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| -rw-r--r-- | include/net/sctp/structs.h | 2177 |
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diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h new file mode 100644 index 000000000..be59e8df0 --- /dev/null +++ b/include/net/sctp/structs.h @@ -0,0 +1,2177 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* SCTP kernel implementation + * (C) Copyright IBM Corp. 2001, 2004 + * Copyright (c) 1999-2000 Cisco, Inc. + * Copyright (c) 1999-2001 Motorola, Inc. + * Copyright (c) 2001 Intel Corp. + * + * This file is part of the SCTP kernel implementation + * + * Please send any bug reports or fixes you make to the + * email addresses: + * lksctp developers <linux-sctp@vger.kernel.org> + * + * Written or modified by: + * Randall Stewart <randall@sctp.chicago.il.us> + * Ken Morneau <kmorneau@cisco.com> + * Qiaobing Xie <qxie1@email.mot.com> + * La Monte H.P. Yarroll <piggy@acm.org> + * Karl Knutson <karl@athena.chicago.il.us> + * Jon Grimm <jgrimm@us.ibm.com> + * Xingang Guo <xingang.guo@intel.com> + * Hui Huang <hui.huang@nokia.com> + * Sridhar Samudrala <sri@us.ibm.com> + * Daisy Chang <daisyc@us.ibm.com> + * Dajiang Zhang <dajiang.zhang@nokia.com> + * Ardelle Fan <ardelle.fan@intel.com> + * Ryan Layer <rmlayer@us.ibm.com> + * Anup Pemmaiah <pemmaiah@cc.usu.edu> + * Kevin Gao <kevin.gao@intel.com> + */ + +#ifndef __sctp_structs_h__ +#define __sctp_structs_h__ + +#include <linux/ktime.h> +#include <linux/generic-radix-tree.h> +#include <linux/rhashtable-types.h> +#include <linux/socket.h> /* linux/in.h needs this!! */ +#include <linux/in.h> /* We get struct sockaddr_in. */ +#include <linux/in6.h> /* We get struct in6_addr */ +#include <linux/ipv6.h> +#include <asm/param.h> /* We get MAXHOSTNAMELEN. */ +#include <linux/atomic.h> /* This gets us atomic counters. */ +#include <linux/skbuff.h> /* We need sk_buff_head. */ +#include <linux/workqueue.h> /* We need tq_struct. */ +#include <linux/sctp.h> /* We need sctp* header structs. */ +#include <net/sctp/auth.h> /* We need auth specific structs */ +#include <net/ip.h> /* For inet_skb_parm */ + +/* A convenience structure for handling sockaddr structures. + * We should wean ourselves off this. + */ +union sctp_addr { + struct sockaddr_in v4; + struct sockaddr_in6 v6; + struct sockaddr sa; +}; + +/* Forward declarations for data structures. */ +struct sctp_globals; +struct sctp_endpoint; +struct sctp_association; +struct sctp_transport; +struct sctp_packet; +struct sctp_chunk; +struct sctp_inq; +struct sctp_outq; +struct sctp_bind_addr; +struct sctp_ulpq; +struct sctp_ep_common; +struct crypto_shash; +struct sctp_stream; + + +#include <net/sctp/tsnmap.h> +#include <net/sctp/ulpevent.h> +#include <net/sctp/ulpqueue.h> +#include <net/sctp/stream_interleave.h> + +/* Structures useful for managing bind/connect. */ + +struct sctp_bind_bucket { + unsigned short port; + signed char fastreuse; + signed char fastreuseport; + kuid_t fastuid; + struct hlist_node node; + struct hlist_head owner; + struct net *net; +}; + +struct sctp_bind_hashbucket { + spinlock_t lock; + struct hlist_head chain; +}; + +/* Used for hashing all associations. */ +struct sctp_hashbucket { + rwlock_t lock; + struct hlist_head chain; +} __attribute__((__aligned__(8))); + + +/* The SCTP globals structure. */ +extern struct sctp_globals { + /* This is a list of groups of functions for each address + * family that we support. + */ + struct list_head address_families; + + /* This is the hash of all endpoints. */ + struct sctp_hashbucket *ep_hashtable; + /* This is the sctp port control hash. */ + struct sctp_bind_hashbucket *port_hashtable; + /* This is the hash of all transports. */ + struct rhltable transport_hashtable; + + /* Sizes of above hashtables. */ + int ep_hashsize; + int port_hashsize; + + /* Default initialization values to be applied to new associations. */ + __u16 max_instreams; + __u16 max_outstreams; + + /* Flag to indicate whether computing and verifying checksum + * is disabled. */ + bool checksum_disable; +} sctp_globals; + +#define sctp_max_instreams (sctp_globals.max_instreams) +#define sctp_max_outstreams (sctp_globals.max_outstreams) +#define sctp_address_families (sctp_globals.address_families) +#define sctp_ep_hashsize (sctp_globals.ep_hashsize) +#define sctp_ep_hashtable (sctp_globals.ep_hashtable) +#define sctp_port_hashsize (sctp_globals.port_hashsize) +#define sctp_port_hashtable (sctp_globals.port_hashtable) +#define sctp_transport_hashtable (sctp_globals.transport_hashtable) +#define sctp_checksum_disable (sctp_globals.checksum_disable) + +/* SCTP Socket type: UDP or TCP style. */ +enum sctp_socket_type { + SCTP_SOCKET_UDP = 0, + SCTP_SOCKET_UDP_HIGH_BANDWIDTH, + SCTP_SOCKET_TCP +}; + +/* Per socket SCTP information. */ +struct sctp_sock { + /* inet_sock has to be the first member of sctp_sock */ + struct inet_sock inet; + /* What kind of a socket is this? */ + enum sctp_socket_type type; + + /* PF_ family specific functions. */ + struct sctp_pf *pf; + + /* Access to HMAC transform. */ + struct crypto_shash *hmac; + char *sctp_hmac_alg; + + /* What is our base endpointer? */ + struct sctp_endpoint *ep; + + struct sctp_bind_bucket *bind_hash; + /* Various Socket Options. */ + __u16 default_stream; + __u32 default_ppid; + __u16 default_flags; + __u32 default_context; + __u32 default_timetolive; + __u32 default_rcv_context; + int max_burst; + + /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to + * the destination address every heartbeat interval. This value + * will be inherited by all new associations. + */ + __u32 hbinterval; + + /* This is the max_retrans value for new associations. */ + __u16 pathmaxrxt; + + __u32 flowlabel; + __u8 dscp; + + __u16 pf_retrans; + __u16 ps_retrans; + + /* The initial Path MTU to use for new associations. */ + __u32 pathmtu; + + /* The default SACK delay timeout for new associations. */ + __u32 sackdelay; + __u32 sackfreq; + + /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ + __u32 param_flags; + + __u32 default_ss; + + struct sctp_rtoinfo rtoinfo; + struct sctp_paddrparams paddrparam; + struct sctp_assocparams assocparams; + + /* + * These two structures must be grouped together for the usercopy + * whitelist region. + */ + __u16 subscribe; + struct sctp_initmsg initmsg; + + int user_frag; + + __u32 autoclose; + __u32 adaptation_ind; + __u32 pd_point; + __u16 nodelay:1, + pf_expose:2, + reuse:1, + disable_fragments:1, + v4mapped:1, + frag_interleave:1, + recvrcvinfo:1, + recvnxtinfo:1, + data_ready_signalled:1; + + atomic_t pd_mode; + + /* Fields after this point will be skipped on copies, like on accept + * and peeloff operations + */ + + /* Receive to here while partial delivery is in effect. */ + struct sk_buff_head pd_lobby; + + struct list_head auto_asconf_list; + int do_auto_asconf; +}; + +static inline struct sctp_sock *sctp_sk(const struct sock *sk) +{ + return (struct sctp_sock *)sk; +} + +static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp) +{ + return (struct sock *)sp; +} + +#if IS_ENABLED(CONFIG_IPV6) +struct sctp6_sock { + struct sctp_sock sctp; + struct ipv6_pinfo inet6; +}; +#endif /* CONFIG_IPV6 */ + + +/* This is our APPLICATION-SPECIFIC state cookie. + * THIS IS NOT DICTATED BY THE SPECIFICATION. + */ +/* These are the parts of an association which we send in the cookie. + * Most of these are straight out of: + * RFC2960 12.2 Parameters necessary per association (i.e. the TCB) + * + */ + +struct sctp_cookie { + + /* My : Tag expected in every inbound packet and sent + * Verification: in the INIT or INIT ACK chunk. + * Tag : + */ + __u32 my_vtag; + + /* Peer's : Tag expected in every outbound packet except + * Verification: in the INIT chunk. + * Tag : + */ + __u32 peer_vtag; + + /* The rest of these are not from the spec, but really need to + * be in the cookie. + */ + + /* My Tie Tag : Assist in discovering a restarting association. */ + __u32 my_ttag; + + /* Peer's Tie Tag: Assist in discovering a restarting association. */ + __u32 peer_ttag; + + /* When does this cookie expire? */ + ktime_t expiration; + + /* Number of inbound/outbound streams which are set + * and negotiated during the INIT process. + */ + __u16 sinit_num_ostreams; + __u16 sinit_max_instreams; + + /* This is the first sequence number I used. */ + __u32 initial_tsn; + + /* This holds the originating address of the INIT packet. */ + union sctp_addr peer_addr; + + /* IG Section 2.35.3 + * Include the source port of the INIT-ACK + */ + __u16 my_port; + + __u8 prsctp_capable; + + /* Padding for future use */ + __u8 padding; + + __u32 adaptation_ind; + + __u8 auth_random[sizeof(struct sctp_paramhdr) + + SCTP_AUTH_RANDOM_LENGTH]; + __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2]; + __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS]; + + /* This is a shim for my peer's INIT packet, followed by + * a copy of the raw address list of the association. + * The length of the raw address list is saved in the + * raw_addr_list_len field, which will be used at the time when + * the association TCB is re-constructed from the cookie. + */ + __u32 raw_addr_list_len; + struct sctp_init_chunk peer_init[]; +}; + + +/* The format of our cookie that we send to our peer. */ +struct sctp_signed_cookie { + __u8 signature[SCTP_SECRET_SIZE]; + __u32 __pad; /* force sctp_cookie alignment to 64 bits */ + struct sctp_cookie c; +} __packed; + +/* This is another convenience type to allocate memory for address + * params for the maximum size and pass such structures around + * internally. + */ +union sctp_addr_param { + struct sctp_paramhdr p; + struct sctp_ipv4addr_param v4; + struct sctp_ipv6addr_param v6; +}; + +/* A convenience type to allow walking through the various + * parameters and avoid casting all over the place. + */ +union sctp_params { + void *v; + struct sctp_paramhdr *p; + struct sctp_cookie_preserve_param *life; + struct sctp_hostname_param *dns; + struct sctp_cookie_param *cookie; + struct sctp_supported_addrs_param *sat; + struct sctp_ipv4addr_param *v4; + struct sctp_ipv6addr_param *v6; + union sctp_addr_param *addr; + struct sctp_adaptation_ind_param *aind; + struct sctp_supported_ext_param *ext; + struct sctp_random_param *random; + struct sctp_chunks_param *chunks; + struct sctp_hmac_algo_param *hmac_algo; + struct sctp_addip_param *addip; +}; + +/* RFC 2960. Section 3.3.5 Heartbeat. + * Heartbeat Information: variable length + * The Sender-specific Heartbeat Info field should normally include + * information about the sender's current time when this HEARTBEAT + * chunk is sent and the destination transport address to which this + * HEARTBEAT is sent (see Section 8.3). + */ +struct sctp_sender_hb_info { + struct sctp_paramhdr param_hdr; + union sctp_addr daddr; + unsigned long sent_at; + __u64 hb_nonce; +}; + +int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt, + gfp_t gfp); +int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid); +void sctp_stream_free(struct sctp_stream *stream); +void sctp_stream_clear(struct sctp_stream *stream); +void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new); + +/* What is the current SSN number for this stream? */ +#define sctp_ssn_peek(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->ssn) + +/* Return the next SSN number for this stream. */ +#define sctp_ssn_next(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->ssn++) + +/* Skip over this ssn and all below. */ +#define sctp_ssn_skip(stream, type, sid, ssn) \ + (sctp_stream_##type((stream), (sid))->ssn = ssn + 1) + +/* What is the current MID number for this stream? */ +#define sctp_mid_peek(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->mid) + +/* Return the next MID number for this stream. */ +#define sctp_mid_next(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->mid++) + +/* Skip over this mid and all below. */ +#define sctp_mid_skip(stream, type, sid, mid) \ + (sctp_stream_##type((stream), (sid))->mid = mid + 1) + +/* What is the current MID_uo number for this stream? */ +#define sctp_mid_uo_peek(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->mid_uo) + +/* Return the next MID_uo number for this stream. */ +#define sctp_mid_uo_next(stream, type, sid) \ + (sctp_stream_##type((stream), (sid))->mid_uo++) + +/* + * Pointers to address related SCTP functions. + * (i.e. things that depend on the address family.) + */ +struct sctp_af { + int (*sctp_xmit) (struct sk_buff *skb, + struct sctp_transport *); + int (*setsockopt) (struct sock *sk, + int level, + int optname, + sockptr_t optval, + unsigned int optlen); + int (*getsockopt) (struct sock *sk, + int level, + int optname, + char __user *optval, + int __user *optlen); + void (*get_dst) (struct sctp_transport *t, + union sctp_addr *saddr, + struct flowi *fl, + struct sock *sk); + void (*get_saddr) (struct sctp_sock *sk, + struct sctp_transport *t, + struct flowi *fl); + void (*copy_addrlist) (struct list_head *, + struct net_device *); + int (*cmp_addr) (const union sctp_addr *addr1, + const union sctp_addr *addr2); + void (*addr_copy) (union sctp_addr *dst, + union sctp_addr *src); + void (*from_skb) (union sctp_addr *, + struct sk_buff *skb, + int saddr); + void (*from_sk) (union sctp_addr *, + struct sock *sk); + bool (*from_addr_param) (union sctp_addr *, + union sctp_addr_param *, + __be16 port, int iif); + int (*to_addr_param) (const union sctp_addr *, + union sctp_addr_param *); + int (*addr_valid) (union sctp_addr *, + struct sctp_sock *, + const struct sk_buff *); + enum sctp_scope (*scope)(union sctp_addr *); + void (*inaddr_any) (union sctp_addr *, __be16); + int (*is_any) (const union sctp_addr *); + int (*available) (union sctp_addr *, + struct sctp_sock *); + int (*skb_iif) (const struct sk_buff *sk); + int (*is_ce) (const struct sk_buff *sk); + void (*seq_dump_addr)(struct seq_file *seq, + union sctp_addr *addr); + void (*ecn_capable)(struct sock *sk); + __u16 net_header_len; + int sockaddr_len; + int (*ip_options_len)(struct sock *sk); + sa_family_t sa_family; + struct list_head list; +}; + +struct sctp_af *sctp_get_af_specific(sa_family_t); +int sctp_register_af(struct sctp_af *); + +/* Protocol family functions. */ +struct sctp_pf { + void (*event_msgname)(struct sctp_ulpevent *, char *, int *); + void (*skb_msgname) (struct sk_buff *, char *, int *); + int (*af_supported) (sa_family_t, struct sctp_sock *); + int (*cmp_addr) (const union sctp_addr *, + const union sctp_addr *, + struct sctp_sock *); + int (*bind_verify) (struct sctp_sock *, union sctp_addr *); + int (*send_verify) (struct sctp_sock *, union sctp_addr *); + int (*supported_addrs)(const struct sctp_sock *, __be16 *); + struct sock *(*create_accept_sk) (struct sock *sk, + struct sctp_association *asoc, + bool kern); + int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr); + void (*to_sk_saddr)(union sctp_addr *, struct sock *sk); + void (*to_sk_daddr)(union sctp_addr *, struct sock *sk); + void (*copy_ip_options)(struct sock *sk, struct sock *newsk); + struct sctp_af *af; +}; + + +/* Structure to track chunk fragments that have been acked, but peer + * fragments of the same message have not. + */ +struct sctp_datamsg { + /* Chunks waiting to be submitted to lower layer. */ + struct list_head chunks; + /* Reference counting. */ + refcount_t refcnt; + /* When is this message no longer interesting to the peer? */ + unsigned long expires_at; + /* Did the messenge fail to send? */ + int send_error; + u8 send_failed:1, + can_delay:1, /* should this message be Nagle delayed */ + abandoned:1; /* should this message be abandoned */ +}; + +struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, + struct sctp_sndrcvinfo *, + struct iov_iter *); +void sctp_datamsg_free(struct sctp_datamsg *); +void sctp_datamsg_put(struct sctp_datamsg *); +void sctp_chunk_fail(struct sctp_chunk *, int error); +int sctp_chunk_abandoned(struct sctp_chunk *); + +/* RFC2960 1.4 Key Terms + * + * o Chunk: A unit of information within an SCTP packet, consisting of + * a chunk header and chunk-specific content. + * + * As a matter of convenience, we remember the SCTP common header for + * each chunk as well as a few other header pointers... + */ +struct sctp_chunk { + struct list_head list; + + refcount_t refcnt; + + /* How many times this chunk have been sent, for prsctp RTX policy */ + int sent_count; + + union { + /* This is our link to the per-transport transmitted list. */ + struct list_head transmitted_list; + /* List in specific stream outq */ + struct list_head stream_list; + }; + + /* This field is used by chunks that hold fragmented data. + * For the first fragment this is the list that holds the rest of + * fragments. For the remaining fragments, this is the link to the + * frag_list maintained in the first fragment. + */ + struct list_head frag_list; + + /* This points to the sk_buff containing the actual data. */ + struct sk_buff *skb; + + union { + /* In case of GSO packets, this will store the head one */ + struct sk_buff *head_skb; + /* In case of auth enabled, this will point to the shkey */ + struct sctp_shared_key *shkey; + }; + + /* These are the SCTP headers by reverse order in a packet. + * Note that some of these may happen more than once. In that + * case, we point at the "current" one, whatever that means + * for that level of header. + */ + + /* We point this at the FIRST TLV parameter to chunk_hdr. */ + union sctp_params param_hdr; + union { + __u8 *v; + struct sctp_datahdr *data_hdr; + struct sctp_inithdr *init_hdr; + struct sctp_sackhdr *sack_hdr; + struct sctp_heartbeathdr *hb_hdr; + struct sctp_sender_hb_info *hbs_hdr; + struct sctp_shutdownhdr *shutdown_hdr; + struct sctp_signed_cookie *cookie_hdr; + struct sctp_ecnehdr *ecne_hdr; + struct sctp_cwrhdr *ecn_cwr_hdr; + struct sctp_errhdr *err_hdr; + struct sctp_addiphdr *addip_hdr; + struct sctp_fwdtsn_hdr *fwdtsn_hdr; + struct sctp_authhdr *auth_hdr; + struct sctp_idatahdr *idata_hdr; + struct sctp_ifwdtsn_hdr *ifwdtsn_hdr; + } subh; + + __u8 *chunk_end; + + struct sctp_chunkhdr *chunk_hdr; + struct sctphdr *sctp_hdr; + + /* This needs to be recoverable for SCTP_SEND_FAILED events. */ + struct sctp_sndrcvinfo sinfo; + + /* Which association does this belong to? */ + struct sctp_association *asoc; + + /* What endpoint received this chunk? */ + struct sctp_ep_common *rcvr; + + /* We fill this in if we are calculating RTT. */ + unsigned long sent_at; + + /* What is the origin IP address for this chunk? */ + union sctp_addr source; + /* Destination address for this chunk. */ + union sctp_addr dest; + + /* For outbound message, track all fragments for SEND_FAILED. */ + struct sctp_datamsg *msg; + + /* For an inbound chunk, this tells us where it came from. + * For an outbound chunk, it tells us where we'd like it to + * go. It is NULL if we have no preference. + */ + struct sctp_transport *transport; + + /* SCTP-AUTH: For the special case inbound processing of COOKIE-ECHO + * we need save a pointer to the AUTH chunk, since the SCTP-AUTH + * spec violates the principle premis that all chunks are processed + * in order. + */ + struct sk_buff *auth_chunk; + +#define SCTP_CAN_FRTX 0x0 +#define SCTP_NEED_FRTX 0x1 +#define SCTP_DONT_FRTX 0x2 + __u16 rtt_in_progress:1, /* This chunk used for RTT calc? */ + has_tsn:1, /* Does this chunk have a TSN yet? */ + has_ssn:1, /* Does this chunk have a SSN yet? */ +#define has_mid has_ssn + singleton:1, /* Only chunk in the packet? */ + end_of_packet:1, /* Last chunk in the packet? */ + ecn_ce_done:1, /* Have we processed the ECN CE bit? */ + pdiscard:1, /* Discard the whole packet now? */ + tsn_gap_acked:1, /* Is this chunk acked by a GAP ACK? */ + data_accepted:1, /* At least 1 chunk accepted */ + auth:1, /* IN: was auth'ed | OUT: needs auth */ + has_asconf:1, /* IN: have seen an asconf before */ + tsn_missing_report:2, /* Data chunk missing counter. */ + fast_retransmit:2; /* Is this chunk fast retransmitted? */ +}; + +#define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1) +void sctp_chunk_hold(struct sctp_chunk *); +void sctp_chunk_put(struct sctp_chunk *); +int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len, + struct iov_iter *from); +void sctp_chunk_free(struct sctp_chunk *); +void *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data); +struct sctp_chunk *sctp_chunkify(struct sk_buff *, + const struct sctp_association *, + struct sock *, gfp_t gfp); +void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, + union sctp_addr *); +const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); + +static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch) +{ + return ntohs(ch->subh.data_hdr->stream); +} + +enum { + SCTP_ADDR_NEW, /* new address added to assoc/ep */ + SCTP_ADDR_SRC, /* address can be used as source */ + SCTP_ADDR_DEL, /* address about to be deleted */ +}; + +/* This is a structure for holding either an IPv6 or an IPv4 address. */ +struct sctp_sockaddr_entry { + struct list_head list; + struct rcu_head rcu; + union sctp_addr a; + __u8 state; + __u8 valid; +}; + +#define SCTP_ADDRESS_TICK_DELAY 500 + +/* This structure holds lists of chunks as we are assembling for + * transmission. + */ +struct sctp_packet { + /* These are the SCTP header values (host order) for the packet. */ + __u16 source_port; + __u16 destination_port; + __u32 vtag; + + /* This contains the payload chunks. */ + struct list_head chunk_list; + + /* This is the overhead of the sctp and ip headers. */ + size_t overhead; + /* This is the total size of all chunks INCLUDING padding. */ + size_t size; + /* This is the maximum size this packet may have */ + size_t max_size; + + /* The packet is destined for this transport address. + * The function we finally use to pass down to the next lower + * layer lives in the transport structure. + */ + struct sctp_transport *transport; + + /* pointer to the auth chunk for this packet */ + struct sctp_chunk *auth; + + u8 has_cookie_echo:1, /* This packet contains a COOKIE-ECHO chunk. */ + has_sack:1, /* This packet contains a SACK chunk. */ + has_auth:1, /* This packet contains an AUTH chunk */ + has_data:1, /* This packet contains at least 1 DATA chunk */ + ipfragok:1; /* So let ip fragment this packet */ +}; + +void sctp_packet_init(struct sctp_packet *, struct sctp_transport *, + __u16 sport, __u16 dport); +void sctp_packet_config(struct sctp_packet *, __u32 vtag, int); +enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet, + struct sctp_chunk *chunk, + int one_packet, gfp_t gfp); +enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet, + struct sctp_chunk *chunk); +int sctp_packet_transmit(struct sctp_packet *, gfp_t); +void sctp_packet_free(struct sctp_packet *); + +static inline int sctp_packet_empty(struct sctp_packet *packet) +{ + return packet->size == packet->overhead; +} + +/* This represents a remote transport address. + * For local transport addresses, we just use union sctp_addr. + * + * RFC2960 Section 1.4 Key Terms + * + * o Transport address: A Transport Address is traditionally defined + * by Network Layer address, Transport Layer protocol and Transport + * Layer port number. In the case of SCTP running over IP, a + * transport address is defined by the combination of an IP address + * and an SCTP port number (where SCTP is the Transport protocol). + * + * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control + * + * o The sender keeps a separate congestion control parameter set for + * each of the destination addresses it can send to (not each + * source-destination pair but for each destination). The parameters + * should decay if the address is not used for a long enough time + * period. + * + */ +struct sctp_transport { + /* A list of transports. */ + struct list_head transports; + struct rhlist_head node; + + /* Reference counting. */ + refcount_t refcnt; + /* RTO-Pending : A flag used to track if one of the DATA + * chunks sent to this address is currently being + * used to compute a RTT. If this flag is 0, + * the next DATA chunk sent to this destination + * should be used to compute a RTT and this flag + * should be set. Every time the RTT + * calculation completes (i.e. the DATA chunk + * is SACK'd) clear this flag. + */ + __u32 rto_pending:1, + + /* + * hb_sent : a flag that signals that we have a pending + * heartbeat. + */ + hb_sent:1, + + /* Is the Path MTU update pending on this tranport */ + pmtu_pending:1, + + dst_pending_confirm:1, /* need to confirm neighbour */ + + /* Has this transport moved the ctsn since we last sacked */ + sack_generation:1; + u32 dst_cookie; + + struct flowi fl; + + /* This is the peer's IP address and port. */ + union sctp_addr ipaddr; + + /* These are the functions we call to handle LLP stuff. */ + struct sctp_af *af_specific; + + /* Which association do we belong to? */ + struct sctp_association *asoc; + + /* RFC2960 + * + * 12.3 Per Transport Address Data + * + * For each destination transport address in the peer's + * address list derived from the INIT or INIT ACK chunk, a + * number of data elements needs to be maintained including: + */ + /* RTO : The current retransmission timeout value. */ + unsigned long rto; + + __u32 rtt; /* This is the most recent RTT. */ + + /* RTTVAR : The current RTT variation. */ + __u32 rttvar; + + /* SRTT : The current smoothed round trip time. */ + __u32 srtt; + + /* + * These are the congestion stats. + */ + /* cwnd : The current congestion window. */ + __u32 cwnd; /* This is the actual cwnd. */ + + /* ssthresh : The current slow start threshold value. */ + __u32 ssthresh; + + /* partial : The tracking method for increase of cwnd when in + * bytes acked : congestion avoidance mode (see Section 6.2.2) + */ + __u32 partial_bytes_acked; + + /* Data that has been sent, but not acknowledged. */ + __u32 flight_size; + + __u32 burst_limited; /* Holds old cwnd when max.burst is applied */ + + /* Destination */ + struct dst_entry *dst; + /* Source address. */ + union sctp_addr saddr; + + /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to + * the destination address every heartbeat interval. + */ + unsigned long hbinterval; + + /* SACK delay timeout */ + unsigned long sackdelay; + __u32 sackfreq; + + atomic_t mtu_info; + + /* When was the last time that we heard from this transport? We use + * this to pick new active and retran paths. + */ + ktime_t last_time_heard; + + /* When was the last time that we sent a chunk using this + * transport? We use this to check for idle transports + */ + unsigned long last_time_sent; + + /* Last time(in jiffies) when cwnd is reduced due to the congestion + * indication based on ECNE chunk. + */ + unsigned long last_time_ecne_reduced; + + /* This is the max_retrans value for the transport and will + * be initialized from the assocs value. This can be changed + * using the SCTP_SET_PEER_ADDR_PARAMS socket option. + */ + __u16 pathmaxrxt; + + __u32 flowlabel; + __u8 dscp; + + /* This is the partially failed retrans value for the transport + * and will be initialized from the assocs value. This can be changed + * using the SCTP_PEER_ADDR_THLDS socket option + */ + __u16 pf_retrans; + /* Used for primary path switchover. */ + __u16 ps_retrans; + /* PMTU : The current known path MTU. */ + __u32 pathmtu; + + /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ + __u32 param_flags; + + /* The number of times INIT has been sent on this transport. */ + int init_sent_count; + + /* state : The current state of this destination, + * : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN. + */ + int state; + + /* These are the error stats for this destination. */ + + /* Error count : The current error count for this destination. */ + unsigned short error_count; + + /* Per : A timer used by each destination. + * Destination : + * Timer : + * + * [Everywhere else in the text this is called T3-rtx. -ed] + */ + struct timer_list T3_rtx_timer; + + /* Heartbeat timer is per destination. */ + struct timer_list hb_timer; + + /* Timer to handle ICMP proto unreachable envets */ + struct timer_list proto_unreach_timer; + + /* Timer to handler reconf chunk rtx */ + struct timer_list reconf_timer; + + /* Since we're using per-destination retransmission timers + * (see above), we're also using per-destination "transmitted" + * queues. This probably ought to be a private struct + * accessible only within the outqueue, but it's not, yet. + */ + struct list_head transmitted; + + /* We build bundle-able packets for this transport here. */ + struct sctp_packet packet; + + /* This is the list of transports that have chunks to send. */ + struct list_head send_ready; + + /* State information saved for SFR_CACC algorithm. The key + * idea in SFR_CACC is to maintain state at the sender on a + * per-destination basis when a changeover happens. + * char changeover_active; + * char cycling_changeover; + * __u32 next_tsn_at_change; + * char cacc_saw_newack; + */ + struct { + /* An unsigned integer, which stores the next TSN to be + * used by the sender, at the moment of changeover. + */ + __u32 next_tsn_at_change; + + /* A flag which indicates the occurrence of a changeover */ + char changeover_active; + + /* A flag which indicates whether the change of primary is + * the first switch to this destination address during an + * active switch. + */ + char cycling_changeover; + + /* A temporary flag, which is used during the processing of + * a SACK to estimate the causative TSN(s)'s group. + */ + char cacc_saw_newack; + } cacc; + + /* 64-bit random number sent with heartbeat. */ + __u64 hb_nonce; + + struct rcu_head rcu; +}; + +struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *, + gfp_t); +void sctp_transport_set_owner(struct sctp_transport *, + struct sctp_association *); +void sctp_transport_route(struct sctp_transport *, union sctp_addr *, + struct sctp_sock *); +void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk); +void sctp_transport_free(struct sctp_transport *); +void sctp_transport_reset_t3_rtx(struct sctp_transport *); +void sctp_transport_reset_hb_timer(struct sctp_transport *); +void sctp_transport_reset_reconf_timer(struct sctp_transport *transport); +int sctp_transport_hold(struct sctp_transport *); +void sctp_transport_put(struct sctp_transport *); +void sctp_transport_update_rto(struct sctp_transport *, __u32); +void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32); +void sctp_transport_lower_cwnd(struct sctp_transport *t, + enum sctp_lower_cwnd reason); +void sctp_transport_burst_limited(struct sctp_transport *); +void sctp_transport_burst_reset(struct sctp_transport *); +unsigned long sctp_transport_timeout(struct sctp_transport *); +void sctp_transport_reset(struct sctp_transport *t); +bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu); +void sctp_transport_immediate_rtx(struct sctp_transport *); +void sctp_transport_dst_release(struct sctp_transport *t); +void sctp_transport_dst_confirm(struct sctp_transport *t); + + +/* This is the structure we use to queue packets as they come into + * SCTP. We write packets to it and read chunks from it. + */ +struct sctp_inq { + /* This is actually a queue of sctp_chunk each + * containing a partially decoded packet. + */ + struct list_head in_chunk_list; + /* This is the packet which is currently off the in queue and is + * being worked on through the inbound chunk processing. + */ + struct sctp_chunk *in_progress; + + /* This is the delayed task to finish delivering inbound + * messages. + */ + struct work_struct immediate; +}; + +void sctp_inq_init(struct sctp_inq *); +void sctp_inq_free(struct sctp_inq *); +void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet); +struct sctp_chunk *sctp_inq_pop(struct sctp_inq *); +struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *); +void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t); + +/* This is the structure we use to hold outbound chunks. You push + * chunks in and they automatically pop out the other end as bundled + * packets (it calls (*output_handler)()). + * + * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1, + * and 8.2 of the v13 draft. + * + * It handles retransmissions. The connection to the timeout portion + * of the state machine is through sctp_..._timeout() and timeout_handler. + * + * If you feed it SACKs, it will eat them. + * + * If you give it big chunks, it will fragment them. + * + * It assigns TSN's to data chunks. This happens at the last possible + * instant before transmission. + * + * When free()'d, it empties itself out via output_handler(). + */ +struct sctp_outq { + struct sctp_association *asoc; + + /* Data pending that has never been transmitted. */ + struct list_head out_chunk_list; + + /* Stream scheduler being used */ + struct sctp_sched_ops *sched; + + unsigned int out_qlen; /* Total length of queued data chunks. */ + + /* Error of send failed, may used in SCTP_SEND_FAILED event. */ + unsigned int error; + + /* These are control chunks we want to send. */ + struct list_head control_chunk_list; + + /* These are chunks that have been sacked but are above the + * CTSN, or cumulative tsn ack point. + */ + struct list_head sacked; + + /* Put chunks on this list to schedule them for + * retransmission. + */ + struct list_head retransmit; + + /* Put chunks on this list to save them for FWD TSN processing as + * they were abandoned. + */ + struct list_head abandoned; + + /* How many unackd bytes do we have in-flight? */ + __u32 outstanding_bytes; + + /* Are we doing fast-rtx on this queue */ + char fast_rtx; + + /* Corked? */ + char cork; +}; + +void sctp_outq_init(struct sctp_association *, struct sctp_outq *); +void sctp_outq_teardown(struct sctp_outq *); +void sctp_outq_free(struct sctp_outq*); +void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t); +int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *); +int sctp_outq_is_empty(const struct sctp_outq *); +void sctp_outq_restart(struct sctp_outq *); + +void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, + enum sctp_retransmit_reason reason); +void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); +void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp); +void sctp_prsctp_prune(struct sctp_association *asoc, + struct sctp_sndrcvinfo *sinfo, int msg_len); +void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn); +/* Uncork and flush an outqueue. */ +static inline void sctp_outq_cork(struct sctp_outq *q) +{ + q->cork = 1; +} + +/* SCTP skb control block. + * sctp_input_cb is currently used on rx and sock rx queue + */ +struct sctp_input_cb { + union { + struct inet_skb_parm h4; +#if IS_ENABLED(CONFIG_IPV6) + struct inet6_skb_parm h6; +#endif + } header; + struct sctp_chunk *chunk; + struct sctp_af *af; +}; +#define SCTP_INPUT_CB(__skb) ((struct sctp_input_cb *)&((__skb)->cb[0])) + +struct sctp_output_cb { + struct sk_buff *last; +}; +#define SCTP_OUTPUT_CB(__skb) ((struct sctp_output_cb *)&((__skb)->cb[0])) + +static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb) +{ + const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk; + + return chunk->head_skb ? : skb; +} + +/* These bind address data fields common between endpoints and associations */ +struct sctp_bind_addr { + + /* RFC 2960 12.1 Parameters necessary for the SCTP instance + * + * SCTP Port: The local SCTP port number the endpoint is + * bound to. + */ + __u16 port; + + /* RFC 2960 12.1 Parameters necessary for the SCTP instance + * + * Address List: The list of IP addresses that this instance + * has bound. This information is passed to one's + * peer(s) in INIT and INIT ACK chunks. + */ + struct list_head address_list; +}; + +void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port); +void sctp_bind_addr_free(struct sctp_bind_addr *); +int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest, + const struct sctp_bind_addr *src, + enum sctp_scope scope, gfp_t gfp, + int flags); +int sctp_bind_addr_dup(struct sctp_bind_addr *dest, + const struct sctp_bind_addr *src, + gfp_t gfp); +int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, + int new_size, __u8 addr_state, gfp_t gfp); +int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *); +int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *, + struct sctp_sock *); +int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *, + struct sctp_sock *, struct sctp_sock *); +int sctp_bind_addr_state(const struct sctp_bind_addr *bp, + const union sctp_addr *addr); +int sctp_bind_addrs_check(struct sctp_sock *sp, + struct sctp_sock *sp2, int cnt2); +union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr *bp, + const union sctp_addr *addrs, + int addrcnt, + struct sctp_sock *opt); +union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp, + int *addrs_len, + gfp_t gfp); +int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len, + __u16 port, gfp_t gfp); + +enum sctp_scope sctp_scope(const union sctp_addr *addr); +int sctp_in_scope(struct net *net, const union sctp_addr *addr, + const enum sctp_scope scope); +int sctp_is_any(struct sock *sk, const union sctp_addr *addr); +int sctp_is_ep_boundall(struct sock *sk); + + +/* What type of endpoint? */ +enum sctp_endpoint_type { + SCTP_EP_TYPE_SOCKET, + SCTP_EP_TYPE_ASSOCIATION, +}; + +/* + * A common base class to bridge the implmentation view of a + * socket (usually listening) endpoint versus an association's + * local endpoint. + * This common structure is useful for several purposes: + * 1) Common interface for lookup routines. + * a) Subfunctions work for either endpoint or association + * b) Single interface to lookup allows hiding the lookup lock rather + * than acquiring it externally. + * 2) Common interface for the inbound chunk handling/state machine. + * 3) Common object handling routines for reference counting, etc. + * 4) Disentangle association lookup from endpoint lookup, where we + * do not have to find our endpoint to find our association. + * + */ + +struct sctp_ep_common { + /* Fields to help us manage our entries in the hash tables. */ + struct hlist_node node; + int hashent; + + /* Runtime type information. What kind of endpoint is this? */ + enum sctp_endpoint_type type; + + /* Some fields to help us manage this object. + * refcnt - Reference count access to this object. + * dead - Do not attempt to use this object. + */ + refcount_t refcnt; + bool dead; + + /* What socket does this endpoint belong to? */ + struct sock *sk; + + /* Cache netns and it won't change once set */ + struct net *net; + + /* This is where we receive inbound chunks. */ + struct sctp_inq inqueue; + + /* This substructure includes the defining parameters of the + * endpoint: + * bind_addr.port is our shared port number. + * bind_addr.address_list is our set of local IP addresses. + */ + struct sctp_bind_addr bind_addr; +}; + + +/* RFC Section 1.4 Key Terms + * + * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a + * multi-homed host, an SCTP endpoint is represented to its peers as a + * combination of a set of eligible destination transport addresses to + * which SCTP packets can be sent and a set of eligible source + * transport addresses from which SCTP packets can be received. + * All transport addresses used by an SCTP endpoint must use the + * same port number, but can use multiple IP addresses. A transport + * address used by an SCTP endpoint must not be used by another + * SCTP endpoint. In other words, a transport address is unique + * to an SCTP endpoint. + * + * From an implementation perspective, each socket has one of these. + * A TCP-style socket will have exactly one association on one of + * these. An UDP-style socket will have multiple associations hanging + * off one of these. + */ + +struct sctp_endpoint { + /* Common substructure for endpoint and association. */ + struct sctp_ep_common base; + + /* Associations: A list of current associations and mappings + * to the data consumers for each association. This + * may be in the form of a hash table or other + * implementation dependent structure. The data + * consumers may be process identification + * information such as file descriptors, named pipe + * pointer, or table pointers dependent on how SCTP + * is implemented. + */ + /* This is really a list of struct sctp_association entries. */ + struct list_head asocs; + + /* Secret Key: A secret key used by this endpoint to compute + * the MAC. This SHOULD be a cryptographic quality + * random number with a sufficient length. + * Discussion in [RFC1750] can be helpful in + * selection of the key. + */ + __u8 secret_key[SCTP_SECRET_SIZE]; + + /* digest: This is a digest of the sctp cookie. This field is + * only used on the receive path when we try to validate + * that the cookie has not been tampered with. We put + * this here so we pre-allocate this once and can re-use + * on every receive. + */ + __u8 *digest; + + /* sendbuf acct. policy. */ + __u32 sndbuf_policy; + + /* rcvbuf acct. policy. */ + __u32 rcvbuf_policy; + + /* SCTP AUTH: array of the HMACs that will be allocated + * we need this per association so that we don't serialize + */ + struct crypto_shash **auth_hmacs; + + /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */ + struct sctp_hmac_algo_param *auth_hmacs_list; + + /* SCTP-AUTH: chunks to authenticate encoded into parameter */ + struct sctp_chunks_param *auth_chunk_list; + + /* SCTP-AUTH: endpoint shared keys */ + struct list_head endpoint_shared_keys; + __u16 active_key_id; + __u8 ecn_enable:1, + auth_enable:1, + intl_enable:1, + prsctp_enable:1, + asconf_enable:1, + reconf_enable:1; + + __u8 strreset_enable; + + /* Security identifiers from incoming (INIT). These are set by + * security_sctp_assoc_request(). These will only be used by + * SCTP TCP type sockets and peeled off connections as they + * cause a new socket to be generated. security_sctp_sk_clone() + * will then plug these into the new socket. + */ + + u32 secid; + u32 peer_secid; + struct rcu_head rcu; +}; + +/* Recover the outter endpoint structure. */ +static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base) +{ + struct sctp_endpoint *ep; + + ep = container_of(base, struct sctp_endpoint, base); + return ep; +} + +/* These are function signatures for manipulating endpoints. */ +struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t); +void sctp_endpoint_free(struct sctp_endpoint *); +void sctp_endpoint_put(struct sctp_endpoint *); +int sctp_endpoint_hold(struct sctp_endpoint *ep); +void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *); +struct sctp_association *sctp_endpoint_lookup_assoc( + const struct sctp_endpoint *ep, + const union sctp_addr *paddr, + struct sctp_transport **); +bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep, + const union sctp_addr *paddr); +struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, + struct net *, const union sctp_addr *); +bool sctp_has_association(struct net *net, const union sctp_addr *laddr, + const union sctp_addr *paddr); + +int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep, + const struct sctp_association *asoc, + enum sctp_cid cid, struct sctp_init_chunk *peer_init, + struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); +int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk, + const union sctp_addr *peer, + struct sctp_init_chunk *init, gfp_t gfp); +__u32 sctp_generate_tag(const struct sctp_endpoint *); +__u32 sctp_generate_tsn(const struct sctp_endpoint *); + +struct sctp_inithdr_host { + __u32 init_tag; + __u32 a_rwnd; + __u16 num_outbound_streams; + __u16 num_inbound_streams; + __u32 initial_tsn; +}; + +struct sctp_stream_priorities { + /* List of priorities scheduled */ + struct list_head prio_sched; + /* List of streams scheduled */ + struct list_head active; + /* The next stream in line */ + struct sctp_stream_out_ext *next; + __u16 prio; + __u16 users; +}; + +struct sctp_stream_out_ext { + __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; + __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; + struct list_head outq; /* chunks enqueued by this stream */ + union { + struct { + /* Scheduled streams list */ + struct list_head prio_list; + struct sctp_stream_priorities *prio_head; + }; + /* Fields used by RR scheduler */ + struct { + struct list_head rr_list; + }; + }; +}; + +struct sctp_stream_out { + union { + __u32 mid; + __u16 ssn; + }; + __u32 mid_uo; + struct sctp_stream_out_ext *ext; + __u8 state; +}; + +struct sctp_stream_in { + union { + __u32 mid; + __u16 ssn; + }; + __u32 mid_uo; + __u32 fsn; + __u32 fsn_uo; + char pd_mode; + char pd_mode_uo; +}; + +struct sctp_stream { + GENRADIX(struct sctp_stream_out) out; + GENRADIX(struct sctp_stream_in) in; + + __u16 outcnt; + __u16 incnt; + /* Current stream being sent, if any */ + struct sctp_stream_out *out_curr; + union { + /* Fields used by priority scheduler */ + struct { + /* List of priorities scheduled */ + struct list_head prio_list; + }; + /* Fields used by RR scheduler */ + struct { + /* List of streams scheduled */ + struct list_head rr_list; + /* The next stream in line */ + struct sctp_stream_out_ext *rr_next; + }; + }; + struct sctp_stream_interleave *si; +}; + +static inline struct sctp_stream_out *sctp_stream_out( + struct sctp_stream *stream, + __u16 sid) +{ + return genradix_ptr(&stream->out, sid); +} + +static inline struct sctp_stream_in *sctp_stream_in( + struct sctp_stream *stream, + __u16 sid) +{ + return genradix_ptr(&stream->in, sid); +} + +#define SCTP_SO(s, i) sctp_stream_out((s), (i)) +#define SCTP_SI(s, i) sctp_stream_in((s), (i)) + +#define SCTP_STREAM_CLOSED 0x00 +#define SCTP_STREAM_OPEN 0x01 + +static inline __u16 sctp_datachk_len(const struct sctp_stream *stream) +{ + return stream->si->data_chunk_len; +} + +static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream) +{ + return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr); +} + +static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream) +{ + return stream->si->ftsn_chunk_len; +} + +static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream) +{ + return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr); +} + +/* SCTP_GET_ASSOC_STATS counters */ +struct sctp_priv_assoc_stats { + /* Maximum observed rto in the association during subsequent + * observations. Value is set to 0 if no RTO measurement took place + * The transport where the max_rto was observed is returned in + * obs_rto_ipaddr + */ + struct sockaddr_storage obs_rto_ipaddr; + __u64 max_obs_rto; + /* Total In and Out SACKs received and sent */ + __u64 isacks; + __u64 osacks; + /* Total In and Out packets received and sent */ + __u64 opackets; + __u64 ipackets; + /* Total retransmitted chunks */ + __u64 rtxchunks; + /* TSN received > next expected */ + __u64 outofseqtsns; + /* Duplicate Chunks received */ + __u64 idupchunks; + /* Gap Ack Blocks received */ + __u64 gapcnt; + /* Unordered data chunks sent and received */ + __u64 ouodchunks; + __u64 iuodchunks; + /* Ordered data chunks sent and received */ + __u64 oodchunks; + __u64 iodchunks; + /* Control chunks sent and received */ + __u64 octrlchunks; + __u64 ictrlchunks; +}; + +/* RFC2960 + * + * 12. Recommended Transmission Control Block (TCB) Parameters + * + * This section details a recommended set of parameters that should + * be contained within the TCB for an implementation. This section is + * for illustrative purposes and should not be deemed as requirements + * on an implementation or as an exhaustive list of all parameters + * inside an SCTP TCB. Each implementation may need its own additional + * parameters for optimization. + */ + + +/* Here we have information about each individual association. */ +struct sctp_association { + + /* A base structure common to endpoint and association. + * In this context, it represents the associations's view + * of the local endpoint of the association. + */ + struct sctp_ep_common base; + + /* Associations on the same socket. */ + struct list_head asocs; + + /* association id. */ + sctp_assoc_t assoc_id; + + /* This is our parent endpoint. */ + struct sctp_endpoint *ep; + + /* These are those association elements needed in the cookie. */ + struct sctp_cookie c; + + /* This is all information about our peer. */ + struct { + /* transport_addr_list + * + * Peer : A list of SCTP transport addresses that the + * Transport : peer is bound to. This information is derived + * Address : from the INIT or INIT ACK and is used to + * List : associate an inbound packet with a given + * : association. Normally this information is + * : hashed or keyed for quick lookup and access + * : of the TCB. + * : The list is also initialized with the list + * : of addresses passed with the sctp_connectx() + * : call. + * + * It is a list of SCTP_transport's. + */ + struct list_head transport_addr_list; + + /* rwnd + * + * Peer Rwnd : Current calculated value of the peer's rwnd. + */ + __u32 rwnd; + + /* transport_count + * + * Peer : A count of the number of peer addresses + * Transport : in the Peer Transport Address List. + * Address : + * Count : + */ + __u16 transport_count; + + /* port + * The transport layer port number. + */ + __u16 port; + + /* primary_path + * + * Primary : This is the current primary destination + * Path : transport address of the peer endpoint. It + * : may also specify a source transport address + * : on this endpoint. + * + * All of these paths live on transport_addr_list. + * + * At the bakeoffs, we discovered that the intent of + * primaryPath is that it only changes when the ULP + * asks to have it changed. We add the activePath to + * designate the connection we are currently using to + * transmit new data and most control chunks. + */ + struct sctp_transport *primary_path; + + /* Cache the primary path address here, when we + * need a an address for msg_name. + */ + union sctp_addr primary_addr; + + /* active_path + * The path that we are currently using to + * transmit new data and most control chunks. + */ + struct sctp_transport *active_path; + + /* retran_path + * + * RFC2960 6.4 Multi-homed SCTP Endpoints + * ... + * Furthermore, when its peer is multi-homed, an + * endpoint SHOULD try to retransmit a chunk to an + * active destination transport address that is + * different from the last destination address to + * which the DATA chunk was sent. + */ + struct sctp_transport *retran_path; + + /* Pointer to last transport I have sent on. */ + struct sctp_transport *last_sent_to; + + /* This is the last transport I have received DATA on. */ + struct sctp_transport *last_data_from; + + /* + * Mapping An array of bits or bytes indicating which out of + * Array order TSN's have been received (relative to the + * Last Rcvd TSN). If no gaps exist, i.e. no out of + * order packets have been received, this array + * will be set to all zero. This structure may be + * in the form of a circular buffer or bit array. + * + * Last Rcvd : This is the last TSN received in + * TSN : sequence. This value is set initially by + * : taking the peer's Initial TSN, received in + * : the INIT or INIT ACK chunk, and subtracting + * : one from it. + * + * Throughout most of the specification this is called the + * "Cumulative TSN ACK Point". In this case, we + * ignore the advice in 12.2 in favour of the term + * used in the bulk of the text. This value is hidden + * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn(). + */ + struct sctp_tsnmap tsn_map; + + /* This mask is used to disable sending the ASCONF chunk + * with specified parameter to peer. + */ + __be16 addip_disabled_mask; + + /* These are capabilities which our peer advertised. */ + __u16 ecn_capable:1, /* Can peer do ECN? */ + ipv4_address:1, /* Peer understands IPv4 addresses? */ + ipv6_address:1, /* Peer understands IPv6 addresses? */ + hostname_address:1, /* Peer understands DNS addresses? */ + asconf_capable:1, /* Does peer support ADDIP? */ + prsctp_capable:1, /* Can peer do PR-SCTP? */ + reconf_capable:1, /* Can peer do RE-CONFIG? */ + intl_capable:1, /* Can peer do INTERLEAVE */ + auth_capable:1, /* Is peer doing SCTP-AUTH? */ + /* sack_needed: + * This flag indicates if the next received + * packet is to be responded to with a + * SACK. This is initialized to 0. When a packet + * is received sack_cnt is incremented. If this value + * reaches 2 or more, a SACK is sent and the + * value is reset to 0. Note: This is used only + * when no DATA chunks are received out of + * order. When DATA chunks are out of order, + * SACK's are not delayed (see Section 6). + */ + sack_needed:1, /* Do we need to sack the peer? */ + sack_generation:1, + zero_window_announced:1; + + __u32 sack_cnt; + + __u32 adaptation_ind; /* Adaptation Code point. */ + + struct sctp_inithdr_host i; + void *cookie; + int cookie_len; + + /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. + * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the + * Initial TSN Value minus 1 + */ + __u32 addip_serial; + + /* SCTP-AUTH: We need to know pears random number, hmac list + * and authenticated chunk list. All that is part of the + * cookie and these are just pointers to those locations + */ + struct sctp_random_param *peer_random; + struct sctp_chunks_param *peer_chunks; + struct sctp_hmac_algo_param *peer_hmacs; + } peer; + + /* State : A state variable indicating what state the + * : association is in, i.e. COOKIE-WAIT, + * : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING, + * : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT. + * + * Note: No "CLOSED" state is illustrated since if a + * association is "CLOSED" its TCB SHOULD be removed. + * + * In this implementation we DO have a CLOSED + * state which is used during initiation and shutdown. + * + * State takes values from SCTP_STATE_*. + */ + enum sctp_state state; + + /* Overall : The overall association error count. + * Error Count : [Clear this any time I get something.] + */ + int overall_error_count; + + /* The cookie life I award for any cookie. */ + ktime_t cookie_life; + + /* These are the association's initial, max, and min RTO values. + * These values will be initialized by system defaults, but can + * be modified via the SCTP_RTOINFO socket option. + */ + unsigned long rto_initial; + unsigned long rto_max; + unsigned long rto_min; + + /* Maximum number of new data packets that can be sent in a burst. */ + int max_burst; + + /* This is the max_retrans value for the association. This value will + * be initialized from system defaults, but can be + * modified by the SCTP_ASSOCINFO socket option. + */ + int max_retrans; + + /* This is the partially failed retrans value for the transport + * and will be initialized from the assocs value. This can be + * changed using the SCTP_PEER_ADDR_THLDS socket option + */ + __u16 pf_retrans; + /* Used for primary path switchover. */ + __u16 ps_retrans; + + /* Maximum number of times the endpoint will retransmit INIT */ + __u16 max_init_attempts; + + /* How many times have we resent an INIT? */ + __u16 init_retries; + + /* The largest timeout or RTO value to use in attempting an INIT */ + unsigned long max_init_timeo; + + /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to + * the destination address every heartbeat interval. This value + * will be inherited by all new transports. + */ + unsigned long hbinterval; + + /* This is the max_retrans value for new transports in the + * association. + */ + __u16 pathmaxrxt; + + __u32 flowlabel; + __u8 dscp; + + /* Flag that path mtu update is pending */ + __u8 pmtu_pending; + + /* Association : The smallest PMTU discovered for all of the + * PMTU : peer's transport addresses. + */ + __u32 pathmtu; + + /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */ + __u32 param_flags; + + __u32 sackfreq; + /* SACK delay timeout */ + unsigned long sackdelay; + + unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES]; + struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES]; + + /* Transport to which SHUTDOWN chunk was last sent. */ + struct sctp_transport *shutdown_last_sent_to; + + /* Transport to which INIT chunk was last sent. */ + struct sctp_transport *init_last_sent_to; + + /* How many times have we resent a SHUTDOWN */ + int shutdown_retries; + + /* Next TSN : The next TSN number to be assigned to a new + * : DATA chunk. This is sent in the INIT or INIT + * : ACK chunk to the peer and incremented each + * : time a DATA chunk is assigned a TSN + * : (normally just prior to transmit or during + * : fragmentation). + */ + __u32 next_tsn; + + /* + * Last Rcvd : This is the last TSN received in sequence. This value + * TSN : is set initially by taking the peer's Initial TSN, + * : received in the INIT or INIT ACK chunk, and + * : subtracting one from it. + * + * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point. + */ + + __u32 ctsn_ack_point; + + /* PR-SCTP Advanced.Peer.Ack.Point */ + __u32 adv_peer_ack_point; + + /* Highest TSN that is acknowledged by incoming SACKs. */ + __u32 highest_sacked; + + /* TSN marking the fast recovery exit point */ + __u32 fast_recovery_exit; + + /* Flag to track the current fast recovery state */ + __u8 fast_recovery; + + /* The number of unacknowledged data chunks. Reported through + * the SCTP_STATUS sockopt. + */ + __u16 unack_data; + + /* The total number of data chunks that we've had to retransmit + * as the result of a T3 timer expiration + */ + __u32 rtx_data_chunks; + + /* This is the association's receive buffer space. This value is used + * to set a_rwnd field in an INIT or a SACK chunk. + */ + __u32 rwnd; + + /* This is the last advertised value of rwnd over a SACK chunk. */ + __u32 a_rwnd; + + /* Number of bytes by which the rwnd has slopped. The rwnd is allowed + * to slop over a maximum of the association's frag_point. + */ + __u32 rwnd_over; + + /* Keeps treack of rwnd pressure. This happens when we have + * a window, but not recevie buffer (i.e small packets). This one + * is releases slowly (1 PMTU at a time ). + */ + __u32 rwnd_press; + + /* This is the sndbuf size in use for the association. + * This corresponds to the sndbuf size for the association, + * as specified in the sk->sndbuf. + */ + int sndbuf_used; + + /* This is the amount of memory that this association has allocated + * in the receive path at any given time. + */ + atomic_t rmem_alloc; + + /* This is the wait queue head for send requests waiting on + * the association sndbuf space. + */ + wait_queue_head_t wait; + + /* The message size at which SCTP fragmentation will occur. */ + __u32 frag_point; + __u32 user_frag; + + /* Counter used to count INIT errors. */ + int init_err_counter; + + /* Count the number of INIT cycles (for doubling timeout). */ + int init_cycle; + + /* Default send parameters. */ + __u16 default_stream; + __u16 default_flags; + __u32 default_ppid; + __u32 default_context; + __u32 default_timetolive; + + /* Default receive parameters */ + __u32 default_rcv_context; + + /* Stream arrays */ + struct sctp_stream stream; + + /* All outbound chunks go through this structure. */ + struct sctp_outq outqueue; + + /* A smart pipe that will handle reordering and fragmentation, + * as well as handle passing events up to the ULP. + */ + struct sctp_ulpq ulpq; + + /* Last TSN that caused an ECNE Chunk to be sent. */ + __u32 last_ecne_tsn; + + /* Last TSN that caused a CWR Chunk to be sent. */ + __u32 last_cwr_tsn; + + /* How many duplicated TSNs have we seen? */ + int numduptsns; + + /* These are to support + * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses + * and Enforcement of Flow and Message Limits" + * <draft-ietf-tsvwg-addip-sctp-02.txt> + * or "ADDIP" for short. + */ + + + + /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks + * + * R1) One and only one ASCONF Chunk MAY be in transit and + * unacknowledged at any one time. If a sender, after sending + * an ASCONF chunk, decides it needs to transfer another + * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk + * returns from the previous ASCONF Chunk before sending a + * subsequent ASCONF. Note this restriction binds each side, + * so at any time two ASCONF may be in-transit on any given + * association (one sent from each endpoint). + * + * [This is our one-and-only-one ASCONF in flight. If we do + * not have an ASCONF in flight, this is NULL.] + */ + struct sctp_chunk *addip_last_asconf; + + /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk. + * + * This is needed to implement itmes E1 - E4 of the updated + * spec. Here is the justification: + * + * Since the peer may bundle multiple ASCONF chunks toward us, + * we now need the ability to cache multiple ACKs. The section + * describes in detail how they are cached and cleaned up. + */ + struct list_head asconf_ack_list; + + /* These ASCONF chunks are waiting to be sent. + * + * These chunaks can't be pushed to outqueue until receiving + * ASCONF_ACK for the previous ASCONF indicated by + * addip_last_asconf, so as to guarantee that only one ASCONF + * is in flight at any time. + * + * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks + * + * In defining the ASCONF Chunk transfer procedures, it is + * essential that these transfers MUST NOT cause congestion + * within the network. To achieve this, we place these + * restrictions on the transfer of ASCONF Chunks: + * + * R1) One and only one ASCONF Chunk MAY be in transit and + * unacknowledged at any one time. If a sender, after sending + * an ASCONF chunk, decides it needs to transfer another + * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk + * returns from the previous ASCONF Chunk before sending a + * subsequent ASCONF. Note this restriction binds each side, + * so at any time two ASCONF may be in-transit on any given + * association (one sent from each endpoint). + * + * + * [I really think this is EXACTLY the sort of intelligence + * which already resides in sctp_outq. Please move this + * queue and its supporting logic down there. --piggy] + */ + struct list_head addip_chunk_list; + + /* ADDIP Section 4.1 ASCONF Chunk Procedures + * + * A2) A serial number should be assigned to the Chunk. The + * serial number SHOULD be a monotonically increasing + * number. The serial number SHOULD be initialized at + * the start of the association to the same value as the + * Initial TSN and every time a new ASCONF chunk is created + * it is incremented by one after assigning the serial number + * to the newly created chunk. + * + * ADDIP + * 3.1.1 Address/Stream Configuration Change Chunk (ASCONF) + * + * Serial Number : 32 bits (unsigned integer) + * + * This value represents a Serial Number for the ASCONF + * Chunk. The valid range of Serial Number is from 0 to + * 4294967295 (2^32 - 1). Serial Numbers wrap back to 0 + * after reaching 4294967295. + */ + __u32 addip_serial; + int src_out_of_asoc_ok; + union sctp_addr *asconf_addr_del_pending; + struct sctp_transport *new_transport; + + /* SCTP AUTH: list of the endpoint shared keys. These + * keys are provided out of band by the user applicaton + * and can't change during the lifetime of the association + */ + struct list_head endpoint_shared_keys; + + /* SCTP AUTH: + * The current generated assocaition shared key (secret) + */ + struct sctp_auth_bytes *asoc_shared_key; + struct sctp_shared_key *shkey; + + /* SCTP AUTH: hmac id of the first peer requested algorithm + * that we support. + */ + __u16 default_hmac_id; + + __u16 active_key_id; + + __u8 need_ecne:1, /* Need to send an ECNE Chunk? */ + temp:1, /* Is it a temporary association? */ + pf_expose:2, /* Expose pf state? */ + force_delay:1; + + __u8 strreset_enable; + __u8 strreset_outstanding; /* request param count on the fly */ + + __u32 strreset_outseq; /* Update after receiving response */ + __u32 strreset_inseq; /* Update after receiving request */ + __u32 strreset_result[2]; /* save the results of last 2 responses */ + + struct sctp_chunk *strreset_chunk; /* save request chunk */ + + struct sctp_priv_assoc_stats stats; + + int sent_cnt_removable; + + __u16 subscribe; + + __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1]; + __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1]; + + struct rcu_head rcu; +}; + + +/* An eyecatcher for determining if we are really looking at an + * association data structure. + */ +enum { + SCTP_ASSOC_EYECATCHER = 0xa550c123, +}; + +/* Recover the outter association structure. */ +static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base) +{ + struct sctp_association *asoc; + + asoc = container_of(base, struct sctp_association, base); + return asoc; +} + +/* These are function signatures for manipulating associations. */ + + +struct sctp_association * +sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk, + enum sctp_scope scope, gfp_t gfp); +void sctp_association_free(struct sctp_association *); +void sctp_association_put(struct sctp_association *); +void sctp_association_hold(struct sctp_association *); + +struct sctp_transport *sctp_assoc_choose_alter_transport( + struct sctp_association *, struct sctp_transport *); +void sctp_assoc_update_retran_path(struct sctp_association *); +struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *, + const union sctp_addr *); +int sctp_assoc_lookup_laddr(struct sctp_association *asoc, + const union sctp_addr *laddr); +struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *, + const union sctp_addr *address, + const gfp_t gfp, + const int peer_state); +void sctp_assoc_del_peer(struct sctp_association *asoc, + const union sctp_addr *addr); +void sctp_assoc_rm_peer(struct sctp_association *asoc, + struct sctp_transport *peer); +void sctp_assoc_control_transport(struct sctp_association *asoc, + struct sctp_transport *transport, + enum sctp_transport_cmd command, + sctp_sn_error_t error); +struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); +void sctp_assoc_migrate(struct sctp_association *, struct sock *); +int sctp_assoc_update(struct sctp_association *old, + struct sctp_association *new); + +__u32 sctp_association_get_next_tsn(struct sctp_association *); + +void sctp_assoc_update_frag_point(struct sctp_association *asoc); +void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu); +void sctp_assoc_sync_pmtu(struct sctp_association *asoc); +void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int); +void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int); +void sctp_assoc_set_primary(struct sctp_association *, + struct sctp_transport *); +void sctp_assoc_del_nonprimary_peers(struct sctp_association *, + struct sctp_transport *); +int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc, + enum sctp_scope scope, gfp_t gfp); +int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, + struct sctp_cookie*, + gfp_t gfp); +int sctp_assoc_set_id(struct sctp_association *, gfp_t); +void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc); +struct sctp_chunk *sctp_assoc_lookup_asconf_ack( + const struct sctp_association *asoc, + __be32 serial); +void sctp_asconf_queue_teardown(struct sctp_association *asoc); + +int sctp_cmp_addr_exact(const union sctp_addr *ss1, + const union sctp_addr *ss2); +struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc); + +/* A convenience structure to parse out SCTP specific CMSGs. */ +struct sctp_cmsgs { + struct sctp_initmsg *init; + struct sctp_sndrcvinfo *srinfo; + struct sctp_sndinfo *sinfo; + struct sctp_prinfo *prinfo; + struct sctp_authinfo *authinfo; + struct msghdr *addrs_msg; +}; + +/* Structure for tracking memory objects */ +struct sctp_dbg_objcnt_entry { + char *label; + atomic_t *counter; +}; + +#endif /* __sctp_structs_h__ */ |