kernel/net/netfilter/nf_conntrack_proto_sctp.c

   1 /*
   2  * Connection tracking protocol helper module for SCTP.
   3  *
   4  * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
   5  * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
   6  *
   7  * SCTP is defined in RFC 2960. References to various sections in this code
   8  * are to this RFC.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  */
  14
  15 #include <linux/types.h>
  16 #include <linux/timer.h>
  17 #include <linux/netfilter.h>
  18 #include <linux/module.h>
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <linux/sctp.h>
  22 #include <linux/string.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/interrupt.h>
  26
  27 #include <net/netfilter/nf_conntrack.h>
  28 #include <net/netfilter/nf_conntrack_l4proto.h>
  29 #include <net/netfilter/nf_conntrack_ecache.h>
  30
  31 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  32    closely.  They're more complex. --RR
  33
  34    And so for me for SCTP :D -Kiran */
  35
  36 static const char *const sctp_conntrack_names[] = {
  37         "NONE",
  38         "CLOSED",
  39         "COOKIE_WAIT",
  40         "COOKIE_ECHOED",
  41         "ESTABLISHED",
  42         "SHUTDOWN_SENT",
  43         "SHUTDOWN_RECD",
  44         "SHUTDOWN_ACK_SENT",
  45         "HEARTBEAT_SENT",
  46         "HEARTBEAT_ACKED",
  47 };
  48
  49 #define SECS  * HZ
  50 #define MINS  * 60 SECS
  51 #define HOURS * 60 MINS
  52 #define DAYS  * 24 HOURS
  53
  54 static unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] __read_mostly = {
  55         [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  56         [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  57         [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  58         [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  59         [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  60         [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  61         [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  62         [SCTP_CONNTRACK_HEARTBEAT_SENT]         = 30 SECS,
  63         [SCTP_CONNTRACK_HEARTBEAT_ACKED]        = 210 SECS,
  64 };
  65
  66 #define sNO SCTP_CONNTRACK_NONE
  67 #define sCL SCTP_CONNTRACK_CLOSED
  68 #define sCW SCTP_CONNTRACK_COOKIE_WAIT
  69 #define sCE SCTP_CONNTRACK_COOKIE_ECHOED
  70 #define sES SCTP_CONNTRACK_ESTABLISHED
  71 #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
  72 #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
  73 #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
  74 #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
  75 #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
  76 #define sIV SCTP_CONNTRACK_MAX
  77
  78 /*
  79         These are the descriptions of the states:
  80
  81 NOTE: These state names are tantalizingly similar to the states of an
  82 SCTP endpoint. But the interpretation of the states is a little different,
  83 considering that these are the states of the connection and not of an end
  84 point. Please note the subtleties. -Kiran
  85
  86 NONE              - Nothing so far.
  87 COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  88                     an INIT_ACK chunk in the reply direction.
  89 COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  90 ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  91 SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  92 SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  93 SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  94                     to that of the SHUTDOWN chunk.
  95 CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  96                     the SHUTDOWN chunk. Connection is closed.
  97 HEARTBEAT_SENT    - We have seen a HEARTBEAT in a new flow.
  98 HEARTBEAT_ACKED   - We have seen a HEARTBEAT-ACK in the direction opposite to
  99                     that of the HEARTBEAT chunk. Secondary connection is
 100                     established.
 101 */
 102
 103 /* TODO
 104  - I have assumed that the first INIT is in the original direction.
 105  This messes things when an INIT comes in the reply direction in CLOSED
 106  state.
 107  - Check the error type in the reply dir before transitioning from
 108 cookie echoed to closed.
 109  - Sec 5.2.4 of RFC 2960
 110  - Full Multi Homing support.
 111 */
 112
 113 /* SCTP conntrack state transitions */
 114 static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 115         {
 116 /*      ORIGINAL        */
 117 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 118 /* init         */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
 119 /* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
 120 /* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 121 /* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
 122 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
 123 /* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
 124 /* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
 125 /* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
 126 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
 127 /* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 128 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
 129         },
 130         {
 131 /*      REPLY   */
 132 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 133 /* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
 134 /* init_ack     */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
 135 /* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
 136 /* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
 137 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
 138 /* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
 139 /* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
 140 /* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
 141 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
 142 /* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 143 /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
 144         }
 145 };
 146
 147 static int sctp_net_id  __read_mostly;
 148 struct sctp_net {
 149         struct nf_proto_net pn;
 150         unsigned int timeouts[SCTP_CONNTRACK_MAX];
 151 };
 152
 153 static inline struct sctp_net *sctp_pernet(struct net *net)
 154 {
 155         return net_generic(net, sctp_net_id);
 156 }
 157
 158 static bool sctp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
 159                               struct net *net, struct nf_conntrack_tuple *tuple)
 160 {
 161         const struct sctphdr *hp;
 162         struct sctphdr _hdr;
 163
 164         /* Actually only need first 8 bytes. */
 165         hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
 166         if (hp == NULL)
 167                 return false;
 168
 169         tuple->src.u.sctp.port = hp->source;
 170         tuple->dst.u.sctp.port = hp->dest;
 171         return true;
 172 }
 173
 174 static bool sctp_invert_tuple(struct nf_conntrack_tuple *tuple,
 175                               const struct nf_conntrack_tuple *orig)
 176 {
 177         tuple->src.u.sctp.port = orig->dst.u.sctp.port;
 178         tuple->dst.u.sctp.port = orig->src.u.sctp.port;
 179         return true;
 180 }
 181
 182 /* Print out the per-protocol part of the tuple. */
 183 static void sctp_print_tuple(struct seq_file *s,
 184                              const struct nf_conntrack_tuple *tuple)
 185 {
 186         seq_printf(s, "sport=%hu dport=%hu ",
 187                    ntohs(tuple->src.u.sctp.port),
 188                    ntohs(tuple->dst.u.sctp.port));
 189 }
 190
 191 /* Print out the private part of the conntrack. */
 192 static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 193 {
 194         enum sctp_conntrack state;
 195
 196         spin_lock_bh(&ct->lock);
 197         state = ct->proto.sctp.state;
 198         spin_unlock_bh(&ct->lock);
 199
 200         seq_printf(s, "%s ", sctp_conntrack_names[state]);
 201 }
 202
 203 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 204 for ((offset) = (dataoff) + sizeof(sctp_sctphdr_t), (count) = 0;        \
 205         (offset) < (skb)->len &&                                        \
 206         ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 207         (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 208
 209 /* Some validity checks to make sure the chunks are fine */
 210 static int do_basic_checks(struct nf_conn *ct,
 211                            const struct sk_buff *skb,
 212                            unsigned int dataoff,
 213                            unsigned long *map)
 214 {
 215         u_int32_t offset, count;
 216         sctp_chunkhdr_t _sch, *sch;
 217         int flag;
 218
 219         flag = 0;
 220
 221         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 222                 pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 223
 224                 if (sch->type == SCTP_CID_INIT ||
 225                     sch->type == SCTP_CID_INIT_ACK ||
 226                     sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 227                         flag = 1;
 228
 229                 /*
 230                  * Cookie Ack/Echo chunks not the first OR
 231                  * Init / Init Ack / Shutdown compl chunks not the only chunks
 232                  * OR zero-length.
 233                  */
 234                 if (((sch->type == SCTP_CID_COOKIE_ACK ||
 235                       sch->type == SCTP_CID_COOKIE_ECHO ||
 236                       flag) &&
 237                      count != 0) || !sch->length) {
 238                         pr_debug("Basic checks failed\n");
 239                         return 1;
 240                 }
 241
 242                 if (map)
 243                         set_bit(sch->type, map);
 244         }
 245
 246         pr_debug("Basic checks passed\n");
 247         return count == 0;
 248 }
 249
 250 static int sctp_new_state(enum ip_conntrack_dir dir,
 251                           enum sctp_conntrack cur_state,
 252                           int chunk_type)
 253 {
 254         int i;
 255
 256         pr_debug("Chunk type: %d\n", chunk_type);
 257
 258         switch (chunk_type) {
 259         case SCTP_CID_INIT:
 260                 pr_debug("SCTP_CID_INIT\n");
 261                 i = 0;
 262                 break;
 263         case SCTP_CID_INIT_ACK:
 264                 pr_debug("SCTP_CID_INIT_ACK\n");
 265                 i = 1;
 266                 break;
 267         case SCTP_CID_ABORT:
 268                 pr_debug("SCTP_CID_ABORT\n");
 269                 i = 2;
 270                 break;
 271         case SCTP_CID_SHUTDOWN:
 272                 pr_debug("SCTP_CID_SHUTDOWN\n");
 273                 i = 3;
 274                 break;
 275         case SCTP_CID_SHUTDOWN_ACK:
 276                 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 277                 i = 4;
 278                 break;
 279         case SCTP_CID_ERROR:
 280                 pr_debug("SCTP_CID_ERROR\n");
 281                 i = 5;
 282                 break;
 283         case SCTP_CID_COOKIE_ECHO:
 284                 pr_debug("SCTP_CID_COOKIE_ECHO\n");
 285                 i = 6;
 286                 break;
 287         case SCTP_CID_COOKIE_ACK:
 288                 pr_debug("SCTP_CID_COOKIE_ACK\n");
 289                 i = 7;
 290                 break;
 291         case SCTP_CID_SHUTDOWN_COMPLETE:
 292                 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 293                 i = 8;
 294                 break;
 295         case SCTP_CID_HEARTBEAT:
 296                 pr_debug("SCTP_CID_HEARTBEAT");
 297                 i = 9;
 298                 break;
 299         case SCTP_CID_HEARTBEAT_ACK:
 300                 pr_debug("SCTP_CID_HEARTBEAT_ACK");
 301                 i = 10;
 302                 break;
 303         default:
 304                 /* Other chunks like DATA or SACK do not change the state */
 305                 pr_debug("Unknown chunk type, Will stay in %s\n",
 306                          sctp_conntrack_names[cur_state]);
 307                 return cur_state;
 308         }
 309
 310         pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 311                  dir, sctp_conntrack_names[cur_state], chunk_type,
 312                  sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 313
 314         return sctp_conntracks[dir][i][cur_state];
 315 }
 316
 317 static unsigned int *sctp_get_timeouts(struct net *net)
 318 {
 319         return sctp_pernet(net)->timeouts;
 320 }
 321
 322 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 323 static int sctp_packet(struct nf_conn *ct,
 324                        const struct sk_buff *skb,
 325                        unsigned int dataoff,
 326                        enum ip_conntrack_info ctinfo,
 327                        u_int8_t pf,
 328                        unsigned int hooknum,
 329                        unsigned int *timeouts)
 330 {
 331         enum sctp_conntrack new_state, old_state;
 332         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 333         const struct sctphdr *sh;
 334         struct sctphdr _sctph;
 335         const struct sctp_chunkhdr *sch;
 336         struct sctp_chunkhdr _sch;
 337         u_int32_t offset, count;
 338         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 339
 340         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 341         if (sh == NULL)
 342                 goto out;
 343
 344         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 345                 goto out;
 346
 347         /* Check the verification tag (Sec 8.5) */
 348         if (!test_bit(SCTP_CID_INIT, map) &&
 349             !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 350             !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 351             !test_bit(SCTP_CID_ABORT, map) &&
 352             !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 353             !test_bit(SCTP_CID_HEARTBEAT, map) &&
 354             !test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
 355             sh->vtag != ct->proto.sctp.vtag[dir]) {
 356                 pr_debug("Verification tag check failed\n");
 357                 goto out;
 358         }
 359
 360         old_state = new_state = SCTP_CONNTRACK_NONE;
 361         spin_lock_bh(&ct->lock);
 362         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 363                 /* Special cases of Verification tag check (Sec 8.5.1) */
 364                 if (sch->type == SCTP_CID_INIT) {
 365                         /* Sec 8.5.1 (A) */
 366                         if (sh->vtag != 0)
 367                                 goto out_unlock;
 368                 } else if (sch->type == SCTP_CID_ABORT) {
 369                         /* Sec 8.5.1 (B) */
 370                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 371                             sh->vtag != ct->proto.sctp.vtag[!dir])
 372                                 goto out_unlock;
 373                 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 374                         /* Sec 8.5.1 (C) */
 375                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 376                             sh->vtag != ct->proto.sctp.vtag[!dir] &&
 377                             sch->flags & SCTP_CHUNK_FLAG_T)
 378                                 goto out_unlock;
 379                 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 380                         /* Sec 8.5.1 (D) */
 381                         if (sh->vtag != ct->proto.sctp.vtag[dir])
 382                                 goto out_unlock;
 383                 } else if (sch->type == SCTP_CID_HEARTBEAT ||
 384                            sch->type == SCTP_CID_HEARTBEAT_ACK) {
 385                         if (ct->proto.sctp.vtag[dir] == 0) {
 386                                 pr_debug("Setting vtag %x for dir %d\n",
 387                                          sh->vtag, dir);
 388                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 389                         } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 390                                 pr_debug("Verification tag check failed\n");
 391                                 goto out_unlock;
 392                         }
 393                 }
 394
 395                 old_state = ct->proto.sctp.state;
 396                 new_state = sctp_new_state(dir, old_state, sch->type);
 397
 398                 /* Invalid */
 399                 if (new_state == SCTP_CONNTRACK_MAX) {
 400                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 401                                  "conntrack=%u\n",
 402                                  dir, sch->type, old_state);
 403                         goto out_unlock;
 404                 }
 405
 406                 /* If it is an INIT or an INIT ACK note down the vtag */
 407                 if (sch->type == SCTP_CID_INIT ||
 408                     sch->type == SCTP_CID_INIT_ACK) {
 409                         sctp_inithdr_t _inithdr, *ih;
 410
 411                         ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 412                                                 sizeof(_inithdr), &_inithdr);
 413                         if (ih == NULL)
 414                                 goto out_unlock;
 415                         pr_debug("Setting vtag %x for dir %d\n",
 416                                  ih->init_tag, !dir);
 417                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
 418                 }
 419
 420                 ct->proto.sctp.state = new_state;
 421                 if (old_state != new_state)
 422                         nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 423         }
 424         spin_unlock_bh(&ct->lock);
 425
 426         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 427
 428         if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 429             dir == IP_CT_DIR_REPLY &&
 430             new_state == SCTP_CONNTRACK_ESTABLISHED) {
 431                 pr_debug("Setting assured bit\n");
 432                 set_bit(IPS_ASSURED_BIT, &ct->status);
 433                 nf_conntrack_event_cache(IPCT_ASSURED, ct);
 434         }
 435
 436         return NF_ACCEPT;
 437
 438 out_unlock:
 439         spin_unlock_bh(&ct->lock);
 440 out:
 441         return -NF_ACCEPT;
 442 }
 443
 444 /* Called when a new connection for this protocol found. */
 445 static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 446                      unsigned int dataoff, unsigned int *timeouts)
 447 {
 448         enum sctp_conntrack new_state;
 449         const struct sctphdr *sh;
 450         struct sctphdr _sctph;
 451         const struct sctp_chunkhdr *sch;
 452         struct sctp_chunkhdr _sch;
 453         u_int32_t offset, count;
 454         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 455
 456         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 457         if (sh == NULL)
 458                 return false;
 459
 460         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 461                 return false;
 462
 463         /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 464         if (test_bit(SCTP_CID_ABORT, map) ||
 465             test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 466             test_bit(SCTP_CID_COOKIE_ACK, map))
 467                 return false;
 468
 469         memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 470         new_state = SCTP_CONNTRACK_MAX;
 471         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 472                 /* Don't need lock here: this conntrack not in circulation yet */
 473                 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 474                                            SCTP_CONNTRACK_NONE, sch->type);
 475
 476                 /* Invalid: delete conntrack */
 477                 if (new_state == SCTP_CONNTRACK_NONE ||
 478                     new_state == SCTP_CONNTRACK_MAX) {
 479                         pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 480                         return false;
 481                 }
 482
 483                 /* Copy the vtag into the state info */
 484                 if (sch->type == SCTP_CID_INIT) {
 485                         if (sh->vtag == 0) {
 486                                 sctp_inithdr_t _inithdr, *ih;
 487
 488                                 ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 489                                                         sizeof(_inithdr), &_inithdr);
 490                                 if (ih == NULL)
 491                                         return false;
 492
 493                                 pr_debug("Setting vtag %x for new conn\n",
 494                                          ih->init_tag);
 495
 496                                 ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 497                                                                 ih->init_tag;
 498                         } else {
 499                                 /* Sec 8.5.1 (A) */
 500                                 return false;
 501                         }
 502                 } else if (sch->type == SCTP_CID_HEARTBEAT) {
 503                         pr_debug("Setting vtag %x for secondary conntrack\n",
 504                                  sh->vtag);
 505                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
 506                 }
 507                 /* If it is a shutdown ack OOTB packet, we expect a return
 508                    shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 509                 else {
 510                         pr_debug("Setting vtag %x for new conn OOTB\n",
 511                                  sh->vtag);
 512                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 513                 }
 514
 515                 ct->proto.sctp.state = new_state;
 516         }
 517
 518         return true;
 519 }
 520
 521 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 522
 523 #include <linux/netfilter/nfnetlink.h>
 524 #include <linux/netfilter/nfnetlink_conntrack.h>
 525
 526 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 527                           struct nf_conn *ct)
 528 {
 529         struct nlattr *nest_parms;
 530
 531         spin_lock_bh(&ct->lock);
 532         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 533         if (!nest_parms)
 534                 goto nla_put_failure;
 535
 536         if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 537             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 538                          ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 539             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 540                          ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 541                 goto nla_put_failure;
 542
 543         spin_unlock_bh(&ct->lock);
 544
 545         nla_nest_end(skb, nest_parms);
 546
 547         return 0;
 548
 549 nla_put_failure:
 550         spin_unlock_bh(&ct->lock);
 551         return -1;
 552 }
 553
 554 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 555         [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 556         [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 557         [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 558 };
 559
 560 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 561 {
 562         struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 563         struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 564         int err;
 565
 566         /* updates may not contain the internal protocol info, skip parsing */
 567         if (!attr)
 568                 return 0;
 569
 570         err = nla_parse_nested(tb,
 571                                CTA_PROTOINFO_SCTP_MAX,
 572                                attr,
 573                                sctp_nla_policy);
 574         if (err < 0)
 575                 return err;
 576
 577         if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 578             !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 579             !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 580                 return -EINVAL;
 581
 582         spin_lock_bh(&ct->lock);
 583         ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 584         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 585                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 586         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 587                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 588         spin_unlock_bh(&ct->lock);
 589
 590         return 0;
 591 }
 592
 593 static int sctp_nlattr_size(void)
 594 {
 595         return nla_total_size(0)        /* CTA_PROTOINFO_SCTP */
 596                 + nla_policy_len(sctp_nla_policy, CTA_PROTOINFO_SCTP_MAX + 1);
 597 }
 598 #endif
 599
 600 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 601
 602 #include <linux/netfilter/nfnetlink.h>
 603 #include <linux/netfilter/nfnetlink_cttimeout.h>
 604
 605 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 606                                       struct net *net, void *data)
 607 {
 608         unsigned int *timeouts = data;
 609         struct sctp_net *sn = sctp_pernet(net);
 610         int i;
 611
 612         /* set default SCTP timeouts. */
 613         for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 614                 timeouts[i] = sn->timeouts[i];
 615
 616         /* there's a 1:1 mapping between attributes and protocol states. */
 617         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 618                 if (tb[i]) {
 619                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 620                 }
 621         }
 622         return 0;
 623 }
 624
 625 static int
 626 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 627 {
 628         const unsigned int *timeouts = data;
 629         int i;
 630
 631         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 632                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 633                         goto nla_put_failure;
 634         }
 635         return 0;
 636
 637 nla_put_failure:
 638         return -ENOSPC;
 639 }
 640
 641 static const struct nla_policy
 642 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 643         [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 644         [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 645         [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 646         [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 647         [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 648         [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 649         [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 650         [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT]       = { .type = NLA_U32 },
 651         [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED]      = { .type = NLA_U32 },
 652 };
 653 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 654
 655
 656 #ifdef CONFIG_SYSCTL
 657 static struct ctl_table sctp_sysctl_table[] = {
 658         {
 659                 .procname       = "nf_conntrack_sctp_timeout_closed",
 660                 .maxlen         = sizeof(unsigned int),
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dointvec_jiffies,
 663         },
 664         {
 665                 .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 666                 .maxlen         = sizeof(unsigned int),
 667                 .mode           = 0644,
 668                 .proc_handler   = proc_dointvec_jiffies,
 669         },
 670         {
 671                 .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 672                 .maxlen         = sizeof(unsigned int),
 673                 .mode           = 0644,
 674                 .proc_handler   = proc_dointvec_jiffies,
 675         },
 676         {
 677                 .procname       = "nf_conntrack_sctp_timeout_established",
 678                 .maxlen         = sizeof(unsigned int),
 679                 .mode           = 0644,
 680                 .proc_handler   = proc_dointvec_jiffies,
 681         },
 682         {
 683                 .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 684                 .maxlen         = sizeof(unsigned int),
 685                 .mode           = 0644,
 686                 .proc_handler   = proc_dointvec_jiffies,
 687         },
 688         {
 689                 .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 690                 .maxlen         = sizeof(unsigned int),
 691                 .mode           = 0644,
 692                 .proc_handler   = proc_dointvec_jiffies,
 693         },
 694         {
 695                 .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 696                 .maxlen         = sizeof(unsigned int),
 697                 .mode           = 0644,
 698                 .proc_handler   = proc_dointvec_jiffies,
 699         },
 700         {
 701                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_sent",
 702                 .maxlen         = sizeof(unsigned int),
 703                 .mode           = 0644,
 704                 .proc_handler   = proc_dointvec_jiffies,
 705         },
 706         {
 707                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_acked",
 708                 .maxlen         = sizeof(unsigned int),
 709                 .mode           = 0644,
 710                 .proc_handler   = proc_dointvec_jiffies,
 711         },
 712         { }
 713 };
 714
 715 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 716 static struct ctl_table sctp_compat_sysctl_table[] = {
 717         {
 718                 .procname       = "ip_conntrack_sctp_timeout_closed",
 719                 .maxlen         = sizeof(unsigned int),
 720                 .mode           = 0644,
 721                 .proc_handler   = proc_dointvec_jiffies,
 722         },
 723         {
 724                 .procname       = "ip_conntrack_sctp_timeout_cookie_wait",
 725                 .maxlen         = sizeof(unsigned int),
 726                 .mode           = 0644,
 727                 .proc_handler   = proc_dointvec_jiffies,
 728         },
 729         {
 730                 .procname       = "ip_conntrack_sctp_timeout_cookie_echoed",
 731                 .maxlen         = sizeof(unsigned int),
 732                 .mode           = 0644,
 733                 .proc_handler   = proc_dointvec_jiffies,
 734         },
 735         {
 736                 .procname       = "ip_conntrack_sctp_timeout_established",
 737                 .maxlen         = sizeof(unsigned int),
 738                 .mode           = 0644,
 739                 .proc_handler   = proc_dointvec_jiffies,
 740         },
 741         {
 742                 .procname       = "ip_conntrack_sctp_timeout_shutdown_sent",
 743                 .maxlen         = sizeof(unsigned int),
 744                 .mode           = 0644,
 745                 .proc_handler   = proc_dointvec_jiffies,
 746         },
 747         {
 748                 .procname       = "ip_conntrack_sctp_timeout_shutdown_recd",
 749                 .maxlen         = sizeof(unsigned int),
 750                 .mode           = 0644,
 751                 .proc_handler   = proc_dointvec_jiffies,
 752         },
 753         {
 754                 .procname       = "ip_conntrack_sctp_timeout_shutdown_ack_sent",
 755                 .maxlen         = sizeof(unsigned int),
 756                 .mode           = 0644,
 757                 .proc_handler   = proc_dointvec_jiffies,
 758         },
 759         { }
 760 };
 761 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 762 #endif
 763
 764 static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
 765                                      struct sctp_net *sn)
 766 {
 767 #ifdef CONFIG_SYSCTL
 768         if (pn->ctl_table)
 769                 return 0;
 770
 771         pn->ctl_table = kmemdup(sctp_sysctl_table,
 772                                 sizeof(sctp_sysctl_table),
 773                                 GFP_KERNEL);
 774         if (!pn->ctl_table)
 775                 return -ENOMEM;
 776
 777         pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 778         pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 779         pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 780         pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 781         pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 782         pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 783         pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 784         pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
 785         pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
 786 #endif
 787         return 0;
 788 }
 789
 790 static int sctp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
 791                                             struct sctp_net *sn)
 792 {
 793 #ifdef CONFIG_SYSCTL
 794 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 795         pn->ctl_compat_table = kmemdup(sctp_compat_sysctl_table,
 796                                        sizeof(sctp_compat_sysctl_table),
 797                                        GFP_KERNEL);
 798         if (!pn->ctl_compat_table)
 799                 return -ENOMEM;
 800
 801         pn->ctl_compat_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 802         pn->ctl_compat_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 803         pn->ctl_compat_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 804         pn->ctl_compat_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 805         pn->ctl_compat_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 806         pn->ctl_compat_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 807         pn->ctl_compat_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 808 #endif
 809 #endif
 810         return 0;
 811 }
 812
 813 static int sctp_init_net(struct net *net, u_int16_t proto)
 814 {
 815         int ret;
 816         struct sctp_net *sn = sctp_pernet(net);
 817         struct nf_proto_net *pn = &sn->pn;
 818
 819         if (!pn->users) {
 820                 int i;
 821
 822                 for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 823                         sn->timeouts[i] = sctp_timeouts[i];
 824         }
 825
 826         if (proto == AF_INET) {
 827                 ret = sctp_kmemdup_compat_sysctl_table(pn, sn);
 828                 if (ret < 0)
 829                         return ret;
 830
 831                 ret = sctp_kmemdup_sysctl_table(pn, sn);
 832                 if (ret < 0)
 833                         nf_ct_kfree_compat_sysctl_table(pn);
 834         } else
 835                 ret = sctp_kmemdup_sysctl_table(pn, sn);
 836
 837         return ret;
 838 }
 839
 840 static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 __read_mostly = {
 841         .l3proto                = PF_INET,
 842         .l4proto                = IPPROTO_SCTP,
 843         .name                   = "sctp",
 844         .pkt_to_tuple           = sctp_pkt_to_tuple,
 845         .invert_tuple           = sctp_invert_tuple,
 846         .print_tuple            = sctp_print_tuple,
 847         .print_conntrack        = sctp_print_conntrack,
 848         .packet                 = sctp_packet,
 849         .get_timeouts           = sctp_get_timeouts,
 850         .new                    = sctp_new,
 851         .me                     = THIS_MODULE,
 852 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 853         .to_nlattr              = sctp_to_nlattr,
 854         .nlattr_size            = sctp_nlattr_size,
 855         .from_nlattr            = nlattr_to_sctp,
 856         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 857         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 858         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 859         .nla_policy             = nf_ct_port_nla_policy,
 860 #endif
 861 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 862         .ctnl_timeout           = {
 863                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 864                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 865                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 866                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 867                 .nla_policy     = sctp_timeout_nla_policy,
 868         },
 869 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 870         .net_id                 = &sctp_net_id,
 871         .init_net               = sctp_init_net,
 872 };
 873
 874 static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 __read_mostly = {
 875         .l3proto                = PF_INET6,
 876         .l4proto                = IPPROTO_SCTP,
 877         .name                   = "sctp",
 878         .pkt_to_tuple           = sctp_pkt_to_tuple,
 879         .invert_tuple           = sctp_invert_tuple,
 880         .print_tuple            = sctp_print_tuple,
 881         .print_conntrack        = sctp_print_conntrack,
 882         .packet                 = sctp_packet,
 883         .get_timeouts           = sctp_get_timeouts,
 884         .new                    = sctp_new,
 885         .me                     = THIS_MODULE,
 886 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 887         .to_nlattr              = sctp_to_nlattr,
 888         .nlattr_size            = sctp_nlattr_size,
 889         .from_nlattr            = nlattr_to_sctp,
 890         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 891         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 892         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 893         .nla_policy             = nf_ct_port_nla_policy,
 894 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 895         .ctnl_timeout           = {
 896                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 897                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 898                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 899                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 900                 .nla_policy     = sctp_timeout_nla_policy,
 901         },
 902 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 903 #endif
 904         .net_id                 = &sctp_net_id,
 905         .init_net               = sctp_init_net,
 906 };
 907
 908 static int sctp_net_init(struct net *net)
 909 {
 910         int ret = 0;
 911
 912         ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_sctp4);
 913         if (ret < 0) {
 914                 pr_err("nf_conntrack_sctp4: pernet registration failed.\n");
 915                 goto out;
 916         }
 917         ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_sctp6);
 918         if (ret < 0) {
 919                 pr_err("nf_conntrack_sctp6: pernet registration failed.\n");
 920                 goto cleanup_sctp4;
 921         }
 922         return 0;
 923
 924 cleanup_sctp4:
 925         nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp4);
 926 out:
 927         return ret;
 928 }
 929
 930 static void sctp_net_exit(struct net *net)
 931 {
 932         nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp6);
 933         nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp4);
 934 }
 935
 936 static struct pernet_operations sctp_net_ops = {
 937         .init = sctp_net_init,
 938         .exit = sctp_net_exit,
 939         .id   = &sctp_net_id,
 940         .size = sizeof(struct sctp_net),
 941 };
 942
 943 static int __init nf_conntrack_proto_sctp_init(void)
 944 {
 945         int ret;
 946
 947         ret = register_pernet_subsys(&sctp_net_ops);
 948         if (ret < 0)
 949                 goto out_pernet;
 950
 951         ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_sctp4);
 952         if (ret < 0)
 953                 goto out_sctp4;
 954
 955         ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_sctp6);
 956         if (ret < 0)
 957                 goto out_sctp6;
 958
 959         return 0;
 960 out_sctp6:
 961         nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 962 out_sctp4:
 963         unregister_pernet_subsys(&sctp_net_ops);
 964 out_pernet:
 965         return ret;
 966 }
 967
 968 static void __exit nf_conntrack_proto_sctp_fini(void)
 969 {
 970         nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp6);
 971         nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 972         unregister_pernet_subsys(&sctp_net_ops);
 973 }
 974
 975 module_init(nf_conntrack_proto_sctp_init);
 976 module_exit(nf_conntrack_proto_sctp_fini);
 977
 978 MODULE_LICENSE("GPL");
 979 MODULE_AUTHOR("Kiran Kumar Immidi");
 980 MODULE_DESCRIPTION("Netfilter connection tracking protocol helper for SCTP");
 981 MODULE_ALIAS("ip_conntrack_proto_sctp");