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added 2.6.29.6 aldebaran kernel
[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / net / netfilter / ipvs / ip_vs_core.c
blobcb3e031335ebc4af9a95e5a359c10c3805c8754d
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 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/ip.h>
30 #include <linux/tcp.h>
31 #include <linux/icmp.h>
32
33 #include <net/ip.h>
34 #include <net/tcp.h>
35 #include <net/udp.h>
36 #include <net/icmp.h> /* for icmp_send */
37 #include <net/route.h>
38
39 #include <linux/netfilter.h>
40 #include <linux/netfilter_ipv4.h>
41
42 #ifdef CONFIG_IP_VS_IPV6
43 #include <net/ipv6.h>
44 #include <linux/netfilter_ipv6.h>
45 #endif
46
47 #include <net/ip_vs.h>
48
49
50 EXPORT_SYMBOL(register_ip_vs_scheduler);
51 EXPORT_SYMBOL(unregister_ip_vs_scheduler);
52 EXPORT_SYMBOL(ip_vs_skb_replace);
53 EXPORT_SYMBOL(ip_vs_proto_name);
54 EXPORT_SYMBOL(ip_vs_conn_new);
55 EXPORT_SYMBOL(ip_vs_conn_in_get);
56 EXPORT_SYMBOL(ip_vs_conn_out_get);
57 #ifdef CONFIG_IP_VS_PROTO_TCP
58 EXPORT_SYMBOL(ip_vs_tcp_conn_listen);
59 #endif
60 EXPORT_SYMBOL(ip_vs_conn_put);
61 #ifdef CONFIG_IP_VS_DEBUG
62 EXPORT_SYMBOL(ip_vs_get_debug_level);
63 #endif
64
65
66 /* ID used in ICMP lookups */
67 #define icmp_id(icmph) (((icmph)->un).echo.id)
68 #define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier)
69
70 const char *ip_vs_proto_name(unsigned proto)
71 {
72 static char buf[20];
73
74 switch (proto) {
75 case IPPROTO_IP:
76 return "IP";
77 case IPPROTO_UDP:
78 return "UDP";
79 case IPPROTO_TCP:
80 return "TCP";
81 case IPPROTO_ICMP:
82 return "ICMP";
83 #ifdef CONFIG_IP_VS_IPV6
84 case IPPROTO_ICMPV6:
85 return "ICMPv6";
86 #endif
87 default:
88 sprintf(buf, "IP_%d", proto);
89 return buf;
90 }
91 }
92
93 void ip_vs_init_hash_table(struct list_head *table, int rows)
94 {
95 while (--rows >= 0)
96 INIT_LIST_HEAD(&table[rows]);
97 }
98
99 static inline void
100 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
101 {
102 struct ip_vs_dest *dest = cp->dest;
103 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
104 spin_lock(&dest->stats.lock);
105 dest->stats.ustats.inpkts++;
106 dest->stats.ustats.inbytes += skb->len;
107 spin_unlock(&dest->stats.lock);
108
109 spin_lock(&dest->svc->stats.lock);
110 dest->svc->stats.ustats.inpkts++;
111 dest->svc->stats.ustats.inbytes += skb->len;
112 spin_unlock(&dest->svc->stats.lock);
113
114 spin_lock(&ip_vs_stats.lock);
115 ip_vs_stats.ustats.inpkts++;
116 ip_vs_stats.ustats.inbytes += skb->len;
117 spin_unlock(&ip_vs_stats.lock);
118 }
119 }
120
121
122 static inline void
123 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
124 {
125 struct ip_vs_dest *dest = cp->dest;
126 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
127 spin_lock(&dest->stats.lock);
128 dest->stats.ustats.outpkts++;
129 dest->stats.ustats.outbytes += skb->len;
130 spin_unlock(&dest->stats.lock);
131
132 spin_lock(&dest->svc->stats.lock);
133 dest->svc->stats.ustats.outpkts++;
134 dest->svc->stats.ustats.outbytes += skb->len;
135 spin_unlock(&dest->svc->stats.lock);
136
137 spin_lock(&ip_vs_stats.lock);
138 ip_vs_stats.ustats.outpkts++;
139 ip_vs_stats.ustats.outbytes += skb->len;
140 spin_unlock(&ip_vs_stats.lock);
141 }
142 }
143
144
145 static inline void
146 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
147 {
148 spin_lock(&cp->dest->stats.lock);
149 cp->dest->stats.ustats.conns++;
150 spin_unlock(&cp->dest->stats.lock);
151
152 spin_lock(&svc->stats.lock);
153 svc->stats.ustats.conns++;
154 spin_unlock(&svc->stats.lock);
155
156 spin_lock(&ip_vs_stats.lock);
157 ip_vs_stats.ustats.conns++;
158 spin_unlock(&ip_vs_stats.lock);
159 }
160
161
162 static inline int
163 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
164 const struct sk_buff *skb,
165 struct ip_vs_protocol *pp)
166 {
167 if (unlikely(!pp->state_transition))
168 return 0;
169 return pp->state_transition(cp, direction, skb, pp);
170 }
171
172
173 /*
174 * IPVS persistent scheduling function
175 * It creates a connection entry according to its template if exists,
176 * or selects a server and creates a connection entry plus a template.
177 * Locking: we are svc user (svc->refcnt), so we hold all dests too
178 * Protocols supported: TCP, UDP
179 */
180 static struct ip_vs_conn *
181 ip_vs_sched_persist(struct ip_vs_service *svc,
182 const struct sk_buff *skb,
183 __be16 ports[2])
184 {
185 struct ip_vs_conn *cp = NULL;
186 struct ip_vs_iphdr iph;
187 struct ip_vs_dest *dest;
188 struct ip_vs_conn *ct;
189 __be16 dport; /* destination port to forward */
190 union nf_inet_addr snet; /* source network of the client,
191 after masking */
192
193 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
194
195 /* Mask saddr with the netmask to adjust template granularity */
196 #ifdef CONFIG_IP_VS_IPV6
197 if (svc->af == AF_INET6)
198 ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
199 else
200 #endif
201 snet.ip = iph.saddr.ip & svc->netmask;
202
203 IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
204 "mnet %s\n",
205 IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(ports[0]),
206 IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(ports[1]),
207 IP_VS_DBG_ADDR(svc->af, &snet));
208
209 /*
210 * As far as we know, FTP is a very complicated network protocol, and
211 * it uses control connection and data connections. For active FTP,
212 * FTP server initialize data connection to the client, its source port
213 * is often 20. For passive FTP, FTP server tells the clients the port
214 * that it passively listens to, and the client issues the data
215 * connection. In the tunneling or direct routing mode, the load
216 * balancer is on the client-to-server half of connection, the port
217 * number is unknown to the load balancer. So, a conn template like
218 * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
219 * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
220 * is created for other persistent services.
221 */
222 if (ports[1] == svc->port) {
223 /* Check if a template already exists */
224 if (svc->port != FTPPORT)
225 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
226 &iph.daddr, ports[1]);
227 else
228 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
229 &iph.daddr, 0);
230
231 if (!ct || !ip_vs_check_template(ct)) {
232 /*
233 * No template found or the dest of the connection
234 * template is not available.
235 */
236 dest = svc->scheduler->schedule(svc, skb);
237 if (dest == NULL) {
238 IP_VS_DBG(1, "p-schedule: no dest found.\n");
239 return NULL;
240 }
241
242 /*
243 * Create a template like <protocol,caddr,0,
244 * vaddr,vport,daddr,dport> for non-ftp service,
245 * and <protocol,caddr,0,vaddr,0,daddr,0>
246 * for ftp service.
247 */
248 if (svc->port != FTPPORT)
249 ct = ip_vs_conn_new(svc->af, iph.protocol,
250 &snet, 0,
251 &iph.daddr,
252 ports[1],
253 &dest->addr, dest->port,
254 IP_VS_CONN_F_TEMPLATE,
255 dest);
256 else
257 ct = ip_vs_conn_new(svc->af, iph.protocol,
258 &snet, 0,
259 &iph.daddr, 0,
260 &dest->addr, 0,
261 IP_VS_CONN_F_TEMPLATE,
262 dest);
263 if (ct == NULL)
264 return NULL;
265
266 ct->timeout = svc->timeout;
267 } else {
268 /* set destination with the found template */
269 dest = ct->dest;
270 }
271 dport = dest->port;
272 } else {
273 /*
274 * Note: persistent fwmark-based services and persistent
275 * port zero service are handled here.
276 * fwmark template: <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
277 * port zero template: <protocol,caddr,0,vaddr,0,daddr,0>
278 */
279 if (svc->fwmark) {
280 union nf_inet_addr fwmark = {
281 .all = { 0, 0, 0, htonl(svc->fwmark) }
282 };
283
284 ct = ip_vs_ct_in_get(svc->af, IPPROTO_IP, &snet, 0,
285 &fwmark, 0);
286 } else
287 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
288 &iph.daddr, 0);
289
290 if (!ct || !ip_vs_check_template(ct)) {
291 /*
292 * If it is not persistent port zero, return NULL,
293 * otherwise create a connection template.
294 */
295 if (svc->port)
296 return NULL;
297
298 dest = svc->scheduler->schedule(svc, skb);
299 if (dest == NULL) {
300 IP_VS_DBG(1, "p-schedule: no dest found.\n");
301 return NULL;
302 }
303
304 /*
305 * Create a template according to the service
306 */
307 if (svc->fwmark) {
308 union nf_inet_addr fwmark = {
309 .all = { 0, 0, 0, htonl(svc->fwmark) }
310 };
311
312 ct = ip_vs_conn_new(svc->af, IPPROTO_IP,
313 &snet, 0,
314 &fwmark, 0,
315 &dest->addr, 0,
316 IP_VS_CONN_F_TEMPLATE,
317 dest);
318 } else
319 ct = ip_vs_conn_new(svc->af, iph.protocol,
320 &snet, 0,
321 &iph.daddr, 0,
322 &dest->addr, 0,
323 IP_VS_CONN_F_TEMPLATE,
324 dest);
325 if (ct == NULL)
326 return NULL;
327
328 ct->timeout = svc->timeout;
329 } else {
330 /* set destination with the found template */
331 dest = ct->dest;
332 }
333 dport = ports[1];
334 }
335
336 /*
337 * Create a new connection according to the template
338 */
339 cp = ip_vs_conn_new(svc->af, iph.protocol,
340 &iph.saddr, ports[0],
341 &iph.daddr, ports[1],
342 &dest->addr, dport,
343 0,
344 dest);
345 if (cp == NULL) {
346 ip_vs_conn_put(ct);
347 return NULL;
348 }
349
350 /*
351 * Add its control
352 */
353 ip_vs_control_add(cp, ct);
354 ip_vs_conn_put(ct);
355
356 ip_vs_conn_stats(cp, svc);
357 return cp;
358 }
359
360
361 /*
362 * IPVS main scheduling function
363 * It selects a server according to the virtual service, and
364 * creates a connection entry.
365 * Protocols supported: TCP, UDP
366 */
367 struct ip_vs_conn *
368 ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
369 {
370 struct ip_vs_conn *cp = NULL;
371 struct ip_vs_iphdr iph;
372 struct ip_vs_dest *dest;
373 __be16 _ports[2], *pptr;
374
375 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
376 pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
377 if (pptr == NULL)
378 return NULL;
379
380 /*
381 * Persistent service
382 */
383 if (svc->flags & IP_VS_SVC_F_PERSISTENT)
384 return ip_vs_sched_persist(svc, skb, pptr);
385
386 /*
387 * Non-persistent service
388 */
389 if (!svc->fwmark && pptr[1] != svc->port) {
390 if (!svc->port)
391 IP_VS_ERR("Schedule: port zero only supported "
392 "in persistent services, "
393 "check your ipvs configuration\n");
394 return NULL;
395 }
396
397 dest = svc->scheduler->schedule(svc, skb);
398 if (dest == NULL) {
399 IP_VS_DBG(1, "Schedule: no dest found.\n");
400 return NULL;
401 }
402
403 /*
404 * Create a connection entry.
405 */
406 cp = ip_vs_conn_new(svc->af, iph.protocol,
407 &iph.saddr, pptr[0],
408 &iph.daddr, pptr[1],
409 &dest->addr, dest->port ? dest->port : pptr[1],
410 0,
411 dest);
412 if (cp == NULL)
413 return NULL;
414
415 IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
416 "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
417 ip_vs_fwd_tag(cp),
418 IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
419 IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
420 IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
421 cp->flags, atomic_read(&cp->refcnt));
422
423 ip_vs_conn_stats(cp, svc);
424 return cp;
425 }
426
427
428 /*
429 * Pass or drop the packet.
430 * Called by ip_vs_in, when the virtual service is available but
431 * no destination is available for a new connection.
432 */
433 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
434 struct ip_vs_protocol *pp)
435 {
436 __be16 _ports[2], *pptr;
437 struct ip_vs_iphdr iph;
438 int unicast;
439 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
440
441 pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
442 if (pptr == NULL) {
443 ip_vs_service_put(svc);
444 return NF_DROP;
445 }
446
447 #ifdef CONFIG_IP_VS_IPV6
448 if (svc->af == AF_INET6)
449 unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
450 else
451 #endif
452 unicast = (inet_addr_type(&init_net, iph.daddr.ip) == RTN_UNICAST);
453
454 /* if it is fwmark-based service, the cache_bypass sysctl is up
455 and the destination is a non-local unicast, then create
456 a cache_bypass connection entry */
457 if (sysctl_ip_vs_cache_bypass && svc->fwmark && unicast) {
458 int ret, cs;
459 struct ip_vs_conn *cp;
460 union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };
461
462 ip_vs_service_put(svc);
463
464 /* create a new connection entry */
465 IP_VS_DBG(6, "ip_vs_leave: create a cache_bypass entry\n");
466 cp = ip_vs_conn_new(svc->af, iph.protocol,
467 &iph.saddr, pptr[0],
468 &iph.daddr, pptr[1],
469 &daddr, 0,
470 IP_VS_CONN_F_BYPASS,
471 NULL);
472 if (cp == NULL)
473 return NF_DROP;
474
475 /* statistics */
476 ip_vs_in_stats(cp, skb);
477
478 /* set state */
479 cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
480
481 /* transmit the first SYN packet */
482 ret = cp->packet_xmit(skb, cp, pp);
483 /* do not touch skb anymore */
484
485 atomic_inc(&cp->in_pkts);
486 ip_vs_conn_put(cp);
487 return ret;
488 }
489
490 /*
491 * When the virtual ftp service is presented, packets destined
492 * for other services on the VIP may get here (except services
493 * listed in the ipvs table), pass the packets, because it is
494 * not ipvs job to decide to drop the packets.
495 */
496 if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
497 ip_vs_service_put(svc);
498 return NF_ACCEPT;
499 }
500
501 ip_vs_service_put(svc);
502
503 /*
504 * Notify the client that the destination is unreachable, and
505 * release the socket buffer.
506 * Since it is in IP layer, the TCP socket is not actually
507 * created, the TCP RST packet cannot be sent, instead that
508 * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
509 */
510 #ifdef CONFIG_IP_VS_IPV6
511 if (svc->af == AF_INET6)
512 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0,
513 skb->dev);
514 else
515 #endif
516 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
517
518 return NF_DROP;
519 }
520
521
522 /*
523 * It is hooked before NF_IP_PRI_NAT_SRC at the NF_INET_POST_ROUTING
524 * chain, and is used for VS/NAT.
525 * It detects packets for VS/NAT connections and sends the packets
526 * immediately. This can avoid that iptable_nat mangles the packets
527 * for VS/NAT.
528 */
529 static unsigned int ip_vs_post_routing(unsigned int hooknum,
530 struct sk_buff *skb,
531 const struct net_device *in,
532 const struct net_device *out,
533 int (*okfn)(struct sk_buff *))
534 {
535 if (!skb->ipvs_property)
536 return NF_ACCEPT;
537 /* The packet was sent from IPVS, exit this chain */
538 return NF_STOP;
539 }
540
541 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
542 {
543 return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
544 }
545
546 static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
547 {
548 int err = ip_defrag(skb, user);
549
550 if (!err)
551 ip_send_check(ip_hdr(skb));
552
553 return err;
554 }
555
556 #ifdef CONFIG_IP_VS_IPV6
557 static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user)
558 {
559 /* TODO IPv6: Find out what to do here for IPv6 */
560 return 0;
561 }
562 #endif
563
564 /*
565 * Packet has been made sufficiently writable in caller
566 * - inout: 1=in->out, 0=out->in
567 */
568 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
569 struct ip_vs_conn *cp, int inout)
570 {
571 struct iphdr *iph = ip_hdr(skb);
572 unsigned int icmp_offset = iph->ihl*4;
573 struct icmphdr *icmph = (struct icmphdr *)(skb_network_header(skb) +
574 icmp_offset);
575 struct iphdr *ciph = (struct iphdr *)(icmph + 1);
576
577 if (inout) {
578 iph->saddr = cp->vaddr.ip;
579 ip_send_check(iph);
580 ciph->daddr = cp->vaddr.ip;
581 ip_send_check(ciph);
582 } else {
583 iph->daddr = cp->daddr.ip;
584 ip_send_check(iph);
585 ciph->saddr = cp->daddr.ip;
586 ip_send_check(ciph);
587 }
588
589 /* the TCP/UDP port */
590 if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol) {
591 __be16 *ports = (void *)ciph + ciph->ihl*4;
592
593 if (inout)
594 ports[1] = cp->vport;
595 else
596 ports[0] = cp->dport;
597 }
598
599 /* And finally the ICMP checksum */
600 icmph->checksum = 0;
601 icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
602 skb->ip_summed = CHECKSUM_UNNECESSARY;
603
604 if (inout)
605 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
606 "Forwarding altered outgoing ICMP");
607 else
608 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
609 "Forwarding altered incoming ICMP");
610 }
611
612 #ifdef CONFIG_IP_VS_IPV6
613 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
614 struct ip_vs_conn *cp, int inout)
615 {
616 struct ipv6hdr *iph = ipv6_hdr(skb);
617 unsigned int icmp_offset = sizeof(struct ipv6hdr);
618 struct icmp6hdr *icmph = (struct icmp6hdr *)(skb_network_header(skb) +
619 icmp_offset);
620 struct ipv6hdr *ciph = (struct ipv6hdr *)(icmph + 1);
621
622 if (inout) {
623 iph->saddr = cp->vaddr.in6;
624 ciph->daddr = cp->vaddr.in6;
625 } else {
626 iph->daddr = cp->daddr.in6;
627 ciph->saddr = cp->daddr.in6;
628 }
629
630 /* the TCP/UDP port */
631 if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr) {
632 __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr);
633
634 if (inout)
635 ports[1] = cp->vport;
636 else
637 ports[0] = cp->dport;
638 }
639
640 /* And finally the ICMP checksum */
641 icmph->icmp6_cksum = 0;
642 /* TODO IPv6: is this correct for ICMPv6? */
643 ip_vs_checksum_complete(skb, icmp_offset);
644 skb->ip_summed = CHECKSUM_UNNECESSARY;
645
646 if (inout)
647 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
648 "Forwarding altered outgoing ICMPv6");
649 else
650 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
651 "Forwarding altered incoming ICMPv6");
652 }
653 #endif
654
655 /* Handle relevant response ICMP messages - forward to the right
656 * destination host. Used for NAT and local client.
657 */
658 static int handle_response_icmp(int af, struct sk_buff *skb,
659 union nf_inet_addr *snet,
660 __u8 protocol, struct ip_vs_conn *cp,
661 struct ip_vs_protocol *pp,
662 unsigned int offset, unsigned int ihl)
663 {
664 unsigned int verdict = NF_DROP;
665
666 if (IP_VS_FWD_METHOD(cp) != 0) {
667 IP_VS_ERR("shouldn't reach here, because the box is on the "
668 "half connection in the tun/dr module.\n");
669 }
670
671 /* Ensure the checksum is correct */
672 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
673 /* Failed checksum! */
674 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
675 IP_VS_DBG_ADDR(af, snet));
676 goto out;
677 }
678
679 if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol)
680 offset += 2 * sizeof(__u16);
681 if (!skb_make_writable(skb, offset))
682 goto out;
683
684 #ifdef CONFIG_IP_VS_IPV6
685 if (af == AF_INET6)
686 ip_vs_nat_icmp_v6(skb, pp, cp, 1);
687 else
688 #endif
689 ip_vs_nat_icmp(skb, pp, cp, 1);
690
691 /* do the statistics and put it back */
692 ip_vs_out_stats(cp, skb);
693
694 skb->ipvs_property = 1;
695 verdict = NF_ACCEPT;
696
697 out:
698 __ip_vs_conn_put(cp);
699
700 return verdict;
701 }
702
703 /*
704 * Handle ICMP messages in the inside-to-outside direction (outgoing).
705 * Find any that might be relevant, check against existing connections.
706 * Currently handles error types - unreachable, quench, ttl exceeded.
707 */
708 static int ip_vs_out_icmp(struct sk_buff *skb, int *related)
709 {
710 struct iphdr *iph;
711 struct icmphdr _icmph, *ic;
712 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
713 struct ip_vs_iphdr ciph;
714 struct ip_vs_conn *cp;
715 struct ip_vs_protocol *pp;
716 unsigned int offset, ihl;
717 union nf_inet_addr snet;
718
719 *related = 1;
720
721 /* reassemble IP fragments */
722 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
723 if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
724 return NF_STOLEN;
725 }
726
727 iph = ip_hdr(skb);
728 offset = ihl = iph->ihl * 4;
729 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
730 if (ic == NULL)
731 return NF_DROP;
732
733 IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
734 ic->type, ntohs(icmp_id(ic)),
735 &iph->saddr, &iph->daddr);
736
737 /*
738 * Work through seeing if this is for us.
739 * These checks are supposed to be in an order that means easy
740 * things are checked first to speed up processing.... however
741 * this means that some packets will manage to get a long way
742 * down this stack and then be rejected, but that's life.
743 */
744 if ((ic->type != ICMP_DEST_UNREACH) &&
745 (ic->type != ICMP_SOURCE_QUENCH) &&
746 (ic->type != ICMP_TIME_EXCEEDED)) {
747 *related = 0;
748 return NF_ACCEPT;
749 }
750
751 /* Now find the contained IP header */
752 offset += sizeof(_icmph);
753 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
754 if (cih == NULL)
755 return NF_ACCEPT; /* The packet looks wrong, ignore */
756
757 pp = ip_vs_proto_get(cih->protocol);
758 if (!pp)
759 return NF_ACCEPT;
760
761 /* Is the embedded protocol header present? */
762 if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
763 pp->dont_defrag))
764 return NF_ACCEPT;
765
766 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMP for");
767
768 offset += cih->ihl * 4;
769
770 ip_vs_fill_iphdr(AF_INET, cih, &ciph);
771 /* The embedded headers contain source and dest in reverse order */
772 cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1);
773 if (!cp)
774 return NF_ACCEPT;
775
776 snet.ip = iph->saddr;
777 return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
778 pp, offset, ihl);
779 }
780
781 #ifdef CONFIG_IP_VS_IPV6
782 static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related)
783 {
784 struct ipv6hdr *iph;
785 struct icmp6hdr _icmph, *ic;
786 struct ipv6hdr _ciph, *cih; /* The ip header contained
787 within the ICMP */
788 struct ip_vs_iphdr ciph;
789 struct ip_vs_conn *cp;
790 struct ip_vs_protocol *pp;
791 unsigned int offset;
792 union nf_inet_addr snet;
793
794 *related = 1;
795
796 /* reassemble IP fragments */
797 if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
798 if (ip_vs_gather_frags_v6(skb, IP_DEFRAG_VS_OUT))
799 return NF_STOLEN;
800 }
801
802 iph = ipv6_hdr(skb);
803 offset = sizeof(struct ipv6hdr);
804 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
805 if (ic == NULL)
806 return NF_DROP;
807
808 IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) %pI6->%pI6\n",
809 ic->icmp6_type, ntohs(icmpv6_id(ic)),
810 &iph->saddr, &iph->daddr);
811
812 /*
813 * Work through seeing if this is for us.
814 * These checks are supposed to be in an order that means easy
815 * things are checked first to speed up processing.... however
816 * this means that some packets will manage to get a long way
817 * down this stack and then be rejected, but that's life.
818 */
819 if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
820 (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
821 (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
822 *related = 0;
823 return NF_ACCEPT;
824 }
825
826 /* Now find the contained IP header */
827 offset += sizeof(_icmph);
828 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
829 if (cih == NULL)
830 return NF_ACCEPT; /* The packet looks wrong, ignore */
831
832 pp = ip_vs_proto_get(cih->nexthdr);
833 if (!pp)
834 return NF_ACCEPT;
835
836 /* Is the embedded protocol header present? */
837 /* TODO: we don't support fragmentation at the moment anyways */
838 if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
839 return NF_ACCEPT;
840
841 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMPv6 for");
842
843 offset += sizeof(struct ipv6hdr);
844
845 ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
846 /* The embedded headers contain source and dest in reverse order */
847 cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1);
848 if (!cp)
849 return NF_ACCEPT;
850
851 ipv6_addr_copy(&snet.in6, &iph->saddr);
852 return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp,
853 pp, offset, sizeof(struct ipv6hdr));
854 }
855 #endif
856
857 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
858 {
859 struct tcphdr _tcph, *th;
860
861 th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
862 if (th == NULL)
863 return 0;
864 return th->rst;
865 }
866
867 /* Handle response packets: rewrite addresses and send away...
868 * Used for NAT and local client.
869 */
870 static unsigned int
871 handle_response(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
872 struct ip_vs_conn *cp, int ihl)
873 {
874 IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet");
875
876 if (!skb_make_writable(skb, ihl))
877 goto drop;
878
879 /* mangle the packet */
880 if (pp->snat_handler && !pp->snat_handler(skb, pp, cp))
881 goto drop;
882
883 #ifdef CONFIG_IP_VS_IPV6
884 if (af == AF_INET6)
885 ipv6_hdr(skb)->saddr = cp->vaddr.in6;
886 else
887 #endif
888 {
889 ip_hdr(skb)->saddr = cp->vaddr.ip;
890 ip_send_check(ip_hdr(skb));
891 }
892
893 /* For policy routing, packets originating from this
894 * machine itself may be routed differently to packets
895 * passing through. We want this packet to be routed as
896 * if it came from this machine itself. So re-compute
897 * the routing information.
898 */
899 #ifdef CONFIG_IP_VS_IPV6
900 if (af == AF_INET6) {
901 if (ip6_route_me_harder(skb) != 0)
902 goto drop;
903 } else
904 #endif
905 if (ip_route_me_harder(skb, RTN_LOCAL) != 0)
906 goto drop;
907
908 IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
909
910 ip_vs_out_stats(cp, skb);
911 ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp);
912 ip_vs_conn_put(cp);
913
914 skb->ipvs_property = 1;
915
916 LeaveFunction(11);
917 return NF_ACCEPT;
918
919 drop:
920 ip_vs_conn_put(cp);
921 kfree_skb(skb);
922 return NF_STOLEN;
923 }
924
925 /*
926 * It is hooked at the NF_INET_FORWARD chain, used only for VS/NAT.
927 * Check if outgoing packet belongs to the established ip_vs_conn.
928 */
929 static unsigned int
930 ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
931 const struct net_device *in, const struct net_device *out,
932 int (*okfn)(struct sk_buff *))
933 {
934 struct ip_vs_iphdr iph;
935 struct ip_vs_protocol *pp;
936 struct ip_vs_conn *cp;
937 int af;
938
939 EnterFunction(11);
940
941 af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6;
942
943 if (skb->ipvs_property)
944 return NF_ACCEPT;
945
946 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
947 #ifdef CONFIG_IP_VS_IPV6
948 if (af == AF_INET6) {
949 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
950 int related, verdict = ip_vs_out_icmp_v6(skb, &related);
951
952 if (related)
953 return verdict;
954 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
955 }
956 } else
957 #endif
958 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
959 int related, verdict = ip_vs_out_icmp(skb, &related);
960
961 if (related)
962 return verdict;
963 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
964 }
965
966 pp = ip_vs_proto_get(iph.protocol);
967 if (unlikely(!pp))
968 return NF_ACCEPT;
969
970 /* reassemble IP fragments */
971 #ifdef CONFIG_IP_VS_IPV6
972 if (af == AF_INET6) {
973 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
974 int related, verdict = ip_vs_out_icmp_v6(skb, &related);
975
976 if (related)
977 return verdict;
978
979 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
980 }
981 } else
982 #endif
983 if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) &&
984 !pp->dont_defrag)) {
985 if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
986 return NF_STOLEN;
987
988 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
989 }
990
991 /*
992 * Check if the packet belongs to an existing entry
993 */
994 cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0);
995
996 if (unlikely(!cp)) {
997 if (sysctl_ip_vs_nat_icmp_send &&
998 (pp->protocol == IPPROTO_TCP ||
999 pp->protocol == IPPROTO_UDP)) {
1000 __be16 _ports[2], *pptr;
1001
1002 pptr = skb_header_pointer(skb, iph.len,
1003 sizeof(_ports), _ports);
1004 if (pptr == NULL)
1005 return NF_ACCEPT; /* Not for me */
1006 if (ip_vs_lookup_real_service(af, iph.protocol,
1007 &iph.saddr,
1008 pptr[0])) {
1009 /*
1010 * Notify the real server: there is no
1011 * existing entry if it is not RST
1012 * packet or not TCP packet.
1013 */
1014 if (iph.protocol != IPPROTO_TCP
1015 || !is_tcp_reset(skb, iph.len)) {
1016 #ifdef CONFIG_IP_VS_IPV6
1017 if (af == AF_INET6)
1018 icmpv6_send(skb,
1019 ICMPV6_DEST_UNREACH,
1020 ICMPV6_PORT_UNREACH,
1021 0, skb->dev);
1022 else
1023 #endif
1024 icmp_send(skb,
1025 ICMP_DEST_UNREACH,
1026 ICMP_PORT_UNREACH, 0);
1027 return NF_DROP;
1028 }
1029 }
1030 }
1031 IP_VS_DBG_PKT(12, pp, skb, 0,
1032 "packet continues traversal as normal");
1033 return NF_ACCEPT;
1034 }
1035
1036 return handle_response(af, skb, pp, cp, iph.len);
1037 }
1038
1039
1040 /*
1041 * Handle ICMP messages in the outside-to-inside direction (incoming).
1042 * Find any that might be relevant, check against existing connections,
1043 * forward to the right destination host if relevant.
1044 * Currently handles error types - unreachable, quench, ttl exceeded.
1045 */
1046 static int
1047 ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
1048 {
1049 struct iphdr *iph;
1050 struct icmphdr _icmph, *ic;
1051 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
1052 struct ip_vs_iphdr ciph;
1053 struct ip_vs_conn *cp;
1054 struct ip_vs_protocol *pp;
1055 unsigned int offset, ihl, verdict;
1056 union nf_inet_addr snet;
1057
1058 *related = 1;
1059
1060 /* reassemble IP fragments */
1061 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
1062 if (ip_vs_gather_frags(skb, hooknum == NF_INET_LOCAL_IN ?
1063 IP_DEFRAG_VS_IN : IP_DEFRAG_VS_FWD))
1064 return NF_STOLEN;
1065 }
1066
1067 iph = ip_hdr(skb);
1068 offset = ihl = iph->ihl * 4;
1069 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1070 if (ic == NULL)
1071 return NF_DROP;
1072
1073 IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1074 ic->type, ntohs(icmp_id(ic)),
1075 &iph->saddr, &iph->daddr);
1076
1077 /*
1078 * Work through seeing if this is for us.
1079 * These checks are supposed to be in an order that means easy
1080 * things are checked first to speed up processing.... however
1081 * this means that some packets will manage to get a long way
1082 * down this stack and then be rejected, but that's life.
1083 */
1084 if ((ic->type != ICMP_DEST_UNREACH) &&
1085 (ic->type != ICMP_SOURCE_QUENCH) &&
1086 (ic->type != ICMP_TIME_EXCEEDED)) {
1087 *related = 0;
1088 return NF_ACCEPT;
1089 }
1090
1091 /* Now find the contained IP header */
1092 offset += sizeof(_icmph);
1093 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1094 if (cih == NULL)
1095 return NF_ACCEPT; /* The packet looks wrong, ignore */
1096
1097 pp = ip_vs_proto_get(cih->protocol);
1098 if (!pp)
1099 return NF_ACCEPT;
1100
1101 /* Is the embedded protocol header present? */
1102 if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1103 pp->dont_defrag))
1104 return NF_ACCEPT;
1105
1106 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMP for");
1107
1108 offset += cih->ihl * 4;
1109
1110 ip_vs_fill_iphdr(AF_INET, cih, &ciph);
1111 /* The embedded headers contain source and dest in reverse order */
1112 cp = pp->conn_in_get(AF_INET, skb, pp, &ciph, offset, 1);
1113 if (!cp) {
1114 /* The packet could also belong to a local client */
1115 cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1);
1116 if (cp) {
1117 snet.ip = iph->saddr;
1118 return handle_response_icmp(AF_INET, skb, &snet,
1119 cih->protocol, cp, pp,
1120 offset, ihl);
1121 }
1122 return NF_ACCEPT;
1123 }
1124
1125 verdict = NF_DROP;
1126
1127 /* Ensure the checksum is correct */
1128 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1129 /* Failed checksum! */
1130 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1131 &iph->saddr);
1132 goto out;
1133 }
1134
1135 /* do the statistics and put it back */
1136 ip_vs_in_stats(cp, skb);
1137 if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
1138 offset += 2 * sizeof(__u16);
1139 verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
1140 /* do not touch skb anymore */
1141
1142 out:
1143 __ip_vs_conn_put(cp);
1144
1145 return verdict;
1146 }
1147
1148 #ifdef CONFIG_IP_VS_IPV6
1149 static int
1150 ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
1151 {
1152 struct ipv6hdr *iph;
1153 struct icmp6hdr _icmph, *ic;
1154 struct ipv6hdr _ciph, *cih; /* The ip header contained
1155 within the ICMP */
1156 struct ip_vs_iphdr ciph;
1157 struct ip_vs_conn *cp;
1158 struct ip_vs_protocol *pp;
1159 unsigned int offset, verdict;
1160 union nf_inet_addr snet;
1161
1162 *related = 1;
1163
1164 /* reassemble IP fragments */
1165 if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
1166 if (ip_vs_gather_frags_v6(skb, hooknum == NF_INET_LOCAL_IN ?
1167 IP_DEFRAG_VS_IN :
1168 IP_DEFRAG_VS_FWD))
1169 return NF_STOLEN;
1170 }
1171
1172 iph = ipv6_hdr(skb);
1173 offset = sizeof(struct ipv6hdr);
1174 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1175 if (ic == NULL)
1176 return NF_DROP;
1177
1178 IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) %pI6->%pI6\n",
1179 ic->icmp6_type, ntohs(icmpv6_id(ic)),
1180 &iph->saddr, &iph->daddr);
1181
1182 /*
1183 * Work through seeing if this is for us.
1184 * These checks are supposed to be in an order that means easy
1185 * things are checked first to speed up processing.... however
1186 * this means that some packets will manage to get a long way
1187 * down this stack and then be rejected, but that's life.
1188 */
1189 if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
1190 (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
1191 (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
1192 *related = 0;
1193 return NF_ACCEPT;
1194 }
1195
1196 /* Now find the contained IP header */
1197 offset += sizeof(_icmph);
1198 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1199 if (cih == NULL)
1200 return NF_ACCEPT; /* The packet looks wrong, ignore */
1201
1202 pp = ip_vs_proto_get(cih->nexthdr);
1203 if (!pp)
1204 return NF_ACCEPT;
1205
1206 /* Is the embedded protocol header present? */
1207 /* TODO: we don't support fragmentation at the moment anyways */
1208 if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
1209 return NF_ACCEPT;
1210
1211 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMPv6 for");
1212
1213 offset += sizeof(struct ipv6hdr);
1214
1215 ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
1216 /* The embedded headers contain source and dest in reverse order */
1217 cp = pp->conn_in_get(AF_INET6, skb, pp, &ciph, offset, 1);
1218 if (!cp) {
1219 /* The packet could also belong to a local client */
1220 cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1);
1221 if (cp) {
1222 ipv6_addr_copy(&snet.in6, &iph->saddr);
1223 return handle_response_icmp(AF_INET6, skb, &snet,
1224 cih->nexthdr,
1225 cp, pp, offset,
1226 sizeof(struct ipv6hdr));
1227 }
1228 return NF_ACCEPT;
1229 }
1230
1231 verdict = NF_DROP;
1232
1233 /* do the statistics and put it back */
1234 ip_vs_in_stats(cp, skb);
1235 if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr)
1236 offset += 2 * sizeof(__u16);
1237 verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
1238 /* do not touch skb anymore */
1239
1240 __ip_vs_conn_put(cp);
1241
1242 return verdict;
1243 }
1244 #endif
1245
1246
1247 /*
1248 * Check if it's for virtual services, look it up,
1249 * and send it on its way...
1250 */
1251 static unsigned int
1252 ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
1253 const struct net_device *in, const struct net_device *out,
1254 int (*okfn)(struct sk_buff *))
1255 {
1256 struct ip_vs_iphdr iph;
1257 struct ip_vs_protocol *pp;
1258 struct ip_vs_conn *cp;
1259 int ret, restart, af;
1260
1261 af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6;
1262
1263 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1264
1265 /*
1266 * Big tappo: only PACKET_HOST, including loopback for local client
1267 * Don't handle local packets on IPv6 for now
1268 */
1269 if (unlikely(skb->pkt_type != PACKET_HOST)) {
1270 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s ignored\n",
1271 skb->pkt_type,
1272 iph.protocol,
1273 IP_VS_DBG_ADDR(af, &iph.daddr));
1274 return NF_ACCEPT;
1275 }
1276
1277 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1278 int related, verdict = ip_vs_in_icmp(skb, &related, hooknum);
1279
1280 if (related)
1281 return verdict;
1282 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1283 }
1284
1285 /* Protocol supported? */
1286 pp = ip_vs_proto_get(iph.protocol);
1287 if (unlikely(!pp))
1288 return NF_ACCEPT;
1289
1290 /*
1291 * Check if the packet belongs to an existing connection entry
1292 */
1293 cp = pp->conn_in_get(af, skb, pp, &iph, iph.len, 0);
1294
1295 if (unlikely(!cp)) {
1296 int v;
1297
1298 /* For local client packets, it could be a response */
1299 cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0);
1300 if (cp)
1301 return handle_response(af, skb, pp, cp, iph.len);
1302
1303 if (!pp->conn_schedule(af, skb, pp, &v, &cp))
1304 return v;
1305 }
1306
1307 if (unlikely(!cp)) {
1308 /* sorry, all this trouble for a no-hit :) */
1309 IP_VS_DBG_PKT(12, pp, skb, 0,
1310 "packet continues traversal as normal");
1311 return NF_ACCEPT;
1312 }
1313
1314 IP_VS_DBG_PKT(11, pp, skb, 0, "Incoming packet");
1315
1316 /* Check the server status */
1317 if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
1318 /* the destination server is not available */
1319
1320 if (sysctl_ip_vs_expire_nodest_conn) {
1321 /* try to expire the connection immediately */
1322 ip_vs_conn_expire_now(cp);
1323 }
1324 /* don't restart its timer, and silently
1325 drop the packet. */
1326 __ip_vs_conn_put(cp);
1327 return NF_DROP;
1328 }
1329
1330 ip_vs_in_stats(cp, skb);
1331 restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
1332 if (cp->packet_xmit)
1333 ret = cp->packet_xmit(skb, cp, pp);
1334 /* do not touch skb anymore */
1335 else {
1336 IP_VS_DBG_RL("warning: packet_xmit is null");
1337 ret = NF_ACCEPT;
1338 }
1339
1340 /* Increase its packet counter and check if it is needed
1341 * to be synchronized
1342 *
1343 * Sync connection if it is about to close to
1344 * encorage the standby servers to update the connections timeout
1345 */
1346 atomic_inc(&cp->in_pkts);
1347 if (af == AF_INET &&
1348 (ip_vs_sync_state & IP_VS_STATE_MASTER) &&
1349 (((cp->protocol != IPPROTO_TCP ||
1350 cp->state == IP_VS_TCP_S_ESTABLISHED) &&
1351 (atomic_read(&cp->in_pkts) % sysctl_ip_vs_sync_threshold[1]
1352 == sysctl_ip_vs_sync_threshold[0])) ||
1353 ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) &&
1354 ((cp->state == IP_VS_TCP_S_FIN_WAIT) ||
1355 (cp->state == IP_VS_TCP_S_CLOSE_WAIT) ||
1356 (cp->state == IP_VS_TCP_S_TIME_WAIT)))))
1357 ip_vs_sync_conn(cp);
1358 cp->old_state = cp->state;
1359
1360 ip_vs_conn_put(cp);
1361 return ret;
1362 }
1363
1364
1365 /*
1366 * It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
1367 * related packets destined for 0.0.0.0/0.
1368 * When fwmark-based virtual service is used, such as transparent
1369 * cache cluster, TCP packets can be marked and routed to ip_vs_in,
1370 * but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
1371 * sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
1372 * and send them to ip_vs_in_icmp.
1373 */
1374 static unsigned int
1375 ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb,
1376 const struct net_device *in, const struct net_device *out,
1377 int (*okfn)(struct sk_buff *))
1378 {
1379 int r;
1380
1381 if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
1382 return NF_ACCEPT;
1383
1384 return ip_vs_in_icmp(skb, &r, hooknum);
1385 }
1386
1387 #ifdef CONFIG_IP_VS_IPV6
1388 static unsigned int
1389 ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
1390 const struct net_device *in, const struct net_device *out,
1391 int (*okfn)(struct sk_buff *))
1392 {
1393 int r;
1394
1395 if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6)
1396 return NF_ACCEPT;
1397
1398 return ip_vs_in_icmp_v6(skb, &r, hooknum);
1399 }
1400 #endif
1401
1402
1403 static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
1404 /* After packet filtering, forward packet through VS/DR, VS/TUN,
1405 * or VS/NAT(change destination), so that filtering rules can be
1406 * applied to IPVS. */
1407 {
1408 .hook = ip_vs_in,
1409 .owner = THIS_MODULE,
1410 .pf = PF_INET,
1411 .hooknum = NF_INET_LOCAL_IN,
1412 .priority = 100,
1413 },
1414 /* After packet filtering, change source only for VS/NAT */
1415 {
1416 .hook = ip_vs_out,
1417 .owner = THIS_MODULE,
1418 .pf = PF_INET,
1419 .hooknum = NF_INET_FORWARD,
1420 .priority = 100,
1421 },
1422 /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1423 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1424 {
1425 .hook = ip_vs_forward_icmp,
1426 .owner = THIS_MODULE,
1427 .pf = PF_INET,
1428 .hooknum = NF_INET_FORWARD,
1429 .priority = 99,
1430 },
1431 /* Before the netfilter connection tracking, exit from POST_ROUTING */
1432 {
1433 .hook = ip_vs_post_routing,
1434 .owner = THIS_MODULE,
1435 .pf = PF_INET,
1436 .hooknum = NF_INET_POST_ROUTING,
1437 .priority = NF_IP_PRI_NAT_SRC-1,
1438 },
1439 #ifdef CONFIG_IP_VS_IPV6
1440 /* After packet filtering, forward packet through VS/DR, VS/TUN,
1441 * or VS/NAT(change destination), so that filtering rules can be
1442 * applied to IPVS. */
1443 {
1444 .hook = ip_vs_in,
1445 .owner = THIS_MODULE,
1446 .pf = PF_INET6,
1447 .hooknum = NF_INET_LOCAL_IN,
1448 .priority = 100,
1449 },
1450 /* After packet filtering, change source only for VS/NAT */
1451 {
1452 .hook = ip_vs_out,
1453 .owner = THIS_MODULE,
1454 .pf = PF_INET6,
1455 .hooknum = NF_INET_FORWARD,
1456 .priority = 100,
1457 },
1458 /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1459 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1460 {
1461 .hook = ip_vs_forward_icmp_v6,
1462 .owner = THIS_MODULE,
1463 .pf = PF_INET6,
1464 .hooknum = NF_INET_FORWARD,
1465 .priority = 99,
1466 },
1467 /* Before the netfilter connection tracking, exit from POST_ROUTING */
1468 {
1469 .hook = ip_vs_post_routing,
1470 .owner = THIS_MODULE,
1471 .pf = PF_INET6,
1472 .hooknum = NF_INET_POST_ROUTING,
1473 .priority = NF_IP6_PRI_NAT_SRC-1,
1474 },
1475 #endif
1476 };
1477
1478
1479 /*
1480 * Initialize IP Virtual Server
1481 */
1482 static int __init ip_vs_init(void)
1483 {
1484 int ret;
1485
1486 ip_vs_estimator_init();
1487
1488 ret = ip_vs_control_init();
1489 if (ret < 0) {
1490 IP_VS_ERR("can't setup control.\n");
1491 goto cleanup_estimator;
1492 }
1493
1494 ip_vs_protocol_init();
1495
1496 ret = ip_vs_app_init();
1497 if (ret < 0) {
1498 IP_VS_ERR("can't setup application helper.\n");
1499 goto cleanup_protocol;
1500 }
1501
1502 ret = ip_vs_conn_init();
1503 if (ret < 0) {
1504 IP_VS_ERR("can't setup connection table.\n");
1505 goto cleanup_app;
1506 }
1507
1508 ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
1509 if (ret < 0) {
1510 IP_VS_ERR("can't register hooks.\n");
1511 goto cleanup_conn;
1512 }
1513
1514 IP_VS_INFO("ipvs loaded.\n");
1515 return ret;
1516
1517 cleanup_conn:
1518 ip_vs_conn_cleanup();
1519 cleanup_app:
1520 ip_vs_app_cleanup();
1521 cleanup_protocol:
1522 ip_vs_protocol_cleanup();
1523 ip_vs_control_cleanup();
1524 cleanup_estimator:
1525 ip_vs_estimator_cleanup();
1526 return ret;
1527 }
1528
1529 static void __exit ip_vs_cleanup(void)
1530 {
1531 nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
1532 ip_vs_conn_cleanup();
1533 ip_vs_app_cleanup();
1534 ip_vs_protocol_cleanup();
1535 ip_vs_control_cleanup();
1536 ip_vs_estimator_cleanup();
1537 IP_VS_INFO("ipvs unloaded.\n");
1538 }
1539
1540 module_init(ip_vs_init);
1541 module_exit(ip_vs_cleanup);
1542 MODULE_LICENSE("GPL");
Nao low-level kernelspace/userspace library that runs on our robots, Nao-Team HTWK