linux/net/netfilter/nf_conntrack_proto_sctp.c
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   1/*
   2 * Connection tracking protocol helper module for SCTP.
   3 *
   4 * Copyright (c) 2004 Kiran Kumar Immidi <immidi_kiran@yahoo.com>
   5 * Copyright (c) 2004-2012 Patrick McHardy <kaber@trash.net>
   6 *
   7 * SCTP is defined in RFC 2960. References to various sections in this code
   8 * are to this RFC.
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License version 2 as
  12 * published by the Free Software Foundation.
  13 */
  14
  15#include <linux/types.h>
  16#include <linux/timer.h>
  17#include <linux/netfilter.h>
  18#include <linux/module.h>
  19#include <linux/in.h>
  20#include <linux/ip.h>
  21#include <linux/sctp.h>
  22#include <linux/string.h>
  23#include <linux/seq_file.h>
  24#include <linux/spinlock.h>
  25#include <linux/interrupt.h>
  26
  27#include <net/netfilter/nf_conntrack.h>
  28#include <net/netfilter/nf_conntrack_l4proto.h>
  29#include <net/netfilter/nf_conntrack_ecache.h>
  30
  31/* FIXME: Examine ipfilter's timeouts and conntrack transitions more
  32   closely.  They're more complex. --RR
  33
  34   And so for me for SCTP :D -Kiran */
  35
  36static const char *const sctp_conntrack_names[] = {
  37        "NONE",
  38        "CLOSED",
  39        "COOKIE_WAIT",
  40        "COOKIE_ECHOED",
  41        "ESTABLISHED",
  42        "SHUTDOWN_SENT",
  43        "SHUTDOWN_RECD",
  44        "SHUTDOWN_ACK_SENT",
  45};
  46
  47#define SECS  * HZ
  48#define MINS  * 60 SECS
  49#define HOURS * 60 MINS
  50#define DAYS  * 24 HOURS
  51
  52static unsigned int sctp_timeouts[SCTP_CONNTRACK_MAX] __read_mostly = {
  53        [SCTP_CONNTRACK_CLOSED]                 = 10 SECS,
  54        [SCTP_CONNTRACK_COOKIE_WAIT]            = 3 SECS,
  55        [SCTP_CONNTRACK_COOKIE_ECHOED]          = 3 SECS,
  56        [SCTP_CONNTRACK_ESTABLISHED]            = 5 DAYS,
  57        [SCTP_CONNTRACK_SHUTDOWN_SENT]          = 300 SECS / 1000,
  58        [SCTP_CONNTRACK_SHUTDOWN_RECD]          = 300 SECS / 1000,
  59        [SCTP_CONNTRACK_SHUTDOWN_ACK_SENT]      = 3 SECS,
  60};
  61
  62#define sNO SCTP_CONNTRACK_NONE
  63#define sCL SCTP_CONNTRACK_CLOSED
  64#define sCW SCTP_CONNTRACK_COOKIE_WAIT
  65#define sCE SCTP_CONNTRACK_COOKIE_ECHOED
  66#define sES SCTP_CONNTRACK_ESTABLISHED
  67#define sSS SCTP_CONNTRACK_SHUTDOWN_SENT
  68#define sSR SCTP_CONNTRACK_SHUTDOWN_RECD
  69#define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT
  70#define sIV SCTP_CONNTRACK_MAX
  71
  72/*
  73        These are the descriptions of the states:
  74
  75NOTE: These state names are tantalizingly similar to the states of an
  76SCTP endpoint. But the interpretation of the states is a little different,
  77considering that these are the states of the connection and not of an end
  78point. Please note the subtleties. -Kiran
  79
  80NONE              - Nothing so far.
  81COOKIE WAIT       - We have seen an INIT chunk in the original direction, or also
  82                    an INIT_ACK chunk in the reply direction.
  83COOKIE ECHOED     - We have seen a COOKIE_ECHO chunk in the original direction.
  84ESTABLISHED       - We have seen a COOKIE_ACK in the reply direction.
  85SHUTDOWN_SENT     - We have seen a SHUTDOWN chunk in the original direction.
  86SHUTDOWN_RECD     - We have seen a SHUTDOWN chunk in the reply directoin.
  87SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite
  88                    to that of the SHUTDOWN chunk.
  89CLOSED            - We have seen a SHUTDOWN_COMPLETE chunk in the direction of
  90                    the SHUTDOWN chunk. Connection is closed.
  91*/
  92
  93/* TODO
  94 - I have assumed that the first INIT is in the original direction.
  95 This messes things when an INIT comes in the reply direction in CLOSED
  96 state.
  97 - Check the error type in the reply dir before transitioning from
  98cookie echoed to closed.
  99 - Sec 5.2.4 of RFC 2960
 100 - Multi Homing support.
 101*/
 102
 103/* SCTP conntrack state transitions */
 104static const u8 sctp_conntracks[2][9][SCTP_CONNTRACK_MAX] = {
 105        {
 106/*      ORIGINAL        */
 107/*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA */
 108/* init         */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA},
 109/* init_ack     */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA},
 110/* abort        */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 111/* shutdown     */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA},
 112/* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA},
 113/* error        */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Can't have Stale cookie*/
 114/* cookie_echo  */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA},/* 5.2.4 - Big TODO */
 115/* cookie_ack   */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Can't come in orig dir */
 116/* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL}
 117        },
 118        {
 119/*      REPLY   */
 120/*                  sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA */
 121/* init         */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* INIT in sCL Big TODO */
 122/* init_ack     */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA},
 123/* abort        */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL},
 124/* shutdown     */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA},
 125/* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA},
 126/* error        */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA},
 127/* cookie_echo  */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Can't come in reply dir */
 128/* cookie_ack   */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA},
 129/* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL}
 130        }
 131};
 132
 133static int sctp_net_id  __read_mostly;
 134struct sctp_net {
 135        struct nf_proto_net pn;
 136        unsigned int timeouts[SCTP_CONNTRACK_MAX];
 137};
 138
 139static inline struct sctp_net *sctp_pernet(struct net *net)
 140{
 141        return net_generic(net, sctp_net_id);
 142}
 143
 144static bool sctp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
 145                              struct nf_conntrack_tuple *tuple)
 146{
 147        const struct sctphdr *hp;
 148        struct sctphdr _hdr;
 149
 150        /* Actually only need first 8 bytes. */
 151        hp = skb_header_pointer(skb, dataoff, 8, &_hdr);
 152        if (hp == NULL)
 153                return false;
 154
 155        tuple->src.u.sctp.port = hp->source;
 156        tuple->dst.u.sctp.port = hp->dest;
 157        return true;
 158}
 159
 160static bool sctp_invert_tuple(struct nf_conntrack_tuple *tuple,
 161                              const struct nf_conntrack_tuple *orig)
 162{
 163        tuple->src.u.sctp.port = orig->dst.u.sctp.port;
 164        tuple->dst.u.sctp.port = orig->src.u.sctp.port;
 165        return true;
 166}
 167
 168/* Print out the per-protocol part of the tuple. */
 169static int sctp_print_tuple(struct seq_file *s,
 170                            const struct nf_conntrack_tuple *tuple)
 171{
 172        return seq_printf(s, "sport=%hu dport=%hu ",
 173                          ntohs(tuple->src.u.sctp.port),
 174                          ntohs(tuple->dst.u.sctp.port));
 175}
 176
 177/* Print out the private part of the conntrack. */
 178static int sctp_print_conntrack(struct seq_file *s, struct nf_conn *ct)
 179{
 180        enum sctp_conntrack state;
 181
 182        spin_lock_bh(&ct->lock);
 183        state = ct->proto.sctp.state;
 184        spin_unlock_bh(&ct->lock);
 185
 186        return seq_printf(s, "%s ", sctp_conntrack_names[state]);
 187}
 188
 189#define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count)     \
 190for ((offset) = (dataoff) + sizeof(sctp_sctphdr_t), (count) = 0;        \
 191        (offset) < (skb)->len &&                                        \
 192        ((sch) = skb_header_pointer((skb), (offset), sizeof(_sch), &(_sch)));   \
 193        (offset) += (ntohs((sch)->length) + 3) & ~3, (count)++)
 194
 195/* Some validity checks to make sure the chunks are fine */
 196static int do_basic_checks(struct nf_conn *ct,
 197                           const struct sk_buff *skb,
 198                           unsigned int dataoff,
 199                           unsigned long *map)
 200{
 201        u_int32_t offset, count;
 202        sctp_chunkhdr_t _sch, *sch;
 203        int flag;
 204
 205        flag = 0;
 206
 207        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 208                pr_debug("Chunk Num: %d  Type: %d\n", count, sch->type);
 209
 210                if (sch->type == SCTP_CID_INIT ||
 211                    sch->type == SCTP_CID_INIT_ACK ||
 212                    sch->type == SCTP_CID_SHUTDOWN_COMPLETE)
 213                        flag = 1;
 214
 215                /*
 216                 * Cookie Ack/Echo chunks not the first OR
 217                 * Init / Init Ack / Shutdown compl chunks not the only chunks
 218                 * OR zero-length.
 219                 */
 220                if (((sch->type == SCTP_CID_COOKIE_ACK ||
 221                      sch->type == SCTP_CID_COOKIE_ECHO ||
 222                      flag) &&
 223                     count != 0) || !sch->length) {
 224                        pr_debug("Basic checks failed\n");
 225                        return 1;
 226                }
 227
 228                if (map)
 229                        set_bit(sch->type, map);
 230        }
 231
 232        pr_debug("Basic checks passed\n");
 233        return count == 0;
 234}
 235
 236static int sctp_new_state(enum ip_conntrack_dir dir,
 237                          enum sctp_conntrack cur_state,
 238                          int chunk_type)
 239{
 240        int i;
 241
 242        pr_debug("Chunk type: %d\n", chunk_type);
 243
 244        switch (chunk_type) {
 245        case SCTP_CID_INIT:
 246                pr_debug("SCTP_CID_INIT\n");
 247                i = 0;
 248                break;
 249        case SCTP_CID_INIT_ACK:
 250                pr_debug("SCTP_CID_INIT_ACK\n");
 251                i = 1;
 252                break;
 253        case SCTP_CID_ABORT:
 254                pr_debug("SCTP_CID_ABORT\n");
 255                i = 2;
 256                break;
 257        case SCTP_CID_SHUTDOWN:
 258                pr_debug("SCTP_CID_SHUTDOWN\n");
 259                i = 3;
 260                break;
 261        case SCTP_CID_SHUTDOWN_ACK:
 262                pr_debug("SCTP_CID_SHUTDOWN_ACK\n");
 263                i = 4;
 264                break;
 265        case SCTP_CID_ERROR:
 266                pr_debug("SCTP_CID_ERROR\n");
 267                i = 5;
 268                break;
 269        case SCTP_CID_COOKIE_ECHO:
 270                pr_debug("SCTP_CID_COOKIE_ECHO\n");
 271                i = 6;
 272                break;
 273        case SCTP_CID_COOKIE_ACK:
 274                pr_debug("SCTP_CID_COOKIE_ACK\n");
 275                i = 7;
 276                break;
 277        case SCTP_CID_SHUTDOWN_COMPLETE:
 278                pr_debug("SCTP_CID_SHUTDOWN_COMPLETE\n");
 279                i = 8;
 280                break;
 281        default:
 282                /* Other chunks like DATA, SACK, HEARTBEAT and
 283                its ACK do not cause a change in state */
 284                pr_debug("Unknown chunk type, Will stay in %s\n",
 285                         sctp_conntrack_names[cur_state]);
 286                return cur_state;
 287        }
 288
 289        pr_debug("dir: %d   cur_state: %s  chunk_type: %d  new_state: %s\n",
 290                 dir, sctp_conntrack_names[cur_state], chunk_type,
 291                 sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]);
 292
 293        return sctp_conntracks[dir][i][cur_state];
 294}
 295
 296static unsigned int *sctp_get_timeouts(struct net *net)
 297{
 298        return sctp_pernet(net)->timeouts;
 299}
 300
 301/* Returns verdict for packet, or -NF_ACCEPT for invalid. */
 302static int sctp_packet(struct nf_conn *ct,
 303                       const struct sk_buff *skb,
 304                       unsigned int dataoff,
 305                       enum ip_conntrack_info ctinfo,
 306                       u_int8_t pf,
 307                       unsigned int hooknum,
 308                       unsigned int *timeouts)
 309{
 310        enum sctp_conntrack new_state, old_state;
 311        enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
 312        const struct sctphdr *sh;
 313        struct sctphdr _sctph;
 314        const struct sctp_chunkhdr *sch;
 315        struct sctp_chunkhdr _sch;
 316        u_int32_t offset, count;
 317        unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 318
 319        sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 320        if (sh == NULL)
 321                goto out;
 322
 323        if (do_basic_checks(ct, skb, dataoff, map) != 0)
 324                goto out;
 325
 326        /* Check the verification tag (Sec 8.5) */
 327        if (!test_bit(SCTP_CID_INIT, map) &&
 328            !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) &&
 329            !test_bit(SCTP_CID_COOKIE_ECHO, map) &&
 330            !test_bit(SCTP_CID_ABORT, map) &&
 331            !test_bit(SCTP_CID_SHUTDOWN_ACK, map) &&
 332            sh->vtag != ct->proto.sctp.vtag[dir]) {
 333                pr_debug("Verification tag check failed\n");
 334                goto out;
 335        }
 336
 337        old_state = new_state = SCTP_CONNTRACK_NONE;
 338        spin_lock_bh(&ct->lock);
 339        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 340                /* Special cases of Verification tag check (Sec 8.5.1) */
 341                if (sch->type == SCTP_CID_INIT) {
 342                        /* Sec 8.5.1 (A) */
 343                        if (sh->vtag != 0)
 344                                goto out_unlock;
 345                } else if (sch->type == SCTP_CID_ABORT) {
 346                        /* Sec 8.5.1 (B) */
 347                        if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 348                            sh->vtag != ct->proto.sctp.vtag[!dir])
 349                                goto out_unlock;
 350                } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) {
 351                        /* Sec 8.5.1 (C) */
 352                        if (sh->vtag != ct->proto.sctp.vtag[dir] &&
 353                            sh->vtag != ct->proto.sctp.vtag[!dir] &&
 354                            sch->flags & SCTP_CHUNK_FLAG_T)
 355                                goto out_unlock;
 356                } else if (sch->type == SCTP_CID_COOKIE_ECHO) {
 357                        /* Sec 8.5.1 (D) */
 358                        if (sh->vtag != ct->proto.sctp.vtag[dir])
 359                                goto out_unlock;
 360                }
 361
 362                old_state = ct->proto.sctp.state;
 363                new_state = sctp_new_state(dir, old_state, sch->type);
 364
 365                /* Invalid */
 366                if (new_state == SCTP_CONNTRACK_MAX) {
 367                        pr_debug("nf_conntrack_sctp: Invalid dir=%i ctype=%u "
 368                                 "conntrack=%u\n",
 369                                 dir, sch->type, old_state);
 370                        goto out_unlock;
 371                }
 372
 373                /* If it is an INIT or an INIT ACK note down the vtag */
 374                if (sch->type == SCTP_CID_INIT ||
 375                    sch->type == SCTP_CID_INIT_ACK) {
 376                        sctp_inithdr_t _inithdr, *ih;
 377
 378                        ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 379                                                sizeof(_inithdr), &_inithdr);
 380                        if (ih == NULL)
 381                                goto out_unlock;
 382                        pr_debug("Setting vtag %x for dir %d\n",
 383                                 ih->init_tag, !dir);
 384                        ct->proto.sctp.vtag[!dir] = ih->init_tag;
 385                }
 386
 387                ct->proto.sctp.state = new_state;
 388                if (old_state != new_state)
 389                        nf_conntrack_event_cache(IPCT_PROTOINFO, ct);
 390        }
 391        spin_unlock_bh(&ct->lock);
 392
 393        nf_ct_refresh_acct(ct, ctinfo, skb, timeouts[new_state]);
 394
 395        if (old_state == SCTP_CONNTRACK_COOKIE_ECHOED &&
 396            dir == IP_CT_DIR_REPLY &&
 397            new_state == SCTP_CONNTRACK_ESTABLISHED) {
 398                pr_debug("Setting assured bit\n");
 399                set_bit(IPS_ASSURED_BIT, &ct->status);
 400                nf_conntrack_event_cache(IPCT_ASSURED, ct);
 401        }
 402
 403        return NF_ACCEPT;
 404
 405out_unlock:
 406        spin_unlock_bh(&ct->lock);
 407out:
 408        return -NF_ACCEPT;
 409}
 410
 411/* Called when a new connection for this protocol found. */
 412static bool sctp_new(struct nf_conn *ct, const struct sk_buff *skb,
 413                     unsigned int dataoff, unsigned int *timeouts)
 414{
 415        enum sctp_conntrack new_state;
 416        const struct sctphdr *sh;
 417        struct sctphdr _sctph;
 418        const struct sctp_chunkhdr *sch;
 419        struct sctp_chunkhdr _sch;
 420        u_int32_t offset, count;
 421        unsigned long map[256 / sizeof(unsigned long)] = { 0 };
 422
 423        sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph);
 424        if (sh == NULL)
 425                return false;
 426
 427        if (do_basic_checks(ct, skb, dataoff, map) != 0)
 428                return false;
 429
 430        /* If an OOTB packet has any of these chunks discard (Sec 8.4) */
 431        if (test_bit(SCTP_CID_ABORT, map) ||
 432            test_bit(SCTP_CID_SHUTDOWN_COMPLETE, map) ||
 433            test_bit(SCTP_CID_COOKIE_ACK, map))
 434                return false;
 435
 436        memset(&ct->proto.sctp, 0, sizeof(ct->proto.sctp));
 437        new_state = SCTP_CONNTRACK_MAX;
 438        for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) {
 439                /* Don't need lock here: this conntrack not in circulation yet */
 440                new_state = sctp_new_state(IP_CT_DIR_ORIGINAL,
 441                                           SCTP_CONNTRACK_NONE, sch->type);
 442
 443                /* Invalid: delete conntrack */
 444                if (new_state == SCTP_CONNTRACK_NONE ||
 445                    new_state == SCTP_CONNTRACK_MAX) {
 446                        pr_debug("nf_conntrack_sctp: invalid new deleting.\n");
 447                        return false;
 448                }
 449
 450                /* Copy the vtag into the state info */
 451                if (sch->type == SCTP_CID_INIT) {
 452                        if (sh->vtag == 0) {
 453                                sctp_inithdr_t _inithdr, *ih;
 454
 455                                ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t),
 456                                                        sizeof(_inithdr), &_inithdr);
 457                                if (ih == NULL)
 458                                        return false;
 459
 460                                pr_debug("Setting vtag %x for new conn\n",
 461                                         ih->init_tag);
 462
 463                                ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 464                                                                ih->init_tag;
 465                        } else {
 466                                /* Sec 8.5.1 (A) */
 467                                return false;
 468                        }
 469                }
 470                /* If it is a shutdown ack OOTB packet, we expect a return
 471                   shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */
 472                else {
 473                        pr_debug("Setting vtag %x for new conn OOTB\n",
 474                                 sh->vtag);
 475                        ct->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag;
 476                }
 477
 478                ct->proto.sctp.state = new_state;
 479        }
 480
 481        return true;
 482}
 483
 484#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 485
 486#include <linux/netfilter/nfnetlink.h>
 487#include <linux/netfilter/nfnetlink_conntrack.h>
 488
 489static int sctp_to_nlattr(struct sk_buff *skb, struct nlattr *nla,
 490                          struct nf_conn *ct)
 491{
 492        struct nlattr *nest_parms;
 493
 494        spin_lock_bh(&ct->lock);
 495        nest_parms = nla_nest_start(skb, CTA_PROTOINFO_SCTP | NLA_F_NESTED);
 496        if (!nest_parms)
 497                goto nla_put_failure;
 498
 499        if (nla_put_u8(skb, CTA_PROTOINFO_SCTP_STATE, ct->proto.sctp.state) ||
 500            nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_ORIGINAL,
 501                         ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL]) ||
 502            nla_put_be32(skb, CTA_PROTOINFO_SCTP_VTAG_REPLY,
 503                         ct->proto.sctp.vtag[IP_CT_DIR_REPLY]))
 504                goto nla_put_failure;
 505
 506        spin_unlock_bh(&ct->lock);
 507
 508        nla_nest_end(skb, nest_parms);
 509
 510        return 0;
 511
 512nla_put_failure:
 513        spin_unlock_bh(&ct->lock);
 514        return -1;
 515}
 516
 517static const struct nla_policy sctp_nla_policy[CTA_PROTOINFO_SCTP_MAX+1] = {
 518        [CTA_PROTOINFO_SCTP_STATE]          = { .type = NLA_U8 },
 519        [CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]  = { .type = NLA_U32 },
 520        [CTA_PROTOINFO_SCTP_VTAG_REPLY]     = { .type = NLA_U32 },
 521};
 522
 523static int nlattr_to_sctp(struct nlattr *cda[], struct nf_conn *ct)
 524{
 525        struct nlattr *attr = cda[CTA_PROTOINFO_SCTP];
 526        struct nlattr *tb[CTA_PROTOINFO_SCTP_MAX+1];
 527        int err;
 528
 529        /* updates may not contain the internal protocol info, skip parsing */
 530        if (!attr)
 531                return 0;
 532
 533        err = nla_parse_nested(tb,
 534                               CTA_PROTOINFO_SCTP_MAX,
 535                               attr,
 536                               sctp_nla_policy);
 537        if (err < 0)
 538                return err;
 539
 540        if (!tb[CTA_PROTOINFO_SCTP_STATE] ||
 541            !tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL] ||
 542            !tb[CTA_PROTOINFO_SCTP_VTAG_REPLY])
 543                return -EINVAL;
 544
 545        spin_lock_bh(&ct->lock);
 546        ct->proto.sctp.state = nla_get_u8(tb[CTA_PROTOINFO_SCTP_STATE]);
 547        ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] =
 548                nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_ORIGINAL]);
 549        ct->proto.sctp.vtag[IP_CT_DIR_REPLY] =
 550                nla_get_be32(tb[CTA_PROTOINFO_SCTP_VTAG_REPLY]);
 551        spin_unlock_bh(&ct->lock);
 552
 553        return 0;
 554}
 555
 556static int sctp_nlattr_size(void)
 557{
 558        return nla_total_size(0)        /* CTA_PROTOINFO_SCTP */
 559                + nla_policy_len(sctp_nla_policy, CTA_PROTOINFO_SCTP_MAX + 1);
 560}
 561#endif
 562
 563#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 564
 565#include <linux/netfilter/nfnetlink.h>
 566#include <linux/netfilter/nfnetlink_cttimeout.h>
 567
 568static int sctp_timeout_nlattr_to_obj(struct nlattr *tb[],
 569                                      struct net *net, void *data)
 570{
 571        unsigned int *timeouts = data;
 572        struct sctp_net *sn = sctp_pernet(net);
 573        int i;
 574
 575        /* set default SCTP timeouts. */
 576        for (i=0; i<SCTP_CONNTRACK_MAX; i++)
 577                timeouts[i] = sn->timeouts[i];
 578
 579        /* there's a 1:1 mapping between attributes and protocol states. */
 580        for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 581                if (tb[i]) {
 582                        timeouts[i] = ntohl(nla_get_be32(tb[i])) * HZ;
 583                }
 584        }
 585        return 0;
 586}
 587
 588static int
 589sctp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 590{
 591        const unsigned int *timeouts = data;
 592        int i;
 593
 594        for (i=CTA_TIMEOUT_SCTP_UNSPEC+1; i<CTA_TIMEOUT_SCTP_MAX+1; i++) {
 595                if (nla_put_be32(skb, i, htonl(timeouts[i] / HZ)))
 596                        goto nla_put_failure;
 597        }
 598        return 0;
 599
 600nla_put_failure:
 601        return -ENOSPC;
 602}
 603
 604static const struct nla_policy
 605sctp_timeout_nla_policy[CTA_TIMEOUT_SCTP_MAX+1] = {
 606        [CTA_TIMEOUT_SCTP_CLOSED]               = { .type = NLA_U32 },
 607        [CTA_TIMEOUT_SCTP_COOKIE_WAIT]          = { .type = NLA_U32 },
 608        [CTA_TIMEOUT_SCTP_COOKIE_ECHOED]        = { .type = NLA_U32 },
 609        [CTA_TIMEOUT_SCTP_ESTABLISHED]          = { .type = NLA_U32 },
 610        [CTA_TIMEOUT_SCTP_SHUTDOWN_SENT]        = { .type = NLA_U32 },
 611        [CTA_TIMEOUT_SCTP_SHUTDOWN_RECD]        = { .type = NLA_U32 },
 612        [CTA_TIMEOUT_SCTP_SHUTDOWN_ACK_SENT]    = { .type = NLA_U32 },
 613};
 614#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 615
 616
 617#ifdef CONFIG_SYSCTL
 618static struct ctl_table sctp_sysctl_table[] = {
 619        {
 620                .procname       = "nf_conntrack_sctp_timeout_closed",
 621                .maxlen         = sizeof(unsigned int),
 622                .mode           = 0644,
 623                .proc_handler   = proc_dointvec_jiffies,
 624        },
 625        {
 626                .procname       = "nf_conntrack_sctp_timeout_cookie_wait",
 627                .maxlen         = sizeof(unsigned int),
 628                .mode           = 0644,
 629                .proc_handler   = proc_dointvec_jiffies,
 630        },
 631        {
 632                .procname       = "nf_conntrack_sctp_timeout_cookie_echoed",
 633                .maxlen         = sizeof(unsigned int),
 634                .mode           = 0644,
 635                .proc_handler   = proc_dointvec_jiffies,
 636        },
 637        {
 638                .procname       = "nf_conntrack_sctp_timeout_established",
 639                .maxlen         = sizeof(unsigned int),
 640                .mode           = 0644,
 641                .proc_handler   = proc_dointvec_jiffies,
 642        },
 643        {
 644                .procname       = "nf_conntrack_sctp_timeout_shutdown_sent",
 645                .maxlen         = sizeof(unsigned int),
 646                .mode           = 0644,
 647                .proc_handler   = proc_dointvec_jiffies,
 648        },
 649        {
 650                .procname       = "nf_conntrack_sctp_timeout_shutdown_recd",
 651                .maxlen         = sizeof(unsigned int),
 652                .mode           = 0644,
 653                .proc_handler   = proc_dointvec_jiffies,
 654        },
 655        {
 656                .procname       = "nf_conntrack_sctp_timeout_shutdown_ack_sent",
 657                .maxlen         = sizeof(unsigned int),
 658                .mode           = 0644,
 659                .proc_handler   = proc_dointvec_jiffies,
 660        },
 661        { }
 662};
 663
 664#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 665static struct ctl_table sctp_compat_sysctl_table[] = {
 666        {
 667                .procname       = "ip_conntrack_sctp_timeout_closed",
 668                .maxlen         = sizeof(unsigned int),
 669                .mode           = 0644,
 670                .proc_handler   = proc_dointvec_jiffies,
 671        },
 672        {
 673                .procname       = "ip_conntrack_sctp_timeout_cookie_wait",
 674                .maxlen         = sizeof(unsigned int),
 675                .mode           = 0644,
 676                .proc_handler   = proc_dointvec_jiffies,
 677        },
 678        {
 679                .procname       = "ip_conntrack_sctp_timeout_cookie_echoed",
 680                .maxlen         = sizeof(unsigned int),
 681                .mode           = 0644,
 682                .proc_handler   = proc_dointvec_jiffies,
 683        },
 684        {
 685                .procname       = "ip_conntrack_sctp_timeout_established",
 686                .maxlen         = sizeof(unsigned int),
 687                .mode           = 0644,
 688                .proc_handler   = proc_dointvec_jiffies,
 689        },
 690        {
 691                .procname       = "ip_conntrack_sctp_timeout_shutdown_sent",
 692                .maxlen         = sizeof(unsigned int),
 693                .mode           = 0644,
 694                .proc_handler   = proc_dointvec_jiffies,
 695        },
 696        {
 697                .procname       = "ip_conntrack_sctp_timeout_shutdown_recd",
 698                .maxlen         = sizeof(unsigned int),
 699                .mode           = 0644,
 700                .proc_handler   = proc_dointvec_jiffies,
 701        },
 702        {
 703                .procname       = "ip_conntrack_sctp_timeout_shutdown_ack_sent",
 704                .maxlen         = sizeof(unsigned int),
 705                .mode           = 0644,
 706                .proc_handler   = proc_dointvec_jiffies,
 707        },
 708        { }
 709};
 710#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
 711#endif
 712
 713static int sctp_kmemdup_sysctl_table(struct nf_proto_net *pn,
 714                                     struct sctp_net *sn)
 715{
 716#ifdef CONFIG_SYSCTL
 717        if (pn->ctl_table)
 718                return 0;
 719
 720        pn->ctl_table = kmemdup(sctp_sysctl_table,
 721                                sizeof(sctp_sysctl_table),
 722                                GFP_KERNEL);
 723        if (!pn->ctl_table)
 724                return -ENOMEM;
 725
 726        pn->ctl_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 727        pn->ctl_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 728        pn->ctl_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 729        pn->ctl_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 730        pn->ctl_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 731        pn->ctl_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 732        pn->ctl_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 733#endif
 734        return 0;
 735}
 736
 737static int sctp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn,
 738                                            struct sctp_net *sn)
 739{
 740#ifdef CONFIG_SYSCTL
 741#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
 742        pn->ctl_compat_table = kmemdup(sctp_compat_sysctl_table,
 743                                       sizeof(sctp_compat_sysctl_table),
 744                                       GFP_KERNEL);
 745        if (!pn->ctl_compat_table)
 746                return -ENOMEM;
 747
 748        pn->ctl_compat_table[0].data = &sn->timeouts[SCTP_CONNTRACK_CLOSED];
 749        pn->ctl_compat_table[1].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_WAIT];
 750        pn->ctl_compat_table[2].data = &sn->timeouts[SCTP_CONNTRACK_COOKIE_ECHOED];
 751        pn->ctl_compat_table[3].data = &sn->timeouts[SCTP_CONNTRACK_ESTABLISHED];
 752        pn->ctl_compat_table[4].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_SENT];
 753        pn->ctl_compat_table[5].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_RECD];
 754        pn->ctl_compat_table[6].data = &sn->timeouts[SCTP_CONNTRACK_SHUTDOWN_ACK_SENT];
 755#endif
 756#endif
 757        return 0;
 758}
 759
 760static int sctp_init_net(struct net *net, u_int16_t proto)
 761{
 762        int ret;
 763        struct sctp_net *sn = sctp_pernet(net);
 764        struct nf_proto_net *pn = &sn->pn;
 765
 766        if (!pn->users) {
 767                int i;
 768
 769                for (i = 0; i < SCTP_CONNTRACK_MAX; i++)
 770                        sn->timeouts[i] = sctp_timeouts[i];
 771        }
 772
 773        if (proto == AF_INET) {
 774                ret = sctp_kmemdup_compat_sysctl_table(pn, sn);
 775                if (ret < 0)
 776                        return ret;
 777
 778                ret = sctp_kmemdup_sysctl_table(pn, sn);
 779                if (ret < 0)
 780                        nf_ct_kfree_compat_sysctl_table(pn);
 781        } else
 782                ret = sctp_kmemdup_sysctl_table(pn, sn);
 783
 784        return ret;
 785}
 786
 787static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 __read_mostly = {
 788        .l3proto                = PF_INET,
 789        .l4proto                = IPPROTO_SCTP,
 790        .name                   = "sctp",
 791        .pkt_to_tuple           = sctp_pkt_to_tuple,
 792        .invert_tuple           = sctp_invert_tuple,
 793        .print_tuple            = sctp_print_tuple,
 794        .print_conntrack        = sctp_print_conntrack,
 795        .packet                 = sctp_packet,
 796        .get_timeouts           = sctp_get_timeouts,
 797        .new                    = sctp_new,
 798        .me                     = THIS_MODULE,
 799#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 800        .to_nlattr              = sctp_to_nlattr,
 801        .nlattr_size            = sctp_nlattr_size,
 802        .from_nlattr            = nlattr_to_sctp,
 803        .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 804        .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 805        .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 806        .nla_policy             = nf_ct_port_nla_policy,
 807#endif
 808#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 809        .ctnl_timeout           = {
 810                .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 811                .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 812                .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 813                .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 814                .nla_policy     = sctp_timeout_nla_policy,
 815        },
 816#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 817        .net_id                 = &sctp_net_id,
 818        .init_net               = sctp_init_net,
 819};
 820
 821static struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 __read_mostly = {
 822        .l3proto                = PF_INET6,
 823        .l4proto                = IPPROTO_SCTP,
 824        .name                   = "sctp",
 825        .pkt_to_tuple           = sctp_pkt_to_tuple,
 826        .invert_tuple           = sctp_invert_tuple,
 827        .print_tuple            = sctp_print_tuple,
 828        .print_conntrack        = sctp_print_conntrack,
 829        .packet                 = sctp_packet,
 830        .get_timeouts           = sctp_get_timeouts,
 831        .new                    = sctp_new,
 832        .me                     = THIS_MODULE,
 833#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 834        .to_nlattr              = sctp_to_nlattr,
 835        .nlattr_size            = sctp_nlattr_size,
 836        .from_nlattr            = nlattr_to_sctp,
 837        .tuple_to_nlattr        = nf_ct_port_tuple_to_nlattr,
 838        .nlattr_tuple_size      = nf_ct_port_nlattr_tuple_size,
 839        .nlattr_to_tuple        = nf_ct_port_nlattr_to_tuple,
 840        .nla_policy             = nf_ct_port_nla_policy,
 841#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 842        .ctnl_timeout           = {
 843                .nlattr_to_obj  = sctp_timeout_nlattr_to_obj,
 844                .obj_to_nlattr  = sctp_timeout_obj_to_nlattr,
 845                .nlattr_max     = CTA_TIMEOUT_SCTP_MAX,
 846                .obj_size       = sizeof(unsigned int) * SCTP_CONNTRACK_MAX,
 847                .nla_policy     = sctp_timeout_nla_policy,
 848        },
 849#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */
 850#endif
 851        .net_id                 = &sctp_net_id,
 852        .init_net               = sctp_init_net,
 853};
 854
 855static int sctp_net_init(struct net *net)
 856{
 857        int ret = 0;
 858
 859        ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_sctp4);
 860        if (ret < 0) {
 861                pr_err("nf_conntrack_sctp4: pernet registration failed.\n");
 862                goto out;
 863        }
 864        ret = nf_ct_l4proto_pernet_register(net, &nf_conntrack_l4proto_sctp6);
 865        if (ret < 0) {
 866                pr_err("nf_conntrack_sctp6: pernet registration failed.\n");
 867                goto cleanup_sctp4;
 868        }
 869        return 0;
 870
 871cleanup_sctp4:
 872        nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp4);
 873out:
 874        return ret;
 875}
 876
 877static void sctp_net_exit(struct net *net)
 878{
 879        nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp6);
 880        nf_ct_l4proto_pernet_unregister(net, &nf_conntrack_l4proto_sctp4);
 881}
 882
 883static struct pernet_operations sctp_net_ops = {
 884        .init = sctp_net_init,
 885        .exit = sctp_net_exit,
 886        .id   = &sctp_net_id,
 887        .size = sizeof(struct sctp_net),
 888};
 889
 890static int __init nf_conntrack_proto_sctp_init(void)
 891{
 892        int ret;
 893
 894        ret = register_pernet_subsys(&sctp_net_ops);
 895        if (ret < 0)
 896                goto out_pernet;
 897
 898        ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_sctp4);
 899        if (ret < 0)
 900                goto out_sctp4;
 901
 902        ret = nf_ct_l4proto_register(&nf_conntrack_l4proto_sctp6);
 903        if (ret < 0)
 904                goto out_sctp6;
 905
 906        return 0;
 907out_sctp6:
 908        nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 909out_sctp4:
 910        unregister_pernet_subsys(&sctp_net_ops);
 911out_pernet:
 912        return ret;
 913}
 914
 915static void __exit nf_conntrack_proto_sctp_fini(void)
 916{
 917        nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp6);
 918        nf_ct_l4proto_unregister(&nf_conntrack_l4proto_sctp4);
 919        unregister_pernet_subsys(&sctp_net_ops);
 920}
 921
 922module_init(nf_conntrack_proto_sctp_init);
 923module_exit(nf_conntrack_proto_sctp_fini);
 924
 925MODULE_LICENSE("GPL");
 926MODULE_AUTHOR("Kiran Kumar Immidi");
 927MODULE_DESCRIPTION("Netfilter connection tracking protocol helper for SCTP");
 928MODULE_ALIAS("ip_conntrack_proto_sctp");
 929
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