/net/netfilter/ipvs/ip_vs_conn.c
C | 1135 lines | 742 code | 192 blank | 201 comment | 118 complexity | 43297c7388fffab80b9463fd8caa505c MD5 | raw file
Possible License(s): CC-BY-SA-3.0, GPL-2.0, LGPL-2.0, AGPL-1.0
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/net.h>
31#include <linux/kernel.h>
32#include <linux/module.h>
33#include <linux/vmalloc.h>
34#include <linux/proc_fs.h> /* for proc_net_* */
35#include <linux/slab.h>
36#include <linux/seq_file.h>
37#include <linux/jhash.h>
38#include <linux/random.h>
39
40#include <net/net_namespace.h>
41#include <net/ip_vs.h>
42
43
44#ifndef CONFIG_IP_VS_TAB_BITS
45#define CONFIG_IP_VS_TAB_BITS 12
46#endif
47
48/*
49 * Connection hash size. Default is what was selected at compile time.
50*/
51int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
52module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
53MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
54
55/* size and mask values */
56int ip_vs_conn_tab_size;
57int ip_vs_conn_tab_mask;
58
59/*
60 * Connection hash table: for input and output packets lookups of IPVS
61 */
62static struct list_head *ip_vs_conn_tab;
63
64/* SLAB cache for IPVS connections */
65static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
66
67/* counter for current IPVS connections */
68static atomic_t ip_vs_conn_count = ATOMIC_INIT(0);
69
70/* counter for no client port connections */
71static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
72
73/* random value for IPVS connection hash */
74static unsigned int ip_vs_conn_rnd;
75
76/*
77 * Fine locking granularity for big connection hash table
78 */
79#define CT_LOCKARRAY_BITS 4
80#define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS)
81#define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1)
82
83struct ip_vs_aligned_lock
84{
85 rwlock_t l;
86} __attribute__((__aligned__(SMP_CACHE_BYTES)));
87
88/* lock array for conn table */
89static struct ip_vs_aligned_lock
90__ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
91
92static inline void ct_read_lock(unsigned key)
93{
94 read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
95}
96
97static inline void ct_read_unlock(unsigned key)
98{
99 read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
100}
101
102static inline void ct_write_lock(unsigned key)
103{
104 write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
105}
106
107static inline void ct_write_unlock(unsigned key)
108{
109 write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
110}
111
112static inline void ct_read_lock_bh(unsigned key)
113{
114 read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
115}
116
117static inline void ct_read_unlock_bh(unsigned key)
118{
119 read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
120}
121
122static inline void ct_write_lock_bh(unsigned key)
123{
124 write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
125}
126
127static inline void ct_write_unlock_bh(unsigned key)
128{
129 write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
130}
131
132
133/*
134 * Returns hash value for IPVS connection entry
135 */
136static unsigned int ip_vs_conn_hashkey(int af, unsigned proto,
137 const union nf_inet_addr *addr,
138 __be16 port)
139{
140#ifdef CONFIG_IP_VS_IPV6
141 if (af == AF_INET6)
142 return jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
143 (__force u32)port, proto, ip_vs_conn_rnd)
144 & ip_vs_conn_tab_mask;
145#endif
146 return jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
147 ip_vs_conn_rnd)
148 & ip_vs_conn_tab_mask;
149}
150
151
152/*
153 * Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port.
154 * returns bool success.
155 */
156static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
157{
158 unsigned hash;
159 int ret;
160
161 /* Hash by protocol, client address and port */
162 hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
163
164 ct_write_lock(hash);
165
166 if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
167 list_add(&cp->c_list, &ip_vs_conn_tab[hash]);
168 cp->flags |= IP_VS_CONN_F_HASHED;
169 atomic_inc(&cp->refcnt);
170 ret = 1;
171 } else {
172 pr_err("%s(): request for already hashed, called from %pF\n",
173 __func__, __builtin_return_address(0));
174 ret = 0;
175 }
176
177 ct_write_unlock(hash);
178
179 return ret;
180}
181
182
183/*
184 * UNhashes ip_vs_conn from ip_vs_conn_tab.
185 * returns bool success.
186 */
187static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
188{
189 unsigned hash;
190 int ret;
191
192 /* unhash it and decrease its reference counter */
193 hash = ip_vs_conn_hashkey(cp->af, cp->protocol, &cp->caddr, cp->cport);
194
195 ct_write_lock(hash);
196
197 if (cp->flags & IP_VS_CONN_F_HASHED) {
198 list_del(&cp->c_list);
199 cp->flags &= ~IP_VS_CONN_F_HASHED;
200 atomic_dec(&cp->refcnt);
201 ret = 1;
202 } else
203 ret = 0;
204
205 ct_write_unlock(hash);
206
207 return ret;
208}
209
210
211/*
212 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
213 * Called for pkts coming from OUTside-to-INside.
214 * s_addr, s_port: pkt source address (foreign host)
215 * d_addr, d_port: pkt dest address (load balancer)
216 */
217static inline struct ip_vs_conn *__ip_vs_conn_in_get
218(int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
219 const union nf_inet_addr *d_addr, __be16 d_port)
220{
221 unsigned hash;
222 struct ip_vs_conn *cp;
223
224 hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
225
226 ct_read_lock(hash);
227
228 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
229 if (cp->af == af &&
230 ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
231 ip_vs_addr_equal(af, d_addr, &cp->vaddr) &&
232 s_port == cp->cport && d_port == cp->vport &&
233 ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
234 protocol == cp->protocol) {
235 /* HIT */
236 atomic_inc(&cp->refcnt);
237 ct_read_unlock(hash);
238 return cp;
239 }
240 }
241
242 ct_read_unlock(hash);
243
244 return NULL;
245}
246
247struct ip_vs_conn *ip_vs_conn_in_get
248(int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
249 const union nf_inet_addr *d_addr, __be16 d_port)
250{
251 struct ip_vs_conn *cp;
252
253 cp = __ip_vs_conn_in_get(af, protocol, s_addr, s_port, d_addr, d_port);
254 if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt))
255 cp = __ip_vs_conn_in_get(af, protocol, s_addr, 0, d_addr,
256 d_port);
257
258 IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
259 ip_vs_proto_name(protocol),
260 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
261 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
262 cp ? "hit" : "not hit");
263
264 return cp;
265}
266
267/* Get reference to connection template */
268struct ip_vs_conn *ip_vs_ct_in_get
269(int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
270 const union nf_inet_addr *d_addr, __be16 d_port)
271{
272 unsigned hash;
273 struct ip_vs_conn *cp;
274
275 hash = ip_vs_conn_hashkey(af, protocol, s_addr, s_port);
276
277 ct_read_lock(hash);
278
279 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
280 if (cp->af == af &&
281 ip_vs_addr_equal(af, s_addr, &cp->caddr) &&
282 /* protocol should only be IPPROTO_IP if
283 * d_addr is a fwmark */
284 ip_vs_addr_equal(protocol == IPPROTO_IP ? AF_UNSPEC : af,
285 d_addr, &cp->vaddr) &&
286 s_port == cp->cport && d_port == cp->vport &&
287 cp->flags & IP_VS_CONN_F_TEMPLATE &&
288 protocol == cp->protocol) {
289 /* HIT */
290 atomic_inc(&cp->refcnt);
291 goto out;
292 }
293 }
294 cp = NULL;
295
296 out:
297 ct_read_unlock(hash);
298
299 IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
300 ip_vs_proto_name(protocol),
301 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
302 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
303 cp ? "hit" : "not hit");
304
305 return cp;
306}
307
308/*
309 * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
310 * Called for pkts coming from inside-to-OUTside.
311 * s_addr, s_port: pkt source address (inside host)
312 * d_addr, d_port: pkt dest address (foreign host)
313 */
314struct ip_vs_conn *ip_vs_conn_out_get
315(int af, int protocol, const union nf_inet_addr *s_addr, __be16 s_port,
316 const union nf_inet_addr *d_addr, __be16 d_port)
317{
318 unsigned hash;
319 struct ip_vs_conn *cp, *ret=NULL;
320
321 /*
322 * Check for "full" addressed entries
323 */
324 hash = ip_vs_conn_hashkey(af, protocol, d_addr, d_port);
325
326 ct_read_lock(hash);
327
328 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
329 if (cp->af == af &&
330 ip_vs_addr_equal(af, d_addr, &cp->caddr) &&
331 ip_vs_addr_equal(af, s_addr, &cp->daddr) &&
332 d_port == cp->cport && s_port == cp->dport &&
333 protocol == cp->protocol) {
334 /* HIT */
335 atomic_inc(&cp->refcnt);
336 ret = cp;
337 break;
338 }
339 }
340
341 ct_read_unlock(hash);
342
343 IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
344 ip_vs_proto_name(protocol),
345 IP_VS_DBG_ADDR(af, s_addr), ntohs(s_port),
346 IP_VS_DBG_ADDR(af, d_addr), ntohs(d_port),
347 ret ? "hit" : "not hit");
348
349 return ret;
350}
351
352
353/*
354 * Put back the conn and restart its timer with its timeout
355 */
356void ip_vs_conn_put(struct ip_vs_conn *cp)
357{
358 /* reset it expire in its timeout */
359 mod_timer(&cp->timer, jiffies+cp->timeout);
360
361 __ip_vs_conn_put(cp);
362}
363
364
365/*
366 * Fill a no_client_port connection with a client port number
367 */
368void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
369{
370 if (ip_vs_conn_unhash(cp)) {
371 spin_lock(&cp->lock);
372 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
373 atomic_dec(&ip_vs_conn_no_cport_cnt);
374 cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
375 cp->cport = cport;
376 }
377 spin_unlock(&cp->lock);
378
379 /* hash on new dport */
380 ip_vs_conn_hash(cp);
381 }
382}
383
384
385/*
386 * Bind a connection entry with the corresponding packet_xmit.
387 * Called by ip_vs_conn_new.
388 */
389static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
390{
391 switch (IP_VS_FWD_METHOD(cp)) {
392 case IP_VS_CONN_F_MASQ:
393 cp->packet_xmit = ip_vs_nat_xmit;
394 break;
395
396 case IP_VS_CONN_F_TUNNEL:
397 cp->packet_xmit = ip_vs_tunnel_xmit;
398 break;
399
400 case IP_VS_CONN_F_DROUTE:
401 cp->packet_xmit = ip_vs_dr_xmit;
402 break;
403
404 case IP_VS_CONN_F_LOCALNODE:
405 cp->packet_xmit = ip_vs_null_xmit;
406 break;
407
408 case IP_VS_CONN_F_BYPASS:
409 cp->packet_xmit = ip_vs_bypass_xmit;
410 break;
411 }
412}
413
414#ifdef CONFIG_IP_VS_IPV6
415static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
416{
417 switch (IP_VS_FWD_METHOD(cp)) {
418 case IP_VS_CONN_F_MASQ:
419 cp->packet_xmit = ip_vs_nat_xmit_v6;
420 break;
421
422 case IP_VS_CONN_F_TUNNEL:
423 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
424 break;
425
426 case IP_VS_CONN_F_DROUTE:
427 cp->packet_xmit = ip_vs_dr_xmit_v6;
428 break;
429
430 case IP_VS_CONN_F_LOCALNODE:
431 cp->packet_xmit = ip_vs_null_xmit;
432 break;
433
434 case IP_VS_CONN_F_BYPASS:
435 cp->packet_xmit = ip_vs_bypass_xmit_v6;
436 break;
437 }
438}
439#endif
440
441
442static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
443{
444 return atomic_read(&dest->activeconns)
445 + atomic_read(&dest->inactconns);
446}
447
448/*
449 * Bind a connection entry with a virtual service destination
450 * Called just after a new connection entry is created.
451 */
452static inline void
453ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
454{
455 /* if dest is NULL, then return directly */
456 if (!dest)
457 return;
458
459 /* Increase the refcnt counter of the dest */
460 atomic_inc(&dest->refcnt);
461
462 /* Bind with the destination and its corresponding transmitter */
463 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
464 (!(cp->flags & IP_VS_CONN_F_TEMPLATE)))
465 /* if the connection is not template and is created
466 * by sync, preserve the activity flag.
467 */
468 cp->flags |= atomic_read(&dest->conn_flags) &
469 (~IP_VS_CONN_F_INACTIVE);
470 else
471 cp->flags |= atomic_read(&dest->conn_flags);
472 cp->dest = dest;
473
474 IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
475 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
476 "dest->refcnt:%d\n",
477 ip_vs_proto_name(cp->protocol),
478 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
479 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
480 IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
481 ip_vs_fwd_tag(cp), cp->state,
482 cp->flags, atomic_read(&cp->refcnt),
483 atomic_read(&dest->refcnt));
484
485 /* Update the connection counters */
486 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
487 /* It is a normal connection, so increase the inactive
488 connection counter because it is in TCP SYNRECV
489 state (inactive) or other protocol inacive state */
490 if ((cp->flags & IP_VS_CONN_F_SYNC) &&
491 (!(cp->flags & IP_VS_CONN_F_INACTIVE)))
492 atomic_inc(&dest->activeconns);
493 else
494 atomic_inc(&dest->inactconns);
495 } else {
496 /* It is a persistent connection/template, so increase
497 the peristent connection counter */
498 atomic_inc(&dest->persistconns);
499 }
500
501 if (dest->u_threshold != 0 &&
502 ip_vs_dest_totalconns(dest) >= dest->u_threshold)
503 dest->flags |= IP_VS_DEST_F_OVERLOAD;
504}
505
506
507/*
508 * Check if there is a destination for the connection, if so
509 * bind the connection to the destination.
510 */
511struct ip_vs_dest *ip_vs_try_bind_dest(struct ip_vs_conn *cp)
512{
513 struct ip_vs_dest *dest;
514
515 if ((cp) && (!cp->dest)) {
516 dest = ip_vs_find_dest(cp->af, &cp->daddr, cp->dport,
517 &cp->vaddr, cp->vport,
518 cp->protocol);
519 ip_vs_bind_dest(cp, dest);
520 return dest;
521 } else
522 return NULL;
523}
524
525
526/*
527 * Unbind a connection entry with its VS destination
528 * Called by the ip_vs_conn_expire function.
529 */
530static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
531{
532 struct ip_vs_dest *dest = cp->dest;
533
534 if (!dest)
535 return;
536
537 IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
538 "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
539 "dest->refcnt:%d\n",
540 ip_vs_proto_name(cp->protocol),
541 IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
542 IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
543 IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
544 ip_vs_fwd_tag(cp), cp->state,
545 cp->flags, atomic_read(&cp->refcnt),
546 atomic_read(&dest->refcnt));
547
548 /* Update the connection counters */
549 if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
550 /* It is a normal connection, so decrease the inactconns
551 or activeconns counter */
552 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
553 atomic_dec(&dest->inactconns);
554 } else {
555 atomic_dec(&dest->activeconns);
556 }
557 } else {
558 /* It is a persistent connection/template, so decrease
559 the peristent connection counter */
560 atomic_dec(&dest->persistconns);
561 }
562
563 if (dest->l_threshold != 0) {
564 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
565 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
566 } else if (dest->u_threshold != 0) {
567 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
568 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
569 } else {
570 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
571 dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
572 }
573
574 /*
575 * Simply decrease the refcnt of the dest, because the
576 * dest will be either in service's destination list
577 * or in the trash.
578 */
579 atomic_dec(&dest->refcnt);
580}
581
582
583/*
584 * Checking if the destination of a connection template is available.
585 * If available, return 1, otherwise invalidate this connection
586 * template and return 0.
587 */
588int ip_vs_check_template(struct ip_vs_conn *ct)
589{
590 struct ip_vs_dest *dest = ct->dest;
591
592 /*
593 * Checking the dest server status.
594 */
595 if ((dest == NULL) ||
596 !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
597 (sysctl_ip_vs_expire_quiescent_template &&
598 (atomic_read(&dest->weight) == 0))) {
599 IP_VS_DBG_BUF(9, "check_template: dest not available for "
600 "protocol %s s:%s:%d v:%s:%d "
601 "-> d:%s:%d\n",
602 ip_vs_proto_name(ct->protocol),
603 IP_VS_DBG_ADDR(ct->af, &ct->caddr),
604 ntohs(ct->cport),
605 IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
606 ntohs(ct->vport),
607 IP_VS_DBG_ADDR(ct->af, &ct->daddr),
608 ntohs(ct->dport));
609
610 /*
611 * Invalidate the connection template
612 */
613 if (ct->vport != htons(0xffff)) {
614 if (ip_vs_conn_unhash(ct)) {
615 ct->dport = htons(0xffff);
616 ct->vport = htons(0xffff);
617 ct->cport = 0;
618 ip_vs_conn_hash(ct);
619 }
620 }
621
622 /*
623 * Simply decrease the refcnt of the template,
624 * don't restart its timer.
625 */
626 atomic_dec(&ct->refcnt);
627 return 0;
628 }
629 return 1;
630}
631
632static void ip_vs_conn_expire(unsigned long data)
633{
634 struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
635
636 cp->timeout = 60*HZ;
637
638 /*
639 * hey, I'm using it
640 */
641 atomic_inc(&cp->refcnt);
642
643 /*
644 * do I control anybody?
645 */
646 if (atomic_read(&cp->n_control))
647 goto expire_later;
648
649 /*
650 * unhash it if it is hashed in the conn table
651 */
652 if (!ip_vs_conn_unhash(cp))
653 goto expire_later;
654
655 /*
656 * refcnt==1 implies I'm the only one referrer
657 */
658 if (likely(atomic_read(&cp->refcnt) == 1)) {
659 /* delete the timer if it is activated by other users */
660 if (timer_pending(&cp->timer))
661 del_timer(&cp->timer);
662
663 /* does anybody control me? */
664 if (cp->control)
665 ip_vs_control_del(cp);
666
667 if (unlikely(cp->app != NULL))
668 ip_vs_unbind_app(cp);
669 ip_vs_unbind_dest(cp);
670 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
671 atomic_dec(&ip_vs_conn_no_cport_cnt);
672 atomic_dec(&ip_vs_conn_count);
673
674 kmem_cache_free(ip_vs_conn_cachep, cp);
675 return;
676 }
677
678 /* hash it back to the table */
679 ip_vs_conn_hash(cp);
680
681 expire_later:
682 IP_VS_DBG(7, "delayed: conn->refcnt-1=%d conn->n_control=%d\n",
683 atomic_read(&cp->refcnt)-1,
684 atomic_read(&cp->n_control));
685
686 ip_vs_conn_put(cp);
687}
688
689
690void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
691{
692 if (del_timer(&cp->timer))
693 mod_timer(&cp->timer, jiffies);
694}
695
696
697/*
698 * Create a new connection entry and hash it into the ip_vs_conn_tab
699 */
700struct ip_vs_conn *
701ip_vs_conn_new(int af, int proto, const union nf_inet_addr *caddr, __be16 cport,
702 const union nf_inet_addr *vaddr, __be16 vport,
703 const union nf_inet_addr *daddr, __be16 dport, unsigned flags,
704 struct ip_vs_dest *dest)
705{
706 struct ip_vs_conn *cp;
707 struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
708
709 cp = kmem_cache_zalloc(ip_vs_conn_cachep, GFP_ATOMIC);
710 if (cp == NULL) {
711 IP_VS_ERR_RL("%s(): no memory\n", __func__);
712 return NULL;
713 }
714
715 INIT_LIST_HEAD(&cp->c_list);
716 setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
717 cp->af = af;
718 cp->protocol = proto;
719 ip_vs_addr_copy(af, &cp->caddr, caddr);
720 cp->cport = cport;
721 ip_vs_addr_copy(af, &cp->vaddr, vaddr);
722 cp->vport = vport;
723 /* proto should only be IPPROTO_IP if d_addr is a fwmark */
724 ip_vs_addr_copy(proto == IPPROTO_IP ? AF_UNSPEC : af,
725 &cp->daddr, daddr);
726 cp->dport = dport;
727 cp->flags = flags;
728 spin_lock_init(&cp->lock);
729
730 /*
731 * Set the entry is referenced by the current thread before hashing
732 * it in the table, so that other thread run ip_vs_random_dropentry
733 * but cannot drop this entry.
734 */
735 atomic_set(&cp->refcnt, 1);
736
737 atomic_set(&cp->n_control, 0);
738 atomic_set(&cp->in_pkts, 0);
739
740 atomic_inc(&ip_vs_conn_count);
741 if (flags & IP_VS_CONN_F_NO_CPORT)
742 atomic_inc(&ip_vs_conn_no_cport_cnt);
743
744 /* Bind the connection with a destination server */
745 ip_vs_bind_dest(cp, dest);
746
747 /* Set its state and timeout */
748 cp->state = 0;
749 cp->timeout = 3*HZ;
750
751 /* Bind its packet transmitter */
752#ifdef CONFIG_IP_VS_IPV6
753 if (af == AF_INET6)
754 ip_vs_bind_xmit_v6(cp);
755 else
756#endif
757 ip_vs_bind_xmit(cp);
758
759 if (unlikely(pp && atomic_read(&pp->appcnt)))
760 ip_vs_bind_app(cp, pp);
761
762 /* Hash it in the ip_vs_conn_tab finally */
763 ip_vs_conn_hash(cp);
764
765 return cp;
766}
767
768
769/*
770 * /proc/net/ip_vs_conn entries
771 */
772#ifdef CONFIG_PROC_FS
773
774static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
775{
776 int idx;
777 struct ip_vs_conn *cp;
778
779 for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
780 ct_read_lock_bh(idx);
781 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
782 if (pos-- == 0) {
783 seq->private = &ip_vs_conn_tab[idx];
784 return cp;
785 }
786 }
787 ct_read_unlock_bh(idx);
788 }
789
790 return NULL;
791}
792
793static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
794{
795 seq->private = NULL;
796 return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
797}
798
799static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
800{
801 struct ip_vs_conn *cp = v;
802 struct list_head *e, *l = seq->private;
803 int idx;
804
805 ++*pos;
806 if (v == SEQ_START_TOKEN)
807 return ip_vs_conn_array(seq, 0);
808
809 /* more on same hash chain? */
810 if ((e = cp->c_list.next) != l)
811 return list_entry(e, struct ip_vs_conn, c_list);
812
813 idx = l - ip_vs_conn_tab;
814 ct_read_unlock_bh(idx);
815
816 while (++idx < ip_vs_conn_tab_size) {
817 ct_read_lock_bh(idx);
818 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
819 seq->private = &ip_vs_conn_tab[idx];
820 return cp;
821 }
822 ct_read_unlock_bh(idx);
823 }
824 seq->private = NULL;
825 return NULL;
826}
827
828static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
829{
830 struct list_head *l = seq->private;
831
832 if (l)
833 ct_read_unlock_bh(l - ip_vs_conn_tab);
834}
835
836static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
837{
838
839 if (v == SEQ_START_TOKEN)
840 seq_puts(seq,
841 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires\n");
842 else {
843 const struct ip_vs_conn *cp = v;
844
845#ifdef CONFIG_IP_VS_IPV6
846 if (cp->af == AF_INET6)
847 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %7lu\n",
848 ip_vs_proto_name(cp->protocol),
849 &cp->caddr.in6, ntohs(cp->cport),
850 &cp->vaddr.in6, ntohs(cp->vport),
851 &cp->daddr.in6, ntohs(cp->dport),
852 ip_vs_state_name(cp->protocol, cp->state),
853 (cp->timer.expires-jiffies)/HZ);
854 else
855#endif
856 seq_printf(seq,
857 "%-3s %08X %04X %08X %04X"
858 " %08X %04X %-11s %7lu\n",
859 ip_vs_proto_name(cp->protocol),
860 ntohl(cp->caddr.ip), ntohs(cp->cport),
861 ntohl(cp->vaddr.ip), ntohs(cp->vport),
862 ntohl(cp->daddr.ip), ntohs(cp->dport),
863 ip_vs_state_name(cp->protocol, cp->state),
864 (cp->timer.expires-jiffies)/HZ);
865 }
866 return 0;
867}
868
869static const struct seq_operations ip_vs_conn_seq_ops = {
870 .start = ip_vs_conn_seq_start,
871 .next = ip_vs_conn_seq_next,
872 .stop = ip_vs_conn_seq_stop,
873 .show = ip_vs_conn_seq_show,
874};
875
876static int ip_vs_conn_open(struct inode *inode, struct file *file)
877{
878 return seq_open(file, &ip_vs_conn_seq_ops);
879}
880
881static const struct file_operations ip_vs_conn_fops = {
882 .owner = THIS_MODULE,
883 .open = ip_vs_conn_open,
884 .read = seq_read,
885 .llseek = seq_lseek,
886 .release = seq_release,
887};
888
889static const char *ip_vs_origin_name(unsigned flags)
890{
891 if (flags & IP_VS_CONN_F_SYNC)
892 return "SYNC";
893 else
894 return "LOCAL";
895}
896
897static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
898{
899
900 if (v == SEQ_START_TOKEN)
901 seq_puts(seq,
902 "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Origin Expires\n");
903 else {
904 const struct ip_vs_conn *cp = v;
905
906#ifdef CONFIG_IP_VS_IPV6
907 if (cp->af == AF_INET6)
908 seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
909 ip_vs_proto_name(cp->protocol),
910 &cp->caddr.in6, ntohs(cp->cport),
911 &cp->vaddr.in6, ntohs(cp->vport),
912 &cp->daddr.in6, ntohs(cp->dport),
913 ip_vs_state_name(cp->protocol, cp->state),
914 ip_vs_origin_name(cp->flags),
915 (cp->timer.expires-jiffies)/HZ);
916 else
917#endif
918 seq_printf(seq,
919 "%-3s %08X %04X %08X %04X "
920 "%08X %04X %-11s %-6s %7lu\n",
921 ip_vs_proto_name(cp->protocol),
922 ntohl(cp->caddr.ip), ntohs(cp->cport),
923 ntohl(cp->vaddr.ip), ntohs(cp->vport),
924 ntohl(cp->daddr.ip), ntohs(cp->dport),
925 ip_vs_state_name(cp->protocol, cp->state),
926 ip_vs_origin_name(cp->flags),
927 (cp->timer.expires-jiffies)/HZ);
928 }
929 return 0;
930}
931
932static const struct seq_operations ip_vs_conn_sync_seq_ops = {
933 .start = ip_vs_conn_seq_start,
934 .next = ip_vs_conn_seq_next,
935 .stop = ip_vs_conn_seq_stop,
936 .show = ip_vs_conn_sync_seq_show,
937};
938
939static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
940{
941 return seq_open(file, &ip_vs_conn_sync_seq_ops);
942}
943
944static const struct file_operations ip_vs_conn_sync_fops = {
945 .owner = THIS_MODULE,
946 .open = ip_vs_conn_sync_open,
947 .read = seq_read,
948 .llseek = seq_lseek,
949 .release = seq_release,
950};
951
952#endif
953
954
955/*
956 * Randomly drop connection entries before running out of memory
957 */
958static inline int todrop_entry(struct ip_vs_conn *cp)
959{
960 /*
961 * The drop rate array needs tuning for real environments.
962 * Called from timer bh only => no locking
963 */
964 static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
965 static char todrop_counter[9] = {0};
966 int i;
967
968 /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
969 This will leave enough time for normal connection to get
970 through. */
971 if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
972 return 0;
973
974 /* Don't drop the entry if its number of incoming packets is not
975 located in [0, 8] */
976 i = atomic_read(&cp->in_pkts);
977 if (i > 8 || i < 0) return 0;
978
979 if (!todrop_rate[i]) return 0;
980 if (--todrop_counter[i] > 0) return 0;
981
982 todrop_counter[i] = todrop_rate[i];
983 return 1;
984}
985
986/* Called from keventd and must protect itself from softirqs */
987void ip_vs_random_dropentry(void)
988{
989 int idx;
990 struct ip_vs_conn *cp;
991
992 /*
993 * Randomly scan 1/32 of the whole table every second
994 */
995 for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
996 unsigned hash = net_random() & ip_vs_conn_tab_mask;
997
998 /*
999 * Lock is actually needed in this loop.
1000 */
1001 ct_write_lock_bh(hash);
1002
1003 list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) {
1004 if (cp->flags & IP_VS_CONN_F_TEMPLATE)
1005 /* connection template */
1006 continue;
1007
1008 if (cp->protocol == IPPROTO_TCP) {
1009 switch(cp->state) {
1010 case IP_VS_TCP_S_SYN_RECV:
1011 case IP_VS_TCP_S_SYNACK:
1012 break;
1013
1014 case IP_VS_TCP_S_ESTABLISHED:
1015 if (todrop_entry(cp))
1016 break;
1017 continue;
1018
1019 default:
1020 continue;
1021 }
1022 } else {
1023 if (!todrop_entry(cp))
1024 continue;
1025 }
1026
1027 IP_VS_DBG(4, "del connection\n");
1028 ip_vs_conn_expire_now(cp);
1029 if (cp->control) {
1030 IP_VS_DBG(4, "del conn template\n");
1031 ip_vs_conn_expire_now(cp->control);
1032 }
1033 }
1034 ct_write_unlock_bh(hash);
1035 }
1036}
1037
1038
1039/*
1040 * Flush all the connection entries in the ip_vs_conn_tab
1041 */
1042static void ip_vs_conn_flush(void)
1043{
1044 int idx;
1045 struct ip_vs_conn *cp;
1046
1047 flush_again:
1048 for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1049 /*
1050 * Lock is actually needed in this loop.
1051 */
1052 ct_write_lock_bh(idx);
1053
1054 list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) {
1055
1056 IP_VS_DBG(4, "del connection\n");
1057 ip_vs_conn_expire_now(cp);
1058 if (cp->control) {
1059 IP_VS_DBG(4, "del conn template\n");
1060 ip_vs_conn_expire_now(cp->control);
1061 }
1062 }
1063 ct_write_unlock_bh(idx);
1064 }
1065
1066 /* the counter may be not NULL, because maybe some conn entries
1067 are run by slow timer handler or unhashed but still referred */
1068 if (atomic_read(&ip_vs_conn_count) != 0) {
1069 schedule();
1070 goto flush_again;
1071 }
1072}
1073
1074
1075int __init ip_vs_conn_init(void)
1076{
1077 int idx;
1078
1079 /* Compute size and mask */
1080 ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1081 ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1082
1083 /*
1084 * Allocate the connection hash table and initialize its list heads
1085 */
1086 ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size *
1087 sizeof(struct list_head));
1088 if (!ip_vs_conn_tab)
1089 return -ENOMEM;
1090
1091 /* Allocate ip_vs_conn slab cache */
1092 ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1093 sizeof(struct ip_vs_conn), 0,
1094 SLAB_HWCACHE_ALIGN, NULL);
1095 if (!ip_vs_conn_cachep) {
1096 vfree(ip_vs_conn_tab);
1097 return -ENOMEM;
1098 }
1099
1100 pr_info("Connection hash table configured "
1101 "(size=%d, memory=%ldKbytes)\n",
1102 ip_vs_conn_tab_size,
1103 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1104 IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1105 sizeof(struct ip_vs_conn));
1106
1107 for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1108 INIT_LIST_HEAD(&ip_vs_conn_tab[idx]);
1109 }
1110
1111 for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) {
1112 rwlock_init(&__ip_vs_conntbl_lock_array[idx].l);
1113 }
1114
1115 proc_net_fops_create(&init_net, "ip_vs_conn", 0, &ip_vs_conn_fops);
1116 proc_net_fops_create(&init_net, "ip_vs_conn_sync", 0, &ip_vs_conn_sync_fops);
1117
1118 /* calculate the random value for connection hash */
1119 get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1120
1121 return 0;
1122}
1123
1124
1125void ip_vs_conn_cleanup(void)
1126{
1127 /* flush all the connection entries first */
1128 ip_vs_conn_flush();
1129
1130 /* Release the empty cache */
1131 kmem_cache_destroy(ip_vs_conn_cachep);
1132 proc_net_remove(&init_net, "ip_vs_conn");
1133 proc_net_remove(&init_net, "ip_vs_conn_sync");
1134 vfree(ip_vs_conn_tab);
1135}