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[net-next-2.6.git] / net / ipv4 / ipvs / ip_vs_sync.c
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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>
14c85021 24#include <linux/inetdevice.h>
1da177e4
LT		 25#include <linux/net.h>
26#include <linux/completion.h>
27#include <linux/delay.h>
28#include <linux/skbuff.h>
29#include <linux/in.h>
30#include <linux/igmp.h> /* for ip_mc_join_group */
14c85021 31#include <linux/udp.h>
1da177e4
LT		 32
33#include <net/ip.h>
34#include <net/sock.h>
35#include <asm/uaccess.h> /* for get_fs and set_fs */
36
37#include <net/ip_vs.h>
38
39#define IP_VS_SYNC_GROUP 0xe0000051 /* multicast addr - 224.0.0.81 */
40#define IP_VS_SYNC_PORT 8848 /* multicast port */
41
42
43/*
44 * IPVS sync connection entry
45 */
46struct ip_vs_sync_conn {
47 __u8 reserved;
48
49 /* Protocol, addresses and port numbers */
50 __u8 protocol; /* Which protocol (TCP/UDP) */
014d730d
AV		 51 __be16 cport;
52 __be16 vport;
53 __be16 dport;
54 __be32 caddr; /* client address */
55 __be32 vaddr; /* virtual address */
56 __be32 daddr; /* destination address */
1da177e4
LT		 57
58 /* Flags and state transition */
014d730d
AV		 59 __be16 flags; /* status flags */
60 __be16 state; /* state info */
1da177e4
LT		 61
62 /* The sequence options start here */
63};
64
65struct ip_vs_sync_conn_options {
66 struct ip_vs_seq in_seq; /* incoming seq. struct */
67 struct ip_vs_seq out_seq; /* outgoing seq. struct */
68};
69
70#define IP_VS_SYNC_CONN_TIMEOUT (3*60*HZ)
71#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn))
72#define FULL_CONN_SIZE \
73(sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options))
74
75
76/*
77 The master mulitcasts messages to the backup load balancers in the
78 following format.
79
80 0 1 2 3
81 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
82 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
83 | Count Conns | SyncID | Size |
84 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
85 | |
86 | IPVS Sync Connection (1) |
87 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
88 | . |
89 | . |
90 | . |
91 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
92 | |
93 | IPVS Sync Connection (n) |
94 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
95*/
96
97#define SYNC_MESG_HEADER_LEN 4
98
99struct ip_vs_sync_mesg {
100 __u8 nr_conns;
101 __u8 syncid;
102 __u16 size;
103
104 /* ip_vs_sync_conn entries start here */
105};
106
107/* the maximum length of sync (sending/receiving) message */
108static int sync_send_mesg_maxlen;
109static int sync_recv_mesg_maxlen;
110
111struct ip_vs_sync_buff {
112 struct list_head list;
113 unsigned long firstuse;
114
115 /* pointers for the message data */
116 struct ip_vs_sync_mesg *mesg;
117 unsigned char *head;
118 unsigned char *end;
119};
120
121
122/* the sync_buff list head and the lock */
123static LIST_HEAD(ip_vs_sync_queue);
124static DEFINE_SPINLOCK(ip_vs_sync_lock);
125
126/* current sync_buff for accepting new conn entries */
127static struct ip_vs_sync_buff *curr_sb = NULL;
128static DEFINE_SPINLOCK(curr_sb_lock);
129
130/* ipvs sync daemon state */
131volatile int ip_vs_sync_state = IP_VS_STATE_NONE;
132volatile int ip_vs_master_syncid = 0;
133volatile int ip_vs_backup_syncid = 0;
134
135/* multicast interface name */
136char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
137char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
138
139/* multicast addr */
140static struct sockaddr_in mcast_addr;
141
142
143static inline void sb_queue_tail(struct ip_vs_sync_buff *sb)
144{
145 spin_lock(&ip_vs_sync_lock);
146 list_add_tail(&sb->list, &ip_vs_sync_queue);
147 spin_unlock(&ip_vs_sync_lock);
148}
149
150static inline struct ip_vs_sync_buff * sb_dequeue(void)
151{
152 struct ip_vs_sync_buff *sb;
153
154 spin_lock_bh(&ip_vs_sync_lock);
155 if (list_empty(&ip_vs_sync_queue)) {
156 sb = NULL;
157 } else {
158 sb = list_entry(ip_vs_sync_queue.next,
159 struct ip_vs_sync_buff,
160 list);
161 list_del(&sb->list);
162 }
163 spin_unlock_bh(&ip_vs_sync_lock);
164
165 return sb;
166}
167
168static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void)
169{
170 struct ip_vs_sync_buff *sb;
171
172 if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
173 return NULL;
174
175 if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) {
176 kfree(sb);
177 return NULL;
178 }
179 sb->mesg->nr_conns = 0;
180 sb->mesg->syncid = ip_vs_master_syncid;
181 sb->mesg->size = 4;
182 sb->head = (unsigned char *)sb->mesg + 4;
183 sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen;
184 sb->firstuse = jiffies;
185 return sb;
186}
187
188static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
189{
190 kfree(sb->mesg);
191 kfree(sb);
192}
193
194/*
195 * Get the current sync buffer if it has been created for more
196 * than the specified time or the specified time is zero.
197 */
198static inline struct ip_vs_sync_buff *
199get_curr_sync_buff(unsigned long time)
200{
201 struct ip_vs_sync_buff *sb;
202
203 spin_lock_bh(&curr_sb_lock);
204 if (curr_sb && (time == 0 ||
205 time_before(jiffies - curr_sb->firstuse, time))) {
206 sb = curr_sb;
207 curr_sb = NULL;
208 } else
209 sb = NULL;
210 spin_unlock_bh(&curr_sb_lock);
211 return sb;
212}
213
214
215/*
216 * Add an ip_vs_conn information into the current sync_buff.
217 * Called by ip_vs_in.
218 */
219void ip_vs_sync_conn(struct ip_vs_conn *cp)
220{
221 struct ip_vs_sync_mesg *m;
222 struct ip_vs_sync_conn *s;
223 int len;
224
225 spin_lock(&curr_sb_lock);
226 if (!curr_sb) {
227 if (!(curr_sb=ip_vs_sync_buff_create())) {
228 spin_unlock(&curr_sb_lock);
229 IP_VS_ERR("ip_vs_sync_buff_create failed.\n");
230 return;
231 }
232 }
233
234 len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
235 SIMPLE_CONN_SIZE;
236 m = curr_sb->mesg;
237 s = (struct ip_vs_sync_conn *)curr_sb->head;
238
239 /* copy members */
240 s->protocol = cp->protocol;
241 s->cport = cp->cport;
242 s->vport = cp->vport;
243 s->dport = cp->dport;
244 s->caddr = cp->caddr;
245 s->vaddr = cp->vaddr;
246 s->daddr = cp->daddr;
247 s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
248 s->state = htons(cp->state);
249 if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
250 struct ip_vs_sync_conn_options *opt =
251 (struct ip_vs_sync_conn_options *)&s[1];
252 memcpy(opt, &cp->in_seq, sizeof(*opt));
253 }
254
255 m->nr_conns++;
256 m->size += len;
257 curr_sb->head += len;
258
259 /* check if there is a space for next one */
260 if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) {
261 sb_queue_tail(curr_sb);
262 curr_sb = NULL;
263 }
264 spin_unlock(&curr_sb_lock);
265
266 /* synchronize its controller if it has */
267 if (cp->control)
268 ip_vs_sync_conn(cp->control);
269}
270
271
272/*
273 * Process received multicast message and create the corresponding
274 * ip_vs_conn entries.
275 */
276static void ip_vs_process_message(const char *buffer, const size_t buflen)
277{
278 struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
279 struct ip_vs_sync_conn *s;
280 struct ip_vs_sync_conn_options *opt;
281 struct ip_vs_conn *cp;
282 char *p;
283 int i;
284
285 /* Convert size back to host byte order */
286 m->size = ntohs(m->size);
287
288 if (buflen != m->size) {
289 IP_VS_ERR("bogus message\n");
290 return;
291 }
292
293 /* SyncID sanity check */
294 if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) {
295 IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n",
296 m->syncid);
297 return;
298 }
299
300 p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
301 for (i=0; i<m->nr_conns; i++) {
87375ab4
JA		 302 unsigned flags;
303
1da177e4 304 s = (struct ip_vs_sync_conn *)p;
87375ab4
JA		 305 flags = ntohs(s->flags);
306 if (!(flags & IP_VS_CONN_F_TEMPLATE))
307 cp = ip_vs_conn_in_get(s->protocol,
308 s->caddr, s->cport,
309 s->vaddr, s->vport);
310 else
311 cp = ip_vs_ct_in_get(s->protocol,
312 s->caddr, s->cport,
313 s->vaddr, s->vport);
1da177e4
LT		 314 if (!cp) {
315 cp = ip_vs_conn_new(s->protocol,
316 s->caddr, s->cport,
317 s->vaddr, s->vport,
318 s->daddr, s->dport,
87375ab4 319 flags, NULL);
1da177e4
LT		 320 if (!cp) {
321 IP_VS_ERR("ip_vs_conn_new failed\n");
322 return;
323 }
324 cp->state = ntohs(s->state);
325 } else if (!cp->dest) {
326 /* it is an entry created by the synchronization */
327 cp->state = ntohs(s->state);
87375ab4 328 cp->flags = flags | IP_VS_CONN_F_HASHED;
1da177e4
LT		 329 } /* Note that we don't touch its state and flags
330 if it is a normal entry. */
331
87375ab4 332 if (flags & IP_VS_CONN_F_SEQ_MASK) {
1da177e4
LT		 333 opt = (struct ip_vs_sync_conn_options *)&s[1];
334 memcpy(&cp->in_seq, opt, sizeof(*opt));
335 p += FULL_CONN_SIZE;
336 } else
337 p += SIMPLE_CONN_SIZE;
338
339 atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
340 cp->timeout = IP_VS_SYNC_CONN_TIMEOUT;
341 ip_vs_conn_put(cp);
342
343 if (p > buffer+buflen) {
344 IP_VS_ERR("bogus message\n");
345 return;
346 }
347 }
348}
349
350
351/*
352 * Setup loopback of outgoing multicasts on a sending socket
353 */
354static void set_mcast_loop(struct sock *sk, u_char loop)
355{
356 struct inet_sock *inet = inet_sk(sk);
357
358 /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
359 lock_sock(sk);
360 inet->mc_loop = loop ? 1 : 0;
361 release_sock(sk);
362}
363
364/*
365 * Specify TTL for outgoing multicasts on a sending socket
366 */
367static void set_mcast_ttl(struct sock *sk, u_char ttl)
368{
369 struct inet_sock *inet = inet_sk(sk);
370
371 /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
372 lock_sock(sk);
373 inet->mc_ttl = ttl;
374 release_sock(sk);
375}
376
377/*
378 * Specifiy default interface for outgoing multicasts
379 */
380static int set_mcast_if(struct sock *sk, char *ifname)
381{
382 struct net_device *dev;
383 struct inet_sock *inet = inet_sk(sk);
384
385 if ((dev = __dev_get_by_name(ifname)) == NULL)
386 return -ENODEV;
387
388 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
389 return -EINVAL;
390
391 lock_sock(sk);
392 inet->mc_index = dev->ifindex;
393 /* inet->mc_addr = 0; */
394 release_sock(sk);
395
396 return 0;
397}
398
399
400/*
401 * Set the maximum length of sync message according to the
402 * specified interface's MTU.
403 */
404static int set_sync_mesg_maxlen(int sync_state)
405{
406 struct net_device *dev;
407 int num;
408
409 if (sync_state == IP_VS_STATE_MASTER) {
410 if ((dev = __dev_get_by_name(ip_vs_master_mcast_ifn)) == NULL)
411 return -ENODEV;
412
413 num = (dev->mtu - sizeof(struct iphdr) -
414 sizeof(struct udphdr) -
415 SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
416 sync_send_mesg_maxlen =
417 SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num;
418 IP_VS_DBG(7, "setting the maximum length of sync sending "
419 "message %d.\n", sync_send_mesg_maxlen);
420 } else if (sync_state == IP_VS_STATE_BACKUP) {
421 if ((dev = __dev_get_by_name(ip_vs_backup_mcast_ifn)) == NULL)
422 return -ENODEV;
423
424 sync_recv_mesg_maxlen = dev->mtu -
425 sizeof(struct iphdr) - sizeof(struct udphdr);
426 IP_VS_DBG(7, "setting the maximum length of sync receiving "
427 "message %d.\n", sync_recv_mesg_maxlen);
428 }
429
430 return 0;
431}
432
433
434/*
435 * Join a multicast group.
436 * the group is specified by a class D multicast address 224.0.0.0/8
437 * in the in_addr structure passed in as a parameter.
438 */
439static int
440join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
441{
442 struct ip_mreqn mreq;
443 struct net_device *dev;
444 int ret;
445
446 memset(&mreq, 0, sizeof(mreq));
447 memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
448
449 if ((dev = __dev_get_by_name(ifname)) == NULL)
450 return -ENODEV;
451 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
452 return -EINVAL;
453
454 mreq.imr_ifindex = dev->ifindex;
455
456 lock_sock(sk);
457 ret = ip_mc_join_group(sk, &mreq);
458 release_sock(sk);
459
460 return ret;
461}
462
463
464static int bind_mcastif_addr(struct socket *sock, char *ifname)
465{
466 struct net_device *dev;
a61ced5d 467 __be32 addr;
1da177e4
LT		 468 struct sockaddr_in sin;
469
470 if ((dev = __dev_get_by_name(ifname)) == NULL)
471 return -ENODEV;
472
473 addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
474 if (!addr)
475 IP_VS_ERR("You probably need to specify IP address on "
476 "multicast interface.\n");
477
478 IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n",
479 ifname, NIPQUAD(addr));
480
481 /* Now bind the socket with the address of multicast interface */
482 sin.sin_family = AF_INET;
483 sin.sin_addr.s_addr = addr;
484 sin.sin_port = 0;
485
486 return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
487}
488
489/*
490 * Set up sending multicast socket over UDP
491 */
492static struct socket * make_send_sock(void)
493{
494 struct socket *sock;
495
496 /* First create a socket */
497 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
498 IP_VS_ERR("Error during creation of socket; terminating\n");
499 return NULL;
500 }
501
502 if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) {
503 IP_VS_ERR("Error setting outbound mcast interface\n");
504 goto error;
505 }
506
507 set_mcast_loop(sock->sk, 0);
508 set_mcast_ttl(sock->sk, 1);
509
510 if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) {
511 IP_VS_ERR("Error binding address of the mcast interface\n");
512 goto error;
513 }
514
515 if (sock->ops->connect(sock,
516 (struct sockaddr*)&mcast_addr,
517 sizeof(struct sockaddr), 0) < 0) {
518 IP_VS_ERR("Error connecting to the multicast addr\n");
519 goto error;
520 }
521
522 return sock;
523
524 error:
525 sock_release(sock);
526 return NULL;
527}
528
529
530/*
531 * Set up receiving multicast socket over UDP
532 */
533static struct socket * make_receive_sock(void)
534{
535 struct socket *sock;
536
537 /* First create a socket */
538 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
539 IP_VS_ERR("Error during creation of socket; terminating\n");
540 return NULL;
541 }
542
543 /* it is equivalent to the REUSEADDR option in user-space */
544 sock->sk->sk_reuse = 1;
545
546 if (sock->ops->bind(sock,
547 (struct sockaddr*)&mcast_addr,
548 sizeof(struct sockaddr)) < 0) {
549 IP_VS_ERR("Error binding to the multicast addr\n");
550 goto error;
551 }
552
553 /* join the multicast group */
554 if (join_mcast_group(sock->sk,
555 (struct in_addr*)&mcast_addr.sin_addr,
556 ip_vs_backup_mcast_ifn) < 0) {
557 IP_VS_ERR("Error joining to the multicast group\n");
558 goto error;
559 }
560
561 return sock;
562
563 error:
564 sock_release(sock);
565 return NULL;
566}
567
568
569static int
570ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
571{
572 struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
573 struct kvec iov;
574 int len;
575
576 EnterFunction(7);
577 iov.iov_base = (void *)buffer;
578 iov.iov_len = length;
579
580 len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
581
582 LeaveFunction(7);
583 return len;
584}
585
586static void
587ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
588{
589 int msize;
590
591 msize = msg->size;
592
593 /* Put size in network byte order */
594 msg->size = htons(msg->size);
595
596 if (ip_vs_send_async(sock, (char *)msg, msize) != msize)
597 IP_VS_ERR("ip_vs_send_async error\n");
598}
599
600static int
601ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
602{
603 struct msghdr msg = {NULL,};
604 struct kvec iov;
605 int len;
606
607 EnterFunction(7);
608
609 /* Receive a packet */
610 iov.iov_base = buffer;
611 iov.iov_len = (size_t)buflen;
612
613 len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0);
614
615 if (len < 0)
616 return -1;
617
618 LeaveFunction(7);
619 return len;
620}
621
622
623static DECLARE_WAIT_QUEUE_HEAD(sync_wait);
624static pid_t sync_master_pid = 0;
625static pid_t sync_backup_pid = 0;
626
627static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait);
628static int stop_master_sync = 0;
629static int stop_backup_sync = 0;
630
631static void sync_master_loop(void)
632{
633 struct socket *sock;
634 struct ip_vs_sync_buff *sb;
635
636 /* create the sending multicast socket */
637 sock = make_send_sock();
638 if (!sock)
639 return;
640
641 IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, "
642 "syncid = %d\n",
643 ip_vs_master_mcast_ifn, ip_vs_master_syncid);
644
645 for (;;) {
646 while ((sb=sb_dequeue())) {
647 ip_vs_send_sync_msg(sock, sb->mesg);
648 ip_vs_sync_buff_release(sb);
649 }
650
651 /* check if entries stay in curr_sb for 2 seconds */
652 if ((sb = get_curr_sync_buff(2*HZ))) {
653 ip_vs_send_sync_msg(sock, sb->mesg);
654 ip_vs_sync_buff_release(sb);
655 }
656
657 if (stop_master_sync)
658 break;
659
89eaeb09 660 msleep_interruptible(1000);
1da177e4
LT		 661 }
662
663 /* clean up the sync_buff queue */
664 while ((sb=sb_dequeue())) {
665 ip_vs_sync_buff_release(sb);
666 }
667
668 /* clean up the current sync_buff */
669 if ((sb = get_curr_sync_buff(0))) {
670 ip_vs_sync_buff_release(sb);
671 }
672
673 /* release the sending multicast socket */
674 sock_release(sock);
675}
676
677
678static void sync_backup_loop(void)
679{
680 struct socket *sock;
681 char *buf;
682 int len;
683
684 if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) {
685 IP_VS_ERR("sync_backup_loop: kmalloc error\n");
686 return;
687 }
688
689 /* create the receiving multicast socket */
690 sock = make_receive_sock();
691 if (!sock)
692 goto out;
693
694 IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, "
695 "syncid = %d\n",
696 ip_vs_backup_mcast_ifn, ip_vs_backup_syncid);
697
698 for (;;) {
699 /* do you have data now? */
700 while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) {
701 if ((len =
702 ip_vs_receive(sock, buf,
703 sync_recv_mesg_maxlen)) <= 0) {
704 IP_VS_ERR("receiving message error\n");
705 break;
706 }
707 /* disable bottom half, because it accessed the data
708 shared by softirq while getting/creating conns */
709 local_bh_disable();
710 ip_vs_process_message(buf, len);
711 local_bh_enable();
712 }
713
714 if (stop_backup_sync)
715 break;
716
89eaeb09 717 msleep_interruptible(1000);
1da177e4
LT		 718 }
719
720 /* release the sending multicast socket */
721 sock_release(sock);
722
723 out:
724 kfree(buf);
725}
726
727
728static void set_sync_pid(int sync_state, pid_t sync_pid)
729{
730 if (sync_state == IP_VS_STATE_MASTER)
731 sync_master_pid = sync_pid;
732 else if (sync_state == IP_VS_STATE_BACKUP)
733 sync_backup_pid = sync_pid;
734}
735
736static void set_stop_sync(int sync_state, int set)
737{
738 if (sync_state == IP_VS_STATE_MASTER)
739 stop_master_sync = set;
740 else if (sync_state == IP_VS_STATE_BACKUP)
741 stop_backup_sync = set;
742 else {
743 stop_master_sync = set;
744 stop_backup_sync = set;
745 }
746}
747
748static int sync_thread(void *startup)
749{
750 DECLARE_WAITQUEUE(wait, current);
751 mm_segment_t oldmm;
752 int state;
753 const char *name;
754
755 /* increase the module use count */
756 ip_vs_use_count_inc();
757
758 if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) {
759 state = IP_VS_STATE_MASTER;
760 name = "ipvs_syncmaster";
761 } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) {
762 state = IP_VS_STATE_BACKUP;
763 name = "ipvs_syncbackup";
764 } else {
765 IP_VS_BUG();
766 ip_vs_use_count_dec();
767 return -EINVAL;
768 }
769
770 daemonize(name);
771
772 oldmm = get_fs();
773 set_fs(KERNEL_DS);
774
775 /* Block all signals */
776 spin_lock_irq(&current->sighand->siglock);
777 siginitsetinv(&current->blocked, 0);
778 recalc_sigpending();
779 spin_unlock_irq(&current->sighand->siglock);
780
781 /* set the maximum length of sync message */
782 set_sync_mesg_maxlen(state);
783
784 /* set up multicast address */
785 mcast_addr.sin_family = AF_INET;
786 mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
787 mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
788
789 add_wait_queue(&sync_wait, &wait);
790
791 set_sync_pid(state, current->pid);
792 complete((struct completion *)startup);
793
794 /* processing master/backup loop here */
795 if (state == IP_VS_STATE_MASTER)
796 sync_master_loop();
797 else if (state == IP_VS_STATE_BACKUP)
798 sync_backup_loop();
799 else IP_VS_BUG();
800
801 remove_wait_queue(&sync_wait, &wait);
802
803 /* thread exits */
804 set_sync_pid(state, 0);
805 IP_VS_INFO("sync thread stopped!\n");
806
807 set_fs(oldmm);
808
809 /* decrease the module use count */
810 ip_vs_use_count_dec();
811
812 set_stop_sync(state, 0);
813 wake_up(&stop_sync_wait);
814
815 return 0;
816}
817
818
819static int fork_sync_thread(void *startup)
820{
821 pid_t pid;
822
823 /* fork the sync thread here, then the parent process of the
824 sync thread is the init process after this thread exits. */
825 repeat:
826 if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
827 IP_VS_ERR("could not create sync_thread due to %d... "
828 "retrying.\n", pid);
89eaeb09 829 msleep_interruptible(1000);
1da177e4
LT		 830 goto repeat;
831 }
832
833 return 0;
834}
835
836
837int start_sync_thread(int state, char *mcast_ifn, __u8 syncid)
838{
6e9a4738 839 DECLARE_COMPLETION_ONSTACK(startup);
1da177e4
LT		 840 pid_t pid;
841
842 if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||
843 (state == IP_VS_STATE_BACKUP && sync_backup_pid))
844 return -EEXIST;
845
846 IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
847 IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",
848 sizeof(struct ip_vs_sync_conn));
849
850 ip_vs_sync_state |= state;
851 if (state == IP_VS_STATE_MASTER) {
37004af3
SH		 852 strlcpy(ip_vs_master_mcast_ifn, mcast_ifn,
853 sizeof(ip_vs_master_mcast_ifn));
1da177e4
LT		 854 ip_vs_master_syncid = syncid;
855 } else {
37004af3
SH		 856 strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn,
857 sizeof(ip_vs_backup_mcast_ifn));
1da177e4
LT		 858 ip_vs_backup_syncid = syncid;
859 }
860
861 repeat:
862 if ((pid = kernel_thread(fork_sync_thread, &startup, 0)) < 0) {
863 IP_VS_ERR("could not create fork_sync_thread due to %d... "
864 "retrying.\n", pid);
89eaeb09 865 msleep_interruptible(1000);
1da177e4
LT		 866 goto repeat;
867 }
868
869 wait_for_completion(&startup);
870
871 return 0;
872}
873
874
875int stop_sync_thread(int state)
876{
877 DECLARE_WAITQUEUE(wait, current);
878
879 if ((state == IP_VS_STATE_MASTER && !sync_master_pid) ||
880 (state == IP_VS_STATE_BACKUP && !sync_backup_pid))
881 return -ESRCH;
882
883 IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);
884 IP_VS_INFO("stopping sync thread %d ...\n",
37004af3
SH		 885 (state == IP_VS_STATE_MASTER) ?
886 sync_master_pid : sync_backup_pid);
1da177e4
LT		 887
888 __set_current_state(TASK_UNINTERRUPTIBLE);
889 add_wait_queue(&stop_sync_wait, &wait);
890 set_stop_sync(state, 1);
891 ip_vs_sync_state -= state;
892 wake_up(&sync_wait);
893 schedule();
894 __set_current_state(TASK_RUNNING);
895 remove_wait_queue(&stop_sync_wait, &wait);
896
897 /* Note: no need to reap the sync thread, because its parent
898 process is the init process */
899
900 if ((state == IP_VS_STATE_MASTER && stop_master_sync) ||
901 (state == IP_VS_STATE_BACKUP && stop_backup_sync))
902 IP_VS_BUG();
903
904 return 0;
905}
Clone of davem's net-next-2.6 tree