Commit | Line | Data |
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1da177e4 LT |
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 */ | |
af1e1cf0 | 23 | #include <linux/netfilter.h> |
1da177e4 LT |
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 | { | |
014d730d | 33 | __be16 _ports[2], *pptr; |
1da177e4 LT |
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 | { | |
014d730d | 54 | __be16 _ports[2], *pptr; |
1da177e4 LT |
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 | ||
c9bdd4b5 | 80 | th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); |
1da177e4 LT |
81 | if (th == NULL) { |
82 | *verdict = NF_DROP; | |
83 | return 0; | |
84 | } | |
85 | ||
86 | if (th->syn && | |
eddc9ec5 ACM |
87 | (svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol, |
88 | ip_hdr(skb)->daddr, th->dest))) { | |
1da177e4 LT |
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 | |
014d730d AV |
115 | tcp_fast_csum_update(struct tcphdr *tcph, __be32 oldip, __be32 newip, |
116 | __be16 oldport, __be16 newport) | |
1da177e4 LT |
117 | { |
118 | tcph->check = | |
f9214b26 AV |
119 | csum_fold(ip_vs_check_diff4(oldip, newip, |
120 | ip_vs_check_diff2(oldport, newport, | |
121 | ~csum_unfold(tcph->check)))); | |
1da177e4 LT |
122 | } |
123 | ||
124 | ||
125 | static int | |
3db05fea | 126 | tcp_snat_handler(struct sk_buff *skb, |
1da177e4 LT |
127 | struct ip_vs_protocol *pp, struct ip_vs_conn *cp) |
128 | { | |
129 | struct tcphdr *tcph; | |
3db05fea | 130 | const unsigned int tcphoff = ip_hdrlen(skb); |
1da177e4 LT |
131 | |
132 | /* csum_check requires unshared skb */ | |
3db05fea | 133 | if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
1da177e4 LT |
134 | return 0; |
135 | ||
136 | if (unlikely(cp->app != NULL)) { | |
137 | /* Some checks before mangling */ | |
3db05fea | 138 | if (pp->csum_check && !pp->csum_check(skb, pp)) |
1da177e4 LT |
139 | return 0; |
140 | ||
141 | /* Call application helper if needed */ | |
3db05fea | 142 | if (!ip_vs_app_pkt_out(cp, skb)) |
1da177e4 LT |
143 | return 0; |
144 | } | |
145 | ||
3db05fea | 146 | tcph = (void *)ip_hdr(skb) + tcphoff; |
1da177e4 LT |
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); | |
3db05fea HX |
154 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
155 | skb->ip_summed = CHECKSUM_NONE; | |
1da177e4 LT |
156 | } else { |
157 | /* full checksum calculation */ | |
158 | tcph->check = 0; | |
3db05fea | 159 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
1da177e4 | 160 | tcph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr, |
3db05fea HX |
161 | skb->len - tcphoff, |
162 | cp->protocol, skb->csum); | |
1da177e4 LT |
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 | |
3db05fea | 172 | tcp_dnat_handler(struct sk_buff *skb, |
1da177e4 LT |
173 | struct ip_vs_protocol *pp, struct ip_vs_conn *cp) |
174 | { | |
175 | struct tcphdr *tcph; | |
3db05fea | 176 | const unsigned int tcphoff = ip_hdrlen(skb); |
1da177e4 LT |
177 | |
178 | /* csum_check requires unshared skb */ | |
3db05fea | 179 | if (!skb_make_writable(skb, tcphoff+sizeof(*tcph))) |
1da177e4 LT |
180 | return 0; |
181 | ||
182 | if (unlikely(cp->app != NULL)) { | |
183 | /* Some checks before mangling */ | |
3db05fea | 184 | if (pp->csum_check && !pp->csum_check(skb, pp)) |
1da177e4 LT |
185 | return 0; |
186 | ||
187 | /* | |
188 | * Attempt ip_vs_app call. | |
189 | * It will fix ip_vs_conn and iph ack_seq stuff | |
190 | */ | |
3db05fea | 191 | if (!ip_vs_app_pkt_in(cp, skb)) |
1da177e4 LT |
192 | return 0; |
193 | } | |
194 | ||
3db05fea | 195 | tcph = (void *)ip_hdr(skb) + tcphoff; |
1da177e4 LT |
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); | |
3db05fea HX |
205 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
206 | skb->ip_summed = CHECKSUM_NONE; | |
1da177e4 LT |
207 | } else { |
208 | /* full checksum calculation */ | |
209 | tcph->check = 0; | |
3db05fea | 210 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); |
1da177e4 | 211 | tcph->check = csum_tcpudp_magic(cp->caddr, cp->daddr, |
3db05fea HX |
212 | skb->len - tcphoff, |
213 | cp->protocol, skb->csum); | |
214 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
1da177e4 LT |
215 | } |
216 | return 1; | |
217 | } | |
218 | ||
219 | ||
220 | static int | |
221 | tcp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp) | |
222 | { | |
c9bdd4b5 | 223 | const unsigned int tcphoff = ip_hdrlen(skb); |
1da177e4 LT |
224 | |
225 | switch (skb->ip_summed) { | |
226 | case CHECKSUM_NONE: | |
227 | skb->csum = skb_checksum(skb, tcphoff, skb->len - tcphoff, 0); | |
84fa7933 | 228 | case CHECKSUM_COMPLETE: |
eddc9ec5 | 229 | if (csum_tcpudp_magic(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
1da177e4 | 230 | skb->len - tcphoff, |
eddc9ec5 | 231 | ip_hdr(skb)->protocol, skb->csum)) { |
1da177e4 LT |
232 | IP_VS_DBG_RL_PKT(0, pp, skb, 0, |
233 | "Failed checksum for"); | |
234 | return 0; | |
235 | } | |
236 | break; | |
237 | default: | |
84fa7933 | 238 | /* No need to checksum. */ |
1da177e4 LT |
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 | ||
9b5b5cff | 250 | static const int tcp_state_off[IP_VS_DIR_LAST] = { |
1da177e4 LT |
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 | ||
1da177e4 LT |
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->" | |
4b5bdf5c | 425 | "%u.%u.%u.%u:%d state: %s->%s conn->refcnt:%d\n", |
1da177e4 LT |
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 | ||
c9bdd4b5 | 466 | th = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_tcph), &_tcph); |
1da177e4 LT |
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 | ||
75e7ce66 | 488 | static inline __u16 tcp_app_hashkey(__be16 port) |
1da177e4 | 489 | { |
75e7ce66 AV |
490 | return (((__force u16)port >> TCP_APP_TAB_BITS) ^ (__force u16)port) |
491 | & TCP_APP_TAB_MASK; | |
1da177e4 LT |
492 | } |
493 | ||
494 | ||
495 | static int tcp_register_app(struct ip_vs_app *inc) | |
496 | { | |
497 | struct ip_vs_app *i; | |
75e7ce66 AV |
498 | __u16 hash; |
499 | __be16 port = inc->port; | |
1da177e4 LT |
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", | |
0dc47877 | 553 | __func__, |
1da177e4 LT |
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 | ||
ba602a81 | 582 | static void ip_vs_tcp_init(struct ip_vs_protocol *pp) |
1da177e4 LT |
583 | { |
584 | IP_VS_INIT_HASH_TABLE(tcp_apps); | |
585 | pp->timeout_table = tcp_timeouts; | |
586 | } | |
587 | ||
588 | ||
ba602a81 | 589 | static void ip_vs_tcp_exit(struct ip_vs_protocol *pp) |
1da177e4 LT |
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), | |
ba602a81 DM |
599 | .init = ip_vs_tcp_init, |
600 | .exit = ip_vs_tcp_exit, | |
1da177e4 LT |
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 | }; |