~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/netfilter/ipvs/ip_vs_core.c

Version: ~ [ linux-5.9 ] ~ [ linux-5.8.14 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.70 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.150 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.200 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.238 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.238 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 EXPORT_SYMBOL(ip_vs_new_conn_out);
 72 
 73 static unsigned int ip_vs_net_id __read_mostly;
 74 /* netns cnt used for uniqueness */
 75 static atomic_t ipvs_netns_cnt = ATOMIC_INIT(0);
 76 
 77 /* ID used in ICMP lookups */
 78 #define icmp_id(icmph)          (((icmph)->un).echo.id)
 79 #define icmpv6_id(icmph)        (icmph->icmp6_dataun.u_echo.identifier)
 80 
 81 const char *ip_vs_proto_name(unsigned int proto)
 82 {
 83         static char buf[20];
 84 
 85         switch (proto) {
 86         case IPPROTO_IP:
 87                 return "IP";
 88         case IPPROTO_UDP:
 89                 return "UDP";
 90         case IPPROTO_TCP:
 91                 return "TCP";
 92         case IPPROTO_SCTP:
 93                 return "SCTP";
 94         case IPPROTO_ICMP:
 95                 return "ICMP";
 96 #ifdef CONFIG_IP_VS_IPV6
 97         case IPPROTO_ICMPV6:
 98                 return "ICMPv6";
 99 #endif
100         default:
101                 sprintf(buf, "IP_%u", proto);
102                 return buf;
103         }
104 }
105 
106 void ip_vs_init_hash_table(struct list_head *table, int rows)
107 {
108         while (--rows >= 0)
109                 INIT_LIST_HEAD(&table[rows]);
110 }
111 
112 static inline void
113 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
114 {
115         struct ip_vs_dest *dest = cp->dest;
116         struct netns_ipvs *ipvs = cp->ipvs;
117 
118         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
119                 struct ip_vs_cpu_stats *s;
120                 struct ip_vs_service *svc;
121 
122                 s = this_cpu_ptr(dest->stats.cpustats);
123                 u64_stats_update_begin(&s->syncp);
124                 s->cnt.inpkts++;
125                 s->cnt.inbytes += skb->len;
126                 u64_stats_update_end(&s->syncp);
127 
128                 svc = rcu_dereference(dest->svc);
129                 s = this_cpu_ptr(svc->stats.cpustats);
130                 u64_stats_update_begin(&s->syncp);
131                 s->cnt.inpkts++;
132                 s->cnt.inbytes += skb->len;
133                 u64_stats_update_end(&s->syncp);
134 
135                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
136                 u64_stats_update_begin(&s->syncp);
137                 s->cnt.inpkts++;
138                 s->cnt.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 = cp->ipvs;
149 
150         if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
151                 struct ip_vs_cpu_stats *s;
152                 struct ip_vs_service *svc;
153 
154                 s = this_cpu_ptr(dest->stats.cpustats);
155                 u64_stats_update_begin(&s->syncp);
156                 s->cnt.outpkts++;
157                 s->cnt.outbytes += skb->len;
158                 u64_stats_update_end(&s->syncp);
159 
160                 svc = rcu_dereference(dest->svc);
161                 s = this_cpu_ptr(svc->stats.cpustats);
162                 u64_stats_update_begin(&s->syncp);
163                 s->cnt.outpkts++;
164                 s->cnt.outbytes += skb->len;
165                 u64_stats_update_end(&s->syncp);
166 
167                 s = this_cpu_ptr(ipvs->tot_stats.cpustats);
168                 u64_stats_update_begin(&s->syncp);
169                 s->cnt.outpkts++;
170                 s->cnt.outbytes += skb->len;
171                 u64_stats_update_end(&s->syncp);
172         }
173 }
174 
175 
176 static inline void
177 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
178 {
179         struct netns_ipvs *ipvs = svc->ipvs;
180         struct ip_vs_cpu_stats *s;
181 
182         s = this_cpu_ptr(cp->dest->stats.cpustats);
183         u64_stats_update_begin(&s->syncp);
184         s->cnt.conns++;
185         u64_stats_update_end(&s->syncp);
186 
187         s = this_cpu_ptr(svc->stats.cpustats);
188         u64_stats_update_begin(&s->syncp);
189         s->cnt.conns++;
190         u64_stats_update_end(&s->syncp);
191 
192         s = this_cpu_ptr(ipvs->tot_stats.cpustats);
193         u64_stats_update_begin(&s->syncp);
194         s->cnt.conns++;
195         u64_stats_update_end(&s->syncp);
196 }
197 
198 
199 static inline void
200 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
201                 const struct sk_buff *skb,
202                 struct ip_vs_proto_data *pd)
203 {
204         if (likely(pd->pp->state_transition))
205                 pd->pp->state_transition(cp, direction, skb, pd);
206 }
207 
208 static inline int
209 ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
210                               struct sk_buff *skb, int protocol,
211                               const union nf_inet_addr *caddr, __be16 cport,
212                               const union nf_inet_addr *vaddr, __be16 vport,
213                               struct ip_vs_conn_param *p)
214 {
215         ip_vs_conn_fill_param(svc->ipvs, svc->af, protocol, caddr, cport, vaddr,
216                               vport, p);
217         p->pe = rcu_dereference(svc->pe);
218         if (p->pe && p->pe->fill_param)
219                 return p->pe->fill_param(p, skb);
220 
221         return 0;
222 }
223 
224 /*
225  *  IPVS persistent scheduling function
226  *  It creates a connection entry according to its template if exists,
227  *  or selects a server and creates a connection entry plus a template.
228  *  Locking: we are svc user (svc->refcnt), so we hold all dests too
229  *  Protocols supported: TCP, UDP
230  */
231 static struct ip_vs_conn *
232 ip_vs_sched_persist(struct ip_vs_service *svc,
233                     struct sk_buff *skb, __be16 src_port, __be16 dst_port,
234                     int *ignored, struct ip_vs_iphdr *iph)
235 {
236         struct ip_vs_conn *cp = NULL;
237         struct ip_vs_dest *dest;
238         struct ip_vs_conn *ct;
239         __be16 dport = 0;               /* destination port to forward */
240         unsigned int flags;
241         struct ip_vs_conn_param param;
242         const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
243         union nf_inet_addr snet;        /* source network of the client,
244                                            after masking */
245         const union nf_inet_addr *src_addr, *dst_addr;
246 
247         if (likely(!ip_vs_iph_inverse(iph))) {
248                 src_addr = &iph->saddr;
249                 dst_addr = &iph->daddr;
250         } else {
251                 src_addr = &iph->daddr;
252                 dst_addr = &iph->saddr;
253         }
254 
255 
256         /* Mask saddr with the netmask to adjust template granularity */
257 #ifdef CONFIG_IP_VS_IPV6
258         if (svc->af == AF_INET6)
259                 ipv6_addr_prefix(&snet.in6, &src_addr->in6,
260                                  (__force __u32) svc->netmask);
261         else
262 #endif
263                 snet.ip = src_addr->ip & svc->netmask;
264 
265         IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
266                       "mnet %s\n",
267                       IP_VS_DBG_ADDR(svc->af, src_addr), ntohs(src_port),
268                       IP_VS_DBG_ADDR(svc->af, dst_addr), ntohs(dst_port),
269                       IP_VS_DBG_ADDR(svc->af, &snet));
270 
271         /*
272          * As far as we know, FTP is a very complicated network protocol, and
273          * it uses control connection and data connections. For active FTP,
274          * FTP server initialize data connection to the client, its source port
275          * is often 20. For passive FTP, FTP server tells the clients the port
276          * that it passively listens to,  and the client issues the data
277          * connection. In the tunneling or direct routing mode, the load
278          * balancer is on the client-to-server half of connection, the port
279          * number is unknown to the load balancer. So, a conn template like
280          * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
281          * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
282          * is created for other persistent services.
283          */
284         {
285                 int protocol = iph->protocol;
286                 const union nf_inet_addr *vaddr = dst_addr;
287                 __be16 vport = 0;
288 
289                 if (dst_port == svc->port) {
290                         /* non-FTP template:
291                          * <protocol, caddr, 0, vaddr, vport, daddr, dport>
292                          * FTP template:
293                          * <protocol, caddr, 0, vaddr, 0, daddr, 0>
294                          */
295                         if (svc->port != FTPPORT)
296                                 vport = dst_port;
297                 } else {
298                         /* Note: persistent fwmark-based services and
299                          * persistent port zero service are handled here.
300                          * fwmark template:
301                          * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
302                          * port zero template:
303                          * <protocol,caddr,0,vaddr,0,daddr,0>
304                          */
305                         if (svc->fwmark) {
306                                 protocol = IPPROTO_IP;
307                                 vaddr = &fwmark;
308                         }
309                 }
310                 /* return *ignored = -1 so NF_DROP can be used */
311                 if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
312                                                   vaddr, vport, &param) < 0) {
313                         *ignored = -1;
314                         return NULL;
315                 }
316         }
317 
318         /* Check if a template already exists */
319         ct = ip_vs_ct_in_get(&param);
320         if (!ct || !ip_vs_check_template(ct, NULL)) {
321                 struct ip_vs_scheduler *sched;
322 
323                 /*
324                  * No template found or the dest of the connection
325                  * template is not available.
326                  * return *ignored=0 i.e. ICMP and NF_DROP
327                  */
328                 sched = rcu_dereference(svc->scheduler);
329                 if (sched) {
330                         /* read svc->sched_data after svc->scheduler */
331                         smp_rmb();
332                         dest = sched->schedule(svc, skb, iph);
333                 } else {
334                         dest = NULL;
335                 }
336                 if (!dest) {
337                         IP_VS_DBG(1, "p-schedule: no dest found.\n");
338                         kfree(param.pe_data);
339                         *ignored = 0;
340                         return NULL;
341                 }
342 
343                 if (dst_port == svc->port && svc->port != FTPPORT)
344                         dport = dest->port;
345 
346                 /* Create a template
347                  * This adds param.pe_data to the template,
348                  * and thus param.pe_data will be destroyed
349                  * when the template expires */
350                 ct = ip_vs_conn_new(&param, dest->af, &dest->addr, dport,
351                                     IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
352                 if (ct == NULL) {
353                         kfree(param.pe_data);
354                         *ignored = -1;
355                         return NULL;
356                 }
357 
358                 ct->timeout = svc->timeout;
359         } else {
360                 /* set destination with the found template */
361                 dest = ct->dest;
362                 kfree(param.pe_data);
363         }
364 
365         dport = dst_port;
366         if (dport == svc->port && dest->port)
367                 dport = dest->port;
368 
369         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
370                  && iph->protocol == IPPROTO_UDP) ?
371                 IP_VS_CONN_F_ONE_PACKET : 0;
372 
373         /*
374          *    Create a new connection according to the template
375          */
376         ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, src_addr,
377                               src_port, dst_addr, dst_port, &param);
378 
379         cp = ip_vs_conn_new(&param, dest->af, &dest->addr, dport, flags, dest,
380                             skb->mark);
381         if (cp == NULL) {
382                 ip_vs_conn_put(ct);
383                 *ignored = -1;
384                 return NULL;
385         }
386 
387         /*
388          *    Add its control
389          */
390         ip_vs_control_add(cp, ct);
391         ip_vs_conn_put(ct);
392 
393         ip_vs_conn_stats(cp, svc);
394         return cp;
395 }
396 
397 
398 /*
399  *  IPVS main scheduling function
400  *  It selects a server according to the virtual service, and
401  *  creates a connection entry.
402  *  Protocols supported: TCP, UDP
403  *
404  *  Usage of *ignored
405  *
406  * 1 :   protocol tried to schedule (eg. on SYN), found svc but the
407  *       svc/scheduler decides that this packet should be accepted with
408  *       NF_ACCEPT because it must not be scheduled.
409  *
410  * 0 :   scheduler can not find destination, so try bypass or
411  *       return ICMP and then NF_DROP (ip_vs_leave).
412  *
413  * -1 :  scheduler tried to schedule but fatal error occurred, eg.
414  *       ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
415  *       failure such as missing Call-ID, ENOMEM on skb_linearize
416  *       or pe_data. In this case we should return NF_DROP without
417  *       any attempts to send ICMP with ip_vs_leave.
418  */
419 struct ip_vs_conn *
420 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
421                struct ip_vs_proto_data *pd, int *ignored,
422                struct ip_vs_iphdr *iph)
423 {
424         struct ip_vs_protocol *pp = pd->pp;
425         struct ip_vs_conn *cp = NULL;
426         struct ip_vs_scheduler *sched;
427         struct ip_vs_dest *dest;
428         __be16 _ports[2], *pptr, cport, vport;
429         const void *caddr, *vaddr;
430         unsigned int flags;
431 
432         *ignored = 1;
433         /*
434          * IPv6 frags, only the first hit here.
435          */
436         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
437         if (pptr == NULL)
438                 return NULL;
439 
440         if (likely(!ip_vs_iph_inverse(iph))) {
441                 cport = pptr[0];
442                 caddr = &iph->saddr;
443                 vport = pptr[1];
444                 vaddr = &iph->daddr;
445         } else {
446                 cport = pptr[1];
447                 caddr = &iph->daddr;
448                 vport = pptr[0];
449                 vaddr = &iph->saddr;
450         }
451 
452         /*
453          * FTPDATA needs this check when using local real server.
454          * Never schedule Active FTPDATA connections from real server.
455          * For LVS-NAT they must be already created. For other methods
456          * with persistence the connection is created on SYN+ACK.
457          */
458         if (cport == FTPDATA) {
459                 IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off,
460                               "Not scheduling FTPDATA");
461                 return NULL;
462         }
463 
464         /*
465          *    Do not schedule replies from local real server.
466          */
467         if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK)) {
468                 iph->hdr_flags ^= IP_VS_HDR_INVERSE;
469                 cp = pp->conn_in_get(svc->ipvs, svc->af, skb, iph);
470                 iph->hdr_flags ^= IP_VS_HDR_INVERSE;
471 
472                 if (cp) {
473                         IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off,
474                                       "Not scheduling reply for existing"
475                                       " connection");
476                         __ip_vs_conn_put(cp);
477                         return NULL;
478                 }
479         }
480 
481         /*
482          *    Persistent service
483          */
484         if (svc->flags & IP_VS_SVC_F_PERSISTENT)
485                 return ip_vs_sched_persist(svc, skb, cport, vport, ignored,
486                                            iph);
487 
488         *ignored = 0;
489 
490         /*
491          *    Non-persistent service
492          */
493         if (!svc->fwmark && vport != svc->port) {
494                 if (!svc->port)
495                         pr_err("Schedule: port zero only supported "
496                                "in persistent services, "
497                                "check your ipvs configuration\n");
498                 return NULL;
499         }
500 
501         sched = rcu_dereference(svc->scheduler);
502         if (sched) {
503                 /* read svc->sched_data after svc->scheduler */
504                 smp_rmb();
505                 dest = sched->schedule(svc, skb, iph);
506         } else {
507                 dest = NULL;
508         }
509         if (dest == NULL) {
510                 IP_VS_DBG(1, "Schedule: no dest found.\n");
511                 return NULL;
512         }
513 
514         flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
515                  && iph->protocol == IPPROTO_UDP) ?
516                 IP_VS_CONN_F_ONE_PACKET : 0;
517 
518         /*
519          *    Create a connection entry.
520          */
521         {
522                 struct ip_vs_conn_param p;
523 
524                 ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
525                                       caddr, cport, vaddr, vport, &p);
526                 cp = ip_vs_conn_new(&p, dest->af, &dest->addr,
527                                     dest->port ? dest->port : vport,
528                                     flags, dest, skb->mark);
529                 if (!cp) {
530                         *ignored = -1;
531                         return NULL;
532                 }
533         }
534 
535         IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
536                       "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
537                       ip_vs_fwd_tag(cp),
538                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
539                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
540                       IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
541                       cp->flags, refcount_read(&cp->refcnt));
542 
543         ip_vs_conn_stats(cp, svc);
544         return cp;
545 }
546 
547 static inline int ip_vs_addr_is_unicast(struct net *net, int af,
548                                         union nf_inet_addr *addr)
549 {
550 #ifdef CONFIG_IP_VS_IPV6
551         if (af == AF_INET6)
552                 return ipv6_addr_type(&addr->in6) & IPV6_ADDR_UNICAST;
553 #endif
554         return (inet_addr_type(net, addr->ip) == RTN_UNICAST);
555 }
556 
557 /*
558  *  Pass or drop the packet.
559  *  Called by ip_vs_in, when the virtual service is available but
560  *  no destination is available for a new connection.
561  */
562 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
563                 struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
564 {
565         __be16 _ports[2], *pptr, dport;
566         struct netns_ipvs *ipvs = svc->ipvs;
567         struct net *net = ipvs->net;
568 
569         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
570         if (!pptr)
571                 return NF_DROP;
572         dport = likely(!ip_vs_iph_inverse(iph)) ? pptr[1] : pptr[0];
573 
574         /* if it is fwmark-based service, the cache_bypass sysctl is up
575            and the destination is a non-local unicast, then create
576            a cache_bypass connection entry */
577         if (sysctl_cache_bypass(ipvs) && svc->fwmark &&
578             !(iph->hdr_flags & (IP_VS_HDR_INVERSE | IP_VS_HDR_ICMP)) &&
579             ip_vs_addr_is_unicast(net, svc->af, &iph->daddr)) {
580                 int ret;
581                 struct ip_vs_conn *cp;
582                 unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
583                                       iph->protocol == IPPROTO_UDP) ?
584                                       IP_VS_CONN_F_ONE_PACKET : 0;
585                 union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };
586 
587                 /* create a new connection entry */
588                 IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
589                 {
590                         struct ip_vs_conn_param p;
591                         ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
592                                               &iph->saddr, pptr[0],
593                                               &iph->daddr, pptr[1], &p);
594                         cp = ip_vs_conn_new(&p, svc->af, &daddr, 0,
595                                             IP_VS_CONN_F_BYPASS | flags,
596                                             NULL, skb->mark);
597                         if (!cp)
598                                 return NF_DROP;
599                 }
600 
601                 /* statistics */
602                 ip_vs_in_stats(cp, skb);
603 
604                 /* set state */
605                 ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
606 
607                 /* transmit the first SYN packet */
608                 ret = cp->packet_xmit(skb, cp, pd->pp, iph);
609                 /* do not touch skb anymore */
610 
611                 if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
612                         atomic_inc(&cp->control->in_pkts);
613                 else
614                         atomic_inc(&cp->in_pkts);
615                 ip_vs_conn_put(cp);
616                 return ret;
617         }
618 
619         /*
620          * When the virtual ftp service is presented, packets destined
621          * for other services on the VIP may get here (except services
622          * listed in the ipvs table), pass the packets, because it is
623          * not ipvs job to decide to drop the packets.
624          */
625         if (svc->port == FTPPORT && dport != FTPPORT)
626                 return NF_ACCEPT;
627 
628         if (unlikely(ip_vs_iph_icmp(iph)))
629                 return NF_DROP;
630 
631         /*
632          * Notify the client that the destination is unreachable, and
633          * release the socket buffer.
634          * Since it is in IP layer, the TCP socket is not actually
635          * created, the TCP RST packet cannot be sent, instead that
636          * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
637          */
638 #ifdef CONFIG_IP_VS_IPV6
639         if (svc->af == AF_INET6) {
640                 if (!skb->dev)
641                         skb->dev = net->loopback_dev;
642                 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
643         } else
644 #endif
645                 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
646 
647         return NF_DROP;
648 }
649 
650 #ifdef CONFIG_SYSCTL
651 
652 static int sysctl_snat_reroute(struct netns_ipvs *ipvs)
653 {
654         return ipvs->sysctl_snat_reroute;
655 }
656 
657 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs)
658 {
659         return ipvs->sysctl_nat_icmp_send;
660 }
661 
662 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
663 {
664         return ipvs->sysctl_expire_nodest_conn;
665 }
666 
667 #else
668 
669 static int sysctl_snat_reroute(struct netns_ipvs *ipvs) { return 0; }
670 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) { return 0; }
671 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; }
672 
673 #endif
674 
675 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
676 {
677         return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
678 }
679 
680 static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum)
681 {
682         if (NF_INET_LOCAL_IN == hooknum)
683                 return IP_DEFRAG_VS_IN;
684         if (NF_INET_FORWARD == hooknum)
685                 return IP_DEFRAG_VS_FWD;
686         return IP_DEFRAG_VS_OUT;
687 }
688 
689 static inline int ip_vs_gather_frags(struct netns_ipvs *ipvs,
690                                      struct sk_buff *skb, u_int32_t user)
691 {
692         int err;
693 
694         local_bh_disable();
695         err = ip_defrag(ipvs->net, skb, user);
696         local_bh_enable();
697         if (!err)
698                 ip_send_check(ip_hdr(skb));
699 
700         return err;
701 }
702 
703 static int ip_vs_route_me_harder(struct netns_ipvs *ipvs, int af,
704                                  struct sk_buff *skb, unsigned int hooknum)
705 {
706         if (!sysctl_snat_reroute(ipvs))
707                 return 0;
708         /* Reroute replies only to remote clients (FORWARD and LOCAL_OUT) */
709         if (NF_INET_LOCAL_IN == hooknum)
710                 return 0;
711 #ifdef CONFIG_IP_VS_IPV6
712         if (af == AF_INET6) {
713                 struct dst_entry *dst = skb_dst(skb);
714 
715                 if (dst->dev && !(dst->dev->flags & IFF_LOOPBACK) &&
716                     ip6_route_me_harder(ipvs->net, skb) != 0)
717                         return 1;
718         } else
719 #endif
720                 if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL) &&
721                     ip_route_me_harder(ipvs->net, skb, RTN_LOCAL) != 0)
722                         return 1;
723 
724         return 0;
725 }
726 
727 /*
728  * Packet has been made sufficiently writable in caller
729  * - inout: 1=in->out, 0=out->in
730  */
731 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
732                     struct ip_vs_conn *cp, int inout)
733 {
734         struct iphdr *iph        = ip_hdr(skb);
735         unsigned int icmp_offset = iph->ihl*4;
736         struct icmphdr *icmph    = (struct icmphdr *)(skb_network_header(skb) +
737                                                       icmp_offset);
738         struct iphdr *ciph       = (struct iphdr *)(icmph + 1);
739 
740         if (inout) {
741                 iph->saddr = cp->vaddr.ip;
742                 ip_send_check(iph);
743                 ciph->daddr = cp->vaddr.ip;
744                 ip_send_check(ciph);
745         } else {
746                 iph->daddr = cp->daddr.ip;
747                 ip_send_check(iph);
748                 ciph->saddr = cp->daddr.ip;
749                 ip_send_check(ciph);
750         }
751 
752         /* the TCP/UDP/SCTP port */
753         if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol ||
754             IPPROTO_SCTP == ciph->protocol) {
755                 __be16 *ports = (void *)ciph + ciph->ihl*4;
756 
757                 if (inout)
758                         ports[1] = cp->vport;
759                 else
760                         ports[0] = cp->dport;
761         }
762 
763         /* And finally the ICMP checksum */
764         icmph->checksum = 0;
765         icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
766         skb->ip_summed = CHECKSUM_UNNECESSARY;
767 
768         if (inout)
769                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
770                         "Forwarding altered outgoing ICMP");
771         else
772                 IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
773                         "Forwarding altered incoming ICMP");
774 }
775 
776 #ifdef CONFIG_IP_VS_IPV6
777 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
778                     struct ip_vs_conn *cp, int inout)
779 {
780         struct ipv6hdr *iph      = ipv6_hdr(skb);
781         unsigned int icmp_offset = 0;
782         unsigned int offs        = 0; /* header offset*/
783         int protocol;
784         struct icmp6hdr *icmph;
785         struct ipv6hdr *ciph;
786         unsigned short fragoffs;
787 
788         ipv6_find_hdr(skb, &icmp_offset, IPPROTO_ICMPV6, &fragoffs, NULL);
789         icmph = (struct icmp6hdr *)(skb_network_header(skb) + icmp_offset);
790         offs = icmp_offset + sizeof(struct icmp6hdr);
791         ciph = (struct ipv6hdr *)(skb_network_header(skb) + offs);
792 
793         protocol = ipv6_find_hdr(skb, &offs, -1, &fragoffs, NULL);
794 
795         if (inout) {
796                 iph->saddr = cp->vaddr.in6;
797                 ciph->daddr = cp->vaddr.in6;
798         } else {
799                 iph->daddr = cp->daddr.in6;
800                 ciph->saddr = cp->daddr.in6;
801         }
802 
803         /* the TCP/UDP/SCTP port */
804         if (!fragoffs && (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
805                           IPPROTO_SCTP == protocol)) {
806                 __be16 *ports = (void *)(skb_network_header(skb) + offs);
807 
808                 IP_VS_DBG(11, "%s() changed port %d to %d\n", __func__,
809                               ntohs(inout ? ports[1] : ports[0]),
810                               ntohs(inout ? cp->vport : cp->dport));
811                 if (inout)
812                         ports[1] = cp->vport;
813                 else
814                         ports[0] = cp->dport;
815         }
816 
817         /* And finally the ICMP checksum */
818         icmph->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr,
819                                               skb->len - icmp_offset,
820                                               IPPROTO_ICMPV6, 0);
821         skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset;
822         skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
823         skb->ip_summed = CHECKSUM_PARTIAL;
824 
825         if (inout)
826                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
827                               (void *)ciph - (void *)iph,
828                               "Forwarding altered outgoing ICMPv6");
829         else
830                 IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
831                               (void *)ciph - (void *)iph,
832                               "Forwarding altered incoming ICMPv6");
833 }
834 #endif
835 
836 /* Handle relevant response ICMP messages - forward to the right
837  * destination host.
838  */
839 static int handle_response_icmp(int af, struct sk_buff *skb,
840                                 union nf_inet_addr *snet,
841                                 __u8 protocol, struct ip_vs_conn *cp,
842                                 struct ip_vs_protocol *pp,
843                                 unsigned int offset, unsigned int ihl,
844                                 unsigned int hooknum)
845 {
846         unsigned int verdict = NF_DROP;
847 
848         if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
849                 goto ignore_cp;
850 
851         /* Ensure the checksum is correct */
852         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
853                 /* Failed checksum! */
854                 IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
855                               IP_VS_DBG_ADDR(af, snet));
856                 goto out;
857         }
858 
859         if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
860             IPPROTO_SCTP == protocol)
861                 offset += 2 * sizeof(__u16);
862         if (!skb_make_writable(skb, offset))
863                 goto out;
864 
865 #ifdef CONFIG_IP_VS_IPV6
866         if (af == AF_INET6)
867                 ip_vs_nat_icmp_v6(skb, pp, cp, 1);
868         else
869 #endif
870                 ip_vs_nat_icmp(skb, pp, cp, 1);
871 
872         if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum))
873                 goto out;
874 
875         /* do the statistics and put it back */
876         ip_vs_out_stats(cp, skb);
877 
878         skb->ipvs_property = 1;
879         if (!(cp->flags & IP_VS_CONN_F_NFCT))
880                 ip_vs_notrack(skb);
881         else
882                 ip_vs_update_conntrack(skb, cp, 0);
883 
884 ignore_cp:
885         verdict = NF_ACCEPT;
886 
887 out:
888         __ip_vs_conn_put(cp);
889 
890         return verdict;
891 }
892 
893 /*
894  *      Handle ICMP messages in the inside-to-outside direction (outgoing).
895  *      Find any that might be relevant, check against existing connections.
896  *      Currently handles error types - unreachable, quench, ttl exceeded.
897  */
898 static int ip_vs_out_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb,
899                           int *related, unsigned int hooknum)
900 {
901         struct iphdr *iph;
902         struct icmphdr  _icmph, *ic;
903         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
904         struct ip_vs_iphdr ciph;
905         struct ip_vs_conn *cp;
906         struct ip_vs_protocol *pp;
907         unsigned int offset, ihl;
908         union nf_inet_addr snet;
909 
910         *related = 1;
911 
912         /* reassemble IP fragments */
913         if (ip_is_fragment(ip_hdr(skb))) {
914                 if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum)))
915                         return NF_STOLEN;
916         }
917 
918         iph = ip_hdr(skb);
919         offset = ihl = iph->ihl * 4;
920         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
921         if (ic == NULL)
922                 return NF_DROP;
923 
924         IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
925                   ic->type, ntohs(icmp_id(ic)),
926                   &iph->saddr, &iph->daddr);
927 
928         /*
929          * Work through seeing if this is for us.
930          * These checks are supposed to be in an order that means easy
931          * things are checked first to speed up processing.... however
932          * this means that some packets will manage to get a long way
933          * down this stack and then be rejected, but that's life.
934          */
935         if ((ic->type != ICMP_DEST_UNREACH) &&
936             (ic->type != ICMP_SOURCE_QUENCH) &&
937             (ic->type != ICMP_TIME_EXCEEDED)) {
938                 *related = 0;
939                 return NF_ACCEPT;
940         }
941 
942         /* Now find the contained IP header */
943         offset += sizeof(_icmph);
944         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
945         if (cih == NULL)
946                 return NF_ACCEPT; /* The packet looks wrong, ignore */
947 
948         pp = ip_vs_proto_get(cih->protocol);
949         if (!pp)
950                 return NF_ACCEPT;
951 
952         /* Is the embedded protocol header present? */
953         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
954                      pp->dont_defrag))
955                 return NF_ACCEPT;
956 
957         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
958                       "Checking outgoing ICMP for");
959 
960         ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, true, &ciph);
961 
962         /* The embedded headers contain source and dest in reverse order */
963         cp = pp->conn_out_get(ipvs, AF_INET, skb, &ciph);
964         if (!cp)
965                 return NF_ACCEPT;
966 
967         snet.ip = iph->saddr;
968         return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
969                                     pp, ciph.len, ihl, hooknum);
970 }
971 
972 #ifdef CONFIG_IP_VS_IPV6
973 static int ip_vs_out_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
974                              int *related,  unsigned int hooknum,
975                              struct ip_vs_iphdr *ipvsh)
976 {
977         struct icmp6hdr _icmph, *ic;
978         struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
979         struct ip_vs_conn *cp;
980         struct ip_vs_protocol *pp;
981         union nf_inet_addr snet;
982         unsigned int offset;
983 
984         *related = 1;
985         ic = frag_safe_skb_hp(skb, ipvsh->len, sizeof(_icmph), &_icmph, ipvsh);
986         if (ic == NULL)
987                 return NF_DROP;
988 
989         /*
990          * Work through seeing if this is for us.
991          * These checks are supposed to be in an order that means easy
992          * things are checked first to speed up processing.... however
993          * this means that some packets will manage to get a long way
994          * down this stack and then be rejected, but that's life.
995          */
996         if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
997                 *related = 0;
998                 return NF_ACCEPT;
999         }
1000         /* Fragment header that is before ICMP header tells us that:
1001          * it's not an error message since they can't be fragmented.
1002          */
1003         if (ipvsh->flags & IP6_FH_F_FRAG)
1004                 return NF_DROP;
1005 
1006         IP_VS_DBG(8, "Outgoing ICMPv6 (%d,%d) %pI6c->%pI6c\n",
1007                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
1008                   &ipvsh->saddr, &ipvsh->daddr);
1009 
1010         if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, ipvsh->len + sizeof(_icmph),
1011                                      true, &ciph))
1012                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1013 
1014         pp = ip_vs_proto_get(ciph.protocol);
1015         if (!pp)
1016                 return NF_ACCEPT;
1017 
1018         /* The embedded headers contain source and dest in reverse order */
1019         cp = pp->conn_out_get(ipvs, AF_INET6, skb, &ciph);
1020         if (!cp)
1021                 return NF_ACCEPT;
1022 
1023         snet.in6 = ciph.saddr.in6;
1024         offset = ciph.len;
1025         return handle_response_icmp(AF_INET6, skb, &snet, ciph.protocol, cp,
1026                                     pp, offset, sizeof(struct ipv6hdr),
1027                                     hooknum);
1028 }
1029 #endif
1030 
1031 /*
1032  * Check if sctp chunc is ABORT chunk
1033  */
1034 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len)
1035 {
1036         struct sctp_chunkhdr *sch, schunk;
1037         sch = skb_header_pointer(skb, nh_len + sizeof(struct sctphdr),
1038                                  sizeof(schunk), &schunk);
1039         if (sch == NULL)
1040                 return 0;
1041         if (sch->type == SCTP_CID_ABORT)
1042                 return 1;
1043         return 0;
1044 }
1045 
1046 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
1047 {
1048         struct tcphdr _tcph, *th;
1049 
1050         th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
1051         if (th == NULL)
1052                 return 0;
1053         return th->rst;
1054 }
1055 
1056 static inline bool is_new_conn(const struct sk_buff *skb,
1057                                struct ip_vs_iphdr *iph)
1058 {
1059         switch (iph->protocol) {
1060         case IPPROTO_TCP: {
1061                 struct tcphdr _tcph, *th;
1062 
1063                 th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph);
1064                 if (th == NULL)
1065                         return false;
1066                 return th->syn;
1067         }
1068         case IPPROTO_SCTP: {
1069                 struct sctp_chunkhdr *sch, schunk;
1070 
1071                 sch = skb_header_pointer(skb, iph->len + sizeof(struct sctphdr),
1072                                          sizeof(schunk), &schunk);
1073                 if (sch == NULL)
1074                         return false;
1075                 return sch->type == SCTP_CID_INIT;
1076         }
1077         default:
1078                 return false;
1079         }
1080 }
1081 
1082 static inline bool is_new_conn_expected(const struct ip_vs_conn *cp,
1083                                         int conn_reuse_mode)
1084 {
1085         /* Controlled (FTP DATA or persistence)? */
1086         if (cp->control)
1087                 return false;
1088 
1089         switch (cp->protocol) {
1090         case IPPROTO_TCP:
1091                 return (cp->state == IP_VS_TCP_S_TIME_WAIT) ||
1092                        (cp->state == IP_VS_TCP_S_CLOSE) ||
1093                         ((conn_reuse_mode & 2) &&
1094                          (cp->state == IP_VS_TCP_S_FIN_WAIT) &&
1095                          (cp->flags & IP_VS_CONN_F_NOOUTPUT));
1096         case IPPROTO_SCTP:
1097                 return cp->state == IP_VS_SCTP_S_CLOSED;
1098         default:
1099                 return false;
1100         }
1101 }
1102 
1103 /* Generic function to create new connections for outgoing RS packets
1104  *
1105  * Pre-requisites for successful connection creation:
1106  * 1) Virtual Service is NOT fwmark based:
1107  *    In fwmark-VS actual vaddr and vport are unknown to IPVS
1108  * 2) Real Server and Virtual Service were NOT configured without port:
1109  *    This is to allow match of different VS to the same RS ip-addr
1110  */
1111 struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
1112                                       struct ip_vs_dest *dest,
1113                                       struct sk_buff *skb,
1114                                       const struct ip_vs_iphdr *iph,
1115                                       __be16 dport,
1116                                       __be16 cport)
1117 {
1118         struct ip_vs_conn_param param;
1119         struct ip_vs_conn *ct = NULL, *cp = NULL;
1120         const union nf_inet_addr *vaddr, *daddr, *caddr;
1121         union nf_inet_addr snet;
1122         __be16 vport;
1123         unsigned int flags;
1124 
1125         EnterFunction(12);
1126         vaddr = &svc->addr;
1127         vport = svc->port;
1128         daddr = &iph->saddr;
1129         caddr = &iph->daddr;
1130 
1131         /* check pre-requisites are satisfied */
1132         if (svc->fwmark)
1133                 return NULL;
1134         if (!vport || !dport)
1135                 return NULL;
1136 
1137         /* for persistent service first create connection template */
1138         if (svc->flags & IP_VS_SVC_F_PERSISTENT) {
1139                 /* apply netmask the same way ingress-side does */
1140 #ifdef CONFIG_IP_VS_IPV6
1141                 if (svc->af == AF_INET6)
1142                         ipv6_addr_prefix(&snet.in6, &caddr->in6,
1143                                          (__force __u32)svc->netmask);
1144                 else
1145 #endif
1146                         snet.ip = caddr->ip & svc->netmask;
1147                 /* fill params and create template if not existent */
1148                 if (ip_vs_conn_fill_param_persist(svc, skb, iph->protocol,
1149                                                   &snet, 0, vaddr,
1150                                                   vport, &param) < 0)
1151                         return NULL;
1152                 ct = ip_vs_ct_in_get(&param);
1153                 /* check if template exists and points to the same dest */
1154                 if (!ct || !ip_vs_check_template(ct, dest)) {
1155                         ct = ip_vs_conn_new(&param, dest->af, daddr, dport,
1156                                             IP_VS_CONN_F_TEMPLATE, dest, 0);
1157                         if (!ct) {
1158                                 kfree(param.pe_data);
1159                                 return NULL;
1160                         }
1161                         ct->timeout = svc->timeout;
1162                 } else {
1163                         kfree(param.pe_data);
1164                 }
1165         }
1166 
1167         /* connection flags */
1168         flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET) &&
1169                  iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;
1170         /* create connection */
1171         ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
1172                               caddr, cport, vaddr, vport, &param);
1173         cp = ip_vs_conn_new(&param, dest->af, daddr, dport, flags, dest, 0);
1174         if (!cp) {
1175                 if (ct)
1176                         ip_vs_conn_put(ct);
1177                 return NULL;
1178         }
1179         if (ct) {
1180                 ip_vs_control_add(cp, ct);
1181                 ip_vs_conn_put(ct);
1182         }
1183         ip_vs_conn_stats(cp, svc);
1184 
1185         /* return connection (will be used to handle outgoing packet) */
1186         IP_VS_DBG_BUF(6, "New connection RS-initiated:%c c:%s:%u v:%s:%u "
1187                       "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
1188                       ip_vs_fwd_tag(cp),
1189                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
1190                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
1191                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
1192                       cp->flags, refcount_read(&cp->refcnt));
1193         LeaveFunction(12);
1194         return cp;
1195 }
1196 
1197 /* Handle outgoing packets which are considered requests initiated by
1198  * real servers, so that subsequent responses from external client can be
1199  * routed to the right real server.
1200  * Used also for outgoing responses in OPS mode.
1201  *
1202  * Connection management is handled by persistent-engine specific callback.
1203  */
1204 static struct ip_vs_conn *__ip_vs_rs_conn_out(unsigned int hooknum,
1205                                               struct netns_ipvs *ipvs,
1206                                               int af, struct sk_buff *skb,
1207                                               const struct ip_vs_iphdr *iph)
1208 {
1209         struct ip_vs_dest *dest;
1210         struct ip_vs_conn *cp = NULL;
1211         __be16 _ports[2], *pptr;
1212 
1213         if (hooknum == NF_INET_LOCAL_IN)
1214                 return NULL;
1215 
1216         pptr = frag_safe_skb_hp(skb, iph->len,
1217                                 sizeof(_ports), _ports, iph);
1218         if (!pptr)
1219                 return NULL;
1220 
1221         dest = ip_vs_find_real_service(ipvs, af, iph->protocol,
1222                                        &iph->saddr, pptr[0]);
1223         if (dest) {
1224                 struct ip_vs_service *svc;
1225                 struct ip_vs_pe *pe;
1226 
1227                 svc = rcu_dereference(dest->svc);
1228                 if (svc) {
1229                         pe = rcu_dereference(svc->pe);
1230                         if (pe && pe->conn_out)
1231                                 cp = pe->conn_out(svc, dest, skb, iph,
1232                                                   pptr[0], pptr[1]);
1233                 }
1234         }
1235 
1236         return cp;
1237 }
1238 
1239 /* Handle response packets: rewrite addresses and send away...
1240  */
1241 static unsigned int
1242 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
1243                 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph,
1244                 unsigned int hooknum)
1245 {
1246         struct ip_vs_protocol *pp = pd->pp;
1247 
1248         IP_VS_DBG_PKT(11, af, pp, skb, iph->off, "Outgoing packet");
1249 
1250         if (!skb_make_writable(skb, iph->len))
1251                 goto drop;
1252 
1253         /* mangle the packet */
1254         if (pp->snat_handler && !pp->snat_handler(skb, pp, cp, iph))
1255                 goto drop;
1256 
1257 #ifdef CONFIG_IP_VS_IPV6
1258         if (af == AF_INET6)
1259                 ipv6_hdr(skb)->saddr = cp->vaddr.in6;
1260         else
1261 #endif
1262         {
1263                 ip_hdr(skb)->saddr = cp->vaddr.ip;
1264                 ip_send_check(ip_hdr(skb));
1265         }
1266 
1267         /*
1268          * nf_iterate does not expect change in the skb->dst->dev.
1269          * It looks like it is not fatal to enable this code for hooks
1270          * where our handlers are at the end of the chain list and
1271          * when all next handlers use skb->dst->dev and not outdev.
1272          * It will definitely route properly the inout NAT traffic
1273          * when multiple paths are used.
1274          */
1275 
1276         /* For policy routing, packets originating from this
1277          * machine itself may be routed differently to packets
1278          * passing through.  We want this packet to be routed as
1279          * if it came from this machine itself.  So re-compute
1280          * the routing information.
1281          */
1282         if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum))
1283                 goto drop;
1284 
1285         IP_VS_DBG_PKT(10, af, pp, skb, iph->off, "After SNAT");
1286 
1287         ip_vs_out_stats(cp, skb);
1288         ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd);
1289         skb->ipvs_property = 1;
1290         if (!(cp->flags & IP_VS_CONN_F_NFCT))
1291                 ip_vs_notrack(skb);
1292         else
1293                 ip_vs_update_conntrack(skb, cp, 0);
1294         ip_vs_conn_put(cp);
1295 
1296         LeaveFunction(11);
1297         return NF_ACCEPT;
1298 
1299 drop:
1300         ip_vs_conn_put(cp);
1301         kfree_skb(skb);
1302         LeaveFunction(11);
1303         return NF_STOLEN;
1304 }
1305 
1306 /*
1307  *      Check if outgoing packet belongs to the established ip_vs_conn.
1308  */
1309 static unsigned int
1310 ip_vs_out(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af)
1311 {
1312         struct ip_vs_iphdr iph;
1313         struct ip_vs_protocol *pp;
1314         struct ip_vs_proto_data *pd;
1315         struct ip_vs_conn *cp;
1316         struct sock *sk;
1317 
1318         EnterFunction(11);
1319 
1320         /* Already marked as IPVS request or reply? */
1321         if (skb->ipvs_property)
1322                 return NF_ACCEPT;
1323 
1324         sk = skb_to_full_sk(skb);
1325         /* Bad... Do not break raw sockets */
1326         if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT &&
1327                      af == AF_INET)) {
1328 
1329                 if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag)
1330                         return NF_ACCEPT;
1331         }
1332 
1333         if (unlikely(!skb_dst(skb)))
1334                 return NF_ACCEPT;
1335 
1336         if (!ipvs->enable)
1337                 return NF_ACCEPT;
1338 
1339         ip_vs_fill_iph_skb(af, skb, false, &iph);
1340 #ifdef CONFIG_IP_VS_IPV6
1341         if (af == AF_INET6) {
1342                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1343                         int related;
1344                         int verdict = ip_vs_out_icmp_v6(ipvs, skb, &related,
1345                                                         hooknum, &iph);
1346 
1347                         if (related)
1348                                 return verdict;
1349                 }
1350         } else
1351 #endif
1352                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1353                         int related;
1354                         int verdict = ip_vs_out_icmp(ipvs, skb, &related, hooknum);
1355 
1356                         if (related)
1357                                 return verdict;
1358                 }
1359 
1360         pd = ip_vs_proto_data_get(ipvs, iph.protocol);
1361         if (unlikely(!pd))
1362                 return NF_ACCEPT;
1363         pp = pd->pp;
1364 
1365         /* reassemble IP fragments */
1366 #ifdef CONFIG_IP_VS_IPV6
1367         if (af == AF_INET)
1368 #endif
1369                 if (unlikely(ip_is_fragment(ip_hdr(skb)) && !pp->dont_defrag)) {
1370                         if (ip_vs_gather_frags(ipvs, skb,
1371                                                ip_vs_defrag_user(hooknum)))
1372                                 return NF_STOLEN;
1373 
1374                         ip_vs_fill_iph_skb(AF_INET, skb, false, &iph);
1375                 }
1376 
1377         /*
1378          * Check if the packet belongs to an existing entry
1379          */
1380         cp = pp->conn_out_get(ipvs, af, skb, &iph);
1381 
1382         if (likely(cp)) {
1383                 if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
1384                         goto ignore_cp;
1385                 return handle_response(af, skb, pd, cp, &iph, hooknum);
1386         }
1387 
1388         /* Check for real-server-started requests */
1389         if (atomic_read(&ipvs->conn_out_counter)) {
1390                 /* Currently only for UDP:
1391                  * connection oriented protocols typically use
1392                  * ephemeral ports for outgoing connections, so
1393                  * related incoming responses would not match any VS
1394                  */
1395                 if (pp->protocol == IPPROTO_UDP) {
1396                         cp = __ip_vs_rs_conn_out(hooknum, ipvs, af, skb, &iph);
1397                         if (likely(cp))
1398                                 return handle_response(af, skb, pd, cp, &iph,
1399                                                        hooknum);
1400                 }
1401         }
1402 
1403         if (sysctl_nat_icmp_send(ipvs) &&
1404             (pp->protocol == IPPROTO_TCP ||
1405              pp->protocol == IPPROTO_UDP ||
1406              pp->protocol == IPPROTO_SCTP)) {
1407                 __be16 _ports[2], *pptr;
1408 
1409                 pptr = frag_safe_skb_hp(skb, iph.len,
1410                                          sizeof(_ports), _ports, &iph);
1411                 if (pptr == NULL)
1412                         return NF_ACCEPT;       /* Not for me */
1413                 if (ip_vs_has_real_service(ipvs, af, iph.protocol, &iph.saddr,
1414                                            pptr[0])) {
1415                         /*
1416                          * Notify the real server: there is no
1417                          * existing entry if it is not RST
1418                          * packet or not TCP packet.
1419                          */
1420                         if ((iph.protocol != IPPROTO_TCP &&
1421                              iph.protocol != IPPROTO_SCTP)
1422                              || ((iph.protocol == IPPROTO_TCP
1423                                   && !is_tcp_reset(skb, iph.len))
1424                                  || (iph.protocol == IPPROTO_SCTP
1425                                         && !is_sctp_abort(skb,
1426                                                 iph.len)))) {
1427 #ifdef CONFIG_IP_VS_IPV6
1428                                 if (af == AF_INET6) {
1429                                         if (!skb->dev)
1430                                                 skb->dev = ipvs->net->loopback_dev;
1431                                         icmpv6_send(skb,
1432                                                     ICMPV6_DEST_UNREACH,
1433                                                     ICMPV6_PORT_UNREACH,
1434                                                     0);
1435                                 } else
1436 #endif
1437                                         icmp_send(skb,
1438                                                   ICMP_DEST_UNREACH,
1439                                                   ICMP_PORT_UNREACH, 0);
1440                                 return NF_DROP;
1441                         }
1442                 }
1443         }
1444 
1445 out:
1446         IP_VS_DBG_PKT(12, af, pp, skb, iph.off,
1447                       "ip_vs_out: packet continues traversal as normal");
1448         return NF_ACCEPT;
1449 
1450 ignore_cp:
1451         __ip_vs_conn_put(cp);
1452         goto out;
1453 }
1454 
1455 /*
1456  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1457  *      used only for VS/NAT.
1458  *      Check if packet is reply for established ip_vs_conn.
1459  */
1460 static unsigned int
1461 ip_vs_reply4(void *priv, struct sk_buff *skb,
1462              const struct nf_hook_state *state)
1463 {
1464         return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET);
1465 }
1466 
1467 /*
1468  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1469  *      Check if packet is reply for established ip_vs_conn.
1470  */
1471 static unsigned int
1472 ip_vs_local_reply4(void *priv, struct sk_buff *skb,
1473                    const struct nf_hook_state *state)
1474 {
1475         return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET);
1476 }
1477 
1478 #ifdef CONFIG_IP_VS_IPV6
1479 
1480 /*
1481  *      It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1482  *      used only for VS/NAT.
1483  *      Check if packet is reply for established ip_vs_conn.
1484  */
1485 static unsigned int
1486 ip_vs_reply6(void *priv, struct sk_buff *skb,
1487              const struct nf_hook_state *state)
1488 {
1489         return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6);
1490 }
1491 
1492 /*
1493  *      It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1494  *      Check if packet is reply for established ip_vs_conn.
1495  */
1496 static unsigned int
1497 ip_vs_local_reply6(void *priv, struct sk_buff *skb,
1498                    const struct nf_hook_state *state)
1499 {
1500         return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6);
1501 }
1502 
1503 #endif
1504 
1505 static unsigned int
1506 ip_vs_try_to_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
1507                       struct ip_vs_proto_data *pd,
1508                       int *verdict, struct ip_vs_conn **cpp,
1509                       struct ip_vs_iphdr *iph)
1510 {
1511         struct ip_vs_protocol *pp = pd->pp;
1512 
1513         if (!iph->fragoffs) {
1514                 /* No (second) fragments need to enter here, as nf_defrag_ipv6
1515                  * replayed fragment zero will already have created the cp
1516                  */
1517 
1518                 /* Schedule and create new connection entry into cpp */
1519                 if (!pp->conn_schedule(ipvs, af, skb, pd, verdict, cpp, iph))
1520                         return 0;
1521         }
1522 
1523         if (unlikely(!*cpp)) {
1524                 /* sorry, all this trouble for a no-hit :) */
1525                 IP_VS_DBG_PKT(12, af, pp, skb, iph->off,
1526                               "ip_vs_in: packet continues traversal as normal");
1527                 if (iph->fragoffs) {
1528                         /* Fragment that couldn't be mapped to a conn entry
1529                          * is missing module nf_defrag_ipv6
1530                          */
1531                         IP_VS_DBG_RL("Unhandled frag, load nf_defrag_ipv6\n");
1532                         IP_VS_DBG_PKT(7, af, pp, skb, iph->off,
1533                                       "unhandled fragment");
1534                 }
1535                 *verdict = NF_ACCEPT;
1536                 return 0;
1537         }
1538 
1539         return 1;
1540 }
1541 
1542 /*
1543  *      Handle ICMP messages in the outside-to-inside direction (incoming).
1544  *      Find any that might be relevant, check against existing connections,
1545  *      forward to the right destination host if relevant.
1546  *      Currently handles error types - unreachable, quench, ttl exceeded.
1547  */
1548 static int
1549 ip_vs_in_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb, int *related,
1550               unsigned int hooknum)
1551 {
1552         struct iphdr *iph;
1553         struct icmphdr  _icmph, *ic;
1554         struct iphdr    _ciph, *cih;    /* The ip header contained within the ICMP */
1555         struct ip_vs_iphdr ciph;
1556         struct ip_vs_conn *cp;
1557         struct ip_vs_protocol *pp;
1558         struct ip_vs_proto_data *pd;
1559         unsigned int offset, offset2, ihl, verdict;
1560         bool ipip, new_cp = false;
1561 
1562         *related = 1;
1563 
1564         /* reassemble IP fragments */
1565         if (ip_is_fragment(ip_hdr(skb))) {
1566                 if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum)))
1567                         return NF_STOLEN;
1568         }
1569 
1570         iph = ip_hdr(skb);
1571         offset = ihl = iph->ihl * 4;
1572         ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1573         if (ic == NULL)
1574                 return NF_DROP;
1575 
1576         IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1577                   ic->type, ntohs(icmp_id(ic)),
1578                   &iph->saddr, &iph->daddr);
1579 
1580         /*
1581          * Work through seeing if this is for us.
1582          * These checks are supposed to be in an order that means easy
1583          * things are checked first to speed up processing.... however
1584          * this means that some packets will manage to get a long way
1585          * down this stack and then be rejected, but that's life.
1586          */
1587         if ((ic->type != ICMP_DEST_UNREACH) &&
1588             (ic->type != ICMP_SOURCE_QUENCH) &&
1589             (ic->type != ICMP_TIME_EXCEEDED)) {
1590                 *related = 0;
1591                 return NF_ACCEPT;
1592         }
1593 
1594         /* Now find the contained IP header */
1595         offset += sizeof(_icmph);
1596         cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1597         if (cih == NULL)
1598                 return NF_ACCEPT; /* The packet looks wrong, ignore */
1599 
1600         /* Special case for errors for IPIP packets */
1601         ipip = false;
1602         if (cih->protocol == IPPROTO_IPIP) {
1603                 if (unlikely(cih->frag_off & htons(IP_OFFSET)))
1604                         return NF_ACCEPT;
1605                 /* Error for our IPIP must arrive at LOCAL_IN */
1606                 if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL))
1607                         return NF_ACCEPT;
1608                 offset += cih->ihl * 4;
1609                 cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1610                 if (cih == NULL)
1611                         return NF_ACCEPT; /* The packet looks wrong, ignore */
1612                 ipip = true;
1613         }
1614 
1615         pd = ip_vs_proto_data_get(ipvs, cih->protocol);
1616         if (!pd)
1617                 return NF_ACCEPT;
1618         pp = pd->pp;
1619 
1620         /* Is the embedded protocol header present? */
1621         if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1622                      pp->dont_defrag))
1623                 return NF_ACCEPT;
1624 
1625         IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
1626                       "Checking incoming ICMP for");
1627 
1628         offset2 = offset;
1629         ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, !ipip, &ciph);
1630         offset = ciph.len;
1631 
1632         /* The embedded headers contain source and dest in reverse order.
1633          * For IPIP this is error for request, not for reply.
1634          */
1635         cp = pp->conn_in_get(ipvs, AF_INET, skb, &ciph);
1636 
1637         if (!cp) {
1638                 int v;
1639 
1640                 if (!sysctl_schedule_icmp(ipvs))
1641                         return NF_ACCEPT;
1642 
1643                 if (!ip_vs_try_to_schedule(ipvs, AF_INET, skb, pd, &v, &cp, &ciph))
1644                         return v;
1645                 new_cp = true;
1646         }
1647 
1648         verdict = NF_DROP;
1649 
1650         /* Ensure the checksum is correct */
1651         if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1652                 /* Failed checksum! */
1653                 IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1654                           &iph->saddr);
1655                 goto out;
1656         }
1657 
1658         if (ipip) {
1659                 __be32 info = ic->un.gateway;
1660                 __u8 type = ic->type;
1661                 __u8 code = ic->code;
1662 
1663                 /* Update the MTU */
1664                 if (ic->type == ICMP_DEST_UNREACH &&
1665                     ic->code == ICMP_FRAG_NEEDED) {
1666                         struct ip_vs_dest *dest = cp->dest;
1667                         u32 mtu = ntohs(ic->un.frag.mtu);
1668                         __be16 frag_off = cih->frag_off;
1669 
1670                         /* Strip outer IP and ICMP, go to IPIP header */
1671                         if (pskb_pull(skb, ihl + sizeof(_icmph)) == NULL)
1672                                 goto ignore_ipip;
1673                         offset2 -= ihl + sizeof(_icmph);
1674                         skb_reset_network_header(skb);
1675                         IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n",
1676                                 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, mtu);
1677                         ipv4_update_pmtu(skb, ipvs->net,
1678                                          mtu, 0, 0, 0, 0);
1679                         /* Client uses PMTUD? */
1680                         if (!(frag_off & htons(IP_DF)))
1681                                 goto ignore_ipip;
1682                         /* Prefer the resulting PMTU */
1683                         if (dest) {
1684                                 struct ip_vs_dest_dst *dest_dst;
1685 
1686                                 dest_dst = rcu_dereference(dest->dest_dst);
1687                                 if (dest_dst)
1688                                         mtu = dst_mtu(dest_dst->dst_cache);
1689                         }
1690                         if (mtu > 68 + sizeof(struct iphdr))
1691                                 mtu -= sizeof(struct iphdr);
1692                         info = htonl(mtu);
1693                 }
1694                 /* Strip outer IP, ICMP and IPIP, go to IP header of
1695                  * original request.
1696                  */
1697                 if (pskb_pull(skb, offset2) == NULL)
1698                         goto ignore_ipip;
1699                 skb_reset_network_header(skb);
1700                 IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n",
1701                         &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1702                         type, code, ntohl(info));
1703                 icmp_send(skb, type, code, info);
1704                 /* ICMP can be shorter but anyways, account it */
1705                 ip_vs_out_stats(cp, skb);
1706 
1707 ignore_ipip:
1708                 consume_skb(skb);
1709                 verdict = NF_STOLEN;
1710                 goto out;
1711         }
1712 
1713         /* do the statistics and put it back */
1714         ip_vs_in_stats(cp, skb);
1715         if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol ||
1716             IPPROTO_SCTP == cih->protocol)
1717                 offset += 2 * sizeof(__u16);
1718         verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum, &ciph);
1719 
1720 out:
1721         if (likely(!new_cp))
1722                 __ip_vs_conn_put(cp);
1723         else
1724                 ip_vs_conn_put(cp);
1725 
1726         return verdict;
1727 }
1728 
1729 #ifdef CONFIG_IP_VS_IPV6
1730 static int ip_vs_in_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
1731                             int *related, unsigned int hooknum,
1732                             struct ip_vs_iphdr *iph)
1733 {
1734         struct icmp6hdr _icmph, *ic;
1735         struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
1736         struct ip_vs_conn *cp;
1737         struct ip_vs_protocol *pp;
1738         struct ip_vs_proto_data *pd;
1739         unsigned int offset, verdict;
1740         bool new_cp = false;
1741 
1742         *related = 1;
1743 
1744         ic = frag_safe_skb_hp(skb, iph->len, sizeof(_icmph), &_icmph, iph);
1745         if (ic == NULL)
1746                 return NF_DROP;
1747 
1748         /*
1749          * Work through seeing if this is for us.
1750          * These checks are supposed to be in an order that means easy
1751          * things are checked first to speed up processing.... however
1752          * this means that some packets will manage to get a long way
1753          * down this stack and then be rejected, but that's life.
1754          */
1755         if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
1756                 *related = 0;
1757                 return NF_ACCEPT;
1758         }
1759         /* Fragment header that is before ICMP header tells us that:
1760          * it's not an error message since they can't be fragmented.
1761          */
1762         if (iph->flags & IP6_FH_F_FRAG)
1763                 return NF_DROP;
1764 
1765         IP_VS_DBG(8, "Incoming ICMPv6 (%d,%d) %pI6c->%pI6c\n",
1766                   ic->icmp6_type, ntohs(icmpv6_id(ic)),
1767                   &iph->saddr, &iph->daddr);
1768 
1769         offset = iph->len + sizeof(_icmph);
1770         if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, offset, true, &ciph))
1771                 return NF_ACCEPT;
1772 
1773         pd = ip_vs_proto_data_get(ipvs, ciph.protocol);
1774         if (!pd)
1775                 return NF_ACCEPT;
1776         pp = pd->pp;
1777 
1778         /* Cannot handle fragmented embedded protocol */
1779         if (ciph.fragoffs)
1780                 return NF_ACCEPT;
1781 
1782         IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset,
1783                       "Checking incoming ICMPv6 for");
1784 
1785         /* The embedded headers contain source and dest in reverse order
1786          * if not from localhost
1787          */
1788         cp = pp->conn_in_get(ipvs, AF_INET6, skb, &ciph);
1789 
1790         if (!cp) {
1791                 int v;
1792 
1793                 if (!sysctl_schedule_icmp(ipvs))
1794                         return NF_ACCEPT;
1795 
1796                 if (!ip_vs_try_to_schedule(ipvs, AF_INET6, skb, pd, &v, &cp, &ciph))
1797                         return v;
1798 
1799                 new_cp = true;
1800         }
1801 
1802         /* VS/TUN, VS/DR and LOCALNODE just let it go */
1803         if ((hooknum == NF_INET_LOCAL_OUT) &&
1804             (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)) {
1805                 verdict = NF_ACCEPT;
1806                 goto out;
1807         }
1808 
1809         /* do the statistics and put it back */
1810         ip_vs_in_stats(cp, skb);
1811 
1812         /* Need to mangle contained IPv6 header in ICMPv6 packet */
1813         offset = ciph.len;
1814         if (IPPROTO_TCP == ciph.protocol || IPPROTO_UDP == ciph.protocol ||
1815             IPPROTO_SCTP == ciph.protocol)
1816                 offset += 2 * sizeof(__u16); /* Also mangle ports */
1817 
1818         verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset, hooknum, &ciph);
1819 
1820 out:
1821         if (likely(!new_cp))
1822                 __ip_vs_conn_put(cp);
1823         else
1824                 ip_vs_conn_put(cp);
1825 
1826         return verdict;
1827 }
1828 #endif
1829 
1830 
1831 /*
1832  *      Check if it's for virtual services, look it up,
1833  *      and send it on its way...
1834  */
1835 static unsigned int
1836 ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af)
1837 {
1838         struct ip_vs_iphdr iph;
1839         struct ip_vs_protocol *pp;
1840         struct ip_vs_proto_data *pd;
1841         struct ip_vs_conn *cp;
1842         int ret, pkts;
1843         int conn_reuse_mode;
1844         struct sock *sk;
1845 
1846         /* Already marked as IPVS request or reply? */
1847         if (skb->ipvs_property)
1848                 return NF_ACCEPT;
1849 
1850         /*
1851          *      Big tappo:
1852          *      - remote client: only PACKET_HOST
1853          *      - route: used for struct net when skb->dev is unset
1854          */
1855         if (unlikely((skb->pkt_type != PACKET_HOST &&
1856                       hooknum != NF_INET_LOCAL_OUT) ||
1857                      !skb_dst(skb))) {
1858                 ip_vs_fill_iph_skb(af, skb, false, &iph);
1859                 IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s"
1860                               " ignored in hook %u\n",
1861                               skb->pkt_type, iph.protocol,
1862                               IP_VS_DBG_ADDR(af, &iph.daddr), hooknum);
1863                 return NF_ACCEPT;
1864         }
1865         /* ipvs enabled in this netns ? */
1866         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
1867                 return NF_ACCEPT;
1868 
1869         ip_vs_fill_iph_skb(af, skb, false, &iph);
1870 
1871         /* Bad... Do not break raw sockets */
1872         sk = skb_to_full_sk(skb);
1873         if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT &&
1874                      af == AF_INET)) {
1875 
1876                 if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag)
1877                         return NF_ACCEPT;
1878         }
1879 
1880 #ifdef CONFIG_IP_VS_IPV6
1881         if (af == AF_INET6) {
1882                 if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1883                         int related;
1884                         int verdict = ip_vs_in_icmp_v6(ipvs, skb, &related,
1885                                                        hooknum, &iph);
1886 
1887                         if (related)
1888                                 return verdict;
1889                 }
1890         } else
1891 #endif
1892                 if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1893                         int related;
1894                         int verdict = ip_vs_in_icmp(ipvs, skb, &related,
1895                                                     hooknum);
1896 
1897                         if (related)
1898                                 return verdict;
1899                 }
1900 
1901         /* Protocol supported? */
1902         pd = ip_vs_proto_data_get(ipvs, iph.protocol);
1903         if (unlikely(!pd)) {
1904                 /* The only way we'll see this packet again is if it's
1905                  * encapsulated, so mark it with ipvs_property=1 so we
1906                  * skip it if we're ignoring tunneled packets
1907                  */
1908                 if (sysctl_ignore_tunneled(ipvs))
1909                         skb->ipvs_property = 1;
1910 
1911                 return NF_ACCEPT;
1912         }
1913         pp = pd->pp;
1914         /*
1915          * Check if the packet belongs to an existing connection entry
1916          */
1917         cp = pp->conn_in_get(ipvs, af, skb, &iph);
1918 
1919         conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
1920         if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) {
1921                 bool uses_ct = false, resched = false;
1922 
1923                 if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
1924                     unlikely(!atomic_read(&cp->dest->weight))) {
1925                         resched = true;
1926                         uses_ct = ip_vs_conn_uses_conntrack(cp, skb);
1927                 } else if (is_new_conn_expected(cp, conn_reuse_mode)) {
1928                         uses_ct = ip_vs_conn_uses_conntrack(cp, skb);
1929                         if (!atomic_read(&cp->n_control)) {
1930                                 resched = true;
1931                         } else {
1932                                 /* Do not reschedule controlling connection
1933                                  * that uses conntrack while it is still
1934                                  * referenced by controlled connection(s).
1935                                  */
1936                                 resched = !uses_ct;
1937                         }
1938                 }
1939 
1940                 if (resched) {
1941                         if (!atomic_read(&cp->n_control))
1942                                 ip_vs_conn_expire_now(cp);
1943                         __ip_vs_conn_put(cp);
1944                         if (uses_ct)
1945                                 return NF_DROP;
1946                         cp = NULL;
1947                 }
1948         }
1949 
1950         if (unlikely(!cp)) {
1951                 int v;
1952 
1953                 if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph))
1954                         return v;
1955         }
1956 
1957         IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet");
1958 
1959         /* Check the server status */
1960         if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
1961                 /* the destination server is not available */
1962 
1963                 if (sysctl_expire_nodest_conn(ipvs)) {
1964                         /* try to expire the connection immediately */
1965                         ip_vs_conn_expire_now(cp);
1966                 }
1967                 /* don't restart its timer, and silently
1968                    drop the packet. */
1969                 __ip_vs_conn_put(cp);
1970                 return NF_DROP;
1971         }
1972 
1973         ip_vs_in_stats(cp, skb);
1974         ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
1975         if (cp->packet_xmit)
1976                 ret = cp->packet_xmit(skb, cp, pp, &iph);
1977                 /* do not touch skb anymore */
1978         else {
1979                 IP_VS_DBG_RL("warning: packet_xmit is null");
1980                 ret = NF_ACCEPT;
1981         }
1982 
1983         /* Increase its packet counter and check if it is needed
1984          * to be synchronized
1985          *
1986          * Sync connection if it is about to close to
1987          * encorage the standby servers to update the connections timeout
1988          *
1989          * For ONE_PKT let ip_vs_sync_conn() do the filter work.
1990          */
1991 
1992         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
1993                 pkts = sysctl_sync_threshold(ipvs);
1994         else
1995                 pkts = atomic_add_return(1, &cp->in_pkts);
1996 
1997         if (ipvs->sync_state & IP_VS_STATE_MASTER)
1998                 ip_vs_sync_conn(ipvs, cp, pkts);
1999         else if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
2000                 /* increment is done inside ip_vs_sync_conn too */
2001                 atomic_inc(&cp->control->in_pkts);
2002 
2003         ip_vs_conn_put(cp);
2004         return ret;
2005 }
2006 
2007 /*
2008  *      AF_INET handler in NF_INET_LOCAL_IN chain
2009  *      Schedule and forward packets from remote clients
2010  */
2011 static unsigned int
2012 ip_vs_remote_request4(void *priv, struct sk_buff *skb,
2013                       const struct nf_hook_state *state)
2014 {
2015         return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET);
2016 }
2017 
2018 /*
2019  *      AF_INET handler in NF_INET_LOCAL_OUT chain
2020  *      Schedule and forward packets from local clients
2021  */
2022 static unsigned int
2023 ip_vs_local_request4(void *priv, struct sk_buff *skb,
2024                      const struct nf_hook_state *state)
2025 {
2026         return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET);
2027 }
2028 
2029 #ifdef CONFIG_IP_VS_IPV6
2030 
2031 /*
2032  *      AF_INET6 handler in NF_INET_LOCAL_IN chain
2033  *      Schedule and forward packets from remote clients
2034  */
2035 static unsigned int
2036 ip_vs_remote_request6(void *priv, struct sk_buff *skb,
2037                       const struct nf_hook_state *state)
2038 {
2039         return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6);
2040 }
2041 
2042 /*
2043  *      AF_INET6 handler in NF_INET_LOCAL_OUT chain
2044  *      Schedule and forward packets from local clients
2045  */
2046 static unsigned int
2047 ip_vs_local_request6(void *priv, struct sk_buff *skb,
2048                      const struct nf_hook_state *state)
2049 {
2050         return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6);
2051 }
2052 
2053 #endif
2054 
2055 
2056 /*
2057  *      It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
2058  *      related packets destined for 0.0.0.0/0.
2059  *      When fwmark-based virtual service is used, such as transparent
2060  *      cache cluster, TCP packets can be marked and routed to ip_vs_in,
2061  *      but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
2062  *      sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
2063  *      and send them to ip_vs_in_icmp.
2064  */
2065 static unsigned int
2066 ip_vs_forward_icmp(void *priv, struct sk_buff *skb,
2067                    const struct nf_hook_state *state)
2068 {
2069         int r;
2070         struct netns_ipvs *ipvs = net_ipvs(state->net);
2071 
2072         if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
2073                 return NF_ACCEPT;
2074 
2075         /* ipvs enabled in this netns ? */
2076         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
2077                 return NF_ACCEPT;
2078 
2079         return ip_vs_in_icmp(ipvs, skb, &r, state->hook);
2080 }
2081 
2082 #ifdef CONFIG_IP_VS_IPV6
2083 static unsigned int
2084 ip_vs_forward_icmp_v6(void *priv, struct sk_buff *skb,
2085                       const struct nf_hook_state *state)
2086 {
2087         int r;
2088         struct netns_ipvs *ipvs = net_ipvs(state->net);
2089         struct ip_vs_iphdr iphdr;
2090 
2091         ip_vs_fill_iph_skb(AF_INET6, skb, false, &iphdr);
2092         if (iphdr.protocol != IPPROTO_ICMPV6)
2093                 return NF_ACCEPT;
2094 
2095         /* ipvs enabled in this netns ? */
2096         if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
2097                 return NF_ACCEPT;
2098 
2099         return ip_vs_in_icmp_v6(ipvs, skb, &r, state->hook, &iphdr);
2100 }
2101 #endif
2102 
2103 
2104 static const struct nf_hook_ops ip_vs_ops[] = {
2105         /* After packet filtering, change source only for VS/NAT */
2106         {
2107                 .hook           = ip_vs_reply4,
2108                 .pf             = NFPROTO_IPV4,
2109                 .hooknum        = NF_INET_LOCAL_IN,
2110                 .priority       = NF_IP_PRI_NAT_SRC - 2,
2111         },
2112         /* After packet filtering, forward packet through VS/DR, VS/TUN,
2113          * or VS/NAT(change destination), so that filtering rules can be
2114          * applied to IPVS. */
2115         {
2116                 .hook           = ip_vs_remote_request4,
2117                 .pf             = NFPROTO_IPV4,
2118                 .hooknum        = NF_INET_LOCAL_IN,
2119                 .priority       = NF_IP_PRI_NAT_SRC - 1,
2120         },
2121         /* Before ip_vs_in, change source only for VS/NAT */
2122         {
2123                 .hook           = ip_vs_local_reply4,
2124                 .pf             = NFPROTO_IPV4,
2125                 .hooknum        = NF_INET_LOCAL_OUT,
2126                 .priority       = NF_IP_PRI_NAT_DST + 1,
2127         },
2128         /* After mangle, schedule and forward local requests */
2129         {
2130                 .hook           = ip_vs_local_request4,
2131                 .pf             = NFPROTO_IPV4,
2132                 .hooknum        = NF_INET_LOCAL_OUT,
2133                 .priority       = NF_IP_PRI_NAT_DST + 2,
2134         },
2135         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
2136          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
2137         {
2138                 .hook           = ip_vs_forward_icmp,
2139                 .pf             = NFPROTO_IPV4,
2140                 .hooknum        = NF_INET_FORWARD,
2141                 .priority       = 99,
2142         },
2143         /* After packet filtering, change source only for VS/NAT */
2144         {
2145                 .hook           = ip_vs_reply4,
2146                 .pf             = NFPROTO_IPV4,
2147                 .hooknum        = NF_INET_FORWARD,
2148                 .priority       = 100,
2149         },
2150 #ifdef CONFIG_IP_VS_IPV6
2151         /* After packet filtering, change source only for VS/NAT */
2152         {
2153                 .hook           = ip_vs_reply6,
2154                 .pf             = NFPROTO_IPV6,
2155                 .hooknum        = NF_INET_LOCAL_IN,
2156                 .priority       = NF_IP6_PRI_NAT_SRC - 2,
2157         },
2158         /* After packet filtering, forward packet through VS/DR, VS/TUN,
2159          * or VS/NAT(change destination), so that filtering rules can be
2160          * applied to IPVS. */
2161         {
2162                 .hook           = ip_vs_remote_request6,
2163                 .pf             = NFPROTO_IPV6,
2164                 .hooknum        = NF_INET_LOCAL_IN,
2165                 .priority       = NF_IP6_PRI_NAT_SRC - 1,
2166         },
2167         /* Before ip_vs_in, change source only for VS/NAT */
2168         {
2169                 .hook           = ip_vs_local_reply6,
2170                 .pf             = NFPROTO_IPV6,
2171                 .hooknum        = NF_INET_LOCAL_OUT,
2172                 .priority       = NF_IP6_PRI_NAT_DST + 1,
2173         },
2174         /* After mangle, schedule and forward local requests */
2175         {
2176                 .hook           = ip_vs_local_request6,
2177                 .pf             = NFPROTO_IPV6,
2178                 .hooknum        = NF_INET_LOCAL_OUT,
2179                 .priority       = NF_IP6_PRI_NAT_DST + 2,
2180         },
2181         /* After packet filtering (but before ip_vs_out_icmp), catch icmp
2182          * destined for 0.0.0.0/0, which is for incoming IPVS connections */
2183         {
2184                 .hook           = ip_vs_forward_icmp_v6,
2185                 .pf             = NFPROTO_IPV6,
2186                 .hooknum        = NF_INET_FORWARD,
2187                 .priority       = 99,
2188         },
2189         /* After packet filtering, change source only for VS/NAT */
2190         {
2191                 .hook           = ip_vs_reply6,
2192                 .pf             = NFPROTO_IPV6,
2193                 .hooknum        = NF_INET_FORWARD,
2194                 .priority       = 100,
2195         },
2196 #endif
2197 };
2198 /*
2199  *      Initialize IP Virtual Server netns mem.
2200  */
2201 static int __net_init __ip_vs_init(struct net *net)
2202 {
2203         struct netns_ipvs *ipvs;
2204         int ret;
2205 
2206         ipvs = net_generic(net, ip_vs_net_id);
2207         if (ipvs == NULL)
2208                 return -ENOMEM;
2209 
2210         /* Hold the beast until a service is registerd */
2211         ipvs->enable = 0;
2212         ipvs->net = net;
2213         /* Counters used for creating unique names */
2214         ipvs->gen = atomic_read(&ipvs_netns_cnt);
2215         atomic_inc(&ipvs_netns_cnt);
2216         net->ipvs = ipvs;
2217 
2218         if (ip_vs_estimator_net_init(ipvs) < 0)
2219                 goto estimator_fail;
2220 
2221         if (ip_vs_control_net_init(ipvs) < 0)
2222                 goto control_fail;
2223 
2224         if (ip_vs_protocol_net_init(ipvs) < 0)
2225                 goto protocol_fail;
2226 
2227         if (ip_vs_app_net_init(ipvs) < 0)
2228                 goto app_fail;
2229 
2230         if (ip_vs_conn_net_init(ipvs) < 0)
2231                 goto conn_fail;
2232 
2233         if (ip_vs_sync_net_init(ipvs) < 0)
2234                 goto sync_fail;
2235 
2236         ret = nf_register_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2237         if (ret < 0)
2238                 goto hook_fail;
2239 
2240         return 0;
2241 /*
2242  * Error handling
2243  */
2244 
2245 hook_fail:
2246         ip_vs_sync_net_cleanup(ipvs);
2247 sync_fail:
2248         ip_vs_conn_net_cleanup(ipvs);
2249 conn_fail:
2250         ip_vs_app_net_cleanup(ipvs);
2251 app_fail:
2252         ip_vs_protocol_net_cleanup(ipvs);
2253 protocol_fail:
2254         ip_vs_control_net_cleanup(ipvs);
2255 control_fail:
2256         ip_vs_estimator_net_cleanup(ipvs);
2257 estimator_fail:
2258         net->ipvs = NULL;
2259         return -ENOMEM;
2260 }
2261 
2262 static void __net_exit __ip_vs_cleanup(struct net *net)
2263 {
2264         struct netns_ipvs *ipvs = net_ipvs(net);
2265 
2266         nf_unregister_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2267         ip_vs_service_net_cleanup(ipvs);        /* ip_vs_flush() with locks */
2268         ip_vs_conn_net_cleanup(ipvs);
2269         ip_vs_app_net_cleanup(ipvs);
2270         ip_vs_protocol_net_cleanup(ipvs);
2271         ip_vs_control_net_cleanup(ipvs);
2272         ip_vs_estimator_net_cleanup(ipvs);
2273         IP_VS_DBG(2, "ipvs netns %d released\n", ipvs->gen);
2274         net->ipvs = NULL;
2275 }
2276 
2277 static void __net_exit __ip_vs_dev_cleanup(struct net *net)
2278 {
2279         struct netns_ipvs *ipvs = net_ipvs(net);
2280         EnterFunction(2);
2281         ipvs->enable = 0;       /* Disable packet reception */
2282         smp_wmb();
2283         ip_vs_sync_net_cleanup(ipvs);
2284         LeaveFunction(2);
2285 }
2286 
2287 static struct pernet_operations ipvs_core_ops = {
2288         .init = __ip_vs_init,
2289         .exit = __ip_vs_cleanup,
2290         .id   = &ip_vs_net_id,
2291         .size = sizeof(struct netns_ipvs),
2292 };
2293 
2294 static struct pernet_operations ipvs_core_dev_ops = {
2295         .exit = __ip_vs_dev_cleanup,
2296 };
2297 
2298 /*
2299  *      Initialize IP Virtual Server
2300  */
2301 static int __init ip_vs_init(void)
2302 {
2303         int ret;
2304 
2305         ret = ip_vs_control_init();
2306         if (ret < 0) {
2307                 pr_err("can't setup control.\n");
2308                 goto exit;
2309         }
2310 
2311         ip_vs_protocol_init();
2312 
2313         ret = ip_vs_conn_init();
2314         if (ret < 0) {
2315                 pr_err("can't setup connection table.\n");
2316                 goto cleanup_protocol;
2317         }
2318 
2319         ret = register_pernet_subsys(&ipvs_core_ops);   /* Alloc ip_vs struct */
2320         if (ret < 0)
2321                 goto cleanup_conn;
2322 
2323         ret = register_pernet_device(&ipvs_core_dev_ops);
2324         if (ret < 0)
2325                 goto cleanup_sub;
2326 
2327         ret = ip_vs_register_nl_ioctl();
2328         if (ret < 0) {
2329                 pr_err("can't register netlink/ioctl.\n");
2330                 goto cleanup_dev;
2331         }
2332 
2333         pr_info("ipvs loaded.\n");
2334 
2335         return ret;
2336 
2337 cleanup_dev:
2338         unregister_pernet_device(&ipvs_core_dev_ops);
2339 cleanup_sub:
2340         unregister_pernet_subsys(&ipvs_core_ops);
2341 cleanup_conn:
2342         ip_vs_conn_cleanup();
2343 cleanup_protocol:
2344         ip_vs_protocol_cleanup();
2345         ip_vs_control_cleanup();
2346 exit:
2347         return ret;
2348 }
2349 
2350 static void __exit ip_vs_cleanup(void)
2351 {
2352         ip_vs_unregister_nl_ioctl();
2353         unregister_pernet_device(&ipvs_core_dev_ops);
2354         unregister_pernet_subsys(&ipvs_core_ops);       /* free ip_vs struct */
2355         ip_vs_conn_cleanup();
2356         ip_vs_protocol_cleanup();
2357         ip_vs_control_cleanup();
2358         pr_info("ipvs unloaded.\n");
2359 }
2360 
2361 module_init(ip_vs_init);
2362 module_exit(ip_vs_cleanup);
2363 MODULE_LICENSE("GPL");
2364 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp