620e40ff79a903c5007682545d29535c07480f0a
[linux-2.6.git] / net / ipv4 / ipvs / ip_vs_proto_tcp.c
1 /*
2  * ip_vs_proto_tcp.c:   TCP load balancing support for IPVS
3  *
4  * Version:     $Id: ip_vs_proto_tcp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
5  *
6  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
7  *              Julian Anastasov <ja@ssi.bg>
8  *
9  *              This program is free software; you can redistribute it and/or
10  *              modify it under the terms of the GNU General Public License
11  *              as published by the Free Software Foundation; either version
12  *              2 of the License, or (at your option) any later version.
13  *
14  * Changes:
15  *
16  */
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 <linux/netfilter.h>
24 #include <linux/netfilter_ipv4.h>
25
26 #include <net/ip_vs.h>
27
28
29 static struct ip_vs_conn *
30 tcp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
31                 const struct iphdr *iph, unsigned int proto_off, int inverse)
32 {
33         __be16 _ports[2], *pptr;
34
35         pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
36         if (pptr == NULL)
37                 return NULL;
38
39         if (likely(!inverse)) {
40                 return ip_vs_conn_in_get(iph->protocol,
41                                          iph->saddr, pptr[0],
42                                          iph->daddr, pptr[1]);
43         } else {
44                 return ip_vs_conn_in_get(iph->protocol,
45                                          iph->daddr, pptr[1],
46                                          iph->saddr, pptr[0]);
47         }
48 }
49
50 static struct ip_vs_conn *
51 tcp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
52                  const struct iphdr *iph, unsigned int proto_off, int inverse)
53 {
54         __be16 _ports[2], *pptr;
55
56         pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
57         if (pptr == NULL)
58                 return NULL;
59
60         if (likely(!inverse)) {
61                 return ip_vs_conn_out_get(iph->protocol,
62                                           iph->saddr, pptr[0],
63                                           iph->daddr, pptr[1]);
64         } else {
65                 return ip_vs_conn_out_get(iph->protocol,
66                                           iph->daddr, pptr[1],
67                                           iph->saddr, pptr[0]);
68         }
69 }
70
71
72 static int
73 tcp_conn_schedule(struct sk_buff *skb,
74                   struct ip_vs_protocol *pp,
75                   int *verdict, struct ip_vs_conn **cpp)
76 {
77         struct ip_vs_service *svc;
78         struct tcphdr _tcph, *th;
79
80         th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
81         if (th == NULL) {
82                 *verdict = NF_DROP;
83                 return 0;
84         }
85
86         if (th->syn &&
87             (svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol,
88                                      ip_hdr(skb)->daddr, th->dest))) {
89                 if (ip_vs_todrop()) {
90                         /*
91                          * It seems that we are very loaded.
92                          * We have to drop this packet :(
93                          */
94                         ip_vs_service_put(svc);
95                         *verdict = NF_DROP;
96                         return 0;
97                 }
98
99                 /*
100                  * Let the virtual server select a real server for the
101                  * incoming connection, and create a connection entry.
102                  */
103                 *cpp = ip_vs_schedule(svc, skb);
104                 if (!*cpp) {
105                         *verdict = ip_vs_leave(svc, skb, pp);
106                         return 0;
107                 }
108                 ip_vs_service_put(svc);
109         }
110         return 1;
111 }
112
113
114 static inline void
115 tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip,
116                      __be16 oldport, __be16 newport)
117 {
118         tcph->check =
119                 csum_fold(ip_vs_check_diff4(oldip, newip,
120                                  ip_vs_check_diff2(oldport, newport,
121                                                 ~csum_unfold(tcph->check))));
122 }
123
124
125 static int
126 tcp_snat_handler(struct sk_buff *skb,
127                  struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
128 {
129         struct tcphdr *tcph;
130         const unsigned int tcphoff = ip_hdrlen(skb);
131
132         /* csum_check requires unshared skb */
133         if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
134                 return 0;
135
136         if (unlikely(cp->app != NULL)) {
137                 /* Some checks before mangling */
138                 if (pp->csum_check && !pp->csum_check(skb, pp))
139                         return 0;
140
141                 /* Call application helper if needed */
142                 if (!ip_vs_app_pkt_out(cp, skb))
143                         return 0;
144         }
145
146         tcph = (void *)ip_hdr(skb) + tcphoff;
147         tcph->source = cp->vport;
148
149         /* Adjust TCP checksums */
150         if (!cp->app) {
151                 /* Only port and addr are changed, do fast csum update */
152                 tcp_fast_csum_update(tcph, cp->daddr, cp->vaddr,
153                                      cp->dport, cp->vport);
154                 if (skb->ip_summed == CHECKSUM_COMPLETE)
155                         skb->ip_summed = CHECKSUM_NONE;
156         } else {
157                 /* full checksum calculation */
158                 tcph->check = 0;
159                 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
160                 tcph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
161                                                 skb->len - tcphoff,
162                                                 cp->protocol, skb->csum);
163                 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
164                           pp->name, tcph->check,
165                           (char*)&(tcph->check) - (char*)tcph);
166         }
167         return 1;
168 }
169
170
171 static int
172 tcp_dnat_handler(struct sk_buff *skb,
173                  struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
174 {
175         struct tcphdr *tcph;
176         const unsigned int tcphoff = ip_hdrlen(skb);
177
178         /* csum_check requires unshared skb */
179         if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
180                 return 0;
181
182         if (unlikely(cp->app != NULL)) {
183                 /* Some checks before mangling */
184                 if (pp->csum_check && !pp->csum_check(skb, pp))
185                         return 0;
186
187                 /*
188                  *      Attempt ip_vs_app call.
189                  *      It will fix ip_vs_conn and iph ack_seq stuff
190                  */
191                 if (!ip_vs_app_pkt_in(cp, skb))
192                         return 0;
193         }
194
195         tcph = (void *)ip_hdr(skb) + tcphoff;
196         tcph->dest = cp->dport;
197
198         /*
199          *      Adjust TCP checksums
200          */
201         if (!cp->app) {
202                 /* Only port and addr are changed, do fast csum update */
203                 tcp_fast_csum_update(tcph, cp->vaddr, cp->daddr,
204                                      cp->vport, cp->dport);
205                 if (skb->ip_summed == CHECKSUM_COMPLETE)
206                         skb->ip_summed = CHECKSUM_NONE;
207         } else {
208                 /* full checksum calculation */
209                 tcph->check = 0;
210                 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
211                 tcph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
212                                                 skb->len - tcphoff,
213                                                 cp->protocol, skb->csum);
214                 skb->ip_summed = CHECKSUM_UNNECESSARY;
215         }
216         return 1;
217 }
218
219
220 static int
221 tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
222 {
223         const unsigned int tcphoff = ip_hdrlen(skb);
224
225         switch (skb->ip_summed) {
226         case CHECKSUM_NONE:
227                 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
228         case CHECKSUM_COMPLETE:
229                 if (csum_tcpudp_magic(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
230                                       skb->len - tcphoff,
231                                       ip_hdr(skb)->protocol, skb->csum)) {
232                         IP_VS_DBG_RL_PKT(0, pp, skb, 0,
233                                          "Failed checksum for");
234                         return 0;
235                 }
236                 break;
237         default:
238                 /* No need to checksum. */
239                 break;
240         }
241
242         return 1;
243 }
244
245
246 #define TCP_DIR_INPUT           0
247 #define TCP_DIR_OUTPUT          4
248 #define TCP_DIR_INPUT_ONLY      8
249
250 static const int tcp_state_off[IP_VS_DIR_LAST] = {
251         [IP_VS_DIR_INPUT]               =       TCP_DIR_INPUT,
252         [IP_VS_DIR_OUTPUT]              =       TCP_DIR_OUTPUT,
253         [IP_VS_DIR_INPUT_ONLY]          =       TCP_DIR_INPUT_ONLY,
254 };
255
256 /*
257  *      Timeout table[state]
258  */
259 static int tcp_timeouts[IP_VS_TCP_S_LAST+1] = {
260         [IP_VS_TCP_S_NONE]              =       2*HZ,
261         [IP_VS_TCP_S_ESTABLISHED]       =       15*60*HZ,
262         [IP_VS_TCP_S_SYN_SENT]          =       2*60*HZ,
263         [IP_VS_TCP_S_SYN_RECV]          =       1*60*HZ,
264         [IP_VS_TCP_S_FIN_WAIT]          =       2*60*HZ,
265         [IP_VS_TCP_S_TIME_WAIT]         =       2*60*HZ,
266         [IP_VS_TCP_S_CLOSE]             =       10*HZ,
267         [IP_VS_TCP_S_CLOSE_WAIT]        =       60*HZ,
268         [IP_VS_TCP_S_LAST_ACK]          =       30*HZ,
269         [IP_VS_TCP_S_LISTEN]            =       2*60*HZ,
270         [IP_VS_TCP_S_SYNACK]            =       120*HZ,
271         [IP_VS_TCP_S_LAST]              =       2*HZ,
272 };
273
274 static char * tcp_state_name_table[IP_VS_TCP_S_LAST+1] = {
275         [IP_VS_TCP_S_NONE]              =       "NONE",
276         [IP_VS_TCP_S_ESTABLISHED]       =       "ESTABLISHED",
277         [IP_VS_TCP_S_SYN_SENT]          =       "SYN_SENT",
278         [IP_VS_TCP_S_SYN_RECV]          =       "SYN_RECV",
279         [IP_VS_TCP_S_FIN_WAIT]          =       "FIN_WAIT",
280         [IP_VS_TCP_S_TIME_WAIT]         =       "TIME_WAIT",
281         [IP_VS_TCP_S_CLOSE]             =       "CLOSE",
282         [IP_VS_TCP_S_CLOSE_WAIT]        =       "CLOSE_WAIT",
283         [IP_VS_TCP_S_LAST_ACK]          =       "LAST_ACK",
284         [IP_VS_TCP_S_LISTEN]            =       "LISTEN",
285         [IP_VS_TCP_S_SYNACK]            =       "SYNACK",
286         [IP_VS_TCP_S_LAST]              =       "BUG!",
287 };
288
289 #define sNO IP_VS_TCP_S_NONE
290 #define sES IP_VS_TCP_S_ESTABLISHED
291 #define sSS IP_VS_TCP_S_SYN_SENT
292 #define sSR IP_VS_TCP_S_SYN_RECV
293 #define sFW IP_VS_TCP_S_FIN_WAIT
294 #define sTW IP_VS_TCP_S_TIME_WAIT
295 #define sCL IP_VS_TCP_S_CLOSE
296 #define sCW IP_VS_TCP_S_CLOSE_WAIT
297 #define sLA IP_VS_TCP_S_LAST_ACK
298 #define sLI IP_VS_TCP_S_LISTEN
299 #define sSA IP_VS_TCP_S_SYNACK
300
301 struct tcp_states_t {
302         int next_state[IP_VS_TCP_S_LAST];
303 };
304
305 static const char * tcp_state_name(int state)
306 {
307         if (state >= IP_VS_TCP_S_LAST)
308                 return "ERR!";
309         return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?";
310 }
311
312 static struct tcp_states_t tcp_states [] = {
313 /*      INPUT */
314 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
315 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
316 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},
317 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
318 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},
319
320 /*      OUTPUT */
321 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
322 /*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},
323 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
324 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
325 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
326
327 /*      INPUT-ONLY */
328 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
329 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
330 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
331 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
332 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
333 };
334
335 static struct tcp_states_t tcp_states_dos [] = {
336 /*      INPUT */
337 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
338 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},
339 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},
340 /*ack*/ {{sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},
341 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
342
343 /*      OUTPUT */
344 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
345 /*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},
346 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
347 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
348 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
349
350 /*      INPUT-ONLY */
351 /*        sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
352 /*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }},
353 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
354 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
355 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
356 };
357
358 static struct tcp_states_t *tcp_state_table = tcp_states;
359
360
361 static void tcp_timeout_change(struct ip_vs_protocol *pp, int flags)
362 {
363         int on = (flags & 1);           /* secure_tcp */
364
365         /*
366         ** FIXME: change secure_tcp to independent sysctl var
367         ** or make it per-service or per-app because it is valid
368         ** for most if not for all of the applications. Something
369         ** like "capabilities" (flags) for each object.
370         */
371         tcp_state_table = (on? tcp_states_dos : tcp_states);
372 }
373
374 static int
375 tcp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
376 {
377         return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_TCP_S_LAST,
378                                        tcp_state_name_table, sname, to);
379 }
380
381 static inline int tcp_state_idx(struct tcphdr *th)
382 {
383         if (th->rst)
384                 return 3;
385         if (th->syn)
386                 return 0;
387         if (th->fin)
388                 return 1;
389         if (th->ack)
390                 return 2;
391         return -1;
392 }
393
394 static inline void
395 set_tcp_state(struct ip_vs_protocol *pp, struct ip_vs_conn *cp,
396               int direction, struct tcphdr *th)
397 {
398         int state_idx;
399         int new_state = IP_VS_TCP_S_CLOSE;
400         int state_off = tcp_state_off[direction];
401
402         /*
403          *    Update state offset to INPUT_ONLY if necessary
404          *    or delete NO_OUTPUT flag if output packet detected
405          */
406         if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
407                 if (state_off == TCP_DIR_OUTPUT)
408                         cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
409                 else
410                         state_off = TCP_DIR_INPUT_ONLY;
411         }
412
413         if ((state_idx = tcp_state_idx(th)) < 0) {
414                 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx);
415                 goto tcp_state_out;
416         }
417
418         new_state = tcp_state_table[state_off+state_idx].next_state[cp->state];
419
420   tcp_state_out:
421         if (new_state != cp->state) {
422                 struct ip_vs_dest *dest = cp->dest;
423
424                 IP_VS_DBG(8, "%s %s [%c%c%c%c] %u.%u.%u.%u:%d->"
425                           "%u.%u.%u.%u:%d state: %s->%s conn->refcnt:%d\n",
426                           pp->name,
427                           (state_off==TCP_DIR_OUTPUT)?"output ":"input ",
428                           th->syn? 'S' : '.',
429                           th->fin? 'F' : '.',
430                           th->ack? 'A' : '.',
431                           th->rst? 'R' : '.',
432                           NIPQUAD(cp->daddr), ntohs(cp->dport),
433                           NIPQUAD(cp->caddr), ntohs(cp->cport),
434                           tcp_state_name(cp->state),
435                           tcp_state_name(new_state),
436                           atomic_read(&cp->refcnt));
437                 if (dest) {
438                         if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
439                             (new_state != IP_VS_TCP_S_ESTABLISHED)) {
440                                 atomic_dec(&dest->activeconns);
441                                 atomic_inc(&dest->inactconns);
442                                 cp->flags |= IP_VS_CONN_F_INACTIVE;
443                         } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
444                                    (new_state == IP_VS_TCP_S_ESTABLISHED)) {
445                                 atomic_inc(&dest->activeconns);
446                                 atomic_dec(&dest->inactconns);
447                                 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
448                         }
449                 }
450         }
451
452         cp->timeout = pp->timeout_table[cp->state = new_state];
453 }
454
455
456 /*
457  *      Handle state transitions
458  */
459 static int
460 tcp_state_transition(struct ip_vs_conn *cp, int direction,
461                      const struct sk_buff *skb,
462                      struct ip_vs_protocol *pp)
463 {
464         struct tcphdr _tcph, *th;
465
466         th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
467         if (th == NULL)
468                 return 0;
469
470         spin_lock(&cp->lock);
471         set_tcp_state(pp, cp, direction, th);
472         spin_unlock(&cp->lock);
473
474         return 1;
475 }
476
477
478 /*
479  *      Hash table for TCP application incarnations
480  */
481 #define TCP_APP_TAB_BITS        4
482 #define TCP_APP_TAB_SIZE        (1 << TCP_APP_TAB_BITS)
483 #define TCP_APP_TAB_MASK        (TCP_APP_TAB_SIZE - 1)
484
485 static struct list_head tcp_apps[TCP_APP_TAB_SIZE];
486 static DEFINE_SPINLOCK(tcp_app_lock);
487
488 static inline __u16 tcp_app_hashkey(__be16 port)
489 {
490         return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port)
491                 & TCP_APP_TAB_MASK;
492 }
493
494
495 static int tcp_register_app(struct ip_vs_app *inc)
496 {
497         struct ip_vs_app *i;
498         __u16 hash;
499         __be16 port = inc->port;
500         int ret = 0;
501
502         hash = tcp_app_hashkey(port);
503
504         spin_lock_bh(&tcp_app_lock);
505         list_for_each_entry(i, &tcp_apps[hash], p_list) {
506                 if (i->port == port) {
507                         ret = -EEXIST;
508                         goto out;
509                 }
510         }
511         list_add(&inc->p_list, &tcp_apps[hash]);
512         atomic_inc(&ip_vs_protocol_tcp.appcnt);
513
514   out:
515         spin_unlock_bh(&tcp_app_lock);
516         return ret;
517 }
518
519
520 static void
521 tcp_unregister_app(struct ip_vs_app *inc)
522 {
523         spin_lock_bh(&tcp_app_lock);
524         atomic_dec(&ip_vs_protocol_tcp.appcnt);
525         list_del(&inc->p_list);
526         spin_unlock_bh(&tcp_app_lock);
527 }
528
529
530 static int
531 tcp_app_conn_bind(struct ip_vs_conn *cp)
532 {
533         int hash;
534         struct ip_vs_app *inc;
535         int result = 0;
536
537         /* Default binding: bind app only for NAT */
538         if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
539                 return 0;
540
541         /* Lookup application incarnations and bind the right one */
542         hash = tcp_app_hashkey(cp->vport);
543
544         spin_lock(&tcp_app_lock);
545         list_for_each_entry(inc, &tcp_apps[hash], p_list) {
546                 if (inc->port == cp->vport) {
547                         if (unlikely(!ip_vs_app_inc_get(inc)))
548                                 break;
549                         spin_unlock(&tcp_app_lock);
550
551                         IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
552                                   "%u.%u.%u.%u:%u to app %s on port %u\n",
553                                   __func__,
554                                   NIPQUAD(cp->caddr), ntohs(cp->cport),
555                                   NIPQUAD(cp->vaddr), ntohs(cp->vport),
556                                   inc->name, ntohs(inc->port));
557                         cp->app = inc;
558                         if (inc->init_conn)
559                                 result = inc->init_conn(inc, cp);
560                         goto out;
561                 }
562         }
563         spin_unlock(&tcp_app_lock);
564
565   out:
566         return result;
567 }
568
569
570 /*
571  *      Set LISTEN timeout. (ip_vs_conn_put will setup timer)
572  */
573 void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp)
574 {
575         spin_lock(&cp->lock);
576         cp->state = IP_VS_TCP_S_LISTEN;
577         cp->timeout = ip_vs_protocol_tcp.timeout_table[IP_VS_TCP_S_LISTEN];
578         spin_unlock(&cp->lock);
579 }
580
581
582 static void ip_vs_tcp_init(struct ip_vs_protocol *pp)
583 {
584         IP_VS_INIT_HASH_TABLE(tcp_apps);
585         pp->timeout_table = tcp_timeouts;
586 }
587
588
589 static void ip_vs_tcp_exit(struct ip_vs_protocol *pp)
590 {
591 }
592
593
594 struct ip_vs_protocol ip_vs_protocol_tcp = {
595         .name =                 "TCP",
596         .protocol =             IPPROTO_TCP,
597         .dont_defrag =          0,
598         .appcnt =               ATOMIC_INIT(0),
599         .init =                 ip_vs_tcp_init,
600         .exit =                 ip_vs_tcp_exit,
601         .register_app =         tcp_register_app,
602         .unregister_app =       tcp_unregister_app,
603         .conn_schedule =        tcp_conn_schedule,
604         .conn_in_get =          tcp_conn_in_get,
605         .conn_out_get =         tcp_conn_out_get,
606         .snat_handler =         tcp_snat_handler,
607         .dnat_handler =         tcp_dnat_handler,
608         .csum_check =           tcp_csum_check,
609         .state_name =           tcp_state_name,
610         .state_transition =     tcp_state_transition,
611         .app_conn_bind =        tcp_app_conn_bind,
612         .debug_packet =         ip_vs_tcpudp_debug_packet,
613         .timeout_change =       tcp_timeout_change,
614         .set_state_timeout =    tcp_set_state_timeout,
615 };