net/netfilter/ipvs/ip_vs_proto_tcp.c

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