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1da177e4 LT |
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 | * Version: $Id: ip_vs_conn.c,v 1.31 2003/04/18 09:03:16 wensong Exp $ | |
9 | * | |
10 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> | |
11 | * Peter Kese <peter.kese@ijs.si> | |
12 | * Julian Anastasov <ja@ssi.bg> | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or | |
15 | * modify it under the terms of the GNU General Public License | |
16 | * as published by the Free Software Foundation; either version | |
17 | * 2 of the License, or (at your option) any later version. | |
18 | * | |
19 | * The IPVS code for kernel 2.2 was done by Wensong Zhang and Peter Kese, | |
20 | * with changes/fixes from Julian Anastasov, Lars Marowsky-Bree, Horms | |
21 | * and others. Many code here is taken from IP MASQ code of kernel 2.2. | |
22 | * | |
23 | * Changes: | |
24 | * | |
25 | */ | |
26 | ||
14c85021 | 27 | #include <linux/in.h> |
1da177e4 | 28 | #include <linux/kernel.h> |
14c85021 | 29 | #include <linux/module.h> |
1da177e4 LT |
30 | #include <linux/vmalloc.h> |
31 | #include <linux/proc_fs.h> /* for proc_net_* */ | |
32 | #include <linux/seq_file.h> | |
33 | #include <linux/jhash.h> | |
34 | #include <linux/random.h> | |
35 | ||
36 | #include <net/ip_vs.h> | |
37 | ||
38 | ||
39 | /* | |
40 | * Connection hash table: for input and output packets lookups of IPVS | |
41 | */ | |
42 | static struct list_head *ip_vs_conn_tab; | |
43 | ||
44 | /* SLAB cache for IPVS connections */ | |
ba89966c | 45 | static kmem_cache_t *ip_vs_conn_cachep __read_mostly; |
1da177e4 LT |
46 | |
47 | /* counter for current IPVS connections */ | |
48 | static atomic_t ip_vs_conn_count = ATOMIC_INIT(0); | |
49 | ||
50 | /* counter for no client port connections */ | |
51 | static atomic_t ip_vs_conn_no_cport_cnt = ATOMIC_INIT(0); | |
52 | ||
53 | /* random value for IPVS connection hash */ | |
54 | static unsigned int ip_vs_conn_rnd; | |
55 | ||
56 | /* | |
57 | * Fine locking granularity for big connection hash table | |
58 | */ | |
59 | #define CT_LOCKARRAY_BITS 4 | |
60 | #define CT_LOCKARRAY_SIZE (1<<CT_LOCKARRAY_BITS) | |
61 | #define CT_LOCKARRAY_MASK (CT_LOCKARRAY_SIZE-1) | |
62 | ||
63 | struct ip_vs_aligned_lock | |
64 | { | |
65 | rwlock_t l; | |
66 | } __attribute__((__aligned__(SMP_CACHE_BYTES))); | |
67 | ||
68 | /* lock array for conn table */ | |
69 | static struct ip_vs_aligned_lock | |
70 | __ip_vs_conntbl_lock_array[CT_LOCKARRAY_SIZE] __cacheline_aligned; | |
71 | ||
72 | static inline void ct_read_lock(unsigned key) | |
73 | { | |
74 | read_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
75 | } | |
76 | ||
77 | static inline void ct_read_unlock(unsigned key) | |
78 | { | |
79 | read_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
80 | } | |
81 | ||
82 | static inline void ct_write_lock(unsigned key) | |
83 | { | |
84 | write_lock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
85 | } | |
86 | ||
87 | static inline void ct_write_unlock(unsigned key) | |
88 | { | |
89 | write_unlock(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
90 | } | |
91 | ||
92 | static inline void ct_read_lock_bh(unsigned key) | |
93 | { | |
94 | read_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
95 | } | |
96 | ||
97 | static inline void ct_read_unlock_bh(unsigned key) | |
98 | { | |
99 | read_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
100 | } | |
101 | ||
102 | static inline void ct_write_lock_bh(unsigned key) | |
103 | { | |
104 | write_lock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
105 | } | |
106 | ||
107 | static inline void ct_write_unlock_bh(unsigned key) | |
108 | { | |
109 | write_unlock_bh(&__ip_vs_conntbl_lock_array[key&CT_LOCKARRAY_MASK].l); | |
110 | } | |
111 | ||
112 | ||
113 | /* | |
114 | * Returns hash value for IPVS connection entry | |
115 | */ | |
116 | static unsigned int ip_vs_conn_hashkey(unsigned proto, __u32 addr, __u16 port) | |
117 | { | |
118 | return jhash_3words(addr, port, proto, ip_vs_conn_rnd) | |
119 | & IP_VS_CONN_TAB_MASK; | |
120 | } | |
121 | ||
122 | ||
123 | /* | |
124 | * Hashes ip_vs_conn in ip_vs_conn_tab by proto,addr,port. | |
125 | * returns bool success. | |
126 | */ | |
127 | static inline int ip_vs_conn_hash(struct ip_vs_conn *cp) | |
128 | { | |
129 | unsigned hash; | |
130 | int ret; | |
131 | ||
132 | /* Hash by protocol, client address and port */ | |
133 | hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport); | |
134 | ||
135 | ct_write_lock(hash); | |
136 | ||
137 | if (!(cp->flags & IP_VS_CONN_F_HASHED)) { | |
138 | list_add(&cp->c_list, &ip_vs_conn_tab[hash]); | |
139 | cp->flags |= IP_VS_CONN_F_HASHED; | |
140 | atomic_inc(&cp->refcnt); | |
141 | ret = 1; | |
142 | } else { | |
143 | IP_VS_ERR("ip_vs_conn_hash(): request for already hashed, " | |
144 | "called from %p\n", __builtin_return_address(0)); | |
145 | ret = 0; | |
146 | } | |
147 | ||
148 | ct_write_unlock(hash); | |
149 | ||
150 | return ret; | |
151 | } | |
152 | ||
153 | ||
154 | /* | |
155 | * UNhashes ip_vs_conn from ip_vs_conn_tab. | |
156 | * returns bool success. | |
157 | */ | |
158 | static inline int ip_vs_conn_unhash(struct ip_vs_conn *cp) | |
159 | { | |
160 | unsigned hash; | |
161 | int ret; | |
162 | ||
163 | /* unhash it and decrease its reference counter */ | |
164 | hash = ip_vs_conn_hashkey(cp->protocol, cp->caddr, cp->cport); | |
165 | ||
166 | ct_write_lock(hash); | |
167 | ||
168 | if (cp->flags & IP_VS_CONN_F_HASHED) { | |
169 | list_del(&cp->c_list); | |
170 | cp->flags &= ~IP_VS_CONN_F_HASHED; | |
171 | atomic_dec(&cp->refcnt); | |
172 | ret = 1; | |
173 | } else | |
174 | ret = 0; | |
175 | ||
176 | ct_write_unlock(hash); | |
177 | ||
178 | return ret; | |
179 | } | |
180 | ||
181 | ||
182 | /* | |
183 | * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab. | |
184 | * Called for pkts coming from OUTside-to-INside. | |
185 | * s_addr, s_port: pkt source address (foreign host) | |
186 | * d_addr, d_port: pkt dest address (load balancer) | |
187 | */ | |
188 | static inline struct ip_vs_conn *__ip_vs_conn_in_get | |
189 | (int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port) | |
190 | { | |
191 | unsigned hash; | |
192 | struct ip_vs_conn *cp; | |
193 | ||
194 | hash = ip_vs_conn_hashkey(protocol, s_addr, s_port); | |
195 | ||
196 | ct_read_lock(hash); | |
197 | ||
198 | list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) { | |
199 | if (s_addr==cp->caddr && s_port==cp->cport && | |
200 | d_port==cp->vport && d_addr==cp->vaddr && | |
87375ab4 | 201 | ((!s_port) ^ (!(cp->flags & IP_VS_CONN_F_NO_CPORT))) && |
1da177e4 LT |
202 | protocol==cp->protocol) { |
203 | /* HIT */ | |
204 | atomic_inc(&cp->refcnt); | |
205 | ct_read_unlock(hash); | |
206 | return cp; | |
207 | } | |
208 | } | |
209 | ||
210 | ct_read_unlock(hash); | |
211 | ||
212 | return NULL; | |
213 | } | |
214 | ||
215 | struct ip_vs_conn *ip_vs_conn_in_get | |
216 | (int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port) | |
217 | { | |
218 | struct ip_vs_conn *cp; | |
219 | ||
220 | cp = __ip_vs_conn_in_get(protocol, s_addr, s_port, d_addr, d_port); | |
221 | if (!cp && atomic_read(&ip_vs_conn_no_cport_cnt)) | |
222 | cp = __ip_vs_conn_in_get(protocol, s_addr, 0, d_addr, d_port); | |
223 | ||
224 | IP_VS_DBG(7, "lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n", | |
225 | ip_vs_proto_name(protocol), | |
226 | NIPQUAD(s_addr), ntohs(s_port), | |
227 | NIPQUAD(d_addr), ntohs(d_port), | |
228 | cp?"hit":"not hit"); | |
229 | ||
230 | return cp; | |
231 | } | |
232 | ||
87375ab4 JA |
233 | /* Get reference to connection template */ |
234 | struct ip_vs_conn *ip_vs_ct_in_get | |
235 | (int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port) | |
236 | { | |
237 | unsigned hash; | |
238 | struct ip_vs_conn *cp; | |
239 | ||
240 | hash = ip_vs_conn_hashkey(protocol, s_addr, s_port); | |
241 | ||
242 | ct_read_lock(hash); | |
243 | ||
244 | list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) { | |
245 | if (s_addr==cp->caddr && s_port==cp->cport && | |
246 | d_port==cp->vport && d_addr==cp->vaddr && | |
247 | cp->flags & IP_VS_CONN_F_TEMPLATE && | |
248 | protocol==cp->protocol) { | |
249 | /* HIT */ | |
250 | atomic_inc(&cp->refcnt); | |
251 | goto out; | |
252 | } | |
253 | } | |
254 | cp = NULL; | |
255 | ||
256 | out: | |
257 | ct_read_unlock(hash); | |
258 | ||
259 | IP_VS_DBG(7, "template lookup/in %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n", | |
260 | ip_vs_proto_name(protocol), | |
261 | NIPQUAD(s_addr), ntohs(s_port), | |
262 | NIPQUAD(d_addr), ntohs(d_port), | |
263 | cp?"hit":"not hit"); | |
264 | ||
265 | return cp; | |
266 | } | |
1da177e4 LT |
267 | |
268 | /* | |
269 | * Gets ip_vs_conn associated with supplied parameters in the ip_vs_conn_tab. | |
270 | * Called for pkts coming from inside-to-OUTside. | |
271 | * s_addr, s_port: pkt source address (inside host) | |
272 | * d_addr, d_port: pkt dest address (foreign host) | |
273 | */ | |
274 | struct ip_vs_conn *ip_vs_conn_out_get | |
275 | (int protocol, __u32 s_addr, __u16 s_port, __u32 d_addr, __u16 d_port) | |
276 | { | |
277 | unsigned hash; | |
278 | struct ip_vs_conn *cp, *ret=NULL; | |
279 | ||
280 | /* | |
281 | * Check for "full" addressed entries | |
282 | */ | |
283 | hash = ip_vs_conn_hashkey(protocol, d_addr, d_port); | |
284 | ||
285 | ct_read_lock(hash); | |
286 | ||
287 | list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) { | |
288 | if (d_addr == cp->caddr && d_port == cp->cport && | |
289 | s_port == cp->dport && s_addr == cp->daddr && | |
290 | protocol == cp->protocol) { | |
291 | /* HIT */ | |
292 | atomic_inc(&cp->refcnt); | |
293 | ret = cp; | |
294 | break; | |
295 | } | |
296 | } | |
297 | ||
298 | ct_read_unlock(hash); | |
299 | ||
300 | IP_VS_DBG(7, "lookup/out %s %u.%u.%u.%u:%d->%u.%u.%u.%u:%d %s\n", | |
301 | ip_vs_proto_name(protocol), | |
302 | NIPQUAD(s_addr), ntohs(s_port), | |
303 | NIPQUAD(d_addr), ntohs(d_port), | |
304 | ret?"hit":"not hit"); | |
305 | ||
306 | return ret; | |
307 | } | |
308 | ||
309 | ||
310 | /* | |
311 | * Put back the conn and restart its timer with its timeout | |
312 | */ | |
313 | void ip_vs_conn_put(struct ip_vs_conn *cp) | |
314 | { | |
315 | /* reset it expire in its timeout */ | |
316 | mod_timer(&cp->timer, jiffies+cp->timeout); | |
317 | ||
318 | __ip_vs_conn_put(cp); | |
319 | } | |
320 | ||
321 | ||
322 | /* | |
323 | * Fill a no_client_port connection with a client port number | |
324 | */ | |
325 | void ip_vs_conn_fill_cport(struct ip_vs_conn *cp, __u16 cport) | |
326 | { | |
327 | if (ip_vs_conn_unhash(cp)) { | |
328 | spin_lock(&cp->lock); | |
329 | if (cp->flags & IP_VS_CONN_F_NO_CPORT) { | |
330 | atomic_dec(&ip_vs_conn_no_cport_cnt); | |
331 | cp->flags &= ~IP_VS_CONN_F_NO_CPORT; | |
332 | cp->cport = cport; | |
333 | } | |
334 | spin_unlock(&cp->lock); | |
335 | ||
336 | /* hash on new dport */ | |
337 | ip_vs_conn_hash(cp); | |
338 | } | |
339 | } | |
340 | ||
341 | ||
342 | /* | |
343 | * Bind a connection entry with the corresponding packet_xmit. | |
344 | * Called by ip_vs_conn_new. | |
345 | */ | |
346 | static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp) | |
347 | { | |
348 | switch (IP_VS_FWD_METHOD(cp)) { | |
349 | case IP_VS_CONN_F_MASQ: | |
350 | cp->packet_xmit = ip_vs_nat_xmit; | |
351 | break; | |
352 | ||
353 | case IP_VS_CONN_F_TUNNEL: | |
354 | cp->packet_xmit = ip_vs_tunnel_xmit; | |
355 | break; | |
356 | ||
357 | case IP_VS_CONN_F_DROUTE: | |
358 | cp->packet_xmit = ip_vs_dr_xmit; | |
359 | break; | |
360 | ||
361 | case IP_VS_CONN_F_LOCALNODE: | |
362 | cp->packet_xmit = ip_vs_null_xmit; | |
363 | break; | |
364 | ||
365 | case IP_VS_CONN_F_BYPASS: | |
366 | cp->packet_xmit = ip_vs_bypass_xmit; | |
367 | break; | |
368 | } | |
369 | } | |
370 | ||
371 | ||
372 | static inline int ip_vs_dest_totalconns(struct ip_vs_dest *dest) | |
373 | { | |
374 | return atomic_read(&dest->activeconns) | |
375 | + atomic_read(&dest->inactconns); | |
376 | } | |
377 | ||
378 | /* | |
379 | * Bind a connection entry with a virtual service destination | |
380 | * Called just after a new connection entry is created. | |
381 | */ | |
382 | static inline void | |
383 | ip_vs_bind_dest(struct ip_vs_conn *cp, struct ip_vs_dest *dest) | |
384 | { | |
385 | /* if dest is NULL, then return directly */ | |
386 | if (!dest) | |
387 | return; | |
388 | ||
389 | /* Increase the refcnt counter of the dest */ | |
390 | atomic_inc(&dest->refcnt); | |
391 | ||
392 | /* Bind with the destination and its corresponding transmitter */ | |
393 | cp->flags |= atomic_read(&dest->conn_flags); | |
394 | cp->dest = dest; | |
395 | ||
396 | IP_VS_DBG(9, "Bind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d " | |
397 | "d:%u.%u.%u.%u:%d fwd:%c s:%u flg:%X cnt:%d destcnt:%d\n", | |
398 | ip_vs_proto_name(cp->protocol), | |
399 | NIPQUAD(cp->caddr), ntohs(cp->cport), | |
400 | NIPQUAD(cp->vaddr), ntohs(cp->vport), | |
401 | NIPQUAD(cp->daddr), ntohs(cp->dport), | |
402 | ip_vs_fwd_tag(cp), cp->state, | |
403 | cp->flags, atomic_read(&cp->refcnt), | |
404 | atomic_read(&dest->refcnt)); | |
405 | ||
406 | /* Update the connection counters */ | |
87375ab4 | 407 | if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { |
1da177e4 LT |
408 | /* It is a normal connection, so increase the inactive |
409 | connection counter because it is in TCP SYNRECV | |
410 | state (inactive) or other protocol inacive state */ | |
411 | atomic_inc(&dest->inactconns); | |
412 | } else { | |
413 | /* It is a persistent connection/template, so increase | |
414 | the peristent connection counter */ | |
415 | atomic_inc(&dest->persistconns); | |
416 | } | |
417 | ||
418 | if (dest->u_threshold != 0 && | |
419 | ip_vs_dest_totalconns(dest) >= dest->u_threshold) | |
420 | dest->flags |= IP_VS_DEST_F_OVERLOAD; | |
421 | } | |
422 | ||
423 | ||
424 | /* | |
425 | * Unbind a connection entry with its VS destination | |
426 | * Called by the ip_vs_conn_expire function. | |
427 | */ | |
428 | static inline void ip_vs_unbind_dest(struct ip_vs_conn *cp) | |
429 | { | |
430 | struct ip_vs_dest *dest = cp->dest; | |
431 | ||
432 | if (!dest) | |
433 | return; | |
434 | ||
435 | IP_VS_DBG(9, "Unbind-dest %s c:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d " | |
436 | "d:%u.%u.%u.%u:%d fwd:%c s:%u flg:%X cnt:%d destcnt:%d\n", | |
437 | ip_vs_proto_name(cp->protocol), | |
438 | NIPQUAD(cp->caddr), ntohs(cp->cport), | |
439 | NIPQUAD(cp->vaddr), ntohs(cp->vport), | |
440 | NIPQUAD(cp->daddr), ntohs(cp->dport), | |
441 | ip_vs_fwd_tag(cp), cp->state, | |
442 | cp->flags, atomic_read(&cp->refcnt), | |
443 | atomic_read(&dest->refcnt)); | |
444 | ||
445 | /* Update the connection counters */ | |
87375ab4 | 446 | if (!(cp->flags & IP_VS_CONN_F_TEMPLATE)) { |
1da177e4 LT |
447 | /* It is a normal connection, so decrease the inactconns |
448 | or activeconns counter */ | |
449 | if (cp->flags & IP_VS_CONN_F_INACTIVE) { | |
450 | atomic_dec(&dest->inactconns); | |
451 | } else { | |
452 | atomic_dec(&dest->activeconns); | |
453 | } | |
454 | } else { | |
455 | /* It is a persistent connection/template, so decrease | |
456 | the peristent connection counter */ | |
457 | atomic_dec(&dest->persistconns); | |
458 | } | |
459 | ||
460 | if (dest->l_threshold != 0) { | |
461 | if (ip_vs_dest_totalconns(dest) < dest->l_threshold) | |
462 | dest->flags &= ~IP_VS_DEST_F_OVERLOAD; | |
463 | } else if (dest->u_threshold != 0) { | |
464 | if (ip_vs_dest_totalconns(dest) * 4 < dest->u_threshold * 3) | |
465 | dest->flags &= ~IP_VS_DEST_F_OVERLOAD; | |
466 | } else { | |
467 | if (dest->flags & IP_VS_DEST_F_OVERLOAD) | |
468 | dest->flags &= ~IP_VS_DEST_F_OVERLOAD; | |
469 | } | |
470 | ||
471 | /* | |
472 | * Simply decrease the refcnt of the dest, because the | |
473 | * dest will be either in service's destination list | |
474 | * or in the trash. | |
475 | */ | |
476 | atomic_dec(&dest->refcnt); | |
477 | } | |
478 | ||
479 | ||
480 | /* | |
481 | * Checking if the destination of a connection template is available. | |
482 | * If available, return 1, otherwise invalidate this connection | |
483 | * template and return 0. | |
484 | */ | |
485 | int ip_vs_check_template(struct ip_vs_conn *ct) | |
486 | { | |
487 | struct ip_vs_dest *dest = ct->dest; | |
488 | ||
489 | /* | |
490 | * Checking the dest server status. | |
491 | */ | |
492 | if ((dest == NULL) || | |
493 | !(dest->flags & IP_VS_DEST_F_AVAILABLE) || | |
494 | (sysctl_ip_vs_expire_quiescent_template && | |
495 | (atomic_read(&dest->weight) == 0))) { | |
496 | IP_VS_DBG(9, "check_template: dest not available for " | |
497 | "protocol %s s:%u.%u.%u.%u:%d v:%u.%u.%u.%u:%d " | |
498 | "-> d:%u.%u.%u.%u:%d\n", | |
499 | ip_vs_proto_name(ct->protocol), | |
500 | NIPQUAD(ct->caddr), ntohs(ct->cport), | |
501 | NIPQUAD(ct->vaddr), ntohs(ct->vport), | |
502 | NIPQUAD(ct->daddr), ntohs(ct->dport)); | |
503 | ||
504 | /* | |
505 | * Invalidate the connection template | |
506 | */ | |
f5e229db | 507 | if (ct->vport != 65535) { |
1da177e4 LT |
508 | if (ip_vs_conn_unhash(ct)) { |
509 | ct->dport = 65535; | |
510 | ct->vport = 65535; | |
511 | ct->cport = 0; | |
512 | ip_vs_conn_hash(ct); | |
513 | } | |
514 | } | |
515 | ||
516 | /* | |
517 | * Simply decrease the refcnt of the template, | |
518 | * don't restart its timer. | |
519 | */ | |
520 | atomic_dec(&ct->refcnt); | |
521 | return 0; | |
522 | } | |
523 | return 1; | |
524 | } | |
525 | ||
526 | static void ip_vs_conn_expire(unsigned long data) | |
527 | { | |
528 | struct ip_vs_conn *cp = (struct ip_vs_conn *)data; | |
529 | ||
530 | cp->timeout = 60*HZ; | |
531 | ||
532 | /* | |
533 | * hey, I'm using it | |
534 | */ | |
535 | atomic_inc(&cp->refcnt); | |
536 | ||
537 | /* | |
538 | * do I control anybody? | |
539 | */ | |
540 | if (atomic_read(&cp->n_control)) | |
541 | goto expire_later; | |
542 | ||
543 | /* | |
544 | * unhash it if it is hashed in the conn table | |
545 | */ | |
546 | if (!ip_vs_conn_unhash(cp)) | |
547 | goto expire_later; | |
548 | ||
549 | /* | |
550 | * refcnt==1 implies I'm the only one referrer | |
551 | */ | |
552 | if (likely(atomic_read(&cp->refcnt) == 1)) { | |
553 | /* delete the timer if it is activated by other users */ | |
554 | if (timer_pending(&cp->timer)) | |
555 | del_timer(&cp->timer); | |
556 | ||
557 | /* does anybody control me? */ | |
558 | if (cp->control) | |
559 | ip_vs_control_del(cp); | |
560 | ||
561 | if (unlikely(cp->app != NULL)) | |
562 | ip_vs_unbind_app(cp); | |
563 | ip_vs_unbind_dest(cp); | |
564 | if (cp->flags & IP_VS_CONN_F_NO_CPORT) | |
565 | atomic_dec(&ip_vs_conn_no_cport_cnt); | |
566 | atomic_dec(&ip_vs_conn_count); | |
567 | ||
568 | kmem_cache_free(ip_vs_conn_cachep, cp); | |
569 | return; | |
570 | } | |
571 | ||
572 | /* hash it back to the table */ | |
573 | ip_vs_conn_hash(cp); | |
574 | ||
575 | expire_later: | |
576 | IP_VS_DBG(7, "delayed: refcnt-1=%d conn.n_control=%d\n", | |
577 | atomic_read(&cp->refcnt)-1, | |
578 | atomic_read(&cp->n_control)); | |
579 | ||
580 | ip_vs_conn_put(cp); | |
581 | } | |
582 | ||
583 | ||
584 | void ip_vs_conn_expire_now(struct ip_vs_conn *cp) | |
585 | { | |
586 | if (del_timer(&cp->timer)) | |
587 | mod_timer(&cp->timer, jiffies); | |
1da177e4 LT |
588 | } |
589 | ||
590 | ||
591 | /* | |
592 | * Create a new connection entry and hash it into the ip_vs_conn_tab | |
593 | */ | |
594 | struct ip_vs_conn * | |
595 | ip_vs_conn_new(int proto, __u32 caddr, __u16 cport, __u32 vaddr, __u16 vport, | |
596 | __u32 daddr, __u16 dport, unsigned flags, | |
597 | struct ip_vs_dest *dest) | |
598 | { | |
599 | struct ip_vs_conn *cp; | |
600 | struct ip_vs_protocol *pp = ip_vs_proto_get(proto); | |
601 | ||
602 | cp = kmem_cache_alloc(ip_vs_conn_cachep, GFP_ATOMIC); | |
603 | if (cp == NULL) { | |
604 | IP_VS_ERR_RL("ip_vs_conn_new: no memory available.\n"); | |
605 | return NULL; | |
606 | } | |
607 | ||
608 | memset(cp, 0, sizeof(*cp)); | |
609 | INIT_LIST_HEAD(&cp->c_list); | |
610 | init_timer(&cp->timer); | |
611 | cp->timer.data = (unsigned long)cp; | |
612 | cp->timer.function = ip_vs_conn_expire; | |
613 | cp->protocol = proto; | |
614 | cp->caddr = caddr; | |
615 | cp->cport = cport; | |
616 | cp->vaddr = vaddr; | |
617 | cp->vport = vport; | |
618 | cp->daddr = daddr; | |
619 | cp->dport = dport; | |
620 | cp->flags = flags; | |
621 | spin_lock_init(&cp->lock); | |
622 | ||
623 | /* | |
624 | * Set the entry is referenced by the current thread before hashing | |
625 | * it in the table, so that other thread run ip_vs_random_dropentry | |
626 | * but cannot drop this entry. | |
627 | */ | |
628 | atomic_set(&cp->refcnt, 1); | |
629 | ||
630 | atomic_set(&cp->n_control, 0); | |
631 | atomic_set(&cp->in_pkts, 0); | |
632 | ||
633 | atomic_inc(&ip_vs_conn_count); | |
634 | if (flags & IP_VS_CONN_F_NO_CPORT) | |
635 | atomic_inc(&ip_vs_conn_no_cport_cnt); | |
636 | ||
637 | /* Bind the connection with a destination server */ | |
638 | ip_vs_bind_dest(cp, dest); | |
639 | ||
640 | /* Set its state and timeout */ | |
641 | cp->state = 0; | |
642 | cp->timeout = 3*HZ; | |
643 | ||
644 | /* Bind its packet transmitter */ | |
645 | ip_vs_bind_xmit(cp); | |
646 | ||
647 | if (unlikely(pp && atomic_read(&pp->appcnt))) | |
648 | ip_vs_bind_app(cp, pp); | |
649 | ||
650 | /* Hash it in the ip_vs_conn_tab finally */ | |
651 | ip_vs_conn_hash(cp); | |
652 | ||
653 | return cp; | |
654 | } | |
655 | ||
656 | ||
657 | /* | |
658 | * /proc/net/ip_vs_conn entries | |
659 | */ | |
660 | #ifdef CONFIG_PROC_FS | |
661 | ||
662 | static void *ip_vs_conn_array(struct seq_file *seq, loff_t pos) | |
663 | { | |
664 | int idx; | |
665 | struct ip_vs_conn *cp; | |
666 | ||
667 | for(idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) { | |
668 | ct_read_lock_bh(idx); | |
669 | list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) { | |
670 | if (pos-- == 0) { | |
671 | seq->private = &ip_vs_conn_tab[idx]; | |
672 | return cp; | |
673 | } | |
674 | } | |
675 | ct_read_unlock_bh(idx); | |
676 | } | |
677 | ||
678 | return NULL; | |
679 | } | |
680 | ||
681 | static void *ip_vs_conn_seq_start(struct seq_file *seq, loff_t *pos) | |
682 | { | |
683 | seq->private = NULL; | |
684 | return *pos ? ip_vs_conn_array(seq, *pos - 1) :SEQ_START_TOKEN; | |
685 | } | |
686 | ||
687 | static void *ip_vs_conn_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
688 | { | |
689 | struct ip_vs_conn *cp = v; | |
690 | struct list_head *e, *l = seq->private; | |
691 | int idx; | |
692 | ||
693 | ++*pos; | |
694 | if (v == SEQ_START_TOKEN) | |
695 | return ip_vs_conn_array(seq, 0); | |
696 | ||
697 | /* more on same hash chain? */ | |
698 | if ((e = cp->c_list.next) != l) | |
699 | return list_entry(e, struct ip_vs_conn, c_list); | |
700 | ||
701 | idx = l - ip_vs_conn_tab; | |
702 | ct_read_unlock_bh(idx); | |
703 | ||
704 | while (++idx < IP_VS_CONN_TAB_SIZE) { | |
705 | ct_read_lock_bh(idx); | |
706 | list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) { | |
707 | seq->private = &ip_vs_conn_tab[idx]; | |
708 | return cp; | |
709 | } | |
710 | ct_read_unlock_bh(idx); | |
711 | } | |
712 | seq->private = NULL; | |
713 | return NULL; | |
714 | } | |
715 | ||
716 | static void ip_vs_conn_seq_stop(struct seq_file *seq, void *v) | |
717 | { | |
718 | struct list_head *l = seq->private; | |
719 | ||
720 | if (l) | |
721 | ct_read_unlock_bh(l - ip_vs_conn_tab); | |
722 | } | |
723 | ||
724 | static int ip_vs_conn_seq_show(struct seq_file *seq, void *v) | |
725 | { | |
726 | ||
727 | if (v == SEQ_START_TOKEN) | |
728 | seq_puts(seq, | |
729 | "Pro FromIP FPrt ToIP TPrt DestIP DPrt State Expires\n"); | |
730 | else { | |
731 | const struct ip_vs_conn *cp = v; | |
732 | ||
733 | seq_printf(seq, | |
734 | "%-3s %08X %04X %08X %04X %08X %04X %-11s %7lu\n", | |
735 | ip_vs_proto_name(cp->protocol), | |
736 | ntohl(cp->caddr), ntohs(cp->cport), | |
737 | ntohl(cp->vaddr), ntohs(cp->vport), | |
738 | ntohl(cp->daddr), ntohs(cp->dport), | |
739 | ip_vs_state_name(cp->protocol, cp->state), | |
740 | (cp->timer.expires-jiffies)/HZ); | |
741 | } | |
742 | return 0; | |
743 | } | |
744 | ||
745 | static struct seq_operations ip_vs_conn_seq_ops = { | |
746 | .start = ip_vs_conn_seq_start, | |
747 | .next = ip_vs_conn_seq_next, | |
748 | .stop = ip_vs_conn_seq_stop, | |
749 | .show = ip_vs_conn_seq_show, | |
750 | }; | |
751 | ||
752 | static int ip_vs_conn_open(struct inode *inode, struct file *file) | |
753 | { | |
754 | return seq_open(file, &ip_vs_conn_seq_ops); | |
755 | } | |
756 | ||
757 | static struct file_operations ip_vs_conn_fops = { | |
758 | .owner = THIS_MODULE, | |
759 | .open = ip_vs_conn_open, | |
760 | .read = seq_read, | |
761 | .llseek = seq_lseek, | |
762 | .release = seq_release, | |
763 | }; | |
764 | #endif | |
765 | ||
766 | ||
767 | /* | |
768 | * Randomly drop connection entries before running out of memory | |
769 | */ | |
770 | static inline int todrop_entry(struct ip_vs_conn *cp) | |
771 | { | |
772 | /* | |
773 | * The drop rate array needs tuning for real environments. | |
774 | * Called from timer bh only => no locking | |
775 | */ | |
9b5b5cff | 776 | static const char todrop_rate[9] = {0, 1, 2, 3, 4, 5, 6, 7, 8}; |
1da177e4 LT |
777 | static char todrop_counter[9] = {0}; |
778 | int i; | |
779 | ||
780 | /* if the conn entry hasn't lasted for 60 seconds, don't drop it. | |
781 | This will leave enough time for normal connection to get | |
782 | through. */ | |
783 | if (time_before(cp->timeout + jiffies, cp->timer.expires + 60*HZ)) | |
784 | return 0; | |
785 | ||
786 | /* Don't drop the entry if its number of incoming packets is not | |
787 | located in [0, 8] */ | |
788 | i = atomic_read(&cp->in_pkts); | |
789 | if (i > 8 || i < 0) return 0; | |
790 | ||
791 | if (!todrop_rate[i]) return 0; | |
792 | if (--todrop_counter[i] > 0) return 0; | |
793 | ||
794 | todrop_counter[i] = todrop_rate[i]; | |
795 | return 1; | |
796 | } | |
797 | ||
af9debd4 | 798 | /* Called from keventd and must protect itself from softirqs */ |
1da177e4 LT |
799 | void ip_vs_random_dropentry(void) |
800 | { | |
801 | int idx; | |
802 | struct ip_vs_conn *cp; | |
1da177e4 LT |
803 | |
804 | /* | |
805 | * Randomly scan 1/32 of the whole table every second | |
806 | */ | |
807 | for (idx = 0; idx < (IP_VS_CONN_TAB_SIZE>>5); idx++) { | |
808 | unsigned hash = net_random() & IP_VS_CONN_TAB_MASK; | |
809 | ||
810 | /* | |
811 | * Lock is actually needed in this loop. | |
812 | */ | |
af9debd4 | 813 | ct_write_lock_bh(hash); |
1da177e4 LT |
814 | |
815 | list_for_each_entry(cp, &ip_vs_conn_tab[hash], c_list) { | |
87375ab4 | 816 | if (cp->flags & IP_VS_CONN_F_TEMPLATE) |
1da177e4 LT |
817 | /* connection template */ |
818 | continue; | |
819 | ||
820 | if (cp->protocol == IPPROTO_TCP) { | |
821 | switch(cp->state) { | |
822 | case IP_VS_TCP_S_SYN_RECV: | |
823 | case IP_VS_TCP_S_SYNACK: | |
824 | break; | |
825 | ||
826 | case IP_VS_TCP_S_ESTABLISHED: | |
827 | if (todrop_entry(cp)) | |
828 | break; | |
829 | continue; | |
830 | ||
831 | default: | |
832 | continue; | |
833 | } | |
834 | } else { | |
835 | if (!todrop_entry(cp)) | |
836 | continue; | |
837 | } | |
838 | ||
1da177e4 LT |
839 | IP_VS_DBG(4, "del connection\n"); |
840 | ip_vs_conn_expire_now(cp); | |
fb3d8949 | 841 | if (cp->control) { |
1da177e4 | 842 | IP_VS_DBG(4, "del conn template\n"); |
fb3d8949 | 843 | ip_vs_conn_expire_now(cp->control); |
1da177e4 | 844 | } |
1da177e4 | 845 | } |
af9debd4 | 846 | ct_write_unlock_bh(hash); |
1da177e4 LT |
847 | } |
848 | } | |
849 | ||
850 | ||
851 | /* | |
852 | * Flush all the connection entries in the ip_vs_conn_tab | |
853 | */ | |
854 | static void ip_vs_conn_flush(void) | |
855 | { | |
856 | int idx; | |
857 | struct ip_vs_conn *cp; | |
1da177e4 LT |
858 | |
859 | flush_again: | |
860 | for (idx=0; idx<IP_VS_CONN_TAB_SIZE; idx++) { | |
861 | /* | |
862 | * Lock is actually needed in this loop. | |
863 | */ | |
864 | ct_write_lock_bh(idx); | |
865 | ||
866 | list_for_each_entry(cp, &ip_vs_conn_tab[idx], c_list) { | |
1da177e4 | 867 | |
1da177e4 LT |
868 | IP_VS_DBG(4, "del connection\n"); |
869 | ip_vs_conn_expire_now(cp); | |
fb3d8949 | 870 | if (cp->control) { |
1da177e4 | 871 | IP_VS_DBG(4, "del conn template\n"); |
fb3d8949 | 872 | ip_vs_conn_expire_now(cp->control); |
1da177e4 | 873 | } |
1da177e4 LT |
874 | } |
875 | ct_write_unlock_bh(idx); | |
876 | } | |
877 | ||
878 | /* the counter may be not NULL, because maybe some conn entries | |
879 | are run by slow timer handler or unhashed but still referred */ | |
880 | if (atomic_read(&ip_vs_conn_count) != 0) { | |
881 | schedule(); | |
882 | goto flush_again; | |
883 | } | |
884 | } | |
885 | ||
886 | ||
887 | int ip_vs_conn_init(void) | |
888 | { | |
889 | int idx; | |
890 | ||
891 | /* | |
892 | * Allocate the connection hash table and initialize its list heads | |
893 | */ | |
894 | ip_vs_conn_tab = vmalloc(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head)); | |
895 | if (!ip_vs_conn_tab) | |
896 | return -ENOMEM; | |
897 | ||
898 | /* Allocate ip_vs_conn slab cache */ | |
899 | ip_vs_conn_cachep = kmem_cache_create("ip_vs_conn", | |
900 | sizeof(struct ip_vs_conn), 0, | |
901 | SLAB_HWCACHE_ALIGN, NULL, NULL); | |
902 | if (!ip_vs_conn_cachep) { | |
903 | vfree(ip_vs_conn_tab); | |
904 | return -ENOMEM; | |
905 | } | |
906 | ||
907 | IP_VS_INFO("Connection hash table configured " | |
908 | "(size=%d, memory=%ldKbytes)\n", | |
909 | IP_VS_CONN_TAB_SIZE, | |
910 | (long)(IP_VS_CONN_TAB_SIZE*sizeof(struct list_head))/1024); | |
911 | IP_VS_DBG(0, "Each connection entry needs %Zd bytes at least\n", | |
912 | sizeof(struct ip_vs_conn)); | |
913 | ||
914 | for (idx = 0; idx < IP_VS_CONN_TAB_SIZE; idx++) { | |
915 | INIT_LIST_HEAD(&ip_vs_conn_tab[idx]); | |
916 | } | |
917 | ||
918 | for (idx = 0; idx < CT_LOCKARRAY_SIZE; idx++) { | |
919 | rwlock_init(&__ip_vs_conntbl_lock_array[idx].l); | |
920 | } | |
921 | ||
922 | proc_net_fops_create("ip_vs_conn", 0, &ip_vs_conn_fops); | |
923 | ||
924 | /* calculate the random value for connection hash */ | |
925 | get_random_bytes(&ip_vs_conn_rnd, sizeof(ip_vs_conn_rnd)); | |
926 | ||
927 | return 0; | |
928 | } | |
929 | ||
930 | ||
931 | void ip_vs_conn_cleanup(void) | |
932 | { | |
933 | /* flush all the connection entries first */ | |
934 | ip_vs_conn_flush(); | |
935 | ||
936 | /* Release the empty cache */ | |
937 | kmem_cache_destroy(ip_vs_conn_cachep); | |
938 | proc_net_remove("ip_vs_conn"); | |
939 | vfree(ip_vs_conn_tab); | |
940 | } |