IPVS: init and cleanup restructuring
[linux-2.6.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 #include <linux/slab.h>
37
38 #include <net/ip.h>
39 #include <net/tcp.h>
40 #include <net/udp.h>
41 #include <net/icmp.h>                   /* for icmp_send */
42 #include <net/route.h>
43 #include <net/ip6_checksum.h>
44 #include <net/netns/generic.h>          /* net_generic() */
45
46 #include <linux/netfilter.h>
47 #include <linux/netfilter_ipv4.h>
48
49 #ifdef CONFIG_IP_VS_IPV6
50 #include <net/ipv6.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <net/ip6_route.h>
53 #endif
54
55 #include <net/ip_vs.h>
56
57
58 EXPORT_SYMBOL(register_ip_vs_scheduler);
59 EXPORT_SYMBOL(unregister_ip_vs_scheduler);
60 EXPORT_SYMBOL(ip_vs_proto_name);
61 EXPORT_SYMBOL(ip_vs_conn_new);
62 EXPORT_SYMBOL(ip_vs_conn_in_get);
63 EXPORT_SYMBOL(ip_vs_conn_out_get);
64 #ifdef CONFIG_IP_VS_PROTO_TCP
65 EXPORT_SYMBOL(ip_vs_tcp_conn_listen);
66 #endif
67 EXPORT_SYMBOL(ip_vs_conn_put);
68 #ifdef CONFIG_IP_VS_DEBUG
69 EXPORT_SYMBOL(ip_vs_get_debug_level);
70 #endif
71
72 int ip_vs_net_id __read_mostly;
73 #ifdef IP_VS_GENERIC_NETNS
74 EXPORT_SYMBOL(ip_vs_net_id);
75 #endif
76 /* netns cnt used for uniqueness */
77 static atomic_t ipvs_netns_cnt = ATOMIC_INIT(0);
78
79 /* ID used in ICMP lookups */
80 #define icmp_id(icmph)          (((icmph)->un).echo.id)
81 #define icmpv6_id(icmph)        (icmph->icmp6_dataun.u_echo.identifier)
82
83 const char *ip_vs_proto_name(unsigned proto)
84 {
85         static char buf[20];
86
87         switch (proto) {
88         case IPPROTO_IP:
89                 return "IP";
90         case IPPROTO_UDP:
91                 return "UDP";
92         case IPPROTO_TCP:
93                 return "TCP";
94         case IPPROTO_SCTP:
95                 return "SCTP";
96         case IPPROTO_ICMP:
97                 return "ICMP";
98 #ifdef CONFIG_IP_VS_IPV6
99         case IPPROTO_ICMPV6:
100                 return "ICMPv6";
101 #endif
102         default:
103                 sprintf(buf, "IP_%d", proto);
104                 return buf;
105         }
106 }
107
108 void ip_vs_init_hash_table(struct list_head *table, int rows)
109 {
110         while (--rows >= 0)
111                 INIT_LIST_HEAD(&table[rows]);
112 }
113
114 static inline void
115 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
116 {
117         struct ip_vs_dest *dest = cp->dest;
118         struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
119
120         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
121                 struct ip_vs_cpu_stats *s;
122
123                 s = this_cpu_ptr(dest->stats.cpustats);
124                 s->ustats.inpkts++;
125                 u64_stats_update_begin(&s->syncp);
126                 s->ustats.inbytes += skb->len;
127                 u64_stats_update_end(&s->syncp);
128
129                 s = this_cpu_ptr(dest->svc->stats.cpustats);
130                 s->ustats.inpkts++;
131                 u64_stats_update_begin(&s->syncp);
132                 s->ustats.inbytes += skb->len;
133                 u64_stats_update_end(&s->syncp);
134
135                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
136                 s->ustats.inpkts++;
137                 u64_stats_update_begin(&s->syncp);
138                 s->ustats.inbytes += skb->len;
139                 u64_stats_update_end(&s->syncp);
140         }
141 }
142
143
144 static inline void
145 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
146 {
147         struct ip_vs_dest *dest = cp->dest;
148         struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
149
150         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
151                 struct ip_vs_cpu_stats *s;
152
153                 s = this_cpu_ptr(dest->stats.cpustats);
154                 s->ustats.outpkts++;
155                 u64_stats_update_begin(&s->syncp);
156                 s->ustats.outbytes += skb->len;
157                 u64_stats_update_end(&s->syncp);
158
159                 s = this_cpu_ptr(dest->svc->stats.cpustats);
160                 s->ustats.outpkts++;
161                 u64_stats_update_begin(&s->syncp);
162                 s->ustats.outbytes += skb->len;
163                 u64_stats_update_end(&s->syncp);
164
165                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
166                 s->ustats.outpkts++;
167                 u64_stats_update_begin(&s->syncp);
168                 s->ustats.outbytes += skb->len;
169                 u64_stats_update_end(&s->syncp);
170         }
171 }
172
173
174 static inline void
175 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
176 {
177         struct netns_ipvs *ipvs = net_ipvs(svc->net);
178         struct ip_vs_cpu_stats *s;
179
180         s = this_cpu_ptr(cp->dest->stats.cpustats);
181         s->ustats.conns++;
182
183         s = this_cpu_ptr(svc->stats.cpustats);
184         s->ustats.conns++;
185
186         s = this_cpu_ptr(ipvs->tot_stats.cpustats);
187         s->ustats.conns++;
188 }
189
190
191 static inline int
192 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
193                 const struct sk_buff *skb,
194                 struct ip_vs_proto_data *pd)
195 {
196         if (unlikely(!pd->pp->state_transition))
197                 return 0;
198         return pd->pp->state_transition(cp, direction, skb, pd);
199 }
200
201 static inline int
202 ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
203                               struct sk_buff *skb, int protocol,
204                               const union nf_inet_addr *caddr, __be16 cport,
205                               const union nf_inet_addr *vaddr, __be16 vport,
206                               struct ip_vs_conn_param *p)
207 {
208         ip_vs_conn_fill_param(svc->net, svc->af, protocol, caddr, cport, vaddr,
209                               vport, p);
210         p->pe = svc->pe;
211         if (p->pe && p->pe->fill_param)
212                 return p->pe->fill_param(p, skb);
213
214         return 0;
215 }
216
217 /*
218  *  IPVS persistent scheduling function
219  *  It creates a connection entry according to its template if exists,
220  *  or selects a server and creates a connection entry plus a template.
221  *  Locking: we are svc user (svc->refcnt), so we hold all dests too
222  *  Protocols supported: TCP, UDP
223  */
224 static struct ip_vs_conn *
225 ip_vs_sched_persist(struct ip_vs_service *svc,
226                     struct sk_buff *skb,
227                     __be16 src_port, __be16 dst_port, int *ignored)
228 {
229         struct ip_vs_conn *cp = NULL;
230         struct ip_vs_iphdr iph;
231         struct ip_vs_dest *dest;
232         struct ip_vs_conn *ct;
233         __be16 dport = 0;               /* destination port to forward */
234         unsigned int flags;
235         struct ip_vs_conn_param param;
236         union nf_inet_addr snet;        /* source network of the client,
237                                            after masking */
238
239         ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
240
241         /* Mask saddr with the netmask to adjust template granularity */
242 #ifdef CONFIG_IP_VS_IPV6
243         if (svc->af == AF_INET6)
244                 ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
245         else
246 #endif
247                 snet.ip = iph.saddr.ip & svc->netmask;
248
249         IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
250                       "mnet %s\n",
251                       IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(src_port),
252                       IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(dst_port),
253                       IP_VS_DBG_ADDR(svc->af, &snet));
254
255         /*
256          * As far as we know, FTP is a very complicated network protocol, and
257          * it uses control connection and data connections. For active FTP,
258          * FTP server initialize data connection to the client, its source port
259          * is often 20. For passive FTP, FTP server tells the clients the port
260          * that it passively listens to,  and the client issues the data
261          * connection. In the tunneling or direct routing mode, the load
262          * balancer is on the client-to-server half of connection, the port
263          * number is unknown to the load balancer. So, a conn template like
264          * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
265          * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
266          * is created for other persistent services.
267          */
268         {
269                 int protocol = iph.protocol;
270                 const union nf_inet_addr *vaddr = &iph.daddr;
271                 const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
272                 __be16 vport = 0;
273
274                 if (dst_port == svc->port) {
275                         /* non-FTP template:
276                          * <protocol, caddr, 0, vaddr, vport, daddr, dport>
277                          * FTP template:
278                          * <protocol, caddr, 0, vaddr, 0, daddr, 0>
279                          */
280                         if (svc->port != FTPPORT)
281                                 vport = dst_port;
282                 } else {
283                         /* Note: persistent fwmark-based services and
284                          * persistent port zero service are handled here.
285                          * fwmark template:
286                          * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
287                          * port zero template:
288                          * <protocol,caddr,0,vaddr,0,daddr,0>
289                          */
290                         if (svc->fwmark) {
291                                 protocol = IPPROTO_IP;
292                                 vaddr = &fwmark;
293                         }
294                 }
295                 /* return *ignored = -1 so NF_DROP can be used */
296                 if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
297                                                   vaddr, vport, &param) < 0) {
298                         *ignored = -1;
299                         return NULL;
300                 }
301         }
302
303         /* Check if a template already exists */
304         ct = ip_vs_ct_in_get(&param);
305         if (!ct || !ip_vs_check_template(ct)) {
306                 /*
307                  * No template found or the dest of the connection
308                  * template is not available.
309                  * return *ignored=0 i.e. ICMP and NF_DROP
310                  */
311                 dest = svc->scheduler->schedule(svc, skb);
312                 if (!dest) {
313                         IP_VS_DBG(1, "p-schedule: no dest found.\n");
314                         kfree(param.pe_data);
315                         *ignored = 0;
316                         return NULL;
317                 }
318
319                 if (dst_port == svc->port && svc->port != FTPPORT)
320                         dport = dest->port;
321
322                 /* Create a template
323                  * This adds param.pe_data to the template,
324                  * and thus param.pe_data will be destroyed
325                  * when the template expires */
326                 ct = ip_vs_conn_new(&param, &dest->addr, dport,
327                                     IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
328                 if (ct == NULL) {
329                         kfree(param.pe_data);
330                         *ignored = -1;
331                         return NULL;
332                 }
333
334                 ct->timeout = svc->timeout;
335         } else {
336                 /* set destination with the found template */
337                 dest = ct->dest;
338                 kfree(param.pe_data);
339         }
340
341         dport = dst_port;
342         if (dport == svc->port && dest->port)
343                 dport = dest->port;
344
345         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
346                  && iph.protocol == IPPROTO_UDP)?
347                 IP_VS_CONN_F_ONE_PACKET : 0;
348
349         /*
350          *    Create a new connection according to the template
351          */
352         ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol, &iph.saddr,
353                               src_port, &iph.daddr, dst_port, &param);
354
355         cp = ip_vs_conn_new(&param, &dest->addr, dport, flags, dest, skb->mark);
356         if (cp == NULL) {
357                 ip_vs_conn_put(ct);
358                 *ignored = -1;
359                 return NULL;
360         }
361
362         /*
363          *    Add its control
364          */
365         ip_vs_control_add(cp, ct);
366         ip_vs_conn_put(ct);
367
368         ip_vs_conn_stats(cp, svc);
369         return cp;
370 }
371
372
373 /*
374  *  IPVS main scheduling function
375  *  It selects a server according to the virtual service, and
376  *  creates a connection entry.
377  *  Protocols supported: TCP, UDP
378  *
379  *  Usage of *ignored
380  *
381  * 1 :   protocol tried to schedule (eg. on SYN), found svc but the
382  *       svc/scheduler decides that this packet should be accepted with
383  *       NF_ACCEPT because it must not be scheduled.
384  *
385  * 0 :   scheduler can not find destination, so try bypass or
386  *       return ICMP and then NF_DROP (ip_vs_leave).
387  *
388  * -1 :  scheduler tried to schedule but fatal error occurred, eg.
389  *       ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
390  *       failure such as missing Call-ID, ENOMEM on skb_linearize
391  *       or pe_data. In this case we should return NF_DROP without
392  *       any attempts to send ICMP with ip_vs_leave.
393  */
394 struct ip_vs_conn *
395 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
396                struct ip_vs_proto_data *pd, int *ignored)
397 {
398         struct ip_vs_protocol *pp = pd->pp;
399         struct ip_vs_conn *cp = NULL;
400         struct ip_vs_iphdr iph;
401         struct ip_vs_dest *dest;
402         __be16 _ports[2], *pptr;
403         unsigned int flags;
404
405         *ignored = 1;
406         ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
407         pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
408         if (pptr == NULL)
409                 return NULL;
410
411         /*
412          * FTPDATA needs this check when using local real server.
413          * Never schedule Active FTPDATA connections from real server.
414          * For LVS-NAT they must be already created. For other methods
415          * with persistence the connection is created on SYN+ACK.
416          */
417         if (pptr[0] == FTPDATA) {
418                 IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
419                               "Not scheduling FTPDATA");
420                 return NULL;
421         }
422
423         /*
424          *    Do not schedule replies from local real server.
425          */
426         if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
427             (cp = pp->conn_in_get(svc->af, skb, &iph, iph.len, 1))) {
428                 IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
429                               "Not scheduling reply for existing connection");
430                 __ip_vs_conn_put(cp);
431                 return NULL;
432         }
433
434         /*
435          *    Persistent service
436          */
437         if (svc->flags & IP_VS_SVC_F_PERSISTENT)
438                 return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored);
439
440         *ignored = 0;
441
442         /*
443          *    Non-persistent service
444          */
445         if (!svc->fwmark && pptr[1] != svc->port) {
446                 if (!svc->port)
447                         pr_err("Schedule: port zero only supported "
448                                "in persistent services, "
449                                "check your ipvs configuration\n");
450                 return NULL;
451         }
452
453         dest = svc->scheduler->schedule(svc, skb);
454         if (dest == NULL) {
455                 IP_VS_DBG(1, "Schedule: no dest found.\n");
456                 return NULL;
457         }
458
459         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
460                  && iph.protocol == IPPROTO_UDP)?
461                 IP_VS_CONN_F_ONE_PACKET : 0;
462
463         /*
464          *    Create a connection entry.
465          */
466         {
467                 struct ip_vs_conn_param p;
468
469                 ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
470                                       &iph.saddr, pptr[0], &iph.daddr, pptr[1],
471                                       &p);
472                 cp = ip_vs_conn_new(&p, &dest->addr,
473                                     dest->port ? dest->port : pptr[1],
474                                     flags, dest, skb->mark);
475                 if (!cp) {
476                         *ignored = -1;
477                         return NULL;
478                 }
479         }
480
481         IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
482                       "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
483                       ip_vs_fwd_tag(cp),
484                       IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
485                       IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
486                       IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
487                       cp->flags, atomic_read(&cp->refcnt));
488
489         ip_vs_conn_stats(cp, svc);
490         return cp;
491 }
492
493
494 /*
495  *  Pass or drop the packet.
496  *  Called by ip_vs_in, when the virtual service is available but
497  *  no destination is available for a new connection.
498  */
499 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
500                 struct ip_vs_proto_data *pd)
501 {
502         __be16 _ports[2], *pptr;
503         struct ip_vs_iphdr iph;
504 #ifdef CONFIG_SYSCTL
505         struct net *net;
506         struct netns_ipvs *ipvs;
507         int unicast;
508 #endif
509
510         ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
511
512         pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
513         if (pptr == NULL) {
514                 ip_vs_service_put(svc);
515                 return NF_DROP;
516         }
517
518 #ifdef CONFIG_SYSCTL
519         net = skb_net(skb);
520
521 #ifdef CONFIG_IP_VS_IPV6
522         if (svc->af == AF_INET6)
523                 unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
524         else
525 #endif
526                 unicast = (inet_addr_type(net, iph.daddr.ip) == RTN_UNICAST);
527
528         /* if it is fwmark-based service, the cache_bypass sysctl is up
529            and the destination is a non-local unicast, then create
530            a cache_bypass connection entry */
531         ipvs = net_ipvs(net);
532         if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
533                 int ret, cs;
534                 struct ip_vs_conn *cp;
535                 unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
536                                       iph.protocol == IPPROTO_UDP)?
537                                       IP_VS_CONN_F_ONE_PACKET : 0;
538                 union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };
539
540                 ip_vs_service_put(svc);
541
542                 /* create a new connection entry */
543                 IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
544                 {
545                         struct ip_vs_conn_param p;
546                         ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
547                                               &iph.saddr, pptr[0],
548                                               &iph.daddr, pptr[1], &p);
549                         cp = ip_vs_conn_new(&p, &daddr, 0,
550                                             IP_VS_CONN_F_BYPASS | flags,
551                                             NULL, skb->mark);
552                         if (!cp)
553                                 return NF_DROP;
554                 }
555
556                 /* statistics */
557                 ip_vs_in_stats(cp, skb);
558
559                 /* set state */
560                 cs = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
561
562                 /* transmit the first SYN packet */
563                 ret = cp->packet_xmit(skb, cp, pd->pp);
564                 /* do not touch skb anymore */
565
566                 atomic_inc(&cp->in_pkts);
567                 ip_vs_conn_put(cp);
568                 return ret;
569         }
570 #endif
571
572         /*
573          * When the virtual ftp service is presented, packets destined
574          * for other services on the VIP may get here (except services
575          * listed in the ipvs table), pass the packets, because it is
576          * not ipvs job to decide to drop the packets.
577          */
578         if ((svc->port == FTPPORT) && (pptr[1] != FTPPORT)) {
579                 ip_vs_service_put(svc);
580                 return NF_ACCEPT;
581         }
582
583         ip_vs_service_put(svc);
584
585         /*
586          * Notify the client that the destination is unreachable, and
587          * release the socket buffer.
588          * Since it is in IP layer, the TCP socket is not actually
589          * created, the TCP RST packet cannot be sent, instead that
590          * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
591          */
592 #ifdef CONFIG_IP_VS_IPV6
593         if (svc->af == AF_INET6) {
594                 if (!skb->dev) {
595                         struct net *net = dev_net(skb_dst(skb)->dev);
596
597                         skb->dev = net->loopback_dev;
598                 }
599                 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
600         } else
601 #endif
602                 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
603
604         return NF_DROP;
605 }
606
607 #ifdef CONFIG_SYSCTL
608
609 static int sysctl_snat_reroute(struct sk_buff *skb)
610 {
611         struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
612         return ipvs->sysctl_snat_reroute;
613 }
614
615 static int sysctl_nat_icmp_send(struct net *net)
616 {
617         struct netns_ipvs *ipvs = net_ipvs(net);
618         return ipvs->sysctl_nat_icmp_send;
619 }
620
621 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
622 {
623         return ipvs->sysctl_expire_nodest_conn;
624 }
625
626 #else
627
628 static int sysctl_snat_reroute(struct sk_buff *skb) { return 0; }
629 static int sysctl_nat_icmp_send(struct net *net) { return 0; }
630 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; }
631
632 #endif
633
634 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
635 {
636         return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
637 }
638
639 static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum)
640 {
641         if (NF_INET_LOCAL_IN == hooknum)
642                 return IP_DEFRAG_VS_IN;
643         if (NF_INET_FORWARD == hooknum)
644                 return IP_DEFRAG_VS_FWD;
645         return IP_DEFRAG_VS_OUT;
646 }
647
648 static inline int ip_vs_gather_frags(struct sk_buff *skb, u_int32_t user)
649 {
650         int err = ip_defrag(skb, user);
651
652         if (!err)
653                 ip_send_check(ip_hdr(skb));
654
655         return err;
656 }
657
658 #ifdef CONFIG_IP_VS_IPV6
659 static inline int ip_vs_gather_frags_v6(struct sk_buff *skb, u_int32_t user)
660 {
661         /* TODO IPv6: Find out what to do here for IPv6 */
662         return 0;
663 }
664 #endif
665
666 static int ip_vs_route_me_harder(int af, struct sk_buff *skb)
667 {
668 #ifdef CONFIG_IP_VS_IPV6
669         if (af == AF_INET6) {
670                 if (sysctl_snat_reroute(skb) && ip6_route_me_harder(skb) != 0)
671                         return 1;
672         } else
673 #endif
674                 if ((sysctl_snat_reroute(skb) ||
675                      skb_rtable(skb)->rt_flags & RTCF_LOCAL) &&
676                     ip_route_me_harder(skb, RTN_LOCAL) != 0)
677                         return 1;
678
679         return 0;
680 }
681
682 /*
683  * Packet has been made sufficiently writable in caller
684  * - inout: 1=in->out, 0=out->in
685  */
686 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
687                     struct ip_vs_conn *cp, int inout)
688 {
689         struct iphdr *iph        = ip_hdr(skb);
690         unsigned int icmp_offset = iph->ihl*4;
691         struct icmphdr *icmph    = (struct icmphdr *)(skb_network_header(skb) +
692                                                       icmp_offset);
693         struct iphdr *ciph       = (struct iphdr *)(icmph + 1);
694
695         if (inout) {
696                 iph->saddr = cp->vaddr.ip;
697                 ip_send_check(iph);
698                 ciph->daddr = cp->vaddr.ip;
699                 ip_send_check(ciph);
700         } else {
701                 iph->daddr = cp->daddr.ip;
702                 ip_send_check(iph);
703                 ciph->saddr = cp->daddr.ip;
704                 ip_send_check(ciph);
705         }
706
707         /* the TCP/UDP/SCTP port */
708         if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol ||
709             IPPROTO_SCTP == ciph->protocol) {
710                 __be16 *ports = (void *)ciph + ciph->ihl*4;
711
712                 if (inout)
713                         ports[1] = cp->vport;
714                 else
715                         ports[0] = cp->dport;
716         }
717
718         /* And finally the ICMP checksum */
719         icmph->checksum = 0;
720         icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
721         skb->ip_summed = CHECKSUM_UNNECESSARY;
722
723         if (inout)
724                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
725                         "Forwarding altered outgoing ICMP");
726         else
727                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
728                         "Forwarding altered incoming ICMP");
729 }
730
731 #ifdef CONFIG_IP_VS_IPV6
732 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
733                     struct ip_vs_conn *cp, int inout)
734 {
735         struct ipv6hdr *iph      = ipv6_hdr(skb);
736         unsigned int icmp_offset = sizeof(struct ipv6hdr);
737         struct icmp6hdr *icmph   = (struct icmp6hdr *)(skb_network_header(skb) +
738                                                       icmp_offset);
739         struct ipv6hdr *ciph     = (struct ipv6hdr *)(icmph + 1);
740
741         if (inout) {
742                 iph->saddr = cp->vaddr.in6;
743                 ciph->daddr = cp->vaddr.in6;
744         } else {
745                 iph->daddr = cp->daddr.in6;
746                 ciph->saddr = cp->daddr.in6;
747         }
748
749         /* the TCP/UDP/SCTP port */
750         if (IPPROTO_TCP == ciph->nexthdr || IPPROTO_UDP == ciph->nexthdr ||
751             IPPROTO_SCTP == ciph->nexthdr) {
752                 __be16 *ports = (void *)ciph + sizeof(struct ipv6hdr);
753
754                 if (inout)
755                         ports[1] = cp->vport;
756                 else
757                         ports[0] = cp->dport;
758         }
759
760         /* And finally the ICMP checksum */
761         icmph->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr,
762                                               skb->len - icmp_offset,
763                                               IPPROTO_ICMPV6, 0);
764         skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset;
765         skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
766         skb->ip_summed = CHECKSUM_PARTIAL;
767
768         if (inout)
769                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
770                               (void *)ciph - (void *)iph,
771                               "Forwarding altered outgoing ICMPv6");
772         else
773                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
774                               (void *)ciph - (void *)iph,
775                               "Forwarding altered incoming ICMPv6");
776 }
777 #endif
778
779 /* Handle relevant response ICMP messages - forward to the right
780  * destination host.
781  */
782 static int handle_response_icmp(int af, struct sk_buff *skb,
783                                 union nf_inet_addr *snet,
784                                 __u8 protocol, struct ip_vs_conn *cp,
785                                 struct ip_vs_protocol *pp,
786                                 unsigned int offset, unsigned int ihl)
787 {
788         unsigned int verdict = NF_DROP;
789
790         if (IP_VS_FWD_METHOD(cp) != 0) {
791                 pr_err("shouldn't reach here, because the box is on the "
792                        "half connection in the tun/dr module.\n");
793         }
794
795         /* Ensure the checksum is correct */
796         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
797                 /* Failed checksum! */
798                 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
799                               IP_VS_DBG_ADDR(af, snet));
800                 goto out;
801         }
802
803         if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
804             IPPROTO_SCTP == protocol)
805                 offset += 2 * sizeof(__u16);
806         if (!skb_make_writable(skb, offset))
807                 goto out;
808
809 #ifdef CONFIG_IP_VS_IPV6
810         if (af == AF_INET6)
811                 ip_vs_nat_icmp_v6(skb, pp, cp, 1);
812         else
813 #endif
814                 ip_vs_nat_icmp(skb, pp, cp, 1);
815
816         if (ip_vs_route_me_harder(af, skb))
817                 goto out;
818
819         /* do the statistics and put it back */
820         ip_vs_out_stats(cp, skb);
821
822         skb->ipvs_property = 1;
823         if (!(cp->flags & IP_VS_CONN_F_NFCT))
824                 ip_vs_notrack(skb);
825         else
826                 ip_vs_update_conntrack(skb, cp, 0);
827         verdict = NF_ACCEPT;
828
829 out:
830         __ip_vs_conn_put(cp);
831
832         return verdict;
833 }
834
835 /*
836  *      Handle ICMP messages in the inside-to-outside direction (outgoing).
837  *      Find any that might be relevant, check against existing connections.
838  *      Currently handles error types - unreachable, quench, ttl exceeded.
839  */
840 static int ip_vs_out_icmp(struct sk_buff *skb, int *related,
841                           unsigned int hooknum)
842 {
843         struct iphdr *iph;
844         struct icmphdr  _icmph, *ic;
845         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
846         struct ip_vs_iphdr ciph;
847         struct ip_vs_conn *cp;
848         struct ip_vs_protocol *pp;
849         unsigned int offset, ihl;
850         union nf_inet_addr snet;
851
852         *related = 1;
853
854         /* reassemble IP fragments */
855         if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
856                 if (ip_vs_gather_frags(skb, ip_vs_defrag_user(hooknum)))
857                         return NF_STOLEN;
858         }
859
860         iph = ip_hdr(skb);
861         offset = ihl = iph->ihl * 4;
862         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
863         if (ic == NULL)
864                 return NF_DROP;
865
866         IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
867                   ic->type, ntohs(icmp_id(ic)),
868                   &iph->saddr, &iph->daddr);
869
870         /*
871          * Work through seeing if this is for us.
872          * These checks are supposed to be in an order that means easy
873          * things are checked first to speed up processing.... however
874          * this means that some packets will manage to get a long way
875          * down this stack and then be rejected, but that's life.
876          */
877         if ((ic->type != ICMP_DEST_UNREACH) &&
878             (ic->type != ICMP_SOURCE_QUENCH) &&
879             (ic->type != ICMP_TIME_EXCEEDED)) {
880                 *related = 0;
881                 return NF_ACCEPT;
882         }
883
884         /* Now find the contained IP header */
885         offset += sizeof(_icmph);
886         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
887         if (cih == NULL)
888                 return NF_ACCEPT; /* The packet looks wrong, ignore */
889
890         pp = ip_vs_proto_get(cih->protocol);
891         if (!pp)
892                 return NF_ACCEPT;
893
894         /* Is the embedded protocol header present? */
895         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
896                      pp->dont_defrag))
897                 return NF_ACCEPT;
898
899         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
900                       "Checking outgoing ICMP for");
901
902         offset += cih->ihl * 4;
903
904         ip_vs_fill_iphdr(AF_INET, cih, &ciph);
905         /* The embedded headers contain source and dest in reverse order */
906         cp = pp->conn_out_get(AF_INET, skb, &ciph, offset, 1);
907         if (!cp)
908                 return NF_ACCEPT;
909
910         snet.ip = iph->saddr;
911         return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
912                                     pp, offset, ihl);
913 }
914
915 #ifdef CONFIG_IP_VS_IPV6
916 static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related,
917                              unsigned int hooknum)
918 {
919         struct ipv6hdr *iph;
920         struct icmp6hdr _icmph, *ic;
921         struct ipv6hdr  _ciph, *cih;    /* The ip header contained
922                                            within the ICMP */
923         struct ip_vs_iphdr ciph;
924         struct ip_vs_conn *cp;
925         struct ip_vs_protocol *pp;
926         unsigned int offset;
927         union nf_inet_addr snet;
928
929         *related = 1;
930
931         /* reassemble IP fragments */
932         if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
933                 if (ip_vs_gather_frags_v6(skb, ip_vs_defrag_user(hooknum)))
934                         return NF_STOLEN;
935         }
936
937         iph = ipv6_hdr(skb);
938         offset = sizeof(struct ipv6hdr);
939         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
940         if (ic == NULL)
941                 return NF_DROP;
942
943         IP_VS_DBG(12, "Outgoing ICMPv6 (%d,%d) %pI6->%pI6\n",
944                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
945                   &iph->saddr, &iph->daddr);
946
947         /*
948          * Work through seeing if this is for us.
949          * These checks are supposed to be in an order that means easy
950          * things are checked first to speed up processing.... however
951          * this means that some packets will manage to get a long way
952          * down this stack and then be rejected, but that's life.
953          */
954         if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
955             (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
956             (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
957                 *related = 0;
958                 return NF_ACCEPT;
959         }
960
961         /* Now find the contained IP header */
962         offset += sizeof(_icmph);
963         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
964         if (cih == NULL)
965                 return NF_ACCEPT; /* The packet looks wrong, ignore */
966
967         pp = ip_vs_proto_get(cih->nexthdr);
968         if (!pp)
969                 return NF_ACCEPT;
970
971         /* Is the embedded protocol header present? */
972         /* TODO: we don't support fragmentation at the moment anyways */
973         if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
974                 return NF_ACCEPT;
975
976         IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset,
977                       "Checking outgoing ICMPv6 for");
978
979         offset += sizeof(struct ipv6hdr);
980
981         ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
982         /* The embedded headers contain source and dest in reverse order */
983         cp = pp->conn_out_get(AF_INET6, skb, &ciph, offset, 1);
984         if (!cp)
985                 return NF_ACCEPT;
986
987         ipv6_addr_copy(&snet.in6, &iph->saddr);
988         return handle_response_icmp(AF_INET6, skb, &snet, cih->nexthdr, cp,
989                                     pp, offset, sizeof(struct ipv6hdr));
990 }
991 #endif
992
993 /*
994  * Check if sctp chunc is ABORT chunk
995  */
996 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len)
997 {
998         sctp_chunkhdr_t *sch, schunk;
999         sch = skb_header_pointer(skb, nh_len + sizeof(sctp_sctphdr_t),
1000                         sizeof(schunk), &schunk);
1001         if (sch == NULL)
1002                 return 0;
1003         if (sch->type == SCTP_CID_ABORT)
1004                 return 1;
1005         return 0;
1006 }
1007
1008 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
1009 {
1010         struct tcphdr _tcph, *th;
1011
1012         th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
1013         if (th == NULL)
1014                 return 0;
1015         return th->rst;
1016 }
1017
1018 /* Handle response packets: rewrite addresses and send away...
1019  */
1020 static unsigned int
1021 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
1022                 struct ip_vs_conn *cp, int ihl)
1023 {
1024         struct ip_vs_protocol *pp = pd->pp;
1025
1026         IP_VS_DBG_PKT(11, af, pp, skb, 0, "Outgoing packet");
1027
1028         if (!skb_make_writable(skb, ihl))
1029                 goto drop;
1030
1031         /* mangle the packet */
1032         if (pp->snat_handler && !pp->snat_handler(skb, pp, cp))
1033                 goto drop;
1034
1035 #ifdef CONFIG_IP_VS_IPV6
1036         if (af == AF_INET6)
1037                 ipv6_hdr(skb)->saddr = cp->vaddr.in6;
1038         else
1039 #endif
1040         {
1041                 ip_hdr(skb)->saddr = cp->vaddr.ip;
1042                 ip_send_check(ip_hdr(skb));
1043         }
1044
1045         /*
1046          * nf_iterate does not expect change in the skb->dst->dev.
1047          * It looks like it is not fatal to enable this code for hooks
1048          * where our handlers are at the end of the chain list and
1049          * when all next handlers use skb->dst->dev and not outdev.
1050          * It will definitely route properly the inout NAT traffic
1051          * when multiple paths are used.
1052          */
1053
1054         /* For policy routing, packets originating from this
1055          * machine itself may be routed differently to packets
1056          * passing through.  We want this packet to be routed as
1057          * if it came from this machine itself.  So re-compute
1058          * the routing information.
1059          */
1060         if (ip_vs_route_me_harder(af, skb))
1061                 goto drop;
1062
1063         IP_VS_DBG_PKT(10, af, pp, skb, 0, "After SNAT");
1064
1065         ip_vs_out_stats(cp, skb);
1066         ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd);
1067         skb->ipvs_property = 1;
1068         if (!(cp->flags & IP_VS_CONN_F_NFCT))
1069                 ip_vs_notrack(skb);
1070         else
1071                 ip_vs_update_conntrack(skb, cp, 0);
1072         ip_vs_conn_put(cp);
1073
1074         LeaveFunction(11);
1075         return NF_ACCEPT;
1076
1077 drop:
1078         ip_vs_conn_put(cp);
1079         kfree_skb(skb);
1080         LeaveFunction(11);
1081         return NF_STOLEN;
1082 }
1083
1084 /*
1085  *      Check if outgoing packet belongs to the established ip_vs_conn.
1086  */
1087 static unsigned int
1088 ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af)
1089 {
1090         struct net *net = NULL;
1091         struct ip_vs_iphdr iph;
1092         struct ip_vs_protocol *pp;
1093         struct ip_vs_proto_data *pd;
1094         struct ip_vs_conn *cp;
1095
1096         EnterFunction(11);
1097
1098         /* Already marked as IPVS request or reply? */
1099         if (skb->ipvs_property)
1100                 return NF_ACCEPT;
1101
1102         /* Bad... Do not break raw sockets */
1103         if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT &&
1104                      af == AF_INET)) {
1105                 struct sock *sk = skb->sk;
1106                 struct inet_sock *inet = inet_sk(skb->sk);
1107
1108                 if (inet && sk->sk_family == PF_INET && inet->nodefrag)
1109                         return NF_ACCEPT;
1110         }
1111
1112         if (unlikely(!skb_dst(skb)))
1113                 return NF_ACCEPT;
1114
1115         net = skb_net(skb);
1116         if (!net_ipvs(net)->enable)
1117                 return NF_ACCEPT;
1118
1119         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1120 #ifdef CONFIG_IP_VS_IPV6
1121         if (af == AF_INET6) {
1122                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1123                         int related;
1124                         int verdict = ip_vs_out_icmp_v6(skb, &related,
1125                                                         hooknum);
1126
1127                         if (related)
1128                                 return verdict;
1129                         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1130                 }
1131         } else
1132 #endif
1133                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1134                         int related;
1135                         int verdict = ip_vs_out_icmp(skb, &related, hooknum);
1136
1137                         if (related)
1138                                 return verdict;
1139                         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1140                 }
1141
1142         pd = ip_vs_proto_data_get(net, iph.protocol);
1143         if (unlikely(!pd))
1144                 return NF_ACCEPT;
1145         pp = pd->pp;
1146
1147         /* reassemble IP fragments */
1148 #ifdef CONFIG_IP_VS_IPV6
1149         if (af == AF_INET6) {
1150                 if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
1151                         if (ip_vs_gather_frags_v6(skb,
1152                                                   ip_vs_defrag_user(hooknum)))
1153                                 return NF_STOLEN;
1154                 }
1155
1156                 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1157         } else
1158 #endif
1159                 if (unlikely(ip_hdr(skb)->frag_off & htons(IP_MF|IP_OFFSET) &&
1160                              !pp->dont_defrag)) {
1161                         if (ip_vs_gather_frags(skb,
1162                                                ip_vs_defrag_user(hooknum)))
1163                                 return NF_STOLEN;
1164
1165                         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1166                 }
1167
1168         /*
1169          * Check if the packet belongs to an existing entry
1170          */
1171         cp = pp->conn_out_get(af, skb, &iph, iph.len, 0);
1172
1173         if (likely(cp))
1174                 return handle_response(af, skb, pd, cp, iph.len);
1175         if (sysctl_nat_icmp_send(net) &&
1176             (pp->protocol == IPPROTO_TCP ||
1177              pp->protocol == IPPROTO_UDP ||
1178              pp->protocol == IPPROTO_SCTP)) {
1179                 __be16 _ports[2], *pptr;
1180
1181                 pptr = skb_header_pointer(skb, iph.len,
1182                                           sizeof(_ports), _ports);
1183                 if (pptr == NULL)
1184                         return NF_ACCEPT;       /* Not for me */
1185                 if (ip_vs_lookup_real_service(net, af, iph.protocol,
1186                                               &iph.saddr,
1187                                               pptr[0])) {
1188                         /*
1189                          * Notify the real server: there is no
1190                          * existing entry if it is not RST
1191                          * packet or not TCP packet.
1192                          */
1193                         if ((iph.protocol != IPPROTO_TCP &&
1194                              iph.protocol != IPPROTO_SCTP)
1195                              || ((iph.protocol == IPPROTO_TCP
1196                                   && !is_tcp_reset(skb, iph.len))
1197                                  || (iph.protocol == IPPROTO_SCTP
1198                                         && !is_sctp_abort(skb,
1199                                                 iph.len)))) {
1200 #ifdef CONFIG_IP_VS_IPV6
1201                                 if (af == AF_INET6) {
1202                                         struct net *net =
1203                                                 dev_net(skb_dst(skb)->dev);
1204
1205                                         if (!skb->dev)
1206                                                 skb->dev = net->loopback_dev;
1207                                         icmpv6_send(skb,
1208                                                     ICMPV6_DEST_UNREACH,
1209                                                     ICMPV6_PORT_UNREACH,
1210                                                     0);
1211                                 } else
1212 #endif
1213                                         icmp_send(skb,
1214                                                   ICMP_DEST_UNREACH,
1215                                                   ICMP_PORT_UNREACH, 0);
1216                                 return NF_DROP;
1217                         }
1218                 }
1219         }
1220         IP_VS_DBG_PKT(12, af, pp, skb, 0,
1221                       "ip_vs_out: packet continues traversal as normal");
1222         return NF_ACCEPT;
1223 }
1224
1225 /*
1226  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1227  *      used only for VS/NAT.
1228  *      Check if packet is reply for established ip_vs_conn.
1229  */
1230 static unsigned int
1231 ip_vs_reply4(unsigned int hooknum, struct sk_buff *skb,
1232              const struct net_device *in, const struct net_device *out,
1233              int (*okfn)(struct sk_buff *))
1234 {
1235         return ip_vs_out(hooknum, skb, AF_INET);
1236 }
1237
1238 /*
1239  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1240  *      Check if packet is reply for established ip_vs_conn.
1241  */
1242 static unsigned int
1243 ip_vs_local_reply4(unsigned int hooknum, struct sk_buff *skb,
1244                    const struct net_device *in, const struct net_device *out,
1245                    int (*okfn)(struct sk_buff *))
1246 {
1247         unsigned int verdict;
1248
1249         /* Disable BH in LOCAL_OUT until all places are fixed */
1250         local_bh_disable();
1251         verdict = ip_vs_out(hooknum, skb, AF_INET);
1252         local_bh_enable();
1253         return verdict;
1254 }
1255
1256 #ifdef CONFIG_IP_VS_IPV6
1257
1258 /*
1259  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1260  *      used only for VS/NAT.
1261  *      Check if packet is reply for established ip_vs_conn.
1262  */
1263 static unsigned int
1264 ip_vs_reply6(unsigned int hooknum, struct sk_buff *skb,
1265              const struct net_device *in, const struct net_device *out,
1266              int (*okfn)(struct sk_buff *))
1267 {
1268         return ip_vs_out(hooknum, skb, AF_INET6);
1269 }
1270
1271 /*
1272  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1273  *      Check if packet is reply for established ip_vs_conn.
1274  */
1275 static unsigned int
1276 ip_vs_local_reply6(unsigned int hooknum, struct sk_buff *skb,
1277                    const struct net_device *in, const struct net_device *out,
1278                    int (*okfn)(struct sk_buff *))
1279 {
1280         unsigned int verdict;
1281
1282         /* Disable BH in LOCAL_OUT until all places are fixed */
1283         local_bh_disable();
1284         verdict = ip_vs_out(hooknum, skb, AF_INET6);
1285         local_bh_enable();
1286         return verdict;
1287 }
1288
1289 #endif
1290
1291 /*
1292  *      Handle ICMP messages in the outside-to-inside direction (incoming).
1293  *      Find any that might be relevant, check against existing connections,
1294  *      forward to the right destination host if relevant.
1295  *      Currently handles error types - unreachable, quench, ttl exceeded.
1296  */
1297 static int
1298 ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
1299 {
1300         struct net *net = NULL;
1301         struct iphdr *iph;
1302         struct icmphdr  _icmph, *ic;
1303         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
1304         struct ip_vs_iphdr ciph;
1305         struct ip_vs_conn *cp;
1306         struct ip_vs_protocol *pp;
1307         struct ip_vs_proto_data *pd;
1308         unsigned int offset, ihl, verdict;
1309
1310         *related = 1;
1311
1312         /* reassemble IP fragments */
1313         if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
1314                 if (ip_vs_gather_frags(skb, ip_vs_defrag_user(hooknum)))
1315                         return NF_STOLEN;
1316         }
1317
1318         iph = ip_hdr(skb);
1319         offset = ihl = iph->ihl * 4;
1320         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1321         if (ic == NULL)
1322                 return NF_DROP;
1323
1324         IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1325                   ic->type, ntohs(icmp_id(ic)),
1326                   &iph->saddr, &iph->daddr);
1327
1328         /*
1329          * Work through seeing if this is for us.
1330          * These checks are supposed to be in an order that means easy
1331          * things are checked first to speed up processing.... however
1332          * this means that some packets will manage to get a long way
1333          * down this stack and then be rejected, but that's life.
1334          */
1335         if ((ic->type != ICMP_DEST_UNREACH) &&
1336             (ic->type != ICMP_SOURCE_QUENCH) &&
1337             (ic->type != ICMP_TIME_EXCEEDED)) {
1338                 *related = 0;
1339                 return NF_ACCEPT;
1340         }
1341
1342         /* Now find the contained IP header */
1343         offset += sizeof(_icmph);
1344         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1345         if (cih == NULL)
1346                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1347
1348         net = skb_net(skb);
1349
1350         pd = ip_vs_proto_data_get(net, cih->protocol);
1351         if (!pd)
1352                 return NF_ACCEPT;
1353         pp = pd->pp;
1354
1355         /* Is the embedded protocol header present? */
1356         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1357                      pp->dont_defrag))
1358                 return NF_ACCEPT;
1359
1360         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
1361                       "Checking incoming ICMP for");
1362
1363         offset += cih->ihl * 4;
1364
1365         ip_vs_fill_iphdr(AF_INET, cih, &ciph);
1366         /* The embedded headers contain source and dest in reverse order */
1367         cp = pp->conn_in_get(AF_INET, skb, &ciph, offset, 1);
1368         if (!cp)
1369                 return NF_ACCEPT;
1370
1371         verdict = NF_DROP;
1372
1373         /* Ensure the checksum is correct */
1374         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1375                 /* Failed checksum! */
1376                 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1377                           &iph->saddr);
1378                 goto out;
1379         }
1380
1381         /* do the statistics and put it back */
1382         ip_vs_in_stats(cp, skb);
1383         if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
1384                 offset += 2 * sizeof(__u16);
1385         verdict = ip_vs_icmp_xmit(skb, cp, pp, offset);
1386         /* LOCALNODE from FORWARD hook is not supported */
1387         if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
1388             skb_rtable(skb)->rt_flags & RTCF_LOCAL) {
1389                 IP_VS_DBG(1, "%s(): "
1390                           "local delivery to %pI4 but in FORWARD\n",
1391                           __func__, &skb_rtable(skb)->rt_dst);
1392                 verdict = NF_DROP;
1393         }
1394
1395   out:
1396         __ip_vs_conn_put(cp);
1397
1398         return verdict;
1399 }
1400
1401 #ifdef CONFIG_IP_VS_IPV6
1402 static int
1403 ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
1404 {
1405         struct net *net = NULL;
1406         struct ipv6hdr *iph;
1407         struct icmp6hdr _icmph, *ic;
1408         struct ipv6hdr  _ciph, *cih;    /* The ip header contained
1409                                            within the ICMP */
1410         struct ip_vs_iphdr ciph;
1411         struct ip_vs_conn *cp;
1412         struct ip_vs_protocol *pp;
1413         struct ip_vs_proto_data *pd;
1414         unsigned int offset, verdict;
1415         struct rt6_info *rt;
1416
1417         *related = 1;
1418
1419         /* reassemble IP fragments */
1420         if (ipv6_hdr(skb)->nexthdr == IPPROTO_FRAGMENT) {
1421                 if (ip_vs_gather_frags_v6(skb, ip_vs_defrag_user(hooknum)))
1422                         return NF_STOLEN;
1423         }
1424
1425         iph = ipv6_hdr(skb);
1426         offset = sizeof(struct ipv6hdr);
1427         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1428         if (ic == NULL)
1429                 return NF_DROP;
1430
1431         IP_VS_DBG(12, "Incoming ICMPv6 (%d,%d) %pI6->%pI6\n",
1432                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
1433                   &iph->saddr, &iph->daddr);
1434
1435         /*
1436          * Work through seeing if this is for us.
1437          * These checks are supposed to be in an order that means easy
1438          * things are checked first to speed up processing.... however
1439          * this means that some packets will manage to get a long way
1440          * down this stack and then be rejected, but that's life.
1441          */
1442         if ((ic->icmp6_type != ICMPV6_DEST_UNREACH) &&
1443             (ic->icmp6_type != ICMPV6_PKT_TOOBIG) &&
1444             (ic->icmp6_type != ICMPV6_TIME_EXCEED)) {
1445                 *related = 0;
1446                 return NF_ACCEPT;
1447         }
1448
1449         /* Now find the contained IP header */
1450         offset += sizeof(_icmph);
1451         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1452         if (cih == NULL)
1453                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1454
1455         net = skb_net(skb);
1456         pd = ip_vs_proto_data_get(net, cih->nexthdr);
1457         if (!pd)
1458                 return NF_ACCEPT;
1459         pp = pd->pp;
1460
1461         /* Is the embedded protocol header present? */
1462         /* TODO: we don't support fragmentation at the moment anyways */
1463         if (unlikely(cih->nexthdr == IPPROTO_FRAGMENT && pp->dont_defrag))
1464                 return NF_ACCEPT;
1465
1466         IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset,
1467                       "Checking incoming ICMPv6 for");
1468
1469         offset += sizeof(struct ipv6hdr);
1470
1471         ip_vs_fill_iphdr(AF_INET6, cih, &ciph);
1472         /* The embedded headers contain source and dest in reverse order */
1473         cp = pp->conn_in_get(AF_INET6, skb, &ciph, offset, 1);
1474         if (!cp)
1475                 return NF_ACCEPT;
1476
1477         verdict = NF_DROP;
1478
1479         /* do the statistics and put it back */
1480         ip_vs_in_stats(cp, skb);
1481         if (IPPROTO_TCP == cih->nexthdr || IPPROTO_UDP == cih->nexthdr ||
1482             IPPROTO_SCTP == cih->nexthdr)
1483                 offset += 2 * sizeof(__u16);
1484         verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset);
1485         /* LOCALNODE from FORWARD hook is not supported */
1486         if (verdict == NF_ACCEPT && hooknum == NF_INET_FORWARD &&
1487             (rt = (struct rt6_info *) skb_dst(skb)) &&
1488             rt->rt6i_dev && rt->rt6i_dev->flags & IFF_LOOPBACK) {
1489                 IP_VS_DBG(1, "%s(): "
1490                           "local delivery to %pI6 but in FORWARD\n",
1491                           __func__, &rt->rt6i_dst);
1492                 verdict = NF_DROP;
1493         }
1494
1495         __ip_vs_conn_put(cp);
1496
1497         return verdict;
1498 }
1499 #endif
1500
1501
1502 /*
1503  *      Check if it's for virtual services, look it up,
1504  *      and send it on its way...
1505  */
1506 static unsigned int
1507 ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
1508 {
1509         struct net *net;
1510         struct ip_vs_iphdr iph;
1511         struct ip_vs_protocol *pp;
1512         struct ip_vs_proto_data *pd;
1513         struct ip_vs_conn *cp;
1514         int ret, restart, pkts;
1515         struct netns_ipvs *ipvs;
1516
1517         /* Already marked as IPVS request or reply? */
1518         if (skb->ipvs_property)
1519                 return NF_ACCEPT;
1520
1521         /*
1522          *      Big tappo:
1523          *      - remote client: only PACKET_HOST
1524          *      - route: used for struct net when skb->dev is unset
1525          */
1526         if (unlikely((skb->pkt_type != PACKET_HOST &&
1527                       hooknum != NF_INET_LOCAL_OUT) ||
1528                      !skb_dst(skb))) {
1529                 ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1530                 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s"
1531                               " ignored in hook %u\n",
1532                               skb->pkt_type, iph.protocol,
1533                               IP_VS_DBG_ADDR(af, &iph.daddr), hooknum);
1534                 return NF_ACCEPT;
1535         }
1536         /* ipvs enabled in this netns ? */
1537         net = skb_net(skb);
1538         if (!net_ipvs(net)->enable)
1539                 return NF_ACCEPT;
1540
1541         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1542
1543         /* Bad... Do not break raw sockets */
1544         if (unlikely(skb->sk != NULL && hooknum == NF_INET_LOCAL_OUT &&
1545                      af == AF_INET)) {
1546                 struct sock *sk = skb->sk;
1547                 struct inet_sock *inet = inet_sk(skb->sk);
1548
1549                 if (inet && sk->sk_family == PF_INET && inet->nodefrag)
1550                         return NF_ACCEPT;
1551         }
1552
1553 #ifdef CONFIG_IP_VS_IPV6
1554         if (af == AF_INET6) {
1555                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1556                         int related;
1557                         int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum);
1558
1559                         if (related)
1560                                 return verdict;
1561                         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1562                 }
1563         } else
1564 #endif
1565                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1566                         int related;
1567                         int verdict = ip_vs_in_icmp(skb, &related, hooknum);
1568
1569                         if (related)
1570                                 return verdict;
1571                         ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);
1572                 }
1573
1574         /* Protocol supported? */
1575         pd = ip_vs_proto_data_get(net, iph.protocol);
1576         if (unlikely(!pd))
1577                 return NF_ACCEPT;
1578         pp = pd->pp;
1579         /*
1580          * Check if the packet belongs to an existing connection entry
1581          */
1582         cp = pp->conn_in_get(af, skb, &iph, iph.len, 0);
1583
1584         if (unlikely(!cp)) {
1585                 int v;
1586
1587                 if (!pp->conn_schedule(af, skb, pd, &v, &cp))
1588                         return v;
1589         }
1590
1591         if (unlikely(!cp)) {
1592                 /* sorry, all this trouble for a no-hit :) */
1593                 IP_VS_DBG_PKT(12, af, pp, skb, 0,
1594                               "ip_vs_in: packet continues traversal as normal");
1595                 return NF_ACCEPT;
1596         }
1597
1598         IP_VS_DBG_PKT(11, af, pp, skb, 0, "Incoming packet");
1599         ipvs = net_ipvs(net);
1600         /* Check the server status */
1601         if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
1602                 /* the destination server is not available */
1603
1604                 if (sysctl_expire_nodest_conn(ipvs)) {
1605                         /* try to expire the connection immediately */
1606                         ip_vs_conn_expire_now(cp);
1607                 }
1608                 /* don't restart its timer, and silently
1609                    drop the packet. */
1610                 __ip_vs_conn_put(cp);
1611                 return NF_DROP;
1612         }
1613
1614         ip_vs_in_stats(cp, skb);
1615         restart = ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
1616         if (cp->packet_xmit)
1617                 ret = cp->packet_xmit(skb, cp, pp);
1618                 /* do not touch skb anymore */
1619         else {
1620                 IP_VS_DBG_RL("warning: packet_xmit is null");
1621                 ret = NF_ACCEPT;
1622         }
1623
1624         /* Increase its packet counter and check if it is needed
1625          * to be synchronized
1626          *
1627          * Sync connection if it is about to close to
1628          * encorage the standby servers to update the connections timeout
1629          *
1630          * For ONE_PKT let ip_vs_sync_conn() do the filter work.
1631          */
1632
1633         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
1634                 pkts = sysctl_sync_threshold(ipvs);
1635         else
1636                 pkts = atomic_add_return(1, &cp->in_pkts);
1637
1638         if ((ipvs->sync_state & IP_VS_STATE_MASTER) &&
1639             cp->protocol == IPPROTO_SCTP) {
1640                 if ((cp->state == IP_VS_SCTP_S_ESTABLISHED &&
1641                         (pkts % sysctl_sync_period(ipvs)
1642                          == sysctl_sync_threshold(ipvs))) ||
1643                                 (cp->old_state != cp->state &&
1644                                  ((cp->state == IP_VS_SCTP_S_CLOSED) ||
1645                                   (cp->state == IP_VS_SCTP_S_SHUT_ACK_CLI) ||
1646                                   (cp->state == IP_VS_SCTP_S_SHUT_ACK_SER)))) {
1647                         ip_vs_sync_conn(net, cp);
1648                         goto out;
1649                 }
1650         }
1651
1652         /* Keep this block last: TCP and others with pp->num_states <= 1 */
1653         else if ((ipvs->sync_state & IP_VS_STATE_MASTER) &&
1654             (((cp->protocol != IPPROTO_TCP ||
1655                cp->state == IP_VS_TCP_S_ESTABLISHED) &&
1656               (pkts % sysctl_sync_period(ipvs)
1657                == sysctl_sync_threshold(ipvs))) ||
1658              ((cp->protocol == IPPROTO_TCP) && (cp->old_state != cp->state) &&
1659               ((cp->state == IP_VS_TCP_S_FIN_WAIT) ||
1660                (cp->state == IP_VS_TCP_S_CLOSE) ||
1661                (cp->state == IP_VS_TCP_S_CLOSE_WAIT) ||
1662                (cp->state == IP_VS_TCP_S_TIME_WAIT)))))
1663                 ip_vs_sync_conn(net, cp);
1664 out:
1665         cp->old_state = cp->state;
1666
1667         ip_vs_conn_put(cp);
1668         return ret;
1669 }
1670
1671 /*
1672  *      AF_INET handler in NF_INET_LOCAL_IN chain
1673  *      Schedule and forward packets from remote clients
1674  */
1675 static unsigned int
1676 ip_vs_remote_request4(unsigned int hooknum, struct sk_buff *skb,
1677                       const struct net_device *in,
1678                       const struct net_device *out,
1679                       int (*okfn)(struct sk_buff *))
1680 {
1681         return ip_vs_in(hooknum, skb, AF_INET);
1682 }
1683
1684 /*
1685  *      AF_INET handler in NF_INET_LOCAL_OUT chain
1686  *      Schedule and forward packets from local clients
1687  */
1688 static unsigned int
1689 ip_vs_local_request4(unsigned int hooknum, struct sk_buff *skb,
1690                      const struct net_device *in, const struct net_device *out,
1691                      int (*okfn)(struct sk_buff *))
1692 {
1693         unsigned int verdict;
1694
1695         /* Disable BH in LOCAL_OUT until all places are fixed */
1696         local_bh_disable();
1697         verdict = ip_vs_in(hooknum, skb, AF_INET);
1698         local_bh_enable();
1699         return verdict;
1700 }
1701
1702 #ifdef CONFIG_IP_VS_IPV6
1703
1704 /*
1705  *      AF_INET6 handler in NF_INET_LOCAL_IN chain
1706  *      Schedule and forward packets from remote clients
1707  */
1708 static unsigned int
1709 ip_vs_remote_request6(unsigned int hooknum, struct sk_buff *skb,
1710                       const struct net_device *in,
1711                       const struct net_device *out,
1712                       int (*okfn)(struct sk_buff *))
1713 {
1714         return ip_vs_in(hooknum, skb, AF_INET6);
1715 }
1716
1717 /*
1718  *      AF_INET6 handler in NF_INET_LOCAL_OUT chain
1719  *      Schedule and forward packets from local clients
1720  */
1721 static unsigned int
1722 ip_vs_local_request6(unsigned int hooknum, struct sk_buff *skb,
1723                      const struct net_device *in, const struct net_device *out,
1724                      int (*okfn)(struct sk_buff *))
1725 {
1726         unsigned int verdict;
1727
1728         /* Disable BH in LOCAL_OUT until all places are fixed */
1729         local_bh_disable();
1730         verdict = ip_vs_in(hooknum, skb, AF_INET6);
1731         local_bh_enable();
1732         return verdict;
1733 }
1734
1735 #endif
1736
1737
1738 /*
1739  *      It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
1740  *      related packets destined for 0.0.0.0/0.
1741  *      When fwmark-based virtual service is used, such as transparent
1742  *      cache cluster, TCP packets can be marked and routed to ip_vs_in,
1743  *      but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
1744  *      sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
1745  *      and send them to ip_vs_in_icmp.
1746  */
1747 static unsigned int
1748 ip_vs_forward_icmp(unsigned int hooknum, struct sk_buff *skb,
1749                    const struct net_device *in, const struct net_device *out,
1750                    int (*okfn)(struct sk_buff *))
1751 {
1752         int r;
1753         struct net *net;
1754
1755         if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
1756                 return NF_ACCEPT;
1757
1758         /* ipvs enabled in this netns ? */
1759         net = skb_net(skb);
1760         if (!net_ipvs(net)->enable)
1761                 return NF_ACCEPT;
1762
1763         return ip_vs_in_icmp(skb, &r, hooknum);
1764 }
1765
1766 #ifdef CONFIG_IP_VS_IPV6
1767 static unsigned int
1768 ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
1769                       const struct net_device *in, const struct net_device *out,
1770                       int (*okfn)(struct sk_buff *))
1771 {
1772         int r;
1773         struct net *net;
1774
1775         if (ipv6_hdr(skb)->nexthdr != IPPROTO_ICMPV6)
1776                 return NF_ACCEPT;
1777
1778         /* ipvs enabled in this netns ? */
1779         net = skb_net(skb);
1780         if (!net_ipvs(net)->enable)
1781                 return NF_ACCEPT;
1782
1783         return ip_vs_in_icmp_v6(skb, &r, hooknum);
1784 }
1785 #endif
1786
1787
1788 static struct nf_hook_ops ip_vs_ops[] __read_mostly = {
1789         /* After packet filtering, change source only for VS/NAT */
1790         {
1791                 .hook           = ip_vs_reply4,
1792                 .owner          = THIS_MODULE,
1793                 .pf             = PF_INET,
1794                 .hooknum        = NF_INET_LOCAL_IN,
1795                 .priority       = 99,
1796         },
1797         /* After packet filtering, forward packet through VS/DR, VS/TUN,
1798          * or VS/NAT(change destination), so that filtering rules can be
1799          * applied to IPVS. */
1800         {
1801                 .hook           = ip_vs_remote_request4,
1802                 .owner          = THIS_MODULE,
1803                 .pf             = PF_INET,
1804                 .hooknum        = NF_INET_LOCAL_IN,
1805                 .priority       = 101,
1806         },
1807         /* Before ip_vs_in, change source only for VS/NAT */
1808         {
1809                 .hook           = ip_vs_local_reply4,
1810                 .owner          = THIS_MODULE,
1811                 .pf             = PF_INET,
1812                 .hooknum        = NF_INET_LOCAL_OUT,
1813                 .priority       = -99,
1814         },
1815         /* After mangle, schedule and forward local requests */
1816         {
1817                 .hook           = ip_vs_local_request4,
1818                 .owner          = THIS_MODULE,
1819                 .pf             = PF_INET,
1820                 .hooknum        = NF_INET_LOCAL_OUT,
1821                 .priority       = -98,
1822         },
1823         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1824          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1825         {
1826                 .hook           = ip_vs_forward_icmp,
1827                 .owner          = THIS_MODULE,
1828                 .pf             = PF_INET,
1829                 .hooknum        = NF_INET_FORWARD,
1830                 .priority       = 99,
1831         },
1832         /* After packet filtering, change source only for VS/NAT */
1833         {
1834                 .hook           = ip_vs_reply4,
1835                 .owner          = THIS_MODULE,
1836                 .pf             = PF_INET,
1837                 .hooknum        = NF_INET_FORWARD,
1838                 .priority       = 100,
1839         },
1840 #ifdef CONFIG_IP_VS_IPV6
1841         /* After packet filtering, change source only for VS/NAT */
1842         {
1843                 .hook           = ip_vs_reply6,
1844                 .owner          = THIS_MODULE,
1845                 .pf             = PF_INET6,
1846                 .hooknum        = NF_INET_LOCAL_IN,
1847                 .priority       = 99,
1848         },
1849         /* After packet filtering, forward packet through VS/DR, VS/TUN,
1850          * or VS/NAT(change destination), so that filtering rules can be
1851          * applied to IPVS. */
1852         {
1853                 .hook           = ip_vs_remote_request6,
1854                 .owner          = THIS_MODULE,
1855                 .pf             = PF_INET6,
1856                 .hooknum        = NF_INET_LOCAL_IN,
1857                 .priority       = 101,
1858         },
1859         /* Before ip_vs_in, change source only for VS/NAT */
1860         {
1861                 .hook           = ip_vs_local_reply6,
1862                 .owner          = THIS_MODULE,
1863                 .pf             = PF_INET,
1864                 .hooknum        = NF_INET_LOCAL_OUT,
1865                 .priority       = -99,
1866         },
1867         /* After mangle, schedule and forward local requests */
1868         {
1869                 .hook           = ip_vs_local_request6,
1870                 .owner          = THIS_MODULE,
1871                 .pf             = PF_INET6,
1872                 .hooknum        = NF_INET_LOCAL_OUT,
1873                 .priority       = -98,
1874         },
1875         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
1876          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
1877         {
1878                 .hook           = ip_vs_forward_icmp_v6,
1879                 .owner          = THIS_MODULE,
1880                 .pf             = PF_INET6,
1881                 .hooknum        = NF_INET_FORWARD,
1882                 .priority       = 99,
1883         },
1884         /* After packet filtering, change source only for VS/NAT */
1885         {
1886                 .hook           = ip_vs_reply6,
1887                 .owner          = THIS_MODULE,
1888                 .pf             = PF_INET6,
1889                 .hooknum        = NF_INET_FORWARD,
1890                 .priority       = 100,
1891         },
1892 #endif
1893 };
1894 /*
1895  *      Initialize IP Virtual Server netns mem.
1896  */
1897 static int __net_init __ip_vs_init(struct net *net)
1898 {
1899         struct netns_ipvs *ipvs;
1900
1901         ipvs = net_generic(net, ip_vs_net_id);
1902         if (ipvs == NULL) {
1903                 pr_err("%s(): no memory.\n", __func__);
1904                 return -ENOMEM;
1905         }
1906         /* Hold the beast until a service is registerd */
1907         ipvs->enable = 0;
1908         ipvs->net = net;
1909         /* Counters used for creating unique names */
1910         ipvs->gen = atomic_read(&ipvs_netns_cnt);
1911         atomic_inc(&ipvs_netns_cnt);
1912         net->ipvs = ipvs;
1913
1914         if (__ip_vs_estimator_init(net) < 0)
1915                 goto estimator_fail;
1916
1917         if (__ip_vs_control_init(net) < 0)
1918                 goto control_fail;
1919
1920         if (__ip_vs_protocol_init(net) < 0)
1921                 goto protocol_fail;
1922
1923         if (__ip_vs_app_init(net) < 0)
1924                 goto app_fail;
1925
1926         if (__ip_vs_conn_init(net) < 0)
1927                 goto conn_fail;
1928
1929         if (__ip_vs_sync_init(net) < 0)
1930                 goto sync_fail;
1931
1932         printk(KERN_INFO "IPVS: Creating netns size=%zu id=%d\n",
1933                          sizeof(struct netns_ipvs), ipvs->gen);
1934         return 0;
1935 /*
1936  * Error handling
1937  */
1938
1939 sync_fail:
1940         __ip_vs_conn_cleanup(net);
1941 conn_fail:
1942         __ip_vs_app_cleanup(net);
1943 app_fail:
1944         __ip_vs_protocol_cleanup(net);
1945 protocol_fail:
1946         __ip_vs_control_cleanup(net);
1947 control_fail:
1948         __ip_vs_estimator_cleanup(net);
1949 estimator_fail:
1950         return -ENOMEM;
1951 }
1952
1953 static void __net_exit __ip_vs_cleanup(struct net *net)
1954 {
1955         __ip_vs_service_cleanup(net);   /* ip_vs_flush() with locks */
1956         __ip_vs_conn_cleanup(net);
1957         __ip_vs_app_cleanup(net);
1958         __ip_vs_protocol_cleanup(net);
1959         __ip_vs_control_cleanup(net);
1960         __ip_vs_estimator_cleanup(net);
1961         IP_VS_DBG(2, "ipvs netns %d released\n", net_ipvs(net)->gen);
1962 }
1963
1964 static void __net_exit __ip_vs_dev_cleanup(struct net *net)
1965 {
1966         EnterFunction(2);
1967         net_ipvs(net)->enable = 0;      /* Disable packet reception */
1968         __ip_vs_sync_cleanup(net);
1969         LeaveFunction(2);
1970 }
1971
1972 static struct pernet_operations ipvs_core_ops = {
1973         .init = __ip_vs_init,
1974         .exit = __ip_vs_cleanup,
1975         .id   = &ip_vs_net_id,
1976         .size = sizeof(struct netns_ipvs),
1977 };
1978
1979 static struct pernet_operations ipvs_core_dev_ops = {
1980         .exit = __ip_vs_dev_cleanup,
1981 };
1982
1983 /*
1984  *      Initialize IP Virtual Server
1985  */
1986 static int __init ip_vs_init(void)
1987 {
1988         int ret;
1989
1990         ip_vs_estimator_init();
1991         ret = ip_vs_control_init();
1992         if (ret < 0) {
1993                 pr_err("can't setup control.\n");
1994                 goto cleanup_estimator;
1995         }
1996
1997         ip_vs_protocol_init();
1998
1999         ret = ip_vs_app_init();
2000         if (ret < 0) {
2001                 pr_err("can't setup application helper.\n");
2002                 goto cleanup_protocol;
2003         }
2004
2005         ret = ip_vs_conn_init();
2006         if (ret < 0) {
2007                 pr_err("can't setup connection table.\n");
2008                 goto cleanup_app;
2009         }
2010
2011         ret = ip_vs_sync_init();
2012         if (ret < 0) {
2013                 pr_err("can't setup sync data.\n");
2014                 goto cleanup_conn;
2015         }
2016
2017         ret = register_pernet_subsys(&ipvs_core_ops);   /* Alloc ip_vs struct */
2018         if (ret < 0)
2019                 goto cleanup_sync;
2020
2021         ret = register_pernet_device(&ipvs_core_dev_ops);
2022         if (ret < 0)
2023                 goto cleanup_sub;
2024
2025         ret = nf_register_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2026         if (ret < 0) {
2027                 pr_err("can't register hooks.\n");
2028                 goto cleanup_dev;
2029         }
2030
2031         pr_info("ipvs loaded.\n");
2032
2033         return ret;
2034
2035 cleanup_dev:
2036         unregister_pernet_device(&ipvs_core_dev_ops);
2037 cleanup_sub:
2038         unregister_pernet_subsys(&ipvs_core_ops);
2039 cleanup_sync:
2040         ip_vs_sync_cleanup();
2041   cleanup_conn:
2042         ip_vs_conn_cleanup();
2043   cleanup_app:
2044         ip_vs_app_cleanup();
2045   cleanup_protocol:
2046         ip_vs_protocol_cleanup();
2047         ip_vs_control_cleanup();
2048   cleanup_estimator:
2049         ip_vs_estimator_cleanup();
2050         return ret;
2051 }
2052
2053 static void __exit ip_vs_cleanup(void)
2054 {
2055         nf_unregister_hooks(ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2056         unregister_pernet_device(&ipvs_core_dev_ops);
2057         unregister_pernet_subsys(&ipvs_core_ops);       /* free ip_vs struct */
2058         ip_vs_sync_cleanup();
2059         ip_vs_conn_cleanup();
2060         ip_vs_app_cleanup();
2061         ip_vs_protocol_cleanup();
2062         ip_vs_control_cleanup();
2063         ip_vs_estimator_cleanup();
2064         pr_info("ipvs unloaded.\n");
2065 }
2066
2067 module_init(ip_vs_init);
2068 module_exit(ip_vs_cleanup);
2069 MODULE_LICENSE("GPL");