1 /*
2 * IPVS An implementation of the IP virtual server support for the
3 * LINUX operating system. IPVS is now implemented as a module
4 * over the Netfilter framework. IPVS can be used to build a
5 * high-performance and highly available server based on a
6 * cluster of servers.
7 *
8 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
9 * Peter Kese <peter.kese@ijs.si>
10 * Julian Anastasov <ja@ssi.bg>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 *
17 * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
18 * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
19 * and others. Many code here is taken from IP MASQ code of kernel 2.2.
20 *
21 * Changes:
22 *
23 */
24
25 #define KMSG_COMPONENT "IPVS"
26 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
27
28 #include <linux/interrupt.h>
29 #include <linux/in.h>
30 #include <linux/inet.h>
31 #include <linux/net.h>
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/vmalloc.h>
35 #include <linux/proc_fs.h> /* for proc_net_* */
36 #include <linux/slab.h>
37 #include <linux/seq_file.h>
38 #include <linux/jhash.h>
39 #include <linux/random.h>
40
41 #include <net/net_namespace.h>
42 #include <net/ip_vs.h>
43
44
45 #ifndef CONFIG_IP_VS_TAB_BITS
46 #define CONFIG_IP_VS_TAB_BITS 12
47 #endif
48
49 /*
50 * Connection hash size. Default is what was selected at compile time.
51 */
52 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
53 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
54 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
55
56 /* size and mask values */
57 int ip_vs_conn_tab_size __read_mostly;
58 static int ip_vs_conn_tab_mask __read_mostly;
59
60 /*
61 * Connection hash table: for input and output packets lookups of IPVS
62 */
63 static struct hlist_head *ip_vs_conn_tab __read_mostly;
64
65 /* SLAB cache for IPVS connections */
66 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
67
68 /* counter for no client port connections */
69 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
70
71 /* random value for IPVS connection hash */
72 static unsigned int ip_vs_conn_rnd __read_mostly;
73
74 /*
75 * Fine locking granularity for big connection hash table
76 */
77 #define CT_LOCKARRAY_BITS 5
78 #define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS)
79 #define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1)
80
81 /* We need an addrstrlen that works with or without v6 */
82 #ifdef CONFIG_IP_VS_IPV6
83 #define IP_VS_ADDRSTRLEN INET6_ADDRSTRLEN
84 #else
85 #define IP_VS_ADDRSTRLEN (8+1)
86 #endif
87
88 struct ip_vs_aligned_lock
89 {
90 spinlock_t l;
91 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
92
93 /* lock array for conn table */
94 static struct ip_vs_aligned_lock
95 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
96
ct_write_lock_bh(unsigned int key)97 static inline void ct_write_lock_bh(unsigned int key)
98 {
99 spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
100 }
101
ct_write_unlock_bh(unsigned int key)102 static inline void ct_write_unlock_bh(unsigned int key)
103 {
104 spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
105 }
106
107 static void ip_vs_conn_expire(struct timer_list *t);
108
109 /*
110 * Returns hash value for IPVS connection entry
111 */
ip_vs_conn_hashkey(struct netns_ipvs * ipvs,int af,unsigned int proto,const union nf_inet_addr * addr,__be16 port)112 static unsigned int ip_vs_conn_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
113 const union nf_inet_addr *addr,
114 __be16 port)
115 {
116 #ifdef CONFIG_IP_VS_IPV6
117 if (af == AF_INET6)
118 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
119 (__force u32)port, proto, ip_vs_conn_rnd) ^
120 ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
121 #endif
122 return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
123 ip_vs_conn_rnd) ^
124 ((size_t)ipvs>>8)) & ip_vs_conn_tab_mask;
125 }
126
ip_vs_conn_hashkey_param(const struct ip_vs_conn_param * p,bool inverse)127 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
128 bool inverse)
129 {
130 const union nf_inet_addr *addr;
131 __be16 port;
132
133 if (p->pe_data && p->pe->hashkey_raw)
134 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
135 ip_vs_conn_tab_mask;
136
137 if (likely(!inverse)) {
138 addr = p->caddr;
139 port = p->cport;
140 } else {
141 addr = p->vaddr;
142 port = p->vport;
143 }
144
145 return ip_vs_conn_hashkey(p->ipvs, p->af, p->protocol, addr, port);
146 }
147
ip_vs_conn_hashkey_conn(const struct ip_vs_conn * cp)148 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
149 {
150 struct ip_vs_conn_param p;
151
152 ip_vs_conn_fill_param(cp->ipvs, cp->af, cp->protocol,
153 &cp->caddr, cp->cport, NULL, 0, &p);
154
155 if (cp->pe) {
156 p.pe = cp->pe;
157 p.pe_data = cp->pe_data;
158 p.pe_data_len = cp->pe_data_len;
159 }
160
161 return ip_vs_conn_hashkey_param(&p, false);
162 }
163
164 /*
165 * Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
166 * returns bool success.
167 */
ip_vs_conn_hash(struct ip_vs_conn * cp)168 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
169 {
170 unsigned int hash;
171 int ret;
172
173 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
174 return 0;
175
176 /* Hash by protocol, client address and port */
177 hash = ip_vs_conn_hashkey_conn(cp);
178
179 ct_write_lock_bh(hash);
180 spin_lock(&cp->lock);
181
182 if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
183 cp->flags |= IP_VS_CONN_F_HASHED;
184 refcount_inc(&cp->refcnt);
185 hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
186 ret = 1;
187 } else {
188 pr_err("%s(): request for already hashed, called from %pS\n",
189 __func__, __builtin_return_address(0));
190 ret = 0;
191 }
192
193 spin_unlock(&cp->lock);
194 ct_write_unlock_bh(hash);
195
196 return ret;
197 }
198
199
200 /*
201 * UNhashes ip_vs_conn from ip_vs_conn_tab.
202 * returns bool success. Caller should hold conn reference.
203 */
ip_vs_conn_unhash(struct ip_vs_conn * cp)204 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
205 {
206 unsigned int hash;
207 int ret;
208
209 /* unhash it and decrease its reference counter */
210 hash = ip_vs_conn_hashkey_conn(cp);
211
212 ct_write_lock_bh(hash);
213 spin_lock(&cp->lock);
214
215 if (cp->flags & IP_VS_CONN_F_HASHED) {
216 hlist_del_rcu(&cp->c_list);
217 cp->flags &= ~IP_VS_CONN_F_HASHED;
218 refcount_dec(&cp->refcnt);
219 ret = 1;
220 } else
221 ret = 0;
222
223 spin_unlock(&cp->lock);
224 ct_write_unlock_bh(hash);
225
226 return ret;
227 }
228
229 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
230 * returns bool success.
231 */
ip_vs_conn_unlink(struct ip_vs_conn * cp)232 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
233 {
234 unsigned int hash;
235 bool ret = false;
236
237 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
238 return refcount_dec_if_one(&cp->refcnt);
239
240 hash = ip_vs_conn_hashkey_conn(cp);
241
242 ct_write_lock_bh(hash);
243 spin_lock(&cp->lock);
244
245 if (cp->flags & IP_VS_CONN_F_HASHED) {
246 /* Decrease refcnt and unlink conn only if we are last user */
247 if (refcount_dec_if_one(&cp->refcnt)) {
248 hlist_del_rcu(&cp->c_list);
249 cp->flags &= ~IP_VS_CONN_F_HASHED;
250 ret = true;
251 }
252 }
253
254 spin_unlock(&cp->lock);
255 ct_write_unlock_bh(hash);
256
257 return ret;
258 }
259
260
261 /*
262 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
263 * Called for pkts coming from OUTside-to-INside.
264 * p->caddr, p->cport: pkt source address (foreign host)
265 * p->vaddr, p->vport: pkt dest address (load balancer)
266 */
267 static inline struct ip_vs_conn *
__ip_vs_conn_in_get(const struct ip_vs_conn_param * p)268 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
269 {
270 unsigned int hash;
271 struct ip_vs_conn *cp;
272
273 hash = ip_vs_conn_hashkey_param(p, false);
274
275 rcu_read_lock();
276
277 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
278 if (p->cport == cp->cport && p->vport == cp->vport &&
279 cp->af == p->af &&
280 ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
281 ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
282 ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
283 p->protocol == cp->protocol &&
284 cp->ipvs == p->ipvs) {
285 if (!__ip_vs_conn_get(cp))
286 continue;
287 /* HIT */
288 rcu_read_unlock();
289 return cp;
290 }
291 }
292
293 rcu_read_unlock();
294
295 return NULL;
296 }
297
ip_vs_conn_in_get(const struct ip_vs_conn_param * p)298 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
299 {
300 struct ip_vs_conn *cp;
301
302 cp = __ip_vs_conn_in_get(p);
303 if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
304 struct ip_vs_conn_param cport_zero_p = *p;
305 cport_zero_p.cport = 0;
306 cp = __ip_vs_conn_in_get(&cport_zero_p);
307 }
308
309 IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
310 ip_vs_proto_name(p->protocol),
311 IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
312 IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
313 cp ? "hit" : "not hit");
314
315 return cp;
316 }
317
318 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)319 ip_vs_conn_fill_param_proto(struct netns_ipvs *ipvs,
320 int af, const struct sk_buff *skb,
321 const struct ip_vs_iphdr *iph,
322 struct ip_vs_conn_param *p)
323 {
324 __be16 _ports[2], *pptr;
325
326 pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports);
327 if (pptr == NULL)
328 return 1;
329
330 if (likely(!ip_vs_iph_inverse(iph)))
331 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->saddr,
332 pptr[0], &iph->daddr, pptr[1], p);
333 else
334 ip_vs_conn_fill_param(ipvs, af, iph->protocol, &iph->daddr,
335 pptr[1], &iph->saddr, pptr[0], p);
336 return 0;
337 }
338
339 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)340 ip_vs_conn_in_get_proto(struct netns_ipvs *ipvs, int af,
341 const struct sk_buff *skb,
342 const struct ip_vs_iphdr *iph)
343 {
344 struct ip_vs_conn_param p;
345
346 if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
347 return NULL;
348
349 return ip_vs_conn_in_get(&p);
350 }
351 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
352
353 /* Get reference to connection template */
ip_vs_ct_in_get(const struct ip_vs_conn_param * p)354 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
355 {
356 unsigned int hash;
357 struct ip_vs_conn *cp;
358
359 hash = ip_vs_conn_hashkey_param(p, false);
360
361 rcu_read_lock();
362
363 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
364 if (unlikely(p->pe_data && p->pe->ct_match)) {
365 if (cp->ipvs != p->ipvs)
366 continue;
367 if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
368 if (__ip_vs_conn_get(cp))
369 goto out;
370 }
371 continue;
372 }
373
374 if (cp->af == p->af &&
375 ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
376 /* protocol should only be IPPROTO_IP if
377 * p->vaddr is a fwmark */
378 ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
379 p->af, p->vaddr, &cp->vaddr) &&
380 p->vport == cp->vport && p->cport == cp->cport &&
381 cp->flags & IP_VS_CONN_F_TEMPLATE &&
382 p->protocol == cp->protocol &&
383 cp->ipvs == p->ipvs) {
384 if (__ip_vs_conn_get(cp))
385 goto out;
386 }
387 }
388 cp = NULL;
389
390 out:
391 rcu_read_unlock();
392
393 IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
394 ip_vs_proto_name(p->protocol),
395 IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
396 IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
397 cp ? "hit" : "not hit");
398
399 return cp;
400 }
401
402 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
403 * Called for pkts coming from inside-to-OUTside.
404 * p->caddr, p->cport: pkt source address (inside host)
405 * p->vaddr, p->vport: pkt dest address (foreign host) */
ip_vs_conn_out_get(const struct ip_vs_conn_param * p)406 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
407 {
408 unsigned int hash;
409 struct ip_vs_conn *cp, *ret=NULL;
410
411 /*
412 * Check for "full" addressed entries
413 */
414 hash = ip_vs_conn_hashkey_param(p, true);
415
416 rcu_read_lock();
417
418 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
419 if (p->vport == cp->cport && p->cport == cp->dport &&
420 cp->af == p->af &&
421 ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
422 ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
423 p->protocol == cp->protocol &&
424 cp->ipvs == p->ipvs) {
425 if (!__ip_vs_conn_get(cp))
426 continue;
427 /* HIT */
428 ret = cp;
429 break;
430 }
431 }
432
433 rcu_read_unlock();
434
435 IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
436 ip_vs_proto_name(p->protocol),
437 IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
438 IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
439 ret ? "hit" : "not hit");
440
441 return ret;
442 }
443
444 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)445 ip_vs_conn_out_get_proto(struct netns_ipvs *ipvs, int af,
446 const struct sk_buff *skb,
447 const struct ip_vs_iphdr *iph)
448 {
449 struct ip_vs_conn_param p;
450
451 if (ip_vs_conn_fill_param_proto(ipvs, af, skb, iph, &p))
452 return NULL;
453
454 return ip_vs_conn_out_get(&p);
455 }
456 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
457
458 /*
459 * Put back the conn and restart its timer with its timeout
460 */
__ip_vs_conn_put_timer(struct ip_vs_conn * cp)461 static void __ip_vs_conn_put_timer(struct ip_vs_conn *cp)
462 {
463 unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
464 0 : cp->timeout;
465 mod_timer(&cp->timer, jiffies+t);
466
467 __ip_vs_conn_put(cp);
468 }
469
ip_vs_conn_put(struct ip_vs_conn * cp)470 void ip_vs_conn_put(struct ip_vs_conn *cp)
471 {
472 if ((cp->flags & IP_VS_CONN_F_ONE_PACKET) &&
473 (refcount_read(&cp->refcnt) == 1) &&
474 !timer_pending(&cp->timer))
475 /* expire connection immediately */
476 ip_vs_conn_expire(&cp->timer);
477 else
478 __ip_vs_conn_put_timer(cp);
479 }
480
481 /*
482 * Fill a no_client_port connection with a client port number
483 */
ip_vs_conn_fill_cport(struct ip_vs_conn * cp,__be16 cport)484 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
485 {
486 if (ip_vs_conn_unhash(cp)) {
487 spin_lock_bh(&cp->lock);
488 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
489 atomic_dec(&ip_vs_conn_no_cport_cnt);
490 cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
491 cp->cport = cport;
492 }
493 spin_unlock_bh(&cp->lock);
494
495 /* hash on new dport */
496 ip_vs_conn_hash(cp);
497 }
498 }
499
500
501 /*
502 * Bind a connection entry with the corresponding packet_xmit.
503 * Called by ip_vs_conn_new.
504 */
ip_vs_bind_xmit(struct ip_vs_conn * cp)505 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
506 {
507 switch (IP_VS_FWD_METHOD(cp)) {
508 case IP_VS_CONN_F_MASQ:
509 cp->packet_xmit = ip_vs_nat_xmit;
510 break;
511
512 case IP_VS_CONN_F_TUNNEL:
513 #ifdef CONFIG_IP_VS_IPV6
514 if (cp->daf == AF_INET6)
515 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
516 else
517 #endif
518 cp->packet_xmit = ip_vs_tunnel_xmit;
519 break;
520
521 case IP_VS_CONN_F_DROUTE:
522 cp->packet_xmit = ip_vs_dr_xmit;
523 break;
524
525 case IP_VS_CONN_F_LOCALNODE:
526 cp->packet_xmit = ip_vs_null_xmit;
527 break;
528
529 case IP_VS_CONN_F_BYPASS:
530 cp->packet_xmit = ip_vs_bypass_xmit;
531 break;
532 }
533 }
534
535 #ifdef CONFIG_IP_VS_IPV6
ip_vs_bind_xmit_v6(struct ip_vs_conn * cp)536 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
537 {
538 switch (IP_VS_FWD_METHOD(cp)) {
539 case IP_VS_CONN_F_MASQ:
540 cp->packet_xmit = ip_vs_nat_xmit_v6;
541 break;
542
543 case IP_VS_CONN_F_TUNNEL:
544 if (cp->daf == AF_INET6)
545 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
546 else
547 cp->packet_xmit = ip_vs_tunnel_xmit;
548 break;
549
550 case IP_VS_CONN_F_DROUTE:
551 cp->packet_xmit = ip_vs_dr_xmit_v6;
552 break;
553
554 case IP_VS_CONN_F_LOCALNODE:
555 cp->packet_xmit = ip_vs_null_xmit;
556 break;
557
558 case IP_VS_CONN_F_BYPASS:
559 cp->packet_xmit = ip_vs_bypass_xmit_v6;
560 break;
561 }
562 }
563 #endif
564
565
ip_vs_dest_totalconns(struct ip_vs_dest * dest)566 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
567 {
568 return atomic_read(&dest->activeconns)
569 + atomic_read(&dest->inactconns);
570 }
571
572 /*
573 * Bind a connection entry with a virtual service destination
574 * Called just after a new connection entry is created.
575 */
576 static inline void
ip_vs_bind_dest(struct ip_vs_conn * cp,struct ip_vs_dest * dest)577 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
578 {
579 unsigned int conn_flags;
580 __u32 flags;
581
582 /* if dest is NULL, then return directly */
583 if (!dest)
584 return;
585
586 /* Increase the refcnt counter of the dest */
587 ip_vs_dest_hold(dest);
588
589 conn_flags = atomic_read(&dest->conn_flags);
590 if (cp->protocol != IPPROTO_UDP)
591 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
592 flags = cp->flags;
593 /* Bind with the destination and its corresponding transmitter */
594 if (flags & IP_VS_CONN_F_SYNC) {
595 /* if the connection is not template and is created
596 * by sync, preserve the activity flag.
597 */
598 if (!(flags & IP_VS_CONN_F_TEMPLATE))
599 conn_flags &= ~IP_VS_CONN_F_INACTIVE;
600 /* connections inherit forwarding method from dest */
601 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
602 }
603 flags |= conn_flags;
604 cp->flags = flags;
605 cp->dest = dest;
606
607 IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
608 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
609 "dest->refcnt:%d\n",
610 ip_vs_proto_name(cp->protocol),
611 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
612 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
613 IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
614 ip_vs_fwd_tag(cp), cp->state,
615 cp->flags, refcount_read(&cp->refcnt),
616 refcount_read(&dest->refcnt));
617
618 /* Update the connection counters */
619 if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
620 /* It is a normal connection, so modify the counters
621 * according to the flags, later the protocol can
622 * update them on state change
623 */
624 if (!(flags & IP_VS_CONN_F_INACTIVE))
625 atomic_inc(&dest->activeconns);
626 else
627 atomic_inc(&dest->inactconns);
628 } else {
629 /* It is a persistent connection/template, so increase
630 the persistent connection counter */
631 atomic_inc(&dest->persistconns);
632 }
633
634 if (dest->u_threshold != 0 &&
635 ip_vs_dest_totalconns(dest) >= dest->u_threshold)
636 dest->flags |= IP_VS_DEST_F_OVERLOAD;
637 }
638
639
640 /*
641 * Check if there is a destination for the connection, if so
642 * bind the connection to the destination.
643 */
ip_vs_try_bind_dest(struct ip_vs_conn * cp)644 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
645 {
646 struct ip_vs_dest *dest;
647
648 rcu_read_lock();
649
650 /* This function is only invoked by the synchronization code. We do
651 * not currently support heterogeneous pools with synchronization,
652 * so we can make the assumption that the svc_af is the same as the
653 * dest_af
654 */
655 dest = ip_vs_find_dest(cp->ipvs, cp->af, cp->af, &cp->daddr,
656 cp->dport, &cp->vaddr, cp->vport,
657 cp->protocol, cp->fwmark, cp->flags);
658 if (dest) {
659 struct ip_vs_proto_data *pd;
660
661 spin_lock_bh(&cp->lock);
662 if (cp->dest) {
663 spin_unlock_bh(&cp->lock);
664 rcu_read_unlock();
665 return;
666 }
667
668 /* Applications work depending on the forwarding method
669 * but better to reassign them always when binding dest */
670 if (cp->app)
671 ip_vs_unbind_app(cp);
672
673 ip_vs_bind_dest(cp, dest);
674 spin_unlock_bh(&cp->lock);
675
676 /* Update its packet transmitter */
677 cp->packet_xmit = NULL;
678 #ifdef CONFIG_IP_VS_IPV6
679 if (cp->af == AF_INET6)
680 ip_vs_bind_xmit_v6(cp);
681 else
682 #endif
683 ip_vs_bind_xmit(cp);
684
685 pd = ip_vs_proto_data_get(cp->ipvs, cp->protocol);
686 if (pd && atomic_read(&pd->appcnt))
687 ip_vs_bind_app(cp, pd->pp);
688 }
689 rcu_read_unlock();
690 }
691
692
693 /*
694 * Unbind a connection entry with its VS destination
695 * Called by the ip_vs_conn_expire function.
696 */
ip_vs_unbind_dest(struct ip_vs_conn * cp)697 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
698 {
699 struct ip_vs_dest *dest = cp->dest;
700
701 if (!dest)
702 return;
703
704 IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
705 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
706 "dest->refcnt:%d\n",
707 ip_vs_proto_name(cp->protocol),
708 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
709 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
710 IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
711 ip_vs_fwd_tag(cp), cp->state,
712 cp->flags, refcount_read(&cp->refcnt),
713 refcount_read(&dest->refcnt));
714
715 /* Update the connection counters */
716 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
717 /* It is a normal connection, so decrease the inactconns
718 or activeconns counter */
719 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
720 atomic_dec(&dest->inactconns);
721 } else {
722 atomic_dec(&dest->activeconns);
723 }
724 } else {
725 /* It is a persistent connection/template, so decrease
726 the persistent connection counter */
727 atomic_dec(&dest->persistconns);
728 }
729
730 if (dest->l_threshold != 0) {
731 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
732 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
733 } else if (dest->u_threshold != 0) {
734 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
735 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
736 } else {
737 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
738 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
739 }
740
741 ip_vs_dest_put(dest);
742 }
743
expire_quiescent_template(struct netns_ipvs * ipvs,struct ip_vs_dest * dest)744 static int expire_quiescent_template(struct netns_ipvs *ipvs,
745 struct ip_vs_dest *dest)
746 {
747 #ifdef CONFIG_SYSCTL
748 return ipvs->sysctl_expire_quiescent_template &&
749 (atomic_read(&dest->weight) == 0);
750 #else
751 return 0;
752 #endif
753 }
754
755 /*
756 * Checking if the destination of a connection template is available.
757 * If available, return 1, otherwise invalidate this connection
758 * template and return 0.
759 */
ip_vs_check_template(struct ip_vs_conn * ct,struct ip_vs_dest * cdest)760 int ip_vs_check_template(struct ip_vs_conn *ct, struct ip_vs_dest *cdest)
761 {
762 struct ip_vs_dest *dest = ct->dest;
763 struct netns_ipvs *ipvs = ct->ipvs;
764
765 /*
766 * Checking the dest server status.
767 */
768 if ((dest == NULL) ||
769 !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
770 expire_quiescent_template(ipvs, dest) ||
771 (cdest && (dest != cdest))) {
772 IP_VS_DBG_BUF(9, "check_template: dest not available for "
773 "protocol %s s:%s:%d v:%s:%d "
774 "-> d:%s:%d\n",
775 ip_vs_proto_name(ct->protocol),
776 IP_VS_DBG_ADDR(ct->af, &ct->caddr),
777 ntohs(ct->cport),
778 IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
779 ntohs(ct->vport),
780 IP_VS_DBG_ADDR(ct->daf, &ct->daddr),
781 ntohs(ct->dport));
782
783 /*
784 * Invalidate the connection template
785 */
786 if (ct->vport != htons(0xffff)) {
787 if (ip_vs_conn_unhash(ct)) {
788 ct->dport = htons(0xffff);
789 ct->vport = htons(0xffff);
790 ct->cport = 0;
791 ip_vs_conn_hash(ct);
792 }
793 }
794
795 /*
796 * Simply decrease the refcnt of the template,
797 * don't restart its timer.
798 */
799 __ip_vs_conn_put(ct);
800 return 0;
801 }
802 return 1;
803 }
804
ip_vs_conn_rcu_free(struct rcu_head * head)805 static void ip_vs_conn_rcu_free(struct rcu_head *head)
806 {
807 struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
808 rcu_head);
809
810 ip_vs_pe_put(cp->pe);
811 kfree(cp->pe_data);
812 kmem_cache_free(ip_vs_conn_cachep, cp);
813 }
814
ip_vs_conn_expire(struct timer_list * t)815 static void ip_vs_conn_expire(struct timer_list *t)
816 {
817 struct ip_vs_conn *cp = from_timer(cp, t, timer);
818 struct netns_ipvs *ipvs = cp->ipvs;
819
820 /*
821 * do I control anybody?
822 */
823 if (atomic_read(&cp->n_control))
824 goto expire_later;
825
826 /* Unlink conn if not referenced anymore */
827 if (likely(ip_vs_conn_unlink(cp))) {
828 struct ip_vs_conn *ct = cp->control;
829
830 /* delete the timer if it is activated by other users */
831 del_timer(&cp->timer);
832
833 /* does anybody control me? */
834 if (ct) {
835 ip_vs_control_del(cp);
836 /* Drop CTL or non-assured TPL if not used anymore */
837 if (!cp->timeout && !atomic_read(&ct->n_control) &&
838 (!(ct->flags & IP_VS_CONN_F_TEMPLATE) ||
839 !(ct->state & IP_VS_CTPL_S_ASSURED))) {
840 IP_VS_DBG(4, "drop controlling connection\n");
841 ct->timeout = 0;
842 ip_vs_conn_expire_now(ct);
843 }
844 }
845
846 if ((cp->flags & IP_VS_CONN_F_NFCT) &&
847 !(cp->flags & IP_VS_CONN_F_ONE_PACKET)) {
848 /* Do not access conntracks during subsys cleanup
849 * because nf_conntrack_find_get can not be used after
850 * conntrack cleanup for the net.
851 */
852 smp_rmb();
853 if (ipvs->enable)
854 ip_vs_conn_drop_conntrack(cp);
855 }
856
857 if (unlikely(cp->app != NULL))
858 ip_vs_unbind_app(cp);
859 ip_vs_unbind_dest(cp);
860 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
861 atomic_dec(&ip_vs_conn_no_cport_cnt);
862 if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
863 ip_vs_conn_rcu_free(&cp->rcu_head);
864 else
865 call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
866 atomic_dec(&ipvs->conn_count);
867 return;
868 }
869
870 expire_later:
871 IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
872 refcount_read(&cp->refcnt),
873 atomic_read(&cp->n_control));
874
875 refcount_inc(&cp->refcnt);
876 cp->timeout = 60*HZ;
877
878 if (ipvs->sync_state & IP_VS_STATE_MASTER)
879 ip_vs_sync_conn(ipvs, cp, sysctl_sync_threshold(ipvs));
880
881 __ip_vs_conn_put_timer(cp);
882 }
883
884 /* Modify timer, so that it expires as soon as possible.
885 * Can be called without reference only if under RCU lock.
886 * We can have such chain of conns linked with ->control: DATA->CTL->TPL
887 * - DATA (eg. FTP) and TPL (persistence) can be present depending on setup
888 * - cp->timeout=0 indicates all conns from chain should be dropped but
889 * TPL is not dropped if in assured state
890 */
ip_vs_conn_expire_now(struct ip_vs_conn * cp)891 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
892 {
893 /* Using mod_timer_pending will ensure the timer is not
894 * modified after the final del_timer in ip_vs_conn_expire.
895 */
896 if (timer_pending(&cp->timer) &&
897 time_after(cp->timer.expires, jiffies))
898 mod_timer_pending(&cp->timer, jiffies);
899 }
900
901
902 /*
903 * Create a new connection entry and hash it into the ip_vs_conn_tab
904 */
905 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)906 ip_vs_conn_new(const struct ip_vs_conn_param *p, int dest_af,
907 const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
908 struct ip_vs_dest *dest, __u32 fwmark)
909 {
910 struct ip_vs_conn *cp;
911 struct netns_ipvs *ipvs = p->ipvs;
912 struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->ipvs,
913 p->protocol);
914
915 cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
916 if (cp == NULL) {
917 IP_VS_ERR_RL("%s(): no memory\n", __func__);
918 return NULL;
919 }
920
921 INIT_HLIST_NODE(&cp->c_list);
922 timer_setup(&cp->timer, ip_vs_conn_expire, 0);
923 cp->ipvs = ipvs;
924 cp->af = p->af;
925 cp->daf = dest_af;
926 cp->protocol = p->protocol;
927 ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
928 cp->cport = p->cport;
929 /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
930 ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
931 &cp->vaddr, p->vaddr);
932 cp->vport = p->vport;
933 ip_vs_addr_set(cp->daf, &cp->daddr, daddr);
934 cp->dport = dport;
935 cp->flags = flags;
936 cp->fwmark = fwmark;
937 if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
938 ip_vs_pe_get(p->pe);
939 cp->pe = p->pe;
940 cp->pe_data = p->pe_data;
941 cp->pe_data_len = p->pe_data_len;
942 } else {
943 cp->pe = NULL;
944 cp->pe_data = NULL;
945 cp->pe_data_len = 0;
946 }
947 spin_lock_init(&cp->lock);
948
949 /*
950 * Set the entry is referenced by the current thread before hashing
951 * it in the table, so that other thread run ip_vs_random_dropentry
952 * but cannot drop this entry.
953 */
954 refcount_set(&cp->refcnt, 1);
955
956 cp->control = NULL;
957 atomic_set(&cp->n_control, 0);
958 atomic_set(&cp->in_pkts, 0);
959
960 cp->packet_xmit = NULL;
961 cp->app = NULL;
962 cp->app_data = NULL;
963 /* reset struct ip_vs_seq */
964 cp->in_seq.delta = 0;
965 cp->out_seq.delta = 0;
966
967 atomic_inc(&ipvs->conn_count);
968 if (flags & IP_VS_CONN_F_NO_CPORT)
969 atomic_inc(&ip_vs_conn_no_cport_cnt);
970
971 /* Bind the connection with a destination server */
972 cp->dest = NULL;
973 ip_vs_bind_dest(cp, dest);
974
975 /* Set its state and timeout */
976 cp->state = 0;
977 cp->old_state = 0;
978 cp->timeout = 3*HZ;
979 cp->sync_endtime = jiffies & ~3UL;
980
981 /* Bind its packet transmitter */
982 #ifdef CONFIG_IP_VS_IPV6
983 if (p->af == AF_INET6)
984 ip_vs_bind_xmit_v6(cp);
985 else
986 #endif
987 ip_vs_bind_xmit(cp);
988
989 if (unlikely(pd && atomic_read(&pd->appcnt)))
990 ip_vs_bind_app(cp, pd->pp);
991
992 /*
993 * Allow conntrack to be preserved. By default, conntrack
994 * is created and destroyed for every packet.
995 * Sometimes keeping conntrack can be useful for
996 * IP_VS_CONN_F_ONE_PACKET too.
997 */
998
999 if (ip_vs_conntrack_enabled(ipvs))
1000 cp->flags |= IP_VS_CONN_F_NFCT;
1001
1002 /* Hash it in the ip_vs_conn_tab finally */
1003 ip_vs_conn_hash(cp);
1004
1005 return cp;
1006 }
1007
1008 /*
1009 * /proc/net/ip_vs_conn entries
1010 */
1011 #ifdef CONFIG_PROC_FS
1012 struct ip_vs_iter_state {
1013 struct seq_net_private p;
1014 struct hlist_head *l;
1015 };
1016
ip_vs_conn_array(struct seq_file * seq,loff_t pos)1017 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
1018 {
1019 int idx;
1020 struct ip_vs_conn *cp;
1021 struct ip_vs_iter_state *iter = seq->private;
1022
1023 for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1024 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1025 /* __ip_vs_conn_get() is not needed by
1026 * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
1027 */
1028 if (pos-- == 0) {
1029 iter->l = &ip_vs_conn_tab[idx];
1030 return cp;
1031 }
1032 }
1033 cond_resched_rcu();
1034 }
1035
1036 return NULL;
1037 }
1038
ip_vs_conn_seq_start(struct seq_file * seq,loff_t * pos)1039 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
1040 __acquires(RCU)
1041 {
1042 struct ip_vs_iter_state *iter = seq->private;
1043
1044 iter->l = NULL;
1045 rcu_read_lock();
1046 return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
1047 }
1048
ip_vs_conn_seq_next(struct seq_file * seq,void * v,loff_t * pos)1049 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1050 {
1051 struct ip_vs_conn *cp = v;
1052 struct ip_vs_iter_state *iter = seq->private;
1053 struct hlist_node *e;
1054 struct hlist_head *l = iter->l;
1055 int idx;
1056
1057 ++*pos;
1058 if (v == SEQ_START_TOKEN)
1059 return ip_vs_conn_array(seq, 0);
1060
1061 /* more on same hash chain? */
1062 e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1063 if (e)
1064 return hlist_entry(e, struct ip_vs_conn, c_list);
1065
1066 idx = l - ip_vs_conn_tab;
1067 while (++idx < ip_vs_conn_tab_size) {
1068 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1069 iter->l = &ip_vs_conn_tab[idx];
1070 return cp;
1071 }
1072 cond_resched_rcu();
1073 }
1074 iter->l = NULL;
1075 return NULL;
1076 }
1077
ip_vs_conn_seq_stop(struct seq_file * seq,void * v)1078 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1079 __releases(RCU)
1080 {
1081 rcu_read_unlock();
1082 }
1083
ip_vs_conn_seq_show(struct seq_file * seq,void * v)1084 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1085 {
1086
1087 if (v == SEQ_START_TOKEN)
1088 seq_puts(seq,
1089 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires PEName PEData\n");
1090 else {
1091 const struct ip_vs_conn *cp = v;
1092 struct net *net = seq_file_net(seq);
1093 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1094 size_t len = 0;
1095 char dbuf[IP_VS_ADDRSTRLEN];
1096
1097 if (!net_eq(cp->ipvs->net, net))
1098 return 0;
1099 if (cp->pe_data) {
1100 pe_data[0] = ' ';
1101 len = strlen(cp->pe->name);
1102 memcpy(pe_data + 1, cp->pe->name, len);
1103 pe_data[len + 1] = ' ';
1104 len += 2;
1105 len += cp->pe->show_pe_data(cp, pe_data + len);
1106 }
1107 pe_data[len] = '\0';
1108
1109 #ifdef CONFIG_IP_VS_IPV6
1110 if (cp->daf == AF_INET6)
1111 snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1112 else
1113 #endif
1114 snprintf(dbuf, sizeof(dbuf), "%08X",
1115 ntohl(cp->daddr.ip));
1116
1117 #ifdef CONFIG_IP_VS_IPV6
1118 if (cp->af == AF_INET6)
1119 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1120 "%s %04X %-11s %7u%s\n",
1121 ip_vs_proto_name(cp->protocol),
1122 &cp->caddr.in6, ntohs(cp->cport),
1123 &cp->vaddr.in6, ntohs(cp->vport),
1124 dbuf, ntohs(cp->dport),
1125 ip_vs_state_name(cp),
1126 jiffies_delta_to_msecs(cp->timer.expires -
1127 jiffies) / 1000,
1128 pe_data);
1129 else
1130 #endif
1131 seq_printf(seq,
1132 "%-3s %08X %04X %08X %04X"
1133 " %s %04X %-11s %7u%s\n",
1134 ip_vs_proto_name(cp->protocol),
1135 ntohl(cp->caddr.ip), ntohs(cp->cport),
1136 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1137 dbuf, ntohs(cp->dport),
1138 ip_vs_state_name(cp),
1139 jiffies_delta_to_msecs(cp->timer.expires -
1140 jiffies) / 1000,
1141 pe_data);
1142 }
1143 return 0;
1144 }
1145
1146 static const struct seq_operations ip_vs_conn_seq_ops = {
1147 .start = ip_vs_conn_seq_start,
1148 .next = ip_vs_conn_seq_next,
1149 .stop = ip_vs_conn_seq_stop,
1150 .show = ip_vs_conn_seq_show,
1151 };
1152
ip_vs_origin_name(unsigned int flags)1153 static const char *ip_vs_origin_name(unsigned int flags)
1154 {
1155 if (flags & IP_VS_CONN_F_SYNC)
1156 return "SYNC";
1157 else
1158 return "LOCAL";
1159 }
1160
ip_vs_conn_sync_seq_show(struct seq_file * seq,void * v)1161 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1162 {
1163 char dbuf[IP_VS_ADDRSTRLEN];
1164
1165 if (v == SEQ_START_TOKEN)
1166 seq_puts(seq,
1167 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n");
1168 else {
1169 const struct ip_vs_conn *cp = v;
1170 struct net *net = seq_file_net(seq);
1171
1172 if (!net_eq(cp->ipvs->net, net))
1173 return 0;
1174
1175 #ifdef CONFIG_IP_VS_IPV6
1176 if (cp->daf == AF_INET6)
1177 snprintf(dbuf, sizeof(dbuf), "%pI6", &cp->daddr.in6);
1178 else
1179 #endif
1180 snprintf(dbuf, sizeof(dbuf), "%08X",
1181 ntohl(cp->daddr.ip));
1182
1183 #ifdef CONFIG_IP_VS_IPV6
1184 if (cp->af == AF_INET6)
1185 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1186 "%s %04X %-11s %-6s %7u\n",
1187 ip_vs_proto_name(cp->protocol),
1188 &cp->caddr.in6, ntohs(cp->cport),
1189 &cp->vaddr.in6, ntohs(cp->vport),
1190 dbuf, ntohs(cp->dport),
1191 ip_vs_state_name(cp),
1192 ip_vs_origin_name(cp->flags),
1193 jiffies_delta_to_msecs(cp->timer.expires -
1194 jiffies) / 1000);
1195 else
1196 #endif
1197 seq_printf(seq,
1198 "%-3s %08X %04X %08X %04X "
1199 "%s %04X %-11s %-6s %7u\n",
1200 ip_vs_proto_name(cp->protocol),
1201 ntohl(cp->caddr.ip), ntohs(cp->cport),
1202 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1203 dbuf, ntohs(cp->dport),
1204 ip_vs_state_name(cp),
1205 ip_vs_origin_name(cp->flags),
1206 jiffies_delta_to_msecs(cp->timer.expires -
1207 jiffies) / 1000);
1208 }
1209 return 0;
1210 }
1211
1212 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1213 .start = ip_vs_conn_seq_start,
1214 .next = ip_vs_conn_seq_next,
1215 .stop = ip_vs_conn_seq_stop,
1216 .show = ip_vs_conn_sync_seq_show,
1217 };
1218 #endif
1219
1220
1221 /* Randomly drop connection entries before running out of memory
1222 * Can be used for DATA and CTL conns. For TPL conns there are exceptions:
1223 * - traffic for services in OPS mode increases ct->in_pkts, so it is supported
1224 * - traffic for services not in OPS mode does not increase ct->in_pkts in
1225 * all cases, so it is not supported
1226 */
todrop_entry(struct ip_vs_conn * cp)1227 static inline int todrop_entry(struct ip_vs_conn *cp)
1228 {
1229 /*
1230 * The drop rate array needs tuning for real environments.
1231 * Called from timer bh only => no locking
1232 */
1233 static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1234 static char todrop_counter[9] = {0};
1235 int i;
1236
1237 /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1238 This will leave enough time for normal connection to get
1239 through. */
1240 if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1241 return 0;
1242
1243 /* Don't drop the entry if its number of incoming packets is not
1244 located in [0, 8] */
1245 i = atomic_read(&cp->in_pkts);
1246 if (i > 8 || i < 0) return 0;
1247
1248 if (!todrop_rate[i]) return 0;
1249 if (--todrop_counter[i] > 0) return 0;
1250
1251 todrop_counter[i] = todrop_rate[i];
1252 return 1;
1253 }
1254
ip_vs_conn_ops_mode(struct ip_vs_conn * cp)1255 static inline bool ip_vs_conn_ops_mode(struct ip_vs_conn *cp)
1256 {
1257 struct ip_vs_service *svc;
1258
1259 if (!cp->dest)
1260 return false;
1261 svc = rcu_dereference(cp->dest->svc);
1262 return svc && (svc->flags & IP_VS_SVC_F_ONEPACKET);
1263 }
1264
1265 /* Called from keventd and must protect itself from softirqs */
ip_vs_random_dropentry(struct netns_ipvs * ipvs)1266 void ip_vs_random_dropentry(struct netns_ipvs *ipvs)
1267 {
1268 int idx;
1269 struct ip_vs_conn *cp;
1270
1271 rcu_read_lock();
1272 /*
1273 * Randomly scan 1/32 of the whole table every second
1274 */
1275 for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1276 unsigned int hash = prandom_u32() & ip_vs_conn_tab_mask;
1277
1278 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1279 if (cp->ipvs != ipvs)
1280 continue;
1281 if (atomic_read(&cp->n_control))
1282 continue;
1283 if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
1284 /* connection template of OPS */
1285 if (ip_vs_conn_ops_mode(cp))
1286 goto try_drop;
1287 if (!(cp->state & IP_VS_CTPL_S_ASSURED))
1288 goto drop;
1289 continue;
1290 }
1291 if (cp->protocol == IPPROTO_TCP) {
1292 switch(cp->state) {
1293 case IP_VS_TCP_S_SYN_RECV:
1294 case IP_VS_TCP_S_SYNACK:
1295 break;
1296
1297 case IP_VS_TCP_S_ESTABLISHED:
1298 if (todrop_entry(cp))
1299 break;
1300 continue;
1301
1302 default:
1303 continue;
1304 }
1305 } else if (cp->protocol == IPPROTO_SCTP) {
1306 switch (cp->state) {
1307 case IP_VS_SCTP_S_INIT1:
1308 case IP_VS_SCTP_S_INIT:
1309 break;
1310 case IP_VS_SCTP_S_ESTABLISHED:
1311 if (todrop_entry(cp))
1312 break;
1313 continue;
1314 default:
1315 continue;
1316 }
1317 } else {
1318 try_drop:
1319 if (!todrop_entry(cp))
1320 continue;
1321 }
1322
1323 drop:
1324 IP_VS_DBG(4, "drop connection\n");
1325 cp->timeout = 0;
1326 ip_vs_conn_expire_now(cp);
1327 }
1328 cond_resched_rcu();
1329 }
1330 rcu_read_unlock();
1331 }
1332
1333
1334 /*
1335 * Flush all the connection entries in the ip_vs_conn_tab
1336 */
ip_vs_conn_flush(struct netns_ipvs * ipvs)1337 static void ip_vs_conn_flush(struct netns_ipvs *ipvs)
1338 {
1339 int idx;
1340 struct ip_vs_conn *cp, *cp_c;
1341
1342 flush_again:
1343 rcu_read_lock();
1344 for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1345
1346 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1347 if (cp->ipvs != ipvs)
1348 continue;
1349 /* As timers are expired in LIFO order, restart
1350 * the timer of controlling connection first, so
1351 * that it is expired after us.
1352 */
1353 cp_c = cp->control;
1354 /* cp->control is valid only with reference to cp */
1355 if (cp_c && __ip_vs_conn_get(cp)) {
1356 IP_VS_DBG(4, "del controlling connection\n");
1357 ip_vs_conn_expire_now(cp_c);
1358 __ip_vs_conn_put(cp);
1359 }
1360 IP_VS_DBG(4, "del connection\n");
1361 ip_vs_conn_expire_now(cp);
1362 }
1363 cond_resched_rcu();
1364 }
1365 rcu_read_unlock();
1366
1367 /* the counter may be not NULL, because maybe some conn entries
1368 are run by slow timer handler or unhashed but still referred */
1369 if (atomic_read(&ipvs->conn_count) != 0) {
1370 schedule();
1371 goto flush_again;
1372 }
1373 }
1374 /*
1375 * per netns init and exit
1376 */
ip_vs_conn_net_init(struct netns_ipvs * ipvs)1377 int __net_init ip_vs_conn_net_init(struct netns_ipvs *ipvs)
1378 {
1379 atomic_set(&ipvs->conn_count, 0);
1380
1381 proc_create_net("ip_vs_conn", 0, ipvs->net->proc_net,
1382 &ip_vs_conn_seq_ops, sizeof(struct ip_vs_iter_state));
1383 proc_create_net("ip_vs_conn_sync", 0, ipvs->net->proc_net,
1384 &ip_vs_conn_sync_seq_ops,
1385 sizeof(struct ip_vs_iter_state));
1386 return 0;
1387 }
1388
ip_vs_conn_net_cleanup(struct netns_ipvs * ipvs)1389 void __net_exit ip_vs_conn_net_cleanup(struct netns_ipvs *ipvs)
1390 {
1391 /* flush all the connection entries first */
1392 ip_vs_conn_flush(ipvs);
1393 remove_proc_entry("ip_vs_conn", ipvs->net->proc_net);
1394 remove_proc_entry("ip_vs_conn_sync", ipvs->net->proc_net);
1395 }
1396
ip_vs_conn_init(void)1397 int __init ip_vs_conn_init(void)
1398 {
1399 int idx;
1400
1401 /* Compute size and mask */
1402 ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1403 ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1404
1405 /*
1406 * Allocate the connection hash table and initialize its list heads
1407 */
1408 ip_vs_conn_tab = vmalloc(array_size(ip_vs_conn_tab_size,
1409 sizeof(*ip_vs_conn_tab)));
1410 if (!ip_vs_conn_tab)
1411 return -ENOMEM;
1412
1413 /* Allocate ip_vs_conn slab cache */
1414 ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1415 sizeof(struct ip_vs_conn), 0,
1416 SLAB_HWCACHE_ALIGN, NULL);
1417 if (!ip_vs_conn_cachep) {
1418 vfree(ip_vs_conn_tab);
1419 return -ENOMEM;
1420 }
1421
1422 pr_info("Connection hash table configured "
1423 "(size=%d, memory=%ldKbytes)\n",
1424 ip_vs_conn_tab_size,
1425 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1426 IP_VS_DBG(0, "Each connection entry needs %zd bytes at least\n",
1427 sizeof(struct ip_vs_conn));
1428
1429 for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1430 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1431
1432 for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) {
1433 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1434 }
1435
1436 /* calculate the random value for connection hash */
1437 get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1438
1439 return 0;
1440 }
1441
ip_vs_conn_cleanup(void)1442 void ip_vs_conn_cleanup(void)
1443 {
1444 /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1445 rcu_barrier();
1446 /* Release the empty cache */
1447 kmem_cache_destroy(ip_vs_conn_cachep);
1448 vfree(ip_vs_conn_tab);
1449 }
1450
