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1 | /* | |
2 | * IPVS An implementation of the IP virtual server support for the | |
3 | * LINUX operating system. IPVS is now implemented as a module | |
4 | * over the Netfilter framework. IPVS can be used to build a | |
5 | * high-performance and highly available server based on a | |
6 | * cluster of servers. | |
7 | * | |
8 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> | |
9 | * Peter Kese <peter.kese@ijs.si> | |
10 | * Julian Anastasov <ja@ssi.bg> | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or | |
13 | * modify it under the terms of the GNU General Public License | |
14 | * as published by the Free Software Foundation; either version | |
15 | * 2 of the License, or (at your option) any later version. | |
16 | * | |
17 | * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese, | |
18 | * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms | |
19 | * and others. | |
20 | * | |
21 | * Changes: | |
22 | * Paul `Rusty' Russell properly handle non-linear skbs | |
23 | * Harald Welte don't use nfcache | |
24 | * | |
25 | */ | |
26 | ||
27 | #define KMSG_COMPONENT "IPVS" | |
28 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
29 | ||
30 | #include <linux/module.h> | |
31 | #include <linux/kernel.h> | |
32 | #include <linux/ip.h> | |
33 | #include <linux/tcp.h> | |
34 | #include <linux/icmp.h> | |
35 | ||
36 | #include <net/ip.h> | |
37 | #include <net/tcp.h> | |
38 | #include <net/udp.h> | |
39 | #include <net/icmp.h> /* for icmp_send */ | |
40 | #include <net/route.h> | |
41 | ||
42 | #include <linux/netfilter.h> | |
43 | #include <linux/netfilter_ipv4.h> | |
44 | ||
45 | #ifdef CONFIG_IP_VS_IPV6 | |
46 | #include <net/ipv6.h> | |
47 | #include <linux/netfilter_ipv6.h> | |
48 | #endif | |
49 | ||
50 | #include <net/ip_vs.h> | |
51 | ||
52 | ||
53 | EXPORT_SYMBOL(register_ip_vs_scheduler); | |
54 | EXPORT_SYMBOL(unregister_ip_vs_scheduler); | |
55 | EXPORT_SYMBOL(ip_vs_skb_replace); | |
56 | EXPORT_SYMBOL(ip_vs_proto_name); | |
57 | EXPORT_SYMBOL(ip_vs_conn_new); | |
58 | EXPORT_SYMBOL(ip_vs_conn_in_get); | |
59 | EXPORT_SYMBOL(ip_vs_conn_out_get); | |
60 | #ifdef CONFIG_IP_VS_PROTO_TCP | |
61 | EXPORT_SYMBOL(ip_vs_tcp_conn_listen); | |
62 | #endif | |
63 | EXPORT_SYMBOL(ip_vs_conn_put); | |
64 | #ifdef CONFIG_IP_VS_DEBUG | |
65 | EXPORT_SYMBOL(ip_vs_get_debug_level); | |
66 | #endif | |
67 | ||
68 | ||
69 | /* ID used in ICMP lookups */ | |
70 | #define icmp_id(icmph) (((icmph)->un).echo.id) | |
71 | #define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier) | |
72 | ||
73 | const char *ip_vs_proto_name(unsigned proto) | |
74 | { | |
75 | static char buf[20]; | |
76 | ||
77 | switch (proto) { | |
78 | case IPPROTO_IP: | |
79 | return "IP"; | |
80 | case IPPROTO_UDP: | |
81 | return "UDP"; | |
82 | case IPPROTO_TCP: | |
83 | return "TCP"; | |
84 | case IPPROTO_ICMP: | |
85 | return "ICMP"; | |
86 | #ifdef CONFIG_IP_VS_IPV6 | |
87 | case IPPROTO_ICMPV6: | |
88 | return "ICMPv6"; | |
89 | #endif | |
90 | default: | |
91 | sprintf(buf, "IP_%d", proto); | |
92 | return buf; | |
93 | } | |
94 | } | |
95 | ||
96 | void ip_vs_init_hash_table(struct list_head *table, int rows) | |
97 | { | |
98 | while (--rows >= 0) | |
99 | INIT_LIST_HEAD(&table[rows]); | |
100 | } | |
101 | ||
102 | static inline void | |
103 | ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb) | |
104 | { | |
105 | struct ip_vs_dest *dest = cp->dest; | |
106 | if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { | |
107 | spin_lock(&dest->stats.lock); | |
108 | dest->stats.ustats.inpkts++; | |
109 | dest->stats.ustats.inbytes += skb->len; | |
110 | spin_unlock(&dest->stats.lock); | |
111 | ||
112 | spin_lock(&dest->svc->stats.lock); | |
113 | dest->svc->stats.ustats.inpkts++; | |
114 | dest->svc->stats.ustats.inbytes += skb->len; | |
115 | spin_unlock(&dest->svc->stats.lock); | |
116 | ||
117 | spin_lock(&ip_vs_stats.lock); | |
118 | ip_vs_stats.ustats.inpkts++; | |
119 | ip_vs_stats.ustats.inbytes += skb->len; | |
120 | spin_unlock(&ip_vs_stats.lock); | |
121 | } | |
122 | } | |
123 | ||
124 | ||
125 | static inline void | |
126 | ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb) | |
127 | { | |
128 | struct ip_vs_dest *dest = cp->dest; | |
129 | if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) { | |
130 | spin_lock(&dest->stats.lock); | |
131 | dest->stats.ustats.outpkts++; | |
132 | dest->stats.ustats.outbytes += skb->len; | |
133 | spin_unlock(&dest->stats.lock); | |
134 | ||
135 | spin_lock(&dest->svc->stats.lock); | |
136 | dest->svc->stats.ustats.outpkts++; | |
137 | dest->svc->stats.ustats.outbytes += skb->len; | |
138 | spin_unlock(&dest->svc->stats.lock); | |
139 | ||
140 | spin_lock(&ip_vs_stats.lock); | |
141 | ip_vs_stats.ustats.outpkts++; | |
142 | ip_vs_stats.ustats.outbytes += skb->len; | |
143 | spin_unlock(&ip_vs_stats.lock); | |
144 | } | |
145 | } | |
146 | ||
147 | ||
148 | static inline void | |
149 | ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc) | |
150 | { | |
151 | spin_lock(&cp->dest->stats.lock); | |
152 | cp->dest->stats.ustats.conns++; | |
153 | spin_unlock(&cp->dest->stats.lock); | |
154 | ||
155 | spin_lock(&svc->stats.lock); | |
156 | svc->stats.ustats.conns++; | |
157 | spin_unlock(&svc->stats.lock); | |
158 | ||
159 | spin_lock(&ip_vs_stats.lock); | |
160 | ip_vs_stats.ustats.conns++; | |
161 | spin_unlock(&ip_vs_stats.lock); | |
162 | } | |
163 | ||
164 | ||
165 | static inline int | |
166 | ip_vs_set_state(struct ip_vs_conn *cp, int direction, | |
167 | const struct sk_buff *skb, | |
168 | struct ip_vs_protocol *pp) | |
169 | { | |
170 | if (unlikely(!pp->state_transition)) | |
171 | return 0; | |
172 | return pp->state_transition(cp, direction, skb, pp); | |
173 | } | |
174 | ||
175 | ||
176 | /* | |
177 | * IPVS persistent scheduling function | |
178 | * It creates a connection entry according to its template if exists, | |
179 | * or selects a server and creates a connection entry plus a template. | |
180 | * Locking: we are svc user (svc->refcnt), so we hold all dests too | |
181 | * Protocols supported: TCP, UDP | |
182 | */ | |
183 | static struct ip_vs_conn * | |
184 | ip_vs_sched_persist(struct ip_vs_service *svc, | |
185 | const struct sk_buff *skb, | |
186 | __be16 ports[2]) | |
187 | { | |
188 | struct ip_vs_conn *cp = NULL; | |
189 | struct ip_vs_iphdr iph; | |
190 | struct ip_vs_dest *dest; | |
191 | struct ip_vs_conn *ct; | |
192 | __be16 dport; /* destination port to forward */ | |
193 | union nf_inet_addr snet; /* source network of the client, | |
194 | after masking */ | |
195 | ||
196 | ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph); | |
197 | ||
198 | /* Mask saddr with the netmask to adjust template granularity */ | |
199 | #ifdef CONFIG_IP_VS_IPV6 | |
200 | if (svc->af == AF_INET6) | |
201 | ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask); | |
202 | else | |
203 | #endif | |
204 | snet.ip = iph.saddr.ip & svc->netmask; | |
205 | ||
206 | IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u " | |
207 | "mnet %s\n", | |
208 | IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(ports[0]), | |
209 | IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(ports[1]), | |
210 | IP_VS_DBG_ADDR(svc->af, &snet)); | |
211 | ||
212 | /* | |
213 | * As far as we know, FTP is a very complicated network protocol, and | |
214 | * it uses control connection and data connections. For active FTP, | |
215 | * FTP server initialize data connection to the client, its source port | |
216 | * is often 20. For passive FTP, FTP server tells the clients the port | |
217 | * that it passively listens to, and the client issues the data | |
218 | * connection. In the tunneling or direct routing mode, the load | |
219 | * balancer is on the client-to-server half of connection, the port | |
220 | * number is unknown to the load balancer. So, a conn template like | |
221 | * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP | |
222 | * service, and a template like <caddr, 0, vaddr, vport, daddr, dport> | |
223 | * is created for other persistent services. | |
224 | */ | |
225 | if (ports[1] == svc->port) { | |
226 | /* Check if a template already exists */ | |
227 | if (svc->port != FTPPORT) | |
228 | ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0, | |
229 | &iph.daddr, ports[1]); | |
230 | else | |
231 | ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0, | |
232 | &iph.daddr, 0); | |
233 | ||
234 | if (!ct || !ip_vs_check_template(ct)) { | |
235 | /* | |
236 | * No template found or the dest of the connection | |
237 | * template is not available. | |
238 | */ | |
239 | dest = svc->scheduler->schedule(svc, skb); | |
240 | if (dest == NULL) { | |
241 | IP_VS_DBG(1, "p-schedule: no dest found.\n"); | |
242 | return NULL; | |
243 | } | |
244 | ||
245 | /* | |
246 | * Create a template like <protocol,caddr,0, | |
247 | * vaddr,vport,daddr,dport> for non-ftp service, | |
248 | * and <protocol,caddr,0,vaddr,0,daddr,0> | |
249 | * for ftp service. | |
250 | */ | |
251 | if (svc->port != FTPPORT) | |
252 | ct = ip_vs_conn_new(svc->af, iph.protocol, | |
253 | &snet, 0, | |
254 | &iph.daddr, | |
255 | ports[1], | |
256 | &dest->addr, dest->port, | |
257 | IP_VS_CONN_F_TEMPLATE, | |
258 | dest); | |
259 | else | |
260 | ct = ip_vs_conn_new(svc->af, iph.protocol, | |
261 | &snet, 0, | |
262 | &iph.daddr, 0, | |
263 | &dest->addr, 0, | |
264 | IP_VS_CONN_F_TEMPLATE, | |
265 | dest); | |
266 | if (ct == NULL) | |
267 | return NULL; | |
268 | ||
269 | ct->timeout = svc->timeout; | |
270 | } else { | |
271 | /* set destination with the found template */ | |
272 | dest = ct->dest; | |
273 | } | |
274 | dport = dest->port; | |
275 | } else { | |
276 | /* | |
277 | * Note: persistent fwmark-based services and persistent | |
278 | * port zero service are handled here. | |
279 | * fwmark template: <IPPROTO_IP,caddr,0,fwmark,0,daddr,0> | |
280 | * port zero template: <protocol,caddr,0,vaddr,0,daddr,0> | |
281 | */ | |
282 | if (svc->fwmark) { | |
283 | union nf_inet_addr fwmark = { | |
284 | .ip = htonl(svc->fwmark) | |
285 | }; | |
286 | ||
287 | ct = ip_vs_ct_in_get(svc->af, IPPROTO_IP, &snet, 0, | |
288 | &fwmark, 0); | |
289 | } else | |
290 | ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0, | |
291 | &iph.daddr, 0); | |
292 | ||
293 | if (!ct || !ip_vs_check_template(ct)) { | |
294 | /* | |
295 | * If it is not persistent port zero, return NULL, | |
296 | * otherwise create a connection template. | |
297 | */ | |
298 | if (svc->port) | |
299 | return NULL; | |
300 | ||
301 | dest = svc->scheduler->schedule(svc, skb); | |
302 | if (dest == NULL) { | |
303 | IP_VS_DBG(1, "p-schedule: no dest found.\n"); | |
304 | return NULL; | |
305 | } | |
306 | ||
307 | /* | |
308 | * Create a template according to the service | |
309 | */ | |
310 | if (svc->fwmark) { | |
311 | union nf_inet_addr fwmark = { | |
312 | .ip = htonl(svc->fwmark) | |
313 | }; | |
314 | ||
315 | ct = ip_vs_conn_new(svc->af, IPPROTO_IP, | |
316 | &snet, 0, | |
317 | &fwmark, 0, | |
318 | &dest->addr, 0, | |
319 | IP_VS_CONN_F_TEMPLATE, | |
320 | dest); | |
321 | } else | |
322 | ct = ip_vs_conn_new(svc->af, iph.protocol, | |
323 | &snet, 0, | |
324 | &iph.daddr, 0, | |
325 | &dest->addr, 0, | |
326 | IP_VS_CONN_F_TEMPLATE, | |
327 | dest); | |
328 | if (ct == NULL) | |
329 | return NULL; | |
330 | ||
331 | ct->timeout = svc->timeout; | |
332 | } else { | |
333 | /* set destination with the found template */ | |
334 | dest = ct->dest; | |
335 | } | |
336 | dport = ports[1]; | |
337 | } | |
338 | ||
339 | /* | |
340 | * Create a new connection according to the template | |
341 | */ | |
342 | cp = ip_vs_conn_new(svc->af, iph.protocol, | |
343 | &iph.saddr, ports[0], | |
344 | &iph.daddr, ports[1], | |
345 | &dest->addr, dport, | |
346 | 0, | |
347 | dest); | |
348 | if (cp == NULL) { | |
349 | ip_vs_conn_put(ct); | |
350 | return NULL; | |
351 | } | |
352 | ||
353 | /* | |
354 | * Add its control | |
355 | */ | |
356 | ip_vs_control_add(cp, ct); | |
357 | ip_vs_conn_put(ct); | |
358 | ||
359 | ip_vs_conn_stats(cp, svc); | |
360 | return cp; | |
361 | } | |
362 | ||
363 | ||
364 | /* | |
365 | * IPVS main scheduling function | |
366 | * It selects a server according to the virtual service, and | |
367 | * creates a connection entry. | |
368 | * Protocols supported: TCP, UDP | |
369 | */ | |
370 | struct ip_vs_conn * | |
371 | ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb) | |
372 | { | |
373 | struct ip_vs_conn *cp = NULL; | |
374 | struct ip_vs_iphdr iph; | |
375 | struct ip_vs_dest *dest; | |
376 | __be16 _ports[2], *pptr; | |
377 | ||
378 | ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph); | |
379 | pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports); | |
380 | if (pptr == NULL) | |
381 | return NULL; | |
382 | ||
383 | /* | |
384 | * Persistent service | |
385 | */ | |
386 | if (svc->flags & IP_VS_SVC_F_PERSISTENT) | |
387 | return ip_vs_sched_persist(svc, skb, pptr); | |
388 | ||
389 | /* | |
390 | * Non-persistent service | |
391 | */ | |
392 | if (!svc->fwmark && pptr[1] != svc->port) { | |
393 | if (!svc->port) | |
394 | IP_VS_ERR("Schedule: port zero only supported " | |
395 | "in persistent services, " | |
396 | "check your ipvs configuration\n"); | |
397 | return NULL; | |
398 | } | |
399 | ||
400 | dest = svc->scheduler->schedule(svc, skb); | |
401 | if (dest == NULL) { | |
402 | IP_VS_DBG(1, "Schedule: no dest found.\n"); | |
403 | return NULL; | |
404 | } | |
405 | ||
406 | /* | |
407 | * Create a connection entry. | |
408 | */ | |
409 | cp = ip_vs_conn_new(svc->af, iph.protocol, | |
410 | &iph.saddr, pptr[0], | |
411 | &iph.daddr, pptr[1], | |
412 | &dest->addr, dest->port ? dest->port : pptr[1], | |
413 | 0, | |
414 | dest); | |
415 | if (cp == NULL) | |
416 | return NULL; | |
417 | ||
418 | IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u " | |
419 | "d:%s:%u conn->flags:%X conn->refcnt:%d\n", | |
420 | ip_vs_fwd_tag(cp), | |
421 | IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport), | |
422 | IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport), | |
423 | IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport), | |
424 | cp->flags, atomic_read(&cp->refcnt)); | |
425 | ||
426 | ip_vs_conn_stats(cp, svc); | |
427 | return cp; | |
428 | } | |
429 | ||
430 | ||
431 | /* | |
432 | * Pass or drop the packet. | |
433 | * Called by ip_vs_in, when the virtual service is available but | |
434 | * no destination is available for a new connection. | |
435 | */ | |
436 | int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb, | |
437 | struct ip_vs_protocol *pp) | |
438 | { | |
439 | __be16 _ports[2], *pptr; | |
440 | struct ip_vs_iphdr iph; | |
441 | int unicast; | |
442 | ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph); | |
443 | ||
444 | pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports); | |
445 | if (pptr == NULL) { | |
446 | ip_vs_service_put(svc); | |
447 | return NF_DROP; | |
448 | } | |
449 | ||
450 | #ifdef CONFIG_IP_VS_IPV6 | |
451 | if (svc->af == AF_INET6) | |
452 | unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST; | |
453 | else | |
454 | #endif | |
455 | unicast = (inet_addr_type(&init_net, iph.daddr.ip) == RTN_UNICAST); | |
456 | ||
457 | /* if it is fwmark-based service, the cache_bypass sysctl is up | |
458 | and the destination is a non-local unicast, then create | |
459 | a cache_bypass connection entry */ | |
460 | if (sysctl_ip_vs_cache_bypass && svc->fwmark && unicast) { | |
461 | int ret, cs; | |
462 | struct ip_vs_conn *cp; | |
463 | union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } }; | |
464 | ||
465 | ip_vs_service_put(svc); | |
466 | ||
467 | /* create a new connection entry */ | |
468 | IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n"); | |
469 | cp = ip_vs_conn_new(svc->af, iph.protocol, | |
470 | &iph.saddr, pptr[0], | |
471 | &iph.daddr, pptr[1], | |
472 | &daddr, 0, | |
473 | IP_VS_CONN_F_BYPASS, | |
474 | NULL); | |
475 | if (cp == NULL) | |
476 | return NF_DROP; | |
477 | ||
478 | /* statistics */ | |
479 | ip_vs_in_stats(cp, skb); | |
480 | ||
481 | /* set state */ | |
482 | cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp); | |
483 | ||
484 | /* transmit the first SYN packet */ | |
485 | ret = cp->packet_xmit(skb, cp, pp); | |
486 | /* do not touch skb anymore */ | |
487 | ||
488 | atomic_inc(&cp->in_pkts); | |
489 | ip_vs_conn_put(cp); | |
490 | return ret; | |
491 | } | |
492 | ||
493 | /* | |
494 | * When the virtual ftp service is presented, packets destined | |
495 | * for other services on the VIP may get here (except services | |
496 | * listed in the ipvs table), pass the packets, because it is | |
497 | * not ipvs job to decide to drop the packets. | |
498 | */ | |
499 | if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) { | |
500 | ip_vs_service_put(svc); | |
501 | return NF_ACCEPT; | |
502 | } | |
503 | ||
504 | ip_vs_service_put(svc); | |
505 | ||
506 | /* | |
507 | * Notify the client that the destination is unreachable, and | |
508 | * release the socket buffer. | |
509 | * Since it is in IP layer, the TCP socket is not actually | |
510 | * created, the TCP RST packet cannot be sent, instead that | |
511 | * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ | |
512 | */ | |
513 | #ifdef CONFIG_IP_VS_IPV6 | |
514 | if (svc->af == AF_INET6) | |
515 | icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, | |
516 | skb->dev); | |
517 | else | |
518 | #endif | |
519 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); | |
520 | ||
521 | return NF_DROP; | |
522 | } | |
523 | ||
524 | ||
525 | /* | |
526 | * It is hooked before NF_IP_PRI_NAT_SRC at the NF_INET_POST_ROUTING | |
527 | * chain, and is used for VS/NAT. | |
528 | * It detects packets for VS/NAT connections and sends the packets | |
529 | * immediately. This can avoid that iptable_nat mangles the packets | |
530 | * for VS/NAT. | |
531 | */ | |
532 | static unsigned int ip_vs_post_routing(unsigned int hooknum, | |
533 | struct sk_buff *skb, | |
534 | const struct net_device *in, | |
535 | const struct net_device *out, | |
536 | int (*okfn)(struct sk_buff *)) | |
537 | { | |
538 | if (!skb->ipvs_property) | |
539 | return NF_ACCEPT; | |
540 | /* The packet was sent from IPVS, exit this chain */ | |
541 | return NF_STOP; | |
542 | } | |
543 | ||
544 | __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset) | |
545 | { | |
546 | return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0)); | |
547 | } | |
548 | ||
549 | static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user) | |
550 | { | |
551 | int err = ip_defrag(skb, user); | |
552 | ||
553 | if (!err) | |
554 | ip_send_check(ip_hdr(skb)); | |
555 | ||
556 | return err; | |
557 | } | |
558 | ||
559 | #ifdef CONFIG_IP_VS_IPV6 | |
560 | static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user) | |
561 | { | |
562 | /* TODO IPv6: Find out what to do here for IPv6 */ | |
563 | return 0; | |
564 | } | |
565 | #endif | |
566 | ||
567 | /* | |
568 | * Packet has been made sufficiently writable in caller | |
569 | * - inout: 1=in->out, 0=out->in | |
570 | */ | |
571 | void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp, | |
572 | struct ip_vs_conn *cp, int inout) | |
573 | { | |
574 | struct iphdr *iph = ip_hdr(skb); | |
575 | unsigned int icmp_offset = iph->ihl*4; | |
576 | struct icmphdr *icmph = (struct icmphdr *)(skb_network_header(skb) + | |
577 | icmp_offset); | |
578 | struct iphdr *ciph = (struct iphdr *)(icmph + 1); | |
579 | ||
580 | if (inout) { | |
581 | iph->saddr = cp->vaddr.ip; | |
582 | ip_send_check(iph); | |
583 | ciph->daddr = cp->vaddr.ip; | |
584 | ip_send_check(ciph); | |
585 | } else { | |
586 | iph->daddr = cp->daddr.ip; | |
587 | ip_send_check(iph); | |
588 | ciph->saddr = cp->daddr.ip; | |
589 | ip_send_check(ciph); | |
590 | } | |
591 | ||
592 | /* the TCP/UDP port */ | |
593 | if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol) { | |
594 | __be16 *ports = (void *)ciph + ciph->ihl*4; | |
595 | ||
596 | if (inout) | |
597 | ports[1] = cp->vport; | |
598 | else | |
599 | ports[0] = cp->dport; | |
600 | } | |
601 | ||
602 | /* And finally the ICMP checksum */ | |
603 | icmph->checksum = 0; | |
604 | icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset); | |
605 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
606 | ||
607 | if (inout) | |
608 | IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, | |
609 | "Forwarding altered outgoing ICMP"); | |
610 | else | |
611 | IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, | |
612 | "Forwarding altered incoming ICMP"); | |
613 | } | |
614 | ||
615 | #ifdef CONFIG_IP_VS_IPV6 | |
616 | void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp, | |
617 | struct ip_vs_conn *cp, int inout) | |
618 | { | |
619 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
620 | unsigned int icmp_offset = sizeof(struct ipv6hdr); | |
621 | struct icmp6hdr *icmph = (struct icmp6hdr *)(skb_network_header(skb) + | |
622 | icmp_offset); | |
623 | struct ipv6hdr *ciph = (struct ipv6hdr *)(icmph + 1); | |
624 | ||
625 | if (inout) { | |
626 | iph->saddr = cp->vaddr.in6; | |
627 | ciph->daddr = cp->vaddr.in6; | |
628 | } else { | |
629 | iph->daddr = cp->daddr.in6; | |
630 | ciph->saddr = cp->daddr.in6; | |
631 | } | |
632 | ||
633 | /* the TCP/UDP port */ | |
634 | if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr) { | |
635 | __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr); | |
636 | ||
637 | if (inout) | |
638 | ports[1] = cp->vport; | |
639 | else | |
640 | ports[0] = cp->dport; | |
641 | } | |
642 | ||
643 | /* And finally the ICMP checksum */ | |
644 | icmph->icmp6_cksum = 0; | |
645 | /* TODO IPv6: is this correct for ICMPv6? */ | |
646 | ip_vs_checksum_complete(skb, icmp_offset); | |
647 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
648 | ||
649 | if (inout) | |
650 | IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, | |
651 | "Forwarding altered outgoing ICMPv6"); | |
652 | else | |
653 | IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph, | |
654 | "Forwarding altered incoming ICMPv6"); | |
655 | } | |
656 | #endif | |
657 | ||
658 | /* Handle relevant response ICMP messages - forward to the right | |
659 | * destination host. Used for NAT and local client. | |
660 | */ | |
661 | static int handle_response_icmp(int af, struct sk_buff *skb, | |
662 | union nf_inet_addr *snet, | |
663 | __u8 protocol, struct ip_vs_conn *cp, | |
664 | struct ip_vs_protocol *pp, | |
665 | unsigned int offset, unsigned int ihl) | |
666 | { | |
667 | unsigned int verdict = NF_DROP; | |
668 | ||
669 | if (IP_VS_FWD_METHOD(cp) != 0) { | |
670 | IP_VS_ERR("shouldn't reach here, because the box is on the " | |
671 | "half connection in the tun/dr module.\n"); | |
672 | } | |
673 | ||
674 | /* Ensure the checksum is correct */ | |
675 | if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { | |
676 | /* Failed checksum! */ | |
677 | IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n", | |
678 | IP_VS_DBG_ADDR(af, snet)); | |
679 | goto out; | |
680 | } | |
681 | ||
682 | if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol) | |
683 | offset += 2 * sizeof(__u16); | |
684 | if (!skb_make_writable(skb, offset)) | |
685 | goto out; | |
686 | ||
687 | #ifdef CONFIG_IP_VS_IPV6 | |
688 | if (af == AF_INET6) | |
689 | ip_vs_nat_icmp_v6(skb, pp, cp, 1); | |
690 | else | |
691 | #endif | |
692 | ip_vs_nat_icmp(skb, pp, cp, 1); | |
693 | ||
694 | /* do the statistics and put it back */ | |
695 | ip_vs_out_stats(cp, skb); | |
696 | ||
697 | skb->ipvs_property = 1; | |
698 | verdict = NF_ACCEPT; | |
699 | ||
700 | out: | |
701 | __ip_vs_conn_put(cp); | |
702 | ||
703 | return verdict; | |
704 | } | |
705 | ||
706 | /* | |
707 | * Handle ICMP messages in the inside-to-outside direction (outgoing). | |
708 | * Find any that might be relevant, check against existing connections. | |
709 | * Currently handles error types - unreachable, quench, ttl exceeded. | |
710 | */ | |
711 | static int ip_vs_out_icmp(struct sk_buff *skb, int *related) | |
712 | { | |
713 | struct iphdr *iph; | |
714 | struct icmphdr _icmph, *ic; | |
715 | struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ | |
716 | struct ip_vs_iphdr ciph; | |
717 | struct ip_vs_conn *cp; | |
718 | struct ip_vs_protocol *pp; | |
719 | unsigned int offset, ihl; | |
720 | union nf_inet_addr snet; | |
721 | ||
722 | *related = 1; | |
723 | ||
724 | /* reassemble IP fragments */ | |
725 | if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { | |
726 | if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT)) | |
727 | return NF_STOLEN; | |
728 | } | |
729 | ||
730 | iph = ip_hdr(skb); | |
731 | offset = ihl = iph->ihl * 4; | |
732 | ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); | |
733 | if (ic == NULL) | |
734 | return NF_DROP; | |
735 | ||
736 | IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n", | |
737 | ic->type, ntohs(icmp_id(ic)), | |
738 | &iph->saddr, &iph->daddr); | |
739 | ||
740 | /* | |
741 | * Work through seeing if this is for us. | |
742 | * These checks are supposed to be in an order that means easy | |
743 | * things are checked first to speed up processing.... however | |
744 | * this means that some packets will manage to get a long way | |
745 | * down this stack and then be rejected, but that's life. | |
746 | */ | |
747 | if ((ic->type != ICMP_DEST_UNREACH) && | |
748 | (ic->type != ICMP_SOURCE_QUENCH) && | |
749 | (ic->type != ICMP_TIME_EXCEEDED)) { | |
750 | *related = 0; | |
751 | return NF_ACCEPT; | |
752 | } | |
753 | ||
754 | /* Now find the contained IP header */ | |
755 | offset += sizeof(_icmph); | |
756 | cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); | |
757 | if (cih == NULL) | |
758 | return NF_ACCEPT; /* The packet looks wrong, ignore */ | |
759 | ||
760 | pp = ip_vs_proto_get(cih->protocol); | |
761 | if (!pp) | |
762 | return NF_ACCEPT; | |
763 | ||
764 | /* Is the embedded protocol header present? */ | |
765 | if (unlikely(cih->frag_off & htons(IP_OFFSET) && | |
766 | pp->dont_defrag)) | |
767 | return NF_ACCEPT; | |
768 | ||
769 | IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMP for"); | |
770 | ||
771 | offset += cih->ihl * 4; | |
772 | ||
773 | ip_vs_fill_iphdr(AF_INET, cih, &ciph); | |
774 | /* The embedded headers contain source and dest in reverse order */ | |
775 | cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1); | |
776 | if (!cp) | |
777 | return NF_ACCEPT; | |
778 | ||
779 | snet.ip = iph->saddr; | |
780 | return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp, | |
781 | pp, offset, ihl); | |
782 | } | |
783 | ||
784 | #ifdef CONFIG_IP_VS_IPV6 | |
785 | static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related) | |
786 | { | |
787 | struct ipv6hdr *iph; | |
788 | struct icmp6hdr _icmph, *ic; | |
789 | struct ipv6hdr _ciph, *cih; /* The ip header contained | |
790 | within the ICMP */ | |
791 | struct ip_vs_iphdr ciph; | |
792 | struct ip_vs_conn *cp; | |
793 | struct ip_vs_protocol *pp; | |
794 | unsigned int offset; | |
795 | union nf_inet_addr snet; | |
796 | ||
797 | *related = 1; | |
798 | ||
799 | /* reassemble IP fragments */ | |
800 | if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) { | |
801 | if (ip_vs_gather_frags_v6(skb, IP_DEFRAG_VS_OUT)) | |
802 | return NF_STOLEN; | |
803 | } | |
804 | ||
805 | iph = ipv6_hdr(skb); | |
806 | offset = sizeof(struct ipv6hdr); | |
807 | ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); | |
808 | if (ic == NULL) | |
809 | return NF_DROP; | |
810 | ||
811 | IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) %pI6->%pI6\n", | |
812 | ic->icmp6_type, ntohs(icmpv6_id(ic)), | |
813 | &iph->saddr, &iph->daddr); | |
814 | ||
815 | /* | |
816 | * Work through seeing if this is for us. | |
817 | * These checks are supposed to be in an order that means easy | |
818 | * things are checked first to speed up processing.... however | |
819 | * this means that some packets will manage to get a long way | |
820 | * down this stack and then be rejected, but that's life. | |
821 | */ | |
822 | if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) && | |
823 | (ic->icmp6_type != ICMPV6_PKT_TOOBIG) && | |
824 | (ic->icmp6_type != ICMPV6_TIME_EXCEED)) { | |
825 | *related = 0; | |
826 | return NF_ACCEPT; | |
827 | } | |
828 | ||
829 | /* Now find the contained IP header */ | |
830 | offset += sizeof(_icmph); | |
831 | cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); | |
832 | if (cih == NULL) | |
833 | return NF_ACCEPT; /* The packet looks wrong, ignore */ | |
834 | ||
835 | pp = ip_vs_proto_get(cih->nexthdr); | |
836 | if (!pp) | |
837 | return NF_ACCEPT; | |
838 | ||
839 | /* Is the embedded protocol header present? */ | |
840 | /* TODO: we don't support fragmentation at the moment anyways */ | |
841 | if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag)) | |
842 | return NF_ACCEPT; | |
843 | ||
844 | IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMPv6 for"); | |
845 | ||
846 | offset += sizeof(struct ipv6hdr); | |
847 | ||
848 | ip_vs_fill_iphdr(AF_INET6, cih, &ciph); | |
849 | /* The embedded headers contain source and dest in reverse order */ | |
850 | cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1); | |
851 | if (!cp) | |
852 | return NF_ACCEPT; | |
853 | ||
854 | ipv6_addr_copy(&snet.in6, &iph->saddr); | |
855 | return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp, | |
856 | pp, offset, sizeof(struct ipv6hdr)); | |
857 | } | |
858 | #endif | |
859 | ||
860 | static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len) | |
861 | { | |
862 | struct tcphdr _tcph, *th; | |
863 | ||
864 | th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph); | |
865 | if (th == NULL) | |
866 | return 0; | |
867 | return th->rst; | |
868 | } | |
869 | ||
870 | /* Handle response packets: rewrite addresses and send away... | |
871 | * Used for NAT and local client. | |
872 | */ | |
873 | static unsigned int | |
874 | handle_response(int af, struct sk_buff *skb, struct ip_vs_protocol *pp, | |
875 | struct ip_vs_conn *cp, int ihl) | |
876 | { | |
877 | IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet"); | |
878 | ||
879 | if (!skb_make_writable(skb, ihl)) | |
880 | goto drop; | |
881 | ||
882 | /* mangle the packet */ | |
883 | if (pp->snat_handler && !pp->snat_handler(skb, pp, cp)) | |
884 | goto drop; | |
885 | ||
886 | #ifdef CONFIG_IP_VS_IPV6 | |
887 | if (af == AF_INET6) | |
888 | ipv6_hdr(skb)->saddr = cp->vaddr.in6; | |
889 | else | |
890 | #endif | |
891 | { | |
892 | ip_hdr(skb)->saddr = cp->vaddr.ip; | |
893 | ip_send_check(ip_hdr(skb)); | |
894 | } | |
895 | ||
896 | /* For policy routing, packets originating from this | |
897 | * machine itself may be routed differently to packets | |
898 | * passing through. We want this packet to be routed as | |
899 | * if it came from this machine itself. So re-compute | |
900 | * the routing information. | |
901 | */ | |
902 | #ifdef CONFIG_IP_VS_IPV6 | |
903 | if (af == AF_INET6) { | |
904 | if (ip6_route_me_harder(skb) != 0) | |
905 | goto drop; | |
906 | } else | |
907 | #endif | |
908 | if (ip_route_me_harder(skb, RTN_LOCAL) != 0) | |
909 | goto drop; | |
910 | ||
911 | IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT"); | |
912 | ||
913 | ip_vs_out_stats(cp, skb); | |
914 | ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp); | |
915 | ip_vs_conn_put(cp); | |
916 | ||
917 | skb->ipvs_property = 1; | |
918 | ||
919 | LeaveFunction(11); | |
920 | return NF_ACCEPT; | |
921 | ||
922 | drop: | |
923 | ip_vs_conn_put(cp); | |
924 | kfree_skb(skb); | |
925 | return NF_STOLEN; | |
926 | } | |
927 | ||
928 | /* | |
929 | * It is hooked at the NF_INET_FORWARD chain, used only for VS/NAT. | |
930 | * Check if outgoing packet belongs to the established ip_vs_conn. | |
931 | */ | |
932 | static unsigned int | |
933 | ip_vs_out(unsigned int hooknum, struct sk_buff *skb, | |
934 | const struct net_device *in, const struct net_device *out, | |
935 | int (*okfn)(struct sk_buff *)) | |
936 | { | |
937 | struct ip_vs_iphdr iph; | |
938 | struct ip_vs_protocol *pp; | |
939 | struct ip_vs_conn *cp; | |
940 | int af; | |
941 | ||
942 | EnterFunction(11); | |
943 | ||
944 | af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6; | |
945 | ||
946 | if (skb->ipvs_property) | |
947 | return NF_ACCEPT; | |
948 | ||
949 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
950 | #ifdef CONFIG_IP_VS_IPV6 | |
951 | if (af == AF_INET6) { | |
952 | if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { | |
953 | int related, verdict = ip_vs_out_icmp_v6(skb, &related); | |
954 | ||
955 | if (related) | |
956 | return verdict; | |
957 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
958 | } | |
959 | } else | |
960 | #endif | |
961 | if (unlikely(iph.protocol == IPPROTO_ICMP)) { | |
962 | int related, verdict = ip_vs_out_icmp(skb, &related); | |
963 | ||
964 | if (related) | |
965 | return verdict; | |
966 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
967 | } | |
968 | ||
969 | pp = ip_vs_proto_get(iph.protocol); | |
970 | if (unlikely(!pp)) | |
971 | return NF_ACCEPT; | |
972 | ||
973 | /* reassemble IP fragments */ | |
974 | #ifdef CONFIG_IP_VS_IPV6 | |
975 | if (af == AF_INET6) { | |
976 | if (unlikely(iph.protocol == IPPROTO_ICMPV6)) { | |
977 | int related, verdict = ip_vs_out_icmp_v6(skb, &related); | |
978 | ||
979 | if (related) | |
980 | return verdict; | |
981 | ||
982 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
983 | } | |
984 | } else | |
985 | #endif | |
986 | if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) && | |
987 | !pp->dont_defrag)) { | |
988 | if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT)) | |
989 | return NF_STOLEN; | |
990 | ||
991 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
992 | } | |
993 | ||
994 | /* | |
995 | * Check if the packet belongs to an existing entry | |
996 | */ | |
997 | cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0); | |
998 | ||
999 | if (unlikely(!cp)) { | |
1000 | if (sysctl_ip_vs_nat_icmp_send && | |
1001 | (pp->protocol == IPPROTO_TCP || | |
1002 | pp->protocol == IPPROTO_UDP)) { | |
1003 | __be16 _ports[2], *pptr; | |
1004 | ||
1005 | pptr = skb_header_pointer(skb, iph.len, | |
1006 | sizeof(_ports), _ports); | |
1007 | if (pptr == NULL) | |
1008 | return NF_ACCEPT; /* Not for me */ | |
1009 | if (ip_vs_lookup_real_service(af, iph.protocol, | |
1010 | &iph.saddr, | |
1011 | pptr[0])) { | |
1012 | /* | |
1013 | * Notify the real server: there is no | |
1014 | * existing entry if it is not RST | |
1015 | * packet or not TCP packet. | |
1016 | */ | |
1017 | if (iph.protocol != IPPROTO_TCP | |
1018 | || !is_tcp_reset(skb, iph.len)) { | |
1019 | #ifdef CONFIG_IP_VS_IPV6 | |
1020 | if (af == AF_INET6) | |
1021 | icmpv6_send(skb, | |
1022 | ICMPV6_DEST_UNREACH, | |
1023 | ICMPV6_PORT_UNREACH, | |
1024 | 0, skb->dev); | |
1025 | else | |
1026 | #endif | |
1027 | icmp_send(skb, | |
1028 | ICMP_DEST_UNREACH, | |
1029 | ICMP_PORT_UNREACH, 0); | |
1030 | return NF_DROP; | |
1031 | } | |
1032 | } | |
1033 | } | |
1034 | IP_VS_DBG_PKT(12, pp, skb, 0, | |
1035 | "packet continues traversal as normal"); | |
1036 | return NF_ACCEPT; | |
1037 | } | |
1038 | ||
1039 | return handle_response(af, skb, pp, cp, iph.len); | |
1040 | } | |
1041 | ||
1042 | ||
1043 | /* | |
1044 | * Handle ICMP messages in the outside-to-inside direction (incoming). | |
1045 | * Find any that might be relevant, check against existing connections, | |
1046 | * forward to the right destination host if relevant. | |
1047 | * Currently handles error types - unreachable, quench, ttl exceeded. | |
1048 | */ | |
1049 | static int | |
1050 | ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum) | |
1051 | { | |
1052 | struct iphdr *iph; | |
1053 | struct icmphdr _icmph, *ic; | |
1054 | struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */ | |
1055 | struct ip_vs_iphdr ciph; | |
1056 | struct ip_vs_conn *cp; | |
1057 | struct ip_vs_protocol *pp; | |
1058 | unsigned int offset, ihl, verdict; | |
1059 | union nf_inet_addr snet; | |
1060 | ||
1061 | *related = 1; | |
1062 | ||
1063 | /* reassemble IP fragments */ | |
1064 | if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { | |
1065 | if (ip_vs_gather_frags(skb, hooknum == NF_INET_LOCAL_IN ? | |
1066 | IP_DEFRAG_VS_IN : IP_DEFRAG_VS_FWD)) | |
1067 | return NF_STOLEN; | |
1068 | } | |
1069 | ||
1070 | iph = ip_hdr(skb); | |
1071 | offset = ihl = iph->ihl * 4; | |
1072 | ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); | |
1073 | if (ic == NULL) | |
1074 | return NF_DROP; | |
1075 | ||
1076 | IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n", | |
1077 | ic->type, ntohs(icmp_id(ic)), | |
1078 | &iph->saddr, &iph->daddr); | |
1079 | ||
1080 | /* | |
1081 | * Work through seeing if this is for us. | |
1082 | * These checks are supposed to be in an order that means easy | |
1083 | * things are checked first to speed up processing.... however | |
1084 | * this means that some packets will manage to get a long way | |
1085 | * down this stack and then be rejected, but that's life. | |
1086 | */ | |
1087 | if ((ic->type != ICMP_DEST_UNREACH) && | |
1088 | (ic->type != ICMP_SOURCE_QUENCH) && | |
1089 | (ic->type != ICMP_TIME_EXCEEDED)) { | |
1090 | *related = 0; | |
1091 | return NF_ACCEPT; | |
1092 | } | |
1093 | ||
1094 | /* Now find the contained IP header */ | |
1095 | offset += sizeof(_icmph); | |
1096 | cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); | |
1097 | if (cih == NULL) | |
1098 | return NF_ACCEPT; /* The packet looks wrong, ignore */ | |
1099 | ||
1100 | pp = ip_vs_proto_get(cih->protocol); | |
1101 | if (!pp) | |
1102 | return NF_ACCEPT; | |
1103 | ||
1104 | /* Is the embedded protocol header present? */ | |
1105 | if (unlikely(cih->frag_off & htons(IP_OFFSET) && | |
1106 | pp->dont_defrag)) | |
1107 | return NF_ACCEPT; | |
1108 | ||
1109 | IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMP for"); | |
1110 | ||
1111 | offset += cih->ihl * 4; | |
1112 | ||
1113 | ip_vs_fill_iphdr(AF_INET, cih, &ciph); | |
1114 | /* The embedded headers contain source and dest in reverse order */ | |
1115 | cp = pp->conn_in_get(AF_INET, skb, pp, &ciph, offset, 1); | |
1116 | if (!cp) { | |
1117 | /* The packet could also belong to a local client */ | |
1118 | cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1); | |
1119 | if (cp) { | |
1120 | snet.ip = iph->saddr; | |
1121 | return handle_response_icmp(AF_INET, skb, &snet, | |
1122 | cih->protocol, cp, pp, | |
1123 | offset, ihl); | |
1124 | } | |
1125 | return NF_ACCEPT; | |
1126 | } | |
1127 | ||
1128 | verdict = NF_DROP; | |
1129 | ||
1130 | /* Ensure the checksum is correct */ | |
1131 | if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) { | |
1132 | /* Failed checksum! */ | |
1133 | IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n", | |
1134 | &iph->saddr); | |
1135 | goto out; | |
1136 | } | |
1137 | ||
1138 | /* do the statistics and put it back */ | |
1139 | ip_vs_in_stats(cp, skb); | |
1140 | if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol) | |
1141 | offset += 2 * sizeof(__u16); | |
1142 | verdict = ip_vs_icmp_xmit(skb, cp, pp, offset); | |
1143 | /* do not touch skb anymore */ | |
1144 | ||
1145 | out: | |
1146 | __ip_vs_conn_put(cp); | |
1147 | ||
1148 | return verdict; | |
1149 | } | |
1150 | ||
1151 | #ifdef CONFIG_IP_VS_IPV6 | |
1152 | static int | |
1153 | ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum) | |
1154 | { | |
1155 | struct ipv6hdr *iph; | |
1156 | struct icmp6hdr _icmph, *ic; | |
1157 | struct ipv6hdr _ciph, *cih; /* The ip header contained | |
1158 | within the ICMP */ | |
1159 | struct ip_vs_iphdr ciph; | |
1160 | struct ip_vs_conn *cp; | |
1161 | struct ip_vs_protocol *pp; | |
1162 | unsigned int offset, verdict; | |
1163 | union nf_inet_addr snet; | |
1164 | ||
1165 | *related = 1; | |
1166 | ||
1167 | /* reassemble IP fragments */ | |
1168 | if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) { | |
1169 | if (ip_vs_gather_frags_v6(skb, hooknum == NF_INET_LOCAL_IN ? | |
1170 | IP_DEFRAG_VS_IN : | |
1171 | IP_DEFRAG_VS_FWD)) | |
1172 | return NF_STOLEN; | |
1173 | } | |
1174 | ||
1175 | iph = ipv6_hdr(skb); | |
1176 | offset = sizeof(struct ipv6hdr); | |
1177 | ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph); | |
1178 | if (ic == NULL) | |
1179 | return NF_DROP; | |
1180 | ||
1181 | IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) %pI6->%pI6\n", | |
1182 | ic->icmp6_type, ntohs(icmpv6_id(ic)), | |
1183 | &iph->saddr, &iph->daddr); | |
1184 | ||
1185 | /* | |
1186 | * Work through seeing if this is for us. | |
1187 | * These checks are supposed to be in an order that means easy | |
1188 | * things are checked first to speed up processing.... however | |
1189 | * this means that some packets will manage to get a long way | |
1190 | * down this stack and then be rejected, but that's life. | |
1191 | */ | |
1192 | if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) && | |
1193 | (ic->icmp6_type != ICMPV6_PKT_TOOBIG) && | |
1194 | (ic->icmp6_type != ICMPV6_TIME_EXCEED)) { | |
1195 | *related = 0; | |
1196 | return NF_ACCEPT; | |
1197 | } | |
1198 | ||
1199 | /* Now find the contained IP header */ | |
1200 | offset += sizeof(_icmph); | |
1201 | cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph); | |
1202 | if (cih == NULL) | |
1203 | return NF_ACCEPT; /* The packet looks wrong, ignore */ | |
1204 | ||
1205 | pp = ip_vs_proto_get(cih->nexthdr); | |
1206 | if (!pp) | |
1207 | return NF_ACCEPT; | |
1208 | ||
1209 | /* Is the embedded protocol header present? */ | |
1210 | /* TODO: we don't support fragmentation at the moment anyways */ | |
1211 | if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag)) | |
1212 | return NF_ACCEPT; | |
1213 | ||
1214 | IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMPv6 for"); | |
1215 | ||
1216 | offset += sizeof(struct ipv6hdr); | |
1217 | ||
1218 | ip_vs_fill_iphdr(AF_INET6, cih, &ciph); | |
1219 | /* The embedded headers contain source and dest in reverse order */ | |
1220 | cp = pp->conn_in_get(AF_INET6, skb, pp, &ciph, offset, 1); | |
1221 | if (!cp) { | |
1222 | /* The packet could also belong to a local client */ | |
1223 | cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1); | |
1224 | if (cp) { | |
1225 | ipv6_addr_copy(&snet.in6, &iph->saddr); | |
1226 | return handle_response_icmp(AF_INET6, skb, &snet, | |
1227 | cih->nexthdr, | |
1228 | cp, pp, offset, | |
1229 | sizeof(struct ipv6hdr)); | |
1230 | } | |
1231 | return NF_ACCEPT; | |
1232 | } | |
1233 | ||
1234 | verdict = NF_DROP; | |
1235 | ||
1236 | /* do the statistics and put it back */ | |
1237 | ip_vs_in_stats(cp, skb); | |
1238 | if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr) | |
1239 | offset += 2 * sizeof(__u16); | |
1240 | verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset); | |
1241 | /* do not touch skb anymore */ | |
1242 | ||
1243 | __ip_vs_conn_put(cp); | |
1244 | ||
1245 | return verdict; | |
1246 | } | |
1247 | #endif | |
1248 | ||
1249 | ||
1250 | /* | |
1251 | * Check if it's for virtual services, look it up, | |
1252 | * and send it on its way... | |
1253 | */ | |
1254 | static unsigned int | |
1255 | ip_vs_in(unsigned int hooknum, struct sk_buff *skb, | |
1256 | const struct net_device *in, const struct net_device *out, | |
1257 | int (*okfn)(struct sk_buff *)) | |
1258 | { | |
1259 | struct ip_vs_iphdr iph; | |
1260 | struct ip_vs_protocol *pp; | |
1261 | struct ip_vs_conn *cp; | |
1262 | int ret, restart, af; | |
1263 | ||
1264 | af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6; | |
1265 | ||
1266 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
1267 | ||
1268 | /* | |
1269 | * Big tappo: only PACKET_HOST, including loopback for local client | |
1270 | * Don't handle local packets on IPv6 for now | |
1271 | */ | |
1272 | if (unlikely(skb->pkt_type != PACKET_HOST)) { | |
1273 | IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s ignored\n", | |
1274 | skb->pkt_type, | |
1275 | iph.protocol, | |
1276 | IP_VS_DBG_ADDR(af, &iph.daddr)); | |
1277 | return NF_ACCEPT; | |
1278 | } | |
1279 | ||
1280 | if (unlikely(iph.protocol == IPPROTO_ICMP)) { | |
1281 | int related, verdict = ip_vs_in_icmp(skb, &related, hooknum); | |
1282 | ||
1283 | if (related) | |
1284 | return verdict; | |
1285 | ip_vs_fill_iphdr(af, skb_network_header(skb), &iph); | |
1286 | } | |
1287 | ||
1288 | /* Protocol supported? */ | |
1289 | pp = ip_vs_proto_get(iph.protocol); | |
1290 | if (unlikely(!pp)) | |
1291 | return NF_ACCEPT; | |
1292 | ||
1293 | /* | |
1294 | * Check if the packet belongs to an existing connection entry | |
1295 | */ | |
1296 | cp = pp->conn_in_get(af, skb, pp, &iph, iph.len, 0); | |
1297 | ||
1298 | if (unlikely(!cp)) { | |
1299 | int v; | |
1300 | ||
1301 | /* For local client packets, it could be a response */ | |
1302 | cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0); | |
1303 | if (cp) | |
1304 | return handle_response(af, skb, pp, cp, iph.len); | |
1305 | ||
1306 | if (!pp->conn_schedule(af, skb, pp, &v, &cp)) | |
1307 | return v; | |
1308 | } | |
1309 | ||
1310 | if (unlikely(!cp)) { | |
1311 | /* sorry, all this trouble for a no-hit :) */ | |
1312 | IP_VS_DBG_PKT(12, pp, skb, 0, | |
1313 | "packet continues traversal as normal"); | |
1314 | return NF_ACCEPT; | |
1315 | } | |
1316 | ||
1317 | IP_VS_DBG_PKT(11, pp, skb, 0, "Incoming packet"); | |
1318 | ||
1319 | /* Check the server status */ | |
1320 | if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) { | |
1321 | /* the destination server is not available */ | |
1322 | ||
1323 | if (sysctl_ip_vs_expire_nodest_conn) { | |
1324 | /* try to expire the connection immediately */ | |
1325 | ip_vs_conn_expire_now(cp); | |
1326 | } | |
1327 | /* don't restart its timer, and silently | |
1328 | drop the packet. */ | |
1329 | __ip_vs_conn_put(cp); | |
1330 | return NF_DROP; | |
1331 | } | |
1332 | ||
1333 | ip_vs_in_stats(cp, skb); | |
1334 | restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp); | |
1335 | if (cp->packet_xmit) | |
1336 | ret = cp->packet_xmit(skb, cp, pp); | |
1337 | /* do not touch skb anymore */ | |
1338 | else { | |
1339 | IP_VS_DBG_RL("warning: packet_xmit is null"); | |
1340 | ret = NF_ACCEPT; | |
1341 | } | |
1342 | ||
1343 | /* Increase its packet counter and check if it is needed | |
1344 | * to be synchronized | |
1345 | * | |
1346 | * Sync connection if it is about to close to | |
1347 | * encorage the standby servers to update the connections timeout | |
1348 | */ | |
1349 | atomic_inc(&cp->in_pkts); | |
1350 | if (af == AF_INET && | |
1351 | (ip_vs_sync_state & IP_VS_STATE_MASTER) && | |
1352 | (((cp->protocol != IPPROTO_TCP || | |
1353 | cp->state == IP_VS_TCP_S_ESTABLISHED) && | |
1354 | (atomic_read(&cp->in_pkts) % sysctl_ip_vs_sync_threshold[1] | |
1355 | == sysctl_ip_vs_sync_threshold[0])) || | |
1356 | ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) && | |
1357 | ((cp->state == IP_VS_TCP_S_FIN_WAIT) || | |
1358 | (cp->state == IP_VS_TCP_S_CLOSE_WAIT) || | |
1359 | (cp->state == IP_VS_TCP_S_TIME_WAIT))))) | |
1360 | ip_vs_sync_conn(cp); | |
1361 | cp->old_state = cp->state; | |
1362 | ||
1363 | ip_vs_conn_put(cp); | |
1364 | return ret; | |
1365 | } | |
1366 | ||
1367 | ||
1368 | /* | |
1369 | * It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP | |
1370 | * related packets destined for 0.0.0.0/0. | |
1371 | * When fwmark-based virtual service is used, such as transparent | |
1372 | * cache cluster, TCP packets can be marked and routed to ip_vs_in, | |
1373 | * but ICMP destined for 0.0.0.0/0 cannot not be easily marked and | |
1374 | * sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain | |
1375 | * and send them to ip_vs_in_icmp. | |
1376 | */ | |
1377 | static unsigned int | |
1378 | ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb, | |
1379 | const struct net_device *in, const struct net_device *out, | |
1380 | int (*okfn)(struct sk_buff *)) | |
1381 | { | |
1382 | int r; | |
1383 | ||
1384 | if (ip_hdr(skb)->protocol != IPPROTO_ICMP) | |
1385 | return NF_ACCEPT; | |
1386 | ||
1387 | return ip_vs_in_icmp(skb, &r, hooknum); | |
1388 | } | |
1389 | ||
1390 | #ifdef CONFIG_IP_VS_IPV6 | |
1391 | static unsigned int | |
1392 | ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb, | |
1393 | const struct net_device *in, const struct net_device *out, | |
1394 | int (*okfn)(struct sk_buff *)) | |
1395 | { | |
1396 | int r; | |
1397 | ||
1398 | if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6) | |
1399 | return NF_ACCEPT; | |
1400 | ||
1401 | return ip_vs_in_icmp_v6(skb, &r, hooknum); | |
1402 | } | |
1403 | #endif | |
1404 | ||
1405 | ||
1406 | static struct nf_hook_ops ip_vs_ops[] __read_mostly = { | |
1407 | /* After packet filtering, forward packet through VS/DR, VS/TUN, | |
1408 | * or VS/NAT(change destination), so that filtering rules can be | |
1409 | * applied to IPVS. */ | |
1410 | { | |
1411 | .hook = ip_vs_in, | |
1412 | .owner = THIS_MODULE, | |
1413 | .pf = PF_INET, | |
1414 | .hooknum = NF_INET_LOCAL_IN, | |
1415 | .priority = 100, | |
1416 | }, | |
1417 | /* After packet filtering, change source only for VS/NAT */ | |
1418 | { | |
1419 | .hook = ip_vs_out, | |
1420 | .owner = THIS_MODULE, | |
1421 | .pf = PF_INET, | |
1422 | .hooknum = NF_INET_FORWARD, | |
1423 | .priority = 100, | |
1424 | }, | |
1425 | /* After packet filtering (but before ip_vs_out_icmp), catch icmp | |
1426 | * destined for 0.0.0.0/0, which is for incoming IPVS connections */ | |
1427 | { | |
1428 | .hook = ip_vs_forward_icmp, | |
1429 | .owner = THIS_MODULE, | |
1430 | .pf = PF_INET, | |
1431 | .hooknum = NF_INET_FORWARD, | |
1432 | .priority = 99, | |
1433 | }, | |
1434 | /* Before the netfilter connection tracking, exit from POST_ROUTING */ | |
1435 | { | |
1436 | .hook = ip_vs_post_routing, | |
1437 | .owner = THIS_MODULE, | |
1438 | .pf = PF_INET, | |
1439 | .hooknum = NF_INET_POST_ROUTING, | |
1440 | .priority = NF_IP_PRI_NAT_SRC-1, | |
1441 | }, | |
1442 | #ifdef CONFIG_IP_VS_IPV6 | |
1443 | /* After packet filtering, forward packet through VS/DR, VS/TUN, | |
1444 | * or VS/NAT(change destination), so that filtering rules can be | |
1445 | * applied to IPVS. */ | |
1446 | { | |
1447 | .hook = ip_vs_in, | |
1448 | .owner = THIS_MODULE, | |
1449 | .pf = PF_INET6, | |
1450 | .hooknum = NF_INET_LOCAL_IN, | |
1451 | .priority = 100, | |
1452 | }, | |
1453 | /* After packet filtering, change source only for VS/NAT */ | |
1454 | { | |
1455 | .hook = ip_vs_out, | |
1456 | .owner = THIS_MODULE, | |
1457 | .pf = PF_INET6, | |
1458 | .hooknum = NF_INET_FORWARD, | |
1459 | .priority = 100, | |
1460 | }, | |
1461 | /* After packet filtering (but before ip_vs_out_icmp), catch icmp | |
1462 | * destined for 0.0.0.0/0, which is for incoming IPVS connections */ | |
1463 | { | |
1464 | .hook = ip_vs_forward_icmp_v6, | |
1465 | .owner = THIS_MODULE, | |
1466 | .pf = PF_INET6, | |
1467 | .hooknum = NF_INET_FORWARD, | |
1468 | .priority = 99, | |
1469 | }, | |
1470 | /* Before the netfilter connection tracking, exit from POST_ROUTING */ | |
1471 | { | |
1472 | .hook = ip_vs_post_routing, | |
1473 | .owner = THIS_MODULE, | |
1474 | .pf = PF_INET6, | |
1475 | .hooknum = NF_INET_POST_ROUTING, | |
1476 | .priority = NF_IP6_PRI_NAT_SRC-1, | |
1477 | }, | |
1478 | #endif | |
1479 | }; | |
1480 | ||
1481 | ||
1482 | /* | |
1483 | * Initialize IP Virtual Server | |
1484 | */ | |
1485 | static int __init ip_vs_init(void) | |
1486 | { | |
1487 | int ret; | |
1488 | ||
1489 | ip_vs_estimator_init(); | |
1490 | ||
1491 | ret = ip_vs_control_init(); | |
1492 | if (ret < 0) { | |
1493 | IP_VS_ERR("can't setup control.\n"); | |
1494 | goto cleanup_estimator; | |
1495 | } | |
1496 | ||
1497 | ip_vs_protocol_init(); | |
1498 | ||
1499 | ret = ip_vs_app_init(); | |
1500 | if (ret < 0) { | |
1501 | IP_VS_ERR("can't setup application helper.\n"); | |
1502 | goto cleanup_protocol; | |
1503 | } | |
1504 | ||
1505 | ret = ip_vs_conn_init(); | |
1506 | if (ret < 0) { | |
1507 | IP_VS_ERR("can't setup connection table.\n"); | |
1508 | goto cleanup_app; | |
1509 | } | |
1510 | ||
1511 | ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); | |
1512 | if (ret < 0) { | |
1513 | IP_VS_ERR("can't register hooks.\n"); | |
1514 | goto cleanup_conn; | |
1515 | } | |
1516 | ||
1517 | IP_VS_INFO("ipvs loaded.\n"); | |
1518 | return ret; | |
1519 | ||
1520 | cleanup_conn: | |
1521 | ip_vs_conn_cleanup(); | |
1522 | cleanup_app: | |
1523 | ip_vs_app_cleanup(); | |
1524 | cleanup_protocol: | |
1525 | ip_vs_protocol_cleanup(); | |
1526 | ip_vs_control_cleanup(); | |
1527 | cleanup_estimator: | |
1528 | ip_vs_estimator_cleanup(); | |
1529 | return ret; | |
1530 | } | |
1531 | ||
1532 | static void __exit ip_vs_cleanup(void) | |
1533 | { | |
1534 | nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops)); | |
1535 | ip_vs_conn_cleanup(); | |
1536 | ip_vs_app_cleanup(); | |
1537 | ip_vs_protocol_cleanup(); | |
1538 | ip_vs_control_cleanup(); | |
1539 | ip_vs_estimator_cleanup(); | |
1540 | IP_VS_INFO("ipvs unloaded.\n"); | |
1541 | } | |
1542 | ||
1543 | module_init(ip_vs_init); | |
1544 | module_exit(ip_vs_cleanup); | |
1545 | MODULE_LICENSE("GPL"); |