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ip_vs_proto_tcp.c
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linux-6.19.14/net/netfilter/ipvs/ip_vs_proto_tcp.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * ip_vs_proto_tcp.c: TCP load balancing support for IPVS 4 * 5 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> 6 * Julian Anastasov <ja@ssi.bg> 7 * 8 * Changes: Hans Schillstrom <hans.schillstrom@ericsson.com> 9 * 10 * Network name space (netns) aware. 11 * Global data moved to netns i.e struct netns_ipvs 12 * tcp_timeouts table has copy per netns in a hash table per 13 * protocol ip_vs_proto_data and is handled by netns 14 */ 15 16#define pr_fmt(fmt) "IPVS: " fmt 17 18#include <linux/kernel.h> 19#include <linux/ip.h> 20#include <linux/tcp.h> /* for tcphdr */ 21#include <net/ip.h> 22#include <net/tcp.h> /* for csum_tcpudp_magic */ 23#include <net/ip6_checksum.h> 24#include <linux/netfilter.h> 25#include <linux/netfilter_ipv4.h> 26#include <linux/indirect_call_wrapper.h> 27 28#include <net/ip_vs.h> 29 30static int 31tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp, 32 unsigned int tcphoff); 33 34static int 35tcp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb, 36 struct ip_vs_proto_data *pd, 37 int *verdict, struct ip_vs_conn **cpp, 38 struct ip_vs_iphdr *iph) 39{ 40 struct ip_vs_service *svc; 41 struct tcphdr _tcph, *th; 42 __be16 _ports[2], *ports = NULL; 43 44 /* In the event of icmp, we're only guaranteed to have the first 8 45 * bytes of the transport header, so we only check the rest of the 46 * TCP packet for non-ICMP packets 47 */ 48 if (likely(!ip_vs_iph_icmp(iph))) { 49 th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); 50 if (th) { 51 if (th->rst || !(sysctl_sloppy_tcp(ipvs) || th->syn)) 52 return 1; 53 ports = &th->source; 54 } 55 } else { 56 ports = skb_header_pointer( 57 skb, iph->len, sizeof(_ports), &_ports); 58 } 59 60 if (!ports) { 61 *verdict = NF_DROP; 62 return 0; 63 } 64 65 /* No !th->ack check to allow scheduling on SYN+ACK for Active FTP */ 66 67 if (likely(!ip_vs_iph_inverse(iph))) 68 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, 69 &iph->daddr, ports[1]); 70 else 71 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol, 72 &iph->saddr, ports[0]); 73 74 if (svc) { 75 int ignored; 76 77 if (ip_vs_todrop(ipvs)) { 78 /* 79 * It seems that we are very loaded. 80 * We have to drop this packet :( 81 */ 82 *verdict = NF_DROP; 83 return 0; 84 } 85 86 /* 87 * Let the virtual server select a real server for the 88 * incoming connection, and create a connection entry. 89 */ 90 *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph); 91 if (!*cpp && ignored <= 0) { 92 if (!ignored) 93 *verdict = ip_vs_leave(svc, skb, pd, iph); 94 else 95 *verdict = NF_DROP; 96 return 0; 97 } 98 } 99 /* NF_ACCEPT */ 100 return 1; 101} 102 103 104static inline void 105tcp_fast_csum_update(int af, struct tcphdr *tcph, 106 const union nf_inet_addr *oldip, 107 const union nf_inet_addr *newip, 108 __be16 oldport, __be16 newport) 109{ 110#ifdef CONFIG_IP_VS_IPV6 111 if (af == AF_INET6) 112 tcph->check = 113 csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, 114 ip_vs_check_diff2(oldport, newport, 115 ~csum_unfold(tcph->check)))); 116 else 117#endif 118 tcph->check = 119 csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, 120 ip_vs_check_diff2(oldport, newport, 121 ~csum_unfold(tcph->check)))); 122} 123 124 125static inline void 126tcp_partial_csum_update(int af, struct tcphdr *tcph, 127 const union nf_inet_addr *oldip, 128 const union nf_inet_addr *newip, 129 __be16 oldlen, __be16 newlen) 130{ 131#ifdef CONFIG_IP_VS_IPV6 132 if (af == AF_INET6) 133 tcph->check = 134 ~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, 135 ip_vs_check_diff2(oldlen, newlen, 136 csum_unfold(tcph->check)))); 137 else 138#endif 139 tcph->check = 140 ~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, 141 ip_vs_check_diff2(oldlen, newlen, 142 csum_unfold(tcph->check)))); 143} 144 145 146INDIRECT_CALLABLE_SCOPE int 147tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, 148 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) 149{ 150 struct tcphdr *tcph; 151 unsigned int tcphoff = iph->len; 152 bool payload_csum = false; 153 int oldlen; 154 155#ifdef CONFIG_IP_VS_IPV6 156 if (cp->af == AF_INET6 && iph->fragoffs) 157 return 1; 158#endif 159 oldlen = skb->len - tcphoff; 160 161 /* csum_check requires unshared skb */ 162 if (skb_ensure_writable(skb, tcphoff + sizeof(*tcph))) 163 return 0; 164 165 if (unlikely(cp->app != NULL)) { 166 int ret; 167 168 /* Some checks before mangling */ 169 if (!tcp_csum_check(cp->af, skb, pp, tcphoff)) 170 return 0; 171 172 /* Call application helper if needed */ 173 if (!(ret = ip_vs_app_pkt_out(cp, skb, iph))) 174 return 0; 175 /* ret=2: csum update is needed after payload mangling */ 176 if (ret == 1) 177 oldlen = skb->len - tcphoff; 178 else 179 payload_csum = true; 180 } 181 182 tcph = (void *)skb_network_header(skb) + tcphoff; 183 tcph->source = cp->vport; 184 185 /* Adjust TCP checksums */ 186 if (skb->ip_summed == CHECKSUM_PARTIAL) { 187 tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, 188 htons(oldlen), 189 htons(skb->len - tcphoff)); 190 } else if (!payload_csum) { 191 /* Only port and addr are changed, do fast csum update */ 192 tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, 193 cp->dport, cp->vport); 194 if (skb->ip_summed == CHECKSUM_COMPLETE) 195 skb->ip_summed = cp->app ? 196 CHECKSUM_UNNECESSARY : CHECKSUM_NONE; 197 } else { 198 /* full checksum calculation */ 199 tcph->check = 0; 200 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); 201#ifdef CONFIG_IP_VS_IPV6 202 if (cp->af == AF_INET6) 203 tcph->check = csum_ipv6_magic(&cp->vaddr.in6, 204 &cp->caddr.in6, 205 skb->len - tcphoff, 206 cp->protocol, skb->csum); 207 else 208#endif 209 tcph->check = csum_tcpudp_magic(cp->vaddr.ip, 210 cp->caddr.ip, 211 skb->len - tcphoff, 212 cp->protocol, 213 skb->csum); 214 skb->ip_summed = CHECKSUM_UNNECESSARY; 215 216 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", 217 pp->name, tcph->check, 218 (char*)&(tcph->check) - (char*)tcph); 219 } 220 return 1; 221} 222 223 224static int 225tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, 226 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) 227{ 228 struct tcphdr *tcph; 229 unsigned int tcphoff = iph->len; 230 bool payload_csum = false; 231 int oldlen; 232 233#ifdef CONFIG_IP_VS_IPV6 234 if (cp->af == AF_INET6 && iph->fragoffs) 235 return 1; 236#endif 237 oldlen = skb->len - tcphoff; 238 239 /* csum_check requires unshared skb */ 240 if (skb_ensure_writable(skb, tcphoff + sizeof(*tcph))) 241 return 0; 242 243 if (unlikely(cp->app != NULL)) { 244 int ret; 245 246 /* Some checks before mangling */ 247 if (!tcp_csum_check(cp->af, skb, pp, tcphoff)) 248 return 0; 249 250 /* 251 * Attempt ip_vs_app call. 252 * It will fix ip_vs_conn and iph ack_seq stuff 253 */ 254 if (!(ret = ip_vs_app_pkt_in(cp, skb, iph))) 255 return 0; 256 /* ret=2: csum update is needed after payload mangling */ 257 if (ret == 1) 258 oldlen = skb->len - tcphoff; 259 else 260 payload_csum = true; 261 } 262 263 tcph = (void *)skb_network_header(skb) + tcphoff; 264 tcph->dest = cp->dport; 265 266 /* 267 * Adjust TCP checksums 268 */ 269 if (skb->ip_summed == CHECKSUM_PARTIAL) { 270 tcp_partial_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, 271 htons(oldlen), 272 htons(skb->len - tcphoff)); 273 } else if (!payload_csum) { 274 /* Only port and addr are changed, do fast csum update */ 275 tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, 276 cp->vport, cp->dport); 277 if (skb->ip_summed == CHECKSUM_COMPLETE) 278 skb->ip_summed = cp->app ? 279 CHECKSUM_UNNECESSARY : CHECKSUM_NONE; 280 } else { 281 /* full checksum calculation */ 282 tcph->check = 0; 283 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); 284#ifdef CONFIG_IP_VS_IPV6 285 if (cp->af == AF_INET6) 286 tcph->check = csum_ipv6_magic(&cp->caddr.in6, 287 &cp->daddr.in6, 288 skb->len - tcphoff, 289 cp->protocol, skb->csum); 290 else 291#endif 292 tcph->check = csum_tcpudp_magic(cp->caddr.ip, 293 cp->daddr.ip, 294 skb->len - tcphoff, 295 cp->protocol, 296 skb->csum); 297 skb->ip_summed = CHECKSUM_UNNECESSARY; 298 } 299 return 1; 300} 301 302 303static int 304tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp, 305 unsigned int tcphoff) 306{ 307 switch (skb->ip_summed) { 308 case CHECKSUM_NONE: 309 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); 310 fallthrough; 311 case CHECKSUM_COMPLETE: 312#ifdef CONFIG_IP_VS_IPV6 313 if (af == AF_INET6) { 314 if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, 315 &ipv6_hdr(skb)->daddr, 316 skb->len - tcphoff, 317 IPPROTO_TCP, 318 skb->csum)) { 319 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, 320 "Failed checksum for"); 321 return 0; 322 } 323 } else 324#endif 325 if (csum_tcpudp_magic(ip_hdr(skb)->saddr, 326 ip_hdr(skb)->daddr, 327 skb->len - tcphoff, 328 ip_hdr(skb)->protocol, 329 skb->csum)) { 330 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, 331 "Failed checksum for"); 332 return 0; 333 } 334 break; 335 default: 336 /* No need to checksum. */ 337 break; 338 } 339 340 return 1; 341} 342 343 344#define TCP_DIR_INPUT 0 345#define TCP_DIR_OUTPUT 4 346#define TCP_DIR_INPUT_ONLY 8 347 348static const int tcp_state_off[IP_VS_DIR_LAST] = { 349 [IP_VS_DIR_INPUT] = TCP_DIR_INPUT, 350 [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT, 351 [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY, 352}; 353 354/* 355 * Timeout table[state] 356 */ 357static const int tcp_timeouts[IP_VS_TCP_S_LAST+1] = { 358 [IP_VS_TCP_S_NONE] = 2*HZ, 359 [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ, 360 [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ, 361 [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ, 362 [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ, 363 [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ, 364 [IP_VS_TCP_S_CLOSE] = 10*HZ, 365 [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ, 366 [IP_VS_TCP_S_LAST_ACK] = 30*HZ, 367 [IP_VS_TCP_S_LISTEN] = 2*60*HZ, 368 [IP_VS_TCP_S_SYNACK] = 120*HZ, 369 [IP_VS_TCP_S_LAST] = 2*HZ, 370}; 371 372static const char *const tcp_state_name_table[IP_VS_TCP_S_LAST+1] = { 373 [IP_VS_TCP_S_NONE] = "NONE", 374 [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED", 375 [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT", 376 [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV", 377 [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT", 378 [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT", 379 [IP_VS_TCP_S_CLOSE] = "CLOSE", 380 [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT", 381 [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK", 382 [IP_VS_TCP_S_LISTEN] = "LISTEN", 383 [IP_VS_TCP_S_SYNACK] = "SYNACK", 384 [IP_VS_TCP_S_LAST] = "BUG!", 385}; 386 387static const bool tcp_state_active_table[IP_VS_TCP_S_LAST] = { 388 [IP_VS_TCP_S_NONE] = false, 389 [IP_VS_TCP_S_ESTABLISHED] = true, 390 [IP_VS_TCP_S_SYN_SENT] = true, 391 [IP_VS_TCP_S_SYN_RECV] = true, 392 [IP_VS_TCP_S_FIN_WAIT] = false, 393 [IP_VS_TCP_S_TIME_WAIT] = false, 394 [IP_VS_TCP_S_CLOSE] = false, 395 [IP_VS_TCP_S_CLOSE_WAIT] = false, 396 [IP_VS_TCP_S_LAST_ACK] = false, 397 [IP_VS_TCP_S_LISTEN] = false, 398 [IP_VS_TCP_S_SYNACK] = true, 399}; 400 401#define sNO IP_VS_TCP_S_NONE 402#define sES IP_VS_TCP_S_ESTABLISHED 403#define sSS IP_VS_TCP_S_SYN_SENT 404#define sSR IP_VS_TCP_S_SYN_RECV 405#define sFW IP_VS_TCP_S_FIN_WAIT 406#define sTW IP_VS_TCP_S_TIME_WAIT 407#define sCL IP_VS_TCP_S_CLOSE 408#define sCW IP_VS_TCP_S_CLOSE_WAIT 409#define sLA IP_VS_TCP_S_LAST_ACK 410#define sLI IP_VS_TCP_S_LISTEN 411#define sSA IP_VS_TCP_S_SYNACK 412 413struct tcp_states_t { 414 int next_state[IP_VS_TCP_S_LAST]; 415}; 416 417static const char * tcp_state_name(int state) 418{ 419 if (state >= IP_VS_TCP_S_LAST) 420 return "ERR!"; 421 return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?"; 422} 423 424static bool tcp_state_active(int state) 425{ 426 if (state >= IP_VS_TCP_S_LAST) 427 return false; 428 return tcp_state_active_table[state]; 429} 430 431static struct tcp_states_t tcp_states[] = { 432/* INPUT */ 433/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 434/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, 435/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }}, 436/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, 437/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }}, 438 439/* OUTPUT */ 440/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 441/*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }}, 442/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, 443/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, 444/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, 445 446/* INPUT-ONLY */ 447/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 448/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, 449/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, 450/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, 451/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, 452}; 453 454static struct tcp_states_t tcp_states_dos[] = { 455/* INPUT */ 456/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 457/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }}, 458/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }}, 459/*ack*/ {{sES, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }}, 460/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, 461 462/* OUTPUT */ 463/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 464/*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }}, 465/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, 466/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, 467/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, 468 469/* INPUT-ONLY */ 470/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ 471/*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }}, 472/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, 473/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, 474/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, 475}; 476 477static void tcp_timeout_change(struct ip_vs_proto_data *pd, int flags) 478{ 479 int on = (flags & 1); /* secure_tcp */ 480 481 /* 482 ** FIXME: change secure_tcp to independent sysctl var 483 ** or make it per-service or per-app because it is valid 484 ** for most if not for all of the applications. Something 485 ** like "capabilities" (flags) for each object. 486 */ 487 pd->tcp_state_table = (on ? tcp_states_dos : tcp_states); 488} 489 490static inline int tcp_state_idx(struct tcphdr *th) 491{ 492 if (th->rst) 493 return 3; 494 if (th->syn) 495 return 0; 496 if (th->fin) 497 return 1; 498 if (th->ack) 499 return 2; 500 return -1; 501} 502 503static inline void 504set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp, 505 int direction, struct tcphdr *th) 506{ 507 int state_idx; 508 int new_state = IP_VS_TCP_S_CLOSE; 509 int state_off = tcp_state_off[direction]; 510 511 /* 512 * Update state offset to INPUT_ONLY if necessary 513 * or delete NO_OUTPUT flag if output packet detected 514 */ 515 if (cp->flags & IP_VS_CONN_F_NOOUTPUT) { 516 if (state_off == TCP_DIR_OUTPUT) 517 cp->flags &= ~IP_VS_CONN_F_NOOUTPUT; 518 else 519 state_off = TCP_DIR_INPUT_ONLY; 520 } 521 522 if ((state_idx = tcp_state_idx(th)) < 0) { 523 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx); 524 goto tcp_state_out; 525 } 526 527 new_state = 528 pd->tcp_state_table[state_off+state_idx].next_state[cp->state]; 529 530 tcp_state_out: 531 if (new_state != cp->state) { 532 struct ip_vs_dest *dest = cp->dest; 533 534 IP_VS_DBG_BUF(8, "%s %s [%c%c%c%c] c:%s:%d v:%s:%d " 535 "d:%s:%d state: %s->%s conn->refcnt:%d\n", 536 pd->pp->name, 537 ((state_off == TCP_DIR_OUTPUT) ? 538 "output " : "input "), 539 th->syn ? 'S' : '.', 540 th->fin ? 'F' : '.', 541 th->ack ? 'A' : '.', 542 th->rst ? 'R' : '.', 543 IP_VS_DBG_ADDR(cp->af, &cp->caddr), 544 ntohs(cp->cport), 545 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), 546 ntohs(cp->vport), 547 IP_VS_DBG_ADDR(cp->daf, &cp->daddr), 548 ntohs(cp->dport), 549 tcp_state_name(cp->state), 550 tcp_state_name(new_state), 551 refcount_read(&cp->refcnt)); 552 553 if (dest) { 554 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) && 555 !tcp_state_active(new_state)) { 556 atomic_dec(&dest->activeconns); 557 atomic_inc(&dest->inactconns); 558 cp->flags |= IP_VS_CONN_F_INACTIVE; 559 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) && 560 tcp_state_active(new_state)) { 561 atomic_inc(&dest->activeconns); 562 atomic_dec(&dest->inactconns); 563 cp->flags &= ~IP_VS_CONN_F_INACTIVE; 564 } 565 } 566 if (new_state == IP_VS_TCP_S_ESTABLISHED) 567 ip_vs_control_assure_ct(cp); 568 } 569 570 if (likely(pd)) 571 cp->timeout = pd->timeout_table[cp->state = new_state]; 572 else /* What to do ? */ 573 cp->timeout = tcp_timeouts[cp->state = new_state]; 574} 575 576/* 577 * Handle state transitions 578 */ 579static void 580tcp_state_transition(struct ip_vs_conn *cp, int direction, 581 const struct sk_buff *skb, 582 struct ip_vs_proto_data *pd) 583{ 584 struct tcphdr _tcph, *th; 585 586#ifdef CONFIG_IP_VS_IPV6 587 int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr); 588#else 589 int ihl = ip_hdrlen(skb); 590#endif 591 592 th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph); 593 if (th == NULL) 594 return; 595 596 spin_lock_bh(&cp->lock); 597 set_tcp_state(pd, cp, direction, th); 598 spin_unlock_bh(&cp->lock); 599} 600 601static inline __u16 tcp_app_hashkey(__be16 port) 602{ 603 return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port) 604 & TCP_APP_TAB_MASK; 605} 606 607 608static int tcp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc) 609{ 610 struct ip_vs_app *i; 611 __u16 hash; 612 __be16 port = inc->port; 613 int ret = 0; 614 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP); 615 616 hash = tcp_app_hashkey(port); 617 618 list_for_each_entry(i, &ipvs->tcp_apps[hash], p_list) { 619 if (i->port == port) { 620 ret = -EEXIST; 621 goto out; 622 } 623 } 624 list_add_rcu(&inc->p_list, &ipvs->tcp_apps[hash]); 625 atomic_inc(&pd->appcnt); 626 627 out: 628 return ret; 629} 630 631 632static void 633tcp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc) 634{ 635 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP); 636 637 atomic_dec(&pd->appcnt); 638 list_del_rcu(&inc->p_list); 639} 640 641 642static int 643tcp_app_conn_bind(struct ip_vs_conn *cp) 644{ 645 struct netns_ipvs *ipvs = cp->ipvs; 646 int hash; 647 struct ip_vs_app *inc; 648 int result = 0; 649 650 /* Default binding: bind app only for NAT */ 651 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) 652 return 0; 653 654 /* Lookup application incarnations and bind the right one */ 655 hash = tcp_app_hashkey(cp->vport); 656 657 list_for_each_entry_rcu(inc, &ipvs->tcp_apps[hash], p_list) { 658 if (inc->port == cp->vport) { 659 if (unlikely(!ip_vs_app_inc_get(inc))) 660 break; 661 662 IP_VS_DBG_BUF(9, "%s(): Binding conn %s:%u->" 663 "%s:%u to app %s on port %u\n", 664 __func__, 665 IP_VS_DBG_ADDR(cp->af, &cp->caddr), 666 ntohs(cp->cport), 667 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), 668 ntohs(cp->vport), 669 inc->name, ntohs(inc->port)); 670 671 cp->app = inc; 672 if (inc->init_conn) 673 result = inc->init_conn(inc, cp); 674 break; 675 } 676 } 677 678 return result; 679} 680 681 682/* 683 * Set LISTEN timeout. (ip_vs_conn_put will setup timer) 684 */ 685void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp) 686{ 687 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(cp->ipvs, IPPROTO_TCP); 688 689 spin_lock_bh(&cp->lock); 690 cp->state = IP_VS_TCP_S_LISTEN; 691 cp->timeout = (pd ? pd->timeout_table[IP_VS_TCP_S_LISTEN] 692 : tcp_timeouts[IP_VS_TCP_S_LISTEN]); 693 spin_unlock_bh(&cp->lock); 694} 695 696/* --------------------------------------------- 697 * timeouts is netns related now. 698 * --------------------------------------------- 699 */ 700static int __ip_vs_tcp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd) 701{ 702 ip_vs_init_hash_table(ipvs->tcp_apps, TCP_APP_TAB_SIZE); 703 pd->timeout_table = ip_vs_create_timeout_table((int *)tcp_timeouts, 704 sizeof(tcp_timeouts)); 705 if (!pd->timeout_table) 706 return -ENOMEM; 707 pd->tcp_state_table = tcp_states; 708 return 0; 709} 710 711static void __ip_vs_tcp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd) 712{ 713 kfree(pd->timeout_table); 714} 715 716 717struct ip_vs_protocol ip_vs_protocol_tcp = { 718 .name = "TCP", 719 .protocol = IPPROTO_TCP, 720 .num_states = IP_VS_TCP_S_LAST, 721 .dont_defrag = 0, 722 .init = NULL, 723 .exit = NULL, 724 .init_netns = __ip_vs_tcp_init, 725 .exit_netns = __ip_vs_tcp_exit, 726 .register_app = tcp_register_app, 727 .unregister_app = tcp_unregister_app, 728 .conn_schedule = tcp_conn_schedule, 729 .conn_in_get = ip_vs_conn_in_get_proto, 730 .conn_out_get = ip_vs_conn_out_get_proto, 731 .snat_handler = tcp_snat_handler, 732 .dnat_handler = tcp_dnat_handler, 733 .state_name = tcp_state_name, 734 .state_transition = tcp_state_transition, 735 .app_conn_bind = tcp_app_conn_bind, 736 .debug_packet = ip_vs_tcpudp_debug_packet, 737 .timeout_change = tcp_timeout_change, 738};
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