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. Many code here is taken from IP MASQ code of kernel 2.2.
16  *
17  * Changes:
18  */
19 
20 #define KMSG_COMPONENT "IPVS"
21 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
22 
23 #include <linux/interrupt.h>
24 #include <linux/in.h>
25 #include <linux/inet.h>
26 #include <linux/net.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/vmalloc.h>
30 #include <linux/proc_fs.h>		/* for proc_net_* */
31 #include <linux/slab.h>
32 #include <linux/seq_file.h>
33 #include <linux/jhash.h>
34 #include <linux/random.h>
35 
36 #include <net/net_namespace.h>
37 #include <net/ip_vs.h>
38 
39 
40 #ifndef CONFIG_IP_VS_TAB_BITS
41 #define CONFIG_IP_VS_TAB_BITS	12
42 #endif
43 
44 /*
45  * Connection hash size. Default is what was selected at compile time.
46 */
47 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
48 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
49 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
50 
51 /* size and mask values */
52 int ip_vs_conn_tab_size __read_mostly;
53 static int ip_vs_conn_tab_mask __read_mostly;
54 
55 /*
56  *  Connection hash table: for input and output packets lookups of IPVS
57  */
58 static struct hlist_head *ip_vs_conn_tab __read_mostly;
59 
60 /*  SLAB cache for IPVS connections */
61 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
62 
63 /*  counter for no client port connections */
64 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
65 
66 /* random value for IPVS connection hash */
67 static unsigned int ip_vs_conn_rnd __read_mostly;
68 
69 /*
70  *  Fine locking granularity for big connection hash table
71  */
72 #define CT_LOCKARRAY_BITS  5
73 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
74 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
75 
76 /* We need an addrstrlen that works with or without v6 */
77 #ifdef CONFIG_IP_VS_IPV6
78 #define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
79 #else
80 #define IP_VS_ADDRSTRLEN (8+1)
81 #endif
82 
83 struct ip_vs_aligned_lock
84 {
85 	spinlock_t	l;
86 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
87 
88 /* lock array for conn table */
89 static struct ip_vs_aligned_lock
90 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
91 
ct_write_lock_bh(unsigned int key)92 static inline void ct_write_lock_bh(unsigned int key)
93 {
94 	spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
95 }
96 
ct_write_unlock_bh(unsigned int key)97 static inline void ct_write_unlock_bh(unsigned int key)
98 {
99 	spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
100 }
101 
102 static void ip_vs_conn_expire(struct timer_list *t);
103 
104 /*
105  *	Returns hash value for IPVS connection entry
106  */
ip_vs_conn_hashkey(struct netns_ipvs * ipvs,int af,unsigned int proto,const union nf_inet_addr * addr,__be16 port)107 static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
108 				       const union nf_inet_addr *addr,
109 				       __be16 port)
110 {
111 #ifdef CONFIG_IP_VS_IPV6
112 	if (af == AF_INET6)
113 		return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
114 				    (__force u32)port, proto, ip_vs_conn_rnd) ^
115 			((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
116 #endif
117 	return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
118 			    ip_vs_conn_rnd) ^
119 		((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
120 }
121 
ip_vs_conn_hashkey_param(const struct ip_vs_conn_param * p,bool inverse)122 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
123 					     bool inverse)
124 {
125 	const union nf_inet_addr *addr;
126 	__be16 port;
127 
128 	if (p->pe_data && p->pe->hashkey_raw)
129 		return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
130 			ip_vs_conn_tab_mask;
131 
132 	if (likely(!inverse)) {
133 		addr = p->caddr;
134 		port = p->cport;
135 	} else {
136 		addr = p->vaddr;
137 		port = p->vport;
138 	}
139 
140 	return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
141 }
142 
ip_vs_conn_hashkey_conn(const struct ip_vs_conn * cp)143 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
144 {
145 	struct ip_vs_conn_param p;
146 
147 	ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
148 			      &cp->caddr, cp->cport, NULL, 0, &p);
149 
150 	if (cp->pe) {
151 		p.pe = cp->pe;
152 		p.pe_data = cp->pe_data;
153 		p.pe_data_len = cp->pe_data_len;
154 	}
155 
156 	return ip_vs_conn_hashkey_param(&p, false);
157 }
158 
159 /*
160  *	Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
161  *	returns bool success.
162  */
ip_vs_conn_hash(struct ip_vs_conn * cp)163 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
164 {
165 	unsigned int hash;
166 	int ret;
167 
168 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
169 		return 0;
170 
171 	/* Hash by protocol, client address and port */
172 	hash = ip_vs_conn_hashkey_conn(cp);
173 
174 	ct_write_lock_bh(hash);
175 	spin_lock(&cp->lock);
176 
177 	if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
178 		cp->flags |= IP_VS_CONN_F_HASHED;
179 		refcount_inc(&cp->refcnt);
180 		hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
181 		ret = 1;
182 	} else {
183 		pr_err("%s(): request for already hashed, called from %pS\n",
184 		       __func__, __builtin_return_address(0));
185 		ret = 0;
186 	}
187 
188 	spin_unlock(&cp->lock);
189 	ct_write_unlock_bh(hash);
190 
191 	return ret;
192 }
193 
194 
195 /*
196  *	UNhashes ip_vs_conn from ip_vs_conn_tab.
197  *	returns bool success. Caller should hold conn reference.
198  */
ip_vs_conn_unhash(struct ip_vs_conn * cp)199 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
200 {
201 	unsigned int hash;
202 	int ret;
203 
204 	/* unhash it and decrease its reference counter */
205 	hash = ip_vs_conn_hashkey_conn(cp);
206 
207 	ct_write_lock_bh(hash);
208 	spin_lock(&cp->lock);
209 
210 	if (cp->flags & IP_VS_CONN_F_HASHED) {
211 		hlist_del_rcu(&cp->c_list);
212 		cp->flags &= ~IP_VS_CONN_F_HASHED;
213 		refcount_dec(&cp->refcnt);
214 		ret = 1;
215 	} else
216 		ret = 0;
217 
218 	spin_unlock(&cp->lock);
219 	ct_write_unlock_bh(hash);
220 
221 	return ret;
222 }
223 
224 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
225  * returns bool success.
226  */
ip_vs_conn_unlink(struct ip_vs_conn * cp)227 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
228 {
229 	unsigned int hash;
230 	bool ret = false;
231 
232 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
233 		return refcount_dec_if_one(&cp->refcnt);
234 
235 	hash = ip_vs_conn_hashkey_conn(cp);
236 
237 	ct_write_lock_bh(hash);
238 	spin_lock(&cp->lock);
239 
240 	if (cp->flags & IP_VS_CONN_F_HASHED) {
241 		/* Decrease refcnt and unlink conn only if we are last user */
242 		if (refcount_dec_if_one(&cp->refcnt)) {
243 			hlist_del_rcu(&cp->c_list);
244 			cp->flags &= ~IP_VS_CONN_F_HASHED;
245 			ret = true;
246 		}
247 	}
248 
249 	spin_unlock(&cp->lock);
250 	ct_write_unlock_bh(hash);
251 
252 	return ret;
253 }
254 
255 
256 /*
257  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
258  *  Called for pkts coming from OUTside-to-INside.
259  *	p->caddr, p->cport: pkt source address (foreign host)
260  *	p->vaddr, p->vport: pkt dest address (load balancer)
261  */
262 static inline struct ip_vs_conn *
__ip_vs_conn_in_get(const struct ip_vs_conn_param * p)263 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
264 {
265 	unsigned int hash;
266 	struct ip_vs_conn *cp;
267 
268 	hash = ip_vs_conn_hashkey_param(p, false);
269 
270 	rcu_read_lock();
271 
272 	hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
273 		if (p->cport == cp->cport && p->vport == cp->vport &&
274 		    cp->af == p->af &&
275 		    ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
276 		    ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
277 		    ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
278 		    p->protocol == cp->protocol &&
279 		    cp->ipvs == p->ipvs) {
280 			if (!__ip_vs_conn_get(cp))
281 				continue;
282 			/* HIT */
283 			rcu_read_unlock();
284 			return cp;
285 		}
286 	}
287 
288 	rcu_read_unlock();
289 
290 	return NULL;
291 }
292 
ip_vs_conn_in_get(const struct ip_vs_conn_param * p)293 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
294 {
295 	struct ip_vs_conn *cp;
296 
297 	cp = __ip_vs_conn_in_get(p);
298 	if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
299 		struct ip_vs_conn_param cport_zero_p = *p;
300 		cport_zero_p.cport = 0;
301 		cp = __ip_vs_conn_in_get(&cport_zero_p);
302 	}
303 
304 	IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
305 		      ip_vs_proto_name(p->protocol),
306 		      IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
307 		      IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
308 		      cp ? "hit" : "not hit");
309 
310 	return cp;
311 }
312 
313 static int
ip_vs_conn_fill_param_proto(struct netns_ipvs * ipvs,int af,const struct sk_buff * skb,const struct ip_vs_iphdr * iph,struct ip_vs_conn_param * p)314 ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
315 			    int af, const struct sk_buff *skb,
316 			    const struct ip_vs_iphdr *iph,
317 			    struct ip_vs_conn_param *p)
318 {
319 	__be16 _ports[2], *pptr;
320 
321 	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
322 	if (pptr == NULL)
323 		return 1;
324 
325 	if (likely(!ip_vs_iph_inverse(iph)))
326 		ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
327 				      pptr[0], &iph->daddr, pptr[1], p);
328 	else
329 		ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
330 				      pptr[1], &iph->saddr, pptr[0], p);
331 	return 0;
332 }
333 
334 struct ip_vs_conn *
ip_vs_conn_in_get_proto(struct netns_ipvs * ipvs,int af,const struct sk_buff * skb,const struct ip_vs_iphdr * iph)335 ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
336 			const struct sk_buff *skb,
337 			const struct ip_vs_iphdr *iph)
338 {
339 	struct ip_vs_conn_param p;
340 
341 	if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
342 		return NULL;
343 
344 	return ip_vs_conn_in_get(&p);
345 }
346 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
347 
348 /* Get reference to connection template */
ip_vs_ct_in_get(const struct ip_vs_conn_param * p)349 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
350 {
351 	unsigned int hash;
352 	struct ip_vs_conn *cp;
353 
354 	hash = ip_vs_conn_hashkey_param(p, false);
355 
356 	rcu_read_lock();
357 
358 	hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
359 		if (unlikely(p->pe_data && p->pe->ct_match)) {
360 			if (cp->ipvs != p->ipvs)
361 				continue;
362 			if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
363 				if (__ip_vs_conn_get(cp))
364 					goto out;
365 			}
366 			continue;
367 		}
368 
369 		if (cp->af == p->af &&
370 		    ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
371 		    /* protocol should only be IPPROTO_IP if
372 		     * p->vaddr is a fwmark */
373 		    ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
374 				     p->af, p->vaddr, &cp->vaddr) &&
375 		    p->vport == cp->vport && p->cport == cp->cport &&
376 		    cp->flags & IP_VS_CONN_F_TEMPLATE &&
377 		    p->protocol == cp->protocol &&
378 		    cp->ipvs == p->ipvs) {
379 			if (__ip_vs_conn_get(cp))
380 				goto out;
381 		}
382 	}
383 	cp = NULL;
384 
385   out:
386 	rcu_read_unlock();
387 
388 	IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
389 		      ip_vs_proto_name(p->protocol),
390 		      IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
391 		      IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
392 		      cp ? "hit" : "not hit");
393 
394 	return cp;
395 }
396 
397 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
398  * Called for pkts coming from inside-to-OUTside.
399  *	p->caddr, p->cport: pkt source address (inside host)
400  *	p->vaddr, p->vport: pkt dest address (foreign host) */
ip_vs_conn_out_get(const struct ip_vs_conn_param * p)401 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
402 {
403 	unsigned int hash;
404 	struct ip_vs_conn *cp, *ret=NULL;
405 	const union nf_inet_addr *saddr;
406 	__be16 sport;
407 
408 	/*
409 	 *	Check for "full" addressed entries
410 	 */
411 	hash = ip_vs_conn_hashkey_param(p, true);
412 
413 	rcu_read_lock();
414 
415 	hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
416 		if (p->vport != cp->cport)
417 			continue;
418 
419 		if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
420 			sport = cp->vport;
421 			saddr = &cp->vaddr;
422 		} else {
423 			sport = cp->dport;
424 			saddr = &cp->daddr;
425 		}
426 
427 		if (p->cport == sport && cp->af == p->af &&
428 		    ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
429 		    ip_vs_addr_equal(p->af, p->caddr, saddr) &&
430 		    p->protocol == cp->protocol &&
431 		    cp->ipvs == p->ipvs) {
432 			if (!__ip_vs_conn_get(cp))
433 				continue;
434 			/* HIT */
435 			ret = cp;
436 			break;
437 		}
438 	}
439 
440 	rcu_read_unlock();
441 
442 	IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
443 		      ip_vs_proto_name(p->protocol),
444 		      IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
445 		      IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
446 		      ret ? "hit" : "not hit");
447 
448 	return ret;
449 }
450 
451 struct ip_vs_conn *
ip_vs_conn_out_get_proto(struct netns_ipvs * ipvs,int af,const struct sk_buff * skb,const struct ip_vs_iphdr * iph)452 ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
453 			 const struct sk_buff *skb,
454 			 const struct ip_vs_iphdr *iph)
455 {
456 	struct ip_vs_conn_param p;
457 
458 	if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
459 		return NULL;
460 
461 	return ip_vs_conn_out_get(&p);
462 }
463 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
464 
465 /*
466  *      Put back the conn and restart its timer with its timeout
467  */
__ip_vs_conn_put_timer(struct ip_vs_conn * cp)468 static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
469 {
470 	unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
471 		0 : cp->timeout;
472 	mod_timer(&cp->timer, jiffies+t);
473 
474 	__ip_vs_conn_put(cp);
475 }
476 
ip_vs_conn_put(struct ip_vs_conn * cp)477 void ip_vs_conn_put(struct ip_vs_conn *cp)
478 {
479 	if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
480 	    (refcount_read(&cp->refcnt) == 1) &&
481 	    !timer_pending(&cp->timer))
482 		/* expire connection immediately */
483 		ip_vs_conn_expire(&cp->timer);
484 	else
485 		__ip_vs_conn_put_timer(cp);
486 }
487 
488 /*
489  *	Fill a no_client_port connection with a client port number
490  */
ip_vs_conn_fill_cport(struct ip_vs_conn * cp,__be16 cport)491 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
492 {
493 	if (ip_vs_conn_unhash(cp)) {
494 		spin_lock_bh(&cp->lock);
495 		if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
496 			atomic_dec(&ip_vs_conn_no_cport_cnt);
497 			cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
498 			cp->cport = cport;
499 		}
500 		spin_unlock_bh(&cp->lock);
501 
502 		/* hash on new dport */
503 		ip_vs_conn_hash(cp);
504 	}
505 }
506 
507 
508 /*
509  *	Bind a connection entry with the corresponding packet_xmit.
510  *	Called by ip_vs_conn_new.
511  */
ip_vs_bind_xmit(struct ip_vs_conn * cp)512 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
513 {
514 	switch (IP_VS_FWD_METHOD(cp)) {
515 	case IP_VS_CONN_F_MASQ:
516 		cp->packet_xmit = ip_vs_nat_xmit;
517 		break;
518 
519 	case IP_VS_CONN_F_TUNNEL:
520 #ifdef CONFIG_IP_VS_IPV6
521 		if (cp->daf == AF_INET6)
522 			cp->packet_xmit = ip_vs_tunnel_xmit_v6;
523 		else
524 #endif
525 			cp->packet_xmit = ip_vs_tunnel_xmit;
526 		break;
527 
528 	case IP_VS_CONN_F_DROUTE:
529 		cp->packet_xmit = ip_vs_dr_xmit;
530 		break;
531 
532 	case IP_VS_CONN_F_LOCALNODE:
533 		cp->packet_xmit = ip_vs_null_xmit;
534 		break;
535 
536 	case IP_VS_CONN_F_BYPASS:
537 		cp->packet_xmit = ip_vs_bypass_xmit;
538 		break;
539 	}
540 }
541 
542 #ifdef CONFIG_IP_VS_IPV6
ip_vs_bind_xmit_v6(struct ip_vs_conn * cp)543 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
544 {
545 	switch (IP_VS_FWD_METHOD(cp)) {
546 	case IP_VS_CONN_F_MASQ:
547 		cp->packet_xmit = ip_vs_nat_xmit_v6;
548 		break;
549 
550 	case IP_VS_CONN_F_TUNNEL:
551 		if (cp->daf == AF_INET6)
552 			cp->packet_xmit = ip_vs_tunnel_xmit_v6;
553 		else
554 			cp->packet_xmit = ip_vs_tunnel_xmit;
555 		break;
556 
557 	case IP_VS_CONN_F_DROUTE:
558 		cp->packet_xmit = ip_vs_dr_xmit_v6;
559 		break;
560 
561 	case IP_VS_CONN_F_LOCALNODE:
562 		cp->packet_xmit = ip_vs_null_xmit;
563 		break;
564 
565 	case IP_VS_CONN_F_BYPASS:
566 		cp->packet_xmit = ip_vs_bypass_xmit_v6;
567 		break;
568 	}
569 }
570 #endif
571 
572 
ip_vs_dest_totalconns(struct ip_vs_dest * dest)573 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
574 {
575 	return atomic_read(&dest->activeconns)
576 		+ atomic_read(&dest->inactconns);
577 }
578 
579 /*
580  *	Bind a connection entry with a virtual service destination
581  *	Called just after a new connection entry is created.
582  */
583 static inline void
ip_vs_bind_dest(struct ip_vs_conn * cp,struct ip_vs_dest * dest)584 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
585 {
586 	unsigned int conn_flags;
587 	__u32 flags;
588 
589 	/* if dest is NULL, then return directly */
590 	if (!dest)
591 		return;
592 
593 	/* Increase the refcnt counter of the dest */
594 	ip_vs_dest_hold(dest);
595 
596 	conn_flags = atomic_read(&dest->conn_flags);
597 	if (cp->protocol != IPPROTO_UDP)
598 		conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
599 	flags = cp->flags;
600 	/* Bind with the destination and its corresponding transmitter */
601 	if (flags & IP_VS_CONN_F_SYNC) {
602 		/* if the connection is not template and is created
603 		 * by sync, preserve the activity flag.
604 		 */
605 		if (!(flags & IP_VS_CONN_F_TEMPLATE))
606 			conn_flags &= ~IP_VS_CONN_F_INACTIVE;
607 		/* connections inherit forwarding method from dest */
608 		flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
609 	}
610 	flags |= conn_flags;
611 	cp->flags = flags;
612 	cp->dest = dest;
613 
614 	IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
615 		      "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
616 		      "dest->refcnt:%d\n",
617 		      ip_vs_proto_name(cp->protocol),
618 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
619 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
620 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
621 		      ip_vs_fwd_tag(cp), cp->state,
622 		      cp->flags, refcount_read(&cp->refcnt),
623 		      refcount_read(&dest->refcnt));
624 
625 	/* Update the connection counters */
626 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
627 		/* It is a normal connection, so modify the counters
628 		 * according to the flags, later the protocol can
629 		 * update them on state change
630 		 */
631 		if (!(flags & IP_VS_CONN_F_INACTIVE))
632 			atomic_inc(&dest->activeconns);
633 		else
634 			atomic_inc(&dest->inactconns);
635 	} else {
636 		/* It is a persistent connection/template, so increase
637 		   the persistent connection counter */
638 		atomic_inc(&dest->persistconns);
639 	}
640 
641 	if (dest->u_threshold != 0 &&
642 	    ip_vs_dest_totalconns(dest) >= dest->u_threshold)
643 		dest->flags |= IP_VS_DEST_F_OVERLOAD;
644 }
645 
646 
647 /*
648  * Check if there is a destination for the connection, if so
649  * bind the connection to the destination.
650  */
ip_vs_try_bind_dest(struct ip_vs_conn * cp)651 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
652 {
653 	struct ip_vs_dest *dest;
654 
655 	rcu_read_lock();
656 
657 	/* This function is only invoked by the synchronization code. We do
658 	 * not currently support heterogeneous pools with synchronization,
659 	 * so we can make the assumption that the svc_af is the same as the
660 	 * dest_af
661 	 */
662 	dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
663 			       cp->dport, &cp->vaddr, cp->vport,
664 			       cp->protocol, cp->fwmark, cp->flags);
665 	if (dest) {
666 		struct ip_vs_proto_data *pd;
667 
668 		spin_lock_bh(&cp->lock);
669 		if (cp->dest) {
670 			spin_unlock_bh(&cp->lock);
671 			rcu_read_unlock();
672 			return;
673 		}
674 
675 		/* Applications work depending on the forwarding method
676 		 * but better to reassign them always when binding dest */
677 		if (cp->app)
678 			ip_vs_unbind_app(cp);
679 
680 		ip_vs_bind_dest(cp, dest);
681 		spin_unlock_bh(&cp->lock);
682 
683 		/* Update its packet transmitter */
684 		cp->packet_xmit = NULL;
685 #ifdef CONFIG_IP_VS_IPV6
686 		if (cp->af == AF_INET6)
687 			ip_vs_bind_xmit_v6(cp);
688 		else
689 #endif
690 			ip_vs_bind_xmit(cp);
691 
692 		pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
693 		if (pd && atomic_read(&pd->appcnt))
694 			ip_vs_bind_app(cp, pd->pp);
695 	}
696 	rcu_read_unlock();
697 }
698 
699 
700 /*
701  *	Unbind a connection entry with its VS destination
702  *	Called by the ip_vs_conn_expire function.
703  */
ip_vs_unbind_dest(struct ip_vs_conn * cp)704 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
705 {
706 	struct ip_vs_dest *dest = cp->dest;
707 
708 	if (!dest)
709 		return;
710 
711 	IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
712 		      "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
713 		      "dest->refcnt:%d\n",
714 		      ip_vs_proto_name(cp->protocol),
715 		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
716 		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
717 		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
718 		      ip_vs_fwd_tag(cp), cp->state,
719 		      cp->flags, refcount_read(&cp->refcnt),
720 		      refcount_read(&dest->refcnt));
721 
722 	/* Update the connection counters */
723 	if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
724 		/* It is a normal connection, so decrease the inactconns
725 		   or activeconns counter */
726 		if (cp->flags & IP_VS_CONN_F_INACTIVE) {
727 			atomic_dec(&dest->inactconns);
728 		} else {
729 			atomic_dec(&dest->activeconns);
730 		}
731 	} else {
732 		/* It is a persistent connection/template, so decrease
733 		   the persistent connection counter */
734 		atomic_dec(&dest->persistconns);
735 	}
736 
737 	if (dest->l_threshold != 0) {
738 		if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
739 			dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
740 	} else if (dest->u_threshold != 0) {
741 		if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
742 			dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
743 	} else {
744 		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
745 			dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
746 	}
747 
748 	ip_vs_dest_put(dest);
749 }
750 
expire_quiescent_template(struct netns_ipvs * ipvs,struct ip_vs_dest * dest)751 static int expire_quiescent_template(struct netns_ipvs *ipvs,
752 				     struct ip_vs_dest *dest)
753 {
754 #ifdef CONFIG_SYSCTL
755 	return ipvs->sysctl_expire_quiescent_template &&
756 		(atomic_read(&dest->weight) == 0);
757 #else
758 	return 0;
759 #endif
760 }
761 
762 /*
763  *	Checking if the destination of a connection template is available.
764  *	If available, return 1, otherwise invalidate this connection
765  *	template and return 0.
766  */
ip_vs_check_template(struct ip_vs_conn * ct,struct ip_vs_dest * cdest)767 int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
768 {
769 	struct ip_vs_dest *dest = ct->dest;
770 	struct netns_ipvs *ipvs = ct->ipvs;
771 
772 	/*
773 	 * Checking the dest server status.
774 	 */
775 	if ((dest == NULL) ||
776 	    !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
777 	    expire_quiescent_template(ipvs, dest) ||
778 	    (cdest && (dest != cdest))) {
779 		IP_VS_DBG_BUF(9, "check_template: dest not available for "
780 			      "protocol %s s:%s:%d v:%s:%d "
781 			      "-> d:%s:%d\n",
782 			      ip_vs_proto_name(ct->protocol),
783 			      IP_VS_DBG_ADDR(ct->af, &ct->caddr),
784 			      ntohs(ct->cport),
785 			      IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
786 			      ntohs(ct->vport),
787 			      IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
788 			      ntohs(ct->dport));
789 
790 		/*
791 		 * Invalidate the connection template
792 		 */
793 		if (ct->vport != htons(0xffff)) {
794 			if (ip_vs_conn_unhash(ct)) {
795 				ct->dport = htons(0xffff);
796 				ct->vport = htons(0xffff);
797 				ct->cport = 0;
798 				ip_vs_conn_hash(ct);
799 			}
800 		}
801 
802 		/*
803 		 * Simply decrease the refcnt of the template,
804 		 * don't restart its timer.
805 		 */
806 		__ip_vs_conn_put(ct);
807 		return 0;
808 	}
809 	return 1;
810 }
811 
ip_vs_conn_rcu_free(struct rcu_head * head)812 static void ip_vs_conn_rcu_free(struct rcu_head *head)
813 {
814 	struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
815 					     rcu_head);
816 
817 	ip_vs_pe_put(cp->pe);
818 	kfree(cp->pe_data);
819 	kmem_cache_free(ip_vs_conn_cachep, cp);
820 }
821 
822 /* Try to delete connection while not holding reference */
ip_vs_conn_del(struct ip_vs_conn * cp)823 static void ip_vs_conn_del(struct ip_vs_conn *cp)
824 {
825 	if (del_timer(&cp->timer)) {
826 		/* Drop cp->control chain too */
827 		if (cp->control)
828 			cp->timeout = 0;
829 		ip_vs_conn_expire(&cp->timer);
830 	}
831 }
832 
833 /* Try to delete connection while holding reference */
ip_vs_conn_del_put(struct ip_vs_conn * cp)834 static void ip_vs_conn_del_put(struct ip_vs_conn *cp)
835 {
836 	if (del_timer(&cp->timer)) {
837 		/* Drop cp->control chain too */
838 		if (cp->control)
839 			cp->timeout = 0;
840 		__ip_vs_conn_put(cp);
841 		ip_vs_conn_expire(&cp->timer);
842 	} else {
843 		__ip_vs_conn_put(cp);
844 	}
845 }
846 
ip_vs_conn_expire(struct timer_list * t)847 static void ip_vs_conn_expire(struct timer_list *t)
848 {
849 	struct ip_vs_conn *cp = from_timer(cp, t, timer);
850 	struct netns_ipvs *ipvs = cp->ipvs;
851 
852 	/*
853 	 *	do I control anybody?
854 	 */
855 	if (atomic_read(&cp->n_control))
856 		goto expire_later;
857 
858 	/* Unlink conn if not referenced anymore */
859 	if (likely(ip_vs_conn_unlink(cp))) {
860 		struct ip_vs_conn *ct = cp->control;
861 
862 		/* delete the timer if it is activated by other users */
863 		del_timer(&cp->timer);
864 
865 		/* does anybody control me? */
866 		if (ct) {
867 			bool has_ref = !cp->timeout && __ip_vs_conn_get(ct);
868 
869 			ip_vs_control_del(cp);
870 			/* Drop CTL or non-assured TPL if not used anymore */
871 			if (has_ref && !atomic_read(&ct->n_control) &&
872 			    (!(ct->flags & IP_VS_CONN_F_TEMPLATE) ||
873 			     !(ct->state & IP_VS_CTPL_S_ASSURED))) {
874 				IP_VS_DBG(4, "drop controlling connection\n");
875 				ip_vs_conn_del_put(ct);
876 			} else if (has_ref) {
877 				__ip_vs_conn_put(ct);
878 			}
879 		}
880 
881 		if ((cp->flags & IP_VS_CONN_F_NFCT) &&
882 		    !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
883 			/* Do not access conntracks during subsys cleanup
884 			 * because nf_conntrack_find_get can not be used after
885 			 * conntrack cleanup for the net.
886 			 */
887 			smp_rmb();
888 			if (ipvs->enable)
889 				ip_vs_conn_drop_conntrack(cp);
890 		}
891 
892 		if (unlikely(cp->app != NULL))
893 			ip_vs_unbind_app(cp);
894 		ip_vs_unbind_dest(cp);
895 		if (cp->flags & IP_VS_CONN_F_NO_CPORT)
896 			atomic_dec(&ip_vs_conn_no_cport_cnt);
897 		if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
898 			ip_vs_conn_rcu_free(&cp->rcu_head);
899 		else
900 			call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
901 		atomic_dec(&ipvs->conn_count);
902 		return;
903 	}
904 
905   expire_later:
906 	IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
907 		  refcount_read(&cp->refcnt),
908 		  atomic_read(&cp->n_control));
909 
910 	refcount_inc(&cp->refcnt);
911 	cp->timeout = 60*HZ;
912 
913 	if (ipvs->sync_state & IP_VS_STATE_MASTER)
914 		ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
915 
916 	__ip_vs_conn_put_timer(cp);
917 }
918 
919 /* Modify timer, so that it expires as soon as possible.
920  * Can be called without reference only if under RCU lock.
921  * We can have such chain of conns linked with ->control: DATA->CTL->TPL
922  * - DATA (eg. FTP) and TPL (persistence) can be present depending on setup
923  * - cp->timeout=0 indicates all conns from chain should be dropped but
924  * TPL is not dropped if in assured state
925  */
ip_vs_conn_expire_now(struct ip_vs_conn * cp)926 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
927 {
928 	/* Using mod_timer_pending will ensure the timer is not
929 	 * modified after the final del_timer in ip_vs_conn_expire.
930 	 */
931 	if (timer_pending(&cp->timer) &&
932 	    time_after(cp->timer.expires, jiffies))
933 		mod_timer_pending(&cp->timer, jiffies);
934 }
935 
936 
937 /*
938  *	Create a new connection entry and hash it into the ip_vs_conn_tab
939  */
940 struct ip_vs_conn *
ip_vs_conn_new(const struct ip_vs_conn_param * p,int dest_af,const union nf_inet_addr * daddr,__be16 dport,unsigned int flags,struct ip_vs_dest * dest,__u32 fwmark)941 ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
942 	       const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
943 	       struct ip_vs_dest *dest, __u32 fwmark)
944 {
945 	struct ip_vs_conn *cp;
946 	struct netns_ipvs *ipvs = p->ipvs;
947 	struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
948 							   p->protocol);
949 
950 	cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
951 	if (cp == NULL) {
952 		IP_VS_ERR_RL("%s(): no memory\n", __func__);
953 		return NULL;
954 	}
955 
956 	INIT_HLIST_NODE(&cp->c_list);
957 	timer_setup(&cp->timer, ip_vs_conn_expire, 0);
958 	cp->ipvs	   = ipvs;
959 	cp->af		   = p->af;
960 	cp->daf		   = dest_af;
961 	cp->protocol	   = p->protocol;
962 	ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
963 	cp->cport	   = p->cport;
964 	/* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
965 	ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
966 		       &cp->vaddr, p->vaddr);
967 	cp->vport	   = p->vport;
968 	ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
969 	cp->dport          = dport;
970 	cp->flags	   = flags;
971 	cp->fwmark         = fwmark;
972 	if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
973 		ip_vs_pe_get(p->pe);
974 		cp->pe = p->pe;
975 		cp->pe_data = p->pe_data;
976 		cp->pe_data_len = p->pe_data_len;
977 	} else {
978 		cp->pe = NULL;
979 		cp->pe_data = NULL;
980 		cp->pe_data_len = 0;
981 	}
982 	spin_lock_init(&cp->lock);
983 
984 	/*
985 	 * Set the entry is referenced by the current thread before hashing
986 	 * it in the table, so that other thread run ip_vs_random_dropentry
987 	 * but cannot drop this entry.
988 	 */
989 	refcount_set(&cp->refcnt, 1);
990 
991 	cp->control = NULL;
992 	atomic_set(&cp->n_control, 0);
993 	atomic_set(&cp->in_pkts, 0);
994 
995 	cp->packet_xmit = NULL;
996 	cp->app = NULL;
997 	cp->app_data = NULL;
998 	/* reset struct ip_vs_seq */
999 	cp->in_seq.delta = 0;
1000 	cp->out_seq.delta = 0;
1001 
1002 	atomic_inc(&ipvs->conn_count);
1003 	if (flags & IP_VS_CONN_F_NO_CPORT)
1004 		atomic_inc(&ip_vs_conn_no_cport_cnt);
1005 
1006 	/* Bind the connection with a destination server */
1007 	cp->dest = NULL;
1008 	ip_vs_bind_dest(cp, dest);
1009 
1010 	/* Set its state and timeout */
1011 	cp->state = 0;
1012 	cp->old_state = 0;
1013 	cp->timeout = 3*HZ;
1014 	cp->sync_endtime = jiffies & ~3UL;
1015 
1016 	/* Bind its packet transmitter */
1017 #ifdef CONFIG_IP_VS_IPV6
1018 	if (p->af == AF_INET6)
1019 		ip_vs_bind_xmit_v6(cp);
1020 	else
1021 #endif
1022 		ip_vs_bind_xmit(cp);
1023 
1024 	if (unlikely(pd && atomic_read(&pd->appcnt)))
1025 		ip_vs_bind_app(cp, pd->pp);
1026 
1027 	/*
1028 	 * Allow conntrack to be preserved. By default, conntrack
1029 	 * is created and destroyed for every packet.
1030 	 * Sometimes keeping conntrack can be useful for
1031 	 * IP_VS_CONN_F_ONE_PACKET too.
1032 	 */
1033 
1034 	if (ip_vs_conntrack_enabled(ipvs))
1035 		cp->flags |= IP_VS_CONN_F_NFCT;
1036 
1037 	/* Hash it in the ip_vs_conn_tab finally */
1038 	ip_vs_conn_hash(cp);
1039 
1040 	return cp;
1041 }
1042 
1043 /*
1044  *	/proc/net/ip_vs_conn entries
1045  */
1046 #ifdef CONFIG_PROC_FS
1047 struct ip_vs_iter_state {
1048 	struct seq_net_private	p;
1049 	struct hlist_head	*l;
1050 };
1051 
ip_vs_conn_array(struct seq_file * seq,loff_t pos)1052 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
1053 {
1054 	int idx;
1055 	struct ip_vs_conn *cp;
1056 	struct ip_vs_iter_state *iter = seq->private;
1057 
1058 	for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1059 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1060 			/* __ip_vs_conn_get() is not needed by
1061 			 * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
1062 			 */
1063 			if (pos-- == 0) {
1064 				iter->l = &ip_vs_conn_tab[idx];
1065 				return cp;
1066 			}
1067 		}
1068 		cond_resched_rcu();
1069 	}
1070 
1071 	return NULL;
1072 }
1073 
ip_vs_conn_seq_start(struct seq_file * seq,loff_t * pos)1074 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
1075 	__acquires(RCU)
1076 {
1077 	struct ip_vs_iter_state *iter = seq->private;
1078 
1079 	iter->l = NULL;
1080 	rcu_read_lock();
1081 	return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
1082 }
1083 
ip_vs_conn_seq_next(struct seq_file * seq,void * v,loff_t * pos)1084 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1085 {
1086 	struct ip_vs_conn *cp = v;
1087 	struct ip_vs_iter_state *iter = seq->private;
1088 	struct hlist_node *e;
1089 	struct hlist_head *l = iter->l;
1090 	int idx;
1091 
1092 	++*pos;
1093 	if (v == SEQ_START_TOKEN)
1094 		return ip_vs_conn_array(seq, 0);
1095 
1096 	/* more on same hash chain? */
1097 	e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1098 	if (e)
1099 		return hlist_entry(e, struct ip_vs_conn, c_list);
1100 
1101 	idx = l - ip_vs_conn_tab;
1102 	while (++idx < ip_vs_conn_tab_size) {
1103 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1104 			iter->l = &ip_vs_conn_tab[idx];
1105 			return cp;
1106 		}
1107 		cond_resched_rcu();
1108 	}
1109 	iter->l = NULL;
1110 	return NULL;
1111 }
1112 
ip_vs_conn_seq_stop(struct seq_file * seq,void * v)1113 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1114 	__releases(RCU)
1115 {
1116 	rcu_read_unlock();
1117 }
1118 
ip_vs_conn_seq_show(struct seq_file * seq,void * v)1119 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1120 {
1121 
1122 	if (v == SEQ_START_TOKEN)
1123 		seq_puts(seq,
1124    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1125 	else {
1126 		const struct ip_vs_conn *cp = v;
1127 		struct net *net = seq_file_net(seq);
1128 		char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1129 		size_t len = 0;
1130 		char dbuf[IP_VS_ADDRSTRLEN];
1131 
1132 		if (!net_eq(cp->ipvs->net, net))
1133 			return 0;
1134 		if (cp->pe_data) {
1135 			pe_data[0] = ' ';
1136 			len = strlen(cp->pe->name);
1137 			memcpy(pe_data + 1, cp->pe->name, len);
1138 			pe_data[len + 1] = ' ';
1139 			len += 2;
1140 			len += cp->pe->show_pe_data(cp, pe_data + len);
1141 		}
1142 		pe_data[len] = '\0';
1143 
1144 #ifdef CONFIG_IP_VS_IPV6
1145 		if (cp->daf == AF_INET6)
1146 			snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1147 		else
1148 #endif
1149 			snprintf(dbuf, sizeof(dbuf), "%08X",
1150 				 ntohl(cp->daddr.ip));
1151 
1152 #ifdef CONFIG_IP_VS_IPV6
1153 		if (cp->af == AF_INET6)
1154 			seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1155 				"%s %04X %-11s %7u%s\n",
1156 				ip_vs_proto_name(cp->protocol),
1157 				&cp->caddr.in6, ntohs(cp->cport),
1158 				&cp->vaddr.in6, ntohs(cp->vport),
1159 				dbuf, ntohs(cp->dport),
1160 				ip_vs_state_name(cp),
1161 				jiffies_delta_to_msecs(cp->timer.expires -
1162 						       jiffies) / 1000,
1163 				pe_data);
1164 		else
1165 #endif
1166 			seq_printf(seq,
1167 				"%-3s %08X %04X %08X %04X"
1168 				" %s %04X %-11s %7u%s\n",
1169 				ip_vs_proto_name(cp->protocol),
1170 				ntohl(cp->caddr.ip), ntohs(cp->cport),
1171 				ntohl(cp->vaddr.ip), ntohs(cp->vport),
1172 				dbuf, ntohs(cp->dport),
1173 				ip_vs_state_name(cp),
1174 				jiffies_delta_to_msecs(cp->timer.expires -
1175 						       jiffies) / 1000,
1176 				pe_data);
1177 	}
1178 	return 0;
1179 }
1180 
1181 static const struct seq_operations ip_vs_conn_seq_ops = {
1182 	.start = ip_vs_conn_seq_start,
1183 	.next  = ip_vs_conn_seq_next,
1184 	.stop  = ip_vs_conn_seq_stop,
1185 	.show  = ip_vs_conn_seq_show,
1186 };
1187 
ip_vs_origin_name(unsigned int flags)1188 static const char *ip_vs_origin_name(unsigned int flags)
1189 {
1190 	if (flags & IP_VS_CONN_F_SYNC)
1191 		return "SYNC";
1192 	else
1193 		return "LOCAL";
1194 }
1195 
ip_vs_conn_sync_seq_show(struct seq_file * seq,void * v)1196 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1197 {
1198 	char dbuf[IP_VS_ADDRSTRLEN];
1199 
1200 	if (v == SEQ_START_TOKEN)
1201 		seq_puts(seq,
1202    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1203 	else {
1204 		const struct ip_vs_conn *cp = v;
1205 		struct net *net = seq_file_net(seq);
1206 
1207 		if (!net_eq(cp->ipvs->net, net))
1208 			return 0;
1209 
1210 #ifdef CONFIG_IP_VS_IPV6
1211 		if (cp->daf == AF_INET6)
1212 			snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1213 		else
1214 #endif
1215 			snprintf(dbuf, sizeof(dbuf), "%08X",
1216 				 ntohl(cp->daddr.ip));
1217 
1218 #ifdef CONFIG_IP_VS_IPV6
1219 		if (cp->af == AF_INET6)
1220 			seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1221 				"%s %04X %-11s %-6s %7u\n",
1222 				ip_vs_proto_name(cp->protocol),
1223 				&cp->caddr.in6, ntohs(cp->cport),
1224 				&cp->vaddr.in6, ntohs(cp->vport),
1225 				dbuf, ntohs(cp->dport),
1226 				ip_vs_state_name(cp),
1227 				ip_vs_origin_name(cp->flags),
1228 				jiffies_delta_to_msecs(cp->timer.expires -
1229 						       jiffies) / 1000);
1230 		else
1231 #endif
1232 			seq_printf(seq,
1233 				"%-3s %08X %04X %08X %04X "
1234 				"%s %04X %-11s %-6s %7u\n",
1235 				ip_vs_proto_name(cp->protocol),
1236 				ntohl(cp->caddr.ip), ntohs(cp->cport),
1237 				ntohl(cp->vaddr.ip), ntohs(cp->vport),
1238 				dbuf, ntohs(cp->dport),
1239 				ip_vs_state_name(cp),
1240 				ip_vs_origin_name(cp->flags),
1241 				jiffies_delta_to_msecs(cp->timer.expires -
1242 						       jiffies) / 1000);
1243 	}
1244 	return 0;
1245 }
1246 
1247 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1248 	.start = ip_vs_conn_seq_start,
1249 	.next  = ip_vs_conn_seq_next,
1250 	.stop  = ip_vs_conn_seq_stop,
1251 	.show  = ip_vs_conn_sync_seq_show,
1252 };
1253 #endif
1254 
1255 
1256 /* Randomly drop connection entries before running out of memory
1257  * Can be used for DATA and CTL conns. For TPL conns there are exceptions:
1258  * - traffic for services in OPS mode increases ct->in_pkts, so it is supported
1259  * - traffic for services not in OPS mode does not increase ct->in_pkts in
1260  * all cases, so it is not supported
1261  */
todrop_entry(struct ip_vs_conn * cp)1262 static inline int todrop_entry(struct ip_vs_conn *cp)
1263 {
1264 	/*
1265 	 * The drop rate array needs tuning for real environments.
1266 	 * Called from timer bh only => no locking
1267 	 */
1268 	static const signed char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1269 	static signed char todrop_counter[9] = {0};
1270 	int i;
1271 
1272 	/* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1273 	   This will leave enough time for normal connection to get
1274 	   through. */
1275 	if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1276 		return 0;
1277 
1278 	/* Don't drop the entry if its number of incoming packets is not
1279 	   located in [0, 8] */
1280 	i = atomic_read(&cp->in_pkts);
1281 	if (i > 8 || i < 0) return 0;
1282 
1283 	if (!todrop_rate[i]) return 0;
1284 	if (--todrop_counter[i] > 0) return 0;
1285 
1286 	todrop_counter[i] = todrop_rate[i];
1287 	return 1;
1288 }
1289 
ip_vs_conn_ops_mode(struct ip_vs_conn * cp)1290 static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
1291 {
1292 	struct ip_vs_service *svc;
1293 
1294 	if (!cp->dest)
1295 		return false;
1296 	svc = rcu_dereference(cp->dest->svc);
1297 	return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
1298 }
1299 
1300 /* Called from keventd and must protect itself from softirqs */
ip_vs_random_dropentry(struct netns_ipvs * ipvs)1301 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
1302 {
1303 	int idx;
1304 	struct ip_vs_conn *cp;
1305 
1306 	rcu_read_lock();
1307 	/*
1308 	 * Randomly scan 1/32 of the whole table every second
1309 	 */
1310 	for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1311 		unsigned int hash = get_random_u32() & ip_vs_conn_tab_mask;
1312 
1313 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1314 			if (cp->ipvs != ipvs)
1315 				continue;
1316 			if (atomic_read(&cp->n_control))
1317 				continue;
1318 			if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
1319 				/* connection template of OPS */
1320 				if (ip_vs_conn_ops_mode(cp))
1321 					goto try_drop;
1322 				if (!(cp->state & IP_VS_CTPL_S_ASSURED))
1323 					goto drop;
1324 				continue;
1325 			}
1326 			if (cp->protocol == IPPROTO_TCP) {
1327 				switch(cp->state) {
1328 				case IP_VS_TCP_S_SYN_RECV:
1329 				case IP_VS_TCP_S_SYNACK:
1330 					break;
1331 
1332 				case IP_VS_TCP_S_ESTABLISHED:
1333 					if (todrop_entry(cp))
1334 						break;
1335 					continue;
1336 
1337 				default:
1338 					continue;
1339 				}
1340 			} else if (cp->protocol == IPPROTO_SCTP) {
1341 				switch (cp->state) {
1342 				case IP_VS_SCTP_S_INIT1:
1343 				case IP_VS_SCTP_S_INIT:
1344 					break;
1345 				case IP_VS_SCTP_S_ESTABLISHED:
1346 					if (todrop_entry(cp))
1347 						break;
1348 					continue;
1349 				default:
1350 					continue;
1351 				}
1352 			} else {
1353 try_drop:
1354 				if (!todrop_entry(cp))
1355 					continue;
1356 			}
1357 
1358 drop:
1359 			IP_VS_DBG(4, "drop connection\n");
1360 			ip_vs_conn_del(cp);
1361 		}
1362 		cond_resched_rcu();
1363 	}
1364 	rcu_read_unlock();
1365 }
1366 
1367 
1368 /*
1369  *      Flush all the connection entries in the ip_vs_conn_tab
1370  */
ip_vs_conn_flush(struct netns_ipvs * ipvs)1371 static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
1372 {
1373 	int idx;
1374 	struct ip_vs_conn *cp, *cp_c;
1375 
1376 flush_again:
1377 	rcu_read_lock();
1378 	for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1379 
1380 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1381 			if (cp->ipvs != ipvs)
1382 				continue;
1383 			if (atomic_read(&cp->n_control))
1384 				continue;
1385 			cp_c = cp->control;
1386 			IP_VS_DBG(4, "del connection\n");
1387 			ip_vs_conn_del(cp);
1388 			if (cp_c && !atomic_read(&cp_c->n_control)) {
1389 				IP_VS_DBG(4, "del controlling connection\n");
1390 				ip_vs_conn_del(cp_c);
1391 			}
1392 		}
1393 		cond_resched_rcu();
1394 	}
1395 	rcu_read_unlock();
1396 
1397 	/* the counter may be not NULL, because maybe some conn entries
1398 	   are run by slow timer handler or unhashed but still referred */
1399 	if (atomic_read(&ipvs->conn_count) != 0) {
1400 		schedule();
1401 		goto flush_again;
1402 	}
1403 }
1404 
1405 #ifdef CONFIG_SYSCTL
ip_vs_expire_nodest_conn_flush(struct netns_ipvs * ipvs)1406 void ip_vs_expire_nodest_conn_flush(struct netns_ipvs *ipvs)
1407 {
1408 	int idx;
1409 	struct ip_vs_conn *cp, *cp_c;
1410 	struct ip_vs_dest *dest;
1411 
1412 	rcu_read_lock();
1413 	for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1414 		hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1415 			if (cp->ipvs != ipvs)
1416 				continue;
1417 
1418 			dest = cp->dest;
1419 			if (!dest || (dest->flags & IP_VS_DEST_F_AVAILABLE))
1420 				continue;
1421 
1422 			if (atomic_read(&cp->n_control))
1423 				continue;
1424 
1425 			cp_c = cp->control;
1426 			IP_VS_DBG(4, "del connection\n");
1427 			ip_vs_conn_del(cp);
1428 			if (cp_c && !atomic_read(&cp_c->n_control)) {
1429 				IP_VS_DBG(4, "del controlling connection\n");
1430 				ip_vs_conn_del(cp_c);
1431 			}
1432 		}
1433 		cond_resched_rcu();
1434 
1435 		/* netns clean up started, abort delayed work */
1436 		if (!ipvs->enable)
1437 			break;
1438 	}
1439 	rcu_read_unlock();
1440 }
1441 #endif
1442 
1443 /*
1444  * per netns init and exit
1445  */
ip_vs_conn_net_init(struct netns_ipvs * ipvs)1446 int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
1447 {
1448 	atomic_set(&ipvs->conn_count, 0);
1449 
1450 #ifdef CONFIG_PROC_FS
1451 	if (!proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
1452 			     &ip_vs_conn_seq_ops,
1453 			     sizeof(struct ip_vs_iter_state)))
1454 		goto err_conn;
1455 
1456 	if (!proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
1457 			     &ip_vs_conn_sync_seq_ops,
1458 			     sizeof(struct ip_vs_iter_state)))
1459 		goto err_conn_sync;
1460 #endif
1461 
1462 	return 0;
1463 
1464 #ifdef CONFIG_PROC_FS
1465 err_conn_sync:
1466 	remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1467 err_conn:
1468 	return -ENOMEM;
1469 #endif
1470 }
1471 
ip_vs_conn_net_cleanup(struct netns_ipvs * ipvs)1472 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
1473 {
1474 	/* flush all the connection entries first */
1475 	ip_vs_conn_flush(ipvs);
1476 #ifdef CONFIG_PROC_FS
1477 	remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1478 	remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
1479 #endif
1480 }
1481 
ip_vs_conn_init(void)1482 int __init ip_vs_conn_init(void)
1483 {
1484 	int idx;
1485 
1486 	/* Compute size and mask */
1487 	if (ip_vs_conn_tab_bits < 8 || ip_vs_conn_tab_bits > 20) {
1488 		pr_info("conn_tab_bits not in [8, 20]. Using default value\n");
1489 		ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
1490 	}
1491 	ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1492 	ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1493 
1494 	/*
1495 	 * Allocate the connection hash table and initialize its list heads
1496 	 */
1497 	ip_vs_conn_tab = vmalloc(array_size(ip_vs_conn_tab_size,
1498 					    sizeof(*ip_vs_conn_tab)));
1499 	if (!ip_vs_conn_tab)
1500 		return -ENOMEM;
1501 
1502 	/* Allocate ip_vs_conn slab cache */
1503 	ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1504 					      sizeof(struct ip_vs_conn), 0,
1505 					      SLAB_HWCACHE_ALIGN, NULL);
1506 	if (!ip_vs_conn_cachep) {
1507 		vfree(ip_vs_conn_tab);
1508 		return -ENOMEM;
1509 	}
1510 
1511 	pr_info("Connection hash table configured "
1512 		"(size=%d, memory=%ldKbytes)\n",
1513 		ip_vs_conn_tab_size,
1514 		(long)(ip_vs_conn_tab_size*sizeof(*ip_vs_conn_tab))/1024);
1515 	IP_VS_DBG(0, "Each connection entry needs %zd bytes at least\n",
1516 		  sizeof(struct ip_vs_conn));
1517 
1518 	for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1519 		INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1520 
1521 	for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1522 		spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1523 	}
1524 
1525 	/* calculate the random value for connection hash */
1526 	get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1527 
1528 	return 0;
1529 }
1530 
ip_vs_conn_cleanup(void)1531 void ip_vs_conn_cleanup(void)
1532 {
1533 	/* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1534 	rcu_barrier();
1535 	/* Release the empty cache */
1536 	kmem_cache_destroy(ip_vs_conn_cachep);
1537 	vfree(ip_vs_conn_tab);
1538 }
1539