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