LXR linux/net/netfilter/nf_conntrack_proto

   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
  32/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  33   closely.  They're more complex. --RR
  34
  35   And so for me for SCTP :D -Kiran */
  36
  37static const char *const sctp_conntrack_names[] = {
  38        "NONE",
  39        "CLOSED",
  40        "COOKIE_WAIT",
  41        "COOKIE_ECHOED",
  42        "ESTABLISHED",
  43        "SHUTDOWN_SENT",
  44        "SHUTDOWN_RECD",
  45        "SHUTDOWN_ACK_SENT",
  46        "HEARTBEAT_SENT",
  47        "HEARTBEAT_ACKED",
  48};
  49
  50#define SECS  * HZ
  51#define MINS  * 60 SECS
  52#define HOURS * 60 MINS
  53#define DAYS  * 24 HOURS
  54
  55static unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] __read_mostly = {
  56        [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  57        [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  58        [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  59        [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  60        [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  61        [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  62        [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  63        [SCTP_CONNTRACK_HEARTBEAT_SENT]         = 30 SECS,
  64        [SCTP_CONNTRACK_HEARTBEAT_ACKED]        = 210 SECS,
  65};
  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
  82NOTE: These state names are tantalizingly similar to the states of an
  83SCTP endpoint. But the interpretation of the states is a little different,
  84considering that these are the states of the connection and not of an end
  85point. Please note the subtleties. -Kiran
  86
  87NONE              - Nothing so far.
  88COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  89                    an INIT_ACK chunk in the reply direction.
  90COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  91ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  92SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  93SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  94SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  95                    to that of the SHUTDOWN chunk.
  96CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  97                    the SHUTDOWN chunk. Connection is closed.
  98HEARTBEAT_SENT    - We have seen a HEARTBEAT in a new flow.
  99HEARTBEAT_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
 109cookie echoed to closed.
 110 - Sec 5.2.4 of RFC 2960
 111 - Full Multi Homing support.
 112*/
 113
 114/* SCTP conntrack state transitions */
 115static 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         */ {sCW, sCW, 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, sCL, 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
 148static inline struct nf_sctp_net *sctp_pernet(struct net *net)
 149{
 150        return &net->ct_sctp;
 151}
 152
 153static bool sctp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
 154                              struct nf_conntrack_tuple *tuple)
 155{
 156        const struct sctphdr *hp;
 157        struct sctphdr _hdr;
 158
 159        /* Actually only need first 8 bytes. */
 160        hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
 161        if (hp == NULL)
 162                return false;
 163
 164        tuple->src.u.sctp.port = hp->source;
 165        tuple->dst.u.sctp.port = hp->dest;
 166        return true;
 167}
 168
 169static bool sctp_invert_tuple(struct nf_conntrack_tuple *tuple,
 170                              const struct nf_conntrack_tuple *orig)
 171{
 172        tuple->src.u.sctp.port = orig->dst.u.sctp.port;
 173        tuple->dst.u.sctp.port = orig->src.u.sctp.port;
 174        return true;
 175}
 176
 177/* Print out the per-protocol part of the tuple. */
 178static int sctp_print_tuple(struct seq_file *s,
 179                            const struct nf_conntrack_tuple *tuple)
 180{
 181        return seq_printf(s, "sport=%hu dport=%hu ",
 182                          ntohs(tuple->src.u.sctp.port),
 183                          ntohs(tuple->dst.u.sctp.port));
 184}
 185
 186/* Print out the private part of the conntrack. */
 187static int sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 188{
 189        enum sctp_conntrack state;
 190
 191        spin_lock_bh(&ct->lock);
 192        state = ct->proto.sctp.state;
 193        spin_unlock_bh(&ct->lock);
 194
 195        return seq_printf(s, "%s ", sctp_conntrack_names[state]);
 196}
 197
 198#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 199for ((offset) = (dataoff) + sizeof(sctp_sctphdr_t), (count) = 0;        \
 200        (offset) < (skb)->len &&                                        \
 201        ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 202        (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 203
 204/* Some validity checks to make sure the chunks are fine */
 205static int do_basic_checks(struct nf_conn *ct,
 206                           const struct sk_buff *skb,
 207                           unsigned int dataoff,
 208                           unsigned long *map)
 209{
 210        u_int32_t offset, count;
 211        sctp_chunkhdr_t _sch, *sch;
 212        int flag;
 213
 214        flag = 0;
 215
 216        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 217                pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 218
 219                if (sch->type == SCTP_CID_INIT ||
 220                    sch->type == SCTP_CID_INIT_ACK ||
 221                    sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 222                        flag = 1;
 223
 224                /*
 225                 * Cookie Ack/Echo chunks not the first OR
 226                 * Init / Init Ack / Shutdown compl chunks not the only chunks
 227                 * OR zero-length.
 228                 */
 229                if (((sch->type == SCTP_CID_COOKIE_ACK ||
 230                      sch->type == SCTP_CID_COOKIE_ECHO ||
 231                      flag) &&
 232                     count != 0) || !sch->length) {
 233                        pr_debug("Basic checks failed\n");
 234                        return 1;
 235                }
 236
 237                if (map)
 238                        set_bit(sch->type, map);
 239        }
 240
 241        pr_debug("Basic checks passed\n");
 242        return count == 0;
 243}
 244
 245static int sctp_new_state(enum ip_conntrack_dir dir,
 246                          enum sctp_conntrack cur_state,
 247                          int chunk_type)
 248{
 249        int i;
 250
 251        pr_debug("Chunk type: %d\n", chunk_type);
 252
 253        switch (chunk_type) {
 254        case SCTP_CID_INIT:
 255                pr_debug("SCTP_CID_INIT\n");
 256                i = 0;
 257                break;
 258        case SCTP_CID_INIT_ACK:
 259                pr_debug("SCTP_CID_INIT_ACK\n");
 260                i = 1;
 261                break;
 262        case SCTP_CID_ABORT:
 263                pr_debug("SCTP_CID_ABORT\n");
 264                i = 2;
 265                break;
 266        case SCTP_CID_SHUTDOWN:
 267                pr_debug("SCTP_CID_SHUTDOWN\n");
 268                i = 3;
 269                break;
 270        case SCTP_CID_SHUTDOWN_ACK:
 271                pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 272                i = 4;
 273                break;
 274        case SCTP_CID_ERROR:
 275                pr_debug("SCTP_CID_ERROR\n");
 276                i = 5;
 277                break;
 278        case SCTP_CID_COOKIE_ECHO:
 279                pr_debug("SCTP_CID_COOKIE_ECHO\n");
 280                i = 6;
 281                break;
 282        case SCTP_CID_COOKIE_ACK:
 283                pr_debug("SCTP_CID_COOKIE_ACK\n");
 284                i = 7;
 285                break;
 286        case SCTP_CID_SHUTDOWN_COMPLETE:
 287                pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 288                i = 8;
 289                break;
 290        case SCTP_CID_HEARTBEAT:
 291                pr_debug("SCTP_CID_HEARTBEAT");
 292                i = 9;
 293                break;
 294        case SCTP_CID_HEARTBEAT_ACK:
 295                pr_debug("SCTP_CID_HEARTBEAT_ACK");
 296                i = 10;
 297                break;
 298        default:
 299                /* Other chunks like DATA or SACK do not change the state */
 300                pr_debug("Unknown chunk type, Will stay in %s\n",
 301                         sctp_conntrack_names[cur_state]);
 302                return cur_state;
 303        }
 304
 305        pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 306                 dir, sctp_conntrack_names[cur_state], chunk_type,
 307                 sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 308
 309        return sctp_conntracks[dir][i][cur_state];
 310}
 311
 312static unsigned int *sctp_get_timeouts(struct net *net)
 313{
 314        return sctp_pernet(net)->timeouts;
 315}
 316
 317/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 318static int sctp_packet(struct nf_conn *ct,
 319                       const struct sk_buff *skb,
 320                       unsigned int dataoff,
 321                       enum ip_conntrack_info ctinfo,
 322                       u_int8_t pf,
 323                       unsigned int hooknum,
 324                       unsigned int *timeouts)
 325{
 326        enum sctp_conntrack new_state, old_state;
 327        enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 328        const struct sctphdr *sh;
 329        struct sctphdr _sctph;
 330        const struct sctp_chunkhdr *sch;
 331        struct sctp_chunkhdr _sch;
 332        u_int32_t offset, count;
 333        unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 334
 335        sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 336        if (sh == NULL)
 337                goto out;
 338
 339        if (do_basic_checks(ct, skb, dataoff, map) != 0)
 340                goto out;
 341
 342        /* Check the verification tag (Sec 8.5) */
 343        if (!test_bit(SCTP_CID_INIT, map) &&
 344            !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 345            !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 346            !test_bit(SCTP_CID_ABORT, map) &&
 347            !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 348            !test_bit(SCTP_CID_HEARTBEAT, map) &&
 349            !test_bit(SCTP_CID_HEARTBEAT_ACK, map) &&
 350            sh->vtag != ct->proto.sctp.vtag[dir]) {
 351                pr_debug("Verification tag check failed\n");
 352                goto out;
 353        }
 354
 355        old_state = new_state = SCTP_CONNTRACK_NONE;
 356        spin_lock_bh(&ct->lock);
 357        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 358                /* Special cases of Verification tag check (Sec 8.5.1) */
 359                if (sch->type == SCTP_CID_INIT) {
 360                        /* Sec 8.5.1 (A) */
 361                        if (sh->vtag != 0)
 362                                goto out_unlock;
 363                } else if (sch->type == SCTP_CID_ABORT) {
 364                        /* Sec 8.5.1 (B) */
 365                        if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 366                            sh->vtag != ct->proto.sctp.vtag[!dir])
 367                                goto out_unlock;
 368                } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 369                        /* Sec 8.5.1 (C) */
 370                        if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 371                            sh->vtag != ct->proto.sctp.vtag[!dir] &&
 372                            sch->flags & SCTP_CHUNK_FLAG_T)
 373                                goto out_unlock;
 374                } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 375                        /* Sec 8.5.1 (D) */
 376                        if (sh->vtag != ct->proto.sctp.vtag[dir])
 377                                goto out_unlock;
 378                } else if (sch->type == SCTP_CID_HEARTBEAT ||
 379                           sch->type == SCTP_CID_HEARTBEAT_ACK) {
 380                        if (ct->proto.sctp.vtag[dir] == 0) {
 381                                pr_debug("Setting vtag %x for dir %d\n",
 382                                         sh->vtag, dir);
 383                                ct->proto.sctp.vtag[dir] = sh->vtag;
 384                        } else if (sh->vtag != ct->proto.sctp.vtag[dir]) {
 385                                pr_debug("Verification tag check failed\n");
 386                                goto out_unlock;
 387                        }
 388                }
 389
 390                old_state = ct->proto.sctp.state;
 391                new_state = sctp_new_state(dir, old_state, sch->type);
 392
 393                /* Invalid */
 394                if (new_state == SCTP_CONNTRACK_MAX) {
 395                        pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 396                                 "conntrack=%u\n",
 397                                 dir, sch->type, old_state);
 398                        goto out_unlock;
 399                }
 400
 401                /* If it is an INIT or an INIT ACK note down the vtag */
 402                if (sch->type == SCTP_CID_INIT ||
 403                    sch->type == SCTP_CID_INIT_ACK) {
 404                        sctp_inithdr_t _inithdr, *ih;
 405
 406                        ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 407                                                sizeof(_inithdr), &_inithdr);
 408                        if (ih == NULL)
 409                                goto out_unlock;
 410                        pr_debug("Setting vtag %x for dir %d\n",
 411                                 ih->init_tag, !dir);
 412                        ct->proto.sctp.vtag[!dir] = ih->init_tag;
 413                }
 414
 415                ct->proto.sctp.state = new_state;
 416                if (old_state != new_state)
 417                        nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 418        }
 419        spin_unlock_bh(&ct->lock);
 420
 421        nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 422
 423        if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 424            dir == IP_CT_DIR_REPLY &&
 425            new_state == SCTP_CONNTRACK_ESTABLISHED) {
 426                pr_debug("Setting assured bit\n");
 427                set_bit(IPS_ASSURED_BIT, &ct->status);
 428                nf_conntrack_event_cache(IPCT_ASSURED, ct);
 429        }
 430
 431        return NF_ACCEPT;
 432
 433out_unlock:
 434        spin_unlock_bh(&ct->lock);
 435out:
 436        return -NF_ACCEPT;
 437}
 438
 439/* Called when a new connection for this protocol found. */
 440static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 441                     unsigned int dataoff, unsigned int *timeouts)
 442{
 443        enum sctp_conntrack new_state;
 444        const struct sctphdr *sh;
 445        struct sctphdr _sctph;
 446        const struct sctp_chunkhdr *sch;
 447        struct sctp_chunkhdr _sch;
 448        u_int32_t offset, count;
 449        unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 450
 451        sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 452        if (sh == NULL)
 453                return false;
 454
 455        if (do_basic_checks(ct, skb, dataoff, map) != 0)
 456                return false;
 457
 458        /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 459        if (test_bit(SCTP_CID_ABORT, map) ||
 460            test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 461            test_bit(SCTP_CID_COOKIE_ACK, map))
 462                return false;
 463
 464        memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 465        new_state = SCTP_CONNTRACK_MAX;
 466        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 467                /* Don't need lock here: this conntrack not in circulation yet */
 468                new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 469                                           SCTP_CONNTRACK_NONE, sch->type);
 470
 471                /* Invalid: delete conntrack */
 472                if (new_state == SCTP_CONNTRACK_NONE ||
 473                    new_state == SCTP_CONNTRACK_MAX) {
 474                        pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 475                        return false;
 476                }
 477
 478                /* Copy the vtag into the state info */
 479                if (sch->type == SCTP_CID_INIT) {
 480                        if (sh->vtag == 0) {
 481                                sctp_inithdr_t _inithdr, *ih;
 482
 483                                ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 484                                                        sizeof(_inithdr), &_inithdr);
 485                                if (ih == NULL)
 486                                        return false;
 487
 488                                pr_debug("Setting vtag %x for new conn\n",
 489                                         ih->init_tag);
 490
 491                                ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 492                                                                ih->init_tag;
 493                        } else {
 494                                /* Sec 8.5.1 (A) */
 495                                return false;
 496                        }
 497                } else if (sch->type == SCTP_CID_HEARTBEAT) {
 498                        pr_debug("Setting vtag %x for secondary conntrack\n",
 499                                 sh->vtag);
 500                        ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag;
 501                }
 502                /* If it is a shutdown ack OOTB packet, we expect a return
 503                   shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 504                else {
 505                        pr_debug("Setting vtag %x for new conn OOTB\n",
 506                                 sh->vtag);
 507                        ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 508                }
 509
 510                ct->proto.sctp.state = new_state;
 511        }
 512
 513        return true;
 514}
 515
 516static int sctp_error(struct net *net, struct nf_conn *tpl, struct sk_buff *skb,
 517                      unsigned int dataoff, enum ip_conntrack_info *ctinfo,
 518                      u8 pf, unsigned int hooknum)
 519{
 520        const struct sctphdr *sh;
 521        const char *logmsg;
 522
 523        if (skb->len < dataoff + sizeof(struct sctphdr)) {
 524                logmsg = "nf_ct_sctp: short packet ";
 525                goto out_invalid;
 526        }
 527        if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
 528            skb->ip_summed == CHECKSUM_NONE) {
 529                if (!skb_make_writable(skb, dataoff + sizeof(struct sctphdr))) {
 530                        logmsg = "nf_ct_sctp: failed to read header ";
 531                        goto out_invalid;
 532                }
 533                sh = (const struct sctphdr *)(skb->data + dataoff);
 534                if (sh->checksum != sctp_compute_cksum(skb, dataoff)) {
 535                        logmsg = "nf_ct_sctp: bad CRC ";
 536                        goto out_invalid;
 537                }
 538                skb->ip_summed = CHECKSUM_UNNECESSARY;
 539        }
 540        return NF_ACCEPT;
 541out_invalid:
 542        if (LOG_INVALID(net, IPPROTO_SCTP))
 543                nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, "%s", logmsg);
 544        return -NF_ACCEPT;
 545}
 546
 547#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 548
 549#include <linux/netfilter/nfnetlink.h>
 550#include <linux/netfilter/nfnetlink_conntrack.h>
 551
 552static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 553                          struct nf_conn *ct)
 554{
 555        struct nlattr *nest_parms;
 556
 557        spin_lock_bh(&ct->lock);
 558        nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 559        if (!nest_parms)
 560                goto nla_put_failure;
 561
 562        if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 563            nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 564                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 565            nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 566                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 567                goto nla_put_failure;
 568
 569        spin_unlock_bh(&ct->lock);
 570
 571        nla_nest_end(skb, nest_parms);
 572
 573        return 0;
 574
 575nla_put_failure:
 576        spin_unlock_bh(&ct->lock);
 577        return -1;
 578}
 579
 580static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 581        [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 582        [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 583        [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 584};
 585
 586static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 587{
 588        struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 589        struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 590        int err;
 591
 592        /* updates may not contain the internal protocol info, skip parsing */
 593        if (!attr)
 594                return 0;
 595
 596        err = nla_parse_nested(tb,
 597                               CTA_PROTOINFO_SCTP_MAX,
 598                               attr,
 599                               sctp_nla_policy);
 600        if (err < 0)
 601                return err;
 602
 603        if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 604            !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 605            !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 606                return -EINVAL;
 607
 608        spin_lock_bh(&ct->lock);
 609        ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 610        ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 611                nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 612        ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 613                nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 614        spin_unlock_bh(&ct->lock);
 615
 616        return 0;
 617}
 618
 619static int sctp_nlattr_size(void)
 620{
 621        return nla_total_size(0)        /* CTA_PROTOINFO_SCTP */
 622                + nla_policy_len(sctp_nla_policy, CTA_PROTOINFO_SCTP_MAX + 1);
 623}
 624#endif
 625
 626#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 627
 628#include <linux/netfilter/nfnetlink.h>
 629#include <linux/netfilter/nfnetlink_cttimeout.h>
 630
 631static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 632                                      struct net *net, void *data)
 633{
 634        unsigned int *timeouts = data;
 635        struct nf_sctp_net *sn = sctp_pernet(net);
 636        int i;
 637
 638        /* set default SCTP timeouts. */
 639        for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 640                timeouts[i] = sn->timeouts[i];
 641
 642        /* there's a 1:1 mapping between attributes and protocol states. */
 643        for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 644                if (tb[i]) {
 645                        timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 646                }
 647        }
 648        return 0;
 649}
 650
 651static int
 652sctp_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
 663nla_put_failure:
 664        return -ENOSPC;
 665}
 666
 667static const struct nla_policy
 668sctp_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_CT_NETLINK_TIMEOUT */
 680
 681
 682#ifdef CONFIG_SYSCTL
 683static struct ctl_table sctp_sysctl_table[] = {
 684        {
 685                .procname       = "nf_conntrack_sctp_timeout_closed",
 686                .maxlen         = sizeof(unsigned int),
 687                .mode           = 0644,
 688                .proc_handler   = proc_dointvec_jiffies,
 689        },
 690        {
 691                .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 692                .maxlen         = sizeof(unsigned int),
 693                .mode           = 0644,
 694                .proc_handler   = proc_dointvec_jiffies,
 695        },
 696        {
 697                .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 698                .maxlen         = sizeof(unsigned int),
 699                .mode           = 0644,
 700                .proc_handler   = proc_dointvec_jiffies,
 701        },
 702        {
 703                .procname       = "nf_conntrack_sctp_timeout_established",
 704                .maxlen         = sizeof(unsigned int),
 705                .mode           = 0644,
 706                .proc_handler   = proc_dointvec_jiffies,
 707        },
 708        {
 709                .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 710                .maxlen         = sizeof(unsigned int),
 711                .mode           = 0644,
 712                .proc_handler   = proc_dointvec_jiffies,
 713        },
 714        {
 715                .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 716                .maxlen         = sizeof(unsigned int),
 717                .mode           = 0644,
 718                .proc_handler   = proc_dointvec_jiffies,
 719        },
 720        {
 721                .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 722                .maxlen         = sizeof(unsigned int),
 723                .mode           = 0644,
 724                .proc_handler   = proc_dointvec_jiffies,
 725        },
 726        {
 727                .procname       = "nf_conntrack_sctp_timeout_heartbeat_sent",
 728                .maxlen         = sizeof(unsigned int),
 729                .mode           = 0644,
 730                .proc_handler   = proc_dointvec_jiffies,
 731        },
 732        {
 733                .procname       = "nf_conntrack_sctp_timeout_heartbeat_acked",
 734                .maxlen         = sizeof(unsigned int),
 735                .mode           = 0644,
 736                .proc_handler   = proc_dointvec_jiffies,
 737        },
 738        { }
 739};
 740
 741#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 742static struct ctl_table sctp_compat_sysctl_table[] = {
 743        {
 744                .procname       = "ip_conntrack_sctp_timeout_closed",
 745                .maxlen         = sizeof(unsigned int),
 746                .mode           = 0644,
 747                .proc_handler   = proc_dointvec_jiffies,
 748        },
 749        {
 750                .procname       = "ip_conntrack_sctp_timeout_cookie_wait",
 751                .maxlen         = sizeof(unsigned int),
 752                .mode           = 0644,
 753                .proc_handler   = proc_dointvec_jiffies,
 754        },
 755        {
 756                .procname       = "ip_conntrack_sctp_timeout_cookie_echoed",
 757                .maxlen         = sizeof(unsigned int),
 758                .mode           = 0644,
 759                .proc_handler   = proc_dointvec_jiffies,
 760        },
 761        {
 762                .procname       = "ip_conntrack_sctp_timeout_established",
 763                .maxlen         = sizeof(unsigned int),
 764                .mode           = 0644,
 765                .proc_handler   = proc_dointvec_jiffies,
 766        },
 767        {
 768                .procname       = "ip_conntrack_sctp_timeout_shutdown_sent",
 769                .maxlen         = sizeof(unsigned int),
 770                .mode           = 0644,
 771                .proc_handler   = proc_dointvec_jiffies,
 772        },
 773        {
 774                .procname       = "ip_conntrack_sctp_timeout_shutdown_recd",
 775                .maxlen         = sizeof(unsigned int),
 776                .mode           = 0644,
 777                .proc_handler   = proc_dointvec_jiffies,
 778        },
 779        {
 780                .procname       = "ip_conntrack_sctp_timeout_shutdown_ack_sent",
 781                .maxlen         = sizeof(unsigned int),
 782                .mode           = 0644,
 783                .proc_handler   = proc_dointvec_jiffies,
 784        },
 785        { }
 786};
 787#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 788#endif
 789
 790static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
 791                                     struct nf_sctp_net *sn)
 792{
 793#ifdef CONFIG_SYSCTL
 794        if (pn->ctl_table)
 795                return 0;
 796
 797        pn->ctl_table = kmemdup(sctp_sysctl_table,
 798                                sizeof(sctp_sysctl_table),
 799                                GFP_KERNEL);
 800        if (!pn->ctl_table)
 801                return -ENOMEM;
 802
 803        pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 804        pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 805        pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 806        pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 807        pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 808        pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 809        pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 810        pn->ctl_table[7].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_SENT];
 811        pn->ctl_table[8].data = &sn->timeouts[SCTP_CONNTRACK_HEARTBEAT_ACKED];
 812#endif
 813        return 0;
 814}
 815
 816static int sctp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
 817                                            struct nf_sctp_net *sn)
 818{
 819#ifdef CONFIG_SYSCTL
 820#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 821        pn->ctl_compat_table = kmemdup(sctp_compat_sysctl_table,
 822                                       sizeof(sctp_compat_sysctl_table),
 823                                       GFP_KERNEL);
 824        if (!pn->ctl_compat_table)
 825                return -ENOMEM;
 826
 827        pn->ctl_compat_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 828        pn->ctl_compat_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 829        pn->ctl_compat_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 830        pn->ctl_compat_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 831        pn->ctl_compat_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 832        pn->ctl_compat_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 833        pn->ctl_compat_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 834#endif
 835#endif
 836        return 0;
 837}
 838
 839static int sctp_init_net(struct net *net, u_int16_t proto)
 840{
 841        int ret;
 842        struct nf_sctp_net *sn = sctp_pernet(net);
 843        struct nf_proto_net *pn = &sn->pn;
 844
 845        if (!pn->users) {
 846                int i;
 847
 848                for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 849                        sn->timeouts[i] = sctp_timeouts[i];
 850        }
 851
 852        if (proto == AF_INET) {
 853                ret = sctp_kmemdup_compat_sysctl_table(pn, sn);
 854                if (ret < 0)
 855                        return ret;
 856
 857                ret = sctp_kmemdup_sysctl_table(pn, sn);
 858                if (ret < 0)
 859                        nf_ct_kfree_compat_sysctl_table(pn);
 860        } else
 861                ret = sctp_kmemdup_sysctl_table(pn, sn);
 862
 863        return ret;
 864}
 865
 866static struct nf_proto_net *sctp_get_net_proto(struct net *net)
 867{
 868        return &net->ct_sctp.pn;
 869}
 870
 871struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 __read_mostly = {
 872        .l3proto                = PF_INET,
 873        .l4proto                = IPPROTO_SCTP,
 874        .name                   = "sctp",
 875        .pkt_to_tuple           = sctp_pkt_to_tuple,
 876        .invert_tuple           = sctp_invert_tuple,
 877        .print_tuple            = sctp_print_tuple,
 878        .print_conntrack        = sctp_print_conntrack,
 879        .packet                 = sctp_packet,
 880        .get_timeouts           = sctp_get_timeouts,
 881        .new                    = sctp_new,
 882        .error                  = sctp_error,
 883        .me                     = THIS_MODULE,
 884#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 885        .to_nlattr              = sctp_to_nlattr,
 886        .nlattr_size            = sctp_nlattr_size,
 887        .from_nlattr            = nlattr_to_sctp,
 888        .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 889        .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 890        .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 891        .nla_policy             = nf_ct_port_nla_policy,
 892#endif
 893#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 894        .ctnl_timeout           = {
 895                .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 896                .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 897                .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 898                .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 899                .nla_policy     = sctp_timeout_nla_policy,
 900        },
 901#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 902        .init_net               = sctp_init_net,
 903        .get_net_proto          = sctp_get_net_proto,
 904};
 905EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp4);
 906
 907struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 __read_mostly = {
 908        .l3proto                = PF_INET6,
 909        .l4proto                = IPPROTO_SCTP,
 910        .name                   = "sctp",
 911        .pkt_to_tuple           = sctp_pkt_to_tuple,
 912        .invert_tuple           = sctp_invert_tuple,
 913        .print_tuple            = sctp_print_tuple,
 914        .print_conntrack        = sctp_print_conntrack,
 915        .packet                 = sctp_packet,
 916        .get_timeouts           = sctp_get_timeouts,
 917        .new                    = sctp_new,
 918        .error                  = sctp_error,
 919        .me                     = THIS_MODULE,
 920#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 921        .to_nlattr              = sctp_to_nlattr,
 922        .nlattr_size            = sctp_nlattr_size,
 923        .from_nlattr            = nlattr_to_sctp,
 924        .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 925        .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 926        .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 927        .nla_policy             = nf_ct_port_nla_policy,
 928#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 929        .ctnl_timeout           = {
 930                .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 931                .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 932                .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 933                .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 934                .nla_policy     = sctp_timeout_nla_policy,
 935        },
 936#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 937#endif
 938        .init_net               = sctp_init_net,
 939        .get_net_proto          = sctp_get_net_proto,
 940};
 941EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_sctp6);
 942