net/netfilter/nf_conntrack_proto_sctp.c

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