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ipv6: drop unused "dev" arg of icmpv6_send()
[deliverable/linux.git] / net / netfilter / ipvs / ip_vs_core.c
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/sctp.h>
35 #include <linux/icmp.h>
36
37 #include <net/ip.h>
38 #include <net/tcp.h>
39 #include <net/udp.h>
40 #include <net/icmp.h> /* for icmp_send */
41 #include <net/route.h>
42
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv4.h>
45
46 #ifdef CONFIG_IP_VS_IPV6
47 #include <net/ipv6.h>
48 #include <linux/netfilter_ipv6.h>
49 #endif
50
51 #include <net/ip_vs.h>
52
53
54 EXPORT_SYMBOL(register_ip_vs_scheduler);
55 EXPORT_SYMBOL(unregister_ip_vs_scheduler);
56 EXPORT_SYMBOL(ip_vs_skb_replace);
57 EXPORT_SYMBOL(ip_vs_proto_name);
58 EXPORT_SYMBOL(ip_vs_conn_new);
59 EXPORT_SYMBOL(ip_vs_conn_in_get);
60 EXPORT_SYMBOL(ip_vs_conn_out_get);
61 #ifdef CONFIG_IP_VS_PROTO_TCP
62 EXPORT_SYMBOL(ip_vs_tcp_conn_listen);
63 #endif
64 EXPORT_SYMBOL(ip_vs_conn_put);
65 #ifdef CONFIG_IP_VS_DEBUG
66 EXPORT_SYMBOL(ip_vs_get_debug_level);
67 #endif
68
69
70 /* ID used in ICMP lookups */
71 #define icmp_id(icmph) (((icmph)->un).echo.id)
72 #define icmpv6_id(icmph) (icmph->icmp6_dataun.u_echo.identifier)
73
74 const char *ip_vs_proto_name(unsigned proto)
75 {
76 static char buf[20];
77
78 switch (proto) {
79 case IPPROTO_IP:
80 return "IP";
81 case IPPROTO_UDP:
82 return "UDP";
83 case IPPROTO_TCP:
84 return "TCP";
85 case IPPROTO_SCTP:
86 return "SCTP";
87 case IPPROTO_ICMP:
88 return "ICMP";
89 #ifdef CONFIG_IP_VS_IPV6
90 case IPPROTO_ICMPV6:
91 return "ICMPv6";
92 #endif
93 default:
94 sprintf(buf, "IP_%d", proto);
95 return buf;
96 }
97 }
98
99 void ip_vs_init_hash_table(struct list_head *table, int rows)
100 {
101 while (--rows >= 0)
102 INIT_LIST_HEAD(&table[rows]);
103 }
104
105 static inline void
106 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
107 {
108 struct ip_vs_dest *dest = cp->dest;
109 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
110 spin_lock(&dest->stats.lock);
111 dest->stats.ustats.inpkts++;
112 dest->stats.ustats.inbytes += skb->len;
113 spin_unlock(&dest->stats.lock);
114
115 spin_lock(&dest->svc->stats.lock);
116 dest->svc->stats.ustats.inpkts++;
117 dest->svc->stats.ustats.inbytes += skb->len;
118 spin_unlock(&dest->svc->stats.lock);
119
120 spin_lock(&ip_vs_stats.lock);
121 ip_vs_stats.ustats.inpkts++;
122 ip_vs_stats.ustats.inbytes += skb->len;
123 spin_unlock(&ip_vs_stats.lock);
124 }
125 }
126
127
128 static inline void
129 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
130 {
131 struct ip_vs_dest *dest = cp->dest;
132 if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
133 spin_lock(&dest->stats.lock);
134 dest->stats.ustats.outpkts++;
135 dest->stats.ustats.outbytes += skb->len;
136 spin_unlock(&dest->stats.lock);
137
138 spin_lock(&dest->svc->stats.lock);
139 dest->svc->stats.ustats.outpkts++;
140 dest->svc->stats.ustats.outbytes += skb->len;
141 spin_unlock(&dest->svc->stats.lock);
142
143 spin_lock(&ip_vs_stats.lock);
144 ip_vs_stats.ustats.outpkts++;
145 ip_vs_stats.ustats.outbytes += skb->len;
146 spin_unlock(&ip_vs_stats.lock);
147 }
148 }
149
150
151 static inline void
152 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
153 {
154 spin_lock(&cp->dest->stats.lock);
155 cp->dest->stats.ustats.conns++;
156 spin_unlock(&cp->dest->stats.lock);
157
158 spin_lock(&svc->stats.lock);
159 svc->stats.ustats.conns++;
160 spin_unlock(&svc->stats.lock);
161
162 spin_lock(&ip_vs_stats.lock);
163 ip_vs_stats.ustats.conns++;
164 spin_unlock(&ip_vs_stats.lock);
165 }
166
167
168 static inline int
169 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
170 const struct sk_buff *skb,
171 struct ip_vs_protocol *pp)
172 {
173 if (unlikely(!pp->state_transition))
174 return 0;
175 return pp->state_transition(cp, direction, skb, pp);
176 }
177
178
179 /*
180 * IPVS persistent scheduling function
181 * It creates a connection entry according to its template if exists,
182 * or selects a server and creates a connection entry plus a template.
183 * Locking: we are svc user (svc->refcnt), so we hold all dests too
184 * Protocols supported: TCP, UDP
185 */
186 static struct ip_vs_conn *
187 ip_vs_sched_persist(struct ip_vs_service *svc,
188 const struct sk_buff *skb,
189 __be16 ports[2])
190 {
191 struct ip_vs_conn *cp = NULL;
192 struct ip_vs_iphdr iph;
193 struct ip_vs_dest *dest;
194 struct ip_vs_conn *ct;
195 __be16 dport; /* destination port to forward */
196 union nf_inet_addr snet; /* source network of the client,
197 after masking */
198
199 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
200
201 /* Mask saddr with the netmask to adjust template granularity */
202 #ifdef CONFIG_IP_VS_IPV6
203 if (svc->af == AF_INET6)
204 ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
205 else
206 #endif
207 snet.ip = iph.saddr.ip & svc->netmask;
208
209 IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
210 "mnet %s\n",
211 IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(ports[0]),
212 IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(ports[1]),
213 IP_VS_DBG_ADDR(svc->af, &snet));
214
215 /*
216 * As far as we know, FTP is a very complicated network protocol, and
217 * it uses control connection and data connections. For active FTP,
218 * FTP server initialize data connection to the client, its source port
219 * is often 20. For passive FTP, FTP server tells the clients the port
220 * that it passively listens to, and the client issues the data
221 * connection. In the tunneling or direct routing mode, the load
222 * balancer is on the client-to-server half of connection, the port
223 * number is unknown to the load balancer. So, a conn template like
224 * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
225 * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
226 * is created for other persistent services.
227 */
228 if (ports[1] == svc->port) {
229 /* Check if a template already exists */
230 if (svc->port != FTPPORT)
231 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
232 &iph.daddr, ports[1]);
233 else
234 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
235 &iph.daddr, 0);
236
237 if (!ct || !ip_vs_check_template(ct)) {
238 /*
239 * No template found or the dest of the connection
240 * template is not available.
241 */
242 dest = svc->scheduler->schedule(svc, skb);
243 if (dest == NULL) {
244 IP_VS_DBG(1, "p-schedule: no dest found.\n");
245 return NULL;
246 }
247
248 /*
249 * Create a template like <protocol,caddr,0,
250 * vaddr,vport,daddr,dport> for non-ftp service,
251 * and <protocol,caddr,0,vaddr,0,daddr,0>
252 * for ftp service.
253 */
254 if (svc->port != FTPPORT)
255 ct = ip_vs_conn_new(svc->af, iph.protocol,
256 &snet, 0,
257 &iph.daddr,
258 ports[1],
259 &dest->addr, dest->port,
260 IP_VS_CONN_F_TEMPLATE,
261 dest);
262 else
263 ct = ip_vs_conn_new(svc->af, iph.protocol,
264 &snet, 0,
265 &iph.daddr, 0,
266 &dest->addr, 0,
267 IP_VS_CONN_F_TEMPLATE,
268 dest);
269 if (ct == NULL)
270 return NULL;
271
272 ct->timeout = svc->timeout;
273 } else {
274 /* set destination with the found template */
275 dest = ct->dest;
276 }
277 dport = dest->port;
278 } else {
279 /*
280 * Note: persistent fwmark-based services and persistent
281 * port zero service are handled here.
282 * fwmark template: <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
283 * port zero template: <protocol,caddr,0,vaddr,0,daddr,0>
284 */
285 if (svc->fwmark) {
286 union nf_inet_addr fwmark = {
287 .ip = htonl(svc->fwmark)
288 };
289
290 ct = ip_vs_ct_in_get(svc->af, IPPROTO_IP, &snet, 0,
291 &fwmark, 0);
292 } else
293 ct = ip_vs_ct_in_get(svc->af, iph.protocol, &snet, 0,
294 &iph.daddr, 0);
295
296 if (!ct || !ip_vs_check_template(ct)) {
297 /*
298 * If it is not persistent port zero, return NULL,
299 * otherwise create a connection template.
300 */
301 if (svc->port)
302 return NULL;
303
304 dest = svc->scheduler->schedule(svc, skb);
305 if (dest == NULL) {
306 IP_VS_DBG(1, "p-schedule: no dest found.\n");
307 return NULL;
308 }
309
310 /*
311 * Create a template according to the service
312 */
313 if (svc->fwmark) {
314 union nf_inet_addr fwmark = {
315 .ip = htonl(svc->fwmark)
316 };
317
318 ct = ip_vs_conn_new(svc->af, IPPROTO_IP,
319 &snet, 0,
320 &fwmark, 0,
321 &dest->addr, 0,
322 IP_VS_CONN_F_TEMPLATE,
323 dest);
324 } else
325 ct = ip_vs_conn_new(svc->af, iph.protocol,
326 &snet, 0,
327 &iph.daddr, 0,
328 &dest->addr, 0,
329 IP_VS_CONN_F_TEMPLATE,
330 dest);
331 if (ct == NULL)
332 return NULL;
333
334 ct->timeout = svc->timeout;
335 } else {
336 /* set destination with the found template */
337 dest = ct->dest;
338 }
339 dport = ports[1];
340 }
341
342 /*
343 * Create a new connection according to the template
344 */
345 cp = ip_vs_conn_new(svc->af, iph.protocol,
346 &iph.saddr, ports[0],
347 &iph.daddr, ports[1],
348 &dest->addr, dport,
349 0,
350 dest);
351 if (cp == NULL) {
352 ip_vs_conn_put(ct);
353 return NULL;
354 }
355
356 /*
357 * Add its control
358 */
359 ip_vs_control_add(cp, ct);
360 ip_vs_conn_put(ct);
361
362 ip_vs_conn_stats(cp, svc);
363 return cp;
364 }
365
366
367 /*
368 * IPVS main scheduling function
369 * It selects a server according to the virtual service, and
370 * creates a connection entry.
371 * Protocols supported: TCP, UDP
372 */
373 struct ip_vs_conn *
374 ip_vs_schedule(struct ip_vs_service *svc, const struct sk_buff *skb)
375 {
376 struct ip_vs_conn *cp = NULL;
377 struct ip_vs_iphdr iph;
378 struct ip_vs_dest *dest;
379 __be16 _ports[2], *pptr;
380
381 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
382 pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
383 if (pptr == NULL)
384 return NULL;
385
386 /*
387 * Persistent service
388 */
389 if (svc->flags & IP_VS_SVC_F_PERSISTENT)
390 return ip_vs_sched_persist(svc, skb, pptr);
391
392 /*
393 * Non-persistent service
394 */
395 if (!svc->fwmark && pptr[1] != svc->port) {
396 if (!svc->port)
397 pr_err("Schedule: port zero only supported "
398 "in persistent services, "
399 "check your ipvs configuration\n");
400 return NULL;
401 }
402
403 dest = svc->scheduler->schedule(svc, skb);
404 if (dest == NULL) {
405 IP_VS_DBG(1, "Schedule: no dest found.\n");
406 return NULL;
407 }
408
409 /*
410 * Create a connection entry.
411 */
412 cp = ip_vs_conn_new(svc->af, iph.protocol,
413 &iph.saddr, pptr[0],
414 &iph.daddr, pptr[1],
415 &dest->addr, dest->port ? dest->port : pptr[1],
416 0,
417 dest);
418 if (cp == NULL)
419 return NULL;
420
421 IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
422 "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
423 ip_vs_fwd_tag(cp),
424 IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
425 IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
426 IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
427 cp->flags, atomic_read(&cp->refcnt));
428
429 ip_vs_conn_stats(cp, svc);
430 return cp;
431 }
432
433
434 /*
435 * Pass or drop the packet.
436 * Called by ip_vs_in, when the virtual service is available but
437 * no destination is available for a new connection.
438 */
439 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
440 struct ip_vs_protocol *pp)
441 {
442 __be16 _ports[2], *pptr;
443 struct ip_vs_iphdr iph;
444 int unicast;
445 ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
446
447 pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
448 if (pptr == NULL) {
449 ip_vs_service_put(svc);
450 return NF_DROP;
451 }
452
453 #ifdef CONFIG_IP_VS_IPV6
454 if (svc->af == AF_INET6)
455 unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
456 else
457 #endif
458 unicast = (inet_addr_type(&init_net, iph.daddr.ip) == RTN_UNICAST);
459
460 /* if it is fwmark-based service, the cache_bypass sysctl is up
461 and the destination is a non-local unicast, then create
462 a cache_bypass connection entry */
463 if (sysctl_ip_vs_cache_bypass && svc->fwmark && unicast) {
464 int ret, cs;
465 struct ip_vs_conn *cp;
466 union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };
467
468 ip_vs_service_put(svc);
469
470 /* create a new connection entry */
471 IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
472 cp = ip_vs_conn_new(svc->af, iph.protocol,
473 &iph.saddr, pptr[0],
474 &iph.daddr, pptr[1],
475 &daddr, 0,
476 IP_VS_CONN_F_BYPASS,
477 NULL);
478 if (cp == NULL)
479 return NF_DROP;
480
481 /* statistics */
482 ip_vs_in_stats(cp, skb);
483
484 /* set state */
485 cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
486
487 /* transmit the first SYN packet */
488 ret = cp->packet_xmit(skb, cp, pp);
489 /* do not touch skb anymore */
490
491 atomic_inc(&cp->in_pkts);
492 ip_vs_conn_put(cp);
493 return ret;
494 }
495
496 /*
497 * When the virtual ftp service is presented, packets destined
498 * for other services on the VIP may get here (except services
499 * listed in the ipvs table), pass the packets, because it is
500 * not ipvs job to decide to drop the packets.
501 */
502 if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
503 ip_vs_service_put(svc);
504 return NF_ACCEPT;
505 }
506
507 ip_vs_service_put(svc);
508
509 /*
510 * Notify the client that the destination is unreachable, and
511 * release the socket buffer.
512 * Since it is in IP layer, the TCP socket is not actually
513 * created, the TCP RST packet cannot be sent, instead that
514 * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
515 */
516 #ifdef CONFIG_IP_VS_IPV6
517 if (svc->af == AF_INET6)
518 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
519 else
520 #endif
521 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
522
523 return NF_DROP;
524 }
525
526
527 /*
528 * It is hooked before NF_IP_PRI_NAT_SRC at the NF_INET_POST_ROUTING
529 * chain, and is used for VS/NAT.
530 * It detects packets for VS/NAT connections and sends the packets
531 * immediately. This can avoid that iptable_nat mangles the packets
532 * for VS/NAT.
533 */
534 static unsigned int ip_vs_post_routing(unsigned int hooknum,
535 struct sk_buff *skb,
536 const struct net_device *in,
537 const struct net_device *out,
538 int (*okfn)(struct sk_buff *))
539 {
540 if (!skb->ipvs_property)
541 return NF_ACCEPT;
542 /* The packet was sent from IPVS, exit this chain */
543 return NF_STOP;
544 }
545
546 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
547 {
548 return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
549 }
550
551 static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
552 {
553 int err = ip_defrag(skb, user);
554
555 if (!err)
556 ip_send_check(ip_hdr(skb));
557
558 return err;
559 }
560
561 #ifdef CONFIG_IP_VS_IPV6
562 static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user)
563 {
564 /* TODO IPv6: Find out what to do here for IPv6 */
565 return 0;
566 }
567 #endif
568
569 /*
570 * Packet has been made sufficiently writable in caller
571 * - inout: 1=in->out, 0=out->in
572 */
573 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
574 struct ip_vs_conn *cp, int inout)
575 {
576 struct iphdr *iph = ip_hdr(skb);
577 unsigned int icmp_offset = iph->ihl*4;
578 struct icmphdr *icmph = (struct icmphdr *)(skb_network_header(skb) +
579 icmp_offset);
580 struct iphdr *ciph = (struct iphdr *)(icmph + 1);
581
582 if (inout) {
583 iph->saddr = cp->vaddr.ip;
584 ip_send_check(iph);
585 ciph->daddr = cp->vaddr.ip;
586 ip_send_check(ciph);
587 } else {
588 iph->daddr = cp->daddr.ip;
589 ip_send_check(iph);
590 ciph->saddr = cp->daddr.ip;
591 ip_send_check(ciph);
592 }
593
594 /* the TCP/UDP/SCTP port */
595 if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol ||
596 IPPROTO_SCTP == ciph->protocol) {
597 __be16 *ports = (void *)ciph + ciph->ihl*4;
598
599 if (inout)
600 ports[1] = cp->vport;
601 else
602 ports[0] = cp->dport;
603 }
604
605 /* And finally the ICMP checksum */
606 icmph->checksum = 0;
607 icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
608 skb->ip_summed = CHECKSUM_UNNECESSARY;
609
610 if (inout)
611 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
612 "Forwarding altered outgoing ICMP");
613 else
614 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
615 "Forwarding altered incoming ICMP");
616 }
617
618 #ifdef CONFIG_IP_VS_IPV6
619 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
620 struct ip_vs_conn *cp, int inout)
621 {
622 struct ipv6hdr *iph = ipv6_hdr(skb);
623 unsigned int icmp_offset = sizeof(struct ipv6hdr);
624 struct icmp6hdr *icmph = (struct icmp6hdr *)(skb_network_header(skb) +
625 icmp_offset);
626 struct ipv6hdr *ciph = (struct ipv6hdr *)(icmph + 1);
627
628 if (inout) {
629 iph->saddr = cp->vaddr.in6;
630 ciph->daddr = cp->vaddr.in6;
631 } else {
632 iph->daddr = cp->daddr.in6;
633 ciph->saddr = cp->daddr.in6;
634 }
635
636 /* the TCP/UDP/SCTP port */
637 if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr ||
638 IPPROTO_SCTP == ciph->nexthdr) {
639 __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr);
640
641 if (inout)
642 ports[1] = cp->vport;
643 else
644 ports[0] = cp->dport;
645 }
646
647 /* And finally the ICMP checksum */
648 icmph->icmp6_cksum = 0;
649 /* TODO IPv6: is this correct for ICMPv6? */
650 ip_vs_checksum_complete(skb, icmp_offset);
651 skb->ip_summed = CHECKSUM_UNNECESSARY;
652
653 if (inout)
654 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
655 "Forwarding altered outgoing ICMPv6");
656 else
657 IP_VS_DBG_PKT(11, pp, skb, (void *)ciph - (void *)iph,
658 "Forwarding altered incoming ICMPv6");
659 }
660 #endif
661
662 /* Handle relevant response ICMP messages - forward to the right
663 * destination host. Used for NAT and local client.
664 */
665 static int handle_response_icmp(int af, struct sk_buff *skb,
666 union nf_inet_addr *snet,
667 __u8 protocol, struct ip_vs_conn *cp,
668 struct ip_vs_protocol *pp,
669 unsigned int offset, unsigned int ihl)
670 {
671 unsigned int verdict = NF_DROP;
672
673 if (IP_VS_FWD_METHOD(cp) != 0) {
674 pr_err("shouldn't reach here, because the box is on the "
675 "half connection in the tun/dr module.\n");
676 }
677
678 /* Ensure the checksum is correct */
679 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
680 /* Failed checksum! */
681 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
682 IP_VS_DBG_ADDR(af, snet));
683 goto out;
684 }
685
686 if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
687 IPPROTO_SCTP == protocol)
688 offset += 2 * sizeof(__u16);
689 if (!skb_make_writable(skb, offset))
690 goto out;
691
692 #ifdef CONFIG_IP_VS_IPV6
693 if (af == AF_INET6)
694 ip_vs_nat_icmp_v6(skb, pp, cp, 1);
695 else
696 #endif
697 ip_vs_nat_icmp(skb, pp, cp, 1);
698
699 /* do the statistics and put it back */
700 ip_vs_out_stats(cp, skb);
701
702 skb->ipvs_property = 1;
703 verdict = NF_ACCEPT;
704
705 out:
706 __ip_vs_conn_put(cp);
707
708 return verdict;
709 }
710
711 /*
712 * Handle ICMP messages in the inside-to-outside direction (outgoing).
713 * Find any that might be relevant, check against existing connections.
714 * Currently handles error types - unreachable, quench, ttl exceeded.
715 */
716 static int ip_vs_out_icmp(struct sk_buff *skb, int *related)
717 {
718 struct iphdr *iph;
719 struct icmphdr _icmph, *ic;
720 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
721 struct ip_vs_iphdr ciph;
722 struct ip_vs_conn *cp;
723 struct ip_vs_protocol *pp;
724 unsigned int offset, ihl;
725 union nf_inet_addr snet;
726
727 *related = 1;
728
729 /* reassemble IP fragments */
730 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
731 if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
732 return NF_STOLEN;
733 }
734
735 iph = ip_hdr(skb);
736 offset = ihl = iph->ihl * 4;
737 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
738 if (ic == NULL)
739 return NF_DROP;
740
741 IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
742 ic->type, ntohs(icmp_id(ic)),
743 &iph->saddr, &iph->daddr);
744
745 /*
746 * Work through seeing if this is for us.
747 * These checks are supposed to be in an order that means easy
748 * things are checked first to speed up processing.... however
749 * this means that some packets will manage to get a long way
750 * down this stack and then be rejected, but that's life.
751 */
752 if ((ic->type != ICMP_DEST_UNREACH) &&
753 (ic->type != ICMP_SOURCE_QUENCH) &&
754 (ic->type != ICMP_TIME_EXCEEDED)) {
755 *related = 0;
756 return NF_ACCEPT;
757 }
758
759 /* Now find the contained IP header */
760 offset += sizeof(_icmph);
761 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
762 if (cih == NULL)
763 return NF_ACCEPT; /* The packet looks wrong, ignore */
764
765 pp = ip_vs_proto_get(cih->protocol);
766 if (!pp)
767 return NF_ACCEPT;
768
769 /* Is the embedded protocol header present? */
770 if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
771 pp->dont_defrag))
772 return NF_ACCEPT;
773
774 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMP for");
775
776 offset += cih->ihl * 4;
777
778 ip_vs_fill_iphdr(AF_INET, cih, &ciph);
779 /* The embedded headers contain source and dest in reverse order */
780 cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1);
781 if (!cp)
782 return NF_ACCEPT;
783
784 snet.ip = iph->saddr;
785 return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
786 pp, offset, ihl);
787 }
788
789 #ifdef CONFIG_IP_VS_IPV6
790 static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related)
791 {
792 struct ipv6hdr *iph;
793 struct icmp6hdr _icmph, *ic;
794 struct ipv6hdr _ciph, *cih; /* The ip header contained
795 within the ICMP */
796 struct ip_vs_iphdr ciph;
797 struct ip_vs_conn *cp;
798 struct ip_vs_protocol *pp;
799 unsigned int offset;
800 union nf_inet_addr snet;
801
802 *related = 1;
803
804 /* reassemble IP fragments */
805 if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
806 if (ip_vs_gather_frags_v6(skb, IP_DEFRAG_VS_OUT))
807 return NF_STOLEN;
808 }
809
810 iph = ipv6_hdr(skb);
811 offset = sizeof(struct ipv6hdr);
812 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
813 if (ic == NULL)
814 return NF_DROP;
815
816 IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) %pI6->%pI6\n",
817 ic->icmp6_type, ntohs(icmpv6_id(ic)),
818 &iph->saddr, &iph->daddr);
819
820 /*
821 * Work through seeing if this is for us.
822 * These checks are supposed to be in an order that means easy
823 * things are checked first to speed up processing.... however
824 * this means that some packets will manage to get a long way
825 * down this stack and then be rejected, but that's life.
826 */
827 if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
828 (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
829 (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
830 *related = 0;
831 return NF_ACCEPT;
832 }
833
834 /* Now find the contained IP header */
835 offset += sizeof(_icmph);
836 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
837 if (cih == NULL)
838 return NF_ACCEPT; /* The packet looks wrong, ignore */
839
840 pp = ip_vs_proto_get(cih->nexthdr);
841 if (!pp)
842 return NF_ACCEPT;
843
844 /* Is the embedded protocol header present? */
845 /* TODO: we don't support fragmentation at the moment anyways */
846 if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
847 return NF_ACCEPT;
848
849 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking outgoing ICMPv6 for");
850
851 offset += sizeof(struct ipv6hdr);
852
853 ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
854 /* The embedded headers contain source and dest in reverse order */
855 cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1);
856 if (!cp)
857 return NF_ACCEPT;
858
859 ipv6_addr_copy(&snet.in6, &iph->saddr);
860 return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp,
861 pp, offset, sizeof(struct ipv6hdr));
862 }
863 #endif
864
865 /*
866 * Check if sctp chunc is ABORT chunk
867 */
868 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len)
869 {
870 sctp_chunkhdr_t *sch, schunk;
871 sch = skb_header_pointer(skb, nh_len + sizeof(sctp_sctphdr_t),
872 sizeof(schunk), &schunk);
873 if (sch == NULL)
874 return 0;
875 if (sch->type == SCTP_CID_ABORT)
876 return 1;
877 return 0;
878 }
879
880 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
881 {
882 struct tcphdr _tcph, *th;
883
884 th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
885 if (th == NULL)
886 return 0;
887 return th->rst;
888 }
889
890 /* Handle response packets: rewrite addresses and send away...
891 * Used for NAT and local client.
892 */
893 static unsigned int
894 handle_response(int af, struct sk_buff *skb, struct ip_vs_protocol *pp,
895 struct ip_vs_conn *cp, int ihl)
896 {
897 IP_VS_DBG_PKT(11, pp, skb, 0, "Outgoing packet");
898
899 if (!skb_make_writable(skb, ihl))
900 goto drop;
901
902 /* mangle the packet */
903 if (pp->snat_handler && !pp->snat_handler(skb, pp, cp))
904 goto drop;
905
906 #ifdef CONFIG_IP_VS_IPV6
907 if (af == AF_INET6)
908 ipv6_hdr(skb)->saddr = cp->vaddr.in6;
909 else
910 #endif
911 {
912 ip_hdr(skb)->saddr = cp->vaddr.ip;
913 ip_send_check(ip_hdr(skb));
914 }
915
916 /* For policy routing, packets originating from this
917 * machine itself may be routed differently to packets
918 * passing through. We want this packet to be routed as
919 * if it came from this machine itself. So re-compute
920 * the routing information.
921 */
922 #ifdef CONFIG_IP_VS_IPV6
923 if (af == AF_INET6) {
924 if (ip6_route_me_harder(skb) != 0)
925 goto drop;
926 } else
927 #endif
928 if (ip_route_me_harder(skb, RTN_LOCAL) != 0)
929 goto drop;
930
931 IP_VS_DBG_PKT(10, pp, skb, 0, "After SNAT");
932
933 ip_vs_out_stats(cp, skb);
934 ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pp);
935 ip_vs_conn_put(cp);
936
937 skb->ipvs_property = 1;
938
939 LeaveFunction(11);
940 return NF_ACCEPT;
941
942 drop:
943 ip_vs_conn_put(cp);
944 kfree_skb(skb);
945 return NF_STOLEN;
946 }
947
948 /*
949 * It is hooked at the NF_INET_FORWARD chain, used only for VS/NAT.
950 * Check if outgoing packet belongs to the established ip_vs_conn.
951 */
952 static unsigned int
953 ip_vs_out(unsigned int hooknum, struct sk_buff *skb,
954 const struct net_device *in, const struct net_device *out,
955 int (*okfn)(struct sk_buff *))
956 {
957 struct ip_vs_iphdr iph;
958 struct ip_vs_protocol *pp;
959 struct ip_vs_conn *cp;
960 int af;
961
962 EnterFunction(11);
963
964 af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6;
965
966 if (skb->ipvs_property)
967 return NF_ACCEPT;
968
969 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
970 #ifdef CONFIG_IP_VS_IPV6
971 if (af == AF_INET6) {
972 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
973 int related, verdict = ip_vs_out_icmp_v6(skb, &related);
974
975 if (related)
976 return verdict;
977 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
978 }
979 } else
980 #endif
981 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
982 int related, verdict = ip_vs_out_icmp(skb, &related);
983
984 if (related)
985 return verdict;
986 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
987 }
988
989 pp = ip_vs_proto_get(iph.protocol);
990 if (unlikely(!pp))
991 return NF_ACCEPT;
992
993 /* reassemble IP fragments */
994 #ifdef CONFIG_IP_VS_IPV6
995 if (af == AF_INET6) {
996 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
997 int related, verdict = ip_vs_out_icmp_v6(skb, &related);
998
999 if (related)
1000 return verdict;
1001
1002 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1003 }
1004 } else
1005 #endif
1006 if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) &&
1007 !pp->dont_defrag)) {
1008 if (ip_vs_gather_frags(skb, IP_DEFRAG_VS_OUT))
1009 return NF_STOLEN;
1010
1011 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1012 }
1013
1014 /*
1015 * Check if the packet belongs to an existing entry
1016 */
1017 cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0);
1018
1019 if (unlikely(!cp)) {
1020 if (sysctl_ip_vs_nat_icmp_send &&
1021 (pp->protocol == IPPROTO_TCP ||
1022 pp->protocol == IPPROTO_UDP ||
1023 pp->protocol == IPPROTO_SCTP)) {
1024 __be16 _ports[2], *pptr;
1025
1026 pptr = skb_header_pointer(skb, iph.len,
1027 sizeof(_ports), _ports);
1028 if (pptr == NULL)
1029 return NF_ACCEPT; /* Not for me */
1030 if (ip_vs_lookup_real_service(af, iph.protocol,
1031 &iph.saddr,
1032 pptr[0])) {
1033 /*
1034 * Notify the real server: there is no
1035 * existing entry if it is not RST
1036 * packet or not TCP packet.
1037 */
1038 if ((iph.protocol != IPPROTO_TCP &&
1039 iph.protocol != IPPROTO_SCTP)
1040 || ((iph.protocol == IPPROTO_TCP
1041 && !is_tcp_reset(skb, iph.len))
1042 || (iph.protocol == IPPROTO_SCTP
1043 && !is_sctp_abort(skb,
1044 iph.len)))) {
1045 #ifdef CONFIG_IP_VS_IPV6
1046 if (af == AF_INET6)
1047 icmpv6_send(skb,
1048 ICMPV6_DEST_UNREACH,
1049 ICMPV6_PORT_UNREACH,
1050 0);
1051 else
1052 #endif
1053 icmp_send(skb,
1054 ICMP_DEST_UNREACH,
1055 ICMP_PORT_UNREACH, 0);
1056 return NF_DROP;
1057 }
1058 }
1059 }
1060 IP_VS_DBG_PKT(12, pp, skb, 0,
1061 "packet continues traversal as normal");
1062 return NF_ACCEPT;
1063 }
1064
1065 return handle_response(af, skb, pp, cp, iph.len);
1066 }
1067
1068
1069 /*
1070 * Handle ICMP messages in the outside-to-inside direction (incoming).
1071 * Find any that might be relevant, check against existing connections,
1072 * forward to the right destination host if relevant.
1073 * Currently handles error types - unreachable, quench, ttl exceeded.
1074 */
1075 static int
1076 ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
1077 {
1078 struct iphdr *iph;
1079 struct icmphdr _icmph, *ic;
1080 struct iphdr _ciph, *cih; /* The ip header contained within the ICMP */
1081 struct ip_vs_iphdr ciph;
1082 struct ip_vs_conn *cp;
1083 struct ip_vs_protocol *pp;
1084 unsigned int offset, ihl, verdict;
1085 union nf_inet_addr snet;
1086
1087 *related = 1;
1088
1089 /* reassemble IP fragments */
1090 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
1091 if (ip_vs_gather_frags(skb, hooknum == NF_INET_LOCAL_IN ?
1092 IP_DEFRAG_VS_IN : IP_DEFRAG_VS_FWD))
1093 return NF_STOLEN;
1094 }
1095
1096 iph = ip_hdr(skb);
1097 offset = ihl = iph->ihl * 4;
1098 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1099 if (ic == NULL)
1100 return NF_DROP;
1101
1102 IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1103 ic->type, ntohs(icmp_id(ic)),
1104 &iph->saddr, &iph->daddr);
1105
1106 /*
1107 * Work through seeing if this is for us.
1108 * These checks are supposed to be in an order that means easy
1109 * things are checked first to speed up processing.... however
1110 * this means that some packets will manage to get a long way
1111 * down this stack and then be rejected, but that's life.
1112 */
1113 if ((ic->type != ICMP_DEST_UNREACH) &&
1114 (ic->type != ICMP_SOURCE_QUENCH) &&
1115 (ic->type != ICMP_TIME_EXCEEDED)) {
1116 *related = 0;
1117 return NF_ACCEPT;
1118 }
1119
1120 /* Now find the contained IP header */
1121 offset += sizeof(_icmph);
1122 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1123 if (cih == NULL)
1124 return NF_ACCEPT; /* The packet looks wrong, ignore */
1125
1126 pp = ip_vs_proto_get(cih->protocol);
1127 if (!pp)
1128 return NF_ACCEPT;
1129
1130 /* Is the embedded protocol header present? */
1131 if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1132 pp->dont_defrag))
1133 return NF_ACCEPT;
1134
1135 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMP for");
1136
1137 offset += cih->ihl * 4;
1138
1139 ip_vs_fill_iphdr(AF_INET, cih, &ciph);
1140 /* The embedded headers contain source and dest in reverse order */
1141 cp = pp->conn_in_get(AF_INET, skb, pp, &ciph, offset, 1);
1142 if (!cp) {
1143 /* The packet could also belong to a local client */
1144 cp = pp->conn_out_get(AF_INET, skb, pp, &ciph, offset, 1);
1145 if (cp) {
1146 snet.ip = iph->saddr;
1147 return handle_response_icmp(AF_INET, skb, &snet,
1148 cih->protocol, cp, pp,
1149 offset, ihl);
1150 }
1151 return NF_ACCEPT;
1152 }
1153
1154 verdict = NF_DROP;
1155
1156 /* Ensure the checksum is correct */
1157 if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1158 /* Failed checksum! */
1159 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1160 &iph->saddr);
1161 goto out;
1162 }
1163
1164 /* do the statistics and put it back */
1165 ip_vs_in_stats(cp, skb);
1166 if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
1167 offset += 2 * sizeof(__u16);
1168 verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
1169 /* do not touch skb anymore */
1170
1171 out:
1172 __ip_vs_conn_put(cp);
1173
1174 return verdict;
1175 }
1176
1177 #ifdef CONFIG_IP_VS_IPV6
1178 static int
1179 ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
1180 {
1181 struct ipv6hdr *iph;
1182 struct icmp6hdr _icmph, *ic;
1183 struct ipv6hdr _ciph, *cih; /* The ip header contained
1184 within the ICMP */
1185 struct ip_vs_iphdr ciph;
1186 struct ip_vs_conn *cp;
1187 struct ip_vs_protocol *pp;
1188 unsigned int offset, verdict;
1189 union nf_inet_addr snet;
1190
1191 *related = 1;
1192
1193 /* reassemble IP fragments */
1194 if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
1195 if (ip_vs_gather_frags_v6(skb, hooknum == NF_INET_LOCAL_IN ?
1196 IP_DEFRAG_VS_IN :
1197 IP_DEFRAG_VS_FWD))
1198 return NF_STOLEN;
1199 }
1200
1201 iph = ipv6_hdr(skb);
1202 offset = sizeof(struct ipv6hdr);
1203 ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1204 if (ic == NULL)
1205 return NF_DROP;
1206
1207 IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) %pI6->%pI6\n",
1208 ic->icmp6_type, ntohs(icmpv6_id(ic)),
1209 &iph->saddr, &iph->daddr);
1210
1211 /*
1212 * Work through seeing if this is for us.
1213 * These checks are supposed to be in an order that means easy
1214 * things are checked first to speed up processing.... however
1215 * this means that some packets will manage to get a long way
1216 * down this stack and then be rejected, but that's life.
1217 */
1218 if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
1219 (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
1220 (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
1221 *related = 0;
1222 return NF_ACCEPT;
1223 }
1224
1225 /* Now find the contained IP header */
1226 offset += sizeof(_icmph);
1227 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1228 if (cih == NULL)
1229 return NF_ACCEPT; /* The packet looks wrong, ignore */
1230
1231 pp = ip_vs_proto_get(cih->nexthdr);
1232 if (!pp)
1233 return NF_ACCEPT;
1234
1235 /* Is the embedded protocol header present? */
1236 /* TODO: we don't support fragmentation at the moment anyways */
1237 if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
1238 return NF_ACCEPT;
1239
1240 IP_VS_DBG_PKT(11, pp, skb, offset, "Checking incoming ICMPv6 for");
1241
1242 offset += sizeof(struct ipv6hdr);
1243
1244 ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
1245 /* The embedded headers contain source and dest in reverse order */
1246 cp = pp->conn_in_get(AF_INET6, skb, pp, &ciph, offset, 1);
1247 if (!cp) {
1248 /* The packet could also belong to a local client */
1249 cp = pp->conn_out_get(AF_INET6, skb, pp, &ciph, offset, 1);
1250 if (cp) {
1251 ipv6_addr_copy(&snet.in6, &iph->saddr);
1252 return handle_response_icmp(AF_INET6, skb, &snet,
1253 cih->nexthdr,
1254 cp, pp, offset,
1255 sizeof(struct ipv6hdr));
1256 }
1257 return NF_ACCEPT;
1258 }
1259
1260 verdict = NF_DROP;
1261
1262 /* do the statistics and put it back */
1263 ip_vs_in_stats(cp, skb);
1264 if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr ||
1265 IPPROTO_SCTP == cih->nexthdr)
1266 offset += 2 * sizeof(__u16);
1267 verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
1268 /* do not touch skb anymore */
1269
1270 __ip_vs_conn_put(cp);
1271
1272 return verdict;
1273 }
1274 #endif
1275
1276
1277 /*
1278 * Check if it's for virtual services, look it up,
1279 * and send it on its way...
1280 */
1281 static unsigned int
1282 ip_vs_in(unsigned int hooknum, struct sk_buff *skb,
1283 const struct net_device *in, const struct net_device *out,
1284 int (*okfn)(struct sk_buff *))
1285 {
1286 struct ip_vs_iphdr iph;
1287 struct ip_vs_protocol *pp;
1288 struct ip_vs_conn *cp;
1289 int ret, restart, af, pkts;
1290
1291 af = (skb->protocol == htons(ETH_P_IP)) ? AF_INET : AF_INET6;
1292
1293 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1294
1295 /*
1296 * Big tappo: only PACKET_HOST, including loopback for local client
1297 * Don't handle local packets on IPv6 for now
1298 */
1299 if (unlikely(skb->pkt_type != PACKET_HOST)) {
1300 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s ignored\n",
1301 skb->pkt_type,
1302 iph.protocol,
1303 IP_VS_DBG_ADDR(af, &iph.daddr));
1304 return NF_ACCEPT;
1305 }
1306
1307 #ifdef CONFIG_IP_VS_IPV6
1308 if (af == AF_INET6) {
1309 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1310 int related, verdict = ip_vs_in_icmp_v6(skb, &related, hooknum);
1311
1312 if (related)
1313 return verdict;
1314 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1315 }
1316 } else
1317 #endif
1318 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1319 int related, verdict = ip_vs_in_icmp(skb, &related, hooknum);
1320
1321 if (related)
1322 return verdict;
1323 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1324 }
1325
1326 /* Protocol supported? */
1327 pp = ip_vs_proto_get(iph.protocol);
1328 if (unlikely(!pp))
1329 return NF_ACCEPT;
1330
1331 /*
1332 * Check if the packet belongs to an existing connection entry
1333 */
1334 cp = pp->conn_in_get(af, skb, pp, &iph, iph.len, 0);
1335
1336 if (unlikely(!cp)) {
1337 int v;
1338
1339 /* For local client packets, it could be a response */
1340 cp = pp->conn_out_get(af, skb, pp, &iph, iph.len, 0);
1341 if (cp)
1342 return handle_response(af, skb, pp, cp, iph.len);
1343
1344 if (!pp->conn_schedule(af, skb, pp, &v, &cp))
1345 return v;
1346 }
1347
1348 if (unlikely(!cp)) {
1349 /* sorry, all this trouble for a no-hit :) */
1350 IP_VS_DBG_PKT(12, pp, skb, 0,
1351 "packet continues traversal as normal");
1352 return NF_ACCEPT;
1353 }
1354
1355 IP_VS_DBG_PKT(11, pp, skb, 0, "Incoming packet");
1356
1357 /* Check the server status */
1358 if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
1359 /* the destination server is not available */
1360
1361 if (sysctl_ip_vs_expire_nodest_conn) {
1362 /* try to expire the connection immediately */
1363 ip_vs_conn_expire_now(cp);
1364 }
1365 /* don't restart its timer, and silently
1366 drop the packet. */
1367 __ip_vs_conn_put(cp);
1368 return NF_DROP;
1369 }
1370
1371 ip_vs_in_stats(cp, skb);
1372 restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pp);
1373 if (cp->packet_xmit)
1374 ret = cp->packet_xmit(skb, cp, pp);
1375 /* do not touch skb anymore */
1376 else {
1377 IP_VS_DBG_RL("warning: packet_xmit is null");
1378 ret = NF_ACCEPT;
1379 }
1380
1381 /* Increase its packet counter and check if it is needed
1382 * to be synchronized
1383 *
1384 * Sync connection if it is about to close to
1385 * encorage the standby servers to update the connections timeout
1386 */
1387 pkts = atomic_add_return(1, &cp->in_pkts);
1388 if (af == AF_INET && (ip_vs_sync_state & IP_VS_STATE_MASTER) &&
1389 cp->protocol == IPPROTO_SCTP) {
1390 if ((cp->state == IP_VS_SCTP_S_ESTABLISHED &&
1391 (atomic_read(&cp->in_pkts) %
1392 sysctl_ip_vs_sync_threshold[1]
1393 == sysctl_ip_vs_sync_threshold[0])) ||
1394 (cp->old_state != cp->state &&
1395 ((cp->state == IP_VS_SCTP_S_CLOSED) ||
1396 (cp->state == IP_VS_SCTP_S_SHUT_ACK_CLI) ||
1397 (cp->state == IP_VS_SCTP_S_SHUT_ACK_SER)))) {
1398 ip_vs_sync_conn(cp);
1399 goto out;
1400 }
1401 }
1402
1403 if (af == AF_INET &&
1404 (ip_vs_sync_state & IP_VS_STATE_MASTER) &&
1405 (((cp->protocol != IPPROTO_TCP ||
1406 cp->state == IP_VS_TCP_S_ESTABLISHED) &&
1407 (pkts % sysctl_ip_vs_sync_threshold[1]
1408 == sysctl_ip_vs_sync_threshold[0])) ||
1409 ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) &&
1410 ((cp->state == IP_VS_TCP_S_FIN_WAIT) ||
1411 (cp->state == IP_VS_TCP_S_CLOSE) ||
1412 (cp->state == IP_VS_TCP_S_CLOSE_WAIT) ||
1413 (cp->state == IP_VS_TCP_S_TIME_WAIT)))))
1414 ip_vs_sync_conn(cp);
1415 out:
1416 cp->old_state = cp->state;
1417
1418 ip_vs_conn_put(cp);
1419 return ret;
1420 }
1421
1422
1423 /*
1424 * It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
1425 * related packets destined for 0.0.0.0/0.
1426 * When fwmark-based virtual service is used, such as transparent
1427 * cache cluster, TCP packets can be marked and routed to ip_vs_in,
1428 * but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
1429 * sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
1430 * and send them to ip_vs_in_icmp.
1431 */
1432 static unsigned int
1433 ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb,
1434 const struct net_device *in, const struct net_device *out,
1435 int (*okfn)(struct sk_buff *))
1436 {
1437 int r;
1438
1439 if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
1440 return NF_ACCEPT;
1441
1442 return ip_vs_in_icmp(skb, &r, hooknum);
1443 }
1444
1445 #ifdef CONFIG_IP_VS_IPV6
1446 static unsigned int
1447 ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
1448 const struct net_device *in, const struct net_device *out,
1449 int (*okfn)(struct sk_buff *))
1450 {
1451 int r;
1452
1453 if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6)
1454 return NF_ACCEPT;
1455
1456 return ip_vs_in_icmp_v6(skb, &r, hooknum);
1457 }
1458 #endif
1459
1460
1461 static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
1462 /* After packet filtering, forward packet through VS/DR, VS/TUN,
1463 * or VS/NAT(change destination), so that filtering rules can be
1464 * applied to IPVS. */
1465 {
1466 .hook = ip_vs_in,
1467 .owner = THIS_MODULE,
1468 .pf = PF_INET,
1469 .hooknum = NF_INET_LOCAL_IN,
1470 .priority = 100,
1471 },
1472 /* After packet filtering, change source only for VS/NAT */
1473 {
1474 .hook = ip_vs_out,
1475 .owner = THIS_MODULE,
1476 .pf = PF_INET,
1477 .hooknum = NF_INET_FORWARD,
1478 .priority = 100,
1479 },
1480 /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1481 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1482 {
1483 .hook = ip_vs_forward_icmp,
1484 .owner = THIS_MODULE,
1485 .pf = PF_INET,
1486 .hooknum = NF_INET_FORWARD,
1487 .priority = 99,
1488 },
1489 /* Before the netfilter connection tracking, exit from POST_ROUTING */
1490 {
1491 .hook = ip_vs_post_routing,
1492 .owner = THIS_MODULE,
1493 .pf = PF_INET,
1494 .hooknum = NF_INET_POST_ROUTING,
1495 .priority = NF_IP_PRI_NAT_SRC-1,
1496 },
1497 #ifdef CONFIG_IP_VS_IPV6
1498 /* After packet filtering, forward packet through VS/DR, VS/TUN,
1499 * or VS/NAT(change destination), so that filtering rules can be
1500 * applied to IPVS. */
1501 {
1502 .hook = ip_vs_in,
1503 .owner = THIS_MODULE,
1504 .pf = PF_INET6,
1505 .hooknum = NF_INET_LOCAL_IN,
1506 .priority = 100,
1507 },
1508 /* After packet filtering, change source only for VS/NAT */
1509 {
1510 .hook = ip_vs_out,
1511 .owner = THIS_MODULE,
1512 .pf = PF_INET6,
1513 .hooknum = NF_INET_FORWARD,
1514 .priority = 100,
1515 },
1516 /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1517 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1518 {
1519 .hook = ip_vs_forward_icmp_v6,
1520 .owner = THIS_MODULE,
1521 .pf = PF_INET6,
1522 .hooknum = NF_INET_FORWARD,
1523 .priority = 99,
1524 },
1525 /* Before the netfilter connection tracking, exit from POST_ROUTING */
1526 {
1527 .hook = ip_vs_post_routing,
1528 .owner = THIS_MODULE,
1529 .pf = PF_INET6,
1530 .hooknum = NF_INET_POST_ROUTING,
1531 .priority = NF_IP6_PRI_NAT_SRC-1,
1532 },
1533 #endif
1534 };
1535
1536
1537 /*
1538 * Initialize IP Virtual Server
1539 */
1540 static int __init ip_vs_init(void)
1541 {
1542 int ret;
1543
1544 ip_vs_estimator_init();
1545
1546 ret = ip_vs_control_init();
1547 if (ret < 0) {
1548 pr_err("can't setup control.\n");
1549 goto cleanup_estimator;
1550 }
1551
1552 ip_vs_protocol_init();
1553
1554 ret = ip_vs_app_init();
1555 if (ret < 0) {
1556 pr_err("can't setup application helper.\n");
1557 goto cleanup_protocol;
1558 }
1559
1560 ret = ip_vs_conn_init();
1561 if (ret < 0) {
1562 pr_err("can't setup connection table.\n");
1563 goto cleanup_app;
1564 }
1565
1566 ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
1567 if (ret < 0) {
1568 pr_err("can't register hooks.\n");
1569 goto cleanup_conn;
1570 }
1571
1572 pr_info("ipvs loaded.\n");
1573 return ret;
1574
1575 cleanup_conn:
1576 ip_vs_conn_cleanup();
1577 cleanup_app:
1578 ip_vs_app_cleanup();
1579 cleanup_protocol:
1580 ip_vs_protocol_cleanup();
1581 ip_vs_control_cleanup();
1582 cleanup_estimator:
1583 ip_vs_estimator_cleanup();
1584 return ret;
1585 }
1586
1587 static void __exit ip_vs_cleanup(void)
1588 {
1589 nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
1590 ip_vs_conn_cleanup();
1591 ip_vs_app_cleanup();
1592 ip_vs_protocol_cleanup();
1593 ip_vs_control_cleanup();
1594 ip_vs_estimator_cleanup();
1595 pr_info("ipvs unloaded.\n");
1596 }
1597
1598 module_init(ip_vs_init);
1599 module_exit(ip_vs_cleanup);
1600 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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