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Merge branch 'davem-next' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[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 *
1da177e4
LT		 8 * Authors: Wensong Zhang <wensong@linuxvirtualserver.org>
9 *
10 * ip_vs_sync: sync connection info from master load balancer to backups
11 * through multicast
12 *
13 * Changes:
14 * Alexandre Cassen : Added master & backup support at a time.
15 * Alexandre Cassen : Added SyncID support for incoming sync
16 * messages filtering.
17 * Justin Ossevoort : Fix endian problem on sync message size.
18 */
19
20#include <linux/module.h>
21#include <linux/slab.h>
14c85021 22#include <linux/inetdevice.h>
1da177e4
LT		 23#include <linux/net.h>
24#include <linux/completion.h>
25#include <linux/delay.h>
26#include <linux/skbuff.h>
27#include <linux/in.h>
28#include <linux/igmp.h> /* for ip_mc_join_group */
14c85021 29#include <linux/udp.h>
1da177e4
LT		 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) */
014d730d
AV		 49 __be16 cport;
50 __be16 vport;
51 __be16 dport;
52 __be32 caddr; /* client address */
53 __be32 vaddr; /* virtual address */
54 __be32 daddr; /* destination address */
1da177e4
LT		 55
56 /* Flags and state transition */
014d730d
AV		 57 __be16 flags; /* status flags */
58 __be16 state; /* state info */
1da177e4
LT		 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
cc0191ae
NH		 68struct ip_vs_sync_thread_data {
69 struct completion *startup;
70 int state;
71};
72
1da177e4
LT		 73#define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn))
74#define FULL_CONN_SIZE \
75(sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options))
76
77
78/*
79 The master mulitcasts messages to the backup load balancers in the
80 following format.
81
82 0 1 2 3
83 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
84 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
85 | Count Conns | SyncID | Size |
86 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
87 | |
88 | IPVS Sync Connection (1) |
89 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
90 | . |
91 | . |
92 | . |
93 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
94 | |
95 | IPVS Sync Connection (n) |
96 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
97*/
98
99#define SYNC_MESG_HEADER_LEN 4
100
101struct ip_vs_sync_mesg {
102 __u8 nr_conns;
103 __u8 syncid;
104 __u16 size;
105
106 /* ip_vs_sync_conn entries start here */
107};
108
109/* the maximum length of sync (sending/receiving) message */
110static int sync_send_mesg_maxlen;
111static int sync_recv_mesg_maxlen;
112
113struct ip_vs_sync_buff {
114 struct list_head list;
115 unsigned long firstuse;
116
117 /* pointers for the message data */
118 struct ip_vs_sync_mesg *mesg;
119 unsigned char *head;
120 unsigned char *end;
121};
122
123
124/* the sync_buff list head and the lock */
125static LIST_HEAD(ip_vs_sync_queue);
126static DEFINE_SPINLOCK(ip_vs_sync_lock);
127
128/* current sync_buff for accepting new conn entries */
129static struct ip_vs_sync_buff *curr_sb = NULL;
130static DEFINE_SPINLOCK(curr_sb_lock);
131
132/* ipvs sync daemon state */
133volatile int ip_vs_sync_state = IP_VS_STATE_NONE;
134volatile int ip_vs_master_syncid = 0;
135volatile int ip_vs_backup_syncid = 0;
136
137/* multicast interface name */
138char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN];
139char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN];
140
141/* multicast addr */
142static struct sockaddr_in mcast_addr;
143
144
145static inline void sb_queue_tail(struct ip_vs_sync_buff *sb)
146{
147 spin_lock(&ip_vs_sync_lock);
148 list_add_tail(&sb->list, &ip_vs_sync_queue);
149 spin_unlock(&ip_vs_sync_lock);
150}
151
152static inline struct ip_vs_sync_buff * sb_dequeue(void)
153{
154 struct ip_vs_sync_buff *sb;
155
156 spin_lock_bh(&ip_vs_sync_lock);
157 if (list_empty(&ip_vs_sync_queue)) {
158 sb = NULL;
159 } else {
160 sb = list_entry(ip_vs_sync_queue.next,
161 struct ip_vs_sync_buff,
162 list);
163 list_del(&sb->list);
164 }
165 spin_unlock_bh(&ip_vs_sync_lock);
166
167 return sb;
168}
169
170static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void)
171{
172 struct ip_vs_sync_buff *sb;
173
174 if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
175 return NULL;
176
177 if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) {
178 kfree(sb);
179 return NULL;
180 }
181 sb->mesg->nr_conns = 0;
182 sb->mesg->syncid = ip_vs_master_syncid;
183 sb->mesg->size = 4;
184 sb->head = (unsigned char *)sb->mesg + 4;
185 sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen;
186 sb->firstuse = jiffies;
187 return sb;
188}
189
190static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
191{
192 kfree(sb->mesg);
193 kfree(sb);
194}
195
196/*
197 * Get the current sync buffer if it has been created for more
198 * than the specified time or the specified time is zero.
199 */
200static inline struct ip_vs_sync_buff *
201get_curr_sync_buff(unsigned long time)
202{
203 struct ip_vs_sync_buff *sb;
204
205 spin_lock_bh(&curr_sb_lock);
206 if (curr_sb && (time == 0 ||
207 time_before(jiffies - curr_sb->firstuse, time))) {
208 sb = curr_sb;
209 curr_sb = NULL;
210 } else
211 sb = NULL;
212 spin_unlock_bh(&curr_sb_lock);
213 return sb;
214}
215
216
217/*
218 * Add an ip_vs_conn information into the current sync_buff.
219 * Called by ip_vs_in.
220 */
221void ip_vs_sync_conn(struct ip_vs_conn *cp)
222{
223 struct ip_vs_sync_mesg *m;
224 struct ip_vs_sync_conn *s;
225 int len;
226
227 spin_lock(&curr_sb_lock);
228 if (!curr_sb) {
229 if (!(curr_sb=ip_vs_sync_buff_create())) {
230 spin_unlock(&curr_sb_lock);
231 IP_VS_ERR("ip_vs_sync_buff_create failed.\n");
232 return;
233 }
234 }
235
236 len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
237 SIMPLE_CONN_SIZE;
238 m = curr_sb->mesg;
239 s = (struct ip_vs_sync_conn *)curr_sb->head;
240
241 /* copy members */
242 s->protocol = cp->protocol;
243 s->cport = cp->cport;
244 s->vport = cp->vport;
245 s->dport = cp->dport;
246 s->caddr = cp->caddr;
247 s->vaddr = cp->vaddr;
248 s->daddr = cp->daddr;
249 s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
250 s->state = htons(cp->state);
251 if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
252 struct ip_vs_sync_conn_options *opt =
253 (struct ip_vs_sync_conn_options *)&s[1];
254 memcpy(opt, &cp->in_seq, sizeof(*opt));
255 }
256
257 m->nr_conns++;
258 m->size += len;
259 curr_sb->head += len;
260
261 /* check if there is a space for next one */
262 if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) {
263 sb_queue_tail(curr_sb);
264 curr_sb = NULL;
265 }
266 spin_unlock(&curr_sb_lock);
267
268 /* synchronize its controller if it has */
269 if (cp->control)
270 ip_vs_sync_conn(cp->control);
271}
272
273
274/*
275 * Process received multicast message and create the corresponding
276 * ip_vs_conn entries.
277 */
278static void ip_vs_process_message(const char *buffer, const size_t buflen)
279{
280 struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer;
281 struct ip_vs_sync_conn *s;
282 struct ip_vs_sync_conn_options *opt;
283 struct ip_vs_conn *cp;
5c81833c 284 struct ip_vs_protocol *pp;
1e356f9c 285 struct ip_vs_dest *dest;
1da177e4
LT		 286 char *p;
287 int i;
288
2ad17def
JA		 289 if (buflen < sizeof(struct ip_vs_sync_mesg)) {
290 IP_VS_ERR_RL("sync message header too short\n");
291 return;
292 }
293
1da177e4
LT		 294 /* Convert size back to host byte order */
295 m->size = ntohs(m->size);
296
297 if (buflen != m->size) {
2ad17def 298 IP_VS_ERR_RL("bogus sync message size\n");
1da177e4
LT		 299 return;
300 }
301
302 /* SyncID sanity check */
303 if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) {
304 IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n",
305 m->syncid);
306 return;
307 }
308
309 p = (char *)buffer + sizeof(struct ip_vs_sync_mesg);
310 for (i=0; i<m->nr_conns; i++) {
b209639e 311 unsigned flags, state;
87375ab4 312
2ad17def
JA		 313 if (p + SIMPLE_CONN_SIZE > buffer+buflen) {
314 IP_VS_ERR_RL("bogus conn in sync message\n");
315 return;
316 }
317 s = (struct ip_vs_sync_conn *) p;
7a4fbb1f 318 flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
2ad17def
JA		 319 flags &= ~IP_VS_CONN_F_HASHED;
320 if (flags & IP_VS_CONN_F_SEQ_MASK) {
321 opt = (struct ip_vs_sync_conn_options *)&s[1];
322 p += FULL_CONN_SIZE;
323 if (p > buffer+buflen) {
324 IP_VS_ERR_RL("bogus conn options in sync message\n");
325 return;
326 }
327 } else {
328 opt = NULL;
329 p += SIMPLE_CONN_SIZE;
330 }
331
b209639e 332 state = ntohs(s->state);
2ad17def
JA		 333 if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
334 pp = ip_vs_proto_get(s->protocol);
335 if (!pp) {
336 IP_VS_ERR_RL("Unsupported protocol %u in sync msg\n",
337 s->protocol);
338 continue;
339 }
340 if (state >= pp->num_states) {
341 IP_VS_DBG(2, "Invalid %s state %u in sync msg\n",
342 pp->name, state);
343 continue;
344 }
345 } else {
346 /* protocol in templates is not used for state/timeout */
347 pp = NULL;
348 if (state > 0) {
349 IP_VS_DBG(2, "Invalid template state %u in sync msg\n",
350 state);
351 state = 0;
352 }
353 }
354
87375ab4
JA		 355 if (!(flags & IP_VS_CONN_F_TEMPLATE))
356 cp = ip_vs_conn_in_get(s->protocol,
357 s->caddr, s->cport,
358 s->vaddr, s->vport);
359 else
360 cp = ip_vs_ct_in_get(s->protocol,
361 s->caddr, s->cport,
362 s->vaddr, s->vport);
1da177e4 363 if (!cp) {
1e356f9c
RB		 364 /*
365 * Find the appropriate destination for the connection.
366 * If it is not found the connection will remain unbound
367 * but still handled.
368 */
369 dest = ip_vs_find_dest(s->daddr, s->dport,
370 s->vaddr, s->vport,
371 s->protocol);
b209639e
RB		 372 /* Set the approprite ativity flag */
373 if (s->protocol == IPPROTO_TCP) {
374 if (state != IP_VS_TCP_S_ESTABLISHED)
375 flags |= IP_VS_CONN_F_INACTIVE;
376 else
377 flags &= ~IP_VS_CONN_F_INACTIVE;
378 }
1da177e4
LT		 379 cp = ip_vs_conn_new(s->protocol,
380 s->caddr, s->cport,
381 s->vaddr, s->vport,
382 s->daddr, s->dport,
1e356f9c
RB		 383 flags, dest);
384 if (dest)
385 atomic_dec(&dest->refcnt);
1da177e4
LT		 386 if (!cp) {
387 IP_VS_ERR("ip_vs_conn_new failed\n");
388 return;
389 }
1da177e4 390 } else if (!cp->dest) {
1e356f9c 391 dest = ip_vs_try_bind_dest(cp);
2ad17def 392 if (dest)
1e356f9c 393 atomic_dec(&dest->refcnt);
b209639e
RB		 394 } else if ((cp->dest) && (cp->protocol == IPPROTO_TCP) &&
395 (cp->state != state)) {
396 /* update active/inactive flag for the connection */
397 dest = cp->dest;
398 if (!(cp->flags & IP_VS_CONN_F_INACTIVE) &&
399 (state != IP_VS_TCP_S_ESTABLISHED)) {
400 atomic_dec(&dest->activeconns);
401 atomic_inc(&dest->inactconns);
402 cp->flags |= IP_VS_CONN_F_INACTIVE;
403 } else if ((cp->flags & IP_VS_CONN_F_INACTIVE) &&
404 (state == IP_VS_TCP_S_ESTABLISHED)) {
405 atomic_inc(&dest->activeconns);
406 atomic_dec(&dest->inactconns);
407 cp->flags &= ~IP_VS_CONN_F_INACTIVE;
408 }
409 }
1da177e4 410
2ad17def 411 if (opt)
1da177e4 412 memcpy(&cp->in_seq, opt, sizeof(*opt));
1da177e4 413 atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
b209639e 414 cp->state = state;
2ad17def
JA		 415 cp->old_state = cp->state;
416 /*
417 * We can not recover the right timeout for templates
418 * in all cases, we can not find the right fwmark
419 * virtual service. If needed, we can do it for
420 * non-fwmark persistent services.
421 */
422 if (!(flags & IP_VS_CONN_F_TEMPLATE) && pp->timeout_table)
423 cp->timeout = pp->timeout_table[state];
424 else
425 cp->timeout = (3*60*HZ);
1da177e4 426 ip_vs_conn_put(cp);
1da177e4
LT		 427 }
428}
429
430
431/*
432 * Setup loopback of outgoing multicasts on a sending socket
433 */
434static void set_mcast_loop(struct sock *sk, u_char loop)
435{
436 struct inet_sock *inet = inet_sk(sk);
437
438 /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
439 lock_sock(sk);
440 inet->mc_loop = loop ? 1 : 0;
441 release_sock(sk);
442}
443
444/*
445 * Specify TTL for outgoing multicasts on a sending socket
446 */
447static void set_mcast_ttl(struct sock *sk, u_char ttl)
448{
449 struct inet_sock *inet = inet_sk(sk);
450
451 /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
452 lock_sock(sk);
453 inet->mc_ttl = ttl;
454 release_sock(sk);
455}
456
457/*
458 * Specifiy default interface for outgoing multicasts
459 */
460static int set_mcast_if(struct sock *sk, char *ifname)
461{
462 struct net_device *dev;
463 struct inet_sock *inet = inet_sk(sk);
464
881d966b 465 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 466 return -ENODEV;
467
468 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
469 return -EINVAL;
470
471 lock_sock(sk);
472 inet->mc_index = dev->ifindex;
473 /* inet->mc_addr = 0; */
474 release_sock(sk);
475
476 return 0;
477}
478
479
480/*
481 * Set the maximum length of sync message according to the
482 * specified interface's MTU.
483 */
484static int set_sync_mesg_maxlen(int sync_state)
485{
486 struct net_device *dev;
487 int num;
488
489 if (sync_state == IP_VS_STATE_MASTER) {
881d966b 490 if ((dev = __dev_get_by_name(&init_net, ip_vs_master_mcast_ifn)) == NULL)
1da177e4
LT		 491 return -ENODEV;
492
493 num = (dev->mtu - sizeof(struct iphdr) -
494 sizeof(struct udphdr) -
495 SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE;
496 sync_send_mesg_maxlen =
497 SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num;
498 IP_VS_DBG(7, "setting the maximum length of sync sending "
499 "message %d.\n", sync_send_mesg_maxlen);
500 } else if (sync_state == IP_VS_STATE_BACKUP) {
881d966b 501 if ((dev = __dev_get_by_name(&init_net, ip_vs_backup_mcast_ifn)) == NULL)
1da177e4
LT		 502 return -ENODEV;
503
504 sync_recv_mesg_maxlen = dev->mtu -
505 sizeof(struct iphdr) - sizeof(struct udphdr);
506 IP_VS_DBG(7, "setting the maximum length of sync receiving "
507 "message %d.\n", sync_recv_mesg_maxlen);
508 }
509
510 return 0;
511}
512
513
514/*
515 * Join a multicast group.
516 * the group is specified by a class D multicast address 224.0.0.0/8
517 * in the in_addr structure passed in as a parameter.
518 */
519static int
520join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
521{
522 struct ip_mreqn mreq;
523 struct net_device *dev;
524 int ret;
525
526 memset(&mreq, 0, sizeof(mreq));
527 memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
528
881d966b 529 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 530 return -ENODEV;
531 if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
532 return -EINVAL;
533
534 mreq.imr_ifindex = dev->ifindex;
535
536 lock_sock(sk);
537 ret = ip_mc_join_group(sk, &mreq);
538 release_sock(sk);
539
540 return ret;
541}
542
543
544static int bind_mcastif_addr(struct socket *sock, char *ifname)
545{
546 struct net_device *dev;
a61ced5d 547 __be32 addr;
1da177e4
LT		 548 struct sockaddr_in sin;
549
881d966b 550 if ((dev = __dev_get_by_name(&init_net, ifname)) == NULL)
1da177e4
LT		 551 return -ENODEV;
552
553 addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
554 if (!addr)
555 IP_VS_ERR("You probably need to specify IP address on "
556 "multicast interface.\n");
557
558 IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n",
559 ifname, NIPQUAD(addr));
560
561 /* Now bind the socket with the address of multicast interface */
562 sin.sin_family = AF_INET;
563 sin.sin_addr.s_addr = addr;
564 sin.sin_port = 0;
565
566 return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
567}
568
569/*
570 * Set up sending multicast socket over UDP
571 */
572static struct socket * make_send_sock(void)
573{
574 struct socket *sock;
575
576 /* First create a socket */
577 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
578 IP_VS_ERR("Error during creation of socket; terminating\n");
579 return NULL;
580 }
581
582 if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) {
583 IP_VS_ERR("Error setting outbound mcast interface\n");
584 goto error;
585 }
586
587 set_mcast_loop(sock->sk, 0);
588 set_mcast_ttl(sock->sk, 1);
589
590 if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) {
591 IP_VS_ERR("Error binding address of the mcast interface\n");
592 goto error;
593 }
594
595 if (sock->ops->connect(sock,
596 (struct sockaddr*)&mcast_addr,
597 sizeof(struct sockaddr), 0) < 0) {
598 IP_VS_ERR("Error connecting to the multicast addr\n");
599 goto error;
600 }
601
602 return sock;
603
604 error:
605 sock_release(sock);
606 return NULL;
607}
608
609
610/*
611 * Set up receiving multicast socket over UDP
612 */
613static struct socket * make_receive_sock(void)
614{
615 struct socket *sock;
616
617 /* First create a socket */
618 if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) {
619 IP_VS_ERR("Error during creation of socket; terminating\n");
620 return NULL;
621 }
622
623 /* it is equivalent to the REUSEADDR option in user-space */
624 sock->sk->sk_reuse = 1;
625
626 if (sock->ops->bind(sock,
627 (struct sockaddr*)&mcast_addr,
628 sizeof(struct sockaddr)) < 0) {
629 IP_VS_ERR("Error binding to the multicast addr\n");
630 goto error;
631 }
632
633 /* join the multicast group */
634 if (join_mcast_group(sock->sk,
635 (struct in_addr*)&mcast_addr.sin_addr,
636 ip_vs_backup_mcast_ifn) < 0) {
637 IP_VS_ERR("Error joining to the multicast group\n");
638 goto error;
639 }
640
641 return sock;
642
643 error:
644 sock_release(sock);
645 return NULL;
646}
647
648
649static int
650ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
651{
652 struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
653 struct kvec iov;
654 int len;
655
656 EnterFunction(7);
657 iov.iov_base = (void *)buffer;
658 iov.iov_len = length;
659
660 len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
661
662 LeaveFunction(7);
663 return len;
664}
665
666static void
667ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
668{
669 int msize;
670
671 msize = msg->size;
672
673 /* Put size in network byte order */
674 msg->size = htons(msg->size);
675
676 if (ip_vs_send_async(sock, (char *)msg, msize) != msize)
677 IP_VS_ERR("ip_vs_send_async error\n");
678}
679
680static int
681ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
682{
683 struct msghdr msg = {NULL,};
684 struct kvec iov;
685 int len;
686
687 EnterFunction(7);
688
689 /* Receive a packet */
690 iov.iov_base = buffer;
691 iov.iov_len = (size_t)buflen;
692
693 len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0);
694
695 if (len < 0)
696 return -1;
697
698 LeaveFunction(7);
699 return len;
700}
701
702
703static DECLARE_WAIT_QUEUE_HEAD(sync_wait);
704static pid_t sync_master_pid = 0;
705static pid_t sync_backup_pid = 0;
706
707static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait);
708static int stop_master_sync = 0;
709static int stop_backup_sync = 0;
710
711static void sync_master_loop(void)
712{
713 struct socket *sock;
714 struct ip_vs_sync_buff *sb;
715
716 /* create the sending multicast socket */
717 sock = make_send_sock();
718 if (!sock)
719 return;
720
721 IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, "
722 "syncid = %d\n",
723 ip_vs_master_mcast_ifn, ip_vs_master_syncid);
724
725 for (;;) {
726 while ((sb=sb_dequeue())) {
727 ip_vs_send_sync_msg(sock, sb->mesg);
728 ip_vs_sync_buff_release(sb);
729 }
730
731 /* check if entries stay in curr_sb for 2 seconds */
732 if ((sb = get_curr_sync_buff(2*HZ))) {
733 ip_vs_send_sync_msg(sock, sb->mesg);
734 ip_vs_sync_buff_release(sb);
735 }
736
737 if (stop_master_sync)
738 break;
739
89eaeb09 740 msleep_interruptible(1000);
1da177e4
LT		 741 }
742
743 /* clean up the sync_buff queue */
744 while ((sb=sb_dequeue())) {
745 ip_vs_sync_buff_release(sb);
746 }
747
748 /* clean up the current sync_buff */
749 if ((sb = get_curr_sync_buff(0))) {
750 ip_vs_sync_buff_release(sb);
751 }
752
753 /* release the sending multicast socket */
754 sock_release(sock);
755}
756
757
758static void sync_backup_loop(void)
759{
760 struct socket *sock;
761 char *buf;
762 int len;
763
764 if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) {
765 IP_VS_ERR("sync_backup_loop: kmalloc error\n");
766 return;
767 }
768
769 /* create the receiving multicast socket */
770 sock = make_receive_sock();
771 if (!sock)
772 goto out;
773
774 IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, "
775 "syncid = %d\n",
776 ip_vs_backup_mcast_ifn, ip_vs_backup_syncid);
777
778 for (;;) {
779 /* do you have data now? */
780 while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) {
781 if ((len =
782 ip_vs_receive(sock, buf,
783 sync_recv_mesg_maxlen)) <= 0) {
784 IP_VS_ERR("receiving message error\n");
785 break;
786 }
787 /* disable bottom half, because it accessed the data
788 shared by softirq while getting/creating conns */
789 local_bh_disable();
790 ip_vs_process_message(buf, len);
791 local_bh_enable();
792 }
793
794 if (stop_backup_sync)
795 break;
796
89eaeb09 797 msleep_interruptible(1000);
1da177e4
LT		 798 }
799
800 /* release the sending multicast socket */
801 sock_release(sock);
802
803 out:
804 kfree(buf);
805}
806
807
808static void set_sync_pid(int sync_state, pid_t sync_pid)
809{
810 if (sync_state == IP_VS_STATE_MASTER)
811 sync_master_pid = sync_pid;
812 else if (sync_state == IP_VS_STATE_BACKUP)
813 sync_backup_pid = sync_pid;
814}
815
816static void set_stop_sync(int sync_state, int set)
817{
818 if (sync_state == IP_VS_STATE_MASTER)
819 stop_master_sync = set;
820 else if (sync_state == IP_VS_STATE_BACKUP)
821 stop_backup_sync = set;
822 else {
823 stop_master_sync = set;
824 stop_backup_sync = set;
825 }
826}
827
828static int sync_thread(void *startup)
829{
830 DECLARE_WAITQUEUE(wait, current);
831 mm_segment_t oldmm;
832 int state;
833 const char *name;
cc0191ae 834 struct ip_vs_sync_thread_data *tinfo = startup;
1da177e4
LT		 835
836 /* increase the module use count */
837 ip_vs_use_count_inc();
838
839 if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) {
840 state = IP_VS_STATE_MASTER;
841 name = "ipvs_syncmaster";
842 } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) {
843 state = IP_VS_STATE_BACKUP;
844 name = "ipvs_syncbackup";
845 } else {
846 IP_VS_BUG();
847 ip_vs_use_count_dec();
848 return -EINVAL;
849 }
850
851 daemonize(name);
852
853 oldmm = get_fs();
854 set_fs(KERNEL_DS);
855
856 /* Block all signals */
857 spin_lock_irq(&current->sighand->siglock);
858 siginitsetinv(&current->blocked, 0);
859 recalc_sigpending();
860 spin_unlock_irq(&current->sighand->siglock);
861
862 /* set the maximum length of sync message */
863 set_sync_mesg_maxlen(state);
864
865 /* set up multicast address */
866 mcast_addr.sin_family = AF_INET;
867 mcast_addr.sin_port = htons(IP_VS_SYNC_PORT);
868 mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP);
869
870 add_wait_queue(&sync_wait, &wait);
871
6651fd56 872 set_sync_pid(state, task_pid_nr(current));
cc0191ae
NH		 873 complete(tinfo->startup);
874
875 /*
876 * once we call the completion queue above, we should
877 * null out that reference, since its allocated on the
878 * stack of the creating kernel thread
879 */
880 tinfo->startup = NULL;
1da177e4
LT		 881
882 /* processing master/backup loop here */
883 if (state == IP_VS_STATE_MASTER)
884 sync_master_loop();
885 else if (state == IP_VS_STATE_BACKUP)
886 sync_backup_loop();
887 else IP_VS_BUG();
888
889 remove_wait_queue(&sync_wait, &wait);
890
891 /* thread exits */
cc0191ae
NH		 892
893 /*
894 * If we weren't explicitly stopped, then we
895 * exited in error, and should undo our state
896 */
897 if ((!stop_master_sync) && (!stop_backup_sync))
898 ip_vs_sync_state -= tinfo->state;
899
1da177e4
LT		 900 set_sync_pid(state, 0);
901 IP_VS_INFO("sync thread stopped!\n");
902
903 set_fs(oldmm);
904
905 /* decrease the module use count */
906 ip_vs_use_count_dec();
907
908 set_stop_sync(state, 0);
909 wake_up(&stop_sync_wait);
910
cc0191ae
NH		 911 /*
912 * we need to free the structure that was allocated
913 * for us in start_sync_thread
914 */
915 kfree(tinfo);
1da177e4
LT		 916 return 0;
917}
918
919
920static int fork_sync_thread(void *startup)
921{
922 pid_t pid;
923
924 /* fork the sync thread here, then the parent process of the
925 sync thread is the init process after this thread exits. */
926 repeat:
927 if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) {
928 IP_VS_ERR("could not create sync_thread due to %d... "
929 "retrying.\n", pid);
89eaeb09 930 msleep_interruptible(1000);
1da177e4
LT		 931 goto repeat;
932 }
933
934 return 0;
935}
936
937
938int start_sync_thread(int state, char *mcast_ifn, __u8 syncid)
939{
6e9a4738 940 DECLARE_COMPLETION_ONSTACK(startup);
1da177e4 941 pid_t pid;
cc0191ae 942 struct ip_vs_sync_thread_data *tinfo;
1da177e4
LT		 943
944 if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||
945 (state == IP_VS_STATE_BACKUP && sync_backup_pid))
946 return -EEXIST;
947
cc0191ae
NH		 948 /*
949 * Note that tinfo will be freed in sync_thread on exit
950 */
951 tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL);
952 if (!tinfo)
953 return -ENOMEM;
954
0dc47877 955 IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current));
1da177e4
LT		 956 IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",
957 sizeof(struct ip_vs_sync_conn));
958
959 ip_vs_sync_state |= state;
960 if (state == IP_VS_STATE_MASTER) {
37004af3
SH		 961 strlcpy(ip_vs_master_mcast_ifn, mcast_ifn,
962 sizeof(ip_vs_master_mcast_ifn));
1da177e4
LT		 963 ip_vs_master_syncid = syncid;
964 } else {
37004af3
SH		 965 strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn,
966 sizeof(ip_vs_backup_mcast_ifn));
1da177e4
LT		 967 ip_vs_backup_syncid = syncid;
968 }
969
cc0191ae
NH		 970 tinfo->state = state;
971 tinfo->startup = &startup;
972
1da177e4 973 repeat:
cc0191ae 974 if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) {
1da177e4
LT		 975 IP_VS_ERR("could not create fork_sync_thread due to %d... "
976 "retrying.\n", pid);
89eaeb09 977 msleep_interruptible(1000);
1da177e4
LT		 978 goto repeat;
979 }
980
981 wait_for_completion(&startup);
982
983 return 0;
984}
985
986
987int stop_sync_thread(int state)
988{
989 DECLARE_WAITQUEUE(wait, current);
990
991 if ((state == IP_VS_STATE_MASTER && !sync_master_pid) ||
992 (state == IP_VS_STATE_BACKUP && !sync_backup_pid))
993 return -ESRCH;
994
0dc47877 995 IP_VS_DBG(7, "%s: pid %d\n", __func__, task_pid_nr(current));
1da177e4 996 IP_VS_INFO("stopping sync thread %d ...\n",
37004af3
SH		 997 (state == IP_VS_STATE_MASTER) ?
998 sync_master_pid : sync_backup_pid);
1da177e4
LT		 999
1000 __set_current_state(TASK_UNINTERRUPTIBLE);
1001 add_wait_queue(&stop_sync_wait, &wait);
1002 set_stop_sync(state, 1);
1003 ip_vs_sync_state -= state;
1004 wake_up(&sync_wait);
1005 schedule();
1006 __set_current_state(TASK_RUNNING);
1007 remove_wait_queue(&stop_sync_wait, &wait);
1008
1009 /* Note: no need to reap the sync thread, because its parent
1010 process is the init process */
1011
1012 if ((state == IP_VS_STATE_MASTER && stop_master_sync) ||
1013 (state == IP_VS_STATE_BACKUP && stop_backup_sync))
1014 IP_VS_BUG();
1015
1016 return 0;
1017}
Linux kernel - Deliverables
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