~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sctp/sm_make_chunk.c

Version: ~ [ linux-5.15-rc5 ] ~ [ linux-5.14.11 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.72 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.152 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.210 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.250 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.286 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.288 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /* SCTP kernel implementation
  3  * (C) Copyright IBM Corp. 2001, 2004
  4  * Copyright (c) 1999-2000 Cisco, Inc.
  5  * Copyright (c) 1999-2001 Motorola, Inc.
  6  * Copyright (c) 2001-2002 Intel Corp.
  7  *
  8  * This file is part of the SCTP kernel implementation
  9  *
 10  * These functions work with the state functions in sctp_sm_statefuns.c
 11  * to implement the state operations.  These functions implement the
 12  * steps which require modifying existing data structures.
 13  *
 14  * Please send any bug reports or fixes you make to the
 15  * email address(es):
 16  *    lksctp developers <linux-sctp@vger.kernel.org>
 17  *
 18  * Written or modified by:
 19  *    La Monte H.P. Yarroll <piggy@acm.org>
 20  *    Karl Knutson          <karl@athena.chicago.il.us>
 21  *    C. Robin              <chris@hundredacre.ac.uk>
 22  *    Jon Grimm             <jgrimm@us.ibm.com>
 23  *    Xingang Guo           <xingang.guo@intel.com>
 24  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
 25  *    Sridhar Samudrala     <sri@us.ibm.com>
 26  *    Daisy Chang           <daisyc@us.ibm.com>
 27  *    Ardelle Fan           <ardelle.fan@intel.com>
 28  *    Kevin Gao             <kevin.gao@intel.com>
 29  */
 30 
 31 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 32 
 33 #include <crypto/hash.h>
 34 #include <linux/types.h>
 35 #include <linux/kernel.h>
 36 #include <linux/ip.h>
 37 #include <linux/ipv6.h>
 38 #include <linux/net.h>
 39 #include <linux/inet.h>
 40 #include <linux/scatterlist.h>
 41 #include <linux/slab.h>
 42 #include <net/sock.h>
 43 
 44 #include <linux/skbuff.h>
 45 #include <linux/random.h>       /* for get_random_bytes */
 46 #include <net/sctp/sctp.h>
 47 #include <net/sctp/sm.h>
 48 
 49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
 50                                             __u8 type, __u8 flags, int paylen,
 51                                             gfp_t gfp);
 52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
 53                                          __u8 flags, int paylen, gfp_t gfp);
 54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
 55                                            __u8 type, __u8 flags, int paylen,
 56                                            gfp_t gfp);
 57 static struct sctp_cookie_param *sctp_pack_cookie(
 58                                         const struct sctp_endpoint *ep,
 59                                         const struct sctp_association *asoc,
 60                                         const struct sctp_chunk *init_chunk,
 61                                         int *cookie_len,
 62                                         const __u8 *raw_addrs, int addrs_len);
 63 static int sctp_process_param(struct sctp_association *asoc,
 64                               union sctp_params param,
 65                               const union sctp_addr *peer_addr,
 66                               gfp_t gfp);
 67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
 68                               const void *data);
 69 
 70 /* Control chunk destructor */
 71 static void sctp_control_release_owner(struct sk_buff *skb)
 72 {
 73         struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
 74 
 75         if (chunk->shkey) {
 76                 struct sctp_shared_key *shkey = chunk->shkey;
 77                 struct sctp_association *asoc = chunk->asoc;
 78 
 79                 /* refcnt == 2 and !list_empty mean after this release, it's
 80                  * not being used anywhere, and it's time to notify userland
 81                  * that this shkey can be freed if it's been deactivated.
 82                  */
 83                 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
 84                     refcount_read(&shkey->refcnt) == 2) {
 85                         struct sctp_ulpevent *ev;
 86 
 87                         ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
 88                                                         SCTP_AUTH_FREE_KEY,
 89                                                         GFP_KERNEL);
 90                         if (ev)
 91                                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 92                 }
 93                 sctp_auth_shkey_release(chunk->shkey);
 94         }
 95 }
 96 
 97 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
 98 {
 99         struct sctp_association *asoc = chunk->asoc;
100         struct sk_buff *skb = chunk->skb;
101 
102         /* TODO: properly account for control chunks.
103          * To do it right we'll need:
104          *  1) endpoint if association isn't known.
105          *  2) proper memory accounting.
106          *
107          *  For now don't do anything for now.
108          */
109         if (chunk->auth) {
110                 chunk->shkey = asoc->shkey;
111                 sctp_auth_shkey_hold(chunk->shkey);
112         }
113         skb->sk = asoc ? asoc->base.sk : NULL;
114         skb_shinfo(skb)->destructor_arg = chunk;
115         skb->destructor = sctp_control_release_owner;
116 }
117 
118 /* What was the inbound interface for this chunk? */
119 int sctp_chunk_iif(const struct sctp_chunk *chunk)
120 {
121         struct sk_buff *skb = chunk->skb;
122 
123         return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
124 }
125 
126 /* RFC 2960 3.3.2 Initiation (INIT) (1)
127  *
128  * Note 2: The ECN capable field is reserved for future use of
129  * Explicit Congestion Notification.
130  */
131 static const struct sctp_paramhdr ecap_param = {
132         SCTP_PARAM_ECN_CAPABLE,
133         cpu_to_be16(sizeof(struct sctp_paramhdr)),
134 };
135 static const struct sctp_paramhdr prsctp_param = {
136         SCTP_PARAM_FWD_TSN_SUPPORT,
137         cpu_to_be16(sizeof(struct sctp_paramhdr)),
138 };
139 
140 /* A helper to initialize an op error inside a provided chunk, as most
141  * cause codes will be embedded inside an abort chunk.
142  */
143 int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
144                     size_t paylen)
145 {
146         struct sctp_errhdr err;
147         __u16 len;
148 
149         /* Cause code constants are now defined in network order.  */
150         err.cause = cause_code;
151         len = sizeof(err) + paylen;
152         err.length = htons(len);
153 
154         if (skb_tailroom(chunk->skb) < len)
155                 return -ENOSPC;
156 
157         chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
158 
159         return 0;
160 }
161 
162 /* 3.3.2 Initiation (INIT) (1)
163  *
164  * This chunk is used to initiate a SCTP association between two
165  * endpoints. The format of the INIT chunk is shown below:
166  *
167  *     0                   1                   2                   3
168  *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
169  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170  *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
171  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
172  *    |                         Initiate Tag                          |
173  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
174  *    |           Advertised Receiver Window Credit (a_rwnd)          |
175  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
176  *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
177  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178  *    |                          Initial TSN                          |
179  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180  *    \                                                               \
181  *    /              Optional/Variable-Length Parameters              /
182  *    \                                                               \
183  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184  *
185  *
186  * The INIT chunk contains the following parameters. Unless otherwise
187  * noted, each parameter MUST only be included once in the INIT chunk.
188  *
189  * Fixed Parameters                     Status
190  * ----------------------------------------------
191  * Initiate Tag                        Mandatory
192  * Advertised Receiver Window Credit   Mandatory
193  * Number of Outbound Streams          Mandatory
194  * Number of Inbound Streams           Mandatory
195  * Initial TSN                         Mandatory
196  *
197  * Variable Parameters                  Status     Type Value
198  * -------------------------------------------------------------
199  * IPv4 Address (Note 1)               Optional    5
200  * IPv6 Address (Note 1)               Optional    6
201  * Cookie Preservative                 Optional    9
202  * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
203  * Host Name Address (Note 3)          Optional    11
204  * Supported Address Types (Note 4)    Optional    12
205  */
206 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
207                                   const struct sctp_bind_addr *bp,
208                                   gfp_t gfp, int vparam_len)
209 {
210         struct net *net = sock_net(asoc->base.sk);
211         struct sctp_supported_ext_param ext_param;
212         struct sctp_adaptation_ind_param aiparam;
213         struct sctp_paramhdr *auth_chunks = NULL;
214         struct sctp_paramhdr *auth_hmacs = NULL;
215         struct sctp_supported_addrs_param sat;
216         struct sctp_endpoint *ep = asoc->ep;
217         struct sctp_chunk *retval = NULL;
218         int num_types, addrs_len = 0;
219         struct sctp_inithdr init;
220         union sctp_params addrs;
221         struct sctp_sock *sp;
222         __u8 extensions[5];
223         size_t chunksize;
224         __be16 types[2];
225         int num_ext = 0;
226 
227         /* RFC 2960 3.3.2 Initiation (INIT) (1)
228          *
229          * Note 1: The INIT chunks can contain multiple addresses that
230          * can be IPv4 and/or IPv6 in any combination.
231          */
232 
233         /* Convert the provided bind address list to raw format. */
234         addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
235 
236         init.init_tag              = htonl(asoc->c.my_vtag);
237         init.a_rwnd                = htonl(asoc->rwnd);
238         init.num_outbound_streams  = htons(asoc->c.sinit_num_ostreams);
239         init.num_inbound_streams   = htons(asoc->c.sinit_max_instreams);
240         init.initial_tsn           = htonl(asoc->c.initial_tsn);
241 
242         /* How many address types are needed? */
243         sp = sctp_sk(asoc->base.sk);
244         num_types = sp->pf->supported_addrs(sp, types);
245 
246         chunksize = sizeof(init) + addrs_len;
247         chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
248         chunksize += sizeof(ecap_param);
249 
250         if (asoc->prsctp_enable)
251                 chunksize += sizeof(prsctp_param);
252 
253         /* ADDIP: Section 4.2.7:
254          *  An implementation supporting this extension [ADDIP] MUST list
255          *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
256          *  INIT-ACK parameters.
257          */
258         if (net->sctp.addip_enable) {
259                 extensions[num_ext] = SCTP_CID_ASCONF;
260                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
261                 num_ext += 2;
262         }
263 
264         if (asoc->reconf_enable) {
265                 extensions[num_ext] = SCTP_CID_RECONF;
266                 num_ext += 1;
267         }
268 
269         if (sp->adaptation_ind)
270                 chunksize += sizeof(aiparam);
271 
272         if (sp->strm_interleave) {
273                 extensions[num_ext] = SCTP_CID_I_DATA;
274                 num_ext += 1;
275         }
276 
277         chunksize += vparam_len;
278 
279         /* Account for AUTH related parameters */
280         if (ep->auth_enable) {
281                 /* Add random parameter length*/
282                 chunksize += sizeof(asoc->c.auth_random);
283 
284                 /* Add HMACS parameter length if any were defined */
285                 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
286                 if (auth_hmacs->length)
287                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
288                 else
289                         auth_hmacs = NULL;
290 
291                 /* Add CHUNKS parameter length */
292                 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
293                 if (auth_chunks->length)
294                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
295                 else
296                         auth_chunks = NULL;
297 
298                 extensions[num_ext] = SCTP_CID_AUTH;
299                 num_ext += 1;
300         }
301 
302         /* If we have any extensions to report, account for that */
303         if (num_ext)
304                 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
305 
306         /* RFC 2960 3.3.2 Initiation (INIT) (1)
307          *
308          * Note 3: An INIT chunk MUST NOT contain more than one Host
309          * Name address parameter. Moreover, the sender of the INIT
310          * MUST NOT combine any other address types with the Host Name
311          * address in the INIT. The receiver of INIT MUST ignore any
312          * other address types if the Host Name address parameter is
313          * present in the received INIT chunk.
314          *
315          * PLEASE DO NOT FIXME [This version does not support Host Name.]
316          */
317 
318         retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
319         if (!retval)
320                 goto nodata;
321 
322         retval->subh.init_hdr =
323                 sctp_addto_chunk(retval, sizeof(init), &init);
324         retval->param_hdr.v =
325                 sctp_addto_chunk(retval, addrs_len, addrs.v);
326 
327         /* RFC 2960 3.3.2 Initiation (INIT) (1)
328          *
329          * Note 4: This parameter, when present, specifies all the
330          * address types the sending endpoint can support. The absence
331          * of this parameter indicates that the sending endpoint can
332          * support any address type.
333          */
334         sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
335         sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
336         sctp_addto_chunk(retval, sizeof(sat), &sat);
337         sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
338 
339         sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
340 
341         /* Add the supported extensions parameter.  Be nice and add this
342          * fist before addiding the parameters for the extensions themselves
343          */
344         if (num_ext) {
345                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
346                 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
347                 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
348                 sctp_addto_param(retval, num_ext, extensions);
349         }
350 
351         if (asoc->prsctp_enable)
352                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
353 
354         if (sp->adaptation_ind) {
355                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
356                 aiparam.param_hdr.length = htons(sizeof(aiparam));
357                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
358                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
359         }
360 
361         /* Add SCTP-AUTH chunks to the parameter list */
362         if (ep->auth_enable) {
363                 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
364                                  asoc->c.auth_random);
365                 if (auth_hmacs)
366                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
367                                         auth_hmacs);
368                 if (auth_chunks)
369                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
370                                         auth_chunks);
371         }
372 nodata:
373         kfree(addrs.v);
374         return retval;
375 }
376 
377 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
378                                       const struct sctp_chunk *chunk,
379                                       gfp_t gfp, int unkparam_len)
380 {
381         struct sctp_supported_ext_param ext_param;
382         struct sctp_adaptation_ind_param aiparam;
383         struct sctp_paramhdr *auth_chunks = NULL;
384         struct sctp_paramhdr *auth_random = NULL;
385         struct sctp_paramhdr *auth_hmacs = NULL;
386         struct sctp_chunk *retval = NULL;
387         struct sctp_cookie_param *cookie;
388         struct sctp_inithdr initack;
389         union sctp_params addrs;
390         struct sctp_sock *sp;
391         __u8 extensions[5];
392         size_t chunksize;
393         int num_ext = 0;
394         int cookie_len;
395         int addrs_len;
396 
397         /* Note: there may be no addresses to embed. */
398         addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
399 
400         initack.init_tag                = htonl(asoc->c.my_vtag);
401         initack.a_rwnd                  = htonl(asoc->rwnd);
402         initack.num_outbound_streams    = htons(asoc->c.sinit_num_ostreams);
403         initack.num_inbound_streams     = htons(asoc->c.sinit_max_instreams);
404         initack.initial_tsn             = htonl(asoc->c.initial_tsn);
405 
406         /* FIXME:  We really ought to build the cookie right
407          * into the packet instead of allocating more fresh memory.
408          */
409         cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
410                                   addrs.v, addrs_len);
411         if (!cookie)
412                 goto nomem_cookie;
413 
414         /* Calculate the total size of allocation, include the reserved
415          * space for reporting unknown parameters if it is specified.
416          */
417         sp = sctp_sk(asoc->base.sk);
418         chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
419 
420         /* Tell peer that we'll do ECN only if peer advertised such cap.  */
421         if (asoc->peer.ecn_capable)
422                 chunksize += sizeof(ecap_param);
423 
424         if (asoc->peer.prsctp_capable)
425                 chunksize += sizeof(prsctp_param);
426 
427         if (asoc->peer.asconf_capable) {
428                 extensions[num_ext] = SCTP_CID_ASCONF;
429                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
430                 num_ext += 2;
431         }
432 
433         if (asoc->peer.reconf_capable) {
434                 extensions[num_ext] = SCTP_CID_RECONF;
435                 num_ext += 1;
436         }
437 
438         if (sp->adaptation_ind)
439                 chunksize += sizeof(aiparam);
440 
441         if (asoc->intl_enable) {
442                 extensions[num_ext] = SCTP_CID_I_DATA;
443                 num_ext += 1;
444         }
445 
446         if (asoc->peer.auth_capable) {
447                 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
448                 chunksize += ntohs(auth_random->length);
449 
450                 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
451                 if (auth_hmacs->length)
452                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
453                 else
454                         auth_hmacs = NULL;
455 
456                 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
457                 if (auth_chunks->length)
458                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
459                 else
460                         auth_chunks = NULL;
461 
462                 extensions[num_ext] = SCTP_CID_AUTH;
463                 num_ext += 1;
464         }
465 
466         if (num_ext)
467                 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
468 
469         /* Now allocate and fill out the chunk.  */
470         retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
471         if (!retval)
472                 goto nomem_chunk;
473 
474         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
475          *
476          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
477          * HEARTBEAT ACK, * etc.) to the same destination transport
478          * address from which it received the DATA or control chunk
479          * to which it is replying.
480          *
481          * [INIT ACK back to where the INIT came from.]
482          */
483         if (chunk->transport)
484                 retval->transport =
485                         sctp_assoc_lookup_paddr(asoc,
486                                                 &chunk->transport->ipaddr);
487 
488         retval->subh.init_hdr =
489                 sctp_addto_chunk(retval, sizeof(initack), &initack);
490         retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
491         sctp_addto_chunk(retval, cookie_len, cookie);
492         if (asoc->peer.ecn_capable)
493                 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
494         if (num_ext) {
495                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
496                 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
497                 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
498                 sctp_addto_param(retval, num_ext, extensions);
499         }
500         if (asoc->peer.prsctp_capable)
501                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
502 
503         if (sp->adaptation_ind) {
504                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
505                 aiparam.param_hdr.length = htons(sizeof(aiparam));
506                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
507                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
508         }
509 
510         if (asoc->peer.auth_capable) {
511                 sctp_addto_chunk(retval, ntohs(auth_random->length),
512                                  auth_random);
513                 if (auth_hmacs)
514                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
515                                         auth_hmacs);
516                 if (auth_chunks)
517                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
518                                         auth_chunks);
519         }
520 
521         /* We need to remove the const qualifier at this point.  */
522         retval->asoc = (struct sctp_association *) asoc;
523 
524 nomem_chunk:
525         kfree(cookie);
526 nomem_cookie:
527         kfree(addrs.v);
528         return retval;
529 }
530 
531 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
532  *
533  * This chunk is used only during the initialization of an association.
534  * It is sent by the initiator of an association to its peer to complete
535  * the initialization process. This chunk MUST precede any DATA chunk
536  * sent within the association, but MAY be bundled with one or more DATA
537  * chunks in the same packet.
538  *
539  *      0                   1                   2                   3
540  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
541  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
542  *     |   Type = 10   |Chunk  Flags   |         Length                |
543  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544  *     /                     Cookie                                    /
545  *     \                                                               \
546  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
547  *
548  * Chunk Flags: 8 bit
549  *
550  *   Set to zero on transmit and ignored on receipt.
551  *
552  * Length: 16 bits (unsigned integer)
553  *
554  *   Set to the size of the chunk in bytes, including the 4 bytes of
555  *   the chunk header and the size of the Cookie.
556  *
557  * Cookie: variable size
558  *
559  *   This field must contain the exact cookie received in the
560  *   State Cookie parameter from the previous INIT ACK.
561  *
562  *   An implementation SHOULD make the cookie as small as possible
563  *   to insure interoperability.
564  */
565 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
566                                          const struct sctp_chunk *chunk)
567 {
568         struct sctp_chunk *retval;
569         int cookie_len;
570         void *cookie;
571 
572         cookie = asoc->peer.cookie;
573         cookie_len = asoc->peer.cookie_len;
574 
575         /* Build a cookie echo chunk.  */
576         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
577                                    cookie_len, GFP_ATOMIC);
578         if (!retval)
579                 goto nodata;
580         retval->subh.cookie_hdr =
581                 sctp_addto_chunk(retval, cookie_len, cookie);
582 
583         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
584          *
585          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
586          * HEARTBEAT ACK, * etc.) to the same destination transport
587          * address from which it * received the DATA or control chunk
588          * to which it is replying.
589          *
590          * [COOKIE ECHO back to where the INIT ACK came from.]
591          */
592         if (chunk)
593                 retval->transport = chunk->transport;
594 
595 nodata:
596         return retval;
597 }
598 
599 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
600  *
601  * This chunk is used only during the initialization of an
602  * association.  It is used to acknowledge the receipt of a COOKIE
603  * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
604  * within the association, but MAY be bundled with one or more DATA
605  * chunks or SACK chunk in the same SCTP packet.
606  *
607  *      0                   1                   2                   3
608  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
609  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
610  *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
611  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612  *
613  * Chunk Flags: 8 bits
614  *
615  *   Set to zero on transmit and ignored on receipt.
616  */
617 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
618                                         const struct sctp_chunk *chunk)
619 {
620         struct sctp_chunk *retval;
621 
622         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
623 
624         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
625          *
626          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
627          * HEARTBEAT ACK, * etc.) to the same destination transport
628          * address from which it * received the DATA or control chunk
629          * to which it is replying.
630          *
631          * [COOKIE ACK back to where the COOKIE ECHO came from.]
632          */
633         if (retval && chunk && chunk->transport)
634                 retval->transport =
635                         sctp_assoc_lookup_paddr(asoc,
636                                                 &chunk->transport->ipaddr);
637 
638         return retval;
639 }
640 
641 /*
642  *  Appendix A: Explicit Congestion Notification:
643  *  CWR:
644  *
645  *  RFC 2481 details a specific bit for a sender to send in the header of
646  *  its next outbound TCP segment to indicate to its peer that it has
647  *  reduced its congestion window.  This is termed the CWR bit.  For
648  *  SCTP the same indication is made by including the CWR chunk.
649  *  This chunk contains one data element, i.e. the TSN number that
650  *  was sent in the ECNE chunk.  This element represents the lowest
651  *  TSN number in the datagram that was originally marked with the
652  *  CE bit.
653  *
654  *     0                   1                   2                   3
655  *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
656  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
657  *    | Chunk Type=13 | Flags=00000000|    Chunk Length = 8           |
658  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659  *    |                      Lowest TSN Number                        |
660  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661  *
662  *     Note: The CWR is considered a Control chunk.
663  */
664 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
665                                  const __u32 lowest_tsn,
666                                  const struct sctp_chunk *chunk)
667 {
668         struct sctp_chunk *retval;
669         struct sctp_cwrhdr cwr;
670 
671         cwr.lowest_tsn = htonl(lowest_tsn);
672         retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
673                                    sizeof(cwr), GFP_ATOMIC);
674 
675         if (!retval)
676                 goto nodata;
677 
678         retval->subh.ecn_cwr_hdr =
679                 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
680 
681         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
682          *
683          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
684          * HEARTBEAT ACK, * etc.) to the same destination transport
685          * address from which it * received the DATA or control chunk
686          * to which it is replying.
687          *
688          * [Report a reduced congestion window back to where the ECNE
689          * came from.]
690          */
691         if (chunk)
692                 retval->transport = chunk->transport;
693 
694 nodata:
695         return retval;
696 }
697 
698 /* Make an ECNE chunk.  This is a congestion experienced report.  */
699 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
700                                   const __u32 lowest_tsn)
701 {
702         struct sctp_chunk *retval;
703         struct sctp_ecnehdr ecne;
704 
705         ecne.lowest_tsn = htonl(lowest_tsn);
706         retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
707                                    sizeof(ecne), GFP_ATOMIC);
708         if (!retval)
709                 goto nodata;
710         retval->subh.ecne_hdr =
711                 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
712 
713 nodata:
714         return retval;
715 }
716 
717 /* Make a DATA chunk for the given association from the provided
718  * parameters.  However, do not populate the data payload.
719  */
720 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
721                                             const struct sctp_sndrcvinfo *sinfo,
722                                             int len, __u8 flags, gfp_t gfp)
723 {
724         struct sctp_chunk *retval;
725         struct sctp_datahdr dp;
726 
727         /* We assign the TSN as LATE as possible, not here when
728          * creating the chunk.
729          */
730         memset(&dp, 0, sizeof(dp));
731         dp.ppid = sinfo->sinfo_ppid;
732         dp.stream = htons(sinfo->sinfo_stream);
733 
734         /* Set the flags for an unordered send.  */
735         if (sinfo->sinfo_flags & SCTP_UNORDERED)
736                 flags |= SCTP_DATA_UNORDERED;
737 
738         retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
739         if (!retval)
740                 return NULL;
741 
742         retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
743         memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
744 
745         return retval;
746 }
747 
748 /* Create a selective ackowledgement (SACK) for the given
749  * association.  This reports on which TSN's we've seen to date,
750  * including duplicates and gaps.
751  */
752 struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
753 {
754         struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
755         struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
756         __u16 num_gabs, num_dup_tsns;
757         struct sctp_transport *trans;
758         struct sctp_chunk *retval;
759         struct sctp_sackhdr sack;
760         __u32 ctsn;
761         int len;
762 
763         memset(gabs, 0, sizeof(gabs));
764         ctsn = sctp_tsnmap_get_ctsn(map);
765 
766         pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
767 
768         /* How much room is needed in the chunk? */
769         num_gabs = sctp_tsnmap_num_gabs(map, gabs);
770         num_dup_tsns = sctp_tsnmap_num_dups(map);
771 
772         /* Initialize the SACK header.  */
773         sack.cum_tsn_ack            = htonl(ctsn);
774         sack.a_rwnd                 = htonl(asoc->a_rwnd);
775         sack.num_gap_ack_blocks     = htons(num_gabs);
776         sack.num_dup_tsns           = htons(num_dup_tsns);
777 
778         len = sizeof(sack)
779                 + sizeof(struct sctp_gap_ack_block) * num_gabs
780                 + sizeof(__u32) * num_dup_tsns;
781 
782         /* Create the chunk.  */
783         retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
784         if (!retval)
785                 goto nodata;
786 
787         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
788          *
789          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
790          * HEARTBEAT ACK, etc.) to the same destination transport
791          * address from which it received the DATA or control chunk to
792          * which it is replying.  This rule should also be followed if
793          * the endpoint is bundling DATA chunks together with the
794          * reply chunk.
795          *
796          * However, when acknowledging multiple DATA chunks received
797          * in packets from different source addresses in a single
798          * SACK, the SACK chunk may be transmitted to one of the
799          * destination transport addresses from which the DATA or
800          * control chunks being acknowledged were received.
801          *
802          * [BUG:  We do not implement the following paragraph.
803          * Perhaps we should remember the last transport we used for a
804          * SACK and avoid that (if possible) if we have seen any
805          * duplicates. --piggy]
806          *
807          * When a receiver of a duplicate DATA chunk sends a SACK to a
808          * multi- homed endpoint it MAY be beneficial to vary the
809          * destination address and not use the source address of the
810          * DATA chunk.  The reason being that receiving a duplicate
811          * from a multi-homed endpoint might indicate that the return
812          * path (as specified in the source address of the DATA chunk)
813          * for the SACK is broken.
814          *
815          * [Send to the address from which we last received a DATA chunk.]
816          */
817         retval->transport = asoc->peer.last_data_from;
818 
819         retval->subh.sack_hdr =
820                 sctp_addto_chunk(retval, sizeof(sack), &sack);
821 
822         /* Add the gap ack block information.   */
823         if (num_gabs)
824                 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
825                                  gabs);
826 
827         /* Add the duplicate TSN information.  */
828         if (num_dup_tsns) {
829                 asoc->stats.idupchunks += num_dup_tsns;
830                 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
831                                  sctp_tsnmap_get_dups(map));
832         }
833         /* Once we have a sack generated, check to see what our sack
834          * generation is, if its 0, reset the transports to 0, and reset
835          * the association generation to 1
836          *
837          * The idea is that zero is never used as a valid generation for the
838          * association so no transport will match after a wrap event like this,
839          * Until the next sack
840          */
841         if (++asoc->peer.sack_generation == 0) {
842                 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
843                                     transports)
844                         trans->sack_generation = 0;
845                 asoc->peer.sack_generation = 1;
846         }
847 nodata:
848         return retval;
849 }
850 
851 /* Make a SHUTDOWN chunk. */
852 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
853                                       const struct sctp_chunk *chunk)
854 {
855         struct sctp_shutdownhdr shut;
856         struct sctp_chunk *retval;
857         __u32 ctsn;
858 
859         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
860         shut.cum_tsn_ack = htonl(ctsn);
861 
862         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
863                                    sizeof(shut), GFP_ATOMIC);
864         if (!retval)
865                 goto nodata;
866 
867         retval->subh.shutdown_hdr =
868                 sctp_addto_chunk(retval, sizeof(shut), &shut);
869 
870         if (chunk)
871                 retval->transport = chunk->transport;
872 nodata:
873         return retval;
874 }
875 
876 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
877                                           const struct sctp_chunk *chunk)
878 {
879         struct sctp_chunk *retval;
880 
881         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
882                                    GFP_ATOMIC);
883 
884         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
885          *
886          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
887          * HEARTBEAT ACK, * etc.) to the same destination transport
888          * address from which it * received the DATA or control chunk
889          * to which it is replying.
890          *
891          * [ACK back to where the SHUTDOWN came from.]
892          */
893         if (retval && chunk)
894                 retval->transport = chunk->transport;
895 
896         return retval;
897 }
898 
899 struct sctp_chunk *sctp_make_shutdown_complete(
900                                         const struct sctp_association *asoc,
901                                         const struct sctp_chunk *chunk)
902 {
903         struct sctp_chunk *retval;
904         __u8 flags = 0;
905 
906         /* Set the T-bit if we have no association (vtag will be
907          * reflected)
908          */
909         flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
910 
911         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
912                                    0, GFP_ATOMIC);
913 
914         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
915          *
916          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
917          * HEARTBEAT ACK, * etc.) to the same destination transport
918          * address from which it * received the DATA or control chunk
919          * to which it is replying.
920          *
921          * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
922          * came from.]
923          */
924         if (retval && chunk)
925                 retval->transport = chunk->transport;
926 
927         return retval;
928 }
929 
930 /* Create an ABORT.  Note that we set the T bit if we have no
931  * association, except when responding to an INIT (sctpimpguide 2.41).
932  */
933 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
934                                    const struct sctp_chunk *chunk,
935                                    const size_t hint)
936 {
937         struct sctp_chunk *retval;
938         __u8 flags = 0;
939 
940         /* Set the T-bit if we have no association and 'chunk' is not
941          * an INIT (vtag will be reflected).
942          */
943         if (!asoc) {
944                 if (chunk && chunk->chunk_hdr &&
945                     chunk->chunk_hdr->type == SCTP_CID_INIT)
946                         flags = 0;
947                 else
948                         flags = SCTP_CHUNK_FLAG_T;
949         }
950 
951         retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
952                                    GFP_ATOMIC);
953 
954         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
955          *
956          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
957          * HEARTBEAT ACK, * etc.) to the same destination transport
958          * address from which it * received the DATA or control chunk
959          * to which it is replying.
960          *
961          * [ABORT back to where the offender came from.]
962          */
963         if (retval && chunk)
964                 retval->transport = chunk->transport;
965 
966         return retval;
967 }
968 
969 /* Helper to create ABORT with a NO_USER_DATA error.  */
970 struct sctp_chunk *sctp_make_abort_no_data(
971                                         const struct sctp_association *asoc,
972                                         const struct sctp_chunk *chunk,
973                                         __u32 tsn)
974 {
975         struct sctp_chunk *retval;
976         __be32 payload;
977 
978         retval = sctp_make_abort(asoc, chunk,
979                                  sizeof(struct sctp_errhdr) + sizeof(tsn));
980 
981         if (!retval)
982                 goto no_mem;
983 
984         /* Put the tsn back into network byte order.  */
985         payload = htonl(tsn);
986         sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
987         sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
988 
989         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
990          *
991          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
992          * HEARTBEAT ACK, * etc.) to the same destination transport
993          * address from which it * received the DATA or control chunk
994          * to which it is replying.
995          *
996          * [ABORT back to where the offender came from.]
997          */
998         if (chunk)
999                 retval->transport = chunk->transport;
1000 
1001 no_mem:
1002         return retval;
1003 }
1004 
1005 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error.  */
1006 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1007                                         struct msghdr *msg,
1008                                         size_t paylen)
1009 {
1010         struct sctp_chunk *retval;
1011         void *payload = NULL;
1012         int err;
1013 
1014         retval = sctp_make_abort(asoc, NULL,
1015                                  sizeof(struct sctp_errhdr) + paylen);
1016         if (!retval)
1017                 goto err_chunk;
1018 
1019         if (paylen) {
1020                 /* Put the msg_iov together into payload.  */
1021                 payload = kmalloc(paylen, GFP_KERNEL);
1022                 if (!payload)
1023                         goto err_payload;
1024 
1025                 err = memcpy_from_msg(payload, msg, paylen);
1026                 if (err < 0)
1027                         goto err_copy;
1028         }
1029 
1030         sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1031         sctp_addto_chunk(retval, paylen, payload);
1032 
1033         if (paylen)
1034                 kfree(payload);
1035 
1036         return retval;
1037 
1038 err_copy:
1039         kfree(payload);
1040 err_payload:
1041         sctp_chunk_free(retval);
1042         retval = NULL;
1043 err_chunk:
1044         return retval;
1045 }
1046 
1047 /* Append bytes to the end of a parameter.  Will panic if chunk is not big
1048  * enough.
1049  */
1050 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1051                               const void *data)
1052 {
1053         int chunklen = ntohs(chunk->chunk_hdr->length);
1054         void *target;
1055 
1056         target = skb_put(chunk->skb, len);
1057 
1058         if (data)
1059                 memcpy(target, data, len);
1060         else
1061                 memset(target, 0, len);
1062 
1063         /* Adjust the chunk length field.  */
1064         chunk->chunk_hdr->length = htons(chunklen + len);
1065         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1066 
1067         return target;
1068 }
1069 
1070 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1071 struct sctp_chunk *sctp_make_abort_violation(
1072                                         const struct sctp_association *asoc,
1073                                         const struct sctp_chunk *chunk,
1074                                         const __u8 *payload,
1075                                         const size_t paylen)
1076 {
1077         struct sctp_chunk  *retval;
1078         struct sctp_paramhdr phdr;
1079 
1080         retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1081                                               paylen + sizeof(phdr));
1082         if (!retval)
1083                 goto end;
1084 
1085         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1086                                                             sizeof(phdr));
1087 
1088         phdr.type = htons(chunk->chunk_hdr->type);
1089         phdr.length = chunk->chunk_hdr->length;
1090         sctp_addto_chunk(retval, paylen, payload);
1091         sctp_addto_param(retval, sizeof(phdr), &phdr);
1092 
1093 end:
1094         return retval;
1095 }
1096 
1097 struct sctp_chunk *sctp_make_violation_paramlen(
1098                                         const struct sctp_association *asoc,
1099                                         const struct sctp_chunk *chunk,
1100                                         struct sctp_paramhdr *param)
1101 {
1102         static const char error[] = "The following parameter had invalid length:";
1103         size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1104                              sizeof(*param);
1105         struct sctp_chunk *retval;
1106 
1107         retval = sctp_make_abort(asoc, chunk, payload_len);
1108         if (!retval)
1109                 goto nodata;
1110 
1111         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1112                         sizeof(error) + sizeof(*param));
1113         sctp_addto_chunk(retval, sizeof(error), error);
1114         sctp_addto_param(retval, sizeof(*param), param);
1115 
1116 nodata:
1117         return retval;
1118 }
1119 
1120 struct sctp_chunk *sctp_make_violation_max_retrans(
1121                                         const struct sctp_association *asoc,
1122                                         const struct sctp_chunk *chunk)
1123 {
1124         static const char error[] = "Association exceeded its max_retrans count";
1125         size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1126         struct sctp_chunk *retval;
1127 
1128         retval = sctp_make_abort(asoc, chunk, payload_len);
1129         if (!retval)
1130                 goto nodata;
1131 
1132         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1133         sctp_addto_chunk(retval, sizeof(error), error);
1134 
1135 nodata:
1136         return retval;
1137 }
1138 
1139 /* Make a HEARTBEAT chunk.  */
1140 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1141                                        const struct sctp_transport *transport)
1142 {
1143         struct sctp_sender_hb_info hbinfo;
1144         struct sctp_chunk *retval;
1145 
1146         retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1147                                    sizeof(hbinfo), GFP_ATOMIC);
1148 
1149         if (!retval)
1150                 goto nodata;
1151 
1152         hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1153         hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1154         hbinfo.daddr = transport->ipaddr;
1155         hbinfo.sent_at = jiffies;
1156         hbinfo.hb_nonce = transport->hb_nonce;
1157 
1158         /* Cast away the 'const', as this is just telling the chunk
1159          * what transport it belongs to.
1160          */
1161         retval->transport = (struct sctp_transport *) transport;
1162         retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1163                                                 &hbinfo);
1164 
1165 nodata:
1166         return retval;
1167 }
1168 
1169 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1170                                            const struct sctp_chunk *chunk,
1171                                            const void *payload,
1172                                            const size_t paylen)
1173 {
1174         struct sctp_chunk *retval;
1175 
1176         retval  = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1177                                     GFP_ATOMIC);
1178         if (!retval)
1179                 goto nodata;
1180 
1181         retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1182 
1183         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1184          *
1185          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1186          * HEARTBEAT ACK, * etc.) to the same destination transport
1187          * address from which it * received the DATA or control chunk
1188          * to which it is replying.
1189          *
1190          * [HBACK back to where the HEARTBEAT came from.]
1191          */
1192         if (chunk)
1193                 retval->transport = chunk->transport;
1194 
1195 nodata:
1196         return retval;
1197 }
1198 
1199 /* Create an Operation Error chunk with the specified space reserved.
1200  * This routine can be used for containing multiple causes in the chunk.
1201  */
1202 static struct sctp_chunk *sctp_make_op_error_space(
1203                                         const struct sctp_association *asoc,
1204                                         const struct sctp_chunk *chunk,
1205                                         size_t size)
1206 {
1207         struct sctp_chunk *retval;
1208 
1209         retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1210                                    sizeof(struct sctp_errhdr) + size,
1211                                    GFP_ATOMIC);
1212         if (!retval)
1213                 goto nodata;
1214 
1215         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1216          *
1217          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1218          * HEARTBEAT ACK, etc.) to the same destination transport
1219          * address from which it received the DATA or control chunk
1220          * to which it is replying.
1221          *
1222          */
1223         if (chunk)
1224                 retval->transport = chunk->transport;
1225 
1226 nodata:
1227         return retval;
1228 }
1229 
1230 /* Create an Operation Error chunk of a fixed size, specifically,
1231  * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1232  * This is a helper function to allocate an error chunk for for those
1233  * invalid parameter codes in which we may not want to report all the
1234  * errors, if the incoming chunk is large. If it can't fit in a single
1235  * packet, we ignore it.
1236  */
1237 static inline struct sctp_chunk *sctp_make_op_error_limited(
1238                                         const struct sctp_association *asoc,
1239                                         const struct sctp_chunk *chunk)
1240 {
1241         size_t size = SCTP_DEFAULT_MAXSEGMENT;
1242         struct sctp_sock *sp = NULL;
1243 
1244         if (asoc) {
1245                 size = min_t(size_t, size, asoc->pathmtu);
1246                 sp = sctp_sk(asoc->base.sk);
1247         }
1248 
1249         size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1250 
1251         return sctp_make_op_error_space(asoc, chunk, size);
1252 }
1253 
1254 /* Create an Operation Error chunk.  */
1255 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1256                                       const struct sctp_chunk *chunk,
1257                                       __be16 cause_code, const void *payload,
1258                                       size_t paylen, size_t reserve_tail)
1259 {
1260         struct sctp_chunk *retval;
1261 
1262         retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1263         if (!retval)
1264                 goto nodata;
1265 
1266         sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1267         sctp_addto_chunk(retval, paylen, payload);
1268         if (reserve_tail)
1269                 sctp_addto_param(retval, reserve_tail, NULL);
1270 
1271 nodata:
1272         return retval;
1273 }
1274 
1275 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1276                                   __u16 key_id)
1277 {
1278         struct sctp_authhdr auth_hdr;
1279         struct sctp_hmac *hmac_desc;
1280         struct sctp_chunk *retval;
1281 
1282         /* Get the first hmac that the peer told us to use */
1283         hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1284         if (unlikely(!hmac_desc))
1285                 return NULL;
1286 
1287         retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1288                                    hmac_desc->hmac_len + sizeof(auth_hdr),
1289                                    GFP_ATOMIC);
1290         if (!retval)
1291                 return NULL;
1292 
1293         auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1294         auth_hdr.shkey_id = htons(key_id);
1295 
1296         retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1297                                                  &auth_hdr);
1298 
1299         skb_put_zero(retval->skb, hmac_desc->hmac_len);
1300 
1301         /* Adjust the chunk header to include the empty MAC */
1302         retval->chunk_hdr->length =
1303                 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1304         retval->chunk_end = skb_tail_pointer(retval->skb);
1305 
1306         return retval;
1307 }
1308 
1309 
1310 /********************************************************************
1311  * 2nd Level Abstractions
1312  ********************************************************************/
1313 
1314 /* Turn an skb into a chunk.
1315  * FIXME: Eventually move the structure directly inside the skb->cb[].
1316  *
1317  * sctpimpguide-05.txt Section 2.8.2
1318  * M1) Each time a new DATA chunk is transmitted
1319  * set the 'TSN.Missing.Report' count for that TSN to 0. The
1320  * 'TSN.Missing.Report' count will be used to determine missing chunks
1321  * and when to fast retransmit.
1322  *
1323  */
1324 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1325                                  const struct sctp_association *asoc,
1326                                  struct sock *sk, gfp_t gfp)
1327 {
1328         struct sctp_chunk *retval;
1329 
1330         retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1331 
1332         if (!retval)
1333                 goto nodata;
1334         if (!sk)
1335                 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1336 
1337         INIT_LIST_HEAD(&retval->list);
1338         retval->skb             = skb;
1339         retval->asoc            = (struct sctp_association *)asoc;
1340         retval->singleton       = 1;
1341 
1342         retval->fast_retransmit = SCTP_CAN_FRTX;
1343 
1344         /* Polish the bead hole.  */
1345         INIT_LIST_HEAD(&retval->transmitted_list);
1346         INIT_LIST_HEAD(&retval->frag_list);
1347         SCTP_DBG_OBJCNT_INC(chunk);
1348         refcount_set(&retval->refcnt, 1);
1349 
1350 nodata:
1351         return retval;
1352 }
1353 
1354 /* Set chunk->source and dest based on the IP header in chunk->skb.  */
1355 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1356                      union sctp_addr *dest)
1357 {
1358         memcpy(&chunk->source, src, sizeof(union sctp_addr));
1359         memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1360 }
1361 
1362 /* Extract the source address from a chunk.  */
1363 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1364 {
1365         /* If we have a known transport, use that.  */
1366         if (chunk->transport) {
1367                 return &chunk->transport->ipaddr;
1368         } else {
1369                 /* Otherwise, extract it from the IP header.  */
1370                 return &chunk->source;
1371         }
1372 }
1373 
1374 /* Create a new chunk, setting the type and flags headers from the
1375  * arguments, reserving enough space for a 'paylen' byte payload.
1376  */
1377 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1378                                            __u8 type, __u8 flags, int paylen,
1379                                            gfp_t gfp)
1380 {
1381         struct sctp_chunkhdr *chunk_hdr;
1382         struct sctp_chunk *retval;
1383         struct sk_buff *skb;
1384         struct sock *sk;
1385         int chunklen;
1386 
1387         chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1388         if (chunklen > SCTP_MAX_CHUNK_LEN)
1389                 goto nodata;
1390 
1391         /* No need to allocate LL here, as this is only a chunk. */
1392         skb = alloc_skb(chunklen, gfp);
1393         if (!skb)
1394                 goto nodata;
1395 
1396         /* Make room for the chunk header.  */
1397         chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1398         chunk_hdr->type   = type;
1399         chunk_hdr->flags  = flags;
1400         chunk_hdr->length = htons(sizeof(*chunk_hdr));
1401 
1402         sk = asoc ? asoc->base.sk : NULL;
1403         retval = sctp_chunkify(skb, asoc, sk, gfp);
1404         if (!retval) {
1405                 kfree_skb(skb);
1406                 goto nodata;
1407         }
1408 
1409         retval->chunk_hdr = chunk_hdr;
1410         retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1411 
1412         /* Determine if the chunk needs to be authenticated */
1413         if (sctp_auth_send_cid(type, asoc))
1414                 retval->auth = 1;
1415 
1416         return retval;
1417 nodata:
1418         return NULL;
1419 }
1420 
1421 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1422                                          __u8 flags, int paylen, gfp_t gfp)
1423 {
1424         return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1425 }
1426 
1427 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1428                                    __u8 flags, int paylen, gfp_t gfp)
1429 {
1430         return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1431 }
1432 
1433 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1434                                             __u8 type, __u8 flags, int paylen,
1435                                             gfp_t gfp)
1436 {
1437         struct sctp_chunk *chunk;
1438 
1439         chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1440         if (chunk)
1441                 sctp_control_set_owner_w(chunk);
1442 
1443         return chunk;
1444 }
1445 
1446 /* Release the memory occupied by a chunk.  */
1447 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1448 {
1449         BUG_ON(!list_empty(&chunk->list));
1450         list_del_init(&chunk->transmitted_list);
1451 
1452         consume_skb(chunk->skb);
1453         consume_skb(chunk->auth_chunk);
1454 
1455         SCTP_DBG_OBJCNT_DEC(chunk);
1456         kmem_cache_free(sctp_chunk_cachep, chunk);
1457 }
1458 
1459 /* Possibly, free the chunk.  */
1460 void sctp_chunk_free(struct sctp_chunk *chunk)
1461 {
1462         /* Release our reference on the message tracker. */
1463         if (chunk->msg)
1464                 sctp_datamsg_put(chunk->msg);
1465 
1466         sctp_chunk_put(chunk);
1467 }
1468 
1469 /* Grab a reference to the chunk. */
1470 void sctp_chunk_hold(struct sctp_chunk *ch)
1471 {
1472         refcount_inc(&ch->refcnt);
1473 }
1474 
1475 /* Release a reference to the chunk. */
1476 void sctp_chunk_put(struct sctp_chunk *ch)
1477 {
1478         if (refcount_dec_and_test(&ch->refcnt))
1479                 sctp_chunk_destroy(ch);
1480 }
1481 
1482 /* Append bytes to the end of a chunk.  Will panic if chunk is not big
1483  * enough.
1484  */
1485 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1486 {
1487         int chunklen = ntohs(chunk->chunk_hdr->length);
1488         int padlen = SCTP_PAD4(chunklen) - chunklen;
1489         void *target;
1490 
1491         skb_put_zero(chunk->skb, padlen);
1492         target = skb_put_data(chunk->skb, data, len);
1493 
1494         /* Adjust the chunk length field.  */
1495         chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1496         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1497 
1498         return target;
1499 }
1500 
1501 /* Append bytes from user space to the end of a chunk.  Will panic if
1502  * chunk is not big enough.
1503  * Returns a kernel err value.
1504  */
1505 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1506                           struct iov_iter *from)
1507 {
1508         void *target;
1509 
1510         /* Make room in chunk for data.  */
1511         target = skb_put(chunk->skb, len);
1512 
1513         /* Copy data (whole iovec) into chunk */
1514         if (!copy_from_iter_full(target, len, from))
1515                 return -EFAULT;
1516 
1517         /* Adjust the chunk length field.  */
1518         chunk->chunk_hdr->length =
1519                 htons(ntohs(chunk->chunk_hdr->length) + len);
1520         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1521 
1522         return 0;
1523 }
1524 
1525 /* Helper function to assign a TSN if needed.  This assumes that both
1526  * the data_hdr and association have already been assigned.
1527  */
1528 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1529 {
1530         struct sctp_stream *stream;
1531         struct sctp_chunk *lchunk;
1532         struct sctp_datamsg *msg;
1533         __u16 ssn, sid;
1534 
1535         if (chunk->has_ssn)
1536                 return;
1537 
1538         /* All fragments will be on the same stream */
1539         sid = ntohs(chunk->subh.data_hdr->stream);
1540         stream = &chunk->asoc->stream;
1541 
1542         /* Now assign the sequence number to the entire message.
1543          * All fragments must have the same stream sequence number.
1544          */
1545         msg = chunk->msg;
1546         list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1547                 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1548                         ssn = 0;
1549                 } else {
1550                         if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1551                                 ssn = sctp_ssn_next(stream, out, sid);
1552                         else
1553                                 ssn = sctp_ssn_peek(stream, out, sid);
1554                 }
1555 
1556                 lchunk->subh.data_hdr->ssn = htons(ssn);
1557                 lchunk->has_ssn = 1;
1558         }
1559 }
1560 
1561 /* Helper function to assign a TSN if needed.  This assumes that both
1562  * the data_hdr and association have already been assigned.
1563  */
1564 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1565 {
1566         if (!chunk->has_tsn) {
1567                 /* This is the last possible instant to
1568                  * assign a TSN.
1569                  */
1570                 chunk->subh.data_hdr->tsn =
1571                         htonl(sctp_association_get_next_tsn(chunk->asoc));
1572                 chunk->has_tsn = 1;
1573         }
1574 }
1575 
1576 /* Create a CLOSED association to use with an incoming packet.  */
1577 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1578                                              struct sctp_chunk *chunk,
1579                                              gfp_t gfp)
1580 {
1581         struct sctp_association *asoc;
1582         enum sctp_scope scope;
1583         struct sk_buff *skb;
1584 
1585         /* Create the bare association.  */
1586         scope = sctp_scope(sctp_source(chunk));
1587         asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1588         if (!asoc)
1589                 goto nodata;
1590         asoc->temp = 1;
1591         skb = chunk->skb;
1592         /* Create an entry for the source address of the packet.  */
1593         SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1594 
1595 nodata:
1596         return asoc;
1597 }
1598 
1599 /* Build a cookie representing asoc.
1600  * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1601  */
1602 static struct sctp_cookie_param *sctp_pack_cookie(
1603                                         const struct sctp_endpoint *ep,
1604                                         const struct sctp_association *asoc,
1605                                         const struct sctp_chunk *init_chunk,
1606                                         int *cookie_len, const __u8 *raw_addrs,
1607                                         int addrs_len)
1608 {
1609         struct sctp_signed_cookie *cookie;
1610         struct sctp_cookie_param *retval;
1611         int headersize, bodysize;
1612 
1613         /* Header size is static data prior to the actual cookie, including
1614          * any padding.
1615          */
1616         headersize = sizeof(struct sctp_paramhdr) +
1617                      (sizeof(struct sctp_signed_cookie) -
1618                       sizeof(struct sctp_cookie));
1619         bodysize = sizeof(struct sctp_cookie)
1620                 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1621 
1622         /* Pad out the cookie to a multiple to make the signature
1623          * functions simpler to write.
1624          */
1625         if (bodysize % SCTP_COOKIE_MULTIPLE)
1626                 bodysize += SCTP_COOKIE_MULTIPLE
1627                         - (bodysize % SCTP_COOKIE_MULTIPLE);
1628         *cookie_len = headersize + bodysize;
1629 
1630         /* Clear this memory since we are sending this data structure
1631          * out on the network.
1632          */
1633         retval = kzalloc(*cookie_len, GFP_ATOMIC);
1634         if (!retval)
1635                 goto nodata;
1636 
1637         cookie = (struct sctp_signed_cookie *) retval->body;
1638 
1639         /* Set up the parameter header.  */
1640         retval->p.type = SCTP_PARAM_STATE_COOKIE;
1641         retval->p.length = htons(*cookie_len);
1642 
1643         /* Copy the cookie part of the association itself.  */
1644         cookie->c = asoc->c;
1645         /* Save the raw address list length in the cookie. */
1646         cookie->c.raw_addr_list_len = addrs_len;
1647 
1648         /* Remember PR-SCTP capability. */
1649         cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1650 
1651         /* Save adaptation indication in the cookie. */
1652         cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1653 
1654         /* Set an expiration time for the cookie.  */
1655         cookie->c.expiration = ktime_add(asoc->cookie_life,
1656                                          ktime_get_real());
1657 
1658         /* Copy the peer's init packet.  */
1659         memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1660                ntohs(init_chunk->chunk_hdr->length));
1661 
1662         /* Copy the raw local address list of the association. */
1663         memcpy((__u8 *)&cookie->c.peer_init[0] +
1664                ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1665 
1666         if (sctp_sk(ep->base.sk)->hmac) {
1667                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1668                 int err;
1669 
1670                 /* Sign the message.  */
1671                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1672 
1673                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1674                                           sizeof(ep->secret_key)) ?:
1675                       crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1676                                           cookie->signature);
1677                 shash_desc_zero(desc);
1678                 if (err)
1679                         goto free_cookie;
1680         }
1681 
1682         return retval;
1683 
1684 free_cookie:
1685         kfree(retval);
1686 nodata:
1687         *cookie_len = 0;
1688         return NULL;
1689 }
1690 
1691 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
1692 struct sctp_association *sctp_unpack_cookie(
1693                                         const struct sctp_endpoint *ep,
1694                                         const struct sctp_association *asoc,
1695                                         struct sctp_chunk *chunk, gfp_t gfp,
1696                                         int *error, struct sctp_chunk **errp)
1697 {
1698         struct sctp_association *retval = NULL;
1699         int headersize, bodysize, fixed_size;
1700         struct sctp_signed_cookie *cookie;
1701         struct sk_buff *skb = chunk->skb;
1702         struct sctp_cookie *bear_cookie;
1703         __u8 *digest = ep->digest;
1704         enum sctp_scope scope;
1705         unsigned int len;
1706         ktime_t kt;
1707 
1708         /* Header size is static data prior to the actual cookie, including
1709          * any padding.
1710          */
1711         headersize = sizeof(struct sctp_chunkhdr) +
1712                      (sizeof(struct sctp_signed_cookie) -
1713                       sizeof(struct sctp_cookie));
1714         bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1715         fixed_size = headersize + sizeof(struct sctp_cookie);
1716 
1717         /* Verify that the chunk looks like it even has a cookie.
1718          * There must be enough room for our cookie and our peer's
1719          * INIT chunk.
1720          */
1721         len = ntohs(chunk->chunk_hdr->length);
1722         if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1723                 goto malformed;
1724 
1725         /* Verify that the cookie has been padded out. */
1726         if (bodysize % SCTP_COOKIE_MULTIPLE)
1727                 goto malformed;
1728 
1729         /* Process the cookie.  */
1730         cookie = chunk->subh.cookie_hdr;
1731         bear_cookie = &cookie->c;
1732 
1733         if (!sctp_sk(ep->base.sk)->hmac)
1734                 goto no_hmac;
1735 
1736         /* Check the signature.  */
1737         {
1738                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1739                 int err;
1740 
1741                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1742 
1743                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1744                                           sizeof(ep->secret_key)) ?:
1745                       crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1746                                           digest);
1747                 shash_desc_zero(desc);
1748 
1749                 if (err) {
1750                         *error = -SCTP_IERROR_NOMEM;
1751                         goto fail;
1752                 }
1753         }
1754 
1755         if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1756                 *error = -SCTP_IERROR_BAD_SIG;
1757                 goto fail;
1758         }
1759 
1760 no_hmac:
1761         /* IG Section 2.35.2:
1762          *  3) Compare the port numbers and the verification tag contained
1763          *     within the COOKIE ECHO chunk to the actual port numbers and the
1764          *     verification tag within the SCTP common header of the received
1765          *     packet. If these values do not match the packet MUST be silently
1766          *     discarded,
1767          */
1768         if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1769                 *error = -SCTP_IERROR_BAD_TAG;
1770                 goto fail;
1771         }
1772 
1773         if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1774             ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1775                 *error = -SCTP_IERROR_BAD_PORTS;
1776                 goto fail;
1777         }
1778 
1779         /* Check to see if the cookie is stale.  If there is already
1780          * an association, there is no need to check cookie's expiration
1781          * for init collision case of lost COOKIE ACK.
1782          * If skb has been timestamped, then use the stamp, otherwise
1783          * use current time.  This introduces a small possibility that
1784          * that a cookie may be considered expired, but his would only slow
1785          * down the new association establishment instead of every packet.
1786          */
1787         if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1788                 kt = skb_get_ktime(skb);
1789         else
1790                 kt = ktime_get_real();
1791 
1792         if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1793                 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1794                 __be32 n = htonl(usecs);
1795 
1796                 /*
1797                  * Section 3.3.10.3 Stale Cookie Error (3)
1798                  *
1799                  * Cause of error
1800                  * ---------------
1801                  * Stale Cookie Error:  Indicates the receipt of a valid State
1802                  * Cookie that has expired.
1803                  */
1804                 *errp = sctp_make_op_error(asoc, chunk,
1805                                            SCTP_ERROR_STALE_COOKIE, &n,
1806                                            sizeof(n), 0);
1807                 if (*errp)
1808                         *error = -SCTP_IERROR_STALE_COOKIE;
1809                 else
1810                         *error = -SCTP_IERROR_NOMEM;
1811 
1812                 goto fail;
1813         }
1814 
1815         /* Make a new base association.  */
1816         scope = sctp_scope(sctp_source(chunk));
1817         retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1818         if (!retval) {
1819                 *error = -SCTP_IERROR_NOMEM;
1820                 goto fail;
1821         }
1822 
1823         /* Set up our peer's port number.  */
1824         retval->peer.port = ntohs(chunk->sctp_hdr->source);
1825 
1826         /* Populate the association from the cookie.  */
1827         memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1828 
1829         if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1830                                                  GFP_ATOMIC) < 0) {
1831                 *error = -SCTP_IERROR_NOMEM;
1832                 goto fail;
1833         }
1834 
1835         /* Also, add the destination address. */
1836         if (list_empty(&retval->base.bind_addr.address_list)) {
1837                 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1838                                    sizeof(chunk->dest), SCTP_ADDR_SRC,
1839                                    GFP_ATOMIC);
1840         }
1841 
1842         retval->next_tsn = retval->c.initial_tsn;
1843         retval->ctsn_ack_point = retval->next_tsn - 1;
1844         retval->addip_serial = retval->c.initial_tsn;
1845         retval->strreset_outseq = retval->c.initial_tsn;
1846         retval->adv_peer_ack_point = retval->ctsn_ack_point;
1847         retval->peer.prsctp_capable = retval->c.prsctp_capable;
1848         retval->peer.adaptation_ind = retval->c.adaptation_ind;
1849 
1850         /* The INIT stuff will be done by the side effects.  */
1851         return retval;
1852 
1853 fail:
1854         if (retval)
1855                 sctp_association_free(retval);
1856 
1857         return NULL;
1858 
1859 malformed:
1860         /* Yikes!  The packet is either corrupt or deliberately
1861          * malformed.
1862          */
1863         *error = -SCTP_IERROR_MALFORMED;
1864         goto fail;
1865 }
1866 
1867 /********************************************************************
1868  * 3rd Level Abstractions
1869  ********************************************************************/
1870 
1871 struct __sctp_missing {
1872         __be32 num_missing;
1873         __be16 type;
1874 }  __packed;
1875 
1876 /*
1877  * Report a missing mandatory parameter.
1878  */
1879 static int sctp_process_missing_param(const struct sctp_association *asoc,
1880                                       enum sctp_param paramtype,
1881                                       struct sctp_chunk *chunk,
1882                                       struct sctp_chunk **errp)
1883 {
1884         struct __sctp_missing report;
1885         __u16 len;
1886 
1887         len = SCTP_PAD4(sizeof(report));
1888 
1889         /* Make an ERROR chunk, preparing enough room for
1890          * returning multiple unknown parameters.
1891          */
1892         if (!*errp)
1893                 *errp = sctp_make_op_error_space(asoc, chunk, len);
1894 
1895         if (*errp) {
1896                 report.num_missing = htonl(1);
1897                 report.type = paramtype;
1898                 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1899                                 sizeof(report));
1900                 sctp_addto_chunk(*errp, sizeof(report), &report);
1901         }
1902 
1903         /* Stop processing this chunk. */
1904         return 0;
1905 }
1906 
1907 /* Report an Invalid Mandatory Parameter.  */
1908 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1909                                       struct sctp_chunk *chunk,
1910                                       struct sctp_chunk **errp)
1911 {
1912         /* Invalid Mandatory Parameter Error has no payload. */
1913 
1914         if (!*errp)
1915                 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1916 
1917         if (*errp)
1918                 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1919 
1920         /* Stop processing this chunk. */
1921         return 0;
1922 }
1923 
1924 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1925                                         struct sctp_paramhdr *param,
1926                                         const struct sctp_chunk *chunk,
1927                                         struct sctp_chunk **errp)
1928 {
1929         /* This is a fatal error.  Any accumulated non-fatal errors are
1930          * not reported.
1931          */
1932         if (*errp)
1933                 sctp_chunk_free(*errp);
1934 
1935         /* Create an error chunk and fill it in with our payload. */
1936         *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1937 
1938         return 0;
1939 }
1940 
1941 
1942 /* Do not attempt to handle the HOST_NAME parm.  However, do
1943  * send back an indicator to the peer.
1944  */
1945 static int sctp_process_hn_param(const struct sctp_association *asoc,
1946                                  union sctp_params param,
1947                                  struct sctp_chunk *chunk,
1948                                  struct sctp_chunk **errp)
1949 {
1950         __u16 len = ntohs(param.p->length);
1951 
1952         /* Processing of the HOST_NAME parameter will generate an
1953          * ABORT.  If we've accumulated any non-fatal errors, they
1954          * would be unrecognized parameters and we should not include
1955          * them in the ABORT.
1956          */
1957         if (*errp)
1958                 sctp_chunk_free(*errp);
1959 
1960         *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
1961                                    param.v, len, 0);
1962 
1963         /* Stop processing this chunk. */
1964         return 0;
1965 }
1966 
1967 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1968 {
1969         __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1970         int have_asconf = 0;
1971         int have_auth = 0;
1972         int i;
1973 
1974         for (i = 0; i < num_ext; i++) {
1975                 switch (param.ext->chunks[i]) {
1976                 case SCTP_CID_AUTH:
1977                         have_auth = 1;
1978                         break;
1979                 case SCTP_CID_ASCONF:
1980                 case SCTP_CID_ASCONF_ACK:
1981                         have_asconf = 1;
1982                         break;
1983                 }
1984         }
1985 
1986         /* ADD-IP Security: The draft requires us to ABORT or ignore the
1987          * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not.  Do this
1988          * only if ADD-IP is turned on and we are not backward-compatible
1989          * mode.
1990          */
1991         if (net->sctp.addip_noauth)
1992                 return 1;
1993 
1994         if (net->sctp.addip_enable && !have_auth && have_asconf)
1995                 return 0;
1996 
1997         return 1;
1998 }
1999 
2000 static void sctp_process_ext_param(struct sctp_association *asoc,
2001                                    union sctp_params param)
2002 {
2003         __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2004         struct net *net = sock_net(asoc->base.sk);
2005         int i;
2006 
2007         for (i = 0; i < num_ext; i++) {
2008                 switch (param.ext->chunks[i]) {
2009                 case SCTP_CID_RECONF:
2010                         if (asoc->reconf_enable &&
2011                             !asoc->peer.reconf_capable)
2012                                 asoc->peer.reconf_capable = 1;
2013                         break;
2014                 case SCTP_CID_FWD_TSN:
2015                         if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
2016                                 asoc->peer.prsctp_capable = 1;
2017                         break;
2018                 case SCTP_CID_AUTH:
2019                         /* if the peer reports AUTH, assume that he
2020                          * supports AUTH.
2021                          */
2022                         if (asoc->ep->auth_enable)
2023                                 asoc->peer.auth_capable = 1;
2024                         break;
2025                 case SCTP_CID_ASCONF:
2026                 case SCTP_CID_ASCONF_ACK:
2027                         if (net->sctp.addip_enable)
2028                                 asoc->peer.asconf_capable = 1;
2029                         break;
2030                 case SCTP_CID_I_DATA:
2031                         if (sctp_sk(asoc->base.sk)->strm_interleave)
2032                                 asoc->intl_enable = 1;
2033                         break;
2034                 default:
2035                         break;
2036                 }
2037         }
2038 }
2039 
2040 /* RFC 3.2.1 & the Implementers Guide 2.2.
2041  *
2042  * The Parameter Types are encoded such that the
2043  * highest-order two bits specify the action that must be
2044  * taken if the processing endpoint does not recognize the
2045  * Parameter Type.
2046  *
2047  * 00 - Stop processing this parameter; do not process any further
2048  *      parameters within this chunk
2049  *
2050  * 01 - Stop processing this parameter, do not process any further
2051  *      parameters within this chunk, and report the unrecognized
2052  *      parameter in an 'Unrecognized Parameter' ERROR chunk.
2053  *
2054  * 10 - Skip this parameter and continue processing.
2055  *
2056  * 11 - Skip this parameter and continue processing but
2057  *      report the unrecognized parameter in an
2058  *      'Unrecognized Parameter' ERROR chunk.
2059  *
2060  * Return value:
2061  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2062  *      SCTP_IERROR_ERROR    - stop and report an error.
2063  *      SCTP_IERROR_NOMEME   - out of memory.
2064  */
2065 static enum sctp_ierror sctp_process_unk_param(
2066                                         const struct sctp_association *asoc,
2067                                         union sctp_params param,
2068                                         struct sctp_chunk *chunk,
2069                                         struct sctp_chunk **errp)
2070 {
2071         int retval = SCTP_IERROR_NO_ERROR;
2072 
2073         switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2074         case SCTP_PARAM_ACTION_DISCARD:
2075                 retval =  SCTP_IERROR_ERROR;
2076                 break;
2077         case SCTP_PARAM_ACTION_SKIP:
2078                 break;
2079         case SCTP_PARAM_ACTION_DISCARD_ERR:
2080                 retval =  SCTP_IERROR_ERROR;
2081                 /* Fall through */
2082         case SCTP_PARAM_ACTION_SKIP_ERR:
2083                 /* Make an ERROR chunk, preparing enough room for
2084                  * returning multiple unknown parameters.
2085                  */
2086                 if (!*errp) {
2087                         *errp = sctp_make_op_error_limited(asoc, chunk);
2088                         if (!*errp) {
2089                                 /* If there is no memory for generating the
2090                                  * ERROR report as specified, an ABORT will be
2091                                  * triggered to the peer and the association
2092                                  * won't be established.
2093                                  */
2094                                 retval = SCTP_IERROR_NOMEM;
2095                                 break;
2096                         }
2097                 }
2098 
2099                 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2100                                      ntohs(param.p->length)))
2101                         sctp_addto_chunk(*errp, ntohs(param.p->length),
2102                                          param.v);
2103                 break;
2104         default:
2105                 break;
2106         }
2107 
2108         return retval;
2109 }
2110 
2111 /* Verify variable length parameters
2112  * Return values:
2113  *      SCTP_IERROR_ABORT - trigger an ABORT
2114  *      SCTP_IERROR_NOMEM - out of memory (abort)
2115  *      SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2116  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2117  */
2118 static enum sctp_ierror sctp_verify_param(struct net *net,
2119                                           const struct sctp_endpoint *ep,
2120                                           const struct sctp_association *asoc,
2121                                           union sctp_params param,
2122                                           enum sctp_cid cid,
2123                                           struct sctp_chunk *chunk,
2124                                           struct sctp_chunk **err_chunk)
2125 {
2126         struct sctp_hmac_algo_param *hmacs;
2127         int retval = SCTP_IERROR_NO_ERROR;
2128         __u16 n_elt, id = 0;
2129         int i;
2130 
2131         /* FIXME - This routine is not looking at each parameter per the
2132          * chunk type, i.e., unrecognized parameters should be further
2133          * identified based on the chunk id.
2134          */
2135 
2136         switch (param.p->type) {
2137         case SCTP_PARAM_IPV4_ADDRESS:
2138         case SCTP_PARAM_IPV6_ADDRESS:
2139         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2140         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2141         case SCTP_PARAM_STATE_COOKIE:
2142         case SCTP_PARAM_HEARTBEAT_INFO:
2143         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2144         case SCTP_PARAM_ECN_CAPABLE:
2145         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2146                 break;
2147 
2148         case SCTP_PARAM_SUPPORTED_EXT:
2149                 if (!sctp_verify_ext_param(net, param))
2150                         return SCTP_IERROR_ABORT;
2151                 break;
2152 
2153         case SCTP_PARAM_SET_PRIMARY:
2154                 if (net->sctp.addip_enable)
2155                         break;
2156                 goto fallthrough;
2157 
2158         case SCTP_PARAM_HOST_NAME_ADDRESS:
2159                 /* Tell the peer, we won't support this param.  */
2160                 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2161                 retval = SCTP_IERROR_ABORT;
2162                 break;
2163 
2164         case SCTP_PARAM_FWD_TSN_SUPPORT:
2165                 if (ep->prsctp_enable)
2166                         break;
2167                 goto fallthrough;
2168 
2169         case SCTP_PARAM_RANDOM:
2170                 if (!ep->auth_enable)
2171                         goto fallthrough;
2172 
2173                 /* SCTP-AUTH: Secion 6.1
2174                  * If the random number is not 32 byte long the association
2175                  * MUST be aborted.  The ABORT chunk SHOULD contain the error
2176                  * cause 'Protocol Violation'.
2177                  */
2178                 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2179                                                sizeof(struct sctp_paramhdr)) {
2180                         sctp_process_inv_paramlength(asoc, param.p,
2181                                                      chunk, err_chunk);
2182                         retval = SCTP_IERROR_ABORT;
2183                 }
2184                 break;
2185 
2186         case SCTP_PARAM_CHUNKS:
2187                 if (!ep->auth_enable)
2188                         goto fallthrough;
2189 
2190                 /* SCTP-AUTH: Section 3.2
2191                  * The CHUNKS parameter MUST be included once in the INIT or
2192                  *  INIT-ACK chunk if the sender wants to receive authenticated
2193                  *  chunks.  Its maximum length is 260 bytes.
2194                  */
2195                 if (260 < ntohs(param.p->length)) {
2196                         sctp_process_inv_paramlength(asoc, param.p,
2197                                                      chunk, err_chunk);
2198                         retval = SCTP_IERROR_ABORT;
2199                 }
2200                 break;
2201 
2202         case SCTP_PARAM_HMAC_ALGO:
2203                 if (!ep->auth_enable)
2204                         goto fallthrough;
2205 
2206                 hmacs = (struct sctp_hmac_algo_param *)param.p;
2207                 n_elt = (ntohs(param.p->length) -
2208                          sizeof(struct sctp_paramhdr)) >> 1;
2209 
2210                 /* SCTP-AUTH: Section 6.1
2211                  * The HMAC algorithm based on SHA-1 MUST be supported and
2212                  * included in the HMAC-ALGO parameter.
2213                  */
2214                 for (i = 0; i < n_elt; i++) {
2215                         id = ntohs(hmacs->hmac_ids[i]);
2216 
2217                         if (id == SCTP_AUTH_HMAC_ID_SHA1)
2218                                 break;
2219                 }
2220 
2221                 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2222                         sctp_process_inv_paramlength(asoc, param.p, chunk,
2223                                                      err_chunk);
2224                         retval = SCTP_IERROR_ABORT;
2225                 }
2226                 break;
2227 fallthrough:
2228         default:
2229                 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2230                          __func__, ntohs(param.p->type), cid);
2231 
2232                 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2233                 break;
2234         }
2235         return retval;
2236 }
2237 
2238 /* Verify the INIT packet before we process it.  */
2239 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2240                      const struct sctp_association *asoc, enum sctp_cid cid,
2241                      struct sctp_init_chunk *peer_init,
2242                      struct sctp_chunk *chunk, struct sctp_chunk **errp)
2243 {
2244         union sctp_params param;
2245         bool has_cookie = false;
2246         int result;
2247 
2248         /* Check for missing mandatory parameters. Note: Initial TSN is
2249          * also mandatory, but is not checked here since the valid range
2250          * is 0..2**32-1. RFC4960, section 3.3.3.
2251          */
2252         if (peer_init->init_hdr.num_outbound_streams == 0 ||
2253             peer_init->init_hdr.num_inbound_streams == 0 ||
2254             peer_init->init_hdr.init_tag == 0 ||
2255             ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2256                 return sctp_process_inv_mandatory(asoc, chunk, errp);
2257 
2258         sctp_walk_params(param, peer_init, init_hdr.params) {
2259                 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2260                         has_cookie = true;
2261         }
2262 
2263         /* There is a possibility that a parameter length was bad and
2264          * in that case we would have stoped walking the parameters.
2265          * The current param.p would point at the bad one.
2266          * Current consensus on the mailing list is to generate a PROTOCOL
2267          * VIOLATION error.  We build the ERROR chunk here and let the normal
2268          * error handling code build and send the packet.
2269          */
2270         if (param.v != (void *)chunk->chunk_end)
2271                 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2272 
2273         /* The only missing mandatory param possible today is
2274          * the state cookie for an INIT-ACK chunk.
2275          */
2276         if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2277                 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2278                                                   chunk, errp);
2279 
2280         /* Verify all the variable length parameters */
2281         sctp_walk_params(param, peer_init, init_hdr.params) {
2282                 result = sctp_verify_param(net, ep, asoc, param, cid,
2283                                            chunk, errp);
2284                 switch (result) {
2285                 case SCTP_IERROR_ABORT:
2286                 case SCTP_IERROR_NOMEM:
2287                         return 0;
2288                 case SCTP_IERROR_ERROR:
2289                         return 1;
2290                 case SCTP_IERROR_NO_ERROR:
2291                 default:
2292                         break;
2293                 }
2294 
2295         } /* for (loop through all parameters) */
2296 
2297         return 1;
2298 }
2299 
2300 /* Unpack the parameters in an INIT packet into an association.
2301  * Returns 0 on failure, else success.
2302  * FIXME:  This is an association method.
2303  */
2304 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2305                       const union sctp_addr *peer_addr,
2306                       struct sctp_init_chunk *peer_init, gfp_t gfp)
2307 {
2308         struct net *net = sock_net(asoc->base.sk);
2309         struct sctp_transport *transport;
2310         struct list_head *pos, *temp;
2311         union sctp_params param;
2312         union sctp_addr addr;
2313         struct sctp_af *af;
2314         int src_match = 0;
2315 
2316         /* We must include the address that the INIT packet came from.
2317          * This is the only address that matters for an INIT packet.
2318          * When processing a COOKIE ECHO, we retrieve the from address
2319          * of the INIT from the cookie.
2320          */
2321 
2322         /* This implementation defaults to making the first transport
2323          * added as the primary transport.  The source address seems to
2324          * be a a better choice than any of the embedded addresses.
2325          */
2326         if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2327                 goto nomem;
2328 
2329         if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2330                 src_match = 1;
2331 
2332         /* Process the initialization parameters.  */
2333         sctp_walk_params(param, peer_init, init_hdr.params) {
2334                 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2335                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2336                         af = sctp_get_af_specific(param_type2af(param.p->type));
2337                         af->from_addr_param(&addr, param.addr,
2338                                             chunk->sctp_hdr->source, 0);
2339                         if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2340                                 src_match = 1;
2341                 }
2342 
2343                 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2344                         goto clean_up;
2345         }
2346 
2347         /* source address of chunk may not match any valid address */
2348         if (!src_match)
2349                 goto clean_up;
2350 
2351         /* AUTH: After processing the parameters, make sure that we
2352          * have all the required info to potentially do authentications.
2353          */
2354         if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2355                                         !asoc->peer.peer_hmacs))
2356                 asoc->peer.auth_capable = 0;
2357 
2358         /* In a non-backward compatible mode, if the peer claims
2359          * support for ADD-IP but not AUTH,  the ADD-IP spec states
2360          * that we MUST ABORT the association. Section 6.  The section
2361          * also give us an option to silently ignore the packet, which
2362          * is what we'll do here.
2363          */
2364         if (!net->sctp.addip_noauth &&
2365              (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2366                 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2367                                                   SCTP_PARAM_DEL_IP |
2368                                                   SCTP_PARAM_SET_PRIMARY);
2369                 asoc->peer.asconf_capable = 0;
2370                 goto clean_up;
2371         }
2372 
2373         /* Walk list of transports, removing transports in the UNKNOWN state. */
2374         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2375                 transport = list_entry(pos, struct sctp_transport, transports);
2376                 if (transport->state == SCTP_UNKNOWN) {
2377                         sctp_assoc_rm_peer(asoc, transport);
2378                 }
2379         }
2380 
2381         /* The fixed INIT headers are always in network byte
2382          * order.
2383          */
2384         asoc->peer.i.init_tag =
2385                 ntohl(peer_init->init_hdr.init_tag);
2386         asoc->peer.i.a_rwnd =
2387                 ntohl(peer_init->init_hdr.a_rwnd);
2388         asoc->peer.i.num_outbound_streams =
2389                 ntohs(peer_init->init_hdr.num_outbound_streams);
2390         asoc->peer.i.num_inbound_streams =
2391                 ntohs(peer_init->init_hdr.num_inbound_streams);
2392         asoc->peer.i.initial_tsn =
2393                 ntohl(peer_init->init_hdr.initial_tsn);
2394 
2395         asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2396 
2397         /* Apply the upper bounds for output streams based on peer's
2398          * number of inbound streams.
2399          */
2400         if (asoc->c.sinit_num_ostreams  >
2401             ntohs(peer_init->init_hdr.num_inbound_streams)) {
2402                 asoc->c.sinit_num_ostreams =
2403                         ntohs(peer_init->init_hdr.num_inbound_streams);
2404         }
2405 
2406         if (asoc->c.sinit_max_instreams >
2407             ntohs(peer_init->init_hdr.num_outbound_streams)) {
2408                 asoc->c.sinit_max_instreams =
2409                         ntohs(peer_init->init_hdr.num_outbound_streams);
2410         }
2411 
2412         /* Copy Initiation tag from INIT to VT_peer in cookie.   */
2413         asoc->c.peer_vtag = asoc->peer.i.init_tag;
2414 
2415         /* Peer Rwnd   : Current calculated value of the peer's rwnd.  */
2416         asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2417 
2418         /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2419          * high (for example, implementations MAY use the size of the receiver
2420          * advertised window).
2421          */
2422         list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2423                         transports) {
2424                 transport->ssthresh = asoc->peer.i.a_rwnd;
2425         }
2426 
2427         /* Set up the TSN tracking pieces.  */
2428         if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2429                                 asoc->peer.i.initial_tsn, gfp))
2430                 goto clean_up;
2431 
2432         /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2433          *
2434          * The stream sequence number in all the streams shall start
2435          * from 0 when the association is established.  Also, when the
2436          * stream sequence number reaches the value 65535 the next
2437          * stream sequence number shall be set to 0.
2438          */
2439 
2440         if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2441                              asoc->c.sinit_max_instreams, gfp))
2442                 goto clean_up;
2443 
2444         /* Update frag_point when stream_interleave may get changed. */
2445         sctp_assoc_update_frag_point(asoc);
2446 
2447         if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2448                 goto clean_up;
2449 
2450         /* ADDIP Section 4.1 ASCONF Chunk Procedures
2451          *
2452          * When an endpoint has an ASCONF signaled change to be sent to the
2453          * remote endpoint it should do the following:
2454          * ...
2455          * A2) A serial number should be assigned to the Chunk. The serial
2456          * number should be a monotonically increasing number. All serial
2457          * numbers are defined to be initialized at the start of the
2458          * association to the same value as the Initial TSN.
2459          */
2460         asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2461         return 1;
2462 
2463 clean_up:
2464         /* Release the transport structures. */
2465         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2466                 transport = list_entry(pos, struct sctp_transport, transports);
2467                 if (transport->state != SCTP_ACTIVE)
2468                         sctp_assoc_rm_peer(asoc, transport);
2469         }
2470 
2471 nomem:
2472         return 0;
2473 }
2474 
2475 
2476 /* Update asoc with the option described in param.
2477  *
2478  * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2479  *
2480  * asoc is the association to update.
2481  * param is the variable length parameter to use for update.
2482  * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2483  * If the current packet is an INIT we want to minimize the amount of
2484  * work we do.  In particular, we should not build transport
2485  * structures for the addresses.
2486  */
2487 static int sctp_process_param(struct sctp_association *asoc,
2488                               union sctp_params param,
2489                               const union sctp_addr *peer_addr,
2490                               gfp_t gfp)
2491 {
2492         struct net *net = sock_net(asoc->base.sk);
2493         struct sctp_endpoint *ep = asoc->ep;
2494         union sctp_addr_param *addr_param;
2495         struct sctp_transport *t;
2496         enum sctp_scope scope;
2497         union sctp_addr addr;
2498         struct sctp_af *af;
2499         int retval = 1, i;
2500         u32 stale;
2501         __u16 sat;
2502 
2503         /* We maintain all INIT parameters in network byte order all the
2504          * time.  This allows us to not worry about whether the parameters
2505          * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2506          */
2507         switch (param.p->type) {
2508         case SCTP_PARAM_IPV6_ADDRESS:
2509                 if (PF_INET6 != asoc->base.sk->sk_family)
2510                         break;
2511                 goto do_addr_param;
2512 
2513         case SCTP_PARAM_IPV4_ADDRESS:
2514                 /* v4 addresses are not allowed on v6-only socket */
2515                 if (ipv6_only_sock(asoc->base.sk))
2516                         break;
2517 do_addr_param:
2518                 af = sctp_get_af_specific(param_type2af(param.p->type));
2519                 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2520                 scope = sctp_scope(peer_addr);
2521                 if (sctp_in_scope(net, &addr, scope))
2522                         if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2523                                 return 0;
2524                 break;
2525 
2526         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2527                 if (!net->sctp.cookie_preserve_enable)
2528                         break;
2529 
2530                 stale = ntohl(param.life->lifespan_increment);
2531 
2532                 /* Suggested Cookie Life span increment's unit is msec,
2533                  * (1/1000sec).
2534                  */
2535                 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2536                 break;
2537 
2538         case SCTP_PARAM_HOST_NAME_ADDRESS:
2539                 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2540                 break;
2541 
2542         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2543                 /* Turn off the default values first so we'll know which
2544                  * ones are really set by the peer.
2545                  */
2546                 asoc->peer.ipv4_address = 0;
2547                 asoc->peer.ipv6_address = 0;
2548 
2549                 /* Assume that peer supports the address family
2550                  * by which it sends a packet.
2551                  */
2552                 if (peer_addr->sa.sa_family == AF_INET6)
2553                         asoc->peer.ipv6_address = 1;
2554                 else if (peer_addr->sa.sa_family == AF_INET)
2555                         asoc->peer.ipv4_address = 1;
2556 
2557                 /* Cycle through address types; avoid divide by 0. */
2558                 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2559                 if (sat)
2560                         sat /= sizeof(__u16);
2561 
2562                 for (i = 0; i < sat; ++i) {
2563                         switch (param.sat->types[i]) {
2564                         case SCTP_PARAM_IPV4_ADDRESS:
2565                                 asoc->peer.ipv4_address = 1;
2566                                 break;
2567 
2568                         case SCTP_PARAM_IPV6_ADDRESS:
2569                                 if (PF_INET6 == asoc->base.sk->sk_family)
2570                                         asoc->peer.ipv6_address = 1;
2571                                 break;
2572 
2573                         case SCTP_PARAM_HOST_NAME_ADDRESS:
2574                                 asoc->peer.hostname_address = 1;
2575                                 break;
2576 
2577                         default: /* Just ignore anything else.  */
2578                                 break;
2579                         }
2580                 }
2581                 break;
2582 
2583         case SCTP_PARAM_STATE_COOKIE:
2584                 asoc->peer.cookie_len =
2585                         ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2586                 if (asoc->peer.cookie)
2587                         kfree(asoc->peer.cookie);
2588                 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2589                 if (!asoc->peer.cookie)
2590                         retval = 0;
2591                 break;
2592 
2593         case SCTP_PARAM_HEARTBEAT_INFO:
2594                 /* Would be odd to receive, but it causes no problems. */
2595                 break;
2596 
2597         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2598                 /* Rejected during verify stage. */
2599                 break;
2600 
2601         case SCTP_PARAM_ECN_CAPABLE:
2602                 asoc->peer.ecn_capable = 1;
2603                 break;
2604 
2605         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2606                 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2607                 break;
2608 
2609         case SCTP_PARAM_SET_PRIMARY:
2610                 if (!net->sctp.addip_enable)
2611                         goto fall_through;
2612 
2613                 addr_param = param.v + sizeof(struct sctp_addip_param);
2614 
2615                 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2616                 if (af == NULL)
2617                         break;
2618 
2619                 af->from_addr_param(&addr, addr_param,
2620                                     htons(asoc->peer.port), 0);
2621 
2622                 /* if the address is invalid, we can't process it.
2623                  * XXX: see spec for what to do.
2624                  */
2625                 if (!af->addr_valid(&addr, NULL, NULL))
2626                         break;
2627 
2628                 t = sctp_assoc_lookup_paddr(asoc, &addr);
2629                 if (!t)
2630                         break;
2631 
2632                 sctp_assoc_set_primary(asoc, t);
2633                 break;
2634 
2635         case SCTP_PARAM_SUPPORTED_EXT:
2636                 sctp_process_ext_param(asoc, param);
2637                 break;
2638 
2639         case SCTP_PARAM_FWD_TSN_SUPPORT:
2640                 if (asoc->prsctp_enable) {
2641                         asoc->peer.prsctp_capable = 1;
2642                         break;
2643                 }
2644                 /* Fall Through */
2645                 goto fall_through;
2646 
2647         case SCTP_PARAM_RANDOM:
2648                 if (!ep->auth_enable)
2649                         goto fall_through;
2650 
2651                 /* Save peer's random parameter */
2652                 if (asoc->peer.peer_random)
2653                         kfree(asoc->peer.peer_random);
2654                 asoc->peer.peer_random = kmemdup(param.p,
2655                                             ntohs(param.p->length), gfp);
2656                 if (!asoc->peer.peer_random) {
2657                         retval = 0;
2658                         break;
2659                 }
2660                 break;
2661 
2662         case SCTP_PARAM_HMAC_ALGO:
2663                 if (!ep->auth_enable)
2664                         goto fall_through;
2665 
2666                 /* Save peer's HMAC list */
2667                 if (asoc->peer.peer_hmacs)
2668                         kfree(asoc->peer.peer_hmacs);
2669                 asoc->peer.peer_hmacs = kmemdup(param.p,
2670                                             ntohs(param.p->length), gfp);
2671                 if (!asoc->peer.peer_hmacs) {
2672                         retval = 0;
2673                         break;
2674                 }
2675 
2676                 /* Set the default HMAC the peer requested*/
2677                 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2678                 break;
2679 
2680         case SCTP_PARAM_CHUNKS:
2681                 if (!ep->auth_enable)
2682                         goto fall_through;
2683 
2684                 if (asoc->peer.peer_chunks)
2685                         kfree(asoc->peer.peer_chunks);
2686                 asoc->peer.peer_chunks = kmemdup(param.p,
2687                                             ntohs(param.p->length), gfp);
2688                 if (!asoc->peer.peer_chunks)
2689                         retval = 0;
2690                 break;
2691 fall_through:
2692         default:
2693                 /* Any unrecognized parameters should have been caught
2694                  * and handled by sctp_verify_param() which should be
2695                  * called prior to this routine.  Simply log the error
2696                  * here.
2697                  */
2698                 pr_debug("%s: ignoring param:%d for association:%p.\n",
2699                          __func__, ntohs(param.p->type), asoc);
2700                 break;
2701         }
2702 
2703         return retval;
2704 }
2705 
2706 /* Select a new verification tag.  */
2707 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2708 {
2709         /* I believe that this random number generator complies with RFC1750.
2710          * A tag of 0 is reserved for special cases (e.g. INIT).
2711          */
2712         __u32 x;
2713 
2714         do {
2715                 get_random_bytes(&x, sizeof(__u32));
2716         } while (x == 0);
2717 
2718         return x;
2719 }
2720 
2721 /* Select an initial TSN to send during startup.  */
2722 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2723 {
2724         __u32 retval;
2725 
2726         get_random_bytes(&retval, sizeof(__u32));
2727         return retval;
2728 }
2729 
2730 /*
2731  * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2732  *      0                   1                   2                   3
2733  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2734  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2735  *     | Type = 0xC1   |  Chunk Flags  |      Chunk Length             |
2736  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2737  *     |                       Serial Number                           |
2738  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2739  *     |                    Address Parameter                          |
2740  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2741  *     |                     ASCONF Parameter #1                       |
2742  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2743  *     \                                                               \
2744  *     /                             ....                              /
2745  *     \                                                               \
2746  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2747  *     |                     ASCONF Parameter #N                       |
2748  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2749  *
2750  * Address Parameter and other parameter will not be wrapped in this function
2751  */
2752 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2753                                            union sctp_addr *addr,
2754                                            int vparam_len)
2755 {
2756         struct sctp_addiphdr asconf;
2757         struct sctp_chunk *retval;
2758         int length = sizeof(asconf) + vparam_len;
2759         union sctp_addr_param addrparam;
2760         int addrlen;
2761         struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2762 
2763         addrlen = af->to_addr_param(addr, &addrparam);
2764         if (!addrlen)
2765                 return NULL;
2766         length += addrlen;
2767 
2768         /* Create the chunk.  */
2769         retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2770                                    GFP_ATOMIC);
2771         if (!retval)
2772                 return NULL;
2773 
2774         asconf.serial = htonl(asoc->addip_serial++);
2775 
2776         retval->subh.addip_hdr =
2777                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2778         retval->param_hdr.v =
2779                 sctp_addto_chunk(retval, addrlen, &addrparam);
2780 
2781         return retval;
2782 }
2783 
2784 /* ADDIP
2785  * 3.2.1 Add IP Address
2786  *      0                   1                   2                   3
2787  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2788  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2789  *     |        Type = 0xC001          |    Length = Variable          |
2790  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2791  *     |               ASCONF-Request Correlation ID                   |
2792  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2793  *     |                       Address Parameter                       |
2794  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2795  *
2796  * 3.2.2 Delete IP Address
2797  *      0                   1                   2                   3
2798  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2799  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2800  *     |        Type = 0xC002          |    Length = Variable          |
2801  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2802  *     |               ASCONF-Request Correlation ID                   |
2803  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2804  *     |                       Address Parameter                       |
2805  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2806  *
2807  */
2808 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2809                                               union sctp_addr *laddr,
2810                                               struct sockaddr *addrs,
2811                                               int addrcnt, __be16 flags)
2812 {
2813         union sctp_addr_param addr_param;
2814         struct sctp_addip_param param;
2815         int paramlen = sizeof(param);
2816         struct sctp_chunk *retval;
2817         int addr_param_len = 0;
2818         union sctp_addr *addr;
2819         int totallen = 0, i;
2820         int del_pickup = 0;
2821         struct sctp_af *af;
2822         void *addr_buf;
2823 
2824         /* Get total length of all the address parameters. */
2825         addr_buf = addrs;
2826         for (i = 0; i < addrcnt; i++) {
2827                 addr = addr_buf;
2828                 af = sctp_get_af_specific(addr->v4.sin_family);
2829                 addr_param_len = af->to_addr_param(addr, &addr_param);
2830 
2831                 totallen += paramlen;
2832                 totallen += addr_param_len;
2833 
2834                 addr_buf += af->sockaddr_len;
2835                 if (asoc->asconf_addr_del_pending && !del_pickup) {
2836                         /* reuse the parameter length from the same scope one */
2837                         totallen += paramlen;
2838                         totallen += addr_param_len;
2839                         del_pickup = 1;
2840 
2841                         pr_debug("%s: picked same-scope del_pending addr, "
2842                                  "totallen for all addresses is %d\n",
2843                                  __func__, totallen);
2844                 }
2845         }
2846 
2847         /* Create an asconf chunk with the required length. */
2848         retval = sctp_make_asconf(asoc, laddr, totallen);
2849         if (!retval)
2850                 return NULL;
2851 
2852         /* Add the address parameters to the asconf chunk. */
2853         addr_buf = addrs;
2854         for (i = 0; i < addrcnt; i++) {
2855                 addr = addr_buf;
2856                 af = sctp_get_af_specific(addr->v4.sin_family);
2857                 addr_param_len = af->to_addr_param(addr, &addr_param);
2858                 param.param_hdr.type = flags;
2859                 param.param_hdr.length = htons(paramlen + addr_param_len);
2860                 param.crr_id = htonl(i);
2861 
2862                 sctp_addto_chunk(retval, paramlen, &param);
2863                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2864 
2865                 addr_buf += af->sockaddr_len;
2866         }
2867         if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2868                 addr = asoc->asconf_addr_del_pending;
2869                 af = sctp_get_af_specific(addr->v4.sin_family);
2870                 addr_param_len = af->to_addr_param(addr, &addr_param);
2871                 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2872                 param.param_hdr.length = htons(paramlen + addr_param_len);
2873                 param.crr_id = htonl(i);
2874 
2875                 sctp_addto_chunk(retval, paramlen, &param);
2876                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2877         }
2878         return retval;
2879 }
2880 
2881 /* ADDIP
2882  * 3.2.4 Set Primary IP Address
2883  *      0                   1                   2                   3
2884  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2885  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2886  *     |        Type =0xC004           |    Length = Variable          |
2887  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2888  *     |               ASCONF-Request Correlation ID                   |
2889  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2890  *     |                       Address Parameter                       |
2891  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2892  *
2893  * Create an ASCONF chunk with Set Primary IP address parameter.
2894  */
2895 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2896                                              union sctp_addr *addr)
2897 {
2898         struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2899         union sctp_addr_param addrparam;
2900         struct sctp_addip_param param;
2901         struct sctp_chunk *retval;
2902         int len = sizeof(param);
2903         int addrlen;
2904 
2905         addrlen = af->to_addr_param(addr, &addrparam);
2906         if (!addrlen)
2907                 return NULL;
2908         len += addrlen;
2909 
2910         /* Create the chunk and make asconf header. */
2911         retval = sctp_make_asconf(asoc, addr, len);
2912         if (!retval)
2913                 return NULL;
2914 
2915         param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2916         param.param_hdr.length = htons(len);
2917         param.crr_id = 0;
2918 
2919         sctp_addto_chunk(retval, sizeof(param), &param);
2920         sctp_addto_chunk(retval, addrlen, &addrparam);
2921 
2922         return retval;
2923 }
2924 
2925 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2926  *      0                   1                   2                   3
2927  *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2928  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2929  *     | Type = 0x80   |  Chunk Flags  |      Chunk Length             |
2930  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931  *     |                       Serial Number                           |
2932  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933  *     |                 ASCONF Parameter Response#1                   |
2934  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2935  *     \                                                               \
2936  *     /                             ....                              /
2937  *     \                                                               \
2938  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2939  *     |                 ASCONF Parameter Response#N                   |
2940  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2941  *
2942  * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2943  */
2944 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2945                                                __u32 serial, int vparam_len)
2946 {
2947         struct sctp_addiphdr asconf;
2948         struct sctp_chunk *retval;
2949         int length = sizeof(asconf) + vparam_len;
2950 
2951         /* Create the chunk.  */
2952         retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2953                                    GFP_ATOMIC);
2954         if (!retval)
2955                 return NULL;
2956 
2957         asconf.serial = htonl(serial);
2958 
2959         retval->subh.addip_hdr =
2960                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2961 
2962         return retval;
2963 }
2964 
2965 /* Add response parameters to an ASCONF_ACK chunk. */
2966 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2967                                      __be16 err_code,
2968                                      struct sctp_addip_param *asconf_param)
2969 {
2970         struct sctp_addip_param ack_param;
2971         struct sctp_errhdr err_param;
2972         int asconf_param_len = 0;
2973         int err_param_len = 0;
2974         __be16 response_type;
2975 
2976         if (SCTP_ERROR_NO_ERROR == err_code) {
2977                 response_type = SCTP_PARAM_SUCCESS_REPORT;
2978         } else {
2979                 response_type = SCTP_PARAM_ERR_CAUSE;
2980                 err_param_len = sizeof(err_param);
2981                 if (asconf_param)
2982                         asconf_param_len =
2983                                  ntohs(asconf_param->param_hdr.length);
2984         }
2985 
2986         /* Add Success Indication or Error Cause Indication parameter. */
2987         ack_param.param_hdr.type = response_type;
2988         ack_param.param_hdr.length = htons(sizeof(ack_param) +
2989                                            err_param_len +
2990                                            asconf_param_len);
2991         ack_param.crr_id = crr_id;
2992         sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2993 
2994         if (SCTP_ERROR_NO_ERROR == err_code)
2995                 return;
2996 
2997         /* Add Error Cause parameter. */
2998         err_param.cause = err_code;
2999         err_param.length = htons(err_param_len + asconf_param_len);
3000         sctp_addto_chunk(chunk, err_param_len, &err_param);
3001 
3002         /* Add the failed TLV copied from ASCONF chunk. */
3003         if (asconf_param)
3004                 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3005 }
3006 
3007 /* Process a asconf parameter. */
3008 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3009                                         struct sctp_chunk *asconf,
3010                                         struct sctp_addip_param *asconf_param)
3011 {
3012         union sctp_addr_param *addr_param;
3013         struct sctp_transport *peer;
3014         union sctp_addr addr;
3015         struct sctp_af *af;
3016 
3017         addr_param = (void *)asconf_param + sizeof(*asconf_param);
3018 
3019         if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3020             asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3021             asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3022                 return SCTP_ERROR_UNKNOWN_PARAM;
3023 
3024         switch (addr_param->p.type) {
3025         case SCTP_PARAM_IPV6_ADDRESS:
3026                 if (!asoc->peer.ipv6_address)
3027                         return SCTP_ERROR_DNS_FAILED;
3028                 break;
3029         case SCTP_PARAM_IPV4_ADDRESS:
3030                 if (!asoc->peer.ipv4_address)
3031                         return SCTP_ERROR_DNS_FAILED;
3032                 break;
3033         default:
3034                 return SCTP_ERROR_DNS_FAILED;
3035         }
3036 
3037         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3038         if (unlikely(!af))
3039                 return SCTP_ERROR_DNS_FAILED;
3040 
3041         af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3042 
3043         /* ADDIP 4.2.1  This parameter MUST NOT contain a broadcast
3044          * or multicast address.
3045          * (note: wildcard is permitted and requires special handling so
3046          *  make sure we check for that)
3047          */
3048         if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3049                 return SCTP_ERROR_DNS_FAILED;
3050 
3051         switch (asconf_param->param_hdr.type) {
3052         case SCTP_PARAM_ADD_IP:
3053                 /* Section 4.2.1:
3054                  * If the address 0.0.0.0 or ::0 is provided, the source
3055                  * address of the packet MUST be added.
3056                  */
3057                 if (af->is_any(&addr))
3058                         memcpy(&addr, &asconf->source, sizeof(addr));
3059 
3060                 if (security_sctp_bind_connect(asoc->ep->base.sk,
3061                                                SCTP_PARAM_ADD_IP,
3062                                                (struct sockaddr *)&addr,
3063                                                af->sockaddr_len))
3064                         return SCTP_ERROR_REQ_REFUSED;
3065 
3066                 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3067                  * request and does not have the local resources to add this
3068                  * new address to the association, it MUST return an Error
3069                  * Cause TLV set to the new error code 'Operation Refused
3070                  * Due to Resource Shortage'.
3071                  */
3072 
3073                 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3074                 if (!peer)
3075                         return SCTP_ERROR_RSRC_LOW;
3076 
3077                 /* Start the heartbeat timer. */
3078                 sctp_transport_reset_hb_timer(peer);
3079                 asoc->new_transport = peer;
3080                 break;
3081         case SCTP_PARAM_DEL_IP:
3082                 /* ADDIP 4.3 D7) If a request is received to delete the
3083                  * last remaining IP address of a peer endpoint, the receiver
3084                  * MUST send an Error Cause TLV with the error cause set to the
3085                  * new error code 'Request to Delete Last Remaining IP Address'.
3086                  */
3087                 if (asoc->peer.transport_count == 1)
3088                         return SCTP_ERROR_DEL_LAST_IP;
3089 
3090                 /* ADDIP 4.3 D8) If a request is received to delete an IP
3091                  * address which is also the source address of the IP packet
3092                  * which contained the ASCONF chunk, the receiver MUST reject
3093                  * this request. To reject the request the receiver MUST send
3094                  * an Error Cause TLV set to the new error code 'Request to
3095                  * Delete Source IP Address'
3096                  */
3097                 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3098                         return SCTP_ERROR_DEL_SRC_IP;
3099 
3100                 /* Section 4.2.2
3101                  * If the address 0.0.0.0 or ::0 is provided, all
3102                  * addresses of the peer except the source address of the
3103                  * packet MUST be deleted.
3104                  */
3105                 if (af->is_any(&addr)) {
3106                         sctp_assoc_set_primary(asoc, asconf->transport);
3107                         sctp_assoc_del_nonprimary_peers(asoc,
3108                                                         asconf->transport);
3109                         return SCTP_ERROR_NO_ERROR;
3110                 }
3111 
3112                 /* If the address is not part of the association, the
3113                  * ASCONF-ACK with Error Cause Indication Parameter
3114                  * which including cause of Unresolvable Address should
3115                  * be sent.
3116                  */
3117                 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3118                 if (!peer)
3119                         return SCTP_ERROR_DNS_FAILED;
3120 
3121                 sctp_assoc_rm_peer(asoc, peer);
3122                 break;
3123         case SCTP_PARAM_SET_PRIMARY:
3124                 /* ADDIP Section 4.2.4
3125                  * If the address 0.0.0.0 or ::0 is provided, the receiver
3126                  * MAY mark the source address of the packet as its
3127                  * primary.
3128                  */
3129                 if (af->is_any(&addr))
3130                         memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3131 
3132                 if (security_sctp_bind_connect(asoc->ep->base.sk,
3133                                                SCTP_PARAM_SET_PRIMARY,
3134                                                (struct sockaddr *)&addr,
3135                                                af->sockaddr_len))
3136                         return SCTP_ERROR_REQ_REFUSED;
3137 
3138                 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3139                 if (!peer)
3140                         return SCTP_ERROR_DNS_FAILED;
3141 
3142                 sctp_assoc_set_primary(asoc, peer);
3143                 break;
3144         }
3145 
3146         return SCTP_ERROR_NO_ERROR;
3147 }
3148 
3149 /* Verify the ASCONF packet before we process it. */
3150 bool sctp_verify_asconf(const struct sctp_association *asoc,
3151                         struct sctp_chunk *chunk, bool addr_param_needed,
3152                         struct sctp_paramhdr **errp)
3153 {
3154         struct sctp_addip_chunk *addip;
3155         bool addr_param_seen = false;
3156         union sctp_params param;
3157 
3158         addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3159         sctp_walk_params(param, addip, addip_hdr.params) {
3160                 size_t length = ntohs(param.p->length);
3161 
3162                 *errp = param.p;
3163                 switch (param.p->type) {
3164                 case SCTP_PARAM_ERR_CAUSE:
3165                         break;
3166                 case SCTP_PARAM_IPV4_ADDRESS:
3167                         if (length != sizeof(struct sctp_ipv4addr_param))
3168                                 return false;
3169                         /* ensure there is only one addr param and it's in the
3170                          * beginning of addip_hdr params, or we reject it.
3171                          */
3172                         if (param.v != addip->addip_hdr.params)
3173                                 return false;
3174                         addr_param_seen = true;
3175                         break;
3176                 case SCTP_PARAM_IPV6_ADDRESS:
3177                         if (length != sizeof(struct sctp_ipv6addr_param))
3178                                 return false;
3179                         if (param.v != addip->addip_hdr.params)
3180                                 return false;
3181                         addr_param_seen = true;
3182                         break;
3183                 case SCTP_PARAM_ADD_IP:
3184                 case SCTP_PARAM_DEL_IP:
3185                 case SCTP_PARAM_SET_PRIMARY:
3186                         /* In ASCONF chunks, these need to be first. */
3187                         if (addr_param_needed && !addr_param_seen)
3188                                 return false;
3189                         length = ntohs(param.addip->param_hdr.length);
3190                         if (length < sizeof(struct sctp_addip_param) +
3191                                      sizeof(**errp))
3192                                 return false;
3193                         break;
3194                 case SCTP_PARAM_SUCCESS_REPORT:
3195                 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3196                         if (length != sizeof(struct sctp_addip_param))
3197                                 return false;
3198                         break;
3199                 default:
3200                         /* This is unkown to us, reject! */
3201                         return false;
3202                 }
3203         }
3204 
3205         /* Remaining sanity checks. */
3206         if (addr_param_needed && !addr_param_seen)
3207                 return false;
3208         if (!addr_param_needed && addr_param_seen)
3209                 return false;
3210         if (param.v != chunk->chunk_end)
3211                 return false;
3212 
3213         return true;
3214 }
3215 
3216 /* Process an incoming ASCONF chunk with the next expected serial no. and
3217  * return an ASCONF_ACK chunk to be sent in response.
3218  */
3219 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3220                                        struct sctp_chunk *asconf)
3221 {
3222         union sctp_addr_param *addr_param;
3223         struct sctp_addip_chunk *addip;
3224         struct sctp_chunk *asconf_ack;
3225         bool all_param_pass = true;
3226         struct sctp_addiphdr *hdr;
3227         int length = 0, chunk_len;
3228         union sctp_params param;
3229         __be16 err_code;
3230         __u32 serial;
3231 
3232         addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3233         chunk_len = ntohs(asconf->chunk_hdr->length) -
3234                     sizeof(struct sctp_chunkhdr);
3235         hdr = (struct sctp_addiphdr *)asconf->skb->data;
3236         serial = ntohl(hdr->serial);
3237 
3238         /* Skip the addiphdr and store a pointer to address parameter.  */
3239         length = sizeof(*hdr);
3240         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3241         chunk_len -= length;
3242 
3243         /* Skip the address parameter and store a pointer to the first
3244          * asconf parameter.
3245          */
3246         length = ntohs(addr_param->p.length);
3247         chunk_len -= length;
3248 
3249         /* create an ASCONF_ACK chunk.
3250          * Based on the definitions of parameters, we know that the size of
3251          * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3252          * parameters.
3253          */
3254         asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3255         if (!asconf_ack)
3256                 goto done;
3257 
3258         /* Process the TLVs contained within the ASCONF chunk. */
3259         sctp_walk_params(param, addip, addip_hdr.params) {
3260                 /* Skip preceeding address parameters. */
3261                 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3262                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3263                         continue;
3264 
3265                 err_code = sctp_process_asconf_param(asoc, asconf,
3266                                                      param.addip);
3267                 /* ADDIP 4.1 A7)
3268                  * If an error response is received for a TLV parameter,
3269                  * all TLVs with no response before the failed TLV are
3270                  * considered successful if not reported.  All TLVs after
3271                  * the failed response are considered unsuccessful unless
3272                  * a specific success indication is present for the parameter.
3273                  */
3274                 if (err_code != SCTP_ERROR_NO_ERROR)
3275                         all_param_pass = false;
3276                 if (!all_param_pass)
3277                         sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3278                                                  err_code, param.addip);
3279 
3280                 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3281                  * an IP address sends an 'Out of Resource' in its response, it
3282                  * MUST also fail any subsequent add or delete requests bundled
3283                  * in the ASCONF.
3284                  */
3285                 if (err_code == SCTP_ERROR_RSRC_LOW)
3286                         goto done;
3287         }
3288 done:
3289         asoc->peer.addip_serial++;
3290 
3291         /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3292          * after freeing the reference to old asconf ack if any.
3293          */
3294         if (asconf_ack) {
3295                 sctp_chunk_hold(asconf_ack);
3296                 list_add_tail(&asconf_ack->transmitted_list,
3297                               &asoc->asconf_ack_list);
3298         }
3299 
3300         return asconf_ack;
3301 }
3302 
3303 /* Process a asconf parameter that is successfully acked. */
3304 static void sctp_asconf_param_success(struct sctp_association *asoc,
3305                                       struct sctp_addip_param *asconf_param)
3306 {
3307         struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3308         union sctp_addr_param *addr_param;
3309         struct sctp_sockaddr_entry *saddr;
3310         struct sctp_transport *transport;
3311         union sctp_addr addr;
3312         struct sctp_af *af;
3313 
3314         addr_param = (void *)asconf_param + sizeof(*asconf_param);
3315 
3316         /* We have checked the packet before, so we do not check again. */
3317         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3318         af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3319 
3320         switch (asconf_param->param_hdr.type) {
3321         case SCTP_PARAM_ADD_IP:
3322                 /* This is always done in BH context with a socket lock
3323                  * held, so the list can not change.
3324                  */
3325                 local_bh_disable();
3326                 list_for_each_entry(saddr, &bp->address_list, list) {
3327                         if (sctp_cmp_addr_exact(&saddr->a, &addr))
3328                                 saddr->state = SCTP_ADDR_SRC;
3329                 }
3330                 local_bh_enable();
3331                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3332                                 transports) {
3333                         sctp_transport_dst_release(transport);
3334                 }
3335                 break;
3336         case SCTP_PARAM_DEL_IP:
3337                 local_bh_disable();
3338                 sctp_del_bind_addr(bp, &addr);
3339                 if (asoc->asconf_addr_del_pending != NULL &&
3340                     sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3341                         kfree(asoc->asconf_addr_del_pending);
3342                         asoc->asconf_addr_del_pending = NULL;
3343                 }
3344                 local_bh_enable();
3345                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3346                                 transports) {
3347                         sctp_transport_dst_release(transport);
3348                 }
3349                 break;
3350         default:
3351                 break;
3352         }
3353 }
3354 
3355 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3356  * for the given asconf parameter.  If there is no response for this parameter,
3357  * return the error code based on the third argument 'no_err'.
3358  * ADDIP 4.1
3359  * A7) If an error response is received for a TLV parameter, all TLVs with no
3360  * response before the failed TLV are considered successful if not reported.
3361  * All TLVs after the failed response are considered unsuccessful unless a
3362  * specific success indication is present for the parameter.
3363  */
3364 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3365                                        struct sctp_addip_param *asconf_param,
3366                                        int no_err)
3367 {
3368         struct sctp_addip_param *asconf_ack_param;
3369         struct sctp_errhdr *err_param;
3370         int asconf_ack_len;
3371         __be16 err_code;
3372         int length;
3373 
3374         if (no_err)
3375                 err_code = SCTP_ERROR_NO_ERROR;
3376         else
3377                 err_code = SCTP_ERROR_REQ_REFUSED;
3378 
3379         asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3380                          sizeof(struct sctp_chunkhdr);
3381 
3382         /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3383          * the first asconf_ack parameter.
3384          */
3385         length = sizeof(struct sctp_addiphdr);
3386         asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3387                                                        length);
3388         asconf_ack_len -= length;
3389 
3390         while (asconf_ack_len > 0) {
3391                 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3392                         switch (asconf_ack_param->param_hdr.type) {
3393                         case SCTP_PARAM_SUCCESS_REPORT:
3394                                 return SCTP_ERROR_NO_ERROR;
3395                         case SCTP_PARAM_ERR_CAUSE:
3396                                 length = sizeof(*asconf_ack_param);
3397                                 err_param = (void *)asconf_ack_param + length;
3398                                 asconf_ack_len -= length;
3399                                 if (asconf_ack_len > 0)
3400                                         return err_param->cause;
3401                                 else
3402                                         return SCTP_ERROR_INV_PARAM;
3403                                 break;
3404                         default:
3405                                 return SCTP_ERROR_INV_PARAM;
3406                         }
3407                 }
3408 
3409                 length = ntohs(asconf_ack_param->param_hdr.length);
3410                 asconf_ack_param = (void *)asconf_ack_param + length;
3411                 asconf_ack_len -= length;
3412         }
3413 
3414         return err_code;
3415 }
3416 
3417 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3418 int sctp_process_asconf_ack(struct sctp_association *asoc,
3419                             struct sctp_chunk *asconf_ack)
3420 {
3421         struct sctp_chunk *asconf = asoc->addip_last_asconf;
3422         struct sctp_addip_param *asconf_param;
3423         __be16 err_code = SCTP_ERROR_NO_ERROR;
3424         union sctp_addr_param *addr_param;
3425         int asconf_len = asconf->skb->len;
3426         int all_param_pass = 0;
3427         int length = 0;
3428         int no_err = 1;
3429         int retval = 0;
3430 
3431         /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3432          * a pointer to address parameter.
3433          */
3434         length = sizeof(struct sctp_addip_chunk);
3435         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3436         asconf_len -= length;
3437 
3438         /* Skip the address parameter in the last asconf sent and store a
3439          * pointer to the first asconf parameter.
3440          */
3441         length = ntohs(addr_param->p.length);
3442         asconf_param = (void *)addr_param + length;
3443         asconf_len -= length;
3444 
3445         /* ADDIP 4.1
3446          * A8) If there is no response(s) to specific TLV parameter(s), and no
3447          * failures are indicated, then all request(s) are considered
3448          * successful.
3449          */
3450         if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3451                 all_param_pass = 1;
3452 
3453         /* Process the TLVs contained in the last sent ASCONF chunk. */
3454         while (asconf_len > 0) {
3455                 if (all_param_pass)
3456                         err_code = SCTP_ERROR_NO_ERROR;
3457                 else {
3458                         err_code = sctp_get_asconf_response(asconf_ack,
3459                                                             asconf_param,
3460                                                             no_err);
3461                         if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3462                                 no_err = 0;
3463                 }
3464 
3465                 switch (err_code) {
3466                 case SCTP_ERROR_NO_ERROR:
3467                         sctp_asconf_param_success(asoc, asconf_param);
3468                         break;
3469 
3470                 case SCTP_ERROR_RSRC_LOW:
3471                         retval = 1;
3472                         break;
3473 
3474                 case SCTP_ERROR_UNKNOWN_PARAM:
3475                         /* Disable sending this type of asconf parameter in
3476                          * future.
3477                          */
3478                         asoc->peer.addip_disabled_mask |=
3479                                 asconf_param->param_hdr.type;
3480                         break;
3481 
3482                 case SCTP_ERROR_REQ_REFUSED:
3483                 case SCTP_ERROR_DEL_LAST_IP:
3484                 case SCTP_ERROR_DEL_SRC_IP:
3485                 default:
3486                          break;
3487                 }
3488 
3489                 /* Skip the processed asconf parameter and move to the next
3490                  * one.
3491                  */
3492                 length = ntohs(asconf_param->param_hdr.length);
3493                 asconf_param = (void *)asconf_param + length;
3494                 asconf_len -= length;
3495         }
3496 
3497         if (no_err && asoc->src_out_of_asoc_ok) {
3498                 asoc->src_out_of_asoc_ok = 0;
3499                 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3500         }
3501 
3502         /* Free the cached last sent asconf chunk. */
3503         list_del_init(&asconf->transmitted_list);
3504         sctp_chunk_free(asconf);
3505         asoc->addip_last_asconf = NULL;
3506 
3507         return retval;
3508 }
3509 
3510 /* Make a FWD TSN chunk. */
3511 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3512                                     __u32 new_cum_tsn, size_t nstreams,
3513                                     struct sctp_fwdtsn_skip *skiplist)
3514 {
3515         struct sctp_chunk *retval = NULL;
3516         struct sctp_fwdtsn_hdr ftsn_hdr;
3517         struct sctp_fwdtsn_skip skip;
3518         size_t hint;
3519         int i;
3520 
3521         hint = (nstreams + 1) * sizeof(__u32);
3522 
3523         retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3524 
3525         if (!retval)
3526                 return NULL;
3527 
3528         ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3529         retval->subh.fwdtsn_hdr =
3530                 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3531 
3532         for (i = 0; i < nstreams; i++) {
3533                 skip.stream = skiplist[i].stream;
3534                 skip.ssn = skiplist[i].ssn;
3535                 sctp_addto_chunk(retval, sizeof(skip), &skip);
3536         }
3537 
3538         return retval;
3539 }
3540 
3541 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3542                                      __u32 new_cum_tsn, size_t nstreams,
3543                                      struct sctp_ifwdtsn_skip *skiplist)
3544 {
3545         struct sctp_chunk *retval = NULL;
3546         struct sctp_ifwdtsn_hdr ftsn_hdr;
3547         size_t hint;
3548 
3549         hint = (nstreams + 1) * sizeof(__u32);
3550 
3551         retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3552                                    GFP_ATOMIC);
3553         if (!retval)
3554                 return NULL;
3555 
3556         ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3557         retval->subh.ifwdtsn_hdr =
3558                 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3559 
3560         sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3561 
3562         return retval;
3563 }
3564 
3565 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
3566  *   0                   1                   2                   3
3567  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3568  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3569  *  | Type = 130    |  Chunk Flags  |      Chunk Length             |
3570  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3571  *  \                                                               \
3572  *  /                  Re-configuration Parameter                   /
3573  *  \                                                               \
3574  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3575  *  \                                                               \
3576  *  /             Re-configuration Parameter (optional)             /
3577  *  \                                                               \
3578  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3579  */
3580 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3581                                            int length)
3582 {
3583         struct sctp_reconf_chunk *reconf;
3584         struct sctp_chunk *retval;
3585 
3586         retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3587                                    GFP_ATOMIC);
3588         if (!retval)
3589                 return NULL;
3590 
3591         reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3592         retval->param_hdr.v = reconf->params;
3593 
3594         return retval;
3595 }
3596 
3597 /* RE-CONFIG 4.1 (STREAM OUT RESET)
3598  *   0                   1                   2                   3
3599  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3600  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3601  *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
3602  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3603  *  |           Re-configuration Request Sequence Number            |
3604  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3605  *  |           Re-configuration Response Sequence Number           |
3606  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3607  *  |                Sender's Last Assigned TSN                     |
3608  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3609  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3610  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3611  *  /                            ......                             /
3612  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3613  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3614  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3615  *
3616  * RE-CONFIG 4.2 (STREAM IN RESET)
3617  *   0                   1                   2                   3
3618  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3619  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3620  *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
3621  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3622  *  |          Re-configuration Request Sequence Number             |
3623  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3624  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3625  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3626  *  /                            ......                             /
3627  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3628  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3629  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3630  */
3631 struct sctp_chunk *sctp_make_strreset_req(
3632                                         const struct sctp_association *asoc,
3633                                         __u16 stream_num, __be16 *stream_list,
3634                                         bool out, bool in)
3635 {
3636         __u16 stream_len = stream_num * sizeof(__u16);
3637         struct sctp_strreset_outreq outreq;
3638         struct sctp_strreset_inreq inreq;
3639         struct sctp_chunk *retval;
3640         __u16 outlen, inlen;
3641 
3642         outlen = (sizeof(outreq) + stream_len) * out;
3643         inlen = (sizeof(inreq) + stream_len) * in;
3644 
3645         retval = sctp_make_reconf(asoc, outlen + inlen);
3646         if (!retval)
3647                 return NULL;
3648 
3649         if (outlen) {
3650                 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3651                 outreq.param_hdr.length = htons(outlen);
3652                 outreq.request_seq = htonl(asoc->strreset_outseq);
3653                 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3654                 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3655 
3656                 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3657 
3658                 if (stream_len)
3659                         sctp_addto_chunk(retval, stream_len, stream_list);
3660         }
3661 
3662         if (inlen) {
3663                 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3664                 inreq.param_hdr.length = htons(inlen);
3665                 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3666 
3667                 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3668 
3669                 if (stream_len)
3670                         sctp_addto_chunk(retval, stream_len, stream_list);
3671         }
3672 
3673         return retval;
3674 }
3675 
3676 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3677  *   0                   1                   2                   3
3678  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3679  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3680  *  |     Parameter Type = 15       |      Parameter Length = 8     |
3681  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3682  *  |         Re-configuration Request Sequence Number              |
3683  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3684  */
3685 struct sctp_chunk *sctp_make_strreset_tsnreq(
3686                                         const struct sctp_association *asoc)
3687 {
3688         struct sctp_strreset_tsnreq tsnreq;
3689         __u16 length = sizeof(tsnreq);
3690         struct sctp_chunk *retval;
3691 
3692         retval = sctp_make_reconf(asoc, length);
3693         if (!retval)
3694                 return NULL;
3695 
3696         tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3697         tsnreq.param_hdr.length = htons(length);
3698         tsnreq.request_seq = htonl(asoc->strreset_outseq);
3699 
3700         sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3701 
3702         return retval;
3703 }
3704 
3705 /* RE-CONFIG 4.5/4.6 (ADD STREAM)
3706  *   0                   1                   2                   3
3707  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3708  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3709  *  |     Parameter Type = 17       |      Parameter Length = 12    |
3710  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3711  *  |          Re-configuration Request Sequence Number             |
3712  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3713  *  |      Number of new streams    |         Reserved              |
3714  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3715  */
3716 struct sctp_chunk *sctp_make_strreset_addstrm(
3717                                         const struct sctp_association *asoc,
3718                                         __u16 out, __u16 in)
3719 {
3720         struct sctp_strreset_addstrm addstrm;
3721         __u16 size = sizeof(addstrm);
3722         struct sctp_chunk *retval;
3723 
3724         retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3725         if (!retval)
3726                 return NULL;
3727 
3728         if (out) {
3729                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3730                 addstrm.param_hdr.length = htons(size);
3731                 addstrm.number_of_streams = htons(out);
3732                 addstrm.request_seq = htonl(asoc->strreset_outseq);
3733                 addstrm.reserved = 0;
3734 
3735                 sctp_addto_chunk(retval, size, &addstrm);
3736         }
3737 
3738         if (in) {
3739                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3740                 addstrm.param_hdr.length = htons(size);
3741                 addstrm.number_of_streams = htons(in);
3742                 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3743                 addstrm.reserved = 0;
3744 
3745                 sctp_addto_chunk(retval, size, &addstrm);
3746         }
3747 
3748         return retval;
3749 }
3750 
3751 /* RE-CONFIG 4.4 (RESP)
3752  *   0                   1                   2                   3
3753  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3754  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3755  *  |     Parameter Type = 16       |      Parameter Length         |
3756  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3757  *  |         Re-configuration Response Sequence Number             |
3758  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3759  *  |                            Result                             |
3760  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3761  */
3762 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3763                                            __u32 result, __u32 sn)
3764 {
3765         struct sctp_strreset_resp resp;
3766         __u16 length = sizeof(resp);
3767         struct sctp_chunk *retval;
3768 
3769         retval = sctp_make_reconf(asoc, length);
3770         if (!retval)
3771                 return NULL;
3772 
3773         resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3774         resp.param_hdr.length = htons(length);
3775         resp.response_seq = htonl(sn);
3776         resp.result = htonl(result);
3777 
3778         sctp_addto_chunk(retval, sizeof(resp), &resp);
3779 
3780         return retval;
3781 }
3782 
3783 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3784  *   0                   1                   2                   3
3785  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3786  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3787  *  |     Parameter Type = 16       |      Parameter Length         |
3788  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3789  *  |         Re-configuration Response Sequence Number             |
3790  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3791  *  |                            Result                             |
3792  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3793  *  |                   Sender's Next TSN (optional)                |
3794  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3795  *  |                  Receiver's Next TSN (optional)               |
3796  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3797  */
3798 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3799                                               __u32 result, __u32 sn,
3800                                               __u32 sender_tsn,
3801                                               __u32 receiver_tsn)
3802 {
3803         struct sctp_strreset_resptsn tsnresp;
3804         __u16 length = sizeof(tsnresp);
3805         struct sctp_chunk *retval;
3806 
3807         retval = sctp_make_reconf(asoc, length);
3808         if (!retval)
3809                 return NULL;
3810 
3811         tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3812         tsnresp.param_hdr.length = htons(length);
3813 
3814         tsnresp.response_seq = htonl(sn);
3815         tsnresp.result = htonl(result);
3816         tsnresp.senders_next_tsn = htonl(sender_tsn);
3817         tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3818 
3819         sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3820 
3821         return retval;
3822 }
3823 
3824 bool sctp_verify_reconf(const struct sctp_association *asoc,
3825                         struct sctp_chunk *chunk,
3826                         struct sctp_paramhdr **errp)
3827 {
3828         struct sctp_reconf_chunk *hdr;
3829         union sctp_params param;
3830         __be16 last = 0;
3831         __u16 cnt = 0;
3832 
3833         hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3834         sctp_walk_params(param, hdr, params) {
3835                 __u16 length = ntohs(param.p->length);
3836 
3837                 *errp = param.p;
3838                 if (cnt++ > 2)
3839                         return false;
3840                 switch (param.p->type) {
3841                 case SCTP_PARAM_RESET_OUT_REQUEST:
3842                         if (length < sizeof(struct sctp_strreset_outreq) ||
3843                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3844                              last != SCTP_PARAM_RESET_IN_REQUEST))
3845                                 return false;
3846                         break;
3847                 case SCTP_PARAM_RESET_IN_REQUEST:
3848                         if (length < sizeof(struct sctp_strreset_inreq) ||
3849                             (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3850                                 return false;
3851                         break;
3852                 case SCTP_PARAM_RESET_RESPONSE:
3853                         if ((length != sizeof(struct sctp_strreset_resp) &&
3854                              length != sizeof(struct sctp_strreset_resptsn)) ||
3855                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3856                              last != SCTP_PARAM_RESET_OUT_REQUEST))
3857                                 return false;
3858                         break;
3859                 case SCTP_PARAM_RESET_TSN_REQUEST:
3860                         if (length !=
3861                             sizeof(struct sctp_strreset_tsnreq) || last)
3862                                 return false;
3863                         break;
3864                 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3865                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3866                             (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3867                                 return false;
3868                         break;
3869                 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3870                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3871                             (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3872                                 return false;
3873                         break;
3874                 default:
3875                         return false;
3876                 }
3877 
3878                 last = param.p->type;
3879         }
3880 
3881         return true;
3882 }
3883 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp