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