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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                         ip_vs_conn_drop_conntrack(cp);
801                         /* Do not access conntracks during subsys cleanup
802                          * because nf_conntrack_find_get can not be used after
803                          * conntrack cleanup for the net.
804                          */
805                         smp_rmb();
806                         if (ipvs->enable)
807                                 ip_vs_conn_drop_conntrack(cp);
808                 }
809 
810                 if (unlikely(cp->app != NULL))
811                         ip_vs_unbind_app(cp);
812                 ip_vs_unbind_dest(cp);
813                 if (cp->flags & IP_VS_CONN_F_NO_CPORT)
814                         atomic_dec(&ip_vs_conn_no_cport_cnt);
815                 call_rcu(&cp->rcu_head, ip_vs_conn_rcu_free);
816                 atomic_dec(&ipvs->conn_count);
817                 return;
818         }
819 
820   expire_later:
821         IP_VS_DBG(7, "delayed: conn->refcnt=%d conn->n_control=%d\n",
822                   atomic_read(&cp->refcnt),
823                   atomic_read(&cp->n_control));
824 
825         atomic_inc(&cp->refcnt);
826         cp->timeout = 60*HZ;
827 
828         if (ipvs->sync_state & IP_VS_STATE_MASTER)
829                 ip_vs_sync_conn(net, cp, sysctl_sync_threshold(ipvs));
830 
831         ip_vs_conn_put(cp);
832 }
833 
834 /* Modify timer, so that it expires as soon as possible.
835  * Can be called without reference only if under RCU lock.
836  */
837 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
838 {
839         /* Using mod_timer_pending will ensure the timer is not
840          * modified after the final del_timer in ip_vs_conn_expire.
841          */
842         if (timer_pending(&cp->timer) &&
843             time_after(cp->timer.expires, jiffies))
844                 mod_timer_pending(&cp->timer, jiffies);
845 }
846 
847 
848 /*
849  *      Create a new connection entry and hash it into the ip_vs_conn_tab
850  */
851 struct ip_vs_conn *
852 ip_vs_conn_new(const struct ip_vs_conn_param *p,
853                const union nf_inet_addr *daddr, __be16 dport, unsigned int flags,
854                struct ip_vs_dest *dest, __u32 fwmark)
855 {
856         struct ip_vs_conn *cp;
857         struct netns_ipvs *ipvs = net_ipvs(p->net);
858         struct ip_vs_proto_data *pd = ip_vs_proto_data_get(p->net,
859                                                            p->protocol);
860 
861         cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC);
862         if (cp == NULL) {
863                 IP_VS_ERR_RL("%s(): no memory\n", __func__);
864                 return NULL;
865         }
866 
867         INIT_HLIST_NODE(&cp->c_list);
868         setup_timer(&cp->timer, ip_vs_conn_expire, (unsigned long)cp);
869         ip_vs_conn_net_set(cp, p->net);
870         cp->af             = p->af;
871         cp->protocol       = p->protocol;
872         ip_vs_addr_set(p->af, &cp->caddr, p->caddr);
873         cp->cport          = p->cport;
874         ip_vs_addr_set(p->af, &cp->vaddr, p->vaddr);
875         cp->vport          = p->vport;
876         /* proto should only be IPPROTO_IP if d_addr is a fwmark */
877         ip_vs_addr_set(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
878                        &cp->daddr, daddr);
879         cp->dport          = dport;
880         cp->flags          = flags;
881         cp->fwmark         = fwmark;
882         if (flags & IP_VS_CONN_F_TEMPLATE && p->pe) {
883                 ip_vs_pe_get(p->pe);
884                 cp->pe = p->pe;
885                 cp->pe_data = p->pe_data;
886                 cp->pe_data_len = p->pe_data_len;
887         } else {
888                 cp->pe = NULL;
889                 cp->pe_data = NULL;
890                 cp->pe_data_len = 0;
891         }
892         spin_lock_init(&cp->lock);
893 
894         /*
895          * Set the entry is referenced by the current thread before hashing
896          * it in the table, so that other thread run ip_vs_random_dropentry
897          * but cannot drop this entry.
898          */
899         atomic_set(&cp->refcnt, 1);
900 
901         cp->control = NULL;
902         atomic_set(&cp->n_control, 0);
903         atomic_set(&cp->in_pkts, 0);
904 
905         cp->packet_xmit = NULL;
906         cp->app = NULL;
907         cp->app_data = NULL;
908         /* reset struct ip_vs_seq */
909         cp->in_seq.delta = 0;
910         cp->out_seq.delta = 0;
911 
912         atomic_inc(&ipvs->conn_count);
913         if (flags & IP_VS_CONN_F_NO_CPORT)
914                 atomic_inc(&ip_vs_conn_no_cport_cnt);
915 
916         /* Bind the connection with a destination server */
917         cp->dest = NULL;
918         ip_vs_bind_dest(cp, dest);
919 
920         /* Set its state and timeout */
921         cp->state = 0;
922         cp->old_state = 0;
923         cp->timeout = 3*HZ;
924         cp->sync_endtime = jiffies & ~3UL;
925 
926         /* Bind its packet transmitter */
927 #ifdef CONFIG_IP_VS_IPV6
928         if (p->af == AF_INET6)
929                 ip_vs_bind_xmit_v6(cp);
930         else
931 #endif
932                 ip_vs_bind_xmit(cp);
933 
934         if (unlikely(pd && atomic_read(&pd->appcnt)))
935                 ip_vs_bind_app(cp, pd->pp);
936 
937         /*
938          * Allow conntrack to be preserved. By default, conntrack
939          * is created and destroyed for every packet.
940          * Sometimes keeping conntrack can be useful for
941          * IP_VS_CONN_F_ONE_PACKET too.
942          */
943 
944         if (ip_vs_conntrack_enabled(ipvs))
945                 cp->flags |= IP_VS_CONN_F_NFCT;
946 
947         /* Hash it in the ip_vs_conn_tab finally */
948         ip_vs_conn_hash(cp);
949 
950         return cp;
951 }
952 
953 /*
954  *      /proc/net/ip_vs_conn entries
955  */
956 #ifdef CONFIG_PROC_FS
957 struct ip_vs_iter_state {
958         struct seq_net_private  p;
959         struct hlist_head       *l;
960 };
961 
962 static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos)
963 {
964         int idx;
965         struct ip_vs_conn *cp;
966         struct ip_vs_iter_state *iter = seq->private;
967 
968         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
969                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
970                         /* __ip_vs_conn_get() is not needed by
971                          * ip_vs_conn_seq_show and ip_vs_conn_sync_seq_show
972                          */
973                         if (pos-- == 0) {
974                                 iter->l = &ip_vs_conn_tab[idx];
975                                 return cp;
976                         }
977                 }
978                 cond_resched_rcu();
979         }
980 
981         return NULL;
982 }
983 
984 static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos)
985         __acquires(RCU)
986 {
987         struct ip_vs_iter_state *iter = seq->private;
988 
989         iter->l = NULL;
990         rcu_read_lock();
991         return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN;
992 }
993 
994 static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos)
995 {
996         struct ip_vs_conn *cp = v;
997         struct ip_vs_iter_state *iter = seq->private;
998         struct hlist_node *e;
999         struct hlist_head *l = iter->l;
1000         int idx;
1001 
1002         ++*pos;
1003         if (v == SEQ_START_TOKEN)
1004                 return ip_vs_conn_array(seq, 0);
1005 
1006         /* more on same hash chain? */
1007         e = rcu_dereference(hlist_next_rcu(&cp->c_list));
1008         if (e)
1009                 return hlist_entry(e, struct ip_vs_conn, c_list);
1010 
1011         idx = l - ip_vs_conn_tab;
1012         while (++idx < ip_vs_conn_tab_size) {
1013                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1014                         iter->l = &ip_vs_conn_tab[idx];
1015                         return cp;
1016                 }
1017                 cond_resched_rcu();
1018         }
1019         iter->l = NULL;
1020         return NULL;
1021 }
1022 
1023 static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v)
1024         __releases(RCU)
1025 {
1026         rcu_read_unlock();
1027 }
1028 
1029 static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
1030 {
1031 
1032         if (v == SEQ_START_TOKEN)
1033                 seq_puts(seq,
1034    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Expires PEName PEData\n");
1035         else {
1036                 const struct ip_vs_conn *cp = v;
1037                 struct net *net = seq_file_net(seq);
1038                 char pe_data[IP_VS_PENAME_MAXLEN + IP_VS_PEDATA_MAXLEN + 3];
1039                 size_t len = 0;
1040 
1041                 if (!ip_vs_conn_net_eq(cp, net))
1042                         return 0;
1043                 if (cp->pe_data) {
1044                         pe_data[0] = ' ';
1045                         len = strlen(cp->pe->name);
1046                         memcpy(pe_data + 1, cp->pe->name, len);
1047                         pe_data[len + 1] = ' ';
1048                         len += 2;
1049                         len += cp->pe->show_pe_data(cp, pe_data + len);
1050                 }
1051                 pe_data[len] = '\0';
1052 
1053 #ifdef CONFIG_IP_VS_IPV6
1054                 if (cp->af == AF_INET6)
1055                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
1056                                 "%pI6 %04X %-11s %7lu%s\n",
1057                                 ip_vs_proto_name(cp->protocol),
1058                                 &cp->caddr.in6, ntohs(cp->cport),
1059                                 &cp->vaddr.in6, ntohs(cp->vport),
1060                                 &cp->daddr.in6, ntohs(cp->dport),
1061                                 ip_vs_state_name(cp->protocol, cp->state),
1062                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1063                 else
1064 #endif
1065                         seq_printf(seq,
1066                                 "%-3s %08X %04X %08X %04X"
1067                                 " %08X %04X %-11s %7lu%s\n",
1068                                 ip_vs_proto_name(cp->protocol),
1069                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1070                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1071                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1072                                 ip_vs_state_name(cp->protocol, cp->state),
1073                                 (cp->timer.expires-jiffies)/HZ, pe_data);
1074         }
1075         return 0;
1076 }
1077 
1078 static const struct seq_operations ip_vs_conn_seq_ops = {
1079         .start = ip_vs_conn_seq_start,
1080         .next  = ip_vs_conn_seq_next,
1081         .stop  = ip_vs_conn_seq_stop,
1082         .show  = ip_vs_conn_seq_show,
1083 };
1084 
1085 static int ip_vs_conn_open(struct inode *inode, struct file *file)
1086 {
1087         return seq_open_net(inode, file, &ip_vs_conn_seq_ops,
1088                             sizeof(struct ip_vs_iter_state));
1089 }
1090 
1091 static const struct file_operations ip_vs_conn_fops = {
1092         .owner   = THIS_MODULE,
1093         .open    = ip_vs_conn_open,
1094         .read    = seq_read,
1095         .llseek  = seq_lseek,
1096         .release = seq_release_net,
1097 };
1098 
1099 static const char *ip_vs_origin_name(unsigned int flags)
1100 {
1101         if (flags & IP_VS_CONN_F_SYNC)
1102                 return "SYNC";
1103         else
1104                 return "LOCAL";
1105 }
1106 
1107 static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
1108 {
1109 
1110         if (v == SEQ_START_TOKEN)
1111                 seq_puts(seq,
1112    "Pro FromIP   FPrt ToIP     TPrt DestIP   DPrt State       Origin Expires\n");
1113         else {
1114                 const struct ip_vs_conn *cp = v;
1115                 struct net *net = seq_file_net(seq);
1116 
1117                 if (!ip_vs_conn_net_eq(cp, net))
1118                         return 0;
1119 
1120 #ifdef CONFIG_IP_VS_IPV6
1121                 if (cp->af == AF_INET6)
1122                         seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X %pI6 %04X %-11s %-6s %7lu\n",
1123                                 ip_vs_proto_name(cp->protocol),
1124                                 &cp->caddr.in6, ntohs(cp->cport),
1125                                 &cp->vaddr.in6, ntohs(cp->vport),
1126                                 &cp->daddr.in6, ntohs(cp->dport),
1127                                 ip_vs_state_name(cp->protocol, cp->state),
1128                                 ip_vs_origin_name(cp->flags),
1129                                 (cp->timer.expires-jiffies)/HZ);
1130                 else
1131 #endif
1132                         seq_printf(seq,
1133                                 "%-3s %08X %04X %08X %04X "
1134                                 "%08X %04X %-11s %-6s %7lu\n",
1135                                 ip_vs_proto_name(cp->protocol),
1136                                 ntohl(cp->caddr.ip), ntohs(cp->cport),
1137                                 ntohl(cp->vaddr.ip), ntohs(cp->vport),
1138                                 ntohl(cp->daddr.ip), ntohs(cp->dport),
1139                                 ip_vs_state_name(cp->protocol, cp->state),
1140                                 ip_vs_origin_name(cp->flags),
1141                                 (cp->timer.expires-jiffies)/HZ);
1142         }
1143         return 0;
1144 }
1145 
1146 static const struct seq_operations ip_vs_conn_sync_seq_ops = {
1147         .start = ip_vs_conn_seq_start,
1148         .next  = ip_vs_conn_seq_next,
1149         .stop  = ip_vs_conn_seq_stop,
1150         .show  = ip_vs_conn_sync_seq_show,
1151 };
1152 
1153 static int ip_vs_conn_sync_open(struct inode *inode, struct file *file)
1154 {
1155         return seq_open_net(inode, file, &ip_vs_conn_sync_seq_ops,
1156                             sizeof(struct ip_vs_iter_state));
1157 }
1158 
1159 static const struct file_operations ip_vs_conn_sync_fops = {
1160         .owner   = THIS_MODULE,
1161         .open    = ip_vs_conn_sync_open,
1162         .read    = seq_read,
1163         .llseek  = seq_lseek,
1164         .release = seq_release_net,
1165 };
1166 
1167 #endif
1168 
1169 
1170 /*
1171  *      Randomly drop connection entries before running out of memory
1172  */
1173 static inline int todrop_entry(struct ip_vs_conn *cp)
1174 {
1175         /*
1176          * The drop rate array needs tuning for real environments.
1177          * Called from timer bh only => no locking
1178          */
1179         static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8};
1180         static char todrop_counter[9] = {0};
1181         int i;
1182 
1183         /* if the conn entry hasn't lasted for 60 seconds, don't drop it.
1184            This will leave enough time for normal connection to get
1185            through. */
1186         if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ))
1187                 return 0;
1188 
1189         /* Don't drop the entry if its number of incoming packets is not
1190            located in [0, 8] */
1191         i = atomic_read(&cp->in_pkts);
1192         if (i > 8 || i < 0) return 0;
1193 
1194         if (!todrop_rate[i]) return 0;
1195         if (--todrop_counter[i] > 0) return 0;
1196 
1197         todrop_counter[i] = todrop_rate[i];
1198         return 1;
1199 }
1200 
1201 /* Called from keventd and must protect itself from softirqs */
1202 void ip_vs_random_dropentry(struct net *net)
1203 {
1204         int idx;
1205         struct ip_vs_conn *cp, *cp_c;
1206 
1207         rcu_read_lock();
1208         /*
1209          * Randomly scan 1/32 of the whole table every second
1210          */
1211         for (idx = 0; idx < (ip_vs_conn_tab_size>>5); idx++) {
1212                 unsigned int hash = net_random() & ip_vs_conn_tab_mask;
1213 
1214                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[hash], c_list) {
1215                         if (cp->flags & IP_VS_CONN_F_TEMPLATE)
1216                                 /* connection template */
1217                                 continue;
1218                         if (!ip_vs_conn_net_eq(cp, net))
1219                                 continue;
1220                         if (cp->protocol == IPPROTO_TCP) {
1221                                 switch(cp->state) {
1222                                 case IP_VS_TCP_S_SYN_RECV:
1223                                 case IP_VS_TCP_S_SYNACK:
1224                                         break;
1225 
1226                                 case IP_VS_TCP_S_ESTABLISHED:
1227                                         if (todrop_entry(cp))
1228                                                 break;
1229                                         continue;
1230 
1231                                 default:
1232                                         continue;
1233                                 }
1234                         } else if (cp->protocol == IPPROTO_SCTP) {
1235                                 switch (cp->state) {
1236                                 case IP_VS_SCTP_S_INIT1:
1237                                 case IP_VS_SCTP_S_INIT:
1238                                         break;
1239                                 case IP_VS_SCTP_S_ESTABLISHED:
1240                                         if (todrop_entry(cp))
1241                                                 break;
1242                                         continue;
1243                                 default:
1244                                         continue;
1245                                 }
1246                         } else {
1247                                 if (!todrop_entry(cp))
1248                                         continue;
1249                         }
1250 
1251                         IP_VS_DBG(4, "del connection\n");
1252                         ip_vs_conn_expire_now(cp);
1253                         cp_c = cp->control;
1254                         /* cp->control is valid only with reference to cp */
1255                         if (cp_c && __ip_vs_conn_get(cp)) {
1256                                 IP_VS_DBG(4, "del conn template\n");
1257                                 ip_vs_conn_expire_now(cp_c);
1258                                 __ip_vs_conn_put(cp);
1259                         }
1260                 }
1261                 cond_resched_rcu();
1262         }
1263         rcu_read_unlock();
1264 }
1265 
1266 
1267 /*
1268  *      Flush all the connection entries in the ip_vs_conn_tab
1269  */
1270 static void ip_vs_conn_flush(struct net *net)
1271 {
1272         int idx;
1273         struct ip_vs_conn *cp, *cp_c;
1274         struct netns_ipvs *ipvs = net_ipvs(net);
1275 
1276 flush_again:
1277         rcu_read_lock();
1278         for (idx = 0; idx < ip_vs_conn_tab_size; idx++) {
1279 
1280                 hlist_for_each_entry_rcu(cp, &ip_vs_conn_tab[idx], c_list) {
1281                         if (!ip_vs_conn_net_eq(cp, net))
1282                                 continue;
1283                         IP_VS_DBG(4, "del connection\n");
1284                         ip_vs_conn_expire_now(cp);
1285                         cp_c = cp->control;
1286                         /* cp->control is valid only with reference to cp */
1287                         if (cp_c && __ip_vs_conn_get(cp)) {
1288                                 IP_VS_DBG(4, "del conn template\n");
1289                                 ip_vs_conn_expire_now(cp_c);
1290                                 __ip_vs_conn_put(cp);
1291                         }
1292                 }
1293                 cond_resched_rcu();
1294         }
1295         rcu_read_unlock();
1296 
1297         /* the counter may be not NULL, because maybe some conn entries
1298            are run by slow timer handler or unhashed but still referred */
1299         if (atomic_read(&ipvs->conn_count) != 0) {
1300                 schedule();
1301                 goto flush_again;
1302         }
1303 }
1304 /*
1305  * per netns init and exit
1306  */
1307 int __net_init ip_vs_conn_net_init(struct net *net)
1308 {
1309         struct netns_ipvs *ipvs = net_ipvs(net);
1310 
1311         atomic_set(&ipvs->conn_count, 0);
1312 
1313         proc_create("ip_vs_conn", 0, net->proc_net, &ip_vs_conn_fops);
1314         proc_create("ip_vs_conn_sync", 0, net->proc_net, &ip_vs_conn_sync_fops);
1315         return 0;
1316 }
1317 
1318 void __net_exit ip_vs_conn_net_cleanup(struct net *net)
1319 {
1320         /* flush all the connection entries first */
1321         ip_vs_conn_flush(net);
1322         remove_proc_entry("ip_vs_conn", net->proc_net);
1323         remove_proc_entry("ip_vs_conn_sync", net->proc_net);
1324 }
1325 
1326 int __init ip_vs_conn_init(void)
1327 {
1328         int idx;
1329 
1330         /* Compute size and mask */
1331         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
1332         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
1333 
1334         /*
1335          * Allocate the connection hash table and initialize its list heads
1336          */
1337         ip_vs_conn_tab = vmalloc(ip_vs_conn_tab_size * sizeof(*ip_vs_conn_tab));
1338         if (!ip_vs_conn_tab)
1339                 return -ENOMEM;
1340 
1341         /* Allocate ip_vs_conn slab cache */
1342         ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn",
1343                                               sizeof(struct ip_vs_conn), 0,
1344                                               SLAB_HWCACHE_ALIGN, NULL);
1345         if (!ip_vs_conn_cachep) {
1346                 vfree(ip_vs_conn_tab);
1347                 return -ENOMEM;
1348         }
1349 
1350         pr_info("Connection hash table configured "
1351                 "(size=%d, memory=%ldKbytes)\n",
1352                 ip_vs_conn_tab_size,
1353                 (long)(ip_vs_conn_tab_size*sizeof(struct list_head))/1024);
1354         IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n",
1355                   sizeof(struct ip_vs_conn));
1356 
1357         for (idx = 0; idx < ip_vs_conn_tab_size; idx++)
1358                 INIT_HLIST_HEAD(&ip_vs_conn_tab[idx]);
1359 
1360         for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++)  {
1361                 spin_lock_init(&__ip_vs_conntbl_lock_array[idx].l);
1362         }
1363 
1364         /* calculate the random value for connection hash */
1365         get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd));
1366 
1367         return 0;
1368 }
1369 
1370 void ip_vs_conn_cleanup(void)
1371 {
1372         /* Wait all ip_vs_conn_rcu_free() callbacks to complete */
1373         rcu_barrier();
1374         /* Release the empty cache */
1375         kmem_cache_destroy(ip_vs_conn_cachep);
1376         vfree(ip_vs_conn_tab);
1377 }
1378 

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