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Merge tag 'asoc-fix-v4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni...
[mirror_ubuntu-bionic-kernel.git] / 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(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
36 struct ip_vs_proto_data *pd,
37 int *verdict, struct ip_vs_conn **cpp,
38 struct ip_vs_iphdr *iph)
39 {
40 struct ip_vs_service *svc;
41 struct tcphdr _tcph, *th;
42 __be16 _ports[2], *ports = NULL;
43
44 /* In the event of icmp, we're only guaranteed to have the first 8
45 * bytes of the transport header, so we only check the rest of the
46 * TCP packet for non-ICMP packets
47 */
48 if (likely(!ip_vs_iph_icmp(iph))) {
49 th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph);
50 if (th) {
51 if (th->rst || !(sysctl_sloppy_tcp(ipvs) || th->syn))
52 return 1;
53 ports = &th->source;
54 }
55 } else {
56 ports = skb_header_pointer(
57 skb, iph->len, sizeof(_ports), &_ports);
58 }
59
60 if (!ports) {
61 *verdict = NF_DROP;
62 return 0;
63 }
64
65 /* No !th->ack check to allow scheduling on SYN+ACK for Active FTP */
66 rcu_read_lock();
67
68 if (likely(!ip_vs_iph_inverse(iph)))
69 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
70 &iph->daddr, ports[1]);
71 else
72 svc = ip_vs_service_find(ipvs, af, skb->mark, iph->protocol,
73 &iph->saddr, ports[0]);
74
75 if (svc) {
76 int ignored;
77
78 if (ip_vs_todrop(ipvs)) {
79 /*
80 * It seems that we are very loaded.
81 * We have to drop this packet :(
82 */
83 rcu_read_unlock();
84 *verdict = NF_DROP;
85 return 0;
86 }
87
88 /*
89 * Let the virtual server select a real server for the
90 * incoming connection, and create a connection entry.
91 */
92 *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph);
93 if (!*cpp && ignored <= 0) {
94 if (!ignored)
95 *verdict = ip_vs_leave(svc, skb, pd, iph);
96 else
97 *verdict = NF_DROP;
98 rcu_read_unlock();
99 return 0;
100 }
101 }
102 rcu_read_unlock();
103 /* NF_ACCEPT */
104 return 1;
105 }
106
107
108 static inline void
109 tcp_fast_csum_update(int af, struct tcphdr *tcph,
110 const union nf_inet_addr *oldip,
111 const union nf_inet_addr *newip,
112 __be16 oldport, __be16 newport)
113 {
114 #ifdef CONFIG_IP_VS_IPV6
115 if (af == AF_INET6)
116 tcph->check =
117 csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
118 ip_vs_check_diff2(oldport, newport,
119 ~csum_unfold(tcph->check))));
120 else
121 #endif
122 tcph->check =
123 csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
124 ip_vs_check_diff2(oldport, newport,
125 ~csum_unfold(tcph->check))));
126 }
127
128
129 static inline void
130 tcp_partial_csum_update(int af, struct tcphdr *tcph,
131 const union nf_inet_addr *oldip,
132 const union nf_inet_addr *newip,
133 __be16 oldlen, __be16 newlen)
134 {
135 #ifdef CONFIG_IP_VS_IPV6
136 if (af == AF_INET6)
137 tcph->check =
138 ~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
139 ip_vs_check_diff2(oldlen, newlen,
140 csum_unfold(tcph->check))));
141 else
142 #endif
143 tcph->check =
144 ~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
145 ip_vs_check_diff2(oldlen, newlen,
146 csum_unfold(tcph->check))));
147 }
148
149
150 static int
151 tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
152 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
153 {
154 struct tcphdr *tcph;
155 unsigned int tcphoff = iph->len;
156 int oldlen;
157 int payload_csum = 0;
158
159 #ifdef CONFIG_IP_VS_IPV6
160 if (cp->af == AF_INET6 && iph->fragoffs)
161 return 1;
162 #endif
163 oldlen = skb->len - tcphoff;
164
165 /* csum_check requires unshared skb */
166 if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
167 return 0;
168
169 if (unlikely(cp->app != NULL)) {
170 int ret;
171
172 /* Some checks before mangling */
173 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
174 return 0;
175
176 /* Call application helper if needed */
177 if (!(ret = ip_vs_app_pkt_out(cp, skb)))
178 return 0;
179 /* ret=2: csum update is needed after payload mangling */
180 if (ret == 1)
181 oldlen = skb->len - tcphoff;
182 else
183 payload_csum = 1;
184 }
185
186 tcph = (void *)skb_network_header(skb) + tcphoff;
187 tcph->source = cp->vport;
188
189 /* Adjust TCP checksums */
190 if (skb->ip_summed == CHECKSUM_PARTIAL) {
191 tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
192 htons(oldlen),
193 htons(skb->len - tcphoff));
194 } else if (!payload_csum) {
195 /* Only port and addr are changed, do fast csum update */
196 tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
197 cp->dport, cp->vport);
198 if (skb->ip_summed == CHECKSUM_COMPLETE)
199 skb->ip_summed = (cp->app && pp->csum_check) ?
200 CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
201 } else {
202 /* full checksum calculation */
203 tcph->check = 0;
204 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
205 #ifdef CONFIG_IP_VS_IPV6
206 if (cp->af == AF_INET6)
207 tcph->check = csum_ipv6_magic(&cp->vaddr.in6,
208 &cp->caddr.in6,
209 skb->len - tcphoff,
210 cp->protocol, skb->csum);
211 else
212 #endif
213 tcph->check = csum_tcpudp_magic(cp->vaddr.ip,
214 cp->caddr.ip,
215 skb->len - tcphoff,
216 cp->protocol,
217 skb->csum);
218 skb->ip_summed = CHECKSUM_UNNECESSARY;
219
220 IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n",
221 pp->name, tcph->check,
222 (char*)&(tcph->check) - (char*)tcph);
223 }
224 return 1;
225 }
226
227
228 static int
229 tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
230 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
231 {
232 struct tcphdr *tcph;
233 unsigned int tcphoff = iph->len;
234 int oldlen;
235 int payload_csum = 0;
236
237 #ifdef CONFIG_IP_VS_IPV6
238 if (cp->af == AF_INET6 && iph->fragoffs)
239 return 1;
240 #endif
241 oldlen = skb->len - tcphoff;
242
243 /* csum_check requires unshared skb */
244 if (!skb_make_writable(skb, tcphoff+sizeof(*tcph)))
245 return 0;
246
247 if (unlikely(cp->app != NULL)) {
248 int ret;
249
250 /* Some checks before mangling */
251 if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
252 return 0;
253
254 /*
255 * Attempt ip_vs_app call.
256 * It will fix ip_vs_conn and iph ack_seq stuff
257 */
258 if (!(ret = ip_vs_app_pkt_in(cp, skb)))
259 return 0;
260 /* ret=2: csum update is needed after payload mangling */
261 if (ret == 1)
262 oldlen = skb->len - tcphoff;
263 else
264 payload_csum = 1;
265 }
266
267 tcph = (void *)skb_network_header(skb) + tcphoff;
268 tcph->dest = cp->dport;
269
270 /*
271 * Adjust TCP checksums
272 */
273 if (skb->ip_summed == CHECKSUM_PARTIAL) {
274 tcp_partial_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
275 htons(oldlen),
276 htons(skb->len - tcphoff));
277 } else if (!payload_csum) {
278 /* Only port and addr are changed, do fast csum update */
279 tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
280 cp->vport, cp->dport);
281 if (skb->ip_summed == CHECKSUM_COMPLETE)
282 skb->ip_summed = (cp->app && pp->csum_check) ?
283 CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
284 } else {
285 /* full checksum calculation */
286 tcph->check = 0;
287 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
288 #ifdef CONFIG_IP_VS_IPV6
289 if (cp->af == AF_INET6)
290 tcph->check = csum_ipv6_magic(&cp->caddr.in6,
291 &cp->daddr.in6,
292 skb->len - tcphoff,
293 cp->protocol, skb->csum);
294 else
295 #endif
296 tcph->check = csum_tcpudp_magic(cp->caddr.ip,
297 cp->daddr.ip,
298 skb->len - tcphoff,
299 cp->protocol,
300 skb->csum);
301 skb->ip_summed = CHECKSUM_UNNECESSARY;
302 }
303 return 1;
304 }
305
306
307 static int
308 tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
309 {
310 unsigned int tcphoff;
311
312 #ifdef CONFIG_IP_VS_IPV6
313 if (af == AF_INET6)
314 tcphoff = sizeof(struct ipv6hdr);
315 else
316 #endif
317 tcphoff = ip_hdrlen(skb);
318
319 switch (skb->ip_summed) {
320 case CHECKSUM_NONE:
321 skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0);
322 case CHECKSUM_COMPLETE:
323 #ifdef CONFIG_IP_VS_IPV6
324 if (af == AF_INET6) {
325 if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
326 &ipv6_hdr(skb)->daddr,
327 skb->len - tcphoff,
328 ipv6_hdr(skb)->nexthdr,
329 skb->csum)) {
330 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
331 "Failed checksum for");
332 return 0;
333 }
334 } else
335 #endif
336 if (csum_tcpudp_magic(ip_hdr(skb)->saddr,
337 ip_hdr(skb)->daddr,
338 skb->len - tcphoff,
339 ip_hdr(skb)->protocol,
340 skb->csum)) {
341 IP_VS_DBG_RL_PKT(0, af, pp, skb, 0,
342 "Failed checksum for");
343 return 0;
344 }
345 break;
346 default:
347 /* No need to checksum. */
348 break;
349 }
350
351 return 1;
352 }
353
354
355 #define TCP_DIR_INPUT 0
356 #define TCP_DIR_OUTPUT 4
357 #define TCP_DIR_INPUT_ONLY 8
358
359 static const int tcp_state_off[IP_VS_DIR_LAST] = {
360 [IP_VS_DIR_INPUT] = TCP_DIR_INPUT,
361 [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT,
362 [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY,
363 };
364
365 /*
366 * Timeout table[state]
367 */
368 static const int tcp_timeouts[IP_VS_TCP_S_LAST+1] = {
369 [IP_VS_TCP_S_NONE] = 2*HZ,
370 [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ,
371 [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ,
372 [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ,
373 [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ,
374 [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ,
375 [IP_VS_TCP_S_CLOSE] = 10*HZ,
376 [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ,
377 [IP_VS_TCP_S_LAST_ACK] = 30*HZ,
378 [IP_VS_TCP_S_LISTEN] = 2*60*HZ,
379 [IP_VS_TCP_S_SYNACK] = 120*HZ,
380 [IP_VS_TCP_S_LAST] = 2*HZ,
381 };
382
383 static const char *const tcp_state_name_table[IP_VS_TCP_S_LAST+1] = {
384 [IP_VS_TCP_S_NONE] = "NONE",
385 [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED",
386 [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT",
387 [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV",
388 [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT",
389 [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT",
390 [IP_VS_TCP_S_CLOSE] = "CLOSE",
391 [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT",
392 [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK",
393 [IP_VS_TCP_S_LISTEN] = "LISTEN",
394 [IP_VS_TCP_S_SYNACK] = "SYNACK",
395 [IP_VS_TCP_S_LAST] = "BUG!",
396 };
397
398 #define sNO IP_VS_TCP_S_NONE
399 #define sES IP_VS_TCP_S_ESTABLISHED
400 #define sSS IP_VS_TCP_S_SYN_SENT
401 #define sSR IP_VS_TCP_S_SYN_RECV
402 #define sFW IP_VS_TCP_S_FIN_WAIT
403 #define sTW IP_VS_TCP_S_TIME_WAIT
404 #define sCL IP_VS_TCP_S_CLOSE
405 #define sCW IP_VS_TCP_S_CLOSE_WAIT
406 #define sLA IP_VS_TCP_S_LAST_ACK
407 #define sLI IP_VS_TCP_S_LISTEN
408 #define sSA IP_VS_TCP_S_SYNACK
409
410 struct tcp_states_t {
411 int next_state[IP_VS_TCP_S_LAST];
412 };
413
414 static const char * tcp_state_name(int state)
415 {
416 if (state >= IP_VS_TCP_S_LAST)
417 return "ERR!";
418 return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?";
419 }
420
421 static struct tcp_states_t tcp_states [] = {
422 /* INPUT */
423 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
424 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
425 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }},
426 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
427 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }},
428
429 /* OUTPUT */
430 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
431 /*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }},
432 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
433 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
434 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
435
436 /* INPUT-ONLY */
437 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
438 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }},
439 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
440 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
441 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
442 };
443
444 static struct tcp_states_t tcp_states_dos [] = {
445 /* INPUT */
446 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
447 /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }},
448 /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }},
449 /*ack*/ {{sES, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }},
450 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
451
452 /* OUTPUT */
453 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
454 /*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }},
455 /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }},
456 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }},
457 /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }},
458
459 /* INPUT-ONLY */
460 /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */
461 /*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }},
462 /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }},
463 /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }},
464 /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }},
465 };
466
467 static void tcp_timeout_change(struct ip_vs_proto_data *pd, int flags)
468 {
469 int on = (flags & 1); /* secure_tcp */
470
471 /*
472 ** FIXME: change secure_tcp to independent sysctl var
473 ** or make it per-service or per-app because it is valid
474 ** for most if not for all of the applications. Something
475 ** like "capabilities" (flags) for each object.
476 */
477 pd->tcp_state_table = (on ? tcp_states_dos : tcp_states);
478 }
479
480 static inline int tcp_state_idx(struct tcphdr *th)
481 {
482 if (th->rst)
483 return 3;
484 if (th->syn)
485 return 0;
486 if (th->fin)
487 return 1;
488 if (th->ack)
489 return 2;
490 return -1;
491 }
492
493 static inline void
494 set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
495 int direction, struct tcphdr *th)
496 {
497 int state_idx;
498 int new_state = IP_VS_TCP_S_CLOSE;
499 int state_off = tcp_state_off[direction];
500
501 /*
502 * Update state offset to INPUT_ONLY if necessary
503 * or delete NO_OUTPUT flag if output packet detected
504 */
505 if (cp->flags & IP_VS_CONN_F_NOOUTPUT) {
506 if (state_off == TCP_DIR_OUTPUT)
507 cp->flags &= ~IP_VS_CONN_F_NOOUTPUT;
508 else
509 state_off = TCP_DIR_INPUT_ONLY;
510 }
511
512 if ((state_idx = tcp_state_idx(th)) < 0) {
513 IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx);
514 goto tcp_state_out;
515 }
516
517 new_state =
518 pd->tcp_state_table[state_off+state_idx].next_state[cp->state];
519
520 tcp_state_out:
521 if (new_state != cp->state) {
522 struct ip_vs_dest *dest = cp->dest;
523
524 IP_VS_DBG_BUF(8, "%s %s [%c%c%c%c] %s:%d->"
525 "%s:%d state: %s->%s conn->refcnt:%d\n",
526 pd->pp->name,
527 ((state_off == TCP_DIR_OUTPUT) ?
528 "output " : "input "),
529 th->syn ? 'S' : '.',
530 th->fin ? 'F' : '.',
531 th->ack ? 'A' : '.',
532 th->rst ? 'R' : '.',
533 IP_VS_DBG_ADDR(cp->daf, &cp->daddr),
534 ntohs(cp->dport),
535 IP_VS_DBG_ADDR(cp->af, &cp->caddr),
536 ntohs(cp->cport),
537 tcp_state_name(cp->state),
538 tcp_state_name(new_state),
539 atomic_read(&cp->refcnt));
540
541 if (dest) {
542 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
543 (new_state != IP_VS_TCP_S_ESTABLISHED)) {
544 atomic_dec(&dest->activeconns);
545 atomic_inc(&dest->inactconns);
546 cp->flags |= IP_VS_CONN_F_INACTIVE;
547 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
548 (new_state == IP_VS_TCP_S_ESTABLISHED)) {
549 atomic_inc(&dest->activeconns);
550 atomic_dec(&dest->inactconns);
551 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
552 }
553 }
554 }
555
556 if (likely(pd))
557 cp->timeout = pd->timeout_table[cp->state = new_state];
558 else /* What to do ? */
559 cp->timeout = tcp_timeouts[cp->state = new_state];
560 }
561
562 /*
563 * Handle state transitions
564 */
565 static void
566 tcp_state_transition(struct ip_vs_conn *cp, int direction,
567 const struct sk_buff *skb,
568 struct ip_vs_proto_data *pd)
569 {
570 struct tcphdr _tcph, *th;
571
572 #ifdef CONFIG_IP_VS_IPV6
573 int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr);
574 #else
575 int ihl = ip_hdrlen(skb);
576 #endif
577
578 th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph);
579 if (th == NULL)
580 return;
581
582 spin_lock_bh(&cp->lock);
583 set_tcp_state(pd, cp, direction, th);
584 spin_unlock_bh(&cp->lock);
585 }
586
587 static inline __u16 tcp_app_hashkey(__be16 port)
588 {
589 return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port)
590 & TCP_APP_TAB_MASK;
591 }
592
593
594 static int tcp_register_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
595 {
596 struct ip_vs_app *i;
597 __u16 hash;
598 __be16 port = inc->port;
599 int ret = 0;
600 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP);
601
602 hash = tcp_app_hashkey(port);
603
604 list_for_each_entry(i, &ipvs->tcp_apps[hash], p_list) {
605 if (i->port == port) {
606 ret = -EEXIST;
607 goto out;
608 }
609 }
610 list_add_rcu(&inc->p_list, &ipvs->tcp_apps[hash]);
611 atomic_inc(&pd->appcnt);
612
613 out:
614 return ret;
615 }
616
617
618 static void
619 tcp_unregister_app(struct netns_ipvs *ipvs, struct ip_vs_app *inc)
620 {
621 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP);
622
623 atomic_dec(&pd->appcnt);
624 list_del_rcu(&inc->p_list);
625 }
626
627
628 static int
629 tcp_app_conn_bind(struct ip_vs_conn *cp)
630 {
631 struct netns_ipvs *ipvs = cp->ipvs;
632 int hash;
633 struct ip_vs_app *inc;
634 int result = 0;
635
636 /* Default binding: bind app only for NAT */
637 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
638 return 0;
639
640 /* Lookup application incarnations and bind the right one */
641 hash = tcp_app_hashkey(cp->vport);
642
643 rcu_read_lock();
644 list_for_each_entry_rcu(inc, &ipvs->tcp_apps[hash], p_list) {
645 if (inc->port == cp->vport) {
646 if (unlikely(!ip_vs_app_inc_get(inc)))
647 break;
648 rcu_read_unlock();
649
650 IP_VS_DBG_BUF(9, "%s(): Binding conn %s:%u->"
651 "%s:%u to app %s on port %u\n",
652 __func__,
653 IP_VS_DBG_ADDR(cp->af, &cp->caddr),
654 ntohs(cp->cport),
655 IP_VS_DBG_ADDR(cp->af, &cp->vaddr),
656 ntohs(cp->vport),
657 inc->name, ntohs(inc->port));
658
659 cp->app = inc;
660 if (inc->init_conn)
661 result = inc->init_conn(inc, cp);
662 goto out;
663 }
664 }
665 rcu_read_unlock();
666
667 out:
668 return result;
669 }
670
671
672 /*
673 * Set LISTEN timeout. (ip_vs_conn_put will setup timer)
674 */
675 void ip_vs_tcp_conn_listen(struct ip_vs_conn *cp)
676 {
677 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(cp->ipvs, IPPROTO_TCP);
678
679 spin_lock_bh(&cp->lock);
680 cp->state = IP_VS_TCP_S_LISTEN;
681 cp->timeout = (pd ? pd->timeout_table[IP_VS_TCP_S_LISTEN]
682 : tcp_timeouts[IP_VS_TCP_S_LISTEN]);
683 spin_unlock_bh(&cp->lock);
684 }
685
686 /* ---------------------------------------------
687 * timeouts is netns related now.
688 * ---------------------------------------------
689 */
690 static int __ip_vs_tcp_init(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
691 {
692 ip_vs_init_hash_table(ipvs->tcp_apps, TCP_APP_TAB_SIZE);
693 pd->timeout_table = ip_vs_create_timeout_table((int *)tcp_timeouts,
694 sizeof(tcp_timeouts));
695 if (!pd->timeout_table)
696 return -ENOMEM;
697 pd->tcp_state_table = tcp_states;
698 return 0;
699 }
700
701 static void __ip_vs_tcp_exit(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
702 {
703 kfree(pd->timeout_table);
704 }
705
706
707 struct ip_vs_protocol ip_vs_protocol_tcp = {
708 .name = "TCP",
709 .protocol = IPPROTO_TCP,
710 .num_states = IP_VS_TCP_S_LAST,
711 .dont_defrag = 0,
712 .init = NULL,
713 .exit = NULL,
714 .init_netns = __ip_vs_tcp_init,
715 .exit_netns = __ip_vs_tcp_exit,
716 .register_app = tcp_register_app,
717 .unregister_app = tcp_unregister_app,
718 .conn_schedule = tcp_conn_schedule,
719 .conn_in_get = ip_vs_conn_in_get_proto,
720 .conn_out_get = ip_vs_conn_out_get_proto,
721 .snat_handler = tcp_snat_handler,
722 .dnat_handler = tcp_dnat_handler,
723 .csum_check = tcp_csum_check,
724 .state_name = tcp_state_name,
725 .state_transition = tcp_state_transition,
726 .app_conn_bind = tcp_app_conn_bind,
727 .debug_packet = ip_vs_tcpudp_debug_packet,
728 .timeout_change = tcp_timeout_change,
729 };
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