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 bool sctp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
 131                               struct nf_conntrack_tuple *tuple)
 132 {
 133         const struct sctphdr *hp;
 134         struct sctphdr _hdr;
 135
 136         /* Actually only need first 8 bytes. */
 137         hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
 138         if (hp == NULL)
 139                 return false;
 140
 141         tuple->src.u.sctp.port = hp->source;
 142         tuple->dst.u.sctp.port = hp->dest;
 143         return true;
 144 }
 145
 146 static bool sctp_invert_tuple(struct nf_conntrack_tuple *tuple,
 147                               const struct nf_conntrack_tuple *orig)
 148 {
 149         tuple->src.u.sctp.port = orig->dst.u.sctp.port;
 150         tuple->dst.u.sctp.port = orig->src.u.sctp.port;
 151         return true;
 152 }
 153
 154 /* Print out the per-protocol part of the tuple. */
 155 static int sctp_print_tuple(struct seq_file *s,
 156                             const struct nf_conntrack_tuple *tuple)
 157 {
 158         return seq_printf(s, "sport=%hu dport=%hu ",
 159                           ntohs(tuple->src.u.sctp.port),
 160                           ntohs(tuple->dst.u.sctp.port));
 161 }
 162
 163 /* Print out the private part of the conntrack. */
 164 static int sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 165 {
 166         enum sctp_conntrack state;
 167
 168         spin_lock_bh(&ct->lock);
 169         state = ct->proto.sctp.state;
 170         spin_unlock_bh(&ct->lock);
 171
 172         return seq_printf(s, "%s ", sctp_conntrack_names[state]);
 173 }
 174
 175 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 176 for ((offset) = (dataoff) + sizeof(sctp_sctphdr_t), (count) = 0;        \
 177         (offset) < (skb)->len &&                                        \
 178         ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 179         (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 180
 181 /* Some validity checks to make sure the chunks are fine */
 182 static int do_basic_checks(struct nf_conn *ct,
 183                            const struct sk_buff *skb,
 184                            unsigned int dataoff,
 185                            unsigned long *map)
 186 {
 187         u_int32_t offset, count;
 188         sctp_chunkhdr_t _sch, *sch;
 189         int flag;
 190
 191         flag = 0;
 192
 193         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 194                 pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 195
 196                 if (sch->type == SCTP_CID_INIT ||
 197                     sch->type == SCTP_CID_INIT_ACK ||
 198                     sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 199                         flag = 1;
 200
 201                 /*
 202                  * Cookie Ack/Echo chunks not the first OR
 203                  * Init / Init Ack / Shutdown compl chunks not the only chunks
 204                  * OR zero-length.
 205                  */
 206                 if (((sch->type == SCTP_CID_COOKIE_ACK ||
 207                       sch->type == SCTP_CID_COOKIE_ECHO ||
 208                       flag) &&
 209                      count != 0) || !sch->length) {
 210                         pr_debug("Basic checks failed\n");
 211                         return 1;
 212                 }
 213
 214                 if (map)
 215                         set_bit(sch->type, map);
 216         }
 217
 218         pr_debug("Basic checks passed\n");
 219         return count == 0;
 220 }
 221
 222 static int sctp_new_state(enum ip_conntrack_dir dir,
 223                           enum sctp_conntrack cur_state,
 224                           int chunk_type)
 225 {
 226         int i;
 227
 228         pr_debug("Chunk type: %d\n", chunk_type);
 229
 230         switch (chunk_type) {
 231         case SCTP_CID_INIT:
 232                 pr_debug("SCTP_CID_INIT\n");
 233                 i = 0;
 234                 break;
 235         case SCTP_CID_INIT_ACK:
 236                 pr_debug("SCTP_CID_INIT_ACK\n");
 237                 i = 1;
 238                 break;
 239         case SCTP_CID_ABORT:
 240                 pr_debug("SCTP_CID_ABORT\n");
 241                 i = 2;
 242                 break;
 243         case SCTP_CID_SHUTDOWN:
 244                 pr_debug("SCTP_CID_SHUTDOWN\n");
 245                 i = 3;
 246                 break;
 247         case SCTP_CID_SHUTDOWN_ACK:
 248                 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 249                 i = 4;
 250                 break;
 251         case SCTP_CID_ERROR:
 252                 pr_debug("SCTP_CID_ERROR\n");
 253                 i = 5;
 254                 break;
 255         case SCTP_CID_COOKIE_ECHO:
 256                 pr_debug("SCTP_CID_COOKIE_ECHO\n");
 257                 i = 6;
 258                 break;
 259         case SCTP_CID_COOKIE_ACK:
 260                 pr_debug("SCTP_CID_COOKIE_ACK\n");
 261                 i = 7;
 262                 break;
 263         case SCTP_CID_SHUTDOWN_COMPLETE:
 264                 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 265                 i = 8;
 266                 break;
 267         default:
 268                 /* Other chunks like DATA, SACK, HEARTBEAT and
 269                 its ACK do not cause a change in state */
 270                 pr_debug("Unknown chunk type, Will stay in %s\n",
 271                          sctp_conntrack_names[cur_state]);
 272                 return cur_state;
 273         }
 274
 275         pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 276                  dir, sctp_conntrack_names[cur_state], chunk_type,
 277                  sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 278
 279         return sctp_conntracks[dir][i][cur_state];
 280 }
 281
 282 static unsigned int *sctp_get_timeouts(struct net *net)
 283 {
 284         return sctp_timeouts;
 285 }
 286
 287 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 288 static int sctp_packet(struct nf_conn *ct,
 289                        const struct sk_buff *skb,
 290                        unsigned int dataoff,
 291                        enum ip_conntrack_info ctinfo,
 292                        u_int8_t pf,
 293                        unsigned int hooknum,
 294                        unsigned int *timeouts)
 295 {
 296         enum sctp_conntrack new_state, old_state;
 297         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 298         const struct sctphdr *sh;
 299         struct sctphdr _sctph;
 300         const struct sctp_chunkhdr *sch;
 301         struct sctp_chunkhdr _sch;
 302         u_int32_t offset, count;
 303         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 304
 305         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 306         if (sh == NULL)
 307                 goto out;
 308
 309         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 310                 goto out;
 311
 312         /* Check the verification tag (Sec 8.5) */
 313         if (!test_bit(SCTP_CID_INIT, map) &&
 314             !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 315             !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 316             !test_bit(SCTP_CID_ABORT, map) &&
 317             !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 318             sh->vtag != ct->proto.sctp.vtag[dir]) {
 319                 pr_debug("Verification tag check failed\n");
 320                 goto out;
 321         }
 322
 323         old_state = new_state = SCTP_CONNTRACK_NONE;
 324         spin_lock_bh(&ct->lock);
 325         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 326                 /* Special cases of Verification tag check (Sec 8.5.1) */
 327                 if (sch->type == SCTP_CID_INIT) {
 328                         /* Sec 8.5.1 (A) */
 329                         if (sh->vtag != 0)
 330                                 goto out_unlock;
 331                 } else if (sch->type == SCTP_CID_ABORT) {
 332                         /* Sec 8.5.1 (B) */
 333                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 334                             sh->vtag != ct->proto.sctp.vtag[!dir])
 335                                 goto out_unlock;
 336                 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 337                         /* Sec 8.5.1 (C) */
 338                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 339                             sh->vtag != ct->proto.sctp.vtag[!dir] &&
 340                             sch->flags & SCTP_CHUNK_FLAG_T)
 341                                 goto out_unlock;
 342                 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 343                         /* Sec 8.5.1 (D) */
 344                         if (sh->vtag != ct->proto.sctp.vtag[dir])
 345                                 goto out_unlock;
 346                 }
 347
 348                 old_state = ct->proto.sctp.state;
 349                 new_state = sctp_new_state(dir, old_state, sch->type);
 350
 351                 /* Invalid */
 352                 if (new_state == SCTP_CONNTRACK_MAX) {
 353                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 354                                  "conntrack=%u\n",
 355                                  dir, sch->type, old_state);
 356                         goto out_unlock;
 357                 }
 358
 359                 /* If it is an INIT or an INIT ACK note down the vtag */
 360                 if (sch->type == SCTP_CID_INIT ||
 361                     sch->type == SCTP_CID_INIT_ACK) {
 362                         sctp_inithdr_t _inithdr, *ih;
 363
 364                         ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 365                                                 sizeof(_inithdr), &_inithdr);
 366                         if (ih == NULL)
 367                                 goto out_unlock;
 368                         pr_debug("Setting vtag %x for dir %d\n",
 369                                  ih->init_tag, !dir);
 370                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
 371                 }
 372
 373                 ct->proto.sctp.state = new_state;
 374                 if (old_state != new_state)
 375                         nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 376         }
 377         spin_unlock_bh(&ct->lock);
 378
 379         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 380
 381         if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 382             dir == IP_CT_DIR_REPLY &&
 383             new_state == SCTP_CONNTRACK_ESTABLISHED) {
 384                 pr_debug("Setting assured bit\n");
 385                 set_bit(IPS_ASSURED_BIT, &ct->status);
 386                 nf_conntrack_event_cache(IPCT_ASSURED, ct);
 387         }
 388
 389         return NF_ACCEPT;
 390
 391 out_unlock:
 392         spin_unlock_bh(&ct->lock);
 393 out:
 394         return -NF_ACCEPT;
 395 }
 396
 397 /* Called when a new connection for this protocol found. */
 398 static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 399                      unsigned int dataoff, unsigned int *timeouts)
 400 {
 401         enum sctp_conntrack new_state;
 402         const struct sctphdr *sh;
 403         struct sctphdr _sctph;
 404         const struct sctp_chunkhdr *sch;
 405         struct sctp_chunkhdr _sch;
 406         u_int32_t offset, count;
 407         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 408
 409         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 410         if (sh == NULL)
 411                 return false;
 412
 413         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 414                 return false;
 415
 416         /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 417         if (test_bit(SCTP_CID_ABORT, map) ||
 418             test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 419             test_bit(SCTP_CID_COOKIE_ACK, map))
 420                 return false;
 421
 422         memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 423         new_state = SCTP_CONNTRACK_MAX;
 424         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 425                 /* Don't need lock here: this conntrack not in circulation yet */
 426                 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 427                                            SCTP_CONNTRACK_NONE, sch->type);
 428
 429                 /* Invalid: delete conntrack */
 430                 if (new_state == SCTP_CONNTRACK_NONE ||
 431                     new_state == SCTP_CONNTRACK_MAX) {
 432                         pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 433                         return false;
 434                 }
 435
 436                 /* Copy the vtag into the state info */
 437                 if (sch->type == SCTP_CID_INIT) {
 438                         if (sh->vtag == 0) {
 439                                 sctp_inithdr_t _inithdr, *ih;
 440
 441                                 ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 442                                                         sizeof(_inithdr), &_inithdr);
 443                                 if (ih == NULL)
 444                                         return false;
 445
 446                                 pr_debug("Setting vtag %x for new conn\n",
 447                                          ih->init_tag);
 448
 449                                 ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 450                                                                 ih->init_tag;
 451                         } else {
 452                                 /* Sec 8.5.1 (A) */
 453                                 return false;
 454                         }
 455                 }
 456                 /* If it is a shutdown ack OOTB packet, we expect a return
 457                    shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 458                 else {
 459                         pr_debug("Setting vtag %x for new conn OOTB\n",
 460                                  sh->vtag);
 461                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 462                 }
 463
 464                 ct->proto.sctp.state = new_state;
 465         }
 466
 467         return true;
 468 }
 469
 470 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 471
 472 #include <linux/netfilter/nfnetlink.h>
 473 #include <linux/netfilter/nfnetlink_conntrack.h>
 474
 475 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 476                           struct nf_conn *ct)
 477 {
 478         struct nlattr *nest_parms;
 479
 480         spin_lock_bh(&ct->lock);
 481         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 482         if (!nest_parms)
 483                 goto nla_put_failure;
 484
 485         if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 486             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 487                          ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 488             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 489                          ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 490                 goto nla_put_failure;
 491
 492         spin_unlock_bh(&ct->lock);
 493
 494         nla_nest_end(skb, nest_parms);
 495
 496         return 0;
 497
 498 nla_put_failure:
 499         spin_unlock_bh(&ct->lock);
 500         return -1;
 501 }
 502
 503 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 504         [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 505         [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 506         [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 507 };
 508
 509 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 510 {
 511         struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 512         struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 513         int err;
 514
 515         /* updates may not contain the internal protocol info, skip parsing */
 516         if (!attr)
 517                 return 0;
 518
 519         err = nla_parse_nested(tb,
 520                                CTA_PROTOINFO_SCTP_MAX,
 521                                attr,
 522                                sctp_nla_policy);
 523         if (err < 0)
 524                 return err;
 525
 526         if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 527             !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 528             !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 529                 return -EINVAL;
 530
 531         spin_lock_bh(&ct->lock);
 532         ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 533         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 534                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 535         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 536                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 537         spin_unlock_bh(&ct->lock);
 538
 539         return 0;
 540 }
 541
 542 static int sctp_nlattr_size(void)
 543 {
 544         return nla_total_size(0)        /* CTA_PROTOINFO_SCTP */
 545                 + nla_policy_len(sctp_nla_policy, CTA_PROTOINFO_SCTP_MAX + 1);
 546 }
 547 #endif
 548
 549 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 550
 551 #include <linux/netfilter/nfnetlink.h>
 552 #include <linux/netfilter/nfnetlink_cttimeout.h>
 553
 554 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[], void *data)
 555 {
 556         unsigned int *timeouts = data;
 557         int i;
 558
 559         /* set default SCTP timeouts. */
 560         for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 561                 timeouts[i] = sctp_timeouts[i];
 562
 563         /* there's a 1:1 mapping between attributes and protocol states. */
 564         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 565                 if (tb[i]) {
 566                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 567                 }
 568         }
 569         return 0;
 570 }
 571
 572 static int
 573 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 574 {
 575         const unsigned int *timeouts = data;
 576         int i;
 577
 578         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 579                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 580                         goto nla_put_failure;
 581         }
 582         return 0;
 583
 584 nla_put_failure:
 585         return -ENOSPC;
 586 }
 587
 588 static const struct nla_policy
 589 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 590         [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 591         [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 592         [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 593         [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 594         [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 595         [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 596         [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 597 };
 598 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 599
 600
 601 #ifdef CONFIG_SYSCTL
 602 static unsigned int sctp_sysctl_table_users;
 603 static struct ctl_table_header *sctp_sysctl_header;
 604 static struct ctl_table sctp_sysctl_table[] = {
 605         {
 606                 .procname       = "nf_conntrack_sctp_timeout_closed",
 607                 .data           = &sctp_timeouts[SCTP_CONNTRACK_CLOSED],
 608                 .maxlen         = sizeof(unsigned int),
 609                 .mode           = 0644,
 610                 .proc_handler   = proc_dointvec_jiffies,
 611         },
 612         {
 613                 .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 614                 .data           = &sctp_timeouts[SCTP_CONNTRACK_COOKIE_WAIT],
 615                 .maxlen         = sizeof(unsigned int),
 616                 .mode           = 0644,
 617                 .proc_handler   = proc_dointvec_jiffies,
 618         },
 619         {
 620                 .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 621                 .data           = &sctp_timeouts[SCTP_CONNTRACK_COOKIE_ECHOED],
 622                 .maxlen         = sizeof(unsigned int),
 623                 .mode           = 0644,
 624                 .proc_handler   = proc_dointvec_jiffies,
 625         },
 626         {
 627                 .procname       = "nf_conntrack_sctp_timeout_established",
 628                 .data           = &sctp_timeouts[SCTP_CONNTRACK_ESTABLISHED],
 629                 .maxlen         = sizeof(unsigned int),
 630                 .mode           = 0644,
 631                 .proc_handler   = proc_dointvec_jiffies,
 632         },
 633         {
 634                 .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 635                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT],
 636                 .maxlen         = sizeof(unsigned int),
 637                 .mode           = 0644,
 638                 .proc_handler   = proc_dointvec_jiffies,
 639         },
 640         {
 641                 .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 642                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD],
 643                 .maxlen         = sizeof(unsigned int),
 644                 .mode           = 0644,
 645                 .proc_handler   = proc_dointvec_jiffies,
 646         },
 647         {
 648                 .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 649                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT],
 650                 .maxlen         = sizeof(unsigned int),
 651                 .mode           = 0644,
 652                 .proc_handler   = proc_dointvec_jiffies,
 653         },
 654         { }
 655 };
 656
 657 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 658 static struct ctl_table sctp_compat_sysctl_table[] = {
 659         {
 660                 .procname       = "ip_conntrack_sctp_timeout_closed",
 661                 .data           = &sctp_timeouts[SCTP_CONNTRACK_CLOSED],
 662                 .maxlen         = sizeof(unsigned int),
 663                 .mode           = 0644,
 664                 .proc_handler   = proc_dointvec_jiffies,
 665         },
 666         {
 667                 .procname       = "ip_conntrack_sctp_timeout_cookie_wait",
 668                 .data           = &sctp_timeouts[SCTP_CONNTRACK_COOKIE_WAIT],
 669                 .maxlen         = sizeof(unsigned int),
 670                 .mode           = 0644,
 671                 .proc_handler   = proc_dointvec_jiffies,
 672         },
 673         {
 674                 .procname       = "ip_conntrack_sctp_timeout_cookie_echoed",
 675                 .data           = &sctp_timeouts[SCTP_CONNTRACK_COOKIE_ECHOED],
 676                 .maxlen         = sizeof(unsigned int),
 677                 .mode           = 0644,
 678                 .proc_handler   = proc_dointvec_jiffies,
 679         },
 680         {
 681                 .procname       = "ip_conntrack_sctp_timeout_established",
 682                 .data           = &sctp_timeouts[SCTP_CONNTRACK_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                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT],
 690                 .maxlen         = sizeof(unsigned int),
 691                 .mode           = 0644,
 692                 .proc_handler   = proc_dointvec_jiffies,
 693         },
 694         {
 695                 .procname       = "ip_conntrack_sctp_timeout_shutdown_recd",
 696                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD],
 697                 .maxlen         = sizeof(unsigned int),
 698                 .mode           = 0644,
 699                 .proc_handler   = proc_dointvec_jiffies,
 700         },
 701         {
 702                 .procname       = "ip_conntrack_sctp_timeout_shutdown_ack_sent",
 703                 .data           = &sctp_timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT],
 704                 .maxlen         = sizeof(unsigned int),
 705                 .mode           = 0644,
 706                 .proc_handler   = proc_dointvec_jiffies,
 707         },
 708         { }
 709 };
 710 #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 711 #endif
 712
 713 static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 __read_mostly = {
 714         .l3proto                = PF_INET,
 715         .l4proto                = IPPROTO_SCTP,
 716         .name                   = "sctp",
 717         .pkt_to_tuple           = sctp_pkt_to_tuple,
 718         .invert_tuple           = sctp_invert_tuple,
 719         .print_tuple            = sctp_print_tuple,
 720         .print_conntrack        = sctp_print_conntrack,
 721         .packet                 = sctp_packet,
 722         .get_timeouts           = sctp_get_timeouts,
 723         .new                    = sctp_new,
 724         .me                     = THIS_MODULE,
 725 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 726         .to_nlattr              = sctp_to_nlattr,
 727         .nlattr_size            = sctp_nlattr_size,
 728         .from_nlattr            = nlattr_to_sctp,
 729         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 730         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 731         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 732         .nla_policy             = nf_ct_port_nla_policy,
 733 #endif
 734 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 735         .ctnl_timeout           = {
 736                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 737                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 738                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 739                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 740                 .nla_policy     = sctp_timeout_nla_policy,
 741         },
 742 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 743 #ifdef CONFIG_SYSCTL
 744         .ctl_table_users        = &sctp_sysctl_table_users,
 745         .ctl_table_header       = &sctp_sysctl_header,
 746         .ctl_table              = sctp_sysctl_table,
 747 #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 748         .ctl_compat_table       = sctp_compat_sysctl_table,
 749 #endif
 750 #endif
 751 };
 752
 753 static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 __read_mostly = {
 754         .l3proto                = PF_INET6,
 755         .l4proto                = IPPROTO_SCTP,
 756         .name                   = "sctp",
 757         .pkt_to_tuple           = sctp_pkt_to_tuple,
 758         .invert_tuple           = sctp_invert_tuple,
 759         .print_tuple            = sctp_print_tuple,
 760         .print_conntrack        = sctp_print_conntrack,
 761         .packet                 = sctp_packet,
 762         .get_timeouts           = sctp_get_timeouts,
 763         .new                    = sctp_new,
 764         .me                     = THIS_MODULE,
 765 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 766         .to_nlattr              = sctp_to_nlattr,
 767         .nlattr_size            = sctp_nlattr_size,
 768         .from_nlattr            = nlattr_to_sctp,
 769         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 770         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 771         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 772         .nla_policy             = nf_ct_port_nla_policy,
 773 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 774         .ctnl_timeout           = {
 775                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 776                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 777                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 778                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 779                 .nla_policy     = sctp_timeout_nla_policy,
 780         },
 781 #endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 782 #endif
 783 #ifdef CONFIG_SYSCTL
 784         .ctl_table_users        = &sctp_sysctl_table_users,
 785         .ctl_table_header       = &sctp_sysctl_header,
 786         .ctl_table              = sctp_sysctl_table,
 787 #endif
 788 };
 789
 790 static int __init nf_conntrack_proto_sctp_init(void)
 791 {
 792         int ret;
 793
 794         ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_sctp4);
 795         if (ret) {
 796                 pr_err("nf_conntrack_l4proto_sctp4: protocol register failed\n");
 797                 goto out;
 798         }
 799         ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_sctp6);
 800         if (ret) {
 801                 pr_err("nf_conntrack_l4proto_sctp6: protocol register failed\n");
 802                 goto cleanup_sctp4;
 803         }
 804
 805         return ret;
 806
 807  cleanup_sctp4:
 808         nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 809  out:
 810         return ret;
 811 }
 812
 813 static void __exit nf_conntrack_proto_sctp_fini(void)
 814 {
 815         nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp6);
 816         nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 817 }
 818
 819 module_init(nf_conntrack_proto_sctp_init);
 820 module_exit(nf_conntrack_proto_sctp_fini);
 821
 822 MODULE_LICENSE("GPL");
 823 MODULE_AUTHOR("Kiran Kumar Immidi");
 824 MODULE_DESCRIPTION("Netfilter connection tracking protocol helper for SCTP");
 825 MODULE_ALIAS("ip_conntrack_proto_sctp");