]> bbs.cooldavid.org Git - net-next-2.6.git/blame - net/ipv4/ipvs/ip_vs_sync.c
git://bbs.cooldavid.org / net-next-2.6.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[IPVS]: Fix for overflows
[net-next-2.6.git] / net / ipv4 / ipvs / ip_vs_sync.c
CommitLineData
1da177e4
LT		 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_sync.c,v 1.13 2003/06/08 09:31:19 wensong Exp $
9 *
10 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
11 *
12 * ip_vs_sync: sync connection info from master load balancer to backups
13 * through multicast
14 *
15 * Changes:
16 * Alexandre Cassen : Added master & backup support at a time.
17 * Alexandre Cassen : Added SyncID support for incoming sync
18 * messages filtering.
19 * Justin Ossevoort : Fix endian problem on sync message size.
20 */
21
22#include <linux/module.h>
23#include <linux/slab.h>
24#include <linux/net.h>
25#include <linux/completion.h>
26#include <linux/delay.h>
27#include <linux/skbuff.h>
28#include <linux/in.h>
29#include <linux/igmp.h> /* for ip_mc_join_group */
30
31#include <net/ip.h>
32#include <net/sock.h>
33#include <asm/uaccess.h> /* for get_fs and set_fs */
34
35#include <net/ip_vs.h>
36
37#define IP_VS_SYNC_GROUP 0xe0000051 /* multicast addr - 224.0.0.81 */
38#define IP_VS_SYNC_PORT 8848 /* multicast port */
39
40
41/*
42 * IPVS sync connection entry
43 */
44struct ip_vs_sync_conn {
45 __u8 reserved;
46
47 /* Protocol, addresses and port numbers */
48 __u8 protocol; /* Which protocol (TCP/UDP) */
49 __u16 cport;
50 __u16 vport;
51 __u16 dport;
52 __u32 caddr; /* client address */
53 __u32 vaddr; /* virtual address */
54 __u32 daddr; /* destination address */
55
56 /* Flags and state transition */
57 __u16 flags; /* status flags */
58 __u16 state; /* state info */
59
60 /* The sequence options start here */
61};
62
63struct ip_vs_sync_conn_options {
64 struct ip_vs_seq in_seq; /* incoming seq. struct */
65 struct ip_vs_seq out_seq; /* outgoing seq. struct */
66};
67
68#define IP_VS_SYNC_CONN_TIMEOUT (3*60*HZ)
69#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn))
70#define FULL_CONN_SIZE \
71(sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options))
72
73
74/*
75 The master mulitcasts messages to the backup load balancers in the
76 following format.
77
78 0 1 2 3
79 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
80 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
81 | Count Conns | SyncID | Size |
82 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
83 | |
84 | IPVS Sync Connection (1) |
85 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
86 | . |
87 | . |
88 | . |
89 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
90 | |
91 | IPVS Sync Connection (n) |
92 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
93*/
94
95#define SYNC_MESG_HEADER_LEN 4
96
97struct ip_vs_sync_mesg {
98 __u8 nr_conns;
99 __u8 syncid;
100 __u16 size;
101
102 /* ip_vs_sync_conn entries start here */
103};
104
105/* the maximum length of sync (sending/receiving) message */
106static int sync_send_mesg_maxlen;
107static int sync_recv_mesg_maxlen;
108
109struct ip_vs_sync_buff {
110 struct list_head list;
111 unsigned long firstuse;
112
113 /* pointers for the message data */
114 struct ip_vs_sync_mesg *mesg;
115 unsigned char *head;
116 unsigned char *end;
117};
118
119
120/* the sync_buff list head and the lock */
121static LIST_HEAD(ip_vs_sync_queue);
122static DEFINE_SPINLOCK(ip_vs_sync_lock);
123
124/* current sync_buff for accepting new conn entries */
125static struct ip_vs_sync_buff *curr_sb = NULL;
126static DEFINE_SPINLOCK(curr_sb_lock);
127
128/* ipvs sync daemon state */
129volatile int ip_vs_sync_state = IP_VS_STATE_NONE;
130volatile int ip_vs_master_syncid = 0;
131volatile int ip_vs_backup_syncid = 0;
132
133/* multicast interface name */
134char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
135char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
136
137/* multicast addr */
138static struct sockaddr_in mcast_addr;
139
140
141static inline void sb_queue_tail(struct ip_vs_sync_buff *sb)
142{
143 spin_lock(&ip_vs_sync_lock);
144 list_add_tail(&sb->list, &ip_vs_sync_queue);
145 spin_unlock(&ip_vs_sync_lock);
146}
147
148static inline struct ip_vs_sync_buff * sb_dequeue(void)
149{
150 struct ip_vs_sync_buff *sb;
151
152 spin_lock_bh(&ip_vs_sync_lock);
153 if (list_empty(&ip_vs_sync_queue)) {
154 sb = NULL;
155 } else {
156 sb = list_entry(ip_vs_sync_queue.next,
157 struct ip_vs_sync_buff,
158 list);
159 list_del(&sb->list);
160 }
161 spin_unlock_bh(&ip_vs_sync_lock);
162
163 return sb;
164}
165
166static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void)
167{
168 struct ip_vs_sync_buff *sb;
169
170 if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
171 return NULL;
172
173 if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) {
174 kfree(sb);
175 return NULL;
176 }
177 sb->mesg->nr_conns = 0;
178 sb->mesg->syncid = ip_vs_master_syncid;
179 sb->mesg->size = 4;
180 sb->head = (unsigned char *)sb->mesg + 4;
181 sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen;
182 sb->firstuse = jiffies;
183 return sb;
184}
185
186static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
187{
188 kfree(sb->mesg);
189 kfree(sb);
190}
191
192/*
193 * Get the current sync buffer if it has been created for more
194 * than the specified time or the specified time is zero.
195 */
196static inline struct ip_vs_sync_buff *
197get_curr_sync_buff(unsigned long time)
198{
199 struct ip_vs_sync_buff *sb;
200
201 spin_lock_bh(&curr_sb_lock);
202 if (curr_sb && (time == 0 ||
203 time_before(jiffies - curr_sb->firstuse, time))) {
204 sb = curr_sb;
205 curr_sb = NULL;
206 } else
207 sb = NULL;
208 spin_unlock_bh(&curr_sb_lock);
209 return sb;
210}
211
212
213/*
214 * Add an ip_vs_conn information into the current sync_buff.
215 * Called by ip_vs_in.
216 */
217void ip_vs_sync_conn(struct ip_vs_conn *cp)
218{
219 struct ip_vs_sync_mesg *m;
220 struct ip_vs_sync_conn *s;
221 int len;
222
223 spin_lock(&curr_sb_lock);
224 if (!curr_sb) {
225 if (!(curr_sb=ip_vs_sync_buff_create())) {
226 spin_unlock(&curr_sb_lock);
227 IP_VS_ERR("ip_vs_sync_buff_create failed.\n");
228 return;
229 }
230 }
231
232 len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
233 SIMPLE_CONN_SIZE;
234 m = curr_sb->mesg;
235 s = (struct ip_vs_sync_conn *)curr_sb->head;
236
237 /* copy members */
238 s->protocol = cp->protocol;
239 s->cport = cp->cport;
240 s->vport = cp->vport;
241 s->dport = cp->dport;
242 s->caddr = cp->caddr;
243 s->vaddr = cp->vaddr;
244 s->daddr = cp->daddr;
245 s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
246 s->state = htons(cp->state);
247 if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
248 struct ip_vs_sync_conn_options *opt =
249 (struct ip_vs_sync_conn_options *)&s[1];
250 memcpy(opt, &cp->in_seq, sizeof(*opt));
251 }
252
253 m->nr_conns++;
254 m->size += len;
255 curr_sb->head += len;
256
257 /* check if there is a space for next one */
258 if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) {
259 sb_queue_tail(curr_sb);
260 curr_sb = NULL;
261 }
262 spin_unlock(&curr_sb_lock);
263
264 /* synchronize its controller if it has */
265 if (cp->control)
266 ip_vs_sync_conn(cp->control);
267}
268
269
270/*
271 * Process received multicast message and create the corresponding
272 * ip_vs_conn entries.
273 */
274static void ip_vs_process_message(const char *buffer, const size_t buflen)
275{
276 struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
277 struct ip_vs_sync_conn *s;
278 struct ip_vs_sync_conn_options *opt;
279 struct ip_vs_conn *cp;
280 char *p;
281 int i;
282
283 /* Convert size back to host byte order */
284 m->size = ntohs(m->size);
285
286 if (buflen != m->size) {
287 IP_VS_ERR("bogus message\n");
288 return;
289 }
290
291 /* SyncID sanity check */
292 if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) {
293 IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n",
294 m->syncid);
295 return;
296 }
297
298 p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
299 for (i=0; i<m->nr_conns; i++) {
300 s = (struct ip_vs_sync_conn *)p;
301 cp = ip_vs_conn_in_get(s->protocol,
302 s->caddr, s->cport,
303 s->vaddr, s->vport);
304 if (!cp) {
305 cp = ip_vs_conn_new(s->protocol,
306 s->caddr, s->cport,
307 s->vaddr, s->vport,
308 s->daddr, s->dport,
309 ntohs(s->flags), NULL);
310 if (!cp) {
311 IP_VS_ERR("ip_vs_conn_new failed\n");
312 return;
313 }
314 cp->state = ntohs(s->state);
315 } else if (!cp->dest) {
316 /* it is an entry created by the synchronization */
317 cp->state = ntohs(s->state);
318 cp->flags = ntohs(s->flags) | IP_VS_CONN_F_HASHED;
319 } /* Note that we don't touch its state and flags
320 if it is a normal entry. */
321
322 if (ntohs(s->flags) & IP_VS_CONN_F_SEQ_MASK) {
323 opt = (struct ip_vs_sync_conn_options *)&s[1];
324 memcpy(&cp->in_seq, opt, sizeof(*opt));
325 p += FULL_CONN_SIZE;
326 } else
327 p += SIMPLE_CONN_SIZE;
328
329 atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
330 cp->timeout = IP_VS_SYNC_CONN_TIMEOUT;
331 ip_vs_conn_put(cp);
332
333 if (p > buffer+buflen) {
334 IP_VS_ERR("bogus message\n");
335 return;
336 }
337 }
338}
339
340
341/*
342 * Setup loopback of outgoing multicasts on a sending socket
343 */
344static void set_mcast_loop(struct sock *sk, u_char loop)
345{
346 struct inet_sock *inet = inet_sk(sk);
347
348 /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
349 lock_sock(sk);
350 inet->mc_loop = loop ? 1 : 0;
351 release_sock(sk);
352}
353
354/*
355 * Specify TTL for outgoing multicasts on a sending socket
356 */
357static void set_mcast_ttl(struct sock *sk, u_char ttl)
358{
359 struct inet_sock *inet = inet_sk(sk);
360
361 /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
362 lock_sock(sk);
363 inet->mc_ttl = ttl;
364 release_sock(sk);
365}
366
367/*
368 * Specifiy default interface for outgoing multicasts
369 */
370static int set_mcast_if(struct sock *sk, char *ifname)
371{
372 struct net_device *dev;
373 struct inet_sock *inet = inet_sk(sk);
374
375 if ((dev = __dev_get_by_name(ifname)) == NULL)
376 return -ENODEV;
377
378 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
379 return -EINVAL;
380
381 lock_sock(sk);
382 inet->mc_index = dev->ifindex;
383 /* inet->mc_addr = 0; */
384 release_sock(sk);
385
386 return 0;
387}
388
389
390/*
391 * Set the maximum length of sync message according to the
392 * specified interface's MTU.
393 */
394static int set_sync_mesg_maxlen(int sync_state)
395{
396 struct net_device *dev;
397 int num;
398
399 if (sync_state == IP_VS_STATE_MASTER) {
400 if ((dev = __dev_get_by_name(ip_vs_master_mcast_ifn)) == NULL)
401 return -ENODEV;
402
403 num = (dev->mtu - sizeof(struct iphdr) -
404 sizeof(struct udphdr) -
405 SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
406 sync_send_mesg_maxlen =
407 SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num;
408 IP_VS_DBG(7, "setting the maximum length of sync sending "
409 "message %d.\n", sync_send_mesg_maxlen);
410 } else if (sync_state == IP_VS_STATE_BACKUP) {
411 if ((dev = __dev_get_by_name(ip_vs_backup_mcast_ifn)) == NULL)
412 return -ENODEV;
413
414 sync_recv_mesg_maxlen = dev->mtu -
415 sizeof(struct iphdr) - sizeof(struct udphdr);
416 IP_VS_DBG(7, "setting the maximum length of sync receiving "
417 "message %d.\n", sync_recv_mesg_maxlen);
418 }
419
420 return 0;
421}
422
423
424/*
425 * Join a multicast group.
426 * the group is specified by a class D multicast address 224.0.0.0/8
427 * in the in_addr structure passed in as a parameter.
428 */
429static int
430join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
431{
432 struct ip_mreqn mreq;
433 struct net_device *dev;
434 int ret;
435
436 memset(&mreq, 0, sizeof(mreq));
437 memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
438
439 if ((dev = __dev_get_by_name(ifname)) == NULL)
440 return -ENODEV;
441 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
442 return -EINVAL;
443
444 mreq.imr_ifindex = dev->ifindex;
445
446 lock_sock(sk);
447 ret = ip_mc_join_group(sk, &mreq);
448 release_sock(sk);
449
450 return ret;
451}
452
453
454static int bind_mcastif_addr(struct socket *sock, char *ifname)
455{
456 struct net_device *dev;
457 u32 addr;
458 struct sockaddr_in sin;
459
460 if ((dev = __dev_get_by_name(ifname)) == NULL)
461 return -ENODEV;
462
463 addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
464 if (!addr)
465 IP_VS_ERR("You probably need to specify IP address on "
466 "multicast interface.\n");
467
468 IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n",
469 ifname, NIPQUAD(addr));
470
471 /* Now bind the socket with the address of multicast interface */
472 sin.sin_family = AF_INET;
473 sin.sin_addr.s_addr = addr;
474 sin.sin_port = 0;
475
476 return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
477}
478
479/*
480 * Set up sending multicast socket over UDP
481 */
482static struct socket * make_send_sock(void)
483{
484 struct socket *sock;
485
486 /* First create a socket */
487 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
488 IP_VS_ERR("Error during creation of socket; terminating\n");
489 return NULL;
490 }
491
492 if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) {
493 IP_VS_ERR("Error setting outbound mcast interface\n");
494 goto error;
495 }
496
497 set_mcast_loop(sock->sk, 0);
498 set_mcast_ttl(sock->sk, 1);
499
500 if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) {
501 IP_VS_ERR("Error binding address of the mcast interface\n");
502 goto error;
503 }
504
505 if (sock->ops->connect(sock,
506 (struct sockaddr*)&mcast_addr,
507 sizeof(struct sockaddr), 0) < 0) {
508 IP_VS_ERR("Error connecting to the multicast addr\n");
509 goto error;
510 }
511
512 return sock;
513
514 error:
515 sock_release(sock);
516 return NULL;
517}
518
519
520/*
521 * Set up receiving multicast socket over UDP
522 */
523static struct socket * make_receive_sock(void)
524{
525 struct socket *sock;
526
527 /* First create a socket */
528 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
529 IP_VS_ERR("Error during creation of socket; terminating\n");
530 return NULL;
531 }
532
533 /* it is equivalent to the REUSEADDR option in user-space */
534 sock->sk->sk_reuse = 1;
535
536 if (sock->ops->bind(sock,
537 (struct sockaddr*)&mcast_addr,
538 sizeof(struct sockaddr)) < 0) {
539 IP_VS_ERR("Error binding to the multicast addr\n");
540 goto error;
541 }
542
543 /* join the multicast group */
544 if (join_mcast_group(sock->sk,
545 (struct in_addr*)&mcast_addr.sin_addr,
546 ip_vs_backup_mcast_ifn) < 0) {
547 IP_VS_ERR("Error joining to the multicast group\n");
548 goto error;
549 }
550
551 return sock;
552
553 error:
554 sock_release(sock);
555 return NULL;
556}
557
558
559static int
560ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
561{
562 struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
563 struct kvec iov;
564 int len;
565
566 EnterFunction(7);
567 iov.iov_base = (void *)buffer;
568 iov.iov_len = length;
569
570 len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
571
572 LeaveFunction(7);
573 return len;
574}
575
576static void
577ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
578{
579 int msize;
580
581 msize = msg->size;
582
583 /* Put size in network byte order */
584 msg->size = htons(msg->size);
585
586 if (ip_vs_send_async(sock, (char *)msg, msize) != msize)
587 IP_VS_ERR("ip_vs_send_async error\n");
588}
589
590static int
591ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
592{
593 struct msghdr msg = {NULL,};
594 struct kvec iov;
595 int len;
596
597 EnterFunction(7);
598
599 /* Receive a packet */
600 iov.iov_base = buffer;
601 iov.iov_len = (size_t)buflen;
602
603 len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0);
604
605 if (len < 0)
606 return -1;
607
608 LeaveFunction(7);
609 return len;
610}
611
612
613static DECLARE_WAIT_QUEUE_HEAD(sync_wait);
614static pid_t sync_master_pid = 0;
615static pid_t sync_backup_pid = 0;
616
617static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait);
618static int stop_master_sync = 0;
619static int stop_backup_sync = 0;
620
621static void sync_master_loop(void)
622{
623 struct socket *sock;
624 struct ip_vs_sync_buff *sb;
625
626 /* create the sending multicast socket */
627 sock = make_send_sock();
628 if (!sock)
629 return;
630
631 IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, "
632 "syncid = %d\n",
633 ip_vs_master_mcast_ifn, ip_vs_master_syncid);
634
635 for (;;) {
636 while ((sb=sb_dequeue())) {
637 ip_vs_send_sync_msg(sock, sb->mesg);
638 ip_vs_sync_buff_release(sb);
639 }
640
641 /* check if entries stay in curr_sb for 2 seconds */
642 if ((sb = get_curr_sync_buff(2*HZ))) {
643 ip_vs_send_sync_msg(sock, sb->mesg);
644 ip_vs_sync_buff_release(sb);
645 }
646
647 if (stop_master_sync)
648 break;
649
650 ssleep(1);
651 }
652
653 /* clean up the sync_buff queue */
654 while ((sb=sb_dequeue())) {
655 ip_vs_sync_buff_release(sb);
656 }
657
658 /* clean up the current sync_buff */
659 if ((sb = get_curr_sync_buff(0))) {
660 ip_vs_sync_buff_release(sb);
661 }
662
663 /* release the sending multicast socket */
664 sock_release(sock);
665}
666
667
668static void sync_backup_loop(void)
669{
670 struct socket *sock;
671 char *buf;
672 int len;
673
674 if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) {
675 IP_VS_ERR("sync_backup_loop: kmalloc error\n");
676 return;
677 }
678
679 /* create the receiving multicast socket */
680 sock = make_receive_sock();
681 if (!sock)
682 goto out;
683
684 IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, "
685 "syncid = %d\n",
686 ip_vs_backup_mcast_ifn, ip_vs_backup_syncid);
687
688 for (;;) {
689 /* do you have data now? */
690 while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) {
691 if ((len =
692 ip_vs_receive(sock, buf,
693 sync_recv_mesg_maxlen)) <= 0) {
694 IP_VS_ERR("receiving message error\n");
695 break;
696 }
697 /* disable bottom half, because it accessed the data
698 shared by softirq while getting/creating conns */
699 local_bh_disable();
700 ip_vs_process_message(buf, len);
701 local_bh_enable();
702 }
703
704 if (stop_backup_sync)
705 break;
706
707 ssleep(1);
708 }
709
710 /* release the sending multicast socket */
711 sock_release(sock);
712
713 out:
714 kfree(buf);
715}
716
717
718static void set_sync_pid(int sync_state, pid_t sync_pid)
719{
720 if (sync_state == IP_VS_STATE_MASTER)
721 sync_master_pid = sync_pid;
722 else if (sync_state == IP_VS_STATE_BACKUP)
723 sync_backup_pid = sync_pid;
724}
725
726static void set_stop_sync(int sync_state, int set)
727{
728 if (sync_state == IP_VS_STATE_MASTER)
729 stop_master_sync = set;
730 else if (sync_state == IP_VS_STATE_BACKUP)
731 stop_backup_sync = set;
732 else {
733 stop_master_sync = set;
734 stop_backup_sync = set;
735 }
736}
737
738static int sync_thread(void *startup)
739{
740 DECLARE_WAITQUEUE(wait, current);
741 mm_segment_t oldmm;
742 int state;
743 const char *name;
744
745 /* increase the module use count */
746 ip_vs_use_count_inc();
747
748 if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) {
749 state = IP_VS_STATE_MASTER;
750 name = "ipvs_syncmaster";
751 } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) {
752 state = IP_VS_STATE_BACKUP;
753 name = "ipvs_syncbackup";
754 } else {
755 IP_VS_BUG();
756 ip_vs_use_count_dec();
757 return -EINVAL;
758 }
759
760 daemonize(name);
761
762 oldmm = get_fs();
763 set_fs(KERNEL_DS);
764
765 /* Block all signals */
766 spin_lock_irq(&current->sighand->siglock);
767 siginitsetinv(&current->blocked, 0);
768 recalc_sigpending();
769 spin_unlock_irq(&current->sighand->siglock);
770
771 /* set the maximum length of sync message */
772 set_sync_mesg_maxlen(state);
773
774 /* set up multicast address */
775 mcast_addr.sin_family = AF_INET;
776 mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
777 mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
778
779 add_wait_queue(&sync_wait, &wait);
780
781 set_sync_pid(state, current->pid);
782 complete((struct completion *)startup);
783
784 /* processing master/backup loop here */
785 if (state == IP_VS_STATE_MASTER)
786 sync_master_loop();
787 else if (state == IP_VS_STATE_BACKUP)
788 sync_backup_loop();
789 else IP_VS_BUG();
790
791 remove_wait_queue(&sync_wait, &wait);
792
793 /* thread exits */
794 set_sync_pid(state, 0);
795 IP_VS_INFO("sync thread stopped!\n");
796
797 set_fs(oldmm);
798
799 /* decrease the module use count */
800 ip_vs_use_count_dec();
801
802 set_stop_sync(state, 0);
803 wake_up(&stop_sync_wait);
804
805 return 0;
806}
807
808
809static int fork_sync_thread(void *startup)
810{
811 pid_t pid;
812
813 /* fork the sync thread here, then the parent process of the
814 sync thread is the init process after this thread exits. */
815 repeat:
816 if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
817 IP_VS_ERR("could not create sync_thread due to %d... "
818 "retrying.\n", pid);
819 ssleep(1);
820 goto repeat;
821 }
822
823 return 0;
824}
825
826
827int start_sync_thread(int state, char *mcast_ifn, __u8 syncid)
828{
829 DECLARE_COMPLETION(startup);
830 pid_t pid;
831
832 if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||
833 (state == IP_VS_STATE_BACKUP && sync_backup_pid))
834 return -EEXIST;
835
836 IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
837 IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",
838 sizeof(struct ip_vs_sync_conn));
839
840 ip_vs_sync_state |= state;
841 if (state == IP_VS_STATE_MASTER) {
4da62fc7 842 strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, sizeof(ip_vs_master_mcast_ifn));
1da177e4
LT		 843 ip_vs_master_syncid = syncid;
844 } else {
4da62fc7 845 strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, sizeof(ip_vs_backup_mcast_ifn));
1da177e4
LT		 846 ip_vs_backup_syncid = syncid;
847 }
848
849 repeat:
850 if ((pid = kernel_thread(fork_sync_thread, &startup, 0)) < 0) {
851 IP_VS_ERR("could not create fork_sync_thread due to %d... "
852 "retrying.\n", pid);
853 ssleep(1);
854 goto repeat;
855 }
856
857 wait_for_completion(&startup);
858
859 return 0;
860}
861
862
863int stop_sync_thread(int state)
864{
865 DECLARE_WAITQUEUE(wait, current);
866
867 if ((state == IP_VS_STATE_MASTER && !sync_master_pid) ||
868 (state == IP_VS_STATE_BACKUP && !sync_backup_pid))
869 return -ESRCH;
870
871 IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
872 IP_VS_INFO("stopping sync thread %d ...\n",
873 (state == IP_VS_STATE_MASTER) ? sync_master_pid : sync_backup_pid);
874
875 __set_current_state(TASK_UNINTERRUPTIBLE);
876 add_wait_queue(&stop_sync_wait, &wait);
877 set_stop_sync(state, 1);
878 ip_vs_sync_state -= state;
879 wake_up(&sync_wait);
880 schedule();
881 __set_current_state(TASK_RUNNING);
882 remove_wait_queue(&stop_sync_wait, &wait);
883
884 /* Note: no need to reap the sync thread, because its parent
885 process is the init process */
886
887 if ((state == IP_VS_STATE_MASTER && stop_master_sync) ||
888 (state == IP_VS_STATE_BACKUP && stop_backup_sync))
889 IP_VS_BUG();
890
891 return 0;
892}
Clone of davem's net-next-2.6 tree