/* SCTP kernel reference 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 reference Implementation * * The SCTP reference implementation is free software; * you can redistribute it and/or modify it under the terms of * the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * The SCTP reference implementation is distributed in the hope that it * will be useful, but WITHOUT ANY WARRANTY; without even the implied * ************************ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with GNU CC; see the file COPYING. If not, write to * the Free Software Foundation, 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * Please send any bug reports or fixes you make to the * email addresses: * lksctp developers * * Or submit a bug report through the following website: * http://www.sf.net/projects/lksctp * * Written or modified by: * Randall Stewart * Ken Morneau * Qiaobing Xie * La Monte H.P. Yarroll * Karl Knutson * Jon Grimm * Xingang Guo * Hui Huang * Sridhar Samudrala * Daisy Chang * Dajiang Zhang * Ardelle Fan * Ryan Layer * Anup Pemmaiah * Kevin Gao * * Any bugs reported given to us we will try to fix... any fixes shared will * be incorporated into the next SCTP release. */ #ifndef __sctp_structs_h__ #define __sctp_structs_h__ #include /* We get struct timespec. */ #include /* linux/in.h needs this!! */ #include /* We get struct sockaddr_in. */ #include /* We get struct in6_addr */ #include #include /* We get MAXHOSTNAMELEN. */ #include /* This gets us atomic counters. */ #include /* We need sk_buff_head. */ #include /* We need tq_struct. */ #include /* We need sctp* header structs. */ /* 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 sctp_ssnmap; struct crypto_hash; #include #include #include /* Structures useful for managing bind/connect. */ struct sctp_bind_bucket { unsigned short port; unsigned short fastreuse; struct sctp_bind_bucket *next; struct sctp_bind_bucket **pprev; struct hlist_head owner; }; struct sctp_bind_hashbucket { spinlock_t lock; struct sctp_bind_bucket *chain; }; /* Used for hashing all associations. */ struct sctp_hashbucket { rwlock_t lock; struct sctp_ep_common *chain; } __attribute__((__aligned__(8))); /* The SCTP globals structure. */ extern struct sctp_globals { /* RFC2960 Section 14. Suggested SCTP Protocol Parameter Values * * The following protocol parameters are RECOMMENDED: * * RTO.Initial - 3 seconds * RTO.Min - 1 second * RTO.Max - 60 seconds * RTO.Alpha - 1/8 (3 when converted to right shifts.) * RTO.Beta - 1/4 (2 when converted to right shifts.) */ unsigned int rto_initial; unsigned int rto_min; unsigned int rto_max; /* Note: rto_alpha and rto_beta are really defined as inverse * powers of two to facilitate integer operations. */ int rto_alpha; int rto_beta; /* Max.Burst - 4 */ int max_burst; /* Whether Cookie Preservative is enabled(1) or not(0) */ int cookie_preserve_enable; /* Valid.Cookie.Life - 60 seconds */ unsigned int valid_cookie_life; /* Delayed SACK timeout 200ms default*/ unsigned int sack_timeout; /* HB.interval - 30 seconds */ unsigned int hb_interval; /* Association.Max.Retrans - 10 attempts * Path.Max.Retrans - 5 attempts (per destination address) * Max.Init.Retransmits - 8 attempts */ int max_retrans_association; int max_retrans_path; int max_retrans_init; /* * Policy for preforming sctp/socket accounting * 0 - do socket level accounting, all assocs share sk_sndbuf * 1 - do sctp accounting, each asoc may use sk_sndbuf bytes */ int sndbuf_policy; /* * Policy for preforming sctp/socket accounting * 0 - do socket level accounting, all assocs share sk_rcvbuf * 1 - do sctp accounting, each asoc may use sk_rcvbuf bytes */ int rcvbuf_policy; /* The following variables are implementation specific. */ /* Default initialization values to be applied to new associations. */ __u16 max_instreams; __u16 max_outstreams; /* 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. */ int ep_hashsize; struct sctp_hashbucket *ep_hashtable; /* This is the hash of all associations. */ int assoc_hashsize; struct sctp_hashbucket *assoc_hashtable; /* This is the sctp port control hash. */ int port_hashsize; int port_rover; spinlock_t port_alloc_lock; /* Protects port_rover. */ struct sctp_bind_hashbucket *port_hashtable; /* This is the global local address list. * We actively maintain this complete list of interfaces on * the system by catching routing events. * * It is a list of sctp_sockaddr_entry. */ struct list_head local_addr_list; spinlock_t local_addr_lock; /* Flag to indicate if addip is enabled. */ int addip_enable; /* Flag to indicate if PR-SCTP is enabled. */ int prsctp_enable; } sctp_globals; #define sctp_rto_initial (sctp_globals.rto_initial) #define sctp_rto_min (sctp_globals.rto_min) #define sctp_rto_max (sctp_globals.rto_max) #define sctp_rto_alpha (sctp_globals.rto_alpha) #define sctp_rto_beta (sctp_globals.rto_beta) #define sctp_max_burst (sctp_globals.max_burst) #define sctp_valid_cookie_life (sctp_globals.valid_cookie_life) #define sctp_cookie_preserve_enable (sctp_globals.cookie_preserve_enable) #define sctp_max_retrans_association (sctp_globals.max_retrans_association) #define sctp_sndbuf_policy (sctp_globals.sndbuf_policy) #define sctp_rcvbuf_policy (sctp_globals.rcvbuf_policy) #define sctp_max_retrans_path (sctp_globals.max_retrans_path) #define sctp_max_retrans_init (sctp_globals.max_retrans_init) #define sctp_sack_timeout (sctp_globals.sack_timeout) #define sctp_hb_interval (sctp_globals.hb_interval) #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_assoc_hashsize (sctp_globals.assoc_hashsize) #define sctp_assoc_hashtable (sctp_globals.assoc_hashtable) #define sctp_port_hashsize (sctp_globals.port_hashsize) #define sctp_port_rover (sctp_globals.port_rover) #define sctp_port_alloc_lock (sctp_globals.port_alloc_lock) #define sctp_port_hashtable (sctp_globals.port_hashtable) #define sctp_local_addr_list (sctp_globals.local_addr_list) #define sctp_local_addr_lock (sctp_globals.local_addr_lock) #define sctp_addip_enable (sctp_globals.addip_enable) #define sctp_prsctp_enable (sctp_globals.prsctp_enable) /* SCTP Socket type: UDP or TCP style. */ typedef enum { SCTP_SOCKET_UDP = 0, SCTP_SOCKET_UDP_HIGH_BANDWIDTH, SCTP_SOCKET_TCP } sctp_socket_type_t; /* 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? */ sctp_socket_type_t type; /* PF_ family specific functions. */ struct sctp_pf *pf; /* Access to HMAC transform. */ struct crypto_hash *hmac; /* 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; /* 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; /* The initial Path MTU to use for new associations. */ __u32 pathmtu; /* The default SACK delay timeout for new associations. */ __u32 sackdelay; /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ __u32 param_flags; struct sctp_initmsg initmsg; struct sctp_rtoinfo rtoinfo; struct sctp_paddrparams paddrparam; struct sctp_event_subscribe subscribe; struct sctp_assocparams assocparams; int user_frag; __u32 autoclose; __u8 nodelay; __u8 disable_fragments; __u8 pd_mode; __u8 v4mapped; __u32 adaption_ind; /* Receive to here while partial delivery is in effect. */ struct sk_buff_head pd_lobby; }; 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 defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 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? */ struct timeval 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 adaption_ind; /* 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[0]; }; /* 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; } __attribute__((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_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_adaption_ind_param *aind; }; /* 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). */ typedef struct sctp_sender_hb_info { struct sctp_paramhdr param_hdr; union sctp_addr daddr; unsigned long sent_at; __u64 hb_nonce; } __attribute__((packed)) sctp_sender_hb_info_t; /* * RFC 2960 1.3.2 Sequenced Delivery within Streams * * The term "stream" is used in SCTP to refer to a sequence of user * messages that are to be delivered to the upper-layer protocol in * order with respect to other messages within the same stream. This is * in contrast to its usage in TCP, where it refers to a sequence of * bytes (in this document a byte is assumed to be eight bits). * ... * * This is the structure we use to track both our outbound and inbound * SSN, or Stream Sequence Numbers. */ struct sctp_stream { __u16 *ssn; unsigned int len; }; struct sctp_ssnmap { struct sctp_stream in; struct sctp_stream out; int malloced; }; struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, gfp_t gfp); void sctp_ssnmap_free(struct sctp_ssnmap *map); void sctp_ssnmap_clear(struct sctp_ssnmap *map); /* What is the current SSN number for this stream? */ static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id) { return stream->ssn[id]; } /* Return the next SSN number for this stream. */ static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id) { return stream->ssn[id]++; } /* Skip over this ssn and all below. */ static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id, __u16 ssn) { stream->ssn[id] = ssn+1; } /* * 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 ipfragok); int (*setsockopt) (struct sock *sk, int level, int optname, char __user *optval, int optlen); int (*getsockopt) (struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); int (*compat_setsockopt) (struct sock *sk, int level, int optname, char __user *optval, int optlen); int (*compat_getsockopt) (struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); struct dst_entry *(*get_dst) (struct sctp_association *asoc, union sctp_addr *daddr, union sctp_addr *saddr); void (*get_saddr) (struct sctp_association *asoc, struct dst_entry *dst, union sctp_addr *daddr, union sctp_addr *saddr); void (*copy_addrlist) (struct list_head *, struct net_device *); void (*dst_saddr) (union sctp_addr *saddr, struct dst_entry *dst, unsigned short port); 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); void (*to_sk_saddr) (union sctp_addr *, struct sock *sk); void (*to_sk_daddr) (union sctp_addr *, struct sock *sk); void (*from_addr_param) (union sctp_addr *, union sctp_addr_param *, __u16 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 *); sctp_scope_t (*scope) (union sctp_addr *); void (*inaddr_any) (union sctp_addr *, unsigned short); 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); __u16 net_header_len; int sockaddr_len; 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 *, __u16 *); struct sock *(*create_accept_sk) (struct sock *sk, struct sctp_association *asoc); void (*addr_v4map) (struct sctp_sock *, union sctp_addr *); 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; /* Chunks that have been transmitted. */ struct list_head track; /* Reference counting. */ atomic_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; char send_failed; /* Control whether chunks from this message can be abandoned. */ char can_abandon; }; struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *, struct sctp_sndrcvinfo *, struct msghdr *, int len); void sctp_datamsg_put(struct sctp_datamsg *); void sctp_datamsg_free(struct sctp_datamsg *); void sctp_datamsg_track(struct sctp_chunk *); 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; atomic_t refcnt; /* This is our link to the per-transport transmitted list. */ struct list_head transmitted_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; /* 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; } 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; __u8 rtt_in_progress; /* Is this chunk used for RTT calculation? */ __u8 resent; /* Has this chunk ever been retransmitted. */ __u8 has_tsn; /* Does this chunk have a TSN yet? */ __u8 has_ssn; /* Does this chunk have a SSN yet? */ __u8 singleton; /* Was this the only chunk in the packet? */ __u8 end_of_packet; /* Was this the last chunk in the packet? */ __u8 ecn_ce_done; /* Have we processed the ECN CE bit? */ __u8 pdiscard; /* Discard the whole packet now? */ __u8 tsn_gap_acked; /* Is this chunk acked by a GAP ACK? */ __s8 fast_retransmit; /* Is this chunk fast retransmitted? */ __u8 tsn_missing_report; /* Data chunk missing counter. */ __u8 data_accepted; /* At least 1 chunk in this packet accepted */ }; void sctp_chunk_hold(struct sctp_chunk *); void sctp_chunk_put(struct sctp_chunk *); int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len, struct iovec *data); 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 *); void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *, union sctp_addr *); const union sctp_addr *sctp_source(const struct sctp_chunk *chunk); /* This is a structure for holding either an IPv6 or an IPv4 address. */ struct sctp_sockaddr_entry { struct list_head list; union sctp_addr a; __u8 use_as_src; }; typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *); /* 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; /* 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; /* This packet contains a COOKIE-ECHO chunk. */ char has_cookie_echo; /* This packet containsa SACK chunk. */ char has_sack; /* SCTP cannot fragment this packet. So let ip fragment it. */ char ipfragok; int malloced; }; struct sctp_packet *sctp_packet_init(struct sctp_packet *, struct sctp_transport *, __u16 sport, __u16 dport); struct sctp_packet *sctp_packet_config(struct sctp_packet *, __u32 vtag, int); sctp_xmit_t sctp_packet_transmit_chunk(struct sctp_packet *, struct sctp_chunk *); sctp_xmit_t sctp_packet_append_chunk(struct sctp_packet *, struct sctp_chunk *); int sctp_packet_transmit(struct sctp_packet *); 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; /* Reference counting. */ atomic_t refcnt; int dead; /* 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: */ __u32 rtt; /* This is the most recent RTT. */ /* RTO : The current retransmission timeout value. */ unsigned long rto; /* RTTVAR : The current RTT variation. */ __u32 rttvar; /* SRTT : The current smoothed round trip time. */ __u32 srtt; /* 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. */ int rto_pending; /* * 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; /* Destination */ struct dst_entry *dst; /* Source address. */ union sctp_addr saddr; /* When was the last time(in jiffies) that a data packet was sent on * this transport? This is used to adjust the cwnd when the transport * becomes inactive. */ unsigned long last_time_used; /* 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; /* When was the last time (in jiffies) that we heard from this * transport? We use this to pick new active and retran paths. */ unsigned long last_time_heard; /* 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 SCTP_SET_PEER_ADDR_PARAMS socket option. */ __u16 pathmaxrxt; /* PMTU : The current known path MTU. */ __u32 pathmtu; /* Flags controling 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_UNKOWN. */ 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; /* 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; int malloced; /* Is this structure kfree()able? */ /* 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 sctp_transport *sctp_transport_new(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 *); void sctp_transport_free(struct sctp_transport *); void sctp_transport_reset_timers(struct sctp_transport *); void 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 *, sctp_lower_cwnd_t); unsigned long sctp_transport_timeout(struct sctp_transport *); /* 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; int malloced; /* Is this structure kfree()able? */ }; 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 *); void sctp_inq_set_th_handler(struct sctp_inq *, void (*)(void *), void *); /* 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; unsigned out_qlen; /* Total length of queued data chunks. */ /* Error of send failed, may used in SCTP_SEND_FAILED event. */ unsigned 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; /* Corked? */ char cork; /* Is this structure empty? */ char empty; /* Are we kfree()able? */ char malloced; }; void sctp_outq_init(struct sctp_association *, struct sctp_outq *); void sctp_outq_teardown(struct sctp_outq *); void sctp_outq_free(struct sctp_outq*); int sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk); int sctp_outq_flush(struct sctp_outq *, int); int sctp_outq_sack(struct sctp_outq *, struct sctp_sackhdr *); int sctp_outq_is_empty(const struct sctp_outq *); void sctp_outq_restart(struct sctp_outq *); void sctp_retransmit(struct sctp_outq *, struct sctp_transport *, sctp_retransmit_reason_t); void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8); int sctp_outq_uncork(struct sctp_outq *); /* Uncork and flush an outqueue. */ static inline void sctp_outq_cork(struct sctp_outq *q) { q->cork = 1; } /* 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; int malloced; /* Are we kfree()able? */ }; 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 sctp_bind_addr *dest, const struct sctp_bind_addr *src, sctp_scope_t scope, gfp_t gfp, int flags); int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *, __u8 use_as_src, 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 *); 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); sctp_scope_t sctp_scope(const union sctp_addr *); int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope); int sctp_is_any(const union sctp_addr *addr); int sctp_addr_is_valid(const union sctp_addr *addr); /* What type of endpoint? */ typedef enum { SCTP_EP_TYPE_SOCKET, SCTP_EP_TYPE_ASSOCIATION, } sctp_endpoint_type_t; /* * 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 sctp_ep_common *next; struct sctp_ep_common **pprev; int hashent; /* Runtime type information. What kind of endpoint is this? */ sctp_endpoint_type_t type; /* Some fields to help us manage this object. * refcnt - Reference count access to this object. * dead - Do not attempt to use this object. * malloced - Do we need to kfree this object? */ atomic_t refcnt; char dead; char malloced; /* What socket does this endpoint belong to? */ struct sock *sk; /* 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; /* Protection during address list comparisons. */ rwlock_t addr_lock; }; /* 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_HOW_MANY_SECRETS][SCTP_SECRET_SIZE]; int current_key; int last_key; int key_changed_at; /* 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; }; /* 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 *); void sctp_endpoint_hold(struct sctp_endpoint *); 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 **); int sctp_endpoint_is_peeled_off(struct sctp_endpoint *, const union sctp_addr *); struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *, const union sctp_addr *); int sctp_has_association(const union sctp_addr *laddr, const union sctp_addr *paddr); int sctp_verify_init(const struct sctp_association *asoc, sctp_cid_t, sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk, struct sctp_chunk **err_chunk); int sctp_process_init(struct sctp_association *, sctp_cid_t cid, const union sctp_addr *peer, sctp_init_chunk_t *init, gfp_t gfp); __u32 sctp_generate_tag(const struct sctp_endpoint *); __u32 sctp_generate_tsn(const struct sctp_endpoint *); /* 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 { /* rwnd * * Peer Rwnd : Current calculated value of the peer's rwnd. */ __u32 rwnd; /* 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; /* 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; __u8 _map[sctp_tsnmap_storage_size(SCTP_TSN_MAP_SIZE)]; /* Ack State : This flag indicates if the next received * : packet is to be responded to with a * : SACK. This is initializedto 0. When a packet * : is received it 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). */ __u8 sack_needed; /* Do we need to sack the peer? */ /* These are capabilities which our peer advertised. */ __u8 ecn_capable; /* Can peer do ECN? */ __u8 ipv4_address; /* Peer understands IPv4 addresses? */ __u8 ipv6_address; /* Peer understands IPv6 addresses? */ __u8 hostname_address;/* Peer understands DNS addresses? */ __u8 asconf_capable; /* Does peer support ADDIP? */ __u8 prsctp_capable; /* Can peer do PR-SCTP? */ __u32 adaption_ind; /* Adaption Code point. */ /* This mask is used to disable sending the ASCONF chunk * with specified parameter to peer. */ __be16 addip_disabled_mask; struct sctp_inithdr i; int cookie_len; void *cookie; /* 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; } 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_*. */ sctp_state_t state; /* The cookie life I award for any cookie. */ struct timeval cookie_life; /* Overall : The overall association error count. * Error Count : [Clear this any time I get something.] */ int overall_error_count; /* 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 initialized from system defaults, but can be * modified by the SCTP_ASSOCINFO socket option. */ int max_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; /* Association : The smallest PMTU discovered for all of the * PMTU : peer's transport addresses. */ __u32 pathmtu; /* Flags controling Heartbeat, SACK delay, and Path MTU Discovery. */ __u32 param_flags; /* 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; /* 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; /* The number of unacknowledged data chunks. Reported through * the SCTP_STATUS sockopt. */ __u16 unack_data; /* 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; /* 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; /* 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; /* This tracks outbound ssn for a given stream. */ struct sctp_ssnmap *ssnmap; /* 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; /* Number of seconds of idle time before an association is closed. * In the association context, this is really used as a boolean * since the real timeout is stored in the timeouts array */ __u32 autoclose; /* These are to support * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses * and Enforcement of Flow and Message Limits" * * 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 4.2 Upon reception of an ASCONF Chunk. * * IMPLEMENTATION NOTE: As an optimization a receiver may wish * to save the last ASCONF-ACK for some predetermined period * of time and instead of re-processing the ASCONF (with the * same serial number) it may just re-transmit the * ASCONF-ACK. It may wish to use the arrival of a new serial * number to discard the previously saved ASCONF-ACK or any * other means it may choose to expire the saved ASCONF-ACK. * * [This is our saved ASCONF-ACK. We invalidate it when a new * ASCONF serial number arrives.] */ struct sctp_chunk *addip_last_asconf_ack; /* 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; /* Need to send an ECNE Chunk? */ char need_ecne; /* Is it a temporary association? */ char temp; }; /* 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 *, const struct sock *, sctp_scope_t 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_init_transport( struct sctp_association *); struct sctp_transport *sctp_assoc_choose_shutdown_transport( struct sctp_association *); 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 *, struct sctp_transport *, sctp_transport_cmd_t, sctp_sn_error_t); struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32); struct sctp_transport *sctp_assoc_is_match(struct sctp_association *, const union sctp_addr *, const union sctp_addr *); void sctp_assoc_migrate(struct sctp_association *, struct sock *); void sctp_assoc_update(struct sctp_association *old, struct sctp_association *new); __u32 sctp_association_get_next_tsn(struct sctp_association *); void sctp_assoc_sync_pmtu(struct sctp_association *); void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned); void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned); void sctp_assoc_set_primary(struct sctp_association *, struct sctp_transport *); int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *, gfp_t); int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *, struct sctp_cookie*, gfp_t gfp); 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. */ typedef struct sctp_cmsgs { struct sctp_initmsg *init; struct sctp_sndrcvinfo *info; } sctp_cmsgs_t; /* Structure for tracking memory objects */ typedef struct { char *label; atomic_t *counter; } sctp_dbg_objcnt_entry_t; #endif /* __sctp_structs_h__ */