1/* (C) 1999-2001 Paul `Rusty' Russell 2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> 3 * (C) 2002-2013 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> 4 * (C) 2006-2012 Patrick McHardy <kaber@trash.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11#include <linux/types.h> 12#include <linux/timer.h> 13#include <linux/module.h> 14#include <linux/in.h> 15#include <linux/tcp.h> 16#include <linux/spinlock.h> 17#include <linux/skbuff.h> 18#include <linux/ipv6.h> 19#include <net/ip6_checksum.h> 20#include <asm/unaligned.h> 21 22#include <net/tcp.h> 23 24#include <linux/netfilter.h> 25#include <linux/netfilter_ipv4.h> 26#include <linux/netfilter_ipv6.h> 27#include <net/netfilter/nf_conntrack.h> 28#include <net/netfilter/nf_conntrack_l4proto.h> 29#include <net/netfilter/nf_conntrack_ecache.h> 30#include <net/netfilter/nf_conntrack_seqadj.h> 31#include <net/netfilter/nf_conntrack_synproxy.h> 32#include <net/netfilter/nf_log.h> 33#include <net/netfilter/ipv4/nf_conntrack_ipv4.h> 34#include <net/netfilter/ipv6/nf_conntrack_ipv6.h> 35 36/* "Be conservative in what you do, 37 be liberal in what you accept from others." 38 If it's non-zero, we mark only out of window RST segments as INVALID. */ 39static int nf_ct_tcp_be_liberal __read_mostly = 0; 40 41/* If it is set to zero, we disable picking up already established 42 connections. */ 43static int nf_ct_tcp_loose __read_mostly = 1; 44 45/* Max number of the retransmitted packets without receiving an (acceptable) 46 ACK from the destination. If this number is reached, a shorter timer 47 will be started. */ 48static int nf_ct_tcp_max_retrans __read_mostly = 3; 49 50 /* FIXME: Examine ipfilter's timeouts and conntrack transitions more 51 closely. They're more complex. --RR */ 52 53static const char *const tcp_conntrack_names[] = { 54 "NONE", 55 "SYN_SENT", 56 "SYN_RECV", 57 "ESTABLISHED", 58 "FIN_WAIT", 59 "CLOSE_WAIT", 60 "LAST_ACK", 61 "TIME_WAIT", 62 "CLOSE", 63 "SYN_SENT2", 64}; 65 66#define SECS * HZ 67#define MINS * 60 SECS 68#define HOURS * 60 MINS 69#define DAYS * 24 HOURS 70 71static unsigned int tcp_timeouts[TCP_CONNTRACK_TIMEOUT_MAX] __read_mostly = { 72 [TCP_CONNTRACK_SYN_SENT] = 2 MINS, 73 [TCP_CONNTRACK_SYN_RECV] = 60 SECS, 74 [TCP_CONNTRACK_ESTABLISHED] = 5 DAYS, 75 [TCP_CONNTRACK_FIN_WAIT] = 2 MINS, 76 [TCP_CONNTRACK_CLOSE_WAIT] = 60 SECS, 77 [TCP_CONNTRACK_LAST_ACK] = 30 SECS, 78 [TCP_CONNTRACK_TIME_WAIT] = 2 MINS, 79 [TCP_CONNTRACK_CLOSE] = 10 SECS, 80 [TCP_CONNTRACK_SYN_SENT2] = 2 MINS, 81/* RFC1122 says the R2 limit should be at least 100 seconds. 82 Linux uses 15 packets as limit, which corresponds 83 to ~13-30min depending on RTO. */ 84 [TCP_CONNTRACK_RETRANS] = 5 MINS, 85 [TCP_CONNTRACK_UNACK] = 5 MINS, 86}; 87 88#define sNO TCP_CONNTRACK_NONE 89#define sSS TCP_CONNTRACK_SYN_SENT 90#define sSR TCP_CONNTRACK_SYN_RECV 91#define sES TCP_CONNTRACK_ESTABLISHED 92#define sFW TCP_CONNTRACK_FIN_WAIT 93#define sCW TCP_CONNTRACK_CLOSE_WAIT 94#define sLA TCP_CONNTRACK_LAST_ACK 95#define sTW TCP_CONNTRACK_TIME_WAIT 96#define sCL TCP_CONNTRACK_CLOSE 97#define sS2 TCP_CONNTRACK_SYN_SENT2 98#define sIV TCP_CONNTRACK_MAX 99#define sIG TCP_CONNTRACK_IGNORE 100 101/* What TCP flags are set from RST/SYN/FIN/ACK. */ 102enum tcp_bit_set { 103 TCP_SYN_SET, 104 TCP_SYNACK_SET, 105 TCP_FIN_SET, 106 TCP_ACK_SET, 107 TCP_RST_SET, 108 TCP_NONE_SET, 109}; 110 111/* 112 * The TCP state transition table needs a few words... 113 * 114 * We are the man in the middle. All the packets go through us 115 * but might get lost in transit to the destination. 116 * It is assumed that the destinations can't receive segments 117 * we haven't seen. 118 * 119 * The checked segment is in window, but our windows are *not* 120 * equivalent with the ones of the sender/receiver. We always 121 * try to guess the state of the current sender. 122 * 123 * The meaning of the states are: 124 * 125 * NONE: initial state 126 * SYN_SENT: SYN-only packet seen 127 * SYN_SENT2: SYN-only packet seen from reply dir, simultaneous open 128 * SYN_RECV: SYN-ACK packet seen 129 * ESTABLISHED: ACK packet seen 130 * FIN_WAIT: FIN packet seen 131 * CLOSE_WAIT: ACK seen (after FIN) 132 * LAST_ACK: FIN seen (after FIN) 133 * TIME_WAIT: last ACK seen 134 * CLOSE: closed connection (RST) 135 * 136 * Packets marked as IGNORED (sIG): 137 * if they may be either invalid or valid 138 * and the receiver may send back a connection 139 * closing RST or a SYN/ACK. 140 * 141 * Packets marked as INVALID (sIV): 142 * if we regard them as truly invalid packets 143 */ 144static const u8 tcp_conntracks[2][6][TCP_CONNTRACK_MAX] = { 145 { 146/* ORIGINAL */ 147/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 148/*syn*/ { sSS, sSS, sIG, sIG, sIG, sIG, sIG, sSS, sSS, sS2 }, 149/* 150 * sNO -> sSS Initialize a new connection 151 * sSS -> sSS Retransmitted SYN 152 * sS2 -> sS2 Late retransmitted SYN 153 * sSR -> sIG 154 * sES -> sIG Error: SYNs in window outside the SYN_SENT state 155 * are errors. Receiver will reply with RST 156 * and close the connection. 157 * Or we are not in sync and hold a dead connection. 158 * sFW -> sIG 159 * sCW -> sIG 160 * sLA -> sIG 161 * sTW -> sSS Reopened connection (RFC 1122). 162 * sCL -> sSS 163 */ 164/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 165/*synack*/ { sIV, sIV, sSR, sIV, sIV, sIV, sIV, sIV, sIV, sSR }, 166/* 167 * sNO -> sIV Too late and no reason to do anything 168 * sSS -> sIV Client can't send SYN and then SYN/ACK 169 * sS2 -> sSR SYN/ACK sent to SYN2 in simultaneous open 170 * sSR -> sSR Late retransmitted SYN/ACK in simultaneous open 171 * sES -> sIV Invalid SYN/ACK packets sent by the client 172 * sFW -> sIV 173 * sCW -> sIV 174 * sLA -> sIV 175 * sTW -> sIV 176 * sCL -> sIV 177 */ 178/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 179/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV }, 180/* 181 * sNO -> sIV Too late and no reason to do anything... 182 * sSS -> sIV Client migth not send FIN in this state: 183 * we enforce waiting for a SYN/ACK reply first. 184 * sS2 -> sIV 185 * sSR -> sFW Close started. 186 * sES -> sFW 187 * sFW -> sLA FIN seen in both directions, waiting for 188 * the last ACK. 189 * Migth be a retransmitted FIN as well... 190 * sCW -> sLA 191 * sLA -> sLA Retransmitted FIN. Remain in the same state. 192 * sTW -> sTW 193 * sCL -> sCL 194 */ 195/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 196/*ack*/ { sES, sIV, sES, sES, sCW, sCW, sTW, sTW, sCL, sIV }, 197/* 198 * sNO -> sES Assumed. 199 * sSS -> sIV ACK is invalid: we haven't seen a SYN/ACK yet. 200 * sS2 -> sIV 201 * sSR -> sES Established state is reached. 202 * sES -> sES :-) 203 * sFW -> sCW Normal close request answered by ACK. 204 * sCW -> sCW 205 * sLA -> sTW Last ACK detected. 206 * sTW -> sTW Retransmitted last ACK. Remain in the same state. 207 * sCL -> sCL 208 */ 209/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 210/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL }, 211/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV } 212 }, 213 { 214/* REPLY */ 215/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 216/*syn*/ { sIV, sS2, sIV, sIV, sIV, sIV, sIV, sSS, sIV, sS2 }, 217/* 218 * sNO -> sIV Never reached. 219 * sSS -> sS2 Simultaneous open 220 * sS2 -> sS2 Retransmitted simultaneous SYN 221 * sSR -> sIV Invalid SYN packets sent by the server 222 * sES -> sIV 223 * sFW -> sIV 224 * sCW -> sIV 225 * sLA -> sIV 226 * sTW -> sSS Reopened connection, but server may have switched role 227 * sCL -> sIV 228 */ 229/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 230/*synack*/ { sIV, sSR, sIG, sIG, sIG, sIG, sIG, sIG, sIG, sSR }, 231/* 232 * sSS -> sSR Standard open. 233 * sS2 -> sSR Simultaneous open 234 * sSR -> sIG Retransmitted SYN/ACK, ignore it. 235 * sES -> sIG Late retransmitted SYN/ACK? 236 * sFW -> sIG Might be SYN/ACK answering ignored SYN 237 * sCW -> sIG 238 * sLA -> sIG 239 * sTW -> sIG 240 * sCL -> sIG 241 */ 242/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 243/*fin*/ { sIV, sIV, sFW, sFW, sLA, sLA, sLA, sTW, sCL, sIV }, 244/* 245 * sSS -> sIV Server might not send FIN in this state. 246 * sS2 -> sIV 247 * sSR -> sFW Close started. 248 * sES -> sFW 249 * sFW -> sLA FIN seen in both directions. 250 * sCW -> sLA 251 * sLA -> sLA Retransmitted FIN. 252 * sTW -> sTW 253 * sCL -> sCL 254 */ 255/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 256/*ack*/ { sIV, sIG, sSR, sES, sCW, sCW, sTW, sTW, sCL, sIG }, 257/* 258 * sSS -> sIG Might be a half-open connection. 259 * sS2 -> sIG 260 * sSR -> sSR Might answer late resent SYN. 261 * sES -> sES :-) 262 * sFW -> sCW Normal close request answered by ACK. 263 * sCW -> sCW 264 * sLA -> sTW Last ACK detected. 265 * sTW -> sTW Retransmitted last ACK. 266 * sCL -> sCL 267 */ 268/* sNO, sSS, sSR, sES, sFW, sCW, sLA, sTW, sCL, sS2 */ 269/*rst*/ { sIV, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL, sCL }, 270/*none*/ { sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV, sIV } 271 } 272}; 273 274static inline struct nf_tcp_net *tcp_pernet(struct net *net) 275{ 276 return &net->ct.nf_ct_proto.tcp; 277} 278 279static bool tcp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff, 280 struct nf_conntrack_tuple *tuple) 281{ 282 const struct tcphdr *hp; 283 struct tcphdr _hdr; 284 285 /* Actually only need first 8 bytes. */ 286 hp = skb_header_pointer(skb, dataoff, 8, &_hdr); 287 if (hp == NULL) 288 return false; 289 290 tuple->src.u.tcp.port = hp->source; 291 tuple->dst.u.tcp.port = hp->dest; 292 293 return true; 294} 295 296static bool tcp_invert_tuple(struct nf_conntrack_tuple *tuple, 297 const struct nf_conntrack_tuple *orig) 298{ 299 tuple->src.u.tcp.port = orig->dst.u.tcp.port; 300 tuple->dst.u.tcp.port = orig->src.u.tcp.port; 301 return true; 302} 303 304/* Print out the per-protocol part of the tuple. */ 305static int tcp_print_tuple(struct seq_file *s, 306 const struct nf_conntrack_tuple *tuple) 307{ 308 return seq_printf(s, "sport=%hu dport=%hu ", 309 ntohs(tuple->src.u.tcp.port), 310 ntohs(tuple->dst.u.tcp.port)); 311} 312 313/* Print out the private part of the conntrack. */ 314static int tcp_print_conntrack(struct seq_file *s, struct nf_conn *ct) 315{ 316 enum tcp_conntrack state; 317 318 spin_lock_bh(&ct->lock); 319 state = ct->proto.tcp.state; 320 spin_unlock_bh(&ct->lock); 321 322 return seq_printf(s, "%s ", tcp_conntrack_names[state]); 323} 324 325static unsigned int get_conntrack_index(const struct tcphdr *tcph) 326{ 327 if (tcph->rst) return TCP_RST_SET; 328 else if (tcph->syn) return (tcph->ack ? TCP_SYNACK_SET : TCP_SYN_SET); 329 else if (tcph->fin) return TCP_FIN_SET; 330 else if (tcph->ack) return TCP_ACK_SET; 331 else return TCP_NONE_SET; 332} 333 334/* TCP connection tracking based on 'Real Stateful TCP Packet Filtering 335 in IP Filter' by Guido van Rooij. 336 337 http://www.sane.nl/events/sane2000/papers.html 338 http://www.darkart.com/mirrors/www.obfuscation.org/ipf/ 339 340 The boundaries and the conditions are changed according to RFC793: 341 the packet must intersect the window (i.e. segments may be 342 after the right or before the left edge) and thus receivers may ACK 343 segments after the right edge of the window. 344 345 td_maxend = max(sack + max(win,1)) seen in reply packets 346 td_maxwin = max(max(win, 1)) + (sack - ack) seen in sent packets 347 td_maxwin += seq + len - sender.td_maxend 348 if seq + len > sender.td_maxend 349 td_end = max(seq + len) seen in sent packets 350 351 I. Upper bound for valid data: seq <= sender.td_maxend 352 II. Lower bound for valid data: seq + len >= sender.td_end - receiver.td_maxwin 353 III. Upper bound for valid (s)ack: sack <= receiver.td_end 354 IV. Lower bound for valid (s)ack: sack >= receiver.td_end - MAXACKWINDOW 355 356 where sack is the highest right edge of sack block found in the packet 357 or ack in the case of packet without SACK option. 358 359 The upper bound limit for a valid (s)ack is not ignored - 360 we doesn't have to deal with fragments. 361*/ 362 363static inline __u32 segment_seq_plus_len(__u32 seq, 364 size_t len, 365 unsigned int dataoff, 366 const struct tcphdr *tcph) 367{ 368 /* XXX Should I use payload length field in IP/IPv6 header ? 369 * - YK */ 370 return (seq + len - dataoff - tcph->doff*4 371 + (tcph->syn ? 1 : 0) + (tcph->fin ? 1 : 0)); 372} 373 374/* Fixme: what about big packets? */ 375#define MAXACKWINCONST 66000 376#define MAXACKWINDOW(sender) \ 377 ((sender)->td_maxwin > MAXACKWINCONST ? (sender)->td_maxwin \ 378 : MAXACKWINCONST) 379 380/* 381 * Simplified tcp_parse_options routine from tcp_input.c 382 */ 383static void tcp_options(const struct sk_buff *skb, 384 unsigned int dataoff, 385 const struct tcphdr *tcph, 386 struct ip_ct_tcp_state *state) 387{ 388 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)]; 389 const unsigned char *ptr; 390 int length = (tcph->doff*4) - sizeof(struct tcphdr); 391 392 if (!length) 393 return; 394 395 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr), 396 length, buff); 397 BUG_ON(ptr == NULL); 398 399 state->td_scale = 400 state->flags = 0; 401 402 while (length > 0) { 403 int opcode=*ptr++; 404 int opsize; 405 406 switch (opcode) { 407 case TCPOPT_EOL: 408 return; 409 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ 410 length--; 411 continue; 412 default: 413 opsize=*ptr++; 414 if (opsize < 2) /* "silly options" */ 415 return; 416 if (opsize > length) 417 return; /* don't parse partial options */ 418 419 if (opcode == TCPOPT_SACK_PERM 420 && opsize == TCPOLEN_SACK_PERM) 421 state->flags |= IP_CT_TCP_FLAG_SACK_PERM; 422 else if (opcode == TCPOPT_WINDOW 423 && opsize == TCPOLEN_WINDOW) { 424 state->td_scale = *(u_int8_t *)ptr; 425 426 if (state->td_scale > 14) { 427 /* See RFC1323 */ 428 state->td_scale = 14; 429 } 430 state->flags |= 431 IP_CT_TCP_FLAG_WINDOW_SCALE; 432 } 433 ptr += opsize - 2; 434 length -= opsize; 435 } 436 } 437} 438 439static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff, 440 const struct tcphdr *tcph, __u32 *sack) 441{ 442 unsigned char buff[(15 * 4) - sizeof(struct tcphdr)]; 443 const unsigned char *ptr; 444 int length = (tcph->doff*4) - sizeof(struct tcphdr); 445 __u32 tmp; 446 447 if (!length) 448 return; 449 450 ptr = skb_header_pointer(skb, dataoff + sizeof(struct tcphdr), 451 length, buff); 452 BUG_ON(ptr == NULL); 453 454 /* Fast path for timestamp-only option */ 455 if (length == TCPOLEN_TSTAMP_ALIGNED 456 && *(__be32 *)ptr == htonl((TCPOPT_NOP << 24) 457 | (TCPOPT_NOP << 16) 458 | (TCPOPT_TIMESTAMP << 8) 459 | TCPOLEN_TIMESTAMP)) 460 return; 461 462 while (length > 0) { 463 int opcode = *ptr++; 464 int opsize, i; 465 466 switch (opcode) { 467 case TCPOPT_EOL: 468 return; 469 case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ 470 length--; 471 continue; 472 default: 473 opsize = *ptr++; 474 if (opsize < 2) /* "silly options" */ 475 return; 476 if (opsize > length) 477 return; /* don't parse partial options */ 478 479 if (opcode == TCPOPT_SACK 480 && opsize >= (TCPOLEN_SACK_BASE 481 + TCPOLEN_SACK_PERBLOCK) 482 && !((opsize - TCPOLEN_SACK_BASE) 483 % TCPOLEN_SACK_PERBLOCK)) { 484 for (i = 0; 485 i < (opsize - TCPOLEN_SACK_BASE); 486 i += TCPOLEN_SACK_PERBLOCK) { 487 tmp = get_unaligned_be32((__be32 *)(ptr+i)+1); 488 489 if (after(tmp, *sack)) 490 *sack = tmp; 491 } 492 return; 493 } 494 ptr += opsize - 2; 495 length -= opsize; 496 } 497 } 498} 499 500static bool tcp_in_window(const struct nf_conn *ct, 501 struct ip_ct_tcp *state, 502 enum ip_conntrack_dir dir, 503 unsigned int index, 504 const struct sk_buff *skb, 505 unsigned int dataoff, 506 const struct tcphdr *tcph, 507 u_int8_t pf) 508{ 509 struct net *net = nf_ct_net(ct); 510 struct nf_tcp_net *tn = tcp_pernet(net); 511 struct ip_ct_tcp_state *sender = &state->seen[dir]; 512 struct ip_ct_tcp_state *receiver = &state->seen[!dir]; 513 const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple; 514 __u32 seq, ack, sack, end, win, swin; 515 s32 receiver_offset; 516 bool res, in_recv_win; 517 518 /* 519 * Get the required data from the packet. 520 */ 521 seq = ntohl(tcph->seq); 522 ack = sack = ntohl(tcph->ack_seq); 523 win = ntohs(tcph->window); 524 end = segment_seq_plus_len(seq, skb->len, dataoff, tcph); 525 526 if (receiver->flags & IP_CT_TCP_FLAG_SACK_PERM) 527 tcp_sack(skb, dataoff, tcph, &sack); 528 529 /* Take into account NAT sequence number mangling */ 530 receiver_offset = nf_ct_seq_offset(ct, !dir, ack - 1); 531 ack -= receiver_offset; 532 sack -= receiver_offset; 533 534 pr_debug("tcp_in_window: START\n"); 535 pr_debug("tcp_in_window: "); 536 nf_ct_dump_tuple(tuple); 537 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n", 538 seq, ack, receiver_offset, sack, receiver_offset, win, end); 539 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i " 540 "receiver end=%u maxend=%u maxwin=%u scale=%i\n", 541 sender->td_end, sender->td_maxend, sender->td_maxwin, 542 sender->td_scale, 543 receiver->td_end, receiver->td_maxend, receiver->td_maxwin, 544 receiver->td_scale); 545 546 if (sender->td_maxwin == 0) { 547 /* 548 * Initialize sender data. 549 */ 550 if (tcph->syn) { 551 /* 552 * SYN-ACK in reply to a SYN 553 * or SYN from reply direction in simultaneous open. 554 */ 555 sender->td_end = 556 sender->td_maxend = end; 557 sender->td_maxwin = (win == 0 ? 1 : win); 558 559 tcp_options(skb, dataoff, tcph, sender); 560 /* 561 * RFC 1323: 562 * Both sides must send the Window Scale option 563 * to enable window scaling in either direction. 564 */ 565 if (!(sender->flags & IP_CT_TCP_FLAG_WINDOW_SCALE 566 && receiver->flags & IP_CT_TCP_FLAG_WINDOW_SCALE)) 567 sender->td_scale = 568 receiver->td_scale = 0; 569 if (!tcph->ack) 570 /* Simultaneous open */ 571 return true; 572 } else { 573 /* 574 * We are in the middle of a connection, 575 * its history is lost for us. 576 * Let's try to use the data from the packet. 577 */ 578 sender->td_end = end; 579 swin = win << sender->td_scale; 580 sender->td_maxwin = (swin == 0 ? 1 : swin); 581 sender->td_maxend = end + sender->td_maxwin; 582 /* 583 * We haven't seen traffic in the other direction yet 584 * but we have to tweak window tracking to pass III 585 * and IV until that happens. 586 */ 587 if (receiver->td_maxwin == 0) 588 receiver->td_end = receiver->td_maxend = sack; 589 } 590 } else if (((state->state == TCP_CONNTRACK_SYN_SENT 591 && dir == IP_CT_DIR_ORIGINAL) 592 || (state->state == TCP_CONNTRACK_SYN_RECV 593 && dir == IP_CT_DIR_REPLY)) 594 && after(end, sender->td_end)) { 595 /* 596 * RFC 793: "if a TCP is reinitialized ... then it need 597 * not wait at all; it must only be sure to use sequence 598 * numbers larger than those recently used." 599 */ 600 sender->td_end = 601 sender->td_maxend = end; 602 sender->td_maxwin = (win == 0 ? 1 : win); 603 604 tcp_options(skb, dataoff, tcph, sender); 605 } 606 607 if (!(tcph->ack)) { 608 /* 609 * If there is no ACK, just pretend it was set and OK. 610 */ 611 ack = sack = receiver->td_end; 612 } else if (((tcp_flag_word(tcph) & (TCP_FLAG_ACK|TCP_FLAG_RST)) == 613 (TCP_FLAG_ACK|TCP_FLAG_RST)) 614 && (ack == 0)) { 615 /* 616 * Broken TCP stacks, that set ACK in RST packets as well 617 * with zero ack value. 618 */ 619 ack = sack = receiver->td_end; 620 } 621 622 if (tcph->rst && seq == 0 && state->state == TCP_CONNTRACK_SYN_SENT) 623 /* 624 * RST sent answering SYN. 625 */ 626 seq = end = sender->td_end; 627 628 pr_debug("tcp_in_window: "); 629 nf_ct_dump_tuple(tuple); 630 pr_debug("seq=%u ack=%u+(%d) sack=%u+(%d) win=%u end=%u\n", 631 seq, ack, receiver_offset, sack, receiver_offset, win, end); 632 pr_debug("tcp_in_window: sender end=%u maxend=%u maxwin=%u scale=%i " 633 "receiver end=%u maxend=%u maxwin=%u scale=%i\n", 634 sender->td_end, sender->td_maxend, sender->td_maxwin, 635 sender->td_scale, 636 receiver->td_end, receiver->td_maxend, receiver->td_maxwin, 637 receiver->td_scale); 638 639 /* Is the ending sequence in the receive window (if available)? */ 640 in_recv_win = !receiver->td_maxwin || 641 after(end, sender->td_end - receiver->td_maxwin - 1); 642 643 pr_debug("tcp_in_window: I=%i II=%i III=%i IV=%i\n", 644 before(seq, sender->td_maxend + 1), 645 (in_recv_win ? 1 : 0), 646 before(sack, receiver->td_end + 1), 647 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)); 648 649 if (before(seq, sender->td_maxend + 1) && 650 in_recv_win && 651 before(sack, receiver->td_end + 1) && 652 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1)) { 653 /* 654 * Take into account window scaling (RFC 1323). 655 */ 656 if (!tcph->syn) 657 win <<= sender->td_scale; 658 659 /* 660 * Update sender data. 661 */ 662 swin = win + (sack - ack); 663 if (sender->td_maxwin < swin) 664 sender->td_maxwin = swin; 665 if (after(end, sender->td_end)) { 666 sender->td_end = end; 667 sender->flags |= IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED; 668 } 669 if (tcph->ack) { 670 if (!(sender->flags & IP_CT_TCP_FLAG_MAXACK_SET)) { 671 sender->td_maxack = ack; 672 sender->flags |= IP_CT_TCP_FLAG_MAXACK_SET; 673 } else if (after(ack, sender->td_maxack)) 674 sender->td_maxack = ack; 675 } 676 677 /* 678 * Update receiver data. 679 */ 680 if (receiver->td_maxwin != 0 && after(end, sender->td_maxend)) 681 receiver->td_maxwin += end - sender->td_maxend; 682 if (after(sack + win, receiver->td_maxend - 1)) { 683 receiver->td_maxend = sack + win; 684 if (win == 0) 685 receiver->td_maxend++; 686 } 687 if (ack == receiver->td_end) 688 receiver->flags &= ~IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED; 689 690 /* 691 * Check retransmissions. 692 */ 693 if (index == TCP_ACK_SET) { 694 if (state->last_dir == dir 695 && state->last_seq == seq 696 && state->last_ack == ack 697 && state->last_end == end 698 && state->last_win == win) 699 state->retrans++; 700 else { 701 state->last_dir = dir; 702 state->last_seq = seq; 703 state->last_ack = ack; 704 state->last_end = end; 705 state->last_win = win; 706 state->retrans = 0; 707 } 708 } 709 res = true; 710 } else { 711 res = false; 712 if (sender->flags & IP_CT_TCP_FLAG_BE_LIBERAL || 713 tn->tcp_be_liberal) 714 res = true; 715 if (!res && LOG_INVALID(net, IPPROTO_TCP)) 716 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 717 "nf_ct_tcp: %s ", 718 before(seq, sender->td_maxend + 1) ? 719 in_recv_win ? 720 before(sack, receiver->td_end + 1) ? 721 after(sack, receiver->td_end - MAXACKWINDOW(sender) - 1) ? "BUG" 722 : "ACK is under the lower bound (possible overly delayed ACK)" 723 : "ACK is over the upper bound (ACKed data not seen yet)" 724 : "SEQ is under the lower bound (already ACKed data retransmitted)" 725 : "SEQ is over the upper bound (over the window of the receiver)"); 726 } 727 728 pr_debug("tcp_in_window: res=%u sender end=%u maxend=%u maxwin=%u " 729 "receiver end=%u maxend=%u maxwin=%u\n", 730 res, sender->td_end, sender->td_maxend, sender->td_maxwin, 731 receiver->td_end, receiver->td_maxend, receiver->td_maxwin); 732 733 return res; 734} 735 736/* table of valid flag combinations - PUSH, ECE and CWR are always valid */ 737static const u8 tcp_valid_flags[(TCPHDR_FIN|TCPHDR_SYN|TCPHDR_RST|TCPHDR_ACK| 738 TCPHDR_URG) + 1] = 739{ 740 [TCPHDR_SYN] = 1, 741 [TCPHDR_SYN|TCPHDR_URG] = 1, 742 [TCPHDR_SYN|TCPHDR_ACK] = 1, 743 [TCPHDR_RST] = 1, 744 [TCPHDR_RST|TCPHDR_ACK] = 1, 745 [TCPHDR_FIN|TCPHDR_ACK] = 1, 746 [TCPHDR_FIN|TCPHDR_ACK|TCPHDR_URG] = 1, 747 [TCPHDR_ACK] = 1, 748 [TCPHDR_ACK|TCPHDR_URG] = 1, 749}; 750 751/* Protect conntrack agaist broken packets. Code taken from ipt_unclean.c. */ 752static int tcp_error(struct net *net, struct nf_conn *tmpl, 753 struct sk_buff *skb, 754 unsigned int dataoff, 755 enum ip_conntrack_info *ctinfo, 756 u_int8_t pf, 757 unsigned int hooknum) 758{ 759 const struct tcphdr *th; 760 struct tcphdr _tcph; 761 unsigned int tcplen = skb->len - dataoff; 762 u_int8_t tcpflags; 763 764 /* Smaller that minimal TCP header? */ 765 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph); 766 if (th == NULL) { 767 if (LOG_INVALID(net, IPPROTO_TCP)) 768 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 769 "nf_ct_tcp: short packet "); 770 return -NF_ACCEPT; 771 } 772 773 /* Not whole TCP header or malformed packet */ 774 if (th->doff*4 < sizeof(struct tcphdr) || tcplen < th->doff*4) { 775 if (LOG_INVALID(net, IPPROTO_TCP)) 776 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 777 "nf_ct_tcp: truncated/malformed packet "); 778 return -NF_ACCEPT; 779 } 780 781 /* Checksum invalid? Ignore. 782 * We skip checking packets on the outgoing path 783 * because the checksum is assumed to be correct. 784 */ 785 /* FIXME: Source route IP option packets --RR */ 786 if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING && 787 nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) { 788 if (LOG_INVALID(net, IPPROTO_TCP)) 789 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 790 "nf_ct_tcp: bad TCP checksum "); 791 return -NF_ACCEPT; 792 } 793 794 /* Check TCP flags. */ 795 tcpflags = (tcp_flag_byte(th) & ~(TCPHDR_ECE|TCPHDR_CWR|TCPHDR_PSH)); 796 if (!tcp_valid_flags[tcpflags]) { 797 if (LOG_INVALID(net, IPPROTO_TCP)) 798 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 799 "nf_ct_tcp: invalid TCP flag combination "); 800 return -NF_ACCEPT; 801 } 802 803 return NF_ACCEPT; 804} 805 806static unsigned int *tcp_get_timeouts(struct net *net) 807{ 808 return tcp_pernet(net)->timeouts; 809} 810 811/* Returns verdict for packet, or -1 for invalid. */ 812static int tcp_packet(struct nf_conn *ct, 813 const struct sk_buff *skb, 814 unsigned int dataoff, 815 enum ip_conntrack_info ctinfo, 816 u_int8_t pf, 817 unsigned int hooknum, 818 unsigned int *timeouts) 819{ 820 struct net *net = nf_ct_net(ct); 821 struct nf_tcp_net *tn = tcp_pernet(net); 822 struct nf_conntrack_tuple *tuple; 823 enum tcp_conntrack new_state, old_state; 824 enum ip_conntrack_dir dir; 825 const struct tcphdr *th; 826 struct tcphdr _tcph; 827 unsigned long timeout; 828 unsigned int index; 829 830 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph); 831 BUG_ON(th == NULL); 832 833 spin_lock_bh(&ct->lock); 834 old_state = ct->proto.tcp.state; 835 dir = CTINFO2DIR(ctinfo); 836 index = get_conntrack_index(th); 837 new_state = tcp_conntracks[dir][index][old_state]; 838 tuple = &ct->tuplehash[dir].tuple; 839 840 switch (new_state) { 841 case TCP_CONNTRACK_SYN_SENT: 842 if (old_state < TCP_CONNTRACK_TIME_WAIT) 843 break; 844 /* RFC 1122: "When a connection is closed actively, 845 * it MUST linger in TIME-WAIT state for a time 2xMSL 846 * (Maximum Segment Lifetime). However, it MAY accept 847 * a new SYN from the remote TCP to reopen the connection 848 * directly from TIME-WAIT state, if..." 849 * We ignore the conditions because we are in the 850 * TIME-WAIT state anyway. 851 * 852 * Handle aborted connections: we and the server 853 * think there is an existing connection but the client 854 * aborts it and starts a new one. 855 */ 856 if (((ct->proto.tcp.seen[dir].flags 857 | ct->proto.tcp.seen[!dir].flags) 858 & IP_CT_TCP_FLAG_CLOSE_INIT) 859 || (ct->proto.tcp.last_dir == dir 860 && ct->proto.tcp.last_index == TCP_RST_SET)) { 861 /* Attempt to reopen a closed/aborted connection. 862 * Delete this connection and look up again. */ 863 spin_unlock_bh(&ct->lock); 864 865 /* Only repeat if we can actually remove the timer. 866 * Destruction may already be in progress in process 867 * context and we must give it a chance to terminate. 868 */ 869 if (nf_ct_kill(ct)) 870 return -NF_REPEAT; 871 return NF_DROP; 872 } 873 /* Fall through */ 874 case TCP_CONNTRACK_IGNORE: 875 /* Ignored packets: 876 * 877 * Our connection entry may be out of sync, so ignore 878 * packets which may signal the real connection between 879 * the client and the server. 880 * 881 * a) SYN in ORIGINAL 882 * b) SYN/ACK in REPLY 883 * c) ACK in reply direction after initial SYN in original. 884 * 885 * If the ignored packet is invalid, the receiver will send 886 * a RST we'll catch below. 887 */ 888 if (index == TCP_SYNACK_SET 889 && ct->proto.tcp.last_index == TCP_SYN_SET 890 && ct->proto.tcp.last_dir != dir 891 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) { 892 /* b) This SYN/ACK acknowledges a SYN that we earlier 893 * ignored as invalid. This means that the client and 894 * the server are both in sync, while the firewall is 895 * not. We get in sync from the previously annotated 896 * values. 897 */ 898 old_state = TCP_CONNTRACK_SYN_SENT; 899 new_state = TCP_CONNTRACK_SYN_RECV; 900 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_end = 901 ct->proto.tcp.last_end; 902 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxend = 903 ct->proto.tcp.last_end; 904 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_maxwin = 905 ct->proto.tcp.last_win == 0 ? 906 1 : ct->proto.tcp.last_win; 907 ct->proto.tcp.seen[ct->proto.tcp.last_dir].td_scale = 908 ct->proto.tcp.last_wscale; 909 ct->proto.tcp.seen[ct->proto.tcp.last_dir].flags = 910 ct->proto.tcp.last_flags; 911 memset(&ct->proto.tcp.seen[dir], 0, 912 sizeof(struct ip_ct_tcp_state)); 913 break; 914 } 915 ct->proto.tcp.last_index = index; 916 ct->proto.tcp.last_dir = dir; 917 ct->proto.tcp.last_seq = ntohl(th->seq); 918 ct->proto.tcp.last_end = 919 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th); 920 ct->proto.tcp.last_win = ntohs(th->window); 921 922 /* a) This is a SYN in ORIGINAL. The client and the server 923 * may be in sync but we are not. In that case, we annotate 924 * the TCP options and let the packet go through. If it is a 925 * valid SYN packet, the server will reply with a SYN/ACK, and 926 * then we'll get in sync. Otherwise, the server ignores it. */ 927 if (index == TCP_SYN_SET && dir == IP_CT_DIR_ORIGINAL) { 928 struct ip_ct_tcp_state seen = {}; 929 930 ct->proto.tcp.last_flags = 931 ct->proto.tcp.last_wscale = 0; 932 tcp_options(skb, dataoff, th, &seen); 933 if (seen.flags & IP_CT_TCP_FLAG_WINDOW_SCALE) { 934 ct->proto.tcp.last_flags |= 935 IP_CT_TCP_FLAG_WINDOW_SCALE; 936 ct->proto.tcp.last_wscale = seen.td_scale; 937 } 938 if (seen.flags & IP_CT_TCP_FLAG_SACK_PERM) { 939 ct->proto.tcp.last_flags |= 940 IP_CT_TCP_FLAG_SACK_PERM; 941 } 942 } 943 spin_unlock_bh(&ct->lock); 944 if (LOG_INVALID(net, IPPROTO_TCP)) 945 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 946 "nf_ct_tcp: invalid packet ignored in " 947 "state %s ", tcp_conntrack_names[old_state]); 948 return NF_ACCEPT; 949 case TCP_CONNTRACK_MAX: 950 /* Special case for SYN proxy: when the SYN to the server or 951 * the SYN/ACK from the server is lost, the client may transmit 952 * a keep-alive packet while in SYN_SENT state. This needs to 953 * be associated with the original conntrack entry in order to 954 * generate a new SYN with the correct sequence number. 955 */ 956 if (nfct_synproxy(ct) && old_state == TCP_CONNTRACK_SYN_SENT && 957 index == TCP_ACK_SET && dir == IP_CT_DIR_ORIGINAL && 958 ct->proto.tcp.last_dir == IP_CT_DIR_ORIGINAL && 959 ct->proto.tcp.seen[dir].td_end - 1 == ntohl(th->seq)) { 960 pr_debug("nf_ct_tcp: SYN proxy client keep alive\n"); 961 spin_unlock_bh(&ct->lock); 962 return NF_ACCEPT; 963 } 964 965 /* Invalid packet */ 966 pr_debug("nf_ct_tcp: Invalid dir=%i index=%u ostate=%u\n", 967 dir, get_conntrack_index(th), old_state); 968 spin_unlock_bh(&ct->lock); 969 if (LOG_INVALID(net, IPPROTO_TCP)) 970 nf_log_packet(net, pf, 0, skb, NULL, NULL, NULL, 971 "nf_ct_tcp: invalid state "); 972 return -NF_ACCEPT; 973 case TCP_CONNTRACK_CLOSE: 974 if (index == TCP_RST_SET 975 && (ct->proto.tcp.seen[!dir].flags & IP_CT_TCP_FLAG_MAXACK_SET) 976 && before(ntohl(th->seq), ct->proto.tcp.seen[!dir].td_maxack)) { 977 /* Invalid RST */ 978 spin_unlock_bh(&ct->lock); 979 if (LOG_INVALID(net, IPPROTO_TCP)) 980 nf_log_packet(net, pf, 0, skb, NULL, NULL, 981 NULL, "nf_ct_tcp: invalid RST "); 982 return -NF_ACCEPT; 983 } 984 if (index == TCP_RST_SET 985 && ((test_bit(IPS_SEEN_REPLY_BIT, &ct->status) 986 && ct->proto.tcp.last_index == TCP_SYN_SET) 987 || (!test_bit(IPS_ASSURED_BIT, &ct->status) 988 && ct->proto.tcp.last_index == TCP_ACK_SET)) 989 && ntohl(th->ack_seq) == ct->proto.tcp.last_end) { 990 /* RST sent to invalid SYN or ACK we had let through 991 * at a) and c) above: 992 * 993 * a) SYN was in window then 994 * c) we hold a half-open connection. 995 * 996 * Delete our connection entry. 997 * We skip window checking, because packet might ACK 998 * segments we ignored. */ 999 goto in_window; 1000 } 1001 /* Just fall through */ 1002 default: 1003 /* Keep compilers happy. */ 1004 break; 1005 } 1006 1007 if (!tcp_in_window(ct, &ct->proto.tcp, dir, index, 1008 skb, dataoff, th, pf)) { 1009 spin_unlock_bh(&ct->lock); 1010 return -NF_ACCEPT; 1011 } 1012 in_window: 1013 /* From now on we have got in-window packets */ 1014 ct->proto.tcp.last_index = index; 1015 ct->proto.tcp.last_dir = dir; 1016 1017 pr_debug("tcp_conntracks: "); 1018 nf_ct_dump_tuple(tuple); 1019 pr_debug("syn=%i ack=%i fin=%i rst=%i old=%i new=%i\n", 1020 (th->syn ? 1 : 0), (th->ack ? 1 : 0), 1021 (th->fin ? 1 : 0), (th->rst ? 1 : 0), 1022 old_state, new_state); 1023 1024 ct->proto.tcp.state = new_state; 1025 if (old_state != new_state 1026 && new_state == TCP_CONNTRACK_FIN_WAIT) 1027 ct->proto.tcp.seen[dir].flags |= IP_CT_TCP_FLAG_CLOSE_INIT; 1028 1029 if (ct->proto.tcp.retrans >= tn->tcp_max_retrans && 1030 timeouts[new_state] > timeouts[TCP_CONNTRACK_RETRANS]) 1031 timeout = timeouts[TCP_CONNTRACK_RETRANS]; 1032 else if ((ct->proto.tcp.seen[0].flags | ct->proto.tcp.seen[1].flags) & 1033 IP_CT_TCP_FLAG_DATA_UNACKNOWLEDGED && 1034 timeouts[new_state] > timeouts[TCP_CONNTRACK_UNACK]) 1035 timeout = timeouts[TCP_CONNTRACK_UNACK]; 1036 else 1037 timeout = timeouts[new_state]; 1038 spin_unlock_bh(&ct->lock); 1039 1040 if (new_state != old_state) 1041 nf_conntrack_event_cache(IPCT_PROTOINFO, ct); 1042 1043 if (!test_bit(IPS_SEEN_REPLY_BIT, &ct->status)) { 1044 /* If only reply is a RST, we can consider ourselves not to 1045 have an established connection: this is a fairly common 1046 problem case, so we can delete the conntrack 1047 immediately. --RR */ 1048 if (th->rst) { 1049 nf_ct_kill_acct(ct, ctinfo, skb); 1050 return NF_ACCEPT; 1051 } 1052 /* ESTABLISHED without SEEN_REPLY, i.e. mid-connection 1053 * pickup with loose=1. Avoid large ESTABLISHED timeout. 1054 */ 1055 if (new_state == TCP_CONNTRACK_ESTABLISHED && 1056 timeout > timeouts[TCP_CONNTRACK_UNACK]) 1057 timeout = timeouts[TCP_CONNTRACK_UNACK]; 1058 } else if (!test_bit(IPS_ASSURED_BIT, &ct->status) 1059 && (old_state == TCP_CONNTRACK_SYN_RECV 1060 || old_state == TCP_CONNTRACK_ESTABLISHED) 1061 && new_state == TCP_CONNTRACK_ESTABLISHED) { 1062 /* Set ASSURED if we see see valid ack in ESTABLISHED 1063 after SYN_RECV or a valid answer for a picked up 1064 connection. */ 1065 set_bit(IPS_ASSURED_BIT, &ct->status); 1066 nf_conntrack_event_cache(IPCT_ASSURED, ct); 1067 } 1068 nf_ct_refresh_acct(ct, ctinfo, skb, timeout); 1069 1070 return NF_ACCEPT; 1071} 1072 1073/* Called when a new connection for this protocol found. */ 1074static bool tcp_new(struct nf_conn *ct, const struct sk_buff *skb, 1075 unsigned int dataoff, unsigned int *timeouts) 1076{ 1077 enum tcp_conntrack new_state; 1078 const struct tcphdr *th; 1079 struct tcphdr _tcph; 1080 struct net *net = nf_ct_net(ct); 1081 struct nf_tcp_net *tn = tcp_pernet(net); 1082 const struct ip_ct_tcp_state *sender = &ct->proto.tcp.seen[0]; 1083 const struct ip_ct_tcp_state *receiver = &ct->proto.tcp.seen[1]; 1084 1085 th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph); 1086 BUG_ON(th == NULL); 1087 1088 /* Don't need lock here: this conntrack not in circulation yet */ 1089 new_state = tcp_conntracks[0][get_conntrack_index(th)][TCP_CONNTRACK_NONE]; 1090 1091 /* Invalid: delete conntrack */ 1092 if (new_state >= TCP_CONNTRACK_MAX) { 1093 pr_debug("nf_ct_tcp: invalid new deleting.\n"); 1094 return false; 1095 } 1096 1097 if (new_state == TCP_CONNTRACK_SYN_SENT) { 1098 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); 1099 /* SYN packet */ 1100 ct->proto.tcp.seen[0].td_end = 1101 segment_seq_plus_len(ntohl(th->seq), skb->len, 1102 dataoff, th); 1103 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); 1104 if (ct->proto.tcp.seen[0].td_maxwin == 0) 1105 ct->proto.tcp.seen[0].td_maxwin = 1; 1106 ct->proto.tcp.seen[0].td_maxend = 1107 ct->proto.tcp.seen[0].td_end; 1108 1109 tcp_options(skb, dataoff, th, &ct->proto.tcp.seen[0]); 1110 } else if (tn->tcp_loose == 0) { 1111 /* Don't try to pick up connections. */ 1112 return false; 1113 } else { 1114 memset(&ct->proto.tcp, 0, sizeof(ct->proto.tcp)); 1115 /* 1116 * We are in the middle of a connection, 1117 * its history is lost for us. 1118 * Let's try to use the data from the packet. 1119 */ 1120 ct->proto.tcp.seen[0].td_end = 1121 segment_seq_plus_len(ntohl(th->seq), skb->len, 1122 dataoff, th); 1123 ct->proto.tcp.seen[0].td_maxwin = ntohs(th->window); 1124 if (ct->proto.tcp.seen[0].td_maxwin == 0) 1125 ct->proto.tcp.seen[0].td_maxwin = 1; 1126 ct->proto.tcp.seen[0].td_maxend = 1127 ct->proto.tcp.seen[0].td_end + 1128 ct->proto.tcp.seen[0].td_maxwin; 1129 1130 /* We assume SACK and liberal window checking to handle 1131 * window scaling */ 1132 ct->proto.tcp.seen[0].flags = 1133 ct->proto.tcp.seen[1].flags = IP_CT_TCP_FLAG_SACK_PERM | 1134 IP_CT_TCP_FLAG_BE_LIBERAL; 1135 } 1136 1137 /* tcp_packet will set them */ 1138 ct->proto.tcp.last_index = TCP_NONE_SET; 1139 1140 pr_debug("tcp_new: sender end=%u maxend=%u maxwin=%u scale=%i " 1141 "receiver end=%u maxend=%u maxwin=%u scale=%i\n", 1142 sender->td_end, sender->td_maxend, sender->td_maxwin, 1143 sender->td_scale, 1144 receiver->td_end, receiver->td_maxend, receiver->td_maxwin, 1145 receiver->td_scale); 1146 return true; 1147} 1148 1149#if IS_ENABLED(CONFIG_NF_CT_NETLINK) 1150 1151#include <linux/netfilter/nfnetlink.h> 1152#include <linux/netfilter/nfnetlink_conntrack.h> 1153 1154static int tcp_to_nlattr(struct sk_buff *skb, struct nlattr *nla, 1155 struct nf_conn *ct) 1156{ 1157 struct nlattr *nest_parms; 1158 struct nf_ct_tcp_flags tmp = {}; 1159 1160 spin_lock_bh(&ct->lock); 1161 nest_parms = nla_nest_start(skb, CTA_PROTOINFO_TCP | NLA_F_NESTED); 1162 if (!nest_parms) 1163 goto nla_put_failure; 1164 1165 if (nla_put_u8(skb, CTA_PROTOINFO_TCP_STATE, ct->proto.tcp.state) || 1166 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_ORIGINAL, 1167 ct->proto.tcp.seen[0].td_scale) || 1168 nla_put_u8(skb, CTA_PROTOINFO_TCP_WSCALE_REPLY, 1169 ct->proto.tcp.seen[1].td_scale)) 1170 goto nla_put_failure; 1171 1172 tmp.flags = ct->proto.tcp.seen[0].flags; 1173 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_ORIGINAL, 1174 sizeof(struct nf_ct_tcp_flags), &tmp)) 1175 goto nla_put_failure; 1176 1177 tmp.flags = ct->proto.tcp.seen[1].flags; 1178 if (nla_put(skb, CTA_PROTOINFO_TCP_FLAGS_REPLY, 1179 sizeof(struct nf_ct_tcp_flags), &tmp)) 1180 goto nla_put_failure; 1181 spin_unlock_bh(&ct->lock); 1182 1183 nla_nest_end(skb, nest_parms); 1184 1185 return 0; 1186 1187nla_put_failure: 1188 spin_unlock_bh(&ct->lock); 1189 return -1; 1190} 1191 1192static const struct nla_policy tcp_nla_policy[CTA_PROTOINFO_TCP_MAX+1] = { 1193 [CTA_PROTOINFO_TCP_STATE] = { .type = NLA_U8 }, 1194 [CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] = { .type = NLA_U8 }, 1195 [CTA_PROTOINFO_TCP_WSCALE_REPLY] = { .type = NLA_U8 }, 1196 [CTA_PROTOINFO_TCP_FLAGS_ORIGINAL] = { .len = sizeof(struct nf_ct_tcp_flags) }, 1197 [CTA_PROTOINFO_TCP_FLAGS_REPLY] = { .len = sizeof(struct nf_ct_tcp_flags) }, 1198}; 1199 1200static int nlattr_to_tcp(struct nlattr *cda[], struct nf_conn *ct) 1201{ 1202 struct nlattr *pattr = cda[CTA_PROTOINFO_TCP]; 1203 struct nlattr *tb[CTA_PROTOINFO_TCP_MAX+1]; 1204 int err; 1205 1206 /* updates could not contain anything about the private 1207 * protocol info, in that case skip the parsing */ 1208 if (!pattr) 1209 return 0; 1210 1211 err = nla_parse_nested(tb, CTA_PROTOINFO_TCP_MAX, pattr, tcp_nla_policy); 1212 if (err < 0) 1213 return err; 1214 1215 if (tb[CTA_PROTOINFO_TCP_STATE] && 1216 nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]) >= TCP_CONNTRACK_MAX) 1217 return -EINVAL; 1218 1219 spin_lock_bh(&ct->lock); 1220 if (tb[CTA_PROTOINFO_TCP_STATE]) 1221 ct->proto.tcp.state = nla_get_u8(tb[CTA_PROTOINFO_TCP_STATE]); 1222 1223 if (tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]) { 1224 struct nf_ct_tcp_flags *attr = 1225 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_ORIGINAL]); 1226 ct->proto.tcp.seen[0].flags &= ~attr->mask; 1227 ct->proto.tcp.seen[0].flags |= attr->flags & attr->mask; 1228 } 1229 1230 if (tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]) { 1231 struct nf_ct_tcp_flags *attr = 1232 nla_data(tb[CTA_PROTOINFO_TCP_FLAGS_REPLY]); 1233 ct->proto.tcp.seen[1].flags &= ~attr->mask; 1234 ct->proto.tcp.seen[1].flags |= attr->flags & attr->mask; 1235 } 1236 1237 if (tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL] && 1238 tb[CTA_PROTOINFO_TCP_WSCALE_REPLY] && 1239 ct->proto.tcp.seen[0].flags & IP_CT_TCP_FLAG_WINDOW_SCALE && 1240 ct->proto.tcp.seen[1].flags & IP_CT_TCP_FLAG_WINDOW_SCALE) { 1241 ct->proto.tcp.seen[0].td_scale = 1242 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_ORIGINAL]); 1243 ct->proto.tcp.seen[1].td_scale = 1244 nla_get_u8(tb[CTA_PROTOINFO_TCP_WSCALE_REPLY]); 1245 } 1246 spin_unlock_bh(&ct->lock); 1247 1248 return 0; 1249} 1250 1251static int tcp_nlattr_size(void) 1252{ 1253 return nla_total_size(0) /* CTA_PROTOINFO_TCP */ 1254 + nla_policy_len(tcp_nla_policy, CTA_PROTOINFO_TCP_MAX + 1); 1255} 1256 1257static int tcp_nlattr_tuple_size(void) 1258{ 1259 return nla_policy_len(nf_ct_port_nla_policy, CTA_PROTO_MAX + 1); 1260} 1261#endif 1262 1263#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 1264 1265#include <linux/netfilter/nfnetlink.h> 1266#include <linux/netfilter/nfnetlink_cttimeout.h> 1267 1268static int tcp_timeout_nlattr_to_obj(struct nlattr *tb[], 1269 struct net *net, void *data) 1270{ 1271 unsigned int *timeouts = data; 1272 struct nf_tcp_net *tn = tcp_pernet(net); 1273 int i; 1274 1275 /* set default TCP timeouts. */ 1276 for (i=0; i<TCP_CONNTRACK_TIMEOUT_MAX; i++) 1277 timeouts[i] = tn->timeouts[i]; 1278 1279 if (tb[CTA_TIMEOUT_TCP_SYN_SENT]) { 1280 timeouts[TCP_CONNTRACK_SYN_SENT] = 1281 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT]))*HZ; 1282 } 1283 if (tb[CTA_TIMEOUT_TCP_SYN_RECV]) { 1284 timeouts[TCP_CONNTRACK_SYN_RECV] = 1285 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_RECV]))*HZ; 1286 } 1287 if (tb[CTA_TIMEOUT_TCP_ESTABLISHED]) { 1288 timeouts[TCP_CONNTRACK_ESTABLISHED] = 1289 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_ESTABLISHED]))*HZ; 1290 } 1291 if (tb[CTA_TIMEOUT_TCP_FIN_WAIT]) { 1292 timeouts[TCP_CONNTRACK_FIN_WAIT] = 1293 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_FIN_WAIT]))*HZ; 1294 } 1295 if (tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]) { 1296 timeouts[TCP_CONNTRACK_CLOSE_WAIT] = 1297 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE_WAIT]))*HZ; 1298 } 1299 if (tb[CTA_TIMEOUT_TCP_LAST_ACK]) { 1300 timeouts[TCP_CONNTRACK_LAST_ACK] = 1301 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_LAST_ACK]))*HZ; 1302 } 1303 if (tb[CTA_TIMEOUT_TCP_TIME_WAIT]) { 1304 timeouts[TCP_CONNTRACK_TIME_WAIT] = 1305 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_TIME_WAIT]))*HZ; 1306 } 1307 if (tb[CTA_TIMEOUT_TCP_CLOSE]) { 1308 timeouts[TCP_CONNTRACK_CLOSE] = 1309 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_CLOSE]))*HZ; 1310 } 1311 if (tb[CTA_TIMEOUT_TCP_SYN_SENT2]) { 1312 timeouts[TCP_CONNTRACK_SYN_SENT2] = 1313 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_SYN_SENT2]))*HZ; 1314 } 1315 if (tb[CTA_TIMEOUT_TCP_RETRANS]) { 1316 timeouts[TCP_CONNTRACK_RETRANS] = 1317 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_RETRANS]))*HZ; 1318 } 1319 if (tb[CTA_TIMEOUT_TCP_UNACK]) { 1320 timeouts[TCP_CONNTRACK_UNACK] = 1321 ntohl(nla_get_be32(tb[CTA_TIMEOUT_TCP_UNACK]))*HZ; 1322 } 1323 return 0; 1324} 1325 1326static int 1327tcp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data) 1328{ 1329 const unsigned int *timeouts = data; 1330 1331 if (nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT, 1332 htonl(timeouts[TCP_CONNTRACK_SYN_SENT] / HZ)) || 1333 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_RECV, 1334 htonl(timeouts[TCP_CONNTRACK_SYN_RECV] / HZ)) || 1335 nla_put_be32(skb, CTA_TIMEOUT_TCP_ESTABLISHED, 1336 htonl(timeouts[TCP_CONNTRACK_ESTABLISHED] / HZ)) || 1337 nla_put_be32(skb, CTA_TIMEOUT_TCP_FIN_WAIT, 1338 htonl(timeouts[TCP_CONNTRACK_FIN_WAIT] / HZ)) || 1339 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE_WAIT, 1340 htonl(timeouts[TCP_CONNTRACK_CLOSE_WAIT] / HZ)) || 1341 nla_put_be32(skb, CTA_TIMEOUT_TCP_LAST_ACK, 1342 htonl(timeouts[TCP_CONNTRACK_LAST_ACK] / HZ)) || 1343 nla_put_be32(skb, CTA_TIMEOUT_TCP_TIME_WAIT, 1344 htonl(timeouts[TCP_CONNTRACK_TIME_WAIT] / HZ)) || 1345 nla_put_be32(skb, CTA_TIMEOUT_TCP_CLOSE, 1346 htonl(timeouts[TCP_CONNTRACK_CLOSE] / HZ)) || 1347 nla_put_be32(skb, CTA_TIMEOUT_TCP_SYN_SENT2, 1348 htonl(timeouts[TCP_CONNTRACK_SYN_SENT2] / HZ)) || 1349 nla_put_be32(skb, CTA_TIMEOUT_TCP_RETRANS, 1350 htonl(timeouts[TCP_CONNTRACK_RETRANS] / HZ)) || 1351 nla_put_be32(skb, CTA_TIMEOUT_TCP_UNACK, 1352 htonl(timeouts[TCP_CONNTRACK_UNACK] / HZ))) 1353 goto nla_put_failure; 1354 return 0; 1355 1356nla_put_failure: 1357 return -ENOSPC; 1358} 1359 1360static const struct nla_policy tcp_timeout_nla_policy[CTA_TIMEOUT_TCP_MAX+1] = { 1361 [CTA_TIMEOUT_TCP_SYN_SENT] = { .type = NLA_U32 }, 1362 [CTA_TIMEOUT_TCP_SYN_RECV] = { .type = NLA_U32 }, 1363 [CTA_TIMEOUT_TCP_ESTABLISHED] = { .type = NLA_U32 }, 1364 [CTA_TIMEOUT_TCP_FIN_WAIT] = { .type = NLA_U32 }, 1365 [CTA_TIMEOUT_TCP_CLOSE_WAIT] = { .type = NLA_U32 }, 1366 [CTA_TIMEOUT_TCP_LAST_ACK] = { .type = NLA_U32 }, 1367 [CTA_TIMEOUT_TCP_TIME_WAIT] = { .type = NLA_U32 }, 1368 [CTA_TIMEOUT_TCP_CLOSE] = { .type = NLA_U32 }, 1369 [CTA_TIMEOUT_TCP_SYN_SENT2] = { .type = NLA_U32 }, 1370 [CTA_TIMEOUT_TCP_RETRANS] = { .type = NLA_U32 }, 1371 [CTA_TIMEOUT_TCP_UNACK] = { .type = NLA_U32 }, 1372}; 1373#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ 1374 1375#ifdef CONFIG_SYSCTL 1376static struct ctl_table tcp_sysctl_table[] = { 1377 { 1378 .procname = "nf_conntrack_tcp_timeout_syn_sent", 1379 .maxlen = sizeof(unsigned int), 1380 .mode = 0644, 1381 .proc_handler = proc_dointvec_jiffies, 1382 }, 1383 { 1384 .procname = "nf_conntrack_tcp_timeout_syn_recv", 1385 .maxlen = sizeof(unsigned int), 1386 .mode = 0644, 1387 .proc_handler = proc_dointvec_jiffies, 1388 }, 1389 { 1390 .procname = "nf_conntrack_tcp_timeout_established", 1391 .maxlen = sizeof(unsigned int), 1392 .mode = 0644, 1393 .proc_handler = proc_dointvec_jiffies, 1394 }, 1395 { 1396 .procname = "nf_conntrack_tcp_timeout_fin_wait", 1397 .maxlen = sizeof(unsigned int), 1398 .mode = 0644, 1399 .proc_handler = proc_dointvec_jiffies, 1400 }, 1401 { 1402 .procname = "nf_conntrack_tcp_timeout_close_wait", 1403 .maxlen = sizeof(unsigned int), 1404 .mode = 0644, 1405 .proc_handler = proc_dointvec_jiffies, 1406 }, 1407 { 1408 .procname = "nf_conntrack_tcp_timeout_last_ack", 1409 .maxlen = sizeof(unsigned int), 1410 .mode = 0644, 1411 .proc_handler = proc_dointvec_jiffies, 1412 }, 1413 { 1414 .procname = "nf_conntrack_tcp_timeout_time_wait", 1415 .maxlen = sizeof(unsigned int), 1416 .mode = 0644, 1417 .proc_handler = proc_dointvec_jiffies, 1418 }, 1419 { 1420 .procname = "nf_conntrack_tcp_timeout_close", 1421 .maxlen = sizeof(unsigned int), 1422 .mode = 0644, 1423 .proc_handler = proc_dointvec_jiffies, 1424 }, 1425 { 1426 .procname = "nf_conntrack_tcp_timeout_max_retrans", 1427 .maxlen = sizeof(unsigned int), 1428 .mode = 0644, 1429 .proc_handler = proc_dointvec_jiffies, 1430 }, 1431 { 1432 .procname = "nf_conntrack_tcp_timeout_unacknowledged", 1433 .maxlen = sizeof(unsigned int), 1434 .mode = 0644, 1435 .proc_handler = proc_dointvec_jiffies, 1436 }, 1437 { 1438 .procname = "nf_conntrack_tcp_loose", 1439 .maxlen = sizeof(unsigned int), 1440 .mode = 0644, 1441 .proc_handler = proc_dointvec, 1442 }, 1443 { 1444 .procname = "nf_conntrack_tcp_be_liberal", 1445 .maxlen = sizeof(unsigned int), 1446 .mode = 0644, 1447 .proc_handler = proc_dointvec, 1448 }, 1449 { 1450 .procname = "nf_conntrack_tcp_max_retrans", 1451 .maxlen = sizeof(unsigned int), 1452 .mode = 0644, 1453 .proc_handler = proc_dointvec, 1454 }, 1455 { } 1456}; 1457 1458#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT 1459static struct ctl_table tcp_compat_sysctl_table[] = { 1460 { 1461 .procname = "ip_conntrack_tcp_timeout_syn_sent", 1462 .maxlen = sizeof(unsigned int), 1463 .mode = 0644, 1464 .proc_handler = proc_dointvec_jiffies, 1465 }, 1466 { 1467 .procname = "ip_conntrack_tcp_timeout_syn_sent2", 1468 .maxlen = sizeof(unsigned int), 1469 .mode = 0644, 1470 .proc_handler = proc_dointvec_jiffies, 1471 }, 1472 { 1473 .procname = "ip_conntrack_tcp_timeout_syn_recv", 1474 .maxlen = sizeof(unsigned int), 1475 .mode = 0644, 1476 .proc_handler = proc_dointvec_jiffies, 1477 }, 1478 { 1479 .procname = "ip_conntrack_tcp_timeout_established", 1480 .maxlen = sizeof(unsigned int), 1481 .mode = 0644, 1482 .proc_handler = proc_dointvec_jiffies, 1483 }, 1484 { 1485 .procname = "ip_conntrack_tcp_timeout_fin_wait", 1486 .maxlen = sizeof(unsigned int), 1487 .mode = 0644, 1488 .proc_handler = proc_dointvec_jiffies, 1489 }, 1490 { 1491 .procname = "ip_conntrack_tcp_timeout_close_wait", 1492 .maxlen = sizeof(unsigned int), 1493 .mode = 0644, 1494 .proc_handler = proc_dointvec_jiffies, 1495 }, 1496 { 1497 .procname = "ip_conntrack_tcp_timeout_last_ack", 1498 .maxlen = sizeof(unsigned int), 1499 .mode = 0644, 1500 .proc_handler = proc_dointvec_jiffies, 1501 }, 1502 { 1503 .procname = "ip_conntrack_tcp_timeout_time_wait", 1504 .maxlen = sizeof(unsigned int), 1505 .mode = 0644, 1506 .proc_handler = proc_dointvec_jiffies, 1507 }, 1508 { 1509 .procname = "ip_conntrack_tcp_timeout_close", 1510 .maxlen = sizeof(unsigned int), 1511 .mode = 0644, 1512 .proc_handler = proc_dointvec_jiffies, 1513 }, 1514 { 1515 .procname = "ip_conntrack_tcp_timeout_max_retrans", 1516 .maxlen = sizeof(unsigned int), 1517 .mode = 0644, 1518 .proc_handler = proc_dointvec_jiffies, 1519 }, 1520 { 1521 .procname = "ip_conntrack_tcp_loose", 1522 .maxlen = sizeof(unsigned int), 1523 .mode = 0644, 1524 .proc_handler = proc_dointvec, 1525 }, 1526 { 1527 .procname = "ip_conntrack_tcp_be_liberal", 1528 .maxlen = sizeof(unsigned int), 1529 .mode = 0644, 1530 .proc_handler = proc_dointvec, 1531 }, 1532 { 1533 .procname = "ip_conntrack_tcp_max_retrans", 1534 .maxlen = sizeof(unsigned int), 1535 .mode = 0644, 1536 .proc_handler = proc_dointvec, 1537 }, 1538 { } 1539}; 1540#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */ 1541#endif /* CONFIG_SYSCTL */ 1542 1543static int tcp_kmemdup_sysctl_table(struct nf_proto_net *pn, 1544 struct nf_tcp_net *tn) 1545{ 1546#ifdef CONFIG_SYSCTL 1547 if (pn->ctl_table) 1548 return 0; 1549 1550 pn->ctl_table = kmemdup(tcp_sysctl_table, 1551 sizeof(tcp_sysctl_table), 1552 GFP_KERNEL); 1553 if (!pn->ctl_table) 1554 return -ENOMEM; 1555 1556 pn->ctl_table[0].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT]; 1557 pn->ctl_table[1].data = &tn->timeouts[TCP_CONNTRACK_SYN_RECV]; 1558 pn->ctl_table[2].data = &tn->timeouts[TCP_CONNTRACK_ESTABLISHED]; 1559 pn->ctl_table[3].data = &tn->timeouts[TCP_CONNTRACK_FIN_WAIT]; 1560 pn->ctl_table[4].data = &tn->timeouts[TCP_CONNTRACK_CLOSE_WAIT]; 1561 pn->ctl_table[5].data = &tn->timeouts[TCP_CONNTRACK_LAST_ACK]; 1562 pn->ctl_table[6].data = &tn->timeouts[TCP_CONNTRACK_TIME_WAIT]; 1563 pn->ctl_table[7].data = &tn->timeouts[TCP_CONNTRACK_CLOSE]; 1564 pn->ctl_table[8].data = &tn->timeouts[TCP_CONNTRACK_RETRANS]; 1565 pn->ctl_table[9].data = &tn->timeouts[TCP_CONNTRACK_UNACK]; 1566 pn->ctl_table[10].data = &tn->tcp_loose; 1567 pn->ctl_table[11].data = &tn->tcp_be_liberal; 1568 pn->ctl_table[12].data = &tn->tcp_max_retrans; 1569#endif 1570 return 0; 1571} 1572 1573static int tcp_kmemdup_compat_sysctl_table(struct nf_proto_net *pn, 1574 struct nf_tcp_net *tn) 1575{ 1576#ifdef CONFIG_SYSCTL 1577#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT 1578 pn->ctl_compat_table = kmemdup(tcp_compat_sysctl_table, 1579 sizeof(tcp_compat_sysctl_table), 1580 GFP_KERNEL); 1581 if (!pn->ctl_compat_table) 1582 return -ENOMEM; 1583 1584 pn->ctl_compat_table[0].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT]; 1585 pn->ctl_compat_table[1].data = &tn->timeouts[TCP_CONNTRACK_SYN_SENT2]; 1586 pn->ctl_compat_table[2].data = &tn->timeouts[TCP_CONNTRACK_SYN_RECV]; 1587 pn->ctl_compat_table[3].data = &tn->timeouts[TCP_CONNTRACK_ESTABLISHED]; 1588 pn->ctl_compat_table[4].data = &tn->timeouts[TCP_CONNTRACK_FIN_WAIT]; 1589 pn->ctl_compat_table[5].data = &tn->timeouts[TCP_CONNTRACK_CLOSE_WAIT]; 1590 pn->ctl_compat_table[6].data = &tn->timeouts[TCP_CONNTRACK_LAST_ACK]; 1591 pn->ctl_compat_table[7].data = &tn->timeouts[TCP_CONNTRACK_TIME_WAIT]; 1592 pn->ctl_compat_table[8].data = &tn->timeouts[TCP_CONNTRACK_CLOSE]; 1593 pn->ctl_compat_table[9].data = &tn->timeouts[TCP_CONNTRACK_RETRANS]; 1594 pn->ctl_compat_table[10].data = &tn->tcp_loose; 1595 pn->ctl_compat_table[11].data = &tn->tcp_be_liberal; 1596 pn->ctl_compat_table[12].data = &tn->tcp_max_retrans; 1597#endif 1598#endif 1599 return 0; 1600} 1601 1602static int tcp_init_net(struct net *net, u_int16_t proto) 1603{ 1604 int ret; 1605 struct nf_tcp_net *tn = tcp_pernet(net); 1606 struct nf_proto_net *pn = &tn->pn; 1607 1608 if (!pn->users) { 1609 int i; 1610 1611 for (i = 0; i < TCP_CONNTRACK_TIMEOUT_MAX; i++) 1612 tn->timeouts[i] = tcp_timeouts[i]; 1613 1614 tn->tcp_loose = nf_ct_tcp_loose; 1615 tn->tcp_be_liberal = nf_ct_tcp_be_liberal; 1616 tn->tcp_max_retrans = nf_ct_tcp_max_retrans; 1617 } 1618 1619 if (proto == AF_INET) { 1620 ret = tcp_kmemdup_compat_sysctl_table(pn, tn); 1621 if (ret < 0) 1622 return ret; 1623 1624 ret = tcp_kmemdup_sysctl_table(pn, tn); 1625 if (ret < 0) 1626 nf_ct_kfree_compat_sysctl_table(pn); 1627 } else 1628 ret = tcp_kmemdup_sysctl_table(pn, tn); 1629 1630 return ret; 1631} 1632 1633static struct nf_proto_net *tcp_get_net_proto(struct net *net) 1634{ 1635 return &net->ct.nf_ct_proto.tcp.pn; 1636} 1637 1638struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 __read_mostly = 1639{ 1640 .l3proto = PF_INET, 1641 .l4proto = IPPROTO_TCP, 1642 .name = "tcp", 1643 .pkt_to_tuple = tcp_pkt_to_tuple, 1644 .invert_tuple = tcp_invert_tuple, 1645 .print_tuple = tcp_print_tuple, 1646 .print_conntrack = tcp_print_conntrack, 1647 .packet = tcp_packet, 1648 .get_timeouts = tcp_get_timeouts, 1649 .new = tcp_new, 1650 .error = tcp_error, 1651#if IS_ENABLED(CONFIG_NF_CT_NETLINK) 1652 .to_nlattr = tcp_to_nlattr, 1653 .nlattr_size = tcp_nlattr_size, 1654 .from_nlattr = nlattr_to_tcp, 1655 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, 1656 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, 1657 .nlattr_tuple_size = tcp_nlattr_tuple_size, 1658 .nla_policy = nf_ct_port_nla_policy, 1659#endif 1660#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 1661 .ctnl_timeout = { 1662 .nlattr_to_obj = tcp_timeout_nlattr_to_obj, 1663 .obj_to_nlattr = tcp_timeout_obj_to_nlattr, 1664 .nlattr_max = CTA_TIMEOUT_TCP_MAX, 1665 .obj_size = sizeof(unsigned int) * 1666 TCP_CONNTRACK_TIMEOUT_MAX, 1667 .nla_policy = tcp_timeout_nla_policy, 1668 }, 1669#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ 1670 .init_net = tcp_init_net, 1671 .get_net_proto = tcp_get_net_proto, 1672}; 1673EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4); 1674 1675struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 __read_mostly = 1676{ 1677 .l3proto = PF_INET6, 1678 .l4proto = IPPROTO_TCP, 1679 .name = "tcp", 1680 .pkt_to_tuple = tcp_pkt_to_tuple, 1681 .invert_tuple = tcp_invert_tuple, 1682 .print_tuple = tcp_print_tuple, 1683 .print_conntrack = tcp_print_conntrack, 1684 .packet = tcp_packet, 1685 .get_timeouts = tcp_get_timeouts, 1686 .new = tcp_new, 1687 .error = tcp_error, 1688#if IS_ENABLED(CONFIG_NF_CT_NETLINK) 1689 .to_nlattr = tcp_to_nlattr, 1690 .nlattr_size = tcp_nlattr_size, 1691 .from_nlattr = nlattr_to_tcp, 1692 .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, 1693 .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, 1694 .nlattr_tuple_size = tcp_nlattr_tuple_size, 1695 .nla_policy = nf_ct_port_nla_policy, 1696#endif 1697#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 1698 .ctnl_timeout = { 1699 .nlattr_to_obj = tcp_timeout_nlattr_to_obj, 1700 .obj_to_nlattr = tcp_timeout_obj_to_nlattr, 1701 .nlattr_max = CTA_TIMEOUT_TCP_MAX, 1702 .obj_size = sizeof(unsigned int) * 1703 TCP_CONNTRACK_TIMEOUT_MAX, 1704 .nla_policy = tcp_timeout_nla_policy, 1705 }, 1706#endif /* CONFIG_NF_CT_NETLINK_TIMEOUT */ 1707 .init_net = tcp_init_net, 1708 .get_net_proto = tcp_get_net_proto, 1709}; 1710EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6); 1711