsockopt, + .addr2sockaddr = inet_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in), +}; + +static int dccp_v4_init_sock(struct sock *sk) +{ + static __u8 dccp_v4_ctl_sock_initialized; + int err = dccp_init_sock(sk, dccp_v4_ctl_sock_initialized); + + if (err == 0) { + if (unlikely(!dccp_v4_ctl_sock_initialized)) + dccp_v4_ctl_sock_initialized = 1; + inet_csk(sk)->icsk_af_ops = &dccp_ipv4_af_ops; + } + + return err; +} + +static struct timewait_sock_ops dccp_timewait_sock_ops = { + .twsk_obj_size = sizeof(struct inet_timewait_sock), +}; + +static struct proto dccp_v4_prot = { + .name = "DCCP", + .owner = THIS_MODULE, + .close = dccp_close, + .connect = dccp_v4_connect, + .disconnect = dccp_disconnect, + .ioctl = dccp_ioctl, + .init = dccp_v4_init_sock, + .setsockopt = dccp_setsockopt, + .getsockopt = dccp_getsockopt, + .sendmsg = dccp_sendmsg, + .recvmsg = dccp_recvmsg, + .backlog_rcv = dccp_v4_do_rcv, + .hash = inet_hash, + .unhash = inet_unhash, + .accept = inet_csk_accept, + .get_port = inet_csk_get_port, + .shutdown = dccp_shutdown, + .destroy = dccp_destroy_sock, + .orphan_count = &dccp_orphan_count, + .max_header = MAX_DCCP_HEADER, + .obj_size = sizeof(struct dccp_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, + .rsk_prot = &dccp_request_sock_ops, + .twsk_prot = &dccp_timewait_sock_ops, + .h.hashinfo = &dccp_hashinfo, +}; + +static const struct net_protocol dccp_v4_protocol = { + .handler = dccp_v4_rcv, + .err_handler = dccp_v4_err, + .no_policy = 1, + .icmp_strict_tag_validation = 1, +}; + +static const struct proto_ops inet_dccp_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_stream_connect, + .socketpair = sock_no_socketpair, + .accept = inet_accept, + .getname = inet_getname, + /* FIXME: work on tcp_poll to rename it to inet_csk_poll */ + .poll = dccp_poll, + .ioctl = inet_ioctl, + .gettstamp = sock_gettstamp, + /* FIXME: work on inet_listen to rename it to sock_common_listen */ + .listen = inet_dccp_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +}; + +static struct inet_protosw dccp_v4_protosw = { + .type = SOCK_DCCP, + .protocol = IPPROTO_DCCP, + .prot = &dccp_v4_prot, + .ops = &inet_dccp_ops, + .flags = INET_PROTOSW_ICSK, +}; + +static int __net_init dccp_v4_init_net(struct net *net) +{ + struct dccp_v4_pernet *pn = net_generic(net, dccp_v4_pernet_id); + + if (dccp_hashinfo.bhash == NULL) + return -ESOCKTNOSUPPORT; + + return inet_ctl_sock_create(&pn->v4_ctl_sk, PF_INET, + SOCK_DCCP, IPPROTO_DCCP, net); +} + +static void __net_exit dccp_v4_exit_net(struct net *net) +{ + struct dccp_v4_pernet *pn = net_generic(net, dccp_v4_pernet_id); + + inet_ctl_sock_destroy(pn->v4_ctl_sk); +} + +static void __net_exit dccp_v4_exit_batch(struct list_head *net_exit_list) +{ + inet_twsk_purge(&dccp_hashinfo, AF_INET); +} + +static struct pernet_operations dccp_v4_ops = { + .init = dccp_v4_init_net, + .exit = dccp_v4_exit_net, + .exit_batch = dccp_v4_exit_batch, + .id = &dccp_v4_pernet_id, + .size = sizeof(struct dccp_v4_pernet), +}; + +static int __init dccp_v4_init(void) +{ + int err = proto_register(&dccp_v4_prot, 1); + + if (err) + goto out; + + inet_register_protosw(&dccp_v4_protosw); + + err = register_pernet_subsys(&dccp_v4_ops); + if (err) + goto out_destroy_ctl_sock; + + err = inet_add_protocol(&dccp_v4_protocol, IPPROTO_DCCP); + if (err) + goto out_proto_unregister; + +out: + return err; +out_proto_unregister: + unregister_pernet_subsys(&dccp_v4_ops); +out_destroy_ctl_sock: + inet_unregister_protosw(&dccp_v4_protosw); + proto_unregister(&dccp_v4_prot); + goto out; +} + +static void __exit dccp_v4_exit(void) +{ + inet_del_protocol(&dccp_v4_protocol, IPPROTO_DCCP); + unregister_pernet_subsys(&dccp_v4_ops); + inet_unregister_protosw(&dccp_v4_protosw); + proto_unregister(&dccp_v4_prot); +} + +module_init(dccp_v4_init); +module_exit(dccp_v4_exit); + +/* + * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) + * values directly, Also cover the case where the protocol is not specified, + * i.e. net-pf-PF_INET-proto-0-type-SOCK_DCCP + */ +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 33, 6); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 0, 6); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arnaldo Carvalho de Melo "); +MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c new file mode 100644 index 000000000..e0b0bf75a --- /dev/null +++ b/net/dccp/ipv6.c @@ -0,0 +1,1181 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * DCCP over IPv6 + * Linux INET6 implementation + * + * Based on net/dccp6/ipv6.c + * + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "dccp.h" +#include "ipv6.h" +#include "feat.h" + +struct dccp_v6_pernet { + struct sock *v6_ctl_sk; +}; + +static unsigned int dccp_v6_pernet_id __read_mostly; + +/* The per-net v6_ctl_sk is used for sending RSTs and ACKs */ + +static const struct inet_connection_sock_af_ops dccp_ipv6_mapped; +static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops; + +/* add pseudo-header to DCCP checksum stored in skb->csum */ +static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb, + const struct in6_addr *saddr, + const struct in6_addr *daddr) +{ + return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum); +} + +static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct dccp_hdr *dh = dccp_hdr(skb); + + dccp_csum_outgoing(skb); + dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr); +} + +static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb) +{ + return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32, + ipv6_hdr(skb)->saddr.s6_addr32, + dccp_hdr(skb)->dccph_dport, + dccp_hdr(skb)->dccph_sport ); + +} + +static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + const struct ipv6hdr *hdr; + const struct dccp_hdr *dh; + struct dccp_sock *dp; + struct ipv6_pinfo *np; + struct sock *sk; + int err; + __u64 seq; + struct net *net = dev_net(skb->dev); + + if (!pskb_may_pull(skb, offset + sizeof(*dh))) + return -EINVAL; + dh = (struct dccp_hdr *)(skb->data + offset); + if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh))) + return -EINVAL; + hdr = (const struct ipv6hdr *)skb->data; + dh = (struct dccp_hdr *)(skb->data + offset); + + sk = __inet6_lookup_established(net, &dccp_hashinfo, + &hdr->daddr, dh->dccph_dport, + &hdr->saddr, ntohs(dh->dccph_sport), + inet6_iif(skb), 0); + + if (!sk) { + __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), + ICMP6_MIB_INERRORS); + return -ENOENT; + } + + if (sk->sk_state == DCCP_TIME_WAIT) { + inet_twsk_put(inet_twsk(sk)); + return 0; + } + seq = dccp_hdr_seq(dh); + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + dccp_req_err(sk, seq); + return 0; + } + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) + __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); + + if (sk->sk_state == DCCP_CLOSED) + goto out; + + dp = dccp_sk(sk); + if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) && + !between48(seq, dp->dccps_awl, dp->dccps_awh)) { + __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); + goto out; + } + + np = inet6_sk(sk); + + if (type == NDISC_REDIRECT) { + if (!sock_owned_by_user(sk)) { + struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); + + if (dst) + dst->ops->redirect(dst, sk, skb); + } + goto out; + } + + if (type == ICMPV6_PKT_TOOBIG) { + struct dst_entry *dst = NULL; + + if (!ip6_sk_accept_pmtu(sk)) + goto out; + + if (sock_owned_by_user(sk)) + goto out; + if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) + goto out; + + dst = inet6_csk_update_pmtu(sk, ntohl(info)); + if (!dst) + goto out; + + if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) + dccp_sync_mss(sk, dst_mtu(dst)); + goto out; + } + + icmpv6_err_convert(type, code, &err); + + /* Might be for an request_sock */ + switch (sk->sk_state) { + case DCCP_REQUESTING: + case DCCP_RESPOND: /* Cannot happen. + It can, it SYNs are crossed. --ANK */ + if (!sock_owned_by_user(sk)) { + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + sk->sk_err = err; + /* + * Wake people up to see the error + * (see connect in sock.c) + */ + sk_error_report(sk); + dccp_done(sk); + } else + sk->sk_err_soft = err; + goto out; + } + + if (!sock_owned_by_user(sk) && np->recverr) { + sk->sk_err = err; + sk_error_report(sk); + } else + sk->sk_err_soft = err; + +out: + bh_unlock_sock(sk); + sock_put(sk); + return 0; +} + + +static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct ipv6_pinfo *np = inet6_sk(sk); + struct sk_buff *skb; + struct in6_addr *final_p, final; + struct flowi6 fl6; + int err = -1; + struct dst_entry *dst; + + memset(&fl6, 0, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.daddr = ireq->ir_v6_rmt_addr; + fl6.saddr = ireq->ir_v6_loc_addr; + fl6.flowlabel = 0; + fl6.flowi6_oif = ireq->ir_iif; + fl6.fl6_dport = ireq->ir_rmt_port; + fl6.fl6_sport = htons(ireq->ir_num); + security_req_classify_flow(req, flowi6_to_flowi_common(&fl6)); + + + rcu_read_lock(); + final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final); + rcu_read_unlock(); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + dst = NULL; + goto done; + } + + skb = dccp_make_response(sk, dst, req); + if (skb != NULL) { + struct dccp_hdr *dh = dccp_hdr(skb); + struct ipv6_txoptions *opt; + + dh->dccph_checksum = dccp_v6_csum_finish(skb, + &ireq->ir_v6_loc_addr, + &ireq->ir_v6_rmt_addr); + fl6.daddr = ireq->ir_v6_rmt_addr; + rcu_read_lock(); + opt = ireq->ipv6_opt; + if (!opt) + opt = rcu_dereference(np->opt); + err = ip6_xmit(sk, skb, &fl6, READ_ONCE(sk->sk_mark), opt, + np->tclass, sk->sk_priority); + rcu_read_unlock(); + err = net_xmit_eval(err); + } + +done: + dst_release(dst); + return err; +} + +static void dccp_v6_reqsk_destructor(struct request_sock *req) +{ + dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); + kfree(inet_rsk(req)->ipv6_opt); + kfree_skb(inet_rsk(req)->pktopts); +} + +static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb) +{ + const struct ipv6hdr *rxip6h; + struct sk_buff *skb; + struct flowi6 fl6; + struct net *net = dev_net(skb_dst(rxskb)->dev); + struct dccp_v6_pernet *pn; + struct sock *ctl_sk; + struct dst_entry *dst; + + if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) + return; + + if (!ipv6_unicast_destination(rxskb)) + return; + + pn = net_generic(net, dccp_v6_pernet_id); + ctl_sk = pn->v6_ctl_sk; + skb = dccp_ctl_make_reset(ctl_sk, rxskb); + if (skb == NULL) + return; + + rxip6h = ipv6_hdr(rxskb); + dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, + &rxip6h->daddr); + + memset(&fl6, 0, sizeof(fl6)); + fl6.daddr = rxip6h->saddr; + fl6.saddr = rxip6h->daddr; + + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.flowi6_oif = inet6_iif(rxskb); + fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; + fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; + security_skb_classify_flow(rxskb, flowi6_to_flowi_common(&fl6)); + + /* sk = NULL, but it is safe for now. RST socket required. */ + dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL); + if (!IS_ERR(dst)) { + skb_dst_set(skb, dst); + ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0); + DCCP_INC_STATS(DCCP_MIB_OUTSEGS); + DCCP_INC_STATS(DCCP_MIB_OUTRSTS); + return; + } + + kfree_skb(skb); +} + +static struct request_sock_ops dccp6_request_sock_ops = { + .family = AF_INET6, + .obj_size = sizeof(struct dccp6_request_sock), + .rtx_syn_ack = dccp_v6_send_response, + .send_ack = dccp_reqsk_send_ack, + .destructor = dccp_v6_reqsk_destructor, + .send_reset = dccp_v6_ctl_send_reset, + .syn_ack_timeout = dccp_syn_ack_timeout, +}; + +static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) +{ + struct request_sock *req; + struct dccp_request_sock *dreq; + struct inet_request_sock *ireq; + struct ipv6_pinfo *np = inet6_sk(sk); + const __be32 service = dccp_hdr_request(skb)->dccph_req_service; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + + if (skb->protocol == htons(ETH_P_IP)) + return dccp_v4_conn_request(sk, skb); + + if (!ipv6_unicast_destination(skb)) + return 0; /* discard, don't send a reset here */ + + if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { + __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); + return 0; + } + + if (dccp_bad_service_code(sk, service)) { + dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; + goto drop; + } + /* + * There are no SYN attacks on IPv6, yet... + */ + dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; + if (inet_csk_reqsk_queue_is_full(sk)) + goto drop; + + if (sk_acceptq_is_full(sk)) + goto drop; + + req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true); + if (req == NULL) + goto drop; + + if (dccp_reqsk_init(req, dccp_sk(sk), skb)) + goto drop_and_free; + + dreq = dccp_rsk(req); + if (dccp_parse_options(sk, dreq, skb)) + goto drop_and_free; + + ireq = inet_rsk(req); + ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; + ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; + ireq->ireq_family = AF_INET6; + ireq->ir_mark = inet_request_mark(sk, skb); + + if (security_inet_conn_request(sk, skb, req)) + goto drop_and_free; + + if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) || + np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || + np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { + refcount_inc(&skb->users); + ireq->pktopts = skb; + } + ireq->ir_iif = READ_ONCE(sk->sk_bound_dev_if); + + /* So that link locals have meaning */ + if (!ireq->ir_iif && + ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) + ireq->ir_iif = inet6_iif(skb); + + /* + * Step 3: Process LISTEN state + * + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie + * + * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). + */ + dreq->dreq_isr = dcb->dccpd_seq; + dreq->dreq_gsr = dreq->dreq_isr; + dreq->dreq_iss = dccp_v6_init_sequence(skb); + dreq->dreq_gss = dreq->dreq_iss; + dreq->dreq_service = service; + + if (dccp_v6_send_response(sk, req)) + goto drop_and_free; + + inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); + reqsk_put(req); + return 0; + +drop_and_free: + reqsk_free(req); +drop: + __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); + return -1; +} + +static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, + struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req) +{ + struct inet_request_sock *ireq = inet_rsk(req); + struct ipv6_pinfo *newnp; + const struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + struct inet_sock *newinet; + struct dccp6_sock *newdp6; + struct sock *newsk; + + if (skb->protocol == htons(ETH_P_IP)) { + /* + * v6 mapped + */ + newsk = dccp_v4_request_recv_sock(sk, skb, req, dst, + req_unhash, own_req); + if (newsk == NULL) + return NULL; + + newdp6 = (struct dccp6_sock *)newsk; + newinet = inet_sk(newsk); + newinet->pinet6 = &newdp6->inet6; + newnp = inet6_sk(newsk); + + memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + + newnp->saddr = newsk->sk_v6_rcv_saddr; + + inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; + newsk->sk_backlog_rcv = dccp_v4_do_rcv; + newnp->pktoptions = NULL; + newnp->opt = NULL; + newnp->ipv6_mc_list = NULL; + newnp->ipv6_ac_list = NULL; + newnp->ipv6_fl_list = NULL; + newnp->mcast_oif = inet_iif(skb); + newnp->mcast_hops = ip_hdr(skb)->ttl; + + /* + * No need to charge this sock to the relevant IPv6 refcnt debug socks count + * here, dccp_create_openreq_child now does this for us, see the comment in + * that function for the gory details. -acme + */ + + /* It is tricky place. Until this moment IPv4 tcp + worked with IPv6 icsk.icsk_af_ops. + Sync it now. + */ + dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); + + return newsk; + } + + + if (sk_acceptq_is_full(sk)) + goto out_overflow; + + if (!dst) { + struct flowi6 fl6; + + dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP); + if (!dst) + goto out; + } + + newsk = dccp_create_openreq_child(sk, req, skb); + if (newsk == NULL) + goto out_nonewsk; + + /* + * No need to charge this sock to the relevant IPv6 refcnt debug socks + * count here, dccp_create_openreq_child now does this for us, see the + * comment in that function for the gory details. -acme + */ + + ip6_dst_store(newsk, dst, NULL, NULL); + newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | + NETIF_F_TSO); + newdp6 = (struct dccp6_sock *)newsk; + newinet = inet_sk(newsk); + newinet->pinet6 = &newdp6->inet6; + newnp = inet6_sk(newsk); + + memcpy(newnp, np, sizeof(struct ipv6_pinfo)); + + newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; + newnp->saddr = ireq->ir_v6_loc_addr; + newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; + newsk->sk_bound_dev_if = ireq->ir_iif; + + /* Now IPv6 options... + + First: no IPv4 options. + */ + newinet->inet_opt = NULL; + + /* Clone RX bits */ + newnp->rxopt.all = np->rxopt.all; + + newnp->ipv6_mc_list = NULL; + newnp->ipv6_ac_list = NULL; + newnp->ipv6_fl_list = NULL; + newnp->pktoptions = NULL; + newnp->opt = NULL; + newnp->mcast_oif = inet6_iif(skb); + newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; + + /* + * Clone native IPv6 options from listening socket (if any) + * + * Yes, keeping reference count would be much more clever, but we make + * one more one thing there: reattach optmem to newsk. + */ + opt = ireq->ipv6_opt; + if (!opt) + opt = rcu_dereference(np->opt); + if (opt) { + opt = ipv6_dup_options(newsk, opt); + RCU_INIT_POINTER(newnp->opt, opt); + } + inet_csk(newsk)->icsk_ext_hdr_len = 0; + if (opt) + inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + + opt->opt_flen; + + dccp_sync_mss(newsk, dst_mtu(dst)); + + newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; + newinet->inet_rcv_saddr = LOOPBACK4_IPV6; + + if (__inet_inherit_port(sk, newsk) < 0) { + inet_csk_prepare_forced_close(newsk); + dccp_done(newsk); + goto out; + } + *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), NULL); + /* Clone pktoptions received with SYN, if we own the req */ + if (*own_req && ireq->pktopts) { + newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk); + consume_skb(ireq->pktopts); + ireq->pktopts = NULL; + } + + return newsk; + +out_overflow: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); +out_nonewsk: + dst_release(dst); +out: + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); + return NULL; +} + +/* The socket must have it's spinlock held when we get + * here. + * + * We have a potential double-lock case here, so even when + * doing backlog processing we use the BH locking scheme. + * This is because we cannot sleep with the original spinlock + * held. + */ +static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct sk_buff *opt_skb = NULL; + + /* Imagine: socket is IPv6. IPv4 packet arrives, + goes to IPv4 receive handler and backlogged. + From backlog it always goes here. Kerboom... + Fortunately, dccp_rcv_established and rcv_established + handle them correctly, but it is not case with + dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK + */ + + if (skb->protocol == htons(ETH_P_IP)) + return dccp_v4_do_rcv(sk, skb); + + if (sk_filter(sk, skb)) + goto discard; + + /* + * socket locking is here for SMP purposes as backlog rcv is currently + * called with bh processing disabled. + */ + + /* Do Stevens' IPV6_PKTOPTIONS. + + Yes, guys, it is the only place in our code, where we + may make it not affecting IPv4. + The rest of code is protocol independent, + and I do not like idea to uglify IPv4. + + Actually, all the idea behind IPV6_PKTOPTIONS + looks not very well thought. For now we latch + options, received in the last packet, enqueued + by tcp. Feel free to propose better solution. + --ANK (980728) + */ + if (np->rxopt.all) + opt_skb = skb_clone_and_charge_r(skb, sk); + + if (sk->sk_state == DCCP_OPEN) { /* Fast path */ + if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) + goto reset; + if (opt_skb) + goto ipv6_pktoptions; + return 0; + } + + /* + * Step 3: Process LISTEN state + * If S.state == LISTEN, + * If P.type == Request or P contains a valid Init Cookie option, + * (* Must scan the packet's options to check for Init + * Cookies. Only Init Cookies are processed here, + * however; other options are processed in Step 8. This + * scan need only be performed if the endpoint uses Init + * Cookies *) + * (* Generate a new socket and switch to that socket *) + * Set S := new socket for this port pair + * S.state = RESPOND + * Choose S.ISS (initial seqno) or set from Init Cookies + * Initialize S.GAR := S.ISS + * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies + * Continue with S.state == RESPOND + * (* A Response packet will be generated in Step 11 *) + * Otherwise, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + * + * NOTE: the check for the packet types is done in + * dccp_rcv_state_process + */ + + if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) + goto reset; + if (opt_skb) + goto ipv6_pktoptions; + return 0; + +reset: + dccp_v6_ctl_send_reset(sk, skb); +discard: + if (opt_skb != NULL) + __kfree_skb(opt_skb); + kfree_skb(skb); + return 0; + +/* Handling IPV6_PKTOPTIONS skb the similar + * way it's done for net/ipv6/tcp_ipv6.c + */ +ipv6_pktoptions: + if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) { + if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) + np->mcast_oif = inet6_iif(opt_skb); + if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) + np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; + if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) + np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); + if (np->repflow) + np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); + if (ipv6_opt_accepted(sk, opt_skb, + &DCCP_SKB_CB(opt_skb)->header.h6)) { + memmove(IP6CB(opt_skb), + &DCCP_SKB_CB(opt_skb)->header.h6, + sizeof(struct inet6_skb_parm)); + opt_skb = xchg(&np->pktoptions, opt_skb); + } else { + __kfree_skb(opt_skb); + opt_skb = xchg(&np->pktoptions, NULL); + } + } + + kfree_skb(opt_skb); + return 0; +} + +static int dccp_v6_rcv(struct sk_buff *skb) +{ + const struct dccp_hdr *dh; + bool refcounted; + struct sock *sk; + int min_cov; + + /* Step 1: Check header basics */ + + if (dccp_invalid_packet(skb)) + goto discard_it; + + /* Step 1: If header checksum is incorrect, drop packet and return. */ + if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, + &ipv6_hdr(skb)->daddr)) { + DCCP_WARN("dropped packet with invalid checksum\n"); + goto discard_it; + } + + dh = dccp_hdr(skb); + + DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); + DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; + + if (dccp_packet_without_ack(skb)) + DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; + else + DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); + +lookup: + sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), + dh->dccph_sport, dh->dccph_dport, + inet6_iif(skb), 0, &refcounted); + if (!sk) { + dccp_pr_debug("failed to look up flow ID in table and " + "get corresponding socket\n"); + goto no_dccp_socket; + } + + /* + * Step 2: + * ... or S.state == TIMEWAIT, + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (sk->sk_state == DCCP_TIME_WAIT) { + dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); + inet_twsk_put(inet_twsk(sk)); + goto no_dccp_socket; + } + + if (sk->sk_state == DCCP_NEW_SYN_RECV) { + struct request_sock *req = inet_reqsk(sk); + struct sock *nsk; + + sk = req->rsk_listener; + if (unlikely(sk->sk_state != DCCP_LISTEN)) { + inet_csk_reqsk_queue_drop_and_put(sk, req); + goto lookup; + } + sock_hold(sk); + refcounted = true; + nsk = dccp_check_req(sk, skb, req); + if (!nsk) { + reqsk_put(req); + goto discard_and_relse; + } + if (nsk == sk) { + reqsk_put(req); + } else if (dccp_child_process(sk, nsk, skb)) { + dccp_v6_ctl_send_reset(sk, skb); + goto discard_and_relse; + } else { + sock_put(sk); + return 0; + } + } + /* + * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage + * o if MinCsCov = 0, only packets with CsCov = 0 are accepted + * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov + */ + min_cov = dccp_sk(sk)->dccps_pcrlen; + if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { + dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", + dh->dccph_cscov, min_cov); + /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ + goto discard_and_relse; + } + + if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_and_relse; + nf_reset_ct(skb); + + return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4, + refcounted) ? -1 : 0; + +no_dccp_socket: + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto discard_it; + /* + * Step 2: + * If no socket ... + * Generate Reset(No Connection) unless P.type == Reset + * Drop packet and return + */ + if (dh->dccph_type != DCCP_PKT_RESET) { + DCCP_SKB_CB(skb)->dccpd_reset_code = + DCCP_RESET_CODE_NO_CONNECTION; + dccp_v6_ctl_send_reset(sk, skb); + } + +discard_it: + kfree_skb(skb); + return 0; + +discard_and_relse: + if (refcounted) + sock_put(sk); + goto discard_it; +} + +static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) +{ + struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; + struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet = inet_sk(sk); + struct ipv6_pinfo *np = inet6_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + struct in6_addr *saddr = NULL, *final_p, final; + struct ipv6_txoptions *opt; + struct flowi6 fl6; + struct dst_entry *dst; + int addr_type; + int err; + + dp->dccps_role = DCCP_ROLE_CLIENT; + + if (addr_len < SIN6_LEN_RFC2133) + return -EINVAL; + + if (usin->sin6_family != AF_INET6) + return -EAFNOSUPPORT; + + memset(&fl6, 0, sizeof(fl6)); + + if (np->sndflow) { + fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; + IP6_ECN_flow_init(fl6.flowlabel); + if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { + struct ip6_flowlabel *flowlabel; + flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); + if (IS_ERR(flowlabel)) + return -EINVAL; + fl6_sock_release(flowlabel); + } + } + /* + * connect() to INADDR_ANY means loopback (BSD'ism). + */ + if (ipv6_addr_any(&usin->sin6_addr)) + usin->sin6_addr.s6_addr[15] = 1; + + addr_type = ipv6_addr_type(&usin->sin6_addr); + + if (addr_type & IPV6_ADDR_MULTICAST) + return -ENETUNREACH; + + if (addr_type & IPV6_ADDR_LINKLOCAL) { + if (addr_len >= sizeof(struct sockaddr_in6) && + usin->sin6_scope_id) { + /* If interface is set while binding, indices + * must coincide. + */ + if (sk->sk_bound_dev_if && + sk->sk_bound_dev_if != usin->sin6_scope_id) + return -EINVAL; + + sk->sk_bound_dev_if = usin->sin6_scope_id; + } + + /* Connect to link-local address requires an interface */ + if (!sk->sk_bound_dev_if) + return -EINVAL; + } + + sk->sk_v6_daddr = usin->sin6_addr; + np->flow_label = fl6.flowlabel; + + /* + * DCCP over IPv4 + */ + if (addr_type == IPV6_ADDR_MAPPED) { + u32 exthdrlen = icsk->icsk_ext_hdr_len; + struct sockaddr_in sin; + + SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); + + if (ipv6_only_sock(sk)) + return -ENETUNREACH; + + sin.sin_family = AF_INET; + sin.sin_port = usin->sin6_port; + sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; + + icsk->icsk_af_ops = &dccp_ipv6_mapped; + sk->sk_backlog_rcv = dccp_v4_do_rcv; + + err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); + if (err) { + icsk->icsk_ext_hdr_len = exthdrlen; + icsk->icsk_af_ops = &dccp_ipv6_af_ops; + sk->sk_backlog_rcv = dccp_v6_do_rcv; + goto failure; + } + np->saddr = sk->sk_v6_rcv_saddr; + return err; + } + + if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) + saddr = &sk->sk_v6_rcv_saddr; + + fl6.flowi6_proto = IPPROTO_DCCP; + fl6.daddr = sk->sk_v6_daddr; + fl6.saddr = saddr ? *saddr : np->saddr; + fl6.flowi6_oif = sk->sk_bound_dev_if; + fl6.fl6_dport = usin->sin6_port; + fl6.fl6_sport = inet->inet_sport; + security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); + + opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); + final_p = fl6_update_dst(&fl6, opt, &final); + + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); + if (IS_ERR(dst)) { + err = PTR_ERR(dst); + goto failure; + } + + if (saddr == NULL) { + saddr = &fl6.saddr; + + err = inet_bhash2_update_saddr(sk, saddr, AF_INET6); + if (err) + goto failure; + } + + /* set the source address */ + np->saddr = *saddr; + inet->inet_rcv_saddr = LOOPBACK4_IPV6; + + ip6_dst_store(sk, dst, NULL, NULL); + + icsk->icsk_ext_hdr_len = 0; + if (opt) + icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen; + + inet->inet_dport = usin->sin6_port; + + dccp_set_state(sk, DCCP_REQUESTING); + err = inet6_hash_connect(&dccp_death_row, sk); + if (err) + goto late_failure; + + dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, + sk->sk_v6_daddr.s6_addr32, + inet->inet_sport, + inet->inet_dport); + err = dccp_connect(sk); + if (err) + goto late_failure; + + return 0; + +late_failure: + dccp_set_state(sk, DCCP_CLOSED); + inet_bhash2_reset_saddr(sk); + __sk_dst_reset(sk); +failure: + inet->inet_dport = 0; + sk->sk_route_caps = 0; + return err; +} + +static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { + .queue_xmit = inet6_csk_xmit, + .send_check = dccp_v6_send_check, + .rebuild_header = inet6_sk_rebuild_header, + .conn_request = dccp_v6_conn_request, + .syn_recv_sock = dccp_v6_request_recv_sock, + .net_header_len = sizeof(struct ipv6hdr), + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .addr2sockaddr = inet6_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in6), +}; + +/* + * DCCP over IPv4 via INET6 API + */ +static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { + .queue_xmit = ip_queue_xmit, + .send_check = dccp_v4_send_check, + .rebuild_header = inet_sk_rebuild_header, + .conn_request = dccp_v6_conn_request, + .syn_recv_sock = dccp_v6_request_recv_sock, + .net_header_len = sizeof(struct iphdr), + .setsockopt = ipv6_setsockopt, + .getsockopt = ipv6_getsockopt, + .addr2sockaddr = inet6_csk_addr2sockaddr, + .sockaddr_len = sizeof(struct sockaddr_in6), +}; + +static void dccp_v6_sk_destruct(struct sock *sk) +{ + dccp_destruct_common(sk); + inet6_sock_destruct(sk); +} + +/* NOTE: A lot of things set to zero explicitly by call to + * sk_alloc() so need not be done here. + */ +static int dccp_v6_init_sock(struct sock *sk) +{ + static __u8 dccp_v6_ctl_sock_initialized; + int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); + + if (err == 0) { + if (unlikely(!dccp_v6_ctl_sock_initialized)) + dccp_v6_ctl_sock_initialized = 1; + inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; + sk->sk_destruct = dccp_v6_sk_destruct; + } + + return err; +} + +static struct timewait_sock_ops dccp6_timewait_sock_ops = { + .twsk_obj_size = sizeof(struct dccp6_timewait_sock), +}; + +static struct proto dccp_v6_prot = { + .name = "DCCPv6", + .owner = THIS_MODULE, + .close = dccp_close, + .connect = dccp_v6_connect, + .disconnect = dccp_disconnect, + .ioctl = dccp_ioctl, + .init = dccp_v6_init_sock, + .setsockopt = dccp_setsockopt, + .getsockopt = dccp_getsockopt, + .sendmsg = dccp_sendmsg, + .recvmsg = dccp_recvmsg, + .backlog_rcv = dccp_v6_do_rcv, + .hash = inet6_hash, + .unhash = inet_unhash, + .accept = inet_csk_accept, + .get_port = inet_csk_get_port, + .shutdown = dccp_shutdown, + .destroy = dccp_destroy_sock, + .orphan_count = &dccp_orphan_count, + .max_header = MAX_DCCP_HEADER, + .obj_size = sizeof(struct dccp6_sock), + .slab_flags = SLAB_TYPESAFE_BY_RCU, + .rsk_prot = &dccp6_request_sock_ops, + .twsk_prot = &dccp6_timewait_sock_ops, + .h.hashinfo = &dccp_hashinfo, +}; + +static const struct inet6_protocol dccp_v6_protocol = { + .handler = dccp_v6_rcv, + .err_handler = dccp_v6_err, + .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, +}; + +static const struct proto_ops inet6_dccp_ops = { + .family = PF_INET6, + .owner = THIS_MODULE, + .release = inet6_release, + .bind = inet6_bind, + .connect = inet_stream_connect, + .socketpair = sock_no_socketpair, + .accept = inet_accept, + .getname = inet6_getname, + .poll = dccp_poll, + .ioctl = inet6_ioctl, + .gettstamp = sock_gettstamp, + .listen = inet_dccp_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +#ifdef CONFIG_COMPAT + .compat_ioctl = inet6_compat_ioctl, +#endif +}; + +static struct inet_protosw dccp_v6_protosw = { + .type = SOCK_DCCP, + .protocol = IPPROTO_DCCP, + .prot = &dccp_v6_prot, + .ops = &inet6_dccp_ops, + .flags = INET_PROTOSW_ICSK, +}; + +static int __net_init dccp_v6_init_net(struct net *net) +{ + struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id); + + if (dccp_hashinfo.bhash == NULL) + return -ESOCKTNOSUPPORT; + + return inet_ctl_sock_create(&pn->v6_ctl_sk, PF_INET6, + SOCK_DCCP, IPPROTO_DCCP, net); +} + +static void __net_exit dccp_v6_exit_net(struct net *net) +{ + struct dccp_v6_pernet *pn = net_generic(net, dccp_v6_pernet_id); + + inet_ctl_sock_destroy(pn->v6_ctl_sk); +} + +static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list) +{ + inet_twsk_purge(&dccp_hashinfo, AF_INET6); +} + +static struct pernet_operations dccp_v6_ops = { + .init = dccp_v6_init_net, + .exit = dccp_v6_exit_net, + .exit_batch = dccp_v6_exit_batch, + .id = &dccp_v6_pernet_id, + .size = sizeof(struct dccp_v6_pernet), +}; + +static int __init dccp_v6_init(void) +{ + int err = proto_register(&dccp_v6_prot, 1); + + if (err) + goto out; + + inet6_register_protosw(&dccp_v6_protosw); + + err = register_pernet_subsys(&dccp_v6_ops); + if (err) + goto out_destroy_ctl_sock; + + err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); + if (err) + goto out_unregister_proto; + +out: + return err; +out_unregister_proto: + unregister_pernet_subsys(&dccp_v6_ops); +out_destroy_ctl_sock: + inet6_unregister_protosw(&dccp_v6_protosw); + proto_unregister(&dccp_v6_prot); + goto out; +} + +static void __exit dccp_v6_exit(void) +{ + inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); + unregister_pernet_subsys(&dccp_v6_ops); + inet6_unregister_protosw(&dccp_v6_protosw); + proto_unregister(&dccp_v6_prot); +} + +module_init(dccp_v6_init); +module_exit(dccp_v6_exit); + +/* + * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) + * values directly, Also cover the case where the protocol is not specified, + * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP + */ +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arnaldo Carvalho de Melo "); +MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); diff --git a/net/dccp/ipv6.h b/net/dccp/ipv6.h new file mode 100644 index 000000000..7e4c2a3b3 --- /dev/null +++ b/net/dccp/ipv6.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _DCCP_IPV6_H +#define _DCCP_IPV6_H +/* + * net/dccp/ipv6.h + * + * An implementation of the DCCP protocol + * Copyright (c) 2005 Arnaldo Carvalho de Melo + */ + +#include +#include + +struct dccp6_sock { + struct dccp_sock dccp; + /* + * ipv6_pinfo has to be the last member of dccp6_sock, + * see inet6_sk_generic. + */ + struct ipv6_pinfo inet6; +}; + +struct dccp6_request_sock { + struct dccp_request_sock dccp; +}; + +struct dccp6_timewait_sock { + struct inet_timewait_sock inet; +}; + +#endif /* _DCCP_IPV6_H */ diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c new file mode 100644 index 000000000..64d805b27 --- /dev/null +++ b/net/dccp/minisocks.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/minisocks.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "ackvec.h" +#include "ccid.h" +#include "dccp.h" +#include "feat.h" + +struct inet_timewait_death_row dccp_death_row = { + .tw_refcount = REFCOUNT_INIT(1), + .sysctl_max_tw_buckets = NR_FILE * 2, + .hashinfo = &dccp_hashinfo, +}; + +EXPORT_SYMBOL_GPL(dccp_death_row); + +void dccp_time_wait(struct sock *sk, int state, int timeo) +{ + struct inet_timewait_sock *tw; + + tw = inet_twsk_alloc(sk, &dccp_death_row, state); + + if (tw != NULL) { + const struct inet_connection_sock *icsk = inet_csk(sk); + const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1); +#if IS_ENABLED(CONFIG_IPV6) + if (tw->tw_family == PF_INET6) { + tw->tw_v6_daddr = sk->sk_v6_daddr; + tw->tw_v6_rcv_saddr = sk->sk_v6_rcv_saddr; + tw->tw_ipv6only = sk->sk_ipv6only; + } +#endif + + /* Get the TIME_WAIT timeout firing. */ + if (timeo < rto) + timeo = rto; + + if (state == DCCP_TIME_WAIT) + timeo = DCCP_TIMEWAIT_LEN; + + /* tw_timer is pinned, so we need to make sure BH are disabled + * in following section, otherwise timer handler could run before + * we complete the initialization. + */ + local_bh_disable(); + inet_twsk_schedule(tw, timeo); + /* Linkage updates. + * Note that access to tw after this point is illegal. + */ + inet_twsk_hashdance(tw, sk, &dccp_hashinfo); + local_bh_enable(); + } else { + /* Sorry, if we're out of memory, just CLOSE this + * socket up. We've got bigger problems than + * non-graceful socket closings. + */ + DCCP_WARN("time wait bucket table overflow\n"); + } + + dccp_done(sk); +} + +struct sock *dccp_create_openreq_child(const struct sock *sk, + const struct request_sock *req, + const struct sk_buff *skb) +{ + /* + * Step 3: Process LISTEN state + * + * (* Generate a new socket and switch to that socket *) + * Set S := new socket for this port pair + */ + struct sock *newsk = inet_csk_clone_lock(sk, req, GFP_ATOMIC); + + if (newsk != NULL) { + struct dccp_request_sock *dreq = dccp_rsk(req); + struct inet_connection_sock *newicsk = inet_csk(newsk); + struct dccp_sock *newdp = dccp_sk(newsk); + + newdp->dccps_role = DCCP_ROLE_SERVER; + newdp->dccps_hc_rx_ackvec = NULL; + newdp->dccps_service_list = NULL; + newdp->dccps_hc_rx_ccid = NULL; + newdp->dccps_hc_tx_ccid = NULL; + newdp->dccps_service = dreq->dreq_service; + newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo; + newdp->dccps_timestamp_time = dreq->dreq_timestamp_time; + newicsk->icsk_rto = DCCP_TIMEOUT_INIT; + + INIT_LIST_HEAD(&newdp->dccps_featneg); + /* + * Step 3: Process LISTEN state + * + * Choose S.ISS (initial seqno) or set from Init Cookies + * Initialize S.GAR := S.ISS + * Set S.ISR, S.GSR from packet (or Init Cookies) + * + * Setting AWL/AWH and SWL/SWH happens as part of the feature + * activation below, as these windows all depend on the local + * and remote Sequence Window feature values (7.5.2). + */ + newdp->dccps_iss = dreq->dreq_iss; + newdp->dccps_gss = dreq->dreq_gss; + newdp->dccps_gar = newdp->dccps_iss; + newdp->dccps_isr = dreq->dreq_isr; + newdp->dccps_gsr = dreq->dreq_gsr; + + /* + * Activate features: initialise CCIDs, sequence windows etc. + */ + if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) { + sk_free_unlock_clone(newsk); + return NULL; + } + dccp_init_xmit_timers(newsk); + + __DCCP_INC_STATS(DCCP_MIB_PASSIVEOPENS); + } + return newsk; +} + +EXPORT_SYMBOL_GPL(dccp_create_openreq_child); + +/* + * Process an incoming packet for RESPOND sockets represented + * as an request_sock. + */ +struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + struct sock *child = NULL; + struct dccp_request_sock *dreq = dccp_rsk(req); + bool own_req; + + /* TCP/DCCP listeners became lockless. + * DCCP stores complex state in its request_sock, so we need + * a protection for them, now this code runs without being protected + * by the parent (listener) lock. + */ + spin_lock_bh(&dreq->dreq_lock); + + /* Check for retransmitted REQUEST */ + if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) { + + if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) { + dccp_pr_debug("Retransmitted REQUEST\n"); + dreq->dreq_gsr = DCCP_SKB_CB(skb)->dccpd_seq; + /* + * Send another RESPONSE packet + * To protect against Request floods, increment retrans + * counter (backoff, monitored by dccp_response_timer). + */ + inet_rtx_syn_ack(sk, req); + } + /* Network Duplicate, discard packet */ + goto out; + } + + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; + + if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK && + dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK) + goto drop; + + /* Invalid ACK */ + if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, + dreq->dreq_iss, dreq->dreq_gss)) { + dccp_pr_debug("Invalid ACK number: ack_seq=%llu, " + "dreq_iss=%llu, dreq_gss=%llu\n", + (unsigned long long) + DCCP_SKB_CB(skb)->dccpd_ack_seq, + (unsigned long long) dreq->dreq_iss, + (unsigned long long) dreq->dreq_gss); + goto drop; + } + + if (dccp_parse_options(sk, dreq, skb)) + goto drop; + + child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL, + req, &own_req); + if (child) { + child = inet_csk_complete_hashdance(sk, child, req, own_req); + goto out; + } + + DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; +drop: + if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET) + req->rsk_ops->send_reset(sk, skb); + + inet_csk_reqsk_queue_drop(sk, req); +out: + spin_unlock_bh(&dreq->dreq_lock); + return child; +} + +EXPORT_SYMBOL_GPL(dccp_check_req); + +/* + * Queue segment on the new socket if the new socket is active, + * otherwise we just shortcircuit this and continue with + * the new socket. + */ +int dccp_child_process(struct sock *parent, struct sock *child, + struct sk_buff *skb) + __releases(child) +{ + int ret = 0; + const int state = child->sk_state; + + if (!sock_owned_by_user(child)) { + ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb), + skb->len); + + /* Wakeup parent, send SIGIO */ + if (state == DCCP_RESPOND && child->sk_state != state) + parent->sk_data_ready(parent); + } else { + /* Alas, it is possible again, because we do lookup + * in main socket hash table and lock on listening + * socket does not protect us more. + */ + __sk_add_backlog(child, skb); + } + + bh_unlock_sock(child); + sock_put(child); + return ret; +} + +EXPORT_SYMBOL_GPL(dccp_child_process); + +void dccp_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, + struct request_sock *rsk) +{ + DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state"); +} + +EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack); + +int dccp_reqsk_init(struct request_sock *req, + struct dccp_sock const *dp, struct sk_buff const *skb) +{ + struct dccp_request_sock *dreq = dccp_rsk(req); + + spin_lock_init(&dreq->dreq_lock); + inet_rsk(req)->ir_rmt_port = dccp_hdr(skb)->dccph_sport; + inet_rsk(req)->ir_num = ntohs(dccp_hdr(skb)->dccph_dport); + inet_rsk(req)->acked = 0; + dreq->dreq_timestamp_echo = 0; + + /* inherit feature negotiation options from listening socket */ + return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg); +} + +EXPORT_SYMBOL_GPL(dccp_reqsk_init); diff --git a/net/dccp/options.c b/net/dccp/options.c new file mode 100644 index 000000000..d24cad050 --- /dev/null +++ b/net/dccp/options.c @@ -0,0 +1,609 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/options.c + * + * An implementation of the DCCP protocol + * Copyright (c) 2005 Aristeu Sergio Rozanski Filho + * Copyright (c) 2005 Arnaldo Carvalho de Melo + * Copyright (c) 2005 Ian McDonald + */ +#include +#include +#include +#include +#include +#include + +#include "ackvec.h" +#include "ccid.h" +#include "dccp.h" +#include "feat.h" + +u64 dccp_decode_value_var(const u8 *bf, const u8 len) +{ + u64 value = 0; + + if (len >= DCCP_OPTVAL_MAXLEN) + value += ((u64)*bf++) << 40; + if (len > 4) + value += ((u64)*bf++) << 32; + if (len > 3) + value += ((u64)*bf++) << 24; + if (len > 2) + value += ((u64)*bf++) << 16; + if (len > 1) + value += ((u64)*bf++) << 8; + if (len > 0) + value += *bf; + + return value; +} + +/** + * dccp_parse_options - Parse DCCP options present in @skb + * @sk: client|server|listening dccp socket (when @dreq != NULL) + * @dreq: request socket to use during connection setup, or NULL + * @skb: frame to parse + */ +int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, + struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + const struct dccp_hdr *dh = dccp_hdr(skb); + const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; + unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); + unsigned char *opt_ptr = options; + const unsigned char *opt_end = (unsigned char *)dh + + (dh->dccph_doff * 4); + struct dccp_options_received *opt_recv = &dp->dccps_options_received; + unsigned char opt, len; + unsigned char *value; + u32 elapsed_time; + __be32 opt_val; + int rc; + int mandatory = 0; + + memset(opt_recv, 0, sizeof(*opt_recv)); + + opt = len = 0; + while (opt_ptr != opt_end) { + opt = *opt_ptr++; + len = 0; + value = NULL; + + /* Check if this isn't a single byte option */ + if (opt > DCCPO_MAX_RESERVED) { + if (opt_ptr == opt_end) + goto out_nonsensical_length; + + len = *opt_ptr++; + if (len < 2) + goto out_nonsensical_length; + /* + * Remove the type and len fields, leaving + * just the value size + */ + len -= 2; + value = opt_ptr; + opt_ptr += len; + + if (opt_ptr > opt_end) + goto out_nonsensical_length; + } + + /* + * CCID-specific options are ignored during connection setup, as + * negotiation may still be in progress (see RFC 4340, 10.3). + * The same applies to Ack Vectors, as these depend on the CCID. + */ + if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC || + opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) + goto ignore_option; + + switch (opt) { + case DCCPO_PADDING: + break; + case DCCPO_MANDATORY: + if (mandatory) + goto out_invalid_option; + if (pkt_type != DCCP_PKT_DATA) + mandatory = 1; + break; + case DCCPO_NDP_COUNT: + if (len > 6) + goto out_invalid_option; + + opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); + dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), + (unsigned long long)opt_recv->dccpor_ndp); + break; + case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: + if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ + break; + if (len == 0) + goto out_invalid_option; + rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, + *value, value + 1, len - 1); + if (rc) + goto out_featneg_failed; + break; + case DCCPO_TIMESTAMP: + if (len != 4) + goto out_invalid_option; + /* + * RFC 4340 13.1: "The precise time corresponding to + * Timestamp Value zero is not specified". We use + * zero to indicate absence of a meaningful timestamp. + */ + opt_val = get_unaligned((__be32 *)value); + if (unlikely(opt_val == 0)) { + DCCP_WARN("Timestamp with zero value\n"); + break; + } + + if (dreq != NULL) { + dreq->dreq_timestamp_echo = ntohl(opt_val); + dreq->dreq_timestamp_time = dccp_timestamp(); + } else { + opt_recv->dccpor_timestamp = + dp->dccps_timestamp_echo = ntohl(opt_val); + dp->dccps_timestamp_time = dccp_timestamp(); + } + dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", + dccp_role(sk), ntohl(opt_val), + (unsigned long long) + DCCP_SKB_CB(skb)->dccpd_ack_seq); + /* schedule an Ack in case this sender is quiescent */ + inet_csk_schedule_ack(sk); + break; + case DCCPO_TIMESTAMP_ECHO: + if (len != 4 && len != 6 && len != 8) + goto out_invalid_option; + + opt_val = get_unaligned((__be32 *)value); + opt_recv->dccpor_timestamp_echo = ntohl(opt_val); + + dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " + "ackno=%llu", dccp_role(sk), + opt_recv->dccpor_timestamp_echo, + len + 2, + (unsigned long long) + DCCP_SKB_CB(skb)->dccpd_ack_seq); + + value += 4; + + if (len == 4) { /* no elapsed time included */ + dccp_pr_debug_cat("\n"); + break; + } + + if (len == 6) { /* 2-byte elapsed time */ + __be16 opt_val2 = get_unaligned((__be16 *)value); + elapsed_time = ntohs(opt_val2); + } else { /* 4-byte elapsed time */ + opt_val = get_unaligned((__be32 *)value); + elapsed_time = ntohl(opt_val); + } + + dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); + + /* Give precedence to the biggest ELAPSED_TIME */ + if (elapsed_time > opt_recv->dccpor_elapsed_time) + opt_recv->dccpor_elapsed_time = elapsed_time; + break; + case DCCPO_ELAPSED_TIME: + if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ + break; + + if (len == 2) { + __be16 opt_val2 = get_unaligned((__be16 *)value); + elapsed_time = ntohs(opt_val2); + } else if (len == 4) { + opt_val = get_unaligned((__be32 *)value); + elapsed_time = ntohl(opt_val); + } else { + goto out_invalid_option; + } + + if (elapsed_time > opt_recv->dccpor_elapsed_time) + opt_recv->dccpor_elapsed_time = elapsed_time; + + dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", + dccp_role(sk), elapsed_time); + break; + case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC: + if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, + pkt_type, opt, value, len)) + goto out_invalid_option; + break; + case DCCPO_ACK_VECTOR_0: + case DCCPO_ACK_VECTOR_1: + if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ + break; + /* + * Ack vectors are processed by the TX CCID if it is + * interested. The RX CCID need not parse Ack Vectors, + * since it is only interested in clearing old state. + */ + fallthrough; + case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC: + if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, + pkt_type, opt, value, len)) + goto out_invalid_option; + break; + default: + DCCP_CRIT("DCCP(%p): option %d(len=%d) not " + "implemented, ignoring", sk, opt, len); + break; + } +ignore_option: + if (opt != DCCPO_MANDATORY) + mandatory = 0; + } + + /* mandatory was the last byte in option list -> reset connection */ + if (mandatory) + goto out_invalid_option; + +out_nonsensical_length: + /* RFC 4340, 5.8: ignore option and all remaining option space */ + return 0; + +out_invalid_option: + DCCP_INC_STATS(DCCP_MIB_INVALIDOPT); + rc = DCCP_RESET_CODE_OPTION_ERROR; +out_featneg_failed: + DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); + DCCP_SKB_CB(skb)->dccpd_reset_code = rc; + DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; + DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; + DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; + return -1; +} + +EXPORT_SYMBOL_GPL(dccp_parse_options); + +void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) +{ + if (len >= DCCP_OPTVAL_MAXLEN) + *to++ = (value & 0xFF0000000000ull) >> 40; + if (len > 4) + *to++ = (value & 0xFF00000000ull) >> 32; + if (len > 3) + *to++ = (value & 0xFF000000) >> 24; + if (len > 2) + *to++ = (value & 0xFF0000) >> 16; + if (len > 1) + *to++ = (value & 0xFF00) >> 8; + if (len > 0) + *to++ = (value & 0xFF); +} + +static inline u8 dccp_ndp_len(const u64 ndp) +{ + if (likely(ndp <= 0xFF)) + return 1; + return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); +} + +int dccp_insert_option(struct sk_buff *skb, const unsigned char option, + const void *value, const unsigned char len) +{ + unsigned char *to; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) + return -1; + + DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; + + to = skb_push(skb, len + 2); + *to++ = option; + *to++ = len + 2; + + memcpy(to, value, len); + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_insert_option); + +static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + u64 ndp = dp->dccps_ndp_count; + + if (dccp_non_data_packet(skb)) + ++dp->dccps_ndp_count; + else + dp->dccps_ndp_count = 0; + + if (ndp > 0) { + unsigned char *ptr; + const int ndp_len = dccp_ndp_len(ndp); + const int len = ndp_len + 2; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + return -1; + + DCCP_SKB_CB(skb)->dccpd_opt_len += len; + + ptr = skb_push(skb, len); + *ptr++ = DCCPO_NDP_COUNT; + *ptr++ = len; + dccp_encode_value_var(ndp, ptr, ndp_len); + } + + return 0; +} + +static inline int dccp_elapsed_time_len(const u32 elapsed_time) +{ + return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; +} + +static int dccp_insert_option_timestamp(struct sk_buff *skb) +{ + __be32 now = htonl(dccp_timestamp()); + /* yes this will overflow but that is the point as we want a + * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ + + return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now)); +} + +static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, + struct dccp_request_sock *dreq, + struct sk_buff *skb) +{ + __be32 tstamp_echo; + unsigned char *to; + u32 elapsed_time, elapsed_time_len, len; + + if (dreq != NULL) { + elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; + tstamp_echo = htonl(dreq->dreq_timestamp_echo); + dreq->dreq_timestamp_echo = 0; + } else { + elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; + tstamp_echo = htonl(dp->dccps_timestamp_echo); + dp->dccps_timestamp_echo = 0; + } + + elapsed_time_len = dccp_elapsed_time_len(elapsed_time); + len = 6 + elapsed_time_len; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + return -1; + + DCCP_SKB_CB(skb)->dccpd_opt_len += len; + + to = skb_push(skb, len); + *to++ = DCCPO_TIMESTAMP_ECHO; + *to++ = len; + + memcpy(to, &tstamp_echo, 4); + to += 4; + + if (elapsed_time_len == 2) { + const __be16 var16 = htons((u16)elapsed_time); + memcpy(to, &var16, 2); + } else if (elapsed_time_len == 4) { + const __be32 var32 = htonl(elapsed_time); + memcpy(to, &var32, 4); + } + + return 0; +} + +static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + const u16 buflen = dccp_ackvec_buflen(av); + /* Figure out how many options do we need to represent the ackvec */ + const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); + u16 len = buflen + 2 * nr_opts; + u8 i, nonce = 0; + const unsigned char *tail, *from; + unsigned char *to; + + if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("Lacking space for %u bytes on %s packet\n", len, + dccp_packet_name(dcb->dccpd_type)); + return -1; + } + /* + * Since Ack Vectors are variable-length, we can not always predict + * their size. To catch exception cases where the space is running out + * on the skb, a separate Sync is scheduled to carry the Ack Vector. + */ + if (len > DCCPAV_MIN_OPTLEN && + len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) { + DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), " + "MPS=%u ==> reduce payload size?\n", len, skb->len, + dcb->dccpd_opt_len, dp->dccps_mss_cache); + dp->dccps_sync_scheduled = 1; + return 0; + } + dcb->dccpd_opt_len += len; + + to = skb_push(skb, len); + len = buflen; + from = av->av_buf + av->av_buf_head; + tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; + + for (i = 0; i < nr_opts; ++i) { + int copylen = len; + + if (len > DCCP_SINGLE_OPT_MAXLEN) + copylen = DCCP_SINGLE_OPT_MAXLEN; + + /* + * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via + * its type; ack_nonce is the sum of all individual buf_nonce's. + */ + nonce ^= av->av_buf_nonce[i]; + + *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i]; + *to++ = copylen + 2; + + /* Check if buf_head wraps */ + if (from + copylen > tail) { + const u16 tailsize = tail - from; + + memcpy(to, from, tailsize); + to += tailsize; + len -= tailsize; + copylen -= tailsize; + from = av->av_buf; + } + + memcpy(to, from, copylen); + from += copylen; + to += copylen; + len -= copylen; + } + /* + * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. + */ + if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce)) + return -ENOBUFS; + return 0; +} + +/** + * dccp_insert_option_mandatory - Mandatory option (5.8.2) + * @skb: frame into which to insert option + * + * Note that since we are using skb_push, this function needs to be called + * _after_ inserting the option it is supposed to influence (stack order). + */ +int dccp_insert_option_mandatory(struct sk_buff *skb) +{ + if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) + return -1; + + DCCP_SKB_CB(skb)->dccpd_opt_len++; + *(u8 *)skb_push(skb, 1) = DCCPO_MANDATORY; + return 0; +} + +/** + * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb + * @skb: frame to insert feature negotiation option into + * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R + * @feat: one out of %dccp_feature_numbers + * @val: NN value or SP array (preferred element first) to copy + * @len: true length of @val in bytes (excluding first element repetition) + * @repeat_first: whether to copy the first element of @val twice + * + * The last argument is used to construct Confirm options, where the preferred + * value and the preference list appear separately (RFC 4340, 6.3.1). Preference + * lists are kept such that the preferred entry is always first, so we only need + * to copy twice, and avoid the overhead of cloning into a bigger array. + */ +int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, + u8 *val, u8 len, bool repeat_first) +{ + u8 tot_len, *to; + + /* take the `Feature' field and possible repetition into account */ + if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { + DCCP_WARN("length %u for feature %u too large\n", len, feat); + return -1; + } + + if (unlikely(val == NULL || len == 0)) + len = repeat_first = false; + tot_len = 3 + repeat_first + len; + + if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("packet too small for feature %d option!\n", feat); + return -1; + } + DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; + + to = skb_push(skb, tot_len); + *to++ = type; + *to++ = tot_len; + *to++ = feat; + + if (repeat_first) + *to++ = *val; + if (len) + memcpy(to, val, len); + return 0; +} + +/* The length of all options needs to be a multiple of 4 (5.8) */ +static void dccp_insert_option_padding(struct sk_buff *skb) +{ + int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; + + if (padding != 0) { + padding = 4 - padding; + memset(skb_push(skb, padding), 0, padding); + DCCP_SKB_CB(skb)->dccpd_opt_len += padding; + } +} + +int dccp_insert_options(struct sock *sk, struct sk_buff *skb) +{ + struct dccp_sock *dp = dccp_sk(sk); + + DCCP_SKB_CB(skb)->dccpd_opt_len = 0; + + if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) + return -1; + + if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { + + /* Feature Negotiation */ + if (dccp_feat_insert_opts(dp, NULL, skb)) + return -1; + + if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { + /* + * Obtain RTT sample from Request/Response exchange. + * This is currently used for TFRC initialisation. + */ + if (dccp_insert_option_timestamp(skb)) + return -1; + + } else if (dccp_ackvec_pending(sk) && + dccp_insert_option_ackvec(sk, skb)) { + return -1; + } + } + + if (dp->dccps_hc_rx_insert_options) { + if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) + return -1; + dp->dccps_hc_rx_insert_options = 0; + } + + if (dp->dccps_timestamp_echo != 0 && + dccp_insert_option_timestamp_echo(dp, NULL, skb)) + return -1; + + dccp_insert_option_padding(skb); + return 0; +} + +int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) +{ + DCCP_SKB_CB(skb)->dccpd_opt_len = 0; + + if (dccp_feat_insert_opts(NULL, dreq, skb)) + return -1; + + /* Obtain RTT sample from Response/Ack exchange (used by TFRC). */ + if (dccp_insert_option_timestamp(skb)) + return -1; + + if (dreq->dreq_timestamp_echo != 0 && + dccp_insert_option_timestamp_echo(NULL, dreq, skb)) + return -1; + + dccp_insert_option_padding(skb); + return 0; +} diff --git a/net/dccp/output.c b/net/dccp/output.c new file mode 100644 index 000000000..fd2eb148d --- /dev/null +++ b/net/dccp/output.c @@ -0,0 +1,709 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/output.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include +#include + +#include +#include + +#include "ackvec.h" +#include "ccid.h" +#include "dccp.h" + +static inline void dccp_event_ack_sent(struct sock *sk) +{ + inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); +} + +/* enqueue @skb on sk_send_head for retransmission, return clone to send now */ +static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb) +{ + skb_set_owner_w(skb, sk); + WARN_ON(sk->sk_send_head); + sk->sk_send_head = skb; + return skb_clone(sk->sk_send_head, gfp_any()); +} + +/* + * All SKB's seen here are completely headerless. It is our + * job to build the DCCP header, and pass the packet down to + * IP so it can do the same plus pass the packet off to the + * device. + */ +static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) +{ + if (likely(skb != NULL)) { + struct inet_sock *inet = inet_sk(sk); + const struct inet_connection_sock *icsk = inet_csk(sk); + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); + struct dccp_hdr *dh; + /* XXX For now we're using only 48 bits sequence numbers */ + const u32 dccp_header_size = sizeof(*dh) + + sizeof(struct dccp_hdr_ext) + + dccp_packet_hdr_len(dcb->dccpd_type); + int err, set_ack = 1; + u64 ackno = dp->dccps_gsr; + /* + * Increment GSS here already in case the option code needs it. + * Update GSS for real only if option processing below succeeds. + */ + dcb->dccpd_seq = ADD48(dp->dccps_gss, 1); + + switch (dcb->dccpd_type) { + case DCCP_PKT_DATA: + set_ack = 0; + fallthrough; + case DCCP_PKT_DATAACK: + case DCCP_PKT_RESET: + break; + + case DCCP_PKT_REQUEST: + set_ack = 0; + /* Use ISS on the first (non-retransmitted) Request. */ + if (icsk->icsk_retransmits == 0) + dcb->dccpd_seq = dp->dccps_iss; + fallthrough; + + case DCCP_PKT_SYNC: + case DCCP_PKT_SYNCACK: + ackno = dcb->dccpd_ack_seq; + fallthrough; + default: + /* + * Set owner/destructor: some skbs are allocated via + * alloc_skb (e.g. when retransmission may happen). + * Only Data, DataAck, and Reset packets should come + * through here with skb->sk set. + */ + WARN_ON(skb->sk); + skb_set_owner_w(skb, sk); + break; + } + + if (dccp_insert_options(sk, skb)) { + kfree_skb(skb); + return -EPROTO; + } + + + /* Build DCCP header and checksum it. */ + dh = dccp_zeroed_hdr(skb, dccp_header_size); + dh->dccph_type = dcb->dccpd_type; + dh->dccph_sport = inet->inet_sport; + dh->dccph_dport = inet->inet_dport; + dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; + dh->dccph_ccval = dcb->dccpd_ccval; + dh->dccph_cscov = dp->dccps_pcslen; + /* XXX For now we're using only 48 bits sequence numbers */ + dh->dccph_x = 1; + + dccp_update_gss(sk, dcb->dccpd_seq); + dccp_hdr_set_seq(dh, dp->dccps_gss); + if (set_ack) + dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); + + switch (dcb->dccpd_type) { + case DCCP_PKT_REQUEST: + dccp_hdr_request(skb)->dccph_req_service = + dp->dccps_service; + /* + * Limit Ack window to ISS <= P.ackno <= GSS, so that + * only Responses to Requests we sent are considered. + */ + dp->dccps_awl = dp->dccps_iss; + break; + case DCCP_PKT_RESET: + dccp_hdr_reset(skb)->dccph_reset_code = + dcb->dccpd_reset_code; + break; + } + + icsk->icsk_af_ops->send_check(sk, skb); + + if (set_ack) + dccp_event_ack_sent(sk); + + DCCP_INC_STATS(DCCP_MIB_OUTSEGS); + + err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl); + return net_xmit_eval(err); + } + return -ENOBUFS; +} + +/** + * dccp_determine_ccmps - Find out about CCID-specific packet-size limits + * @dp: socket to find packet size limits of + * + * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.), + * since the RX CCID is restricted to feedback packets (Acks), which are small + * in comparison with the data traffic. A value of 0 means "no current CCMPS". + */ +static u32 dccp_determine_ccmps(const struct dccp_sock *dp) +{ + const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid; + + if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL) + return 0; + return tx_ccid->ccid_ops->ccid_ccmps; +} + +unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct dccp_sock *dp = dccp_sk(sk); + u32 ccmps = dccp_determine_ccmps(dp); + u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu; + + /* Account for header lengths and IPv4/v6 option overhead */ + cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len + + sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext)); + + /* + * Leave enough headroom for common DCCP header options. + * This only considers options which may appear on DCCP-Data packets, as + * per table 3 in RFC 4340, 5.8. When running out of space for other + * options (eg. Ack Vector which can take up to 255 bytes), it is better + * to schedule a separate Ack. Thus we leave headroom for the following: + * - 1 byte for Slow Receiver (11.6) + * - 6 bytes for Timestamp (13.1) + * - 10 bytes for Timestamp Echo (13.3) + * - 8 bytes for NDP count (7.7, when activated) + * - 6 bytes for Data Checksum (9.3) + * - %DCCPAV_MIN_OPTLEN bytes for Ack Vector size (11.4, when enabled) + */ + cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 + + (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4); + + /* And store cached results */ + icsk->icsk_pmtu_cookie = pmtu; + WRITE_ONCE(dp->dccps_mss_cache, cur_mps); + + return cur_mps; +} + +EXPORT_SYMBOL_GPL(dccp_sync_mss); + +void dccp_write_space(struct sock *sk) +{ + struct socket_wq *wq; + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (skwq_has_sleeper(wq)) + wake_up_interruptible(&wq->wait); + /* Should agree with poll, otherwise some programs break */ + if (sock_writeable(sk)) + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + + rcu_read_unlock(); +} + +/** + * dccp_wait_for_ccid - Await CCID send permission + * @sk: socket to wait for + * @delay: timeout in jiffies + * + * This is used by CCIDs which need to delay the send time in process context. + */ +static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay) +{ + DEFINE_WAIT(wait); + long remaining; + + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + sk->sk_write_pending++; + release_sock(sk); + + remaining = schedule_timeout(delay); + + lock_sock(sk); + sk->sk_write_pending--; + finish_wait(sk_sleep(sk), &wait); + + if (signal_pending(current) || sk->sk_err) + return -1; + return remaining; +} + +/** + * dccp_xmit_packet - Send data packet under control of CCID + * @sk: socket to send data packet on + * + * Transmits next-queued payload and informs CCID to account for the packet. + */ +static void dccp_xmit_packet(struct sock *sk) +{ + int err, len; + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb = dccp_qpolicy_pop(sk); + + if (unlikely(skb == NULL)) + return; + len = skb->len; + + if (sk->sk_state == DCCP_PARTOPEN) { + const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; + /* + * See 8.1.5 - Handshake Completion. + * + * For robustness we resend Confirm options until the client has + * entered OPEN. During the initial feature negotiation, the MPS + * is smaller than usual, reduced by the Change/Confirm options. + */ + if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { + DCCP_WARN("Payload too large (%d) for featneg.\n", len); + dccp_send_ack(sk); + dccp_feat_list_purge(&dp->dccps_featneg); + } + + inet_csk_schedule_ack(sk); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, + inet_csk(sk)->icsk_rto, + DCCP_RTO_MAX); + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; + } else if (dccp_ack_pending(sk)) { + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; + } else { + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA; + } + + err = dccp_transmit_skb(sk, skb); + if (err) + dccp_pr_debug("transmit_skb() returned err=%d\n", err); + /* + * Register this one as sent even if an error occurred. To the remote + * end a local packet drop is indistinguishable from network loss, i.e. + * any local drop will eventually be reported via receiver feedback. + */ + ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len); + + /* + * If the CCID needs to transfer additional header options out-of-band + * (e.g. Ack Vectors or feature-negotiation options), it activates this + * flag to schedule a Sync. The Sync will automatically incorporate all + * currently pending header options, thus clearing the backlog. + */ + if (dp->dccps_sync_scheduled) + dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); +} + +/** + * dccp_flush_write_queue - Drain queue at end of connection + * @sk: socket to be drained + * @time_budget: time allowed to drain the queue + * + * Since dccp_sendmsg queues packets without waiting for them to be sent, it may + * happen that the TX queue is not empty at the end of a connection. We give the + * HC-sender CCID a grace period of up to @time_budget jiffies. If this function + * returns with a non-empty write queue, it will be purged later. + */ +void dccp_flush_write_queue(struct sock *sk, long *time_budget) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb; + long delay, rc; + + while (*time_budget > 0 && (skb = skb_peek(&sk->sk_write_queue))) { + rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); + + switch (ccid_packet_dequeue_eval(rc)) { + case CCID_PACKET_WILL_DEQUEUE_LATER: + /* + * If the CCID determines when to send, the next sending + * time is unknown or the CCID may not even send again + * (e.g. remote host crashes or lost Ack packets). + */ + DCCP_WARN("CCID did not manage to send all packets\n"); + return; + case CCID_PACKET_DELAY: + delay = msecs_to_jiffies(rc); + if (delay > *time_budget) + return; + rc = dccp_wait_for_ccid(sk, delay); + if (rc < 0) + return; + *time_budget -= (delay - rc); + /* check again if we can send now */ + break; + case CCID_PACKET_SEND_AT_ONCE: + dccp_xmit_packet(sk); + break; + case CCID_PACKET_ERR: + skb_dequeue(&sk->sk_write_queue); + kfree_skb(skb); + dccp_pr_debug("packet discarded due to err=%ld\n", rc); + } + } +} + +void dccp_write_xmit(struct sock *sk) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb; + + while ((skb = dccp_qpolicy_top(sk))) { + int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); + + switch (ccid_packet_dequeue_eval(rc)) { + case CCID_PACKET_WILL_DEQUEUE_LATER: + return; + case CCID_PACKET_DELAY: + sk_reset_timer(sk, &dp->dccps_xmit_timer, + jiffies + msecs_to_jiffies(rc)); + return; + case CCID_PACKET_SEND_AT_ONCE: + dccp_xmit_packet(sk); + break; + case CCID_PACKET_ERR: + dccp_qpolicy_drop(sk, skb); + dccp_pr_debug("packet discarded due to err=%d\n", rc); + } + } +} + +/** + * dccp_retransmit_skb - Retransmit Request, Close, or CloseReq packets + * @sk: socket to perform retransmit on + * + * There are only four retransmittable packet types in DCCP: + * - Request in client-REQUEST state (sec. 8.1.1), + * - CloseReq in server-CLOSEREQ state (sec. 8.3), + * - Close in node-CLOSING state (sec. 8.3), + * - Acks in client-PARTOPEN state (sec. 8.1.5, handled by dccp_delack_timer()). + * This function expects sk->sk_send_head to contain the original skb. + */ +int dccp_retransmit_skb(struct sock *sk) +{ + WARN_ON(sk->sk_send_head == NULL); + + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) + return -EHOSTUNREACH; /* Routing failure or similar. */ + + /* this count is used to distinguish original and retransmitted skb */ + inet_csk(sk)->icsk_retransmits++; + + return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC)); +} + +struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst, + struct request_sock *req) +{ + struct dccp_hdr *dh; + struct dccp_request_sock *dreq; + const u32 dccp_header_size = sizeof(struct dccp_hdr) + + sizeof(struct dccp_hdr_ext) + + sizeof(struct dccp_hdr_response); + struct sk_buff *skb; + + /* sk is marked const to clearly express we dont hold socket lock. + * sock_wmalloc() will atomically change sk->sk_wmem_alloc, + * it is safe to promote sk to non const. + */ + skb = sock_wmalloc((struct sock *)sk, MAX_DCCP_HEADER, 1, + GFP_ATOMIC); + if (!skb) + return NULL; + + skb_reserve(skb, MAX_DCCP_HEADER); + + skb_dst_set(skb, dst_clone(dst)); + + dreq = dccp_rsk(req); + if (inet_rsk(req)->acked) /* increase GSS upon retransmission */ + dccp_inc_seqno(&dreq->dreq_gss); + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; + DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss; + + /* Resolve feature dependencies resulting from choice of CCID */ + if (dccp_feat_server_ccid_dependencies(dreq)) + goto response_failed; + + if (dccp_insert_options_rsk(dreq, skb)) + goto response_failed; + + /* Build and checksum header */ + dh = dccp_zeroed_hdr(skb, dccp_header_size); + + dh->dccph_sport = htons(inet_rsk(req)->ir_num); + dh->dccph_dport = inet_rsk(req)->ir_rmt_port; + dh->dccph_doff = (dccp_header_size + + DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; + dh->dccph_type = DCCP_PKT_RESPONSE; + dh->dccph_x = 1; + dccp_hdr_set_seq(dh, dreq->dreq_gss); + dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr); + dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; + + dccp_csum_outgoing(skb); + + /* We use `acked' to remember that a Response was already sent. */ + inet_rsk(req)->acked = 1; + DCCP_INC_STATS(DCCP_MIB_OUTSEGS); + return skb; +response_failed: + kfree_skb(skb); + return NULL; +} + +EXPORT_SYMBOL_GPL(dccp_make_response); + +/* answer offending packet in @rcv_skb with Reset from control socket @ctl */ +struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb) +{ + struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb); + const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) + + sizeof(struct dccp_hdr_ext) + + sizeof(struct dccp_hdr_reset); + struct dccp_hdr_reset *dhr; + struct sk_buff *skb; + + skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); + if (skb == NULL) + return NULL; + + skb_reserve(skb, sk->sk_prot->max_header); + + /* Swap the send and the receive. */ + dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len); + dh->dccph_type = DCCP_PKT_RESET; + dh->dccph_sport = rxdh->dccph_dport; + dh->dccph_dport = rxdh->dccph_sport; + dh->dccph_doff = dccp_hdr_reset_len / 4; + dh->dccph_x = 1; + + dhr = dccp_hdr_reset(skb); + dhr->dccph_reset_code = dcb->dccpd_reset_code; + + switch (dcb->dccpd_reset_code) { + case DCCP_RESET_CODE_PACKET_ERROR: + dhr->dccph_reset_data[0] = rxdh->dccph_type; + break; + case DCCP_RESET_CODE_OPTION_ERROR: + case DCCP_RESET_CODE_MANDATORY_ERROR: + memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3); + break; + } + /* + * From RFC 4340, 8.3.1: + * If P.ackno exists, set R.seqno := P.ackno + 1. + * Else set R.seqno := 0. + */ + if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) + dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1)); + dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq); + + dccp_csum_outgoing(skb); + return skb; +} + +EXPORT_SYMBOL_GPL(dccp_ctl_make_reset); + +/* send Reset on established socket, to close or abort the connection */ +int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) +{ + struct sk_buff *skb; + /* + * FIXME: what if rebuild_header fails? + * Should we be doing a rebuild_header here? + */ + int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk); + + if (err != 0) + return err; + + skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); + if (skb == NULL) + return -ENOBUFS; + + /* Reserve space for headers and prepare control bits. */ + skb_reserve(skb, sk->sk_prot->max_header); + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; + DCCP_SKB_CB(skb)->dccpd_reset_code = code; + + return dccp_transmit_skb(sk, skb); +} + +/* + * Do all connect socket setups that can be done AF independent. + */ +int dccp_connect(struct sock *sk) +{ + struct sk_buff *skb; + struct dccp_sock *dp = dccp_sk(sk); + struct dst_entry *dst = __sk_dst_get(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + + sk->sk_err = 0; + sock_reset_flag(sk, SOCK_DONE); + + dccp_sync_mss(sk, dst_mtu(dst)); + + /* do not connect if feature negotiation setup fails */ + if (dccp_feat_finalise_settings(dccp_sk(sk))) + return -EPROTO; + + /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */ + dp->dccps_gar = dp->dccps_iss; + + skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); + if (unlikely(skb == NULL)) + return -ENOBUFS; + + /* Reserve space for headers. */ + skb_reserve(skb, sk->sk_prot->max_header); + + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; + + dccp_transmit_skb(sk, dccp_skb_entail(sk, skb)); + DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); + + /* Timer for repeating the REQUEST until an answer. */ + icsk->icsk_retransmits = 0; + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + icsk->icsk_rto, DCCP_RTO_MAX); + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_connect); + +void dccp_send_ack(struct sock *sk) +{ + /* If we have been reset, we may not send again. */ + if (sk->sk_state != DCCP_CLOSED) { + struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, + GFP_ATOMIC); + + if (skb == NULL) { + inet_csk_schedule_ack(sk); + inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; + inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, + TCP_DELACK_MAX, + DCCP_RTO_MAX); + return; + } + + /* Reserve space for headers */ + skb_reserve(skb, sk->sk_prot->max_header); + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; + dccp_transmit_skb(sk, skb); + } +} + +EXPORT_SYMBOL_GPL(dccp_send_ack); + +#if 0 +/* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ +void dccp_send_delayed_ack(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + /* + * FIXME: tune this timer. elapsed time fixes the skew, so no problem + * with using 2s, and active senders also piggyback the ACK into a + * DATAACK packet, so this is really for quiescent senders. + */ + unsigned long timeout = jiffies + 2 * HZ; + + /* Use new timeout only if there wasn't a older one earlier. */ + if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { + /* If delack timer was blocked or is about to expire, + * send ACK now. + * + * FIXME: check the "about to expire" part + */ + if (icsk->icsk_ack.blocked) { + dccp_send_ack(sk); + return; + } + + if (!time_before(timeout, icsk->icsk_ack.timeout)) + timeout = icsk->icsk_ack.timeout; + } + icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; + icsk->icsk_ack.timeout = timeout; + sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); +} +#endif + +void dccp_send_sync(struct sock *sk, const u64 ackno, + const enum dccp_pkt_type pkt_type) +{ + /* + * We are not putting this on the write queue, so + * dccp_transmit_skb() will set the ownership to this + * sock. + */ + struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); + + if (skb == NULL) { + /* FIXME: how to make sure the sync is sent? */ + DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type)); + return; + } + + /* Reserve space for headers and prepare control bits. */ + skb_reserve(skb, sk->sk_prot->max_header); + DCCP_SKB_CB(skb)->dccpd_type = pkt_type; + DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; + + /* + * Clear the flag in case the Sync was scheduled for out-of-band data, + * such as carrying a long Ack Vector. + */ + dccp_sk(sk)->dccps_sync_scheduled = 0; + + dccp_transmit_skb(sk, skb); +} + +EXPORT_SYMBOL_GPL(dccp_send_sync); + +/* + * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This + * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under + * any circumstances. + */ +void dccp_send_close(struct sock *sk, const int active) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb; + const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; + + skb = alloc_skb(sk->sk_prot->max_header, prio); + if (skb == NULL) + return; + + /* Reserve space for headers and prepare control bits. */ + skb_reserve(skb, sk->sk_prot->max_header); + if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait) + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ; + else + DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE; + + if (active) { + skb = dccp_skb_entail(sk, skb); + /* + * Retransmission timer for active-close: RFC 4340, 8.3 requires + * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ + * state can be left. The initial timeout is 2 RTTs. + * Since RTT measurement is done by the CCIDs, there is no easy + * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4 + * is too low (200ms); we use a high value to avoid unnecessary + * retransmissions when the link RTT is > 0.2 seconds. + * FIXME: Let main module sample RTTs and use that instead. + */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + DCCP_TIMEOUT_INIT, DCCP_RTO_MAX); + } + dccp_transmit_skb(sk, skb); +} diff --git a/net/dccp/proto.c b/net/dccp/proto.c new file mode 100644 index 000000000..c522c76a9 --- /dev/null +++ b/net/dccp/proto.c @@ -0,0 +1,1290 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/proto.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#include "ccid.h" +#include "dccp.h" +#include "feat.h" + +#define CREATE_TRACE_POINTS +#include "trace.h" + +DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly; + +EXPORT_SYMBOL_GPL(dccp_statistics); + +DEFINE_PER_CPU(unsigned int, dccp_orphan_count); +EXPORT_PER_CPU_SYMBOL_GPL(dccp_orphan_count); + +struct inet_hashinfo dccp_hashinfo; +EXPORT_SYMBOL_GPL(dccp_hashinfo); + +/* the maximum queue length for tx in packets. 0 is no limit */ +int sysctl_dccp_tx_qlen __read_mostly = 5; + +#ifdef CONFIG_IP_DCCP_DEBUG +static const char *dccp_state_name(const int state) +{ + static const char *const dccp_state_names[] = { + [DCCP_OPEN] = "OPEN", + [DCCP_REQUESTING] = "REQUESTING", + [DCCP_PARTOPEN] = "PARTOPEN", + [DCCP_LISTEN] = "LISTEN", + [DCCP_RESPOND] = "RESPOND", + [DCCP_CLOSING] = "CLOSING", + [DCCP_ACTIVE_CLOSEREQ] = "CLOSEREQ", + [DCCP_PASSIVE_CLOSE] = "PASSIVE_CLOSE", + [DCCP_PASSIVE_CLOSEREQ] = "PASSIVE_CLOSEREQ", + [DCCP_TIME_WAIT] = "TIME_WAIT", + [DCCP_CLOSED] = "CLOSED", + }; + + if (state >= DCCP_MAX_STATES) + return "INVALID STATE!"; + else + return dccp_state_names[state]; +} +#endif + +void dccp_set_state(struct sock *sk, const int state) +{ + const int oldstate = sk->sk_state; + + dccp_pr_debug("%s(%p) %s --> %s\n", dccp_role(sk), sk, + dccp_state_name(oldstate), dccp_state_name(state)); + WARN_ON(state == oldstate); + + switch (state) { + case DCCP_OPEN: + if (oldstate != DCCP_OPEN) + DCCP_INC_STATS(DCCP_MIB_CURRESTAB); + /* Client retransmits all Confirm options until entering OPEN */ + if (oldstate == DCCP_PARTOPEN) + dccp_feat_list_purge(&dccp_sk(sk)->dccps_featneg); + break; + + case DCCP_CLOSED: + if (oldstate == DCCP_OPEN || oldstate == DCCP_ACTIVE_CLOSEREQ || + oldstate == DCCP_CLOSING) + DCCP_INC_STATS(DCCP_MIB_ESTABRESETS); + + sk->sk_prot->unhash(sk); + if (inet_csk(sk)->icsk_bind_hash != NULL && + !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) + inet_put_port(sk); + fallthrough; + default: + if (oldstate == DCCP_OPEN) + DCCP_DEC_STATS(DCCP_MIB_CURRESTAB); + } + + /* Change state AFTER socket is unhashed to avoid closed + * socket sitting in hash tables. + */ + inet_sk_set_state(sk, state); +} + +EXPORT_SYMBOL_GPL(dccp_set_state); + +static void dccp_finish_passive_close(struct sock *sk) +{ + switch (sk->sk_state) { + case DCCP_PASSIVE_CLOSE: + /* Node (client or server) has received Close packet. */ + dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); + dccp_set_state(sk, DCCP_CLOSED); + break; + case DCCP_PASSIVE_CLOSEREQ: + /* + * Client received CloseReq. We set the `active' flag so that + * dccp_send_close() retransmits the Close as per RFC 4340, 8.3. + */ + dccp_send_close(sk, 1); + dccp_set_state(sk, DCCP_CLOSING); + } +} + +void dccp_done(struct sock *sk) +{ + dccp_set_state(sk, DCCP_CLOSED); + dccp_clear_xmit_timers(sk); + + sk->sk_shutdown = SHUTDOWN_MASK; + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_state_change(sk); + else + inet_csk_destroy_sock(sk); +} + +EXPORT_SYMBOL_GPL(dccp_done); + +const char *dccp_packet_name(const int type) +{ + static const char *const dccp_packet_names[] = { + [DCCP_PKT_REQUEST] = "REQUEST", + [DCCP_PKT_RESPONSE] = "RESPONSE", + [DCCP_PKT_DATA] = "DATA", + [DCCP_PKT_ACK] = "ACK", + [DCCP_PKT_DATAACK] = "DATAACK", + [DCCP_PKT_CLOSEREQ] = "CLOSEREQ", + [DCCP_PKT_CLOSE] = "CLOSE", + [DCCP_PKT_RESET] = "RESET", + [DCCP_PKT_SYNC] = "SYNC", + [DCCP_PKT_SYNCACK] = "SYNCACK", + }; + + if (type >= DCCP_NR_PKT_TYPES) + return "INVALID"; + else + return dccp_packet_names[type]; +} + +EXPORT_SYMBOL_GPL(dccp_packet_name); + +void dccp_destruct_common(struct sock *sk) +{ + struct dccp_sock *dp = dccp_sk(sk); + + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + dp->dccps_hc_tx_ccid = NULL; +} +EXPORT_SYMBOL_GPL(dccp_destruct_common); + +static void dccp_sk_destruct(struct sock *sk) +{ + dccp_destruct_common(sk); + inet_sock_destruct(sk); +} + +int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_rto = DCCP_TIMEOUT_INIT; + icsk->icsk_syn_retries = sysctl_dccp_request_retries; + sk->sk_state = DCCP_CLOSED; + sk->sk_write_space = dccp_write_space; + sk->sk_destruct = dccp_sk_destruct; + icsk->icsk_sync_mss = dccp_sync_mss; + dp->dccps_mss_cache = 536; + dp->dccps_rate_last = jiffies; + dp->dccps_role = DCCP_ROLE_UNDEFINED; + dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT; + dp->dccps_tx_qlen = sysctl_dccp_tx_qlen; + + dccp_init_xmit_timers(sk); + + INIT_LIST_HEAD(&dp->dccps_featneg); + /* control socket doesn't need feat nego */ + if (likely(ctl_sock_initialized)) + return dccp_feat_init(sk); + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_init_sock); + +void dccp_destroy_sock(struct sock *sk) +{ + struct dccp_sock *dp = dccp_sk(sk); + + __skb_queue_purge(&sk->sk_write_queue); + if (sk->sk_send_head != NULL) { + kfree_skb(sk->sk_send_head); + sk->sk_send_head = NULL; + } + + /* Clean up a referenced DCCP bind bucket. */ + if (inet_csk(sk)->icsk_bind_hash != NULL) + inet_put_port(sk); + + kfree(dp->dccps_service_list); + dp->dccps_service_list = NULL; + + if (dp->dccps_hc_rx_ackvec != NULL) { + dccp_ackvec_free(dp->dccps_hc_rx_ackvec); + dp->dccps_hc_rx_ackvec = NULL; + } + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + dp->dccps_hc_rx_ccid = NULL; + + /* clean up feature negotiation state */ + dccp_feat_list_purge(&dp->dccps_featneg); +} + +EXPORT_SYMBOL_GPL(dccp_destroy_sock); + +static inline int dccp_need_reset(int state) +{ + return state != DCCP_CLOSED && state != DCCP_LISTEN && + state != DCCP_REQUESTING; +} + +int dccp_disconnect(struct sock *sk, int flags) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + struct inet_sock *inet = inet_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); + const int old_state = sk->sk_state; + + if (old_state != DCCP_CLOSED) + dccp_set_state(sk, DCCP_CLOSED); + + /* + * This corresponds to the ABORT function of RFC793, sec. 3.8 + * TCP uses a RST segment, DCCP a Reset packet with Code 2, "Aborted". + */ + if (old_state == DCCP_LISTEN) { + inet_csk_listen_stop(sk); + } else if (dccp_need_reset(old_state)) { + dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); + sk->sk_err = ECONNRESET; + } else if (old_state == DCCP_REQUESTING) + sk->sk_err = ECONNRESET; + + dccp_clear_xmit_timers(sk); + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + dp->dccps_hc_rx_ccid = NULL; + + __skb_queue_purge(&sk->sk_receive_queue); + __skb_queue_purge(&sk->sk_write_queue); + if (sk->sk_send_head != NULL) { + __kfree_skb(sk->sk_send_head); + sk->sk_send_head = NULL; + } + + inet->inet_dport = 0; + + inet_bhash2_reset_saddr(sk); + + sk->sk_shutdown = 0; + sock_reset_flag(sk, SOCK_DONE); + + icsk->icsk_backoff = 0; + inet_csk_delack_init(sk); + __sk_dst_reset(sk); + + WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); + + sk_error_report(sk); + return 0; +} + +EXPORT_SYMBOL_GPL(dccp_disconnect); + +/* + * Wait for a DCCP event. + * + * Note that we don't need to lock the socket, as the upper poll layers + * take care of normal races (between the test and the event) and we don't + * go look at any of the socket buffers directly. + */ +__poll_t dccp_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + __poll_t mask; + u8 shutdown; + int state; + + sock_poll_wait(file, sock, wait); + + state = inet_sk_state_load(sk); + if (state == DCCP_LISTEN) + return inet_csk_listen_poll(sk); + + /* Socket is not locked. We are protected from async events + by poll logic and correct handling of state changes + made by another threads is impossible in any case. + */ + + mask = 0; + if (READ_ONCE(sk->sk_err)) + mask = EPOLLERR; + shutdown = READ_ONCE(sk->sk_shutdown); + + if (shutdown == SHUTDOWN_MASK || state == DCCP_CLOSED) + mask |= EPOLLHUP; + if (shutdown & RCV_SHUTDOWN) + mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; + + /* Connected? */ + if ((1 << state) & ~(DCCPF_REQUESTING | DCCPF_RESPOND)) { + if (atomic_read(&sk->sk_rmem_alloc) > 0) + mask |= EPOLLIN | EPOLLRDNORM; + + if (!(shutdown & SEND_SHUTDOWN)) { + if (sk_stream_is_writeable(sk)) { + mask |= EPOLLOUT | EPOLLWRNORM; + } else { /* send SIGIO later */ + sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk); + set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); + + /* Race breaker. If space is freed after + * wspace test but before the flags are set, + * IO signal will be lost. + */ + if (sk_stream_is_writeable(sk)) + mask |= EPOLLOUT | EPOLLWRNORM; + } + } + } + return mask; +} +EXPORT_SYMBOL_GPL(dccp_poll); + +int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) +{ + int rc = -ENOTCONN; + + lock_sock(sk); + + if (sk->sk_state == DCCP_LISTEN) + goto out; + + switch (cmd) { + case SIOCOUTQ: { + int amount = sk_wmem_alloc_get(sk); + /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and + * always 0, comparably to UDP. + */ + + rc = put_user(amount, (int __user *)arg); + } + break; + case SIOCINQ: { + struct sk_buff *skb; + unsigned long amount = 0; + + skb = skb_peek(&sk->sk_receive_queue); + if (skb != NULL) { + /* + * We will only return the amount of this packet since + * that is all that will be read. + */ + amount = skb->len; + } + rc = put_user(amount, (int __user *)arg); + } + break; + default: + rc = -ENOIOCTLCMD; + break; + } +out: + release_sock(sk); + return rc; +} + +EXPORT_SYMBOL_GPL(dccp_ioctl); + +static int dccp_setsockopt_service(struct sock *sk, const __be32 service, + sockptr_t optval, unsigned int optlen) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_service_list *sl = NULL; + + if (service == DCCP_SERVICE_INVALID_VALUE || + optlen > DCCP_SERVICE_LIST_MAX_LEN * sizeof(u32)) + return -EINVAL; + + if (optlen > sizeof(service)) { + sl = kmalloc(optlen, GFP_KERNEL); + if (sl == NULL) + return -ENOMEM; + + sl->dccpsl_nr = optlen / sizeof(u32) - 1; + if (copy_from_sockptr_offset(sl->dccpsl_list, optval, + sizeof(service), optlen - sizeof(service)) || + dccp_list_has_service(sl, DCCP_SERVICE_INVALID_VALUE)) { + kfree(sl); + return -EFAULT; + } + } + + lock_sock(sk); + dp->dccps_service = service; + + kfree(dp->dccps_service_list); + + dp->dccps_service_list = sl; + release_sock(sk); + return 0; +} + +static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) +{ + u8 *list, len; + int i, rc; + + if (cscov < 0 || cscov > 15) + return -EINVAL; + /* + * Populate a list of permissible values, in the range cscov...15. This + * is necessary since feature negotiation of single values only works if + * both sides incidentally choose the same value. Since the list starts + * lowest-value first, negotiation will pick the smallest shared value. + */ + if (cscov == 0) + return 0; + len = 16 - cscov; + + list = kmalloc(len, GFP_KERNEL); + if (list == NULL) + return -ENOBUFS; + + for (i = 0; i < len; i++) + list[i] = cscov++; + + rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); + + if (rc == 0) { + if (rx) + dccp_sk(sk)->dccps_pcrlen = cscov; + else + dccp_sk(sk)->dccps_pcslen = cscov; + } + kfree(list); + return rc; +} + +static int dccp_setsockopt_ccid(struct sock *sk, int type, + sockptr_t optval, unsigned int optlen) +{ + u8 *val; + int rc = 0; + + if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS) + return -EINVAL; + + val = memdup_sockptr(optval, optlen); + if (IS_ERR(val)) + return PTR_ERR(val); + + lock_sock(sk); + if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID) + rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen); + + if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID)) + rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen); + release_sock(sk); + + kfree(val); + return rc; +} + +static int do_dccp_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen) +{ + struct dccp_sock *dp = dccp_sk(sk); + int val, err = 0; + + switch (optname) { + case DCCP_SOCKOPT_PACKET_SIZE: + DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); + return 0; + case DCCP_SOCKOPT_CHANGE_L: + case DCCP_SOCKOPT_CHANGE_R: + DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n"); + return 0; + case DCCP_SOCKOPT_CCID: + case DCCP_SOCKOPT_RX_CCID: + case DCCP_SOCKOPT_TX_CCID: + return dccp_setsockopt_ccid(sk, optname, optval, optlen); + } + + if (optlen < (int)sizeof(int)) + return -EINVAL; + + if (copy_from_sockptr(&val, optval, sizeof(int))) + return -EFAULT; + + if (optname == DCCP_SOCKOPT_SERVICE) + return dccp_setsockopt_service(sk, val, optval, optlen); + + lock_sock(sk); + switch (optname) { + case DCCP_SOCKOPT_SERVER_TIMEWAIT: + if (dp->dccps_role != DCCP_ROLE_SERVER) + err = -EOPNOTSUPP; + else + dp->dccps_server_timewait = (val != 0); + break; + case DCCP_SOCKOPT_SEND_CSCOV: + err = dccp_setsockopt_cscov(sk, val, false); + break; + case DCCP_SOCKOPT_RECV_CSCOV: + err = dccp_setsockopt_cscov(sk, val, true); + break; + case DCCP_SOCKOPT_QPOLICY_ID: + if (sk->sk_state != DCCP_CLOSED) + err = -EISCONN; + else if (val < 0 || val >= DCCPQ_POLICY_MAX) + err = -EINVAL; + else + dp->dccps_qpolicy = val; + break; + case DCCP_SOCKOPT_QPOLICY_TXQLEN: + if (val < 0) + err = -EINVAL; + else + dp->dccps_tx_qlen = val; + break; + default: + err = -ENOPROTOOPT; + break; + } + release_sock(sk); + + return err; +} + +int dccp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen) +{ + if (level != SOL_DCCP) + return inet_csk(sk)->icsk_af_ops->setsockopt(sk, level, + optname, optval, + optlen); + return do_dccp_setsockopt(sk, level, optname, optval, optlen); +} + +EXPORT_SYMBOL_GPL(dccp_setsockopt); + +static int dccp_getsockopt_service(struct sock *sk, int len, + __be32 __user *optval, + int __user *optlen) +{ + const struct dccp_sock *dp = dccp_sk(sk); + const struct dccp_service_list *sl; + int err = -ENOENT, slen = 0, total_len = sizeof(u32); + + lock_sock(sk); + if ((sl = dp->dccps_service_list) != NULL) { + slen = sl->dccpsl_nr * sizeof(u32); + total_len += slen; + } + + err = -EINVAL; + if (total_len > len) + goto out; + + err = 0; + if (put_user(total_len, optlen) || + put_user(dp->dccps_service, optval) || + (sl != NULL && copy_to_user(optval + 1, sl->dccpsl_list, slen))) + err = -EFAULT; +out: + release_sock(sk); + return err; +} + +static int do_dccp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + struct dccp_sock *dp; + int val, len; + + if (get_user(len, optlen)) + return -EFAULT; + + if (len < (int)sizeof(int)) + return -EINVAL; + + dp = dccp_sk(sk); + + switch (optname) { + case DCCP_SOCKOPT_PACKET_SIZE: + DCCP_WARN("sockopt(PACKET_SIZE) is deprecated: fix your app\n"); + return 0; + case DCCP_SOCKOPT_SERVICE: + return dccp_getsockopt_service(sk, len, + (__be32 __user *)optval, optlen); + case DCCP_SOCKOPT_GET_CUR_MPS: + val = READ_ONCE(dp->dccps_mss_cache); + break; + case DCCP_SOCKOPT_AVAILABLE_CCIDS: + return ccid_getsockopt_builtin_ccids(sk, len, optval, optlen); + case DCCP_SOCKOPT_TX_CCID: + val = ccid_get_current_tx_ccid(dp); + if (val < 0) + return -ENOPROTOOPT; + break; + case DCCP_SOCKOPT_RX_CCID: + val = ccid_get_current_rx_ccid(dp); + if (val < 0) + return -ENOPROTOOPT; + break; + case DCCP_SOCKOPT_SERVER_TIMEWAIT: + val = dp->dccps_server_timewait; + break; + case DCCP_SOCKOPT_SEND_CSCOV: + val = dp->dccps_pcslen; + break; + case DCCP_SOCKOPT_RECV_CSCOV: + val = dp->dccps_pcrlen; + break; + case DCCP_SOCKOPT_QPOLICY_ID: + val = dp->dccps_qpolicy; + break; + case DCCP_SOCKOPT_QPOLICY_TXQLEN: + val = dp->dccps_tx_qlen; + break; + case 128 ... 191: + return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname, + len, (u32 __user *)optval, optlen); + case 192 ... 255: + return ccid_hc_tx_getsockopt(dp->dccps_hc_tx_ccid, sk, optname, + len, (u32 __user *)optval, optlen); + default: + return -ENOPROTOOPT; + } + + len = sizeof(val); + if (put_user(len, optlen) || copy_to_user(optval, &val, len)) + return -EFAULT; + + return 0; +} + +int dccp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen) +{ + if (level != SOL_DCCP) + return inet_csk(sk)->icsk_af_ops->getsockopt(sk, level, + optname, optval, + optlen); + return do_dccp_getsockopt(sk, level, optname, optval, optlen); +} + +EXPORT_SYMBOL_GPL(dccp_getsockopt); + +static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb) +{ + struct cmsghdr *cmsg; + + /* + * Assign an (opaque) qpolicy priority value to skb->priority. + * + * We are overloading this skb field for use with the qpolicy subystem. + * The skb->priority is normally used for the SO_PRIORITY option, which + * is initialised from sk_priority. Since the assignment of sk_priority + * to skb->priority happens later (on layer 3), we overload this field + * for use with queueing priorities as long as the skb is on layer 4. + * The default priority value (if nothing is set) is 0. + */ + skb->priority = 0; + + for_each_cmsghdr(cmsg, msg) { + if (!CMSG_OK(msg, cmsg)) + return -EINVAL; + + if (cmsg->cmsg_level != SOL_DCCP) + continue; + + if (cmsg->cmsg_type <= DCCP_SCM_QPOLICY_MAX && + !dccp_qpolicy_param_ok(skb->sk, cmsg->cmsg_type)) + return -EINVAL; + + switch (cmsg->cmsg_type) { + case DCCP_SCM_PRIORITY: + if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32))) + return -EINVAL; + skb->priority = *(__u32 *)CMSG_DATA(cmsg); + break; + default: + return -EINVAL; + } + } + return 0; +} + +int dccp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) +{ + const struct dccp_sock *dp = dccp_sk(sk); + const int flags = msg->msg_flags; + const int noblock = flags & MSG_DONTWAIT; + struct sk_buff *skb; + int rc, size; + long timeo; + + trace_dccp_probe(sk, len); + + if (len > READ_ONCE(dp->dccps_mss_cache)) + return -EMSGSIZE; + + lock_sock(sk); + + timeo = sock_sndtimeo(sk, noblock); + + /* + * We have to use sk_stream_wait_connect here to set sk_write_pending, + * so that the trick in dccp_rcv_request_sent_state_process. + */ + /* Wait for a connection to finish. */ + if ((1 << sk->sk_state) & ~(DCCPF_OPEN | DCCPF_PARTOPEN)) + if ((rc = sk_stream_wait_connect(sk, &timeo)) != 0) + goto out_release; + + size = sk->sk_prot->max_header + len; + release_sock(sk); + skb = sock_alloc_send_skb(sk, size, noblock, &rc); + lock_sock(sk); + if (skb == NULL) + goto out_release; + + if (dccp_qpolicy_full(sk)) { + rc = -EAGAIN; + goto out_discard; + } + + if (sk->sk_state == DCCP_CLOSED) { + rc = -ENOTCONN; + goto out_discard; + } + + /* We need to check dccps_mss_cache after socket is locked. */ + if (len > dp->dccps_mss_cache) { + rc = -EMSGSIZE; + goto out_discard; + } + + skb_reserve(skb, sk->sk_prot->max_header); + rc = memcpy_from_msg(skb_put(skb, len), msg, len); + if (rc != 0) + goto out_discard; + + rc = dccp_msghdr_parse(msg, skb); + if (rc != 0) + goto out_discard; + + dccp_qpolicy_push(sk, skb); + /* + * The xmit_timer is set if the TX CCID is rate-based and will expire + * when congestion control permits to release further packets into the + * network. Window-based CCIDs do not use this timer. + */ + if (!timer_pending(&dp->dccps_xmit_timer)) + dccp_write_xmit(sk); +out_release: + release_sock(sk); + return rc ? : len; +out_discard: + kfree_skb(skb); + goto out_release; +} + +EXPORT_SYMBOL_GPL(dccp_sendmsg); + +int dccp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, + int *addr_len) +{ + const struct dccp_hdr *dh; + long timeo; + + lock_sock(sk); + + if (sk->sk_state == DCCP_LISTEN) { + len = -ENOTCONN; + goto out; + } + + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + + do { + struct sk_buff *skb = skb_peek(&sk->sk_receive_queue); + + if (skb == NULL) + goto verify_sock_status; + + dh = dccp_hdr(skb); + + switch (dh->dccph_type) { + case DCCP_PKT_DATA: + case DCCP_PKT_DATAACK: + goto found_ok_skb; + + case DCCP_PKT_CLOSE: + case DCCP_PKT_CLOSEREQ: + if (!(flags & MSG_PEEK)) + dccp_finish_passive_close(sk); + fallthrough; + case DCCP_PKT_RESET: + dccp_pr_debug("found fin (%s) ok!\n", + dccp_packet_name(dh->dccph_type)); + len = 0; + goto found_fin_ok; + default: + dccp_pr_debug("packet_type=%s\n", + dccp_packet_name(dh->dccph_type)); + sk_eat_skb(sk, skb); + } +verify_sock_status: + if (sock_flag(sk, SOCK_DONE)) { + len = 0; + break; + } + + if (sk->sk_err) { + len = sock_error(sk); + break; + } + + if (sk->sk_shutdown & RCV_SHUTDOWN) { + len = 0; + break; + } + + if (sk->sk_state == DCCP_CLOSED) { + if (!sock_flag(sk, SOCK_DONE)) { + /* This occurs when user tries to read + * from never connected socket. + */ + len = -ENOTCONN; + break; + } + len = 0; + break; + } + + if (!timeo) { + len = -EAGAIN; + break; + } + + if (signal_pending(current)) { + len = sock_intr_errno(timeo); + break; + } + + sk_wait_data(sk, &timeo, NULL); + continue; + found_ok_skb: + if (len > skb->len) + len = skb->len; + else if (len < skb->len) + msg->msg_flags |= MSG_TRUNC; + + if (skb_copy_datagram_msg(skb, 0, msg, len)) { + /* Exception. Bailout! */ + len = -EFAULT; + break; + } + if (flags & MSG_TRUNC) + len = skb->len; + found_fin_ok: + if (!(flags & MSG_PEEK)) + sk_eat_skb(sk, skb); + break; + } while (1); +out: + release_sock(sk); + return len; +} + +EXPORT_SYMBOL_GPL(dccp_recvmsg); + +int inet_dccp_listen(struct socket *sock, int backlog) +{ + struct sock *sk = sock->sk; + unsigned char old_state; + int err; + + lock_sock(sk); + + err = -EINVAL; + if (sock->state != SS_UNCONNECTED || sock->type != SOCK_DCCP) + goto out; + + old_state = sk->sk_state; + if (!((1 << old_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) + goto out; + + WRITE_ONCE(sk->sk_max_ack_backlog, backlog); + /* Really, if the socket is already in listen state + * we can only allow the backlog to be adjusted. + */ + if (old_state != DCCP_LISTEN) { + struct dccp_sock *dp = dccp_sk(sk); + + dp->dccps_role = DCCP_ROLE_LISTEN; + + /* do not start to listen if feature negotiation setup fails */ + if (dccp_feat_finalise_settings(dp)) { + err = -EPROTO; + goto out; + } + + err = inet_csk_listen_start(sk); + if (err) + goto out; + } + err = 0; + +out: + release_sock(sk); + return err; +} + +EXPORT_SYMBOL_GPL(inet_dccp_listen); + +static void dccp_terminate_connection(struct sock *sk) +{ + u8 next_state = DCCP_CLOSED; + + switch (sk->sk_state) { + case DCCP_PASSIVE_CLOSE: + case DCCP_PASSIVE_CLOSEREQ: + dccp_finish_passive_close(sk); + break; + case DCCP_PARTOPEN: + dccp_pr_debug("Stop PARTOPEN timer (%p)\n", sk); + inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); + fallthrough; + case DCCP_OPEN: + dccp_send_close(sk, 1); + + if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER && + !dccp_sk(sk)->dccps_server_timewait) + next_state = DCCP_ACTIVE_CLOSEREQ; + else + next_state = DCCP_CLOSING; + fallthrough; + default: + dccp_set_state(sk, next_state); + } +} + +void dccp_close(struct sock *sk, long timeout) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct sk_buff *skb; + u32 data_was_unread = 0; + int state; + + lock_sock(sk); + + sk->sk_shutdown = SHUTDOWN_MASK; + + if (sk->sk_state == DCCP_LISTEN) { + dccp_set_state(sk, DCCP_CLOSED); + + /* Special case. */ + inet_csk_listen_stop(sk); + + goto adjudge_to_death; + } + + sk_stop_timer(sk, &dp->dccps_xmit_timer); + + /* + * We need to flush the recv. buffs. We do this only on the + * descriptor close, not protocol-sourced closes, because the + *reader process may not have drained the data yet! + */ + while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { + data_was_unread += skb->len; + __kfree_skb(skb); + } + + /* If socket has been already reset kill it. */ + if (sk->sk_state == DCCP_CLOSED) + goto adjudge_to_death; + + if (data_was_unread) { + /* Unread data was tossed, send an appropriate Reset Code */ + DCCP_WARN("ABORT with %u bytes unread\n", data_was_unread); + dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); + dccp_set_state(sk, DCCP_CLOSED); + } else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) { + /* Check zero linger _after_ checking for unread data. */ + sk->sk_prot->disconnect(sk, 0); + } else if (sk->sk_state != DCCP_CLOSED) { + /* + * Normal connection termination. May need to wait if there are + * still packets in the TX queue that are delayed by the CCID. + */ + dccp_flush_write_queue(sk, &timeout); + dccp_terminate_connection(sk); + } + + /* + * Flush write queue. This may be necessary in several cases: + * - we have been closed by the peer but still have application data; + * - abortive termination (unread data or zero linger time), + * - normal termination but queue could not be flushed within time limit + */ + __skb_queue_purge(&sk->sk_write_queue); + + sk_stream_wait_close(sk, timeout); + +adjudge_to_death: + state = sk->sk_state; + sock_hold(sk); + sock_orphan(sk); + + /* + * It is the last release_sock in its life. It will remove backlog. + */ + release_sock(sk); + /* + * Now socket is owned by kernel and we acquire BH lock + * to finish close. No need to check for user refs. + */ + local_bh_disable(); + bh_lock_sock(sk); + WARN_ON(sock_owned_by_user(sk)); + + this_cpu_inc(dccp_orphan_count); + + /* Have we already been destroyed by a softirq or backlog? */ + if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED) + goto out; + + if (sk->sk_state == DCCP_CLOSED) + inet_csk_destroy_sock(sk); + + /* Otherwise, socket is reprieved until protocol close. */ + +out: + bh_unlock_sock(sk); + local_bh_enable(); + sock_put(sk); +} + +EXPORT_SYMBOL_GPL(dccp_close); + +void dccp_shutdown(struct sock *sk, int how) +{ + dccp_pr_debug("called shutdown(%x)\n", how); +} + +EXPORT_SYMBOL_GPL(dccp_shutdown); + +static inline int __init dccp_mib_init(void) +{ + dccp_statistics = alloc_percpu(struct dccp_mib); + if (!dccp_statistics) + return -ENOMEM; + return 0; +} + +static inline void dccp_mib_exit(void) +{ + free_percpu(dccp_statistics); +} + +static int thash_entries; +module_param(thash_entries, int, 0444); +MODULE_PARM_DESC(thash_entries, "Number of ehash buckets"); + +#ifdef CONFIG_IP_DCCP_DEBUG +bool dccp_debug; +module_param(dccp_debug, bool, 0644); +MODULE_PARM_DESC(dccp_debug, "Enable debug messages"); + +EXPORT_SYMBOL_GPL(dccp_debug); +#endif + +static int __init dccp_init(void) +{ + unsigned long goal; + unsigned long nr_pages = totalram_pages(); + int ehash_order, bhash_order, i; + int rc; + + BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > + sizeof_field(struct sk_buff, cb)); + rc = inet_hashinfo2_init_mod(&dccp_hashinfo); + if (rc) + goto out_fail; + rc = -ENOBUFS; + dccp_hashinfo.bind_bucket_cachep = + kmem_cache_create("dccp_bind_bucket", + sizeof(struct inet_bind_bucket), 0, + SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); + if (!dccp_hashinfo.bind_bucket_cachep) + goto out_free_hashinfo2; + dccp_hashinfo.bind2_bucket_cachep = + kmem_cache_create("dccp_bind2_bucket", + sizeof(struct inet_bind2_bucket), 0, + SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); + if (!dccp_hashinfo.bind2_bucket_cachep) + goto out_free_bind_bucket_cachep; + + /* + * Size and allocate the main established and bind bucket + * hash tables. + * + * The methodology is similar to that of the buffer cache. + */ + if (nr_pages >= (128 * 1024)) + goal = nr_pages >> (21 - PAGE_SHIFT); + else + goal = nr_pages >> (23 - PAGE_SHIFT); + + if (thash_entries) + goal = (thash_entries * + sizeof(struct inet_ehash_bucket)) >> PAGE_SHIFT; + for (ehash_order = 0; (1UL << ehash_order) < goal; ehash_order++) + ; + do { + unsigned long hash_size = (1UL << ehash_order) * PAGE_SIZE / + sizeof(struct inet_ehash_bucket); + + while (hash_size & (hash_size - 1)) + hash_size--; + dccp_hashinfo.ehash_mask = hash_size - 1; + dccp_hashinfo.ehash = (struct inet_ehash_bucket *) + __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, ehash_order); + } while (!dccp_hashinfo.ehash && --ehash_order > 0); + + if (!dccp_hashinfo.ehash) { + DCCP_CRIT("Failed to allocate DCCP established hash table"); + goto out_free_bind2_bucket_cachep; + } + + for (i = 0; i <= dccp_hashinfo.ehash_mask; i++) + INIT_HLIST_NULLS_HEAD(&dccp_hashinfo.ehash[i].chain, i); + + if (inet_ehash_locks_alloc(&dccp_hashinfo)) + goto out_free_dccp_ehash; + + bhash_order = ehash_order; + + do { + dccp_hashinfo.bhash_size = (1UL << bhash_order) * PAGE_SIZE / + sizeof(struct inet_bind_hashbucket); + if ((dccp_hashinfo.bhash_size > (64 * 1024)) && + bhash_order > 0) + continue; + dccp_hashinfo.bhash = (struct inet_bind_hashbucket *) + __get_free_pages(GFP_ATOMIC|__GFP_NOWARN, bhash_order); + } while (!dccp_hashinfo.bhash && --bhash_order >= 0); + + if (!dccp_hashinfo.bhash) { + DCCP_CRIT("Failed to allocate DCCP bind hash table"); + goto out_free_dccp_locks; + } + + dccp_hashinfo.bhash2 = (struct inet_bind_hashbucket *) + __get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order); + + if (!dccp_hashinfo.bhash2) { + DCCP_CRIT("Failed to allocate DCCP bind2 hash table"); + goto out_free_dccp_bhash; + } + + for (i = 0; i < dccp_hashinfo.bhash_size; i++) { + spin_lock_init(&dccp_hashinfo.bhash[i].lock); + INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain); + spin_lock_init(&dccp_hashinfo.bhash2[i].lock); + INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain); + } + + dccp_hashinfo.pernet = false; + + rc = dccp_mib_init(); + if (rc) + goto out_free_dccp_bhash2; + + rc = dccp_ackvec_init(); + if (rc) + goto out_free_dccp_mib; + + rc = dccp_sysctl_init(); + if (rc) + goto out_ackvec_exit; + + rc = ccid_initialize_builtins(); + if (rc) + goto out_sysctl_exit; + + dccp_timestamping_init(); + + return 0; + +out_sysctl_exit: + dccp_sysctl_exit(); +out_ackvec_exit: + dccp_ackvec_exit(); +out_free_dccp_mib: + dccp_mib_exit(); +out_free_dccp_bhash2: + free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order); +out_free_dccp_bhash: + free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); +out_free_dccp_locks: + inet_ehash_locks_free(&dccp_hashinfo); +out_free_dccp_ehash: + free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order); +out_free_bind2_bucket_cachep: + kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep); +out_free_bind_bucket_cachep: + kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); +out_free_hashinfo2: + inet_hashinfo2_free_mod(&dccp_hashinfo); +out_fail: + dccp_hashinfo.bhash = NULL; + dccp_hashinfo.bhash2 = NULL; + dccp_hashinfo.ehash = NULL; + dccp_hashinfo.bind_bucket_cachep = NULL; + dccp_hashinfo.bind2_bucket_cachep = NULL; + return rc; +} + +static void __exit dccp_fini(void) +{ + int bhash_order = get_order(dccp_hashinfo.bhash_size * + sizeof(struct inet_bind_hashbucket)); + + ccid_cleanup_builtins(); + dccp_mib_exit(); + free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order); + free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order); + free_pages((unsigned long)dccp_hashinfo.ehash, + get_order((dccp_hashinfo.ehash_mask + 1) * + sizeof(struct inet_ehash_bucket))); + inet_ehash_locks_free(&dccp_hashinfo); + kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep); + dccp_ackvec_exit(); + dccp_sysctl_exit(); + inet_hashinfo2_free_mod(&dccp_hashinfo); +} + +module_init(dccp_init); +module_exit(dccp_fini); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Arnaldo Carvalho de Melo "); +MODULE_DESCRIPTION("DCCP - Datagram Congestion Controlled Protocol"); diff --git a/net/dccp/qpolicy.c b/net/dccp/qpolicy.c new file mode 100644 index 000000000..5ba204ec0 --- /dev/null +++ b/net/dccp/qpolicy.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/qpolicy.c + * + * Policy-based packet dequeueing interface for DCCP. + * + * Copyright (c) 2008 Tomasz Grobelny + */ +#include "dccp.h" + +/* + * Simple Dequeueing Policy: + * If tx_qlen is different from 0, enqueue up to tx_qlen elements. + */ +static void qpolicy_simple_push(struct sock *sk, struct sk_buff *skb) +{ + skb_queue_tail(&sk->sk_write_queue, skb); +} + +static bool qpolicy_simple_full(struct sock *sk) +{ + return dccp_sk(sk)->dccps_tx_qlen && + sk->sk_write_queue.qlen >= dccp_sk(sk)->dccps_tx_qlen; +} + +static struct sk_buff *qpolicy_simple_top(struct sock *sk) +{ + return skb_peek(&sk->sk_write_queue); +} + +/* + * Priority-based Dequeueing Policy: + * If tx_qlen is different from 0 and the queue has reached its upper bound + * of tx_qlen elements, replace older packets lowest-priority-first. + */ +static struct sk_buff *qpolicy_prio_best_skb(struct sock *sk) +{ + struct sk_buff *skb, *best = NULL; + + skb_queue_walk(&sk->sk_write_queue, skb) + if (best == NULL || skb->priority > best->priority) + best = skb; + return best; +} + +static struct sk_buff *qpolicy_prio_worst_skb(struct sock *sk) +{ + struct sk_buff *skb, *worst = NULL; + + skb_queue_walk(&sk->sk_write_queue, skb) + if (worst == NULL || skb->priority < worst->priority) + worst = skb; + return worst; +} + +static bool qpolicy_prio_full(struct sock *sk) +{ + if (qpolicy_simple_full(sk)) + dccp_qpolicy_drop(sk, qpolicy_prio_worst_skb(sk)); + return false; +} + +/** + * struct dccp_qpolicy_operations - TX Packet Dequeueing Interface + * @push: add a new @skb to the write queue + * @full: indicates that no more packets will be admitted + * @top: peeks at whatever the queueing policy defines as its `top' + * @params: parameter passed to policy operation + */ +struct dccp_qpolicy_operations { + void (*push) (struct sock *sk, struct sk_buff *skb); + bool (*full) (struct sock *sk); + struct sk_buff* (*top) (struct sock *sk); + __be32 params; +}; + +static struct dccp_qpolicy_operations qpol_table[DCCPQ_POLICY_MAX] = { + [DCCPQ_POLICY_SIMPLE] = { + .push = qpolicy_simple_push, + .full = qpolicy_simple_full, + .top = qpolicy_simple_top, + .params = 0, + }, + [DCCPQ_POLICY_PRIO] = { + .push = qpolicy_simple_push, + .full = qpolicy_prio_full, + .top = qpolicy_prio_best_skb, + .params = DCCP_SCM_PRIORITY, + }, +}; + +/* + * Externally visible interface + */ +void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb) +{ + qpol_table[dccp_sk(sk)->dccps_qpolicy].push(sk, skb); +} + +bool dccp_qpolicy_full(struct sock *sk) +{ + return qpol_table[dccp_sk(sk)->dccps_qpolicy].full(sk); +} + +void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb) +{ + if (skb != NULL) { + skb_unlink(skb, &sk->sk_write_queue); + kfree_skb(skb); + } +} + +struct sk_buff *dccp_qpolicy_top(struct sock *sk) +{ + return qpol_table[dccp_sk(sk)->dccps_qpolicy].top(sk); +} + +struct sk_buff *dccp_qpolicy_pop(struct sock *sk) +{ + struct sk_buff *skb = dccp_qpolicy_top(sk); + + if (skb != NULL) { + /* Clear any skb fields that we used internally */ + skb->priority = 0; + skb_unlink(skb, &sk->sk_write_queue); + } + return skb; +} + +bool dccp_qpolicy_param_ok(struct sock *sk, __be32 param) +{ + /* check if exactly one bit is set */ + if (!param || (param & (param - 1))) + return false; + return (qpol_table[dccp_sk(sk)->dccps_qpolicy].params & param) == param; +} diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c new file mode 100644 index 000000000..ee8d4f5af --- /dev/null +++ b/net/dccp/sysctl.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * net/dccp/sysctl.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include "dccp.h" +#include "feat.h" + +#ifndef CONFIG_SYSCTL +#error This file should not be compiled without CONFIG_SYSCTL defined +#endif + +/* Boundary values */ +static int u8_max = 0xFF; +static unsigned long seqw_min = DCCPF_SEQ_WMIN, + seqw_max = 0xFFFFFFFF; /* maximum on 32 bit */ + +static struct ctl_table dccp_default_table[] = { + { + .procname = "seq_window", + .data = &sysctl_dccp_sequence_window, + .maxlen = sizeof(sysctl_dccp_sequence_window), + .mode = 0644, + .proc_handler = proc_doulongvec_minmax, + .extra1 = &seqw_min, /* RFC 4340, 7.5.2 */ + .extra2 = &seqw_max, + }, + { + .procname = "rx_ccid", + .data = &sysctl_dccp_rx_ccid, + .maxlen = sizeof(sysctl_dccp_rx_ccid), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &u8_max, /* RFC 4340, 10. */ + }, + { + .procname = "tx_ccid", + .data = &sysctl_dccp_tx_ccid, + .maxlen = sizeof(sysctl_dccp_tx_ccid), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &u8_max, /* RFC 4340, 10. */ + }, + { + .procname = "request_retries", + .data = &sysctl_dccp_request_retries, + .maxlen = sizeof(sysctl_dccp_request_retries), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = &u8_max, + }, + { + .procname = "retries1", + .data = &sysctl_dccp_retries1, + .maxlen = sizeof(sysctl_dccp_retries1), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &u8_max, + }, + { + .procname = "retries2", + .data = &sysctl_dccp_retries2, + .maxlen = sizeof(sysctl_dccp_retries2), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = &u8_max, + }, + { + .procname = "tx_qlen", + .data = &sysctl_dccp_tx_qlen, + .maxlen = sizeof(sysctl_dccp_tx_qlen), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + }, + { + .procname = "sync_ratelimit", + .data = &sysctl_dccp_sync_ratelimit, + .maxlen = sizeof(sysctl_dccp_sync_ratelimit), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + + { } +}; + +static struct ctl_table_header *dccp_table_header; + +int __init dccp_sysctl_init(void) +{ + dccp_table_header = register_net_sysctl(&init_net, "net/dccp/default", + dccp_default_table); + + return dccp_table_header != NULL ? 0 : -ENOMEM; +} + +void dccp_sysctl_exit(void) +{ + if (dccp_table_header != NULL) { + unregister_net_sysctl_table(dccp_table_header); + dccp_table_header = NULL; + } +} diff --git a/net/dccp/timer.c b/net/dccp/timer.c new file mode 100644 index 000000000..27a3b37ac --- /dev/null +++ b/net/dccp/timer.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/dccp/timer.c + * + * An implementation of the DCCP protocol + * Arnaldo Carvalho de Melo + */ + +#include +#include +#include + +#include "dccp.h" + +/* sysctl variables governing numbers of retransmission attempts */ +int sysctl_dccp_request_retries __read_mostly = TCP_SYN_RETRIES; +int sysctl_dccp_retries1 __read_mostly = TCP_RETR1; +int sysctl_dccp_retries2 __read_mostly = TCP_RETR2; + +static void dccp_write_err(struct sock *sk) +{ + sk->sk_err = sk->sk_err_soft ? : ETIMEDOUT; + sk_error_report(sk); + + dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED); + dccp_done(sk); + __DCCP_INC_STATS(DCCP_MIB_ABORTONTIMEOUT); +} + +/* A write timeout has occurred. Process the after effects. */ +static int dccp_write_timeout(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + int retry_until; + + if (sk->sk_state == DCCP_REQUESTING || sk->sk_state == DCCP_PARTOPEN) { + if (icsk->icsk_retransmits != 0) + dst_negative_advice(sk); + retry_until = icsk->icsk_syn_retries ? + : sysctl_dccp_request_retries; + } else { + if (icsk->icsk_retransmits >= sysctl_dccp_retries1) { + /* NOTE. draft-ietf-tcpimpl-pmtud-01.txt requires pmtu + black hole detection. :-( + + It is place to make it. It is not made. I do not want + to make it. It is disguisting. It does not work in any + case. Let me to cite the same draft, which requires for + us to implement this: + + "The one security concern raised by this memo is that ICMP black holes + are often caused by over-zealous security administrators who block + all ICMP messages. It is vitally important that those who design and + deploy security systems understand the impact of strict filtering on + upper-layer protocols. The safest web site in the world is worthless + if most TCP implementations cannot transfer data from it. It would + be far nicer to have all of the black holes fixed rather than fixing + all of the TCP implementations." + + Golden words :-). + */ + + dst_negative_advice(sk); + } + + retry_until = sysctl_dccp_retries2; + /* + * FIXME: see tcp_write_timout and tcp_out_of_resources + */ + } + + if (icsk->icsk_retransmits >= retry_until) { + /* Has it gone just too far? */ + dccp_write_err(sk); + return 1; + } + return 0; +} + +/* + * The DCCP retransmit timer. + */ +static void dccp_retransmit_timer(struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + /* + * More than 4MSL (8 minutes) has passed, a RESET(aborted) was + * sent, no need to retransmit, this sock is dead. + */ + if (dccp_write_timeout(sk)) + return; + + /* + * We want to know the number of packets retransmitted, not the + * total number of retransmissions of clones of original packets. + */ + if (icsk->icsk_retransmits == 0) + __DCCP_INC_STATS(DCCP_MIB_TIMEOUTS); + + if (dccp_retransmit_skb(sk) != 0) { + /* + * Retransmission failed because of local congestion, + * do not backoff. + */ + if (--icsk->icsk_retransmits == 0) + icsk->icsk_retransmits = 1; + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + min(icsk->icsk_rto, + TCP_RESOURCE_PROBE_INTERVAL), + DCCP_RTO_MAX); + return; + } + + icsk->icsk_backoff++; + + icsk->icsk_rto = min(icsk->icsk_rto << 1, DCCP_RTO_MAX); + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, + DCCP_RTO_MAX); + if (icsk->icsk_retransmits > sysctl_dccp_retries1) + __sk_dst_reset(sk); +} + +static void dccp_write_timer(struct timer_list *t) +{ + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_retransmit_timer); + struct sock *sk = &icsk->icsk_inet.sk; + int event = 0; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + /* Try again later */ + sk_reset_timer(sk, &icsk->icsk_retransmit_timer, + jiffies + (HZ / 20)); + goto out; + } + + if (sk->sk_state == DCCP_CLOSED || !icsk->icsk_pending) + goto out; + + if (time_after(icsk->icsk_timeout, jiffies)) { + sk_reset_timer(sk, &icsk->icsk_retransmit_timer, + icsk->icsk_timeout); + goto out; + } + + event = icsk->icsk_pending; + icsk->icsk_pending = 0; + + switch (event) { + case ICSK_TIME_RETRANS: + dccp_retransmit_timer(sk); + break; + } +out: + bh_unlock_sock(sk); + sock_put(sk); +} + +static void dccp_keepalive_timer(struct timer_list *t) +{ + struct sock *sk = from_timer(sk, t, sk_timer); + + pr_err("dccp should not use a keepalive timer !\n"); + sock_put(sk); +} + +/* This is the same as tcp_delack_timer, sans prequeue & mem_reclaim stuff */ +static void dccp_delack_timer(struct timer_list *t) +{ + struct inet_connection_sock *icsk = + from_timer(icsk, t, icsk_delack_timer); + struct sock *sk = &icsk->icsk_inet.sk; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) { + /* Try again later. */ + __NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKLOCKED); + sk_reset_timer(sk, &icsk->icsk_delack_timer, + jiffies + TCP_DELACK_MIN); + goto out; + } + + if (sk->sk_state == DCCP_CLOSED || + !(icsk->icsk_ack.pending & ICSK_ACK_TIMER)) + goto out; + if (time_after(icsk->icsk_ack.timeout, jiffies)) { + sk_reset_timer(sk, &icsk->icsk_delack_timer, + icsk->icsk_ack.timeout); + goto out; + } + + icsk->icsk_ack.pending &= ~ICSK_ACK_TIMER; + + if (inet_csk_ack_scheduled(sk)) { + if (!inet_csk_in_pingpong_mode(sk)) { + /* Delayed ACK missed: inflate ATO. */ + icsk->icsk_ack.ato = min(icsk->icsk_ack.ato << 1, + icsk->icsk_rto); + } else { + /* Delayed ACK missed: leave pingpong mode and + * deflate ATO. + */ + inet_csk_exit_pingpong_mode(sk); + icsk->icsk_ack.ato = TCP_ATO_MIN; + } + dccp_send_ack(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_DELAYEDACKS); + } +out: + bh_unlock_sock(sk); + sock_put(sk); +} + +/** + * dccp_write_xmitlet - Workhorse for CCID packet dequeueing interface + * @t: pointer to the tasklet associated with this handler + * + * See the comments above %ccid_dequeueing_decision for supported modes. + */ +static void dccp_write_xmitlet(struct tasklet_struct *t) +{ + struct dccp_sock *dp = from_tasklet(dp, t, dccps_xmitlet); + struct sock *sk = &dp->dccps_inet_connection.icsk_inet.sk; + + bh_lock_sock(sk); + if (sock_owned_by_user(sk)) + sk_reset_timer(sk, &dccp_sk(sk)->dccps_xmit_timer, jiffies + 1); + else + dccp_write_xmit(sk); + bh_unlock_sock(sk); + sock_put(sk); +} + +static void dccp_write_xmit_timer(struct timer_list *t) +{ + struct dccp_sock *dp = from_timer(dp, t, dccps_xmit_timer); + + dccp_write_xmitlet(&dp->dccps_xmitlet); +} + +void dccp_init_xmit_timers(struct sock *sk) +{ + struct dccp_sock *dp = dccp_sk(sk); + + tasklet_setup(&dp->dccps_xmitlet, dccp_write_xmitlet); + timer_setup(&dp->dccps_xmit_timer, dccp_write_xmit_timer, 0); + inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer, + &dccp_keepalive_timer); +} + +static ktime_t dccp_timestamp_seed; +/** + * dccp_timestamp - 10s of microseconds time source + * Returns the number of 10s of microseconds since loading DCCP. This is native + * DCCP time difference format (RFC 4340, sec. 13). + * Please note: This will wrap around about circa every 11.9 hours. + */ +u32 dccp_timestamp(void) +{ + u64 delta = (u64)ktime_us_delta(ktime_get_real(), dccp_timestamp_seed); + + do_div(delta, 10); + return delta; +} +EXPORT_SYMBOL_GPL(dccp_timestamp); + +void __init dccp_timestamping_init(void) +{ + dccp_timestamp_seed = ktime_get_real(); +} diff --git a/net/dccp/trace.h b/net/dccp/trace.h new file mode 100644 index 000000000..5a43b3508 --- /dev/null +++ b/net/dccp/trace.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM dccp + +#if !defined(_TRACE_DCCP_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_DCCP_H + +#include +#include "dccp.h" +#include "ccids/ccid3.h" +#include +#include + +TRACE_EVENT(dccp_probe, + + TP_PROTO(struct sock *sk, size_t size), + + TP_ARGS(sk, size), + + TP_STRUCT__entry( + /* sockaddr_in6 is always bigger than sockaddr_in */ + __array(__u8, saddr, sizeof(struct sockaddr_in6)) + __array(__u8, daddr, sizeof(struct sockaddr_in6)) + __field(__u16, sport) + __field(__u16, dport) + __field(__u16, size) + __field(__u16, tx_s) + __field(__u32, tx_rtt) + __field(__u32, tx_p) + __field(__u32, tx_x_calc) + __field(__u64, tx_x_recv) + __field(__u64, tx_x) + __field(__u32, tx_t_ipi) + ), + + TP_fast_assign( + const struct inet_sock *inet = inet_sk(sk); + struct ccid3_hc_tx_sock *hc = NULL; + + if (ccid_get_current_tx_ccid(dccp_sk(sk)) == DCCPC_CCID3) + hc = ccid3_hc_tx_sk(sk); + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + + TP_STORE_ADDR_PORTS(__entry, inet, sk); + + /* For filtering use */ + __entry->sport = ntohs(inet->inet_sport); + __entry->dport = ntohs(inet->inet_dport); + + __entry->size = size; + if (hc) { + __entry->tx_s = hc->tx_s; + __entry->tx_rtt = hc->tx_rtt; + __entry->tx_p = hc->tx_p; + __entry->tx_x_calc = hc->tx_x_calc; + __entry->tx_x_recv = hc->tx_x_recv >> 6; + __entry->tx_x = hc->tx_x >> 6; + __entry->tx_t_ipi = hc->tx_t_ipi; + } else { + __entry->tx_s = 0; + memset_startat(__entry, 0, tx_rtt); + } + ), + + TP_printk("src=%pISpc dest=%pISpc size=%d tx_s=%d tx_rtt=%d " + "tx_p=%d tx_x_calc=%u tx_x_recv=%llu tx_x=%llu tx_t_ipi=%d", + __entry->saddr, __entry->daddr, __entry->size, + __entry->tx_s, __entry->tx_rtt, __entry->tx_p, + __entry->tx_x_calc, __entry->tx_x_recv, __entry->tx_x, + __entry->tx_t_ipi) +); + +#endif /* _TRACE_TCP_H */ + +/* This part must be outside protection */ +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE trace +#include -- cgit v1.2.3