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/in.h>
  19 #include <linux/ip.h>
  20 #include <linux/sctp.h>
  21 #include <linux/string.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/interrupt.h>
  25 #include <net/sctp/checksum.h>
  26
  27 #include <net/netfilter/nf_log.h>
  28 #include <net/netfilter/nf_conntrack.h>
  29 #include <net/netfilter/nf_conntrack_l4proto.h>
  30 #include <net/netfilter/nf_conntrack_ecache.h>
  31 #include <net/netfilter/nf_conntrack_timeout.h>
  32
  33 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  34    closely.  They're more complex. --RR
  35
  36    And so for me for SCTP :D -Kiran */
  37
  38 static const char *const sctp_conntrack_names[] = {
  39         "NONE",
  40         "CLOSED",
  41         "COOKIE_WAIT",
  42         "COOKIE_ECHOED",
  43         "ESTABLISHED",
  44         "SHUTDOWN_SENT",
  45         "SHUTDOWN_RECD",
  46         "SHUTDOWN_ACK_SENT",
  47         "HEARTBEAT_SENT",
  48         "HEARTBEAT_ACKED",
  49 };
  50
  51 #define SECS  * HZ
  52 #define MINS  * 60 SECS
  53 #define HOURS * 60 MINS
  54 #define DAYS  * 24 HOURS
  55
  56 static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
  57         [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  58         [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  59         [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  60         [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  61         [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  62         [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  63         [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  64         [SCTP_CONNTRACK_HEARTBEAT_SENT]         = 30 SECS,
  65         [SCTP_CONNTRACK_HEARTBEAT_ACKED]        = 210 SECS,
  66 };
  67
  68 #define sNO SCTP_CONNTRACK_NONE
  69 #define sCL SCTP_CONNTRACK_CLOSED
  70 #define sCW SCTP_CONNTRACK_COOKIE_WAIT
  71 #define sCE SCTP_CONNTRACK_COOKIE_ECHOED
  72 #define sES SCTP_CONNTRACK_ESTABLISHED
  73 #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
  74 #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
  75 #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
  76 #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
  77 #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
  78 #define sIV SCTP_CONNTRACK_MAX
  79
  80 /*
  81         These are the descriptions of the states:
  82
  83 NOTE: These state names are tantalizingly similar to the states of an
  84 SCTP endpoint. But the interpretation of the states is a little different,
  85 considering that these are the states of the connection and not of an end
  86 point. Please note the subtleties. -Kiran
  87
  88 NONE              - Nothing so far.
  89 COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  90                     an INIT_ACK chunk in the reply direction.
  91 COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  92 ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  93 SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  94 SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  95 SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  96                     to that of the SHUTDOWN chunk.
  97 CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  98                     the SHUTDOWN chunk. Connection is closed.
  99 HEARTBEAT_SENT    - We have seen a HEARTBEAT in a new flow.
 100 HEARTBEAT_ACKED   - We have seen a HEARTBEAT-ACK in the direction opposite to
 101                     that of the HEARTBEAT chunk. Secondary connection is
 102                     established.
 103 */
 104
 105 /* TODO
 106  - I have assumed that the first INIT is in the original direction.
 107  This messes things when an INIT comes in the reply direction in CLOSED
 108  state.
 109  - Check the error type in the reply dir before transitioning from
 110 cookie echoed to closed.
 111  - Sec 5.2.4 of RFC 2960
 112  - Full Multi Homing support.
 113 */
 114
 115 /* SCTP conntrack state transitions */
 116 static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 117         {
 118 /*      ORIGINAL        */
 119 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 120 /* init         */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
 121 /* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
 122 /* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 123 /* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
 124 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
 125 /* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
 126 /* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
 127 /* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
 128 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
 129 /* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 130 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
 131         },
 132         {
 133 /*      REPLY   */
 134 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 135 /* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
 136 /* init_ack     */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
 137 /* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
 138 /* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
 139 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
 140 /* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
 141 /* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
 142 /* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
 143 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
 144 /* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 145 /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
 146         }
 147 };
 148
 149 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 150 /* Print out the private part of the conntrack. */
 151 static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 152 {
 153         seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
 154 }
 155 #endif
 156
 157 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 158 for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0;        \
 159         (offset) < (skb)->len &&                                        \
 160         ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 161         (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 162
 163 /* Some validity checks to make sure the chunks are fine */
 164 static int do_basic_checks(struct nf_conn *ct,
 165                            const struct sk_buff *skb,
 166                            unsigned int dataoff,
 167                            unsigned long *map)
 168 {
 169         u_int32_t offset, count;
 170         struct sctp_chunkhdr _sch, *sch;
 171         int flag;
 172
 173         flag = 0;
 174
 175         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 176                 pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 177
 178                 if (sch->type == SCTP_CID_INIT ||
 179                     sch->type == SCTP_CID_INIT_ACK ||
 180                     sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 181                         flag = 1;
 182
 183                 /*
 184                  * Cookie Ack/Echo chunks not the first OR
 185                  * Init / Init Ack / Shutdown compl chunks not the only chunks
 186                  * OR zero-length.
 187                  */
 188                 if (((sch->type == SCTP_CID_COOKIE_ACK ||
 189                       sch->type == SCTP_CID_COOKIE_ECHO ||
 190                       flag) &&
 191                      count != 0) || !sch->length) {
 192                         pr_debug("Basic checks failed\n");
 193                         return 1;
 194                 }
 195
 196                 if (map)
 197                         set_bit(sch->type, map);
 198         }
 199
 200         pr_debug("Basic checks passed\n");
 201         return count == 0;
 202 }
 203
 204 static int sctp_new_state(enum ip_conntrack_dir dir,
 205                           enum sctp_conntrack cur_state,
 206                           int chunk_type)
 207 {
 208         int i;
 209
 210         pr_debug("Chunk type: %d\n", chunk_type);
 211
 212         switch (chunk_type) {
 213         case SCTP_CID_INIT:
 214                 pr_debug("SCTP_CID_INIT\n");
 215                 i = 0;
 216                 break;
 217         case SCTP_CID_INIT_ACK:
 218                 pr_debug("SCTP_CID_INIT_ACK\n");
 219                 i = 1;
 220                 break;
 221         case SCTP_CID_ABORT:
 222                 pr_debug("SCTP_CID_ABORT\n");
 223                 i = 2;
 224                 break;
 225         case SCTP_CID_SHUTDOWN:
 226                 pr_debug("SCTP_CID_SHUTDOWN\n");
 227                 i = 3;
 228                 break;
 229         case SCTP_CID_SHUTDOWN_ACK:
 230                 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 231                 i = 4;
 232                 break;
 233         case SCTP_CID_ERROR:
 234                 pr_debug("SCTP_CID_ERROR\n");
 235                 i = 5;
 236                 break;
 237         case SCTP_CID_COOKIE_ECHO:
 238                 pr_debug("SCTP_CID_COOKIE_ECHO\n");
 239                 i = 6;
 240                 break;
 241         case SCTP_CID_COOKIE_ACK:
 242                 pr_debug("SCTP_CID_COOKIE_ACK\n");
 243                 i = 7;
 244                 break;
 245         case SCTP_CID_SHUTDOWN_COMPLETE:
 246                 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 247                 i = 8;
 248                 break;
 249         case SCTP_CID_HEARTBEAT:
 250                 pr_debug("SCTP_CID_HEARTBEAT");
 251                 i = 9;
 252                 break;
 253         case SCTP_CID_HEARTBEAT_ACK:
 254                 pr_debug("SCTP_CID_HEARTBEAT_ACK");
 255                 i = 10;
 256                 break;
 257         default:
 258                 /* Other chunks like DATA or SACK do not change the state */
 259                 pr_debug("Unknown chunk type, Will stay in %s\n",
 260                          sctp_conntrack_names[cur_state]);
 261                 return cur_state;
 262         }
 263
 264         pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 265                  dir, sctp_conntrack_names[cur_state], chunk_type,
 266                  sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 267
 268         return sctp_conntracks[dir][i][cur_state];
 269 }
 270
 271 /* Don't need lock here: this conntrack not in circulation yet */
 272 static noinline bool
 273 sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 274          const struct sctphdr *sh, unsigned int dataoff)
 275 {
 276         enum sctp_conntrack new_state;
 277         const struct sctp_chunkhdr *sch;
 278         struct sctp_chunkhdr _sch;
 279         u32 offset, count;
 280
 281         memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 282         new_state = SCTP_CONNTRACK_MAX;
 283         for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) {
 284                 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 285                                            SCTP_CONNTRACK_NONE, sch->type);
 286
 287                 /* Invalid: delete conntrack */
 288                 if (new_state == SCTP_CONNTRACK_NONE ||
 289                     new_state == SCTP_CONNTRACK_MAX) {
 290                         pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 291                         return false;
 292                 }
 293
 294                 /* Copy the vtag into the state info */
 295                 if (sch->type == SCTP_CID_INIT) {
 296                         struct sctp_inithdr _inithdr, *ih;
 297                         /* Sec 8.5.1 (A) */
 298                         if (sh->vtag)
 299                                 return false;
 300
 301                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 302                                                 sizeof(_inithdr), &_inithdr);
 303                         if (!ih)
 304                                 return false;
 305
 306                         pr_debug("Setting vtag %x for new conn\n",
 307                                  ih->init_tag);
 308
 309                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
 310                 } else if (sch->type == SCTP_CID_HEARTBEAT) {
 311                         pr_debug("Setting vtag %x for secondary conntrack\n",
 312                                  sh->vtag);
 313                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
 314                 } else {
 315                 /* If it is a shutdown ack OOTB packet, we expect a return
 316                    shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 317                         pr_debug("Setting vtag %x for new conn OOTB\n",
 318                                  sh->vtag);
 319                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 320                 }
 321
 322                 ct->proto.sctp.state = new_state;
 323         }
 324
 325         return true;
 326 }
 327
 328 static bool sctp_error(struct sk_buff *skb,
 329                        unsigned int dataoff,
 330                        const struct nf_hook_state *state)
 331 {
 332         const struct sctphdr *sh;
 333         const char *logmsg;
 334
 335         if (skb->len < dataoff + sizeof(struct sctphdr)) {
 336                 logmsg = "nf_ct_sctp: short packet ";
 337                 goto out_invalid;
 338         }
 339         if (state->hook == NF_INET_PRE_ROUTING &&
 340             state->net->ct.sysctl_checksum &&
 341             skb->ip_summed == CHECKSUM_NONE) {
 342                 if (!skb_make_writable(skb, dataoff + sizeof(struct sctphdr))) {
 343                         logmsg = "nf_ct_sctp: failed to read header ";
 344                         goto out_invalid;
 345                 }
 346                 sh = (const struct sctphdr *)(skb->data + dataoff);
 347                 if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
 348                         logmsg = "nf_ct_sctp: bad CRC ";
 349                         goto out_invalid;
 350                 }
 351                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 352         }
 353         return false;
 354 out_invalid:
 355         nf_l4proto_log_invalid(skb, state->net, state->pf, IPPROTO_SCTP, "%s", logmsg);
 356         return true;
 357 }
 358
 359 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 360 static int sctp_packet(struct nf_conn *ct,
 361                        struct sk_buff *skb,
 362                        unsigned int dataoff,
 363                        enum ip_conntrack_info ctinfo,
 364                        const struct nf_hook_state *state)
 365 {
 366         enum sctp_conntrack new_state, old_state;
 367         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 368         const struct sctphdr *sh;
 369         struct sctphdr _sctph;
 370         const struct sctp_chunkhdr *sch;
 371         struct sctp_chunkhdr _sch;
 372         u_int32_t offset, count;
 373         unsigned int *timeouts;
 374         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 375
 376         if (sctp_error(skb, dataoff, state))
 377                 return -NF_ACCEPT;
 378
 379         sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 380         if (sh == NULL)
 381                 goto out;
 382
 383         if (do_basic_checks(ct, skb, dataoff, map) != 0)
 384                 goto out;
 385
 386         if (!nf_ct_is_confirmed(ct)) {
 387                 /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 388                 if (test_bit(SCTP_CID_ABORT, map) ||
 389                     test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 390                     test_bit(SCTP_CID_COOKIE_ACK, map))
 391                         return -NF_ACCEPT;
 392
 393                 if (!sctp_new(ct, skb, sh, dataoff))
 394                         return -NF_ACCEPT;
 395         }
 396
 397         /* Check the verification tag (Sec 8.5) */
 398         if (!test_bit(SCTP_CID_INIT, map) &&
 399             !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 400             !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 401             !test_bit(SCTP_CID_ABORT, map) &&
 402             !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 403             !test_bit(SCTP_CID_HEARTBEAT, map) &&
 404             !test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
 405             sh->vtag != ct->proto.sctp.vtag[dir]) {
 406                 pr_debug("Verification tag check failed\n");
 407                 goto out;
 408         }
 409
 410         old_state = new_state = SCTP_CONNTRACK_NONE;
 411         spin_lock_bh(&ct->lock);
 412         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 413                 /* Special cases of Verification tag check (Sec 8.5.1) */
 414                 if (sch->type == SCTP_CID_INIT) {
 415                         /* Sec 8.5.1 (A) */
 416                         if (sh->vtag != 0)
 417                                 goto out_unlock;
 418                 } else if (sch->type == SCTP_CID_ABORT) {
 419                         /* Sec 8.5.1 (B) */
 420                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 421                             sh->vtag != ct->proto.sctp.vtag[!dir])
 422                                 goto out_unlock;
 423                 } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 424                         /* Sec 8.5.1 (C) */
 425                         if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 426                             sh->vtag != ct->proto.sctp.vtag[!dir] &&
 427                             sch->flags & SCTP_CHUNK_FLAG_T)
 428                                 goto out_unlock;
 429                 } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 430                         /* Sec 8.5.1 (D) */
 431                         if (sh->vtag != ct->proto.sctp.vtag[dir])
 432                                 goto out_unlock;
 433                 } else if (sch->type == SCTP_CID_HEARTBEAT ||
 434                            sch->type == SCTP_CID_HEARTBEAT_ACK) {
 435                         if (ct->proto.sctp.vtag[dir] == 0) {
 436                                 pr_debug("Setting vtag %x for dir %d\n",
 437                                          sh->vtag, dir);
 438                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 439                         } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 440                                 pr_debug("Verification tag check failed\n");
 441                                 goto out_unlock;
 442                         }
 443                 }
 444
 445                 old_state = ct->proto.sctp.state;
 446                 new_state = sctp_new_state(dir, old_state, sch->type);
 447
 448                 /* Invalid */
 449                 if (new_state == SCTP_CONNTRACK_MAX) {
 450                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 451                                  "conntrack=%u\n",
 452                                  dir, sch->type, old_state);
 453                         goto out_unlock;
 454                 }
 455
 456                 /* If it is an INIT or an INIT ACK note down the vtag */
 457                 if (sch->type == SCTP_CID_INIT ||
 458                     sch->type == SCTP_CID_INIT_ACK) {
 459                         struct sctp_inithdr _inithdr, *ih;
 460
 461                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 462                                                 sizeof(_inithdr), &_inithdr);
 463                         if (ih == NULL)
 464                                 goto out_unlock;
 465                         pr_debug("Setting vtag %x for dir %d\n",
 466                                  ih->init_tag, !dir);
 467                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
 468                 }
 469
 470                 ct->proto.sctp.state = new_state;
 471                 if (old_state != new_state)
 472                         nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 473         }
 474         spin_unlock_bh(&ct->lock);
 475
 476         timeouts = nf_ct_timeout_lookup(ct);
 477         if (!timeouts)
 478                 timeouts = nf_sctp_pernet(nf_ct_net(ct))->timeouts;
 479
 480         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 481
 482         if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 483             dir == IP_CT_DIR_REPLY &&
 484             new_state == SCTP_CONNTRACK_ESTABLISHED) {
 485                 pr_debug("Setting assured bit\n");
 486                 set_bit(IPS_ASSURED_BIT, &ct->status);
 487                 nf_conntrack_event_cache(IPCT_ASSURED, ct);
 488         }
 489
 490         return NF_ACCEPT;
 491
 492 out_unlock:
 493         spin_unlock_bh(&ct->lock);
 494 out:
 495         return -NF_ACCEPT;
 496 }
 497
 498 static bool sctp_can_early_drop(const struct nf_conn *ct)
 499 {
 500         switch (ct->proto.sctp.state) {
 501         case SCTP_CONNTRACK_SHUTDOWN_SENT:
 502         case SCTP_CONNTRACK_SHUTDOWN_RECD:
 503         case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
 504                 return true;
 505         default:
 506                 break;
 507         }
 508
 509         return false;
 510 }
 511
 512 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 513
 514 #include <linux/netfilter/nfnetlink.h>
 515 #include <linux/netfilter/nfnetlink_conntrack.h>
 516
 517 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 518                           struct nf_conn *ct)
 519 {
 520         struct nlattr *nest_parms;
 521
 522         spin_lock_bh(&ct->lock);
 523         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 524         if (!nest_parms)
 525                 goto nla_put_failure;
 526
 527         if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 528             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 529                          ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 530             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 531                          ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 532                 goto nla_put_failure;
 533
 534         spin_unlock_bh(&ct->lock);
 535
 536         nla_nest_end(skb, nest_parms);
 537
 538         return 0;
 539
 540 nla_put_failure:
 541         spin_unlock_bh(&ct->lock);
 542         return -1;
 543 }
 544
 545 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 546         [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 547         [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 548         [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 549 };
 550
 551 #define SCTP_NLATTR_SIZE ( \
 552                 NLA_ALIGN(NLA_HDRLEN + 1) + \
 553                 NLA_ALIGN(NLA_HDRLEN + 4) + \
 554                 NLA_ALIGN(NLA_HDRLEN + 4))
 555
 556 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 557 {
 558         struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 559         struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 560         int err;
 561
 562         /* updates may not contain the internal protocol info, skip parsing */
 563         if (!attr)
 564                 return 0;
 565
 566         err = nla_parse_nested(tb, CTA_PROTOINFO_SCTP_MAX, attr,
 567                                sctp_nla_policy, NULL);
 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 #endif
 587
 588 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 589
 590 #include <linux/netfilter/nfnetlink.h>
 591 #include <linux/netfilter/nfnetlink_cttimeout.h>
 592
 593 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 594                                       struct net *net, void *data)
 595 {
 596         unsigned int *timeouts = data;
 597         struct nf_sctp_net *sn = nf_sctp_pernet(net);
 598         int i;
 599
 600         /* set default SCTP timeouts. */
 601         for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 602                 timeouts[i] = sn->timeouts[i];
 603
 604         /* there's a 1:1 mapping between attributes and protocol states. */
 605         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 606                 if (tb[i]) {
 607                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 608                 }
 609         }
 610
 611         timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED];
 612         return 0;
 613 }
 614
 615 static int
 616 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 617 {
 618         const unsigned int *timeouts = data;
 619         int i;
 620
 621         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 622                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 623                         goto nla_put_failure;
 624         }
 625         return 0;
 626
 627 nla_put_failure:
 628         return -ENOSPC;
 629 }
 630
 631 static const struct nla_policy
 632 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 633         [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 634         [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 635         [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 636         [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 637         [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 638         [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 639         [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 640         [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT]       = { .type = NLA_U32 },
 641         [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED]      = { .type = NLA_U32 },
 642 };
 643 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 644
 645
 646 #ifdef CONFIG_SYSCTL
 647 static struct ctl_table sctp_sysctl_table[] = {
 648         {
 649                 .procname       = "nf_conntrack_sctp_timeout_closed",
 650                 .maxlen         = sizeof(unsigned int),
 651                 .mode           = 0644,
 652                 .proc_handler   = proc_dointvec_jiffies,
 653         },
 654         {
 655                 .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 656                 .maxlen         = sizeof(unsigned int),
 657                 .mode           = 0644,
 658                 .proc_handler   = proc_dointvec_jiffies,
 659         },
 660         {
 661                 .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 662                 .maxlen         = sizeof(unsigned int),
 663                 .mode           = 0644,
 664                 .proc_handler   = proc_dointvec_jiffies,
 665         },
 666         {
 667                 .procname       = "nf_conntrack_sctp_timeout_established",
 668                 .maxlen         = sizeof(unsigned int),
 669                 .mode           = 0644,
 670                 .proc_handler   = proc_dointvec_jiffies,
 671         },
 672         {
 673                 .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 674                 .maxlen         = sizeof(unsigned int),
 675                 .mode           = 0644,
 676                 .proc_handler   = proc_dointvec_jiffies,
 677         },
 678         {
 679                 .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 680                 .maxlen         = sizeof(unsigned int),
 681                 .mode           = 0644,
 682                 .proc_handler   = proc_dointvec_jiffies,
 683         },
 684         {
 685                 .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 686                 .maxlen         = sizeof(unsigned int),
 687                 .mode           = 0644,
 688                 .proc_handler   = proc_dointvec_jiffies,
 689         },
 690         {
 691                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_sent",
 692                 .maxlen         = sizeof(unsigned int),
 693                 .mode           = 0644,
 694                 .proc_handler   = proc_dointvec_jiffies,
 695         },
 696         {
 697                 .procname       = "nf_conntrack_sctp_timeout_heartbeat_acked",
 698                 .maxlen         = sizeof(unsigned int),
 699                 .mode           = 0644,
 700                 .proc_handler   = proc_dointvec_jiffies,
 701         },
 702         { }
 703 };
 704 #endif
 705
 706 static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
 707                                      struct nf_sctp_net *sn)
 708 {
 709 #ifdef CONFIG_SYSCTL
 710         if (pn->ctl_table)
 711                 return 0;
 712
 713         pn->ctl_table = kmemdup(sctp_sysctl_table,
 714                                 sizeof(sctp_sysctl_table),
 715                                 GFP_KERNEL);
 716         if (!pn->ctl_table)
 717                 return -ENOMEM;
 718
 719         pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 720         pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 721         pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 722         pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 723         pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 724         pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 725         pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 726         pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
 727         pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
 728 #endif
 729         return 0;
 730 }
 731
 732 static int sctp_init_net(struct net *net)
 733 {
 734         struct nf_sctp_net *sn = nf_sctp_pernet(net);
 735         struct nf_proto_net *pn = &sn->pn;
 736
 737         if (!pn->users) {
 738                 int i;
 739
 740                 for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 741                         sn->timeouts[i] = sctp_timeouts[i];
 742
 743                 /* timeouts[0] is unused, init it so ->timeouts[0] contains
 744                  * 'new' timeout, like udp or icmp.
 745                  */
 746                 sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED];
 747         }
 748
 749         return sctp_kmemdup_sysctl_table(pn, sn);
 750 }
 751
 752 static struct nf_proto_net *sctp_get_net_proto(struct net *net)
 753 {
 754         return &net->ct.nf_ct_proto.sctp.pn;
 755 }
 756
 757 const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = {
 758         .l4proto                = IPPROTO_SCTP,
 759 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 760         .print_conntrack        = sctp_print_conntrack,
 761 #endif
 762         .packet                 = sctp_packet,
 763         .can_early_drop         = sctp_can_early_drop,
 764         .me                     = THIS_MODULE,
 765 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 766         .nlattr_size            = SCTP_NLATTR_SIZE,
 767         .to_nlattr              = sctp_to_nlattr,
 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 #endif
 774 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 775         .ctnl_timeout           = {
 776                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 777                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 778                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 779                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 780                 .nla_policy     = sctp_timeout_nla_policy,
 781         },
 782 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 783         .init_net               = sctp_init_net,
 784         .get_net_proto          = sctp_get_net_proto,
 785 };