tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_ipv4.h>
24
25#include <net/ip_vs.h>
26
27
28static struct ip_vs_conn *
29tcp_conn_in_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
30 const struct iphdr *iph, unsigned int proto_off, int inverse)
31{
32 __be16 _ports[2], *pptr;
33
34 pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
35 if (pptr == NULL)
36 return NULL;
37
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]);
46 }
47}
48
49static struct ip_vs_conn *
50tcp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp,
51 const struct iphdr *iph, unsigned int proto_off, int inverse)
52{
53 __be16 _ports[2], *pptr;
54
55 pptr = skb_header_pointer(skb, proto_off, sizeof(_ports), _ports);
56 if (pptr == NULL)
57 return NULL;
58
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]);
67 }
68}
69
70
71static int
72tcp_conn_schedule(struct sk_buff *skb,
73 struct ip_vs_protocol *pp,
74 int *verdict, struct ip_vs_conn **cpp)
75{
76 struct ip_vs_service *svc;
77 struct tcphdr _tcph, *th;
78
79 th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
80 if (th == NULL) {
81 *verdict = NF_DROP;
82 return 0;
83 }
84
85 if (th->syn &&
86 (svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol,
87 ip_hdr(skb)->daddr, th->dest))) {
88 if (ip_vs_todrop()) {
89 /*
90 * It seems that we are very loaded.
91 * We have to drop this packet :(
92 */
93 ip_vs_service_put(svc);
94 *verdict = NF_DROP;
95 return 0;
96 }
97
98 /*
99 * Let the virtual server select a real server for the
100 * incoming connection, and create a connection entry.
101 */
102 *cpp = ip_vs_schedule(svc, skb);
103 if (!*cpp) {
104 *verdict = ip_vs_leave(svc, skb, pp);
105 return 0;
106 }
107 ip_vs_service_put(svc);
108 }
109 return 1;
110}
111
112
113static inline void
114tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip,
115 __be16 oldport, __be16 newport)
116{
117 tcph->check =
118 csum_fold(ip_vs_check_diff4(oldip, newip,
119 ip_vs_check_diff2(oldport, newport,
120 ~csum_unfold(tcph->check))));
121}
122
123
124static int
125tcp_snat_handler(struct sk_buff **pskb,
126 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
127{
128 struct tcphdr *tcph;
129 const unsigned int tcphoff = ip_hdrlen(*pskb);
130
131 /* csum_check requires unshared skb */
132 if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
133 return 0;
134
135 if (unlikely(cp->app != NULL)) {
136 /* Some checks before mangling */
137 if (pp->csum_check && !pp->csum_check(*pskb, pp))
138 return 0;
139
140 /* Call application helper if needed */
141 if (!ip_vs_app_pkt_out(cp, pskb))
142 return 0;
143 }
144
145 tcph = (void *)ip_hdr(*pskb) + tcphoff;
146 tcph->source = cp->vport;
147
148 /* Adjust TCP checksums */
149 if (!cp->app) {
150 /* Only port and addr are changed, do fast csum update */
151 tcp_fast_csum_update(tcph, cp->daddr, cp->vaddr,
152 cp->dport, cp->vport);
153 if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
154 (*pskb)->ip_summed = CHECKSUM_NONE;
155 } else {
156 /* full checksum calculation */
157 tcph->check = 0;
158 (*pskb)->csum = skb_checksum(*pskb, tcphoff,
159 (*pskb)->len - tcphoff, 0);
160 tcph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr,
161 (*pskb)->len - tcphoff,
162 cp->protocol,
163 (*pskb)->csum);
164 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
165 pp->name, tcph->check,
166 (char*)&(tcph->check) - (char*)tcph);
167 }
168 return 1;
169}
170
171
172static int
173tcp_dnat_handler(struct sk_buff **pskb,
174 struct ip_vs_protocol *pp, struct ip_vs_conn *cp)
175{
176 struct tcphdr *tcph;
177 const unsigned int tcphoff = ip_hdrlen(*pskb);
178
179 /* csum_check requires unshared skb */
180 if (!ip_vs_make_skb_writable(pskb, tcphoff+sizeof(*tcph)))
181 return 0;
182
183 if (unlikely(cp->app != NULL)) {
184 /* Some checks before mangling */
185 if (pp->csum_check && !pp->csum_check(*pskb, pp))
186 return 0;
187
188 /*
189 * Attempt ip_vs_app call.
190 * It will fix ip_vs_conn and iph ack_seq stuff
191 */
192 if (!ip_vs_app_pkt_in(cp, pskb))
193 return 0;
194 }
195
196 tcph = (void *)ip_hdr(*pskb) + tcphoff;
197 tcph->dest = cp->dport;
198
199 /*
200 * Adjust TCP checksums
201 */
202 if (!cp->app) {
203 /* Only port and addr are changed, do fast csum update */
204 tcp_fast_csum_update(tcph, cp->vaddr, cp->daddr,
205 cp->vport, cp->dport);
206 if ((*pskb)->ip_summed == CHECKSUM_COMPLETE)
207 (*pskb)->ip_summed = CHECKSUM_NONE;
208 } else {
209 /* full checksum calculation */
210 tcph->check = 0;
211 (*pskb)->csum = skb_checksum(*pskb, tcphoff,
212 (*pskb)->len - tcphoff, 0);
213 tcph->check = csum_tcpudp_magic(cp->caddr, cp->daddr,
214 (*pskb)->len - tcphoff,
215 cp->protocol,
216 (*pskb)->csum);
217 (*pskb)->ip_summed = CHECKSUM_UNNECESSARY;
218 }
219 return 1;
220}
221
222
223static int
224tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp)
225{
226 const unsigned int tcphoff = ip_hdrlen(skb);
227
228 switch (skb->ip_summed) {
229 case CHECKSUM_NONE:
230 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
231 case CHECKSUM_COMPLETE:
232 if (csum_tcpudp_magic(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
233 skb->len - tcphoff,
234 ip_hdr(skb)->protocol, skb->csum)) {
235 IP_VS_DBG_RL_PKT(0, pp, skb, 0,
236 "Failed checksum for");
237 return 0;
238 }
239 break;
240 default:
241 /* No need to checksum. */
242 break;
243 }
244
245 return 1;
246}
247
248
249#define TCP_DIR_INPUT 0
250#define TCP_DIR_OUTPUT 4
251#define TCP_DIR_INPUT_ONLY 8
252
253static const int tcp_state_off[IP_VS_DIR_LAST] = {
254 [IP_VS_DIR_INPUT] = TCP_DIR_INPUT,
255 [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT,
256 [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY,
257};
258
259/*
260 * Timeout table[state]
261 */
262static int tcp_timeouts[IP_VS_TCP_S_LAST+1] = {
263 [IP_VS_TCP_S_NONE] = 2*HZ,
264 [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ,
265 [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ,
266 [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ,
267 [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ,
268 [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ,
269 [IP_VS_TCP_S_CLOSE] = 10*HZ,
270 [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ,
271 [IP_VS_TCP_S_LAST_ACK] = 30*HZ,
272 [IP_VS_TCP_S_LISTEN] = 2*60*HZ,
273 [IP_VS_TCP_S_SYNACK] = 120*HZ,
274 [IP_VS_TCP_S_LAST] = 2*HZ,
275};
276
277static char * tcp_state_name_table[IP_VS_TCP_S_LAST+1] = {
278 [IP_VS_TCP_S_NONE] = "NONE",
279 [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED",
280 [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT",
281 [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV",
282 [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT",
283 [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT",
284 [IP_VS_TCP_S_CLOSE] = "CLOSE",
285 [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT",
286 [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK",
287 [IP_VS_TCP_S_LISTEN] = "LISTEN",
288 [IP_VS_TCP_S_SYNACK] = "SYNACK",
289 [IP_VS_TCP_S_LAST] = "BUG!",
290};
291
292#define sNO IP_VS_TCP_S_NONE
293#define sES IP_VS_TCP_S_ESTABLISHED
294#define sSS IP_VS_TCP_S_SYN_SENT
295#define sSR IP_VS_TCP_S_SYN_RECV
296#define sFW IP_VS_TCP_S_FIN_WAIT
297#define sTW IP_VS_TCP_S_TIME_WAIT
298#define sCL IP_VS_TCP_S_CLOSE
299#define sCW IP_VS_TCP_S_CLOSE_WAIT
300#define sLA IP_VS_TCP_S_LAST_ACK
301#define sLI IP_VS_TCP_S_LISTEN
302#define sSA IP_VS_TCP_S_SYNACK
303
304struct tcp_states_t {
305 int next_state[IP_VS_TCP_S_LAST];
306};
307
308static const char * tcp_state_name(int state)
309{
310 if (state >= IP_VS_TCP_S_LAST)
311 return "ERR!";
312 return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?";
313}
314
315static struct tcp_states_t tcp_states [] = {
316/* INPUT */
317/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
318/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
319/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},
320/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
321/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},
322
323/* OUTPUT */
324/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
325/*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},
326/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
327/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
328/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
329
330/* INPUT-ONLY */
331/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
332/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
333/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
334/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
335/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
336};
337
338static struct tcp_states_t tcp_states_dos [] = {
339/* INPUT */
340/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
341/*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},
342/*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},
343/*ack*/ {{sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},
344/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
345
346/* OUTPUT */
347/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
348/*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},
349/*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
350/*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
351/*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
352
353/* INPUT-ONLY */
354/* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
355/*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }},
356/*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
357/*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
358/*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
359};
360
361static struct tcp_states_t *tcp_state_table = tcp_states;
362
363
364static void tcp_timeout_change(struct ip_vs_protocol *pp, int flags)
365{
366 int on = (flags & 1); /* secure_tcp */
367
368 /*
369 ** FIXME: change secure_tcp to independent sysctl var
370 ** or make it per-service or per-app because it is valid
371 ** for most if not for all of the applications. Something
372 ** like "capabilities" (flags) for each object.
373 */
374 tcp_state_table = (on? tcp_states_dos : tcp_states);
375}
376
377static int
378tcp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to)
379{
380 return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_TCP_S_LAST,
381 tcp_state_name_table, sname, to);
382}
383
384static inline int tcp_state_idx(struct tcphdr *th)
385{
386 if (th->rst)
387 return 3;
388 if (th->syn)
389 return 0;
390 if (th->fin)
391 return 1;
392 if (th->ack)
393 return 2;
394 return -1;
395}
396
397static inline void
398set_tcp_state(struct ip_vs_protocol *pp, struct ip_vs_conn *cp,
399 int direction, struct tcphdr *th)
400{
401 int state_idx;
402 int new_state = IP_VS_TCP_S_CLOSE;
403 int state_off = tcp_state_off[direction];
404
405 /*
406 * Update state offset to INPUT_ONLY if necessary
407 * or delete NO_OUTPUT flag if output packet detected
408 */
409 if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
410 if (state_off == TCP_DIR_OUTPUT)
411 cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
412 else
413 state_off = TCP_DIR_INPUT_ONLY;
414 }
415
416 if ((state_idx = tcp_state_idx(th)) < 0) {
417 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx);
418 goto tcp_state_out;
419 }
420
421 new_state = tcp_state_table[state_off+state_idx].next_state[cp->state];
422
423 tcp_state_out:
424 if (new_state != cp->state) {
425 struct ip_vs_dest *dest = cp->dest;
426
427 IP_VS_DBG(8, "%s %s [%c%c%c%c] %u.%u.%u.%u:%d->"
428 "%u.%u.%u.%u:%d state: %s->%s conn->refcnt:%d\n",
429 pp->name,
430 (state_off==TCP_DIR_OUTPUT)?"output ":"input ",
431 th->syn? 'S' : '.',
432 th->fin? 'F' : '.',
433 th->ack? 'A' : '.',
434 th->rst? 'R' : '.',
435 NIPQUAD(cp->daddr), ntohs(cp->dport),
436 NIPQUAD(cp->caddr), ntohs(cp->cport),
437 tcp_state_name(cp->state),
438 tcp_state_name(new_state),
439 atomic_read(&cp->refcnt));
440 if (dest) {
441 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
442 (new_state != IP_VS_TCP_S_ESTABLISHED)) {
443 atomic_dec(&dest->activeconns);
444 atomic_inc(&dest->inactconns);
445 cp->flags |= IP_VS_CONN_F_INACTIVE;
446 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
447 (new_state == IP_VS_TCP_S_ESTABLISHED)) {
448 atomic_inc(&dest->activeconns);
449 atomic_dec(&dest->inactconns);
450 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
451 }
452 }
453 }
454
455 cp->timeout = pp->timeout_table[cp->state = new_state];
456}
457
458
459/*
460 * Handle state transitions
461 */
462static int
463tcp_state_transition(struct ip_vs_conn *cp, int direction,
464 const struct sk_buff *skb,
465 struct ip_vs_protocol *pp)
466{
467 struct tcphdr _tcph, *th;
468
469 th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph);
470 if (th == NULL)
471 return 0;
472
473 spin_lock(&cp->lock);
474 set_tcp_state(pp, cp, direction, th);
475 spin_unlock(&cp->lock);
476
477 return 1;
478}
479
480
481/*
482 * Hash table for TCP application incarnations
483 */
484#define TCP_APP_TAB_BITS 4
485#define TCP_APP_TAB_SIZE (1 << TCP_APP_TAB_BITS)
486#define TCP_APP_TAB_MASK (TCP_APP_TAB_SIZE - 1)
487
488static struct list_head tcp_apps[TCP_APP_TAB_SIZE];
489static DEFINE_SPINLOCK(tcp_app_lock);
490
491static inline __u16 tcp_app_hashkey(__be16 port)
492{
493 return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port)
494 & TCP_APP_TAB_MASK;
495}
496
497
498static int tcp_register_app(struct ip_vs_app *inc)
499{
500 struct ip_vs_app *i;
501 __u16 hash;
502 __be16 port = inc->port;
503 int ret = 0;
504
505 hash = tcp_app_hashkey(port);
506
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;
512 }
513 }
514 list_add(&inc->p_list, &tcp_apps[hash]);
515 atomic_inc(&ip_vs_protocol_tcp.appcnt);
516
517 out:
518 spin_unlock_bh(&tcp_app_lock);
519 return ret;
520}
521
522
523static void
524tcp_unregister_app(struct ip_vs_app *inc)
525{
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);
530}
531
532
533static int
534tcp_app_conn_bind(struct ip_vs_conn *cp)
535{
536 int hash;
537 struct ip_vs_app *inc;
538 int result = 0;
539
540 /* Default binding: bind app only for NAT */
541 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
542 return 0;
543
544 /* Lookup application incarnations and bind the right one */
545 hash = tcp_app_hashkey(cp->vport);
546
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);
553
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;
564 }
565 }
566 spin_unlock(&tcp_app_lock);
567
568 out:
569 return result;
570}
571
572
573/*
574 * Set LISTEN timeout. (ip_vs_conn_put will setup timer)
575 */
576void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp)
577{
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);
582}
583
584
585static void ip_vs_tcp_init(struct ip_vs_protocol *pp)
586{
587 IP_VS_INIT_HASH_TABLE(tcp_apps);
588 pp->timeout_table = tcp_timeouts;
589}
590
591
592static void ip_vs_tcp_exit(struct ip_vs_protocol *pp)
593{
594}
595
596
597struct 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,
618};