Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * ip_vs_proto_udp.c: UDP load balancing support for IPVS | |
3 | * | |
4 | * Version: $Id: ip_vs_proto_udp.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 | ||
14c85021 ACM |
18 | #include <linux/in.h> |
19 | #include <linux/ip.h> | |
1da177e4 | 20 | #include <linux/kernel.h> |
af1e1cf0 | 21 | #include <linux/netfilter.h> |
1da177e4 | 22 | #include <linux/netfilter_ipv4.h> |
14c85021 | 23 | #include <linux/udp.h> |
1da177e4 LT |
24 | |
25 | #include <net/ip_vs.h> | |
c9bdd4b5 | 26 | #include <net/ip.h> |
1da177e4 LT |
27 | |
28 | static struct ip_vs_conn * | |
29 | udp_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 | struct ip_vs_conn *cp; | |
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 | cp = ip_vs_conn_in_get(iph->protocol, | |
41 | iph->saddr, pptr[0], | |
42 | iph->daddr, pptr[1]); | |
43 | } else { | |
44 | cp = ip_vs_conn_in_get(iph->protocol, | |
45 | iph->daddr, pptr[1], | |
46 | iph->saddr, pptr[0]); | |
47 | } | |
48 | ||
49 | return cp; | |
50 | } | |
51 | ||
52 | ||
53 | static struct ip_vs_conn * | |
54 | udp_conn_out_get(const struct sk_buff *skb, struct ip_vs_protocol *pp, | |
55 | const struct iphdr *iph, unsigned int proto_off, int inverse) | |
56 | { | |
57 | struct ip_vs_conn *cp; | |
014d730d | 58 | __be16 _ports[2], *pptr; |
1da177e4 | 59 | |
c9bdd4b5 | 60 | pptr = skb_header_pointer(skb, ip_hdrlen(skb), |
1da177e4 LT |
61 | sizeof(_ports), _ports); |
62 | if (pptr == NULL) | |
63 | return NULL; | |
64 | ||
65 | if (likely(!inverse)) { | |
66 | cp = ip_vs_conn_out_get(iph->protocol, | |
67 | iph->saddr, pptr[0], | |
68 | iph->daddr, pptr[1]); | |
69 | } else { | |
70 | cp = ip_vs_conn_out_get(iph->protocol, | |
71 | iph->daddr, pptr[1], | |
72 | iph->saddr, pptr[0]); | |
73 | } | |
74 | ||
75 | return cp; | |
76 | } | |
77 | ||
78 | ||
79 | static int | |
80 | udp_conn_schedule(struct sk_buff *skb, struct ip_vs_protocol *pp, | |
81 | int *verdict, struct ip_vs_conn **cpp) | |
82 | { | |
83 | struct ip_vs_service *svc; | |
84 | struct udphdr _udph, *uh; | |
85 | ||
c9bdd4b5 | 86 | uh = skb_header_pointer(skb, ip_hdrlen(skb), |
1da177e4 LT |
87 | sizeof(_udph), &_udph); |
88 | if (uh == NULL) { | |
89 | *verdict = NF_DROP; | |
90 | return 0; | |
91 | } | |
92 | ||
eddc9ec5 ACM |
93 | if ((svc = ip_vs_service_get(skb->mark, ip_hdr(skb)->protocol, |
94 | ip_hdr(skb)->daddr, uh->dest))) { | |
1da177e4 LT |
95 | if (ip_vs_todrop()) { |
96 | /* | |
97 | * It seems that we are very loaded. | |
98 | * We have to drop this packet :( | |
99 | */ | |
100 | ip_vs_service_put(svc); | |
101 | *verdict = NF_DROP; | |
102 | return 0; | |
103 | } | |
104 | ||
105 | /* | |
106 | * Let the virtual server select a real server for the | |
107 | * incoming connection, and create a connection entry. | |
108 | */ | |
109 | *cpp = ip_vs_schedule(svc, skb); | |
110 | if (!*cpp) { | |
111 | *verdict = ip_vs_leave(svc, skb, pp); | |
112 | return 0; | |
113 | } | |
114 | ip_vs_service_put(svc); | |
115 | } | |
116 | return 1; | |
117 | } | |
118 | ||
119 | ||
120 | static inline void | |
014d730d AV |
121 | udp_fast_csum_update(struct udphdr *uhdr, __be32 oldip, __be32 newip, |
122 | __be16 oldport, __be16 newport) | |
1da177e4 LT |
123 | { |
124 | uhdr->check = | |
f9214b26 AV |
125 | csum_fold(ip_vs_check_diff4(oldip, newip, |
126 | ip_vs_check_diff2(oldport, newport, | |
127 | ~csum_unfold(uhdr->check)))); | |
1da177e4 | 128 | if (!uhdr->check) |
f6ab0288 | 129 | uhdr->check = CSUM_MANGLED_0; |
1da177e4 LT |
130 | } |
131 | ||
132 | static int | |
3db05fea | 133 | udp_snat_handler(struct sk_buff *skb, |
1da177e4 LT |
134 | struct ip_vs_protocol *pp, struct ip_vs_conn *cp) |
135 | { | |
136 | struct udphdr *udph; | |
3db05fea | 137 | const unsigned int udphoff = ip_hdrlen(skb); |
1da177e4 LT |
138 | |
139 | /* csum_check requires unshared skb */ | |
3db05fea | 140 | if (!skb_make_writable(skb, udphoff+sizeof(*udph))) |
1da177e4 LT |
141 | return 0; |
142 | ||
143 | if (unlikely(cp->app != NULL)) { | |
144 | /* Some checks before mangling */ | |
3db05fea | 145 | if (pp->csum_check && !pp->csum_check(skb, pp)) |
1da177e4 LT |
146 | return 0; |
147 | ||
148 | /* | |
149 | * Call application helper if needed | |
150 | */ | |
3db05fea | 151 | if (!ip_vs_app_pkt_out(cp, skb)) |
1da177e4 LT |
152 | return 0; |
153 | } | |
154 | ||
3db05fea | 155 | udph = (void *)ip_hdr(skb) + udphoff; |
1da177e4 LT |
156 | udph->source = cp->vport; |
157 | ||
158 | /* | |
159 | * Adjust UDP checksums | |
160 | */ | |
161 | if (!cp->app && (udph->check != 0)) { | |
162 | /* Only port and addr are changed, do fast csum update */ | |
163 | udp_fast_csum_update(udph, cp->daddr, cp->vaddr, | |
164 | cp->dport, cp->vport); | |
3db05fea HX |
165 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
166 | skb->ip_summed = CHECKSUM_NONE; | |
1da177e4 LT |
167 | } else { |
168 | /* full checksum calculation */ | |
169 | udph->check = 0; | |
3db05fea | 170 | skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0); |
1da177e4 | 171 | udph->check = csum_tcpudp_magic(cp->vaddr, cp->caddr, |
3db05fea HX |
172 | skb->len - udphoff, |
173 | cp->protocol, skb->csum); | |
1da177e4 | 174 | if (udph->check == 0) |
f6ab0288 | 175 | udph->check = CSUM_MANGLED_0; |
1da177e4 LT |
176 | IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", |
177 | pp->name, udph->check, | |
178 | (char*)&(udph->check) - (char*)udph); | |
179 | } | |
180 | return 1; | |
181 | } | |
182 | ||
183 | ||
184 | static int | |
3db05fea | 185 | udp_dnat_handler(struct sk_buff *skb, |
1da177e4 LT |
186 | struct ip_vs_protocol *pp, struct ip_vs_conn *cp) |
187 | { | |
188 | struct udphdr *udph; | |
3db05fea | 189 | unsigned int udphoff = ip_hdrlen(skb); |
1da177e4 LT |
190 | |
191 | /* csum_check requires unshared skb */ | |
3db05fea | 192 | if (!skb_make_writable(skb, udphoff+sizeof(*udph))) |
1da177e4 LT |
193 | return 0; |
194 | ||
195 | if (unlikely(cp->app != NULL)) { | |
196 | /* Some checks before mangling */ | |
3db05fea | 197 | if (pp->csum_check && !pp->csum_check(skb, pp)) |
1da177e4 LT |
198 | return 0; |
199 | ||
200 | /* | |
201 | * Attempt ip_vs_app call. | |
202 | * It will fix ip_vs_conn | |
203 | */ | |
3db05fea | 204 | if (!ip_vs_app_pkt_in(cp, skb)) |
1da177e4 LT |
205 | return 0; |
206 | } | |
207 | ||
3db05fea | 208 | udph = (void *)ip_hdr(skb) + udphoff; |
1da177e4 LT |
209 | udph->dest = cp->dport; |
210 | ||
211 | /* | |
212 | * Adjust UDP checksums | |
213 | */ | |
214 | if (!cp->app && (udph->check != 0)) { | |
215 | /* Only port and addr are changed, do fast csum update */ | |
216 | udp_fast_csum_update(udph, cp->vaddr, cp->daddr, | |
217 | cp->vport, cp->dport); | |
3db05fea HX |
218 | if (skb->ip_summed == CHECKSUM_COMPLETE) |
219 | skb->ip_summed = CHECKSUM_NONE; | |
1da177e4 LT |
220 | } else { |
221 | /* full checksum calculation */ | |
222 | udph->check = 0; | |
3db05fea | 223 | skb->csum = skb_checksum(skb, udphoff, skb->len - udphoff, 0); |
1da177e4 | 224 | udph->check = csum_tcpudp_magic(cp->caddr, cp->daddr, |
3db05fea HX |
225 | skb->len - udphoff, |
226 | cp->protocol, skb->csum); | |
1da177e4 | 227 | if (udph->check == 0) |
f6ab0288 | 228 | udph->check = CSUM_MANGLED_0; |
3db05fea | 229 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 LT |
230 | } |
231 | return 1; | |
232 | } | |
233 | ||
234 | ||
235 | static int | |
236 | udp_csum_check(struct sk_buff *skb, struct ip_vs_protocol *pp) | |
237 | { | |
238 | struct udphdr _udph, *uh; | |
c9bdd4b5 | 239 | const unsigned int udphoff = ip_hdrlen(skb); |
1da177e4 LT |
240 | |
241 | uh = skb_header_pointer(skb, udphoff, sizeof(_udph), &_udph); | |
242 | if (uh == NULL) | |
243 | return 0; | |
244 | ||
245 | if (uh->check != 0) { | |
246 | switch (skb->ip_summed) { | |
247 | case CHECKSUM_NONE: | |
248 | skb->csum = skb_checksum(skb, udphoff, | |
249 | skb->len - udphoff, 0); | |
84fa7933 | 250 | case CHECKSUM_COMPLETE: |
eddc9ec5 ACM |
251 | if (csum_tcpudp_magic(ip_hdr(skb)->saddr, |
252 | ip_hdr(skb)->daddr, | |
1da177e4 | 253 | skb->len - udphoff, |
eddc9ec5 | 254 | ip_hdr(skb)->protocol, |
1da177e4 LT |
255 | skb->csum)) { |
256 | IP_VS_DBG_RL_PKT(0, pp, skb, 0, | |
257 | "Failed checksum for"); | |
258 | return 0; | |
259 | } | |
260 | break; | |
261 | default: | |
84fa7933 | 262 | /* No need to checksum. */ |
1da177e4 LT |
263 | break; |
264 | } | |
265 | } | |
266 | return 1; | |
267 | } | |
268 | ||
269 | ||
270 | /* | |
271 | * Note: the caller guarantees that only one of register_app, | |
272 | * unregister_app or app_conn_bind is called each time. | |
273 | */ | |
274 | ||
275 | #define UDP_APP_TAB_BITS 4 | |
276 | #define UDP_APP_TAB_SIZE (1 << UDP_APP_TAB_BITS) | |
277 | #define UDP_APP_TAB_MASK (UDP_APP_TAB_SIZE - 1) | |
278 | ||
279 | static struct list_head udp_apps[UDP_APP_TAB_SIZE]; | |
280 | static DEFINE_SPINLOCK(udp_app_lock); | |
281 | ||
75e7ce66 | 282 | static inline __u16 udp_app_hashkey(__be16 port) |
1da177e4 | 283 | { |
75e7ce66 AV |
284 | return (((__force u16)port >> UDP_APP_TAB_BITS) ^ (__force u16)port) |
285 | & UDP_APP_TAB_MASK; | |
1da177e4 LT |
286 | } |
287 | ||
288 | ||
289 | static int udp_register_app(struct ip_vs_app *inc) | |
290 | { | |
291 | struct ip_vs_app *i; | |
75e7ce66 AV |
292 | __u16 hash; |
293 | __be16 port = inc->port; | |
1da177e4 LT |
294 | int ret = 0; |
295 | ||
296 | hash = udp_app_hashkey(port); | |
297 | ||
298 | ||
299 | spin_lock_bh(&udp_app_lock); | |
300 | list_for_each_entry(i, &udp_apps[hash], p_list) { | |
301 | if (i->port == port) { | |
302 | ret = -EEXIST; | |
303 | goto out; | |
304 | } | |
305 | } | |
306 | list_add(&inc->p_list, &udp_apps[hash]); | |
307 | atomic_inc(&ip_vs_protocol_udp.appcnt); | |
308 | ||
309 | out: | |
310 | spin_unlock_bh(&udp_app_lock); | |
311 | return ret; | |
312 | } | |
313 | ||
314 | ||
315 | static void | |
316 | udp_unregister_app(struct ip_vs_app *inc) | |
317 | { | |
318 | spin_lock_bh(&udp_app_lock); | |
319 | atomic_dec(&ip_vs_protocol_udp.appcnt); | |
320 | list_del(&inc->p_list); | |
321 | spin_unlock_bh(&udp_app_lock); | |
322 | } | |
323 | ||
324 | ||
325 | static int udp_app_conn_bind(struct ip_vs_conn *cp) | |
326 | { | |
327 | int hash; | |
328 | struct ip_vs_app *inc; | |
329 | int result = 0; | |
330 | ||
331 | /* Default binding: bind app only for NAT */ | |
332 | if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) | |
333 | return 0; | |
334 | ||
335 | /* Lookup application incarnations and bind the right one */ | |
336 | hash = udp_app_hashkey(cp->vport); | |
337 | ||
338 | spin_lock(&udp_app_lock); | |
339 | list_for_each_entry(inc, &udp_apps[hash], p_list) { | |
340 | if (inc->port == cp->vport) { | |
341 | if (unlikely(!ip_vs_app_inc_get(inc))) | |
342 | break; | |
343 | spin_unlock(&udp_app_lock); | |
344 | ||
345 | IP_VS_DBG(9, "%s: Binding conn %u.%u.%u.%u:%u->" | |
346 | "%u.%u.%u.%u:%u to app %s on port %u\n", | |
0dc47877 | 347 | __func__, |
1da177e4 LT |
348 | NIPQUAD(cp->caddr), ntohs(cp->cport), |
349 | NIPQUAD(cp->vaddr), ntohs(cp->vport), | |
350 | inc->name, ntohs(inc->port)); | |
351 | cp->app = inc; | |
352 | if (inc->init_conn) | |
353 | result = inc->init_conn(inc, cp); | |
354 | goto out; | |
355 | } | |
356 | } | |
357 | spin_unlock(&udp_app_lock); | |
358 | ||
359 | out: | |
360 | return result; | |
361 | } | |
362 | ||
363 | ||
364 | static int udp_timeouts[IP_VS_UDP_S_LAST+1] = { | |
365 | [IP_VS_UDP_S_NORMAL] = 5*60*HZ, | |
366 | [IP_VS_UDP_S_LAST] = 2*HZ, | |
367 | }; | |
368 | ||
369 | static char * udp_state_name_table[IP_VS_UDP_S_LAST+1] = { | |
370 | [IP_VS_UDP_S_NORMAL] = "UDP", | |
371 | [IP_VS_UDP_S_LAST] = "BUG!", | |
372 | }; | |
373 | ||
374 | ||
375 | static int | |
376 | udp_set_state_timeout(struct ip_vs_protocol *pp, char *sname, int to) | |
377 | { | |
378 | return ip_vs_set_state_timeout(pp->timeout_table, IP_VS_UDP_S_LAST, | |
379 | udp_state_name_table, sname, to); | |
380 | } | |
381 | ||
382 | static const char * udp_state_name(int state) | |
383 | { | |
384 | if (state >= IP_VS_UDP_S_LAST) | |
385 | return "ERR!"; | |
386 | return udp_state_name_table[state] ? udp_state_name_table[state] : "?"; | |
387 | } | |
388 | ||
389 | static int | |
390 | udp_state_transition(struct ip_vs_conn *cp, int direction, | |
391 | const struct sk_buff *skb, | |
392 | struct ip_vs_protocol *pp) | |
393 | { | |
394 | cp->timeout = pp->timeout_table[IP_VS_UDP_S_NORMAL]; | |
395 | return 1; | |
396 | } | |
397 | ||
398 | static void udp_init(struct ip_vs_protocol *pp) | |
399 | { | |
400 | IP_VS_INIT_HASH_TABLE(udp_apps); | |
401 | pp->timeout_table = udp_timeouts; | |
402 | } | |
403 | ||
404 | static void udp_exit(struct ip_vs_protocol *pp) | |
405 | { | |
406 | } | |
407 | ||
408 | ||
409 | struct ip_vs_protocol ip_vs_protocol_udp = { | |
410 | .name = "UDP", | |
411 | .protocol = IPPROTO_UDP, | |
412 | .dont_defrag = 0, | |
413 | .init = udp_init, | |
414 | .exit = udp_exit, | |
415 | .conn_schedule = udp_conn_schedule, | |
416 | .conn_in_get = udp_conn_in_get, | |
417 | .conn_out_get = udp_conn_out_get, | |
418 | .snat_handler = udp_snat_handler, | |
419 | .dnat_handler = udp_dnat_handler, | |
420 | .csum_check = udp_csum_check, | |
421 | .state_transition = udp_state_transition, | |
422 | .state_name = udp_state_name, | |
423 | .register_app = udp_register_app, | |
424 | .unregister_app = udp_unregister_app, | |
425 | .app_conn_bind = udp_app_conn_bind, | |
426 | .debug_packet = ip_vs_tcpudp_debug_packet, | |
427 | .timeout_change = NULL, | |
428 | .set_state_timeout = udp_set_state_timeout, | |
429 | }; |