xref: /linux/net/netfilter/ipvs/ip_vs_sync.c (revision 84318277d6334c6981ab326d4acc87c6a6ddc9b8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IPVS         An implementation of the IP virtual server support for the
4  *              LINUX operating system.  IPVS is now implemented as a module
5  *              over the NetFilter framework. IPVS can be used to build a
6  *              high-performance and highly available server based on a
7  *              cluster of servers.
8  *
9  * Version 1,   is capable of handling both version 0 and 1 messages.
10  *              Version 0 is the plain old format.
11  *              Note Version 0 receivers will just drop Ver 1 messages.
12  *              Version 1 is capable of handle IPv6, Persistence data,
13  *              time-outs, and firewall marks.
14  *              In ver.1 "ip_vs_sync_conn_options" will be sent in netw. order.
15  *              Ver. 0 can be turned on by sysctl -w net.ipv4.vs.sync_version=0
16  *
17  * Definitions  Message: is a complete datagram
18  *              Sync_conn: is a part of a Message
19  *              Param Data is an option to a Sync_conn.
20  *
21  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
22  *
23  * ip_vs_sync:  sync connection info from master load balancer to backups
24  *              through multicast
25  *
26  * Changes:
27  *	Alexandre Cassen	:	Added master & backup support at a time.
28  *	Alexandre Cassen	:	Added SyncID support for incoming sync
29  *					messages filtering.
30  *	Justin Ossevoort	:	Fix endian problem on sync message size.
31  *	Hans Schillstrom	:	Added Version 1: i.e. IPv6,
32  *					Persistence support, fwmark and time-out.
33  */
34 
35 #define pr_fmt(fmt) "IPVS: " 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 #include <linux/sched/signal.h>
52 
53 #include <linux/unaligned.h>		/* Used for ntoh_seq and hton_seq */
54 
55 #include <net/ip.h>
56 #include <net/sock.h>
57 
58 #include <net/ip_vs.h>
59 
60 #define IP_VS_SYNC_GROUP 0xe0000051    /* multicast addr - 224.0.0.81 */
61 #define IP_VS_SYNC_PORT  8848          /* multicast port */
62 
63 #define SYNC_PROTO_VER  1		/* Protocol version in header */
64 
65 static struct lock_class_key __ipvs_sync_key;
66 /*
67  *	IPVS sync connection entry
68  *	Version 0, i.e. original version.
69  */
70 struct ip_vs_sync_conn_v0 {
71 	__u8			reserved;
72 
73 	/* Protocol, addresses and port numbers */
74 	__u8			protocol;       /* Which protocol (TCP/UDP) */
75 	__be16			cport;
76 	__be16                  vport;
77 	__be16                  dport;
78 	__be32                  caddr;          /* client address */
79 	__be32                  vaddr;          /* virtual address */
80 	__be32                  daddr;          /* destination address */
81 
82 	/* Flags and state transition */
83 	__be16                  flags;          /* status flags */
84 	__be16                  state;          /* state info */
85 
86 	/* The sequence options start here */
87 };
88 
89 struct ip_vs_sync_conn_options {
90 	struct ip_vs_seq        in_seq;         /* incoming seq. struct */
91 	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */
92 };
93 
94 /*
95      Sync Connection format (sync_conn)
96 
97        0                   1                   2                   3
98        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
99       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
100       |    Type       |    Protocol   | Ver.  |        Size           |
101       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
102       |                             Flags                             |
103       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
104       |            State              |         cport                 |
105       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
106       |            vport              |         dport                 |
107       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
108       |                             fwmark                            |
109       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
110       |                             timeout  (in sec.)                |
111       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
112       |                              ...                              |
113       |                        IP-Addresses  (v4 or v6)               |
114       |                              ...                              |
115       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
116   Optional Parameters.
117       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
118       | Param. Type    | Param. Length |   Param. data                |
119       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
120       |                              ...                              |
121       |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
122       |                               | Param Type    | Param. Length |
123       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
124       |                           Param  data                         |
125       |         Last Param data should be padded for 32 bit alignment |
126       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
127 */
128 
129 /*
130  *  Type 0, IPv4 sync connection format
131  */
132 struct ip_vs_sync_v4 {
133 	__u8			type;
134 	__u8			protocol;	/* Which protocol (TCP/UDP) */
135 	__be16			ver_size;	/* Version msb 4 bits */
136 	/* Flags and state transition */
137 	__be32			flags;		/* status flags */
138 	__be16			state;		/* state info 	*/
139 	/* Protocol, addresses and port numbers */
140 	__be16			cport;
141 	__be16			vport;
142 	__be16			dport;
143 	__be32			fwmark;		/* Firewall mark from skb */
144 	__be32			timeout;	/* cp timeout */
145 	__be32			caddr;		/* client address */
146 	__be32			vaddr;		/* virtual address */
147 	__be32			daddr;		/* destination address */
148 	/* The sequence options start here */
149 	/* PE data padded to 32bit alignment after seq. options */
150 };
151 /*
152  * Type 2 messages IPv6
153  */
154 struct ip_vs_sync_v6 {
155 	__u8			type;
156 	__u8			protocol;	/* Which protocol (TCP/UDP) */
157 	__be16			ver_size;	/* Version msb 4 bits */
158 	/* Flags and state transition */
159 	__be32			flags;		/* status flags */
160 	__be16			state;		/* state info 	*/
161 	/* Protocol, addresses and port numbers */
162 	__be16			cport;
163 	__be16			vport;
164 	__be16			dport;
165 	__be32			fwmark;		/* Firewall mark from skb */
166 	__be32			timeout;	/* cp timeout */
167 	struct in6_addr		caddr;		/* client address */
168 	struct in6_addr		vaddr;		/* virtual address */
169 	struct in6_addr		daddr;		/* destination address */
170 	/* The sequence options start here */
171 	/* PE data padded to 32bit alignment after seq. options */
172 };
173 
174 union ip_vs_sync_conn {
175 	struct ip_vs_sync_v4	v4;
176 	struct ip_vs_sync_v6	v6;
177 };
178 
179 /* Bits in Type field in above */
180 #define STYPE_INET6		0
181 #define STYPE_F_INET6		(1 << STYPE_INET6)
182 
183 #define SVER_SHIFT		12		/* Shift to get version */
184 #define SVER_MASK		0x0fff		/* Mask to strip version */
185 
186 #define IPVS_OPT_SEQ_DATA	1
187 #define IPVS_OPT_PE_DATA	2
188 #define IPVS_OPT_PE_NAME	3
189 #define IPVS_OPT_PARAM		7
190 
191 #define IPVS_OPT_F_SEQ_DATA	(1 << (IPVS_OPT_SEQ_DATA-1))
192 #define IPVS_OPT_F_PE_DATA	(1 << (IPVS_OPT_PE_DATA-1))
193 #define IPVS_OPT_F_PE_NAME	(1 << (IPVS_OPT_PE_NAME-1))
194 #define IPVS_OPT_F_PARAM	(1 << (IPVS_OPT_PARAM-1))
195 
196 struct ip_vs_sync_thread_data {
197 	struct task_struct *task;
198 	struct netns_ipvs *ipvs;
199 	struct socket *sock;
200 	char *buf;
201 	int id;
202 };
203 
204 /* Version 0 definition of packet sizes */
205 #define SIMPLE_CONN_SIZE  (sizeof(struct ip_vs_sync_conn_v0))
206 #define FULL_CONN_SIZE  \
207 (sizeof(struct ip_vs_sync_conn_v0) + sizeof(struct ip_vs_sync_conn_options))
208 
209 
210 /*
211   The master mulitcasts messages (Datagrams) to the backup load balancers
212   in the following format.
213 
214  Version 1:
215   Note, first byte should be Zero, so ver 0 receivers will drop the packet.
216 
217        0                   1                   2                   3
218        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
219       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
220       |      0        |    SyncID     |            Size               |
221       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
222       |  Count Conns  |    Version    |    Reserved, set to Zero      |
223       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
224       |                                                               |
225       |                    IPVS Sync Connection (1)                   |
226       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
227       |                            .                                  |
228       ~                            .                                  ~
229       |                            .                                  |
230       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
231       |                                                               |
232       |                    IPVS Sync Connection (n)                   |
233       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
234 
235  Version 0 Header
236        0                   1                   2                   3
237        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
238       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
239       |  Count Conns  |    SyncID     |            Size               |
240       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
241       |                    IPVS Sync Connection (1)                   |
242 */
243 
244 /* Version 0 header */
245 struct ip_vs_sync_mesg_v0 {
246 	__u8                    nr_conns;
247 	__u8                    syncid;
248 	__be16                  size;
249 
250 	/* ip_vs_sync_conn entries start here */
251 };
252 
253 /* Version 1 header */
254 struct ip_vs_sync_mesg {
255 	__u8			reserved;	/* must be zero */
256 	__u8			syncid;
257 	__be16			size;
258 	__u8			nr_conns;
259 	__s8			version;	/* SYNC_PROTO_VER  */
260 	__u16			spare;
261 	/* ip_vs_sync_conn entries start here */
262 };
263 
264 union ipvs_sockaddr {
265 	struct sockaddr_in	in;
266 	struct sockaddr_in6	in6;
267 };
268 
269 struct ip_vs_sync_buff {
270 	struct list_head        list;
271 	unsigned long           firstuse;
272 
273 	/* pointers for the message data */
274 	struct ip_vs_sync_mesg  *mesg;
275 	unsigned char           *head;
276 	unsigned char           *end;
277 };
278 
279 /*
280  * Copy of struct ip_vs_seq
281  * From unaligned network order to aligned host order
282  */
283 static void ntoh_seq(struct ip_vs_seq *no, struct ip_vs_seq *ho)
284 {
285 	memset(ho, 0, sizeof(*ho));
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 			int id = (int)(ms - ipvs->ms);
376 
377 			wake_up_process(ipvs->master_tinfo[id].task);
378 		}
379 	} else
380 		ip_vs_sync_buff_release(sb);
381 	spin_unlock(&ipvs->sync_lock);
382 }
383 
384 /*
385  *	Get the current sync buffer if it has been created for more
386  *	than the specified time or the specified time is zero.
387  */
388 static inline struct ip_vs_sync_buff *
389 get_curr_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms,
390 		   unsigned long time)
391 {
392 	struct ip_vs_sync_buff *sb;
393 
394 	spin_lock_bh(&ipvs->sync_buff_lock);
395 	sb = ms->sync_buff;
396 	if (sb && time_after_eq(jiffies - sb->firstuse, time)) {
397 		ms->sync_buff = NULL;
398 		__set_current_state(TASK_RUNNING);
399 	} else
400 		sb = NULL;
401 	spin_unlock_bh(&ipvs->sync_buff_lock);
402 	return sb;
403 }
404 
405 static inline int
406 select_master_thread_id(struct netns_ipvs *ipvs, struct ip_vs_conn *cp)
407 {
408 	return ((long) cp >> (1 + ilog2(sizeof(*cp)))) & ipvs->threads_mask;
409 }
410 
411 /*
412  * Create a new sync buffer for Version 0 proto.
413  */
414 static inline struct ip_vs_sync_buff *
415 ip_vs_sync_buff_create_v0(struct netns_ipvs *ipvs, unsigned int len)
416 {
417 	struct ip_vs_sync_buff *sb;
418 	struct ip_vs_sync_mesg_v0 *mesg;
419 
420 	if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC)))
421 		return NULL;
422 
423 	len = max_t(unsigned int, len + sizeof(struct ip_vs_sync_mesg_v0),
424 		    ipvs->mcfg.sync_maxlen);
425 	sb->mesg = kmalloc(len, GFP_ATOMIC);
426 	if (!sb->mesg) {
427 		kfree(sb);
428 		return NULL;
429 	}
430 	mesg = (struct ip_vs_sync_mesg_v0 *)sb->mesg;
431 	mesg->nr_conns = 0;
432 	mesg->syncid = ipvs->mcfg.syncid;
433 	mesg->size = htons(sizeof(struct ip_vs_sync_mesg_v0));
434 	sb->head = (unsigned char *)mesg + sizeof(struct ip_vs_sync_mesg_v0);
435 	sb->end = (unsigned char *)mesg + len;
436 	sb->firstuse = jiffies;
437 	return sb;
438 }
439 
440 /* Check if connection is controlled by persistence */
441 static inline bool in_persistence(struct ip_vs_conn *cp)
442 {
443 	for (cp = cp->control; cp; cp = cp->control) {
444 		if (cp->flags & IP_VS_CONN_F_TEMPLATE)
445 			return true;
446 	}
447 	return false;
448 }
449 
450 /* Check if conn should be synced.
451  * pkts: conn packets, use sysctl_sync_threshold to avoid packet check
452  * - (1) sync_refresh_period: reduce sync rate. Additionally, retry
453  *	sync_retries times with period of sync_refresh_period/8
454  * - (2) if both sync_refresh_period and sync_period are 0 send sync only
455  *	for state changes or only once when pkts matches sync_threshold
456  * - (3) templates: rate can be reduced only with sync_refresh_period or
457  *	with (2)
458  */
459 static int ip_vs_sync_conn_needed(struct netns_ipvs *ipvs,
460 				  struct ip_vs_conn *cp, int pkts)
461 {
462 	unsigned long orig = READ_ONCE(cp->sync_endtime);
463 	unsigned long now = jiffies;
464 	unsigned long n = (now + cp->timeout) & ~3UL;
465 	unsigned int sync_refresh_period;
466 	int sync_period;
467 	int force;
468 
469 	/* Check if we sync in current state */
470 	if (unlikely(cp->flags & IP_VS_CONN_F_TEMPLATE))
471 		force = 0;
472 	else if (unlikely(sysctl_sync_persist_mode(ipvs) && in_persistence(cp)))
473 		return 0;
474 	else if (likely(cp->protocol == IPPROTO_TCP)) {
475 		if (!((1 << cp->state) &
476 		      ((1 << IP_VS_TCP_S_ESTABLISHED) |
477 		       (1 << IP_VS_TCP_S_FIN_WAIT) |
478 		       (1 << IP_VS_TCP_S_CLOSE) |
479 		       (1 << IP_VS_TCP_S_CLOSE_WAIT) |
480 		       (1 << IP_VS_TCP_S_TIME_WAIT))))
481 			return 0;
482 		force = cp->state != cp->old_state;
483 		if (force && cp->state != IP_VS_TCP_S_ESTABLISHED)
484 			goto set;
485 	} else if (unlikely(cp->protocol == IPPROTO_SCTP)) {
486 		if (!((1 << cp->state) &
487 		      ((1 << IP_VS_SCTP_S_ESTABLISHED) |
488 		       (1 << IP_VS_SCTP_S_SHUTDOWN_SENT) |
489 		       (1 << IP_VS_SCTP_S_SHUTDOWN_RECEIVED) |
490 		       (1 << IP_VS_SCTP_S_SHUTDOWN_ACK_SENT) |
491 		       (1 << IP_VS_SCTP_S_CLOSED))))
492 			return 0;
493 		force = cp->state != cp->old_state;
494 		if (force && cp->state != IP_VS_SCTP_S_ESTABLISHED)
495 			goto set;
496 	} else {
497 		/* UDP or another protocol with single state */
498 		force = 0;
499 	}
500 
501 	sync_refresh_period = sysctl_sync_refresh_period(ipvs);
502 	if (sync_refresh_period > 0) {
503 		long diff = n - orig;
504 		long min_diff = max(cp->timeout >> 1, 10UL * HZ);
505 
506 		/* Avoid sync if difference is below sync_refresh_period
507 		 * and below the half timeout.
508 		 */
509 		if (abs(diff) < min_t(long, sync_refresh_period, min_diff)) {
510 			int retries = orig & 3;
511 
512 			if (retries >= sysctl_sync_retries(ipvs))
513 				return 0;
514 			if (time_before(now, orig - cp->timeout +
515 					(sync_refresh_period >> 3)))
516 				return 0;
517 			n |= retries + 1;
518 		}
519 	}
520 	sync_period = sysctl_sync_period(ipvs);
521 	if (sync_period > 0) {
522 		if (!(cp->flags & IP_VS_CONN_F_TEMPLATE) &&
523 		    pkts % sync_period != sysctl_sync_threshold(ipvs))
524 			return 0;
525 	} else if (!sync_refresh_period &&
526 		   pkts != sysctl_sync_threshold(ipvs))
527 		return 0;
528 
529 set:
530 	cp->old_state = cp->state;
531 	n = cmpxchg(&cp->sync_endtime, orig, n);
532 	return n == orig || force;
533 }
534 
535 /*
536  *      Version 0 , could be switched in by sys_ctl.
537  *      Add an ip_vs_conn information into the current sync_buff.
538  */
539 static void ip_vs_sync_conn_v0(struct netns_ipvs *ipvs, struct ip_vs_conn *cp,
540 			       int pkts)
541 {
542 	struct ip_vs_sync_mesg_v0 *m;
543 	struct ip_vs_sync_conn_v0 *s;
544 	struct ip_vs_sync_buff *buff;
545 	struct ipvs_master_sync_state *ms;
546 	int id;
547 	unsigned int len;
548 
549 	if (unlikely(cp->af != AF_INET))
550 		return;
551 	/* Do not sync ONE PACKET */
552 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
553 		return;
554 
555 	if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
556 		return;
557 
558 	spin_lock_bh(&ipvs->sync_buff_lock);
559 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
560 		spin_unlock_bh(&ipvs->sync_buff_lock);
561 		return;
562 	}
563 
564 	id = select_master_thread_id(ipvs, cp);
565 	ms = &ipvs->ms[id];
566 	buff = ms->sync_buff;
567 	len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE :
568 		SIMPLE_CONN_SIZE;
569 	if (buff) {
570 		m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
571 		/* Send buffer if it is for v1 */
572 		if (buff->head + len > buff->end || !m->nr_conns) {
573 			sb_queue_tail(ipvs, ms);
574 			ms->sync_buff = NULL;
575 			buff = NULL;
576 		}
577 	}
578 	if (!buff) {
579 		buff = ip_vs_sync_buff_create_v0(ipvs, len);
580 		if (!buff) {
581 			spin_unlock_bh(&ipvs->sync_buff_lock);
582 			pr_err("ip_vs_sync_buff_create failed.\n");
583 			return;
584 		}
585 		ms->sync_buff = buff;
586 	}
587 
588 	m = (struct ip_vs_sync_mesg_v0 *) buff->mesg;
589 	s = (struct ip_vs_sync_conn_v0 *) buff->head;
590 
591 	/* copy members */
592 	s->reserved = 0;
593 	s->protocol = cp->protocol;
594 	s->cport = cp->cport;
595 	s->vport = cp->vport;
596 	s->dport = cp->dport;
597 	s->caddr = cp->caddr.ip;
598 	s->vaddr = cp->vaddr.ip;
599 	s->daddr = cp->daddr.ip;
600 	s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED);
601 	s->state = htons(cp->state);
602 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
603 		struct ip_vs_sync_conn_options *opt =
604 			(struct ip_vs_sync_conn_options *)&s[1];
605 		memcpy(opt, &cp->sync_conn_opt, sizeof(*opt));
606 	}
607 
608 	m->nr_conns++;
609 	m->size = htons(ntohs(m->size) + len);
610 	buff->head += len;
611 	spin_unlock_bh(&ipvs->sync_buff_lock);
612 
613 	/* synchronize its controller if it has */
614 	cp = cp->control;
615 	if (cp) {
616 		if (cp->flags & IP_VS_CONN_F_TEMPLATE)
617 			pkts = atomic_inc_return(&cp->in_pkts);
618 		else
619 			pkts = sysctl_sync_threshold(ipvs);
620 		ip_vs_sync_conn(ipvs, cp, pkts);
621 	}
622 }
623 
624 /*
625  *      Add an ip_vs_conn information into the current sync_buff.
626  *      Called by ip_vs_in.
627  *      Sending Version 1 messages
628  */
629 void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts)
630 {
631 	struct ip_vs_sync_mesg *m;
632 	union ip_vs_sync_conn *s;
633 	struct ip_vs_sync_buff *buff;
634 	struct ipvs_master_sync_state *ms;
635 	int id;
636 	__u8 *p;
637 	unsigned int len, pe_name_len, pad;
638 
639 	/* Handle old version of the protocol */
640 	if (sysctl_sync_ver(ipvs) == 0) {
641 		ip_vs_sync_conn_v0(ipvs, cp, pkts);
642 		return;
643 	}
644 	/* Do not sync ONE PACKET */
645 	if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
646 		goto control;
647 sloop:
648 	if (!ip_vs_sync_conn_needed(ipvs, cp, pkts))
649 		goto control;
650 
651 	/* Sanity checks */
652 	pe_name_len = 0;
653 	if (cp->pe_data_len) {
654 		if (!cp->pe_data || !cp->dest) {
655 			IP_VS_ERR_RL("SYNC, connection pe_data invalid\n");
656 			return;
657 		}
658 		pe_name_len = strnlen(cp->pe->name, IP_VS_PENAME_MAXLEN);
659 	}
660 
661 	spin_lock_bh(&ipvs->sync_buff_lock);
662 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
663 		spin_unlock_bh(&ipvs->sync_buff_lock);
664 		return;
665 	}
666 
667 	id = select_master_thread_id(ipvs, cp);
668 	ms = &ipvs->ms[id];
669 
670 #ifdef CONFIG_IP_VS_IPV6
671 	if (cp->af == AF_INET6)
672 		len = sizeof(struct ip_vs_sync_v6);
673 	else
674 #endif
675 		len = sizeof(struct ip_vs_sync_v4);
676 
677 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK)
678 		len += sizeof(struct ip_vs_sync_conn_options) + 2;
679 
680 	if (cp->pe_data_len)
681 		len += cp->pe_data_len + 2;	/* + Param hdr field */
682 	if (pe_name_len)
683 		len += pe_name_len + 2;
684 
685 	/* check if there is a space for this one  */
686 	pad = 0;
687 	buff = ms->sync_buff;
688 	if (buff) {
689 		m = buff->mesg;
690 		pad = (4 - (size_t) buff->head) & 3;
691 		/* Send buffer if it is for v0 */
692 		if (buff->head + len + pad > buff->end || m->reserved) {
693 			sb_queue_tail(ipvs, ms);
694 			ms->sync_buff = NULL;
695 			buff = NULL;
696 			pad = 0;
697 		}
698 	}
699 
700 	if (!buff) {
701 		buff = ip_vs_sync_buff_create(ipvs, len);
702 		if (!buff) {
703 			spin_unlock_bh(&ipvs->sync_buff_lock);
704 			pr_err("ip_vs_sync_buff_create failed.\n");
705 			return;
706 		}
707 		ms->sync_buff = buff;
708 		m = buff->mesg;
709 	}
710 
711 	p = buff->head;
712 	buff->head += pad + len;
713 	m->size = htons(ntohs(m->size) + pad + len);
714 	/* Add ev. padding from prev. sync_conn */
715 	while (pad--)
716 		*(p++) = 0;
717 
718 	s = (union ip_vs_sync_conn *)p;
719 
720 	/* Set message type  & copy members */
721 	s->v4.type = (cp->af == AF_INET6 ? STYPE_F_INET6 : 0);
722 	s->v4.ver_size = htons(len & SVER_MASK);	/* Version 0 */
723 	s->v4.flags = htonl(cp->flags & ~IP_VS_CONN_F_HASHED);
724 	s->v4.state = htons(cp->state);
725 	s->v4.protocol = cp->protocol;
726 	s->v4.cport = cp->cport;
727 	s->v4.vport = cp->vport;
728 	s->v4.dport = cp->dport;
729 	s->v4.fwmark = htonl(cp->fwmark);
730 	s->v4.timeout = htonl(cp->timeout / HZ);
731 	m->nr_conns++;
732 
733 #ifdef CONFIG_IP_VS_IPV6
734 	if (cp->af == AF_INET6) {
735 		p += sizeof(struct ip_vs_sync_v6);
736 		s->v6.caddr = cp->caddr.in6;
737 		s->v6.vaddr = cp->vaddr.in6;
738 		s->v6.daddr = cp->daddr.in6;
739 	} else
740 #endif
741 	{
742 		p += sizeof(struct ip_vs_sync_v4);	/* options ptr */
743 		s->v4.caddr = cp->caddr.ip;
744 		s->v4.vaddr = cp->vaddr.ip;
745 		s->v4.daddr = cp->daddr.ip;
746 	}
747 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
748 		*(p++) = IPVS_OPT_SEQ_DATA;
749 		*(p++) = sizeof(struct ip_vs_sync_conn_options);
750 		hton_seq((struct ip_vs_seq *)p, &cp->in_seq);
751 		p += sizeof(struct ip_vs_seq);
752 		hton_seq((struct ip_vs_seq *)p, &cp->out_seq);
753 		p += sizeof(struct ip_vs_seq);
754 	}
755 	/* Handle pe data */
756 	if (cp->pe_data_len && cp->pe_data) {
757 		*(p++) = IPVS_OPT_PE_DATA;
758 		*(p++) = cp->pe_data_len;
759 		memcpy(p, cp->pe_data, cp->pe_data_len);
760 		p += cp->pe_data_len;
761 		if (pe_name_len) {
762 			/* Add PE_NAME */
763 			*(p++) = IPVS_OPT_PE_NAME;
764 			*(p++) = pe_name_len;
765 			memcpy(p, cp->pe->name, pe_name_len);
766 			p += pe_name_len;
767 		}
768 	}
769 
770 	spin_unlock_bh(&ipvs->sync_buff_lock);
771 
772 control:
773 	/* synchronize its controller if it has */
774 	cp = cp->control;
775 	if (!cp)
776 		return;
777 	if (cp->flags & IP_VS_CONN_F_TEMPLATE)
778 		pkts = atomic_inc_return(&cp->in_pkts);
779 	else
780 		pkts = sysctl_sync_threshold(ipvs);
781 	goto sloop;
782 }
783 
784 /*
785  *  fill_param used by version 1
786  */
787 static inline int
788 ip_vs_conn_fill_param_sync(struct netns_ipvs *ipvs, int af, union ip_vs_sync_conn *sc,
789 			   struct ip_vs_conn_param *p,
790 			   __u8 *pe_data, unsigned int pe_data_len,
791 			   __u8 *pe_name, unsigned int pe_name_len)
792 {
793 #ifdef CONFIG_IP_VS_IPV6
794 	if (af == AF_INET6)
795 		ip_vs_conn_fill_param(ipvs, af, sc->v6.protocol,
796 				      (const union nf_inet_addr *)&sc->v6.caddr,
797 				      sc->v6.cport,
798 				      (const union nf_inet_addr *)&sc->v6.vaddr,
799 				      sc->v6.vport, p);
800 	else
801 #endif
802 		ip_vs_conn_fill_param(ipvs, af, sc->v4.protocol,
803 				      (const union nf_inet_addr *)&sc->v4.caddr,
804 				      sc->v4.cport,
805 				      (const union nf_inet_addr *)&sc->v4.vaddr,
806 				      sc->v4.vport, p);
807 	/* Handle pe data */
808 	if (pe_data_len) {
809 		if (pe_name_len) {
810 			char buff[IP_VS_PENAME_MAXLEN+1];
811 
812 			memcpy(buff, pe_name, pe_name_len);
813 			buff[pe_name_len]=0;
814 			p->pe = __ip_vs_pe_getbyname(buff);
815 			if (!p->pe) {
816 				IP_VS_DBG(3, "BACKUP, no %s engine found/loaded\n",
817 					     buff);
818 				return 1;
819 			}
820 		} else {
821 			IP_VS_ERR_RL("BACKUP, Invalid PE parameters\n");
822 			return 1;
823 		}
824 
825 		p->pe_data = kmemdup(pe_data, pe_data_len, GFP_ATOMIC);
826 		if (!p->pe_data) {
827 			module_put(p->pe->module);
828 			return -ENOMEM;
829 		}
830 		p->pe_data_len = pe_data_len;
831 	}
832 	return 0;
833 }
834 
835 /*
836  *  Connection Add / Update.
837  *  Common for version 0 and 1 reception of backup sync_conns.
838  *  Param: ...
839  *         timeout is in sec.
840  */
841 static void ip_vs_proc_conn(struct netns_ipvs *ipvs, struct ip_vs_conn_param *param,
842 			    unsigned int flags, unsigned int state,
843 			    unsigned int protocol, unsigned int type,
844 			    const union nf_inet_addr *daddr, __be16 dport,
845 			    unsigned long timeout, __u32 fwmark,
846 			    struct ip_vs_sync_conn_options *opt)
847 {
848 	struct ip_vs_dest *dest;
849 	struct ip_vs_conn *cp;
850 
851 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
852 		cp = ip_vs_conn_in_get(param);
853 		if (cp && ((cp->dport != dport) ||
854 			   !ip_vs_addr_equal(cp->daf, &cp->daddr, daddr))) {
855 			if (!(flags & IP_VS_CONN_F_INACTIVE)) {
856 				ip_vs_conn_expire_now(cp);
857 				__ip_vs_conn_put(cp);
858 				cp = NULL;
859 			} else {
860 				/* This is the expiration message for the
861 				 * connection that was already replaced, so we
862 				 * just ignore it.
863 				 */
864 				__ip_vs_conn_put(cp);
865 				kfree(param->pe_data);
866 				return;
867 			}
868 		}
869 	} else {
870 		cp = ip_vs_ct_in_get(param);
871 	}
872 
873 	if (cp) {
874 		/* Free pe_data */
875 		kfree(param->pe_data);
876 
877 		dest = cp->dest;
878 		spin_lock_bh(&cp->lock);
879 		if ((cp->flags ^ flags) & IP_VS_CONN_F_INACTIVE &&
880 		    !(flags & IP_VS_CONN_F_TEMPLATE) && dest) {
881 			if (flags & IP_VS_CONN_F_INACTIVE) {
882 				atomic_dec(&dest->activeconns);
883 				atomic_inc(&dest->inactconns);
884 			} else {
885 				atomic_inc(&dest->activeconns);
886 				atomic_dec(&dest->inactconns);
887 			}
888 		}
889 		flags &= IP_VS_CONN_F_BACKUP_UPD_MASK;
890 		flags |= cp->flags & ~IP_VS_CONN_F_BACKUP_UPD_MASK;
891 		cp->flags = flags;
892 		spin_unlock_bh(&cp->lock);
893 		if (!dest)
894 			ip_vs_try_bind_dest(cp);
895 	} else {
896 		/*
897 		 * Find the appropriate destination for the connection.
898 		 * If it is not found the connection will remain unbound
899 		 * but still handled.
900 		 */
901 		rcu_read_lock();
902 		/* This function is only invoked by the synchronization
903 		 * code. We do not currently support heterogeneous pools
904 		 * with synchronization, so we can make the assumption that
905 		 * the svc_af is the same as the dest_af
906 		 */
907 		dest = ip_vs_find_dest(ipvs, type, type, daddr, dport,
908 				       param->vaddr, param->vport, protocol,
909 				       fwmark, flags);
910 
911 		cp = ip_vs_conn_new(param, type, daddr, dport, flags, dest,
912 				    fwmark);
913 		rcu_read_unlock();
914 		if (!cp) {
915 			kfree(param->pe_data);
916 			IP_VS_DBG(2, "BACKUP, add new conn. failed\n");
917 			return;
918 		}
919 		if (!(flags & IP_VS_CONN_F_TEMPLATE))
920 			kfree(param->pe_data);
921 	}
922 
923 	if (opt) {
924 		cp->in_seq = opt->in_seq;
925 		cp->out_seq = opt->out_seq;
926 	}
927 	atomic_set(&cp->in_pkts, sysctl_sync_threshold(ipvs));
928 	cp->state = state;
929 	cp->old_state = cp->state;
930 	/*
931 	 * For Ver 0 messages style
932 	 *  - Not possible to recover the right timeout for templates
933 	 *  - can not find the right fwmark
934 	 *    virtual service. If needed, we can do it for
935 	 *    non-fwmark persistent services.
936 	 * Ver 1 messages style.
937 	 *  - No problem.
938 	 */
939 	if (timeout) {
940 		if (timeout > MAX_SCHEDULE_TIMEOUT / HZ)
941 			timeout = MAX_SCHEDULE_TIMEOUT / HZ;
942 		cp->timeout = timeout*HZ;
943 	} else {
944 		struct ip_vs_proto_data *pd;
945 
946 		pd = ip_vs_proto_data_get(ipvs, protocol);
947 		if (!(flags & IP_VS_CONN_F_TEMPLATE) && pd && pd->timeout_table)
948 			cp->timeout = pd->timeout_table[state];
949 		else
950 			cp->timeout = (3*60*HZ);
951 	}
952 	ip_vs_conn_put(cp);
953 }
954 
955 /*
956  *  Process received multicast message for Version 0
957  */
958 static void ip_vs_process_message_v0(struct netns_ipvs *ipvs, const char *buffer,
959 				     const size_t buflen)
960 {
961 	struct ip_vs_sync_mesg_v0 *m = (struct ip_vs_sync_mesg_v0 *)buffer;
962 	struct ip_vs_sync_conn_v0 *s;
963 	struct ip_vs_sync_conn_options *opt;
964 	struct ip_vs_protocol *pp;
965 	struct ip_vs_conn_param param;
966 	char *p;
967 	int i;
968 
969 	p = (char *)buffer + sizeof(struct ip_vs_sync_mesg_v0);
970 	for (i=0; i<m->nr_conns; i++) {
971 		unsigned int flags, state;
972 
973 		if (p + SIMPLE_CONN_SIZE > buffer+buflen) {
974 			IP_VS_ERR_RL("BACKUP v0, bogus conn\n");
975 			return;
976 		}
977 		s = (struct ip_vs_sync_conn_v0 *) p;
978 		flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
979 		flags &= ~IP_VS_CONN_F_HASHED;
980 		if (flags & IP_VS_CONN_F_SEQ_MASK) {
981 			opt = (struct ip_vs_sync_conn_options *)&s[1];
982 			p += FULL_CONN_SIZE;
983 			if (p > buffer+buflen) {
984 				IP_VS_ERR_RL("BACKUP v0, Dropping buffer bogus conn options\n");
985 				return;
986 			}
987 		} else {
988 			opt = NULL;
989 			p += SIMPLE_CONN_SIZE;
990 		}
991 
992 		state = ntohs(s->state);
993 		if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
994 			pp = ip_vs_proto_get(s->protocol);
995 			if (!pp) {
996 				IP_VS_DBG(2, "BACKUP v0, Unsupported protocol %u\n",
997 					s->protocol);
998 				continue;
999 			}
1000 			if (state >= pp->num_states) {
1001 				IP_VS_DBG(2, "BACKUP v0, Invalid %s state %u\n",
1002 					pp->name, state);
1003 				continue;
1004 			}
1005 		} else {
1006 			if (state >= IP_VS_CTPL_S_LAST)
1007 				IP_VS_DBG(7, "BACKUP v0, Invalid tpl state %u\n",
1008 					  state);
1009 		}
1010 
1011 		ip_vs_conn_fill_param(ipvs, AF_INET, s->protocol,
1012 				      (const union nf_inet_addr *)&s->caddr,
1013 				      s->cport,
1014 				      (const union nf_inet_addr *)&s->vaddr,
1015 				      s->vport, &param);
1016 
1017 		/* Send timeout as Zero */
1018 		ip_vs_proc_conn(ipvs, &param, flags, state, s->protocol, AF_INET,
1019 				(union nf_inet_addr *)&s->daddr, s->dport,
1020 				0, 0, opt);
1021 	}
1022 }
1023 
1024 /*
1025  * Handle options
1026  */
1027 static inline int ip_vs_proc_seqopt(__u8 *p, unsigned int plen,
1028 				    __u32 *opt_flags,
1029 				    struct ip_vs_sync_conn_options *opt)
1030 {
1031 	struct ip_vs_sync_conn_options *topt;
1032 
1033 	topt = (struct ip_vs_sync_conn_options *)p;
1034 
1035 	if (plen != sizeof(struct ip_vs_sync_conn_options)) {
1036 		IP_VS_DBG(2, "BACKUP, bogus conn options length\n");
1037 		return -EINVAL;
1038 	}
1039 	if (*opt_flags & IPVS_OPT_F_SEQ_DATA) {
1040 		IP_VS_DBG(2, "BACKUP, conn options found twice\n");
1041 		return -EINVAL;
1042 	}
1043 	ntoh_seq(&topt->in_seq, &opt->in_seq);
1044 	ntoh_seq(&topt->out_seq, &opt->out_seq);
1045 	*opt_flags |= IPVS_OPT_F_SEQ_DATA;
1046 	return 0;
1047 }
1048 
1049 static int ip_vs_proc_str(__u8 *p, unsigned int plen, unsigned int *data_len,
1050 			  __u8 **data, unsigned int maxlen,
1051 			  __u32 *opt_flags, __u32 flag)
1052 {
1053 	if (plen > maxlen) {
1054 		IP_VS_DBG(2, "BACKUP, bogus par.data len > %d\n", maxlen);
1055 		return -EINVAL;
1056 	}
1057 	if (*opt_flags & flag) {
1058 		IP_VS_DBG(2, "BACKUP, Par.data found twice 0x%x\n", flag);
1059 		return -EINVAL;
1060 	}
1061 	*data_len = plen;
1062 	*data = p;
1063 	*opt_flags |= flag;
1064 	return 0;
1065 }
1066 /*
1067  *   Process a Version 1 sync. connection
1068  */
1069 static inline int ip_vs_proc_sync_conn(struct netns_ipvs *ipvs, __u8 *p, __u8 *msg_end)
1070 {
1071 	struct ip_vs_sync_conn_options opt;
1072 	union  ip_vs_sync_conn *s;
1073 	struct ip_vs_protocol *pp;
1074 	struct ip_vs_conn_param param;
1075 	__u32 flags;
1076 	unsigned int af, state, pe_data_len=0, pe_name_len=0;
1077 	__u8 *pe_data=NULL, *pe_name=NULL;
1078 	__u32 opt_flags=0;
1079 	int retc=0;
1080 
1081 	s = (union ip_vs_sync_conn *) p;
1082 
1083 	if (s->v6.type & STYPE_F_INET6) {
1084 #ifdef CONFIG_IP_VS_IPV6
1085 		af = AF_INET6;
1086 		p += sizeof(struct ip_vs_sync_v6);
1087 #else
1088 		IP_VS_DBG(3,"BACKUP, IPv6 msg received, and IPVS is not compiled for IPv6\n");
1089 		retc = 10;
1090 		goto out;
1091 #endif
1092 	} else if (!s->v4.type) {
1093 		af = AF_INET;
1094 		p += sizeof(struct ip_vs_sync_v4);
1095 	} else {
1096 		return -10;
1097 	}
1098 	if (p > msg_end)
1099 		return -20;
1100 
1101 	/* Process optional params check Type & Len. */
1102 	while (p < msg_end) {
1103 		int ptype;
1104 		int plen;
1105 
1106 		if (p+2 > msg_end)
1107 			return -30;
1108 		ptype = *(p++);
1109 		plen  = *(p++);
1110 
1111 		if (!plen || ((p + plen) > msg_end))
1112 			return -40;
1113 		/* Handle seq option  p = param data */
1114 		switch (ptype & ~IPVS_OPT_F_PARAM) {
1115 		case IPVS_OPT_SEQ_DATA:
1116 			if (ip_vs_proc_seqopt(p, plen, &opt_flags, &opt))
1117 				return -50;
1118 			break;
1119 
1120 		case IPVS_OPT_PE_DATA:
1121 			if (ip_vs_proc_str(p, plen, &pe_data_len, &pe_data,
1122 					   IP_VS_PEDATA_MAXLEN, &opt_flags,
1123 					   IPVS_OPT_F_PE_DATA))
1124 				return -60;
1125 			break;
1126 
1127 		case IPVS_OPT_PE_NAME:
1128 			if (ip_vs_proc_str(p, plen,&pe_name_len, &pe_name,
1129 					   IP_VS_PENAME_MAXLEN, &opt_flags,
1130 					   IPVS_OPT_F_PE_NAME))
1131 				return -70;
1132 			break;
1133 
1134 		default:
1135 			/* Param data mandatory ? */
1136 			if (!(ptype & IPVS_OPT_F_PARAM)) {
1137 				IP_VS_DBG(3, "BACKUP, Unknown mandatory param %d found\n",
1138 					  ptype & ~IPVS_OPT_F_PARAM);
1139 				retc = 20;
1140 				goto out;
1141 			}
1142 		}
1143 		p += plen;  /* Next option */
1144 	}
1145 
1146 	/* Get flags and Mask off unsupported */
1147 	flags  = ntohl(s->v4.flags) & IP_VS_CONN_F_BACKUP_MASK;
1148 	flags |= IP_VS_CONN_F_SYNC;
1149 	state = ntohs(s->v4.state);
1150 
1151 	if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
1152 		pp = ip_vs_proto_get(s->v4.protocol);
1153 		if (!pp) {
1154 			IP_VS_DBG(3,"BACKUP, Unsupported protocol %u\n",
1155 				s->v4.protocol);
1156 			retc = 30;
1157 			goto out;
1158 		}
1159 		if (state >= pp->num_states) {
1160 			IP_VS_DBG(3, "BACKUP, Invalid %s state %u\n",
1161 				pp->name, state);
1162 			retc = 40;
1163 			goto out;
1164 		}
1165 	} else {
1166 		if (state >= IP_VS_CTPL_S_LAST)
1167 			IP_VS_DBG(7, "BACKUP, Invalid tpl state %u\n",
1168 				  state);
1169 	}
1170 	if (ip_vs_conn_fill_param_sync(ipvs, af, s, &param, pe_data,
1171 				       pe_data_len, pe_name, pe_name_len)) {
1172 		retc = 50;
1173 		goto out;
1174 	}
1175 	/* If only IPv4, just silent skip IPv6 */
1176 	if (af == AF_INET)
1177 		ip_vs_proc_conn(ipvs, &param, flags, state, s->v4.protocol, af,
1178 				(union nf_inet_addr *)&s->v4.daddr, s->v4.dport,
1179 				ntohl(s->v4.timeout), ntohl(s->v4.fwmark),
1180 				(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
1181 				);
1182 #ifdef CONFIG_IP_VS_IPV6
1183 	else
1184 		ip_vs_proc_conn(ipvs, &param, flags, state, s->v6.protocol, af,
1185 				(union nf_inet_addr *)&s->v6.daddr, s->v6.dport,
1186 				ntohl(s->v6.timeout), ntohl(s->v6.fwmark),
1187 				(opt_flags & IPVS_OPT_F_SEQ_DATA ? &opt : NULL)
1188 				);
1189 #endif
1190 	ip_vs_pe_put(param.pe);
1191 	return 0;
1192 	/* Error exit */
1193 out:
1194 	IP_VS_DBG(2, "BACKUP, Single msg dropped err:%d\n", retc);
1195 	return retc;
1196 
1197 }
1198 /*
1199  *      Process received multicast message and create the corresponding
1200  *      ip_vs_conn entries.
1201  *      Handles Version 0 & 1
1202  */
1203 static void ip_vs_process_message(struct netns_ipvs *ipvs, __u8 *buffer,
1204 				  const size_t buflen)
1205 {
1206 	struct ip_vs_sync_mesg *m2 = (struct ip_vs_sync_mesg *)buffer;
1207 	__u8 *p, *msg_end;
1208 	int i, nr_conns;
1209 
1210 	if (buflen < sizeof(struct ip_vs_sync_mesg_v0)) {
1211 		IP_VS_DBG(2, "BACKUP, message header too short\n");
1212 		return;
1213 	}
1214 
1215 	if (buflen != ntohs(m2->size)) {
1216 		IP_VS_DBG(2, "BACKUP, bogus message size\n");
1217 		return;
1218 	}
1219 	/* SyncID sanity check */
1220 	if (ipvs->bcfg.syncid != 0 && m2->syncid != ipvs->bcfg.syncid) {
1221 		IP_VS_DBG(7, "BACKUP, Ignoring syncid = %d\n", m2->syncid);
1222 		return;
1223 	}
1224 	/* Handle version 1  message */
1225 	if ((m2->version == SYNC_PROTO_VER) && (m2->reserved == 0)
1226 	    && (m2->spare == 0)) {
1227 
1228 		msg_end = buffer + sizeof(struct ip_vs_sync_mesg);
1229 		nr_conns = m2->nr_conns;
1230 
1231 		for (i=0; i<nr_conns; i++) {
1232 			union ip_vs_sync_conn *s;
1233 			unsigned int size;
1234 			int retc;
1235 
1236 			p = msg_end;
1237 			if (p + sizeof(s->v4) > buffer+buflen) {
1238 				IP_VS_ERR_RL("BACKUP, Dropping buffer, too small\n");
1239 				return;
1240 			}
1241 			s = (union ip_vs_sync_conn *)p;
1242 			size = ntohs(s->v4.ver_size) & SVER_MASK;
1243 			msg_end = p + size;
1244 			/* Basic sanity checks */
1245 			if (msg_end  > buffer+buflen) {
1246 				IP_VS_ERR_RL("BACKUP, Dropping buffer, msg > buffer\n");
1247 				return;
1248 			}
1249 			if (ntohs(s->v4.ver_size) >> SVER_SHIFT) {
1250 				IP_VS_ERR_RL("BACKUP, Dropping buffer, Unknown version %d\n",
1251 					      ntohs(s->v4.ver_size) >> SVER_SHIFT);
1252 				return;
1253 			}
1254 			/* Process a single sync_conn */
1255 			retc = ip_vs_proc_sync_conn(ipvs, p, msg_end);
1256 			if (retc < 0) {
1257 				IP_VS_ERR_RL("BACKUP, Dropping buffer, Err: %d in decoding\n",
1258 					     retc);
1259 				return;
1260 			}
1261 			/* Make sure we have 32 bit alignment */
1262 			msg_end = p + ((size + 3) & ~3);
1263 		}
1264 	} else {
1265 		/* Old type of message */
1266 		ip_vs_process_message_v0(ipvs, buffer, buflen);
1267 		return;
1268 	}
1269 }
1270 
1271 
1272 /*
1273  *      Setup sndbuf (mode=1) or rcvbuf (mode=0)
1274  */
1275 static void set_sock_size(struct sock *sk, int mode, int val)
1276 {
1277 	/* setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &val, sizeof(val)); */
1278 	/* setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)); */
1279 	lock_sock(sk);
1280 	if (mode) {
1281 		val = clamp_t(int, val, (SOCK_MIN_SNDBUF + 1) / 2,
1282 			      READ_ONCE(sysctl_wmem_max));
1283 		sk->sk_sndbuf = val * 2;
1284 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1285 	} else {
1286 		val = clamp_t(int, val, (SOCK_MIN_RCVBUF + 1) / 2,
1287 			      READ_ONCE(sysctl_rmem_max));
1288 		sk->sk_rcvbuf = val * 2;
1289 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1290 	}
1291 	release_sock(sk);
1292 }
1293 
1294 /*
1295  *      Setup loopback of outgoing multicasts on a sending socket
1296  */
1297 static void set_mcast_loop(struct sock *sk, u_char loop)
1298 {
1299 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */
1300 	inet_assign_bit(MC_LOOP, sk, loop);
1301 #ifdef CONFIG_IP_VS_IPV6
1302 	if (READ_ONCE(sk->sk_family) == AF_INET6) {
1303 		/* IPV6_MULTICAST_LOOP */
1304 		inet6_assign_bit(MC6_LOOP, sk, loop);
1305 	}
1306 #endif
1307 }
1308 
1309 /*
1310  *      Specify TTL for outgoing multicasts on a sending socket
1311  */
1312 static void set_mcast_ttl(struct sock *sk, u_char ttl)
1313 {
1314 	struct inet_sock *inet = inet_sk(sk);
1315 
1316 	/* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */
1317 	lock_sock(sk);
1318 	WRITE_ONCE(inet->mc_ttl, ttl);
1319 #ifdef CONFIG_IP_VS_IPV6
1320 	if (sk->sk_family == AF_INET6) {
1321 		struct ipv6_pinfo *np = inet6_sk(sk);
1322 
1323 		/* IPV6_MULTICAST_HOPS */
1324 		WRITE_ONCE(np->mcast_hops, ttl);
1325 	}
1326 #endif
1327 	release_sock(sk);
1328 }
1329 
1330 /* Control fragmentation of messages */
1331 static void set_mcast_pmtudisc(struct sock *sk, int val)
1332 {
1333 	struct inet_sock *inet = inet_sk(sk);
1334 
1335 	/* setsockopt(sock, SOL_IP, IP_MTU_DISCOVER, &val, sizeof(val)); */
1336 	lock_sock(sk);
1337 	WRITE_ONCE(inet->pmtudisc, val);
1338 #ifdef CONFIG_IP_VS_IPV6
1339 	if (sk->sk_family == AF_INET6) {
1340 		struct ipv6_pinfo *np = inet6_sk(sk);
1341 
1342 		/* IPV6_MTU_DISCOVER */
1343 		WRITE_ONCE(np->pmtudisc, val);
1344 	}
1345 #endif
1346 	release_sock(sk);
1347 }
1348 
1349 /*
1350  *      Specifiy default interface for outgoing multicasts
1351  */
1352 static int set_mcast_if(struct sock *sk, struct net_device *dev)
1353 {
1354 	struct inet_sock *inet = inet_sk(sk);
1355 
1356 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1357 		return -EINVAL;
1358 
1359 	lock_sock(sk);
1360 	inet->mc_index = dev->ifindex;
1361 	/*  inet->mc_addr  = 0; */
1362 #ifdef CONFIG_IP_VS_IPV6
1363 	if (sk->sk_family == AF_INET6) {
1364 		struct ipv6_pinfo *np = inet6_sk(sk);
1365 
1366 		/* IPV6_MULTICAST_IF */
1367 		WRITE_ONCE(np->mcast_oif, dev->ifindex);
1368 	}
1369 #endif
1370 	release_sock(sk);
1371 
1372 	return 0;
1373 }
1374 
1375 
1376 /*
1377  *      Join a multicast group.
1378  *      the group is specified by a class D multicast address 224.0.0.0/8
1379  *      in the in_addr structure passed in as a parameter.
1380  */
1381 static int
1382 join_mcast_group(struct sock *sk, struct in_addr *addr, struct net_device *dev)
1383 {
1384 	struct ip_mreqn mreq;
1385 	int ret;
1386 
1387 	memset(&mreq, 0, sizeof(mreq));
1388 	memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr));
1389 
1390 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1391 		return -EINVAL;
1392 
1393 	mreq.imr_ifindex = dev->ifindex;
1394 
1395 	lock_sock(sk);
1396 	ret = ip_mc_join_group(sk, &mreq);
1397 	release_sock(sk);
1398 
1399 	return ret;
1400 }
1401 
1402 #ifdef CONFIG_IP_VS_IPV6
1403 static int join_mcast_group6(struct sock *sk, struct in6_addr *addr,
1404 			     struct net_device *dev)
1405 {
1406 	int ret;
1407 
1408 	if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if)
1409 		return -EINVAL;
1410 
1411 	lock_sock(sk);
1412 	ret = ipv6_sock_mc_join(sk, dev->ifindex, addr);
1413 	release_sock(sk);
1414 
1415 	return ret;
1416 }
1417 #endif
1418 
1419 static int bind_mcastif_addr(struct socket *sock, struct net_device *dev)
1420 {
1421 	__be32 addr;
1422 	struct sockaddr_in sin;
1423 
1424 	addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
1425 	if (!addr)
1426 		pr_err("You probably need to specify IP address on "
1427 		       "multicast interface.\n");
1428 
1429 	IP_VS_DBG(7, "binding socket with (%s) %pI4\n",
1430 		  dev->name, &addr);
1431 
1432 	/* Now bind the socket with the address of multicast interface */
1433 	sin.sin_family	     = AF_INET;
1434 	sin.sin_addr.s_addr  = addr;
1435 	sin.sin_port         = 0;
1436 
1437 	return kernel_bind(sock, (struct sockaddr_unsized *)&sin, sizeof(sin));
1438 }
1439 
1440 static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
1441 			       struct ipvs_sync_daemon_cfg *c, int id)
1442 {
1443 	if (AF_INET6 == c->mcast_af) {
1444 		sa->in6 = (struct sockaddr_in6) {
1445 			.sin6_family = AF_INET6,
1446 			.sin6_port = htons(c->mcast_port + id),
1447 		};
1448 		sa->in6.sin6_addr = c->mcast_group.in6;
1449 		*salen = sizeof(sa->in6);
1450 	} else {
1451 		sa->in = (struct sockaddr_in) {
1452 			.sin_family = AF_INET,
1453 			.sin_port = htons(c->mcast_port + id),
1454 		};
1455 		sa->in.sin_addr = c->mcast_group.in;
1456 		*salen = sizeof(sa->in);
1457 	}
1458 }
1459 
1460 /*
1461  *      Set up sending multicast socket over UDP
1462  */
1463 static int make_send_sock(struct netns_ipvs *ipvs, int id,
1464 			  struct net_device *dev, struct socket **sock_ret)
1465 {
1466 	/* multicast addr */
1467 	union ipvs_sockaddr mcast_addr;
1468 	struct socket *sock;
1469 	int result, salen;
1470 
1471 	/* First create a socket */
1472 	result = sock_create_kern(ipvs->net, ipvs->mcfg.mcast_af, SOCK_DGRAM,
1473 				  IPPROTO_UDP, &sock);
1474 	if (result < 0) {
1475 		pr_err("Error during creation of socket; terminating\n");
1476 		goto error;
1477 	}
1478 	*sock_ret = sock;
1479 	result = set_mcast_if(sock->sk, dev);
1480 	if (result < 0) {
1481 		pr_err("Error setting outbound mcast interface\n");
1482 		goto error;
1483 	}
1484 
1485 	set_mcast_loop(sock->sk, 0);
1486 	set_mcast_ttl(sock->sk, ipvs->mcfg.mcast_ttl);
1487 	/* Allow fragmentation if MTU changes */
1488 	set_mcast_pmtudisc(sock->sk, IP_PMTUDISC_DONT);
1489 	result = sysctl_sync_sock_size(ipvs);
1490 	if (result > 0)
1491 		set_sock_size(sock->sk, 1, result);
1492 
1493 	if (AF_INET == ipvs->mcfg.mcast_af)
1494 		result = bind_mcastif_addr(sock, dev);
1495 	else
1496 		result = 0;
1497 	if (result < 0) {
1498 		pr_err("Error binding address of the mcast interface\n");
1499 		goto error;
1500 	}
1501 
1502 	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->mcfg, id);
1503 	result = kernel_connect(sock, (struct sockaddr_unsized *)&mcast_addr,
1504 				salen, 0);
1505 	if (result < 0) {
1506 		pr_err("Error connecting to the multicast addr\n");
1507 		goto error;
1508 	}
1509 
1510 	return 0;
1511 
1512 error:
1513 	return result;
1514 }
1515 
1516 
1517 /*
1518  *      Set up receiving multicast socket over UDP
1519  */
1520 static int make_receive_sock(struct netns_ipvs *ipvs, int id,
1521 			     struct net_device *dev, struct socket **sock_ret)
1522 {
1523 	/* multicast addr */
1524 	union ipvs_sockaddr mcast_addr;
1525 	struct socket *sock;
1526 	int result, salen;
1527 
1528 	/* First create a socket */
1529 	result = sock_create_kern(ipvs->net, ipvs->bcfg.mcast_af, SOCK_DGRAM,
1530 				  IPPROTO_UDP, &sock);
1531 	if (result < 0) {
1532 		pr_err("Error during creation of socket; terminating\n");
1533 		goto error;
1534 	}
1535 	*sock_ret = sock;
1536 	/* it is equivalent to the REUSEADDR option in user-space */
1537 	sock->sk->sk_reuse = SK_CAN_REUSE;
1538 	result = sysctl_sync_sock_size(ipvs);
1539 	if (result > 0)
1540 		set_sock_size(sock->sk, 0, result);
1541 
1542 	get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
1543 	sock->sk->sk_bound_dev_if = dev->ifindex;
1544 	result = kernel_bind(sock, (struct sockaddr_unsized *)&mcast_addr, salen);
1545 	if (result < 0) {
1546 		pr_err("Error binding to the multicast addr\n");
1547 		goto error;
1548 	}
1549 
1550 	/* join the multicast group */
1551 #ifdef CONFIG_IP_VS_IPV6
1552 	if (ipvs->bcfg.mcast_af == AF_INET6)
1553 		result = join_mcast_group6(sock->sk, &mcast_addr.in6.sin6_addr,
1554 					   dev);
1555 	else
1556 #endif
1557 		result = join_mcast_group(sock->sk, &mcast_addr.in.sin_addr,
1558 					  dev);
1559 	if (result < 0) {
1560 		pr_err("Error joining to the multicast group\n");
1561 		goto error;
1562 	}
1563 
1564 	return 0;
1565 
1566 error:
1567 	return result;
1568 }
1569 
1570 
1571 static int
1572 ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length)
1573 {
1574 	struct msghdr	msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL};
1575 	struct kvec	iov;
1576 	int		len;
1577 
1578 	iov.iov_base     = (void *)buffer;
1579 	iov.iov_len      = length;
1580 
1581 	len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length));
1582 
1583 	return len;
1584 }
1585 
1586 static int
1587 ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg)
1588 {
1589 	int msize;
1590 	int ret;
1591 
1592 	msize = ntohs(msg->size);
1593 
1594 	ret = ip_vs_send_async(sock, (char *)msg, msize);
1595 	if (ret >= 0 || ret == -EAGAIN)
1596 		return ret;
1597 	pr_err("ip_vs_send_async error %d\n", ret);
1598 	return 0;
1599 }
1600 
1601 static int
1602 ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen)
1603 {
1604 	struct msghdr		msg = {NULL,};
1605 	struct kvec		iov = {buffer, buflen};
1606 	int			len;
1607 
1608 	/* Receive a packet */
1609 	iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, buflen);
1610 	len = sock_recvmsg(sock, &msg, MSG_DONTWAIT);
1611 	if (len < 0)
1612 		return len;
1613 
1614 	return len;
1615 }
1616 
1617 /* Wakeup the master thread for sending */
1618 static void master_wakeup_work_handler(struct work_struct *work)
1619 {
1620 	struct ipvs_master_sync_state *ms =
1621 		container_of(work, struct ipvs_master_sync_state,
1622 			     master_wakeup_work.work);
1623 	struct netns_ipvs *ipvs = ms->ipvs;
1624 
1625 	spin_lock_bh(&ipvs->sync_lock);
1626 	if (ms->sync_queue_len &&
1627 	    ms->sync_queue_delay < IPVS_SYNC_WAKEUP_RATE) {
1628 		int id = (int)(ms - ipvs->ms);
1629 
1630 		ms->sync_queue_delay = IPVS_SYNC_WAKEUP_RATE;
1631 		wake_up_process(ipvs->master_tinfo[id].task);
1632 	}
1633 	spin_unlock_bh(&ipvs->sync_lock);
1634 }
1635 
1636 /* Get next buffer to send */
1637 static inline struct ip_vs_sync_buff *
1638 next_sync_buff(struct netns_ipvs *ipvs, struct ipvs_master_sync_state *ms)
1639 {
1640 	struct ip_vs_sync_buff *sb;
1641 
1642 	sb = sb_dequeue(ipvs, ms);
1643 	if (sb)
1644 		return sb;
1645 	/* Do not delay entries in buffer for more than 2 seconds */
1646 	return get_curr_sync_buff(ipvs, ms, IPVS_SYNC_FLUSH_TIME);
1647 }
1648 
1649 static int sync_thread_master(void *data)
1650 {
1651 	struct ip_vs_sync_thread_data *tinfo = data;
1652 	struct netns_ipvs *ipvs = tinfo->ipvs;
1653 	struct ipvs_master_sync_state *ms = &ipvs->ms[tinfo->id];
1654 	struct sock *sk = tinfo->sock->sk;
1655 	struct ip_vs_sync_buff *sb;
1656 
1657 	pr_info("sync thread started: state = MASTER, mcast_ifn = %s, "
1658 		"syncid = %d, id = %d\n",
1659 		ipvs->mcfg.mcast_ifn, ipvs->mcfg.syncid, tinfo->id);
1660 
1661 	for (;;) {
1662 		sb = next_sync_buff(ipvs, ms);
1663 		if (unlikely(kthread_should_stop()))
1664 			break;
1665 		if (!sb) {
1666 			schedule_timeout(IPVS_SYNC_CHECK_PERIOD);
1667 			continue;
1668 		}
1669 		while (ip_vs_send_sync_msg(tinfo->sock, sb->mesg) < 0) {
1670 			/* (Ab)use interruptible sleep to avoid increasing
1671 			 * the load avg.
1672 			 */
1673 			__wait_event_interruptible(*sk_sleep(sk),
1674 						   sock_writeable(sk) ||
1675 						   kthread_should_stop());
1676 			if (unlikely(kthread_should_stop()))
1677 				goto done;
1678 		}
1679 		ip_vs_sync_buff_release(sb);
1680 	}
1681 
1682 done:
1683 	__set_current_state(TASK_RUNNING);
1684 	if (sb)
1685 		ip_vs_sync_buff_release(sb);
1686 
1687 	/* clean up the sync_buff queue */
1688 	while ((sb = sb_dequeue(ipvs, ms)))
1689 		ip_vs_sync_buff_release(sb);
1690 	__set_current_state(TASK_RUNNING);
1691 
1692 	/* clean up the current sync_buff */
1693 	sb = get_curr_sync_buff(ipvs, ms, 0);
1694 	if (sb)
1695 		ip_vs_sync_buff_release(sb);
1696 
1697 	return 0;
1698 }
1699 
1700 
1701 static int sync_thread_backup(void *data)
1702 {
1703 	struct ip_vs_sync_thread_data *tinfo = data;
1704 	struct netns_ipvs *ipvs = tinfo->ipvs;
1705 	struct sock *sk = tinfo->sock->sk;
1706 	struct udp_sock *up = udp_sk(sk);
1707 	int len;
1708 
1709 	pr_info("sync thread started: state = BACKUP, mcast_ifn = %s, "
1710 		"syncid = %d, id = %d\n",
1711 		ipvs->bcfg.mcast_ifn, ipvs->bcfg.syncid, tinfo->id);
1712 
1713 	while (!kthread_should_stop()) {
1714 		wait_event_interruptible(*sk_sleep(sk),
1715 					 !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1716 					 !skb_queue_empty_lockless(&up->reader_queue) ||
1717 					 kthread_should_stop());
1718 
1719 		/* do we have data now? */
1720 		while (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
1721 		       !skb_queue_empty_lockless(&up->reader_queue)) {
1722 			len = ip_vs_receive(tinfo->sock, tinfo->buf,
1723 					ipvs->bcfg.sync_maxlen);
1724 			if (len <= 0) {
1725 				if (len != -EAGAIN)
1726 					pr_err("receiving message error\n");
1727 				break;
1728 			}
1729 
1730 			ip_vs_process_message(ipvs, tinfo->buf, len);
1731 		}
1732 	}
1733 
1734 	return 0;
1735 }
1736 
1737 
1738 int start_sync_thread(struct netns_ipvs *ipvs, struct ipvs_sync_daemon_cfg *c,
1739 		      int state)
1740 {
1741 	struct ip_vs_sync_thread_data *ti = NULL, *tinfo;
1742 	struct task_struct *task;
1743 	struct net_device *dev;
1744 	char *name;
1745 	int (*threadfn)(void *data);
1746 	int id = 0, count, hlen;
1747 	int result = -ENOMEM;
1748 	u16 mtu, min_mtu;
1749 
1750 	IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
1751 	IP_VS_DBG(7, "Each ip_vs_sync_conn entry needs %zd bytes\n",
1752 		  sizeof(struct ip_vs_sync_conn_v0));
1753 
1754 	/* increase the module use count */
1755 	if (!ip_vs_use_count_inc())
1756 		return -ENOPROTOOPT;
1757 
1758 	/* Do not hold one mutex and then to block on another */
1759 	for (;;) {
1760 		rtnl_lock();
1761 		if (mutex_trylock(&ipvs->sync_mutex))
1762 			break;
1763 		rtnl_unlock();
1764 		mutex_lock(&ipvs->sync_mutex);
1765 		if (rtnl_trylock())
1766 			break;
1767 		mutex_unlock(&ipvs->sync_mutex);
1768 	}
1769 
1770 	if (!ipvs->sync_state) {
1771 		count = clamp(sysctl_sync_ports(ipvs), 1, IPVS_SYNC_PORTS_MAX);
1772 		ipvs->threads_mask = count - 1;
1773 	} else
1774 		count = ipvs->threads_mask + 1;
1775 
1776 	if (c->mcast_af == AF_UNSPEC) {
1777 		c->mcast_af = AF_INET;
1778 		c->mcast_group.ip = cpu_to_be32(IP_VS_SYNC_GROUP);
1779 	}
1780 	if (!c->mcast_port)
1781 		c->mcast_port = IP_VS_SYNC_PORT;
1782 	if (!c->mcast_ttl)
1783 		c->mcast_ttl = 1;
1784 
1785 	dev = __dev_get_by_name(ipvs->net, c->mcast_ifn);
1786 	if (!dev) {
1787 		pr_err("Unknown mcast interface: %s\n", c->mcast_ifn);
1788 		result = -ENODEV;
1789 		goto out_early;
1790 	}
1791 	hlen = (AF_INET6 == c->mcast_af) ?
1792 	       sizeof(struct ipv6hdr) + sizeof(struct udphdr) :
1793 	       sizeof(struct iphdr) + sizeof(struct udphdr);
1794 	mtu = (state == IP_VS_STATE_BACKUP) ?
1795 		  clamp(dev->mtu, 1500U, 65535U) : 1500U;
1796 	min_mtu = (state == IP_VS_STATE_BACKUP) ? 1024 : 1;
1797 
1798 	if (c->sync_maxlen)
1799 		c->sync_maxlen = clamp_t(unsigned int,
1800 					 c->sync_maxlen, min_mtu,
1801 					 65535 - hlen);
1802 	else
1803 		c->sync_maxlen = mtu - hlen;
1804 
1805 	if (state == IP_VS_STATE_MASTER) {
1806 		result = -EEXIST;
1807 		if (ipvs->ms)
1808 			goto out_early;
1809 
1810 		ipvs->mcfg = *c;
1811 		name = "ipvs-m:%d:%d";
1812 		threadfn = sync_thread_master;
1813 	} else if (state == IP_VS_STATE_BACKUP) {
1814 		result = -EEXIST;
1815 		if (ipvs->backup_tinfo)
1816 			goto out_early;
1817 
1818 		ipvs->bcfg = *c;
1819 		name = "ipvs-b:%d:%d";
1820 		threadfn = sync_thread_backup;
1821 	} else {
1822 		result = -EINVAL;
1823 		goto out_early;
1824 	}
1825 
1826 	if (state == IP_VS_STATE_MASTER) {
1827 		struct ipvs_master_sync_state *ms;
1828 
1829 		result = -ENOMEM;
1830 		ipvs->ms = kcalloc(count, sizeof(ipvs->ms[0]), GFP_KERNEL);
1831 		if (!ipvs->ms)
1832 			goto out;
1833 		ms = ipvs->ms;
1834 		for (id = 0; id < count; id++, ms++) {
1835 			INIT_LIST_HEAD(&ms->sync_queue);
1836 			ms->sync_queue_len = 0;
1837 			ms->sync_queue_delay = 0;
1838 			INIT_DELAYED_WORK(&ms->master_wakeup_work,
1839 					  master_wakeup_work_handler);
1840 			ms->ipvs = ipvs;
1841 		}
1842 	}
1843 	result = -ENOMEM;
1844 	ti = kcalloc(count, sizeof(struct ip_vs_sync_thread_data),
1845 		     GFP_KERNEL);
1846 	if (!ti)
1847 		goto out;
1848 
1849 	for (id = 0; id < count; id++) {
1850 		tinfo = &ti[id];
1851 		tinfo->ipvs = ipvs;
1852 		if (state == IP_VS_STATE_BACKUP) {
1853 			result = -ENOMEM;
1854 			tinfo->buf = kmalloc(ipvs->bcfg.sync_maxlen,
1855 					     GFP_KERNEL);
1856 			if (!tinfo->buf)
1857 				goto out;
1858 		}
1859 		tinfo->id = id;
1860 		if (state == IP_VS_STATE_MASTER)
1861 			result = make_send_sock(ipvs, id, dev, &tinfo->sock);
1862 		else
1863 			result = make_receive_sock(ipvs, id, dev, &tinfo->sock);
1864 		if (result < 0)
1865 			goto out;
1866 
1867 		task = kthread_run(threadfn, tinfo, name, ipvs->gen, id);
1868 		if (IS_ERR(task)) {
1869 			result = PTR_ERR(task);
1870 			goto out;
1871 		}
1872 		tinfo->task = task;
1873 	}
1874 
1875 	/* mark as active */
1876 
1877 	if (state == IP_VS_STATE_MASTER)
1878 		ipvs->master_tinfo = ti;
1879 	else
1880 		ipvs->backup_tinfo = ti;
1881 	spin_lock_bh(&ipvs->sync_buff_lock);
1882 	ipvs->sync_state |= state;
1883 	spin_unlock_bh(&ipvs->sync_buff_lock);
1884 
1885 	mutex_unlock(&ipvs->sync_mutex);
1886 	rtnl_unlock();
1887 
1888 	return 0;
1889 
1890 out:
1891 	/* We do not need RTNL lock anymore, release it here so that
1892 	 * sock_release below can use rtnl_lock to leave the mcast group.
1893 	 */
1894 	rtnl_unlock();
1895 	id = min(id, count - 1);
1896 	if (ti) {
1897 		for (tinfo = ti + id; tinfo >= ti; tinfo--) {
1898 			if (tinfo->task)
1899 				kthread_stop(tinfo->task);
1900 		}
1901 	}
1902 	if (!(ipvs->sync_state & IP_VS_STATE_MASTER)) {
1903 		kfree(ipvs->ms);
1904 		ipvs->ms = NULL;
1905 	}
1906 	mutex_unlock(&ipvs->sync_mutex);
1907 
1908 	/* No more mutexes, release socks */
1909 	if (ti) {
1910 		for (tinfo = ti + id; tinfo >= ti; tinfo--) {
1911 			if (tinfo->sock)
1912 				sock_release(tinfo->sock);
1913 			kfree(tinfo->buf);
1914 		}
1915 		kfree(ti);
1916 	}
1917 
1918 	/* decrease the module use count */
1919 	ip_vs_use_count_dec();
1920 	return result;
1921 
1922 out_early:
1923 	mutex_unlock(&ipvs->sync_mutex);
1924 	rtnl_unlock();
1925 
1926 	/* decrease the module use count */
1927 	ip_vs_use_count_dec();
1928 	return result;
1929 }
1930 
1931 
1932 int stop_sync_thread(struct netns_ipvs *ipvs, int state)
1933 {
1934 	struct ip_vs_sync_thread_data *ti, *tinfo;
1935 	int id;
1936 	int retc = -EINVAL;
1937 
1938 	IP_VS_DBG(7, "%s(): pid %d\n", __func__, task_pid_nr(current));
1939 
1940 	mutex_lock(&ipvs->sync_mutex);
1941 	if (state == IP_VS_STATE_MASTER) {
1942 		retc = -ESRCH;
1943 		if (!ipvs->ms)
1944 			goto err;
1945 		ti = ipvs->master_tinfo;
1946 
1947 		/*
1948 		 * The lock synchronizes with sb_queue_tail(), so that we don't
1949 		 * add sync buffers to the queue, when we are already in
1950 		 * progress of stopping the master sync daemon.
1951 		 */
1952 
1953 		spin_lock_bh(&ipvs->sync_buff_lock);
1954 		spin_lock(&ipvs->sync_lock);
1955 		ipvs->sync_state &= ~IP_VS_STATE_MASTER;
1956 		spin_unlock(&ipvs->sync_lock);
1957 		spin_unlock_bh(&ipvs->sync_buff_lock);
1958 
1959 		retc = 0;
1960 		for (id = ipvs->threads_mask; id >= 0; id--) {
1961 			struct ipvs_master_sync_state *ms = &ipvs->ms[id];
1962 			int ret;
1963 
1964 			tinfo = &ti[id];
1965 			pr_info("stopping master sync thread %d ...\n",
1966 				task_pid_nr(tinfo->task));
1967 			cancel_delayed_work_sync(&ms->master_wakeup_work);
1968 			ret = kthread_stop(tinfo->task);
1969 			if (retc >= 0)
1970 				retc = ret;
1971 		}
1972 		kfree(ipvs->ms);
1973 		ipvs->ms = NULL;
1974 		ipvs->master_tinfo = NULL;
1975 	} else if (state == IP_VS_STATE_BACKUP) {
1976 		retc = -ESRCH;
1977 		if (!ipvs->backup_tinfo)
1978 			goto err;
1979 		ti = ipvs->backup_tinfo;
1980 
1981 		ipvs->sync_state &= ~IP_VS_STATE_BACKUP;
1982 		retc = 0;
1983 		for (id = ipvs->threads_mask; id >= 0; id--) {
1984 			int ret;
1985 
1986 			tinfo = &ti[id];
1987 			pr_info("stopping backup sync thread %d ...\n",
1988 				task_pid_nr(tinfo->task));
1989 			ret = kthread_stop(tinfo->task);
1990 			if (retc >= 0)
1991 				retc = ret;
1992 		}
1993 		ipvs->backup_tinfo = NULL;
1994 	} else {
1995 		goto err;
1996 	}
1997 	id = ipvs->threads_mask;
1998 	mutex_unlock(&ipvs->sync_mutex);
1999 
2000 	/* No more mutexes, release socks */
2001 	for (tinfo = ti + id; tinfo >= ti; tinfo--) {
2002 		if (tinfo->sock)
2003 			sock_release(tinfo->sock);
2004 		kfree(tinfo->buf);
2005 	}
2006 	kfree(ti);
2007 
2008 	/* decrease the module use count */
2009 	ip_vs_use_count_dec();
2010 	return retc;
2011 
2012 err:
2013 	mutex_unlock(&ipvs->sync_mutex);
2014 	return retc;
2015 }
2016 
2017 /*
2018  * Initialize data struct for each netns
2019  */
2020 int __net_init ip_vs_sync_net_init(struct netns_ipvs *ipvs)
2021 {
2022 	__mutex_init(&ipvs->sync_mutex, "ipvs->sync_mutex", &__ipvs_sync_key);
2023 	spin_lock_init(&ipvs->sync_lock);
2024 	spin_lock_init(&ipvs->sync_buff_lock);
2025 	return 0;
2026 }
2027 
2028 void ip_vs_sync_net_cleanup(struct netns_ipvs *ipvs)
2029 {
2030 	int retc;
2031 
2032 	retc = stop_sync_thread(ipvs, IP_VS_STATE_MASTER);
2033 	if (retc && retc != -ESRCH)
2034 		pr_err("Failed to stop Master Daemon\n");
2035 
2036 	retc = stop_sync_thread(ipvs, IP_VS_STATE_BACKUP);
2037 	if (retc && retc != -ESRCH)
2038 		pr_err("Failed to stop Backup Daemon\n");
2039 }
2040