1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * IPVS         An implementation of the IP virtual server support for the
4  *              LINUX operating system.  IPVS is now implemented as a module
5  *              over the Netfilter framework. IPVS can be used to build a
6  *              high-performance and highly available server based on a
7  *              cluster of servers.
8  *
9  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
10  *              Peter Kese <peter.kese@ijs.si>
11  *              Julian Anastasov <ja@ssi.bg>
12  *
13  * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
14  * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
15  * and others.
16  *
17  * Changes:
18  *	Paul `Rusty' Russell		properly handle non-linear skbs
19  *	Harald Welte			don't use nfcache
20  */
21 
22 #define KMSG_COMPONENT "IPVS"
23 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
24 
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/ip.h>
28 #include <linux/tcp.h>
29 #include <linux/sctp.h>
30 #include <linux/icmp.h>
31 #include <linux/slab.h>
32 
33 #include <net/ip.h>
34 #include <net/tcp.h>
35 #include <net/udp.h>
36 #include <net/icmp.h>                   /* for icmp_send */
37 #include <net/gue.h>
38 #include <net/gre.h>
39 #include <net/route.h>
40 #include <net/ip6_checksum.h>
41 #include <net/netns/generic.h>		/* net_generic() */
42 
43 #include <linux/netfilter.h>
44 #include <linux/netfilter_ipv4.h>
45 
46 #ifdef CONFIG_IP_VS_IPV6
47 #include <net/ipv6.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <net/ip6_route.h>
50 #endif
51 
52 #include <net/ip_vs.h>
53 #include <linux/indirect_call_wrapper.h>
54 
55 
56 EXPORT_SYMBOL(register_ip_vs_scheduler);
57 EXPORT_SYMBOL(unregister_ip_vs_scheduler);
58 EXPORT_SYMBOL(ip_vs_proto_name);
59 EXPORT_SYMBOL(ip_vs_conn_new);
60 EXPORT_SYMBOL(ip_vs_conn_in_get);
61 EXPORT_SYMBOL(ip_vs_conn_out_get);
62 #ifdef CONFIG_IP_VS_PROTO_TCP
63 EXPORT_SYMBOL(ip_vs_tcp_conn_listen);
64 #endif
65 EXPORT_SYMBOL(ip_vs_conn_put);
66 #ifdef CONFIG_IP_VS_DEBUG
67 EXPORT_SYMBOL(ip_vs_get_debug_level);
68 #endif
69 EXPORT_SYMBOL(ip_vs_new_conn_out);
70 
71 #ifdef CONFIG_IP_VS_PROTO_TCP
72 INDIRECT_CALLABLE_DECLARE(int
73 	tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
74 			 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph));
75 #endif
76 
77 #ifdef CONFIG_IP_VS_PROTO_UDP
78 INDIRECT_CALLABLE_DECLARE(int
79 	udp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
80 			 struct ip_vs_conn *cp, struct ip_vs_iphdr *iph));
81 #endif
82 
83 #if defined(CONFIG_IP_VS_PROTO_TCP) && defined(CONFIG_IP_VS_PROTO_UDP)
84 #define SNAT_CALL(f, ...) \
85 	INDIRECT_CALL_2(f, tcp_snat_handler, udp_snat_handler, __VA_ARGS__)
86 #elif defined(CONFIG_IP_VS_PROTO_TCP)
87 #define SNAT_CALL(f, ...) INDIRECT_CALL_1(f, tcp_snat_handler, __VA_ARGS__)
88 #elif defined(CONFIG_IP_VS_PROTO_UDP)
89 #define SNAT_CALL(f, ...) INDIRECT_CALL_1(f, udp_snat_handler, __VA_ARGS__)
90 #else
91 #define SNAT_CALL(f, ...) f(__VA_ARGS__)
92 #endif
93 
94 static unsigned int ip_vs_net_id __read_mostly;
95 /* netns cnt used for uniqueness */
96 static atomic_t ipvs_netns_cnt = ATOMIC_INIT(0);
97 
98 /* ID used in ICMP lookups */
99 #define icmp_id(icmph)          (((icmph)->un).echo.id)
100 #define icmpv6_id(icmph)        (icmph->icmp6_dataun.u_echo.identifier)
101 
ip_vs_proto_name(unsigned int proto)102 const char *ip_vs_proto_name(unsigned int proto)
103 {
104 	static char buf[20];
105 
106 	switch (proto) {
107 	case IPPROTO_IP:
108 		return "IP";
109 	case IPPROTO_UDP:
110 		return "UDP";
111 	case IPPROTO_TCP:
112 		return "TCP";
113 	case IPPROTO_SCTP:
114 		return "SCTP";
115 	case IPPROTO_ICMP:
116 		return "ICMP";
117 #ifdef CONFIG_IP_VS_IPV6
118 	case IPPROTO_ICMPV6:
119 		return "ICMPv6";
120 #endif
121 	default:
122 		sprintf(buf, "IP_%u", proto);
123 		return buf;
124 	}
125 }
126 
ip_vs_init_hash_table(struct list_head * table,int rows)127 void ip_vs_init_hash_table(struct list_head *table, int rows)
128 {
129 	while (--rows >= 0)
130 		INIT_LIST_HEAD(&table[rows]);
131 }
132 
133 static inline void
ip_vs_in_stats(struct ip_vs_conn * cp,struct sk_buff * skb)134 ip_vs_in_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
135 {
136 	struct ip_vs_dest *dest = cp->dest;
137 	struct netns_ipvs *ipvs = cp->ipvs;
138 
139 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
140 		struct ip_vs_cpu_stats *s;
141 		struct ip_vs_service *svc;
142 
143 		local_bh_disable();
144 
145 		s = this_cpu_ptr(dest->stats.cpustats);
146 		u64_stats_update_begin(&s->syncp);
147 		s->cnt.inpkts++;
148 		s->cnt.inbytes += skb->len;
149 		u64_stats_update_end(&s->syncp);
150 
151 		svc = rcu_dereference(dest->svc);
152 		s = this_cpu_ptr(svc->stats.cpustats);
153 		u64_stats_update_begin(&s->syncp);
154 		s->cnt.inpkts++;
155 		s->cnt.inbytes += skb->len;
156 		u64_stats_update_end(&s->syncp);
157 
158 		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
159 		u64_stats_update_begin(&s->syncp);
160 		s->cnt.inpkts++;
161 		s->cnt.inbytes += skb->len;
162 		u64_stats_update_end(&s->syncp);
163 
164 		local_bh_enable();
165 	}
166 }
167 
168 
169 static inline void
ip_vs_out_stats(struct ip_vs_conn * cp,struct sk_buff * skb)170 ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
171 {
172 	struct ip_vs_dest *dest = cp->dest;
173 	struct netns_ipvs *ipvs = cp->ipvs;
174 
175 	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
176 		struct ip_vs_cpu_stats *s;
177 		struct ip_vs_service *svc;
178 
179 		local_bh_disable();
180 
181 		s = this_cpu_ptr(dest->stats.cpustats);
182 		u64_stats_update_begin(&s->syncp);
183 		s->cnt.outpkts++;
184 		s->cnt.outbytes += skb->len;
185 		u64_stats_update_end(&s->syncp);
186 
187 		svc = rcu_dereference(dest->svc);
188 		s = this_cpu_ptr(svc->stats.cpustats);
189 		u64_stats_update_begin(&s->syncp);
190 		s->cnt.outpkts++;
191 		s->cnt.outbytes += skb->len;
192 		u64_stats_update_end(&s->syncp);
193 
194 		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
195 		u64_stats_update_begin(&s->syncp);
196 		s->cnt.outpkts++;
197 		s->cnt.outbytes += skb->len;
198 		u64_stats_update_end(&s->syncp);
199 
200 		local_bh_enable();
201 	}
202 }
203 
204 
205 static inline void
ip_vs_conn_stats(struct ip_vs_conn * cp,struct ip_vs_service * svc)206 ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
207 {
208 	struct netns_ipvs *ipvs = svc->ipvs;
209 	struct ip_vs_cpu_stats *s;
210 
211 	local_bh_disable();
212 
213 	s = this_cpu_ptr(cp->dest->stats.cpustats);
214 	u64_stats_update_begin(&s->syncp);
215 	s->cnt.conns++;
216 	u64_stats_update_end(&s->syncp);
217 
218 	s = this_cpu_ptr(svc->stats.cpustats);
219 	u64_stats_update_begin(&s->syncp);
220 	s->cnt.conns++;
221 	u64_stats_update_end(&s->syncp);
222 
223 	s = this_cpu_ptr(ipvs->tot_stats.cpustats);
224 	u64_stats_update_begin(&s->syncp);
225 	s->cnt.conns++;
226 	u64_stats_update_end(&s->syncp);
227 
228 	local_bh_enable();
229 }
230 
231 
232 static inline void
ip_vs_set_state(struct ip_vs_conn * cp,int direction,const struct sk_buff * skb,struct ip_vs_proto_data * pd)233 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
234 		const struct sk_buff *skb,
235 		struct ip_vs_proto_data *pd)
236 {
237 	if (likely(pd->pp->state_transition))
238 		pd->pp->state_transition(cp, direction, skb, pd);
239 }
240 
241 static inline int
ip_vs_conn_fill_param_persist(const struct ip_vs_service * svc,struct sk_buff * skb,int protocol,const union nf_inet_addr * caddr,__be16 cport,const union nf_inet_addr * vaddr,__be16 vport,struct ip_vs_conn_param * p)242 ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
243 			      struct sk_buff *skb, int protocol,
244 			      const union nf_inet_addr *caddr, __be16 cport,
245 			      const union nf_inet_addr *vaddr, __be16 vport,
246 			      struct ip_vs_conn_param *p)
247 {
248 	ip_vs_conn_fill_param(svc->ipvs, svc->af, protocol, caddr, cport, vaddr,
249 			      vport, p);
250 	p->pe = rcu_dereference(svc->pe);
251 	if (p->pe && p->pe->fill_param)
252 		return p->pe->fill_param(p, skb);
253 
254 	return 0;
255 }
256 
257 /*
258  *  IPVS persistent scheduling function
259  *  It creates a connection entry according to its template if exists,
260  *  or selects a server and creates a connection entry plus a template.
261  *  Locking: we are svc user (svc->refcnt), so we hold all dests too
262  *  Protocols supported: TCP, UDP
263  */
264 static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service * svc,struct sk_buff * skb,__be16 src_port,__be16 dst_port,int * ignored,struct ip_vs_iphdr * iph)265 ip_vs_sched_persist(struct ip_vs_service *svc,
266 		    struct sk_buff *skb, __be16 src_port, __be16 dst_port,
267 		    int *ignored, struct ip_vs_iphdr *iph)
268 {
269 	struct ip_vs_conn *cp = NULL;
270 	struct ip_vs_dest *dest;
271 	struct ip_vs_conn *ct;
272 	__be16 dport = 0;		/* destination port to forward */
273 	unsigned int flags;
274 	struct ip_vs_conn_param param;
275 	const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
276 	union nf_inet_addr snet;	/* source network of the client,
277 					   after masking */
278 	const union nf_inet_addr *src_addr, *dst_addr;
279 
280 	if (likely(!ip_vs_iph_inverse(iph))) {
281 		src_addr = &iph->saddr;
282 		dst_addr = &iph->daddr;
283 	} else {
284 		src_addr = &iph->daddr;
285 		dst_addr = &iph->saddr;
286 	}
287 
288 
289 	/* Mask saddr with the netmask to adjust template granularity */
290 #ifdef CONFIG_IP_VS_IPV6
291 	if (svc->af == AF_INET6)
292 		ipv6_addr_prefix(&snet.in6, &src_addr->in6,
293 				 (__force __u32) svc->netmask);
294 	else
295 #endif
296 		snet.ip = src_addr->ip & svc->netmask;
297 
298 	IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
299 		      "mnet %s\n",
300 		      IP_VS_DBG_ADDR(svc->af, src_addr), ntohs(src_port),
301 		      IP_VS_DBG_ADDR(svc->af, dst_addr), ntohs(dst_port),
302 		      IP_VS_DBG_ADDR(svc->af, &snet));
303 
304 	/*
305 	 * As far as we know, FTP is a very complicated network protocol, and
306 	 * it uses control connection and data connections. For active FTP,
307 	 * FTP server initialize data connection to the client, its source port
308 	 * is often 20. For passive FTP, FTP server tells the clients the port
309 	 * that it passively listens to,  and the client issues the data
310 	 * connection. In the tunneling or direct routing mode, the load
311 	 * balancer is on the client-to-server half of connection, the port
312 	 * number is unknown to the load balancer. So, a conn template like
313 	 * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
314 	 * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
315 	 * is created for other persistent services.
316 	 */
317 	{
318 		int protocol = iph->protocol;
319 		const union nf_inet_addr *vaddr = dst_addr;
320 		__be16 vport = 0;
321 
322 		if (dst_port == svc->port) {
323 			/* non-FTP template:
324 			 * <protocol, caddr, 0, vaddr, vport, daddr, dport>
325 			 * FTP template:
326 			 * <protocol, caddr, 0, vaddr, 0, daddr, 0>
327 			 */
328 			if (svc->port != FTPPORT)
329 				vport = dst_port;
330 		} else {
331 			/* Note: persistent fwmark-based services and
332 			 * persistent port zero service are handled here.
333 			 * fwmark template:
334 			 * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
335 			 * port zero template:
336 			 * <protocol,caddr,0,vaddr,0,daddr,0>
337 			 */
338 			if (svc->fwmark) {
339 				protocol = IPPROTO_IP;
340 				vaddr = &fwmark;
341 			}
342 		}
343 		/* return *ignored = -1 so NF_DROP can be used */
344 		if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
345 						  vaddr, vport, &param) < 0) {
346 			*ignored = -1;
347 			return NULL;
348 		}
349 	}
350 
351 	/* Check if a template already exists */
352 	ct = ip_vs_ct_in_get(&param);
353 	if (!ct || !ip_vs_check_template(ct, NULL)) {
354 		struct ip_vs_scheduler *sched;
355 
356 		/*
357 		 * No template found or the dest of the connection
358 		 * template is not available.
359 		 * return *ignored=0 i.e. ICMP and NF_DROP
360 		 */
361 		sched = rcu_dereference(svc->scheduler);
362 		if (sched) {
363 			/* read svc->sched_data after svc->scheduler */
364 			smp_rmb();
365 			dest = sched->schedule(svc, skb, iph);
366 		} else {
367 			dest = NULL;
368 		}
369 		if (!dest) {
370 			IP_VS_DBG(1, "p-schedule: no dest found.\n");
371 			kfree(param.pe_data);
372 			*ignored = 0;
373 			return NULL;
374 		}
375 
376 		if (dst_port == svc->port && svc->port != FTPPORT)
377 			dport = dest->port;
378 
379 		/* Create a template
380 		 * This adds param.pe_data to the template,
381 		 * and thus param.pe_data will be destroyed
382 		 * when the template expires */
383 		ct = ip_vs_conn_new(&param, dest->af, &dest->addr, dport,
384 				    IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
385 		if (ct == NULL) {
386 			kfree(param.pe_data);
387 			*ignored = -1;
388 			return NULL;
389 		}
390 
391 		ct->timeout = svc->timeout;
392 	} else {
393 		/* set destination with the found template */
394 		dest = ct->dest;
395 		kfree(param.pe_data);
396 	}
397 
398 	dport = dst_port;
399 	if (dport == svc->port && dest->port)
400 		dport = dest->port;
401 
402 	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
403 		 && iph->protocol == IPPROTO_UDP) ?
404 		IP_VS_CONN_F_ONE_PACKET : 0;
405 
406 	/*
407 	 *    Create a new connection according to the template
408 	 */
409 	ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol, src_addr,
410 			      src_port, dst_addr, dst_port, &param);
411 
412 	cp = ip_vs_conn_new(&param, dest->af, &dest->addr, dport, flags, dest,
413 			    skb->mark);
414 	if (cp == NULL) {
415 		ip_vs_conn_put(ct);
416 		*ignored = -1;
417 		return NULL;
418 	}
419 
420 	/*
421 	 *    Add its control
422 	 */
423 	ip_vs_control_add(cp, ct);
424 	ip_vs_conn_put(ct);
425 
426 	ip_vs_conn_stats(cp, svc);
427 	return cp;
428 }
429 
430 
431 /*
432  *  IPVS main scheduling function
433  *  It selects a server according to the virtual service, and
434  *  creates a connection entry.
435  *  Protocols supported: TCP, UDP
436  *
437  *  Usage of *ignored
438  *
439  * 1 :   protocol tried to schedule (eg. on SYN), found svc but the
440  *       svc/scheduler decides that this packet should be accepted with
441  *       NF_ACCEPT because it must not be scheduled.
442  *
443  * 0 :   scheduler can not find destination, so try bypass or
444  *       return ICMP and then NF_DROP (ip_vs_leave).
445  *
446  * -1 :  scheduler tried to schedule but fatal error occurred, eg.
447  *       ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
448  *       failure such as missing Call-ID, ENOMEM on skb_linearize
449  *       or pe_data. In this case we should return NF_DROP without
450  *       any attempts to send ICMP with ip_vs_leave.
451  */
452 struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service * svc,struct sk_buff * skb,struct ip_vs_proto_data * pd,int * ignored,struct ip_vs_iphdr * iph)453 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
454 	       struct ip_vs_proto_data *pd, int *ignored,
455 	       struct ip_vs_iphdr *iph)
456 {
457 	struct ip_vs_protocol *pp = pd->pp;
458 	struct ip_vs_conn *cp = NULL;
459 	struct ip_vs_scheduler *sched;
460 	struct ip_vs_dest *dest;
461 	__be16 _ports[2], *pptr, cport, vport;
462 	const void *caddr, *vaddr;
463 	unsigned int flags;
464 
465 	*ignored = 1;
466 	/*
467 	 * IPv6 frags, only the first hit here.
468 	 */
469 	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
470 	if (pptr == NULL)
471 		return NULL;
472 
473 	if (likely(!ip_vs_iph_inverse(iph))) {
474 		cport = pptr[0];
475 		caddr = &iph->saddr;
476 		vport = pptr[1];
477 		vaddr = &iph->daddr;
478 	} else {
479 		cport = pptr[1];
480 		caddr = &iph->daddr;
481 		vport = pptr[0];
482 		vaddr = &iph->saddr;
483 	}
484 
485 	/*
486 	 * FTPDATA needs this check when using local real server.
487 	 * Never schedule Active FTPDATA connections from real server.
488 	 * For LVS-NAT they must be already created. For other methods
489 	 * with persistence the connection is created on SYN+ACK.
490 	 */
491 	if (cport == FTPDATA) {
492 		IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off,
493 			      "Not scheduling FTPDATA");
494 		return NULL;
495 	}
496 
497 	/*
498 	 *    Do not schedule replies from local real server.
499 	 */
500 	if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK)) {
501 		iph->hdr_flags ^= IP_VS_HDR_INVERSE;
502 		cp = INDIRECT_CALL_1(pp->conn_in_get,
503 				     ip_vs_conn_in_get_proto, svc->ipvs,
504 				     svc->af, skb, iph);
505 		iph->hdr_flags ^= IP_VS_HDR_INVERSE;
506 
507 		if (cp) {
508 			IP_VS_DBG_PKT(12, svc->af, pp, skb, iph->off,
509 				      "Not scheduling reply for existing"
510 				      " connection");
511 			__ip_vs_conn_put(cp);
512 			return NULL;
513 		}
514 	}
515 
516 	/*
517 	 *    Persistent service
518 	 */
519 	if (svc->flags & IP_VS_SVC_F_PERSISTENT)
520 		return ip_vs_sched_persist(svc, skb, cport, vport, ignored,
521 					   iph);
522 
523 	*ignored = 0;
524 
525 	/*
526 	 *    Non-persistent service
527 	 */
528 	if (!svc->fwmark && vport != svc->port) {
529 		if (!svc->port)
530 			pr_err("Schedule: port zero only supported "
531 			       "in persistent services, "
532 			       "check your ipvs configuration\n");
533 		return NULL;
534 	}
535 
536 	sched = rcu_dereference(svc->scheduler);
537 	if (sched) {
538 		/* read svc->sched_data after svc->scheduler */
539 		smp_rmb();
540 		dest = sched->schedule(svc, skb, iph);
541 	} else {
542 		dest = NULL;
543 	}
544 	if (dest == NULL) {
545 		IP_VS_DBG(1, "Schedule: no dest found.\n");
546 		return NULL;
547 	}
548 
549 	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
550 		 && iph->protocol == IPPROTO_UDP) ?
551 		IP_VS_CONN_F_ONE_PACKET : 0;
552 
553 	/*
554 	 *    Create a connection entry.
555 	 */
556 	{
557 		struct ip_vs_conn_param p;
558 
559 		ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
560 				      caddr, cport, vaddr, vport, &p);
561 		cp = ip_vs_conn_new(&p, dest->af, &dest->addr,
562 				    dest->port ? dest->port : vport,
563 				    flags, dest, skb->mark);
564 		if (!cp) {
565 			*ignored = -1;
566 			return NULL;
567 		}
568 	}
569 
570 	IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
571 		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
572 		      ip_vs_fwd_tag(cp),
573 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
574 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
575 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
576 		      cp->flags, refcount_read(&cp->refcnt));
577 
578 	ip_vs_conn_stats(cp, svc);
579 	return cp;
580 }
581 
ip_vs_addr_is_unicast(struct net * net,int af,union nf_inet_addr * addr)582 static inline int ip_vs_addr_is_unicast(struct net *net, int af,
583 					union nf_inet_addr *addr)
584 {
585 #ifdef CONFIG_IP_VS_IPV6
586 	if (af == AF_INET6)
587 		return ipv6_addr_type(&addr->in6) & IPV6_ADDR_UNICAST;
588 #endif
589 	return (inet_addr_type(net, addr->ip) == RTN_UNICAST);
590 }
591 
592 /*
593  *  Pass or drop the packet.
594  *  Called by ip_vs_in, when the virtual service is available but
595  *  no destination is available for a new connection.
596  */
ip_vs_leave(struct ip_vs_service * svc,struct sk_buff * skb,struct ip_vs_proto_data * pd,struct ip_vs_iphdr * iph)597 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
598 		struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
599 {
600 	__be16 _ports[2], *pptr, dport;
601 	struct netns_ipvs *ipvs = svc->ipvs;
602 	struct net *net = ipvs->net;
603 
604 	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
605 	if (!pptr)
606 		return NF_DROP;
607 	dport = likely(!ip_vs_iph_inverse(iph)) ? pptr[1] : pptr[0];
608 
609 	/* if it is fwmark-based service, the cache_bypass sysctl is up
610 	   and the destination is a non-local unicast, then create
611 	   a cache_bypass connection entry */
612 	if (sysctl_cache_bypass(ipvs) && svc->fwmark &&
613 	    !(iph->hdr_flags & (IP_VS_HDR_INVERSE | IP_VS_HDR_ICMP)) &&
614 	    ip_vs_addr_is_unicast(net, svc->af, &iph->daddr)) {
615 		int ret;
616 		struct ip_vs_conn *cp;
617 		unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
618 				      iph->protocol == IPPROTO_UDP) ?
619 				      IP_VS_CONN_F_ONE_PACKET : 0;
620 		union nf_inet_addr daddr = { .all = { 0, 0, 0, 0 } };
621 
622 		/* create a new connection entry */
623 		IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
624 		{
625 			struct ip_vs_conn_param p;
626 			ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
627 					      &iph->saddr, pptr[0],
628 					      &iph->daddr, pptr[1], &p);
629 			cp = ip_vs_conn_new(&p, svc->af, &daddr, 0,
630 					    IP_VS_CONN_F_BYPASS | flags,
631 					    NULL, skb->mark);
632 			if (!cp)
633 				return NF_DROP;
634 		}
635 
636 		/* statistics */
637 		ip_vs_in_stats(cp, skb);
638 
639 		/* set state */
640 		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
641 
642 		/* transmit the first SYN packet */
643 		ret = cp->packet_xmit(skb, cp, pd->pp, iph);
644 		/* do not touch skb anymore */
645 
646 		if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
647 			atomic_inc(&cp->control->in_pkts);
648 		else
649 			atomic_inc(&cp->in_pkts);
650 		ip_vs_conn_put(cp);
651 		return ret;
652 	}
653 
654 	/*
655 	 * When the virtual ftp service is presented, packets destined
656 	 * for other services on the VIP may get here (except services
657 	 * listed in the ipvs table), pass the packets, because it is
658 	 * not ipvs job to decide to drop the packets.
659 	 */
660 	if (svc->port == FTPPORT && dport != FTPPORT)
661 		return NF_ACCEPT;
662 
663 	if (unlikely(ip_vs_iph_icmp(iph)))
664 		return NF_DROP;
665 
666 	/*
667 	 * Notify the client that the destination is unreachable, and
668 	 * release the socket buffer.
669 	 * Since it is in IP layer, the TCP socket is not actually
670 	 * created, the TCP RST packet cannot be sent, instead that
671 	 * ICMP_PORT_UNREACH is sent here no matter it is TCP/UDP. --WZ
672 	 */
673 #ifdef CONFIG_IP_VS_IPV6
674 	if (svc->af == AF_INET6) {
675 		if (!skb->dev)
676 			skb->dev = net->loopback_dev;
677 		icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
678 	} else
679 #endif
680 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
681 
682 	return NF_DROP;
683 }
684 
685 #ifdef CONFIG_SYSCTL
686 
sysctl_snat_reroute(struct netns_ipvs * ipvs)687 static int sysctl_snat_reroute(struct netns_ipvs *ipvs)
688 {
689 	return ipvs->sysctl_snat_reroute;
690 }
691 
sysctl_nat_icmp_send(struct netns_ipvs * ipvs)692 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs)
693 {
694 	return ipvs->sysctl_nat_icmp_send;
695 }
696 
sysctl_expire_nodest_conn(struct netns_ipvs * ipvs)697 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs)
698 {
699 	return ipvs->sysctl_expire_nodest_conn;
700 }
701 
702 #else
703 
sysctl_snat_reroute(struct netns_ipvs * ipvs)704 static int sysctl_snat_reroute(struct netns_ipvs *ipvs) { return 0; }
sysctl_nat_icmp_send(struct netns_ipvs * ipvs)705 static int sysctl_nat_icmp_send(struct netns_ipvs *ipvs) { return 0; }
sysctl_expire_nodest_conn(struct netns_ipvs * ipvs)706 static int sysctl_expire_nodest_conn(struct netns_ipvs *ipvs) { return 0; }
707 
708 #endif
709 
ip_vs_checksum_complete(struct sk_buff * skb,int offset)710 __sum16 ip_vs_checksum_complete(struct sk_buff *skb, int offset)
711 {
712 	return csum_fold(skb_checksum(skb, offset, skb->len - offset, 0));
713 }
714 
ip_vs_defrag_user(unsigned int hooknum)715 static inline enum ip_defrag_users ip_vs_defrag_user(unsigned int hooknum)
716 {
717 	if (NF_INET_LOCAL_IN == hooknum)
718 		return IP_DEFRAG_VS_IN;
719 	if (NF_INET_FORWARD == hooknum)
720 		return IP_DEFRAG_VS_FWD;
721 	return IP_DEFRAG_VS_OUT;
722 }
723 
ip_vs_gather_frags(struct netns_ipvs * ipvs,struct sk_buff * skb,u_int32_t user)724 static inline int ip_vs_gather_frags(struct netns_ipvs *ipvs,
725 				     struct sk_buff *skb, u_int32_t user)
726 {
727 	int err;
728 
729 	local_bh_disable();
730 	err = ip_defrag(ipvs->net, skb, user);
731 	local_bh_enable();
732 	if (!err)
733 		ip_send_check(ip_hdr(skb));
734 
735 	return err;
736 }
737 
ip_vs_route_me_harder(struct netns_ipvs * ipvs,int af,struct sk_buff * skb,unsigned int hooknum)738 static int ip_vs_route_me_harder(struct netns_ipvs *ipvs, int af,
739 				 struct sk_buff *skb, unsigned int hooknum)
740 {
741 	if (!sysctl_snat_reroute(ipvs))
742 		return 0;
743 	/* Reroute replies only to remote clients (FORWARD and LOCAL_OUT) */
744 	if (NF_INET_LOCAL_IN == hooknum)
745 		return 0;
746 #ifdef CONFIG_IP_VS_IPV6
747 	if (af == AF_INET6) {
748 		struct dst_entry *dst = skb_dst(skb);
749 
750 		if (dst->dev && !(dst->dev->flags & IFF_LOOPBACK) &&
751 		    ip6_route_me_harder(ipvs->net, skb) != 0)
752 			return 1;
753 	} else
754 #endif
755 		if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL) &&
756 		    ip_route_me_harder(ipvs->net, skb, RTN_LOCAL) != 0)
757 			return 1;
758 
759 	return 0;
760 }
761 
762 /*
763  * Packet has been made sufficiently writable in caller
764  * - inout: 1=in->out, 0=out->in
765  */
ip_vs_nat_icmp(struct sk_buff * skb,struct ip_vs_protocol * pp,struct ip_vs_conn * cp,int inout)766 void ip_vs_nat_icmp(struct sk_buff *skb, struct ip_vs_protocol *pp,
767 		    struct ip_vs_conn *cp, int inout)
768 {
769 	struct iphdr *iph	 = ip_hdr(skb);
770 	unsigned int icmp_offset = iph->ihl*4;
771 	struct icmphdr *icmph	 = (struct icmphdr *)(skb_network_header(skb) +
772 						      icmp_offset);
773 	struct iphdr *ciph	 = (struct iphdr *)(icmph + 1);
774 
775 	if (inout) {
776 		iph->saddr = cp->vaddr.ip;
777 		ip_send_check(iph);
778 		ciph->daddr = cp->vaddr.ip;
779 		ip_send_check(ciph);
780 	} else {
781 		iph->daddr = cp->daddr.ip;
782 		ip_send_check(iph);
783 		ciph->saddr = cp->daddr.ip;
784 		ip_send_check(ciph);
785 	}
786 
787 	/* the TCP/UDP/SCTP port */
788 	if (IPPROTO_TCP == ciph->protocol || IPPROTO_UDP == ciph->protocol ||
789 	    IPPROTO_SCTP == ciph->protocol) {
790 		__be16 *ports = (void *)ciph + ciph->ihl*4;
791 
792 		if (inout)
793 			ports[1] = cp->vport;
794 		else
795 			ports[0] = cp->dport;
796 	}
797 
798 	/* And finally the ICMP checksum */
799 	icmph->checksum = 0;
800 	icmph->checksum = ip_vs_checksum_complete(skb, icmp_offset);
801 	skb->ip_summed = CHECKSUM_UNNECESSARY;
802 
803 	if (inout)
804 		IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
805 			"Forwarding altered outgoing ICMP");
806 	else
807 		IP_VS_DBG_PKT(11, AF_INET, pp, skb, (void *)ciph - (void *)iph,
808 			"Forwarding altered incoming ICMP");
809 }
810 
811 #ifdef CONFIG_IP_VS_IPV6
ip_vs_nat_icmp_v6(struct sk_buff * skb,struct ip_vs_protocol * pp,struct ip_vs_conn * cp,int inout)812 void ip_vs_nat_icmp_v6(struct sk_buff *skb, struct ip_vs_protocol *pp,
813 		    struct ip_vs_conn *cp, int inout)
814 {
815 	struct ipv6hdr *iph	 = ipv6_hdr(skb);
816 	unsigned int icmp_offset = 0;
817 	unsigned int offs	 = 0; /* header offset*/
818 	int protocol;
819 	struct icmp6hdr *icmph;
820 	struct ipv6hdr *ciph;
821 	unsigned short fragoffs;
822 
823 	ipv6_find_hdr(skb, &icmp_offset, IPPROTO_ICMPV6, &fragoffs, NULL);
824 	icmph = (struct icmp6hdr *)(skb_network_header(skb) + icmp_offset);
825 	offs = icmp_offset + sizeof(struct icmp6hdr);
826 	ciph = (struct ipv6hdr *)(skb_network_header(skb) + offs);
827 
828 	protocol = ipv6_find_hdr(skb, &offs, -1, &fragoffs, NULL);
829 
830 	if (inout) {
831 		iph->saddr = cp->vaddr.in6;
832 		ciph->daddr = cp->vaddr.in6;
833 	} else {
834 		iph->daddr = cp->daddr.in6;
835 		ciph->saddr = cp->daddr.in6;
836 	}
837 
838 	/* the TCP/UDP/SCTP port */
839 	if (!fragoffs && (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
840 			  IPPROTO_SCTP == protocol)) {
841 		__be16 *ports = (void *)(skb_network_header(skb) + offs);
842 
843 		IP_VS_DBG(11, "%s() changed port %d to %d\n", __func__,
844 			      ntohs(inout ? ports[1] : ports[0]),
845 			      ntohs(inout ? cp->vport : cp->dport));
846 		if (inout)
847 			ports[1] = cp->vport;
848 		else
849 			ports[0] = cp->dport;
850 	}
851 
852 	/* And finally the ICMP checksum */
853 	icmph->icmp6_cksum = ~csum_ipv6_magic(&iph->saddr, &iph->daddr,
854 					      skb->len - icmp_offset,
855 					      IPPROTO_ICMPV6, 0);
856 	skb->csum_start = skb_network_header(skb) - skb->head + icmp_offset;
857 	skb->csum_offset = offsetof(struct icmp6hdr, icmp6_cksum);
858 	skb->ip_summed = CHECKSUM_PARTIAL;
859 
860 	if (inout)
861 		IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
862 			      (void *)ciph - (void *)iph,
863 			      "Forwarding altered outgoing ICMPv6");
864 	else
865 		IP_VS_DBG_PKT(11, AF_INET6, pp, skb,
866 			      (void *)ciph - (void *)iph,
867 			      "Forwarding altered incoming ICMPv6");
868 }
869 #endif
870 
871 /* Handle relevant response ICMP messages - forward to the right
872  * destination host.
873  */
handle_response_icmp(int af,struct sk_buff * skb,union nf_inet_addr * snet,__u8 protocol,struct ip_vs_conn * cp,struct ip_vs_protocol * pp,unsigned int offset,unsigned int ihl,unsigned int hooknum)874 static int handle_response_icmp(int af, struct sk_buff *skb,
875 				union nf_inet_addr *snet,
876 				__u8 protocol, struct ip_vs_conn *cp,
877 				struct ip_vs_protocol *pp,
878 				unsigned int offset, unsigned int ihl,
879 				unsigned int hooknum)
880 {
881 	unsigned int verdict = NF_DROP;
882 
883 	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
884 		goto ignore_cp;
885 
886 	/* Ensure the checksum is correct */
887 	if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
888 		/* Failed checksum! */
889 		IP_VS_DBG_BUF(1, "Forward ICMP: failed checksum from %s!\n",
890 			      IP_VS_DBG_ADDR(af, snet));
891 		goto out;
892 	}
893 
894 	if (IPPROTO_TCP == protocol || IPPROTO_UDP == protocol ||
895 	    IPPROTO_SCTP == protocol)
896 		offset += 2 * sizeof(__u16);
897 	if (skb_ensure_writable(skb, offset))
898 		goto out;
899 
900 #ifdef CONFIG_IP_VS_IPV6
901 	if (af == AF_INET6)
902 		ip_vs_nat_icmp_v6(skb, pp, cp, 1);
903 	else
904 #endif
905 		ip_vs_nat_icmp(skb, pp, cp, 1);
906 
907 	if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum))
908 		goto out;
909 
910 	/* do the statistics and put it back */
911 	ip_vs_out_stats(cp, skb);
912 
913 	skb->ipvs_property = 1;
914 	if (!(cp->flags & IP_VS_CONN_F_NFCT))
915 		ip_vs_notrack(skb);
916 	else
917 		ip_vs_update_conntrack(skb, cp, 0);
918 
919 ignore_cp:
920 	verdict = NF_ACCEPT;
921 
922 out:
923 	__ip_vs_conn_put(cp);
924 
925 	return verdict;
926 }
927 
928 /*
929  *	Handle ICMP messages in the inside-to-outside direction (outgoing).
930  *	Find any that might be relevant, check against existing connections.
931  *	Currently handles error types - unreachable, quench, ttl exceeded.
932  */
ip_vs_out_icmp(struct netns_ipvs * ipvs,struct sk_buff * skb,int * related,unsigned int hooknum)933 static int ip_vs_out_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb,
934 			  int *related, unsigned int hooknum)
935 {
936 	struct iphdr *iph;
937 	struct icmphdr	_icmph, *ic;
938 	struct iphdr	_ciph, *cih;	/* The ip header contained within the ICMP */
939 	struct ip_vs_iphdr ciph;
940 	struct ip_vs_conn *cp;
941 	struct ip_vs_protocol *pp;
942 	unsigned int offset, ihl;
943 	union nf_inet_addr snet;
944 
945 	*related = 1;
946 
947 	/* reassemble IP fragments */
948 	if (ip_is_fragment(ip_hdr(skb))) {
949 		if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum)))
950 			return NF_STOLEN;
951 	}
952 
953 	iph = ip_hdr(skb);
954 	offset = ihl = iph->ihl * 4;
955 	ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
956 	if (ic == NULL)
957 		return NF_DROP;
958 
959 	IP_VS_DBG(12, "Outgoing ICMP (%d,%d) %pI4->%pI4\n",
960 		  ic->type, ntohs(icmp_id(ic)),
961 		  &iph->saddr, &iph->daddr);
962 
963 	/*
964 	 * Work through seeing if this is for us.
965 	 * These checks are supposed to be in an order that means easy
966 	 * things are checked first to speed up processing.... however
967 	 * this means that some packets will manage to get a long way
968 	 * down this stack and then be rejected, but that's life.
969 	 */
970 	if ((ic->type != ICMP_DEST_UNREACH) &&
971 	    (ic->type != ICMP_SOURCE_QUENCH) &&
972 	    (ic->type != ICMP_TIME_EXCEEDED)) {
973 		*related = 0;
974 		return NF_ACCEPT;
975 	}
976 
977 	/* Now find the contained IP header */
978 	offset += sizeof(_icmph);
979 	cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
980 	if (cih == NULL)
981 		return NF_ACCEPT; /* The packet looks wrong, ignore */
982 
983 	pp = ip_vs_proto_get(cih->protocol);
984 	if (!pp)
985 		return NF_ACCEPT;
986 
987 	/* Is the embedded protocol header present? */
988 	if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
989 		     pp->dont_defrag))
990 		return NF_ACCEPT;
991 
992 	IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
993 		      "Checking outgoing ICMP for");
994 
995 	ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, true, &ciph);
996 
997 	/* The embedded headers contain source and dest in reverse order */
998 	cp = INDIRECT_CALL_1(pp->conn_out_get, ip_vs_conn_out_get_proto,
999 			     ipvs, AF_INET, skb, &ciph);
1000 	if (!cp)
1001 		return NF_ACCEPT;
1002 
1003 	snet.ip = iph->saddr;
1004 	return handle_response_icmp(AF_INET, skb, &snet, cih->protocol, cp,
1005 				    pp, ciph.len, ihl, hooknum);
1006 }
1007 
1008 #ifdef CONFIG_IP_VS_IPV6
ip_vs_out_icmp_v6(struct netns_ipvs * ipvs,struct sk_buff * skb,int * related,unsigned int hooknum,struct ip_vs_iphdr * ipvsh)1009 static int ip_vs_out_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
1010 			     int *related,  unsigned int hooknum,
1011 			     struct ip_vs_iphdr *ipvsh)
1012 {
1013 	struct icmp6hdr	_icmph, *ic;
1014 	struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
1015 	struct ip_vs_conn *cp;
1016 	struct ip_vs_protocol *pp;
1017 	union nf_inet_addr snet;
1018 	unsigned int offset;
1019 
1020 	*related = 1;
1021 	ic = frag_safe_skb_hp(skb, ipvsh->len, sizeof(_icmph), &_icmph);
1022 	if (ic == NULL)
1023 		return NF_DROP;
1024 
1025 	/*
1026 	 * Work through seeing if this is for us.
1027 	 * These checks are supposed to be in an order that means easy
1028 	 * things are checked first to speed up processing.... however
1029 	 * this means that some packets will manage to get a long way
1030 	 * down this stack and then be rejected, but that's life.
1031 	 */
1032 	if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
1033 		*related = 0;
1034 		return NF_ACCEPT;
1035 	}
1036 	/* Fragment header that is before ICMP header tells us that:
1037 	 * it's not an error message since they can't be fragmented.
1038 	 */
1039 	if (ipvsh->flags & IP6_FH_F_FRAG)
1040 		return NF_DROP;
1041 
1042 	IP_VS_DBG(8, "Outgoing ICMPv6 (%d,%d) %pI6c->%pI6c\n",
1043 		  ic->icmp6_type, ntohs(icmpv6_id(ic)),
1044 		  &ipvsh->saddr, &ipvsh->daddr);
1045 
1046 	if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, ipvsh->len + sizeof(_icmph),
1047 				     true, &ciph))
1048 		return NF_ACCEPT; /* The packet looks wrong, ignore */
1049 
1050 	pp = ip_vs_proto_get(ciph.protocol);
1051 	if (!pp)
1052 		return NF_ACCEPT;
1053 
1054 	/* The embedded headers contain source and dest in reverse order */
1055 	cp = INDIRECT_CALL_1(pp->conn_out_get, ip_vs_conn_out_get_proto,
1056 			     ipvs, AF_INET6, skb, &ciph);
1057 	if (!cp)
1058 		return NF_ACCEPT;
1059 
1060 	snet.in6 = ciph.saddr.in6;
1061 	offset = ciph.len;
1062 	return handle_response_icmp(AF_INET6, skb, &snet, ciph.protocol, cp,
1063 				    pp, offset, sizeof(struct ipv6hdr),
1064 				    hooknum);
1065 }
1066 #endif
1067 
1068 /*
1069  * Check if sctp chunc is ABORT chunk
1070  */
is_sctp_abort(const struct sk_buff * skb,int nh_len)1071 static inline int is_sctp_abort(const struct sk_buff *skb, int nh_len)
1072 {
1073 	struct sctp_chunkhdr *sch, schunk;
1074 	sch = skb_header_pointer(skb, nh_len + sizeof(struct sctphdr),
1075 				 sizeof(schunk), &schunk);
1076 	if (sch == NULL)
1077 		return 0;
1078 	if (sch->type == SCTP_CID_ABORT)
1079 		return 1;
1080 	return 0;
1081 }
1082 
is_tcp_reset(const struct sk_buff * skb,int nh_len)1083 static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
1084 {
1085 	struct tcphdr _tcph, *th;
1086 
1087 	th = skb_header_pointer(skb, nh_len, sizeof(_tcph), &_tcph);
1088 	if (th == NULL)
1089 		return 0;
1090 	return th->rst;
1091 }
1092 
is_new_conn(const struct sk_buff * skb,struct ip_vs_iphdr * iph)1093 static inline bool is_new_conn(const struct sk_buff *skb,
1094 			       struct ip_vs_iphdr *iph)
1095 {
1096 	switch (iph->protocol) {
1097 	case IPPROTO_TCP: {
1098 		struct tcphdr _tcph, *th;
1099 
1100 		th = skb_header_pointer(skb, iph->len, sizeof(_tcph), &_tcph);
1101 		if (th == NULL)
1102 			return false;
1103 		return th->syn;
1104 	}
1105 	case IPPROTO_SCTP: {
1106 		struct sctp_chunkhdr *sch, schunk;
1107 
1108 		sch = skb_header_pointer(skb, iph->len + sizeof(struct sctphdr),
1109 					 sizeof(schunk), &schunk);
1110 		if (sch == NULL)
1111 			return false;
1112 		return sch->type == SCTP_CID_INIT;
1113 	}
1114 	default:
1115 		return false;
1116 	}
1117 }
1118 
is_new_conn_expected(const struct ip_vs_conn * cp,int conn_reuse_mode)1119 static inline bool is_new_conn_expected(const struct ip_vs_conn *cp,
1120 					int conn_reuse_mode)
1121 {
1122 	/* Controlled (FTP DATA or persistence)? */
1123 	if (cp->control)
1124 		return false;
1125 
1126 	switch (cp->protocol) {
1127 	case IPPROTO_TCP:
1128 		return (cp->state == IP_VS_TCP_S_TIME_WAIT) ||
1129 		       (cp->state == IP_VS_TCP_S_CLOSE) ||
1130 			((conn_reuse_mode & 2) &&
1131 			 (cp->state == IP_VS_TCP_S_FIN_WAIT) &&
1132 			 (cp->flags & IP_VS_CONN_F_NOOUTPUT));
1133 	case IPPROTO_SCTP:
1134 		return cp->state == IP_VS_SCTP_S_CLOSED;
1135 	default:
1136 		return false;
1137 	}
1138 }
1139 
1140 /* Generic function to create new connections for outgoing RS packets
1141  *
1142  * Pre-requisites for successful connection creation:
1143  * 1) Virtual Service is NOT fwmark based:
1144  *    In fwmark-VS actual vaddr and vport are unknown to IPVS
1145  * 2) Real Server and Virtual Service were NOT configured without port:
1146  *    This is to allow match of different VS to the same RS ip-addr
1147  */
ip_vs_new_conn_out(struct ip_vs_service * svc,struct ip_vs_dest * dest,struct sk_buff * skb,const struct ip_vs_iphdr * iph,__be16 dport,__be16 cport)1148 struct ip_vs_conn *ip_vs_new_conn_out(struct ip_vs_service *svc,
1149 				      struct ip_vs_dest *dest,
1150 				      struct sk_buff *skb,
1151 				      const struct ip_vs_iphdr *iph,
1152 				      __be16 dport,
1153 				      __be16 cport)
1154 {
1155 	struct ip_vs_conn_param param;
1156 	struct ip_vs_conn *ct = NULL, *cp = NULL;
1157 	const union nf_inet_addr *vaddr, *daddr, *caddr;
1158 	union nf_inet_addr snet;
1159 	__be16 vport;
1160 	unsigned int flags;
1161 
1162 	EnterFunction(12);
1163 	vaddr = &svc->addr;
1164 	vport = svc->port;
1165 	daddr = &iph->saddr;
1166 	caddr = &iph->daddr;
1167 
1168 	/* check pre-requisites are satisfied */
1169 	if (svc->fwmark)
1170 		return NULL;
1171 	if (!vport || !dport)
1172 		return NULL;
1173 
1174 	/* for persistent service first create connection template */
1175 	if (svc->flags & IP_VS_SVC_F_PERSISTENT) {
1176 		/* apply netmask the same way ingress-side does */
1177 #ifdef CONFIG_IP_VS_IPV6
1178 		if (svc->af == AF_INET6)
1179 			ipv6_addr_prefix(&snet.in6, &caddr->in6,
1180 					 (__force __u32)svc->netmask);
1181 		else
1182 #endif
1183 			snet.ip = caddr->ip & svc->netmask;
1184 		/* fill params and create template if not existent */
1185 		if (ip_vs_conn_fill_param_persist(svc, skb, iph->protocol,
1186 						  &snet, 0, vaddr,
1187 						  vport, &param) < 0)
1188 			return NULL;
1189 		ct = ip_vs_ct_in_get(&param);
1190 		/* check if template exists and points to the same dest */
1191 		if (!ct || !ip_vs_check_template(ct, dest)) {
1192 			ct = ip_vs_conn_new(&param, dest->af, daddr, dport,
1193 					    IP_VS_CONN_F_TEMPLATE, dest, 0);
1194 			if (!ct) {
1195 				kfree(param.pe_data);
1196 				return NULL;
1197 			}
1198 			ct->timeout = svc->timeout;
1199 		} else {
1200 			kfree(param.pe_data);
1201 		}
1202 	}
1203 
1204 	/* connection flags */
1205 	flags = ((svc->flags & IP_VS_SVC_F_ONEPACKET) &&
1206 		 iph->protocol == IPPROTO_UDP) ? IP_VS_CONN_F_ONE_PACKET : 0;
1207 	/* create connection */
1208 	ip_vs_conn_fill_param(svc->ipvs, svc->af, iph->protocol,
1209 			      caddr, cport, vaddr, vport, &param);
1210 	cp = ip_vs_conn_new(&param, dest->af, daddr, dport, flags, dest, 0);
1211 	if (!cp) {
1212 		if (ct)
1213 			ip_vs_conn_put(ct);
1214 		return NULL;
1215 	}
1216 	if (ct) {
1217 		ip_vs_control_add(cp, ct);
1218 		ip_vs_conn_put(ct);
1219 	}
1220 	ip_vs_conn_stats(cp, svc);
1221 
1222 	/* return connection (will be used to handle outgoing packet) */
1223 	IP_VS_DBG_BUF(6, "New connection RS-initiated:%c c:%s:%u v:%s:%u "
1224 		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
1225 		      ip_vs_fwd_tag(cp),
1226 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
1227 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
1228 		      IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
1229 		      cp->flags, refcount_read(&cp->refcnt));
1230 	LeaveFunction(12);
1231 	return cp;
1232 }
1233 
1234 /* Handle outgoing packets which are considered requests initiated by
1235  * real servers, so that subsequent responses from external client can be
1236  * routed to the right real server.
1237  * Used also for outgoing responses in OPS mode.
1238  *
1239  * Connection management is handled by persistent-engine specific callback.
1240  */
__ip_vs_rs_conn_out(unsigned int hooknum,struct netns_ipvs * ipvs,int af,struct sk_buff * skb,const struct ip_vs_iphdr * iph)1241 static struct ip_vs_conn *__ip_vs_rs_conn_out(unsigned int hooknum,
1242 					      struct netns_ipvs *ipvs,
1243 					      int af, struct sk_buff *skb,
1244 					      const struct ip_vs_iphdr *iph)
1245 {
1246 	struct ip_vs_dest *dest;
1247 	struct ip_vs_conn *cp = NULL;
1248 	__be16 _ports[2], *pptr;
1249 
1250 	if (hooknum == NF_INET_LOCAL_IN)
1251 		return NULL;
1252 
1253 	pptr = frag_safe_skb_hp(skb, iph->len,
1254 				sizeof(_ports), _ports);
1255 	if (!pptr)
1256 		return NULL;
1257 
1258 	dest = ip_vs_find_real_service(ipvs, af, iph->protocol,
1259 				       &iph->saddr, pptr[0]);
1260 	if (dest) {
1261 		struct ip_vs_service *svc;
1262 		struct ip_vs_pe *pe;
1263 
1264 		svc = rcu_dereference(dest->svc);
1265 		if (svc) {
1266 			pe = rcu_dereference(svc->pe);
1267 			if (pe && pe->conn_out)
1268 				cp = pe->conn_out(svc, dest, skb, iph,
1269 						  pptr[0], pptr[1]);
1270 		}
1271 	}
1272 
1273 	return cp;
1274 }
1275 
1276 /* Handle response packets: rewrite addresses and send away...
1277  */
1278 static unsigned int
handle_response(int af,struct sk_buff * skb,struct ip_vs_proto_data * pd,struct ip_vs_conn * cp,struct ip_vs_iphdr * iph,unsigned int hooknum)1279 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
1280 		struct ip_vs_conn *cp, struct ip_vs_iphdr *iph,
1281 		unsigned int hooknum)
1282 {
1283 	struct ip_vs_protocol *pp = pd->pp;
1284 
1285 	IP_VS_DBG_PKT(11, af, pp, skb, iph->off, "Outgoing packet");
1286 
1287 	if (skb_ensure_writable(skb, iph->len))
1288 		goto drop;
1289 
1290 	/* mangle the packet */
1291 	if (pp->snat_handler &&
1292 	    !SNAT_CALL(pp->snat_handler, skb, pp, cp, iph))
1293 		goto drop;
1294 
1295 #ifdef CONFIG_IP_VS_IPV6
1296 	if (af == AF_INET6)
1297 		ipv6_hdr(skb)->saddr = cp->vaddr.in6;
1298 	else
1299 #endif
1300 	{
1301 		ip_hdr(skb)->saddr = cp->vaddr.ip;
1302 		ip_send_check(ip_hdr(skb));
1303 	}
1304 
1305 	/*
1306 	 * nf_iterate does not expect change in the skb->dst->dev.
1307 	 * It looks like it is not fatal to enable this code for hooks
1308 	 * where our handlers are at the end of the chain list and
1309 	 * when all next handlers use skb->dst->dev and not outdev.
1310 	 * It will definitely route properly the inout NAT traffic
1311 	 * when multiple paths are used.
1312 	 */
1313 
1314 	/* For policy routing, packets originating from this
1315 	 * machine itself may be routed differently to packets
1316 	 * passing through.  We want this packet to be routed as
1317 	 * if it came from this machine itself.  So re-compute
1318 	 * the routing information.
1319 	 */
1320 	if (ip_vs_route_me_harder(cp->ipvs, af, skb, hooknum))
1321 		goto drop;
1322 
1323 	IP_VS_DBG_PKT(10, af, pp, skb, iph->off, "After SNAT");
1324 
1325 	ip_vs_out_stats(cp, skb);
1326 	ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd);
1327 	skb->ipvs_property = 1;
1328 	if (!(cp->flags & IP_VS_CONN_F_NFCT))
1329 		ip_vs_notrack(skb);
1330 	else
1331 		ip_vs_update_conntrack(skb, cp, 0);
1332 	ip_vs_conn_put(cp);
1333 
1334 	LeaveFunction(11);
1335 	return NF_ACCEPT;
1336 
1337 drop:
1338 	ip_vs_conn_put(cp);
1339 	kfree_skb(skb);
1340 	LeaveFunction(11);
1341 	return NF_STOLEN;
1342 }
1343 
1344 /*
1345  *	Check if outgoing packet belongs to the established ip_vs_conn.
1346  */
1347 static unsigned int
ip_vs_out(struct netns_ipvs * ipvs,unsigned int hooknum,struct sk_buff * skb,int af)1348 ip_vs_out(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af)
1349 {
1350 	struct ip_vs_iphdr iph;
1351 	struct ip_vs_protocol *pp;
1352 	struct ip_vs_proto_data *pd;
1353 	struct ip_vs_conn *cp;
1354 	struct sock *sk;
1355 
1356 	EnterFunction(11);
1357 
1358 	/* Already marked as IPVS request or reply? */
1359 	if (skb->ipvs_property)
1360 		return NF_ACCEPT;
1361 
1362 	sk = skb_to_full_sk(skb);
1363 	/* Bad... Do not break raw sockets */
1364 	if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT &&
1365 		     af == AF_INET)) {
1366 
1367 		if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag)
1368 			return NF_ACCEPT;
1369 	}
1370 
1371 	if (unlikely(!skb_dst(skb)))
1372 		return NF_ACCEPT;
1373 
1374 	if (!ipvs->enable)
1375 		return NF_ACCEPT;
1376 
1377 	ip_vs_fill_iph_skb(af, skb, false, &iph);
1378 #ifdef CONFIG_IP_VS_IPV6
1379 	if (af == AF_INET6) {
1380 		if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
1381 			int related;
1382 			int verdict = ip_vs_out_icmp_v6(ipvs, skb, &related,
1383 							hooknum, &iph);
1384 
1385 			if (related)
1386 				return verdict;
1387 		}
1388 	} else
1389 #endif
1390 		if (unlikely(iph.protocol == IPPROTO_ICMP)) {
1391 			int related;
1392 			int verdict = ip_vs_out_icmp(ipvs, skb, &related, hooknum);
1393 
1394 			if (related)
1395 				return verdict;
1396 		}
1397 
1398 	pd = ip_vs_proto_data_get(ipvs, iph.protocol);
1399 	if (unlikely(!pd))
1400 		return NF_ACCEPT;
1401 	pp = pd->pp;
1402 
1403 	/* reassemble IP fragments */
1404 #ifdef CONFIG_IP_VS_IPV6
1405 	if (af == AF_INET)
1406 #endif
1407 		if (unlikely(ip_is_fragment(ip_hdr(skb)) && !pp->dont_defrag)) {
1408 			if (ip_vs_gather_frags(ipvs, skb,
1409 					       ip_vs_defrag_user(hooknum)))
1410 				return NF_STOLEN;
1411 
1412 			ip_vs_fill_iph_skb(AF_INET, skb, false, &iph);
1413 		}
1414 
1415 	/*
1416 	 * Check if the packet belongs to an existing entry
1417 	 */
1418 	cp = INDIRECT_CALL_1(pp->conn_out_get, ip_vs_conn_out_get_proto,
1419 			     ipvs, af, skb, &iph);
1420 
1421 	if (likely(cp)) {
1422 		if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)
1423 			goto ignore_cp;
1424 		return handle_response(af, skb, pd, cp, &iph, hooknum);
1425 	}
1426 
1427 	/* Check for real-server-started requests */
1428 	if (atomic_read(&ipvs->conn_out_counter)) {
1429 		/* Currently only for UDP:
1430 		 * connection oriented protocols typically use
1431 		 * ephemeral ports for outgoing connections, so
1432 		 * related incoming responses would not match any VS
1433 		 */
1434 		if (pp->protocol == IPPROTO_UDP) {
1435 			cp = __ip_vs_rs_conn_out(hooknum, ipvs, af, skb, &iph);
1436 			if (likely(cp))
1437 				return handle_response(af, skb, pd, cp, &iph,
1438 						       hooknum);
1439 		}
1440 	}
1441 
1442 	if (sysctl_nat_icmp_send(ipvs) &&
1443 	    (pp->protocol == IPPROTO_TCP ||
1444 	     pp->protocol == IPPROTO_UDP ||
1445 	     pp->protocol == IPPROTO_SCTP)) {
1446 		__be16 _ports[2], *pptr;
1447 
1448 		pptr = frag_safe_skb_hp(skb, iph.len,
1449 					 sizeof(_ports), _ports);
1450 		if (pptr == NULL)
1451 			return NF_ACCEPT;	/* Not for me */
1452 		if (ip_vs_has_real_service(ipvs, af, iph.protocol, &iph.saddr,
1453 					   pptr[0])) {
1454 			/*
1455 			 * Notify the real server: there is no
1456 			 * existing entry if it is not RST
1457 			 * packet or not TCP packet.
1458 			 */
1459 			if ((iph.protocol != IPPROTO_TCP &&
1460 			     iph.protocol != IPPROTO_SCTP)
1461 			     || ((iph.protocol == IPPROTO_TCP
1462 				  && !is_tcp_reset(skb, iph.len))
1463 				 || (iph.protocol == IPPROTO_SCTP
1464 					&& !is_sctp_abort(skb,
1465 						iph.len)))) {
1466 #ifdef CONFIG_IP_VS_IPV6
1467 				if (af == AF_INET6) {
1468 					if (!skb->dev)
1469 						skb->dev = ipvs->net->loopback_dev;
1470 					icmpv6_send(skb,
1471 						    ICMPV6_DEST_UNREACH,
1472 						    ICMPV6_PORT_UNREACH,
1473 						    0);
1474 				} else
1475 #endif
1476 					icmp_send(skb,
1477 						  ICMP_DEST_UNREACH,
1478 						  ICMP_PORT_UNREACH, 0);
1479 				return NF_DROP;
1480 			}
1481 		}
1482 	}
1483 
1484 out:
1485 	IP_VS_DBG_PKT(12, af, pp, skb, iph.off,
1486 		      "ip_vs_out: packet continues traversal as normal");
1487 	return NF_ACCEPT;
1488 
1489 ignore_cp:
1490 	__ip_vs_conn_put(cp);
1491 	goto out;
1492 }
1493 
1494 /*
1495  *	It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1496  *	used only for VS/NAT.
1497  *	Check if packet is reply for established ip_vs_conn.
1498  */
1499 static unsigned int
ip_vs_reply4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1500 ip_vs_reply4(void *priv, struct sk_buff *skb,
1501 	     const struct nf_hook_state *state)
1502 {
1503 	return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET);
1504 }
1505 
1506 /*
1507  *	It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1508  *	Check if packet is reply for established ip_vs_conn.
1509  */
1510 static unsigned int
ip_vs_local_reply4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1511 ip_vs_local_reply4(void *priv, struct sk_buff *skb,
1512 		   const struct nf_hook_state *state)
1513 {
1514 	return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET);
1515 }
1516 
1517 #ifdef CONFIG_IP_VS_IPV6
1518 
1519 /*
1520  *	It is hooked at the NF_INET_FORWARD and NF_INET_LOCAL_IN chain,
1521  *	used only for VS/NAT.
1522  *	Check if packet is reply for established ip_vs_conn.
1523  */
1524 static unsigned int
ip_vs_reply6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1525 ip_vs_reply6(void *priv, struct sk_buff *skb,
1526 	     const struct nf_hook_state *state)
1527 {
1528 	return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6);
1529 }
1530 
1531 /*
1532  *	It is hooked at the NF_INET_LOCAL_OUT chain, used only for VS/NAT.
1533  *	Check if packet is reply for established ip_vs_conn.
1534  */
1535 static unsigned int
ip_vs_local_reply6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)1536 ip_vs_local_reply6(void *priv, struct sk_buff *skb,
1537 		   const struct nf_hook_state *state)
1538 {
1539 	return ip_vs_out(net_ipvs(state->net), state->hook, skb, AF_INET6);
1540 }
1541 
1542 #endif
1543 
1544 static unsigned int
ip_vs_try_to_schedule(struct netns_ipvs * ipvs,int af,struct sk_buff * skb,struct ip_vs_proto_data * pd,int * verdict,struct ip_vs_conn ** cpp,struct ip_vs_iphdr * iph)1545 ip_vs_try_to_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
1546 		      struct ip_vs_proto_data *pd,
1547 		      int *verdict, struct ip_vs_conn **cpp,
1548 		      struct ip_vs_iphdr *iph)
1549 {
1550 	struct ip_vs_protocol *pp = pd->pp;
1551 
1552 	if (!iph->fragoffs) {
1553 		/* No (second) fragments need to enter here, as nf_defrag_ipv6
1554 		 * replayed fragment zero will already have created the cp
1555 		 */
1556 
1557 		/* Schedule and create new connection entry into cpp */
1558 		if (!pp->conn_schedule(ipvs, af, skb, pd, verdict, cpp, iph))
1559 			return 0;
1560 	}
1561 
1562 	if (unlikely(!*cpp)) {
1563 		/* sorry, all this trouble for a no-hit :) */
1564 		IP_VS_DBG_PKT(12, af, pp, skb, iph->off,
1565 			      "ip_vs_in: packet continues traversal as normal");
1566 
1567 		/* Fragment couldn't be mapped to a conn entry */
1568 		if (iph->fragoffs)
1569 			IP_VS_DBG_PKT(7, af, pp, skb, iph->off,
1570 				      "unhandled fragment");
1571 
1572 		*verdict = NF_ACCEPT;
1573 		return 0;
1574 	}
1575 
1576 	return 1;
1577 }
1578 
1579 /* Check the UDP tunnel and return its header length */
ipvs_udp_decap(struct netns_ipvs * ipvs,struct sk_buff * skb,unsigned int offset,__u16 af,const union nf_inet_addr * daddr,__u8 * proto)1580 static int ipvs_udp_decap(struct netns_ipvs *ipvs, struct sk_buff *skb,
1581 			  unsigned int offset, __u16 af,
1582 			  const union nf_inet_addr *daddr, __u8 *proto)
1583 {
1584 	struct udphdr _udph, *udph;
1585 	struct ip_vs_dest *dest;
1586 
1587 	udph = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
1588 	if (!udph)
1589 		goto unk;
1590 	offset += sizeof(struct udphdr);
1591 	dest = ip_vs_find_tunnel(ipvs, af, daddr, udph->dest);
1592 	if (!dest)
1593 		goto unk;
1594 	if (dest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GUE) {
1595 		struct guehdr _gueh, *gueh;
1596 
1597 		gueh = skb_header_pointer(skb, offset, sizeof(_gueh), &_gueh);
1598 		if (!gueh)
1599 			goto unk;
1600 		if (gueh->control != 0 || gueh->version != 0)
1601 			goto unk;
1602 		/* Later we can support also IPPROTO_IPV6 */
1603 		if (gueh->proto_ctype != IPPROTO_IPIP)
1604 			goto unk;
1605 		*proto = gueh->proto_ctype;
1606 		return sizeof(struct udphdr) + sizeof(struct guehdr) +
1607 		       (gueh->hlen << 2);
1608 	}
1609 
1610 unk:
1611 	return 0;
1612 }
1613 
1614 /* Check the GRE tunnel and return its header length */
ipvs_gre_decap(struct netns_ipvs * ipvs,struct sk_buff * skb,unsigned int offset,__u16 af,const union nf_inet_addr * daddr,__u8 * proto)1615 static int ipvs_gre_decap(struct netns_ipvs *ipvs, struct sk_buff *skb,
1616 			  unsigned int offset, __u16 af,
1617 			  const union nf_inet_addr *daddr, __u8 *proto)
1618 {
1619 	struct gre_base_hdr _greh, *greh;
1620 	struct ip_vs_dest *dest;
1621 
1622 	greh = skb_header_pointer(skb, offset, sizeof(_greh), &_greh);
1623 	if (!greh)
1624 		goto unk;
1625 	dest = ip_vs_find_tunnel(ipvs, af, daddr, 0);
1626 	if (!dest)
1627 		goto unk;
1628 	if (dest->tun_type == IP_VS_CONN_F_TUNNEL_TYPE_GRE) {
1629 		__be16 type;
1630 
1631 		/* Only support version 0 and C (csum) */
1632 		if ((greh->flags & ~GRE_CSUM) != 0)
1633 			goto unk;
1634 		type = greh->protocol;
1635 		/* Later we can support also IPPROTO_IPV6 */
1636 		if (type != htons(ETH_P_IP))
1637 			goto unk;
1638 		*proto = IPPROTO_IPIP;
1639 		return gre_calc_hlen(gre_flags_to_tnl_flags(greh->flags));
1640 	}
1641 
1642 unk:
1643 	return 0;
1644 }
1645 
1646 /*
1647  *	Handle ICMP messages in the outside-to-inside direction (incoming).
1648  *	Find any that might be relevant, check against existing connections,
1649  *	forward to the right destination host if relevant.
1650  *	Currently handles error types - unreachable, quench, ttl exceeded.
1651  */
1652 static int
ip_vs_in_icmp(struct netns_ipvs * ipvs,struct sk_buff * skb,int * related,unsigned int hooknum)1653 ip_vs_in_icmp(struct netns_ipvs *ipvs, struct sk_buff *skb, int *related,
1654 	      unsigned int hooknum)
1655 {
1656 	struct iphdr *iph;
1657 	struct icmphdr	_icmph, *ic;
1658 	struct iphdr	_ciph, *cih;	/* The ip header contained within the ICMP */
1659 	struct ip_vs_iphdr ciph;
1660 	struct ip_vs_conn *cp;
1661 	struct ip_vs_protocol *pp;
1662 	struct ip_vs_proto_data *pd;
1663 	unsigned int offset, offset2, ihl, verdict;
1664 	bool ipip, new_cp = false;
1665 	union nf_inet_addr *raddr;
1666 
1667 	*related = 1;
1668 
1669 	/* reassemble IP fragments */
1670 	if (ip_is_fragment(ip_hdr(skb))) {
1671 		if (ip_vs_gather_frags(ipvs, skb, ip_vs_defrag_user(hooknum)))
1672 			return NF_STOLEN;
1673 	}
1674 
1675 	iph = ip_hdr(skb);
1676 	offset = ihl = iph->ihl * 4;
1677 	ic = skb_header_pointer(skb, offset, sizeof(_icmph), &_icmph);
1678 	if (ic == NULL)
1679 		return NF_DROP;
1680 
1681 	IP_VS_DBG(12, "Incoming ICMP (%d,%d) %pI4->%pI4\n",
1682 		  ic->type, ntohs(icmp_id(ic)),
1683 		  &iph->saddr, &iph->daddr);
1684 
1685 	/*
1686 	 * Work through seeing if this is for us.
1687 	 * These checks are supposed to be in an order that means easy
1688 	 * things are checked first to speed up processing.... however
1689 	 * this means that some packets will manage to get a long way
1690 	 * down this stack and then be rejected, but that's life.
1691 	 */
1692 	if ((ic->type != ICMP_DEST_UNREACH) &&
1693 	    (ic->type != ICMP_SOURCE_QUENCH) &&
1694 	    (ic->type != ICMP_TIME_EXCEEDED)) {
1695 		*related = 0;
1696 		return NF_ACCEPT;
1697 	}
1698 
1699 	/* Now find the contained IP header */
1700 	offset += sizeof(_icmph);
1701 	cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1702 	if (cih == NULL)
1703 		return NF_ACCEPT; /* The packet looks wrong, ignore */
1704 	raddr = (union nf_inet_addr *)&cih->daddr;
1705 
1706 	/* Special case for errors for IPIP packets */
1707 	ipip = false;
1708 	if (cih->protocol == IPPROTO_IPIP) {
1709 		struct ip_vs_dest *dest;
1710 
1711 		if (unlikely(cih->frag_off & htons(IP_OFFSET)))
1712 			return NF_ACCEPT;
1713 		/* Error for our IPIP must arrive at LOCAL_IN */
1714 		if (!(skb_rtable(skb)->rt_flags & RTCF_LOCAL))
1715 			return NF_ACCEPT;
1716 		dest = ip_vs_find_tunnel(ipvs, AF_INET, raddr, 0);
1717 		/* Only for known tunnel */
1718 		if (!dest || dest->tun_type != IP_VS_CONN_F_TUNNEL_TYPE_IPIP)
1719 			return NF_ACCEPT;
1720 		offset += cih->ihl * 4;
1721 		cih = skb_header_pointer(skb, offset, sizeof(_ciph), &_ciph);
1722 		if (cih == NULL)
1723 			return NF_ACCEPT; /* The packet looks wrong, ignore */
1724 		ipip = true;
1725 	} else if ((cih->protocol == IPPROTO_UDP ||	/* Can be UDP encap */
1726 		    cih->protocol == IPPROTO_GRE) &&	/* Can be GRE encap */
1727 		   /* Error for our tunnel must arrive at LOCAL_IN */
1728 		   (skb_rtable(skb)->rt_flags & RTCF_LOCAL)) {
1729 		__u8 iproto;
1730 		int ulen;
1731 
1732 		/* Non-first fragment has no UDP header */
1733 		if (unlikely(cih->frag_off & htons(IP_OFFSET)))
1734 			return NF_ACCEPT;
1735 		offset2 = offset + cih->ihl * 4;
1736 		if (cih->protocol == IPPROTO_UDP)
1737 			ulen = ipvs_udp_decap(ipvs, skb, offset2, AF_INET,
1738 					      raddr, &iproto);
1739 		else
1740 			ulen = ipvs_gre_decap(ipvs, skb, offset2, AF_INET,
1741 					      raddr, &iproto);
1742 		if (ulen > 0) {
1743 			/* Skip IP and UDP/GRE tunnel headers */
1744 			offset = offset2 + ulen;
1745 			/* Now we should be at the original IP header */
1746 			cih = skb_header_pointer(skb, offset, sizeof(_ciph),
1747 						 &_ciph);
1748 			if (cih && cih->version == 4 && cih->ihl >= 5 &&
1749 			    iproto == IPPROTO_IPIP)
1750 				ipip = true;
1751 			else
1752 				return NF_ACCEPT;
1753 		}
1754 	}
1755 
1756 	pd = ip_vs_proto_data_get(ipvs, cih->protocol);
1757 	if (!pd)
1758 		return NF_ACCEPT;
1759 	pp = pd->pp;
1760 
1761 	/* Is the embedded protocol header present? */
1762 	if (unlikely(cih->frag_off & htons(IP_OFFSET) &&
1763 		     pp->dont_defrag))
1764 		return NF_ACCEPT;
1765 
1766 	IP_VS_DBG_PKT(11, AF_INET, pp, skb, offset,
1767 		      "Checking incoming ICMP for");
1768 
1769 	offset2 = offset;
1770 	ip_vs_fill_iph_skb_icmp(AF_INET, skb, offset, !ipip, &ciph);
1771 	offset = ciph.len;
1772 
1773 	/* The embedded headers contain source and dest in reverse order.
1774 	 * For IPIP this is error for request, not for reply.
1775 	 */
1776 	cp = INDIRECT_CALL_1(pp->conn_in_get, ip_vs_conn_in_get_proto,
1777 			     ipvs, AF_INET, skb, &ciph);
1778 
1779 	if (!cp) {
1780 		int v;
1781 
1782 		if (ipip || !sysctl_schedule_icmp(ipvs))
1783 			return NF_ACCEPT;
1784 
1785 		if (!ip_vs_try_to_schedule(ipvs, AF_INET, skb, pd, &v, &cp, &ciph))
1786 			return v;
1787 		new_cp = true;
1788 	}
1789 
1790 	verdict = NF_DROP;
1791 
1792 	/* Ensure the checksum is correct */
1793 	if (!skb_csum_unnecessary(skb) && ip_vs_checksum_complete(skb, ihl)) {
1794 		/* Failed checksum! */
1795 		IP_VS_DBG(1, "Incoming ICMP: failed checksum from %pI4!\n",
1796 			  &iph->saddr);
1797 		goto out;
1798 	}
1799 
1800 	if (ipip) {
1801 		__be32 info = ic->un.gateway;
1802 		__u8 type = ic->type;
1803 		__u8 code = ic->code;
1804 
1805 		/* Update the MTU */
1806 		if (ic->type == ICMP_DEST_UNREACH &&
1807 		    ic->code == ICMP_FRAG_NEEDED) {
1808 			struct ip_vs_dest *dest = cp->dest;
1809 			u32 mtu = ntohs(ic->un.frag.mtu);
1810 			__be16 frag_off = cih->frag_off;
1811 
1812 			/* Strip outer IP and ICMP, go to IPIP header */
1813 			if (pskb_pull(skb, ihl + sizeof(_icmph)) == NULL)
1814 				goto ignore_ipip;
1815 			offset2 -= ihl + sizeof(_icmph);
1816 			skb_reset_network_header(skb);
1817 			IP_VS_DBG(12, "ICMP for IPIP %pI4->%pI4: mtu=%u\n",
1818 				&ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr, mtu);
1819 			ipv4_update_pmtu(skb, ipvs->net, mtu, 0, 0);
1820 			/* Client uses PMTUD? */
1821 			if (!(frag_off & htons(IP_DF)))
1822 				goto ignore_ipip;
1823 			/* Prefer the resulting PMTU */
1824 			if (dest) {
1825 				struct ip_vs_dest_dst *dest_dst;
1826 
1827 				dest_dst = rcu_dereference(dest->dest_dst);
1828 				if (dest_dst)
1829 					mtu = dst_mtu(dest_dst->dst_cache);
1830 			}
1831 			if (mtu > 68 + sizeof(struct iphdr))
1832 				mtu -= sizeof(struct iphdr);
1833 			info = htonl(mtu);
1834 		}
1835 		/* Strip outer IP, ICMP and IPIP, go to IP header of
1836 		 * original request.
1837 		 */
1838 		if (pskb_pull(skb, offset2) == NULL)
1839 			goto ignore_ipip;
1840 		skb_reset_network_header(skb);
1841 		IP_VS_DBG(12, "Sending ICMP for %pI4->%pI4: t=%u, c=%u, i=%u\n",
1842 			&ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1843 			type, code, ntohl(info));
1844 		icmp_send(skb, type, code, info);
1845 		/* ICMP can be shorter but anyways, account it */
1846 		ip_vs_out_stats(cp, skb);
1847 
1848 ignore_ipip:
1849 		consume_skb(skb);
1850 		verdict = NF_STOLEN;
1851 		goto out;
1852 	}
1853 
1854 	/* do the statistics and put it back */
1855 	ip_vs_in_stats(cp, skb);
1856 	if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol ||
1857 	    IPPROTO_SCTP == cih->protocol)
1858 		offset += 2 * sizeof(__u16);
1859 	verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum, &ciph);
1860 
1861 out:
1862 	if (likely(!new_cp))
1863 		__ip_vs_conn_put(cp);
1864 	else
1865 		ip_vs_conn_put(cp);
1866 
1867 	return verdict;
1868 }
1869 
1870 #ifdef CONFIG_IP_VS_IPV6
ip_vs_in_icmp_v6(struct netns_ipvs * ipvs,struct sk_buff * skb,int * related,unsigned int hooknum,struct ip_vs_iphdr * iph)1871 static int ip_vs_in_icmp_v6(struct netns_ipvs *ipvs, struct sk_buff *skb,
1872 			    int *related, unsigned int hooknum,
1873 			    struct ip_vs_iphdr *iph)
1874 {
1875 	struct icmp6hdr	_icmph, *ic;
1876 	struct ip_vs_iphdr ciph = {.flags = 0, .fragoffs = 0};/*Contained IP */
1877 	struct ip_vs_conn *cp;
1878 	struct ip_vs_protocol *pp;
1879 	struct ip_vs_proto_data *pd;
1880 	unsigned int offset, verdict;
1881 	bool new_cp = false;
1882 
1883 	*related = 1;
1884 
1885 	ic = frag_safe_skb_hp(skb, iph->len, sizeof(_icmph), &_icmph);
1886 	if (ic == NULL)
1887 		return NF_DROP;
1888 
1889 	/*
1890 	 * Work through seeing if this is for us.
1891 	 * These checks are supposed to be in an order that means easy
1892 	 * things are checked first to speed up processing.... however
1893 	 * this means that some packets will manage to get a long way
1894 	 * down this stack and then be rejected, but that's life.
1895 	 */
1896 	if (ic->icmp6_type & ICMPV6_INFOMSG_MASK) {
1897 		*related = 0;
1898 		return NF_ACCEPT;
1899 	}
1900 	/* Fragment header that is before ICMP header tells us that:
1901 	 * it's not an error message since they can't be fragmented.
1902 	 */
1903 	if (iph->flags & IP6_FH_F_FRAG)
1904 		return NF_DROP;
1905 
1906 	IP_VS_DBG(8, "Incoming ICMPv6 (%d,%d) %pI6c->%pI6c\n",
1907 		  ic->icmp6_type, ntohs(icmpv6_id(ic)),
1908 		  &iph->saddr, &iph->daddr);
1909 
1910 	offset = iph->len + sizeof(_icmph);
1911 	if (!ip_vs_fill_iph_skb_icmp(AF_INET6, skb, offset, true, &ciph))
1912 		return NF_ACCEPT;
1913 
1914 	pd = ip_vs_proto_data_get(ipvs, ciph.protocol);
1915 	if (!pd)
1916 		return NF_ACCEPT;
1917 	pp = pd->pp;
1918 
1919 	/* Cannot handle fragmented embedded protocol */
1920 	if (ciph.fragoffs)
1921 		return NF_ACCEPT;
1922 
1923 	IP_VS_DBG_PKT(11, AF_INET6, pp, skb, offset,
1924 		      "Checking incoming ICMPv6 for");
1925 
1926 	/* The embedded headers contain source and dest in reverse order
1927 	 * if not from localhost
1928 	 */
1929 	cp = INDIRECT_CALL_1(pp->conn_in_get, ip_vs_conn_in_get_proto,
1930 			     ipvs, AF_INET6, skb, &ciph);
1931 
1932 	if (!cp) {
1933 		int v;
1934 
1935 		if (!sysctl_schedule_icmp(ipvs))
1936 			return NF_ACCEPT;
1937 
1938 		if (!ip_vs_try_to_schedule(ipvs, AF_INET6, skb, pd, &v, &cp, &ciph))
1939 			return v;
1940 
1941 		new_cp = true;
1942 	}
1943 
1944 	/* VS/TUN, VS/DR and LOCALNODE just let it go */
1945 	if ((hooknum == NF_INET_LOCAL_OUT) &&
1946 	    (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ)) {
1947 		verdict = NF_ACCEPT;
1948 		goto out;
1949 	}
1950 
1951 	/* do the statistics and put it back */
1952 	ip_vs_in_stats(cp, skb);
1953 
1954 	/* Need to mangle contained IPv6 header in ICMPv6 packet */
1955 	offset = ciph.len;
1956 	if (IPPROTO_TCP == ciph.protocol || IPPROTO_UDP == ciph.protocol ||
1957 	    IPPROTO_SCTP == ciph.protocol)
1958 		offset += 2 * sizeof(__u16); /* Also mangle ports */
1959 
1960 	verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, offset, hooknum, &ciph);
1961 
1962 out:
1963 	if (likely(!new_cp))
1964 		__ip_vs_conn_put(cp);
1965 	else
1966 		ip_vs_conn_put(cp);
1967 
1968 	return verdict;
1969 }
1970 #endif
1971 
1972 
1973 /*
1974  *	Check if it's for virtual services, look it up,
1975  *	and send it on its way...
1976  */
1977 static unsigned int
ip_vs_in(struct netns_ipvs * ipvs,unsigned int hooknum,struct sk_buff * skb,int af)1978 ip_vs_in(struct netns_ipvs *ipvs, unsigned int hooknum, struct sk_buff *skb, int af)
1979 {
1980 	struct ip_vs_iphdr iph;
1981 	struct ip_vs_protocol *pp;
1982 	struct ip_vs_proto_data *pd;
1983 	struct ip_vs_conn *cp;
1984 	int ret, pkts;
1985 	int conn_reuse_mode;
1986 	struct sock *sk;
1987 
1988 	/* Already marked as IPVS request or reply? */
1989 	if (skb->ipvs_property)
1990 		return NF_ACCEPT;
1991 
1992 	/*
1993 	 *	Big tappo:
1994 	 *	- remote client: only PACKET_HOST
1995 	 *	- route: used for struct net when skb->dev is unset
1996 	 */
1997 	if (unlikely((skb->pkt_type != PACKET_HOST &&
1998 		      hooknum != NF_INET_LOCAL_OUT) ||
1999 		     !skb_dst(skb))) {
2000 		ip_vs_fill_iph_skb(af, skb, false, &iph);
2001 		IP_VS_DBG_BUF(12, "packet type=%d proto=%d daddr=%s"
2002 			      " ignored in hook %u\n",
2003 			      skb->pkt_type, iph.protocol,
2004 			      IP_VS_DBG_ADDR(af, &iph.daddr), hooknum);
2005 		return NF_ACCEPT;
2006 	}
2007 	/* ipvs enabled in this netns ? */
2008 	if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
2009 		return NF_ACCEPT;
2010 
2011 	ip_vs_fill_iph_skb(af, skb, false, &iph);
2012 
2013 	/* Bad... Do not break raw sockets */
2014 	sk = skb_to_full_sk(skb);
2015 	if (unlikely(sk && hooknum == NF_INET_LOCAL_OUT &&
2016 		     af == AF_INET)) {
2017 
2018 		if (sk->sk_family == PF_INET && inet_sk(sk)->nodefrag)
2019 			return NF_ACCEPT;
2020 	}
2021 
2022 #ifdef CONFIG_IP_VS_IPV6
2023 	if (af == AF_INET6) {
2024 		if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
2025 			int related;
2026 			int verdict = ip_vs_in_icmp_v6(ipvs, skb, &related,
2027 						       hooknum, &iph);
2028 
2029 			if (related)
2030 				return verdict;
2031 		}
2032 	} else
2033 #endif
2034 		if (unlikely(iph.protocol == IPPROTO_ICMP)) {
2035 			int related;
2036 			int verdict = ip_vs_in_icmp(ipvs, skb, &related,
2037 						    hooknum);
2038 
2039 			if (related)
2040 				return verdict;
2041 		}
2042 
2043 	/* Protocol supported? */
2044 	pd = ip_vs_proto_data_get(ipvs, iph.protocol);
2045 	if (unlikely(!pd)) {
2046 		/* The only way we'll see this packet again is if it's
2047 		 * encapsulated, so mark it with ipvs_property=1 so we
2048 		 * skip it if we're ignoring tunneled packets
2049 		 */
2050 		if (sysctl_ignore_tunneled(ipvs))
2051 			skb->ipvs_property = 1;
2052 
2053 		return NF_ACCEPT;
2054 	}
2055 	pp = pd->pp;
2056 	/*
2057 	 * Check if the packet belongs to an existing connection entry
2058 	 */
2059 	cp = INDIRECT_CALL_1(pp->conn_in_get, ip_vs_conn_in_get_proto,
2060 			     ipvs, af, skb, &iph);
2061 
2062 	conn_reuse_mode = sysctl_conn_reuse_mode(ipvs);
2063 	if (conn_reuse_mode && !iph.fragoffs && is_new_conn(skb, &iph) && cp) {
2064 		bool uses_ct = false, resched = false;
2065 
2066 		if (unlikely(sysctl_expire_nodest_conn(ipvs)) && cp->dest &&
2067 		    unlikely(!atomic_read(&cp->dest->weight))) {
2068 			resched = true;
2069 			uses_ct = ip_vs_conn_uses_conntrack(cp, skb);
2070 		} else if (is_new_conn_expected(cp, conn_reuse_mode)) {
2071 			uses_ct = ip_vs_conn_uses_conntrack(cp, skb);
2072 			if (!atomic_read(&cp->n_control)) {
2073 				resched = true;
2074 			} else {
2075 				/* Do not reschedule controlling connection
2076 				 * that uses conntrack while it is still
2077 				 * referenced by controlled connection(s).
2078 				 */
2079 				resched = !uses_ct;
2080 			}
2081 		}
2082 
2083 		if (resched) {
2084 			if (!atomic_read(&cp->n_control))
2085 				ip_vs_conn_expire_now(cp);
2086 			__ip_vs_conn_put(cp);
2087 			if (uses_ct)
2088 				return NF_DROP;
2089 			cp = NULL;
2090 		}
2091 	}
2092 
2093 	if (unlikely(!cp)) {
2094 		int v;
2095 
2096 		if (!ip_vs_try_to_schedule(ipvs, af, skb, pd, &v, &cp, &iph))
2097 			return v;
2098 	}
2099 
2100 	IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet");
2101 
2102 	/* Check the server status */
2103 	if (cp->dest && !(cp->dest->flags & IP_VS_DEST_F_AVAILABLE)) {
2104 		/* the destination server is not available */
2105 
2106 		__u32 flags = cp->flags;
2107 
2108 		/* when timer already started, silently drop the packet.*/
2109 		if (timer_pending(&cp->timer))
2110 			__ip_vs_conn_put(cp);
2111 		else
2112 			ip_vs_conn_put(cp);
2113 
2114 		if (sysctl_expire_nodest_conn(ipvs) &&
2115 		    !(flags & IP_VS_CONN_F_ONE_PACKET)) {
2116 			/* try to expire the connection immediately */
2117 			ip_vs_conn_expire_now(cp);
2118 		}
2119 
2120 		return NF_DROP;
2121 	}
2122 
2123 	ip_vs_in_stats(cp, skb);
2124 	ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
2125 	if (cp->packet_xmit)
2126 		ret = cp->packet_xmit(skb, cp, pp, &iph);
2127 		/* do not touch skb anymore */
2128 	else {
2129 		IP_VS_DBG_RL("warning: packet_xmit is null");
2130 		ret = NF_ACCEPT;
2131 	}
2132 
2133 	/* Increase its packet counter and check if it is needed
2134 	 * to be synchronized
2135 	 *
2136 	 * Sync connection if it is about to close to
2137 	 * encorage the standby servers to update the connections timeout
2138 	 *
2139 	 * For ONE_PKT let ip_vs_sync_conn() do the filter work.
2140 	 */
2141 
2142 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
2143 		pkts = sysctl_sync_threshold(ipvs);
2144 	else
2145 		pkts = atomic_add_return(1, &cp->in_pkts);
2146 
2147 	if (ipvs->sync_state & IP_VS_STATE_MASTER)
2148 		ip_vs_sync_conn(ipvs, cp, pkts);
2149 	else if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) && cp->control)
2150 		/* increment is done inside ip_vs_sync_conn too */
2151 		atomic_inc(&cp->control->in_pkts);
2152 
2153 	ip_vs_conn_put(cp);
2154 	return ret;
2155 }
2156 
2157 /*
2158  *	AF_INET handler in NF_INET_LOCAL_IN chain
2159  *	Schedule and forward packets from remote clients
2160  */
2161 static unsigned int
ip_vs_remote_request4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2162 ip_vs_remote_request4(void *priv, struct sk_buff *skb,
2163 		      const struct nf_hook_state *state)
2164 {
2165 	return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET);
2166 }
2167 
2168 /*
2169  *	AF_INET handler in NF_INET_LOCAL_OUT chain
2170  *	Schedule and forward packets from local clients
2171  */
2172 static unsigned int
ip_vs_local_request4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2173 ip_vs_local_request4(void *priv, struct sk_buff *skb,
2174 		     const struct nf_hook_state *state)
2175 {
2176 	return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET);
2177 }
2178 
2179 #ifdef CONFIG_IP_VS_IPV6
2180 
2181 /*
2182  *	AF_INET6 handler in NF_INET_LOCAL_IN chain
2183  *	Schedule and forward packets from remote clients
2184  */
2185 static unsigned int
ip_vs_remote_request6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2186 ip_vs_remote_request6(void *priv, struct sk_buff *skb,
2187 		      const struct nf_hook_state *state)
2188 {
2189 	return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6);
2190 }
2191 
2192 /*
2193  *	AF_INET6 handler in NF_INET_LOCAL_OUT chain
2194  *	Schedule and forward packets from local clients
2195  */
2196 static unsigned int
ip_vs_local_request6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2197 ip_vs_local_request6(void *priv, struct sk_buff *skb,
2198 		     const struct nf_hook_state *state)
2199 {
2200 	return ip_vs_in(net_ipvs(state->net), state->hook, skb, AF_INET6);
2201 }
2202 
2203 #endif
2204 
2205 
2206 /*
2207  *	It is hooked at the NF_INET_FORWARD chain, in order to catch ICMP
2208  *      related packets destined for 0.0.0.0/0.
2209  *      When fwmark-based virtual service is used, such as transparent
2210  *      cache cluster, TCP packets can be marked and routed to ip_vs_in,
2211  *      but ICMP destined for 0.0.0.0/0 cannot not be easily marked and
2212  *      sent to ip_vs_in_icmp. So, catch them at the NF_INET_FORWARD chain
2213  *      and send them to ip_vs_in_icmp.
2214  */
2215 static unsigned int
ip_vs_forward_icmp(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2216 ip_vs_forward_icmp(void *priv, struct sk_buff *skb,
2217 		   const struct nf_hook_state *state)
2218 {
2219 	int r;
2220 	struct netns_ipvs *ipvs = net_ipvs(state->net);
2221 
2222 	if (ip_hdr(skb)->protocol != IPPROTO_ICMP)
2223 		return NF_ACCEPT;
2224 
2225 	/* ipvs enabled in this netns ? */
2226 	if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
2227 		return NF_ACCEPT;
2228 
2229 	return ip_vs_in_icmp(ipvs, skb, &r, state->hook);
2230 }
2231 
2232 #ifdef CONFIG_IP_VS_IPV6
2233 static unsigned int
ip_vs_forward_icmp_v6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2234 ip_vs_forward_icmp_v6(void *priv, struct sk_buff *skb,
2235 		      const struct nf_hook_state *state)
2236 {
2237 	int r;
2238 	struct netns_ipvs *ipvs = net_ipvs(state->net);
2239 	struct ip_vs_iphdr iphdr;
2240 
2241 	ip_vs_fill_iph_skb(AF_INET6, skb, false, &iphdr);
2242 	if (iphdr.protocol != IPPROTO_ICMPV6)
2243 		return NF_ACCEPT;
2244 
2245 	/* ipvs enabled in this netns ? */
2246 	if (unlikely(sysctl_backup_only(ipvs) || !ipvs->enable))
2247 		return NF_ACCEPT;
2248 
2249 	return ip_vs_in_icmp_v6(ipvs, skb, &r, state->hook, &iphdr);
2250 }
2251 #endif
2252 
2253 
2254 static const struct nf_hook_ops ip_vs_ops[] = {
2255 	/* After packet filtering, change source only for VS/NAT */
2256 	{
2257 		.hook		= ip_vs_reply4,
2258 		.pf		= NFPROTO_IPV4,
2259 		.hooknum	= NF_INET_LOCAL_IN,
2260 		.priority	= NF_IP_PRI_NAT_SRC - 2,
2261 	},
2262 	/* After packet filtering, forward packet through VS/DR, VS/TUN,
2263 	 * or VS/NAT(change destination), so that filtering rules can be
2264 	 * applied to IPVS. */
2265 	{
2266 		.hook		= ip_vs_remote_request4,
2267 		.pf		= NFPROTO_IPV4,
2268 		.hooknum	= NF_INET_LOCAL_IN,
2269 		.priority	= NF_IP_PRI_NAT_SRC - 1,
2270 	},
2271 	/* Before ip_vs_in, change source only for VS/NAT */
2272 	{
2273 		.hook		= ip_vs_local_reply4,
2274 		.pf		= NFPROTO_IPV4,
2275 		.hooknum	= NF_INET_LOCAL_OUT,
2276 		.priority	= NF_IP_PRI_NAT_DST + 1,
2277 	},
2278 	/* After mangle, schedule and forward local requests */
2279 	{
2280 		.hook		= ip_vs_local_request4,
2281 		.pf		= NFPROTO_IPV4,
2282 		.hooknum	= NF_INET_LOCAL_OUT,
2283 		.priority	= NF_IP_PRI_NAT_DST + 2,
2284 	},
2285 	/* After packet filtering (but before ip_vs_out_icmp), catch icmp
2286 	 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
2287 	{
2288 		.hook		= ip_vs_forward_icmp,
2289 		.pf		= NFPROTO_IPV4,
2290 		.hooknum	= NF_INET_FORWARD,
2291 		.priority	= 99,
2292 	},
2293 	/* After packet filtering, change source only for VS/NAT */
2294 	{
2295 		.hook		= ip_vs_reply4,
2296 		.pf		= NFPROTO_IPV4,
2297 		.hooknum	= NF_INET_FORWARD,
2298 		.priority	= 100,
2299 	},
2300 #ifdef CONFIG_IP_VS_IPV6
2301 	/* After packet filtering, change source only for VS/NAT */
2302 	{
2303 		.hook		= ip_vs_reply6,
2304 		.pf		= NFPROTO_IPV6,
2305 		.hooknum	= NF_INET_LOCAL_IN,
2306 		.priority	= NF_IP6_PRI_NAT_SRC - 2,
2307 	},
2308 	/* After packet filtering, forward packet through VS/DR, VS/TUN,
2309 	 * or VS/NAT(change destination), so that filtering rules can be
2310 	 * applied to IPVS. */
2311 	{
2312 		.hook		= ip_vs_remote_request6,
2313 		.pf		= NFPROTO_IPV6,
2314 		.hooknum	= NF_INET_LOCAL_IN,
2315 		.priority	= NF_IP6_PRI_NAT_SRC - 1,
2316 	},
2317 	/* Before ip_vs_in, change source only for VS/NAT */
2318 	{
2319 		.hook		= ip_vs_local_reply6,
2320 		.pf		= NFPROTO_IPV6,
2321 		.hooknum	= NF_INET_LOCAL_OUT,
2322 		.priority	= NF_IP6_PRI_NAT_DST + 1,
2323 	},
2324 	/* After mangle, schedule and forward local requests */
2325 	{
2326 		.hook		= ip_vs_local_request6,
2327 		.pf		= NFPROTO_IPV6,
2328 		.hooknum	= NF_INET_LOCAL_OUT,
2329 		.priority	= NF_IP6_PRI_NAT_DST + 2,
2330 	},
2331 	/* After packet filtering (but before ip_vs_out_icmp), catch icmp
2332 	 * destined for 0.0.0.0/0, which is for incoming IPVS connections */
2333 	{
2334 		.hook		= ip_vs_forward_icmp_v6,
2335 		.pf		= NFPROTO_IPV6,
2336 		.hooknum	= NF_INET_FORWARD,
2337 		.priority	= 99,
2338 	},
2339 	/* After packet filtering, change source only for VS/NAT */
2340 	{
2341 		.hook		= ip_vs_reply6,
2342 		.pf		= NFPROTO_IPV6,
2343 		.hooknum	= NF_INET_FORWARD,
2344 		.priority	= 100,
2345 	},
2346 #endif
2347 };
2348 /*
2349  *	Initialize IP Virtual Server netns mem.
2350  */
__ip_vs_init(struct net * net)2351 static int __net_init __ip_vs_init(struct net *net)
2352 {
2353 	struct netns_ipvs *ipvs;
2354 
2355 	ipvs = net_generic(net, ip_vs_net_id);
2356 	if (ipvs == NULL)
2357 		return -ENOMEM;
2358 
2359 	/* Hold the beast until a service is registerd */
2360 	ipvs->enable = 0;
2361 	ipvs->net = net;
2362 	/* Counters used for creating unique names */
2363 	ipvs->gen = atomic_read(&ipvs_netns_cnt);
2364 	atomic_inc(&ipvs_netns_cnt);
2365 	net->ipvs = ipvs;
2366 
2367 	if (ip_vs_estimator_net_init(ipvs) < 0)
2368 		goto estimator_fail;
2369 
2370 	if (ip_vs_control_net_init(ipvs) < 0)
2371 		goto control_fail;
2372 
2373 	if (ip_vs_protocol_net_init(ipvs) < 0)
2374 		goto protocol_fail;
2375 
2376 	if (ip_vs_app_net_init(ipvs) < 0)
2377 		goto app_fail;
2378 
2379 	if (ip_vs_conn_net_init(ipvs) < 0)
2380 		goto conn_fail;
2381 
2382 	if (ip_vs_sync_net_init(ipvs) < 0)
2383 		goto sync_fail;
2384 
2385 	return 0;
2386 /*
2387  * Error handling
2388  */
2389 
2390 sync_fail:
2391 	ip_vs_conn_net_cleanup(ipvs);
2392 conn_fail:
2393 	ip_vs_app_net_cleanup(ipvs);
2394 app_fail:
2395 	ip_vs_protocol_net_cleanup(ipvs);
2396 protocol_fail:
2397 	ip_vs_control_net_cleanup(ipvs);
2398 control_fail:
2399 	ip_vs_estimator_net_cleanup(ipvs);
2400 estimator_fail:
2401 	net->ipvs = NULL;
2402 	return -ENOMEM;
2403 }
2404 
__ip_vs_cleanup(struct net * net)2405 static void __net_exit __ip_vs_cleanup(struct net *net)
2406 {
2407 	struct netns_ipvs *ipvs = net_ipvs(net);
2408 
2409 	ip_vs_service_net_cleanup(ipvs);	/* ip_vs_flush() with locks */
2410 	ip_vs_conn_net_cleanup(ipvs);
2411 	ip_vs_app_net_cleanup(ipvs);
2412 	ip_vs_protocol_net_cleanup(ipvs);
2413 	ip_vs_control_net_cleanup(ipvs);
2414 	ip_vs_estimator_net_cleanup(ipvs);
2415 	IP_VS_DBG(2, "ipvs netns %d released\n", ipvs->gen);
2416 	net->ipvs = NULL;
2417 }
2418 
__ip_vs_dev_init(struct net * net)2419 static int __net_init __ip_vs_dev_init(struct net *net)
2420 {
2421 	int ret;
2422 
2423 	ret = nf_register_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2424 	if (ret < 0)
2425 		goto hook_fail;
2426 	return 0;
2427 
2428 hook_fail:
2429 	return ret;
2430 }
2431 
__ip_vs_dev_cleanup(struct net * net)2432 static void __net_exit __ip_vs_dev_cleanup(struct net *net)
2433 {
2434 	struct netns_ipvs *ipvs = net_ipvs(net);
2435 	EnterFunction(2);
2436 	nf_unregister_net_hooks(net, ip_vs_ops, ARRAY_SIZE(ip_vs_ops));
2437 	ipvs->enable = 0;	/* Disable packet reception */
2438 	smp_wmb();
2439 	ip_vs_sync_net_cleanup(ipvs);
2440 	LeaveFunction(2);
2441 }
2442 
2443 static struct pernet_operations ipvs_core_ops = {
2444 	.init = __ip_vs_init,
2445 	.exit = __ip_vs_cleanup,
2446 	.id   = &ip_vs_net_id,
2447 	.size = sizeof(struct netns_ipvs),
2448 };
2449 
2450 static struct pernet_operations ipvs_core_dev_ops = {
2451 	.init = __ip_vs_dev_init,
2452 	.exit = __ip_vs_dev_cleanup,
2453 };
2454 
2455 /*
2456  *	Initialize IP Virtual Server
2457  */
ip_vs_init(void)2458 static int __init ip_vs_init(void)
2459 {
2460 	int ret;
2461 
2462 	ret = ip_vs_control_init();
2463 	if (ret < 0) {
2464 		pr_err("can't setup control.\n");
2465 		goto exit;
2466 	}
2467 
2468 	ip_vs_protocol_init();
2469 
2470 	ret = ip_vs_conn_init();
2471 	if (ret < 0) {
2472 		pr_err("can't setup connection table.\n");
2473 		goto cleanup_protocol;
2474 	}
2475 
2476 	ret = register_pernet_subsys(&ipvs_core_ops);	/* Alloc ip_vs struct */
2477 	if (ret < 0)
2478 		goto cleanup_conn;
2479 
2480 	ret = register_pernet_device(&ipvs_core_dev_ops);
2481 	if (ret < 0)
2482 		goto cleanup_sub;
2483 
2484 	ret = ip_vs_register_nl_ioctl();
2485 	if (ret < 0) {
2486 		pr_err("can't register netlink/ioctl.\n");
2487 		goto cleanup_dev;
2488 	}
2489 
2490 	pr_info("ipvs loaded.\n");
2491 
2492 	return ret;
2493 
2494 cleanup_dev:
2495 	unregister_pernet_device(&ipvs_core_dev_ops);
2496 cleanup_sub:
2497 	unregister_pernet_subsys(&ipvs_core_ops);
2498 cleanup_conn:
2499 	ip_vs_conn_cleanup();
2500 cleanup_protocol:
2501 	ip_vs_protocol_cleanup();
2502 	ip_vs_control_cleanup();
2503 exit:
2504 	return ret;
2505 }
2506 
ip_vs_cleanup(void)2507 static void __exit ip_vs_cleanup(void)
2508 {
2509 	ip_vs_unregister_nl_ioctl();
2510 	unregister_pernet_device(&ipvs_core_dev_ops);
2511 	unregister_pernet_subsys(&ipvs_core_ops);	/* free ip_vs struct */
2512 	ip_vs_conn_cleanup();
2513 	ip_vs_protocol_cleanup();
2514 	ip_vs_control_cleanup();
2515 	pr_info("ipvs unloaded.\n");
2516 }
2517 
2518 module_init(ip_vs_init);
2519 module_exit(ip_vs_cleanup);
2520 MODULE_LICENSE("GPL");
2521