xref: /openbmc/linux/net/netfilter/ipvs/ip_vs_sync.c (revision 23c2b932)
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 1,   is capable of handling both version 0 and 1 messages.
9  *              Version 0 is the plain old format.
10  *              Note Version 0 receivers will just drop Ver 1 messages.
11  *              Version 1 is capable of handle IPv6, Persistence data,
12  *              time-outs, and firewall marks.
13  *              In ver.1 "ip_vs_sync_conn_options" will be sent in netw. order.
14  *              Ver. 0 can be turned on by sysctl -w net.ipv4.vs.sync_version=0
15  *
16  * Definitions  Message: is a complete datagram
17  *              Sync_conn: is a part of a Message
18  *              Param Data is an option to a Sync_conn.
19  *
20  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
21  *
22  * ip_vs_sync:  sync connection info from master load balancer to backups
23  *              through multicast
24  *
25  * Changes:
26  *	Alexandre Cassen	:	Added master & backup support at a time.
27  *	Alexandre Cassen	:	Added SyncID support for incoming sync
28  *					messages filtering.
29  *	Justin Ossevoort	:	Fix endian problem on sync message size.
30  *	Hans Schillstrom	:	Added Version 1: i.e. IPv6,
31  *					Persistence support, fwmark and time-out.
32  */
33 
34 #define KMSG_COMPONENT "IPVS"
35 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
36 
37 #include <linux/module.h>
38 #include <linux/slab.h>
39 #include <linux/inetdevice.h>
40 #include <linux/net.h>
41 #include <linux/completion.h>
42 #include <linux/delay.h>
43 #include <linux/skbuff.h>
44 #include <linux/in.h>
45 #include <linux/igmp.h>                 /* for ip_mc_join_group */
46 #include <linux/udp.h>
47 #include <linux/err.h>
48 #include <linux/kthread.h>
49 #include <linux/wait.h>
50 #include <linux/kernel.h>
51 
52 #include <asm/unaligned.h>		/* Used for ntoh_seq and hton_seq */
53 
54 #include <net/ip.h>
55 #include <net/sock.h>
56 
57 #include <net/ip_vs.h>
58 
59 #define IP_VS_SYNC_GROUP 0xe0000051    /* multicast addr - 224.0.0.81 */
60 #define IP_VS_SYNC_PORT  8848          /* multicast port */
61 
62 #define SYNC_PROTO_VER  1		/* Protocol version in header */
63 
64 static struct lock_class_key __ipvs_sync_key;
65 /*
66  *	IPVS sync connection entry
67  *	Version 0, i.e. original version.
68  */
69 struct ip_vs_sync_conn_v0 {
70 	__u8			reserved;
71 
72 	/* Protocol, addresses and port numbers */
73 	__u8			protocol;       /* Which protocol (TCP/UDP) */
74 	__be16			cport;
75 	__be16                  vport;
76 	__be16                  dport;
77 	__be32                  caddr;          /* client address */
78 	__be32                  vaddr;          /* virtual address */
79 	__be32                  daddr;          /* destination address */
80 
81 	/* Flags and state transition */
82 	__be16                  flags;          /* status flags */
83 	__be16                  state;          /* state info */
84 
85 	/* The sequence options start here */
86 };
87 
88 struct ip_vs_sync_conn_options {
89 	struct ip_vs_seq        in_seq;         /* incoming seq. struct */
90 	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */
91 };
92 
93 /*
94      Sync Connection format (sync_conn)
95 
96        0                   1                   2                   3
97        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
98       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
99       |    Type       |    Protocol   | Ver.  |        Size           |
100       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
101       |                             Flags                             |
102       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
103       |            State              |         cport                 |
104       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
105       |            vport              |         dport                 |
106       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
107       |                             fwmark                            |
108       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
109       |                             timeout  (in sec.)                |
110       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
111       |                              ...                              |
112       |                        IP-Addresses  (v4 or v6)               |
113       |                              ...                              |
114       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
115   Optional Parameters.
116       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
117       | Param. Type    | Param. Length |   Param. data                |
118       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
119       |                              ...                              |
120       |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
121       |                               | Param Type    | Param. Length |
122       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
123       |                           Param  data                         |
124       |         Last Param data should be padded for 32 bit alignment |
125       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
126 */
127 
128 /*
129  *  Type 0, IPv4 sync connection format
130  */
131 struct ip_vs_sync_v4 {
132 	__u8			type;
133 	__u8			protocol;	/* Which protocol (TCP/UDP) */
134 	__be16			ver_size;	/* Version msb 4 bits */
135 	/* Flags and state transition */
136 	__be32			flags;		/* status flags */
137 	__be16			state;		/* state info 	*/
138 	/* Protocol, addresses and port numbers */
139 	__be16			cport;
140 	__be16			vport;
141 	__be16			dport;
142 	__be32			fwmark;		/* Firewall mark from skb */
143 	__be32			timeout;	/* cp timeout */
144 	__be32			caddr;		/* client address */
145 	__be32			vaddr;		/* virtual address */
146 	__be32			daddr;		/* destination address */
147 	/* The sequence options start here */
148 	/* PE data padded to 32bit alignment after seq. options */
149 };
150 /*
151  * Type 2 messages IPv6
152  */
153 struct ip_vs_sync_v6 {
154 	__u8			type;
155 	__u8			protocol;	/* Which protocol (TCP/UDP) */
156 	__be16			ver_size;	/* Version msb 4 bits */
157 	/* Flags and state transition */
158 	__be32			flags;		/* status flags */
159 	__be16			state;		/* state info 	*/
160 	/* Protocol, addresses and port numbers */
161 	__be16			cport;
162 	__be16			vport;
163 	__be16			dport;
164 	__be32			fwmark;		/* Firewall mark from skb */
165 	__be32			timeout;	/* cp timeout */
166 	struct in6_addr		caddr;		/* client address */
167 	struct in6_addr		vaddr;		/* virtual address */
168 	struct in6_addr		daddr;		/* destination address */
169 	/* The sequence options start here */
170 	/* PE data padded to 32bit alignment after seq. options */
171 };
172 
173 union ip_vs_sync_conn {
174 	struct ip_vs_sync_v4	v4;
175 	struct ip_vs_sync_v6	v6;
176 };
177 
178 /* Bits in Type field in above */
179 #define STYPE_INET6		0
180 #define STYPE_F_INET6		(1 << STYPE_INET6)
181 
182 #define SVER_SHIFT		12		/* Shift to get version */
183 #define SVER_MASK		0x0fff		/* Mask to strip version */
184 
185 #define IPVS_OPT_SEQ_DATA	1
186 #define IPVS_OPT_PE_DATA	2
187 #define IPVS_OPT_PE_NAME	3
188 #define IPVS_OPT_PARAM		7
189 
190 #define IPVS_OPT_F_SEQ_DATA	(1 << (IPVS_OPT_SEQ_DATA-1))
191 #define IPVS_OPT_F_PE_DATA	(1 << (IPVS_OPT_PE_DATA-1))
192 #define IPVS_OPT_F_PE_NAME	(1 << (IPVS_OPT_PE_NAME-1))
193 #define IPVS_OPT_F_PARAM	(1 << (IPVS_OPT_PARAM-1))
194 
195 struct ip_vs_sync_thread_data {
196 	struct netns_ipvs *ipvs;
197 	struct socket *sock;
198 	char *buf;
199 	int id;
200 };
201 
202 /* Version 0 definition of packet sizes */
203 #define SIMPLE_CONN_SIZE  (sizeof(struct ip_vs_sync_conn_v0))
204 #define FULL_CONN_SIZE  \
205 (sizeof(struct ip_vs_sync_conn_v0) + sizeof(struct ip_vs_sync_conn_options))
206 
207 
208 /*
209   The master mulitcasts messages (Datagrams) to the backup load balancers
210   in the following format.
211 
212  Version 1:
213   Note, first byte should be Zero, so ver 0 receivers will drop the packet.
214 
215        0                   1                   2                   3
216        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
217       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
218       |      0        |    SyncID     |            Size               |
219       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
220       |  Count Conns  |    Version    |    Reserved, set to Zero      |
221       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
222       |                                                               |
223       |                    IPVS Sync Connection (1)                   |
224       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
225       |                            .                                  |
226       ~                            .                                  ~
227       |                            .                                  |
228       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
229       |                                                               |
230       |                    IPVS Sync Connection (n)                   |
231       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
232 
233  Version 0 Header
234        0                   1                   2                   3
235        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
236       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
237       |  Count Conns  |    SyncID     |            Size               |
238       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
239       |                    IPVS Sync Connection (1)                   |
240 */
241 
242 #define SYNC_MESG_HEADER_LEN	4
243 #define MAX_CONNS_PER_SYNCBUFF	255 /* nr_conns in ip_vs_sync_mesg is 8 bit */
244 
245 /* Version 0 header */
246 struct ip_vs_sync_mesg_v0 {
247 	__u8                    nr_conns;
248 	__u8                    syncid;
249 	__be16                  size;
250 
251 	/* ip_vs_sync_conn entries start here */
252 };
253 
254 /* Version 1 header */
255 struct ip_vs_sync_mesg {
256 	__u8			reserved;	/* must be zero */
257 	__u8			syncid;
258 	__be16			size;
259 	__u8			nr_conns;
260 	__s8			version;	/* SYNC_PROTO_VER  */
261 	__u16			spare;
262 	/* ip_vs_sync_conn entries start here */
263 };
264 
265 union ipvs_sockaddr {
266 	struct sockaddr_in	in;
267 	struct sockaddr_in6	in6;
268 };
269 
270 struct ip_vs_sync_buff {
271 	struct list_head        list;
272 	unsigned long           firstuse;
273 
274 	/* pointers for the message data */
275 	struct ip_vs_sync_mesg  *mesg;
276 	unsigned char           *head;
277 	unsigned char           *end;
278 };
279 
280 /*
281  * Copy of struct ip_vs_seq
282  * From unaligned network order to aligned host order
283  */
284 static void ntoh_seq(struct ip_vs_seq *no, struct ip_vs_seq *ho)
285 {
286 	ho->init_seq       = get_unaligned_be32(&no->init_seq);
287 	ho->delta          = get_unaligned_be32(&no->delta);
288 	ho->previous_delta = get_unaligned_be32(&no->previous_delta);
289 }
290 
291 /*
292  * Copy of struct ip_vs_seq
293  * From Aligned host order to unaligned network order
294  */
295 static void hton_seq(struct ip_vs_seq *ho, struct ip_vs_seq *no)
296 {
297 	put_unaligned_be32(ho->init_seq, &no->init_seq);
298 	put_unaligned_be32(ho->delta, &no->delta);
299 	put_unaligned_be32(ho->previous_delta, &no->previous_delta);
300 }
301 
302 static inline struct ip_vs_sync_buff *
303 sb_dequeue(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
304 {
305 	struct ip_vs_sync_buff *sb;
306 
307 	spin_lock_bh(&ipvs->sync_lock);
308 	if (list_empty(&ms->sync_queue)) {
309 		sb = NULL;
310 		__set_current_state(TASK_INTERRUPTIBLE);
311 	} else {
312 		sb = list_entry(ms->sync_queue.next, struct ip_vs_sync_buff,
313 				list);
314 		list_del(&sb->list);
315 		ms->sync_queue_len--;
316 		if (!ms->sync_queue_len)
317 			ms->sync_queue_delay = 0;
318 	}
319 	spin_unlock_bh(&ipvs->sync_lock);
320 
321 	return sb;
322 }
323 
324 /*
325  * Create a new sync buffer for Version 1 proto.
326  */
327 static inline struct ip_vs_sync_buff *
328 ip_vs_sync_buff_create(struct netns_ipvs *ipvs, unsigned int len)
329 {
330 	struct ip_vs_sync_buff *sb;
331 
332 	if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
333 		return NULL;
334 
335 	len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg),
336 		    ipvs->mcfg.sync_maxlen);
337 	sb->mesg = kmalloc(len, GFP_ATOMIC);
338 	if (!sb->mesg) {
339 		kfree(sb);
340 		return NULL;
341 	}
342 	sb->mesg->reserved = 0;  /* old nr_conns i.e. must be zero now */
343 	sb->mesg->version = SYNC_PROTO_VER;
344 	sb->mesg->syncid = ipvs->mcfg.syncid;
345 	sb->mesg->size = htons(sizeof(struct ip_vs_sync_mesg));
346 	sb->mesg->nr_conns = 0;
347 	sb->mesg->spare = 0;
348 	sb->head = (unsigned char *)sb->mesg + sizeof(struct ip_vs_sync_mesg);
349 	sb->end = (unsigned char *)sb->mesg + len;
350 
351 	sb->firstuse = jiffies;
352 	return sb;
353 }
354 
355 static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb)
356 {
357 	kfree(sb->mesg);
358 	kfree(sb);
359 }
360 
361 static inline void sb_queue_tail(struct netns_ipvs *ipvs,
362 				 struct ipvs_master_sync_state *ms)
363 {
364 	struct ip_vs_sync_buff *sb = ms->sync_buff;
365 
366 	spin_lock(&ipvs->sync_lock);
367 	if (ipvs->sync_state & IP_VS_STATE_MASTER &&
368 	    ms->sync_queue_len < sysctl_sync_qlen_max(ipvs)) {
369 		if (!ms->sync_queue_len)
370 			schedule_delayed_work(&ms->master_wakeup_work,
371 					      max(IPVS_SYNC_SEND_DELAY, 1));
372 		ms->sync_queue_len++;
373 		list_add_tail(&sb->list, &ms->sync_queue);
374 		if ((++ms->sync_queue_delay) == IPVS_SYNC_WAKEUP_RATE)
375 			wake_up_process(ms->master_thread);
376 	} else
377 		ip_vs_sync_buff_release(sb);
378 	spin_unlock(&ipvs->sync_lock);
379 }
380 
381 /*
382  *	Get the current sync buffer if it has been created for more
383  *	than the specified time or the specified time is zero.
384  */
385 static inline struct ip_vs_sync_buff *
386 get_curr_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms,
387 		   unsigned long time)
388 {
389 	struct ip_vs_sync_buff *sb;
390 
391 	spin_lock_bh(&ipvs->sync_buff_lock);
392 	sb = ms->sync_buff;
393 	if (sb && time_after_eq(jiffies - sb->firstuse, time)) {
394 		ms->sync_buff = NULL;
395 		__set_current_state(TASK_RUNNING);
396 	} else
397 		sb = NULL;
398 	spin_unlock_bh(&ipvs->sync_buff_lock);
399 	return sb;
400 }
401 
402 static inline int
403 select_master_thread_id(struct netns_ipvs *ipvs, struct ip_vs_conn *cp)
404 {
405 	return ((long) cp >> (1 + ilog2(sizeof(*cp)))) & ipvs->threads_mask;
406 }
407 
408 /*
409  * Create a new sync buffer for Version 0 proto.
410  */
411 static inline struct ip_vs_sync_buff *
412 ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs, unsigned int len)
413 {
414 	struct ip_vs_sync_buff *sb;
415 	struct ip_vs_sync_mesg_v0 *mesg;
416 
417 	if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
418 		return NULL;
419 
420 	len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg_v0),
421 		    ipvs->mcfg.sync_maxlen);
422 	sb->mesg = kmalloc(len, GFP_ATOMIC);
423 	if (!sb->mesg) {
424 		kfree(sb);
425 		return NULL;
426 	}
427 	mesg = (struct ip_vs_sync_mesg_v0 *)sb->mesg;
428 	mesg->nr_conns = 0;
429 	mesg->syncid = ipvs->mcfg.syncid;
430 	mesg->size = htons(sizeof(struct ip_vs_sync_mesg_v0));
431 	sb->head = (unsigned char *)mesg + sizeof(struct ip_vs_sync_mesg_v0);
432 	sb->end = (unsigned char *)mesg + len;
433 	sb->firstuse = jiffies;
434 	return sb;
435 }
436 
437 /* Check if connection is controlled by persistence */
438 static inline bool in_persistence(struct ip_vs_conn *cp)
439 {
440 	for (cp = cp->control; cp; cp = cp->control) {
441 		if (cp->flags & IP_VS_CONN_F_TEMPLATE)
442 			return true;
443 	}
444 	return false;
445 }
446 
447 /* Check if conn should be synced.
448  * pkts: conn packets, use sysctl_sync_threshold to avoid packet check
449  * - (1) sync_refresh_period: reduce sync rate. Additionally, retry
450  *	sync_retries times with period of sync_refresh_period/8
451  * - (2) if both sync_refresh_period and sync_period are 0 send sync only
452  *	for state changes or only once when pkts matches sync_threshold
453  * - (3) templates: rate can be reduced only with sync_refresh_period or
454  *	with (2)
455  */
456 static int ip_vs_sync_conn_needed(struct netns_ipvs *ipvs,
457 				  struct ip_vs_conn *cp, int pkts)
458 {
459 	unsigned long orig = ACCESS_ONCE(cp->sync_endtime);
460 	unsigned long now = jiffies;
461 	unsigned long n = (now + cp->timeout) & ~3UL;
462 	unsigned int sync_refresh_period;
463 	int sync_period;
464 	int force;
465 
466 	/* Check if we sync in current state */
467 	if (unlikely(cp->flags & IP_VS_CONN_F_TEMPLATE))
468 		force = 0;
469 	else if (unlikely(sysctl_sync_persist_mode(ipvs) && in_persistence(cp)))
470 		return 0;
471 	else if (likely(cp->protocol == IPPROTO_TCP)) {
472 		if (!((1 << cp->state) &
473 		      ((1 << IP_VS_TCP_S_ESTABLISHED) |
474 		       (1 << IP_VS_TCP_S_FIN_WAIT) |
475 		       (1 << IP_VS_TCP_S_CLOSE) |
476 		       (1 << IP_VS_TCP_S_CLOSE_WAIT) |
477 		       (1 << IP_VS_TCP_S_TIME_WAIT))))
478 			return 0;
479 		force = cp->state != cp->old_state;
480 		if (force && cp->state != IP_VS_TCP_S_ESTABLISHED)
481 			goto set;
482 	} else if (unlikely(cp->protocol == IPPROTO_SCTP)) {
483 		if (!((1 << cp->state) &
484 		      ((1 << IP_VS_SCTP_S_ESTABLISHED) |
485 		       (1 << IP_VS_SCTP_S_SHUTDOWN_SENT) |
486 		       (1 << IP_VS_SCTP_S_SHUTDOWN_RECEIVED) |
487 		       (1 << IP_VS_SCTP_S_SHUTDOWN_ACK_SENT) |
488 		       (1 << IP_VS_SCTP_S_CLOSED))))
489 			return 0;
490 		force = cp->state != cp->old_state;
491 		if (force && cp->state != IP_VS_SCTP_S_ESTABLISHED)
492 			goto set;
493 	} else {
494 		/* UDP or another protocol with single state */
495 		force = 0;
496 	}
497 
498 	sync_refresh_period = sysctl_sync_refresh_period(ipvs);
499 	if (sync_refresh_period > 0) {
500 		long diff = n - orig;
501 		long min_diff = max(cp->timeout >> 1, 10UL * HZ);
502 
503 		/* Avoid sync if difference is below sync_refresh_period
504 		 * and below the half timeout.
505 		 */
506 		if (abs(diff) < min_t(long, sync_refresh_period, min_diff)) {
507 			int retries = orig & 3;
508 
509 			if (retries >= sysctl_sync_retries(ipvs))
510 				return 0;
511 			if (time_before(now, orig - cp->timeout +
512 					(sync_refresh_period >> 3)))
513 				return 0;
514 			n |= retries + 1;
515 		}
516 	}
517 	sync_period = sysctl_sync_period(ipvs);
518 	if (sync_period > 0) {
519 		if (!(cp->flags & IP_VS_CONN_F_TEMPLATE) &&
520 		    pkts % sync_period != sysctl_sync_threshold(ipvs))
521 			return 0;
522 	} else if (sync_refresh_period <= 0 &&
523 		   pkts != sysctl_sync_threshold(ipvs))
524 		return 0;
525 
526 set:
527 	cp->old_state = cp->state;
528 	n = cmpxchg(&cp->sync_endtime, orig, n);
529 	return n == orig || force;
530 }
531 
532 /*
533  *      Version 0 , could be switched in by sys_ctl.
534  *      Add an ip_vs_conn information into the current sync_buff.
535  */
536 static void ip_vs_sync_conn_v0(struct netns_ipvs *ipvs, struct ip_vs_conn *cp,
537 			       int pkts)
538 {
539 	struct ip_vs_sync_mesg_v0 *m;
540 	struct ip_vs_sync_conn_v0 *s;
541 	struct ip_vs_sync_buff *buff;
542 	struct ipvs_master_sync_state *ms;
543 	int id;
544 	unsigned int len;
545 
546 	if (unlikely(cp->af != AF_INET))
547 		return;
548 	/* Do not sync ONE PACKET */
549 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
550 		return;
551 
552 	if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
553 		return;
554 
555 	spin_lock_bh(&ipvs->sync_buff_lock);
556 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
557 		spin_unlock_bh(&ipvs->sync_buff_lock);
558 		return;
559 	}
560 
561 	id = select_master_thread_id(ipvs, cp);
562 	ms = &ipvs->ms[id];
563 	buff = ms->sync_buff;
564 	len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
565 		SIMPLE_CONN_SIZE;
566 	if (buff) {
567 		m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
568 		/* Send buffer if it is for v1 */
569 		if (buff->head + len > buff->end || !m->nr_conns) {
570 			sb_queue_tail(ipvs, ms);
571 			ms->sync_buff = NULL;
572 			buff = NULL;
573 		}
574 	}
575 	if (!buff) {
576 		buff = ip_vs_sync_buff_create_v0(ipvs, len);
577 		if (!buff) {
578 			spin_unlock_bh(&ipvs->sync_buff_lock);
579 			pr_err("ip_vs_sync_buff_create failed.\n");
580 			return;
581 		}
582 		ms->sync_buff = buff;
583 	}
584 
585 	m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
586 	s = (struct ip_vs_sync_conn_v0 *) buff->head;
587 
588 	/* copy members */
589 	s->reserved = 0;
590 	s->protocol = cp->protocol;
591 	s->cport = cp->cport;
592 	s->vport = cp->vport;
593 	s->dport = cp->dport;
594 	s->caddr = cp->caddr.ip;
595 	s->vaddr = cp->vaddr.ip;
596 	s->daddr = cp->daddr.ip;
597 	s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
598 	s->state = htons(cp->state);
599 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
600 		struct ip_vs_sync_conn_options *opt =
601 			(struct ip_vs_sync_conn_options *)&s[1];
602 		memcpy(opt, &cp->in_seq, sizeof(*opt));
603 	}
604 
605 	m->nr_conns++;
606 	m->size = htons(ntohs(m->size) + len);
607 	buff->head += len;
608 	spin_unlock_bh(&ipvs->sync_buff_lock);
609 
610 	/* synchronize its controller if it has */
611 	cp = cp->control;
612 	if (cp) {
613 		if (cp->flags & IP_VS_CONN_F_TEMPLATE)
614 			pkts = atomic_add_return(1, &cp->in_pkts);
615 		else
616 			pkts = sysctl_sync_threshold(ipvs);
617 		ip_vs_sync_conn(ipvs, cp, pkts);
618 	}
619 }
620 
621 /*
622  *      Add an ip_vs_conn information into the current sync_buff.
623  *      Called by ip_vs_in.
624  *      Sending Version 1 messages
625  */
626 void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts)
627 {
628 	struct ip_vs_sync_mesg *m;
629 	union ip_vs_sync_conn *s;
630 	struct ip_vs_sync_buff *buff;
631 	struct ipvs_master_sync_state *ms;
632 	int id;
633 	__u8 *p;
634 	unsigned int len, pe_name_len, pad;
635 
636 	/* Handle old version of the protocol */
637 	if (sysctl_sync_ver(ipvs) == 0) {
638 		ip_vs_sync_conn_v0(ipvs, cp, pkts);
639 		return;
640 	}
641 	/* Do not sync ONE PACKET */
642 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
643 		goto control;
644 sloop:
645 	if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
646 		goto control;
647 
648 	/* Sanity checks */
649 	pe_name_len = 0;
650 	if (cp->pe_data_len) {
651 		if (!cp->pe_data || !cp->dest) {
652 			IP_VS_ERR_RL("SYNC, connection pe_data invalid\n");
653 			return;
654 		}
655 		pe_name_len = strnlen(cp->pe->name, IP_VS_PENAME_MAXLEN);
656 	}
657 
658 	spin_lock_bh(&ipvs->sync_buff_lock);
659 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
660 		spin_unlock_bh(&ipvs->sync_buff_lock);
661 		return;
662 	}
663 
664 	id = select_master_thread_id(ipvs, cp);
665 	ms = &ipvs->ms[id];
666 
667 #ifdef CONFIG_IP_VS_IPV6
668 	if (cp->af == AF_INET6)
669 		len = sizeof(struct ip_vs_sync_v6);
670 	else
671 #endif
672 		len = sizeof(struct ip_vs_sync_v4);
673 
674 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK)
675 		len += sizeof(struct ip_vs_sync_conn_options) + 2;
676 
677 	if (cp->pe_data_len)
678 		len += cp->pe_data_len + 2;	/* + Param hdr field */
679 	if (pe_name_len)
680 		len += pe_name_len + 2;
681 
682 	/* check if there is a space for this one  */
683 	pad = 0;
684 	buff = ms->sync_buff;
685 	if (buff) {
686 		m = buff->mesg;
687 		pad = (4 - (size_t) buff->head) & 3;
688 		/* Send buffer if it is for v0 */
689 		if (buff->head + len + pad > buff->end || m->reserved) {
690 			sb_queue_tail(ipvs, ms);
691 			ms->sync_buff = NULL;
692 			buff = NULL;
693 			pad = 0;
694 		}
695 	}
696 
697 	if (!buff) {
698 		buff = ip_vs_sync_buff_create(ipvs, len);
699 		if (!buff) {
700 			spin_unlock_bh(&ipvs->sync_buff_lock);
701 			pr_err("ip_vs_sync_buff_create failed.\n");
702 			return;
703 		}
704 		ms->sync_buff = buff;
705 		m = buff->mesg;
706 	}
707 
708 	p = buff->head;
709 	buff->head += pad + len;
710 	m->size = htons(ntohs(m->size) + pad + len);
711 	/* Add ev. padding from prev. sync_conn */
712 	while (pad--)
713 		*(p++) = 0;
714 
715 	s = (union ip_vs_sync_conn *)p;
716 
717 	/* Set message type  & copy members */
718 	s->v4.type = (cp->af == AF_INET6 ? STYPE_F_INET6 : 0);
719 	s->v4.ver_size = htons(len & SVER_MASK);	/* Version 0 */
720 	s->v4.flags = htonl(cp->flags & ~IP_VS_CONN_F_HASHED);
721 	s->v4.state = htons(cp->state);
722 	s->v4.protocol = cp->protocol;
723 	s->v4.cport = cp->cport;
724 	s->v4.vport = cp->vport;
725 	s->v4.dport = cp->dport;
726 	s->v4.fwmark = htonl(cp->fwmark);
727 	s->v4.timeout = htonl(cp->timeout / HZ);
728 	m->nr_conns++;
729 
730 #ifdef CONFIG_IP_VS_IPV6
731 	if (cp->af == AF_INET6) {
732 		p += sizeof(struct ip_vs_sync_v6);
733 		s->v6.caddr = cp->caddr.in6;
734 		s->v6.vaddr = cp->vaddr.in6;
735 		s->v6.daddr = cp->daddr.in6;
736 	} else
737 #endif
738 	{
739 		p += sizeof(struct ip_vs_sync_v4);	/* options ptr */
740 		s->v4.caddr = cp->caddr.ip;
741 		s->v4.vaddr = cp->vaddr.ip;
742 		s->v4.daddr = cp->daddr.ip;
743 	}
744 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
745 		*(p++) = IPVS_OPT_SEQ_DATA;
746 		*(p++) = sizeof(struct ip_vs_sync_conn_options);
747 		hton_seq((struct ip_vs_seq *)p, &cp->in_seq);
748 		p += sizeof(struct ip_vs_seq);
749 		hton_seq((struct ip_vs_seq *)p, &cp->out_seq);
750 		p += sizeof(struct ip_vs_seq);
751 	}
752 	/* Handle pe data */
753 	if (cp->pe_data_len && cp->pe_data) {
754 		*(p++) = IPVS_OPT_PE_DATA;
755 		*(p++) = cp->pe_data_len;
756 		memcpy(p, cp->pe_data, cp->pe_data_len);
757 		p += cp->pe_data_len;
758 		if (pe_name_len) {
759 			/* Add PE_NAME */
760 			*(p++) = IPVS_OPT_PE_NAME;
761 			*(p++) = pe_name_len;
762 			memcpy(p, cp->pe->name, pe_name_len);
763 			p += pe_name_len;
764 		}
765 	}
766 
767 	spin_unlock_bh(&ipvs->sync_buff_lock);
768 
769 control:
770 	/* synchronize its controller if it has */
771 	cp = cp->control;
772 	if (!cp)
773 		return;
774 	if (cp->flags & IP_VS_CONN_F_TEMPLATE)
775 		pkts = atomic_add_return(1, &cp->in_pkts);
776 	else
777 		pkts = sysctl_sync_threshold(ipvs);
778 	goto sloop;
779 }
780 
781 /*
782  *  fill_param used by version 1
783  */
784 static inline int
785 ip_vs_conn_fill_param_sync(struct netns_ipvs *ipvs, int af, union ip_vs_sync_conn *sc,
786 			   struct ip_vs_conn_param *p,
787 			   __u8 *pe_data, unsigned int pe_data_len,
788 			   __u8 *pe_name, unsigned int pe_name_len)
789 {
790 #ifdef CONFIG_IP_VS_IPV6
791 	if (af == AF_INET6)
792 		ip_vs_conn_fill_param(ipvs, af, sc->v6.protocol,
793 				      (const union nf_inet_addr *)&sc->v6.caddr,
794 				      sc->v6.cport,
795 				      (const union nf_inet_addr *)&sc->v6.vaddr,
796 				      sc->v6.vport, p);
797 	else
798 #endif
799 		ip_vs_conn_fill_param(ipvs, af, sc->v4.protocol,
800 				      (const union nf_inet_addr *)&sc->v4.caddr,
801 				      sc->v4.cport,
802 				      (const union nf_inet_addr *)&sc->v4.vaddr,
803 				      sc->v4.vport, p);
804 	/* Handle pe data */
805 	if (pe_data_len) {
806 		if (pe_name_len) {
807 			char buff[IP_VS_PENAME_MAXLEN+1];
808 
809 			memcpy(buff, pe_name, pe_name_len);
810 			buff[pe_name_len]=0;
811 			p->pe = __ip_vs_pe_getbyname(buff);
812 			if (!p->pe) {
813 				IP_VS_DBG(3, "BACKUP, no %s engine found/loaded\n",
814 					     buff);
815 				return 1;
816 			}
817 		} else {
818 			IP_VS_ERR_RL("BACKUP, Invalid PE parameters\n");
819 			return 1;
820 		}
821 
822 		p->pe_data = kmemdup(pe_data, pe_data_len, GFP_ATOMIC);
823 		if (!p->pe_data) {
824 			module_put(p->pe->module);
825 			return -ENOMEM;
826 		}
827 		p->pe_data_len = pe_data_len;
828 	}
829 	return 0;
830 }
831 
832 /*
833  *  Connection Add / Update.
834  *  Common for version 0 and 1 reception of backup sync_conns.
835  *  Param: ...
836  *         timeout is in sec.
837  */
838 static void ip_vs_proc_conn(struct netns_ipvs *ipvs, struct ip_vs_conn_param *param,
839 			    unsigned int flags, unsigned int state,
840 			    unsigned int protocol, unsigned int type,
841 			    const union nf_inet_addr *daddr, __be16 dport,
842 			    unsigned long timeout, __u32 fwmark,
843 			    struct ip_vs_sync_conn_options *opt)
844 {
845 	struct ip_vs_dest *dest;
846 	struct ip_vs_conn *cp;
847 
848 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
849 		cp = ip_vs_conn_in_get(param);
850 		if (cp && ((cp->dport != dport) ||
851 			   !ip_vs_addr_equal(cp->daf, &cp->daddr, daddr))) {
852 			if (!(flags & IP_VS_CONN_F_INACTIVE)) {
853 				ip_vs_conn_expire_now(cp);
854 				__ip_vs_conn_put(cp);
855 				cp = NULL;
856 			} else {
857 				/* This is the expiration message for the
858 				 * connection that was already replaced, so we
859 				 * just ignore it.
860 				 */
861 				__ip_vs_conn_put(cp);
862 				kfree(param->pe_data);
863 				return;
864 			}
865 		}
866 	} else {
867 		cp = ip_vs_ct_in_get(param);
868 	}
869 
870 	if (cp) {
871 		/* Free pe_data */
872 		kfree(param->pe_data);
873 
874 		dest = cp->dest;
875 		spin_lock_bh(&cp->lock);
876 		if ((cp->flags ^ flags) & IP_VS_CONN_F_INACTIVE &&
877 		    !(flags & IP_VS_CONN_F_TEMPLATE) && dest) {
878 			if (flags & IP_VS_CONN_F_INACTIVE) {
879 				atomic_dec(&dest->activeconns);
880 				atomic_inc(&dest->inactconns);
881 			} else {
882 				atomic_inc(&dest->activeconns);
883 				atomic_dec(&dest->inactconns);
884 			}
885 		}
886 		flags &= IP_VS_CONN_F_BACKUP_UPD_MASK;
887 		flags |= cp->flags & ~IP_VS_CONN_F_BACKUP_UPD_MASK;
888 		cp->flags = flags;
889 		spin_unlock_bh(&cp->lock);
890 		if (!dest)
891 			ip_vs_try_bind_dest(cp);
892 	} else {
893 		/*
894 		 * Find the appropriate destination for the connection.
895 		 * If it is not found the connection will remain unbound
896 		 * but still handled.
897 		 */
898 		rcu_read_lock();
899 		/* This function is only invoked by the synchronization
900 		 * code. We do not currently support heterogeneous pools
901 		 * with synchronization, so we can make the assumption that
902 		 * the svc_af is the same as the dest_af
903 		 */
904 		dest = ip_vs_find_dest(ipvs, type, type, daddr, dport,
905 				       param->vaddr, param->vport, protocol,
906 				       fwmark, flags);
907 
908 		cp = ip_vs_conn_new(param, type, daddr, dport, flags, dest,
909 				    fwmark);
910 		rcu_read_unlock();
911 		if (!cp) {
912 			kfree(param->pe_data);
913 			IP_VS_DBG(2, "BACKUP, add new conn. failed\n");
914 			return;
915 		}
916 		if (!(flags & IP_VS_CONN_F_TEMPLATE))
917 			kfree(param->pe_data);
918 	}
919 
920 	if (opt)
921 		memcpy(&cp->in_seq, opt, sizeof(*opt));
922 	atomic_set(&cp->in_pkts, sysctl_sync_threshold(ipvs));
923 	cp->state = state;
924 	cp->old_state = cp->state;
925 	/*
926 	 * For Ver 0 messages style
927 	 *  - Not possible to recover the right timeout for templates
928 	 *  - can not find the right fwmark
929 	 *    virtual service. If needed, we can do it for
930 	 *    non-fwmark persistent services.
931 	 * Ver 1 messages style.
932 	 *  - No problem.
933 	 */
934 	if (timeout) {
935 		if (timeout > MAX_SCHEDULE_TIMEOUT / HZ)
936 			timeout = MAX_SCHEDULE_TIMEOUT / HZ;
937 		cp->timeout = timeout*HZ;
938 	} else {
939 		struct ip_vs_proto_data *pd;
940 
941 		pd = ip_vs_proto_data_get(ipvs, protocol);
942 		if (!(flags & IP_VS_CONN_F_TEMPLATE) && pd && pd->timeout_table)
943 			cp->timeout = pd->timeout_table[state];
944 		else
945 			cp->timeout = (3*60*HZ);
946 	}
947 	ip_vs_conn_put(cp);
948 }
949 
950 /*
951  *  Process received multicast message for Version 0
952  */
953 static void ip_vs_process_message_v0(struct netns_ipvs *ipvs, const char *buffer,
954 				     const size_t buflen)
955 {
956 	struct ip_vs_sync_mesg_v0 *m = (struct ip_vs_sync_mesg_v0 *)buffer;
957 	struct ip_vs_sync_conn_v0 *s;
958 	struct ip_vs_sync_conn_options *opt;
959 	struct ip_vs_protocol *pp;
960 	struct ip_vs_conn_param param;
961 	char *p;
962 	int i;
963 
964 	p = (char *)buffer + sizeof(struct ip_vs_sync_mesg_v0);
965 	for (i=0; i<m->nr_conns; i++) {
966 		unsigned int flags, state;
967 
968 		if (p + SIMPLE_CONN_SIZE > buffer+buflen) {
969 			IP_VS_ERR_RL("BACKUP v0, bogus conn\n");
970 			return;
971 		}
972 		s = (struct ip_vs_sync_conn_v0 *) p;
973 		flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
974 		flags &= ~IP_VS_CONN_F_HASHED;
975 		if (flags & IP_VS_CONN_F_SEQ_MASK) {
976 			opt = (struct ip_vs_sync_conn_options *)&s[1];
977 			p += FULL_CONN_SIZE;
978 			if (p > buffer+buflen) {
979 				IP_VS_ERR_RL("BACKUP v0, Dropping buffer bogus conn options\n");
980 				return;
981 			}
982 		} else {
983 			opt = NULL;
984 			p += SIMPLE_CONN_SIZE;
985 		}
986 
987 		state = ntohs(s->state);
988 		if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
989 			pp = ip_vs_proto_get(s->protocol);
990 			if (!pp) {
991 				IP_VS_DBG(2, "BACKUP v0, Unsupported protocol %u\n",
992 					s->protocol);
993 				continue;
994 			}
995 			if (state >= pp->num_states) {
996 				IP_VS_DBG(2, "BACKUP v0, Invalid %s state %u\n",
997 					pp->name, state);
998 				continue;
999 			}
1000 		} else {
1001 			/* protocol in templates is not used for state/timeout */
1002 			if (state > 0) {
1003 				IP_VS_DBG(2, "BACKUP v0, Invalid template state %u\n",
1004 					state);
1005 				state = 0;
1006 			}
1007 		}
1008 
1009 		ip_vs_conn_fill_param(ipvs, AF_INET, s->protocol,
1010 				      (const union nf_inet_addr *)&s->caddr,
1011 				      s->cport,
1012 				      (const union nf_inet_addr *)&s->vaddr,
1013 				      s->vport, &param);
1014 
1015 		/* Send timeout as Zero */
1016 		ip_vs_proc_conn(ipvs, &param, flags, state, s->protocol, AF_INET,
1017 				(union nf_inet_addr *)&s->daddr, s->dport,
1018 				0, 0, opt);
1019 	}
1020 }
1021 
1022 /*
1023  * Handle options
1024  */
1025 static inline int ip_vs_proc_seqopt(__u8 *p, unsigned int plen,
1026 				    __u32 *opt_flags,
1027 				    struct ip_vs_sync_conn_options *opt)
1028 {
1029 	struct ip_vs_sync_conn_options *topt;
1030 
1031 	topt = (struct ip_vs_sync_conn_options *)p;
1032 
1033 	if (plen != sizeof(struct ip_vs_sync_conn_options)) {
1034 		IP_VS_DBG(2, "BACKUP, bogus conn options length\n");
1035 		return -EINVAL;
1036 	}
1037 	if (*opt_flags & IPVS_OPT_F_SEQ_DATA) {
1038 		IP_VS_DBG(2, "BACKUP, conn options found twice\n");
1039 		return -EINVAL;
1040 	}
1041 	ntoh_seq(&topt->in_seq, &opt->in_seq);
1042 	ntoh_seq(&topt->out_seq, &opt->out_seq);
1043 	*opt_flags |= IPVS_OPT_F_SEQ_DATA;
1044 	return 0;
1045 }
1046 
1047 static int ip_vs_proc_str(__u8 *p, unsigned int plen, unsigned int *data_len,
1048 			  __u8 **data, unsigned int maxlen,
1049 			  __u32 *opt_flags, __u32 flag)
1050 {
1051 	if (plen > maxlen) {
1052 		IP_VS_DBG(2, "BACKUP, bogus par.data len > %d\n", maxlen);
1053 		return -EINVAL;
1054 	}
1055 	if (*opt_flags & flag) {
1056 		IP_VS_DBG(2, "BACKUP, Par.data found twice 0x%x\n", flag);
1057 		return -EINVAL;
1058 	}
1059 	*data_len = plen;
1060 	*data = p;
1061 	*opt_flags |= flag;
1062 	return 0;
1063 }
1064 /*
1065  *   Process a Version 1 sync. connection
1066  */
1067 static inline int ip_vs_proc_sync_conn(struct netns_ipvs *ipvs, __u8 *p, __u8 *msg_end)
1068 {
1069 	struct ip_vs_sync_conn_options opt;
1070 	union  ip_vs_sync_conn *s;
1071 	struct ip_vs_protocol *pp;
1072 	struct ip_vs_conn_param param;
1073 	__u32 flags;
1074 	unsigned int af, state, pe_data_len=0, pe_name_len=0;
1075 	__u8 *pe_data=NULL, *pe_name=NULL;
1076 	__u32 opt_flags=0;
1077 	int retc=0;
1078 
1079 	s = (union ip_vs_sync_conn *) p;
1080 
1081 	if (s->v6.type & STYPE_F_INET6) {
1082 #ifdef CONFIG_IP_VS_IPV6
1083 		af = AF_INET6;
1084 		p += sizeof(struct ip_vs_sync_v6);
1085 #else
1086 		IP_VS_DBG(3,"BACKUP, IPv6 msg received, and IPVS is not compiled for IPv6\n");
1087 		retc = 10;
1088 		goto out;
1089 #endif
1090 	} else if (!s->v4.type) {
1091 		af = AF_INET;
1092 		p += sizeof(struct ip_vs_sync_v4);
1093 	} else {
1094 		return -10;
1095 	}
1096 	if (p > msg_end)
1097 		return -20;
1098 
1099 	/* Process optional params check Type & Len. */
1100 	while (p < msg_end) {
1101 		int ptype;
1102 		int plen;
1103 
1104 		if (p+2 > msg_end)
1105 			return -30;
1106 		ptype = *(p++);
1107 		plen  = *(p++);
1108 
1109 		if (!plen || ((p + plen) > msg_end))
1110 			return -40;
1111 		/* Handle seq option  p = param data */
1112 		switch (ptype & ~IPVS_OPT_F_PARAM) {
1113 		case IPVS_OPT_SEQ_DATA:
1114 			if (ip_vs_proc_seqopt(p, plen, &opt_flags, &opt))
1115 				return -50;
1116 			break;
1117 
1118 		case IPVS_OPT_PE_DATA:
1119 			if (ip_vs_proc_str(p, plen, &pe_data_len, &pe_data,
1120 					   IP_VS_PEDATA_MAXLEN, &opt_flags,
1121 					   IPVS_OPT_F_PE_DATA))
1122 				return -60;
1123 			break;
1124 
1125 		case IPVS_OPT_PE_NAME:
1126 			if (ip_vs_proc_str(p, plen,&pe_name_len, &pe_name,
1127 					   IP_VS_PENAME_MAXLEN, &opt_flags,
1128 					   IPVS_OPT_F_PE_NAME))
1129 				return -70;
1130 			break;
1131 
1132 		default:
1133 			/* Param data mandatory ? */
1134 			if (!(ptype & IPVS_OPT_F_PARAM)) {
1135 				IP_VS_DBG(3, "BACKUP, Unknown mandatory param %d found\n",
1136 					  ptype & ~IPVS_OPT_F_PARAM);
1137 				retc = 20;
1138 				goto out;
1139 			}
1140 		}
1141 		p += plen;  /* Next option */
1142 	}
1143 
1144 	/* Get flags and Mask off unsupported */
1145 	flags  = ntohl(s->v4.flags) & IP_VS_CONN_F_BACKUP_MASK;
1146 	flags |= IP_VS_CONN_F_SYNC;
1147 	state = ntohs(s->v4.state);
1148 
1149 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
1150 		pp = ip_vs_proto_get(s->v4.protocol);
1151 		if (!pp) {
1152 			IP_VS_DBG(3,"BACKUP, Unsupported protocol %u\n",
1153 				s->v4.protocol);
1154 			retc = 30;
1155 			goto out;
1156 		}
1157 		if (state >= pp->num_states) {
1158 			IP_VS_DBG(3, "BACKUP, Invalid %s state %u\n",
1159 				pp->name, state);
1160 			retc = 40;
1161 			goto out;
1162 		}
1163 	} else {
1164 		/* protocol in templates is not used for state/timeout */
1165 		if (state > 0) {
1166 			IP_VS_DBG(3, "BACKUP, Invalid template state %u\n",
1167 				state);
1168 			state = 0;
1169 		}
1170 	}
1171 	if (ip_vs_conn_fill_param_sync(ipvs, af, s, &param, pe_data,
1172 				       pe_data_len, pe_name, pe_name_len)) {
1173 		retc = 50;
1174 		goto out;
1175 	}
1176 	/* If only IPv4, just silent skip IPv6 */
1177 	if (af == AF_INET)
1178 		ip_vs_proc_conn(ipvs, &param, flags, state, s->v4.protocol, af,
1179 				(union nf_inet_addr *)&s->v4.daddr, s->v4.dport,
1180 				ntohl(s->v4.timeout), ntohl(s->v4.fwmark),
1181 				(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
1182 				);
1183 #ifdef CONFIG_IP_VS_IPV6
1184 	else
1185 		ip_vs_proc_conn(ipvs, &param, flags, state, s->v6.protocol, af,
1186 				(union nf_inet_addr *)&s->v6.daddr, s->v6.dport,
1187 				ntohl(s->v6.timeout), ntohl(s->v6.fwmark),
1188 				(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
1189 				);
1190 #endif
1191 	ip_vs_pe_put(param.pe);
1192 	return 0;
1193 	/* Error exit */
1194 out:
1195 	IP_VS_DBG(2, "BACKUP, Single msg dropped err:%d\n", retc);
1196 	return retc;
1197 
1198 }
1199 /*
1200  *      Process received multicast message and create the corresponding
1201  *      ip_vs_conn entries.
1202  *      Handles Version 0 & 1
1203  */
1204 static void ip_vs_process_message(struct netns_ipvs *ipvs, __u8 *buffer,
1205 				  const size_t buflen)
1206 {
1207 	struct ip_vs_sync_mesg *m2 = (struct ip_vs_sync_mesg *)buffer;
1208 	__u8 *p, *msg_end;
1209 	int i, nr_conns;
1210 
1211 	if (buflen < sizeof(struct ip_vs_sync_mesg_v0)) {
1212 		IP_VS_DBG(2, "BACKUP, message header too short\n");
1213 		return;
1214 	}
1215 
1216 	if (buflen != ntohs(m2->size)) {
1217 		IP_VS_DBG(2, "BACKUP, bogus message size\n");
1218 		return;
1219 	}
1220 	/* SyncID sanity check */
1221 	if (ipvs->bcfg.syncid != 0 && m2->syncid != ipvs->bcfg.syncid) {
1222 		IP_VS_DBG(7, "BACKUP, Ignoring syncid = %d\n", m2->syncid);
1223 		return;
1224 	}
1225 	/* Handle version 1  message */
1226 	if ((m2->version == SYNC_PROTO_VER) && (m2->reserved == 0)
1227 	    && (m2->spare == 0)) {
1228 
1229 		msg_end = buffer + sizeof(struct ip_vs_sync_mesg);
1230 		nr_conns = m2->nr_conns;
1231 
1232 		for (i=0; i<nr_conns; i++) {
1233 			union ip_vs_sync_conn *s;
1234 			unsigned int size;
1235 			int retc;
1236 
1237 			p = msg_end;
1238 			if (p + sizeof(s->v4) > buffer+buflen) {
1239 				IP_VS_ERR_RL("BACKUP, Dropping buffer, to small\n");
1240 				return;
1241 			}
1242 			s = (union ip_vs_sync_conn *)p;
1243 			size = ntohs(s->v4.ver_size) & SVER_MASK;
1244 			msg_end = p + size;
1245 			/* Basic sanity checks */
1246 			if (msg_end  > buffer+buflen) {
1247 				IP_VS_ERR_RL("BACKUP, Dropping buffer, msg > buffer\n");
1248 				return;
1249 			}
1250 			if (ntohs(s->v4.ver_size) >> SVER_SHIFT) {
1251 				IP_VS_ERR_RL("BACKUP, Dropping buffer, Unknown version %d\n",
1252 					      ntohs(s->v4.ver_size) >> SVER_SHIFT);
1253 				return;
1254 			}
1255 			/* Process a single sync_conn */
1256 			retc = ip_vs_proc_sync_conn(ipvs, p, msg_end);
1257 			if (retc < 0) {
1258 				IP_VS_ERR_RL("BACKUP, Dropping buffer, Err: %d in decoding\n",
1259 					     retc);
1260 				return;
1261 			}
1262 			/* Make sure we have 32 bit alignment */
1263 			msg_end = p + ((size + 3) & ~3);
1264 		}
1265 	} else {
1266 		/* Old type of message */
1267 		ip_vs_process_message_v0(ipvs, buffer, buflen);
1268 		return;
1269 	}
1270 }
1271 
1272 
1273 /*
1274  *      Setup sndbuf (mode=1) or rcvbuf (mode=0)
1275  */
1276 static void set_sock_size(struct sock *sk, int mode, int val)
1277 {
1278 	/* setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &val, sizeof(val)); */
1279 	/* setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)); */
1280 	lock_sock(sk);
1281 	if (mode) {
1282 		val = clamp_t(int, val, (SOCK_MIN_SNDBUF + 1) / 2,
1283 			      sysctl_wmem_max);
1284 		sk->sk_sndbuf = val * 2;
1285 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1286 	} else {
1287 		val = clamp_t(int, val, (SOCK_MIN_RCVBUF + 1) / 2,
1288 			      sysctl_rmem_max);
1289 		sk->sk_rcvbuf = val * 2;
1290 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1291 	}
1292 	release_sock(sk);
1293 }
1294 
1295 /*
1296  *      Setup loopback of outgoing multicasts on a sending socket
1297  */
1298 static void set_mcast_loop(struct sock *sk, u_char loop)
1299 {
1300 	struct inet_sock *inet = inet_sk(sk);
1301 
1302 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
1303 	lock_sock(sk);
1304 	inet->mc_loop = loop ? 1 : 0;
1305 #ifdef CONFIG_IP_VS_IPV6
1306 	if (sk->sk_family == AF_INET6) {
1307 		struct ipv6_pinfo *np = inet6_sk(sk);
1308 
1309 		/* IPV6_MULTICAST_LOOP */
1310 		np->mc_loop = loop ? 1 : 0;
1311 	}
1312 #endif
1313 	release_sock(sk);
1314 }
1315 
1316 /*
1317  *      Specify TTL for outgoing multicasts on a sending socket
1318  */
1319 static void set_mcast_ttl(struct sock *sk, u_char ttl)
1320 {
1321 	struct inet_sock *inet = inet_sk(sk);
1322 
1323 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
1324 	lock_sock(sk);
1325 	inet->mc_ttl = ttl;
1326 #ifdef CONFIG_IP_VS_IPV6
1327 	if (sk->sk_family == AF_INET6) {
1328 		struct ipv6_pinfo *np = inet6_sk(sk);
1329 
1330 		/* IPV6_MULTICAST_HOPS */
1331 		np->mcast_hops = ttl;
1332 	}
1333 #endif
1334 	release_sock(sk);
1335 }
1336 
1337 /* Control fragmentation of messages */
1338 static void set_mcast_pmtudisc(struct sock *sk, int val)
1339 {
1340 	struct inet_sock *inet = inet_sk(sk);
1341 
1342 	/* setsockopt(sock, SOL_IP, IP_MTU_DISCOVER, &val, sizeof(val)); */
1343 	lock_sock(sk);
1344 	inet->pmtudisc = val;
1345 #ifdef CONFIG_IP_VS_IPV6
1346 	if (sk->sk_family == AF_INET6) {
1347 		struct ipv6_pinfo *np = inet6_sk(sk);
1348 
1349 		/* IPV6_MTU_DISCOVER */
1350 		np->pmtudisc = val;
1351 	}
1352 #endif
1353 	release_sock(sk);
1354 }
1355 
1356 /*
1357  *      Specifiy default interface for outgoing multicasts
1358  */
1359 static int set_mcast_if(struct sock *sk, char *ifname)
1360 {
1361 	struct net_device *dev;
1362 	struct inet_sock *inet = inet_sk(sk);
1363 	struct net *net = sock_net(sk);
1364 
1365 	dev = __dev_get_by_name(net, ifname);
1366 	if (!dev)
1367 		return -ENODEV;
1368 
1369 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1370 		return -EINVAL;
1371 
1372 	lock_sock(sk);
1373 	inet->mc_index = dev->ifindex;
1374 	/*  inet->mc_addr  = 0; */
1375 #ifdef CONFIG_IP_VS_IPV6
1376 	if (sk->sk_family == AF_INET6) {
1377 		struct ipv6_pinfo *np = inet6_sk(sk);
1378 
1379 		/* IPV6_MULTICAST_IF */
1380 		np->mcast_oif = dev->ifindex;
1381 	}
1382 #endif
1383 	release_sock(sk);
1384 
1385 	return 0;
1386 }
1387 
1388 
1389 /*
1390  *      Join a multicast group.
1391  *      the group is specified by a class D multicast address 224.0.0.0/8
1392  *      in the in_addr structure passed in as a parameter.
1393  */
1394 static int
1395 join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname)
1396 {
1397 	struct net *net = sock_net(sk);
1398 	struct ip_mreqn mreq;
1399 	struct net_device *dev;
1400 	int ret;
1401 
1402 	memset(&mreq, 0, sizeof(mreq));
1403 	memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
1404 
1405 	dev = __dev_get_by_name(net, ifname);
1406 	if (!dev)
1407 		return -ENODEV;
1408 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1409 		return -EINVAL;
1410 
1411 	mreq.imr_ifindex = dev->ifindex;
1412 
1413 	lock_sock(sk);
1414 	ret = ip_mc_join_group(sk, &mreq);
1415 	release_sock(sk);
1416 
1417 	return ret;
1418 }
1419 
1420 #ifdef CONFIG_IP_VS_IPV6
1421 static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
1422 			     char *ifname)
1423 {
1424 	struct net *net = sock_net(sk);
1425 	struct net_device *dev;
1426 	int ret;
1427 
1428 	dev = __dev_get_by_name(net, ifname);
1429 	if (!dev)
1430 		return -ENODEV;
1431 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1432 		return -EINVAL;
1433 
1434 	lock_sock(sk);
1435 	ret = ipv6_sock_mc_join(sk, dev->ifindex, addr);
1436 	release_sock(sk);
1437 
1438 	return ret;
1439 }
1440 #endif
1441 
1442 static int bind_mcastif_addr(struct socket *sock, char *ifname)
1443 {
1444 	struct net *net = sock_net(sock->sk);
1445 	struct net_device *dev;
1446 	__be32 addr;
1447 	struct sockaddr_in sin;
1448 
1449 	dev = __dev_get_by_name(net, ifname);
1450 	if (!dev)
1451 		return -ENODEV;
1452 
1453 	addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
1454 	if (!addr)
1455 		pr_err("You probably need to specify IP address on "
1456 		       "multicast interface.\n");
1457 
1458 	IP_VS_DBG(7, "binding socket with (%s) %pI4\n",
1459 		  ifname, &addr);
1460 
1461 	/* Now bind the socket with the address of multicast interface */
1462 	sin.sin_family	     = AF_INET;
1463 	sin.sin_addr.s_addr  = addr;
1464 	sin.sin_port         = 0;
1465 
1466 	return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
1467 }
1468 
1469 static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
1470 			       struct ipvs_sync_daemon_cfg *c, int id)
1471 {
1472 	if (AF_INET6 == c->mcast_af) {
1473 		sa->in6 = (struct sockaddr_in6) {
1474 			.sin6_family = AF_INET6,
1475 			.sin6_port = htons(c->mcast_port + id),
1476 		};
1477 		sa->in6.sin6_addr = c->mcast_group.in6;
1478 		*salen = sizeof(sa->in6);
1479 	} else {
1480 		sa->in = (struct sockaddr_in) {
1481 			.sin_family = AF_INET,
1482 			.sin_port = htons(c->mcast_port + id),
1483 		};
1484 		sa->in.sin_addr = c->mcast_group.in;
1485 		*salen = sizeof(sa->in);
1486 	}
1487 }
1488 
1489 /*
1490  *      Set up sending multicast socket over UDP
1491  */
1492 static struct socket *make_send_sock(struct netns_ipvs *ipvs, int id)
1493 {
1494 	/* multicast addr */
1495 	union ipvs_sockaddr mcast_addr;
1496 	struct socket *sock;
1497 	int result, salen;
1498 
1499 	/* First create a socket */
1500 	result = sock_create_kern(ipvs->net, ipvs->mcfg.mcast_af, SOCK_DGRAM,
1501 				  IPPROTO_UDP, &sock);
1502 	if (result < 0) {
1503 		pr_err("Error during creation of socket; terminating\n");
1504 		return ERR_PTR(result);
1505 	}
1506 	result = set_mcast_if(sock->sk, ipvs->mcfg.mcast_ifn);
1507 	if (result < 0) {
1508 		pr_err("Error setting outbound mcast interface\n");
1509 		goto error;
1510 	}
1511 
1512 	set_mcast_loop(sock->sk, 0);
1513 	set_mcast_ttl(sock->sk, ipvs->mcfg.mcast_ttl);
1514 	/* Allow fragmentation if MTU changes */
1515 	set_mcast_pmtudisc(sock->sk, IP_PMTUDISC_DONT);
1516 	result = sysctl_sync_sock_size(ipvs);
1517 	if (result > 0)
1518 		set_sock_size(sock->sk, 1, result);
1519 
1520 	if (AF_INET == ipvs->mcfg.mcast_af)
1521 		result = bind_mcastif_addr(sock, ipvs->mcfg.mcast_ifn);
1522 	else
1523 		result = 0;
1524 	if (result < 0) {
1525 		pr_err("Error binding address of the mcast interface\n");
1526 		goto error;
1527 	}
1528 
1529 	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->mcfg, id);
1530 	result = sock->ops->connect(sock, (struct sockaddr *) &mcast_addr,
1531 				    salen, 0);
1532 	if (result < 0) {
1533 		pr_err("Error connecting to the multicast addr\n");
1534 		goto error;
1535 	}
1536 
1537 	return sock;
1538 
1539 error:
1540 	sock_release(sock);
1541 	return ERR_PTR(result);
1542 }
1543 
1544 
1545 /*
1546  *      Set up receiving multicast socket over UDP
1547  */
1548 static struct socket *make_receive_sock(struct netns_ipvs *ipvs, int id,
1549 					int ifindex)
1550 {
1551 	/* multicast addr */
1552 	union ipvs_sockaddr mcast_addr;
1553 	struct socket *sock;
1554 	int result, salen;
1555 
1556 	/* First create a socket */
1557 	result = sock_create_kern(ipvs->net, ipvs->bcfg.mcast_af, SOCK_DGRAM,
1558 				  IPPROTO_UDP, &sock);
1559 	if (result < 0) {
1560 		pr_err("Error during creation of socket; terminating\n");
1561 		return ERR_PTR(result);
1562 	}
1563 	/* it is equivalent to the REUSEADDR option in user-space */
1564 	sock->sk->sk_reuse = SK_CAN_REUSE;
1565 	result = sysctl_sync_sock_size(ipvs);
1566 	if (result > 0)
1567 		set_sock_size(sock->sk, 0, result);
1568 
1569 	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
1570 	sock->sk->sk_bound_dev_if = ifindex;
1571 	result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen);
1572 	if (result < 0) {
1573 		pr_err("Error binding to the multicast addr\n");
1574 		goto error;
1575 	}
1576 
1577 	/* join the multicast group */
1578 #ifdef CONFIG_IP_VS_IPV6
1579 	if (ipvs->bcfg.mcast_af == AF_INET6)
1580 		result = join_mcast_group6(sock->sk, &mcast_addr.in6.sin6_addr,
1581 					   ipvs->bcfg.mcast_ifn);
1582 	else
1583 #endif
1584 		result = join_mcast_group(sock->sk, &mcast_addr.in.sin_addr,
1585 					  ipvs->bcfg.mcast_ifn);
1586 	if (result < 0) {
1587 		pr_err("Error joining to the multicast group\n");
1588 		goto error;
1589 	}
1590 
1591 	return sock;
1592 
1593 error:
1594 	sock_release(sock);
1595 	return ERR_PTR(result);
1596 }
1597 
1598 
1599 static int
1600 ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
1601 {
1602 	struct msghdr	msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
1603 	struct kvec	iov;
1604 	int		len;
1605 
1606 	EnterFunction(7);
1607 	iov.iov_base     = (void *)buffer;
1608 	iov.iov_len      = length;
1609 
1610 	len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
1611 
1612 	LeaveFunction(7);
1613 	return len;
1614 }
1615 
1616 static int
1617 ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
1618 {
1619 	int msize;
1620 	int ret;
1621 
1622 	msize = ntohs(msg->size);
1623 
1624 	ret = ip_vs_send_async(sock, (char *)msg, msize);
1625 	if (ret >= 0 || ret == -EAGAIN)
1626 		return ret;
1627 	pr_err("ip_vs_send_async error %d\n", ret);
1628 	return 0;
1629 }
1630 
1631 static int
1632 ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
1633 {
1634 	struct msghdr		msg = {NULL,};
1635 	struct kvec		iov;
1636 	int			len;
1637 
1638 	EnterFunction(7);
1639 
1640 	/* Receive a packet */
1641 	iov.iov_base     = buffer;
1642 	iov.iov_len      = (size_t)buflen;
1643 
1644 	len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, MSG_DONTWAIT);
1645 
1646 	if (len < 0)
1647 		return len;
1648 
1649 	LeaveFunction(7);
1650 	return len;
1651 }
1652 
1653 /* Wakeup the master thread for sending */
1654 static void master_wakeup_work_handler(struct work_struct *work)
1655 {
1656 	struct ipvs_master_sync_state *ms =
1657 		container_of(work, struct ipvs_master_sync_state,
1658 			     master_wakeup_work.work);
1659 	struct netns_ipvs *ipvs = ms->ipvs;
1660 
1661 	spin_lock_bh(&ipvs->sync_lock);
1662 	if (ms->sync_queue_len &&
1663 	    ms->sync_queue_delay < IPVS_SYNC_WAKEUP_RATE) {
1664 		ms->sync_queue_delay = IPVS_SYNC_WAKEUP_RATE;
1665 		wake_up_process(ms->master_thread);
1666 	}
1667 	spin_unlock_bh(&ipvs->sync_lock);
1668 }
1669 
1670 /* Get next buffer to send */
1671 static inline struct ip_vs_sync_buff *
1672 next_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
1673 {
1674 	struct ip_vs_sync_buff *sb;
1675 
1676 	sb = sb_dequeue(ipvs, ms);
1677 	if (sb)
1678 		return sb;
1679 	/* Do not delay entries in buffer for more than 2 seconds */
1680 	return get_curr_sync_buff(ipvs, ms, IPVS_SYNC_FLUSH_TIME);
1681 }
1682 
1683 static int sync_thread_master(void *data)
1684 {
1685 	struct ip_vs_sync_thread_data *tinfo = data;
1686 	struct netns_ipvs *ipvs = tinfo->ipvs;
1687 	struct ipvs_master_sync_state *ms = &ipvs->ms[tinfo->id];
1688 	struct sock *sk = tinfo->sock->sk;
1689 	struct ip_vs_sync_buff *sb;
1690 
1691 	pr_info("sync thread started: state = MASTER, mcast_ifn = %s, "
1692 		"syncid = %d, id = %d\n",
1693 		ipvs->mcfg.mcast_ifn, ipvs->mcfg.syncid, tinfo->id);
1694 
1695 	for (;;) {
1696 		sb = next_sync_buff(ipvs, ms);
1697 		if (unlikely(kthread_should_stop()))
1698 			break;
1699 		if (!sb) {
1700 			schedule_timeout(IPVS_SYNC_CHECK_PERIOD);
1701 			continue;
1702 		}
1703 		while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) {
1704 			/* (Ab)use interruptible sleep to avoid increasing
1705 			 * the load avg.
1706 			 */
1707 			__wait_event_interruptible(*sk_sleep(sk),
1708 						   sock_writeable(sk) ||
1709 						   kthread_should_stop());
1710 			if (unlikely(kthread_should_stop()))
1711 				goto done;
1712 		}
1713 		ip_vs_sync_buff_release(sb);
1714 	}
1715 
1716 done:
1717 	__set_current_state(TASK_RUNNING);
1718 	if (sb)
1719 		ip_vs_sync_buff_release(sb);
1720 
1721 	/* clean up the sync_buff queue */
1722 	while ((sb = sb_dequeue(ipvs, ms)))
1723 		ip_vs_sync_buff_release(sb);
1724 	__set_current_state(TASK_RUNNING);
1725 
1726 	/* clean up the current sync_buff */
1727 	sb = get_curr_sync_buff(ipvs, ms, 0);
1728 	if (sb)
1729 		ip_vs_sync_buff_release(sb);
1730 
1731 	/* release the sending multicast socket */
1732 	sock_release(tinfo->sock);
1733 	kfree(tinfo);
1734 
1735 	return 0;
1736 }
1737 
1738 
1739 static int sync_thread_backup(void *data)
1740 {
1741 	struct ip_vs_sync_thread_data *tinfo = data;
1742 	struct netns_ipvs *ipvs = tinfo->ipvs;
1743 	int len;
1744 
1745 	pr_info("sync thread started: state = BACKUP, mcast_ifn = %s, "
1746 		"syncid = %d, id = %d\n",
1747 		ipvs->bcfg.mcast_ifn, ipvs->bcfg.syncid, tinfo->id);
1748 
1749 	while (!kthread_should_stop()) {
1750 		wait_event_interruptible(*sk_sleep(tinfo->sock->sk),
1751 			 !skb_queue_empty(&tinfo->sock->sk->sk_receive_queue)
1752 			 || kthread_should_stop());
1753 
1754 		/* do we have data now? */
1755 		while (!skb_queue_empty(&(tinfo->sock->sk->sk_receive_queue))) {
1756 			len = ip_vs_receive(tinfo->sock, tinfo->buf,
1757 					ipvs->bcfg.sync_maxlen);
1758 			if (len <= 0) {
1759 				if (len != -EAGAIN)
1760 					pr_err("receiving message error\n");
1761 				break;
1762 			}
1763 
1764 			ip_vs_process_message(ipvs, tinfo->buf, len);
1765 		}
1766 	}
1767 
1768 	/* release the sending multicast socket */
1769 	sock_release(tinfo->sock);
1770 	kfree(tinfo->buf);
1771 	kfree(tinfo);
1772 
1773 	return 0;
1774 }
1775 
1776 
1777 int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
1778 		      int state)
1779 {
1780 	struct ip_vs_sync_thread_data *tinfo;
1781 	struct task_struct **array = NULL, *task;
1782 	struct socket *sock;
1783 	struct net_device *dev;
1784 	char *name;
1785 	int (*threadfn)(void *data);
1786 	int id, count, hlen;
1787 	int result = -ENOMEM;
1788 	u16 mtu, min_mtu;
1789 
1790 	IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
1791 	IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %Zd bytes\n",
1792 		  sizeof(struct ip_vs_sync_conn_v0));
1793 
1794 	if (!ipvs->sync_state) {
1795 		count = clamp(sysctl_sync_ports(ipvs), 1, IPVS_SYNC_PORTS_MAX);
1796 		ipvs->threads_mask = count - 1;
1797 	} else
1798 		count = ipvs->threads_mask + 1;
1799 
1800 	if (c->mcast_af == AF_UNSPEC) {
1801 		c->mcast_af = AF_INET;
1802 		c->mcast_group.ip = cpu_to_be32(IP_VS_SYNC_GROUP);
1803 	}
1804 	if (!c->mcast_port)
1805 		c->mcast_port = IP_VS_SYNC_PORT;
1806 	if (!c->mcast_ttl)
1807 		c->mcast_ttl = 1;
1808 
1809 	dev = __dev_get_by_name(ipvs->net, c->mcast_ifn);
1810 	if (!dev) {
1811 		pr_err("Unknown mcast interface: %s\n", c->mcast_ifn);
1812 		return -ENODEV;
1813 	}
1814 	hlen = (AF_INET6 == c->mcast_af) ?
1815 	       sizeof(struct ipv6hdr) + sizeof(struct udphdr) :
1816 	       sizeof(struct iphdr) + sizeof(struct udphdr);
1817 	mtu = (state == IP_VS_STATE_BACKUP) ?
1818 		  clamp(dev->mtu, 1500U, 65535U) : 1500U;
1819 	min_mtu = (state == IP_VS_STATE_BACKUP) ? 1024 : 1;
1820 
1821 	if (c->sync_maxlen)
1822 		c->sync_maxlen = clamp_t(unsigned int,
1823 					 c->sync_maxlen, min_mtu,
1824 					 65535 - hlen);
1825 	else
1826 		c->sync_maxlen = mtu - hlen;
1827 
1828 	if (state == IP_VS_STATE_MASTER) {
1829 		if (ipvs->ms)
1830 			return -EEXIST;
1831 
1832 		ipvs->mcfg = *c;
1833 		name = "ipvs-m:%d:%d";
1834 		threadfn = sync_thread_master;
1835 	} else if (state == IP_VS_STATE_BACKUP) {
1836 		if (ipvs->backup_threads)
1837 			return -EEXIST;
1838 
1839 		ipvs->bcfg = *c;
1840 		name = "ipvs-b:%d:%d";
1841 		threadfn = sync_thread_backup;
1842 	} else {
1843 		return -EINVAL;
1844 	}
1845 
1846 	if (state == IP_VS_STATE_MASTER) {
1847 		struct ipvs_master_sync_state *ms;
1848 
1849 		ipvs->ms = kzalloc(count * sizeof(ipvs->ms[0]), GFP_KERNEL);
1850 		if (!ipvs->ms)
1851 			goto out;
1852 		ms = ipvs->ms;
1853 		for (id = 0; id < count; id++, ms++) {
1854 			INIT_LIST_HEAD(&ms->sync_queue);
1855 			ms->sync_queue_len = 0;
1856 			ms->sync_queue_delay = 0;
1857 			INIT_DELAYED_WORK(&ms->master_wakeup_work,
1858 					  master_wakeup_work_handler);
1859 			ms->ipvs = ipvs;
1860 		}
1861 	} else {
1862 		array = kzalloc(count * sizeof(struct task_struct *),
1863 				GFP_KERNEL);
1864 		if (!array)
1865 			goto out;
1866 	}
1867 
1868 	tinfo = NULL;
1869 	for (id = 0; id < count; id++) {
1870 		if (state == IP_VS_STATE_MASTER)
1871 			sock = make_send_sock(ipvs, id);
1872 		else
1873 			sock = make_receive_sock(ipvs, id, dev->ifindex);
1874 		if (IS_ERR(sock)) {
1875 			result = PTR_ERR(sock);
1876 			goto outtinfo;
1877 		}
1878 		tinfo = kmalloc(sizeof(*tinfo), GFP_KERNEL);
1879 		if (!tinfo)
1880 			goto outsocket;
1881 		tinfo->ipvs = ipvs;
1882 		tinfo->sock = sock;
1883 		if (state == IP_VS_STATE_BACKUP) {
1884 			tinfo->buf = kmalloc(ipvs->bcfg.sync_maxlen,
1885 					     GFP_KERNEL);
1886 			if (!tinfo->buf)
1887 				goto outtinfo;
1888 		} else {
1889 			tinfo->buf = NULL;
1890 		}
1891 		tinfo->id = id;
1892 
1893 		task = kthread_run(threadfn, tinfo, name, ipvs->gen, id);
1894 		if (IS_ERR(task)) {
1895 			result = PTR_ERR(task);
1896 			goto outtinfo;
1897 		}
1898 		tinfo = NULL;
1899 		if (state == IP_VS_STATE_MASTER)
1900 			ipvs->ms[id].master_thread = task;
1901 		else
1902 			array[id] = task;
1903 	}
1904 
1905 	/* mark as active */
1906 
1907 	if (state == IP_VS_STATE_BACKUP)
1908 		ipvs->backup_threads = array;
1909 	spin_lock_bh(&ipvs->sync_buff_lock);
1910 	ipvs->sync_state |= state;
1911 	spin_unlock_bh(&ipvs->sync_buff_lock);
1912 
1913 	/* increase the module use count */
1914 	ip_vs_use_count_inc();
1915 
1916 	return 0;
1917 
1918 outsocket:
1919 	sock_release(sock);
1920 
1921 outtinfo:
1922 	if (tinfo) {
1923 		sock_release(tinfo->sock);
1924 		kfree(tinfo->buf);
1925 		kfree(tinfo);
1926 	}
1927 	count = id;
1928 	while (count-- > 0) {
1929 		if (state == IP_VS_STATE_MASTER)
1930 			kthread_stop(ipvs->ms[count].master_thread);
1931 		else
1932 			kthread_stop(array[count]);
1933 	}
1934 	kfree(array);
1935 
1936 out:
1937 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
1938 		kfree(ipvs->ms);
1939 		ipvs->ms = NULL;
1940 	}
1941 	return result;
1942 }
1943 
1944 
1945 int stop_sync_thread(struct netns_ipvs *ipvs, int state)
1946 {
1947 	struct task_struct **array;
1948 	int id;
1949 	int retc = -EINVAL;
1950 
1951 	IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
1952 
1953 	if (state == IP_VS_STATE_MASTER) {
1954 		if (!ipvs->ms)
1955 			return -ESRCH;
1956 
1957 		/*
1958 		 * The lock synchronizes with sb_queue_tail(), so that we don't
1959 		 * add sync buffers to the queue, when we are already in
1960 		 * progress of stopping the master sync daemon.
1961 		 */
1962 
1963 		spin_lock_bh(&ipvs->sync_buff_lock);
1964 		spin_lock(&ipvs->sync_lock);
1965 		ipvs->sync_state &= ~IP_VS_STATE_MASTER;
1966 		spin_unlock(&ipvs->sync_lock);
1967 		spin_unlock_bh(&ipvs->sync_buff_lock);
1968 
1969 		retc = 0;
1970 		for (id = ipvs->threads_mask; id >= 0; id--) {
1971 			struct ipvs_master_sync_state *ms = &ipvs->ms[id];
1972 			int ret;
1973 
1974 			pr_info("stopping master sync thread %d ...\n",
1975 				task_pid_nr(ms->master_thread));
1976 			cancel_delayed_work_sync(&ms->master_wakeup_work);
1977 			ret = kthread_stop(ms->master_thread);
1978 			if (retc >= 0)
1979 				retc = ret;
1980 		}
1981 		kfree(ipvs->ms);
1982 		ipvs->ms = NULL;
1983 	} else if (state == IP_VS_STATE_BACKUP) {
1984 		if (!ipvs->backup_threads)
1985 			return -ESRCH;
1986 
1987 		ipvs->sync_state &= ~IP_VS_STATE_BACKUP;
1988 		array = ipvs->backup_threads;
1989 		retc = 0;
1990 		for (id = ipvs->threads_mask; id >= 0; id--) {
1991 			int ret;
1992 
1993 			pr_info("stopping backup sync thread %d ...\n",
1994 				task_pid_nr(array[id]));
1995 			ret = kthread_stop(array[id]);
1996 			if (retc >= 0)
1997 				retc = ret;
1998 		}
1999 		kfree(array);
2000 		ipvs->backup_threads = NULL;
2001 	}
2002 
2003 	/* decrease the module use count */
2004 	ip_vs_use_count_dec();
2005 
2006 	return retc;
2007 }
2008 
2009 /*
2010  * Initialize data struct for each netns
2011  */
2012 int __net_init ip_vs_sync_net_init(struct netns_ipvs *ipvs)
2013 {
2014 	__mutex_init(&ipvs->sync_mutex, "ipvs->sync_mutex", &__ipvs_sync_key);
2015 	spin_lock_init(&ipvs->sync_lock);
2016 	spin_lock_init(&ipvs->sync_buff_lock);
2017 	return 0;
2018 }
2019 
2020 void ip_vs_sync_net_cleanup(struct netns_ipvs *ipvs)
2021 {
2022 	int retc;
2023 
2024 	mutex_lock(&ipvs->sync_mutex);
2025 	retc = stop_sync_thread(ipvs, IP_VS_STATE_MASTER);
2026 	if (retc && retc != -ESRCH)
2027 		pr_err("Failed to stop Master Daemon\n");
2028 
2029 	retc = stop_sync_thread(ipvs, IP_VS_STATE_BACKUP);
2030 	if (retc && retc != -ESRCH)
2031 		pr_err("Failed to stop Backup Daemon\n");
2032 	mutex_unlock(&ipvs->sync_mutex);
2033 }
2034