/* 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; __u32 probe_interval; __be16 udp_port; __be16 encap_port; /* 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; __u32 probe_size; }; 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 (*skb_sdif)(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 */ pmtu_probe:1, /* Used by PLPMTUD, can be set in s HB chunk */ 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; unsigned long probe_interval; /* 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; __be16 encap_port; /* 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; /* Timer to send a probe HB packet for PLPMTUD */ struct timer_list probe_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; struct { __u16 pmtu; __u16 probe_size; __u16 probe_high; __u8 probe_count; __u8 state; } pl; /* plpmtud related */ /* 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); void sctp_transport_reset_probe_timer(struct sctp_transport *transport); void sctp_transport_reset_raise_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); void sctp_transport_pl_send(struct sctp_transport *t); bool sctp_transport_pl_recv(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_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; __be16 encap_port; }; #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 { /* 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; /* Fields to help us manage our entries in the hash tables. */ struct hlist_node node; int hashent; /* 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; 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 *ep, struct net *net, const union sctp_addr *laddr, int dif, int sdif); bool sctp_has_association(struct net *net, const union sctp_addr *laddr, const union sctp_addr *paddr, int dif, int sdif); 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 { struct list_head fc_list; __u32 fc_length; __u16 fc_weight; }; }; }; 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 { struct list_head fc_list; }; }; 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? */ 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; unsigned long probe_interval; __be16 encap_port; /* 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]; /* 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; }; /* 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__ */