net/netfilter/nf_conntrack_proto_sctp.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Connection tracking protocol helper module for SCTP.
   4  *
   5  * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
   6  * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
   7  *
   8  * SCTP is defined in RFC 2960. References to various sections in this code
   9  * are to this RFC.
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/timer.h>
  14 #include <linux/netfilter.h>
  15 #include <linux/in.h>
  16 #include <linux/ip.h>
  17 #include <linux/sctp.h>
  18 #include <linux/string.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/interrupt.h>
  22 #include <net/sctp/checksum.h>
  23
  24 #include <net/netfilter/nf_log.h>
  25 #include <net/netfilter/nf_conntrack.h>
  26 #include <net/netfilter/nf_conntrack_l4proto.h>
  27 #include <net/netfilter/nf_conntrack_ecache.h>
  28 #include <net/netfilter/nf_conntrack_timeout.h>
  29
  30 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  31    closely.  They're more complex. --RR
  32
  33    And so for me for SCTP :D -Kiran */
  34
  35 static const char *const sctp_conntrack_names[] = {
  36         "NONE",
  37         "CLOSED",
  38         "COOKIE_WAIT",
  39         "COOKIE_ECHOED",
  40         "ESTABLISHED",
  41         "SHUTDOWN_SENT",
  42         "SHUTDOWN_RECD",
  43         "SHUTDOWN_ACK_SENT",
  44         "HEARTBEAT_SENT",
  45         "HEARTBEAT_ACKED",
  46 };
  47
  48 #define SECS  * HZ
  49 #define MINS  * 60 SECS
  50 #define HOURS * 60 MINS
  51 #define DAYS  * 24 HOURS
  52
  53 static const unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] = {
  54         [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  55         [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  56         [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  57         [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  58         [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  59         [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  60         [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  61         [SCTP_CONNTRACK_HEARTBEAT_SENT]         = 30 SECS,
  62         [SCTP_CONNTRACK_HEARTBEAT_ACKED]        = 210 SECS,
  63 };
  64
  65 #define SCTP_FLAG_HEARTBEAT_VTAG_FAILED 1
  66
  67 #define sNO SCTP_CONNTRACK_NONE
  68 #define sCL SCTP_CONNTRACK_CLOSED
  69 #define sCW SCTP_CONNTRACK_COOKIE_WAIT
  70 #define sCE SCTP_CONNTRACK_COOKIE_ECHOED
  71 #define sES SCTP_CONNTRACK_ESTABLISHED
  72 #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
  73 #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
  74 #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
  75 #define sHS SCTP_CONNTRACK_HEARTBEAT_SENT
  76 #define sHA SCTP_CONNTRACK_HEARTBEAT_ACKED
  77 #define sIV SCTP_CONNTRACK_MAX
  78
  79 /*
  80         These are the descriptions of the states:
  81
  82 NOTE: These state names are tantalizingly similar to the states of an
  83 SCTP endpoint. But the interpretation of the states is a little different,
  84 considering that these are the states of the connection and not of an end
  85 point. Please note the subtleties. -Kiran
  86
  87 NONE              - Nothing so far.
  88 COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  89                     an INIT_ACK chunk in the reply direction.
  90 COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  91 ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  92 SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  93 SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  94 SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  95                     to that of the SHUTDOWN chunk.
  96 CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  97                     the SHUTDOWN chunk. Connection is closed.
  98 HEARTBEAT_SENT    - We have seen a HEARTBEAT in a new flow.
  99 HEARTBEAT_ACKED   - We have seen a HEARTBEAT-ACK in the direction opposite to
 100                     that of the HEARTBEAT chunk. Secondary connection is
 101                     established.
 102 */
 103
 104 /* TODO
 105  - I have assumed that the first INIT is in the original direction.
 106  This messes things when an INIT comes in the reply direction in CLOSED
 107  state.
 108  - Check the error type in the reply dir before transitioning from
 109 cookie echoed to closed.
 110  - Sec 5.2.4 of RFC 2960
 111  - Full Multi Homing support.
 112 */
 113
 114 /* SCTP conntrack state transitions */
 115 static const u8 sctp_conntracks[2][11][SCTP_CONNTRACK_MAX] = {
 116         {
 117 /*      ORIGINAL        */
 118 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 119 /* init         */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCW, sHA},
 120 /* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},
 121 /* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 122 /* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA, sCL, sSS},
 123 /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA, sSA, sHA},
 124 /* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't have Stale cookie*/
 125 /* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* 5.2.4 - Big TODO */
 126 /* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sCL, sHA},/* Can't come in orig dir */
 127 /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL, sCL, sHA},
 128 /* heartbeat    */ {sHS, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 129 /* heartbeat_ack*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA}
 130         },
 131         {
 132 /*      REPLY   */
 133 /*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA */
 134 /* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* INIT in sCL Big TODO */
 135 /* init_ack     */ {sIV, sCW, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},
 136 /* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sIV, sCL},
 137 /* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA, sIV, sSR},
 138 /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA, sIV, sHA},
 139 /* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA, sIV, sHA},
 140 /* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sIV, sHA},/* Can't come in reply dir */
 141 /* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA, sIV, sHA},
 142 /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL, sIV, sHA},
 143 /* heartbeat    */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHS, sHA},
 144 /* heartbeat_ack*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA, sHA, sHA}
 145         }
 146 };
 147
 148 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 149 /* Print out the private part of the conntrack. */
 150 static void sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 151 {
 152         seq_printf(s, "%s ", sctp_conntrack_names[ct->proto.sctp.state]);
 153 }
 154 #endif
 155
 156 #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 157 for ((offset) = (dataoff) + sizeof(struct sctphdr), (count) = 0;        \
 158         (offset) < (skb)->len &&                                        \
 159         ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 160         (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 161
 162 /* Some validity checks to make sure the chunks are fine */
 163 static int do_basic_checks(struct nf_conn *ct,
 164                            const struct sk_buff *skb,
 165                            unsigned int dataoff,
 166                            unsigned long *map)
 167 {
 168         u_int32_t offset, count;
 169         struct sctp_chunkhdr _sch, *sch;
 170         int flag;
 171
 172         flag = 0;
 173
 174         for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 175                 pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 176
 177                 if (sch->type == SCTP_CID_INIT ||
 178                     sch->type == SCTP_CID_INIT_ACK ||
 179                     sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 180                         flag = 1;
 181
 182                 /*
 183                  * Cookie Ack/Echo chunks not the first OR
 184                  * Init / Init Ack / Shutdown compl chunks not the only chunks
 185                  * OR zero-length.
 186                  */
 187                 if (((sch->type == SCTP_CID_COOKIE_ACK ||
 188                       sch->type == SCTP_CID_COOKIE_ECHO ||
 189                       flag) &&
 190                      count != 0) || !sch->length) {
 191                         pr_debug("Basic checks failed\n");
 192                         return 1;
 193                 }
 194
 195                 if (map)
 196                         set_bit(sch->type, map);
 197         }
 198
 199         pr_debug("Basic checks passed\n");
 200         return count == 0;
 201 }
 202
 203 static int sctp_new_state(enum ip_conntrack_dir dir,
 204                           enum sctp_conntrack cur_state,
 205                           int chunk_type)
 206 {
 207         int i;
 208
 209         pr_debug("Chunk type: %d\n", chunk_type);
 210
 211         switch (chunk_type) {
 212         case SCTP_CID_INIT:
 213                 pr_debug("SCTP_CID_INIT\n");
 214                 i = 0;
 215                 break;
 216         case SCTP_CID_INIT_ACK:
 217                 pr_debug("SCTP_CID_INIT_ACK\n");
 218                 i = 1;
 219                 break;
 220         case SCTP_CID_ABORT:
 221                 pr_debug("SCTP_CID_ABORT\n");
 222                 i = 2;
 223                 break;
 224         case SCTP_CID_SHUTDOWN:
 225                 pr_debug("SCTP_CID_SHUTDOWN\n");
 226                 i = 3;
 227                 break;
 228         case SCTP_CID_SHUTDOWN_ACK:
 229                 pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 230                 i = 4;
 231                 break;
 232         case SCTP_CID_ERROR:
 233                 pr_debug("SCTP_CID_ERROR\n");
 234                 i = 5;
 235                 break;
 236         case SCTP_CID_COOKIE_ECHO:
 237                 pr_debug("SCTP_CID_COOKIE_ECHO\n");
 238                 i = 6;
 239                 break;
 240         case SCTP_CID_COOKIE_ACK:
 241                 pr_debug("SCTP_CID_COOKIE_ACK\n");
 242                 i = 7;
 243                 break;
 244         case SCTP_CID_SHUTDOWN_COMPLETE:
 245                 pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 246                 i = 8;
 247                 break;
 248         case SCTP_CID_HEARTBEAT:
 249                 pr_debug("SCTP_CID_HEARTBEAT");
 250                 i = 9;
 251                 break;
 252         case SCTP_CID_HEARTBEAT_ACK:
 253                 pr_debug("SCTP_CID_HEARTBEAT_ACK");
 254                 i = 10;
 255                 break;
 256         default:
 257                 /* Other chunks like DATA or SACK do not change the state */
 258                 pr_debug("Unknown chunk type, Will stay in %s\n",
 259                          sctp_conntrack_names[cur_state]);
 260                 return cur_state;
 261         }
 262
 263         pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 264                  dir, sctp_conntrack_names[cur_state], chunk_type,
 265                  sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 266
 267         return sctp_conntracks[dir][i][cur_state];
 268 }
 269
 270 /* Don't need lock here: this conntrack not in circulation yet */
 271 static noinline bool
 272 sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 273          const struct sctphdr *sh, unsigned int dataoff)
 274 {
 275         enum sctp_conntrack new_state;
 276         const struct sctp_chunkhdr *sch;
 277         struct sctp_chunkhdr _sch;
 278         u32 offset, count;
 279
 280         memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 281         new_state = SCTP_CONNTRACK_MAX;
 282         for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) {
 283                 new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 284                                            SCTP_CONNTRACK_NONE, sch->type);
 285
 286                 /* Invalid: delete conntrack */
 287                 if (new_state == SCTP_CONNTRACK_NONE ||
 288                     new_state == SCTP_CONNTRACK_MAX) {
 289                         pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 290                         return false;
 291                 }
 292
 293                 /* Copy the vtag into the state info */
 294                 if (sch->type == SCTP_CID_INIT) {
 295                         struct sctp_inithdr _inithdr, *ih;
 296                         /* Sec 8.5.1 (A) */
 297                         if (sh->vtag)
 298                                 return false;
 299
 300                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 301                                                 sizeof(_inithdr), &_inithdr);
 302                         if (!ih)
 303                                 return false;
 304
 305                         pr_debug("Setting vtag %x for new conn\n",
 306                                  ih->init_tag);
 307
 308                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = ih->init_tag;
 309                 } else if (sch->type == SCTP_CID_HEARTBEAT) {
 310                         pr_debug("Setting vtag %x for secondary conntrack\n",
 311                                  sh->vtag);
 312                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
 313                 } else {
 314                 /* If it is a shutdown ack OOTB packet, we expect a return
 315                    shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 316                         pr_debug("Setting vtag %x for new conn OOTB\n",
 317                                  sh->vtag);
 318                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 319                 }
 320
 321                 ct->proto.sctp.state = SCTP_CONNTRACK_NONE;
 322         }
 323
 324         return true;
 325 }
 326
 327 static bool sctp_error(struct sk_buff *skb,
 328                        unsigned int dataoff,
 329                        const struct nf_hook_state *state)
 330 {
 331         const struct sctphdr *sh;
 332         const char *logmsg;
 333
 334         if (skb->len < dataoff + sizeof(struct sctphdr)) {
 335                 logmsg = "nf_ct_sctp: short packet ";
 336                 goto out_invalid;
 337         }
 338         if (state->hook == NF_INET_PRE_ROUTING &&
 339             state->net->ct.sysctl_checksum &&
 340             skb->ip_summed == CHECKSUM_NONE) {
 341                 if (skb_ensure_writable(skb, dataoff + sizeof(*sh))) {
 342                         logmsg = "nf_ct_sctp: failed to read header ";
 343                         goto out_invalid;
 344                 }
 345                 sh = (const struct sctphdr *)(skb->data + dataoff);
 346                 if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
 347                         logmsg = "nf_ct_sctp: bad CRC ";
 348                         goto out_invalid;
 349                 }
 350                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 351         }
 352         return false;
 353 out_invalid:
 354         nf_l4proto_log_invalid(skb, state, IPPROTO_SCTP, "%s", logmsg);
 355         return true;
 356 }
 357
 358 /* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 359 int nf_conntrack_sctp_packet(struct nf_conn *ct,
 360                              struct sk_buff *skb,
 361                              unsigned int dataoff,
 362                              enum ip_conntrack_info ctinfo,
 363                              const struct nf_hook_state *state)
 364 {
 365         enum sctp_conntrack new_state, old_state;
 366         enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 367         const struct sctphdr *sh;
 368         struct sctphdr _sctph;
 369         const struct sctp_chunkhdr *sch;
 370         struct sctp_chunkhdr _sch;
 371         u_int32_t offset, count;
 372         unsigned int *timeouts;
 373         unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 374         bool ignore = false;
 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                         if (ct->proto.sctp.vtag[dir] == 0) {
 435                                 pr_debug("Setting %d vtag %x for dir %d\n", sch->type, sh->vtag, dir);
 436                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 437                         } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 438                                 if (test_bit(SCTP_CID_DATA, map) || ignore)
 439                                         goto out_unlock;
 440
 441                                 ct->proto.sctp.flags |= SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
 442                                 ct->proto.sctp.last_dir = dir;
 443                                 ignore = true;
 444                                 continue;
 445                         } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) {
 446                                 ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
 447                         }
 448                 } else if (sch->type == SCTP_CID_HEARTBEAT_ACK) {
 449                         if (ct->proto.sctp.vtag[dir] == 0) {
 450                                 pr_debug("Setting vtag %x for dir %d\n",
 451                                          sh->vtag, dir);
 452                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 453                         } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 454                                 if (test_bit(SCTP_CID_DATA, map) || ignore)
 455                                         goto out_unlock;
 456
 457                                 if ((ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) == 0 ||
 458                                     ct->proto.sctp.last_dir == dir)
 459                                         goto out_unlock;
 460
 461                                 ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
 462                                 ct->proto.sctp.vtag[dir] = sh->vtag;
 463                                 ct->proto.sctp.vtag[!dir] = 0;
 464                         } else if (ct->proto.sctp.flags & SCTP_FLAG_HEARTBEAT_VTAG_FAILED) {
 465                                 ct->proto.sctp.flags &= ~SCTP_FLAG_HEARTBEAT_VTAG_FAILED;
 466                         }
 467                 }
 468
 469                 old_state = ct->proto.sctp.state;
 470                 new_state = sctp_new_state(dir, old_state, sch->type);
 471
 472                 /* Invalid */
 473                 if (new_state == SCTP_CONNTRACK_MAX) {
 474                         pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 475                                  "conntrack=%u\n",
 476                                  dir, sch->type, old_state);
 477                         goto out_unlock;
 478                 }
 479
 480                 /* If it is an INIT or an INIT ACK note down the vtag */
 481                 if (sch->type == SCTP_CID_INIT ||
 482                     sch->type == SCTP_CID_INIT_ACK) {
 483                         struct sctp_inithdr _inithdr, *ih;
 484
 485                         ih = skb_header_pointer(skb, offset + sizeof(_sch),
 486                                                 sizeof(_inithdr), &_inithdr);
 487                         if (ih == NULL)
 488                                 goto out_unlock;
 489                         pr_debug("Setting vtag %x for dir %d\n",
 490                                  ih->init_tag, !dir);
 491                         ct->proto.sctp.vtag[!dir] = ih->init_tag;
 492                 }
 493
 494                 ct->proto.sctp.state = new_state;
 495                 if (old_state != new_state)
 496                         nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 497         }
 498         spin_unlock_bh(&ct->lock);
 499
 500         /* allow but do not refresh timeout */
 501         if (ignore)
 502                 return NF_ACCEPT;
 503
 504         timeouts = nf_ct_timeout_lookup(ct);
 505         if (!timeouts)
 506                 timeouts = nf_sctp_pernet(nf_ct_net(ct))->timeouts;
 507
 508         nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 509
 510         if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 511             dir == IP_CT_DIR_REPLY &&
 512             new_state == SCTP_CONNTRACK_ESTABLISHED) {
 513                 pr_debug("Setting assured bit\n");
 514                 set_bit(IPS_ASSURED_BIT, &ct->status);
 515                 nf_conntrack_event_cache(IPCT_ASSURED, ct);
 516         }
 517
 518         return NF_ACCEPT;
 519
 520 out_unlock:
 521         spin_unlock_bh(&ct->lock);
 522 out:
 523         return -NF_ACCEPT;
 524 }
 525
 526 static bool sctp_can_early_drop(const struct nf_conn *ct)
 527 {
 528         switch (ct->proto.sctp.state) {
 529         case SCTP_CONNTRACK_SHUTDOWN_SENT:
 530         case SCTP_CONNTRACK_SHUTDOWN_RECD:
 531         case SCTP_CONNTRACK_SHUTDOWN_ACK_SENT:
 532                 return true;
 533         default:
 534                 break;
 535         }
 536
 537         return false;
 538 }
 539
 540 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 541
 542 #include <linux/netfilter/nfnetlink.h>
 543 #include <linux/netfilter/nfnetlink_conntrack.h>
 544
 545 static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 546                           struct nf_conn *ct, bool destroy)
 547 {
 548         struct nlattr *nest_parms;
 549
 550         spin_lock_bh(&ct->lock);
 551         nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP);
 552         if (!nest_parms)
 553                 goto nla_put_failure;
 554
 555         if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state))
 556                 goto nla_put_failure;
 557
 558         if (destroy)
 559                 goto skip_state;
 560
 561         if (nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 562                          ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 563             nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 564                          ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 565                 goto nla_put_failure;
 566
 567 skip_state:
 568         spin_unlock_bh(&ct->lock);
 569         nla_nest_end(skb, nest_parms);
 570
 571         return 0;
 572
 573 nla_put_failure:
 574         spin_unlock_bh(&ct->lock);
 575         return -1;
 576 }
 577
 578 static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 579         [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 580         [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 581         [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 582 };
 583
 584 #define SCTP_NLATTR_SIZE ( \
 585                 NLA_ALIGN(NLA_HDRLEN + 1) + \
 586                 NLA_ALIGN(NLA_HDRLEN + 4) + \
 587                 NLA_ALIGN(NLA_HDRLEN + 4))
 588
 589 static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 590 {
 591         struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 592         struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 593         int err;
 594
 595         /* updates may not contain the internal protocol info, skip parsing */
 596         if (!attr)
 597                 return 0;
 598
 599         err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_SCTP_MAX, attr,
 600                                           sctp_nla_policy, NULL);
 601         if (err < 0)
 602                 return err;
 603
 604         if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 605             !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 606             !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 607                 return -EINVAL;
 608
 609         spin_lock_bh(&ct->lock);
 610         ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 611         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 612                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 613         ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 614                 nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 615         spin_unlock_bh(&ct->lock);
 616
 617         return 0;
 618 }
 619 #endif
 620
 621 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 622
 623 #include <linux/netfilter/nfnetlink.h>
 624 #include <linux/netfilter/nfnetlink_cttimeout.h>
 625
 626 static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 627                                       struct net *net, void *data)
 628 {
 629         unsigned int *timeouts = data;
 630         struct nf_sctp_net *sn = nf_sctp_pernet(net);
 631         int i;
 632
 633         if (!timeouts)
 634                 timeouts = sn->timeouts;
 635
 636         /* set default SCTP timeouts. */
 637         for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 638                 timeouts[i] = sn->timeouts[i];
 639
 640         /* there's a 1:1 mapping between attributes and protocol states. */
 641         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 642                 if (tb[i]) {
 643                         timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 644                 }
 645         }
 646
 647         timeouts[CTA_TIMEOUT_SCTP_UNSPEC] = timeouts[CTA_TIMEOUT_SCTP_CLOSED];
 648         return 0;
 649 }
 650
 651 static int
 652 sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 653 {
 654         const unsigned int *timeouts = data;
 655         int i;
 656
 657         for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 658                 if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 659                         goto nla_put_failure;
 660         }
 661         return 0;
 662
 663 nla_put_failure:
 664         return -ENOSPC;
 665 }
 666
 667 static const struct nla_policy
 668 sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 669         [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 670         [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 671         [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 672         [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 673         [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 674         [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 675         [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 676         [CTA_TIMEOUT_SCTP_HEARTBEAT_SENT]       = { .type = NLA_U32 },
 677         [CTA_TIMEOUT_SCTP_HEARTBEAT_ACKED]      = { .type = NLA_U32 },
 678 };
 679 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 680
 681 void nf_conntrack_sctp_init_net(struct net *net)
 682 {
 683         struct nf_sctp_net *sn = nf_sctp_pernet(net);
 684         int i;
 685
 686         for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 687                 sn->timeouts[i] = sctp_timeouts[i];
 688
 689         /* timeouts[0] is unused, init it so ->timeouts[0] contains
 690          * 'new' timeout, like udp or icmp.
 691          */
 692         sn->timeouts[0] = sctp_timeouts[SCTP_CONNTRACK_CLOSED];
 693 }
 694
 695 const struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp = {
 696         .l4proto                = IPPROTO_SCTP,
 697 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 698         .print_conntrack        = sctp_print_conntrack,
 699 #endif
 700         .can_early_drop         = sctp_can_early_drop,
 701 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 702         .nlattr_size            = SCTP_NLATTR_SIZE,
 703         .to_nlattr              = sctp_to_nlattr,
 704         .from_nlattr            = nlattr_to_sctp,
 705         .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 706         .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 707         .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 708         .nla_policy             = nf_ct_port_nla_policy,
 709 #endif
 710 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 711         .ctnl_timeout           = {
 712                 .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 713                 .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 714                 .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 715                 .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 716                 .nla_policy     = sctp_timeout_nla_policy,
 717         },
 718 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 719 };