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bridge: kernel panic when unloading bridge module
[deliverable/linux.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>
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
cc0191ae
NH		 70struct ip_vs_sync_thread_data {
71 struct completion *startup;
72 int state;
73};
74
1da177e4
LT		 75#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn))
76#define FULL_CONN_SIZE \
77(sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options))
78
79
80/*
81 The master mulitcasts messages to the backup load balancers in the
82 following format.
83
84 0 1 2 3
85 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
86 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
87 | Count Conns | SyncID | Size |
88 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
89 | |
90 | IPVS Sync Connection (1) |
91 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
92 | . |
93 | . |
94 | . |
95 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
96 | |
97 | IPVS Sync Connection (n) |
98 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
99*/
100
101#define SYNC_MESG_HEADER_LEN 4
102
103struct ip_vs_sync_mesg {
104 __u8 nr_conns;
105 __u8 syncid;
106 __u16 size;
107
108 /* ip_vs_sync_conn entries start here */
109};
110
111/* the maximum length of sync (sending/receiving) message */
112static int sync_send_mesg_maxlen;
113static int sync_recv_mesg_maxlen;
114
115struct ip_vs_sync_buff {
116 struct list_head list;
117 unsigned long firstuse;
118
119 /* pointers for the message data */
120 struct ip_vs_sync_mesg *mesg;
121 unsigned char *head;
122 unsigned char *end;
123};
124
125
126/* the sync_buff list head and the lock */
127static LIST_HEAD(ip_vs_sync_queue);
128static DEFINE_SPINLOCK(ip_vs_sync_lock);
129
130/* current sync_buff for accepting new conn entries */
131static struct ip_vs_sync_buff *curr_sb = NULL;
132static DEFINE_SPINLOCK(curr_sb_lock);
133
134/* ipvs sync daemon state */
135volatile int ip_vs_sync_state = IP_VS_STATE_NONE;
136volatile int ip_vs_master_syncid = 0;
137volatile int ip_vs_backup_syncid = 0;
138
139/* multicast interface name */
140char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
141char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
142
143/* multicast addr */
144static struct sockaddr_in mcast_addr;
145
146
147static inline void sb_queue_tail(struct ip_vs_sync_buff *sb)
148{
149 spin_lock(&ip_vs_sync_lock);
150 list_add_tail(&sb->list, &ip_vs_sync_queue);
151 spin_unlock(&ip_vs_sync_lock);
152}
153
154static inline struct ip_vs_sync_buff * sb_dequeue(void)
155{
156 struct ip_vs_sync_buff *sb;
157
158 spin_lock_bh(&ip_vs_sync_lock);
159 if (list_empty(&ip_vs_sync_queue)) {
160 sb = NULL;
161 } else {
162 sb = list_entry(ip_vs_sync_queue.next,
163 struct ip_vs_sync_buff,
164 list);
165 list_del(&sb->list);
166 }
167 spin_unlock_bh(&ip_vs_sync_lock);
168
169 return sb;
170}
171
172static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void)
173{
174 struct ip_vs_sync_buff *sb;
175
176 if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
177 return NULL;
178
179 if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) {
180 kfree(sb);
181 return NULL;
182 }
183 sb->mesg->nr_conns = 0;
184 sb->mesg->syncid = ip_vs_master_syncid;
185 sb->mesg->size = 4;
186 sb->head = (unsigned char *)sb->mesg + 4;
187 sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen;
188 sb->firstuse = jiffies;
189 return sb;
190}
191
192static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
193{
194 kfree(sb->mesg);
195 kfree(sb);
196}
197
198/*
199 * Get the current sync buffer if it has been created for more
200 * than the specified time or the specified time is zero.
201 */
202static inline struct ip_vs_sync_buff *
203get_curr_sync_buff(unsigned long time)
204{
205 struct ip_vs_sync_buff *sb;
206
207 spin_lock_bh(&curr_sb_lock);
208 if (curr_sb && (time == 0 ||
209 time_before(jiffies - curr_sb->firstuse, time))) {
210 sb = curr_sb;
211 curr_sb = NULL;
212 } else
213 sb = NULL;
214 spin_unlock_bh(&curr_sb_lock);
215 return sb;
216}
217
218
219/*
220 * Add an ip_vs_conn information into the current sync_buff.
221 * Called by ip_vs_in.
222 */
223void ip_vs_sync_conn(struct ip_vs_conn *cp)
224{
225 struct ip_vs_sync_mesg *m;
226 struct ip_vs_sync_conn *s;
227 int len;
228
229 spin_lock(&curr_sb_lock);
230 if (!curr_sb) {
231 if (!(curr_sb=ip_vs_sync_buff_create())) {
232 spin_unlock(&curr_sb_lock);
233 IP_VS_ERR("ip_vs_sync_buff_create failed.\n");
234 return;
235 }
236 }
237
238 len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
239 SIMPLE_CONN_SIZE;
240 m = curr_sb->mesg;
241 s = (struct ip_vs_sync_conn *)curr_sb->head;
242
243 /* copy members */
244 s->protocol = cp->protocol;
245 s->cport = cp->cport;
246 s->vport = cp->vport;
247 s->dport = cp->dport;
248 s->caddr = cp->caddr;
249 s->vaddr = cp->vaddr;
250 s->daddr = cp->daddr;
251 s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
252 s->state = htons(cp->state);
253 if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
254 struct ip_vs_sync_conn_options *opt =
255 (struct ip_vs_sync_conn_options *)&s[1];
256 memcpy(opt, &cp->in_seq, sizeof(*opt));
257 }
258
259 m->nr_conns++;
260 m->size += len;
261 curr_sb->head += len;
262
263 /* check if there is a space for next one */
264 if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) {
265 sb_queue_tail(curr_sb);
266 curr_sb = NULL;
267 }
268 spin_unlock(&curr_sb_lock);
269
270 /* synchronize its controller if it has */
271 if (cp->control)
272 ip_vs_sync_conn(cp->control);
273}
274
275
276/*
277 * Process received multicast message and create the corresponding
278 * ip_vs_conn entries.
279 */
280static void ip_vs_process_message(const char *buffer, const size_t buflen)
281{
282 struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
283 struct ip_vs_sync_conn *s;
284 struct ip_vs_sync_conn_options *opt;
285 struct ip_vs_conn *cp;
5c81833c 286 struct ip_vs_protocol *pp;
1e356f9c 287 struct ip_vs_dest *dest;
1da177e4
LT		 288 char *p;
289 int i;
290
291 /* Convert size back to host byte order */
292 m->size = ntohs(m->size);
293
294 if (buflen != m->size) {
295 IP_VS_ERR("bogus message\n");
296 return;
297 }
298
299 /* SyncID sanity check */
300 if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) {
301 IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n",
302 m->syncid);
303 return;
304 }
305
306 p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
307 for (i=0; i<m->nr_conns; i++) {
b209639e 308 unsigned flags, state;
87375ab4 309
1da177e4 310 s = (struct ip_vs_sync_conn *)p;
7a4fbb1f 311 flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
b209639e 312 state = ntohs(s->state);
87375ab4
JA		 313 if (!(flags & IP_VS_CONN_F_TEMPLATE))
314 cp = ip_vs_conn_in_get(s->protocol,
315 s->caddr, s->cport,
316 s->vaddr, s->vport);
317 else
318 cp = ip_vs_ct_in_get(s->protocol,
319 s->caddr, s->cport,
320 s->vaddr, s->vport);
1da177e4 321 if (!cp) {
1e356f9c
RB		 322 /*
323 * Find the appropriate destination for the connection.
324 * If it is not found the connection will remain unbound
325 * but still handled.
326 */
327 dest = ip_vs_find_dest(s->daddr, s->dport,
328 s->vaddr, s->vport,
329 s->protocol);
b209639e
RB		 330 /* Set the approprite ativity flag */
331 if (s->protocol == IPPROTO_TCP) {
332 if (state != IP_VS_TCP_S_ESTABLISHED)
333 flags |= IP_VS_CONN_F_INACTIVE;
334 else
335 flags &= ~IP_VS_CONN_F_INACTIVE;
336 }
1da177e4
LT		 337 cp = ip_vs_conn_new(s->protocol,
338 s->caddr, s->cport,
339 s->vaddr, s->vport,
340 s->daddr, s->dport,
1e356f9c
RB		 341 flags, dest);
342 if (dest)
343 atomic_dec(&dest->refcnt);
1da177e4
LT		 344 if (!cp) {
345 IP_VS_ERR("ip_vs_conn_new failed\n");
346 return;
347 }
b209639e 348 cp->state = state;
1da177e4 349 } else if (!cp->dest) {
1e356f9c
RB		 350 dest = ip_vs_try_bind_dest(cp);
351 if (!dest) {
352 /* it is an unbound entry created by
353 * synchronization */
1e356f9c
RB		 354 cp->flags = flags | IP_VS_CONN_F_HASHED;
355 } else
356 atomic_dec(&dest->refcnt);
b209639e
RB		 357 } else if ((cp->dest) && (cp->protocol == IPPROTO_TCP) &&
358 (cp->state != state)) {
359 /* update active/inactive flag for the connection */
360 dest = cp->dest;
361 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
362 (state != IP_VS_TCP_S_ESTABLISHED)) {
363 atomic_dec(&dest->activeconns);
364 atomic_inc(&dest->inactconns);
365 cp->flags |= IP_VS_CONN_F_INACTIVE;
366 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
367 (state == IP_VS_TCP_S_ESTABLISHED)) {
368 atomic_inc(&dest->activeconns);
369 atomic_dec(&dest->inactconns);
370 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
371 }
372 }
1da177e4 373
87375ab4 374 if (flags & IP_VS_CONN_F_SEQ_MASK) {
1da177e4
LT		 375 opt = (struct ip_vs_sync_conn_options *)&s[1];
376 memcpy(&cp->in_seq, opt, sizeof(*opt));
377 p += FULL_CONN_SIZE;
378 } else
379 p += SIMPLE_CONN_SIZE;
380
381 atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
b209639e 382 cp->state = state;
5c81833c
AG		 383 pp = ip_vs_proto_get(s->protocol);
384 cp->timeout = pp->timeout_table[cp->state];
1da177e4
LT		 385 ip_vs_conn_put(cp);
386
387 if (p > buffer+buflen) {
388 IP_VS_ERR("bogus message\n");
389 return;
390 }
391 }
392}
393
394
395/*
396 * Setup loopback of outgoing multicasts on a sending socket
397 */
398static void set_mcast_loop(struct sock *sk, u_char loop)
399{
400 struct inet_sock *inet = inet_sk(sk);
401
402 /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
403 lock_sock(sk);
404 inet->mc_loop = loop ? 1 : 0;
405 release_sock(sk);
406}
407
408/*
409 * Specify TTL for outgoing multicasts on a sending socket
410 */
411static void set_mcast_ttl(struct sock *sk, u_char ttl)
412{
413 struct inet_sock *inet = inet_sk(sk);
414
415 /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
416 lock_sock(sk);
417 inet->mc_ttl = ttl;
418 release_sock(sk);
419}
420
421/*
422 * Specifiy default interface for outgoing multicasts
423 */
424static int set_mcast_if(struct sock *sk, char *ifname)
425{
426 struct net_device *dev;
427 struct inet_sock *inet = inet_sk(sk);
428
881d966b 429 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 430 return -ENODEV;
431
432 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
433 return -EINVAL;
434
435 lock_sock(sk);
436 inet->mc_index = dev->ifindex;
437 /* inet->mc_addr = 0; */
438 release_sock(sk);
439
440 return 0;
441}
442
443
444/*
445 * Set the maximum length of sync message according to the
446 * specified interface's MTU.
447 */
448static int set_sync_mesg_maxlen(int sync_state)
449{
450 struct net_device *dev;
451 int num;
452
453 if (sync_state == IP_VS_STATE_MASTER) {
881d966b 454 if ((dev = __dev_get_by_name(&init_net, ip_vs_master_mcast_ifn)) == NULL)
1da177e4
LT		 455 return -ENODEV;
456
457 num = (dev->mtu - sizeof(struct iphdr) -
458 sizeof(struct udphdr) -
459 SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
460 sync_send_mesg_maxlen =
461 SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num;
462 IP_VS_DBG(7, "setting the maximum length of sync sending "
463 "message %d.\n", sync_send_mesg_maxlen);
464 } else if (sync_state == IP_VS_STATE_BACKUP) {
881d966b 465 if ((dev = __dev_get_by_name(&init_net, ip_vs_backup_mcast_ifn)) == NULL)
1da177e4
LT		 466 return -ENODEV;
467
468 sync_recv_mesg_maxlen = dev->mtu -
469 sizeof(struct iphdr) - sizeof(struct udphdr);
470 IP_VS_DBG(7, "setting the maximum length of sync receiving "
471 "message %d.\n", sync_recv_mesg_maxlen);
472 }
473
474 return 0;
475}
476
477
478/*
479 * Join a multicast group.
480 * the group is specified by a class D multicast address 224.0.0.0/8
481 * in the in_addr structure passed in as a parameter.
482 */
483static int
484join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
485{
486 struct ip_mreqn mreq;
487 struct net_device *dev;
488 int ret;
489
490 memset(&mreq, 0, sizeof(mreq));
491 memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
492
881d966b 493 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 494 return -ENODEV;
495 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
496 return -EINVAL;
497
498 mreq.imr_ifindex = dev->ifindex;
499
500 lock_sock(sk);
501 ret = ip_mc_join_group(sk, &mreq);
502 release_sock(sk);
503
504 return ret;
505}
506
507
508static int bind_mcastif_addr(struct socket *sock, char *ifname)
509{
510 struct net_device *dev;
a61ced5d 511 __be32 addr;
1da177e4
LT		 512 struct sockaddr_in sin;
513
881d966b 514 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 515 return -ENODEV;
516
517 addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
518 if (!addr)
519 IP_VS_ERR("You probably need to specify IP address on "
520 "multicast interface.\n");
521
522 IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n",
523 ifname, NIPQUAD(addr));
524
525 /* Now bind the socket with the address of multicast interface */
526 sin.sin_family = AF_INET;
527 sin.sin_addr.s_addr = addr;
528 sin.sin_port = 0;
529
530 return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
531}
532
533/*
534 * Set up sending multicast socket over UDP
535 */
536static struct socket * make_send_sock(void)
537{
538 struct socket *sock;
539
540 /* First create a socket */
541 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
542 IP_VS_ERR("Error during creation of socket; terminating\n");
543 return NULL;
544 }
545
546 if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) {
547 IP_VS_ERR("Error setting outbound mcast interface\n");
548 goto error;
549 }
550
551 set_mcast_loop(sock->sk, 0);
552 set_mcast_ttl(sock->sk, 1);
553
554 if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) {
555 IP_VS_ERR("Error binding address of the mcast interface\n");
556 goto error;
557 }
558
559 if (sock->ops->connect(sock,
560 (struct sockaddr*)&mcast_addr,
561 sizeof(struct sockaddr), 0) < 0) {
562 IP_VS_ERR("Error connecting to the multicast addr\n");
563 goto error;
564 }
565
566 return sock;
567
568 error:
569 sock_release(sock);
570 return NULL;
571}
572
573
574/*
575 * Set up receiving multicast socket over UDP
576 */
577static struct socket * make_receive_sock(void)
578{
579 struct socket *sock;
580
581 /* First create a socket */
582 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
583 IP_VS_ERR("Error during creation of socket; terminating\n");
584 return NULL;
585 }
586
587 /* it is equivalent to the REUSEADDR option in user-space */
588 sock->sk->sk_reuse = 1;
589
590 if (sock->ops->bind(sock,
591 (struct sockaddr*)&mcast_addr,
592 sizeof(struct sockaddr)) < 0) {
593 IP_VS_ERR("Error binding to the multicast addr\n");
594 goto error;
595 }
596
597 /* join the multicast group */
598 if (join_mcast_group(sock->sk,
599 (struct in_addr*)&mcast_addr.sin_addr,
600 ip_vs_backup_mcast_ifn) < 0) {
601 IP_VS_ERR("Error joining to the multicast group\n");
602 goto error;
603 }
604
605 return sock;
606
607 error:
608 sock_release(sock);
609 return NULL;
610}
611
612
613static int
614ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
615{
616 struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
617 struct kvec iov;
618 int len;
619
620 EnterFunction(7);
621 iov.iov_base = (void *)buffer;
622 iov.iov_len = length;
623
624 len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
625
626 LeaveFunction(7);
627 return len;
628}
629
630static void
631ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
632{
633 int msize;
634
635 msize = msg->size;
636
637 /* Put size in network byte order */
638 msg->size = htons(msg->size);
639
640 if (ip_vs_send_async(sock, (char *)msg, msize) != msize)
641 IP_VS_ERR("ip_vs_send_async error\n");
642}
643
644static int
645ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
646{
647 struct msghdr msg = {NULL,};
648 struct kvec iov;
649 int len;
650
651 EnterFunction(7);
652
653 /* Receive a packet */
654 iov.iov_base = buffer;
655 iov.iov_len = (size_t)buflen;
656
657 len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0);
658
659 if (len < 0)
660 return -1;
661
662 LeaveFunction(7);
663 return len;
664}
665
666
667static DECLARE_WAIT_QUEUE_HEAD(sync_wait);
668static pid_t sync_master_pid = 0;
669static pid_t sync_backup_pid = 0;
670
671static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait);
672static int stop_master_sync = 0;
673static int stop_backup_sync = 0;
674
675static void sync_master_loop(void)
676{
677 struct socket *sock;
678 struct ip_vs_sync_buff *sb;
679
680 /* create the sending multicast socket */
681 sock = make_send_sock();
682 if (!sock)
683 return;
684
685 IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, "
686 "syncid = %d\n",
687 ip_vs_master_mcast_ifn, ip_vs_master_syncid);
688
689 for (;;) {
690 while ((sb=sb_dequeue())) {
691 ip_vs_send_sync_msg(sock, sb->mesg);
692 ip_vs_sync_buff_release(sb);
693 }
694
695 /* check if entries stay in curr_sb for 2 seconds */
696 if ((sb = get_curr_sync_buff(2*HZ))) {
697 ip_vs_send_sync_msg(sock, sb->mesg);
698 ip_vs_sync_buff_release(sb);
699 }
700
701 if (stop_master_sync)
702 break;
703
89eaeb09 704 msleep_interruptible(1000);
1da177e4
LT		 705 }
706
707 /* clean up the sync_buff queue */
708 while ((sb=sb_dequeue())) {
709 ip_vs_sync_buff_release(sb);
710 }
711
712 /* clean up the current sync_buff */
713 if ((sb = get_curr_sync_buff(0))) {
714 ip_vs_sync_buff_release(sb);
715 }
716
717 /* release the sending multicast socket */
718 sock_release(sock);
719}
720
721
722static void sync_backup_loop(void)
723{
724 struct socket *sock;
725 char *buf;
726 int len;
727
728 if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) {
729 IP_VS_ERR("sync_backup_loop: kmalloc error\n");
730 return;
731 }
732
733 /* create the receiving multicast socket */
734 sock = make_receive_sock();
735 if (!sock)
736 goto out;
737
738 IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, "
739 "syncid = %d\n",
740 ip_vs_backup_mcast_ifn, ip_vs_backup_syncid);
741
742 for (;;) {
743 /* do you have data now? */
744 while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) {
745 if ((len =
746 ip_vs_receive(sock, buf,
747 sync_recv_mesg_maxlen)) <= 0) {
748 IP_VS_ERR("receiving message error\n");
749 break;
750 }
751 /* disable bottom half, because it accessed the data
752 shared by softirq while getting/creating conns */
753 local_bh_disable();
754 ip_vs_process_message(buf, len);
755 local_bh_enable();
756 }
757
758 if (stop_backup_sync)
759 break;
760
89eaeb09 761 msleep_interruptible(1000);
1da177e4
LT		 762 }
763
764 /* release the sending multicast socket */
765 sock_release(sock);
766
767 out:
768 kfree(buf);
769}
770
771
772static void set_sync_pid(int sync_state, pid_t sync_pid)
773{
774 if (sync_state == IP_VS_STATE_MASTER)
775 sync_master_pid = sync_pid;
776 else if (sync_state == IP_VS_STATE_BACKUP)
777 sync_backup_pid = sync_pid;
778}
779
780static void set_stop_sync(int sync_state, int set)
781{
782 if (sync_state == IP_VS_STATE_MASTER)
783 stop_master_sync = set;
784 else if (sync_state == IP_VS_STATE_BACKUP)
785 stop_backup_sync = set;
786 else {
787 stop_master_sync = set;
788 stop_backup_sync = set;
789 }
790}
791
792static int sync_thread(void *startup)
793{
794 DECLARE_WAITQUEUE(wait, current);
795 mm_segment_t oldmm;
796 int state;
797 const char *name;
cc0191ae 798 struct ip_vs_sync_thread_data *tinfo = startup;
1da177e4
LT		 799
800 /* increase the module use count */
801 ip_vs_use_count_inc();
802
803 if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) {
804 state = IP_VS_STATE_MASTER;
805 name = "ipvs_syncmaster";
806 } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) {
807 state = IP_VS_STATE_BACKUP;
808 name = "ipvs_syncbackup";
809 } else {
810 IP_VS_BUG();
811 ip_vs_use_count_dec();
812 return -EINVAL;
813 }
814
815 daemonize(name);
816
817 oldmm = get_fs();
818 set_fs(KERNEL_DS);
819
820 /* Block all signals */
821 spin_lock_irq(&current->sighand->siglock);
822 siginitsetinv(&current->blocked, 0);
823 recalc_sigpending();
824 spin_unlock_irq(&current->sighand->siglock);
825
826 /* set the maximum length of sync message */
827 set_sync_mesg_maxlen(state);
828
829 /* set up multicast address */
830 mcast_addr.sin_family = AF_INET;
831 mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
832 mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
833
834 add_wait_queue(&sync_wait, &wait);
835
6651fd56 836 set_sync_pid(state, task_pid_nr(current));
cc0191ae
NH		 837 complete(tinfo->startup);
838
839 /*
840 * once we call the completion queue above, we should
841 * null out that reference, since its allocated on the
842 * stack of the creating kernel thread
843 */
844 tinfo->startup = NULL;
1da177e4
LT		 845
846 /* processing master/backup loop here */
847 if (state == IP_VS_STATE_MASTER)
848 sync_master_loop();
849 else if (state == IP_VS_STATE_BACKUP)
850 sync_backup_loop();
851 else IP_VS_BUG();
852
853 remove_wait_queue(&sync_wait, &wait);
854
855 /* thread exits */
cc0191ae
NH		 856
857 /*
858 * If we weren't explicitly stopped, then we
859 * exited in error, and should undo our state
860 */
861 if ((!stop_master_sync) && (!stop_backup_sync))
862 ip_vs_sync_state -= tinfo->state;
863
1da177e4
LT		 864 set_sync_pid(state, 0);
865 IP_VS_INFO("sync thread stopped!\n");
866
867 set_fs(oldmm);
868
869 /* decrease the module use count */
870 ip_vs_use_count_dec();
871
872 set_stop_sync(state, 0);
873 wake_up(&stop_sync_wait);
874
cc0191ae
NH		 875 /*
876 * we need to free the structure that was allocated
877 * for us in start_sync_thread
878 */
879 kfree(tinfo);
1da177e4
LT		 880 return 0;
881}
882
883
884static int fork_sync_thread(void *startup)
885{
886 pid_t pid;
887
888 /* fork the sync thread here, then the parent process of the
889 sync thread is the init process after this thread exits. */
890 repeat:
891 if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
892 IP_VS_ERR("could not create sync_thread due to %d... "
893 "retrying.\n", pid);
89eaeb09 894 msleep_interruptible(1000);
1da177e4
LT		 895 goto repeat;
896 }
897
898 return 0;
899}
900
901
902int start_sync_thread(int state, char *mcast_ifn, __u8 syncid)
903{
6e9a4738 904 DECLARE_COMPLETION_ONSTACK(startup);
1da177e4 905 pid_t pid;
cc0191ae 906 struct ip_vs_sync_thread_data *tinfo;
1da177e4
LT		 907
908 if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||
909 (state == IP_VS_STATE_BACKUP && sync_backup_pid))
910 return -EEXIST;
911
cc0191ae
NH		 912 /*
913 * Note that tinfo will be freed in sync_thread on exit
914 */
915 tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL);
916 if (!tinfo)
917 return -ENOMEM;
918
0dc47877 919 IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current));
1da177e4
LT		 920 IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",
921 sizeof(struct ip_vs_sync_conn));
922
923 ip_vs_sync_state |= state;
924 if (state == IP_VS_STATE_MASTER) {
37004af3
SH		 925 strlcpy(ip_vs_master_mcast_ifn, mcast_ifn,
926 sizeof(ip_vs_master_mcast_ifn));
1da177e4
LT		 927 ip_vs_master_syncid = syncid;
928 } else {
37004af3
SH		 929 strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn,
930 sizeof(ip_vs_backup_mcast_ifn));
1da177e4
LT		 931 ip_vs_backup_syncid = syncid;
932 }
933
cc0191ae
NH		 934 tinfo->state = state;
935 tinfo->startup = &startup;
936
1da177e4 937 repeat:
cc0191ae 938 if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) {
1da177e4
LT		 939 IP_VS_ERR("could not create fork_sync_thread due to %d... "
940 "retrying.\n", pid);
89eaeb09 941 msleep_interruptible(1000);
1da177e4
LT		 942 goto repeat;
943 }
944
945 wait_for_completion(&startup);
946
947 return 0;
948}
949
950
951int stop_sync_thread(int state)
952{
953 DECLARE_WAITQUEUE(wait, current);
954
955 if ((state == IP_VS_STATE_MASTER && !sync_master_pid) ||
956 (state == IP_VS_STATE_BACKUP && !sync_backup_pid))
957 return -ESRCH;
958
0dc47877 959 IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current));
1da177e4 960 IP_VS_INFO("stopping sync thread %d ...\n",
37004af3
SH		 961 (state == IP_VS_STATE_MASTER) ?
962 sync_master_pid : sync_backup_pid);
1da177e4
LT		 963
964 __set_current_state(TASK_UNINTERRUPTIBLE);
965 add_wait_queue(&stop_sync_wait, &wait);
966 set_stop_sync(state, 1);
967 ip_vs_sync_state -= state;
968 wake_up(&sync_wait);
969 schedule();
970 __set_current_state(TASK_RUNNING);
971 remove_wait_queue(&stop_sync_wait, &wait);
972
973 /* Note: no need to reap the sync thread, because its parent
974 process is the init process */
975
976 if ((state == IP_VS_STATE_MASTER && stop_master_sync) ||
977 (state == IP_VS_STATE_BACKUP && stop_backup_sync))
978 IP_VS_BUG();
979
980 return 0;
981}
Linux kernel - Deliverables
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