net/netfilter/nf_conntrack_proto_sctp.c

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