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Linux/net/netfilter/ipvs/ip_vs_conn.c

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  1 /*
  2  * IPVS         An implementation of the IP virtual server support for the
  3  *              LINUX operating system.  IPVS is now implemented as a module
  4  *              over the Netfilter framework. IPVS can be used to build a
  5  *              high-performance and highly available server based on a
  6  *              cluster of servers.
  7  *
  8  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
  9  *              Peter Kese <peter.kese@ijs.si>
 10  *              Julian Anastasov <ja@ssi.bg>
 11  *
 12  *              This program is free software; you can redistribute it and/or
 13  *              modify it under the terms of the GNU General Public License
 14  *              as published by the Free Software Foundation; either version
 15  *              2 of the License, or (at your option) any later version.
 16  *
 17  * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese,
 18  * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms
 19  * and others. Many code here is taken from IP MASQ code of kernel 2.2.
 20  *
 21  * Changes:
 22  *
 23  */
 24 
 25 #define KMSG_COMPONENT "IPVS"
 26 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 27 
 28 #include <linux/interrupt.h>
 29 #include <linux/in.h>
 30 #include <linux/net.h>
 31 #include <linux/kernel.h>
 32 #include <linux/module.h>
 33 #include <linux/vmalloc.h>
 34 #include <linux/proc_fs.h>              /* for proc_net_* */
 35 #include <linux/slab.h>
 36 #include <linux/seq_file.h>
 37 #include <linux/jhash.h>
 38 #include <linux/random.h>
 39 
 40 #include <net/net_namespace.h>
 41 #include <net/ip_vs.h>
 42 
 43 
 44 #ifndef CONFIG_IP_VS_TAB_BITS
 45 #define CONFIG_IP_VS_TAB_BITS   12
 46 #endif
 47 
 48 /*
 49  * Connection hash size. Default is what was selected at compile time.
 50 */
 51 static int ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
 52 module_param_named(conn_tab_bits, ip_vs_conn_tab_bits, int, 0444);
 53 MODULE_PARM_DESC(conn_tab_bits, "Set connections' hash size");
 54 
 55 /* size and mask values */
 56 int ip_vs_conn_tab_size __read_mostly;
 57 static int ip_vs_conn_tab_mask __read_mostly;
 58 
 59 /*
 60  *  Connection hash table: for input and output packets lookups of IPVS
 61  */
 62 static struct hlist_head *ip_vs_conn_tab __read_mostly;
 63 
 64 /*  SLAB cache for IPVS connections */
 65 static struct kmem_cache *ip_vs_conn_cachep __read_mostly;
 66 
 67 /*  counter for no client port connections */
 68 static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0);
 69 
 70 /* random value for IPVS connection hash */
 71 static unsigned int ip_vs_conn_rnd __read_mostly;
 72 
 73 /*
 74  *  Fine locking granularity for big connection hash table
 75  */
 76 #define CT_LOCKARRAY_BITS  5
 77 #define CT_LOCKARRAY_SIZE  (1<<CT_LOCKARRAY_BITS)
 78 #define CT_LOCKARRAY_MASK  (CT_LOCKARRAY_SIZE-1)
 79 
 80 struct ip_vs_aligned_lock
 81 {
 82         spinlock_t      l;
 83 } __attribute__((__aligned__(SMP_CACHE_BYTES)));
 84 
 85 /* lock array for conn table */
 86 static struct ip_vs_aligned_lock
 87 __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned;
 88 
 89 static inline void ct_write_lock_bh(unsigned int key)
 90 {
 91         spin_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 92 }
 93 
 94 static inline void ct_write_unlock_bh(unsigned int key)
 95 {
 96         spin_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l);
 97 }
 98 
 99 
100 /*
101  *      Returns hash value for IPVS connection entry
102  */
103 static unsigned int ip_vs_conn_hashkey(struct net *net, int af, unsigned int proto,
104                                        const union nf_inet_addr *addr,
105                                        __be16 port)
106 {
107 #ifdef CONFIG_IP_VS_IPV6
108         if (af == AF_INET6)
109                 return (jhash_3words(jhash(addr, 16, ip_vs_conn_rnd),
110                                     (__force u32)port, proto, ip_vs_conn_rnd) ^
111                         ((size_t)net>>8)) & ip_vs_conn_tab_mask;
112 #endif
113         return (jhash_3words((__force u32)addr->ip, (__force u32)port, proto,
114                             ip_vs_conn_rnd) ^
115                 ((size_t)net>>8)) & ip_vs_conn_tab_mask;
116 }
117 
118 static unsigned int ip_vs_conn_hashkey_param(const struct ip_vs_conn_param *p,
119                                              bool inverse)
120 {
121         const union nf_inet_addr *addr;
122         __be16 port;
123 
124         if (p->pe_data && p->pe->hashkey_raw)
125                 return p->pe->hashkey_raw(p, ip_vs_conn_rnd, inverse) &
126                         ip_vs_conn_tab_mask;
127 
128         if (likely(!inverse)) {
129                 addr = p->caddr;
130                 port = p->cport;
131         } else {
132                 addr = p->vaddr;
133                 port = p->vport;
134         }
135 
136         return ip_vs_conn_hashkey(p->net, p->af, p->protocol, addr, port);
137 }
138 
139 static unsigned int ip_vs_conn_hashkey_conn(const struct ip_vs_conn *cp)
140 {
141         struct ip_vs_conn_param p;
142 
143         ip_vs_conn_fill_param(ip_vs_conn_net(cp), cp->af, cp->protocol,
144                               &cp->caddr, cp->cport, NULL, 0, &p);
145 
146         if (cp->pe) {
147                 p.pe = cp->pe;
148                 p.pe_data = cp->pe_data;
149                 p.pe_data_len = cp->pe_data_len;
150         }
151 
152         return ip_vs_conn_hashkey_param(&p, false);
153 }
154 
155 /*
156  *      Hashes ip_vs_conn in ip_vs_conn_tab by netns,proto,addr,port.
157  *      returns bool success.
158  */
159 static inline int ip_vs_conn_hash(struct ip_vs_conn *cp)
160 {
161         unsigned int hash;
162         int ret;
163 
164         if (cp->flags & IP_VS_CONN_F_ONE_PACKET)
165                 return 0;
166 
167         /* Hash by protocol, client address and port */
168         hash = ip_vs_conn_hashkey_conn(cp);
169 
170         ct_write_lock_bh(hash);
171         spin_lock(&cp->lock);
172 
173         if (!(cp->flags & IP_VS_CONN_F_HASHED)) {
174                 cp->flags |= IP_VS_CONN_F_HASHED;
175                 atomic_inc(&cp->refcnt);
176                 hlist_add_head_rcu(&cp->c_list, &ip_vs_conn_tab[hash]);
177                 ret = 1;
178         } else {
179                 pr_err("%s(): request for already hashed, called from %pF\n",
180                        __func__, __builtin_return_address(0));
181                 ret = 0;
182         }
183 
184         spin_unlock(&cp->lock);
185         ct_write_unlock_bh(hash);
186 
187         return ret;
188 }
189 
190 
191 /*
192  *      UNhashes ip_vs_conn from ip_vs_conn_tab.
193  *      returns bool success. Caller should hold conn reference.
194  */
195 static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp)
196 {
197         unsigned int hash;
198         int ret;
199 
200         /* unhash it and decrease its reference counter */
201         hash = ip_vs_conn_hashkey_conn(cp);
202 
203         ct_write_lock_bh(hash);
204         spin_lock(&cp->lock);
205 
206         if (cp->flags & IP_VS_CONN_F_HASHED) {
207                 hlist_del_rcu(&cp->c_list);
208                 cp->flags &= ~IP_VS_CONN_F_HASHED;
209                 atomic_dec(&cp->refcnt);
210                 ret = 1;
211         } else
212                 ret = 0;
213 
214         spin_unlock(&cp->lock);
215         ct_write_unlock_bh(hash);
216 
217         return ret;
218 }
219 
220 /* Try to unlink ip_vs_conn from ip_vs_conn_tab.
221  * returns bool success.
222  */
223 static inline bool ip_vs_conn_unlink(struct ip_vs_conn *cp)
224 {
225         unsigned int hash;
226         bool ret;
227 
228         hash = ip_vs_conn_hashkey_conn(cp);
229 
230         ct_write_lock_bh(hash);
231         spin_lock(&cp->lock);
232 
233         if (cp->flags & IP_VS_CONN_F_HASHED) {
234                 ret = false;
235                 /* Decrease refcnt and unlink conn only if we are last user */
236                 if (atomic_cmpxchg(&cp->refcnt, 1, 0) == 1) {
237                         hlist_del_rcu(&cp->c_list);
238                         cp->flags &= ~IP_VS_CONN_F_HASHED;
239                         ret = true;
240                 }
241         } else
242                 ret = atomic_read(&cp->refcnt) ? false : true;
243 
244         spin_unlock(&cp->lock);
245         ct_write_unlock_bh(hash);
246 
247         return ret;
248 }
249 
250 
251 /*
252  *  Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
253  *  Called for pkts coming from OUTside-to-INside.
254  *      p->caddr, p->cport: pkt source address (foreign host)
255  *      p->vaddr, p->vport: pkt dest address (load balancer)
256  */
257 static inline struct ip_vs_conn *
258 __ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
259 {
260         unsigned int hash;
261         struct ip_vs_conn *cp;
262 
263         hash = ip_vs_conn_hashkey_param(p, false);
264 
265         rcu_read_lock();
266 
267         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
268                 if (p->cport == cp->cport && p->vport == cp->vport &&
269                     cp->af == p->af &&
270                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
271                     ip_vs_addr_equal(p->af, p->vaddr, &cp->vaddr) &&
272                     ((!p->cport) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) &&
273                     p->protocol == cp->protocol &&
274                     ip_vs_conn_net_eq(cp, p->net)) {
275                         if (!__ip_vs_conn_get(cp))
276                                 continue;
277                         /* HIT */
278                         rcu_read_unlock();
279                         return cp;
280                 }
281         }
282 
283         rcu_read_unlock();
284 
285         return NULL;
286 }
287 
288 struct ip_vs_conn *ip_vs_conn_in_get(const struct ip_vs_conn_param *p)
289 {
290         struct ip_vs_conn *cp;
291 
292         cp = __ip_vs_conn_in_get(p);
293         if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) {
294                 struct ip_vs_conn_param cport_zero_p = *p;
295                 cport_zero_p.cport = 0;
296                 cp = __ip_vs_conn_in_get(&cport_zero_p);
297         }
298 
299         IP_VS_DBG_BUF(9, "lookup/in %s %s:%d->%s:%d %s\n",
300                       ip_vs_proto_name(p->protocol),
301                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
302                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
303                       cp ? "hit" : "not hit");
304 
305         return cp;
306 }
307 
308 static int
309 ip_vs_conn_fill_param_proto(int af, const struct sk_buff *skb,
310                             const struct ip_vs_iphdr *iph,
311                             int inverse, struct ip_vs_conn_param *p)
312 {
313         __be16 _ports[2], *pptr;
314         struct net *net = skb_net(skb);
315 
316         pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
317         if (pptr == NULL)
318                 return 1;
319 
320         if (likely(!inverse))
321                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->saddr,
322                                       pptr[0], &iph->daddr, pptr[1], p);
323         else
324                 ip_vs_conn_fill_param(net, af, iph->protocol, &iph->daddr,
325                                       pptr[1], &iph->saddr, pptr[0], p);
326         return 0;
327 }
328 
329 struct ip_vs_conn *
330 ip_vs_conn_in_get_proto(int af, const struct sk_buff *skb,
331                         const struct ip_vs_iphdr *iph, int inverse)
332 {
333         struct ip_vs_conn_param p;
334 
335         if (ip_vs_conn_fill_param_proto(af, skb, iph, inverse, &p))
336                 return NULL;
337 
338         return ip_vs_conn_in_get(&p);
339 }
340 EXPORT_SYMBOL_GPL(ip_vs_conn_in_get_proto);
341 
342 /* Get reference to connection template */
343 struct ip_vs_conn *ip_vs_ct_in_get(const struct ip_vs_conn_param *p)
344 {
345         unsigned int hash;
346         struct ip_vs_conn *cp;
347 
348         hash = ip_vs_conn_hashkey_param(p, false);
349 
350         rcu_read_lock();
351 
352         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
353                 if (unlikely(p->pe_data && p->pe->ct_match)) {
354                         if (!ip_vs_conn_net_eq(cp, p->net))
355                                 continue;
356                         if (p->pe == cp->pe && p->pe->ct_match(p, cp)) {
357                                 if (__ip_vs_conn_get(cp))
358                                         goto out;
359                         }
360                         continue;
361                 }
362 
363                 if (cp->af == p->af &&
364                     ip_vs_addr_equal(p->af, p->caddr, &cp->caddr) &&
365                     /* protocol should only be IPPROTO_IP if
366                      * p->vaddr is a fwmark */
367                     ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC :
368                                      p->af, p->vaddr, &cp->vaddr) &&
369                     p->vport == cp->vport && p->cport == cp->cport &&
370                     cp->flags & IP_VS_CONN_F_TEMPLATE &&
371                     p->protocol == cp->protocol &&
372                     ip_vs_conn_net_eq(cp, p->net)) {
373                         if (__ip_vs_conn_get(cp))
374                                 goto out;
375                 }
376         }
377         cp = NULL;
378 
379   out:
380         rcu_read_unlock();
381 
382         IP_VS_DBG_BUF(9, "template lookup/in %s %s:%d->%s:%d %s\n",
383                       ip_vs_proto_name(p->protocol),
384                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
385                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
386                       cp ? "hit" : "not hit");
387 
388         return cp;
389 }
390 
391 /* Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab.
392  * Called for pkts coming from inside-to-OUTside.
393  *      p->caddr, p->cport: pkt source address (inside host)
394  *      p->vaddr, p->vport: pkt dest address (foreign host) */
395 struct ip_vs_conn *ip_vs_conn_out_get(const struct ip_vs_conn_param *p)
396 {
397         unsigned int hash;
398         struct ip_vs_conn *cp, *ret=NULL;
399 
400         /*
401          *      Check for "full" addressed entries
402          */
403         hash = ip_vs_conn_hashkey_param(p, true);
404 
405         rcu_read_lock();
406 
407         hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
408                 if (p->vport == cp->cport && p->cport == cp->dport &&
409                     cp->af == p->af &&
410                     ip_vs_addr_equal(p->af, p->vaddr, &cp->caddr) &&
411                     ip_vs_addr_equal(p->af, p->caddr, &cp->daddr) &&
412                     p->protocol == cp->protocol &&
413                     ip_vs_conn_net_eq(cp, p->net)) {
414                         if (!__ip_vs_conn_get(cp))
415                                 continue;
416                         /* HIT */
417                         ret = cp;
418                         break;
419                 }
420         }
421 
422         rcu_read_unlock();
423 
424         IP_VS_DBG_BUF(9, "lookup/out %s %s:%d->%s:%d %s\n",
425                       ip_vs_proto_name(p->protocol),
426                       IP_VS_DBG_ADDR(p->af, p->caddr), ntohs(p->cport),
427                       IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
428                       ret ? "hit" : "not hit");
429 
430         return ret;
431 }
432 
433 struct ip_vs_conn *
434 ip_vs_conn_out_get_proto(int af, const struct sk_buff *skb,
435                          const struct ip_vs_iphdr *iph, int inverse)
436 {
437         struct ip_vs_conn_param p;
438 
439         if (ip_vs_conn_fill_param_proto(af, skb, iph, inverse, &p))
440                 return NULL;
441 
442         return ip_vs_conn_out_get(&p);
443 }
444 EXPORT_SYMBOL_GPL(ip_vs_conn_out_get_proto);
445 
446 /*
447  *      Put back the conn and restart its timer with its timeout
448  */
449 void ip_vs_conn_put(struct ip_vs_conn *cp)
450 {
451         unsigned long t = (cp->flags & IP_VS_CONN_F_ONE_PACKET) ?
452                 0 : cp->timeout;
453         mod_timer(&cp->timer, jiffies+t);
454 
455         __ip_vs_conn_put(cp);
456 }
457 
458 
459 /*
460  *      Fill a no_client_port connection with a client port number
461  */
462 void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __be16 cport)
463 {
464         if (ip_vs_conn_unhash(cp)) {
465                 spin_lock_bh(&cp->lock);
466                 if (cp->flags & IP_VS_CONN_F_NO_CPORT) {
467                         atomic_dec(&ip_vs_conn_no_cport_cnt);
468                         cp->flags &= ~IP_VS_CONN_F_NO_CPORT;
469                         cp->cport = cport;
470                 }
471                 spin_unlock_bh(&cp->lock);
472 
473                 /* hash on new dport */
474                 ip_vs_conn_hash(cp);
475         }
476 }
477 
478 
479 /*
480  *      Bind a connection entry with the corresponding packet_xmit.
481  *      Called by ip_vs_conn_new.
482  */
483 static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp)
484 {
485         switch (IP_VS_FWD_METHOD(cp)) {
486         case IP_VS_CONN_F_MASQ:
487                 cp->packet_xmit = ip_vs_nat_xmit;
488                 break;
489 
490         case IP_VS_CONN_F_TUNNEL:
491                 cp->packet_xmit = ip_vs_tunnel_xmit;
492                 break;
493 
494         case IP_VS_CONN_F_DROUTE:
495                 cp->packet_xmit = ip_vs_dr_xmit;
496                 break;
497 
498         case IP_VS_CONN_F_LOCALNODE:
499                 cp->packet_xmit = ip_vs_null_xmit;
500                 break;
501 
502         case IP_VS_CONN_F_BYPASS:
503                 cp->packet_xmit = ip_vs_bypass_xmit;
504                 break;
505         }
506 }
507 
508 #ifdef CONFIG_IP_VS_IPV6
509 static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp)
510 {
511         switch (IP_VS_FWD_METHOD(cp)) {
512         case IP_VS_CONN_F_MASQ:
513                 cp->packet_xmit = ip_vs_nat_xmit_v6;
514                 break;
515 
516         case IP_VS_CONN_F_TUNNEL:
517                 cp->packet_xmit = ip_vs_tunnel_xmit_v6;
518                 break;
519 
520         case IP_VS_CONN_F_DROUTE:
521                 cp->packet_xmit = ip_vs_dr_xmit_v6;
522                 break;
523 
524         case IP_VS_CONN_F_LOCALNODE:
525                 cp->packet_xmit = ip_vs_null_xmit;
526                 break;
527 
528         case IP_VS_CONN_F_BYPASS:
529                 cp->packet_xmit = ip_vs_bypass_xmit_v6;
530                 break;
531         }
532 }
533 #endif
534 
535 
536 static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest)
537 {
538         return atomic_read(&dest->activeconns)
539                 + atomic_read(&dest->inactconns);
540 }
541 
542 /*
543  *      Bind a connection entry with a virtual service destination
544  *      Called just after a new connection entry is created.
545  */
546 static inline void
547 ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest)
548 {
549         unsigned int conn_flags;
550         __u32 flags;
551 
552         /* if dest is NULL, then return directly */
553         if (!dest)
554                 return;
555 
556         /* Increase the refcnt counter of the dest */
557         ip_vs_dest_hold(dest);
558 
559         conn_flags = atomic_read(&dest->conn_flags);
560         if (cp->protocol != IPPROTO_UDP)
561                 conn_flags &= ~IP_VS_CONN_F_ONE_PACKET;
562         flags = cp->flags;
563         /* Bind with the destination and its corresponding transmitter */
564         if (flags & IP_VS_CONN_F_SYNC) {
565                 /* if the connection is not template and is created
566                  * by sync, preserve the activity flag.
567                  */
568                 if (!(flags & IP_VS_CONN_F_TEMPLATE))
569                         conn_flags &= ~IP_VS_CONN_F_INACTIVE;
570                 /* connections inherit forwarding method from dest */
571                 flags &= ~(IP_VS_CONN_F_FWD_MASK | IP_VS_CONN_F_NOOUTPUT);
572         }
573         flags |= conn_flags;
574         cp->flags = flags;
575         cp->dest = dest;
576 
577         IP_VS_DBG_BUF(7, "Bind-dest %s c:%s:%d v:%s:%d "
578                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
579                       "dest->refcnt:%d\n",
580                       ip_vs_proto_name(cp->protocol),
581                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
582                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
583                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
584                       ip_vs_fwd_tag(cp), cp->state,
585                       cp->flags, atomic_read(&cp->refcnt),
586                       atomic_read(&dest->refcnt));
587 
588         /* Update the connection counters */
589         if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
590                 /* It is a normal connection, so modify the counters
591                  * according to the flags, later the protocol can
592                  * update them on state change
593                  */
594                 if (!(flags & IP_VS_CONN_F_INACTIVE))
595                         atomic_inc(&dest->activeconns);
596                 else
597                         atomic_inc(&dest->inactconns);
598         } else {
599                 /* It is a persistent connection/template, so increase
600                    the persistent connection counter */
601                 atomic_inc(&dest->persistconns);
602         }
603 
604         if (dest->u_threshold != 0 &&
605             ip_vs_dest_totalconns(dest) >= dest->u_threshold)
606                 dest->flags |= IP_VS_DEST_F_OVERLOAD;
607 }
608 
609 
610 /*
611  * Check if there is a destination for the connection, if so
612  * bind the connection to the destination.
613  */
614 void ip_vs_try_bind_dest(struct ip_vs_conn *cp)
615 {
616         struct ip_vs_dest *dest;
617 
618         rcu_read_lock();
619         dest = ip_vs_find_dest(ip_vs_conn_net(cp), cp->af, &cp->daddr,
620                                cp->dport, &cp->vaddr, cp->vport,
621                                cp->protocol, cp->fwmark, cp->flags);
622         if (dest) {
623                 struct ip_vs_proto_data *pd;
624 
625                 spin_lock_bh(&cp->lock);
626                 if (cp->dest) {
627                         spin_unlock_bh(&cp->lock);
628                         rcu_read_unlock();
629                         return;
630                 }
631 
632                 /* Applications work depending on the forwarding method
633                  * but better to reassign them always when binding dest */
634                 if (cp->app)
635                         ip_vs_unbind_app(cp);
636 
637                 ip_vs_bind_dest(cp, dest);
638                 spin_unlock_bh(&cp->lock);
639 
640                 /* Update its packet transmitter */
641                 cp->packet_xmit = NULL;
642 #ifdef CONFIG_IP_VS_IPV6
643                 if (cp->af == AF_INET6)
644                         ip_vs_bind_xmit_v6(cp);
645                 else
646 #endif
647                         ip_vs_bind_xmit(cp);
648 
649                 pd = ip_vs_proto_data_get(ip_vs_conn_net(cp), cp->protocol);
650                 if (pd && atomic_read(&pd->appcnt))
651                         ip_vs_bind_app(cp, pd->pp);
652         }
653         rcu_read_unlock();
654 }
655 
656 
657 /*
658  *      Unbind a connection entry with its VS destination
659  *      Called by the ip_vs_conn_expire function.
660  */
661 static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp)
662 {
663         struct ip_vs_dest *dest = cp->dest;
664 
665         if (!dest)
666                 return;
667 
668         IP_VS_DBG_BUF(7, "Unbind-dest %s c:%s:%d v:%s:%d "
669                       "d:%s:%d fwd:%c s:%u conn->flags:%X conn->refcnt:%d "
670                       "dest->refcnt:%d\n",
671                       ip_vs_proto_name(cp->protocol),
672                       IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
673                       IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
674                       IP_VS_DBG_ADDR(cp->af, &cp->daddr), ntohs(cp->dport),
675                       ip_vs_fwd_tag(cp), cp->state,
676                       cp->flags, atomic_read(&cp->refcnt),
677                       atomic_read(&dest->refcnt));
678 
679         /* Update the connection counters */
680         if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) {
681                 /* It is a normal connection, so decrease the inactconns
682                    or activeconns counter */
683                 if (cp->flags & IP_VS_CONN_F_INACTIVE) {
684                         atomic_dec(&dest->inactconns);
685                 } else {
686                         atomic_dec(&dest->activeconns);
687                 }
688         } else {
689                 /* It is a persistent connection/template, so decrease
690                    the persistent connection counter */
691                 atomic_dec(&dest->persistconns);
692         }
693 
694         if (dest->l_threshold != 0) {
695                 if (ip_vs_dest_totalconns(dest) < dest->l_threshold)
696                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
697         } else if (dest->u_threshold != 0) {
698                 if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3)
699                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
700         } else {
701                 if (dest->flags & IP_VS_DEST_F_OVERLOAD)
702                         dest->flags &= ~IP_VS_DEST_F_OVERLOAD;
703         }
704 
705         ip_vs_dest_put(dest);
706 }
707 
708 static int expire_quiescent_template(struct netns_ipvs *ipvs,
709                                      struct ip_vs_dest *dest)
710 {
711 #ifdef CONFIG_SYSCTL
712         return ipvs->sysctl_expire_quiescent_template &&
713                 (atomic_read(&dest->weight) == 0);
714 #else
715         return 0;
716 #endif
717 }
718 
719 /*
720  *      Checking if the destination of a connection template is available.
721  *      If available, return 1, otherwise invalidate this connection
722  *      template and return 0.
723  */
724 int ip_vs_check_template(struct ip_vs_conn *ct)
725 {
726         struct ip_vs_dest *dest = ct->dest;
727         struct netns_ipvs *ipvs = net_ipvs(ip_vs_conn_net(ct));
728 
729         /*
730          * Checking the dest server status.
731          */
732         if ((dest == NULL) ||
733             !(dest->flags & IP_VS_DEST_F_AVAILABLE) ||
734             expire_quiescent_template(ipvs, dest)) {
735                 IP_VS_DBG_BUF(9, "check_template: dest not available for "
736                               "protocol %s s:%s:%d v:%s:%d "
737                               "-> d:%s:%d\n",
738                               ip_vs_proto_name(ct->protocol),
739                               IP_VS_DBG_ADDR(ct->af, &ct->caddr),
740                               ntohs(ct->cport),
741                               IP_VS_DBG_ADDR(ct->af, &ct->vaddr),
742                               ntohs(ct->vport),
743                               IP_VS_DBG_ADDR(ct->af, &ct->daddr),
744                               ntohs(ct->dport));
745 
746                 /*
747                  * Invalidate the connection template
748                  */
749                 if (ct->vport != htons(0xffff)) {
750                         if (ip_vs_conn_unhash(ct)) {
751                                 ct->dport = htons(0xffff);
752                                 ct->vport = htons(0xffff);
753                                 ct->cport = 0;
754                                 ip_vs_conn_hash(ct);
755                         }
756                 }
757 
758                 /*
759                  * Simply decrease the refcnt of the template,
760                  * don't restart its timer.
761                  */
762                 __ip_vs_conn_put(ct);
763                 return 0;
764         }
765         return 1;
766 }
767 
768 static void ip_vs_conn_rcu_free(struct rcu_head *head)
769 {
770         struct ip_vs_conn *cp = container_of(head, struct ip_vs_conn,
771                                              rcu_head);
772 
773         ip_vs_pe_put(cp->pe);
774         kfree(cp->pe_data);
775         kmem_cache_free(ip_vs_conn_cachep, cp);
776 }
777 
778 static void ip_vs_conn_expire(unsigned long data)
779 {
780         struct ip_vs_conn *cp = (struct ip_vs_conn *)data;
781         struct net *net = ip_vs_conn_net(cp);
782         struct netns_ipvs *ipvs = net_ipvs(net);
783 
784         /*
785          *      do I control anybody?
786          */
787         if (atomic_read(&cp->n_control))
788                 goto expire_later;
789 
790         /* Unlink conn if not referenced anymore */
791         if (likely(ip_vs_conn_unlink(cp))) {
792                 /* delete the timer if it is activated by other users */
793                 del_timer(&cp->timer);
794 
795                 /* does anybody control me? */
796                 if (cp->control)
797                         ip_vs_control_del(cp);
798 
799                 if (cp->flags & IP_VS_CONN_F_NFCT) {
800                         /* Do not access conntracks during subsys cleanup
801                          * because nf_conntrack_find_get can not be used after
802                          * conntrack cleanup for the net.
803                          */
804                         smp_rmb();
805                         if (ipvs->enable)
806                                 ip_vs_conn_drop_conntrack(cp);
807                 }
808 
809                 if (unlikely(cp->app != NULL))
810                         ip_vs_unbind_app(cp);
811                 ip_vs_unbind_dest(cp);
812                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
813                         atomic_dec(&ip_vs_conn_no_cport_cnt);
814                 call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
815                 atomic_dec(&ipvs->conn_count);
816                 return;
817         }
818 
819   expire_later:
820         IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
821                   atomic_read(&cp->refcnt),
822                   atomic_read(&cp->n_control));
823 
824         atomic_inc(&cp->refcnt);
825         cp->timeout = 60*HZ;
826 
827         if (ipvs->sync_state & IP_VS_STATE_MASTER)
828                 ip_vs_sync_conn(net, cp, sysctl_sync_threshold(ipvs));
829 
830         ip_vs_conn_put(cp);
831 }
832 
833 /* Modify timer, so that it expires as soon as possible.
834  * Can be called without reference only if under RCU lock.
835  */
836 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
837 {
838         /* Using mod_timer_pending will ensure the timer is not
839          * modified after the final del_timer in ip_vs_conn_expire.
840          */
841         if (timer_pending(&cp->timer) &&
842             time_after(cp->timer.expires, jiffies))
843                 mod_timer_pending(&cp->timer, jiffies);
844 }
845 
846 
847 /*
848  *      Create a new connection entry and hash it into the ip_vs_conn_tab
849  */
850 struct ip_vs_conn *
851 ip_vs_conn_new(const struct ip_vs_conn_param *p,
852                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
853                struct ip_vs_dest *dest, __u32 fwmark)
854 {
855         struct ip_vs_conn *cp;
856         struct netns_ipvs *ipvs = net_ipvs(p->net);
857         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->net,
858                                                            p->protocol);
859 
860         cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
861         if (cp == NULL) {
862                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
863                 return NULL;
864         }
865 
866         INIT_HLIST_NODE(&cp->c_list);
867         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
868         ip_vs_conn_net_set(cp, p->net);
869         cp->af             = p->af;
870         cp->protocol       = p->protocol;
871         ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
872         cp->cport          = p->cport;
873         /* proto should only be IPPROTO_IP if p->vaddr is a fwmark */
874         ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
875                        &cp->vaddr, p->vaddr);
876         cp->vport          = p->vport;
877         ip_vs_addr_set(p->af, &cp->daddr, daddr);
878         cp->dport          = dport;
879         cp->flags          = flags;
880         cp->fwmark         = fwmark;
881         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
882                 ip_vs_pe_get(p->pe);
883                 cp->pe = p->pe;
884                 cp->pe_data = p->pe_data;
885                 cp->pe_data_len = p->pe_data_len;
886         } else {
887                 cp->pe = NULL;
888                 cp->pe_data = NULL;
889                 cp->pe_data_len = 0;
890         }
891         spin_lock_init(&cp->lock);
892 
893         /*
894          * Set the entry is referenced by the current thread before hashing
895          * it in the table, so that other thread run ip_vs_random_dropentry
896          * but cannot drop this entry.
897          */
898         atomic_set(&cp->refcnt, 1);
899 
900         cp->control = NULL;
901         atomic_set(&cp->n_control, 0);
902         atomic_set(&cp->in_pkts, 0);
903 
904         cp->packet_xmit = NULL;
905         cp->app = NULL;
906         cp->app_data = NULL;
907         /* reset struct ip_vs_seq */
908         cp->in_seq.delta = 0;
909         cp->out_seq.delta = 0;
910 
911         atomic_inc(&ipvs->conn_count);
912         if (flags & IP_VS_CONN_F_NO_CPORT)
913                 atomic_inc(&ip_vs_conn_no_cport_cnt);
914 
915         /* Bind the connection with a destination server */
916         cp->dest = NULL;
917         ip_vs_bind_dest(cp, dest);
918 
919         /* Set its state and timeout */
920         cp->state = 0;
921         cp->old_state = 0;
922         cp->timeout = 3*HZ;
923         cp->sync_endtime = jiffies & ~3UL;
924 
925         /* Bind its packet transmitter */
926 #ifdef CONFIG_IP_VS_IPV6
927         if (p->af == AF_INET6)
928                 ip_vs_bind_xmit_v6(cp);
929         else
930 #endif
931                 ip_vs_bind_xmit(cp);
932 
933         if (unlikely(pd && atomic_read(&pd->appcnt)))
934                 ip_vs_bind_app(cp, pd->pp);
935 
936         /*
937          * Allow conntrack to be preserved. By default, conntrack
938          * is created and destroyed for every packet.
939          * Sometimes keeping conntrack can be useful for
940          * IP_VS_CONN_F_ONE_PACKET too.
941          */
942 
943         if (ip_vs_conntrack_enabled(ipvs))
944                 cp->flags |= IP_VS_CONN_F_NFCT;
945 
946         /* Hash it in the ip_vs_conn_tab finally */
947         ip_vs_conn_hash(cp);
948 
949         return cp;
950 }
951 
952 /*
953  *      /proc/net/ip_vs_conn entries
954  */
955 #ifdef CONFIG_PROC_FS
956 struct ip_vs_iter_state {
957         struct seq_net_private  p;
958         struct hlist_head       *l;
959 };
960 
961 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
962 {
963         int idx;
964         struct ip_vs_conn *cp;
965         struct ip_vs_iter_state *iter = seq->private;
966 
967         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
968                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
969                         /* __ip_vs_conn_get() is not needed by
970                          * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
971                          */
972                         if (pos-- == 0) {
973                                 iter->l = &ip_vs_conn_tab[idx];
974                                 return cp;
975                         }
976                 }
977                 cond_resched_rcu();
978         }
979 
980         return NULL;
981 }
982 
983 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
984         __acquires(RCU)
985 {
986         struct ip_vs_iter_state *iter = seq->private;
987 
988         iter->l = NULL;
989         rcu_read_lock();
990         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
991 }
992 
993 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
994 {
995         struct ip_vs_conn *cp = v;
996         struct ip_vs_iter_state *iter = seq->private;
997         struct hlist_node *e;
998         struct hlist_head *l = iter->l;
999         int idx;
1000 
1001         ++*pos;
1002         if (v == SEQ_START_TOKEN)
1003                 return ip_vs_conn_array(seq, 0);
1004 
1005         /* more on same hash chain? */
1006         e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1007         if (e)
1008                 return hlist_entry(e, struct ip_vs_conn, c_list);
1009 
1010         idx = l - ip_vs_conn_tab;
1011         while (++idx < ip_vs_conn_tab_size) {
1012                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1013                         iter->l = &ip_vs_conn_tab[idx];
1014                         return cp;
1015                 }
1016                 cond_resched_rcu();
1017         }
1018         iter->l = NULL;
1019         return NULL;
1020 }
1021 
1022 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1023         __releases(RCU)
1024 {
1025         rcu_read_unlock();
1026 }
1027 
1028 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1029 {
1030 
1031         if (v == SEQ_START_TOKEN)
1032                 seq_puts(seq,
1033    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1034         else {
1035                 const struct ip_vs_conn *cp = v;
1036                 struct net *net = seq_file_net(seq);
1037                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1038                 size_t len = 0;
1039 
1040                 if (!ip_vs_conn_net_eq(cp, net))
1041                         return 0;
1042                 if (cp->pe_data) {
1043                         pe_data[0] = ' ';
1044                         len = strlen(cp->pe->name);
1045                         memcpy(pe_data + 1, cp->pe->name, len);
1046                         pe_data[len + 1] = ' ';
1047                         len += 2;
1048                         len += cp->pe->show_pe_data(cp, pe_data + len);
1049                 }
1050                 pe_data[len] = '\0';
1051 
1052 #ifdef CONFIG_IP_VS_IPV6
1053                 if (cp->af == AF_INET6)
1054                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1055                                 "%pI6 %04X %-11s %7lu%s\n",
1056                                 ip_vs_proto_name(cp->protocol),
1057                                 &cp->caddr.in6, ntohs(cp->cport),
1058                                 &cp->vaddr.in6, ntohs(cp->vport),
1059                                 &cp->daddr.in6, ntohs(cp->dport),
1060                                 ip_vs_state_name(cp->protocol, cp->state),
1061                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1062                 else
1063 #endif
1064                         seq_printf(seq,
1065                                 "%-3s %08X %04X %08X %04X"
1066                                 " %08X %04X %-11s %7lu%s\n",
1067                                 ip_vs_proto_name(cp->protocol),
1068                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1069                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1070                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1071                                 ip_vs_state_name(cp->protocol, cp->state),
1072                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1073         }
1074         return 0;
1075 }
1076 
1077 static const struct seq_operations ip_vs_conn_seq_ops = {
1078         .start = ip_vs_conn_seq_start,
1079         .next  = ip_vs_conn_seq_next,
1080         .stop  = ip_vs_conn_seq_stop,
1081         .show  = ip_vs_conn_seq_show,
1082 };
1083 
1084 static int ip_vs_conn_open(struct inode *inode, struct file *file)
1085 {
1086         return seq_open_net(inode, file, &ip_vs_conn_seq_ops,
1087                             sizeof(struct ip_vs_iter_state));
1088 }
1089 
1090 static const struct file_operations ip_vs_conn_fops = {
1091         .owner   = THIS_MODULE,
1092         .open    = ip_vs_conn_open,
1093         .read    = seq_read,
1094         .llseek  = seq_lseek,
1095         .release = seq_release_net,
1096 };
1097 
1098 static const char *ip_vs_origin_name(unsigned int flags)
1099 {
1100         if (flags & IP_VS_CONN_F_SYNC)
1101                 return "SYNC";
1102         else
1103                 return "LOCAL";
1104 }
1105 
1106 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1107 {
1108 
1109         if (v == SEQ_START_TOKEN)
1110                 seq_puts(seq,
1111    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1112         else {
1113                 const struct ip_vs_conn *cp = v;
1114                 struct net *net = seq_file_net(seq);
1115 
1116                 if (!ip_vs_conn_net_eq(cp, net))
1117                         return 0;
1118 
1119 #ifdef CONFIG_IP_VS_IPV6
1120                 if (cp->af == AF_INET6)
1121                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
1122                                 ip_vs_proto_name(cp->protocol),
1123                                 &cp->caddr.in6, ntohs(cp->cport),
1124                                 &cp->vaddr.in6, ntohs(cp->vport),
1125                                 &cp->daddr.in6, ntohs(cp->dport),
1126                                 ip_vs_state_name(cp->protocol, cp->state),
1127                                 ip_vs_origin_name(cp->flags),
1128                                 (cp->timer.expires-jiffies)/HZ);
1129                 else
1130 #endif
1131                         seq_printf(seq,
1132                                 "%-3s %08X %04X %08X %04X "
1133                                 "%08X %04X %-11s %-6s %7lu\n",
1134                                 ip_vs_proto_name(cp->protocol),
1135                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1136                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1137                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1138                                 ip_vs_state_name(cp->protocol, cp->state),
1139                                 ip_vs_origin_name(cp->flags),
1140                                 (cp->timer.expires-jiffies)/HZ);
1141         }
1142         return 0;
1143 }
1144 
1145 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1146         .start = ip_vs_conn_seq_start,
1147         .next  = ip_vs_conn_seq_next,
1148         .stop  = ip_vs_conn_seq_stop,
1149         .show  = ip_vs_conn_sync_seq_show,
1150 };
1151 
1152 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
1153 {
1154         return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops,
1155                             sizeof(struct ip_vs_iter_state));
1156 }
1157 
1158 static const struct file_operations ip_vs_conn_sync_fops = {
1159         .owner   = THIS_MODULE,
1160         .open    = ip_vs_conn_sync_open,
1161         .read    = seq_read,
1162         .llseek  = seq_lseek,
1163         .release = seq_release_net,
1164 };
1165 
1166 #endif
1167 
1168 
1169 /*
1170  *      Randomly drop connection entries before running out of memory
1171  */
1172 static inline int todrop_entry(struct ip_vs_conn *cp)
1173 {
1174         /*
1175          * The drop rate array needs tuning for real environments.
1176          * Called from timer bh only => no locking
1177          */
1178         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1179         static char todrop_counter[9] = {0};
1180         int i;
1181 
1182         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1183            This will leave enough time for normal connection to get
1184            through. */
1185         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1186                 return 0;
1187 
1188         /* Don't drop the entry if its number of incoming packets is not
1189            located in [0, 8] */
1190         i = atomic_read(&cp->in_pkts);
1191         if (i > 8 || i < 0) return 0;
1192 
1193         if (!todrop_rate[i]) return 0;
1194         if (--todrop_counter[i] > 0) return 0;
1195 
1196         todrop_counter[i] = todrop_rate[i];
1197         return 1;
1198 }
1199 
1200 /* Called from keventd and must protect itself from softirqs */
1201 void ip_vs_random_dropentry(struct net *net)
1202 {
1203         int idx;
1204         struct ip_vs_conn *cp, *cp_c;
1205 
1206         rcu_read_lock();
1207         /*
1208          * Randomly scan 1/32 of the whole table every second
1209          */
1210         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1211                 unsigned int hash = net_random() & ip_vs_conn_tab_mask;
1212 
1213                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1214                         if (cp->flags & IP_VS_CONN_F_TEMPLATE)
1215                                 /* connection template */
1216                                 continue;
1217                         if (!ip_vs_conn_net_eq(cp, net))
1218                                 continue;
1219                         if (cp->protocol == IPPROTO_TCP) {
1220                                 switch(cp->state) {
1221                                 case IP_VS_TCP_S_SYN_RECV:
1222                                 case IP_VS_TCP_S_SYNACK:
1223                                         break;
1224 
1225                                 case IP_VS_TCP_S_ESTABLISHED:
1226                                         if (todrop_entry(cp))
1227                                                 break;
1228                                         continue;
1229 
1230                                 default:
1231                                         continue;
1232                                 }
1233                         } else if (cp->protocol == IPPROTO_SCTP) {
1234                                 switch (cp->state) {
1235                                 case IP_VS_SCTP_S_INIT1:
1236                                 case IP_VS_SCTP_S_INIT:
1237                                         break;
1238                                 case IP_VS_SCTP_S_ESTABLISHED:
1239                                         if (todrop_entry(cp))
1240                                                 break;
1241                                         continue;
1242                                 default:
1243                                         continue;
1244                                 }
1245                         } else {
1246                                 if (!todrop_entry(cp))
1247                                         continue;
1248                         }
1249 
1250                         IP_VS_DBG(4, "del connection\n");
1251                         ip_vs_conn_expire_now(cp);
1252                         cp_c = cp->control;
1253                         /* cp->control is valid only with reference to cp */
1254                         if (cp_c && __ip_vs_conn_get(cp)) {
1255                                 IP_VS_DBG(4, "del conn template\n");
1256                                 ip_vs_conn_expire_now(cp_c);
1257                                 __ip_vs_conn_put(cp);
1258                         }
1259                 }
1260                 cond_resched_rcu();
1261         }
1262         rcu_read_unlock();
1263 }
1264 
1265 
1266 /*
1267  *      Flush all the connection entries in the ip_vs_conn_tab
1268  */
1269 static void ip_vs_conn_flush(struct net *net)
1270 {
1271         int idx;
1272         struct ip_vs_conn *cp, *cp_c;
1273         struct netns_ipvs *ipvs = net_ipvs(net);
1274 
1275 flush_again:
1276         rcu_read_lock();
1277         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1278 
1279                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1280                         if (!ip_vs_conn_net_eq(cp, net))
1281                                 continue;
1282                         IP_VS_DBG(4, "del connection\n");
1283                         ip_vs_conn_expire_now(cp);
1284                         cp_c = cp->control;
1285                         /* cp->control is valid only with reference to cp */
1286                         if (cp_c && __ip_vs_conn_get(cp)) {
1287                                 IP_VS_DBG(4, "del conn template\n");
1288                                 ip_vs_conn_expire_now(cp_c);
1289                                 __ip_vs_conn_put(cp);
1290                         }
1291                 }
1292                 cond_resched_rcu();
1293         }
1294         rcu_read_unlock();
1295 
1296         /* the counter may be not NULL, because maybe some conn entries
1297            are run by slow timer handler or unhashed but still referred */
1298         if (atomic_read(&ipvs->conn_count) != 0) {
1299                 schedule();
1300                 goto flush_again;
1301         }
1302 }
1303 /*
1304  * per netns init and exit
1305  */
1306 int __net_init ip_vs_conn_net_init(struct net *net)
1307 {
1308         struct netns_ipvs *ipvs = net_ipvs(net);
1309 
1310         atomic_set(&ipvs->conn_count, 0);
1311 
1312         proc_create("ip_vs_conn", 0, net->proc_net, &ip_vs_conn_fops);
1313         proc_create("ip_vs_conn_sync", 0, net->proc_net, &ip_vs_conn_sync_fops);
1314         return 0;
1315 }
1316 
1317 void __net_exit ip_vs_conn_net_cleanup(struct net *net)
1318 {
1319         /* flush all the connection entries first */
1320         ip_vs_conn_flush(net);
1321         remove_proc_entry("ip_vs_conn", net->proc_net);
1322         remove_proc_entry("ip_vs_conn_sync", net->proc_net);
1323 }
1324 
1325 int __init ip_vs_conn_init(void)
1326 {
1327         int idx;
1328 
1329         /* Compute size and mask */
1330         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1331         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1332 
1333         /*
1334          * Allocate the connection hash table and initialize its list heads
1335          */
1336         ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab));
1337         if (!ip_vs_conn_tab)
1338                 return -ENOMEM;
1339 
1340         /* Allocate ip_vs_conn slab cache */
1341         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1342                                               sizeof(struct ip_vs_conn), 0,
1343                                               SLAB_HWCACHE_ALIGN, NULL);
1344         if (!ip_vs_conn_cachep) {
1345                 vfree(ip_vs_conn_tab);
1346                 return -ENOMEM;
1347         }
1348 
1349         pr_info("Connection hash table configured "
1350                 "(size=%d, memory=%ldKbytes)\n",
1351                 ip_vs_conn_tab_size,
1352                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1353         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1354                   sizeof(struct ip_vs_conn));
1355 
1356         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1357                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1358 
1359         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1360                 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1361         }
1362 
1363         /* calculate the random value for connection hash */
1364         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1365 
1366         return 0;
1367 }
1368 
1369 void ip_vs_conn_cleanup(void)
1370 {
1371         /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1372         rcu_barrier();
1373         /* Release the empty cache */
1374         kmem_cache_destroy(ip_vs_conn_cachep);
1375         vfree(ip_vs_conn_tab);
1376 }
1377 

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