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TOMOYO Linux Cross Reference
Linux/include/net/sctp/structs.h

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  1 /* SCTP kernel implementation
  2  * (C) Copyright IBM Corp. 2001, 2004
  3  * Copyright (c) 1999-2000 Cisco, Inc.
  4  * Copyright (c) 1999-2001 Motorola, Inc.
  5  * Copyright (c) 2001 Intel Corp.
  6  *
  7  * This file is part of the SCTP kernel implementation
  8  *
  9  * This SCTP implementation is free software;
 10  * you can redistribute it and/or modify it under the terms of
 11  * the GNU General Public License as published by
 12  * the Free Software Foundation; either version 2, or (at your option)
 13  * any later version.
 14  *
 15  * This SCTP implementation is distributed in the hope that it
 16  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 17  *                 ************************
 18  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 19  * See the GNU General Public License for more details.
 20  *
 21  * You should have received a copy of the GNU General Public License
 22  * along with GNU CC; see the file COPYING.  If not, see
 23  * <http://www.gnu.org/licenses/>.
 24  *
 25  * Please send any bug reports or fixes you make to the
 26  * email addresses:
 27  *    lksctp developers <linux-sctp@vger.kernel.org>
 28  *
 29  * Written or modified by:
 30  *    Randall Stewart       <randall@sctp.chicago.il.us>
 31  *    Ken Morneau           <kmorneau@cisco.com>
 32  *    Qiaobing Xie          <qxie1@email.mot.com>
 33  *    La Monte H.P. Yarroll <piggy@acm.org>
 34  *    Karl Knutson          <karl@athena.chicago.il.us>
 35  *    Jon Grimm             <jgrimm@us.ibm.com>
 36  *    Xingang Guo           <xingang.guo@intel.com>
 37  *    Hui Huang             <hui.huang@nokia.com>
 38  *    Sridhar Samudrala     <sri@us.ibm.com>
 39  *    Daisy Chang           <daisyc@us.ibm.com>
 40  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
 41  *    Ardelle Fan           <ardelle.fan@intel.com>
 42  *    Ryan Layer            <rmlayer@us.ibm.com>
 43  *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
 44  *    Kevin Gao             <kevin.gao@intel.com>
 45  */
 46 
 47 #ifndef __sctp_structs_h__
 48 #define __sctp_structs_h__
 49 
 50 #include <linux/ktime.h>
 51 #include <linux/rhashtable-types.h>
 52 #include <linux/socket.h>       /* linux/in.h needs this!!    */
 53 #include <linux/in.h>           /* We get struct sockaddr_in. */
 54 #include <linux/in6.h>          /* We get struct in6_addr     */
 55 #include <linux/ipv6.h>
 56 #include <asm/param.h>          /* We get MAXHOSTNAMELEN.     */
 57 #include <linux/atomic.h>               /* This gets us atomic counters.  */
 58 #include <linux/skbuff.h>       /* We need sk_buff_head. */
 59 #include <linux/workqueue.h>    /* We need tq_struct.    */
 60 #include <linux/flex_array.h>   /* We need flex_array.   */
 61 #include <linux/sctp.h>         /* We need sctp* header structs.  */
 62 #include <net/sctp/auth.h>      /* We need auth specific structs */
 63 #include <net/ip.h>             /* For inet_skb_parm */
 64 
 65 /* A convenience structure for handling sockaddr structures.
 66  * We should wean ourselves off this.
 67  */
 68 union sctp_addr {
 69         struct sockaddr_in v4;
 70         struct sockaddr_in6 v6;
 71         struct sockaddr sa;
 72 };
 73 
 74 /* Forward declarations for data structures. */
 75 struct sctp_globals;
 76 struct sctp_endpoint;
 77 struct sctp_association;
 78 struct sctp_transport;
 79 struct sctp_packet;
 80 struct sctp_chunk;
 81 struct sctp_inq;
 82 struct sctp_outq;
 83 struct sctp_bind_addr;
 84 struct sctp_ulpq;
 85 struct sctp_ep_common;
 86 struct crypto_shash;
 87 struct sctp_stream;
 88 
 89 
 90 #include <net/sctp/tsnmap.h>
 91 #include <net/sctp/ulpevent.h>
 92 #include <net/sctp/ulpqueue.h>
 93 #include <net/sctp/stream_interleave.h>
 94 
 95 /* Structures useful for managing bind/connect. */
 96 
 97 struct sctp_bind_bucket {
 98         unsigned short  port;
 99         unsigned short  fastreuse;
100         struct hlist_node       node;
101         struct hlist_head       owner;
102         struct net      *net;
103 };
104 
105 struct sctp_bind_hashbucket {
106         spinlock_t      lock;
107         struct hlist_head       chain;
108 };
109 
110 /* Used for hashing all associations.  */
111 struct sctp_hashbucket {
112         rwlock_t        lock;
113         struct hlist_head       chain;
114 } __attribute__((__aligned__(8)));
115 
116 
117 /* The SCTP globals structure. */
118 extern struct sctp_globals {
119         /* This is a list of groups of functions for each address
120          * family that we support.
121          */
122         struct list_head address_families;
123 
124         /* This is the hash of all endpoints. */
125         struct sctp_hashbucket *ep_hashtable;
126         /* This is the sctp port control hash.  */
127         struct sctp_bind_hashbucket *port_hashtable;
128         /* This is the hash of all transports. */
129         struct rhltable transport_hashtable;
130 
131         /* Sizes of above hashtables. */
132         int ep_hashsize;
133         int port_hashsize;
134 
135         /* Default initialization values to be applied to new associations. */
136         __u16 max_instreams;
137         __u16 max_outstreams;
138 
139         /* Flag to indicate whether computing and verifying checksum
140          * is disabled. */
141         bool checksum_disable;
142 } sctp_globals;
143 
144 #define sctp_max_instreams              (sctp_globals.max_instreams)
145 #define sctp_max_outstreams             (sctp_globals.max_outstreams)
146 #define sctp_address_families           (sctp_globals.address_families)
147 #define sctp_ep_hashsize                (sctp_globals.ep_hashsize)
148 #define sctp_ep_hashtable               (sctp_globals.ep_hashtable)
149 #define sctp_port_hashsize              (sctp_globals.port_hashsize)
150 #define sctp_port_hashtable             (sctp_globals.port_hashtable)
151 #define sctp_transport_hashtable        (sctp_globals.transport_hashtable)
152 #define sctp_checksum_disable           (sctp_globals.checksum_disable)
153 
154 /* SCTP Socket type: UDP or TCP style. */
155 enum sctp_socket_type {
156         SCTP_SOCKET_UDP = 0,
157         SCTP_SOCKET_UDP_HIGH_BANDWIDTH,
158         SCTP_SOCKET_TCP
159 };
160 
161 /* Per socket SCTP information. */
162 struct sctp_sock {
163         /* inet_sock has to be the first member of sctp_sock */
164         struct inet_sock inet;
165         /* What kind of a socket is this? */
166         enum sctp_socket_type type;
167 
168         /* PF_ family specific functions.  */
169         struct sctp_pf *pf;
170 
171         /* Access to HMAC transform. */
172         struct crypto_shash *hmac;
173         char *sctp_hmac_alg;
174 
175         /* What is our base endpointer? */
176         struct sctp_endpoint *ep;
177 
178         struct sctp_bind_bucket *bind_hash;
179         /* Various Socket Options.  */
180         __u16 default_stream;
181         __u32 default_ppid;
182         __u16 default_flags;
183         __u32 default_context;
184         __u32 default_timetolive;
185         __u32 default_rcv_context;
186         int max_burst;
187 
188         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
189          * the destination address every heartbeat interval. This value
190          * will be inherited by all new associations.
191          */
192         __u32 hbinterval;
193 
194         /* This is the max_retrans value for new associations. */
195         __u16 pathmaxrxt;
196 
197         __u32 flowlabel;
198         __u8  dscp;
199 
200         /* The initial Path MTU to use for new associations. */
201         __u32 pathmtu;
202 
203         /* The default SACK delay timeout for new associations. */
204         __u32 sackdelay;
205         __u32 sackfreq;
206 
207         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
208         __u32 param_flags;
209 
210         struct sctp_rtoinfo rtoinfo;
211         struct sctp_paddrparams paddrparam;
212         struct sctp_assocparams assocparams;
213 
214         /*
215          * These two structures must be grouped together for the usercopy
216          * whitelist region.
217          */
218         struct sctp_event_subscribe subscribe;
219         struct sctp_initmsg initmsg;
220 
221         int user_frag;
222 
223         __u32 autoclose;
224         __u32 adaptation_ind;
225         __u32 pd_point;
226         __u16   nodelay:1,
227                 reuse:1,
228                 disable_fragments:1,
229                 v4mapped:1,
230                 frag_interleave:1,
231                 strm_interleave:1,
232                 recvrcvinfo:1,
233                 recvnxtinfo:1,
234                 data_ready_signalled:1;
235 
236         atomic_t pd_mode;
237         /* Receive to here while partial delivery is in effect. */
238         struct sk_buff_head pd_lobby;
239 
240         /* These must be the last fields, as they will skipped on copies,
241          * like on accept and peeloff operations
242          */
243         struct list_head auto_asconf_list;
244         int do_auto_asconf;
245 };
246 
247 static inline struct sctp_sock *sctp_sk(const struct sock *sk)
248 {
249        return (struct sctp_sock *)sk;
250 }
251 
252 static inline struct sock *sctp_opt2sk(const struct sctp_sock *sp)
253 {
254        return (struct sock *)sp;
255 }
256 
257 #if IS_ENABLED(CONFIG_IPV6)
258 struct sctp6_sock {
259        struct sctp_sock  sctp;
260        struct ipv6_pinfo inet6;
261 };
262 #endif /* CONFIG_IPV6 */
263 
264 
265 /* This is our APPLICATION-SPECIFIC state cookie.
266  * THIS IS NOT DICTATED BY THE SPECIFICATION.
267  */
268 /* These are the parts of an association which we send in the cookie.
269  * Most of these are straight out of:
270  * RFC2960 12.2 Parameters necessary per association (i.e. the TCB)
271  *
272  */
273 
274 struct sctp_cookie {
275 
276         /* My          : Tag expected in every inbound packet and sent
277          * Verification: in the INIT or INIT ACK chunk.
278          * Tag         :
279          */
280         __u32 my_vtag;
281 
282         /* Peer's      : Tag expected in every outbound packet except
283          * Verification: in the INIT chunk.
284          * Tag         :
285          */
286         __u32 peer_vtag;
287 
288         /* The rest of these are not from the spec, but really need to
289          * be in the cookie.
290          */
291 
292         /* My Tie Tag  : Assist in discovering a restarting association. */
293         __u32 my_ttag;
294 
295         /* Peer's Tie Tag: Assist in discovering a restarting association. */
296         __u32 peer_ttag;
297 
298         /* When does this cookie expire? */
299         ktime_t expiration;
300 
301         /* Number of inbound/outbound streams which are set
302          * and negotiated during the INIT process.
303          */
304         __u16 sinit_num_ostreams;
305         __u16 sinit_max_instreams;
306 
307         /* This is the first sequence number I used.  */
308         __u32 initial_tsn;
309 
310         /* This holds the originating address of the INIT packet.  */
311         union sctp_addr peer_addr;
312 
313         /* IG Section 2.35.3 
314          * Include the source port of the INIT-ACK
315          */
316         __u16           my_port;
317 
318         __u8 prsctp_capable;
319 
320         /* Padding for future use */
321         __u8 padding;           
322 
323         __u32 adaptation_ind;
324 
325         __u8 auth_random[sizeof(struct sctp_paramhdr) +
326                          SCTP_AUTH_RANDOM_LENGTH];
327         __u8 auth_hmacs[SCTP_AUTH_NUM_HMACS * sizeof(__u16) + 2];
328         __u8 auth_chunks[sizeof(struct sctp_paramhdr) + SCTP_AUTH_MAX_CHUNKS];
329 
330         /* This is a shim for my peer's INIT packet, followed by
331          * a copy of the raw address list of the association.
332          * The length of the raw address list is saved in the
333          * raw_addr_list_len field, which will be used at the time when
334          * the association TCB is re-constructed from the cookie.
335          */
336         __u32 raw_addr_list_len;
337         struct sctp_init_chunk peer_init[0];
338 };
339 
340 
341 /* The format of our cookie that we send to our peer. */
342 struct sctp_signed_cookie {
343         __u8 signature[SCTP_SECRET_SIZE];
344         __u32 __pad;            /* force sctp_cookie alignment to 64 bits */
345         struct sctp_cookie c;
346 } __packed;
347 
348 /* This is another convenience type to allocate memory for address
349  * params for the maximum size and pass such structures around
350  * internally.
351  */
352 union sctp_addr_param {
353         struct sctp_paramhdr p;
354         struct sctp_ipv4addr_param v4;
355         struct sctp_ipv6addr_param v6;
356 };
357 
358 /* A convenience type to allow walking through the various
359  * parameters and avoid casting all over the place.
360  */
361 union sctp_params {
362         void *v;
363         struct sctp_paramhdr *p;
364         struct sctp_cookie_preserve_param *life;
365         struct sctp_hostname_param *dns;
366         struct sctp_cookie_param *cookie;
367         struct sctp_supported_addrs_param *sat;
368         struct sctp_ipv4addr_param *v4;
369         struct sctp_ipv6addr_param *v6;
370         union sctp_addr_param *addr;
371         struct sctp_adaptation_ind_param *aind;
372         struct sctp_supported_ext_param *ext;
373         struct sctp_random_param *random;
374         struct sctp_chunks_param *chunks;
375         struct sctp_hmac_algo_param *hmac_algo;
376         struct sctp_addip_param *addip;
377 };
378 
379 /* RFC 2960.  Section 3.3.5 Heartbeat.
380  *    Heartbeat Information: variable length
381  *    The Sender-specific Heartbeat Info field should normally include
382  *    information about the sender's current time when this HEARTBEAT
383  *    chunk is sent and the destination transport address to which this
384  *    HEARTBEAT is sent (see Section 8.3).
385  */
386 struct sctp_sender_hb_info {
387         struct sctp_paramhdr param_hdr;
388         union sctp_addr daddr;
389         unsigned long sent_at;
390         __u64 hb_nonce;
391 };
392 
393 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
394                      gfp_t gfp);
395 int sctp_stream_init_ext(struct sctp_stream *stream, __u16 sid);
396 void sctp_stream_free(struct sctp_stream *stream);
397 void sctp_stream_clear(struct sctp_stream *stream);
398 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new);
399 
400 /* What is the current SSN number for this stream? */
401 #define sctp_ssn_peek(stream, type, sid) \
402         (sctp_stream_##type((stream), (sid))->ssn)
403 
404 /* Return the next SSN number for this stream.  */
405 #define sctp_ssn_next(stream, type, sid) \
406         (sctp_stream_##type((stream), (sid))->ssn++)
407 
408 /* Skip over this ssn and all below. */
409 #define sctp_ssn_skip(stream, type, sid, ssn) \
410         (sctp_stream_##type((stream), (sid))->ssn = ssn + 1)
411 
412 /* What is the current MID number for this stream? */
413 #define sctp_mid_peek(stream, type, sid) \
414         (sctp_stream_##type((stream), (sid))->mid)
415 
416 /* Return the next MID number for this stream.  */
417 #define sctp_mid_next(stream, type, sid) \
418         (sctp_stream_##type((stream), (sid))->mid++)
419 
420 /* Skip over this mid and all below. */
421 #define sctp_mid_skip(stream, type, sid, mid) \
422         (sctp_stream_##type((stream), (sid))->mid = mid + 1)
423 
424 /* What is the current MID_uo number for this stream? */
425 #define sctp_mid_uo_peek(stream, type, sid) \
426         (sctp_stream_##type((stream), (sid))->mid_uo)
427 
428 /* Return the next MID_uo number for this stream.  */
429 #define sctp_mid_uo_next(stream, type, sid) \
430         (sctp_stream_##type((stream), (sid))->mid_uo++)
431 
432 /*
433  * Pointers to address related SCTP functions.
434  * (i.e. things that depend on the address family.)
435  */
436 struct sctp_af {
437         int             (*sctp_xmit)    (struct sk_buff *skb,
438                                          struct sctp_transport *);
439         int             (*setsockopt)   (struct sock *sk,
440                                          int level,
441                                          int optname,
442                                          char __user *optval,
443                                          unsigned int optlen);
444         int             (*getsockopt)   (struct sock *sk,
445                                          int level,
446                                          int optname,
447                                          char __user *optval,
448                                          int __user *optlen);
449         int             (*compat_setsockopt)    (struct sock *sk,
450                                          int level,
451                                          int optname,
452                                          char __user *optval,
453                                          unsigned int optlen);
454         int             (*compat_getsockopt)    (struct sock *sk,
455                                          int level,
456                                          int optname,
457                                          char __user *optval,
458                                          int __user *optlen);
459         void            (*get_dst)      (struct sctp_transport *t,
460                                          union sctp_addr *saddr,
461                                          struct flowi *fl,
462                                          struct sock *sk);
463         void            (*get_saddr)    (struct sctp_sock *sk,
464                                          struct sctp_transport *t,
465                                          struct flowi *fl);
466         void            (*copy_addrlist) (struct list_head *,
467                                           struct net_device *);
468         int             (*cmp_addr)     (const union sctp_addr *addr1,
469                                          const union sctp_addr *addr2);
470         void            (*addr_copy)    (union sctp_addr *dst,
471                                          union sctp_addr *src);
472         void            (*from_skb)     (union sctp_addr *,
473                                          struct sk_buff *skb,
474                                          int saddr);
475         void            (*from_sk)      (union sctp_addr *,
476                                          struct sock *sk);
477         void            (*from_addr_param) (union sctp_addr *,
478                                             union sctp_addr_param *,
479                                             __be16 port, int iif);
480         int             (*to_addr_param) (const union sctp_addr *,
481                                           union sctp_addr_param *); 
482         int             (*addr_valid)   (union sctp_addr *,
483                                          struct sctp_sock *,
484                                          const struct sk_buff *);
485         enum sctp_scope (*scope)(union sctp_addr *);
486         void            (*inaddr_any)   (union sctp_addr *, __be16);
487         int             (*is_any)       (const union sctp_addr *);
488         int             (*available)    (union sctp_addr *,
489                                          struct sctp_sock *);
490         int             (*skb_iif)      (const struct sk_buff *sk);
491         int             (*is_ce)        (const struct sk_buff *sk);
492         void            (*seq_dump_addr)(struct seq_file *seq,
493                                          union sctp_addr *addr);
494         void            (*ecn_capable)(struct sock *sk);
495         __u16           net_header_len;
496         int             sockaddr_len;
497         int             (*ip_options_len)(struct sock *sk);
498         sa_family_t     sa_family;
499         struct list_head list;
500 };
501 
502 struct sctp_af *sctp_get_af_specific(sa_family_t);
503 int sctp_register_af(struct sctp_af *);
504 
505 /* Protocol family functions. */
506 struct sctp_pf {
507         void (*event_msgname)(struct sctp_ulpevent *, char *, int *);
508         void (*skb_msgname)  (struct sk_buff *, char *, int *);
509         int  (*af_supported) (sa_family_t, struct sctp_sock *);
510         int  (*cmp_addr) (const union sctp_addr *,
511                           const union sctp_addr *,
512                           struct sctp_sock *);
513         int  (*bind_verify) (struct sctp_sock *, union sctp_addr *);
514         int  (*send_verify) (struct sctp_sock *, union sctp_addr *);
515         int  (*supported_addrs)(const struct sctp_sock *, __be16 *);
516         struct sock *(*create_accept_sk) (struct sock *sk,
517                                           struct sctp_association *asoc,
518                                           bool kern);
519         int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr);
520         void (*to_sk_saddr)(union sctp_addr *, struct sock *sk);
521         void (*to_sk_daddr)(union sctp_addr *, struct sock *sk);
522         void (*copy_ip_options)(struct sock *sk, struct sock *newsk);
523         struct sctp_af *af;
524 };
525 
526 
527 /* Structure to track chunk fragments that have been acked, but peer
528  * fragments of the same message have not.
529  */
530 struct sctp_datamsg {
531         /* Chunks waiting to be submitted to lower layer. */
532         struct list_head chunks;
533         /* Reference counting. */
534         refcount_t refcnt;
535         /* When is this message no longer interesting to the peer? */
536         unsigned long expires_at;
537         /* Did the messenge fail to send? */
538         int send_error;
539         u8 send_failed:1,
540            can_delay:1, /* should this message be Nagle delayed */
541            abandoned:1; /* should this message be abandoned */
542 };
543 
544 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *,
545                                             struct sctp_sndrcvinfo *,
546                                             struct iov_iter *);
547 void sctp_datamsg_free(struct sctp_datamsg *);
548 void sctp_datamsg_put(struct sctp_datamsg *);
549 void sctp_chunk_fail(struct sctp_chunk *, int error);
550 int sctp_chunk_abandoned(struct sctp_chunk *);
551 
552 /* RFC2960 1.4 Key Terms
553  *
554  * o Chunk: A unit of information within an SCTP packet, consisting of
555  * a chunk header and chunk-specific content.
556  *
557  * As a matter of convenience, we remember the SCTP common header for
558  * each chunk as well as a few other header pointers...
559  */
560 struct sctp_chunk {
561         struct list_head list;
562 
563         refcount_t refcnt;
564 
565         /* How many times this chunk have been sent, for prsctp RTX policy */
566         int sent_count;
567 
568         union {
569                 /* This is our link to the per-transport transmitted list.  */
570                 struct list_head transmitted_list;
571                 /* List in specific stream outq */
572                 struct list_head stream_list;
573         };
574 
575         /* This field is used by chunks that hold fragmented data.
576          * For the first fragment this is the list that holds the rest of
577          * fragments. For the remaining fragments, this is the link to the
578          * frag_list maintained in the first fragment.
579          */
580         struct list_head frag_list;
581 
582         /* This points to the sk_buff containing the actual data.  */
583         struct sk_buff *skb;
584 
585         union {
586                 /* In case of GSO packets, this will store the head one */
587                 struct sk_buff *head_skb;
588                 /* In case of auth enabled, this will point to the shkey */
589                 struct sctp_shared_key *shkey;
590         };
591 
592         /* These are the SCTP headers by reverse order in a packet.
593          * Note that some of these may happen more than once.  In that
594          * case, we point at the "current" one, whatever that means
595          * for that level of header.
596          */
597 
598         /* We point this at the FIRST TLV parameter to chunk_hdr.  */
599         union sctp_params param_hdr;
600         union {
601                 __u8 *v;
602                 struct sctp_datahdr *data_hdr;
603                 struct sctp_inithdr *init_hdr;
604                 struct sctp_sackhdr *sack_hdr;
605                 struct sctp_heartbeathdr *hb_hdr;
606                 struct sctp_sender_hb_info *hbs_hdr;
607                 struct sctp_shutdownhdr *shutdown_hdr;
608                 struct sctp_signed_cookie *cookie_hdr;
609                 struct sctp_ecnehdr *ecne_hdr;
610                 struct sctp_cwrhdr *ecn_cwr_hdr;
611                 struct sctp_errhdr *err_hdr;
612                 struct sctp_addiphdr *addip_hdr;
613                 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
614                 struct sctp_authhdr *auth_hdr;
615                 struct sctp_idatahdr *idata_hdr;
616                 struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
617         } subh;
618 
619         __u8 *chunk_end;
620 
621         struct sctp_chunkhdr *chunk_hdr;
622         struct sctphdr *sctp_hdr;
623 
624         /* This needs to be recoverable for SCTP_SEND_FAILED events. */
625         struct sctp_sndrcvinfo sinfo;
626 
627         /* Which association does this belong to?  */
628         struct sctp_association *asoc;
629 
630         /* What endpoint received this chunk? */
631         struct sctp_ep_common *rcvr;
632 
633         /* We fill this in if we are calculating RTT. */
634         unsigned long sent_at;
635 
636         /* What is the origin IP address for this chunk?  */
637         union sctp_addr source;
638         /* Destination address for this chunk. */
639         union sctp_addr dest;
640 
641         /* For outbound message, track all fragments for SEND_FAILED. */
642         struct sctp_datamsg *msg;
643 
644         /* For an inbound chunk, this tells us where it came from.
645          * For an outbound chunk, it tells us where we'd like it to
646          * go.  It is NULL if we have no preference.
647          */
648         struct sctp_transport *transport;
649 
650         /* SCTP-AUTH:  For the special case inbound processing of COOKIE-ECHO
651          * we need save a pointer to the AUTH chunk, since the SCTP-AUTH
652          * spec violates the principle premis that all chunks are processed
653          * in order.
654          */
655         struct sk_buff *auth_chunk;
656 
657 #define SCTP_CAN_FRTX 0x0
658 #define SCTP_NEED_FRTX 0x1
659 #define SCTP_DONT_FRTX 0x2
660         __u16   rtt_in_progress:1,      /* This chunk used for RTT calc? */
661                 has_tsn:1,              /* Does this chunk have a TSN yet? */
662                 has_ssn:1,              /* Does this chunk have a SSN yet? */
663 #define has_mid has_ssn
664                 singleton:1,            /* Only chunk in the packet? */
665                 end_of_packet:1,        /* Last chunk in the packet? */
666                 ecn_ce_done:1,          /* Have we processed the ECN CE bit? */
667                 pdiscard:1,             /* Discard the whole packet now? */
668                 tsn_gap_acked:1,        /* Is this chunk acked by a GAP ACK? */
669                 data_accepted:1,        /* At least 1 chunk accepted */
670                 auth:1,                 /* IN: was auth'ed | OUT: needs auth */
671                 has_asconf:1,           /* IN: have seen an asconf before */
672                 tsn_missing_report:2,   /* Data chunk missing counter. */
673                 fast_retransmit:2;      /* Is this chunk fast retransmitted? */
674 };
675 
676 #define sctp_chunk_retransmitted(chunk) (chunk->sent_count > 1)
677 void sctp_chunk_hold(struct sctp_chunk *);
678 void sctp_chunk_put(struct sctp_chunk *);
679 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
680                           struct iov_iter *from);
681 void sctp_chunk_free(struct sctp_chunk *);
682 void  *sctp_addto_chunk(struct sctp_chunk *, int len, const void *data);
683 struct sctp_chunk *sctp_chunkify(struct sk_buff *,
684                                  const struct sctp_association *,
685                                  struct sock *, gfp_t gfp);
686 void sctp_init_addrs(struct sctp_chunk *, union sctp_addr *,
687                      union sctp_addr *);
688 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk);
689 
690 static inline __u16 sctp_chunk_stream_no(struct sctp_chunk *ch)
691 {
692         return ntohs(ch->subh.data_hdr->stream);
693 }
694 
695 enum {
696         SCTP_ADDR_NEW,          /* new address added to assoc/ep */
697         SCTP_ADDR_SRC,          /* address can be used as source */
698         SCTP_ADDR_DEL,          /* address about to be deleted */
699 };
700 
701 /* This is a structure for holding either an IPv6 or an IPv4 address.  */
702 struct sctp_sockaddr_entry {
703         struct list_head list;
704         struct rcu_head rcu;
705         union sctp_addr a;
706         __u8 state;
707         __u8 valid;
708 };
709 
710 #define SCTP_ADDRESS_TICK_DELAY 500
711 
712 /* This structure holds lists of chunks as we are assembling for
713  * transmission.
714  */
715 struct sctp_packet {
716         /* These are the SCTP header values (host order) for the packet. */
717         __u16 source_port;
718         __u16 destination_port;
719         __u32 vtag;
720 
721         /* This contains the payload chunks.  */
722         struct list_head chunk_list;
723 
724         /* This is the overhead of the sctp and ip headers. */
725         size_t overhead;
726         /* This is the total size of all chunks INCLUDING padding.  */
727         size_t size;
728         /* This is the maximum size this packet may have */
729         size_t max_size;
730 
731         /* The packet is destined for this transport address.
732          * The function we finally use to pass down to the next lower
733          * layer lives in the transport structure.
734          */
735         struct sctp_transport *transport;
736 
737         /* pointer to the auth chunk for this packet */
738         struct sctp_chunk *auth;
739 
740         u8  has_cookie_echo:1,  /* This packet contains a COOKIE-ECHO chunk. */
741             has_sack:1,         /* This packet contains a SACK chunk. */
742             has_auth:1,         /* This packet contains an AUTH chunk */
743             has_data:1,         /* This packet contains at least 1 DATA chunk */
744             ipfragok:1;         /* So let ip fragment this packet */
745 };
746 
747 void sctp_packet_init(struct sctp_packet *, struct sctp_transport *,
748                       __u16 sport, __u16 dport);
749 void sctp_packet_config(struct sctp_packet *, __u32 vtag, int);
750 enum sctp_xmit sctp_packet_transmit_chunk(struct sctp_packet *packet,
751                                           struct sctp_chunk *chunk,
752                                           int one_packet, gfp_t gfp);
753 enum sctp_xmit sctp_packet_append_chunk(struct sctp_packet *packet,
754                                         struct sctp_chunk *chunk);
755 int sctp_packet_transmit(struct sctp_packet *, gfp_t);
756 void sctp_packet_free(struct sctp_packet *);
757 
758 static inline int sctp_packet_empty(struct sctp_packet *packet)
759 {
760         return packet->size == packet->overhead;
761 }
762 
763 /* This represents a remote transport address.
764  * For local transport addresses, we just use union sctp_addr.
765  *
766  * RFC2960 Section 1.4 Key Terms
767  *
768  *   o  Transport address:  A Transport Address is traditionally defined
769  *      by Network Layer address, Transport Layer protocol and Transport
770  *      Layer port number.  In the case of SCTP running over IP, a
771  *      transport address is defined by the combination of an IP address
772  *      and an SCTP port number (where SCTP is the Transport protocol).
773  *
774  * RFC2960 Section 7.1 SCTP Differences from TCP Congestion control
775  *
776  *   o  The sender keeps a separate congestion control parameter set for
777  *      each of the destination addresses it can send to (not each
778  *      source-destination pair but for each destination).  The parameters
779  *      should decay if the address is not used for a long enough time
780  *      period.
781  *
782  */
783 struct sctp_transport {
784         /* A list of transports. */
785         struct list_head transports;
786         struct rhlist_head node;
787 
788         /* Reference counting. */
789         refcount_t refcnt;
790                 /* RTO-Pending : A flag used to track if one of the DATA
791                  *              chunks sent to this address is currently being
792                  *              used to compute a RTT. If this flag is 0,
793                  *              the next DATA chunk sent to this destination
794                  *              should be used to compute a RTT and this flag
795                  *              should be set. Every time the RTT
796                  *              calculation completes (i.e. the DATA chunk
797                  *              is SACK'd) clear this flag.
798                  */
799         __u32   rto_pending:1,
800 
801                 /*
802                  * hb_sent : a flag that signals that we have a pending
803                  * heartbeat.
804                  */
805                 hb_sent:1,
806 
807                 /* Is the Path MTU update pending on this tranport */
808                 pmtu_pending:1,
809 
810                 dst_pending_confirm:1,  /* need to confirm neighbour */
811 
812                 /* Has this transport moved the ctsn since we last sacked */
813                 sack_generation:1;
814         u32 dst_cookie;
815 
816         struct flowi fl;
817 
818         /* This is the peer's IP address and port. */
819         union sctp_addr ipaddr;
820 
821         /* These are the functions we call to handle LLP stuff.  */
822         struct sctp_af *af_specific;
823 
824         /* Which association do we belong to?  */
825         struct sctp_association *asoc;
826 
827         /* RFC2960
828          *
829          * 12.3 Per Transport Address Data
830          *
831          * For each destination transport address in the peer's
832          * address list derived from the INIT or INIT ACK chunk, a
833          * number of data elements needs to be maintained including:
834          */
835         /* RTO         : The current retransmission timeout value.  */
836         unsigned long rto;
837 
838         __u32 rtt;              /* This is the most recent RTT.  */
839 
840         /* RTTVAR      : The current RTT variation.  */
841         __u32 rttvar;
842 
843         /* SRTT        : The current smoothed round trip time.  */
844         __u32 srtt;
845 
846         /*
847          * These are the congestion stats.
848          */
849         /* cwnd        : The current congestion window.  */
850         __u32 cwnd;               /* This is the actual cwnd.  */
851 
852         /* ssthresh    : The current slow start threshold value.  */
853         __u32 ssthresh;
854 
855         /* partial     : The tracking method for increase of cwnd when in
856          * bytes acked : congestion avoidance mode (see Section 6.2.2)
857          */
858         __u32 partial_bytes_acked;
859 
860         /* Data that has been sent, but not acknowledged. */
861         __u32 flight_size;
862 
863         __u32 burst_limited;    /* Holds old cwnd when max.burst is applied */
864 
865         /* Destination */
866         struct dst_entry *dst;
867         /* Source address. */
868         union sctp_addr saddr;
869 
870         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
871          * the destination address every heartbeat interval.
872          */
873         unsigned long hbinterval;
874 
875         /* SACK delay timeout */
876         unsigned long sackdelay;
877         __u32 sackfreq;
878 
879         atomic_t mtu_info;
880 
881         /* When was the last time that we heard from this transport? We use
882          * this to pick new active and retran paths.
883          */
884         ktime_t last_time_heard;
885 
886         /* When was the last time that we sent a chunk using this
887          * transport? We use this to check for idle transports
888          */
889         unsigned long last_time_sent;
890 
891         /* Last time(in jiffies) when cwnd is reduced due to the congestion
892          * indication based on ECNE chunk.
893          */
894         unsigned long last_time_ecne_reduced;
895 
896         /* This is the max_retrans value for the transport and will
897          * be initialized from the assocs value.  This can be changed
898          * using the SCTP_SET_PEER_ADDR_PARAMS socket option.
899          */
900         __u16 pathmaxrxt;
901 
902         __u32 flowlabel;
903         __u8  dscp;
904 
905         /* This is the partially failed retrans value for the transport
906          * and will be initialized from the assocs value.  This can be changed
907          * using the SCTP_PEER_ADDR_THLDS socket option
908          */
909         int pf_retrans;
910         /* PMTU       : The current known path MTU.  */
911         __u32 pathmtu;
912 
913         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
914         __u32 param_flags;
915 
916         /* The number of times INIT has been sent on this transport. */
917         int init_sent_count;
918 
919         /* state       : The current state of this destination,
920          *             : i.e. SCTP_ACTIVE, SCTP_INACTIVE, SCTP_UNKNOWN.
921          */
922         int state;
923 
924         /* These are the error stats for this destination.  */
925 
926         /* Error count : The current error count for this destination.  */
927         unsigned short error_count;
928 
929         /* Per         : A timer used by each destination.
930          * Destination :
931          * Timer       :
932          *
933          * [Everywhere else in the text this is called T3-rtx. -ed]
934          */
935         struct timer_list T3_rtx_timer;
936 
937         /* Heartbeat timer is per destination. */
938         struct timer_list hb_timer;
939 
940         /* Timer to handle ICMP proto unreachable envets */
941         struct timer_list proto_unreach_timer;
942 
943         /* Timer to handler reconf chunk rtx */
944         struct timer_list reconf_timer;
945 
946         /* Since we're using per-destination retransmission timers
947          * (see above), we're also using per-destination "transmitted"
948          * queues.  This probably ought to be a private struct
949          * accessible only within the outqueue, but it's not, yet.
950          */
951         struct list_head transmitted;
952 
953         /* We build bundle-able packets for this transport here.  */
954         struct sctp_packet packet;
955 
956         /* This is the list of transports that have chunks to send.  */
957         struct list_head send_ready;
958 
959         /* State information saved for SFR_CACC algorithm. The key
960          * idea in SFR_CACC is to maintain state at the sender on a
961          * per-destination basis when a changeover happens.
962          *      char changeover_active;
963          *      char cycling_changeover;
964          *      __u32 next_tsn_at_change;
965          *      char cacc_saw_newack;
966          */
967         struct {
968                 /* An unsigned integer, which stores the next TSN to be
969                  * used by the sender, at the moment of changeover.
970                  */
971                 __u32 next_tsn_at_change;
972 
973                 /* A flag which indicates the occurrence of a changeover */
974                 char changeover_active;
975 
976                 /* A flag which indicates whether the change of primary is
977                  * the first switch to this destination address during an
978                  * active switch.
979                  */
980                 char cycling_changeover;
981 
982                 /* A temporary flag, which is used during the processing of
983                  * a SACK to estimate the causative TSN(s)'s group.
984                  */
985                 char cacc_saw_newack;
986         } cacc;
987 
988         /* 64-bit random number sent with heartbeat. */
989         __u64 hb_nonce;
990 
991         struct rcu_head rcu;
992 };
993 
994 struct sctp_transport *sctp_transport_new(struct net *, const union sctp_addr *,
995                                           gfp_t);
996 void sctp_transport_set_owner(struct sctp_transport *,
997                               struct sctp_association *);
998 void sctp_transport_route(struct sctp_transport *, union sctp_addr *,
999                           struct sctp_sock *);
1000 void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
1001 void sctp_transport_free(struct sctp_transport *);
1002 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
1003 void sctp_transport_reset_hb_timer(struct sctp_transport *);
1004 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
1005 int sctp_transport_hold(struct sctp_transport *);
1006 void sctp_transport_put(struct sctp_transport *);
1007 void sctp_transport_update_rto(struct sctp_transport *, __u32);
1008 void sctp_transport_raise_cwnd(struct sctp_transport *, __u32, __u32);
1009 void sctp_transport_lower_cwnd(struct sctp_transport *t,
1010                                enum sctp_lower_cwnd reason);
1011 void sctp_transport_burst_limited(struct sctp_transport *);
1012 void sctp_transport_burst_reset(struct sctp_transport *);
1013 unsigned long sctp_transport_timeout(struct sctp_transport *);
1014 void sctp_transport_reset(struct sctp_transport *t);
1015 bool sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu);
1016 void sctp_transport_immediate_rtx(struct sctp_transport *);
1017 void sctp_transport_dst_release(struct sctp_transport *t);
1018 void sctp_transport_dst_confirm(struct sctp_transport *t);
1019 
1020 
1021 /* This is the structure we use to queue packets as they come into
1022  * SCTP.  We write packets to it and read chunks from it.
1023  */
1024 struct sctp_inq {
1025         /* This is actually a queue of sctp_chunk each
1026          * containing a partially decoded packet.
1027          */
1028         struct list_head in_chunk_list;
1029         /* This is the packet which is currently off the in queue and is
1030          * being worked on through the inbound chunk processing.
1031          */
1032         struct sctp_chunk *in_progress;
1033 
1034         /* This is the delayed task to finish delivering inbound
1035          * messages.
1036          */
1037         struct work_struct immediate;
1038 };
1039 
1040 void sctp_inq_init(struct sctp_inq *);
1041 void sctp_inq_free(struct sctp_inq *);
1042 void sctp_inq_push(struct sctp_inq *, struct sctp_chunk *packet);
1043 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *);
1044 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *);
1045 void sctp_inq_set_th_handler(struct sctp_inq *, work_func_t);
1046 
1047 /* This is the structure we use to hold outbound chunks.  You push
1048  * chunks in and they automatically pop out the other end as bundled
1049  * packets (it calls (*output_handler)()).
1050  *
1051  * This structure covers sections 6.3, 6.4, 6.7, 6.8, 6.10, 7., 8.1,
1052  * and 8.2 of the v13 draft.
1053  *
1054  * It handles retransmissions.  The connection to the timeout portion
1055  * of the state machine is through sctp_..._timeout() and timeout_handler.
1056  *
1057  * If you feed it SACKs, it will eat them.
1058  *
1059  * If you give it big chunks, it will fragment them.
1060  *
1061  * It assigns TSN's to data chunks.  This happens at the last possible
1062  * instant before transmission.
1063  *
1064  * When free()'d, it empties itself out via output_handler().
1065  */
1066 struct sctp_outq {
1067         struct sctp_association *asoc;
1068 
1069         /* Data pending that has never been transmitted.  */
1070         struct list_head out_chunk_list;
1071 
1072         /* Stream scheduler being used */
1073         struct sctp_sched_ops *sched;
1074 
1075         unsigned int out_qlen;  /* Total length of queued data chunks. */
1076 
1077         /* Error of send failed, may used in SCTP_SEND_FAILED event. */
1078         unsigned int error;
1079 
1080         /* These are control chunks we want to send.  */
1081         struct list_head control_chunk_list;
1082 
1083         /* These are chunks that have been sacked but are above the
1084          * CTSN, or cumulative tsn ack point.
1085          */
1086         struct list_head sacked;
1087 
1088         /* Put chunks on this list to schedule them for
1089          * retransmission.
1090          */
1091         struct list_head retransmit;
1092 
1093         /* Put chunks on this list to save them for FWD TSN processing as
1094          * they were abandoned.
1095          */
1096         struct list_head abandoned;
1097 
1098         /* How many unackd bytes do we have in-flight?  */
1099         __u32 outstanding_bytes;
1100 
1101         /* Are we doing fast-rtx on this queue */
1102         char fast_rtx;
1103 
1104         /* Corked? */
1105         char cork;
1106 };
1107 
1108 void sctp_outq_init(struct sctp_association *, struct sctp_outq *);
1109 void sctp_outq_teardown(struct sctp_outq *);
1110 void sctp_outq_free(struct sctp_outq*);
1111 void sctp_outq_tail(struct sctp_outq *, struct sctp_chunk *chunk, gfp_t);
1112 int sctp_outq_sack(struct sctp_outq *, struct sctp_chunk *);
1113 int sctp_outq_is_empty(const struct sctp_outq *);
1114 void sctp_outq_restart(struct sctp_outq *);
1115 
1116 void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
1117                      enum sctp_retransmit_reason reason);
1118 void sctp_retransmit_mark(struct sctp_outq *, struct sctp_transport *, __u8);
1119 void sctp_outq_uncork(struct sctp_outq *, gfp_t gfp);
1120 void sctp_prsctp_prune(struct sctp_association *asoc,
1121                        struct sctp_sndrcvinfo *sinfo, int msg_len);
1122 void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 sack_ctsn);
1123 /* Uncork and flush an outqueue.  */
1124 static inline void sctp_outq_cork(struct sctp_outq *q)
1125 {
1126         q->cork = 1;
1127 }
1128 
1129 /* SCTP skb control block.
1130  * sctp_input_cb is currently used on rx and sock rx queue
1131  */
1132 struct sctp_input_cb {
1133         union {
1134                 struct inet_skb_parm    h4;
1135 #if IS_ENABLED(CONFIG_IPV6)
1136                 struct inet6_skb_parm   h6;
1137 #endif
1138         } header;
1139         struct sctp_chunk *chunk;
1140         struct sctp_af *af;
1141 };
1142 #define SCTP_INPUT_CB(__skb)    ((struct sctp_input_cb *)&((__skb)->cb[0]))
1143 
1144 struct sctp_output_cb {
1145         struct sk_buff *last;
1146 };
1147 #define SCTP_OUTPUT_CB(__skb)   ((struct sctp_output_cb *)&((__skb)->cb[0]))
1148 
1149 static inline const struct sk_buff *sctp_gso_headskb(const struct sk_buff *skb)
1150 {
1151         const struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
1152 
1153         return chunk->head_skb ? : skb;
1154 }
1155 
1156 /* These bind address data fields common between endpoints and associations */
1157 struct sctp_bind_addr {
1158 
1159         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1160          *
1161          * SCTP Port:   The local SCTP port number the endpoint is
1162          *              bound to.
1163          */
1164         __u16 port;
1165 
1166         /* RFC 2960 12.1 Parameters necessary for the SCTP instance
1167          *
1168          * Address List: The list of IP addresses that this instance
1169          *      has bound.  This information is passed to one's
1170          *      peer(s) in INIT and INIT ACK chunks.
1171          */
1172         struct list_head address_list;
1173 };
1174 
1175 void sctp_bind_addr_init(struct sctp_bind_addr *, __u16 port);
1176 void sctp_bind_addr_free(struct sctp_bind_addr *);
1177 int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
1178                         const struct sctp_bind_addr *src,
1179                         enum sctp_scope scope, gfp_t gfp,
1180                         int flags);
1181 int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
1182                         const struct sctp_bind_addr *src,
1183                         gfp_t gfp);
1184 int sctp_add_bind_addr(struct sctp_bind_addr *, union sctp_addr *,
1185                        int new_size, __u8 addr_state, gfp_t gfp);
1186 int sctp_del_bind_addr(struct sctp_bind_addr *, union sctp_addr *);
1187 int sctp_bind_addr_match(struct sctp_bind_addr *, const union sctp_addr *,
1188                          struct sctp_sock *);
1189 int sctp_bind_addr_conflict(struct sctp_bind_addr *, const union sctp_addr *,
1190                          struct sctp_sock *, struct sctp_sock *);
1191 int sctp_bind_addr_state(const struct sctp_bind_addr *bp,
1192                          const union sctp_addr *addr);
1193 union sctp_addr *sctp_find_unmatch_addr(struct sctp_bind_addr   *bp,
1194                                         const union sctp_addr   *addrs,
1195                                         int                     addrcnt,
1196                                         struct sctp_sock        *opt);
1197 union sctp_params sctp_bind_addrs_to_raw(const struct sctp_bind_addr *bp,
1198                                          int *addrs_len,
1199                                          gfp_t gfp);
1200 int sctp_raw_to_bind_addrs(struct sctp_bind_addr *bp, __u8 *raw, int len,
1201                            __u16 port, gfp_t gfp);
1202 
1203 enum sctp_scope sctp_scope(const union sctp_addr *addr);
1204 int sctp_in_scope(struct net *net, const union sctp_addr *addr,
1205                   const enum sctp_scope scope);
1206 int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
1207 int sctp_is_ep_boundall(struct sock *sk);
1208 
1209 
1210 /* What type of endpoint?  */
1211 enum sctp_endpoint_type {
1212         SCTP_EP_TYPE_SOCKET,
1213         SCTP_EP_TYPE_ASSOCIATION,
1214 };
1215 
1216 /*
1217  * A common base class to bridge the implmentation view of a
1218  * socket (usually listening) endpoint versus an association's
1219  * local endpoint.
1220  * This common structure is useful for several purposes:
1221  *   1) Common interface for lookup routines.
1222  *      a) Subfunctions work for either endpoint or association
1223  *      b) Single interface to lookup allows hiding the lookup lock rather
1224  *         than acquiring it externally.
1225  *   2) Common interface for the inbound chunk handling/state machine.
1226  *   3) Common object handling routines for reference counting, etc.
1227  *   4) Disentangle association lookup from endpoint lookup, where we
1228  *      do not have to find our endpoint to find our association.
1229  *
1230  */
1231 
1232 struct sctp_ep_common {
1233         /* Fields to help us manage our entries in the hash tables. */
1234         struct hlist_node node;
1235         int hashent;
1236 
1237         /* Runtime type information.  What kind of endpoint is this? */
1238         enum sctp_endpoint_type type;
1239 
1240         /* Some fields to help us manage this object.
1241          *   refcnt   - Reference count access to this object.
1242          *   dead     - Do not attempt to use this object.
1243          */
1244         refcount_t    refcnt;
1245         bool        dead;
1246 
1247         /* What socket does this endpoint belong to?  */
1248         struct sock *sk;
1249 
1250         /* This is where we receive inbound chunks.  */
1251         struct sctp_inq   inqueue;
1252 
1253         /* This substructure includes the defining parameters of the
1254          * endpoint:
1255          * bind_addr.port is our shared port number.
1256          * bind_addr.address_list is our set of local IP addresses.
1257          */
1258         struct sctp_bind_addr bind_addr;
1259 };
1260 
1261 
1262 /* RFC Section 1.4 Key Terms
1263  *
1264  * o SCTP endpoint: The logical sender/receiver of SCTP packets. On a
1265  *   multi-homed host, an SCTP endpoint is represented to its peers as a
1266  *   combination of a set of eligible destination transport addresses to
1267  *   which SCTP packets can be sent and a set of eligible source
1268  *   transport addresses from which SCTP packets can be received.
1269  *   All transport addresses used by an SCTP endpoint must use the
1270  *   same port number, but can use multiple IP addresses. A transport
1271  *   address used by an SCTP endpoint must not be used by another
1272  *   SCTP endpoint. In other words, a transport address is unique
1273  *   to an SCTP endpoint.
1274  *
1275  * From an implementation perspective, each socket has one of these.
1276  * A TCP-style socket will have exactly one association on one of
1277  * these.  An UDP-style socket will have multiple associations hanging
1278  * off one of these.
1279  */
1280 
1281 struct sctp_endpoint {
1282         /* Common substructure for endpoint and association. */
1283         struct sctp_ep_common base;
1284 
1285         /* Associations: A list of current associations and mappings
1286          *            to the data consumers for each association. This
1287          *            may be in the form of a hash table or other
1288          *            implementation dependent structure. The data
1289          *            consumers may be process identification
1290          *            information such as file descriptors, named pipe
1291          *            pointer, or table pointers dependent on how SCTP
1292          *            is implemented.
1293          */
1294         /* This is really a list of struct sctp_association entries. */
1295         struct list_head asocs;
1296 
1297         /* Secret Key: A secret key used by this endpoint to compute
1298          *            the MAC.  This SHOULD be a cryptographic quality
1299          *            random number with a sufficient length.
1300          *            Discussion in [RFC1750] can be helpful in
1301          *            selection of the key.
1302          */
1303         __u8 secret_key[SCTP_SECRET_SIZE];
1304 
1305         /* digest:  This is a digest of the sctp cookie.  This field is
1306          *          only used on the receive path when we try to validate
1307          *          that the cookie has not been tampered with.  We put
1308          *          this here so we pre-allocate this once and can re-use
1309          *          on every receive.
1310          */
1311         __u8 *digest;
1312  
1313         /* sendbuf acct. policy.        */
1314         __u32 sndbuf_policy;
1315 
1316         /* rcvbuf acct. policy. */
1317         __u32 rcvbuf_policy;
1318 
1319         /* SCTP AUTH: array of the HMACs that will be allocated
1320          * we need this per association so that we don't serialize
1321          */
1322         struct crypto_shash **auth_hmacs;
1323 
1324         /* SCTP-AUTH: hmacs for the endpoint encoded into parameter */
1325          struct sctp_hmac_algo_param *auth_hmacs_list;
1326 
1327         /* SCTP-AUTH: chunks to authenticate encoded into parameter */
1328         struct sctp_chunks_param *auth_chunk_list;
1329 
1330         /* SCTP-AUTH: endpoint shared keys */
1331         struct list_head endpoint_shared_keys;
1332         __u16 active_key_id;
1333         __u8  auth_enable:1,
1334               prsctp_enable:1,
1335               reconf_enable:1;
1336 
1337         __u8  strreset_enable;
1338 
1339         /* Security identifiers from incoming (INIT). These are set by
1340          * security_sctp_assoc_request(). These will only be used by
1341          * SCTP TCP type sockets and peeled off connections as they
1342          * cause a new socket to be generated. security_sctp_sk_clone()
1343          * will then plug these into the new socket.
1344          */
1345 
1346         u32 secid;
1347         u32 peer_secid;
1348 };
1349 
1350 /* Recover the outter endpoint structure. */
1351 static inline struct sctp_endpoint *sctp_ep(struct sctp_ep_common *base)
1352 {
1353         struct sctp_endpoint *ep;
1354 
1355         ep = container_of(base, struct sctp_endpoint, base);
1356         return ep;
1357 }
1358 
1359 /* These are function signatures for manipulating endpoints.  */
1360 struct sctp_endpoint *sctp_endpoint_new(struct sock *, gfp_t);
1361 void sctp_endpoint_free(struct sctp_endpoint *);
1362 void sctp_endpoint_put(struct sctp_endpoint *);
1363 void sctp_endpoint_hold(struct sctp_endpoint *);
1364 void sctp_endpoint_add_asoc(struct sctp_endpoint *, struct sctp_association *);
1365 struct sctp_association *sctp_endpoint_lookup_assoc(
1366         const struct sctp_endpoint *ep,
1367         const union sctp_addr *paddr,
1368         struct sctp_transport **);
1369 bool sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
1370                                  const union sctp_addr *paddr);
1371 struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *,
1372                                         struct net *, const union sctp_addr *);
1373 bool sctp_has_association(struct net *net, const union sctp_addr *laddr,
1374                           const union sctp_addr *paddr);
1375 
1376 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
1377                      const struct sctp_association *asoc,
1378                      enum sctp_cid cid, struct sctp_init_chunk *peer_init,
1379                      struct sctp_chunk *chunk, struct sctp_chunk **err_chunk);
1380 int sctp_process_init(struct sctp_association *, struct sctp_chunk *chunk,
1381                       const union sctp_addr *peer,
1382                       struct sctp_init_chunk *init, gfp_t gfp);
1383 __u32 sctp_generate_tag(const struct sctp_endpoint *);
1384 __u32 sctp_generate_tsn(const struct sctp_endpoint *);
1385 
1386 struct sctp_inithdr_host {
1387         __u32 init_tag;
1388         __u32 a_rwnd;
1389         __u16 num_outbound_streams;
1390         __u16 num_inbound_streams;
1391         __u32 initial_tsn;
1392 };
1393 
1394 struct sctp_stream_priorities {
1395         /* List of priorities scheduled */
1396         struct list_head prio_sched;
1397         /* List of streams scheduled */
1398         struct list_head active;
1399         /* The next stream stream in line */
1400         struct sctp_stream_out_ext *next;
1401         __u16 prio;
1402 };
1403 
1404 struct sctp_stream_out_ext {
1405         __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
1406         __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
1407         struct list_head outq; /* chunks enqueued by this stream */
1408         union {
1409                 struct {
1410                         /* Scheduled streams list */
1411                         struct list_head prio_list;
1412                         struct sctp_stream_priorities *prio_head;
1413                 };
1414                 /* Fields used by RR scheduler */
1415                 struct {
1416                         struct list_head rr_list;
1417                 };
1418         };
1419 };
1420 
1421 struct sctp_stream_out {
1422         union {
1423                 __u32 mid;
1424                 __u16 ssn;
1425         };
1426         __u32 mid_uo;
1427         struct sctp_stream_out_ext *ext;
1428         __u8 state;
1429 };
1430 
1431 struct sctp_stream_in {
1432         union {
1433                 __u32 mid;
1434                 __u16 ssn;
1435         };
1436         __u32 mid_uo;
1437         __u32 fsn;
1438         __u32 fsn_uo;
1439         char pd_mode;
1440         char pd_mode_uo;
1441 };
1442 
1443 struct sctp_stream {
1444         struct flex_array *out;
1445         struct flex_array *in;
1446         __u16 outcnt;
1447         __u16 incnt;
1448         /* Current stream being sent, if any */
1449         struct sctp_stream_out *out_curr;
1450         union {
1451                 /* Fields used by priority scheduler */
1452                 struct {
1453                         /* List of priorities scheduled */
1454                         struct list_head prio_list;
1455                 };
1456                 /* Fields used by RR scheduler */
1457                 struct {
1458                         /* List of streams scheduled */
1459                         struct list_head rr_list;
1460                         /* The next stream stream in line */
1461                         struct sctp_stream_out_ext *rr_next;
1462                 };
1463         };
1464         struct sctp_stream_interleave *si;
1465 };
1466 
1467 static inline struct sctp_stream_out *sctp_stream_out(
1468         const struct sctp_stream *stream,
1469         __u16 sid)
1470 {
1471         return flex_array_get(stream->out, sid);
1472 }
1473 
1474 static inline struct sctp_stream_in *sctp_stream_in(
1475         const struct sctp_stream *stream,
1476         __u16 sid)
1477 {
1478         return flex_array_get(stream->in, sid);
1479 }
1480 
1481 #define SCTP_SO(s, i) sctp_stream_out((s), (i))
1482 #define SCTP_SI(s, i) sctp_stream_in((s), (i))
1483 
1484 #define SCTP_STREAM_CLOSED              0x00
1485 #define SCTP_STREAM_OPEN                0x01
1486 
1487 static inline __u16 sctp_datachk_len(const struct sctp_stream *stream)
1488 {
1489         return stream->si->data_chunk_len;
1490 }
1491 
1492 static inline __u16 sctp_datahdr_len(const struct sctp_stream *stream)
1493 {
1494         return stream->si->data_chunk_len - sizeof(struct sctp_chunkhdr);
1495 }
1496 
1497 static inline __u16 sctp_ftsnchk_len(const struct sctp_stream *stream)
1498 {
1499         return stream->si->ftsn_chunk_len;
1500 }
1501 
1502 static inline __u16 sctp_ftsnhdr_len(const struct sctp_stream *stream)
1503 {
1504         return stream->si->ftsn_chunk_len - sizeof(struct sctp_chunkhdr);
1505 }
1506 
1507 /* SCTP_GET_ASSOC_STATS counters */
1508 struct sctp_priv_assoc_stats {
1509         /* Maximum observed rto in the association during subsequent
1510          * observations. Value is set to 0 if no RTO measurement took place
1511          * The transport where the max_rto was observed is returned in
1512          * obs_rto_ipaddr
1513          */
1514         struct sockaddr_storage obs_rto_ipaddr;
1515         __u64 max_obs_rto;
1516         /* Total In and Out SACKs received and sent */
1517         __u64 isacks;
1518         __u64 osacks;
1519         /* Total In and Out packets received and sent */
1520         __u64 opackets;
1521         __u64 ipackets;
1522         /* Total retransmitted chunks */
1523         __u64 rtxchunks;
1524         /* TSN received > next expected */
1525         __u64 outofseqtsns;
1526         /* Duplicate Chunks received */
1527         __u64 idupchunks;
1528         /* Gap Ack Blocks received */
1529         __u64 gapcnt;
1530         /* Unordered data chunks sent and received */
1531         __u64 ouodchunks;
1532         __u64 iuodchunks;
1533         /* Ordered data chunks sent and received */
1534         __u64 oodchunks;
1535         __u64 iodchunks;
1536         /* Control chunks sent and received */
1537         __u64 octrlchunks;
1538         __u64 ictrlchunks;
1539 };
1540 
1541 /* RFC2960
1542  *
1543  * 12. Recommended Transmission Control Block (TCB) Parameters
1544  *
1545  * This section details a recommended set of parameters that should
1546  * be contained within the TCB for an implementation. This section is
1547  * for illustrative purposes and should not be deemed as requirements
1548  * on an implementation or as an exhaustive list of all parameters
1549  * inside an SCTP TCB. Each implementation may need its own additional
1550  * parameters for optimization.
1551  */
1552 
1553 
1554 /* Here we have information about each individual association. */
1555 struct sctp_association {
1556 
1557         /* A base structure common to endpoint and association.
1558          * In this context, it represents the associations's view
1559          * of the local endpoint of the association.
1560          */
1561         struct sctp_ep_common base;
1562 
1563         /* Associations on the same socket. */
1564         struct list_head asocs;
1565 
1566         /* association id. */
1567         sctp_assoc_t assoc_id;
1568 
1569         /* This is our parent endpoint.  */
1570         struct sctp_endpoint *ep;
1571 
1572         /* These are those association elements needed in the cookie.  */
1573         struct sctp_cookie c;
1574 
1575         /* This is all information about our peer.  */
1576         struct {
1577                 /* transport_addr_list
1578                  *
1579                  * Peer        : A list of SCTP transport addresses that the
1580                  * Transport   : peer is bound to. This information is derived
1581                  * Address     : from the INIT or INIT ACK and is used to
1582                  * List        : associate an inbound packet with a given
1583                  *             : association. Normally this information is
1584                  *             : hashed or keyed for quick lookup and access
1585                  *             : of the TCB.
1586                  *             : The list is also initialized with the list
1587                  *             : of addresses passed with the sctp_connectx()
1588                  *             : call.
1589                  *
1590                  * It is a list of SCTP_transport's.
1591                  */
1592                 struct list_head transport_addr_list;
1593 
1594                 /* rwnd
1595                  *
1596                  * Peer Rwnd   : Current calculated value of the peer's rwnd.
1597                  */
1598                 __u32 rwnd;
1599 
1600                 /* transport_count
1601                  *
1602                  * Peer        : A count of the number of peer addresses
1603                  * Transport   : in the Peer Transport Address List.
1604                  * Address     :
1605                  * Count       :
1606                  */
1607                 __u16 transport_count;
1608 
1609                 /* port
1610                  *   The transport layer port number.
1611                  */
1612                 __u16 port;
1613 
1614                 /* primary_path
1615                  *
1616                  * Primary     : This is the current primary destination
1617                  * Path        : transport address of the peer endpoint.  It
1618                  *             : may also specify a source transport address
1619                  *             : on this endpoint.
1620                  *
1621                  * All of these paths live on transport_addr_list.
1622                  *
1623                  * At the bakeoffs, we discovered that the intent of
1624                  * primaryPath is that it only changes when the ULP
1625                  * asks to have it changed.  We add the activePath to
1626                  * designate the connection we are currently using to
1627                  * transmit new data and most control chunks.
1628                  */
1629                 struct sctp_transport *primary_path;
1630 
1631                 /* Cache the primary path address here, when we
1632                  * need a an address for msg_name.
1633                  */
1634                 union sctp_addr primary_addr;
1635 
1636                 /* active_path
1637                  *   The path that we are currently using to
1638                  *   transmit new data and most control chunks.
1639                  */
1640                 struct sctp_transport *active_path;
1641 
1642                 /* retran_path
1643                  *
1644                  * RFC2960 6.4 Multi-homed SCTP Endpoints
1645                  * ...
1646                  * Furthermore, when its peer is multi-homed, an
1647                  * endpoint SHOULD try to retransmit a chunk to an
1648                  * active destination transport address that is
1649                  * different from the last destination address to
1650                  * which the DATA chunk was sent.
1651                  */
1652                 struct sctp_transport *retran_path;
1653 
1654                 /* Pointer to last transport I have sent on.  */
1655                 struct sctp_transport *last_sent_to;
1656 
1657                 /* This is the last transport I have received DATA on.  */
1658                 struct sctp_transport *last_data_from;
1659 
1660                 /*
1661                  * Mapping  An array of bits or bytes indicating which out of
1662                  * Array    order TSN's have been received (relative to the
1663                  *          Last Rcvd TSN). If no gaps exist, i.e. no out of
1664                  *          order packets have been received, this array
1665                  *          will be set to all zero. This structure may be
1666                  *          in the form of a circular buffer or bit array.
1667                  *
1668                  * Last Rcvd   : This is the last TSN received in
1669                  * TSN         : sequence. This value is set initially by
1670                  *             : taking the peer's Initial TSN, received in
1671                  *             : the INIT or INIT ACK chunk, and subtracting
1672                  *             : one from it.
1673                  *
1674                  * Throughout most of the specification this is called the
1675                  * "Cumulative TSN ACK Point".  In this case, we
1676                  * ignore the advice in 12.2 in favour of the term
1677                  * used in the bulk of the text.  This value is hidden
1678                  * in tsn_map--we get it by calling sctp_tsnmap_get_ctsn().
1679                  */
1680                 struct sctp_tsnmap tsn_map;
1681 
1682                 /* This mask is used to disable sending the ASCONF chunk
1683                  * with specified parameter to peer.
1684                  */
1685                 __be16 addip_disabled_mask;
1686 
1687                 /* These are capabilities which our peer advertised.  */
1688                 __u8    ecn_capable:1,      /* Can peer do ECN? */
1689                         ipv4_address:1,     /* Peer understands IPv4 addresses? */
1690                         ipv6_address:1,     /* Peer understands IPv6 addresses? */
1691                         hostname_address:1, /* Peer understands DNS addresses? */
1692                         asconf_capable:1,   /* Does peer support ADDIP? */
1693                         prsctp_capable:1,   /* Can peer do PR-SCTP? */
1694                         reconf_capable:1,   /* Can peer do RE-CONFIG? */
1695                         auth_capable:1;     /* Is peer doing SCTP-AUTH? */
1696 
1697                 /* sack_needed : This flag indicates if the next received
1698                  *             : packet is to be responded to with a
1699                  *             : SACK. This is initialized to 0.  When a packet
1700                  *             : is received sack_cnt is incremented. If this value
1701                  *             : reaches 2 or more, a SACK is sent and the
1702                  *             : value is reset to 0. Note: This is used only
1703                  *             : when no DATA chunks are received out of
1704                  *             : order.  When DATA chunks are out of order,
1705                  *             : SACK's are not delayed (see Section 6).
1706                  */
1707                 __u8    sack_needed:1,     /* Do we need to sack the peer? */
1708                         sack_generation:1,
1709                         zero_window_announced:1;
1710                 __u32   sack_cnt;
1711 
1712                 __u32   adaptation_ind;  /* Adaptation Code point. */
1713 
1714                 struct sctp_inithdr_host i;
1715                 void *cookie;
1716                 int cookie_len;
1717 
1718                 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk.
1719                  * C1) ... "Peer-Serial-Number'. This value MUST be initialized to the
1720                  * Initial TSN Value minus 1
1721                  */
1722                 __u32 addip_serial;
1723 
1724                 /* SCTP-AUTH: We need to know pears random number, hmac list
1725                  * and authenticated chunk list.  All that is part of the
1726                  * cookie and these are just pointers to those locations
1727                  */
1728                 struct sctp_random_param *peer_random;
1729                 struct sctp_chunks_param *peer_chunks;
1730                 struct sctp_hmac_algo_param *peer_hmacs;
1731         } peer;
1732 
1733         /* State       : A state variable indicating what state the
1734          *             : association is in, i.e. COOKIE-WAIT,
1735          *             : COOKIE-ECHOED, ESTABLISHED, SHUTDOWN-PENDING,
1736          *             : SHUTDOWN-SENT, SHUTDOWN-RECEIVED, SHUTDOWN-ACK-SENT.
1737          *
1738          *              Note: No "CLOSED" state is illustrated since if a
1739          *              association is "CLOSED" its TCB SHOULD be removed.
1740          *
1741          *              In this implementation we DO have a CLOSED
1742          *              state which is used during initiation and shutdown.
1743          *
1744          *              State takes values from SCTP_STATE_*.
1745          */
1746         enum sctp_state state;
1747 
1748         /* Overall     : The overall association error count.
1749          * Error Count : [Clear this any time I get something.]
1750          */
1751         int overall_error_count;
1752 
1753         /* The cookie life I award for any cookie.  */
1754         ktime_t cookie_life;
1755 
1756         /* These are the association's initial, max, and min RTO values.
1757          * These values will be initialized by system defaults, but can
1758          * be modified via the SCTP_RTOINFO socket option.
1759          */
1760         unsigned long rto_initial;
1761         unsigned long rto_max;
1762         unsigned long rto_min;
1763 
1764         /* Maximum number of new data packets that can be sent in a burst.  */
1765         int max_burst;
1766 
1767         /* This is the max_retrans value for the association.  This value will
1768          * be initialized initialized from system defaults, but can be
1769          * modified by the SCTP_ASSOCINFO socket option.
1770          */
1771         int max_retrans;
1772 
1773         /* This is the partially failed retrans value for the transport
1774          * and will be initialized from the assocs value.  This can be
1775          * changed using the SCTP_PEER_ADDR_THLDS socket option
1776          */
1777         int pf_retrans;
1778 
1779         /* Maximum number of times the endpoint will retransmit INIT  */
1780         __u16 max_init_attempts;
1781 
1782         /* How many times have we resent an INIT? */
1783         __u16 init_retries;
1784 
1785         /* The largest timeout or RTO value to use in attempting an INIT */
1786         unsigned long max_init_timeo;
1787 
1788         /* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
1789          * the destination address every heartbeat interval. This value
1790          * will be inherited by all new transports.
1791          */
1792         unsigned long hbinterval;
1793 
1794         /* This is the max_retrans value for new transports in the
1795          * association.
1796          */
1797         __u16 pathmaxrxt;
1798 
1799         __u32 flowlabel;
1800         __u8  dscp;
1801 
1802         /* Flag that path mtu update is pending */
1803         __u8   pmtu_pending;
1804 
1805         /* Association : The smallest PMTU discovered for all of the
1806          * PMTU        : peer's transport addresses.
1807          */
1808         __u32 pathmtu;
1809 
1810         /* Flags controlling Heartbeat, SACK delay, and Path MTU Discovery. */
1811         __u32 param_flags;
1812 
1813         __u32 sackfreq;
1814         /* SACK delay timeout */
1815         unsigned long sackdelay;
1816 
1817         unsigned long timeouts[SCTP_NUM_TIMEOUT_TYPES];
1818         struct timer_list timers[SCTP_NUM_TIMEOUT_TYPES];
1819 
1820         /* Transport to which SHUTDOWN chunk was last sent.  */
1821         struct sctp_transport *shutdown_last_sent_to;
1822 
1823         /* Transport to which INIT chunk was last sent.  */
1824         struct sctp_transport *init_last_sent_to;
1825 
1826         /* How many times have we resent a SHUTDOWN */
1827         int shutdown_retries;
1828 
1829         /* Next TSN    : The next TSN number to be assigned to a new
1830          *             : DATA chunk.  This is sent in the INIT or INIT
1831          *             : ACK chunk to the peer and incremented each
1832          *             : time a DATA chunk is assigned a TSN
1833          *             : (normally just prior to transmit or during
1834          *             : fragmentation).
1835          */
1836         __u32 next_tsn;
1837 
1838         /*
1839          * Last Rcvd   : This is the last TSN received in sequence.  This value
1840          * TSN         : is set initially by taking the peer's Initial TSN,
1841          *             : received in the INIT or INIT ACK chunk, and
1842          *             : subtracting one from it.
1843          *
1844          * Most of RFC 2960 refers to this as the Cumulative TSN Ack Point.
1845          */
1846 
1847         __u32 ctsn_ack_point;
1848 
1849         /* PR-SCTP Advanced.Peer.Ack.Point */
1850         __u32 adv_peer_ack_point;
1851 
1852         /* Highest TSN that is acknowledged by incoming SACKs. */
1853         __u32 highest_sacked;
1854 
1855         /* TSN marking the fast recovery exit point */
1856         __u32 fast_recovery_exit;
1857 
1858         /* Flag to track the current fast recovery state */
1859         __u8 fast_recovery;
1860 
1861         /* The number of unacknowledged data chunks.  Reported through
1862          * the SCTP_STATUS sockopt.
1863          */
1864         __u16 unack_data;
1865 
1866         /* The total number of data chunks that we've had to retransmit
1867          * as the result of a T3 timer expiration
1868          */
1869         __u32 rtx_data_chunks;
1870 
1871         /* This is the association's receive buffer space.  This value is used
1872          * to set a_rwnd field in an INIT or a SACK chunk.
1873          */
1874         __u32 rwnd;
1875 
1876         /* This is the last advertised value of rwnd over a SACK chunk. */
1877         __u32 a_rwnd;
1878 
1879         /* Number of bytes by which the rwnd has slopped.  The rwnd is allowed
1880          * to slop over a maximum of the association's frag_point.
1881          */
1882         __u32 rwnd_over;
1883 
1884         /* Keeps treack of rwnd pressure.  This happens when we have
1885          * a window, but not recevie buffer (i.e small packets).  This one
1886          * is releases slowly (1 PMTU at a time ).
1887          */
1888         __u32 rwnd_press;
1889 
1890         /* This is the sndbuf size in use for the association.
1891          * This corresponds to the sndbuf size for the association,
1892          * as specified in the sk->sndbuf.
1893          */
1894         int sndbuf_used;
1895 
1896         /* This is the amount of memory that this association has allocated
1897          * in the receive path at any given time.
1898          */
1899         atomic_t rmem_alloc;
1900 
1901         /* This is the wait queue head for send requests waiting on
1902          * the association sndbuf space.
1903          */
1904         wait_queue_head_t       wait;
1905 
1906         /* The message size at which SCTP fragmentation will occur. */
1907         __u32 frag_point;
1908         __u32 user_frag;
1909 
1910         /* Counter used to count INIT errors. */
1911         int init_err_counter;
1912 
1913         /* Count the number of INIT cycles (for doubling timeout). */
1914         int init_cycle;
1915 
1916         /* Default send parameters. */
1917         __u16 default_stream;
1918         __u16 default_flags;
1919         __u32 default_ppid;
1920         __u32 default_context;
1921         __u32 default_timetolive;
1922 
1923         /* Default receive parameters */
1924         __u32 default_rcv_context;
1925 
1926         /* Stream arrays */
1927         struct sctp_stream stream;
1928 
1929         /* All outbound chunks go through this structure.  */
1930         struct sctp_outq outqueue;
1931 
1932         /* A smart pipe that will handle reordering and fragmentation,
1933          * as well as handle passing events up to the ULP.
1934          */
1935         struct sctp_ulpq ulpq;
1936 
1937         /* Last TSN that caused an ECNE Chunk to be sent.  */
1938         __u32 last_ecne_tsn;
1939 
1940         /* Last TSN that caused a CWR Chunk to be sent.  */
1941         __u32 last_cwr_tsn;
1942 
1943         /* How many duplicated TSNs have we seen?  */
1944         int numduptsns;
1945 
1946         /* These are to support
1947          * "SCTP Extensions for Dynamic Reconfiguration of IP Addresses
1948          *  and Enforcement of Flow and Message Limits"
1949          * <draft-ietf-tsvwg-addip-sctp-02.txt>
1950          * or "ADDIP" for short.
1951          */
1952 
1953 
1954 
1955         /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1956          *
1957          * R1) One and only one ASCONF Chunk MAY be in transit and
1958          * unacknowledged at any one time.  If a sender, after sending
1959          * an ASCONF chunk, decides it needs to transfer another
1960          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
1961          * returns from the previous ASCONF Chunk before sending a
1962          * subsequent ASCONF. Note this restriction binds each side,
1963          * so at any time two ASCONF may be in-transit on any given
1964          * association (one sent from each endpoint).
1965          *
1966          * [This is our one-and-only-one ASCONF in flight.  If we do
1967          * not have an ASCONF in flight, this is NULL.]
1968          */
1969         struct sctp_chunk *addip_last_asconf;
1970 
1971         /* ADDIP Section 5.2 Upon reception of an ASCONF Chunk.
1972          *
1973          * This is needed to implement itmes E1 - E4 of the updated
1974          * spec.  Here is the justification:
1975          *
1976          * Since the peer may bundle multiple ASCONF chunks toward us,
1977          * we now need the ability to cache multiple ACKs.  The section
1978          * describes in detail how they are cached and cleaned up.
1979          */
1980         struct list_head asconf_ack_list;
1981 
1982         /* These ASCONF chunks are waiting to be sent.
1983          *
1984          * These chunaks can't be pushed to outqueue until receiving
1985          * ASCONF_ACK for the previous ASCONF indicated by
1986          * addip_last_asconf, so as to guarantee that only one ASCONF
1987          * is in flight at any time.
1988          *
1989          * ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
1990          *
1991          * In defining the ASCONF Chunk transfer procedures, it is
1992          * essential that these transfers MUST NOT cause congestion
1993          * within the network.  To achieve this, we place these
1994          * restrictions on the transfer of ASCONF Chunks:
1995          *
1996          * R1) One and only one ASCONF Chunk MAY be in transit and
1997          * unacknowledged at any one time.  If a sender, after sending
1998          * an ASCONF chunk, decides it needs to transfer another
1999          * ASCONF Chunk, it MUST wait until the ASCONF-ACK Chunk
2000          * returns from the previous ASCONF Chunk before sending a
2001          * subsequent ASCONF. Note this restriction binds each side,
2002          * so at any time two ASCONF may be in-transit on any given
2003          * association (one sent from each endpoint).
2004          *
2005          *
2006          * [I really think this is EXACTLY the sort of intelligence
2007          *  which already resides in sctp_outq.  Please move this
2008          *  queue and its supporting logic down there.  --piggy]
2009          */
2010         struct list_head addip_chunk_list;
2011 
2012         /* ADDIP Section 4.1 ASCONF Chunk Procedures
2013          *
2014          * A2) A serial number should be assigned to the Chunk. The
2015          * serial number SHOULD be a monotonically increasing
2016          * number. The serial number SHOULD be initialized at
2017          * the start of the association to the same value as the
2018          * Initial TSN and every time a new ASCONF chunk is created
2019          * it is incremented by one after assigning the serial number
2020          * to the newly created chunk.
2021          *
2022          * ADDIP
2023          * 3.1.1  Address/Stream Configuration Change Chunk (ASCONF)
2024          *
2025          * Serial Number : 32 bits (unsigned integer)
2026          *
2027          * This value represents a Serial Number for the ASCONF
2028          * Chunk. The valid range of Serial Number is from 0 to
2029          * 4294967295 (2^32 - 1).  Serial Numbers wrap back to 0
2030          * after reaching 4294967295.
2031          */
2032         __u32 addip_serial;
2033         int src_out_of_asoc_ok;
2034         union sctp_addr *asconf_addr_del_pending;
2035         struct sctp_transport *new_transport;
2036 
2037         /* SCTP AUTH: list of the endpoint shared keys.  These
2038          * keys are provided out of band by the user applicaton
2039          * and can't change during the lifetime of the association
2040          */
2041         struct list_head endpoint_shared_keys;
2042 
2043         /* SCTP AUTH:
2044          * The current generated assocaition shared key (secret)
2045          */
2046         struct sctp_auth_bytes *asoc_shared_key;
2047         struct sctp_shared_key *shkey;
2048 
2049         /* SCTP AUTH: hmac id of the first peer requested algorithm
2050          * that we support.
2051          */
2052         __u16 default_hmac_id;
2053 
2054         __u16 active_key_id;
2055 
2056         __u8 need_ecne:1,       /* Need to send an ECNE Chunk? */
2057              temp:1,            /* Is it a temporary association? */
2058              force_delay:1,
2059              intl_enable:1,
2060              prsctp_enable:1,
2061              reconf_enable:1;
2062 
2063         __u8 strreset_enable;
2064         __u8 strreset_outstanding; /* request param count on the fly */
2065 
2066         __u32 strreset_outseq; /* Update after receiving response */
2067         __u32 strreset_inseq; /* Update after receiving request */
2068         __u32 strreset_result[2]; /* save the results of last 2 responses */
2069 
2070         struct sctp_chunk *strreset_chunk; /* save request chunk */
2071 
2072         struct sctp_priv_assoc_stats stats;
2073 
2074         int sent_cnt_removable;
2075 
2076         __u64 abandoned_unsent[SCTP_PR_INDEX(MAX) + 1];
2077         __u64 abandoned_sent[SCTP_PR_INDEX(MAX) + 1];
2078 
2079         struct rcu_head rcu;
2080 };
2081 
2082 
2083 /* An eyecatcher for determining if we are really looking at an
2084  * association data structure.
2085  */
2086 enum {
2087         SCTP_ASSOC_EYECATCHER = 0xa550c123,
2088 };
2089 
2090 /* Recover the outter association structure. */
2091 static inline struct sctp_association *sctp_assoc(struct sctp_ep_common *base)
2092 {
2093         struct sctp_association *asoc;
2094 
2095         asoc = container_of(base, struct sctp_association, base);
2096         return asoc;
2097 }
2098 
2099 /* These are function signatures for manipulating associations.  */
2100 
2101 
2102 struct sctp_association *
2103 sctp_association_new(const struct sctp_endpoint *ep, const struct sock *sk,
2104                      enum sctp_scope scope, gfp_t gfp);
2105 void sctp_association_free(struct sctp_association *);
2106 void sctp_association_put(struct sctp_association *);
2107 void sctp_association_hold(struct sctp_association *);
2108 
2109 struct sctp_transport *sctp_assoc_choose_alter_transport(
2110         struct sctp_association *, struct sctp_transport *);
2111 void sctp_assoc_update_retran_path(struct sctp_association *);
2112 struct sctp_transport *sctp_assoc_lookup_paddr(const struct sctp_association *,
2113                                           const union sctp_addr *);
2114 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
2115                             const union sctp_addr *laddr);
2116 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *,
2117                                      const union sctp_addr *address,
2118                                      const gfp_t gfp,
2119                                      const int peer_state);
2120 void sctp_assoc_del_peer(struct sctp_association *asoc,
2121                          const union sctp_addr *addr);
2122 void sctp_assoc_rm_peer(struct sctp_association *asoc,
2123                          struct sctp_transport *peer);
2124 void sctp_assoc_control_transport(struct sctp_association *asoc,
2125                                   struct sctp_transport *transport,
2126                                   enum sctp_transport_cmd command,
2127                                   sctp_sn_error_t error);
2128 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *, __u32);
2129 void sctp_assoc_migrate(struct sctp_association *, struct sock *);
2130 int sctp_assoc_update(struct sctp_association *old,
2131                       struct sctp_association *new);
2132 
2133 __u32 sctp_association_get_next_tsn(struct sctp_association *);
2134 
2135 void sctp_assoc_update_frag_point(struct sctp_association *asoc);
2136 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
2137 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
2138 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
2139 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
2140 void sctp_assoc_set_primary(struct sctp_association *,
2141                             struct sctp_transport *);
2142 void sctp_assoc_del_nonprimary_peers(struct sctp_association *,
2143                                     struct sctp_transport *);
2144 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
2145                                      enum sctp_scope scope, gfp_t gfp);
2146 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *,
2147                                          struct sctp_cookie*,
2148                                          gfp_t gfp);
2149 int sctp_assoc_set_id(struct sctp_association *, gfp_t);
2150 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc);
2151 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
2152                                         const struct sctp_association *asoc,
2153                                         __be32 serial);
2154 void sctp_asconf_queue_teardown(struct sctp_association *asoc);
2155 
2156 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
2157                         const union sctp_addr *ss2);
2158 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc);
2159 
2160 /* A convenience structure to parse out SCTP specific CMSGs. */
2161 struct sctp_cmsgs {
2162         struct sctp_initmsg *init;
2163         struct sctp_sndrcvinfo *srinfo;
2164         struct sctp_sndinfo *sinfo;
2165         struct sctp_prinfo *prinfo;
2166         struct sctp_authinfo *authinfo;
2167         struct msghdr *addrs_msg;
2168 };
2169 
2170 /* Structure for tracking memory objects */
2171 struct sctp_dbg_objcnt_entry {
2172         char *label;
2173         atomic_t *counter;
2174 };
2175 
2176 #endif /* __sctp_structs_h__ */
2177 

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