1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * IPVS:        Locality-Based Least-Connection with Replication scheduler
4 *
5 * Authors:     Wensong Zhang <wensong@gnuchina.org>
6 *
7 * Changes:
8 *     Julian Anastasov        :    Added the missing (dest->weight>0)
9 *                                  condition in the ip_vs_dest_set_max.
10 */
11
12/*
13 * The lblc/r algorithm is as follows (pseudo code):
14 *
15 *       if serverSet[dest_ip] is null then
16 *               n, serverSet[dest_ip] <- {weighted least-conn node};
17 *       else
18 *               n <- {least-conn (alive) node in serverSet[dest_ip]};
19 *               if (n is null) OR
20 *                  (n.conns>n.weight AND
21 *                   there is a node m with m.conns<m.weight/2) then
22 *                   n <- {weighted least-conn node};
23 *                   add n to serverSet[dest_ip];
24 *               if |serverSet[dest_ip]| > 1 AND
25 *                   now - serverSet[dest_ip].lastMod > T then
26 *                   m <- {most conn node in serverSet[dest_ip]};
27 *                   remove m from serverSet[dest_ip];
28 *       if serverSet[dest_ip] changed then
29 *               serverSet[dest_ip].lastMod <- now;
30 *
31 *       return n;
32 *
33 */
34
35#define KMSG_COMPONENT "IPVS"
36#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
37
38#include <linux/ip.h>
39#include <linux/module.h>
40#include <linux/kernel.h>
41#include <linux/skbuff.h>
42#include <linux/jiffies.h>
43#include <linux/list.h>
44#include <linux/slab.h>
45#include <linux/hash.h>
46
47/* for sysctl */
48#include <linux/fs.h>
49#include <linux/sysctl.h>
50#include <net/net_namespace.h>
51
52#include <net/ip_vs.h>
53
54
55/*
56 *    It is for garbage collection of stale IPVS lblcr entries,
57 *    when the table is full.
58 */
59#define CHECK_EXPIRE_INTERVAL   (60*HZ)
60#define ENTRY_TIMEOUT           (6*60*HZ)
61
62#define DEFAULT_EXPIRATION	(24*60*60*HZ)
63
64/*
65 *    It is for full expiration check.
66 *    When there is no partial expiration check (garbage collection)
67 *    in a half hour, do a full expiration check to collect stale
68 *    entries that haven't been touched for a day.
69 */
70#define COUNT_FOR_FULL_EXPIRATION   30
71
72/*
73 *     for IPVS lblcr entry hash table
74 */
75#ifndef CONFIG_IP_VS_LBLCR_TAB_BITS
76#define CONFIG_IP_VS_LBLCR_TAB_BITS      10
77#endif
78#define IP_VS_LBLCR_TAB_BITS     CONFIG_IP_VS_LBLCR_TAB_BITS
79#define IP_VS_LBLCR_TAB_SIZE     (1 << IP_VS_LBLCR_TAB_BITS)
80#define IP_VS_LBLCR_TAB_MASK     (IP_VS_LBLCR_TAB_SIZE - 1)
81
82
83/*
84 *      IPVS destination set structure and operations
85 */
86struct ip_vs_dest_set_elem {
87	struct list_head	list;          /* list link */
88	struct ip_vs_dest	*dest;		/* destination server */
89	struct rcu_head		rcu_head;
90};
91
92struct ip_vs_dest_set {
93	atomic_t                size;           /* set size */
94	unsigned long           lastmod;        /* last modified time */
95	struct list_head	list;           /* destination list */
96};
97
98
99static void ip_vs_dest_set_insert(struct ip_vs_dest_set *set,
100				  struct ip_vs_dest *dest, bool check)
101{
102	struct ip_vs_dest_set_elem *e;
103
104	if (check) {
105		list_for_each_entry(e, &set->list, list) {
106			if (e->dest == dest)
107				return;
108		}
109	}
110
111	e = kmalloc(sizeof(*e), GFP_ATOMIC);
112	if (e == NULL)
113		return;
114
115	ip_vs_dest_hold(dest);
116	e->dest = dest;
117
118	list_add_rcu(&e->list, &set->list);
119	atomic_inc(&set->size);
120
121	set->lastmod = jiffies;
122}
123
124static void ip_vs_lblcr_elem_rcu_free(struct rcu_head *head)
125{
126	struct ip_vs_dest_set_elem *e;
127
128	e = container_of(head, struct ip_vs_dest_set_elem, rcu_head);
129	ip_vs_dest_put_and_free(e->dest);
130	kfree(e);
131}
132
133static void
134ip_vs_dest_set_erase(struct ip_vs_dest_set *set, struct ip_vs_dest *dest)
135{
136	struct ip_vs_dest_set_elem *e;
137
138	list_for_each_entry(e, &set->list, list) {
139		if (e->dest == dest) {
140			/* HIT */
141			atomic_dec(&set->size);
142			set->lastmod = jiffies;
143			list_del_rcu(&e->list);
144			call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
145			break;
146		}
147	}
148}
149
150static void ip_vs_dest_set_eraseall(struct ip_vs_dest_set *set)
151{
152	struct ip_vs_dest_set_elem *e, *ep;
153
154	list_for_each_entry_safe(e, ep, &set->list, list) {
155		list_del_rcu(&e->list);
156		call_rcu(&e->rcu_head, ip_vs_lblcr_elem_rcu_free);
157	}
158}
159
160/* get weighted least-connection node in the destination set */
161static inline struct ip_vs_dest *ip_vs_dest_set_min(struct ip_vs_dest_set *set)
162{
163	struct ip_vs_dest_set_elem *e;
164	struct ip_vs_dest *dest, *least;
165	int loh, doh;
166
167	/* select the first destination server, whose weight > 0 */
168	list_for_each_entry_rcu(e, &set->list, list) {
169		least = e->dest;
170		if (least->flags & IP_VS_DEST_F_OVERLOAD)
171			continue;
172
173		if ((atomic_read(&least->weight) > 0)
174		    && (least->flags & IP_VS_DEST_F_AVAILABLE)) {
175			loh = ip_vs_dest_conn_overhead(least);
176			goto nextstage;
177		}
178	}
179	return NULL;
180
181	/* find the destination with the weighted least load */
182  nextstage:
183	list_for_each_entry_continue_rcu(e, &set->list, list) {
184		dest = e->dest;
185		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
186			continue;
187
188		doh = ip_vs_dest_conn_overhead(dest);
189		if (((__s64)loh * atomic_read(&dest->weight) >
190		     (__s64)doh * atomic_read(&least->weight))
191		    && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
192			least = dest;
193			loh = doh;
194		}
195	}
196
197	IP_VS_DBG_BUF(6, "%s(): server %s:%d "
198		      "activeconns %d refcnt %d weight %d overhead %d\n",
199		      __func__,
200		      IP_VS_DBG_ADDR(least->af, &least->addr),
201		      ntohs(least->port),
202		      atomic_read(&least->activeconns),
203		      refcount_read(&least->refcnt),
204		      atomic_read(&least->weight), loh);
205	return least;
206}
207
208
209/* get weighted most-connection node in the destination set */
210static inline struct ip_vs_dest *ip_vs_dest_set_max(struct ip_vs_dest_set *set)
211{
212	struct ip_vs_dest_set_elem *e;
213	struct ip_vs_dest *dest, *most;
214	int moh, doh;
215
216	if (set == NULL)
217		return NULL;
218
219	/* select the first destination server, whose weight > 0 */
220	list_for_each_entry(e, &set->list, list) {
221		most = e->dest;
222		if (atomic_read(&most->weight) > 0) {
223			moh = ip_vs_dest_conn_overhead(most);
224			goto nextstage;
225		}
226	}
227	return NULL;
228
229	/* find the destination with the weighted most load */
230  nextstage:
231	list_for_each_entry_continue(e, &set->list, list) {
232		dest = e->dest;
233		doh = ip_vs_dest_conn_overhead(dest);
234		/* moh/mw < doh/dw ==> moh*dw < doh*mw, where mw,dw>0 */
235		if (((__s64)moh * atomic_read(&dest->weight) <
236		     (__s64)doh * atomic_read(&most->weight))
237		    && (atomic_read(&dest->weight) > 0)) {
238			most = dest;
239			moh = doh;
240		}
241	}
242
243	IP_VS_DBG_BUF(6, "%s(): server %s:%d "
244		      "activeconns %d refcnt %d weight %d overhead %d\n",
245		      __func__,
246		      IP_VS_DBG_ADDR(most->af, &most->addr), ntohs(most->port),
247		      atomic_read(&most->activeconns),
248		      refcount_read(&most->refcnt),
249		      atomic_read(&most->weight), moh);
250	return most;
251}
252
253
254/*
255 *      IPVS lblcr entry represents an association between destination
256 *      IP address and its destination server set
257 */
258struct ip_vs_lblcr_entry {
259	struct hlist_node       list;
260	int			af;		/* address family */
261	union nf_inet_addr      addr;           /* destination IP address */
262	struct ip_vs_dest_set   set;            /* destination server set */
263	unsigned long           lastuse;        /* last used time */
264	struct rcu_head		rcu_head;
265};
266
267
268/*
269 *      IPVS lblcr hash table
270 */
271struct ip_vs_lblcr_table {
272	struct rcu_head		rcu_head;
273	struct hlist_head	bucket[IP_VS_LBLCR_TAB_SIZE];  /* hash bucket */
274	atomic_t                entries;        /* number of entries */
275	int                     max_size;       /* maximum size of entries */
276	struct timer_list       periodic_timer; /* collect stale entries */
277	struct ip_vs_service	*svc;		/* pointer back to service */
278	int                     rover;          /* rover for expire check */
279	int                     counter;        /* counter for no expire */
280	bool			dead;
281};
282
283
284#ifdef CONFIG_SYSCTL
285/*
286 *      IPVS LBLCR sysctl table
287 */
288
289static struct ctl_table vs_vars_table[] = {
290	{
291		.procname	= "lblcr_expiration",
292		.data		= NULL,
293		.maxlen		= sizeof(int),
294		.mode		= 0644,
295		.proc_handler	= proc_dointvec_jiffies,
296	},
297	{ }
298};
299#endif
300
301static inline void ip_vs_lblcr_free(struct ip_vs_lblcr_entry *en)
302{
303	hlist_del_rcu(&en->list);
304	ip_vs_dest_set_eraseall(&en->set);
305	kfree_rcu(en, rcu_head);
306}
307
308
309/*
310 *	Returns hash value for IPVS LBLCR entry
311 */
312static inline unsigned int
313ip_vs_lblcr_hashkey(int af, const union nf_inet_addr *addr)
314{
315	__be32 addr_fold = addr->ip;
316
317#ifdef CONFIG_IP_VS_IPV6
318	if (af == AF_INET6)
319		addr_fold = addr->ip6[0]^addr->ip6[1]^
320			    addr->ip6[2]^addr->ip6[3];
321#endif
322	return hash_32(ntohl(addr_fold), IP_VS_LBLCR_TAB_BITS);
323}
324
325
326/*
327 *	Hash an entry in the ip_vs_lblcr_table.
328 *	returns bool success.
329 */
330static void
331ip_vs_lblcr_hash(struct ip_vs_lblcr_table *tbl, struct ip_vs_lblcr_entry *en)
332{
333	unsigned int hash = ip_vs_lblcr_hashkey(en->af, &en->addr);
334
335	hlist_add_head_rcu(&en->list, &tbl->bucket[hash]);
336	atomic_inc(&tbl->entries);
337}
338
339
340/* Get ip_vs_lblcr_entry associated with supplied parameters. */
341static inline struct ip_vs_lblcr_entry *
342ip_vs_lblcr_get(int af, struct ip_vs_lblcr_table *tbl,
343		const union nf_inet_addr *addr)
344{
345	unsigned int hash = ip_vs_lblcr_hashkey(af, addr);
346	struct ip_vs_lblcr_entry *en;
347
348	hlist_for_each_entry_rcu(en, &tbl->bucket[hash], list)
349		if (ip_vs_addr_equal(af, &en->addr, addr))
350			return en;
351
352	return NULL;
353}
354
355
356/*
357 * Create or update an ip_vs_lblcr_entry, which is a mapping of a destination
358 * IP address to a server. Called under spin lock.
359 */
360static inline struct ip_vs_lblcr_entry *
361ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, const union nf_inet_addr *daddr,
362		u16 af, struct ip_vs_dest *dest)
363{
364	struct ip_vs_lblcr_entry *en;
365
366	en = ip_vs_lblcr_get(af, tbl, daddr);
367	if (!en) {
368		en = kmalloc(sizeof(*en), GFP_ATOMIC);
369		if (!en)
370			return NULL;
371
372		en->af = af;
373		ip_vs_addr_copy(af, &en->addr, daddr);
374		en->lastuse = jiffies;
375
376		/* initialize its dest set */
377		atomic_set(&(en->set.size), 0);
378		INIT_LIST_HEAD(&en->set.list);
379
380		ip_vs_dest_set_insert(&en->set, dest, false);
381
382		ip_vs_lblcr_hash(tbl, en);
383		return en;
384	}
385
386	ip_vs_dest_set_insert(&en->set, dest, true);
387
388	return en;
389}
390
391
392/*
393 *      Flush all the entries of the specified table.
394 */
395static void ip_vs_lblcr_flush(struct ip_vs_service *svc)
396{
397	struct ip_vs_lblcr_table *tbl = svc->sched_data;
398	int i;
399	struct ip_vs_lblcr_entry *en;
400	struct hlist_node *next;
401
402	spin_lock_bh(&svc->sched_lock);
403	tbl->dead = true;
404	for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) {
405		hlist_for_each_entry_safe(en, next, &tbl->bucket[i], list) {
406			ip_vs_lblcr_free(en);
407		}
408	}
409	spin_unlock_bh(&svc->sched_lock);
410}
411
412static int sysctl_lblcr_expiration(struct ip_vs_service *svc)
413{
414#ifdef CONFIG_SYSCTL
415	return svc->ipvs->sysctl_lblcr_expiration;
416#else
417	return DEFAULT_EXPIRATION;
418#endif
419}
420
421static inline void ip_vs_lblcr_full_check(struct ip_vs_service *svc)
422{
423	struct ip_vs_lblcr_table *tbl = svc->sched_data;
424	unsigned long now = jiffies;
425	int i, j;
426	struct ip_vs_lblcr_entry *en;
427	struct hlist_node *next;
428
429	for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) {
430		j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
431
432		spin_lock(&svc->sched_lock);
433		hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) {
434			if (time_after(en->lastuse +
435				       sysctl_lblcr_expiration(svc), now))
436				continue;
437
438			ip_vs_lblcr_free(en);
439			atomic_dec(&tbl->entries);
440		}
441		spin_unlock(&svc->sched_lock);
442	}
443	tbl->rover = j;
444}
445
446
447/*
448 *      Periodical timer handler for IPVS lblcr table
449 *      It is used to collect stale entries when the number of entries
450 *      exceeds the maximum size of the table.
451 *
452 *      Fixme: we probably need more complicated algorithm to collect
453 *             entries that have not been used for a long time even
454 *             if the number of entries doesn't exceed the maximum size
455 *             of the table.
456 *      The full expiration check is for this purpose now.
457 */
458static void ip_vs_lblcr_check_expire(struct timer_list *t)
459{
460	struct ip_vs_lblcr_table *tbl = from_timer(tbl, t, periodic_timer);
461	struct ip_vs_service *svc = tbl->svc;
462	unsigned long now = jiffies;
463	int goal;
464	int i, j;
465	struct ip_vs_lblcr_entry *en;
466	struct hlist_node *next;
467
468	if ((tbl->counter % COUNT_FOR_FULL_EXPIRATION) == 0) {
469		/* do full expiration check */
470		ip_vs_lblcr_full_check(svc);
471		tbl->counter = 1;
472		goto out;
473	}
474
475	if (atomic_read(&tbl->entries) <= tbl->max_size) {
476		tbl->counter++;
477		goto out;
478	}
479
480	goal = (atomic_read(&tbl->entries) - tbl->max_size)*4/3;
481	if (goal > tbl->max_size/2)
482		goal = tbl->max_size/2;
483
484	for (i = 0, j = tbl->rover; i < IP_VS_LBLCR_TAB_SIZE; i++) {
485		j = (j + 1) & IP_VS_LBLCR_TAB_MASK;
486
487		spin_lock(&svc->sched_lock);
488		hlist_for_each_entry_safe(en, next, &tbl->bucket[j], list) {
489			if (time_before(now, en->lastuse+ENTRY_TIMEOUT))
490				continue;
491
492			ip_vs_lblcr_free(en);
493			atomic_dec(&tbl->entries);
494			goal--;
495		}
496		spin_unlock(&svc->sched_lock);
497		if (goal <= 0)
498			break;
499	}
500	tbl->rover = j;
501
502  out:
503	mod_timer(&tbl->periodic_timer, jiffies+CHECK_EXPIRE_INTERVAL);
504}
505
506static int ip_vs_lblcr_init_svc(struct ip_vs_service *svc)
507{
508	int i;
509	struct ip_vs_lblcr_table *tbl;
510
511	/*
512	 *    Allocate the ip_vs_lblcr_table for this service
513	 */
514	tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);
515	if (tbl == NULL)
516		return -ENOMEM;
517
518	svc->sched_data = tbl;
519	IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) allocated for "
520		  "current service\n", sizeof(*tbl));
521
522	/*
523	 *    Initialize the hash buckets
524	 */
525	for (i = 0; i < IP_VS_LBLCR_TAB_SIZE; i++) {
526		INIT_HLIST_HEAD(&tbl->bucket[i]);
527	}
528	tbl->max_size = IP_VS_LBLCR_TAB_SIZE*16;
529	tbl->rover = 0;
530	tbl->counter = 1;
531	tbl->dead = false;
532	tbl->svc = svc;
533	atomic_set(&tbl->entries, 0);
534
535	/*
536	 *    Hook periodic timer for garbage collection
537	 */
538	timer_setup(&tbl->periodic_timer, ip_vs_lblcr_check_expire, 0);
539	mod_timer(&tbl->periodic_timer, jiffies + CHECK_EXPIRE_INTERVAL);
540
541	return 0;
542}
543
544
545static void ip_vs_lblcr_done_svc(struct ip_vs_service *svc)
546{
547	struct ip_vs_lblcr_table *tbl = svc->sched_data;
548
549	/* remove periodic timer */
550	del_timer_sync(&tbl->periodic_timer);
551
552	/* got to clean up table entries here */
553	ip_vs_lblcr_flush(svc);
554
555	/* release the table itself */
556	kfree_rcu(tbl, rcu_head);
557	IP_VS_DBG(6, "LBLCR hash table (memory=%zdbytes) released\n",
558		  sizeof(*tbl));
559}
560
561
562static inline struct ip_vs_dest *
563__ip_vs_lblcr_schedule(struct ip_vs_service *svc)
564{
565	struct ip_vs_dest *dest, *least;
566	int loh, doh;
567
568	/*
569	 * We use the following formula to estimate the load:
570	 *                (dest overhead) / dest->weight
571	 *
572	 * Remember -- no floats in kernel mode!!!
573	 * The comparison of h1*w2 > h2*w1 is equivalent to that of
574	 *                h1/w1 > h2/w2
575	 * if every weight is larger than zero.
576	 *
577	 * The server with weight=0 is quiesced and will not receive any
578	 * new connection.
579	 */
580	list_for_each_entry_rcu(dest, &svc->destinations, n_list) {
581		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
582			continue;
583
584		if (atomic_read(&dest->weight) > 0) {
585			least = dest;
586			loh = ip_vs_dest_conn_overhead(least);
587			goto nextstage;
588		}
589	}
590	return NULL;
591
592	/*
593	 *    Find the destination with the least load.
594	 */
595  nextstage:
596	list_for_each_entry_continue_rcu(dest, &svc->destinations, n_list) {
597		if (dest->flags & IP_VS_DEST_F_OVERLOAD)
598			continue;
599
600		doh = ip_vs_dest_conn_overhead(dest);
601		if ((__s64)loh * atomic_read(&dest->weight) >
602		    (__s64)doh * atomic_read(&least->weight)) {
603			least = dest;
604			loh = doh;
605		}
606	}
607
608	IP_VS_DBG_BUF(6, "LBLCR: server %s:%d "
609		      "activeconns %d refcnt %d weight %d overhead %d\n",
610		      IP_VS_DBG_ADDR(least->af, &least->addr),
611		      ntohs(least->port),
612		      atomic_read(&least->activeconns),
613		      refcount_read(&least->refcnt),
614		      atomic_read(&least->weight), loh);
615
616	return least;
617}
618
619
620/*
621 *   If this destination server is overloaded and there is a less loaded
622 *   server, then return true.
623 */
624static inline int
625is_overloaded(struct ip_vs_dest *dest, struct ip_vs_service *svc)
626{
627	if (atomic_read(&dest->activeconns) > atomic_read(&dest->weight)) {
628		struct ip_vs_dest *d;
629
630		list_for_each_entry_rcu(d, &svc->destinations, n_list) {
631			if (atomic_read(&d->activeconns)*2
632			    < atomic_read(&d->weight)) {
633				return 1;
634			}
635		}
636	}
637	return 0;
638}
639
640
641/*
642 *    Locality-Based (weighted) Least-Connection scheduling
643 */
644static struct ip_vs_dest *
645ip_vs_lblcr_schedule(struct ip_vs_service *svc, const struct sk_buff *skb,
646		     struct ip_vs_iphdr *iph)
647{
648	struct ip_vs_lblcr_table *tbl = svc->sched_data;
649	struct ip_vs_dest *dest;
650	struct ip_vs_lblcr_entry *en;
651
652	IP_VS_DBG(6, "%s(): Scheduling...\n", __func__);
653
654	/* First look in our cache */
655	en = ip_vs_lblcr_get(svc->af, tbl, &iph->daddr);
656	if (en) {
657		en->lastuse = jiffies;
658
659		/* Get the least loaded destination */
660		dest = ip_vs_dest_set_min(&en->set);
661
662		/* More than one destination + enough time passed by, cleanup */
663		if (atomic_read(&en->set.size) > 1 &&
664		    time_after(jiffies, en->set.lastmod +
665				sysctl_lblcr_expiration(svc))) {
666			spin_lock_bh(&svc->sched_lock);
667			if (atomic_read(&en->set.size) > 1) {
668				struct ip_vs_dest *m;
669
670				m = ip_vs_dest_set_max(&en->set);
671				if (m)
672					ip_vs_dest_set_erase(&en->set, m);
673			}
674			spin_unlock_bh(&svc->sched_lock);
675		}
676
677		/* If the destination is not overloaded, use it */
678		if (dest && !is_overloaded(dest, svc))
679			goto out;
680
681		/* The cache entry is invalid, time to schedule */
682		dest = __ip_vs_lblcr_schedule(svc);
683		if (!dest) {
684			ip_vs_scheduler_err(svc, "no destination available");
685			return NULL;
686		}
687
688		/* Update our cache entry */
689		spin_lock_bh(&svc->sched_lock);
690		if (!tbl->dead)
691			ip_vs_dest_set_insert(&en->set, dest, true);
692		spin_unlock_bh(&svc->sched_lock);
693		goto out;
694	}
695
696	/* No cache entry, time to schedule */
697	dest = __ip_vs_lblcr_schedule(svc);
698	if (!dest) {
699		IP_VS_DBG(1, "no destination available\n");
700		return NULL;
701	}
702
703	/* If we fail to create a cache entry, we'll just use the valid dest */
704	spin_lock_bh(&svc->sched_lock);
705	if (!tbl->dead)
706		ip_vs_lblcr_new(tbl, &iph->daddr, svc->af, dest);
707	spin_unlock_bh(&svc->sched_lock);
708
709out:
710	IP_VS_DBG_BUF(6, "LBLCR: destination IP address %s --> server %s:%d\n",
711		      IP_VS_DBG_ADDR(svc->af, &iph->daddr),
712		      IP_VS_DBG_ADDR(dest->af, &dest->addr), ntohs(dest->port));
713
714	return dest;
715}
716
717
718/*
719 *      IPVS LBLCR Scheduler structure
720 */
721static struct ip_vs_scheduler ip_vs_lblcr_scheduler =
722{
723	.name =			"lblcr",
724	.refcnt =		ATOMIC_INIT(0),
725	.module =		THIS_MODULE,
726	.n_list =		LIST_HEAD_INIT(ip_vs_lblcr_scheduler.n_list),
727	.init_service =		ip_vs_lblcr_init_svc,
728	.done_service =		ip_vs_lblcr_done_svc,
729	.schedule =		ip_vs_lblcr_schedule,
730};
731
732/*
733 *  per netns init.
734 */
735#ifdef CONFIG_SYSCTL
736static int __net_init __ip_vs_lblcr_init(struct net *net)
737{
738	struct netns_ipvs *ipvs = net_ipvs(net);
739
740	if (!ipvs)
741		return -ENOENT;
742
743	if (!net_eq(net, &init_net)) {
744		ipvs->lblcr_ctl_table = kmemdup(vs_vars_table,
745						sizeof(vs_vars_table),
746						GFP_KERNEL);
747		if (ipvs->lblcr_ctl_table == NULL)
748			return -ENOMEM;
749
750		/* Don't export sysctls to unprivileged users */
751		if (net->user_ns != &init_user_ns)
752			ipvs->lblcr_ctl_table[0].procname = NULL;
753	} else
754		ipvs->lblcr_ctl_table = vs_vars_table;
755	ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION;
756	ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
757
758	ipvs->lblcr_ctl_header =
759		register_net_sysctl(net, "net/ipv4/vs", ipvs->lblcr_ctl_table);
760	if (!ipvs->lblcr_ctl_header) {
761		if (!net_eq(net, &init_net))
762			kfree(ipvs->lblcr_ctl_table);
763		return -ENOMEM;
764	}
765
766	return 0;
767}
768
769static void __net_exit __ip_vs_lblcr_exit(struct net *net)
770{
771	struct netns_ipvs *ipvs = net_ipvs(net);
772
773	unregister_net_sysctl_table(ipvs->lblcr_ctl_header);
774
775	if (!net_eq(net, &init_net))
776		kfree(ipvs->lblcr_ctl_table);
777}
778
779#else
780
781static int __net_init __ip_vs_lblcr_init(struct net *net) { return 0; }
782static void __net_exit __ip_vs_lblcr_exit(struct net *net) { }
783
784#endif
785
786static struct pernet_operations ip_vs_lblcr_ops = {
787	.init = __ip_vs_lblcr_init,
788	.exit = __ip_vs_lblcr_exit,
789};
790
791static int __init ip_vs_lblcr_init(void)
792{
793	int ret;
794
795	ret = register_pernet_subsys(&ip_vs_lblcr_ops);
796	if (ret)
797		return ret;
798
799	ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
800	if (ret)
801		unregister_pernet_subsys(&ip_vs_lblcr_ops);
802	return ret;
803}
804
805static void __exit ip_vs_lblcr_cleanup(void)
806{
807	unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
808	unregister_pernet_subsys(&ip_vs_lblcr_ops);
809	rcu_barrier();
810}
811
812
813module_init(ip_vs_lblcr_init);
814module_exit(ip_vs_lblcr_cleanup);
815MODULE_LICENSE("GPL");
816