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

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

Version: ~ [ linux-5.12-rc7 ] ~ [ linux-5.11.13 ] ~ [ linux-5.10.29 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.111 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.186 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.230 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.266 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.266 ] ~ [ 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 /* SCTP kernel implementation
  2  * (C) Copyright IBM Corp. 2001, 2004
  3  * Copyright (c) 1999-2000 Cisco, Inc.
  4  * Copyright (c) 1999-2001 Motorola, Inc.
  5  * Copyright (c) 2001-2002 Intel Corp.
  6  *
  7  * This file is part of the SCTP kernel implementation
  8  *
  9  * These functions work with the state functions in sctp_sm_statefuns.c
 10  * to implement the state operations.  These functions implement the
 11  * steps which require modifying existing data structures.
 12  *
 13  * This SCTP implementation is free software;
 14  * you can redistribute it and/or modify it under the terms of
 15  * the GNU General Public License as published by
 16  * the Free Software Foundation; either version 2, or (at your option)
 17  * any later version.
 18  *
 19  * This SCTP implementation is distributed in the hope that it
 20  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 21  *                 ************************
 22  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 23  * See the GNU General Public License for more details.
 24  *
 25  * You should have received a copy of the GNU General Public License
 26  * along with GNU CC; see the file COPYING.  If not, see
 27  * <http://www.gnu.org/licenses/>.
 28  *
 29  * Please send any bug reports or fixes you make to the
 30  * email address(es):
 31  *    lksctp developers <linux-sctp@vger.kernel.org>
 32  *
 33  * Written or modified by:
 34  *    La Monte H.P. Yarroll <piggy@acm.org>
 35  *    Karl Knutson          <karl@athena.chicago.il.us>
 36  *    C. Robin              <chris@hundredacre.ac.uk>
 37  *    Jon Grimm             <jgrimm@us.ibm.com>
 38  *    Xingang Guo           <xingang.guo@intel.com>
 39  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
 40  *    Sridhar Samudrala     <sri@us.ibm.com>
 41  *    Daisy Chang           <daisyc@us.ibm.com>
 42  *    Ardelle Fan           <ardelle.fan@intel.com>
 43  *    Kevin Gao             <kevin.gao@intel.com>
 44  */
 45 
 46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 47 
 48 #include <crypto/hash.h>
 49 #include <linux/types.h>
 50 #include <linux/kernel.h>
 51 #include <linux/ip.h>
 52 #include <linux/ipv6.h>
 53 #include <linux/net.h>
 54 #include <linux/inet.h>
 55 #include <linux/scatterlist.h>
 56 #include <linux/slab.h>
 57 #include <net/sock.h>
 58 
 59 #include <linux/skbuff.h>
 60 #include <linux/random.h>       /* for get_random_bytes */
 61 #include <net/sctp/sctp.h>
 62 #include <net/sctp/sm.h>
 63 
 64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
 65                                             __u8 type, __u8 flags, int paylen,
 66                                             gfp_t gfp);
 67 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
 68                                          __u8 flags, int paylen, gfp_t gfp);
 69 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
 70                                            __u8 type, __u8 flags, int paylen,
 71                                            gfp_t gfp);
 72 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
 73                                         const struct sctp_association *asoc,
 74                                         const struct sctp_chunk *init_chunk,
 75                                         int *cookie_len,
 76                                         const __u8 *raw_addrs, int addrs_len);
 77 static int sctp_process_param(struct sctp_association *asoc,
 78                               union sctp_params param,
 79                               const union sctp_addr *peer_addr,
 80                               gfp_t gfp);
 81 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
 82                               const void *data);
 83 static void  *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
 84                                      const void *data);
 85 
 86 /* Control chunk destructor */
 87 static void sctp_control_release_owner(struct sk_buff *skb)
 88 {
 89         /*TODO: do memory release */
 90 }
 91 
 92 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
 93 {
 94         struct sctp_association *asoc = chunk->asoc;
 95         struct sk_buff *skb = chunk->skb;
 96 
 97         /* TODO: properly account for control chunks.
 98          * To do it right we'll need:
 99          *  1) endpoint if association isn't known.
100          *  2) proper memory accounting.
101          *
102          *  For now don't do anything for now.
103          */
104         skb->sk = asoc ? asoc->base.sk : NULL;
105         skb->destructor = sctp_control_release_owner;
106 }
107 
108 /* What was the inbound interface for this chunk? */
109 int sctp_chunk_iif(const struct sctp_chunk *chunk)
110 {
111         struct sk_buff *skb = chunk->skb;
112 
113         return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
114 }
115 
116 /* RFC 2960 3.3.2 Initiation (INIT) (1)
117  *
118  * Note 2: The ECN capable field is reserved for future use of
119  * Explicit Congestion Notification.
120  */
121 static const struct sctp_paramhdr ecap_param = {
122         SCTP_PARAM_ECN_CAPABLE,
123         cpu_to_be16(sizeof(struct sctp_paramhdr)),
124 };
125 static const struct sctp_paramhdr prsctp_param = {
126         SCTP_PARAM_FWD_TSN_SUPPORT,
127         cpu_to_be16(sizeof(struct sctp_paramhdr)),
128 };
129 
130 /* A helper to initialize an op error inside a
131  * provided chunk, as most cause codes will be embedded inside an
132  * abort chunk.
133  */
134 void  sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
135                       size_t paylen)
136 {
137         sctp_errhdr_t err;
138         __u16 len;
139 
140         /* Cause code constants are now defined in network order.  */
141         err.cause = cause_code;
142         len = sizeof(sctp_errhdr_t) + paylen;
143         err.length  = htons(len);
144         chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
145 }
146 
147 /* A helper to initialize an op error inside a
148  * provided chunk, as most cause codes will be embedded inside an
149  * abort chunk.  Differs from sctp_init_cause in that it won't oops
150  * if there isn't enough space in the op error chunk
151  */
152 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
153                       size_t paylen)
154 {
155         sctp_errhdr_t err;
156         __u16 len;
157 
158         /* Cause code constants are now defined in network order.  */
159         err.cause = cause_code;
160         len = sizeof(sctp_errhdr_t) + paylen;
161         err.length  = htons(len);
162 
163         if (skb_tailroom(chunk->skb) < len)
164                 return -ENOSPC;
165         chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
166                                                      sizeof(sctp_errhdr_t),
167                                                      &err);
168         return 0;
169 }
170 /* 3.3.2 Initiation (INIT) (1)
171  *
172  * This chunk is used to initiate a SCTP association between two
173  * endpoints. The format of the INIT chunk is shown below:
174  *
175  *     0                   1                   2                   3
176  *     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
177  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178  *    |   Type = 1    |  Chunk Flags  |      Chunk Length             |
179  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180  *    |                         Initiate Tag                          |
181  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
182  *    |           Advertised Receiver Window Credit (a_rwnd)          |
183  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184  *    |  Number of Outbound Streams   |  Number of Inbound Streams    |
185  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
186  *    |                          Initial TSN                          |
187  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
188  *    \                                                               \
189  *    /              Optional/Variable-Length Parameters              /
190  *    \                                                               \
191  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
192  *
193  *
194  * The INIT chunk contains the following parameters. Unless otherwise
195  * noted, each parameter MUST only be included once in the INIT chunk.
196  *
197  * Fixed Parameters                     Status
198  * ----------------------------------------------
199  * Initiate Tag                        Mandatory
200  * Advertised Receiver Window Credit   Mandatory
201  * Number of Outbound Streams          Mandatory
202  * Number of Inbound Streams           Mandatory
203  * Initial TSN                         Mandatory
204  *
205  * Variable Parameters                  Status     Type Value
206  * -------------------------------------------------------------
207  * IPv4 Address (Note 1)               Optional    5
208  * IPv6 Address (Note 1)               Optional    6
209  * Cookie Preservative                 Optional    9
210  * Reserved for ECN Capable (Note 2)   Optional    32768 (0x8000)
211  * Host Name Address (Note 3)          Optional    11
212  * Supported Address Types (Note 4)    Optional    12
213  */
214 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
215                              const struct sctp_bind_addr *bp,
216                              gfp_t gfp, int vparam_len)
217 {
218         struct net *net = sock_net(asoc->base.sk);
219         struct sctp_endpoint *ep = asoc->ep;
220         sctp_inithdr_t init;
221         union sctp_params addrs;
222         size_t chunksize;
223         struct sctp_chunk *retval = NULL;
224         int num_types, addrs_len = 0;
225         struct sctp_sock *sp;
226         sctp_supported_addrs_param_t sat;
227         __be16 types[2];
228         sctp_adaptation_ind_param_t aiparam;
229         sctp_supported_ext_param_t ext_param;
230         int num_ext = 0;
231         __u8 extensions[3];
232         sctp_paramhdr_t *auth_chunks = NULL,
233                         *auth_hmacs = NULL;
234 
235         /* RFC 2960 3.3.2 Initiation (INIT) (1)
236          *
237          * Note 1: The INIT chunks can contain multiple addresses that
238          * can be IPv4 and/or IPv6 in any combination.
239          */
240         retval = NULL;
241 
242         /* Convert the provided bind address list to raw format. */
243         addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
244 
245         init.init_tag              = htonl(asoc->c.my_vtag);
246         init.a_rwnd                = htonl(asoc->rwnd);
247         init.num_outbound_streams  = htons(asoc->c.sinit_num_ostreams);
248         init.num_inbound_streams   = htons(asoc->c.sinit_max_instreams);
249         init.initial_tsn           = htonl(asoc->c.initial_tsn);
250 
251         /* How many address types are needed? */
252         sp = sctp_sk(asoc->base.sk);
253         num_types = sp->pf->supported_addrs(sp, types);
254 
255         chunksize = sizeof(init) + addrs_len;
256         chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
257         chunksize += sizeof(ecap_param);
258 
259         if (asoc->prsctp_enable)
260                 chunksize += sizeof(prsctp_param);
261 
262         /* ADDIP: Section 4.2.7:
263          *  An implementation supporting this extension [ADDIP] MUST list
264          *  the ASCONF,the ASCONF-ACK, and the AUTH  chunks in its INIT and
265          *  INIT-ACK parameters.
266          */
267         if (net->sctp.addip_enable) {
268                 extensions[num_ext] = SCTP_CID_ASCONF;
269                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
270                 num_ext += 2;
271         }
272 
273         if (asoc->reconf_enable) {
274                 extensions[num_ext] = SCTP_CID_RECONF;
275                 num_ext += 1;
276         }
277 
278         if (sp->adaptation_ind)
279                 chunksize += sizeof(aiparam);
280 
281         chunksize += vparam_len;
282 
283         /* Account for AUTH related parameters */
284         if (ep->auth_enable) {
285                 /* Add random parameter length*/
286                 chunksize += sizeof(asoc->c.auth_random);
287 
288                 /* Add HMACS parameter length if any were defined */
289                 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
290                 if (auth_hmacs->length)
291                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
292                 else
293                         auth_hmacs = NULL;
294 
295                 /* Add CHUNKS parameter length */
296                 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
297                 if (auth_chunks->length)
298                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
299                 else
300                         auth_chunks = NULL;
301 
302                 extensions[num_ext] = SCTP_CID_AUTH;
303                 num_ext += 1;
304         }
305 
306         /* If we have any extensions to report, account for that */
307         if (num_ext)
308                 chunksize += SCTP_PAD4(sizeof(sctp_supported_ext_param_t) +
309                                        num_ext);
310 
311         /* RFC 2960 3.3.2 Initiation (INIT) (1)
312          *
313          * Note 3: An INIT chunk MUST NOT contain more than one Host
314          * Name address parameter. Moreover, the sender of the INIT
315          * MUST NOT combine any other address types with the Host Name
316          * address in the INIT. The receiver of INIT MUST ignore any
317          * other address types if the Host Name address parameter is
318          * present in the received INIT chunk.
319          *
320          * PLEASE DO NOT FIXME [This version does not support Host Name.]
321          */
322 
323         retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
324         if (!retval)
325                 goto nodata;
326 
327         retval->subh.init_hdr =
328                 sctp_addto_chunk(retval, sizeof(init), &init);
329         retval->param_hdr.v =
330                 sctp_addto_chunk(retval, addrs_len, addrs.v);
331 
332         /* RFC 2960 3.3.2 Initiation (INIT) (1)
333          *
334          * Note 4: This parameter, when present, specifies all the
335          * address types the sending endpoint can support. The absence
336          * of this parameter indicates that the sending endpoint can
337          * support any address type.
338          */
339         sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
340         sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
341         sctp_addto_chunk(retval, sizeof(sat), &sat);
342         sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
343 
344         sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
345 
346         /* Add the supported extensions parameter.  Be nice and add this
347          * fist before addiding the parameters for the extensions themselves
348          */
349         if (num_ext) {
350                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
351                 ext_param.param_hdr.length =
352                             htons(sizeof(sctp_supported_ext_param_t) + num_ext);
353                 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
354                                 &ext_param);
355                 sctp_addto_param(retval, num_ext, extensions);
356         }
357 
358         if (asoc->prsctp_enable)
359                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
360 
361         if (sp->adaptation_ind) {
362                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
363                 aiparam.param_hdr.length = htons(sizeof(aiparam));
364                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
365                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
366         }
367 
368         /* Add SCTP-AUTH chunks to the parameter list */
369         if (ep->auth_enable) {
370                 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
371                                  asoc->c.auth_random);
372                 if (auth_hmacs)
373                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
374                                         auth_hmacs);
375                 if (auth_chunks)
376                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
377                                         auth_chunks);
378         }
379 nodata:
380         kfree(addrs.v);
381         return retval;
382 }
383 
384 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
385                                  const struct sctp_chunk *chunk,
386                                  gfp_t gfp, int unkparam_len)
387 {
388         sctp_inithdr_t initack;
389         struct sctp_chunk *retval;
390         union sctp_params addrs;
391         struct sctp_sock *sp;
392         int addrs_len;
393         sctp_cookie_param_t *cookie;
394         int cookie_len;
395         size_t chunksize;
396         sctp_adaptation_ind_param_t aiparam;
397         sctp_supported_ext_param_t ext_param;
398         int num_ext = 0;
399         __u8 extensions[3];
400         sctp_paramhdr_t *auth_chunks = NULL,
401                         *auth_hmacs = NULL,
402                         *auth_random = NULL;
403 
404         retval = NULL;
405 
406         /* Note: there may be no addresses to embed. */
407         addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
408 
409         initack.init_tag                = htonl(asoc->c.my_vtag);
410         initack.a_rwnd                  = htonl(asoc->rwnd);
411         initack.num_outbound_streams    = htons(asoc->c.sinit_num_ostreams);
412         initack.num_inbound_streams     = htons(asoc->c.sinit_max_instreams);
413         initack.initial_tsn             = htonl(asoc->c.initial_tsn);
414 
415         /* FIXME:  We really ought to build the cookie right
416          * into the packet instead of allocating more fresh memory.
417          */
418         cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
419                                   addrs.v, addrs_len);
420         if (!cookie)
421                 goto nomem_cookie;
422 
423         /* Calculate the total size of allocation, include the reserved
424          * space for reporting unknown parameters if it is specified.
425          */
426         sp = sctp_sk(asoc->base.sk);
427         chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
428 
429         /* Tell peer that we'll do ECN only if peer advertised such cap.  */
430         if (asoc->peer.ecn_capable)
431                 chunksize += sizeof(ecap_param);
432 
433         if (asoc->peer.prsctp_capable)
434                 chunksize += sizeof(prsctp_param);
435 
436         if (asoc->peer.asconf_capable) {
437                 extensions[num_ext] = SCTP_CID_ASCONF;
438                 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
439                 num_ext += 2;
440         }
441 
442         if (asoc->peer.reconf_capable) {
443                 extensions[num_ext] = SCTP_CID_RECONF;
444                 num_ext += 1;
445         }
446 
447         if (sp->adaptation_ind)
448                 chunksize += sizeof(aiparam);
449 
450         if (asoc->peer.auth_capable) {
451                 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
452                 chunksize += ntohs(auth_random->length);
453 
454                 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
455                 if (auth_hmacs->length)
456                         chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
457                 else
458                         auth_hmacs = NULL;
459 
460                 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
461                 if (auth_chunks->length)
462                         chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
463                 else
464                         auth_chunks = NULL;
465 
466                 extensions[num_ext] = SCTP_CID_AUTH;
467                 num_ext += 1;
468         }
469 
470         if (num_ext)
471                 chunksize += SCTP_PAD4(sizeof(sctp_supported_ext_param_t) +
472                                        num_ext);
473 
474         /* Now allocate and fill out the chunk.  */
475         retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
476         if (!retval)
477                 goto nomem_chunk;
478 
479         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
480          *
481          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
482          * HEARTBEAT ACK, * etc.) to the same destination transport
483          * address from which it received the DATA or control chunk
484          * to which it is replying.
485          *
486          * [INIT ACK back to where the INIT came from.]
487          */
488         retval->transport = chunk->transport;
489 
490         retval->subh.init_hdr =
491                 sctp_addto_chunk(retval, sizeof(initack), &initack);
492         retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
493         sctp_addto_chunk(retval, cookie_len, cookie);
494         if (asoc->peer.ecn_capable)
495                 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
496         if (num_ext) {
497                 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
498                 ext_param.param_hdr.length =
499                             htons(sizeof(sctp_supported_ext_param_t) + num_ext);
500                 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
501                                  &ext_param);
502                 sctp_addto_param(retval, num_ext, extensions);
503         }
504         if (asoc->peer.prsctp_capable)
505                 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
506 
507         if (sp->adaptation_ind) {
508                 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
509                 aiparam.param_hdr.length = htons(sizeof(aiparam));
510                 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
511                 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
512         }
513 
514         if (asoc->peer.auth_capable) {
515                 sctp_addto_chunk(retval, ntohs(auth_random->length),
516                                  auth_random);
517                 if (auth_hmacs)
518                         sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
519                                         auth_hmacs);
520                 if (auth_chunks)
521                         sctp_addto_chunk(retval, ntohs(auth_chunks->length),
522                                         auth_chunks);
523         }
524 
525         /* We need to remove the const qualifier at this point.  */
526         retval->asoc = (struct sctp_association *) asoc;
527 
528 nomem_chunk:
529         kfree(cookie);
530 nomem_cookie:
531         kfree(addrs.v);
532         return retval;
533 }
534 
535 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
536  *
537  * This chunk is used only during the initialization of an association.
538  * It is sent by the initiator of an association to its peer to complete
539  * the initialization process. This chunk MUST precede any DATA chunk
540  * sent within the association, but MAY be bundled with one or more DATA
541  * chunks in the same packet.
542  *
543  *      0                   1                   2                   3
544  *      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
545  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546  *     |   Type = 10   |Chunk  Flags   |         Length                |
547  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
548  *     /                     Cookie                                    /
549  *     \                                                               \
550  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
551  *
552  * Chunk Flags: 8 bit
553  *
554  *   Set to zero on transmit and ignored on receipt.
555  *
556  * Length: 16 bits (unsigned integer)
557  *
558  *   Set to the size of the chunk in bytes, including the 4 bytes of
559  *   the chunk header and the size of the Cookie.
560  *
561  * Cookie: variable size
562  *
563  *   This field must contain the exact cookie received in the
564  *   State Cookie parameter from the previous INIT ACK.
565  *
566  *   An implementation SHOULD make the cookie as small as possible
567  *   to insure interoperability.
568  */
569 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
570                                     const struct sctp_chunk *chunk)
571 {
572         struct sctp_chunk *retval;
573         void *cookie;
574         int cookie_len;
575 
576         cookie = asoc->peer.cookie;
577         cookie_len = asoc->peer.cookie_len;
578 
579         /* Build a cookie echo chunk.  */
580         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
581                                    cookie_len, GFP_ATOMIC);
582         if (!retval)
583                 goto nodata;
584         retval->subh.cookie_hdr =
585                 sctp_addto_chunk(retval, cookie_len, cookie);
586 
587         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
588          *
589          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
590          * HEARTBEAT ACK, * etc.) to the same destination transport
591          * address from which it * received the DATA or control chunk
592          * to which it is replying.
593          *
594          * [COOKIE ECHO back to where the INIT ACK came from.]
595          */
596         if (chunk)
597                 retval->transport = chunk->transport;
598 
599 nodata:
600         return retval;
601 }
602 
603 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
604  *
605  * This chunk is used only during the initialization of an
606  * association.  It is used to acknowledge the receipt of a COOKIE
607  * ECHO chunk.  This chunk MUST precede any DATA or SACK chunk sent
608  * within the association, but MAY be bundled with one or more DATA
609  * chunks or SACK chunk in the same SCTP packet.
610  *
611  *      0                   1                   2                   3
612  *      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
613  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
614  *     |   Type = 11   |Chunk  Flags   |     Length = 4                |
615  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
616  *
617  * Chunk Flags: 8 bits
618  *
619  *   Set to zero on transmit and ignored on receipt.
620  */
621 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
622                                    const struct sctp_chunk *chunk)
623 {
624         struct sctp_chunk *retval;
625 
626         retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
627 
628         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
629          *
630          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
631          * HEARTBEAT ACK, * etc.) to the same destination transport
632          * address from which it * received the DATA or control chunk
633          * to which it is replying.
634          *
635          * [COOKIE ACK back to where the COOKIE ECHO came from.]
636          */
637         if (retval && chunk)
638                 retval->transport = chunk->transport;
639 
640         return retval;
641 }
642 
643 /*
644  *  Appendix A: Explicit Congestion Notification:
645  *  CWR:
646  *
647  *  RFC 2481 details a specific bit for a sender to send in the header of
648  *  its next outbound TCP segment to indicate to its peer that it has
649  *  reduced its congestion window.  This is termed the CWR bit.  For
650  *  SCTP the same indication is made by including the CWR chunk.
651  *  This chunk contains one data element, i.e. the TSN number that
652  *  was sent in the ECNE chunk.  This element represents the lowest
653  *  TSN number in the datagram that was originally marked with the
654  *  CE bit.
655  *
656  *     0                   1                   2                   3
657  *     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
658  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659  *    | Chunk Type=13 | Flags=00000000|    Chunk Length = 8           |
660  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661  *    |                      Lowest TSN Number                        |
662  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
663  *
664  *     Note: The CWR is considered a Control chunk.
665  */
666 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
667                             const __u32 lowest_tsn,
668                             const struct sctp_chunk *chunk)
669 {
670         struct sctp_chunk *retval;
671         sctp_cwrhdr_t cwr;
672 
673         cwr.lowest_tsn = htonl(lowest_tsn);
674         retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
675                                    sizeof(sctp_cwrhdr_t), GFP_ATOMIC);
676 
677         if (!retval)
678                 goto nodata;
679 
680         retval->subh.ecn_cwr_hdr =
681                 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
682 
683         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
684          *
685          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
686          * HEARTBEAT ACK, * etc.) to the same destination transport
687          * address from which it * received the DATA or control chunk
688          * to which it is replying.
689          *
690          * [Report a reduced congestion window back to where the ECNE
691          * came from.]
692          */
693         if (chunk)
694                 retval->transport = chunk->transport;
695 
696 nodata:
697         return retval;
698 }
699 
700 /* Make an ECNE chunk.  This is a congestion experienced report.  */
701 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
702                              const __u32 lowest_tsn)
703 {
704         struct sctp_chunk *retval;
705         sctp_ecnehdr_t ecne;
706 
707         ecne.lowest_tsn = htonl(lowest_tsn);
708         retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
709                                    sizeof(sctp_ecnehdr_t), GFP_ATOMIC);
710         if (!retval)
711                 goto nodata;
712         retval->subh.ecne_hdr =
713                 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
714 
715 nodata:
716         return retval;
717 }
718 
719 /* Make a DATA chunk for the given association from the provided
720  * parameters.  However, do not populate the data payload.
721  */
722 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
723                                        const struct sctp_sndrcvinfo *sinfo,
724                                        int data_len, __u8 flags, __u16 ssn,
725                                        gfp_t gfp)
726 {
727         struct sctp_chunk *retval;
728         struct sctp_datahdr dp;
729         int chunk_len;
730 
731         /* We assign the TSN as LATE as possible, not here when
732          * creating the chunk.
733          */
734         dp.tsn = 0;
735         dp.stream = htons(sinfo->sinfo_stream);
736         dp.ppid   = sinfo->sinfo_ppid;
737 
738         /* Set the flags for an unordered send.  */
739         if (sinfo->sinfo_flags & SCTP_UNORDERED) {
740                 flags |= SCTP_DATA_UNORDERED;
741                 dp.ssn = 0;
742         } else
743                 dp.ssn = htons(ssn);
744 
745         chunk_len = sizeof(dp) + data_len;
746         retval = sctp_make_data(asoc, flags, chunk_len, gfp);
747         if (!retval)
748                 goto nodata;
749 
750         retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
751         memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
752 
753 nodata:
754         return retval;
755 }
756 
757 /* Create a selective ackowledgement (SACK) for the given
758  * association.  This reports on which TSN's we've seen to date,
759  * including duplicates and gaps.
760  */
761 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
762 {
763         struct sctp_chunk *retval;
764         struct sctp_sackhdr sack;
765         int len;
766         __u32 ctsn;
767         __u16 num_gabs, num_dup_tsns;
768         struct sctp_association *aptr = (struct sctp_association *)asoc;
769         struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
770         struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
771         struct sctp_transport *trans;
772 
773         memset(gabs, 0, sizeof(gabs));
774         ctsn = sctp_tsnmap_get_ctsn(map);
775 
776         pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
777 
778         /* How much room is needed in the chunk? */
779         num_gabs = sctp_tsnmap_num_gabs(map, gabs);
780         num_dup_tsns = sctp_tsnmap_num_dups(map);
781 
782         /* Initialize the SACK header.  */
783         sack.cum_tsn_ack            = htonl(ctsn);
784         sack.a_rwnd                 = htonl(asoc->a_rwnd);
785         sack.num_gap_ack_blocks     = htons(num_gabs);
786         sack.num_dup_tsns           = htons(num_dup_tsns);
787 
788         len = sizeof(sack)
789                 + sizeof(struct sctp_gap_ack_block) * num_gabs
790                 + sizeof(__u32) * num_dup_tsns;
791 
792         /* Create the chunk.  */
793         retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
794         if (!retval)
795                 goto nodata;
796 
797         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
798          *
799          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
800          * HEARTBEAT ACK, etc.) to the same destination transport
801          * address from which it received the DATA or control chunk to
802          * which it is replying.  This rule should also be followed if
803          * the endpoint is bundling DATA chunks together with the
804          * reply chunk.
805          *
806          * However, when acknowledging multiple DATA chunks received
807          * in packets from different source addresses in a single
808          * SACK, the SACK chunk may be transmitted to one of the
809          * destination transport addresses from which the DATA or
810          * control chunks being acknowledged were received.
811          *
812          * [BUG:  We do not implement the following paragraph.
813          * Perhaps we should remember the last transport we used for a
814          * SACK and avoid that (if possible) if we have seen any
815          * duplicates. --piggy]
816          *
817          * When a receiver of a duplicate DATA chunk sends a SACK to a
818          * multi- homed endpoint it MAY be beneficial to vary the
819          * destination address and not use the source address of the
820          * DATA chunk.  The reason being that receiving a duplicate
821          * from a multi-homed endpoint might indicate that the return
822          * path (as specified in the source address of the DATA chunk)
823          * for the SACK is broken.
824          *
825          * [Send to the address from which we last received a DATA chunk.]
826          */
827         retval->transport = asoc->peer.last_data_from;
828 
829         retval->subh.sack_hdr =
830                 sctp_addto_chunk(retval, sizeof(sack), &sack);
831 
832         /* Add the gap ack block information.   */
833         if (num_gabs)
834                 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
835                                  gabs);
836 
837         /* Add the duplicate TSN information.  */
838         if (num_dup_tsns) {
839                 aptr->stats.idupchunks += num_dup_tsns;
840                 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
841                                  sctp_tsnmap_get_dups(map));
842         }
843         /* Once we have a sack generated, check to see what our sack
844          * generation is, if its 0, reset the transports to 0, and reset
845          * the association generation to 1
846          *
847          * The idea is that zero is never used as a valid generation for the
848          * association so no transport will match after a wrap event like this,
849          * Until the next sack
850          */
851         if (++aptr->peer.sack_generation == 0) {
852                 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
853                                     transports)
854                         trans->sack_generation = 0;
855                 aptr->peer.sack_generation = 1;
856         }
857 nodata:
858         return retval;
859 }
860 
861 /* Make a SHUTDOWN chunk. */
862 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
863                                       const struct sctp_chunk *chunk)
864 {
865         struct sctp_chunk *retval;
866         sctp_shutdownhdr_t shut;
867         __u32 ctsn;
868 
869         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
870         shut.cum_tsn_ack = htonl(ctsn);
871 
872         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
873                                    sizeof(sctp_shutdownhdr_t), GFP_ATOMIC);
874         if (!retval)
875                 goto nodata;
876 
877         retval->subh.shutdown_hdr =
878                 sctp_addto_chunk(retval, sizeof(shut), &shut);
879 
880         if (chunk)
881                 retval->transport = chunk->transport;
882 nodata:
883         return retval;
884 }
885 
886 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
887                                      const struct sctp_chunk *chunk)
888 {
889         struct sctp_chunk *retval;
890 
891         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
892                                    GFP_ATOMIC);
893 
894         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
895          *
896          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
897          * HEARTBEAT ACK, * etc.) to the same destination transport
898          * address from which it * received the DATA or control chunk
899          * to which it is replying.
900          *
901          * [ACK back to where the SHUTDOWN came from.]
902          */
903         if (retval && chunk)
904                 retval->transport = chunk->transport;
905 
906         return retval;
907 }
908 
909 struct sctp_chunk *sctp_make_shutdown_complete(
910         const struct sctp_association *asoc,
911         const struct sctp_chunk *chunk)
912 {
913         struct sctp_chunk *retval;
914         __u8 flags = 0;
915 
916         /* Set the T-bit if we have no association (vtag will be
917          * reflected)
918          */
919         flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
920 
921         retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
922                                    0, GFP_ATOMIC);
923 
924         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
925          *
926          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
927          * HEARTBEAT ACK, * etc.) to the same destination transport
928          * address from which it * received the DATA or control chunk
929          * to which it is replying.
930          *
931          * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
932          * came from.]
933          */
934         if (retval && chunk)
935                 retval->transport = chunk->transport;
936 
937         return retval;
938 }
939 
940 /* Create an ABORT.  Note that we set the T bit if we have no
941  * association, except when responding to an INIT (sctpimpguide 2.41).
942  */
943 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
944                               const struct sctp_chunk *chunk,
945                               const size_t hint)
946 {
947         struct sctp_chunk *retval;
948         __u8 flags = 0;
949 
950         /* Set the T-bit if we have no association and 'chunk' is not
951          * an INIT (vtag will be reflected).
952          */
953         if (!asoc) {
954                 if (chunk && chunk->chunk_hdr &&
955                     chunk->chunk_hdr->type == SCTP_CID_INIT)
956                         flags = 0;
957                 else
958                         flags = SCTP_CHUNK_FLAG_T;
959         }
960 
961         retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
962                                    GFP_ATOMIC);
963 
964         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
965          *
966          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
967          * HEARTBEAT ACK, * etc.) to the same destination transport
968          * address from which it * received the DATA or control chunk
969          * to which it is replying.
970          *
971          * [ABORT back to where the offender came from.]
972          */
973         if (retval && chunk)
974                 retval->transport = chunk->transport;
975 
976         return retval;
977 }
978 
979 /* Helper to create ABORT with a NO_USER_DATA error.  */
980 struct sctp_chunk *sctp_make_abort_no_data(
981         const struct sctp_association *asoc,
982         const struct sctp_chunk *chunk, __u32 tsn)
983 {
984         struct sctp_chunk *retval;
985         __be32 payload;
986 
987         retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
988                                  + sizeof(tsn));
989 
990         if (!retval)
991                 goto no_mem;
992 
993         /* Put the tsn back into network byte order.  */
994         payload = htonl(tsn);
995         sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
996         sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
997 
998         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
999          *
1000          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1001          * HEARTBEAT ACK, * etc.) to the same destination transport
1002          * address from which it * received the DATA or control chunk
1003          * to which it is replying.
1004          *
1005          * [ABORT back to where the offender came from.]
1006          */
1007         if (chunk)
1008                 retval->transport = chunk->transport;
1009 
1010 no_mem:
1011         return retval;
1012 }
1013 
1014 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error.  */
1015 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1016                                         struct msghdr *msg,
1017                                         size_t paylen)
1018 {
1019         struct sctp_chunk *retval;
1020         void *payload = NULL;
1021         int err;
1022 
1023         retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1024         if (!retval)
1025                 goto err_chunk;
1026 
1027         if (paylen) {
1028                 /* Put the msg_iov together into payload.  */
1029                 payload = kmalloc(paylen, GFP_KERNEL);
1030                 if (!payload)
1031                         goto err_payload;
1032 
1033                 err = memcpy_from_msg(payload, msg, paylen);
1034                 if (err < 0)
1035                         goto err_copy;
1036         }
1037 
1038         sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1039         sctp_addto_chunk(retval, paylen, payload);
1040 
1041         if (paylen)
1042                 kfree(payload);
1043 
1044         return retval;
1045 
1046 err_copy:
1047         kfree(payload);
1048 err_payload:
1049         sctp_chunk_free(retval);
1050         retval = NULL;
1051 err_chunk:
1052         return retval;
1053 }
1054 
1055 /* Append bytes to the end of a parameter.  Will panic if chunk is not big
1056  * enough.
1057  */
1058 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1059                               const void *data)
1060 {
1061         void *target;
1062         int chunklen = ntohs(chunk->chunk_hdr->length);
1063 
1064         target = skb_put(chunk->skb, len);
1065 
1066         if (data)
1067                 memcpy(target, data, len);
1068         else
1069                 memset(target, 0, len);
1070 
1071         /* Adjust the chunk length field.  */
1072         chunk->chunk_hdr->length = htons(chunklen + len);
1073         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1074 
1075         return target;
1076 }
1077 
1078 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1079 struct sctp_chunk *sctp_make_abort_violation(
1080         const struct sctp_association *asoc,
1081         const struct sctp_chunk *chunk,
1082         const __u8   *payload,
1083         const size_t paylen)
1084 {
1085         struct sctp_chunk  *retval;
1086         struct sctp_paramhdr phdr;
1087 
1088         retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1089                                         + sizeof(sctp_paramhdr_t));
1090         if (!retval)
1091                 goto end;
1092 
1093         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1094                                         + sizeof(sctp_paramhdr_t));
1095 
1096         phdr.type = htons(chunk->chunk_hdr->type);
1097         phdr.length = chunk->chunk_hdr->length;
1098         sctp_addto_chunk(retval, paylen, payload);
1099         sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1100 
1101 end:
1102         return retval;
1103 }
1104 
1105 struct sctp_chunk *sctp_make_violation_paramlen(
1106         const struct sctp_association *asoc,
1107         const struct sctp_chunk *chunk,
1108         struct sctp_paramhdr *param)
1109 {
1110         struct sctp_chunk *retval;
1111         static const char error[] = "The following parameter had invalid length:";
1112         size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1113                                 sizeof(sctp_paramhdr_t);
1114 
1115         retval = sctp_make_abort(asoc, chunk, payload_len);
1116         if (!retval)
1117                 goto nodata;
1118 
1119         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1120                         sizeof(error) + sizeof(sctp_paramhdr_t));
1121         sctp_addto_chunk(retval, sizeof(error), error);
1122         sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1123 
1124 nodata:
1125         return retval;
1126 }
1127 
1128 struct sctp_chunk *sctp_make_violation_max_retrans(
1129         const struct sctp_association *asoc,
1130         const struct sctp_chunk *chunk)
1131 {
1132         struct sctp_chunk *retval;
1133         static const char error[] = "Association exceeded its max_retans count";
1134         size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1135 
1136         retval = sctp_make_abort(asoc, chunk, payload_len);
1137         if (!retval)
1138                 goto nodata;
1139 
1140         sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1141         sctp_addto_chunk(retval, sizeof(error), error);
1142 
1143 nodata:
1144         return retval;
1145 }
1146 
1147 /* Make a HEARTBEAT chunk.  */
1148 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1149                                   const struct sctp_transport *transport)
1150 {
1151         struct sctp_chunk *retval;
1152         sctp_sender_hb_info_t hbinfo;
1153 
1154         retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1155                                    sizeof(hbinfo), GFP_ATOMIC);
1156 
1157         if (!retval)
1158                 goto nodata;
1159 
1160         hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1161         hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1162         hbinfo.daddr = transport->ipaddr;
1163         hbinfo.sent_at = jiffies;
1164         hbinfo.hb_nonce = transport->hb_nonce;
1165 
1166         /* Cast away the 'const', as this is just telling the chunk
1167          * what transport it belongs to.
1168          */
1169         retval->transport = (struct sctp_transport *) transport;
1170         retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1171                                                 &hbinfo);
1172 
1173 nodata:
1174         return retval;
1175 }
1176 
1177 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1178                                       const struct sctp_chunk *chunk,
1179                                       const void *payload, const size_t paylen)
1180 {
1181         struct sctp_chunk *retval;
1182 
1183         retval  = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1184                                     GFP_ATOMIC);
1185         if (!retval)
1186                 goto nodata;
1187 
1188         retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1189 
1190         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1191          *
1192          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1193          * HEARTBEAT ACK, * etc.) to the same destination transport
1194          * address from which it * received the DATA or control chunk
1195          * to which it is replying.
1196          *
1197          * [HBACK back to where the HEARTBEAT came from.]
1198          */
1199         if (chunk)
1200                 retval->transport = chunk->transport;
1201 
1202 nodata:
1203         return retval;
1204 }
1205 
1206 /* Create an Operation Error chunk with the specified space reserved.
1207  * This routine can be used for containing multiple causes in the chunk.
1208  */
1209 static struct sctp_chunk *sctp_make_op_error_space(
1210         const struct sctp_association *asoc,
1211         const struct sctp_chunk *chunk,
1212         size_t size)
1213 {
1214         struct sctp_chunk *retval;
1215 
1216         retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1217                                    sizeof(sctp_errhdr_t) + size, GFP_ATOMIC);
1218         if (!retval)
1219                 goto nodata;
1220 
1221         /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1222          *
1223          * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1224          * HEARTBEAT ACK, etc.) to the same destination transport
1225          * address from which it received the DATA or control chunk
1226          * to which it is replying.
1227          *
1228          */
1229         if (chunk)
1230                 retval->transport = chunk->transport;
1231 
1232 nodata:
1233         return retval;
1234 }
1235 
1236 /* Create an Operation Error chunk of a fixed size,
1237  * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1238  * This is a helper function to allocate an error chunk for
1239  * for those invalid parameter codes in which we may not want
1240  * to report all the errors, if the incoming chunk is large
1241  */
1242 static inline struct sctp_chunk *sctp_make_op_error_fixed(
1243         const struct sctp_association *asoc,
1244         const struct sctp_chunk *chunk)
1245 {
1246         size_t size = asoc ? asoc->pathmtu : 0;
1247 
1248         if (!size)
1249                 size = SCTP_DEFAULT_MAXSEGMENT;
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 {
1277         struct sctp_chunk *retval;
1278         struct sctp_hmac *hmac_desc;
1279         struct sctp_authhdr auth_hdr;
1280         __u8 *hmac;
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(sctp_authhdr_t),
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(asoc->active_key_id);
1295 
1296         retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1297                                                 &auth_hdr);
1298 
1299         hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1300         memset(hmac, 0, hmac_desc->hmac_len);
1301 
1302         /* Adjust the chunk header to include the empty MAC */
1303         retval->chunk_hdr->length =
1304                 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1305         retval->chunk_end = skb_tail_pointer(retval->skb);
1306 
1307         return retval;
1308 }
1309 
1310 
1311 /********************************************************************
1312  * 2nd Level Abstractions
1313  ********************************************************************/
1314 
1315 /* Turn an skb into a chunk.
1316  * FIXME: Eventually move the structure directly inside the skb->cb[].
1317  *
1318  * sctpimpguide-05.txt Section 2.8.2
1319  * M1) Each time a new DATA chunk is transmitted
1320  * set the 'TSN.Missing.Report' count for that TSN to 0. The
1321  * 'TSN.Missing.Report' count will be used to determine missing chunks
1322  * and when to fast retransmit.
1323  *
1324  */
1325 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1326                             const struct sctp_association *asoc,
1327                             struct sock *sk, gfp_t gfp)
1328 {
1329         struct sctp_chunk *retval;
1330 
1331         retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1332 
1333         if (!retval)
1334                 goto nodata;
1335         if (!sk)
1336                 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1337 
1338         INIT_LIST_HEAD(&retval->list);
1339         retval->skb             = skb;
1340         retval->asoc            = (struct sctp_association *)asoc;
1341         retval->singleton       = 1;
1342 
1343         retval->fast_retransmit = SCTP_CAN_FRTX;
1344 
1345         /* Polish the bead hole.  */
1346         INIT_LIST_HEAD(&retval->transmitted_list);
1347         INIT_LIST_HEAD(&retval->frag_list);
1348         SCTP_DBG_OBJCNT_INC(chunk);
1349         atomic_set(&retval->refcnt, 1);
1350 
1351 nodata:
1352         return retval;
1353 }
1354 
1355 /* Set chunk->source and dest based on the IP header in chunk->skb.  */
1356 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1357                      union sctp_addr *dest)
1358 {
1359         memcpy(&chunk->source, src, sizeof(union sctp_addr));
1360         memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1361 }
1362 
1363 /* Extract the source address from a chunk.  */
1364 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1365 {
1366         /* If we have a known transport, use that.  */
1367         if (chunk->transport) {
1368                 return &chunk->transport->ipaddr;
1369         } else {
1370                 /* Otherwise, extract it from the IP header.  */
1371                 return &chunk->source;
1372         }
1373 }
1374 
1375 /* Create a new chunk, setting the type and flags headers from the
1376  * arguments, reserving enough space for a 'paylen' byte payload.
1377  */
1378 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1379                                             __u8 type, __u8 flags, int paylen,
1380                                             gfp_t gfp)
1381 {
1382         struct sctp_chunk *retval;
1383         sctp_chunkhdr_t *chunk_hdr;
1384         struct sk_buff *skb;
1385         struct sock *sk;
1386 
1387         /* No need to allocate LL here, as this is only a chunk. */
1388         skb = alloc_skb(SCTP_PAD4(sizeof(sctp_chunkhdr_t) + paylen), gfp);
1389         if (!skb)
1390                 goto nodata;
1391 
1392         /* Make room for the chunk header.  */
1393         chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1394         chunk_hdr->type   = type;
1395         chunk_hdr->flags  = flags;
1396         chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1397 
1398         sk = asoc ? asoc->base.sk : NULL;
1399         retval = sctp_chunkify(skb, asoc, sk, gfp);
1400         if (!retval) {
1401                 kfree_skb(skb);
1402                 goto nodata;
1403         }
1404 
1405         retval->chunk_hdr = chunk_hdr;
1406         retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1407 
1408         /* Determine if the chunk needs to be authenticated */
1409         if (sctp_auth_send_cid(type, asoc))
1410                 retval->auth = 1;
1411 
1412         return retval;
1413 nodata:
1414         return NULL;
1415 }
1416 
1417 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1418                                          __u8 flags, int paylen, gfp_t gfp)
1419 {
1420         return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1421 }
1422 
1423 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1424                                             __u8 type, __u8 flags, int paylen,
1425                                             gfp_t gfp)
1426 {
1427         struct sctp_chunk *chunk;
1428 
1429         chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1430         if (chunk)
1431                 sctp_control_set_owner_w(chunk);
1432 
1433         return chunk;
1434 }
1435 
1436 /* Release the memory occupied by a chunk.  */
1437 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1438 {
1439         BUG_ON(!list_empty(&chunk->list));
1440         list_del_init(&chunk->transmitted_list);
1441 
1442         consume_skb(chunk->skb);
1443         consume_skb(chunk->auth_chunk);
1444 
1445         SCTP_DBG_OBJCNT_DEC(chunk);
1446         kmem_cache_free(sctp_chunk_cachep, chunk);
1447 }
1448 
1449 /* Possibly, free the chunk.  */
1450 void sctp_chunk_free(struct sctp_chunk *chunk)
1451 {
1452         /* Release our reference on the message tracker. */
1453         if (chunk->msg)
1454                 sctp_datamsg_put(chunk->msg);
1455 
1456         sctp_chunk_put(chunk);
1457 }
1458 
1459 /* Grab a reference to the chunk. */
1460 void sctp_chunk_hold(struct sctp_chunk *ch)
1461 {
1462         atomic_inc(&ch->refcnt);
1463 }
1464 
1465 /* Release a reference to the chunk. */
1466 void sctp_chunk_put(struct sctp_chunk *ch)
1467 {
1468         if (atomic_dec_and_test(&ch->refcnt))
1469                 sctp_chunk_destroy(ch);
1470 }
1471 
1472 /* Append bytes to the end of a chunk.  Will panic if chunk is not big
1473  * enough.
1474  */
1475 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1476 {
1477         void *target;
1478         void *padding;
1479         int chunklen = ntohs(chunk->chunk_hdr->length);
1480         int padlen = SCTP_PAD4(chunklen) - chunklen;
1481 
1482         padding = skb_put(chunk->skb, padlen);
1483         target = skb_put(chunk->skb, len);
1484 
1485         memset(padding, 0, padlen);
1486         memcpy(target, data, len);
1487 
1488         /* Adjust the chunk length field.  */
1489         chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1490         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1491 
1492         return target;
1493 }
1494 
1495 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1496  * space in the chunk
1497  */
1498 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1499                                     int len, const void *data)
1500 {
1501         if (skb_tailroom(chunk->skb) >= len)
1502                 return sctp_addto_chunk(chunk, len, data);
1503         else
1504                 return NULL;
1505 }
1506 
1507 /* Append bytes from user space to the end of a chunk.  Will panic if
1508  * chunk is not big enough.
1509  * Returns a kernel err value.
1510  */
1511 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1512                           struct iov_iter *from)
1513 {
1514         void *target;
1515         ssize_t copied;
1516 
1517         /* Make room in chunk for data.  */
1518         target = skb_put(chunk->skb, len);
1519 
1520         /* Copy data (whole iovec) into chunk */
1521         copied = copy_from_iter(target, len, from);
1522         if (copied != len)
1523                 return -EFAULT;
1524 
1525         /* Adjust the chunk length field.  */
1526         chunk->chunk_hdr->length =
1527                 htons(ntohs(chunk->chunk_hdr->length) + len);
1528         chunk->chunk_end = skb_tail_pointer(chunk->skb);
1529 
1530         return 0;
1531 }
1532 
1533 /* Helper function to assign a TSN if needed.  This assumes that both
1534  * the data_hdr and association have already been assigned.
1535  */
1536 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1537 {
1538         struct sctp_datamsg *msg;
1539         struct sctp_chunk *lchunk;
1540         struct sctp_stream *stream;
1541         __u16 ssn;
1542         __u16 sid;
1543 
1544         if (chunk->has_ssn)
1545                 return;
1546 
1547         /* All fragments will be on the same stream */
1548         sid = ntohs(chunk->subh.data_hdr->stream);
1549         stream = chunk->asoc->stream;
1550 
1551         /* Now assign the sequence number to the entire message.
1552          * All fragments must have the same stream sequence number.
1553          */
1554         msg = chunk->msg;
1555         list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1556                 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1557                         ssn = 0;
1558                 } else {
1559                         if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1560                                 ssn = sctp_ssn_next(stream, out, sid);
1561                         else
1562                                 ssn = sctp_ssn_peek(stream, out, sid);
1563                 }
1564 
1565                 lchunk->subh.data_hdr->ssn = htons(ssn);
1566                 lchunk->has_ssn = 1;
1567         }
1568 }
1569 
1570 /* Helper function to assign a TSN if needed.  This assumes that both
1571  * the data_hdr and association have already been assigned.
1572  */
1573 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1574 {
1575         if (!chunk->has_tsn) {
1576                 /* This is the last possible instant to
1577                  * assign a TSN.
1578                  */
1579                 chunk->subh.data_hdr->tsn =
1580                         htonl(sctp_association_get_next_tsn(chunk->asoc));
1581                 chunk->has_tsn = 1;
1582         }
1583 }
1584 
1585 /* Create a CLOSED association to use with an incoming packet.  */
1586 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1587                                         struct sctp_chunk *chunk,
1588                                         gfp_t gfp)
1589 {
1590         struct sctp_association *asoc;
1591         struct sk_buff *skb;
1592         sctp_scope_t scope;
1593 
1594         /* Create the bare association.  */
1595         scope = sctp_scope(sctp_source(chunk));
1596         asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1597         if (!asoc)
1598                 goto nodata;
1599         asoc->temp = 1;
1600         skb = chunk->skb;
1601         /* Create an entry for the source address of the packet.  */
1602         SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1603 
1604 nodata:
1605         return asoc;
1606 }
1607 
1608 /* Build a cookie representing asoc.
1609  * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1610  */
1611 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1612                                       const struct sctp_association *asoc,
1613                                       const struct sctp_chunk *init_chunk,
1614                                       int *cookie_len,
1615                                       const __u8 *raw_addrs, int addrs_len)
1616 {
1617         sctp_cookie_param_t *retval;
1618         struct sctp_signed_cookie *cookie;
1619         int headersize, bodysize;
1620 
1621         /* Header size is static data prior to the actual cookie, including
1622          * any padding.
1623          */
1624         headersize = sizeof(sctp_paramhdr_t) +
1625                      (sizeof(struct sctp_signed_cookie) -
1626                       sizeof(struct sctp_cookie));
1627         bodysize = sizeof(struct sctp_cookie)
1628                 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1629 
1630         /* Pad out the cookie to a multiple to make the signature
1631          * functions simpler to write.
1632          */
1633         if (bodysize % SCTP_COOKIE_MULTIPLE)
1634                 bodysize += SCTP_COOKIE_MULTIPLE
1635                         - (bodysize % SCTP_COOKIE_MULTIPLE);
1636         *cookie_len = headersize + bodysize;
1637 
1638         /* Clear this memory since we are sending this data structure
1639          * out on the network.
1640          */
1641         retval = kzalloc(*cookie_len, GFP_ATOMIC);
1642         if (!retval)
1643                 goto nodata;
1644 
1645         cookie = (struct sctp_signed_cookie *) retval->body;
1646 
1647         /* Set up the parameter header.  */
1648         retval->p.type = SCTP_PARAM_STATE_COOKIE;
1649         retval->p.length = htons(*cookie_len);
1650 
1651         /* Copy the cookie part of the association itself.  */
1652         cookie->c = asoc->c;
1653         /* Save the raw address list length in the cookie. */
1654         cookie->c.raw_addr_list_len = addrs_len;
1655 
1656         /* Remember PR-SCTP capability. */
1657         cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1658 
1659         /* Save adaptation indication in the cookie. */
1660         cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1661 
1662         /* Set an expiration time for the cookie.  */
1663         cookie->c.expiration = ktime_add(asoc->cookie_life,
1664                                          ktime_get_real());
1665 
1666         /* Copy the peer's init packet.  */
1667         memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1668                ntohs(init_chunk->chunk_hdr->length));
1669 
1670         /* Copy the raw local address list of the association. */
1671         memcpy((__u8 *)&cookie->c.peer_init[0] +
1672                ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1673 
1674         if (sctp_sk(ep->base.sk)->hmac) {
1675                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1676                 int err;
1677 
1678                 /* Sign the message.  */
1679                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1680                 desc->flags = 0;
1681 
1682                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1683                                           sizeof(ep->secret_key)) ?:
1684                       crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1685                                           cookie->signature);
1686                 shash_desc_zero(desc);
1687                 if (err)
1688                         goto free_cookie;
1689         }
1690 
1691         return retval;
1692 
1693 free_cookie:
1694         kfree(retval);
1695 nodata:
1696         *cookie_len = 0;
1697         return NULL;
1698 }
1699 
1700 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association.  */
1701 struct sctp_association *sctp_unpack_cookie(
1702         const struct sctp_endpoint *ep,
1703         const struct sctp_association *asoc,
1704         struct sctp_chunk *chunk, gfp_t gfp,
1705         int *error, struct sctp_chunk **errp)
1706 {
1707         struct sctp_association *retval = NULL;
1708         struct sctp_signed_cookie *cookie;
1709         struct sctp_cookie *bear_cookie;
1710         int headersize, bodysize, fixed_size;
1711         __u8 *digest = ep->digest;
1712         unsigned int len;
1713         sctp_scope_t scope;
1714         struct sk_buff *skb = chunk->skb;
1715         ktime_t kt;
1716 
1717         /* Header size is static data prior to the actual cookie, including
1718          * any padding.
1719          */
1720         headersize = sizeof(sctp_chunkhdr_t) +
1721                      (sizeof(struct sctp_signed_cookie) -
1722                       sizeof(struct sctp_cookie));
1723         bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1724         fixed_size = headersize + sizeof(struct sctp_cookie);
1725 
1726         /* Verify that the chunk looks like it even has a cookie.
1727          * There must be enough room for our cookie and our peer's
1728          * INIT chunk.
1729          */
1730         len = ntohs(chunk->chunk_hdr->length);
1731         if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1732                 goto malformed;
1733 
1734         /* Verify that the cookie has been padded out. */
1735         if (bodysize % SCTP_COOKIE_MULTIPLE)
1736                 goto malformed;
1737 
1738         /* Process the cookie.  */
1739         cookie = chunk->subh.cookie_hdr;
1740         bear_cookie = &cookie->c;
1741 
1742         if (!sctp_sk(ep->base.sk)->hmac)
1743                 goto no_hmac;
1744 
1745         /* Check the signature.  */
1746         {
1747                 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1748                 int err;
1749 
1750                 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1751                 desc->flags = 0;
1752 
1753                 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1754                                           sizeof(ep->secret_key)) ?:
1755                       crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1756                                           digest);
1757                 shash_desc_zero(desc);
1758 
1759                 if (err) {
1760                         *error = -SCTP_IERROR_NOMEM;
1761                         goto fail;
1762                 }
1763         }
1764 
1765         if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1766                 *error = -SCTP_IERROR_BAD_SIG;
1767                 goto fail;
1768         }
1769 
1770 no_hmac:
1771         /* IG Section 2.35.2:
1772          *  3) Compare the port numbers and the verification tag contained
1773          *     within the COOKIE ECHO chunk to the actual port numbers and the
1774          *     verification tag within the SCTP common header of the received
1775          *     packet. If these values do not match the packet MUST be silently
1776          *     discarded,
1777          */
1778         if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1779                 *error = -SCTP_IERROR_BAD_TAG;
1780                 goto fail;
1781         }
1782 
1783         if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1784             ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1785                 *error = -SCTP_IERROR_BAD_PORTS;
1786                 goto fail;
1787         }
1788 
1789         /* Check to see if the cookie is stale.  If there is already
1790          * an association, there is no need to check cookie's expiration
1791          * for init collision case of lost COOKIE ACK.
1792          * If skb has been timestamped, then use the stamp, otherwise
1793          * use current time.  This introduces a small possibility that
1794          * that a cookie may be considered expired, but his would only slow
1795          * down the new association establishment instead of every packet.
1796          */
1797         if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1798                 kt = skb_get_ktime(skb);
1799         else
1800                 kt = ktime_get_real();
1801 
1802         if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1803                 /*
1804                  * Section 3.3.10.3 Stale Cookie Error (3)
1805                  *
1806                  * Cause of error
1807                  * ---------------
1808                  * Stale Cookie Error:  Indicates the receipt of a valid State
1809                  * Cookie that has expired.
1810                  */
1811                 len = ntohs(chunk->chunk_hdr->length);
1812                 *errp = sctp_make_op_error_space(asoc, chunk, len);
1813                 if (*errp) {
1814                         suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1815                         __be32 n = htonl(usecs);
1816 
1817                         sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1818                                         sizeof(n));
1819                         sctp_addto_chunk(*errp, sizeof(n), &n);
1820                         *error = -SCTP_IERROR_STALE_COOKIE;
1821                 } else
1822                         *error = -SCTP_IERROR_NOMEM;
1823 
1824                 goto fail;
1825         }
1826 
1827         /* Make a new base association.  */
1828         scope = sctp_scope(sctp_source(chunk));
1829         retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1830         if (!retval) {
1831                 *error = -SCTP_IERROR_NOMEM;
1832                 goto fail;
1833         }
1834 
1835         /* Set up our peer's port number.  */
1836         retval->peer.port = ntohs(chunk->sctp_hdr->source);
1837 
1838         /* Populate the association from the cookie.  */
1839         memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1840 
1841         if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1842                                                  GFP_ATOMIC) < 0) {
1843                 *error = -SCTP_IERROR_NOMEM;
1844                 goto fail;
1845         }
1846 
1847         /* Also, add the destination address. */
1848         if (list_empty(&retval->base.bind_addr.address_list)) {
1849                 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1850                                    sizeof(chunk->dest), SCTP_ADDR_SRC,
1851                                    GFP_ATOMIC);
1852         }
1853 
1854         retval->next_tsn = retval->c.initial_tsn;
1855         retval->ctsn_ack_point = retval->next_tsn - 1;
1856         retval->addip_serial = retval->c.initial_tsn;
1857         retval->strreset_outseq = retval->c.initial_tsn;
1858         retval->adv_peer_ack_point = retval->ctsn_ack_point;
1859         retval->peer.prsctp_capable = retval->c.prsctp_capable;
1860         retval->peer.adaptation_ind = retval->c.adaptation_ind;
1861 
1862         /* The INIT stuff will be done by the side effects.  */
1863         return retval;
1864 
1865 fail:
1866         if (retval)
1867                 sctp_association_free(retval);
1868 
1869         return NULL;
1870 
1871 malformed:
1872         /* Yikes!  The packet is either corrupt or deliberately
1873          * malformed.
1874          */
1875         *error = -SCTP_IERROR_MALFORMED;
1876         goto fail;
1877 }
1878 
1879 /********************************************************************
1880  * 3rd Level Abstractions
1881  ********************************************************************/
1882 
1883 struct __sctp_missing {
1884         __be32 num_missing;
1885         __be16 type;
1886 }  __packed;
1887 
1888 /*
1889  * Report a missing mandatory parameter.
1890  */
1891 static int sctp_process_missing_param(const struct sctp_association *asoc,
1892                                       sctp_param_t paramtype,
1893                                       struct sctp_chunk *chunk,
1894                                       struct sctp_chunk **errp)
1895 {
1896         struct __sctp_missing report;
1897         __u16 len;
1898 
1899         len = SCTP_PAD4(sizeof(report));
1900 
1901         /* Make an ERROR chunk, preparing enough room for
1902          * returning multiple unknown parameters.
1903          */
1904         if (!*errp)
1905                 *errp = sctp_make_op_error_space(asoc, chunk, len);
1906 
1907         if (*errp) {
1908                 report.num_missing = htonl(1);
1909                 report.type = paramtype;
1910                 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1911                                 sizeof(report));
1912                 sctp_addto_chunk(*errp, sizeof(report), &report);
1913         }
1914 
1915         /* Stop processing this chunk. */
1916         return 0;
1917 }
1918 
1919 /* Report an Invalid Mandatory Parameter.  */
1920 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1921                                       struct sctp_chunk *chunk,
1922                                       struct sctp_chunk **errp)
1923 {
1924         /* Invalid Mandatory Parameter Error has no payload. */
1925 
1926         if (!*errp)
1927                 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1928 
1929         if (*errp)
1930                 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1931 
1932         /* Stop processing this chunk. */
1933         return 0;
1934 }
1935 
1936 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1937                                         struct sctp_paramhdr *param,
1938                                         const struct sctp_chunk *chunk,
1939                                         struct sctp_chunk **errp)
1940 {
1941         /* This is a fatal error.  Any accumulated non-fatal errors are
1942          * not reported.
1943          */
1944         if (*errp)
1945                 sctp_chunk_free(*errp);
1946 
1947         /* Create an error chunk and fill it in with our payload. */
1948         *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1949 
1950         return 0;
1951 }
1952 
1953 
1954 /* Do not attempt to handle the HOST_NAME parm.  However, do
1955  * send back an indicator to the peer.
1956  */
1957 static int sctp_process_hn_param(const struct sctp_association *asoc,
1958                                  union sctp_params param,
1959                                  struct sctp_chunk *chunk,
1960                                  struct sctp_chunk **errp)
1961 {
1962         __u16 len = ntohs(param.p->length);
1963 
1964         /* Processing of the HOST_NAME parameter will generate an
1965          * ABORT.  If we've accumulated any non-fatal errors, they
1966          * would be unrecognized parameters and we should not include
1967          * them in the ABORT.
1968          */
1969         if (*errp)
1970                 sctp_chunk_free(*errp);
1971 
1972         *errp = sctp_make_op_error_space(asoc, chunk, len);
1973 
1974         if (*errp) {
1975                 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1976                 sctp_addto_chunk(*errp, len, param.v);
1977         }
1978 
1979         /* Stop processing this chunk. */
1980         return 0;
1981 }
1982 
1983 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1984 {
1985         __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1986         int have_auth = 0;
1987         int have_asconf = 0;
1988         int i;
1989 
1990         for (i = 0; i < num_ext; i++) {
1991                 switch (param.ext->chunks[i]) {
1992                 case SCTP_CID_AUTH:
1993                         have_auth = 1;
1994                         break;
1995                 case SCTP_CID_ASCONF:
1996                 case SCTP_CID_ASCONF_ACK:
1997                         have_asconf = 1;
1998                         break;
1999                 }
2000         }
2001 
2002         /* ADD-IP Security: The draft requires us to ABORT or ignore the
2003          * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not.  Do this
2004          * only if ADD-IP is turned on and we are not backward-compatible
2005          * mode.
2006          */
2007         if (net->sctp.addip_noauth)
2008                 return 1;
2009 
2010         if (net->sctp.addip_enable && !have_auth && have_asconf)
2011                 return 0;
2012 
2013         return 1;
2014 }
2015 
2016 static void sctp_process_ext_param(struct sctp_association *asoc,
2017                                     union sctp_params param)
2018 {
2019         struct net *net = sock_net(asoc->base.sk);
2020         __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2021         int i;
2022 
2023         for (i = 0; i < num_ext; i++) {
2024                 switch (param.ext->chunks[i]) {
2025                 case SCTP_CID_RECONF:
2026                         if (asoc->reconf_enable &&
2027                             !asoc->peer.reconf_capable)
2028                                 asoc->peer.reconf_capable = 1;
2029                         break;
2030                 case SCTP_CID_FWD_TSN:
2031                         if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
2032                                 asoc->peer.prsctp_capable = 1;
2033                         break;
2034                 case SCTP_CID_AUTH:
2035                         /* if the peer reports AUTH, assume that he
2036                          * supports AUTH.
2037                          */
2038                         if (asoc->ep->auth_enable)
2039                                 asoc->peer.auth_capable = 1;
2040                         break;
2041                 case SCTP_CID_ASCONF:
2042                 case SCTP_CID_ASCONF_ACK:
2043                         if (net->sctp.addip_enable)
2044                                 asoc->peer.asconf_capable = 1;
2045                         break;
2046                 default:
2047                         break;
2048                 }
2049         }
2050 }
2051 
2052 /* RFC 3.2.1 & the Implementers Guide 2.2.
2053  *
2054  * The Parameter Types are encoded such that the
2055  * highest-order two bits specify the action that must be
2056  * taken if the processing endpoint does not recognize the
2057  * Parameter Type.
2058  *
2059  * 00 - Stop processing this parameter; do not process any further
2060  *      parameters within this chunk
2061  *
2062  * 01 - Stop processing this parameter, do not process any further
2063  *      parameters within this chunk, and report the unrecognized
2064  *      parameter in an 'Unrecognized Parameter' ERROR chunk.
2065  *
2066  * 10 - Skip this parameter and continue processing.
2067  *
2068  * 11 - Skip this parameter and continue processing but
2069  *      report the unrecognized parameter in an
2070  *      'Unrecognized Parameter' ERROR chunk.
2071  *
2072  * Return value:
2073  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2074  *      SCTP_IERROR_ERROR    - stop and report an error.
2075  *      SCTP_IERROR_NOMEME   - out of memory.
2076  */
2077 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2078                                             union sctp_params param,
2079                                             struct sctp_chunk *chunk,
2080                                             struct sctp_chunk **errp)
2081 {
2082         int retval = SCTP_IERROR_NO_ERROR;
2083 
2084         switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2085         case SCTP_PARAM_ACTION_DISCARD:
2086                 retval =  SCTP_IERROR_ERROR;
2087                 break;
2088         case SCTP_PARAM_ACTION_SKIP:
2089                 break;
2090         case SCTP_PARAM_ACTION_DISCARD_ERR:
2091                 retval =  SCTP_IERROR_ERROR;
2092                 /* Fall through */
2093         case SCTP_PARAM_ACTION_SKIP_ERR:
2094                 /* Make an ERROR chunk, preparing enough room for
2095                  * returning multiple unknown parameters.
2096                  */
2097                 if (NULL == *errp)
2098                         *errp = sctp_make_op_error_fixed(asoc, chunk);
2099 
2100                 if (*errp) {
2101                         if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2102                                         SCTP_PAD4(ntohs(param.p->length))))
2103                                 sctp_addto_chunk_fixed(*errp,
2104                                                 SCTP_PAD4(ntohs(param.p->length)),
2105                                                 param.v);
2106                 } else {
2107                         /* If there is no memory for generating the ERROR
2108                          * report as specified, an ABORT will be triggered
2109                          * to the peer and the association won't be
2110                          * established.
2111                          */
2112                         retval = SCTP_IERROR_NOMEM;
2113                 }
2114                 break;
2115         default:
2116                 break;
2117         }
2118 
2119         return retval;
2120 }
2121 
2122 /* Verify variable length parameters
2123  * Return values:
2124  *      SCTP_IERROR_ABORT - trigger an ABORT
2125  *      SCTP_IERROR_NOMEM - out of memory (abort)
2126  *      SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2127  *      SCTP_IERROR_NO_ERROR - continue with the chunk
2128  */
2129 static sctp_ierror_t sctp_verify_param(struct net *net,
2130                                         const struct sctp_endpoint *ep,
2131                                         const struct sctp_association *asoc,
2132                                         union sctp_params param,
2133                                         sctp_cid_t cid,
2134                                         struct sctp_chunk *chunk,
2135                                         struct sctp_chunk **err_chunk)
2136 {
2137         struct sctp_hmac_algo_param *hmacs;
2138         int retval = SCTP_IERROR_NO_ERROR;
2139         __u16 n_elt, id = 0;
2140         int i;
2141 
2142         /* FIXME - This routine is not looking at each parameter per the
2143          * chunk type, i.e., unrecognized parameters should be further
2144          * identified based on the chunk id.
2145          */
2146 
2147         switch (param.p->type) {
2148         case SCTP_PARAM_IPV4_ADDRESS:
2149         case SCTP_PARAM_IPV6_ADDRESS:
2150         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2151         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2152         case SCTP_PARAM_STATE_COOKIE:
2153         case SCTP_PARAM_HEARTBEAT_INFO:
2154         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2155         case SCTP_PARAM_ECN_CAPABLE:
2156         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2157                 break;
2158 
2159         case SCTP_PARAM_SUPPORTED_EXT:
2160                 if (!sctp_verify_ext_param(net, param))
2161                         return SCTP_IERROR_ABORT;
2162                 break;
2163 
2164         case SCTP_PARAM_SET_PRIMARY:
2165                 if (net->sctp.addip_enable)
2166                         break;
2167                 goto fallthrough;
2168 
2169         case SCTP_PARAM_HOST_NAME_ADDRESS:
2170                 /* Tell the peer, we won't support this param.  */
2171                 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2172                 retval = SCTP_IERROR_ABORT;
2173                 break;
2174 
2175         case SCTP_PARAM_FWD_TSN_SUPPORT:
2176                 if (ep->prsctp_enable)
2177                         break;
2178                 goto fallthrough;
2179 
2180         case SCTP_PARAM_RANDOM:
2181                 if (!ep->auth_enable)
2182                         goto fallthrough;
2183 
2184                 /* SCTP-AUTH: Secion 6.1
2185                  * If the random number is not 32 byte long the association
2186                  * MUST be aborted.  The ABORT chunk SHOULD contain the error
2187                  * cause 'Protocol Violation'.
2188                  */
2189                 if (SCTP_AUTH_RANDOM_LENGTH !=
2190                         ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2191                         sctp_process_inv_paramlength(asoc, param.p,
2192                                                         chunk, err_chunk);
2193                         retval = SCTP_IERROR_ABORT;
2194                 }
2195                 break;
2196 
2197         case SCTP_PARAM_CHUNKS:
2198                 if (!ep->auth_enable)
2199                         goto fallthrough;
2200 
2201                 /* SCTP-AUTH: Section 3.2
2202                  * The CHUNKS parameter MUST be included once in the INIT or
2203                  *  INIT-ACK chunk if the sender wants to receive authenticated
2204                  *  chunks.  Its maximum length is 260 bytes.
2205                  */
2206                 if (260 < ntohs(param.p->length)) {
2207                         sctp_process_inv_paramlength(asoc, param.p,
2208                                                      chunk, err_chunk);
2209                         retval = SCTP_IERROR_ABORT;
2210                 }
2211                 break;
2212 
2213         case SCTP_PARAM_HMAC_ALGO:
2214                 if (!ep->auth_enable)
2215                         goto fallthrough;
2216 
2217                 hmacs = (struct sctp_hmac_algo_param *)param.p;
2218                 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2219 
2220                 /* SCTP-AUTH: Section 6.1
2221                  * The HMAC algorithm based on SHA-1 MUST be supported and
2222                  * included in the HMAC-ALGO parameter.
2223                  */
2224                 for (i = 0; i < n_elt; i++) {
2225                         id = ntohs(hmacs->hmac_ids[i]);
2226 
2227                         if (id == SCTP_AUTH_HMAC_ID_SHA1)
2228                                 break;
2229                 }
2230 
2231                 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2232                         sctp_process_inv_paramlength(asoc, param.p, chunk,
2233                                                      err_chunk);
2234                         retval = SCTP_IERROR_ABORT;
2235                 }
2236                 break;
2237 fallthrough:
2238         default:
2239                 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2240                          __func__, ntohs(param.p->type), cid);
2241 
2242                 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2243                 break;
2244         }
2245         return retval;
2246 }
2247 
2248 /* Verify the INIT packet before we process it.  */
2249 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2250                      const struct sctp_association *asoc, sctp_cid_t cid,
2251                      sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2252                      struct sctp_chunk **errp)
2253 {
2254         union sctp_params param;
2255         bool has_cookie = false;
2256         int result;
2257 
2258         /* Check for missing mandatory parameters. Note: Initial TSN is
2259          * also mandatory, but is not checked here since the valid range
2260          * is 0..2**32-1. RFC4960, section 3.3.3.
2261          */
2262         if (peer_init->init_hdr.num_outbound_streams == 0 ||
2263             peer_init->init_hdr.num_inbound_streams == 0 ||
2264             peer_init->init_hdr.init_tag == 0 ||
2265             ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2266                 return sctp_process_inv_mandatory(asoc, chunk, errp);
2267 
2268         sctp_walk_params(param, peer_init, init_hdr.params) {
2269                 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2270                         has_cookie = true;
2271         }
2272 
2273         /* There is a possibility that a parameter length was bad and
2274          * in that case we would have stoped walking the parameters.
2275          * The current param.p would point at the bad one.
2276          * Current consensus on the mailing list is to generate a PROTOCOL
2277          * VIOLATION error.  We build the ERROR chunk here and let the normal
2278          * error handling code build and send the packet.
2279          */
2280         if (param.v != (void *)chunk->chunk_end)
2281                 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2282 
2283         /* The only missing mandatory param possible today is
2284          * the state cookie for an INIT-ACK chunk.
2285          */
2286         if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2287                 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2288                                                   chunk, errp);
2289 
2290         /* Verify all the variable length parameters */
2291         sctp_walk_params(param, peer_init, init_hdr.params) {
2292                 result = sctp_verify_param(net, ep, asoc, param, cid,
2293                                            chunk, errp);
2294                 switch (result) {
2295                 case SCTP_IERROR_ABORT:
2296                 case SCTP_IERROR_NOMEM:
2297                         return 0;
2298                 case SCTP_IERROR_ERROR:
2299                         return 1;
2300                 case SCTP_IERROR_NO_ERROR:
2301                 default:
2302                         break;
2303                 }
2304 
2305         } /* for (loop through all parameters) */
2306 
2307         return 1;
2308 }
2309 
2310 /* Unpack the parameters in an INIT packet into an association.
2311  * Returns 0 on failure, else success.
2312  * FIXME:  This is an association method.
2313  */
2314 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2315                       const union sctp_addr *peer_addr,
2316                       sctp_init_chunk_t *peer_init, gfp_t gfp)
2317 {
2318         struct net *net = sock_net(asoc->base.sk);
2319         union sctp_params param;
2320         struct sctp_transport *transport;
2321         struct list_head *pos, *temp;
2322         struct sctp_af *af;
2323         union sctp_addr addr;
2324         char *cookie;
2325         int src_match = 0;
2326 
2327         /* We must include the address that the INIT packet came from.
2328          * This is the only address that matters for an INIT packet.
2329          * When processing a COOKIE ECHO, we retrieve the from address
2330          * of the INIT from the cookie.
2331          */
2332 
2333         /* This implementation defaults to making the first transport
2334          * added as the primary transport.  The source address seems to
2335          * be a a better choice than any of the embedded addresses.
2336          */
2337         if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2338                 goto nomem;
2339 
2340         if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2341                 src_match = 1;
2342 
2343         /* Process the initialization parameters.  */
2344         sctp_walk_params(param, peer_init, init_hdr.params) {
2345                 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2346                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2347                         af = sctp_get_af_specific(param_type2af(param.p->type));
2348                         af->from_addr_param(&addr, param.addr,
2349                                             chunk->sctp_hdr->source, 0);
2350                         if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2351                                 src_match = 1;
2352                 }
2353 
2354                 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2355                         goto clean_up;
2356         }
2357 
2358         /* source address of chunk may not match any valid address */
2359         if (!src_match)
2360                 goto clean_up;
2361 
2362         /* AUTH: After processing the parameters, make sure that we
2363          * have all the required info to potentially do authentications.
2364          */
2365         if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2366                                         !asoc->peer.peer_hmacs))
2367                 asoc->peer.auth_capable = 0;
2368 
2369         /* In a non-backward compatible mode, if the peer claims
2370          * support for ADD-IP but not AUTH,  the ADD-IP spec states
2371          * that we MUST ABORT the association. Section 6.  The section
2372          * also give us an option to silently ignore the packet, which
2373          * is what we'll do here.
2374          */
2375         if (!net->sctp.addip_noauth &&
2376              (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2377                 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2378                                                   SCTP_PARAM_DEL_IP |
2379                                                   SCTP_PARAM_SET_PRIMARY);
2380                 asoc->peer.asconf_capable = 0;
2381                 goto clean_up;
2382         }
2383 
2384         /* Walk list of transports, removing transports in the UNKNOWN state. */
2385         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2386                 transport = list_entry(pos, struct sctp_transport, transports);
2387                 if (transport->state == SCTP_UNKNOWN) {
2388                         sctp_assoc_rm_peer(asoc, transport);
2389                 }
2390         }
2391 
2392         /* The fixed INIT headers are always in network byte
2393          * order.
2394          */
2395         asoc->peer.i.init_tag =
2396                 ntohl(peer_init->init_hdr.init_tag);
2397         asoc->peer.i.a_rwnd =
2398                 ntohl(peer_init->init_hdr.a_rwnd);
2399         asoc->peer.i.num_outbound_streams =
2400                 ntohs(peer_init->init_hdr.num_outbound_streams);
2401         asoc->peer.i.num_inbound_streams =
2402                 ntohs(peer_init->init_hdr.num_inbound_streams);
2403         asoc->peer.i.initial_tsn =
2404                 ntohl(peer_init->init_hdr.initial_tsn);
2405 
2406         asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2407 
2408         /* Apply the upper bounds for output streams based on peer's
2409          * number of inbound streams.
2410          */
2411         if (asoc->c.sinit_num_ostreams  >
2412             ntohs(peer_init->init_hdr.num_inbound_streams)) {
2413                 asoc->c.sinit_num_ostreams =
2414                         ntohs(peer_init->init_hdr.num_inbound_streams);
2415         }
2416 
2417         if (asoc->c.sinit_max_instreams >
2418             ntohs(peer_init->init_hdr.num_outbound_streams)) {
2419                 asoc->c.sinit_max_instreams =
2420                         ntohs(peer_init->init_hdr.num_outbound_streams);
2421         }
2422 
2423         /* Copy Initiation tag from INIT to VT_peer in cookie.   */
2424         asoc->c.peer_vtag = asoc->peer.i.init_tag;
2425 
2426         /* Peer Rwnd   : Current calculated value of the peer's rwnd.  */
2427         asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2428 
2429         /* Copy cookie in case we need to resend COOKIE-ECHO. */
2430         cookie = asoc->peer.cookie;
2431         if (cookie) {
2432                 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2433                 if (!asoc->peer.cookie)
2434                         goto clean_up;
2435         }
2436 
2437         /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2438          * high (for example, implementations MAY use the size of the receiver
2439          * advertised window).
2440          */
2441         list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2442                         transports) {
2443                 transport->ssthresh = asoc->peer.i.a_rwnd;
2444         }
2445 
2446         /* Set up the TSN tracking pieces.  */
2447         if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2448                                 asoc->peer.i.initial_tsn, gfp))
2449                 goto clean_up;
2450 
2451         /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2452          *
2453          * The stream sequence number in all the streams shall start
2454          * from 0 when the association is established.  Also, when the
2455          * stream sequence number reaches the value 65535 the next
2456          * stream sequence number shall be set to 0.
2457          */
2458 
2459         /* Allocate storage for the negotiated streams if it is not a temporary
2460          * association.
2461          */
2462         if (!asoc->temp) {
2463                 if (sctp_stream_init(asoc, gfp))
2464                         goto clean_up;
2465 
2466                 if (sctp_assoc_set_id(asoc, gfp))
2467                         goto clean_up;
2468         }
2469 
2470         /* ADDIP Section 4.1 ASCONF Chunk Procedures
2471          *
2472          * When an endpoint has an ASCONF signaled change to be sent to the
2473          * remote endpoint it should do the following:
2474          * ...
2475          * A2) A serial number should be assigned to the Chunk. The serial
2476          * number should be a monotonically increasing number. All serial
2477          * numbers are defined to be initialized at the start of the
2478          * association to the same value as the Initial TSN.
2479          */
2480         asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2481         return 1;
2482 
2483 clean_up:
2484         /* Release the transport structures. */
2485         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2486                 transport = list_entry(pos, struct sctp_transport, transports);
2487                 if (transport->state != SCTP_ACTIVE)
2488                         sctp_assoc_rm_peer(asoc, transport);
2489         }
2490 
2491 nomem:
2492         return 0;
2493 }
2494 
2495 
2496 /* Update asoc with the option described in param.
2497  *
2498  * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2499  *
2500  * asoc is the association to update.
2501  * param is the variable length parameter to use for update.
2502  * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2503  * If the current packet is an INIT we want to minimize the amount of
2504  * work we do.  In particular, we should not build transport
2505  * structures for the addresses.
2506  */
2507 static int sctp_process_param(struct sctp_association *asoc,
2508                               union sctp_params param,
2509                               const union sctp_addr *peer_addr,
2510                               gfp_t gfp)
2511 {
2512         struct net *net = sock_net(asoc->base.sk);
2513         union sctp_addr addr;
2514         int i;
2515         __u16 sat;
2516         int retval = 1;
2517         sctp_scope_t scope;
2518         u32 stale;
2519         struct sctp_af *af;
2520         union sctp_addr_param *addr_param;
2521         struct sctp_transport *t;
2522         struct sctp_endpoint *ep = asoc->ep;
2523 
2524         /* We maintain all INIT parameters in network byte order all the
2525          * time.  This allows us to not worry about whether the parameters
2526          * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2527          */
2528         switch (param.p->type) {
2529         case SCTP_PARAM_IPV6_ADDRESS:
2530                 if (PF_INET6 != asoc->base.sk->sk_family)
2531                         break;
2532                 goto do_addr_param;
2533 
2534         case SCTP_PARAM_IPV4_ADDRESS:
2535                 /* v4 addresses are not allowed on v6-only socket */
2536                 if (ipv6_only_sock(asoc->base.sk))
2537                         break;
2538 do_addr_param:
2539                 af = sctp_get_af_specific(param_type2af(param.p->type));
2540                 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2541                 scope = sctp_scope(peer_addr);
2542                 if (sctp_in_scope(net, &addr, scope))
2543                         if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2544                                 return 0;
2545                 break;
2546 
2547         case SCTP_PARAM_COOKIE_PRESERVATIVE:
2548                 if (!net->sctp.cookie_preserve_enable)
2549                         break;
2550 
2551                 stale = ntohl(param.life->lifespan_increment);
2552 
2553                 /* Suggested Cookie Life span increment's unit is msec,
2554                  * (1/1000sec).
2555                  */
2556                 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2557                 break;
2558 
2559         case SCTP_PARAM_HOST_NAME_ADDRESS:
2560                 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2561                 break;
2562 
2563         case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2564                 /* Turn off the default values first so we'll know which
2565                  * ones are really set by the peer.
2566                  */
2567                 asoc->peer.ipv4_address = 0;
2568                 asoc->peer.ipv6_address = 0;
2569 
2570                 /* Assume that peer supports the address family
2571                  * by which it sends a packet.
2572                  */
2573                 if (peer_addr->sa.sa_family == AF_INET6)
2574                         asoc->peer.ipv6_address = 1;
2575                 else if (peer_addr->sa.sa_family == AF_INET)
2576                         asoc->peer.ipv4_address = 1;
2577 
2578                 /* Cycle through address types; avoid divide by 0. */
2579                 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2580                 if (sat)
2581                         sat /= sizeof(__u16);
2582 
2583                 for (i = 0; i < sat; ++i) {
2584                         switch (param.sat->types[i]) {
2585                         case SCTP_PARAM_IPV4_ADDRESS:
2586                                 asoc->peer.ipv4_address = 1;
2587                                 break;
2588 
2589                         case SCTP_PARAM_IPV6_ADDRESS:
2590                                 if (PF_INET6 == asoc->base.sk->sk_family)
2591                                         asoc->peer.ipv6_address = 1;
2592                                 break;
2593 
2594                         case SCTP_PARAM_HOST_NAME_ADDRESS:
2595                                 asoc->peer.hostname_address = 1;
2596                                 break;
2597 
2598                         default: /* Just ignore anything else.  */
2599                                 break;
2600                         }
2601                 }
2602                 break;
2603 
2604         case SCTP_PARAM_STATE_COOKIE:
2605                 asoc->peer.cookie_len =
2606                         ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2607                 asoc->peer.cookie = param.cookie->body;
2608                 break;
2609 
2610         case SCTP_PARAM_HEARTBEAT_INFO:
2611                 /* Would be odd to receive, but it causes no problems. */
2612                 break;
2613 
2614         case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2615                 /* Rejected during verify stage. */
2616                 break;
2617 
2618         case SCTP_PARAM_ECN_CAPABLE:
2619                 asoc->peer.ecn_capable = 1;
2620                 break;
2621 
2622         case SCTP_PARAM_ADAPTATION_LAYER_IND:
2623                 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2624                 break;
2625 
2626         case SCTP_PARAM_SET_PRIMARY:
2627                 if (!net->sctp.addip_enable)
2628                         goto fall_through;
2629 
2630                 addr_param = param.v + sizeof(sctp_addip_param_t);
2631 
2632                 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2633                 if (af == NULL)
2634                         break;
2635 
2636                 af->from_addr_param(&addr, addr_param,
2637                                     htons(asoc->peer.port), 0);
2638 
2639                 /* if the address is invalid, we can't process it.
2640                  * XXX: see spec for what to do.
2641                  */
2642                 if (!af->addr_valid(&addr, NULL, NULL))
2643                         break;
2644 
2645                 t = sctp_assoc_lookup_paddr(asoc, &addr);
2646                 if (!t)
2647                         break;
2648 
2649                 sctp_assoc_set_primary(asoc, t);
2650                 break;
2651 
2652         case SCTP_PARAM_SUPPORTED_EXT:
2653                 sctp_process_ext_param(asoc, param);
2654                 break;
2655 
2656         case SCTP_PARAM_FWD_TSN_SUPPORT:
2657                 if (asoc->prsctp_enable) {
2658                         asoc->peer.prsctp_capable = 1;
2659                         break;
2660                 }
2661                 /* Fall Through */
2662                 goto fall_through;
2663 
2664         case SCTP_PARAM_RANDOM:
2665                 if (!ep->auth_enable)
2666                         goto fall_through;
2667 
2668                 /* Save peer's random parameter */
2669                 asoc->peer.peer_random = kmemdup(param.p,
2670                                             ntohs(param.p->length), gfp);
2671                 if (!asoc->peer.peer_random) {
2672                         retval = 0;
2673                         break;
2674                 }
2675                 break;
2676 
2677         case SCTP_PARAM_HMAC_ALGO:
2678                 if (!ep->auth_enable)
2679                         goto fall_through;
2680 
2681                 /* Save peer's HMAC list */
2682                 asoc->peer.peer_hmacs = kmemdup(param.p,
2683                                             ntohs(param.p->length), gfp);
2684                 if (!asoc->peer.peer_hmacs) {
2685                         retval = 0;
2686                         break;
2687                 }
2688 
2689                 /* Set the default HMAC the peer requested*/
2690                 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2691                 break;
2692 
2693         case SCTP_PARAM_CHUNKS:
2694                 if (!ep->auth_enable)
2695                         goto fall_through;
2696 
2697                 asoc->peer.peer_chunks = kmemdup(param.p,
2698                                             ntohs(param.p->length), gfp);
2699                 if (!asoc->peer.peer_chunks)
2700                         retval = 0;
2701                 break;
2702 fall_through:
2703         default:
2704                 /* Any unrecognized parameters should have been caught
2705                  * and handled by sctp_verify_param() which should be
2706                  * called prior to this routine.  Simply log the error
2707                  * here.
2708                  */
2709                 pr_debug("%s: ignoring param:%d for association:%p.\n",
2710                          __func__, ntohs(param.p->type), asoc);
2711                 break;
2712         }
2713 
2714         return retval;
2715 }
2716 
2717 /* Select a new verification tag.  */
2718 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2719 {
2720         /* I believe that this random number generator complies with RFC1750.
2721          * A tag of 0 is reserved for special cases (e.g. INIT).
2722          */
2723         __u32 x;
2724 
2725         do {
2726                 get_random_bytes(&x, sizeof(__u32));
2727         } while (x == 0);
2728 
2729         return x;
2730 }
2731 
2732 /* Select an initial TSN to send during startup.  */
2733 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2734 {
2735         __u32 retval;
2736 
2737         get_random_bytes(&retval, sizeof(__u32));
2738         return retval;
2739 }
2740 
2741 /*
2742  * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2743  *      0                   1                   2                   3
2744  *      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
2745  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2746  *     | Type = 0xC1   |  Chunk Flags  |      Chunk Length             |
2747  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2748  *     |                       Serial Number                           |
2749  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2750  *     |                    Address Parameter                          |
2751  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2752  *     |                     ASCONF Parameter #1                       |
2753  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2754  *     \                                                               \
2755  *     /                             ....                              /
2756  *     \                                                               \
2757  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2758  *     |                     ASCONF Parameter #N                       |
2759  *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2760  *
2761  * Address Parameter and other parameter will not be wrapped in this function
2762  */
2763 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2764                                            union sctp_addr *addr,
2765                                            int vparam_len)
2766 {
2767         sctp_addiphdr_t asconf;
2768         struct sctp_chunk *retval;
2769         int length = sizeof(asconf) + vparam_len;
2770         union sctp_addr_param addrparam;
2771         int addrlen;
2772         struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2773 
2774         addrlen = af->to_addr_param(addr, &addrparam);
2775         if (!addrlen)
2776                 return NULL;
2777         length += addrlen;
2778 
2779         /* Create the chunk.  */
2780         retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2781                                    GFP_ATOMIC);
2782         if (!retval)
2783                 return NULL;
2784 
2785         asconf.serial = htonl(asoc->addip_serial++);
2786 
2787         retval->subh.addip_hdr =
2788                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2789         retval->param_hdr.v =
2790                 sctp_addto_chunk(retval, addrlen, &addrparam);
2791 
2792         return retval;
2793 }
2794 
2795 /* ADDIP
2796  * 3.2.1 Add 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 = 0xC001          |    Length = Variable          |
2801  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2802  *     |               ASCONF-Request Correlation ID                   |
2803  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2804  *     |                       Address Parameter                       |
2805  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2806  *
2807  * 3.2.2 Delete IP Address
2808  *      0                   1                   2                   3
2809  *      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
2810  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2811  *     |        Type = 0xC002          |    Length = Variable          |
2812  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2813  *     |               ASCONF-Request Correlation ID                   |
2814  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2815  *     |                       Address Parameter                       |
2816  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2817  *
2818  */
2819 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2820                                               union sctp_addr         *laddr,
2821                                               struct sockaddr         *addrs,
2822                                               int                     addrcnt,
2823                                               __be16                  flags)
2824 {
2825         sctp_addip_param_t      param;
2826         struct sctp_chunk       *retval;
2827         union sctp_addr_param   addr_param;
2828         union sctp_addr         *addr;
2829         void                    *addr_buf;
2830         struct sctp_af          *af;
2831         int                     paramlen = sizeof(param);
2832         int                     addr_param_len = 0;
2833         int                     totallen = 0;
2834         int                     i;
2835         int                     del_pickup = 0;
2836 
2837         /* Get total length of all the address parameters. */
2838         addr_buf = addrs;
2839         for (i = 0; i < addrcnt; i++) {
2840                 addr = addr_buf;
2841                 af = sctp_get_af_specific(addr->v4.sin_family);
2842                 addr_param_len = af->to_addr_param(addr, &addr_param);
2843 
2844                 totallen += paramlen;
2845                 totallen += addr_param_len;
2846 
2847                 addr_buf += af->sockaddr_len;
2848                 if (asoc->asconf_addr_del_pending && !del_pickup) {
2849                         /* reuse the parameter length from the same scope one */
2850                         totallen += paramlen;
2851                         totallen += addr_param_len;
2852                         del_pickup = 1;
2853 
2854                         pr_debug("%s: picked same-scope del_pending addr, "
2855                                  "totallen for all addresses is %d\n",
2856                                  __func__, totallen);
2857                 }
2858         }
2859 
2860         /* Create an asconf chunk with the required length. */
2861         retval = sctp_make_asconf(asoc, laddr, totallen);
2862         if (!retval)
2863                 return NULL;
2864 
2865         /* Add the address parameters to the asconf chunk. */
2866         addr_buf = addrs;
2867         for (i = 0; i < addrcnt; i++) {
2868                 addr = addr_buf;
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 = flags;
2872                 param.param_hdr.length = htons(paramlen + addr_param_len);
2873                 param.crr_id = i;
2874 
2875                 sctp_addto_chunk(retval, paramlen, &param);
2876                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2877 
2878                 addr_buf += af->sockaddr_len;
2879         }
2880         if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2881                 addr = asoc->asconf_addr_del_pending;
2882                 af = sctp_get_af_specific(addr->v4.sin_family);
2883                 addr_param_len = af->to_addr_param(addr, &addr_param);
2884                 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2885                 param.param_hdr.length = htons(paramlen + addr_param_len);
2886                 param.crr_id = i;
2887 
2888                 sctp_addto_chunk(retval, paramlen, &param);
2889                 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2890         }
2891         return retval;
2892 }
2893 
2894 /* ADDIP
2895  * 3.2.4 Set Primary IP Address
2896  *      0                   1                   2                   3
2897  *      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
2898  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2899  *     |        Type =0xC004           |    Length = Variable          |
2900  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2901  *     |               ASCONF-Request Correlation ID                   |
2902  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2903  *     |                       Address Parameter                       |
2904  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2905  *
2906  * Create an ASCONF chunk with Set Primary IP address parameter.
2907  */
2908 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2909                                              union sctp_addr *addr)
2910 {
2911         sctp_addip_param_t      param;
2912         struct sctp_chunk       *retval;
2913         int                     len = sizeof(param);
2914         union sctp_addr_param   addrparam;
2915         int                     addrlen;
2916         struct sctp_af          *af = sctp_get_af_specific(addr->v4.sin_family);
2917 
2918         addrlen = af->to_addr_param(addr, &addrparam);
2919         if (!addrlen)
2920                 return NULL;
2921         len += addrlen;
2922 
2923         /* Create the chunk and make asconf header. */
2924         retval = sctp_make_asconf(asoc, addr, len);
2925         if (!retval)
2926                 return NULL;
2927 
2928         param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2929         param.param_hdr.length = htons(len);
2930         param.crr_id = 0;
2931 
2932         sctp_addto_chunk(retval, sizeof(param), &param);
2933         sctp_addto_chunk(retval, addrlen, &addrparam);
2934 
2935         return retval;
2936 }
2937 
2938 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2939  *      0                   1                   2                   3
2940  *      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
2941  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2942  *     | Type = 0x80   |  Chunk Flags  |      Chunk Length             |
2943  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2944  *     |                       Serial Number                           |
2945  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2946  *     |                 ASCONF Parameter Response#1                   |
2947  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2948  *     \                                                               \
2949  *     /                             ....                              /
2950  *     \                                                               \
2951  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2952  *     |                 ASCONF Parameter Response#N                   |
2953  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2954  *
2955  * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2956  */
2957 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2958                                                __u32 serial, int vparam_len)
2959 {
2960         sctp_addiphdr_t         asconf;
2961         struct sctp_chunk       *retval;
2962         int                     length = sizeof(asconf) + vparam_len;
2963 
2964         /* Create the chunk.  */
2965         retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2966                                    GFP_ATOMIC);
2967         if (!retval)
2968                 return NULL;
2969 
2970         asconf.serial = htonl(serial);
2971 
2972         retval->subh.addip_hdr =
2973                 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2974 
2975         return retval;
2976 }
2977 
2978 /* Add response parameters to an ASCONF_ACK chunk. */
2979 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2980                               __be16 err_code, sctp_addip_param_t *asconf_param)
2981 {
2982         sctp_addip_param_t      ack_param;
2983         sctp_errhdr_t           err_param;
2984         int                     asconf_param_len = 0;
2985         int                     err_param_len = 0;
2986         __be16                  response_type;
2987 
2988         if (SCTP_ERROR_NO_ERROR == err_code) {
2989                 response_type = SCTP_PARAM_SUCCESS_REPORT;
2990         } else {
2991                 response_type = SCTP_PARAM_ERR_CAUSE;
2992                 err_param_len = sizeof(err_param);
2993                 if (asconf_param)
2994                         asconf_param_len =
2995                                  ntohs(asconf_param->param_hdr.length);
2996         }
2997 
2998         /* Add Success Indication or Error Cause Indication parameter. */
2999         ack_param.param_hdr.type = response_type;
3000         ack_param.param_hdr.length = htons(sizeof(ack_param) +
3001                                            err_param_len +
3002                                            asconf_param_len);
3003         ack_param.crr_id = crr_id;
3004         sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3005 
3006         if (SCTP_ERROR_NO_ERROR == err_code)
3007                 return;
3008 
3009         /* Add Error Cause parameter. */
3010         err_param.cause = err_code;
3011         err_param.length = htons(err_param_len + asconf_param_len);
3012         sctp_addto_chunk(chunk, err_param_len, &err_param);
3013 
3014         /* Add the failed TLV copied from ASCONF chunk. */
3015         if (asconf_param)
3016                 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3017 }
3018 
3019 /* Process a asconf parameter. */
3020 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3021                                        struct sctp_chunk *asconf,
3022                                        sctp_addip_param_t *asconf_param)
3023 {
3024         struct sctp_transport *peer;
3025         struct sctp_af *af;
3026         union sctp_addr addr;
3027         union sctp_addr_param *addr_param;
3028 
3029         addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3030 
3031         if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3032             asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3033             asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3034                 return SCTP_ERROR_UNKNOWN_PARAM;
3035 
3036         switch (addr_param->p.type) {
3037         case SCTP_PARAM_IPV6_ADDRESS:
3038                 if (!asoc->peer.ipv6_address)
3039                         return SCTP_ERROR_DNS_FAILED;
3040                 break;
3041         case SCTP_PARAM_IPV4_ADDRESS:
3042                 if (!asoc->peer.ipv4_address)
3043                         return SCTP_ERROR_DNS_FAILED;
3044                 break;
3045         default:
3046                 return SCTP_ERROR_DNS_FAILED;
3047         }
3048 
3049         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3050         if (unlikely(!af))
3051                 return SCTP_ERROR_DNS_FAILED;
3052 
3053         af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3054 
3055         /* ADDIP 4.2.1  This parameter MUST NOT contain a broadcast
3056          * or multicast address.
3057          * (note: wildcard is permitted and requires special handling so
3058          *  make sure we check for that)
3059          */
3060         if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3061                 return SCTP_ERROR_DNS_FAILED;
3062 
3063         switch (asconf_param->param_hdr.type) {
3064         case SCTP_PARAM_ADD_IP:
3065                 /* Section 4.2.1:
3066                  * If the address 0.0.0.0 or ::0 is provided, the source
3067                  * address of the packet MUST be added.
3068                  */
3069                 if (af->is_any(&addr))
3070                         memcpy(&addr, &asconf->source, sizeof(addr));
3071 
3072                 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3073                  * request and does not have the local resources to add this
3074                  * new address to the association, it MUST return an Error
3075                  * Cause TLV set to the new error code 'Operation Refused
3076                  * Due to Resource Shortage'.
3077                  */
3078 
3079                 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3080                 if (!peer)
3081                         return SCTP_ERROR_RSRC_LOW;
3082 
3083                 /* Start the heartbeat timer. */
3084                 sctp_transport_reset_hb_timer(peer);
3085                 asoc->new_transport = peer;
3086                 break;
3087         case SCTP_PARAM_DEL_IP:
3088                 /* ADDIP 4.3 D7) If a request is received to delete the
3089                  * last remaining IP address of a peer endpoint, the receiver
3090                  * MUST send an Error Cause TLV with the error cause set to the
3091                  * new error code 'Request to Delete Last Remaining IP Address'.
3092                  */
3093                 if (asoc->peer.transport_count == 1)
3094                         return SCTP_ERROR_DEL_LAST_IP;
3095 
3096                 /* ADDIP 4.3 D8) If a request is received to delete an IP
3097                  * address which is also the source address of the IP packet
3098                  * which contained the ASCONF chunk, the receiver MUST reject
3099                  * this request. To reject the request the receiver MUST send
3100                  * an Error Cause TLV set to the new error code 'Request to
3101                  * Delete Source IP Address'
3102                  */
3103                 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3104                         return SCTP_ERROR_DEL_SRC_IP;
3105 
3106                 /* Section 4.2.2
3107                  * If the address 0.0.0.0 or ::0 is provided, all
3108                  * addresses of the peer except the source address of the
3109                  * packet MUST be deleted.
3110                  */
3111                 if (af->is_any(&addr)) {
3112                         sctp_assoc_set_primary(asoc, asconf->transport);
3113                         sctp_assoc_del_nonprimary_peers(asoc,
3114                                                         asconf->transport);
3115                         return SCTP_ERROR_NO_ERROR;
3116                 }
3117 
3118                 /* If the address is not part of the association, the
3119                  * ASCONF-ACK with Error Cause Indication Parameter
3120                  * which including cause of Unresolvable Address should
3121                  * be sent.
3122                  */
3123                 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3124                 if (!peer)
3125                         return SCTP_ERROR_DNS_FAILED;
3126 
3127                 sctp_assoc_rm_peer(asoc, peer);
3128                 break;
3129         case SCTP_PARAM_SET_PRIMARY:
3130                 /* ADDIP Section 4.2.4
3131                  * If the address 0.0.0.0 or ::0 is provided, the receiver
3132                  * MAY mark the source address of the packet as its
3133                  * primary.
3134                  */
3135                 if (af->is_any(&addr))
3136                         memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
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         sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
3155         union sctp_params param;
3156         bool addr_param_seen = false;
3157 
3158         sctp_walk_params(param, addip, addip_hdr.params) {
3159                 size_t length = ntohs(param.p->length);
3160 
3161                 *errp = param.p;
3162                 switch (param.p->type) {
3163                 case SCTP_PARAM_ERR_CAUSE:
3164                         break;
3165                 case SCTP_PARAM_IPV4_ADDRESS:
3166                         if (length != sizeof(sctp_ipv4addr_param_t))
3167                                 return false;
3168                         /* ensure there is only one addr param and it's in the
3169                          * beginning of addip_hdr params, or we reject it.
3170                          */
3171                         if (param.v != addip->addip_hdr.params)
3172                                 return false;
3173                         addr_param_seen = true;
3174                         break;
3175                 case SCTP_PARAM_IPV6_ADDRESS:
3176                         if (length != sizeof(sctp_ipv6addr_param_t))
3177                                 return false;
3178                         if (param.v != addip->addip_hdr.params)
3179                                 return false;
3180                         addr_param_seen = true;
3181                         break;
3182                 case SCTP_PARAM_ADD_IP:
3183                 case SCTP_PARAM_DEL_IP:
3184                 case SCTP_PARAM_SET_PRIMARY:
3185                         /* In ASCONF chunks, these need to be first. */
3186                         if (addr_param_needed && !addr_param_seen)
3187                                 return false;
3188                         length = ntohs(param.addip->param_hdr.length);
3189                         if (length < sizeof(sctp_addip_param_t) +
3190                                      sizeof(sctp_paramhdr_t))
3191                                 return false;
3192                         break;
3193                 case SCTP_PARAM_SUCCESS_REPORT:
3194                 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3195                         if (length != sizeof(sctp_addip_param_t))
3196                                 return false;
3197                         break;
3198                 default:
3199                         /* This is unkown to us, reject! */
3200                         return false;
3201                 }
3202         }
3203 
3204         /* Remaining sanity checks. */
3205         if (addr_param_needed && !addr_param_seen)
3206                 return false;
3207         if (!addr_param_needed && addr_param_seen)
3208                 return false;
3209         if (param.v != chunk->chunk_end)
3210                 return false;
3211 
3212         return true;
3213 }
3214 
3215 /* Process an incoming ASCONF chunk with the next expected serial no. and
3216  * return an ASCONF_ACK chunk to be sent in response.
3217  */
3218 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3219                                        struct sctp_chunk *asconf)
3220 {
3221         sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
3222         bool all_param_pass = true;
3223         union sctp_params param;
3224         sctp_addiphdr_t         *hdr;
3225         union sctp_addr_param   *addr_param;
3226         struct sctp_chunk       *asconf_ack;
3227         __be16  err_code;
3228         int     length = 0;
3229         int     chunk_len;
3230         __u32   serial;
3231 
3232         chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3233         hdr = (sctp_addiphdr_t *)asconf->skb->data;
3234         serial = ntohl(hdr->serial);
3235 
3236         /* Skip the addiphdr and store a pointer to address parameter.  */
3237         length = sizeof(sctp_addiphdr_t);
3238         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3239         chunk_len -= length;
3240 
3241         /* Skip the address parameter and store a pointer to the first
3242          * asconf parameter.
3243          */
3244         length = ntohs(addr_param->p.length);
3245         chunk_len -= length;
3246 
3247         /* create an ASCONF_ACK chunk.
3248          * Based on the definitions of parameters, we know that the size of
3249          * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3250          * parameters.
3251          */
3252         asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3253         if (!asconf_ack)
3254                 goto done;
3255 
3256         /* Process the TLVs contained within the ASCONF chunk. */
3257         sctp_walk_params(param, addip, addip_hdr.params) {
3258                 /* Skip preceeding address parameters. */
3259                 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3260                     param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3261                         continue;
3262 
3263                 err_code = sctp_process_asconf_param(asoc, asconf,
3264                                                      param.addip);
3265                 /* ADDIP 4.1 A7)
3266                  * If an error response is received for a TLV parameter,
3267                  * all TLVs with no response before the failed TLV are
3268                  * considered successful if not reported.  All TLVs after
3269                  * the failed response are considered unsuccessful unless
3270                  * a specific success indication is present for the parameter.
3271                  */
3272                 if (err_code != SCTP_ERROR_NO_ERROR)
3273                         all_param_pass = false;
3274                 if (!all_param_pass)
3275                         sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3276                                                  err_code, param.addip);
3277 
3278                 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3279                  * an IP address sends an 'Out of Resource' in its response, it
3280                  * MUST also fail any subsequent add or delete requests bundled
3281                  * in the ASCONF.
3282                  */
3283                 if (err_code == SCTP_ERROR_RSRC_LOW)
3284                         goto done;
3285         }
3286 done:
3287         asoc->peer.addip_serial++;
3288 
3289         /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3290          * after freeing the reference to old asconf ack if any.
3291          */
3292         if (asconf_ack) {
3293                 sctp_chunk_hold(asconf_ack);
3294                 list_add_tail(&asconf_ack->transmitted_list,
3295                               &asoc->asconf_ack_list);
3296         }
3297 
3298         return asconf_ack;
3299 }
3300 
3301 /* Process a asconf parameter that is successfully acked. */
3302 static void sctp_asconf_param_success(struct sctp_association *asoc,
3303                                      sctp_addip_param_t *asconf_param)
3304 {
3305         struct sctp_af *af;
3306         union sctp_addr addr;
3307         struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3308         union sctp_addr_param *addr_param;
3309         struct sctp_transport *transport;
3310         struct sctp_sockaddr_entry *saddr;
3311 
3312         addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3313 
3314         /* We have checked the packet before, so we do not check again. */
3315         af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3316         af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3317 
3318         switch (asconf_param->param_hdr.type) {
3319         case SCTP_PARAM_ADD_IP:
3320                 /* This is always done in BH context with a socket lock
3321                  * held, so the list can not change.
3322                  */
3323                 local_bh_disable();
3324                 list_for_each_entry(saddr, &bp->address_list, list) {
3325                         if (sctp_cmp_addr_exact(&saddr->a, &addr))
3326                                 saddr->state = SCTP_ADDR_SRC;
3327                 }
3328                 local_bh_enable();
3329                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3330                                 transports) {
3331                         sctp_transport_dst_release(transport);
3332                 }
3333                 break;
3334         case SCTP_PARAM_DEL_IP:
3335                 local_bh_disable();
3336                 sctp_del_bind_addr(bp, &addr);
3337                 if (asoc->asconf_addr_del_pending != NULL &&
3338                     sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3339                         kfree(asoc->asconf_addr_del_pending);
3340                         asoc->asconf_addr_del_pending = NULL;
3341                 }
3342                 local_bh_enable();
3343                 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3344                                 transports) {
3345                         sctp_transport_dst_release(transport);
3346                 }
3347                 break;
3348         default:
3349                 break;
3350         }
3351 }
3352 
3353 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3354  * for the given asconf parameter.  If there is no response for this parameter,
3355  * return the error code based on the third argument 'no_err'.
3356  * ADDIP 4.1
3357  * A7) If an error response is received for a TLV parameter, all TLVs with no
3358  * response before the failed TLV are considered successful if not reported.
3359  * All TLVs after the failed response are considered unsuccessful unless a
3360  * specific success indication is present for the parameter.
3361  */
3362 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3363                                       sctp_addip_param_t *asconf_param,
3364                                       int no_err)
3365 {
3366         sctp_addip_param_t      *asconf_ack_param;
3367         sctp_errhdr_t           *err_param;
3368         int                     length;
3369         int                     asconf_ack_len;
3370         __be16                  err_code;
3371 
3372         if (no_err)
3373                 err_code = SCTP_ERROR_NO_ERROR;
3374         else
3375                 err_code = SCTP_ERROR_REQ_REFUSED;
3376 
3377         asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3378                              sizeof(sctp_chunkhdr_t);
3379 
3380         /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3381          * the first asconf_ack parameter.
3382          */
3383         length = sizeof(sctp_addiphdr_t);
3384         asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3385                                                   length);
3386         asconf_ack_len -= length;
3387 
3388         while (asconf_ack_len > 0) {
3389                 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3390                         switch (asconf_ack_param->param_hdr.type) {
3391                         case SCTP_PARAM_SUCCESS_REPORT:
3392                                 return SCTP_ERROR_NO_ERROR;
3393                         case SCTP_PARAM_ERR_CAUSE:
3394                                 length = sizeof(sctp_addip_param_t);
3395                                 err_param = (void *)asconf_ack_param + length;
3396                                 asconf_ack_len -= length;
3397                                 if (asconf_ack_len > 0)
3398                                         return err_param->cause;
3399                                 else
3400                                         return SCTP_ERROR_INV_PARAM;
3401                                 break;
3402                         default:
3403                                 return SCTP_ERROR_INV_PARAM;
3404                         }
3405                 }
3406 
3407                 length = ntohs(asconf_ack_param->param_hdr.length);
3408                 asconf_ack_param = (void *)asconf_ack_param + length;
3409                 asconf_ack_len -= length;
3410         }
3411 
3412         return err_code;
3413 }
3414 
3415 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3416 int sctp_process_asconf_ack(struct sctp_association *asoc,
3417                             struct sctp_chunk *asconf_ack)
3418 {
3419         struct sctp_chunk       *asconf = asoc->addip_last_asconf;
3420         union sctp_addr_param   *addr_param;
3421         sctp_addip_param_t      *asconf_param;
3422         int     length = 0;
3423         int     asconf_len = asconf->skb->len;
3424         int     all_param_pass = 0;
3425         int     no_err = 1;
3426         int     retval = 0;
3427         __be16  err_code = SCTP_ERROR_NO_ERROR;
3428 
3429         /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3430          * a pointer to address parameter.
3431          */
3432         length = sizeof(sctp_addip_chunk_t);
3433         addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3434         asconf_len -= length;
3435 
3436         /* Skip the address parameter in the last asconf sent and store a
3437          * pointer to the first asconf parameter.
3438          */
3439         length = ntohs(addr_param->p.length);
3440         asconf_param = (void *)addr_param + length;
3441         asconf_len -= length;
3442 
3443         /* ADDIP 4.1
3444          * A8) If there is no response(s) to specific TLV parameter(s), and no
3445          * failures are indicated, then all request(s) are considered
3446          * successful.
3447          */
3448         if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3449                 all_param_pass = 1;
3450 
3451         /* Process the TLVs contained in the last sent ASCONF chunk. */
3452         while (asconf_len > 0) {
3453                 if (all_param_pass)
3454                         err_code = SCTP_ERROR_NO_ERROR;
3455                 else {
3456                         err_code = sctp_get_asconf_response(asconf_ack,
3457                                                             asconf_param,
3458                                                             no_err);
3459                         if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3460                                 no_err = 0;
3461                 }
3462 
3463                 switch (err_code) {
3464                 case SCTP_ERROR_NO_ERROR:
3465                         sctp_asconf_param_success(asoc, asconf_param);
3466                         break;
3467 
3468                 case SCTP_ERROR_RSRC_LOW:
3469                         retval = 1;
3470                         break;
3471 
3472                 case SCTP_ERROR_UNKNOWN_PARAM:
3473                         /* Disable sending this type of asconf parameter in
3474                          * future.
3475                          */
3476                         asoc->peer.addip_disabled_mask |=
3477                                 asconf_param->param_hdr.type;
3478                         break;
3479 
3480                 case SCTP_ERROR_REQ_REFUSED:
3481                 case SCTP_ERROR_DEL_LAST_IP:
3482                 case SCTP_ERROR_DEL_SRC_IP:
3483                 default:
3484                          break;
3485                 }
3486 
3487                 /* Skip the processed asconf parameter and move to the next
3488                  * one.
3489                  */
3490                 length = ntohs(asconf_param->param_hdr.length);
3491                 asconf_param = (void *)asconf_param + length;
3492                 asconf_len -= length;
3493         }
3494 
3495         if (no_err && asoc->src_out_of_asoc_ok) {
3496                 asoc->src_out_of_asoc_ok = 0;
3497                 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3498         }
3499 
3500         /* Free the cached last sent asconf chunk. */
3501         list_del_init(&asconf->transmitted_list);
3502         sctp_chunk_free(asconf);
3503         asoc->addip_last_asconf = NULL;
3504 
3505         return retval;
3506 }
3507 
3508 /* Make a FWD TSN chunk. */
3509 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3510                                     __u32 new_cum_tsn, size_t nstreams,
3511                                     struct sctp_fwdtsn_skip *skiplist)
3512 {
3513         struct sctp_chunk *retval = NULL;
3514         struct sctp_fwdtsn_hdr ftsn_hdr;
3515         struct sctp_fwdtsn_skip skip;
3516         size_t hint;
3517         int i;
3518 
3519         hint = (nstreams + 1) * sizeof(__u32);
3520 
3521         retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3522 
3523         if (!retval)
3524                 return NULL;
3525 
3526         ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3527         retval->subh.fwdtsn_hdr =
3528                 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3529 
3530         for (i = 0; i < nstreams; i++) {
3531                 skip.stream = skiplist[i].stream;
3532                 skip.ssn = skiplist[i].ssn;
3533                 sctp_addto_chunk(retval, sizeof(skip), &skip);
3534         }
3535 
3536         return retval;
3537 }
3538 
3539 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
3540  *   0                   1                   2                   3
3541  *   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
3542  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3543  *  | Type = 130    |  Chunk Flags  |      Chunk Length             |
3544  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3545  *  \                                                               \
3546  *  /                  Re-configuration Parameter                   /
3547  *  \                                                               \
3548  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3549  *  \                                                               \
3550  *  /             Re-configuration Parameter (optional)             /
3551  *  \                                                               \
3552  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3553  */
3554 static struct sctp_chunk *sctp_make_reconf(
3555                                 const struct sctp_association *asoc,
3556                                 int length)
3557 {
3558         struct sctp_reconf_chunk *reconf;
3559         struct sctp_chunk *retval;
3560 
3561         retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3562                                    GFP_ATOMIC);
3563         if (!retval)
3564                 return NULL;
3565 
3566         reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3567         retval->param_hdr.v = reconf->params;
3568 
3569         return retval;
3570 }
3571 
3572 /* RE-CONFIG 4.1 (STREAM OUT RESET)
3573  *   0                   1                   2                   3
3574  *   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
3575  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3576  *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
3577  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3578  *  |           Re-configuration Request Sequence Number            |
3579  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3580  *  |           Re-configuration Response Sequence Number           |
3581  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3582  *  |                Sender's Last Assigned TSN                     |
3583  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3584  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3585  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3586  *  /                            ......                             /
3587  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3588  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3589  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3590  *
3591  * RE-CONFIG 4.2 (STREAM IN RESET)
3592  *   0                   1                   2                   3
3593  *   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
3594  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3595  *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
3596  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3597  *  |          Re-configuration Request Sequence Number             |
3598  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3599  *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
3600  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3601  *  /                            ......                             /
3602  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3603  *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
3604  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3605  */
3606 struct sctp_chunk *sctp_make_strreset_req(
3607                                 const struct sctp_association *asoc,
3608                                 __u16 stream_num, __u16 *stream_list,
3609                                 bool out, bool in)
3610 {
3611         struct sctp_strreset_outreq outreq;
3612         __u16 stream_len = stream_num * 2;
3613         struct sctp_strreset_inreq inreq;
3614         struct sctp_chunk *retval;
3615         __u16 outlen, inlen;
3616 
3617         outlen = (sizeof(outreq) + stream_len) * out;
3618         inlen = (sizeof(inreq) + stream_len) * in;
3619 
3620         retval = sctp_make_reconf(asoc, outlen + inlen);
3621         if (!retval)
3622                 return NULL;
3623 
3624         if (outlen) {
3625                 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3626                 outreq.param_hdr.length = htons(outlen);
3627                 outreq.request_seq = htonl(asoc->strreset_outseq);
3628                 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3629                 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3630 
3631                 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3632 
3633                 if (stream_len)
3634                         sctp_addto_chunk(retval, stream_len, stream_list);
3635         }
3636 
3637         if (inlen) {
3638                 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3639                 inreq.param_hdr.length = htons(inlen);
3640                 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3641 
3642                 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3643 
3644                 if (stream_len)
3645                         sctp_addto_chunk(retval, stream_len, stream_list);
3646         }
3647 
3648         return retval;
3649 }
3650 
3651 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3652  *   0                   1                   2                   3
3653  *   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
3654  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3655  *  |     Parameter Type = 15       |      Parameter Length = 8     |
3656  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3657  *  |         Re-configuration Request Sequence Number              |
3658  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3659  */
3660 struct sctp_chunk *sctp_make_strreset_tsnreq(
3661                                 const struct sctp_association *asoc)
3662 {
3663         struct sctp_strreset_tsnreq tsnreq;
3664         __u16 length = sizeof(tsnreq);
3665         struct sctp_chunk *retval;
3666 
3667         retval = sctp_make_reconf(asoc, length);
3668         if (!retval)
3669                 return NULL;
3670 
3671         tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3672         tsnreq.param_hdr.length = htons(length);
3673         tsnreq.request_seq = htonl(asoc->strreset_outseq);
3674 
3675         sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3676 
3677         return retval;
3678 }
3679 
3680 /* RE-CONFIG 4.5/4.6 (ADD STREAM)
3681  *   0                   1                   2                   3
3682  *   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
3683  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3684  *  |     Parameter Type = 17       |      Parameter Length = 12    |
3685  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3686  *  |          Re-configuration Request Sequence Number             |
3687  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3688  *  |      Number of new streams    |         Reserved              |
3689  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3690  */
3691 struct sctp_chunk *sctp_make_strreset_addstrm(
3692                                 const struct sctp_association *asoc,
3693                                 __u16 out, __u16 in)
3694 {
3695         struct sctp_strreset_addstrm addstrm;
3696         __u16 size = sizeof(addstrm);
3697         struct sctp_chunk *retval;
3698 
3699         retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3700         if (!retval)
3701                 return NULL;
3702 
3703         if (out) {
3704                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3705                 addstrm.param_hdr.length = htons(size);
3706                 addstrm.number_of_streams = htons(out);
3707                 addstrm.request_seq = htonl(asoc->strreset_outseq);
3708                 addstrm.reserved = 0;
3709 
3710                 sctp_addto_chunk(retval, size, &addstrm);
3711         }
3712 
3713         if (in) {
3714                 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3715                 addstrm.param_hdr.length = htons(size);
3716                 addstrm.number_of_streams = htons(in);
3717                 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3718                 addstrm.reserved = 0;
3719 
3720                 sctp_addto_chunk(retval, size, &addstrm);
3721         }
3722 
3723         return retval;
3724 }
3725 
3726 /* RE-CONFIG 4.4 (RESP)
3727  *   0                   1                   2                   3
3728  *   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
3729  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3730  *  |     Parameter Type = 16       |      Parameter Length         |
3731  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3732  *  |         Re-configuration Response Sequence Number             |
3733  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3734  *  |                            Result                             |
3735  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3736  */
3737 struct sctp_chunk *sctp_make_strreset_resp(
3738                                 const struct sctp_association *asoc,
3739                                 __u32 result, __u32 sn)
3740 {
3741         struct sctp_strreset_resp resp;
3742         __u16 length = sizeof(resp);
3743         struct sctp_chunk *retval;
3744 
3745         retval = sctp_make_reconf(asoc, length);
3746         if (!retval)
3747                 return NULL;
3748 
3749         resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3750         resp.param_hdr.length = htons(length);
3751         resp.response_seq = htonl(sn);
3752         resp.result = htonl(result);
3753 
3754         sctp_addto_chunk(retval, sizeof(resp), &resp);
3755 
3756         return retval;
3757 }
3758 
3759 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3760  *   0                   1                   2                   3
3761  *   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
3762  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3763  *  |     Parameter Type = 16       |      Parameter Length         |
3764  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3765  *  |         Re-configuration Response Sequence Number             |
3766  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3767  *  |                            Result                             |
3768  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3769  *  |                   Sender's Next TSN (optional)                |
3770  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3771  *  |                  Receiver's Next TSN (optional)               |
3772  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3773  */
3774 struct sctp_chunk *sctp_make_strreset_tsnresp(
3775                                         struct sctp_association *asoc,
3776                                         __u32 result, __u32 sn,
3777                                         __u32 sender_tsn, __u32 receiver_tsn)
3778 {
3779         struct sctp_strreset_resptsn tsnresp;
3780         __u16 length = sizeof(tsnresp);
3781         struct sctp_chunk *retval;
3782 
3783         retval = sctp_make_reconf(asoc, length);
3784         if (!retval)
3785                 return NULL;
3786 
3787         tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3788         tsnresp.param_hdr.length = htons(length);
3789 
3790         tsnresp.response_seq = htonl(sn);
3791         tsnresp.result = htonl(result);
3792         tsnresp.senders_next_tsn = htonl(sender_tsn);
3793         tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3794 
3795         sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3796 
3797         return retval;
3798 }
3799 
3800 bool sctp_verify_reconf(const struct sctp_association *asoc,
3801                         struct sctp_chunk *chunk,
3802                         struct sctp_paramhdr **errp)
3803 {
3804         struct sctp_reconf_chunk *hdr;
3805         union sctp_params param;
3806         __u16 last = 0, cnt = 0;
3807 
3808         hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3809         sctp_walk_params(param, hdr, params) {
3810                 __u16 length = ntohs(param.p->length);
3811 
3812                 *errp = param.p;
3813                 if (cnt++ > 2)
3814                         return false;
3815                 switch (param.p->type) {
3816                 case SCTP_PARAM_RESET_OUT_REQUEST:
3817                         if (length < sizeof(struct sctp_strreset_outreq) ||
3818                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3819                              last != SCTP_PARAM_RESET_IN_REQUEST))
3820                                 return false;
3821                         break;
3822                 case SCTP_PARAM_RESET_IN_REQUEST:
3823                         if (length < sizeof(struct sctp_strreset_inreq) ||
3824                             (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3825                                 return false;
3826                         break;
3827                 case SCTP_PARAM_RESET_RESPONSE:
3828                         if ((length != sizeof(struct sctp_strreset_resp) &&
3829                              length != sizeof(struct sctp_strreset_resptsn)) ||
3830                             (last && last != SCTP_PARAM_RESET_RESPONSE &&
3831                              last != SCTP_PARAM_RESET_OUT_REQUEST))
3832                                 return false;
3833                         break;
3834                 case SCTP_PARAM_RESET_TSN_REQUEST:
3835                         if (length !=
3836                             sizeof(struct sctp_strreset_tsnreq) || last)
3837                                 return false;
3838                         break;
3839                 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3840                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3841                             (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3842                                 return false;
3843                         break;
3844                 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3845                         if (length != sizeof(struct sctp_strreset_addstrm) ||
3846                             (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3847                                 return false;
3848                         break;
3849                 default:
3850                         return false;
3851                 }
3852 
3853                 last = param.p->type;
3854         }
3855 
3856         return true;
3857 }
3858 

~ [ 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