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ipvs: Fix IPv4 FWMARK virtual services
[linux-2.6.git] / net / netfilter / ipvs / ip_vs_conn.c
blob77bfdfeb966e99c0e0212271319fbe4c7eafbe98
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 #include <linux/interrupt.h>
26 #include <linux/in.h>
27 #include <linux/net.h>
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/vmalloc.h>
31 #include <linux/proc_fs.h> /* for proc_net_* */
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 /*
41 * Connection hash table: for input and output packets lookups of IPVS
42 */
43 static struct list_head *ip_vs_conn_tab;
44
45 /* SLAB cache for IPVS connections */
46 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
47
48 /* counter for current IPVS connections */
49 static atomic_t ip_vs_conn_count = ATOMIC_INIT(0);
50
51 /* counter for no client port connections */
52 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
53
54 /* random value for IPVS connection hash */
55 static unsigned int ip_vs_conn_rnd;
56
57 /*
58 * Fine locking granularity for big connection hash table
59 */
60 #define CT_LOCKARRAY_BITS 4
61 #define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS)
62 #define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1)
63
64 struct ip_vs_aligned_lock
65 {
66 rwlock_t l;
67 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
68
69 /* lock array for conn table */
70 static struct ip_vs_aligned_lock
71 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
72
73 static inline void ct_read_lock(unsigned key)
74 {
75 read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
76 }
77
78 static inline void ct_read_unlock(unsigned key)
79 {
80 read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
81 }
82
83 static inline void ct_write_lock(unsigned key)
84 {
85 write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
86 }
87
88 static inline void ct_write_unlock(unsigned key)
89 {
90 write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
91 }
92
93 static inline void ct_read_lock_bh(unsigned key)
94 {
95 read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
96 }
97
98 static inline void ct_read_unlock_bh(unsigned key)
99 {
100 read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
101 }
102
103 static inline void ct_write_lock_bh(unsigned key)
104 {
105 write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
106 }
107
108 static inline void ct_write_unlock_bh(unsigned key)
109 {
110 write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
111 }
112
113
114 /*
115 * Returns hash value for IPVS connection entry
116 */
117 static unsigned int ip_vs_conn_hashkey(int af, unsigned proto,
118 const union nf_inet_addr *addr,
119 __be16 port)
120 {
121 #ifdef CONFIG_IP_VS_IPV6
122 if (af == AF_INET6)
123 return jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
124 (__force u32)port, proto, ip_vs_conn_rnd)
125 & IP_VS_CONN_TAB_MASK;
126 #endif
127 return jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
128 ip_vs_conn_rnd)
129 & IP_VS_CONN_TAB_MASK;
130 }
131
132
133 /*
134 * Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port.
135 * returns bool success.
136 */
137 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
138 {
139 unsigned hash;
140 int ret;
141
142 /* Hash by protocol, client address and port */
143 hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
144
145 ct_write_lock(hash);
146
147 if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
148 list_add(&cp->c_list, &ip_vs_conn_tab[hash]);
149 cp->flags |= IP_VS_CONN_F_HASHED;
150 atomic_inc(&cp->refcnt);
151 ret = 1;
152 } else {
153 IP_VS_ERR("ip_vs_conn_hash(): request for already hashed, "
154 "called from %p\n", __builtin_return_address(0));
155 ret = 0;
156 }
157
158 ct_write_unlock(hash);
159
160 return ret;
161 }
162
163
164 /*
165 * UNhashes ip_vs_conn from ip_vs_conn_tab.
166 * returns bool success.
167 */
168 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
169 {
170 unsigned hash;
171 int ret;
172
173 /* unhash it and decrease its reference counter */
174 hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
175
176 ct_write_lock(hash);
177
178 if (cp->flags & IP_VS_CONN_F_HASHED) {
179 list_del(&cp->c_list);
180 cp->flags &= ~IP_VS_CONN_F_HASHED;
181 atomic_dec(&cp->refcnt);
182 ret = 1;
183 } else
184 ret = 0;
185
186 ct_write_unlock(hash);
187
188 return ret;
189 }
190
191
192 /*
193 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
194 * Called for pkts coming from OUTside-to-INside.
195 * s_addr, s_port: pkt source address (foreign host)
196 * d_addr, d_port: pkt dest address (load balancer)
197 */
198 static inline struct ip_vs_conn *__ip_vs_conn_in_get
199 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
200 const union nf_inet_addr *d_addr, __be16 d_port)
201 {
202 unsigned hash;
203 struct ip_vs_conn *cp;
204
205 hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
206
207 ct_read_lock(hash);
208
209 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
210 if (cp->af == af &&
211 ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
212 ip_vs_addr_equal(af, d_addr, &cp->vaddr) &&
213 s_port == cp->cport && d_port == cp->vport &&
214 ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
215 protocol == cp->protocol) {
216 /* HIT */
217 atomic_inc(&cp->refcnt);
218 ct_read_unlock(hash);
219 return cp;
220 }
221 }
222
223 ct_read_unlock(hash);
224
225 return NULL;
226 }
227
228 struct ip_vs_conn *ip_vs_conn_in_get
229 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
230 const union nf_inet_addr *d_addr, __be16 d_port)
231 {
232 struct ip_vs_conn *cp;
233
234 cp = __ip_vs_conn_in_get(af, protocol, s_addr, s_port, d_addr, d_port);
235 if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt))
236 cp = __ip_vs_conn_in_get(af, protocol, s_addr, 0, d_addr,
237 d_port);
238
239 IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
240 ip_vs_proto_name(protocol),
241 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
242 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
243 cp ? "hit" : "not hit");
244
245 return cp;
246 }
247
248 /* Get reference to connection template */
249 struct ip_vs_conn *ip_vs_ct_in_get
250 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
251 const union nf_inet_addr *d_addr, __be16 d_port)
252 {
253 unsigned hash;
254 struct ip_vs_conn *cp;
255
256 hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
257
258 ct_read_lock(hash);
259
260 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
261 if (cp->af == af &&
262 ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
263 /* protocol should only be IPPROTO_IP if
264 * d_addr is a fwmark */
265 ip_vs_addr_equal(protocol == IPPROTO_IP ? AF_UNSPEC : af,
266 d_addr, &cp->vaddr) &&
267 s_port == cp->cport && d_port == cp->vport &&
268 cp->flags & IP_VS_CONN_F_TEMPLATE &&
269 protocol == cp->protocol) {
270 /* HIT */
271 atomic_inc(&cp->refcnt);
272 goto out;
273 }
274 }
275 cp = NULL;
276
277 out:
278 ct_read_unlock(hash);
279
280 IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
281 ip_vs_proto_name(protocol),
282 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
283 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
284 cp ? "hit" : "not hit");
285
286 return cp;
287 }
288
289 /*
290 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
291 * Called for pkts coming from inside-to-OUTside.
292 * s_addr, s_port: pkt source address (inside host)
293 * d_addr, d_port: pkt dest address (foreign host)
294 */
295 struct ip_vs_conn *ip_vs_conn_out_get
296 (int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
297 const union nf_inet_addr *d_addr, __be16 d_port)
298 {
299 unsigned hash;
300 struct ip_vs_conn *cp, *ret=NULL;
301
302 /*
303 * Check for "full" addressed entries
304 */
305 hash = ip_vs_conn_hashkey(af, protocol, d_addr, d_port);
306
307 ct_read_lock(hash);
308
309 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
310 if (cp->af == af &&
311 ip_vs_addr_equal(af, d_addr, &cp->caddr) &&
312 ip_vs_addr_equal(af, s_addr, &cp->daddr) &&
313 d_port == cp->cport && s_port == cp->dport &&
314 protocol == cp->protocol) {
315 /* HIT */
316 atomic_inc(&cp->refcnt);
317 ret = cp;
318 break;
319 }
320 }
321
322 ct_read_unlock(hash);
323
324 IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
325 ip_vs_proto_name(protocol),
326 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
327 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
328 ret ? "hit" : "not hit");
329
330 return ret;
331 }
332
333
334 /*
335 * Put back the conn and restart its timer with its timeout
336 */
337 void ip_vs_conn_put(struct ip_vs_conn *cp)
338 {
339 /* reset it expire in its timeout */
340 mod_timer(&cp->timer, jiffies+cp->timeout);
341
342 __ip_vs_conn_put(cp);
343 }
344
345
346 /*
347 * Fill a no_client_port connection with a client port number
348 */
349 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
350 {
351 if (ip_vs_conn_unhash(cp)) {
352 spin_lock(&cp->lock);
353 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
354 atomic_dec(&ip_vs_conn_no_cport_cnt);
355 cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
356 cp->cport = cport;
357 }
358 spin_unlock(&cp->lock);
359
360 /* hash on new dport */
361 ip_vs_conn_hash(cp);
362 }
363 }
364
365
366 /*
367 * Bind a connection entry with the corresponding packet_xmit.
368 * Called by ip_vs_conn_new.
369 */
370 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
371 {
372 switch (IP_VS_FWD_METHOD(cp)) {
373 case IP_VS_CONN_F_MASQ:
374 cp->packet_xmit = ip_vs_nat_xmit;
375 break;
376
377 case IP_VS_CONN_F_TUNNEL:
378 cp->packet_xmit = ip_vs_tunnel_xmit;
379 break;
380
381 case IP_VS_CONN_F_DROUTE:
382 cp->packet_xmit = ip_vs_dr_xmit;
383 break;
384
385 case IP_VS_CONN_F_LOCALNODE:
386 cp->packet_xmit = ip_vs_null_xmit;
387 break;
388
389 case IP_VS_CONN_F_BYPASS:
390 cp->packet_xmit = ip_vs_bypass_xmit;
391 break;
392 }
393 }
394
395 #ifdef CONFIG_IP_VS_IPV6
396 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
397 {
398 switch (IP_VS_FWD_METHOD(cp)) {
399 case IP_VS_CONN_F_MASQ:
400 cp->packet_xmit = ip_vs_nat_xmit_v6;
401 break;
402
403 case IP_VS_CONN_F_TUNNEL:
404 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
405 break;
406
407 case IP_VS_CONN_F_DROUTE:
408 cp->packet_xmit = ip_vs_dr_xmit_v6;
409 break;
410
411 case IP_VS_CONN_F_LOCALNODE:
412 cp->packet_xmit = ip_vs_null_xmit;
413 break;
414
415 case IP_VS_CONN_F_BYPASS:
416 cp->packet_xmit = ip_vs_bypass_xmit_v6;
417 break;
418 }
419 }
420 #endif
421
422
423 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
424 {
425 return atomic_read(&dest->activeconns)
426 + atomic_read(&dest->inactconns);
427 }
428
429 /*
430 * Bind a connection entry with a virtual service destination
431 * Called just after a new connection entry is created.
432 */
433 static inline void
434 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
435 {
436 /* if dest is NULL, then return directly */
437 if (!dest)
438 return;
439
440 /* Increase the refcnt counter of the dest */
441 atomic_inc(&dest->refcnt);
442
443 /* Bind with the destination and its corresponding transmitter */
444 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
445 (!(cp->flags & IP_VS_CONN_F_TEMPLATE)))
446 /* if the connection is not template and is created
447 * by sync, preserve the activity flag.
448 */
449 cp->flags |= atomic_read(&dest->conn_flags) &
450 (~IP_VS_CONN_F_INACTIVE);
451 else
452 cp->flags |= atomic_read(&dest->conn_flags);
453 cp->dest = dest;
454
455 IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
456 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
457 "dest->refcnt:%d\n",
458 ip_vs_proto_name(cp->protocol),
459 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
460 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
461 IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
462 ip_vs_fwd_tag(cp), cp->state,
463 cp->flags, atomic_read(&cp->refcnt),
464 atomic_read(&dest->refcnt));
465
466 /* Update the connection counters */
467 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
468 /* It is a normal connection, so increase the inactive
469 connection counter because it is in TCP SYNRECV
470 state (inactive) or other protocol inacive state */
471 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
472 (!(cp->flags & IP_VS_CONN_F_INACTIVE)))
473 atomic_inc(&dest->activeconns);
474 else
475 atomic_inc(&dest->inactconns);
476 } else {
477 /* It is a persistent connection/template, so increase
478 the peristent connection counter */
479 atomic_inc(&dest->persistconns);
480 }
481
482 if (dest->u_threshold != 0 &&
483 ip_vs_dest_totalconns(dest) >= dest->u_threshold)
484 dest->flags |= IP_VS_DEST_F_OVERLOAD;
485 }
486
487
488 /*
489 * Check if there is a destination for the connection, if so
490 * bind the connection to the destination.
491 */
492 struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
493 {
494 struct ip_vs_dest *dest;
495
496 if ((cp) && (!cp->dest)) {
497 dest = ip_vs_find_dest(cp->af, &cp->daddr, cp->dport,
498 &cp->vaddr, cp->vport,
499 cp->protocol);
500 ip_vs_bind_dest(cp, dest);
501 return dest;
502 } else
503 return NULL;
504 }
505
506
507 /*
508 * Unbind a connection entry with its VS destination
509 * Called by the ip_vs_conn_expire function.
510 */
511 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
512 {
513 struct ip_vs_dest *dest = cp->dest;
514
515 if (!dest)
516 return;
517
518 IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
519 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
520 "dest->refcnt:%d\n",
521 ip_vs_proto_name(cp->protocol),
522 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
523 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
524 IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
525 ip_vs_fwd_tag(cp), cp->state,
526 cp->flags, atomic_read(&cp->refcnt),
527 atomic_read(&dest->refcnt));
528
529 /* Update the connection counters */
530 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
531 /* It is a normal connection, so decrease the inactconns
532 or activeconns counter */
533 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
534 atomic_dec(&dest->inactconns);
535 } else {
536 atomic_dec(&dest->activeconns);
537 }
538 } else {
539 /* It is a persistent connection/template, so decrease
540 the peristent connection counter */
541 atomic_dec(&dest->persistconns);
542 }
543
544 if (dest->l_threshold != 0) {
545 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
546 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
547 } else if (dest->u_threshold != 0) {
548 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
549 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
550 } else {
551 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
552 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
553 }
554
555 /*
556 * Simply decrease the refcnt of the dest, because the
557 * dest will be either in service's destination list
558 * or in the trash.
559 */
560 atomic_dec(&dest->refcnt);
561 }
562
563
564 /*
565 * Checking if the destination of a connection template is available.
566 * If available, return 1, otherwise invalidate this connection
567 * template and return 0.
568 */
569 int ip_vs_check_template(struct ip_vs_conn *ct)
570 {
571 struct ip_vs_dest *dest = ct->dest;
572
573 /*
574 * Checking the dest server status.
575 */
576 if ((dest == NULL) ||
577 !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
578 (sysctl_ip_vs_expire_quiescent_template &&
579 (atomic_read(&dest->weight) == 0))) {
580 IP_VS_DBG_BUF(9, "check_template: dest not available for "
581 "protocol %s s:%s:%d v:%s:%d "
582 "-> d:%s:%d\n",
583 ip_vs_proto_name(ct->protocol),
584 IP_VS_DBG_ADDR(ct->af, &ct->caddr),
585 ntohs(ct->cport),
586 IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
587 ntohs(ct->vport),
588 IP_VS_DBG_ADDR(ct->af, &ct->daddr),
589 ntohs(ct->dport));
590
591 /*
592 * Invalidate the connection template
593 */
594 if (ct->vport != htons(0xffff)) {
595 if (ip_vs_conn_unhash(ct)) {
596 ct->dport = htons(0xffff);
597 ct->vport = htons(0xffff);
598 ct->cport = 0;
599 ip_vs_conn_hash(ct);
600 }
601 }
602
603 /*
604 * Simply decrease the refcnt of the template,
605 * don't restart its timer.
606 */
607 atomic_dec(&ct->refcnt);
608 return 0;
609 }
610 return 1;
611 }
612
613 static void ip_vs_conn_expire(unsigned long data)
614 {
615 struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
616
617 cp->timeout = 60*HZ;
618
619 /*
620 * hey, I'm using it
621 */
622 atomic_inc(&cp->refcnt);
623
624 /*
625 * do I control anybody?
626 */
627 if (atomic_read(&cp->n_control))
628 goto expire_later;
629
630 /*
631 * unhash it if it is hashed in the conn table
632 */
633 if (!ip_vs_conn_unhash(cp))
634 goto expire_later;
635
636 /*
637 * refcnt==1 implies I'm the only one referrer
638 */
639 if (likely(atomic_read(&cp->refcnt) == 1)) {
640 /* delete the timer if it is activated by other users */
641 if (timer_pending(&cp->timer))
642 del_timer(&cp->timer);
643
644 /* does anybody control me? */
645 if (cp->control)
646 ip_vs_control_del(cp);
647
648 if (unlikely(cp->app != NULL))
649 ip_vs_unbind_app(cp);
650 ip_vs_unbind_dest(cp);
651 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
652 atomic_dec(&ip_vs_conn_no_cport_cnt);
653 atomic_dec(&ip_vs_conn_count);
654
655 kmem_cache_free(ip_vs_conn_cachep, cp);
656 return;
657 }
658
659 /* hash it back to the table */
660 ip_vs_conn_hash(cp);
661
662 expire_later:
663 IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
664 atomic_read(&cp->refcnt)-1,
665 atomic_read(&cp->n_control));
666
667 ip_vs_conn_put(cp);
668 }
669
670
671 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
672 {
673 if (del_timer(&cp->timer))
674 mod_timer(&cp->timer, jiffies);
675 }
676
677
678 /*
679 * Create a new connection entry and hash it into the ip_vs_conn_tab
680 */
681 struct ip_vs_conn *
682 ip_vs_conn_new(int af, int proto, const union nf_inet_addr *caddr, __be16 cport,
683 const union nf_inet_addr *vaddr, __be16 vport,
684 const union nf_inet_addr *daddr, __be16 dport, unsigned flags,
685 struct ip_vs_dest *dest)
686 {
687 struct ip_vs_conn *cp;
688 struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
689
690 cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
691 if (cp == NULL) {
692 IP_VS_ERR_RL("ip_vs_conn_new: no memory available.\n");
693 return NULL;
694 }
695
696 INIT_LIST_HEAD(&cp->c_list);
697 setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
698 cp->af = af;
699 cp->protocol = proto;
700 ip_vs_addr_copy(af, &cp->caddr, caddr);
701 cp->cport = cport;
702 ip_vs_addr_copy(af, &cp->vaddr, vaddr);
703 cp->vport = vport;
704 /* proto should only be IPPROTO_IP if d_addr is a fwmark */
705 ip_vs_addr_copy(proto == IPPROTO_IP ? AF_UNSPEC : af,
706 &cp->daddr, daddr);
707 cp->dport = dport;
708 cp->flags = flags;
709 spin_lock_init(&cp->lock);
710
711 /*
712 * Set the entry is referenced by the current thread before hashing
713 * it in the table, so that other thread run ip_vs_random_dropentry
714 * but cannot drop this entry.
715 */
716 atomic_set(&cp->refcnt, 1);
717
718 atomic_set(&cp->n_control, 0);
719 atomic_set(&cp->in_pkts, 0);
720
721 atomic_inc(&ip_vs_conn_count);
722 if (flags & IP_VS_CONN_F_NO_CPORT)
723 atomic_inc(&ip_vs_conn_no_cport_cnt);
724
725 /* Bind the connection with a destination server */
726 ip_vs_bind_dest(cp, dest);
727
728 /* Set its state and timeout */
729 cp->state = 0;
730 cp->timeout = 3*HZ;
731
732 /* Bind its packet transmitter */
733 #ifdef CONFIG_IP_VS_IPV6
734 if (af == AF_INET6)
735 ip_vs_bind_xmit_v6(cp);
736 else
737 #endif
738 ip_vs_bind_xmit(cp);
739
740 if (unlikely(pp && atomic_read(&pp->appcnt)))
741 ip_vs_bind_app(cp, pp);
742
743 /* Hash it in the ip_vs_conn_tab finally */
744 ip_vs_conn_hash(cp);
745
746 return cp;
747 }
748
749
750 /*
751 * /proc/net/ip_vs_conn entries
752 */
753 #ifdef CONFIG_PROC_FS
754
755 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
756 {
757 int idx;
758 struct ip_vs_conn *cp;
759
760 for(idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
761 ct_read_lock_bh(idx);
762 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
763 if (pos-- == 0) {
764 seq->private = &ip_vs_conn_tab[idx];
765 return cp;
766 }
767 }
768 ct_read_unlock_bh(idx);
769 }
770
771 return NULL;
772 }
773
774 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
775 {
776 seq->private = NULL;
777 return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
778 }
779
780 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
781 {
782 struct ip_vs_conn *cp = v;
783 struct list_head *e, *l = seq->private;
784 int idx;
785
786 ++*pos;
787 if (v == SEQ_START_TOKEN)
788 return ip_vs_conn_array(seq, 0);
789
790 /* more on same hash chain? */
791 if ((e = cp->c_list.next) != l)
792 return list_entry(e, struct ip_vs_conn, c_list);
793
794 idx = l - ip_vs_conn_tab;
795 ct_read_unlock_bh(idx);
796
797 while (++idx < IP_VS_CONN_TAB_SIZE) {
798 ct_read_lock_bh(idx);
799 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
800 seq->private = &ip_vs_conn_tab[idx];
801 return cp;
802 }
803 ct_read_unlock_bh(idx);
804 }
805 seq->private = NULL;
806 return NULL;
807 }
808
809 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
810 {
811 struct list_head *l = seq->private;
812
813 if (l)
814 ct_read_unlock_bh(l - ip_vs_conn_tab);
815 }
816
817 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
818 {
819
820 if (v == SEQ_START_TOKEN)
821 seq_puts(seq,
822 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires\n");
823 else {
824 const struct ip_vs_conn *cp = v;
825
826 #ifdef CONFIG_IP_VS_IPV6
827 if (cp->af == AF_INET6)
828 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %7lu\n",
829 ip_vs_proto_name(cp->protocol),
830 &cp->caddr.in6, ntohs(cp->cport),
831 &cp->vaddr.in6, ntohs(cp->vport),
832 &cp->daddr.in6, ntohs(cp->dport),
833 ip_vs_state_name(cp->protocol, cp->state),
834 (cp->timer.expires-jiffies)/HZ);
835 else
836 #endif
837 seq_printf(seq,
838 "%-3s %08X %04X %08X %04X"
839 " %08X %04X %-11s %7lu\n",
840 ip_vs_proto_name(cp->protocol),
841 ntohl(cp->caddr.ip), ntohs(cp->cport),
842 ntohl(cp->vaddr.ip), ntohs(cp->vport),
843 ntohl(cp->daddr.ip), ntohs(cp->dport),
844 ip_vs_state_name(cp->protocol, cp->state),
845 (cp->timer.expires-jiffies)/HZ);
846 }
847 return 0;
848 }
849
850 static const struct seq_operations ip_vs_conn_seq_ops = {
851 .start = ip_vs_conn_seq_start,
852 .next = ip_vs_conn_seq_next,
853 .stop = ip_vs_conn_seq_stop,
854 .show = ip_vs_conn_seq_show,
855 };
856
857 static int ip_vs_conn_open(struct inode *inode, struct file *file)
858 {
859 return seq_open(file, &ip_vs_conn_seq_ops);
860 }
861
862 static const struct file_operations ip_vs_conn_fops = {
863 .owner = THIS_MODULE,
864 .open = ip_vs_conn_open,
865 .read = seq_read,
866 .llseek = seq_lseek,
867 .release = seq_release,
868 };
869
870 static const char *ip_vs_origin_name(unsigned flags)
871 {
872 if (flags & IP_VS_CONN_F_SYNC)
873 return "SYNC";
874 else
875 return "LOCAL";
876 }
877
878 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
879 {
880
881 if (v == SEQ_START_TOKEN)
882 seq_puts(seq,
883 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n");
884 else {
885 const struct ip_vs_conn *cp = v;
886
887 #ifdef CONFIG_IP_VS_IPV6
888 if (cp->af == AF_INET6)
889 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
890 ip_vs_proto_name(cp->protocol),
891 &cp->caddr.in6, ntohs(cp->cport),
892 &cp->vaddr.in6, ntohs(cp->vport),
893 &cp->daddr.in6, ntohs(cp->dport),
894 ip_vs_state_name(cp->protocol, cp->state),
895 ip_vs_origin_name(cp->flags),
896 (cp->timer.expires-jiffies)/HZ);
897 else
898 #endif
899 seq_printf(seq,
900 "%-3s %08X %04X %08X %04X "
901 "%08X %04X %-11s %-6s %7lu\n",
902 ip_vs_proto_name(cp->protocol),
903 ntohl(cp->caddr.ip), ntohs(cp->cport),
904 ntohl(cp->vaddr.ip), ntohs(cp->vport),
905 ntohl(cp->daddr.ip), ntohs(cp->dport),
906 ip_vs_state_name(cp->protocol, cp->state),
907 ip_vs_origin_name(cp->flags),
908 (cp->timer.expires-jiffies)/HZ);
909 }
910 return 0;
911 }
912
913 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
914 .start = ip_vs_conn_seq_start,
915 .next = ip_vs_conn_seq_next,
916 .stop = ip_vs_conn_seq_stop,
917 .show = ip_vs_conn_sync_seq_show,
918 };
919
920 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
921 {
922 return seq_open(file, &ip_vs_conn_sync_seq_ops);
923 }
924
925 static const struct file_operations ip_vs_conn_sync_fops = {
926 .owner = THIS_MODULE,
927 .open = ip_vs_conn_sync_open,
928 .read = seq_read,
929 .llseek = seq_lseek,
930 .release = seq_release,
931 };
932
933 #endif
934
935
936 /*
937 * Randomly drop connection entries before running out of memory
938 */
939 static inline int todrop_entry(struct ip_vs_conn *cp)
940 {
941 /*
942 * The drop rate array needs tuning for real environments.
943 * Called from timer bh only => no locking
944 */
945 static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
946 static char todrop_counter[9] = {0};
947 int i;
948
949 /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
950 This will leave enough time for normal connection to get
951 through. */
952 if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
953 return 0;
954
955 /* Don't drop the entry if its number of incoming packets is not
956 located in [0, 8] */
957 i = atomic_read(&cp->in_pkts);
958 if (i > 8 || i < 0) return 0;
959
960 if (!todrop_rate[i]) return 0;
961 if (--todrop_counter[i] > 0) return 0;
962
963 todrop_counter[i] = todrop_rate[i];
964 return 1;
965 }
966
967 /* Called from keventd and must protect itself from softirqs */
968 void ip_vs_random_dropentry(void)
969 {
970 int idx;
971 struct ip_vs_conn *cp;
972
973 /*
974 * Randomly scan 1/32 of the whole table every second
975 */
976 for (idx = 0; idx < (IP_VS_CONN_TAB_SIZE>>5); idx++) {
977 unsigned hash = net_random() & IP_VS_CONN_TAB_MASK;
978
979 /*
980 * Lock is actually needed in this loop.
981 */
982 ct_write_lock_bh(hash);
983
984 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
985 if (cp->flags & IP_VS_CONN_F_TEMPLATE)
986 /* connection template */
987 continue;
988
989 if (cp->protocol == IPPROTO_TCP) {
990 switch(cp->state) {
991 case IP_VS_TCP_S_SYN_RECV:
992 case IP_VS_TCP_S_SYNACK:
993 break;
994
995 case IP_VS_TCP_S_ESTABLISHED:
996 if (todrop_entry(cp))
997 break;
998 continue;
999
1000 default:
1001 continue;
1002 }
1003 } else {
1004 if (!todrop_entry(cp))
1005 continue;
1006 }
1007
1008 IP_VS_DBG(4, "del connection\n");
1009 ip_vs_conn_expire_now(cp);
1010 if (cp->control) {
1011 IP_VS_DBG(4, "del conn template\n");
1012 ip_vs_conn_expire_now(cp->control);
1013 }
1014 }
1015 ct_write_unlock_bh(hash);
1016 }
1017 }
1018
1019
1020 /*
1021 * Flush all the connection entries in the ip_vs_conn_tab
1022 */
1023 static void ip_vs_conn_flush(void)
1024 {
1025 int idx;
1026 struct ip_vs_conn *cp;
1027
1028 flush_again:
1029 for (idx=0; idx<IP_VS_CONN_TAB_SIZE; idx++) {
1030 /*
1031 * Lock is actually needed in this loop.
1032 */
1033 ct_write_lock_bh(idx);
1034
1035 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
1036
1037 IP_VS_DBG(4, "del connection\n");
1038 ip_vs_conn_expire_now(cp);
1039 if (cp->control) {
1040 IP_VS_DBG(4, "del conn template\n");
1041 ip_vs_conn_expire_now(cp->control);
1042 }
1043 }
1044 ct_write_unlock_bh(idx);
1045 }
1046
1047 /* the counter may be not NULL, because maybe some conn entries
1048 are run by slow timer handler or unhashed but still referred */
1049 if (atomic_read(&ip_vs_conn_count) != 0) {
1050 schedule();
1051 goto flush_again;
1052 }
1053 }
1054
1055
1056 int __init ip_vs_conn_init(void)
1057 {
1058 int idx;
1059
1060 /*
1061 * Allocate the connection hash table and initialize its list heads
1062 */
1063 ip_vs_conn_tab = vmalloc(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head));
1064 if (!ip_vs_conn_tab)
1065 return -ENOMEM;
1066
1067 /* Allocate ip_vs_conn slab cache */
1068 ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1069 sizeof(struct ip_vs_conn), 0,
1070 SLAB_HWCACHE_ALIGN, NULL);
1071 if (!ip_vs_conn_cachep) {
1072 vfree(ip_vs_conn_tab);
1073 return -ENOMEM;
1074 }
1075
1076 IP_VS_INFO("Connection hash table configured "
1077 "(size=%d, memory=%ldKbytes)\n",
1078 IP_VS_CONN_TAB_SIZE,
1079 (long)(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head))/1024);
1080 IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1081 sizeof(struct ip_vs_conn));
1082
1083 for (idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
1084 INIT_LIST_HEAD(&ip_vs_conn_tab[idx]);
1085 }
1086
1087 for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) {
1088 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1089 }
1090
1091 proc_net_fops_create(&init_net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1092 proc_net_fops_create(&init_net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1093
1094 /* calculate the random value for connection hash */
1095 get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1096
1097 return 0;
1098 }
1099
1100
1101 void ip_vs_conn_cleanup(void)
1102 {
1103 /* flush all the connection entries first */
1104 ip_vs_conn_flush();
1105
1106 /* Release the empty cache */
1107 kmem_cache_destroy(ip_vs_conn_cachep);
1108 proc_net_remove(&init_net, "ip_vs_conn");
1109 proc_net_remove(&init_net, "ip_vs_conn_sync");
1110 vfree(ip_vs_conn_tab);
1111 }
Linus' kernel tree