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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * ip_vs_proto_tcp.c: TCP load balancing support for IPVS | |
3 | * | |
1da177e4 LT |
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 | * | |
4a85b96c | 12 | * Changes: Hans Schillstrom <hans.schillstrom@ericsson.com> |
1da177e4 | 13 | * |
4a85b96c HS |
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 | |
1da177e4 LT |
18 | */ |
19 | ||
9aada7ac HE |
20 | #define KMSG_COMPONENT "IPVS" |
21 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
22 | ||
1da177e4 LT |
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 */ | |
63f2c046 | 28 | #include <net/ip6_checksum.h> |
af1e1cf0 | 29 | #include <linux/netfilter.h> |
1da177e4 LT |
30 | #include <linux/netfilter_ipv4.h> |
31 | ||
32 | #include <net/ip_vs.h> | |
33 | ||
1da177e4 | 34 | static int |
9330419d | 35 | tcp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd, |
d4383f04 JDB |
36 | int *verdict, struct ip_vs_conn **cpp, |
37 | struct ip_vs_iphdr *iph) | |
1da177e4 | 38 | { |
fc723250 | 39 | struct net *net; |
1da177e4 LT |
40 | struct ip_vs_service *svc; |
41 | struct tcphdr _tcph, *th; | |
42 | ||
d4383f04 | 43 | th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph); |
1da177e4 LT |
44 | if (th == NULL) { |
45 | *verdict = NF_DROP; | |
46 | return 0; | |
47 | } | |
fc723250 | 48 | net = skb_net(skb); |
190ecd27 | 49 | /* No !th->ack check to allow scheduling on SYN+ACK for Active FTP */ |
ceec4c38 | 50 | rcu_read_lock(); |
1da177e4 | 51 | if (th->syn && |
ceec4c38 JA |
52 | (svc = ip_vs_service_find(net, af, skb->mark, iph->protocol, |
53 | &iph->daddr, th->dest))) { | |
190ecd27 JA |
54 | int ignored; |
55 | ||
a0840e2e | 56 | if (ip_vs_todrop(net_ipvs(net))) { |
1da177e4 LT |
57 | /* |
58 | * It seems that we are very loaded. | |
59 | * We have to drop this packet :( | |
60 | */ | |
ceec4c38 | 61 | rcu_read_unlock(); |
1da177e4 LT |
62 | *verdict = NF_DROP; |
63 | return 0; | |
64 | } | |
65 | ||
66 | /* | |
67 | * Let the virtual server select a real server for the | |
68 | * incoming connection, and create a connection entry. | |
69 | */ | |
d4383f04 | 70 | *cpp = ip_vs_schedule(svc, skb, pd, &ignored, iph); |
a5959d53 HS |
71 | if (!*cpp && ignored <= 0) { |
72 | if (!ignored) | |
d4383f04 | 73 | *verdict = ip_vs_leave(svc, skb, pd, iph); |
ceec4c38 | 74 | else |
a5959d53 | 75 | *verdict = NF_DROP; |
ceec4c38 | 76 | rcu_read_unlock(); |
1da177e4 LT |
77 | return 0; |
78 | } | |
1da177e4 | 79 | } |
ceec4c38 | 80 | rcu_read_unlock(); |
a5959d53 | 81 | /* NF_ACCEPT */ |
1da177e4 LT |
82 | return 1; |
83 | } | |
84 | ||
85 | ||
86 | static inline void | |
0bbdd42b JV |
87 | tcp_fast_csum_update(int af, struct tcphdr *tcph, |
88 | const union nf_inet_addr *oldip, | |
89 | const union nf_inet_addr *newip, | |
014d730d | 90 | __be16 oldport, __be16 newport) |
1da177e4 | 91 | { |
0bbdd42b JV |
92 | #ifdef CONFIG_IP_VS_IPV6 |
93 | if (af == AF_INET6) | |
94 | tcph->check = | |
95 | csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, | |
96 | ip_vs_check_diff2(oldport, newport, | |
97 | ~csum_unfold(tcph->check)))); | |
98 | else | |
99 | #endif | |
1da177e4 | 100 | tcph->check = |
0bbdd42b | 101 | csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, |
f9214b26 AV |
102 | ip_vs_check_diff2(oldport, newport, |
103 | ~csum_unfold(tcph->check)))); | |
1da177e4 LT |
104 | } |
105 | ||
106 | ||
503e81f6 SH |
107 | static inline void |
108 | tcp_partial_csum_update(int af, struct tcphdr *tcph, | |
109 | const union nf_inet_addr *oldip, | |
110 | const union nf_inet_addr *newip, | |
111 | __be16 oldlen, __be16 newlen) | |
112 | { | |
113 | #ifdef CONFIG_IP_VS_IPV6 | |
114 | if (af == AF_INET6) | |
115 | tcph->check = | |
5bc9068e | 116 | ~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6, |
503e81f6 | 117 | ip_vs_check_diff2(oldlen, newlen, |
5bc9068e | 118 | csum_unfold(tcph->check)))); |
503e81f6 SH |
119 | else |
120 | #endif | |
121 | tcph->check = | |
5bc9068e | 122 | ~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip, |
503e81f6 | 123 | ip_vs_check_diff2(oldlen, newlen, |
5bc9068e | 124 | csum_unfold(tcph->check)))); |
503e81f6 SH |
125 | } |
126 | ||
127 | ||
1da177e4 | 128 | static int |
d4383f04 JDB |
129 | tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, |
130 | struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) | |
1da177e4 LT |
131 | { |
132 | struct tcphdr *tcph; | |
d4383f04 | 133 | unsigned int tcphoff = iph->len; |
503e81f6 | 134 | int oldlen; |
8b27b10f | 135 | int payload_csum = 0; |
0bbdd42b JV |
136 | |
137 | #ifdef CONFIG_IP_VS_IPV6 | |
d4383f04 | 138 | if (cp->af == AF_INET6 && iph->fragoffs) |
63dca2c0 | 139 | return 1; |
0bbdd42b | 140 | #endif |
503e81f6 | 141 | oldlen = skb->len - tcphoff; |
1da177e4 LT |
142 | |
143 | /* csum_check requires unshared skb */ | |
3db05fea | 144 | if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
1da177e4 LT |
145 | return 0; |
146 | ||
147 | if (unlikely(cp->app != NULL)) { | |
8b27b10f JA |
148 | int ret; |
149 | ||
1da177e4 | 150 | /* Some checks before mangling */ |
0bbdd42b | 151 | if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) |
1da177e4 LT |
152 | return 0; |
153 | ||
154 | /* Call application helper if needed */ | |
8b27b10f | 155 | if (!(ret = ip_vs_app_pkt_out(cp, skb))) |
1da177e4 | 156 | return 0; |
8b27b10f JA |
157 | /* ret=2: csum update is needed after payload mangling */ |
158 | if (ret == 1) | |
159 | oldlen = skb->len - tcphoff; | |
160 | else | |
161 | payload_csum = 1; | |
1da177e4 LT |
162 | } |
163 | ||
0bbdd42b | 164 | tcph = (void *)skb_network_header(skb) + tcphoff; |
1da177e4 LT |
165 | tcph->source = cp->vport; |
166 | ||
167 | /* Adjust TCP checksums */ | |
503e81f6 SH |
168 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
169 | tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, | |
ca62059b HH |
170 | htons(oldlen), |
171 | htons(skb->len - tcphoff)); | |
8b27b10f | 172 | } else if (!payload_csum) { |
1da177e4 | 173 | /* Only port and addr are changed, do fast csum update */ |
0bbdd42b | 174 | tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, |
1da177e4 | 175 | cp->dport, cp->vport); |
3db05fea | 176 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
8b27b10f JA |
177 | skb->ip_summed = (cp->app && pp->csum_check) ? |
178 | CHECKSUM_UNNECESSARY : CHECKSUM_NONE; | |
1da177e4 LT |
179 | } else { |
180 | /* full checksum calculation */ | |
181 | tcph->check = 0; | |
3db05fea | 182 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
0bbdd42b JV |
183 | #ifdef CONFIG_IP_VS_IPV6 |
184 | if (cp->af == AF_INET6) | |
185 | tcph->check = csum_ipv6_magic(&cp->vaddr.in6, | |
186 | &cp->caddr.in6, | |
187 | skb->len - tcphoff, | |
188 | cp->protocol, skb->csum); | |
189 | else | |
190 | #endif | |
191 | tcph->check = csum_tcpudp_magic(cp->vaddr.ip, | |
192 | cp->caddr.ip, | |
193 | skb->len - tcphoff, | |
194 | cp->protocol, | |
195 | skb->csum); | |
8b27b10f | 196 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
0bbdd42b | 197 | |
1da177e4 LT |
198 | IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", |
199 | pp->name, tcph->check, | |
200 | (char*)&(tcph->check) - (char*)tcph); | |
201 | } | |
202 | return 1; | |
203 | } | |
204 | ||
205 | ||
206 | static int | |
d4383f04 JDB |
207 | tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp, |
208 | struct ip_vs_conn *cp, struct ip_vs_iphdr *iph) | |
1da177e4 LT |
209 | { |
210 | struct tcphdr *tcph; | |
d4383f04 | 211 | unsigned int tcphoff = iph->len; |
503e81f6 | 212 | int oldlen; |
8b27b10f | 213 | int payload_csum = 0; |
0bbdd42b JV |
214 | |
215 | #ifdef CONFIG_IP_VS_IPV6 | |
d4383f04 | 216 | if (cp->af == AF_INET6 && iph->fragoffs) |
63dca2c0 | 217 | return 1; |
0bbdd42b | 218 | #endif |
503e81f6 | 219 | oldlen = skb->len - tcphoff; |
1da177e4 LT |
220 | |
221 | /* csum_check requires unshared skb */ | |
3db05fea | 222 | if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
1da177e4 LT |
223 | return 0; |
224 | ||
225 | if (unlikely(cp->app != NULL)) { | |
8b27b10f JA |
226 | int ret; |
227 | ||
1da177e4 | 228 | /* Some checks before mangling */ |
0bbdd42b | 229 | if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) |
1da177e4 LT |
230 | return 0; |
231 | ||
232 | /* | |
233 | * Attempt ip_vs_app call. | |
234 | * It will fix ip_vs_conn and iph ack_seq stuff | |
235 | */ | |
8b27b10f | 236 | if (!(ret = ip_vs_app_pkt_in(cp, skb))) |
1da177e4 | 237 | return 0; |
8b27b10f JA |
238 | /* ret=2: csum update is needed after payload mangling */ |
239 | if (ret == 1) | |
240 | oldlen = skb->len - tcphoff; | |
241 | else | |
242 | payload_csum = 1; | |
1da177e4 LT |
243 | } |
244 | ||
0bbdd42b | 245 | tcph = (void *)skb_network_header(skb) + tcphoff; |
1da177e4 LT |
246 | tcph->dest = cp->dport; |
247 | ||
248 | /* | |
249 | * Adjust TCP checksums | |
250 | */ | |
503e81f6 | 251 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
5bc9068e | 252 | tcp_partial_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, |
ca62059b HH |
253 | htons(oldlen), |
254 | htons(skb->len - tcphoff)); | |
8b27b10f | 255 | } else if (!payload_csum) { |
1da177e4 | 256 | /* Only port and addr are changed, do fast csum update */ |
0bbdd42b | 257 | tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, |
1da177e4 | 258 | cp->vport, cp->dport); |
3db05fea | 259 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
8b27b10f JA |
260 | skb->ip_summed = (cp->app && pp->csum_check) ? |
261 | CHECKSUM_UNNECESSARY : CHECKSUM_NONE; | |
1da177e4 LT |
262 | } else { |
263 | /* full checksum calculation */ | |
264 | tcph->check = 0; | |
3db05fea | 265 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
0bbdd42b JV |
266 | #ifdef CONFIG_IP_VS_IPV6 |
267 | if (cp->af == AF_INET6) | |
268 | tcph->check = csum_ipv6_magic(&cp->caddr.in6, | |
269 | &cp->daddr.in6, | |
270 | skb->len - tcphoff, | |
271 | cp->protocol, skb->csum); | |
272 | else | |
273 | #endif | |
274 | tcph->check = csum_tcpudp_magic(cp->caddr.ip, | |
275 | cp->daddr.ip, | |
276 | skb->len - tcphoff, | |
277 | cp->protocol, | |
278 | skb->csum); | |
3db05fea | 279 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 LT |
280 | } |
281 | return 1; | |
282 | } | |
283 | ||
284 | ||
285 | static int | |
51ef348b | 286 | tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp) |
1da177e4 | 287 | { |
51ef348b JV |
288 | unsigned int tcphoff; |
289 | ||
290 | #ifdef CONFIG_IP_VS_IPV6 | |
291 | if (af == AF_INET6) | |
292 | tcphoff = sizeof(struct ipv6hdr); | |
293 | else | |
294 | #endif | |
295 | tcphoff = ip_hdrlen(skb); | |
1da177e4 LT |
296 | |
297 | switch (skb->ip_summed) { | |
298 | case CHECKSUM_NONE: | |
299 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); | |
84fa7933 | 300 | case CHECKSUM_COMPLETE: |
51ef348b JV |
301 | #ifdef CONFIG_IP_VS_IPV6 |
302 | if (af == AF_INET6) { | |
303 | if (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, | |
304 | &ipv6_hdr(skb)->daddr, | |
305 | skb->len - tcphoff, | |
306 | ipv6_hdr(skb)->nexthdr, | |
307 | skb->csum)) { | |
0d79641a | 308 | IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, |
51ef348b JV |
309 | "Failed checksum for"); |
310 | return 0; | |
311 | } | |
312 | } else | |
313 | #endif | |
314 | if (csum_tcpudp_magic(ip_hdr(skb)->saddr, | |
315 | ip_hdr(skb)->daddr, | |
316 | skb->len - tcphoff, | |
317 | ip_hdr(skb)->protocol, | |
318 | skb->csum)) { | |
0d79641a | 319 | IP_VS_DBG_RL_PKT(0, af, pp, skb, 0, |
51ef348b JV |
320 | "Failed checksum for"); |
321 | return 0; | |
322 | } | |
1da177e4 LT |
323 | break; |
324 | default: | |
84fa7933 | 325 | /* No need to checksum. */ |
1da177e4 LT |
326 | break; |
327 | } | |
328 | ||
329 | return 1; | |
330 | } | |
331 | ||
332 | ||
333 | #define TCP_DIR_INPUT 0 | |
334 | #define TCP_DIR_OUTPUT 4 | |
335 | #define TCP_DIR_INPUT_ONLY 8 | |
336 | ||
9b5b5cff | 337 | static const int tcp_state_off[IP_VS_DIR_LAST] = { |
1da177e4 LT |
338 | [IP_VS_DIR_INPUT] = TCP_DIR_INPUT, |
339 | [IP_VS_DIR_OUTPUT] = TCP_DIR_OUTPUT, | |
340 | [IP_VS_DIR_INPUT_ONLY] = TCP_DIR_INPUT_ONLY, | |
341 | }; | |
342 | ||
343 | /* | |
344 | * Timeout table[state] | |
345 | */ | |
4a85b96c | 346 | static const int tcp_timeouts[IP_VS_TCP_S_LAST+1] = { |
1da177e4 LT |
347 | [IP_VS_TCP_S_NONE] = 2*HZ, |
348 | [IP_VS_TCP_S_ESTABLISHED] = 15*60*HZ, | |
349 | [IP_VS_TCP_S_SYN_SENT] = 2*60*HZ, | |
350 | [IP_VS_TCP_S_SYN_RECV] = 1*60*HZ, | |
351 | [IP_VS_TCP_S_FIN_WAIT] = 2*60*HZ, | |
352 | [IP_VS_TCP_S_TIME_WAIT] = 2*60*HZ, | |
353 | [IP_VS_TCP_S_CLOSE] = 10*HZ, | |
354 | [IP_VS_TCP_S_CLOSE_WAIT] = 60*HZ, | |
355 | [IP_VS_TCP_S_LAST_ACK] = 30*HZ, | |
356 | [IP_VS_TCP_S_LISTEN] = 2*60*HZ, | |
357 | [IP_VS_TCP_S_SYNACK] = 120*HZ, | |
358 | [IP_VS_TCP_S_LAST] = 2*HZ, | |
359 | }; | |
360 | ||
36cbd3dc | 361 | static const char *const tcp_state_name_table[IP_VS_TCP_S_LAST+1] = { |
1da177e4 LT |
362 | [IP_VS_TCP_S_NONE] = "NONE", |
363 | [IP_VS_TCP_S_ESTABLISHED] = "ESTABLISHED", | |
364 | [IP_VS_TCP_S_SYN_SENT] = "SYN_SENT", | |
365 | [IP_VS_TCP_S_SYN_RECV] = "SYN_RECV", | |
366 | [IP_VS_TCP_S_FIN_WAIT] = "FIN_WAIT", | |
367 | [IP_VS_TCP_S_TIME_WAIT] = "TIME_WAIT", | |
368 | [IP_VS_TCP_S_CLOSE] = "CLOSE", | |
369 | [IP_VS_TCP_S_CLOSE_WAIT] = "CLOSE_WAIT", | |
370 | [IP_VS_TCP_S_LAST_ACK] = "LAST_ACK", | |
371 | [IP_VS_TCP_S_LISTEN] = "LISTEN", | |
372 | [IP_VS_TCP_S_SYNACK] = "SYNACK", | |
373 | [IP_VS_TCP_S_LAST] = "BUG!", | |
374 | }; | |
375 | ||
376 | #define sNO IP_VS_TCP_S_NONE | |
377 | #define sES IP_VS_TCP_S_ESTABLISHED | |
378 | #define sSS IP_VS_TCP_S_SYN_SENT | |
379 | #define sSR IP_VS_TCP_S_SYN_RECV | |
380 | #define sFW IP_VS_TCP_S_FIN_WAIT | |
381 | #define sTW IP_VS_TCP_S_TIME_WAIT | |
382 | #define sCL IP_VS_TCP_S_CLOSE | |
383 | #define sCW IP_VS_TCP_S_CLOSE_WAIT | |
384 | #define sLA IP_VS_TCP_S_LAST_ACK | |
385 | #define sLI IP_VS_TCP_S_LISTEN | |
386 | #define sSA IP_VS_TCP_S_SYNACK | |
387 | ||
388 | struct tcp_states_t { | |
389 | int next_state[IP_VS_TCP_S_LAST]; | |
390 | }; | |
391 | ||
392 | static const char * tcp_state_name(int state) | |
393 | { | |
394 | if (state >= IP_VS_TCP_S_LAST) | |
395 | return "ERR!"; | |
396 | return tcp_state_name_table[state] ? tcp_state_name_table[state] : "?"; | |
397 | } | |
398 | ||
399 | static struct tcp_states_t tcp_states [] = { | |
400 | /* INPUT */ | |
401 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
402 | /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, | |
403 | /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sTW }}, | |
404 | /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, | |
405 | /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sSR }}, | |
406 | ||
407 | /* OUTPUT */ | |
408 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
409 | /*syn*/ {{sSS, sES, sSS, sSR, sSS, sSS, sSS, sSS, sSS, sLI, sSR }}, | |
410 | /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, | |
411 | /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, | |
412 | /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, | |
413 | ||
414 | /* INPUT-ONLY */ | |
415 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
416 | /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSR }}, | |
417 | /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, | |
418 | /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, | |
419 | /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, | |
420 | }; | |
421 | ||
422 | static struct tcp_states_t tcp_states_dos [] = { | |
423 | /* INPUT */ | |
424 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
425 | /*syn*/ {{sSR, sES, sES, sSR, sSR, sSR, sSR, sSR, sSR, sSR, sSA }}, | |
426 | /*fin*/ {{sCL, sCW, sSS, sTW, sTW, sTW, sCL, sCW, sLA, sLI, sSA }}, | |
427 | /*ack*/ {{sCL, sES, sSS, sSR, sFW, sTW, sCL, sCW, sCL, sLI, sSA }}, | |
428 | /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, | |
429 | ||
430 | /* OUTPUT */ | |
431 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
432 | /*syn*/ {{sSS, sES, sSS, sSA, sSS, sSS, sSS, sSS, sSS, sLI, sSA }}, | |
433 | /*fin*/ {{sTW, sFW, sSS, sTW, sFW, sTW, sCL, sTW, sLA, sLI, sTW }}, | |
434 | /*ack*/ {{sES, sES, sSS, sES, sFW, sTW, sCL, sCW, sLA, sES, sES }}, | |
435 | /*rst*/ {{sCL, sCL, sSS, sCL, sCL, sTW, sCL, sCL, sCL, sCL, sCL }}, | |
436 | ||
437 | /* INPUT-ONLY */ | |
438 | /* sNO, sES, sSS, sSR, sFW, sTW, sCL, sCW, sLA, sLI, sSA */ | |
439 | /*syn*/ {{sSA, sES, sES, sSR, sSA, sSA, sSA, sSA, sSA, sSA, sSA }}, | |
440 | /*fin*/ {{sCL, sFW, sSS, sTW, sFW, sTW, sCL, sCW, sLA, sLI, sTW }}, | |
441 | /*ack*/ {{sCL, sES, sSS, sES, sFW, sTW, sCL, sCW, sCL, sLI, sES }}, | |
442 | /*rst*/ {{sCL, sCL, sCL, sSR, sCL, sCL, sCL, sCL, sLA, sLI, sCL }}, | |
443 | }; | |
444 | ||
9330419d | 445 | static void tcp_timeout_change(struct ip_vs_proto_data *pd, int flags) |
1da177e4 LT |
446 | { |
447 | int on = (flags & 1); /* secure_tcp */ | |
448 | ||
449 | /* | |
450 | ** FIXME: change secure_tcp to independent sysctl var | |
451 | ** or make it per-service or per-app because it is valid | |
452 | ** for most if not for all of the applications. Something | |
453 | ** like "capabilities" (flags) for each object. | |
454 | */ | |
9330419d | 455 | pd->tcp_state_table = (on ? tcp_states_dos : tcp_states); |
1da177e4 LT |
456 | } |
457 | ||
1da177e4 LT |
458 | static inline int tcp_state_idx(struct tcphdr *th) |
459 | { | |
460 | if (th->rst) | |
461 | return 3; | |
462 | if (th->syn) | |
463 | return 0; | |
464 | if (th->fin) | |
465 | return 1; | |
466 | if (th->ack) | |
467 | return 2; | |
468 | return -1; | |
469 | } | |
470 | ||
471 | static inline void | |
9330419d | 472 | set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp, |
1da177e4 LT |
473 | int direction, struct tcphdr *th) |
474 | { | |
475 | int state_idx; | |
476 | int new_state = IP_VS_TCP_S_CLOSE; | |
477 | int state_off = tcp_state_off[direction]; | |
478 | ||
479 | /* | |
480 | * Update state offset to INPUT_ONLY if necessary | |
481 | * or delete NO_OUTPUT flag if output packet detected | |
482 | */ | |
483 | if (cp->flags & IP_VS_CONN_F_NOOUTPUT) { | |
484 | if (state_off == TCP_DIR_OUTPUT) | |
485 | cp->flags &= ~IP_VS_CONN_F_NOOUTPUT; | |
486 | else | |
487 | state_off = TCP_DIR_INPUT_ONLY; | |
488 | } | |
489 | ||
490 | if ((state_idx = tcp_state_idx(th)) < 0) { | |
491 | IP_VS_DBG(8, "tcp_state_idx=%d!!!\n", state_idx); | |
492 | goto tcp_state_out; | |
493 | } | |
494 | ||
9330419d HS |
495 | new_state = |
496 | pd->tcp_state_table[state_off+state_idx].next_state[cp->state]; | |
1da177e4 LT |
497 | |
498 | tcp_state_out: | |
499 | if (new_state != cp->state) { | |
500 | struct ip_vs_dest *dest = cp->dest; | |
501 | ||
cfc78c5a JV |
502 | IP_VS_DBG_BUF(8, "%s %s [%c%c%c%c] %s:%d->" |
503 | "%s:%d state: %s->%s conn->refcnt:%d\n", | |
9330419d | 504 | pd->pp->name, |
cfc78c5a JV |
505 | ((state_off == TCP_DIR_OUTPUT) ? |
506 | "output " : "input "), | |
507 | th->syn ? 'S' : '.', | |
508 | th->fin ? 'F' : '.', | |
509 | th->ack ? 'A' : '.', | |
510 | th->rst ? 'R' : '.', | |
511 | IP_VS_DBG_ADDR(cp->af, &cp->daddr), | |
512 | ntohs(cp->dport), | |
513 | IP_VS_DBG_ADDR(cp->af, &cp->caddr), | |
514 | ntohs(cp->cport), | |
515 | tcp_state_name(cp->state), | |
516 | tcp_state_name(new_state), | |
517 | atomic_read(&cp->refcnt)); | |
518 | ||
1da177e4 LT |
519 | if (dest) { |
520 | if (!(cp->flags & IP_VS_CONN_F_INACTIVE) && | |
521 | (new_state != IP_VS_TCP_S_ESTABLISHED)) { | |
522 | atomic_dec(&dest->activeconns); | |
523 | atomic_inc(&dest->inactconns); | |
524 | cp->flags |= IP_VS_CONN_F_INACTIVE; | |
525 | } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) && | |
526 | (new_state == IP_VS_TCP_S_ESTABLISHED)) { | |
527 | atomic_inc(&dest->activeconns); | |
528 | atomic_dec(&dest->inactconns); | |
529 | cp->flags &= ~IP_VS_CONN_F_INACTIVE; | |
530 | } | |
531 | } | |
532 | } | |
533 | ||
4a85b96c HS |
534 | if (likely(pd)) |
535 | cp->timeout = pd->timeout_table[cp->state = new_state]; | |
536 | else /* What to do ? */ | |
537 | cp->timeout = tcp_timeouts[cp->state = new_state]; | |
1da177e4 LT |
538 | } |
539 | ||
1da177e4 LT |
540 | /* |
541 | * Handle state transitions | |
542 | */ | |
4a516f11 | 543 | static void |
1da177e4 LT |
544 | tcp_state_transition(struct ip_vs_conn *cp, int direction, |
545 | const struct sk_buff *skb, | |
9330419d | 546 | struct ip_vs_proto_data *pd) |
1da177e4 LT |
547 | { |
548 | struct tcphdr _tcph, *th; | |
549 | ||
0bbdd42b JV |
550 | #ifdef CONFIG_IP_VS_IPV6 |
551 | int ihl = cp->af == AF_INET ? ip_hdrlen(skb) : sizeof(struct ipv6hdr); | |
552 | #else | |
553 | int ihl = ip_hdrlen(skb); | |
554 | #endif | |
555 | ||
556 | th = skb_header_pointer(skb, ihl, sizeof(_tcph), &_tcph); | |
1da177e4 | 557 | if (th == NULL) |
4a516f11 | 558 | return; |
1da177e4 LT |
559 | |
560 | spin_lock(&cp->lock); | |
9330419d | 561 | set_tcp_state(pd, cp, direction, th); |
1da177e4 | 562 | spin_unlock(&cp->lock); |
1da177e4 LT |
563 | } |
564 | ||
75e7ce66 | 565 | static inline __u16 tcp_app_hashkey(__be16 port) |
1da177e4 | 566 | { |
75e7ce66 AV |
567 | return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port) |
568 | & TCP_APP_TAB_MASK; | |
1da177e4 LT |
569 | } |
570 | ||
571 | ||
ab8a5e84 | 572 | static int tcp_register_app(struct net *net, struct ip_vs_app *inc) |
1da177e4 LT |
573 | { |
574 | struct ip_vs_app *i; | |
75e7ce66 AV |
575 | __u16 hash; |
576 | __be16 port = inc->port; | |
1da177e4 | 577 | int ret = 0; |
ab8a5e84 HS |
578 | struct netns_ipvs *ipvs = net_ipvs(net); |
579 | struct ip_vs_proto_data *pd = ip_vs_proto_data_get(net, IPPROTO_TCP); | |
1da177e4 LT |
580 | |
581 | hash = tcp_app_hashkey(port); | |
582 | ||
4a85b96c | 583 | list_for_each_entry(i, &ipvs->tcp_apps[hash], p_list) { |
1da177e4 LT |
584 | if (i->port == port) { |
585 | ret = -EEXIST; | |
586 | goto out; | |
587 | } | |
588 | } | |
363c97d7 | 589 | list_add_rcu(&inc->p_list, &ipvs->tcp_apps[hash]); |
9bbac6a9 | 590 | atomic_inc(&pd->appcnt); |
1da177e4 LT |
591 | |
592 | out: | |
1da177e4 LT |
593 | return ret; |
594 | } | |
595 | ||
596 | ||
597 | static void | |
ab8a5e84 | 598 | tcp_unregister_app(struct net *net, struct ip_vs_app *inc) |
1da177e4 | 599 | { |
ab8a5e84 | 600 | struct ip_vs_proto_data *pd = ip_vs_proto_data_get(net, IPPROTO_TCP); |
4a85b96c | 601 | |
9bbac6a9 | 602 | atomic_dec(&pd->appcnt); |
363c97d7 | 603 | list_del_rcu(&inc->p_list); |
1da177e4 LT |
604 | } |
605 | ||
606 | ||
607 | static int | |
608 | tcp_app_conn_bind(struct ip_vs_conn *cp) | |
609 | { | |
6e67e586 | 610 | struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(cp)); |
1da177e4 LT |
611 | int hash; |
612 | struct ip_vs_app *inc; | |
613 | int result = 0; | |
614 | ||
615 | /* Default binding: bind app only for NAT */ | |
616 | if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) | |
617 | return 0; | |
618 | ||
619 | /* Lookup application incarnations and bind the right one */ | |
620 | hash = tcp_app_hashkey(cp->vport); | |
621 | ||
363c97d7 JA |
622 | rcu_read_lock(); |
623 | list_for_each_entry_rcu(inc, &ipvs->tcp_apps[hash], p_list) { | |
1da177e4 LT |
624 | if (inc->port == cp->vport) { |
625 | if (unlikely(!ip_vs_app_inc_get(inc))) | |
626 | break; | |
363c97d7 | 627 | rcu_read_unlock(); |
1da177e4 | 628 | |
1e3e238e | 629 | IP_VS_DBG_BUF(9, "%s(): Binding conn %s:%u->" |
cfc78c5a JV |
630 | "%s:%u to app %s on port %u\n", |
631 | __func__, | |
632 | IP_VS_DBG_ADDR(cp->af, &cp->caddr), | |
633 | ntohs(cp->cport), | |
634 | IP_VS_DBG_ADDR(cp->af, &cp->vaddr), | |
635 | ntohs(cp->vport), | |
636 | inc->name, ntohs(inc->port)); | |
637 | ||
1da177e4 LT |
638 | cp->app = inc; |
639 | if (inc->init_conn) | |
640 | result = inc->init_conn(inc, cp); | |
641 | goto out; | |
642 | } | |
643 | } | |
363c97d7 | 644 | rcu_read_unlock(); |
1da177e4 LT |
645 | |
646 | out: | |
647 | return result; | |
648 | } | |
649 | ||
650 | ||
651 | /* | |
652 | * Set LISTEN timeout. (ip_vs_conn_put will setup timer) | |
653 | */ | |
4a85b96c | 654 | void ip_vs_tcp_conn_listen(struct net *net, struct ip_vs_conn *cp) |
1da177e4 | 655 | { |
4a85b96c HS |
656 | struct ip_vs_proto_data *pd = ip_vs_proto_data_get(net, IPPROTO_TCP); |
657 | ||
1da177e4 LT |
658 | spin_lock(&cp->lock); |
659 | cp->state = IP_VS_TCP_S_LISTEN; | |
4a85b96c HS |
660 | cp->timeout = (pd ? pd->timeout_table[IP_VS_TCP_S_LISTEN] |
661 | : tcp_timeouts[IP_VS_TCP_S_LISTEN]); | |
1da177e4 LT |
662 | spin_unlock(&cp->lock); |
663 | } | |
664 | ||
4a85b96c HS |
665 | /* --------------------------------------------- |
666 | * timeouts is netns related now. | |
667 | * --------------------------------------------- | |
668 | */ | |
582b8e3e | 669 | static int __ip_vs_tcp_init(struct net *net, struct ip_vs_proto_data *pd) |
1da177e4 | 670 | { |
4a85b96c | 671 | struct netns_ipvs *ipvs = net_ipvs(net); |
1da177e4 | 672 | |
4a85b96c | 673 | ip_vs_init_hash_table(ipvs->tcp_apps, TCP_APP_TAB_SIZE); |
4a85b96c HS |
674 | pd->timeout_table = ip_vs_create_timeout_table((int *)tcp_timeouts, |
675 | sizeof(tcp_timeouts)); | |
582b8e3e HS |
676 | if (!pd->timeout_table) |
677 | return -ENOMEM; | |
9330419d | 678 | pd->tcp_state_table = tcp_states; |
582b8e3e | 679 | return 0; |
4a85b96c | 680 | } |
1da177e4 | 681 | |
4a85b96c | 682 | static void __ip_vs_tcp_exit(struct net *net, struct ip_vs_proto_data *pd) |
1da177e4 | 683 | { |
4a85b96c | 684 | kfree(pd->timeout_table); |
1da177e4 LT |
685 | } |
686 | ||
687 | ||
688 | struct ip_vs_protocol ip_vs_protocol_tcp = { | |
689 | .name = "TCP", | |
690 | .protocol = IPPROTO_TCP, | |
2ad17def | 691 | .num_states = IP_VS_TCP_S_LAST, |
1da177e4 | 692 | .dont_defrag = 0, |
4a85b96c HS |
693 | .init = NULL, |
694 | .exit = NULL, | |
695 | .init_netns = __ip_vs_tcp_init, | |
696 | .exit_netns = __ip_vs_tcp_exit, | |
1da177e4 LT |
697 | .register_app = tcp_register_app, |
698 | .unregister_app = tcp_unregister_app, | |
699 | .conn_schedule = tcp_conn_schedule, | |
5c0d2374 SH |
700 | .conn_in_get = ip_vs_conn_in_get_proto, |
701 | .conn_out_get = ip_vs_conn_out_get_proto, | |
1da177e4 LT |
702 | .snat_handler = tcp_snat_handler, |
703 | .dnat_handler = tcp_dnat_handler, | |
704 | .csum_check = tcp_csum_check, | |
705 | .state_name = tcp_state_name, | |
706 | .state_transition = tcp_state_transition, | |
707 | .app_conn_bind = tcp_app_conn_bind, | |
708 | .debug_packet = ip_vs_tcpudp_debug_packet, | |
709 | .timeout_change = tcp_timeout_change, | |
1da177e4 | 710 | }; |