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Merge branches 'release', 'cpuidle-2.6.25' and 'idle' into release
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / ipvs / ip_vs_conn.c
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 * Version: $Id: ip_vs_conn.c,v 1.31 2003/04/18 09:03:16 wensong Exp $
9 *
10 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
11 * Peter Kese <peter.kese@ijs.si>
12 * Julian Anastasov <ja@ssi.bg>
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
20 * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
21 * and others. Many code here is taken from IP MASQ code of kernel 2.2.
22 *
23 * Changes:
24 *
25 */
26
27 #include <linux/interrupt.h>
28 #include <linux/in.h>
29 #include <linux/net.h>
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/vmalloc.h>
33 #include <linux/proc_fs.h> /* for proc_net_* */
34 #include <linux/seq_file.h>
35 #include <linux/jhash.h>
36 #include <linux/random.h>
37
38 #include <net/net_namespace.h>
39 #include <net/ip_vs.h>
40
41
42 /*
43 * Connection hash table: for input and output packets lookups of IPVS
44 */
45 static struct list_head *ip_vs_conn_tab;
46
47 /* SLAB cache for IPVS connections */
48 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
49
50 /* counter for current IPVS connections */
51 static atomic_t ip_vs_conn_count = ATOMIC_INIT(0);
52
53 /* counter for no client port connections */
54 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
55
56 /* random value for IPVS connection hash */
57 static unsigned int ip_vs_conn_rnd;
58
59 /*
60 * Fine locking granularity for big connection hash table
61 */
62 #define CT_LOCKARRAY_BITS 4
63 #define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS)
64 #define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1)
65
66 struct ip_vs_aligned_lock
67 {
68 rwlock_t l;
69 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
70
71 /* lock array for conn table */
72 static struct ip_vs_aligned_lock
73 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
74
75 static inline void ct_read_lock(unsigned key)
76 {
77 read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
78 }
79
80 static inline void ct_read_unlock(unsigned key)
81 {
82 read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
83 }
84
85 static inline void ct_write_lock(unsigned key)
86 {
87 write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
88 }
89
90 static inline void ct_write_unlock(unsigned key)
91 {
92 write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
93 }
94
95 static inline void ct_read_lock_bh(unsigned key)
96 {
97 read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
98 }
99
100 static inline void ct_read_unlock_bh(unsigned key)
101 {
102 read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
103 }
104
105 static inline void ct_write_lock_bh(unsigned key)
106 {
107 write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
108 }
109
110 static inline void ct_write_unlock_bh(unsigned key)
111 {
112 write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
113 }
114
115
116 /*
117 * Returns hash value for IPVS connection entry
118 */
119 static unsigned int ip_vs_conn_hashkey(unsigned proto, __be32 addr, __be16 port)
120 {
121 return jhash_3words((__force u32)addr, (__force u32)port, proto, ip_vs_conn_rnd)
122 & IP_VS_CONN_TAB_MASK;
123 }
124
125
126 /*
127 * Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port.
128 * returns bool success.
129 */
130 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
131 {
132 unsigned hash;
133 int ret;
134
135 /* Hash by protocol, client address and port */
136 hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport);
137
138 ct_write_lock(hash);
139
140 if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
141 list_add(&cp->c_list, &ip_vs_conn_tab[hash]);
142 cp->flags |= IP_VS_CONN_F_HASHED;
143 atomic_inc(&cp->refcnt);
144 ret = 1;
145 } else {
146 IP_VS_ERR("ip_vs_conn_hash(): request for already hashed, "
147 "called from %p\n", __builtin_return_address(0));
148 ret = 0;
149 }
150
151 ct_write_unlock(hash);
152
153 return ret;
154 }
155
156
157 /*
158 * UNhashes ip_vs_conn from ip_vs_conn_tab.
159 * returns bool success.
160 */
161 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
162 {
163 unsigned hash;
164 int ret;
165
166 /* unhash it and decrease its reference counter */
167 hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport);
168
169 ct_write_lock(hash);
170
171 if (cp->flags & IP_VS_CONN_F_HASHED) {
172 list_del(&cp->c_list);
173 cp->flags &= ~IP_VS_CONN_F_HASHED;
174 atomic_dec(&cp->refcnt);
175 ret = 1;
176 } else
177 ret = 0;
178
179 ct_write_unlock(hash);
180
181 return ret;
182 }
183
184
185 /*
186 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
187 * Called for pkts coming from OUTside-to-INside.
188 * s_addr, s_port: pkt source address (foreign host)
189 * d_addr, d_port: pkt dest address (load balancer)
190 */
191 static inline struct ip_vs_conn *__ip_vs_conn_in_get
192 (int protocol, __be32 s_addr, __be16 s_port, __be32 d_addr, __be16 d_port)
193 {
194 unsigned hash;
195 struct ip_vs_conn *cp;
196
197 hash = ip_vs_conn_hashkey(protocol, s_addr, s_port);
198
199 ct_read_lock(hash);
200
201 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
202 if (s_addr==cp->caddr && s_port==cp->cport &&
203 d_port==cp->vport && d_addr==cp->vaddr &&
204 ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
205 protocol==cp->protocol) {
206 /* HIT */
207 atomic_inc(&cp->refcnt);
208 ct_read_unlock(hash);
209 return cp;
210 }
211 }
212
213 ct_read_unlock(hash);
214
215 return NULL;
216 }
217
218 struct ip_vs_conn *ip_vs_conn_in_get
219 (int protocol, __be32 s_addr, __be16 s_port, __be32 d_addr, __be16 d_port)
220 {
221 struct ip_vs_conn *cp;
222
223 cp = __ip_vs_conn_in_get(protocol, s_addr, s_port, d_addr, d_port);
224 if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt))
225 cp = __ip_vs_conn_in_get(protocol, s_addr, 0, d_addr, d_port);
226
227 IP_VS_DBG(9, "lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
228 ip_vs_proto_name(protocol),
229 NIPQUAD(s_addr), ntohs(s_port),
230 NIPQUAD(d_addr), ntohs(d_port),
231 cp?"hit":"not hit");
232
233 return cp;
234 }
235
236 /* Get reference to connection template */
237 struct ip_vs_conn *ip_vs_ct_in_get
238 (int protocol, __be32 s_addr, __be16 s_port, __be32 d_addr, __be16 d_port)
239 {
240 unsigned hash;
241 struct ip_vs_conn *cp;
242
243 hash = ip_vs_conn_hashkey(protocol, s_addr, s_port);
244
245 ct_read_lock(hash);
246
247 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
248 if (s_addr==cp->caddr && s_port==cp->cport &&
249 d_port==cp->vport && d_addr==cp->vaddr &&
250 cp->flags & IP_VS_CONN_F_TEMPLATE &&
251 protocol==cp->protocol) {
252 /* HIT */
253 atomic_inc(&cp->refcnt);
254 goto out;
255 }
256 }
257 cp = NULL;
258
259 out:
260 ct_read_unlock(hash);
261
262 IP_VS_DBG(9, "template lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
263 ip_vs_proto_name(protocol),
264 NIPQUAD(s_addr), ntohs(s_port),
265 NIPQUAD(d_addr), ntohs(d_port),
266 cp?"hit":"not hit");
267
268 return cp;
269 }
270
271 /*
272 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
273 * Called for pkts coming from inside-to-OUTside.
274 * s_addr, s_port: pkt source address (inside host)
275 * d_addr, d_port: pkt dest address (foreign host)
276 */
277 struct ip_vs_conn *ip_vs_conn_out_get
278 (int protocol, __be32 s_addr, __be16 s_port, __be32 d_addr, __be16 d_port)
279 {
280 unsigned hash;
281 struct ip_vs_conn *cp, *ret=NULL;
282
283 /*
284 * Check for "full" addressed entries
285 */
286 hash = ip_vs_conn_hashkey(protocol, d_addr, d_port);
287
288 ct_read_lock(hash);
289
290 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
291 if (d_addr == cp->caddr && d_port == cp->cport &&
292 s_port == cp->dport && s_addr == cp->daddr &&
293 protocol == cp->protocol) {
294 /* HIT */
295 atomic_inc(&cp->refcnt);
296 ret = cp;
297 break;
298 }
299 }
300
301 ct_read_unlock(hash);
302
303 IP_VS_DBG(9, "lookup/out %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n",
304 ip_vs_proto_name(protocol),
305 NIPQUAD(s_addr), ntohs(s_port),
306 NIPQUAD(d_addr), ntohs(d_port),
307 ret?"hit":"not hit");
308
309 return ret;
310 }
311
312
313 /*
314 * Put back the conn and restart its timer with its timeout
315 */
316 void ip_vs_conn_put(struct ip_vs_conn *cp)
317 {
318 /* reset it expire in its timeout */
319 mod_timer(&cp->timer, jiffies+cp->timeout);
320
321 __ip_vs_conn_put(cp);
322 }
323
324
325 /*
326 * Fill a no_client_port connection with a client port number
327 */
328 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
329 {
330 if (ip_vs_conn_unhash(cp)) {
331 spin_lock(&cp->lock);
332 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
333 atomic_dec(&ip_vs_conn_no_cport_cnt);
334 cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
335 cp->cport = cport;
336 }
337 spin_unlock(&cp->lock);
338
339 /* hash on new dport */
340 ip_vs_conn_hash(cp);
341 }
342 }
343
344
345 /*
346 * Bind a connection entry with the corresponding packet_xmit.
347 * Called by ip_vs_conn_new.
348 */
349 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
350 {
351 switch (IP_VS_FWD_METHOD(cp)) {
352 case IP_VS_CONN_F_MASQ:
353 cp->packet_xmit = ip_vs_nat_xmit;
354 break;
355
356 case IP_VS_CONN_F_TUNNEL:
357 cp->packet_xmit = ip_vs_tunnel_xmit;
358 break;
359
360 case IP_VS_CONN_F_DROUTE:
361 cp->packet_xmit = ip_vs_dr_xmit;
362 break;
363
364 case IP_VS_CONN_F_LOCALNODE:
365 cp->packet_xmit = ip_vs_null_xmit;
366 break;
367
368 case IP_VS_CONN_F_BYPASS:
369 cp->packet_xmit = ip_vs_bypass_xmit;
370 break;
371 }
372 }
373
374
375 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
376 {
377 return atomic_read(&dest->activeconns)
378 + atomic_read(&dest->inactconns);
379 }
380
381 /*
382 * Bind a connection entry with a virtual service destination
383 * Called just after a new connection entry is created.
384 */
385 static inline void
386 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
387 {
388 /* if dest is NULL, then return directly */
389 if (!dest)
390 return;
391
392 /* Increase the refcnt counter of the dest */
393 atomic_inc(&dest->refcnt);
394
395 /* Bind with the destination and its corresponding transmitter */
396 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
397 (!(cp->flags & IP_VS_CONN_F_TEMPLATE)))
398 /* if the connection is not template and is created
399 * by sync, preserve the activity flag.
400 */
401 cp->flags |= atomic_read(&dest->conn_flags) &
402 (~IP_VS_CONN_F_INACTIVE);
403 else
404 cp->flags |= atomic_read(&dest->conn_flags);
405 cp->dest = dest;
406
407 IP_VS_DBG(7, "Bind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
408 "d:%u.%u.%u.%u:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
409 "dest->refcnt:%d\n",
410 ip_vs_proto_name(cp->protocol),
411 NIPQUAD(cp->caddr), ntohs(cp->cport),
412 NIPQUAD(cp->vaddr), ntohs(cp->vport),
413 NIPQUAD(cp->daddr), ntohs(cp->dport),
414 ip_vs_fwd_tag(cp), cp->state,
415 cp->flags, atomic_read(&cp->refcnt),
416 atomic_read(&dest->refcnt));
417
418 /* Update the connection counters */
419 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
420 /* It is a normal connection, so increase the inactive
421 connection counter because it is in TCP SYNRECV
422 state (inactive) or other protocol inacive state */
423 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
424 (!(cp->flags & IP_VS_CONN_F_INACTIVE)))
425 atomic_inc(&dest->activeconns);
426 else
427 atomic_inc(&dest->inactconns);
428 } else {
429 /* It is a persistent connection/template, so increase
430 the peristent connection counter */
431 atomic_inc(&dest->persistconns);
432 }
433
434 if (dest->u_threshold != 0 &&
435 ip_vs_dest_totalconns(dest) >= dest->u_threshold)
436 dest->flags |= IP_VS_DEST_F_OVERLOAD;
437 }
438
439
440 /*
441 * Check if there is a destination for the connection, if so
442 * bind the connection to the destination.
443 */
444 struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
445 {
446 struct ip_vs_dest *dest;
447
448 if ((cp) && (!cp->dest)) {
449 dest = ip_vs_find_dest(cp->daddr, cp->dport,
450 cp->vaddr, cp->vport, cp->protocol);
451 ip_vs_bind_dest(cp, dest);
452 return dest;
453 } else
454 return NULL;
455 }
456
457
458 /*
459 * Unbind a connection entry with its VS destination
460 * Called by the ip_vs_conn_expire function.
461 */
462 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
463 {
464 struct ip_vs_dest *dest = cp->dest;
465
466 if (!dest)
467 return;
468
469 IP_VS_DBG(7, "Unbind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
470 "d:%u.%u.%u.%u:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
471 "dest->refcnt:%d\n",
472 ip_vs_proto_name(cp->protocol),
473 NIPQUAD(cp->caddr), ntohs(cp->cport),
474 NIPQUAD(cp->vaddr), ntohs(cp->vport),
475 NIPQUAD(cp->daddr), ntohs(cp->dport),
476 ip_vs_fwd_tag(cp), cp->state,
477 cp->flags, atomic_read(&cp->refcnt),
478 atomic_read(&dest->refcnt));
479
480 /* Update the connection counters */
481 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
482 /* It is a normal connection, so decrease the inactconns
483 or activeconns counter */
484 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
485 atomic_dec(&dest->inactconns);
486 } else {
487 atomic_dec(&dest->activeconns);
488 }
489 } else {
490 /* It is a persistent connection/template, so decrease
491 the peristent connection counter */
492 atomic_dec(&dest->persistconns);
493 }
494
495 if (dest->l_threshold != 0) {
496 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
497 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
498 } else if (dest->u_threshold != 0) {
499 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
500 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
501 } else {
502 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
503 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
504 }
505
506 /*
507 * Simply decrease the refcnt of the dest, because the
508 * dest will be either in service's destination list
509 * or in the trash.
510 */
511 atomic_dec(&dest->refcnt);
512 }
513
514
515 /*
516 * Checking if the destination of a connection template is available.
517 * If available, return 1, otherwise invalidate this connection
518 * template and return 0.
519 */
520 int ip_vs_check_template(struct ip_vs_conn *ct)
521 {
522 struct ip_vs_dest *dest = ct->dest;
523
524 /*
525 * Checking the dest server status.
526 */
527 if ((dest == NULL) ||
528 !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
529 (sysctl_ip_vs_expire_quiescent_template &&
530 (atomic_read(&dest->weight) == 0))) {
531 IP_VS_DBG(9, "check_template: dest not available for "
532 "protocol %s s:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d "
533 "-> d:%u.%u.%u.%u:%d\n",
534 ip_vs_proto_name(ct->protocol),
535 NIPQUAD(ct->caddr), ntohs(ct->cport),
536 NIPQUAD(ct->vaddr), ntohs(ct->vport),
537 NIPQUAD(ct->daddr), ntohs(ct->dport));
538
539 /*
540 * Invalidate the connection template
541 */
542 if (ct->vport != htons(0xffff)) {
543 if (ip_vs_conn_unhash(ct)) {
544 ct->dport = htons(0xffff);
545 ct->vport = htons(0xffff);
546 ct->cport = 0;
547 ip_vs_conn_hash(ct);
548 }
549 }
550
551 /*
552 * Simply decrease the refcnt of the template,
553 * don't restart its timer.
554 */
555 atomic_dec(&ct->refcnt);
556 return 0;
557 }
558 return 1;
559 }
560
561 static void ip_vs_conn_expire(unsigned long data)
562 {
563 struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
564
565 cp->timeout = 60*HZ;
566
567 /*
568 * hey, I'm using it
569 */
570 atomic_inc(&cp->refcnt);
571
572 /*
573 * do I control anybody?
574 */
575 if (atomic_read(&cp->n_control))
576 goto expire_later;
577
578 /*
579 * unhash it if it is hashed in the conn table
580 */
581 if (!ip_vs_conn_unhash(cp))
582 goto expire_later;
583
584 /*
585 * refcnt==1 implies I'm the only one referrer
586 */
587 if (likely(atomic_read(&cp->refcnt) == 1)) {
588 /* delete the timer if it is activated by other users */
589 if (timer_pending(&cp->timer))
590 del_timer(&cp->timer);
591
592 /* does anybody control me? */
593 if (cp->control)
594 ip_vs_control_del(cp);
595
596 if (unlikely(cp->app != NULL))
597 ip_vs_unbind_app(cp);
598 ip_vs_unbind_dest(cp);
599 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
600 atomic_dec(&ip_vs_conn_no_cport_cnt);
601 atomic_dec(&ip_vs_conn_count);
602
603 kmem_cache_free(ip_vs_conn_cachep, cp);
604 return;
605 }
606
607 /* hash it back to the table */
608 ip_vs_conn_hash(cp);
609
610 expire_later:
611 IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
612 atomic_read(&cp->refcnt)-1,
613 atomic_read(&cp->n_control));
614
615 ip_vs_conn_put(cp);
616 }
617
618
619 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
620 {
621 if (del_timer(&cp->timer))
622 mod_timer(&cp->timer, jiffies);
623 }
624
625
626 /*
627 * Create a new connection entry and hash it into the ip_vs_conn_tab
628 */
629 struct ip_vs_conn *
630 ip_vs_conn_new(int proto, __be32 caddr, __be16 cport, __be32 vaddr, __be16 vport,
631 __be32 daddr, __be16 dport, unsigned flags,
632 struct ip_vs_dest *dest)
633 {
634 struct ip_vs_conn *cp;
635 struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
636
637 cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
638 if (cp == NULL) {
639 IP_VS_ERR_RL("ip_vs_conn_new: no memory available.\n");
640 return NULL;
641 }
642
643 INIT_LIST_HEAD(&cp->c_list);
644 setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
645 cp->protocol = proto;
646 cp->caddr = caddr;
647 cp->cport = cport;
648 cp->vaddr = vaddr;
649 cp->vport = vport;
650 cp->daddr = daddr;
651 cp->dport = dport;
652 cp->flags = flags;
653 spin_lock_init(&cp->lock);
654
655 /*
656 * Set the entry is referenced by the current thread before hashing
657 * it in the table, so that other thread run ip_vs_random_dropentry
658 * but cannot drop this entry.
659 */
660 atomic_set(&cp->refcnt, 1);
661
662 atomic_set(&cp->n_control, 0);
663 atomic_set(&cp->in_pkts, 0);
664
665 atomic_inc(&ip_vs_conn_count);
666 if (flags & IP_VS_CONN_F_NO_CPORT)
667 atomic_inc(&ip_vs_conn_no_cport_cnt);
668
669 /* Bind the connection with a destination server */
670 ip_vs_bind_dest(cp, dest);
671
672 /* Set its state and timeout */
673 cp->state = 0;
674 cp->timeout = 3*HZ;
675
676 /* Bind its packet transmitter */
677 ip_vs_bind_xmit(cp);
678
679 if (unlikely(pp && atomic_read(&pp->appcnt)))
680 ip_vs_bind_app(cp, pp);
681
682 /* Hash it in the ip_vs_conn_tab finally */
683 ip_vs_conn_hash(cp);
684
685 return cp;
686 }
687
688
689 /*
690 * /proc/net/ip_vs_conn entries
691 */
692 #ifdef CONFIG_PROC_FS
693
694 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
695 {
696 int idx;
697 struct ip_vs_conn *cp;
698
699 for(idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
700 ct_read_lock_bh(idx);
701 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
702 if (pos-- == 0) {
703 seq->private = &ip_vs_conn_tab[idx];
704 return cp;
705 }
706 }
707 ct_read_unlock_bh(idx);
708 }
709
710 return NULL;
711 }
712
713 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
714 {
715 seq->private = NULL;
716 return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
717 }
718
719 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
720 {
721 struct ip_vs_conn *cp = v;
722 struct list_head *e, *l = seq->private;
723 int idx;
724
725 ++*pos;
726 if (v == SEQ_START_TOKEN)
727 return ip_vs_conn_array(seq, 0);
728
729 /* more on same hash chain? */
730 if ((e = cp->c_list.next) != l)
731 return list_entry(e, struct ip_vs_conn, c_list);
732
733 idx = l - ip_vs_conn_tab;
734 ct_read_unlock_bh(idx);
735
736 while (++idx < IP_VS_CONN_TAB_SIZE) {
737 ct_read_lock_bh(idx);
738 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
739 seq->private = &ip_vs_conn_tab[idx];
740 return cp;
741 }
742 ct_read_unlock_bh(idx);
743 }
744 seq->private = NULL;
745 return NULL;
746 }
747
748 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
749 {
750 struct list_head *l = seq->private;
751
752 if (l)
753 ct_read_unlock_bh(l - ip_vs_conn_tab);
754 }
755
756 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
757 {
758
759 if (v == SEQ_START_TOKEN)
760 seq_puts(seq,
761 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires\n");
762 else {
763 const struct ip_vs_conn *cp = v;
764
765 seq_printf(seq,
766 "%-3s %08X %04X %08X %04X %08X %04X %-11s %7lu\n",
767 ip_vs_proto_name(cp->protocol),
768 ntohl(cp->caddr), ntohs(cp->cport),
769 ntohl(cp->vaddr), ntohs(cp->vport),
770 ntohl(cp->daddr), ntohs(cp->dport),
771 ip_vs_state_name(cp->protocol, cp->state),
772 (cp->timer.expires-jiffies)/HZ);
773 }
774 return 0;
775 }
776
777 static const struct seq_operations ip_vs_conn_seq_ops = {
778 .start = ip_vs_conn_seq_start,
779 .next = ip_vs_conn_seq_next,
780 .stop = ip_vs_conn_seq_stop,
781 .show = ip_vs_conn_seq_show,
782 };
783
784 static int ip_vs_conn_open(struct inode *inode, struct file *file)
785 {
786 return seq_open(file, &ip_vs_conn_seq_ops);
787 }
788
789 static const struct file_operations ip_vs_conn_fops = {
790 .owner = THIS_MODULE,
791 .open = ip_vs_conn_open,
792 .read = seq_read,
793 .llseek = seq_lseek,
794 .release = seq_release,
795 };
796
797 static const char *ip_vs_origin_name(unsigned flags)
798 {
799 if (flags & IP_VS_CONN_F_SYNC)
800 return "SYNC";
801 else
802 return "LOCAL";
803 }
804
805 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
806 {
807
808 if (v == SEQ_START_TOKEN)
809 seq_puts(seq,
810 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n");
811 else {
812 const struct ip_vs_conn *cp = v;
813
814 seq_printf(seq,
815 "%-3s %08X %04X %08X %04X %08X %04X %-11s %-6s %7lu\n",
816 ip_vs_proto_name(cp->protocol),
817 ntohl(cp->caddr), ntohs(cp->cport),
818 ntohl(cp->vaddr), ntohs(cp->vport),
819 ntohl(cp->daddr), ntohs(cp->dport),
820 ip_vs_state_name(cp->protocol, cp->state),
821 ip_vs_origin_name(cp->flags),
822 (cp->timer.expires-jiffies)/HZ);
823 }
824 return 0;
825 }
826
827 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
828 .start = ip_vs_conn_seq_start,
829 .next = ip_vs_conn_seq_next,
830 .stop = ip_vs_conn_seq_stop,
831 .show = ip_vs_conn_sync_seq_show,
832 };
833
834 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
835 {
836 return seq_open(file, &ip_vs_conn_sync_seq_ops);
837 }
838
839 static const struct file_operations ip_vs_conn_sync_fops = {
840 .owner = THIS_MODULE,
841 .open = ip_vs_conn_sync_open,
842 .read = seq_read,
843 .llseek = seq_lseek,
844 .release = seq_release,
845 };
846
847 #endif
848
849
850 /*
851 * Randomly drop connection entries before running out of memory
852 */
853 static inline int todrop_entry(struct ip_vs_conn *cp)
854 {
855 /*
856 * The drop rate array needs tuning for real environments.
857 * Called from timer bh only => no locking
858 */
859 static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
860 static char todrop_counter[9] = {0};
861 int i;
862
863 /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
864 This will leave enough time for normal connection to get
865 through. */
866 if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
867 return 0;
868
869 /* Don't drop the entry if its number of incoming packets is not
870 located in [0, 8] */
871 i = atomic_read(&cp->in_pkts);
872 if (i > 8 || i < 0) return 0;
873
874 if (!todrop_rate[i]) return 0;
875 if (--todrop_counter[i] > 0) return 0;
876
877 todrop_counter[i] = todrop_rate[i];
878 return 1;
879 }
880
881 /* Called from keventd and must protect itself from softirqs */
882 void ip_vs_random_dropentry(void)
883 {
884 int idx;
885 struct ip_vs_conn *cp;
886
887 /*
888 * Randomly scan 1/32 of the whole table every second
889 */
890 for (idx = 0; idx < (IP_VS_CONN_TAB_SIZE>>5); idx++) {
891 unsigned hash = net_random() & IP_VS_CONN_TAB_MASK;
892
893 /*
894 * Lock is actually needed in this loop.
895 */
896 ct_write_lock_bh(hash);
897
898 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
899 if (cp->flags & IP_VS_CONN_F_TEMPLATE)
900 /* connection template */
901 continue;
902
903 if (cp->protocol == IPPROTO_TCP) {
904 switch(cp->state) {
905 case IP_VS_TCP_S_SYN_RECV:
906 case IP_VS_TCP_S_SYNACK:
907 break;
908
909 case IP_VS_TCP_S_ESTABLISHED:
910 if (todrop_entry(cp))
911 break;
912 continue;
913
914 default:
915 continue;
916 }
917 } else {
918 if (!todrop_entry(cp))
919 continue;
920 }
921
922 IP_VS_DBG(4, "del connection\n");
923 ip_vs_conn_expire_now(cp);
924 if (cp->control) {
925 IP_VS_DBG(4, "del conn template\n");
926 ip_vs_conn_expire_now(cp->control);
927 }
928 }
929 ct_write_unlock_bh(hash);
930 }
931 }
932
933
934 /*
935 * Flush all the connection entries in the ip_vs_conn_tab
936 */
937 static void ip_vs_conn_flush(void)
938 {
939 int idx;
940 struct ip_vs_conn *cp;
941
942 flush_again:
943 for (idx=0; idx<IP_VS_CONN_TAB_SIZE; idx++) {
944 /*
945 * Lock is actually needed in this loop.
946 */
947 ct_write_lock_bh(idx);
948
949 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
950
951 IP_VS_DBG(4, "del connection\n");
952 ip_vs_conn_expire_now(cp);
953 if (cp->control) {
954 IP_VS_DBG(4, "del conn template\n");
955 ip_vs_conn_expire_now(cp->control);
956 }
957 }
958 ct_write_unlock_bh(idx);
959 }
960
961 /* the counter may be not NULL, because maybe some conn entries
962 are run by slow timer handler or unhashed but still referred */
963 if (atomic_read(&ip_vs_conn_count) != 0) {
964 schedule();
965 goto flush_again;
966 }
967 }
968
969
970 int ip_vs_conn_init(void)
971 {
972 int idx;
973
974 /*
975 * Allocate the connection hash table and initialize its list heads
976 */
977 ip_vs_conn_tab = vmalloc(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head));
978 if (!ip_vs_conn_tab)
979 return -ENOMEM;
980
981 /* Allocate ip_vs_conn slab cache */
982 ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
983 sizeof(struct ip_vs_conn), 0,
984 SLAB_HWCACHE_ALIGN, NULL);
985 if (!ip_vs_conn_cachep) {
986 vfree(ip_vs_conn_tab);
987 return -ENOMEM;
988 }
989
990 IP_VS_INFO("Connection hash table configured "
991 "(size=%d, memory=%ldKbytes)\n",
992 IP_VS_CONN_TAB_SIZE,
993 (long)(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head))/1024);
994 IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
995 sizeof(struct ip_vs_conn));
996
997 for (idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) {
998 INIT_LIST_HEAD(&ip_vs_conn_tab[idx]);
999 }
1000
1001 for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) {
1002 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1003 }
1004
1005 proc_net_fops_create(&init_net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1006 proc_net_fops_create(&init_net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1007
1008 /* calculate the random value for connection hash */
1009 get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1010
1011 return 0;
1012 }
1013
1014
1015 void ip_vs_conn_cleanup(void)
1016 {
1017 /* flush all the connection entries first */
1018 ip_vs_conn_flush();
1019
1020 /* Release the empty cache */
1021 kmem_cache_destroy(ip_vs_conn_cachep);
1022 proc_net_remove(&init_net, "ip_vs_conn");
1023 proc_net_remove(&init_net, "ip_vs_conn_sync");
1024 vfree(ip_vs_conn_tab);
1025 }
kernel source for telekom puls (alcatel/mediatek)