Fix extraneous '&' in recent NFS client cleanup
[linux-2.6/libata-dev.git] / net / ipv4 / ipvs / ip_vs_proto_tcp.c
blobbfe779e74590e14be21af29fa35c6a54551ec231
1 /*
2 * ip_vs_proto_tcp.c: TCP load balancing support for IPVS
4 * Version: $Id: ip_vs_proto_tcp.c,v 1.3 2002/11/30 01:50:35 wensong Exp $
6 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
7 * Julian Anastasov <ja@ssi.bg>
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.
14 * Changes:
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_ipv4.h>
25 #include <net/ip_vs.h>
28 static struct ip_vs_conn *
29 tcp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
30 const struct iphdr *iph, unsigned int proto_off, int inverse)
32 __be16 _ports[2], *pptr;
34 pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
35 if (pptr == NULL)
36 return NULL;
38 if (likely(!inverse)) {
39 return ip_vs_conn_in_get(iph->protocol,
40 iph->saddr, pptr[0],
41 iph->daddr, pptr[1]);
42 } else {
43 return ip_vs_conn_in_get(iph->protocol,
44 iph->daddr, pptr[1],
45 iph->saddr, pptr[0]);
49 static struct ip_vs_conn *
50 tcp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
51 const struct iphdr *iph, unsigned int proto_off, int inverse)
53 __be16 _ports[2], *pptr;
55 pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
56 if (pptr == NULL)
57 return NULL;
59 if (likely(!inverse)) {
60 return ip_vs_conn_out_get(iph->protocol,
61 iph->saddr, pptr[0],
62 iph->daddr, pptr[1]);
63 } else {
64 return ip_vs_conn_out_get(iph->protocol,
65 iph->daddr, pptr[1],
66 iph->saddr, pptr[0]);
71 static int
72 tcp_conn_schedule(struct sk_buff *skb,
73 struct ip_vs_protocol *pp,
74 int *verdict, struct ip_vs_conn **cpp)
76 struct ip_vs_service *svc;
77 struct tcphdr _tcph, *th;
79 th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
80 sizeof(_tcph), &_tcph);
81 if (th == NULL) {
82 *verdict = NF_DROP;
83 return 0;
86 if (th->syn &&
87 (svc = ip_vs_service_get(skb->nfmark, skb->nh.iph->protocol,
88 skb->nh.iph->daddr, th->dest))) {
89 if (ip_vs_todrop()) {
91 * It seems that we are very loaded.
92 * We have to drop this packet :(
94 ip_vs_service_put(svc);
95 *verdict = NF_DROP;
96 return 0;
100 * Let the virtual server select a real server for the
101 * incoming connection, and create a connection entry.
103 *cpp = ip_vs_schedule(svc, skb);
104 if (!*cpp) {
105 *verdict = ip_vs_leave(svc, skb, pp);
106 return 0;
108 ip_vs_service_put(svc);
110 return 1;
114 static inline void
115 tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip,
116 __be16 oldport, __be16 newport)
118 tcph->check =
119 ip_vs_check_diff(~oldip, newip,
120 ip_vs_check_diff(oldport ^ htonl(0xFFFF),
121 newport, tcph->check));
125 static int
126 tcp_snat_handler(struct sk_buff **pskb,
127 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
129 struct tcphdr *tcph;
130 unsigned int tcphoff = (*pskb)->nh.iph->ihl * 4;
132 /* csum_check requires unshared skb */
133 if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
134 return 0;
136 if (unlikely(cp->app != NULL)) {
137 /* Some checks before mangling */
138 if (pp->csum_check && !pp->csum_check(*pskb, pp))
139 return 0;
141 /* Call application helper if needed */
142 if (!ip_vs_app_pkt_out(cp, pskb))
143 return 0;
146 tcph = (void *)(*pskb)->nh.iph + tcphoff;
147 tcph->source = cp->vport;
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 ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
155 (*pskb)->ip_summed = CHECKSUM_NONE;
156 } else {
157 /* full checksum calculation */
158 tcph->check = 0;
159 (*pskb)->csum = skb_checksum(*pskb, tcphoff,
160 (*pskb)->len - tcphoff, 0);
161 tcph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
162 (*pskb)->len - tcphoff,
163 cp->protocol,
164 (*pskb)->csum);
165 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
166 pp->name, tcph->check,
167 (char*)&(tcph->check) - (char*)tcph);
169 return 1;
173 static int
174 tcp_dnat_handler(struct sk_buff **pskb,
175 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
177 struct tcphdr *tcph;
178 unsigned int tcphoff = (*pskb)->nh.iph->ihl * 4;
180 /* csum_check requires unshared skb */
181 if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
182 return 0;
184 if (unlikely(cp->app != NULL)) {
185 /* Some checks before mangling */
186 if (pp->csum_check && !pp->csum_check(*pskb, pp))
187 return 0;
190 * Attempt ip_vs_app call.
191 * It will fix ip_vs_conn and iph ack_seq stuff
193 if (!ip_vs_app_pkt_in(cp, pskb))
194 return 0;
197 tcph = (void *)(*pskb)->nh.iph + tcphoff;
198 tcph->dest = cp->dport;
201 * Adjust TCP checksums
203 if (!cp->app) {
204 /* Only port and addr are changed, do fast csum update */
205 tcp_fast_csum_update(tcph, cp->vaddr, cp->daddr,
206 cp->vport, cp->dport);
207 if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
208 (*pskb)->ip_summed = CHECKSUM_NONE;
209 } else {
210 /* full checksum calculation */
211 tcph->check = 0;
212 (*pskb)->csum = skb_checksum(*pskb, tcphoff,
213 (*pskb)->len - tcphoff, 0);
214 tcph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
215 (*pskb)->len - tcphoff,
216 cp->protocol,
217 (*pskb)->csum);
218 (*pskb)->ip_summed = CHECKSUM_UNNECESSARY;
220 return 1;
224 static int
225 tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
227 unsigned int tcphoff = skb->nh.iph->ihl*4;
229 switch (skb->ip_summed) {
230 case CHECKSUM_NONE:
231 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
232 case CHECKSUM_COMPLETE:
233 if (csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr,
234 skb->len - tcphoff,
235 skb->nh.iph->protocol, skb->csum)) {
236 IP_VS_DBG_RL_PKT(0, pp, skb, 0,
237 "Failed checksum for");
238 return 0;
240 break;
241 default:
242 /* No need to checksum. */
243 break;
246 return 1;
250 #define TCP_DIR_INPUT 0
251 #define TCP_DIR_OUTPUT 4
252 #define TCP_DIR_INPUT_ONLY 8
254 static const int tcp_state_off[IP_VS_DIR_LAST] = {
255 [IP_VS_DIR_INPUT] = TCP_DIR_INPUT,
256 [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT,
257 [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY,
261 * Timeout table[state]
263 static int tcp_timeouts[IP_VS_TCP_S_LAST+1] = {
264 [IP_VS_TCP_S_NONE] = 2*HZ,
265 [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ,
266 [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ,
267 [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ,
268 [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ,
269 [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ,
270 [IP_VS_TCP_S_CLOSE] = 10*HZ,
271 [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ,
272 [IP_VS_TCP_S_LAST_ACK] = 30*HZ,
273 [IP_VS_TCP_S_LISTEN] = 2*60*HZ,
274 [IP_VS_TCP_S_SYNACK] = 120*HZ,
275 [IP_VS_TCP_S_LAST] = 2*HZ,
278 static char * tcp_state_name_table[IP_VS_TCP_S_LAST+1] = {
279 [IP_VS_TCP_S_NONE] = "NONE",
280 [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED",
281 [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT",
282 [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV",
283 [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT",
284 [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT",
285 [IP_VS_TCP_S_CLOSE] = "CLOSE",
286 [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT",
287 [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK",
288 [IP_VS_TCP_S_LISTEN] = "LISTEN",
289 [IP_VS_TCP_S_SYNACK] = "SYNACK",
290 [IP_VS_TCP_S_LAST] = "BUG!",
293 #define sNO IP_VS_TCP_S_NONE
294 #define sES IP_VS_TCP_S_ESTABLISHED
295 #define sSS IP_VS_TCP_S_SYN_SENT
296 #define sSR IP_VS_TCP_S_SYN_RECV
297 #define sFW IP_VS_TCP_S_FIN_WAIT
298 #define sTW IP_VS_TCP_S_TIME_WAIT
299 #define sCL IP_VS_TCP_S_CLOSE
300 #define sCW IP_VS_TCP_S_CLOSE_WAIT
301 #define sLA IP_VS_TCP_S_LAST_ACK
302 #define sLI IP_VS_TCP_S_LISTEN
303 #define sSA IP_VS_TCP_S_SYNACK
305 struct tcp_states_t {
306 int next_state[IP_VS_TCP_S_LAST];
309 static const char * tcp_state_name(int state)
311 if (state >= IP_VS_TCP_S_LAST)
312 return "ERR!";
313 return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?";
316 static struct tcp_states_t tcp_states [] = {
317 /* INPUT */
318 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
319 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
320 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},
321 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
322 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},
324 /* OUTPUT */
325 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
326 /*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},
327 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
328 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
329 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
331 /* INPUT-ONLY */
332 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
333 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
334 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
335 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
336 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
339 static struct tcp_states_t tcp_states_dos [] = {
340 /* INPUT */
341 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
342 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},
343 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},
344 /*ack*/ {{sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},
345 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
347 /* OUTPUT */
348 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
349 /*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},
350 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
351 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
352 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
354 /* INPUT-ONLY */
355 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
356 /*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }},
357 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
358 /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
359 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
362 static struct tcp_states_t *tcp_state_table = tcp_states;
365 static void tcp_timeout_change(struct ip_vs_protocol *pp, int flags)
367 int on = (flags & 1); /* secure_tcp */
370 ** FIXME: change secure_tcp to independent sysctl var
371 ** or make it per-service or per-app because it is valid
372 ** for most if not for all of the applications. Something
373 ** like "capabilities" (flags) for each object.
375 tcp_state_table = (on? tcp_states_dos : tcp_states);
378 static int
379 tcp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
381 return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_TCP_S_LAST,
382 tcp_state_name_table, sname, to);
385 static inline int tcp_state_idx(struct tcphdr *th)
387 if (th->rst)
388 return 3;
389 if (th->syn)
390 return 0;
391 if (th->fin)
392 return 1;
393 if (th->ack)
394 return 2;
395 return -1;
398 static inline void
399 set_tcp_state(struct ip_vs_protocol *pp, struct ip_vs_conn *cp,
400 int direction, struct tcphdr *th)
402 int state_idx;
403 int new_state = IP_VS_TCP_S_CLOSE;
404 int state_off = tcp_state_off[direction];
407 * Update state offset to INPUT_ONLY if necessary
408 * or delete NO_OUTPUT flag if output packet detected
410 if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
411 if (state_off == TCP_DIR_OUTPUT)
412 cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
413 else
414 state_off = TCP_DIR_INPUT_ONLY;
417 if ((state_idx = tcp_state_idx(th)) < 0) {
418 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx);
419 goto tcp_state_out;
422 new_state = tcp_state_table[state_off+state_idx].next_state[cp->state];
424 tcp_state_out:
425 if (new_state != cp->state) {
426 struct ip_vs_dest *dest = cp->dest;
428 IP_VS_DBG(8, "%s %s [%c%c%c%c] %u.%u.%u.%u:%d->"
429 "%u.%u.%u.%u:%d state: %s->%s conn->refcnt:%d\n",
430 pp->name,
431 (state_off==TCP_DIR_OUTPUT)?"output ":"input ",
432 th->syn? 'S' : '.',
433 th->fin? 'F' : '.',
434 th->ack? 'A' : '.',
435 th->rst? 'R' : '.',
436 NIPQUAD(cp->daddr), ntohs(cp->dport),
437 NIPQUAD(cp->caddr), ntohs(cp->cport),
438 tcp_state_name(cp->state),
439 tcp_state_name(new_state),
440 atomic_read(&cp->refcnt));
441 if (dest) {
442 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
443 (new_state != IP_VS_TCP_S_ESTABLISHED)) {
444 atomic_dec(&dest->activeconns);
445 atomic_inc(&dest->inactconns);
446 cp->flags |= IP_VS_CONN_F_INACTIVE;
447 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
448 (new_state == IP_VS_TCP_S_ESTABLISHED)) {
449 atomic_inc(&dest->activeconns);
450 atomic_dec(&dest->inactconns);
451 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
456 cp->timeout = pp->timeout_table[cp->state = new_state];
461 * Handle state transitions
463 static int
464 tcp_state_transition(struct ip_vs_conn *cp, int direction,
465 const struct sk_buff *skb,
466 struct ip_vs_protocol *pp)
468 struct tcphdr _tcph, *th;
470 th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
471 sizeof(_tcph), &_tcph);
472 if (th == NULL)
473 return 0;
475 spin_lock(&cp->lock);
476 set_tcp_state(pp, cp, direction, th);
477 spin_unlock(&cp->lock);
479 return 1;
484 * Hash table for TCP application incarnations
486 #define TCP_APP_TAB_BITS 4
487 #define TCP_APP_TAB_SIZE (1 << TCP_APP_TAB_BITS)
488 #define TCP_APP_TAB_MASK (TCP_APP_TAB_SIZE - 1)
490 static struct list_head tcp_apps[TCP_APP_TAB_SIZE];
491 static DEFINE_SPINLOCK(tcp_app_lock);
493 static inline __u16 tcp_app_hashkey(__u16 port)
495 return ((port >> TCP_APP_TAB_BITS) ^ port) & TCP_APP_TAB_MASK;
499 static int tcp_register_app(struct ip_vs_app *inc)
501 struct ip_vs_app *i;
502 __u16 hash, port = inc->port;
503 int ret = 0;
505 hash = tcp_app_hashkey(port);
507 spin_lock_bh(&tcp_app_lock);
508 list_for_each_entry(i, &tcp_apps[hash], p_list) {
509 if (i->port == port) {
510 ret = -EEXIST;
511 goto out;
514 list_add(&inc->p_list, &tcp_apps[hash]);
515 atomic_inc(&ip_vs_protocol_tcp.appcnt);
517 out:
518 spin_unlock_bh(&tcp_app_lock);
519 return ret;
523 static void
524 tcp_unregister_app(struct ip_vs_app *inc)
526 spin_lock_bh(&tcp_app_lock);
527 atomic_dec(&ip_vs_protocol_tcp.appcnt);
528 list_del(&inc->p_list);
529 spin_unlock_bh(&tcp_app_lock);
533 static int
534 tcp_app_conn_bind(struct ip_vs_conn *cp)
536 int hash;
537 struct ip_vs_app *inc;
538 int result = 0;
540 /* Default binding: bind app only for NAT */
541 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
542 return 0;
544 /* Lookup application incarnations and bind the right one */
545 hash = tcp_app_hashkey(cp->vport);
547 spin_lock(&tcp_app_lock);
548 list_for_each_entry(inc, &tcp_apps[hash], p_list) {
549 if (inc->port == cp->vport) {
550 if (unlikely(!ip_vs_app_inc_get(inc)))
551 break;
552 spin_unlock(&tcp_app_lock);
554 IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->"
555 "%u.%u.%u.%u:%u to app %s on port %u\n",
556 __FUNCTION__,
557 NIPQUAD(cp->caddr), ntohs(cp->cport),
558 NIPQUAD(cp->vaddr), ntohs(cp->vport),
559 inc->name, ntohs(inc->port));
560 cp->app = inc;
561 if (inc->init_conn)
562 result = inc->init_conn(inc, cp);
563 goto out;
566 spin_unlock(&tcp_app_lock);
568 out:
569 return result;
574 * Set LISTEN timeout. (ip_vs_conn_put will setup timer)
576 void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp)
578 spin_lock(&cp->lock);
579 cp->state = IP_VS_TCP_S_LISTEN;
580 cp->timeout = ip_vs_protocol_tcp.timeout_table[IP_VS_TCP_S_LISTEN];
581 spin_unlock(&cp->lock);
585 static void ip_vs_tcp_init(struct ip_vs_protocol *pp)
587 IP_VS_INIT_HASH_TABLE(tcp_apps);
588 pp->timeout_table = tcp_timeouts;
592 static void ip_vs_tcp_exit(struct ip_vs_protocol *pp)
597 struct ip_vs_protocol ip_vs_protocol_tcp = {
598 .name = "TCP",
599 .protocol = IPPROTO_TCP,
600 .dont_defrag = 0,
601 .appcnt = ATOMIC_INIT(0),
602 .init = ip_vs_tcp_init,
603 .exit = ip_vs_tcp_exit,
604 .register_app = tcp_register_app,
605 .unregister_app = tcp_unregister_app,
606 .conn_schedule = tcp_conn_schedule,
607 .conn_in_get = tcp_conn_in_get,
608 .conn_out_get = tcp_conn_out_get,
609 .snat_handler = tcp_snat_handler,
610 .dnat_handler = tcp_dnat_handler,
611 .csum_check = tcp_csum_check,
612 .state_name = tcp_state_name,
613 .state_transition = tcp_state_transition,
614 .app_conn_bind = tcp_app_conn_bind,
615 .debug_packet = ip_vs_tcpudp_debug_packet,
616 .timeout_change = tcp_timeout_change,
617 .set_state_timeout = tcp_set_state_timeout,