diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_proto_sctp.c')
-rw-r--r-- | net/netfilter/nf_conntrack_proto_sctp.c | 730 |
1 files changed, 730 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c new file mode 100644 index 0000000000..c6bd533983 --- /dev/null +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -0,0 +1,730 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Connection tracking protocol helper module for SCTP. + * + * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com> + * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net> + * + * SCTP is defined in RFC 2960. References to various sections in this code + * are to this RFC. + */ + +#include <linux/types.h> +#include <linux/timer.h> +#include <linux/netfilter.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/sctp.h> +#include <linux/string.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <net/sctp/checksum.h> + +#include <net/netfilter/nf_log.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_l4proto.h> +#include <net/netfilter/nf_conntrack_ecache.h> +#include <net/netfilter/nf_conntrack_timeout.h> + +static const char *const sctp_conntrack_names[] = { + [SCTP_CONNTRACK_NONE] = "NONE", + [SCTP_CONNTRACK_CLOSED] = "CLOSED", + [SCTP_CONNTRACK_COOKIE_WAIT] = "COOKIE_WAIT", + [SCTP_CONNTRACK_COOKIE_ECHOED] = "COOKIE_ECHOED", + [SCTP_CONNTRACK_ESTABLISHED] = "ESTABLISHED", + [SCTP_CONNTRACK_SHUTDOWN_SENT] = "SHUTDOWN_SENT", + [SCTP_CONNTRACK_SHUTDOWN_RECD] = "SHUTDOWN_RECD", + [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = "SHUTDOWN_ACK_SENT", + [SCTP_CONNTRACK_HEARTBEAT_SENT] = "HEARTBEAT_SENT", +}; + +#define SECS * HZ +#define MINS * 60 SECS +#define HOURS * 60 MINS +#define DAYS * 24 HOURS + +static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = { + [SCTP_CONNTRACK_CLOSED] = 10 SECS, + [SCTP_CONNTRACK_COOKIE_WAIT] = 3 SECS, + [SCTP_CONNTRACK_COOKIE_ECHOED] = 3 SECS, + [SCTP_CONNTRACK_ESTABLISHED] = 210 SECS, + [SCTP_CONNTRACK_SHUTDOWN_SENT] = 3 SECS, + [SCTP_CONNTRACK_SHUTDOWN_RECD] = 3 SECS, + [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT] = 3 SECS, + [SCTP_CONNTRACK_HEARTBEAT_SENT] = 30 SECS, +}; + +#define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1 + +#define sNO SCTP_CONNTRACK_NONE +#define sCL SCTP_CONNTRACK_CLOSED +#define sCW SCTP_CONNTRACK_COOKIE_WAIT +#define sCE SCTP_CONNTRACK_COOKIE_ECHOED +#define sES SCTP_CONNTRACK_ESTABLISHED +#define sSS SCTP_CONNTRACK_SHUTDOWN_SENT +#define sSR SCTP_CONNTRACK_SHUTDOWN_RECD +#define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT +#define sHS SCTP_CONNTRACK_HEARTBEAT_SENT +#define sIV SCTP_CONNTRACK_MAX + +/* + These are the descriptions of the states: + +NOTE: These state names are tantalizingly similar to the states of an +SCTP endpoint. But the interpretation of the states is a little different, +considering that these are the states of the connection and not of an end +point. Please note the subtleties. -Kiran + +NONE - Nothing so far. +COOKIE WAIT - We have seen an INIT chunk in the original direction, or also + an INIT_ACK chunk in the reply direction. +COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction. +ESTABLISHED - We have seen a COOKIE_ACK in the reply direction. +SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction. +SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply direction. +SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite + to that of the SHUTDOWN chunk. +CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of + the SHUTDOWN chunk. Connection is closed. +HEARTBEAT_SENT - We have seen a HEARTBEAT in a new flow. +*/ + +/* TODO + - I have assumed that the first INIT is in the original direction. + This messes things when an INIT comes in the reply direction in CLOSED + state. + - Check the error type in the reply dir before transitioning from +cookie echoed to closed. + - Sec 5.2.4 of RFC 2960 + - Full Multi Homing support. +*/ + +/* SCTP conntrack state transitions */ +static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = { + { +/* ORIGINAL */ +/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */ +/* init */ {sCL, sCL, sCW, sCE, sES, sCL, sCL, sSA, sCW}, +/* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL}, +/* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL}, +/* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL}, +/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA}, +/* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL},/* Can't have Stale cookie*/ +/* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL},/* 5.2.4 - Big TODO */ +/* cookie_ack */ {sCL, sCL, sCW, sES, sES, sSS, sSR, sSA, sCL},/* Can't come in orig dir */ +/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL}, +/* heartbeat */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS}, +/* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS}, + }, + { +/* REPLY */ +/* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS */ +/* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV},/* INIT in sCL Big TODO */ +/* init_ack */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV}, +/* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV}, +/* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV}, +/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV}, +/* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV}, +/* cookie_echo */ {sIV, sCL, sCE, sCE, sES, sSS, sSR, sSA, sIV},/* Can't come in reply dir */ +/* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV}, +/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV}, +/* heartbeat */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS}, +/* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sES}, + } +}; + +#ifdef CONFIG_NF_CONNTRACK_PROCFS +/* Print out the private part of the conntrack. */ +static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct) +{ + seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]); +} +#endif + +/* do_basic_checks ensures sch->length > 0, do not use before */ +#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \ +for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0; \ + (offset) < (skb)->len && \ + ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch))); \ + (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++) + +/* Some validity checks to make sure the chunks are fine */ +static int do_basic_checks(struct nf_conn *ct, + const struct sk_buff *skb, + unsigned int dataoff, + unsigned long *map, + const struct nf_hook_state *state) +{ + u_int32_t offset, count; + struct sctp_chunkhdr _sch, *sch; + int flag; + + flag = 0; + + for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { + if (sch->type == SCTP_CID_INIT || + sch->type == SCTP_CID_INIT_ACK || + sch->type == SCTP_CID_SHUTDOWN_COMPLETE) + flag = 1; + + /* + * Cookie Ack/Echo chunks not the first OR + * Init / Init Ack / Shutdown compl chunks not the only chunks + * OR zero-length. + */ + if (((sch->type == SCTP_CID_COOKIE_ACK || + sch->type == SCTP_CID_COOKIE_ECHO || + flag) && + count != 0) || !sch->length) { + nf_ct_l4proto_log_invalid(skb, ct, state, + "%s failed. chunk num %d, type %d, len %d flag %d\n", + __func__, count, sch->type, sch->length, flag); + return 1; + } + + if (map) + set_bit(sch->type, map); + } + + return count == 0; +} + +static int sctp_new_state(enum ip_conntrack_dir dir, + enum sctp_conntrack cur_state, + int chunk_type) +{ + int i; + + switch (chunk_type) { + case SCTP_CID_INIT: + i = 0; + break; + case SCTP_CID_INIT_ACK: + i = 1; + break; + case SCTP_CID_ABORT: + i = 2; + break; + case SCTP_CID_SHUTDOWN: + i = 3; + break; + case SCTP_CID_SHUTDOWN_ACK: + i = 4; + break; + case SCTP_CID_ERROR: + i = 5; + break; + case SCTP_CID_COOKIE_ECHO: + i = 6; + break; + case SCTP_CID_COOKIE_ACK: + i = 7; + break; + case SCTP_CID_SHUTDOWN_COMPLETE: + i = 8; + break; + case SCTP_CID_HEARTBEAT: + i = 9; + break; + case SCTP_CID_HEARTBEAT_ACK: + i = 10; + break; + default: + /* Other chunks like DATA or SACK do not change the state */ + pr_debug("Unknown chunk type %d, Will stay in %s\n", + chunk_type, sctp_conntrack_names[cur_state]); + return cur_state; + } + + return sctp_conntracks[dir][i][cur_state]; +} + +/* Don't need lock here: this conntrack not in circulation yet */ +static noinline bool +sctp_new(struct nf_conn *ct, const struct sk_buff *skb, + const struct sctphdr *sh, unsigned int dataoff) +{ + enum sctp_conntrack new_state; + const struct sctp_chunkhdr *sch; + struct sctp_chunkhdr _sch; + u32 offset, count; + + memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp)); + new_state = SCTP_CONNTRACK_MAX; + for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) { + new_state = sctp_new_state(IP_CT_DIR_ORIGINAL, + SCTP_CONNTRACK_NONE, sch->type); + + /* Invalid: delete conntrack */ + if (new_state == SCTP_CONNTRACK_NONE || + new_state == SCTP_CONNTRACK_MAX) { + pr_debug("nf_conntrack_sctp: invalid new deleting.\n"); + return false; + } + + /* Copy the vtag into the state info */ + if (sch->type == SCTP_CID_INIT) { + struct sctp_inithdr _inithdr, *ih; + /* Sec 8.5.1 (A) */ + if (sh->vtag) + return false; + + ih = skb_header_pointer(skb, offset + sizeof(_sch), + sizeof(_inithdr), &_inithdr); + if (!ih) + return false; + + pr_debug("Setting vtag %x for new conn\n", + ih->init_tag); + + ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag; + } else if (sch->type == SCTP_CID_HEARTBEAT) { + pr_debug("Setting vtag %x for secondary conntrack\n", + sh->vtag); + ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag; + } else { + /* If it is a shutdown ack OOTB packet, we expect a return + shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ + pr_debug("Setting vtag %x for new conn OOTB\n", + sh->vtag); + ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag; + } + + ct->proto.sctp.state = SCTP_CONNTRACK_NONE; + } + + return true; +} + +static bool sctp_error(struct sk_buff *skb, + unsigned int dataoff, + const struct nf_hook_state *state) +{ + const struct sctphdr *sh; + const char *logmsg; + + if (skb->len < dataoff + sizeof(struct sctphdr)) { + logmsg = "nf_ct_sctp: short packet "; + goto out_invalid; + } + if (state->hook == NF_INET_PRE_ROUTING && + state->net->ct.sysctl_checksum && + skb->ip_summed == CHECKSUM_NONE) { + if (skb_ensure_writable(skb, dataoff + sizeof(*sh))) { + logmsg = "nf_ct_sctp: failed to read header "; + goto out_invalid; + } + sh = (const struct sctphdr *)(skb->data + dataoff); + if (sh->checksum != sctp_compute_cksum(skb, dataoff)) { + logmsg = "nf_ct_sctp: bad CRC "; + goto out_invalid; + } + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + return false; +out_invalid: + nf_l4proto_log_invalid(skb, state, IPPROTO_SCTP, "%s", logmsg); + return true; +} + +/* Returns verdict for packet, or -NF_ACCEPT for invalid. */ +int nf_conntrack_sctp_packet(struct nf_conn *ct, + struct sk_buff *skb, + unsigned int dataoff, + enum ip_conntrack_info ctinfo, + const struct nf_hook_state *state) +{ + enum sctp_conntrack new_state, old_state; + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + const struct sctphdr *sh; + struct sctphdr _sctph; + const struct sctp_chunkhdr *sch; + struct sctp_chunkhdr _sch; + u_int32_t offset, count; + unsigned int *timeouts; + unsigned long map[256 / sizeof(unsigned long)] = { 0 }; + bool ignore = false; + + if (sctp_error(skb, dataoff, state)) + return -NF_ACCEPT; + + sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); + if (sh == NULL) + goto out; + + if (do_basic_checks(ct, skb, dataoff, map, state) != 0) + goto out; + + if (!nf_ct_is_confirmed(ct)) { + /* If an OOTB packet has any of these chunks discard (Sec 8.4) */ + if (test_bit(SCTP_CID_ABORT, map) || + test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) || + test_bit(SCTP_CID_COOKIE_ACK, map)) + return -NF_ACCEPT; + + if (!sctp_new(ct, skb, sh, dataoff)) + return -NF_ACCEPT; + } + + /* Check the verification tag (Sec 8.5) */ + if (!test_bit(SCTP_CID_INIT, map) && + !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) && + !test_bit(SCTP_CID_COOKIE_ECHO, map) && + !test_bit(SCTP_CID_ABORT, map) && + !test_bit(SCTP_CID_SHUTDOWN_ACK, map) && + !test_bit(SCTP_CID_HEARTBEAT, map) && + !test_bit(SCTP_CID_HEARTBEAT_ACK, map) && + sh->vtag != ct->proto.sctp.vtag[dir]) { + nf_ct_l4proto_log_invalid(skb, ct, state, + "verification tag check failed %x vs %x for dir %d", + sh->vtag, ct->proto.sctp.vtag[dir], dir); + goto out; + } + + old_state = new_state = SCTP_CONNTRACK_NONE; + spin_lock_bh(&ct->lock); + for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { + /* Special cases of Verification tag check (Sec 8.5.1) */ + if (sch->type == SCTP_CID_INIT) { + /* (A) vtag MUST be zero */ + if (sh->vtag != 0) + goto out_unlock; + } else if (sch->type == SCTP_CID_ABORT) { + /* (B) vtag MUST match own vtag if T flag is unset OR + * MUST match peer's vtag if T flag is set + */ + if ((!(sch->flags & SCTP_CHUNK_FLAG_T) && + sh->vtag != ct->proto.sctp.vtag[dir]) || + ((sch->flags & SCTP_CHUNK_FLAG_T) && + sh->vtag != ct->proto.sctp.vtag[!dir])) + goto out_unlock; + } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) { + /* (C) vtag MUST match own vtag if T flag is unset OR + * MUST match peer's vtag if T flag is set + */ + if ((!(sch->flags & SCTP_CHUNK_FLAG_T) && + sh->vtag != ct->proto.sctp.vtag[dir]) || + ((sch->flags & SCTP_CHUNK_FLAG_T) && + sh->vtag != ct->proto.sctp.vtag[!dir])) + goto out_unlock; + } else if (sch->type == SCTP_CID_COOKIE_ECHO) { + /* (D) vtag must be same as init_vtag as found in INIT_ACK */ + if (sh->vtag != ct->proto.sctp.vtag[dir]) + goto out_unlock; + } else if (sch->type == SCTP_CID_COOKIE_ACK) { + ct->proto.sctp.init[dir] = 0; + ct->proto.sctp.init[!dir] = 0; + } else if (sch->type == SCTP_CID_HEARTBEAT) { + if (ct->proto.sctp.vtag[dir] == 0) { + pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir); + ct->proto.sctp.vtag[dir] = sh->vtag; + } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { + if (test_bit(SCTP_CID_DATA, map) || ignore) + goto out_unlock; + + ct->proto.sctp.flags |= SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + ct->proto.sctp.last_dir = dir; + ignore = true; + continue; + } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + } + } else if (sch->type == SCTP_CID_HEARTBEAT_ACK) { + if (ct->proto.sctp.vtag[dir] == 0) { + pr_debug("Setting vtag %x for dir %d\n", + sh->vtag, dir); + ct->proto.sctp.vtag[dir] = sh->vtag; + } else if (sh->vtag != ct->proto.sctp.vtag[dir]) { + if (test_bit(SCTP_CID_DATA, map) || ignore) + goto out_unlock; + + if ((ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) == 0 || + ct->proto.sctp.last_dir == dir) + goto out_unlock; + + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + ct->proto.sctp.vtag[dir] = sh->vtag; + ct->proto.sctp.vtag[!dir] = 0; + } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) { + ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED; + } + } + + old_state = ct->proto.sctp.state; + new_state = sctp_new_state(dir, old_state, sch->type); + + /* Invalid */ + if (new_state == SCTP_CONNTRACK_MAX) { + nf_ct_l4proto_log_invalid(skb, ct, state, + "Invalid, old_state %d, dir %d, type %d", + old_state, dir, sch->type); + + goto out_unlock; + } + + /* If it is an INIT or an INIT ACK note down the vtag */ + if (sch->type == SCTP_CID_INIT) { + struct sctp_inithdr _ih, *ih; + + ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih); + if (!ih) + goto out_unlock; + + if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir]) + ct->proto.sctp.init[!dir] = 0; + ct->proto.sctp.init[dir] = 1; + + pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir); + ct->proto.sctp.vtag[!dir] = ih->init_tag; + + /* don't renew timeout on init retransmit so + * port reuse by client or NAT middlebox cannot + * keep entry alive indefinitely (incl. nat info). + */ + if (new_state == SCTP_CONNTRACK_CLOSED && + old_state == SCTP_CONNTRACK_CLOSED && + nf_ct_is_confirmed(ct)) + ignore = true; + } else if (sch->type == SCTP_CID_INIT_ACK) { + struct sctp_inithdr _ih, *ih; + __be32 vtag; + + ih = skb_header_pointer(skb, offset + sizeof(_sch), sizeof(*ih), &_ih); + if (!ih) + goto out_unlock; + + vtag = ct->proto.sctp.vtag[!dir]; + if (!ct->proto.sctp.init[!dir] && vtag && vtag != ih->init_tag) + goto out_unlock; + /* collision */ + if (ct->proto.sctp.init[dir] && ct->proto.sctp.init[!dir] && + vtag != ih->init_tag) + goto out_unlock; + + pr_debug("Setting vtag %x for dir %d\n", ih->init_tag, !dir); + ct->proto.sctp.vtag[!dir] = ih->init_tag; + } + + ct->proto.sctp.state = new_state; + if (old_state != new_state) { + nf_conntrack_event_cache(IPCT_PROTOINFO, ct); + if (new_state == SCTP_CONNTRACK_ESTABLISHED && + !test_and_set_bit(IPS_ASSURED_BIT, &ct->status)) + nf_conntrack_event_cache(IPCT_ASSURED, ct); + } + } + spin_unlock_bh(&ct->lock); + + /* allow but do not refresh timeout */ + if (ignore) + return NF_ACCEPT; + + timeouts = nf_ct_timeout_lookup(ct); + if (!timeouts) + timeouts = nf_sctp_pernet(nf_ct_net(ct))->timeouts; + + nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]); + + return NF_ACCEPT; + +out_unlock: + spin_unlock_bh(&ct->lock); +out: + return -NF_ACCEPT; +} + +static bool sctp_can_early_drop(const struct nf_conn *ct) +{ + switch (ct->proto.sctp.state) { + case SCTP_CONNTRACK_SHUTDOWN_SENT: + case SCTP_CONNTRACK_SHUTDOWN_RECD: + case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT: + return true; + default: + break; + } + + return false; +} + +#if IS_ENABLED(CONFIG_NF_CT_NETLINK) + +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nfnetlink_conntrack.h> + +static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla, + struct nf_conn *ct, bool destroy) +{ + struct nlattr *nest_parms; + + spin_lock_bh(&ct->lock); + nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP); + if (!nest_parms) + goto nla_put_failure; + + if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state)) + goto nla_put_failure; + + if (destroy) + goto skip_state; + + if (nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL, + ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) || + nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY, + ct->proto.sctp.vtag[IP_CT_DIR_REPLY])) + goto nla_put_failure; + +skip_state: + spin_unlock_bh(&ct->lock); + nla_nest_end(skb, nest_parms); + + return 0; + +nla_put_failure: + spin_unlock_bh(&ct->lock); + return -1; +} + +static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = { + [CTA_PROTOINFO_SCTP_STATE] = { .type = NLA_U8 }, + [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] = { .type = NLA_U32 }, + [CTA_PROTOINFO_SCTP_VTAG_REPLY] = { .type = NLA_U32 }, +}; + +#define SCTP_NLATTR_SIZE ( \ + NLA_ALIGN(NLA_HDRLEN + 1) + \ + NLA_ALIGN(NLA_HDRLEN + 4) + \ + NLA_ALIGN(NLA_HDRLEN + 4)) + +static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct) +{ + struct nlattr *attr = cda[CTA_PROTOINFO_SCTP]; + struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1]; + int err; + + /* updates may not contain the internal protocol info, skip parsing */ + if (!attr) + return 0; + + err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_SCTP_MAX, attr, + sctp_nla_policy, NULL); + if (err < 0) + return err; + + if (!tb[CTA_PROTOINFO_SCTP_STATE] || + !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] || + !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]) + return -EINVAL; + + spin_lock_bh(&ct->lock); + ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]); + ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = + nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]); + ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = + nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]); + spin_unlock_bh(&ct->lock); + + return 0; +} +#endif + +#ifdef CONFIG_NF_CONNTRACK_TIMEOUT + +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nfnetlink_cttimeout.h> + +static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[], + struct net *net, void *data) +{ + unsigned int *timeouts = data; + struct nf_sctp_net *sn = nf_sctp_pernet(net); + int i; + + if (!timeouts) + timeouts = sn->timeouts; + + /* set default SCTP timeouts. */ + for (i=0; i<SCTP_CONNTRACK_MAX; i++) + timeouts[i] = sn->timeouts[i]; + + /* there's a 1:1 mapping between attributes and protocol states. */ + for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) { + if (tb[i]) { + timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ; + } + } + + timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED]; + return 0; +} + +static int +sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) +{ + const unsigned int *timeouts = data; + int i; + + for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) { + if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ))) + goto nla_put_failure; + } + return 0; + +nla_put_failure: + return -ENOSPC; +} + +static const struct nla_policy +sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = { + [CTA_TIMEOUT_SCTP_CLOSED] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_COOKIE_WAIT] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_COOKIE_ECHOED] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_ESTABLISHED] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT] = { .type = NLA_U32 }, + [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED] = { .type = NLA_U32 }, +}; +#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ + +void nf_conntrack_sctp_init_net(struct net *net) +{ + struct nf_sctp_net *sn = nf_sctp_pernet(net); + int i; + + for (i = 0; i < SCTP_CONNTRACK_MAX; i++) + sn->timeouts[i] = sctp_timeouts[i]; + + /* timeouts[0] is unused, init it so ->timeouts[0] contains + * 'new' timeout, like udp or icmp. + */ + sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED]; +} + +const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = { + .l4proto = IPPROTO_SCTP, +#ifdef CONFIG_NF_CONNTRACK_PROCFS + .print_conntrack = sctp_print_conntrack, +#endif + .can_early_drop = sctp_can_early_drop, +#if IS_ENABLED(CONFIG_NF_CT_NETLINK) + .nlattr_size = SCTP_NLATTR_SIZE, + .to_nlattr = sctp_to_nlattr, + .from_nlattr = nlattr_to_sctp, + .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, + .nlattr_tuple_size = nf_ct_port_nlattr_tuple_size, + .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, + .nla_policy = nf_ct_port_nla_policy, +#endif +#ifdef CONFIG_NF_CONNTRACK_TIMEOUT + .ctnl_timeout = { + .nlattr_to_obj = sctp_timeout_nlattr_to_obj, + .obj_to_nlattr = sctp_timeout_obj_to_nlattr, + .nlattr_max = CTA_TIMEOUT_SCTP_MAX, + .obj_size = sizeof(unsigned int) * SCTP_CONNTRACK_MAX, + .nla_policy = sctp_timeout_nla_policy, + }, +#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */ +}; |