| 1 | /* |
| 2 | * Connection tracking protocol helper module for SCTP. |
| 3 | * |
| 4 | * SCTP is defined in RFC 2960. References to various sections in this code |
| 5 | * are to this RFC. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * 17 Oct 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> |
| 12 | * - enable working with L3 protocol independent connection tracking. |
| 13 | * |
| 14 | * Derived from net/ipv4/ip_conntrack_sctp.c |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * Added support for proc manipulation of timeouts. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/types.h> |
| 22 | #include <linux/sched.h> |
| 23 | #include <linux/timer.h> |
| 24 | #include <linux/netfilter.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/in.h> |
| 27 | #include <linux/ip.h> |
| 28 | #include <linux/sctp.h> |
| 29 | #include <linux/string.h> |
| 30 | #include <linux/seq_file.h> |
| 31 | #include <linux/spinlock.h> |
| 32 | #include <linux/interrupt.h> |
| 33 | |
| 34 | #include <net/netfilter/nf_conntrack.h> |
| 35 | #include <net/netfilter/nf_conntrack_l4proto.h> |
| 36 | #include <net/netfilter/nf_conntrack_ecache.h> |
| 37 | |
| 38 | #if 0 |
| 39 | #define DEBUGP(format, ...) printk(format, ## __VA_ARGS__) |
| 40 | #else |
| 41 | #define DEBUGP(format, args...) |
| 42 | #endif |
| 43 | |
| 44 | /* Protects conntrack->proto.sctp */ |
| 45 | static DEFINE_RWLOCK(sctp_lock); |
| 46 | |
| 47 | /* FIXME: Examine ipfilter's timeouts and conntrack transitions more |
| 48 | closely. They're more complex. --RR |
| 49 | |
| 50 | And so for me for SCTP :D -Kiran */ |
| 51 | |
| 52 | static const char *sctp_conntrack_names[] = { |
| 53 | "NONE", |
| 54 | "CLOSED", |
| 55 | "COOKIE_WAIT", |
| 56 | "COOKIE_ECHOED", |
| 57 | "ESTABLISHED", |
| 58 | "SHUTDOWN_SENT", |
| 59 | "SHUTDOWN_RECD", |
| 60 | "SHUTDOWN_ACK_SENT", |
| 61 | }; |
| 62 | |
| 63 | #define SECS * HZ |
| 64 | #define MINS * 60 SECS |
| 65 | #define HOURS * 60 MINS |
| 66 | #define DAYS * 24 HOURS |
| 67 | |
| 68 | static unsigned int nf_ct_sctp_timeout_closed __read_mostly = 10 SECS; |
| 69 | static unsigned int nf_ct_sctp_timeout_cookie_wait __read_mostly = 3 SECS; |
| 70 | static unsigned int nf_ct_sctp_timeout_cookie_echoed __read_mostly = 3 SECS; |
| 71 | static unsigned int nf_ct_sctp_timeout_established __read_mostly = 5 DAYS; |
| 72 | static unsigned int nf_ct_sctp_timeout_shutdown_sent __read_mostly = 300 SECS / 1000; |
| 73 | static unsigned int nf_ct_sctp_timeout_shutdown_recd __read_mostly = 300 SECS / 1000; |
| 74 | static unsigned int nf_ct_sctp_timeout_shutdown_ack_sent __read_mostly = 3 SECS; |
| 75 | |
| 76 | static unsigned int * sctp_timeouts[] |
| 77 | = { NULL, /* SCTP_CONNTRACK_NONE */ |
| 78 | &nf_ct_sctp_timeout_closed, /* SCTP_CONNTRACK_CLOSED */ |
| 79 | &nf_ct_sctp_timeout_cookie_wait, /* SCTP_CONNTRACK_COOKIE_WAIT */ |
| 80 | &nf_ct_sctp_timeout_cookie_echoed, /* SCTP_CONNTRACK_COOKIE_ECHOED */ |
| 81 | &nf_ct_sctp_timeout_established, /* SCTP_CONNTRACK_ESTABLISHED */ |
| 82 | &nf_ct_sctp_timeout_shutdown_sent, /* SCTP_CONNTRACK_SHUTDOWN_SENT */ |
| 83 | &nf_ct_sctp_timeout_shutdown_recd, /* SCTP_CONNTRACK_SHUTDOWN_RECD */ |
| 84 | &nf_ct_sctp_timeout_shutdown_ack_sent /* SCTP_CONNTRACK_SHUTDOWN_ACK_SENT */ |
| 85 | }; |
| 86 | |
| 87 | #define sNO SCTP_CONNTRACK_NONE |
| 88 | #define sCL SCTP_CONNTRACK_CLOSED |
| 89 | #define sCW SCTP_CONNTRACK_COOKIE_WAIT |
| 90 | #define sCE SCTP_CONNTRACK_COOKIE_ECHOED |
| 91 | #define sES SCTP_CONNTRACK_ESTABLISHED |
| 92 | #define sSS SCTP_CONNTRACK_SHUTDOWN_SENT |
| 93 | #define sSR SCTP_CONNTRACK_SHUTDOWN_RECD |
| 94 | #define sSA SCTP_CONNTRACK_SHUTDOWN_ACK_SENT |
| 95 | #define sIV SCTP_CONNTRACK_MAX |
| 96 | |
| 97 | /* |
| 98 | These are the descriptions of the states: |
| 99 | |
| 100 | NOTE: These state names are tantalizingly similar to the states of an |
| 101 | SCTP endpoint. But the interpretation of the states is a little different, |
| 102 | considering that these are the states of the connection and not of an end |
| 103 | point. Please note the subtleties. -Kiran |
| 104 | |
| 105 | NONE - Nothing so far. |
| 106 | COOKIE WAIT - We have seen an INIT chunk in the original direction, or also |
| 107 | an INIT_ACK chunk in the reply direction. |
| 108 | COOKIE ECHOED - We have seen a COOKIE_ECHO chunk in the original direction. |
| 109 | ESTABLISHED - We have seen a COOKIE_ACK in the reply direction. |
| 110 | SHUTDOWN_SENT - We have seen a SHUTDOWN chunk in the original direction. |
| 111 | SHUTDOWN_RECD - We have seen a SHUTDOWN chunk in the reply directoin. |
| 112 | SHUTDOWN_ACK_SENT - We have seen a SHUTDOWN_ACK chunk in the direction opposite |
| 113 | to that of the SHUTDOWN chunk. |
| 114 | CLOSED - We have seen a SHUTDOWN_COMPLETE chunk in the direction of |
| 115 | the SHUTDOWN chunk. Connection is closed. |
| 116 | */ |
| 117 | |
| 118 | /* TODO |
| 119 | - I have assumed that the first INIT is in the original direction. |
| 120 | This messes things when an INIT comes in the reply direction in CLOSED |
| 121 | state. |
| 122 | - Check the error type in the reply dir before transitioning from |
| 123 | cookie echoed to closed. |
| 124 | - Sec 5.2.4 of RFC 2960 |
| 125 | - Multi Homing support. |
| 126 | */ |
| 127 | |
| 128 | /* SCTP conntrack state transitions */ |
| 129 | static enum sctp_conntrack sctp_conntracks[2][9][SCTP_CONNTRACK_MAX] = { |
| 130 | { |
| 131 | /* ORIGINAL */ |
| 132 | /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA */ |
| 133 | /* init */ {sCW, sCW, sCW, sCE, sES, sSS, sSR, sSA}, |
| 134 | /* init_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA}, |
| 135 | /* abort */ {sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL}, |
| 136 | /* shutdown */ {sCL, sCL, sCW, sCE, sSS, sSS, sSR, sSA}, |
| 137 | /* shutdown_ack */ {sSA, sCL, sCW, sCE, sES, sSA, sSA, sSA}, |
| 138 | /* error */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Cant have Stale cookie*/ |
| 139 | /* cookie_echo */ {sCL, sCL, sCE, sCE, sES, sSS, sSR, sSA},/* 5.2.4 - Big TODO */ |
| 140 | /* cookie_ack */ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Cant come in orig dir */ |
| 141 | /* shutdown_comp*/ {sCL, sCL, sCW, sCE, sES, sSS, sSR, sCL} |
| 142 | }, |
| 143 | { |
| 144 | /* REPLY */ |
| 145 | /* sNO, sCL, sCW, sCE, sES, sSS, sSR, sSA */ |
| 146 | /* init */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* INIT in sCL Big TODO */ |
| 147 | /* init_ack */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA}, |
| 148 | /* abort */ {sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL}, |
| 149 | /* shutdown */ {sIV, sCL, sCW, sCE, sSR, sSS, sSR, sSA}, |
| 150 | /* shutdown_ack */ {sIV, sCL, sCW, sCE, sES, sSA, sSA, sSA}, |
| 151 | /* error */ {sIV, sCL, sCW, sCL, sES, sSS, sSR, sSA}, |
| 152 | /* cookie_echo */ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sSA},/* Cant come in reply dir */ |
| 153 | /* cookie_ack */ {sIV, sCL, sCW, sES, sES, sSS, sSR, sSA}, |
| 154 | /* shutdown_comp*/ {sIV, sCL, sCW, sCE, sES, sSS, sSR, sCL} |
| 155 | } |
| 156 | }; |
| 157 | |
| 158 | static int sctp_pkt_to_tuple(const struct sk_buff *skb, |
| 159 | unsigned int dataoff, |
| 160 | struct nf_conntrack_tuple *tuple) |
| 161 | { |
| 162 | sctp_sctphdr_t _hdr, *hp; |
| 163 | |
| 164 | DEBUGP(__FUNCTION__); |
| 165 | DEBUGP("\n"); |
| 166 | |
| 167 | /* Actually only need first 8 bytes. */ |
| 168 | hp = skb_header_pointer(skb, dataoff, 8, &_hdr); |
| 169 | if (hp == NULL) |
| 170 | return 0; |
| 171 | |
| 172 | tuple->src.u.sctp.port = hp->source; |
| 173 | tuple->dst.u.sctp.port = hp->dest; |
| 174 | return 1; |
| 175 | } |
| 176 | |
| 177 | static int sctp_invert_tuple(struct nf_conntrack_tuple *tuple, |
| 178 | const struct nf_conntrack_tuple *orig) |
| 179 | { |
| 180 | DEBUGP(__FUNCTION__); |
| 181 | DEBUGP("\n"); |
| 182 | |
| 183 | tuple->src.u.sctp.port = orig->dst.u.sctp.port; |
| 184 | tuple->dst.u.sctp.port = orig->src.u.sctp.port; |
| 185 | return 1; |
| 186 | } |
| 187 | |
| 188 | /* Print out the per-protocol part of the tuple. */ |
| 189 | static int sctp_print_tuple(struct seq_file *s, |
| 190 | const struct nf_conntrack_tuple *tuple) |
| 191 | { |
| 192 | DEBUGP(__FUNCTION__); |
| 193 | DEBUGP("\n"); |
| 194 | |
| 195 | return seq_printf(s, "sport=%hu dport=%hu ", |
| 196 | ntohs(tuple->src.u.sctp.port), |
| 197 | ntohs(tuple->dst.u.sctp.port)); |
| 198 | } |
| 199 | |
| 200 | /* Print out the private part of the conntrack. */ |
| 201 | static int sctp_print_conntrack(struct seq_file *s, |
| 202 | const struct nf_conn *conntrack) |
| 203 | { |
| 204 | enum sctp_conntrack state; |
| 205 | |
| 206 | DEBUGP(__FUNCTION__); |
| 207 | DEBUGP("\n"); |
| 208 | |
| 209 | read_lock_bh(&sctp_lock); |
| 210 | state = conntrack->proto.sctp.state; |
| 211 | read_unlock_bh(&sctp_lock); |
| 212 | |
| 213 | return seq_printf(s, "%s ", sctp_conntrack_names[state]); |
| 214 | } |
| 215 | |
| 216 | #define for_each_sctp_chunk(skb, sch, _sch, offset, dataoff, count) \ |
| 217 | for (offset = dataoff + sizeof(sctp_sctphdr_t), count = 0; \ |
| 218 | offset < skb->len && \ |
| 219 | (sch = skb_header_pointer(skb, offset, sizeof(_sch), &_sch)); \ |
| 220 | offset += (ntohs(sch->length) + 3) & ~3, count++) |
| 221 | |
| 222 | /* Some validity checks to make sure the chunks are fine */ |
| 223 | static int do_basic_checks(struct nf_conn *conntrack, |
| 224 | const struct sk_buff *skb, |
| 225 | unsigned int dataoff, |
| 226 | char *map) |
| 227 | { |
| 228 | u_int32_t offset, count; |
| 229 | sctp_chunkhdr_t _sch, *sch; |
| 230 | int flag; |
| 231 | |
| 232 | DEBUGP(__FUNCTION__); |
| 233 | DEBUGP("\n"); |
| 234 | |
| 235 | flag = 0; |
| 236 | |
| 237 | for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { |
| 238 | DEBUGP("Chunk Num: %d Type: %d\n", count, sch->type); |
| 239 | |
| 240 | if (sch->type == SCTP_CID_INIT |
| 241 | || sch->type == SCTP_CID_INIT_ACK |
| 242 | || sch->type == SCTP_CID_SHUTDOWN_COMPLETE) { |
| 243 | flag = 1; |
| 244 | } |
| 245 | |
| 246 | /* |
| 247 | * Cookie Ack/Echo chunks not the first OR |
| 248 | * Init / Init Ack / Shutdown compl chunks not the only chunks |
| 249 | * OR zero-length. |
| 250 | */ |
| 251 | if (((sch->type == SCTP_CID_COOKIE_ACK |
| 252 | || sch->type == SCTP_CID_COOKIE_ECHO |
| 253 | || flag) |
| 254 | && count !=0) || !sch->length) { |
| 255 | DEBUGP("Basic checks failed\n"); |
| 256 | return 1; |
| 257 | } |
| 258 | |
| 259 | if (map) { |
| 260 | set_bit(sch->type, (void *)map); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | DEBUGP("Basic checks passed\n"); |
| 265 | return count == 0; |
| 266 | } |
| 267 | |
| 268 | static int new_state(enum ip_conntrack_dir dir, |
| 269 | enum sctp_conntrack cur_state, |
| 270 | int chunk_type) |
| 271 | { |
| 272 | int i; |
| 273 | |
| 274 | DEBUGP(__FUNCTION__); |
| 275 | DEBUGP("\n"); |
| 276 | |
| 277 | DEBUGP("Chunk type: %d\n", chunk_type); |
| 278 | |
| 279 | switch (chunk_type) { |
| 280 | case SCTP_CID_INIT: |
| 281 | DEBUGP("SCTP_CID_INIT\n"); |
| 282 | i = 0; break; |
| 283 | case SCTP_CID_INIT_ACK: |
| 284 | DEBUGP("SCTP_CID_INIT_ACK\n"); |
| 285 | i = 1; break; |
| 286 | case SCTP_CID_ABORT: |
| 287 | DEBUGP("SCTP_CID_ABORT\n"); |
| 288 | i = 2; break; |
| 289 | case SCTP_CID_SHUTDOWN: |
| 290 | DEBUGP("SCTP_CID_SHUTDOWN\n"); |
| 291 | i = 3; break; |
| 292 | case SCTP_CID_SHUTDOWN_ACK: |
| 293 | DEBUGP("SCTP_CID_SHUTDOWN_ACK\n"); |
| 294 | i = 4; break; |
| 295 | case SCTP_CID_ERROR: |
| 296 | DEBUGP("SCTP_CID_ERROR\n"); |
| 297 | i = 5; break; |
| 298 | case SCTP_CID_COOKIE_ECHO: |
| 299 | DEBUGP("SCTP_CID_COOKIE_ECHO\n"); |
| 300 | i = 6; break; |
| 301 | case SCTP_CID_COOKIE_ACK: |
| 302 | DEBUGP("SCTP_CID_COOKIE_ACK\n"); |
| 303 | i = 7; break; |
| 304 | case SCTP_CID_SHUTDOWN_COMPLETE: |
| 305 | DEBUGP("SCTP_CID_SHUTDOWN_COMPLETE\n"); |
| 306 | i = 8; break; |
| 307 | default: |
| 308 | /* Other chunks like DATA, SACK, HEARTBEAT and |
| 309 | its ACK do not cause a change in state */ |
| 310 | DEBUGP("Unknown chunk type, Will stay in %s\n", |
| 311 | sctp_conntrack_names[cur_state]); |
| 312 | return cur_state; |
| 313 | } |
| 314 | |
| 315 | DEBUGP("dir: %d cur_state: %s chunk_type: %d new_state: %s\n", |
| 316 | dir, sctp_conntrack_names[cur_state], chunk_type, |
| 317 | sctp_conntrack_names[sctp_conntracks[dir][i][cur_state]]); |
| 318 | |
| 319 | return sctp_conntracks[dir][i][cur_state]; |
| 320 | } |
| 321 | |
| 322 | /* Returns verdict for packet, or -1 for invalid. */ |
| 323 | static int sctp_packet(struct nf_conn *conntrack, |
| 324 | const struct sk_buff *skb, |
| 325 | unsigned int dataoff, |
| 326 | enum ip_conntrack_info ctinfo, |
| 327 | int pf, |
| 328 | unsigned int hooknum) |
| 329 | { |
| 330 | enum sctp_conntrack newconntrack, oldsctpstate; |
| 331 | sctp_sctphdr_t _sctph, *sh; |
| 332 | sctp_chunkhdr_t _sch, *sch; |
| 333 | u_int32_t offset, count; |
| 334 | char map[256 / sizeof (char)] = {0}; |
| 335 | |
| 336 | DEBUGP(__FUNCTION__); |
| 337 | DEBUGP("\n"); |
| 338 | |
| 339 | sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); |
| 340 | if (sh == NULL) |
| 341 | return -1; |
| 342 | |
| 343 | if (do_basic_checks(conntrack, skb, dataoff, map) != 0) |
| 344 | return -1; |
| 345 | |
| 346 | /* Check the verification tag (Sec 8.5) */ |
| 347 | if (!test_bit(SCTP_CID_INIT, (void *)map) |
| 348 | && !test_bit(SCTP_CID_SHUTDOWN_COMPLETE, (void *)map) |
| 349 | && !test_bit(SCTP_CID_COOKIE_ECHO, (void *)map) |
| 350 | && !test_bit(SCTP_CID_ABORT, (void *)map) |
| 351 | && !test_bit(SCTP_CID_SHUTDOWN_ACK, (void *)map) |
| 352 | && (sh->vtag != conntrack->proto.sctp.vtag[CTINFO2DIR(ctinfo)])) { |
| 353 | DEBUGP("Verification tag check failed\n"); |
| 354 | return -1; |
| 355 | } |
| 356 | |
| 357 | oldsctpstate = newconntrack = SCTP_CONNTRACK_MAX; |
| 358 | for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { |
| 359 | write_lock_bh(&sctp_lock); |
| 360 | |
| 361 | /* Special cases of Verification tag check (Sec 8.5.1) */ |
| 362 | if (sch->type == SCTP_CID_INIT) { |
| 363 | /* Sec 8.5.1 (A) */ |
| 364 | if (sh->vtag != 0) { |
| 365 | write_unlock_bh(&sctp_lock); |
| 366 | return -1; |
| 367 | } |
| 368 | } else if (sch->type == SCTP_CID_ABORT) { |
| 369 | /* Sec 8.5.1 (B) */ |
| 370 | if (!(sh->vtag == conntrack->proto.sctp.vtag[CTINFO2DIR(ctinfo)]) |
| 371 | && !(sh->vtag == conntrack->proto.sctp.vtag |
| 372 | [1 - CTINFO2DIR(ctinfo)])) { |
| 373 | write_unlock_bh(&sctp_lock); |
| 374 | return -1; |
| 375 | } |
| 376 | } else if (sch->type == SCTP_CID_SHUTDOWN_COMPLETE) { |
| 377 | /* Sec 8.5.1 (C) */ |
| 378 | if (!(sh->vtag == conntrack->proto.sctp.vtag[CTINFO2DIR(ctinfo)]) |
| 379 | && !(sh->vtag == conntrack->proto.sctp.vtag |
| 380 | [1 - CTINFO2DIR(ctinfo)] |
| 381 | && (sch->flags & 1))) { |
| 382 | write_unlock_bh(&sctp_lock); |
| 383 | return -1; |
| 384 | } |
| 385 | } else if (sch->type == SCTP_CID_COOKIE_ECHO) { |
| 386 | /* Sec 8.5.1 (D) */ |
| 387 | if (!(sh->vtag == conntrack->proto.sctp.vtag[CTINFO2DIR(ctinfo)])) { |
| 388 | write_unlock_bh(&sctp_lock); |
| 389 | return -1; |
| 390 | } |
| 391 | } |
| 392 | |
| 393 | oldsctpstate = conntrack->proto.sctp.state; |
| 394 | newconntrack = new_state(CTINFO2DIR(ctinfo), oldsctpstate, sch->type); |
| 395 | |
| 396 | /* Invalid */ |
| 397 | if (newconntrack == SCTP_CONNTRACK_MAX) { |
| 398 | DEBUGP("nf_conntrack_sctp: Invalid dir=%i ctype=%u conntrack=%u\n", |
| 399 | CTINFO2DIR(ctinfo), sch->type, oldsctpstate); |
| 400 | write_unlock_bh(&sctp_lock); |
| 401 | return -1; |
| 402 | } |
| 403 | |
| 404 | /* If it is an INIT or an INIT ACK note down the vtag */ |
| 405 | if (sch->type == SCTP_CID_INIT |
| 406 | || sch->type == SCTP_CID_INIT_ACK) { |
| 407 | sctp_inithdr_t _inithdr, *ih; |
| 408 | |
| 409 | ih = skb_header_pointer(skb, offset + sizeof(sctp_chunkhdr_t), |
| 410 | sizeof(_inithdr), &_inithdr); |
| 411 | if (ih == NULL) { |
| 412 | write_unlock_bh(&sctp_lock); |
| 413 | return -1; |
| 414 | } |
| 415 | DEBUGP("Setting vtag %x for dir %d\n", |
| 416 | ih->init_tag, !CTINFO2DIR(ctinfo)); |
| 417 | conntrack->proto.sctp.vtag[!CTINFO2DIR(ctinfo)] = ih->init_tag; |
| 418 | } |
| 419 | |
| 420 | conntrack->proto.sctp.state = newconntrack; |
| 421 | if (oldsctpstate != newconntrack) |
| 422 | nf_conntrack_event_cache(IPCT_PROTOINFO, skb); |
| 423 | write_unlock_bh(&sctp_lock); |
| 424 | } |
| 425 | |
| 426 | nf_ct_refresh_acct(conntrack, ctinfo, skb, *sctp_timeouts[newconntrack]); |
| 427 | |
| 428 | if (oldsctpstate == SCTP_CONNTRACK_COOKIE_ECHOED |
| 429 | && CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY |
| 430 | && newconntrack == SCTP_CONNTRACK_ESTABLISHED) { |
| 431 | DEBUGP("Setting assured bit\n"); |
| 432 | set_bit(IPS_ASSURED_BIT, &conntrack->status); |
| 433 | nf_conntrack_event_cache(IPCT_STATUS, skb); |
| 434 | } |
| 435 | |
| 436 | return NF_ACCEPT; |
| 437 | } |
| 438 | |
| 439 | /* Called when a new connection for this protocol found. */ |
| 440 | static int sctp_new(struct nf_conn *conntrack, const struct sk_buff *skb, |
| 441 | unsigned int dataoff) |
| 442 | { |
| 443 | enum sctp_conntrack newconntrack; |
| 444 | sctp_sctphdr_t _sctph, *sh; |
| 445 | sctp_chunkhdr_t _sch, *sch; |
| 446 | u_int32_t offset, count; |
| 447 | char map[256 / sizeof (char)] = {0}; |
| 448 | |
| 449 | DEBUGP(__FUNCTION__); |
| 450 | DEBUGP("\n"); |
| 451 | |
| 452 | sh = skb_header_pointer(skb, dataoff, sizeof(_sctph), &_sctph); |
| 453 | if (sh == NULL) |
| 454 | return 0; |
| 455 | |
| 456 | if (do_basic_checks(conntrack, skb, dataoff, map) != 0) |
| 457 | return 0; |
| 458 | |
| 459 | /* If an OOTB packet has any of these chunks discard (Sec 8.4) */ |
| 460 | if ((test_bit (SCTP_CID_ABORT, (void *)map)) |
| 461 | || (test_bit (SCTP_CID_SHUTDOWN_COMPLETE, (void *)map)) |
| 462 | || (test_bit (SCTP_CID_COOKIE_ACK, (void *)map))) { |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | newconntrack = SCTP_CONNTRACK_MAX; |
| 467 | for_each_sctp_chunk (skb, sch, _sch, offset, dataoff, count) { |
| 468 | /* Don't need lock here: this conntrack not in circulation yet */ |
| 469 | newconntrack = new_state(IP_CT_DIR_ORIGINAL, |
| 470 | SCTP_CONNTRACK_NONE, sch->type); |
| 471 | |
| 472 | /* Invalid: delete conntrack */ |
| 473 | if (newconntrack == SCTP_CONNTRACK_MAX) { |
| 474 | DEBUGP("nf_conntrack_sctp: invalid new deleting.\n"); |
| 475 | return 0; |
| 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 0; |
| 487 | |
| 488 | DEBUGP("Setting vtag %x for new conn\n", |
| 489 | ih->init_tag); |
| 490 | |
| 491 | conntrack->proto.sctp.vtag[IP_CT_DIR_REPLY] = |
| 492 | ih->init_tag; |
| 493 | } else { |
| 494 | /* Sec 8.5.1 (A) */ |
| 495 | return 0; |
| 496 | } |
| 497 | } |
| 498 | /* If it is a shutdown ack OOTB packet, we expect a return |
| 499 | shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ |
| 500 | else { |
| 501 | DEBUGP("Setting vtag %x for new conn OOTB\n", |
| 502 | sh->vtag); |
| 503 | conntrack->proto.sctp.vtag[IP_CT_DIR_REPLY] = sh->vtag; |
| 504 | } |
| 505 | |
| 506 | conntrack->proto.sctp.state = newconntrack; |
| 507 | } |
| 508 | |
| 509 | return 1; |
| 510 | } |
| 511 | |
| 512 | #ifdef CONFIG_SYSCTL |
| 513 | static unsigned int sctp_sysctl_table_users; |
| 514 | static struct ctl_table_header *sctp_sysctl_header; |
| 515 | static struct ctl_table sctp_sysctl_table[] = { |
| 516 | { |
| 517 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_CLOSED, |
| 518 | .procname = "nf_conntrack_sctp_timeout_closed", |
| 519 | .data = &nf_ct_sctp_timeout_closed, |
| 520 | .maxlen = sizeof(unsigned int), |
| 521 | .mode = 0644, |
| 522 | .proc_handler = &proc_dointvec_jiffies, |
| 523 | }, |
| 524 | { |
| 525 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_WAIT, |
| 526 | .procname = "nf_conntrack_sctp_timeout_cookie_wait", |
| 527 | .data = &nf_ct_sctp_timeout_cookie_wait, |
| 528 | .maxlen = sizeof(unsigned int), |
| 529 | .mode = 0644, |
| 530 | .proc_handler = &proc_dointvec_jiffies, |
| 531 | }, |
| 532 | { |
| 533 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_ECHOED, |
| 534 | .procname = "nf_conntrack_sctp_timeout_cookie_echoed", |
| 535 | .data = &nf_ct_sctp_timeout_cookie_echoed, |
| 536 | .maxlen = sizeof(unsigned int), |
| 537 | .mode = 0644, |
| 538 | .proc_handler = &proc_dointvec_jiffies, |
| 539 | }, |
| 540 | { |
| 541 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_ESTABLISHED, |
| 542 | .procname = "nf_conntrack_sctp_timeout_established", |
| 543 | .data = &nf_ct_sctp_timeout_established, |
| 544 | .maxlen = sizeof(unsigned int), |
| 545 | .mode = 0644, |
| 546 | .proc_handler = &proc_dointvec_jiffies, |
| 547 | }, |
| 548 | { |
| 549 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_SENT, |
| 550 | .procname = "nf_conntrack_sctp_timeout_shutdown_sent", |
| 551 | .data = &nf_ct_sctp_timeout_shutdown_sent, |
| 552 | .maxlen = sizeof(unsigned int), |
| 553 | .mode = 0644, |
| 554 | .proc_handler = &proc_dointvec_jiffies, |
| 555 | }, |
| 556 | { |
| 557 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_RECD, |
| 558 | .procname = "nf_conntrack_sctp_timeout_shutdown_recd", |
| 559 | .data = &nf_ct_sctp_timeout_shutdown_recd, |
| 560 | .maxlen = sizeof(unsigned int), |
| 561 | .mode = 0644, |
| 562 | .proc_handler = &proc_dointvec_jiffies, |
| 563 | }, |
| 564 | { |
| 565 | .ctl_name = NET_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_ACK_SENT, |
| 566 | .procname = "nf_conntrack_sctp_timeout_shutdown_ack_sent", |
| 567 | .data = &nf_ct_sctp_timeout_shutdown_ack_sent, |
| 568 | .maxlen = sizeof(unsigned int), |
| 569 | .mode = 0644, |
| 570 | .proc_handler = &proc_dointvec_jiffies, |
| 571 | }, |
| 572 | { |
| 573 | .ctl_name = 0 |
| 574 | } |
| 575 | }; |
| 576 | |
| 577 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
| 578 | static struct ctl_table sctp_compat_sysctl_table[] = { |
| 579 | { |
| 580 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_CLOSED, |
| 581 | .procname = "ip_conntrack_sctp_timeout_closed", |
| 582 | .data = &nf_ct_sctp_timeout_closed, |
| 583 | .maxlen = sizeof(unsigned int), |
| 584 | .mode = 0644, |
| 585 | .proc_handler = &proc_dointvec_jiffies, |
| 586 | }, |
| 587 | { |
| 588 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_WAIT, |
| 589 | .procname = "ip_conntrack_sctp_timeout_cookie_wait", |
| 590 | .data = &nf_ct_sctp_timeout_cookie_wait, |
| 591 | .maxlen = sizeof(unsigned int), |
| 592 | .mode = 0644, |
| 593 | .proc_handler = &proc_dointvec_jiffies, |
| 594 | }, |
| 595 | { |
| 596 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_COOKIE_ECHOED, |
| 597 | .procname = "ip_conntrack_sctp_timeout_cookie_echoed", |
| 598 | .data = &nf_ct_sctp_timeout_cookie_echoed, |
| 599 | .maxlen = sizeof(unsigned int), |
| 600 | .mode = 0644, |
| 601 | .proc_handler = &proc_dointvec_jiffies, |
| 602 | }, |
| 603 | { |
| 604 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_ESTABLISHED, |
| 605 | .procname = "ip_conntrack_sctp_timeout_established", |
| 606 | .data = &nf_ct_sctp_timeout_established, |
| 607 | .maxlen = sizeof(unsigned int), |
| 608 | .mode = 0644, |
| 609 | .proc_handler = &proc_dointvec_jiffies, |
| 610 | }, |
| 611 | { |
| 612 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_SENT, |
| 613 | .procname = "ip_conntrack_sctp_timeout_shutdown_sent", |
| 614 | .data = &nf_ct_sctp_timeout_shutdown_sent, |
| 615 | .maxlen = sizeof(unsigned int), |
| 616 | .mode = 0644, |
| 617 | .proc_handler = &proc_dointvec_jiffies, |
| 618 | }, |
| 619 | { |
| 620 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_RECD, |
| 621 | .procname = "ip_conntrack_sctp_timeout_shutdown_recd", |
| 622 | .data = &nf_ct_sctp_timeout_shutdown_recd, |
| 623 | .maxlen = sizeof(unsigned int), |
| 624 | .mode = 0644, |
| 625 | .proc_handler = &proc_dointvec_jiffies, |
| 626 | }, |
| 627 | { |
| 628 | .ctl_name = NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_ACK_SENT, |
| 629 | .procname = "ip_conntrack_sctp_timeout_shutdown_ack_sent", |
| 630 | .data = &nf_ct_sctp_timeout_shutdown_ack_sent, |
| 631 | .maxlen = sizeof(unsigned int), |
| 632 | .mode = 0644, |
| 633 | .proc_handler = &proc_dointvec_jiffies, |
| 634 | }, |
| 635 | { |
| 636 | .ctl_name = 0 |
| 637 | } |
| 638 | }; |
| 639 | #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ |
| 640 | #endif |
| 641 | |
| 642 | struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp4 = { |
| 643 | .l3proto = PF_INET, |
| 644 | .l4proto = IPPROTO_SCTP, |
| 645 | .name = "sctp", |
| 646 | .pkt_to_tuple = sctp_pkt_to_tuple, |
| 647 | .invert_tuple = sctp_invert_tuple, |
| 648 | .print_tuple = sctp_print_tuple, |
| 649 | .print_conntrack = sctp_print_conntrack, |
| 650 | .packet = sctp_packet, |
| 651 | .new = sctp_new, |
| 652 | .me = THIS_MODULE, |
| 653 | #ifdef CONFIG_SYSCTL |
| 654 | .ctl_table_users = &sctp_sysctl_table_users, |
| 655 | .ctl_table_header = &sctp_sysctl_header, |
| 656 | .ctl_table = sctp_sysctl_table, |
| 657 | #ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT |
| 658 | .ctl_compat_table = sctp_compat_sysctl_table, |
| 659 | #endif |
| 660 | #endif |
| 661 | }; |
| 662 | |
| 663 | struct nf_conntrack_l4proto nf_conntrack_l4proto_sctp6 = { |
| 664 | .l3proto = PF_INET6, |
| 665 | .l4proto = IPPROTO_SCTP, |
| 666 | .name = "sctp", |
| 667 | .pkt_to_tuple = sctp_pkt_to_tuple, |
| 668 | .invert_tuple = sctp_invert_tuple, |
| 669 | .print_tuple = sctp_print_tuple, |
| 670 | .print_conntrack = sctp_print_conntrack, |
| 671 | .packet = sctp_packet, |
| 672 | .new = sctp_new, |
| 673 | .me = THIS_MODULE, |
| 674 | #ifdef CONFIG_SYSCTL |
| 675 | .ctl_table_users = &sctp_sysctl_table_users, |
| 676 | .ctl_table_header = &sctp_sysctl_header, |
| 677 | .ctl_table = sctp_sysctl_table, |
| 678 | #endif |
| 679 | }; |
| 680 | |
| 681 | int __init nf_conntrack_proto_sctp_init(void) |
| 682 | { |
| 683 | int ret; |
| 684 | |
| 685 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_sctp4); |
| 686 | if (ret) { |
| 687 | printk("nf_conntrack_l4proto_sctp4: protocol register failed\n"); |
| 688 | goto out; |
| 689 | } |
| 690 | ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_sctp6); |
| 691 | if (ret) { |
| 692 | printk("nf_conntrack_l4proto_sctp6: protocol register failed\n"); |
| 693 | goto cleanup_sctp4; |
| 694 | } |
| 695 | |
| 696 | return ret; |
| 697 | |
| 698 | cleanup_sctp4: |
| 699 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp4); |
| 700 | out: |
| 701 | DEBUGP("SCTP conntrack module loading %s\n", |
| 702 | ret ? "failed": "succeeded"); |
| 703 | return ret; |
| 704 | } |
| 705 | |
| 706 | void __exit nf_conntrack_proto_sctp_fini(void) |
| 707 | { |
| 708 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp6); |
| 709 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_sctp4); |
| 710 | DEBUGP("SCTP conntrack module unloaded\n"); |
| 711 | } |
| 712 | |
| 713 | module_init(nf_conntrack_proto_sctp_init); |
| 714 | module_exit(nf_conntrack_proto_sctp_fini); |
| 715 | |
| 716 | MODULE_LICENSE("GPL"); |
| 717 | MODULE_AUTHOR("Kiran Kumar Immidi"); |
| 718 | MODULE_DESCRIPTION("Netfilter connection tracking protocol helper for SCTP"); |
| 719 | MODULE_ALIAS("ip_conntrack_proto_sctp"); |