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 */
86 struct 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
92 struct 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
ip_vs_dest_set_insert(struct ip_vs_dest_set * set,struct ip_vs_dest * dest,bool check)99 static 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
ip_vs_lblcr_elem_rcu_free(struct rcu_head * head)124 static 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
133 static void
ip_vs_dest_set_erase(struct ip_vs_dest_set * set,struct ip_vs_dest * dest)134 ip_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
ip_vs_dest_set_eraseall(struct ip_vs_dest_set * set)150 static 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 */
ip_vs_dest_set_min(struct ip_vs_dest_set * set)161 static 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 */
ip_vs_dest_set_max(struct ip_vs_dest_set * set)210 static 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 */
258 struct 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 */
271 struct 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
289 static 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
ip_vs_lblcr_free(struct ip_vs_lblcr_entry * en)301 static 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 */
312 static inline unsigned int
ip_vs_lblcr_hashkey(int af,const union nf_inet_addr * addr)313 ip_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 */
330 static void
ip_vs_lblcr_hash(struct ip_vs_lblcr_table * tbl,struct ip_vs_lblcr_entry * en)331 ip_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. */
341 static inline struct ip_vs_lblcr_entry *
ip_vs_lblcr_get(int af,struct ip_vs_lblcr_table * tbl,const union nf_inet_addr * addr)342 ip_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 */
360 static inline struct ip_vs_lblcr_entry *
ip_vs_lblcr_new(struct ip_vs_lblcr_table * tbl,const union nf_inet_addr * daddr,u16 af,struct ip_vs_dest * dest)361 ip_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 */
ip_vs_lblcr_flush(struct ip_vs_service * svc)395 static 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
sysctl_lblcr_expiration(struct ip_vs_service * svc)412 static 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
ip_vs_lblcr_full_check(struct ip_vs_service * svc)421 static 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 */
ip_vs_lblcr_check_expire(struct timer_list * t)458 static 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
ip_vs_lblcr_init_svc(struct ip_vs_service * svc)506 static 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
ip_vs_lblcr_done_svc(struct ip_vs_service * svc)545 static 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 timer_shutdown_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
562 static inline struct ip_vs_dest *
__ip_vs_lblcr_schedule(struct ip_vs_service * svc)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 */
624 static inline int
is_overloaded(struct ip_vs_dest * dest,struct ip_vs_service * svc)625 is_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 */
644 static struct ip_vs_dest *
ip_vs_lblcr_schedule(struct ip_vs_service * svc,const struct sk_buff * skb,struct ip_vs_iphdr * iph)645 ip_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
709 out:
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 */
721 static 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
__ip_vs_lblcr_init(struct net * net)736 static int __net_init __ip_vs_lblcr_init(struct net *net)
737 {
738 struct netns_ipvs *ipvs = net_ipvs(net);
739 size_t vars_table_size = ARRAY_SIZE(vs_vars_table);
740
741 if (!ipvs)
742 return -ENOENT;
743
744 if (!net_eq(net, &init_net)) {
745 ipvs->lblcr_ctl_table = kmemdup(vs_vars_table,
746 sizeof(vs_vars_table),
747 GFP_KERNEL);
748 if (ipvs->lblcr_ctl_table == NULL)
749 return -ENOMEM;
750
751 /* Don't export sysctls to unprivileged users */
752 if (net->user_ns != &init_user_ns) {
753 ipvs->lblcr_ctl_table[0].procname = NULL;
754 vars_table_size = 0;
755 }
756 } else
757 ipvs->lblcr_ctl_table = vs_vars_table;
758 ipvs->sysctl_lblcr_expiration = DEFAULT_EXPIRATION;
759 ipvs->lblcr_ctl_table[0].data = &ipvs->sysctl_lblcr_expiration;
760
761 ipvs->lblcr_ctl_header = register_net_sysctl_sz(net, "net/ipv4/vs",
762 ipvs->lblcr_ctl_table,
763 vars_table_size);
764 if (!ipvs->lblcr_ctl_header) {
765 if (!net_eq(net, &init_net))
766 kfree(ipvs->lblcr_ctl_table);
767 return -ENOMEM;
768 }
769
770 return 0;
771 }
772
__ip_vs_lblcr_exit(struct net * net)773 static void __net_exit __ip_vs_lblcr_exit(struct net *net)
774 {
775 struct netns_ipvs *ipvs = net_ipvs(net);
776
777 unregister_net_sysctl_table(ipvs->lblcr_ctl_header);
778
779 if (!net_eq(net, &init_net))
780 kfree(ipvs->lblcr_ctl_table);
781 }
782
783 #else
784
__ip_vs_lblcr_init(struct net * net)785 static int __net_init __ip_vs_lblcr_init(struct net *net) { return 0; }
__ip_vs_lblcr_exit(struct net * net)786 static void __net_exit __ip_vs_lblcr_exit(struct net *net) { }
787
788 #endif
789
790 static struct pernet_operations ip_vs_lblcr_ops = {
791 .init = __ip_vs_lblcr_init,
792 .exit = __ip_vs_lblcr_exit,
793 };
794
ip_vs_lblcr_init(void)795 static int __init ip_vs_lblcr_init(void)
796 {
797 int ret;
798
799 ret = register_pernet_subsys(&ip_vs_lblcr_ops);
800 if (ret)
801 return ret;
802
803 ret = register_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
804 if (ret)
805 unregister_pernet_subsys(&ip_vs_lblcr_ops);
806 return ret;
807 }
808
ip_vs_lblcr_cleanup(void)809 static void __exit ip_vs_lblcr_cleanup(void)
810 {
811 unregister_ip_vs_scheduler(&ip_vs_lblcr_scheduler);
812 unregister_pernet_subsys(&ip_vs_lblcr_ops);
813 rcu_barrier();
814 }
815
816
817 module_init(ip_vs_lblcr_init);
818 module_exit(ip_vs_lblcr_cleanup);
819 MODULE_LICENSE("GPL");
820