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sys/netinet/tcp_hostcache.c
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1 /*- 2 * Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote 14 * products derived from this software without specific prior written 15 * permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD: src/sys/netinet/tcp_hostcache.c,v 1.7.2.2 2005/02/13 18:18:33 rwatson Exp $ 30 */ 31 32 /* 33 * The tcp_hostcache moves the tcp specific cached metrics from the routing 34 * table into a dedicated structure indexed by the remote IP address. It 35 * keeps information on the measured tcp parameters of past tcp sessions 36 * to have better initial start values for following connections from the 37 * same source. Depending on the network parameters (delay, bandwidth, max 38 * MTU, congestion window) between local and remote site this can lead to 39 * significant speedups for new tcp connections after the first one. 40 * 41 * Due to this new tcp_hostcache all tcp specific metrics information in 42 * the routing table has been removed. The INPCB no longer keeps a pointer 43 * to the routing entry and protocol initiated route cloning has been 44 * removed as well. With these changes the routing table has gone back 45 * to being more lightwight and only carries information related to packet 46 * forwarding. 47 * 48 * Tcp_hostcache is designed for multiple concurrent access in SMP 49 * environments and high contention. All bucket rows have their own 50 * lock and thus multiple lookups and modifies can be done at the same 51 * time as long as they are in different bucket rows. If a request for 52 * insertion of a new record can't be satisfied it simply returns an 53 * empty structure. Nobody and nothing shall ever point directly to 54 * any entry in tcp_hostcache. All communication is done in an object 55 * oriented way and only funtions of tcp_hostcache will manipulate hostcache 56 * entries. Otherwise we are unable to achieve good behaviour in concurrent 57 * access situations. Since tcp_hostcache is only caching information there 58 * are no fatal consequences if we either can't satisfy any particular request 59 * or have to drop/overwrite an existing entry because of bucket limit 60 * memory constrains. 61 */ 62 63 /* 64 * Many thanks to jlemon for basic structure of tcp_syncache which is being 65 * followed here. 66 */ 67 68 #include "opt_inet6.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/mutex.h> 75 #include <sys/malloc.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/sysctl.h> 79 80 #include <net/if.h> 81 82 #include <netinet/in.h> 83 #include <netinet/in_systm.h> 84 #include <netinet/ip.h> 85 #include <netinet/in_var.h> 86 #include <netinet/in_pcb.h> 87 #include <netinet/ip_var.h> 88 #ifdef INET6 89 #include <netinet/ip6.h> 90 #include <netinet6/ip6_var.h> 91 #endif 92 #include <netinet/tcp.h> 93 #include <netinet/tcp_var.h> 94 #ifdef INET6 95 #include <netinet6/tcp6_var.h> 96 #endif 97 98 #include <vm/uma.h> 99 100 101 TAILQ_HEAD(hc_qhead, hc_metrics); 102 103 struct hc_head { 104 struct hc_qhead hch_bucket; 105 u_int hch_length; 106 struct mtx hch_mtx; 107 }; 108 109 struct hc_metrics { 110 /* housekeeping */ 111 TAILQ_ENTRY(hc_metrics) rmx_q; 112 struct hc_head *rmx_head; /* head of bucket tail queue */ 113 struct in_addr ip4; /* IP address */ 114 struct in6_addr ip6; /* IP6 address */ 115 /* endpoint specific values for tcp */ 116 u_long rmx_mtu; /* MTU for this path */ 117 u_long rmx_ssthresh; /* outbound gateway buffer limit */ 118 u_long rmx_rtt; /* estimated round trip time */ 119 u_long rmx_rttvar; /* estimated rtt variance */ 120 u_long rmx_bandwidth; /* estimated bandwidth */ 121 u_long rmx_cwnd; /* congestion window */ 122 u_long rmx_sendpipe; /* outbound delay-bandwidth product */ 123 u_long rmx_recvpipe; /* inbound delay-bandwidth product */ 124 struct rmxp_tao rmx_tao; /* TAO cache for T/TCP */ 125 /* tcp hostcache internal data */ 126 int rmx_expire; /* lifetime for object */ 127 u_long rmx_hits; /* number of hits */ 128 u_long rmx_updates; /* number of updates */ 129 }; 130 131 /* Arbitrary values */ 132 #define TCP_HOSTCACHE_HASHSIZE 512 133 #define TCP_HOSTCACHE_BUCKETLIMIT 30 134 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 135 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 136 137 struct tcp_hostcache { 138 struct hc_head *hashbase; 139 uma_zone_t zone; 140 u_int hashsize; 141 u_int hashmask; 142 u_int bucket_limit; 143 u_int cache_count; 144 u_int cache_limit; 145 int expire; 146 int purgeall; 147 }; 148 static struct tcp_hostcache tcp_hostcache; 149 150 static struct callout tcp_hc_callout; 151 152 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 153 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 154 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 155 static void tcp_hc_purge(void *); 156 157 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, "TCP Host cache"); 158 159 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_RDTUN, 160 &tcp_hostcache.cache_limit, 0, "Overall entry limit for hostcache"); 161 162 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_RDTUN, 163 &tcp_hostcache.hashsize, 0, "Size of TCP hostcache hashtable"); 164 165 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, CTLFLAG_RDTUN, 166 &tcp_hostcache.bucket_limit, 0, "Per-bucket hash limit for hostcache"); 167 168 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_RD, 169 &tcp_hostcache.cache_count, 0, "Current number of entries in hostcache"); 170 171 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_RW, 172 &tcp_hostcache.expire, 0, "Expire time of TCP hostcache entries"); 173 174 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_RW, 175 &tcp_hostcache.purgeall, 0, "Expire all entires on next purge run"); 176 177 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 178 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 179 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 180 181 182 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 183 184 #define HOSTCACHE_HASH(ip) \ 185 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 186 tcp_hostcache.hashmask) 187 188 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 189 #define HOSTCACHE_HASH6(ip6) \ 190 (((ip6)->s6_addr32[0] ^ \ 191 (ip6)->s6_addr32[1] ^ \ 192 (ip6)->s6_addr32[2] ^ \ 193 (ip6)->s6_addr32[3]) & \ 194 tcp_hostcache.hashmask) 195 196 #define THC_LOCK(lp) mtx_lock(lp) 197 #define THC_UNLOCK(lp) mtx_unlock(lp) 198 199 void 200 tcp_hc_init(void) 201 { 202 int i; 203 204 /* 205 * Initialize hostcache structures 206 */ 207 tcp_hostcache.cache_count = 0; 208 tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 209 tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 210 tcp_hostcache.cache_limit = 211 tcp_hostcache.hashsize * tcp_hostcache.bucket_limit; 212 tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 213 214 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 215 &tcp_hostcache.hashsize); 216 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 217 &tcp_hostcache.cache_limit); 218 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 219 &tcp_hostcache.bucket_limit); 220 if (!powerof2(tcp_hostcache.hashsize)) { 221 printf("WARNING: hostcache hash size is not a power of 2.\n"); 222 tcp_hostcache.hashsize = 512; /* safe default */ 223 } 224 tcp_hostcache.hashmask = tcp_hostcache.hashsize - 1; 225 226 /* 227 * Allocate the hash table 228 */ 229 tcp_hostcache.hashbase = (struct hc_head *) 230 malloc(tcp_hostcache.hashsize * sizeof(struct hc_head), 231 M_HOSTCACHE, M_WAITOK | M_ZERO); 232 233 /* 234 * Initialize the hash buckets 235 */ 236 for (i = 0; i < tcp_hostcache.hashsize; i++) { 237 TAILQ_INIT(&tcp_hostcache.hashbase[i].hch_bucket); 238 tcp_hostcache.hashbase[i].hch_length = 0; 239 mtx_init(&tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 240 NULL, MTX_DEF); 241 } 242 243 /* 244 * Allocate the hostcache entries. 245 */ 246 tcp_hostcache.zone = uma_zcreate("hostcache", sizeof(struct hc_metrics), 247 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 248 uma_zone_set_max(tcp_hostcache.zone, tcp_hostcache.cache_limit); 249 250 /* 251 * Set up periodic cache cleanup. 252 */ 253 callout_init(&tcp_hc_callout, CALLOUT_MPSAFE); 254 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 255 } 256 257 /* 258 * Internal function: lookup an entry in the hostcache or return NULL. 259 * 260 * If an entry has been returned, the caller becomes responsible for 261 * unlocking the bucket row after he is done reading/modifying the entry. 262 */ 263 static struct hc_metrics * 264 tcp_hc_lookup(struct in_conninfo *inc) 265 { 266 int hash; 267 struct hc_head *hc_head; 268 struct hc_metrics *hc_entry; 269 270 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 271 272 /* 273 * Hash the foreign ip address. 274 */ 275 if (inc->inc_isipv6) 276 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 277 else 278 hash = HOSTCACHE_HASH(&inc->inc_faddr); 279 280 hc_head = &tcp_hostcache.hashbase[hash]; 281 282 /* 283 * aquire lock for this bucket row 284 * we release the lock if we don't find an entry, 285 * otherwise the caller has to unlock after he is done 286 */ 287 THC_LOCK(&hc_head->hch_mtx); 288 289 /* 290 * circle through entries in bucket row looking for a match 291 */ 292 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 293 if (inc->inc_isipv6) { 294 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 295 sizeof(inc->inc6_faddr)) == 0) 296 return hc_entry; 297 } else { 298 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 299 sizeof(inc->inc_faddr)) == 0) 300 return hc_entry; 301 } 302 } 303 304 /* 305 * We were unsuccessful and didn't find anything 306 */ 307 THC_UNLOCK(&hc_head->hch_mtx); 308 return NULL; 309 } 310 311 /* 312 * Internal function: insert an entry into the hostcache or return NULL 313 * if unable to allocate a new one. 314 * 315 * If an entry has been returned, the caller becomes responsible for 316 * unlocking the bucket row after he is done reading/modifying the entry. 317 */ 318 static struct hc_metrics * 319 tcp_hc_insert(struct in_conninfo *inc) 320 { 321 int hash; 322 struct hc_head *hc_head; 323 struct hc_metrics *hc_entry; 324 325 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 326 327 /* 328 * Hash the foreign ip address 329 */ 330 if (inc->inc_isipv6) 331 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 332 else 333 hash = HOSTCACHE_HASH(&inc->inc_faddr); 334 335 hc_head = &tcp_hostcache.hashbase[hash]; 336 337 /* 338 * aquire lock for this bucket row 339 * we release the lock if we don't find an entry, 340 * otherwise the caller has to unlock after he is done 341 */ 342 THC_LOCK(&hc_head->hch_mtx); 343 344 /* 345 * If the bucket limit is reached reuse the least used element 346 */ 347 if (hc_head->hch_length >= tcp_hostcache.bucket_limit || 348 tcp_hostcache.cache_count >= tcp_hostcache.cache_limit) { 349 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 350 /* 351 * At first we were dropping the last element, just to 352 * reaquire it in the next two lines again which ain't 353 * very efficient. Instead just reuse the least used element. 354 * Maybe we drop something that is still "in-use" but we can 355 * be "lossy". 356 */ 357 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 358 tcp_hostcache.hashbase[hash].hch_length--; 359 tcp_hostcache.cache_count--; 360 tcpstat.tcps_hc_bucketoverflow++; 361 #if 0 362 uma_zfree(tcp_hostcache.zone, hc_entry); 363 #endif 364 } else { 365 /* 366 * Allocate a new entry, or balk if not possible 367 */ 368 hc_entry = uma_zalloc(tcp_hostcache.zone, M_NOWAIT); 369 if (hc_entry == NULL) { 370 THC_UNLOCK(&hc_head->hch_mtx); 371 return NULL; 372 } 373 } 374 375 /* 376 * Initialize basic information of hostcache entry 377 */ 378 bzero(hc_entry, sizeof(*hc_entry)); 379 if (inc->inc_isipv6) 380 bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 381 else 382 hc_entry->ip4 = inc->inc_faddr; 383 hc_entry->rmx_head = hc_head; 384 hc_entry->rmx_expire = tcp_hostcache.expire; 385 386 /* 387 * Put it upfront 388 */ 389 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 390 tcp_hostcache.hashbase[hash].hch_length++; 391 tcp_hostcache.cache_count++; 392 tcpstat.tcps_hc_added++; 393 394 return hc_entry; 395 } 396 397 /* 398 * External function: lookup an entry in the hostcache and fill out the 399 * supplied tcp metrics structure. Fills in null when no entry was found 400 * or a value is not set. 401 */ 402 void 403 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 404 { 405 struct hc_metrics *hc_entry; 406 407 /* 408 * Find the right bucket 409 */ 410 hc_entry = tcp_hc_lookup(inc); 411 412 /* 413 * If we don't have an existing object 414 */ 415 if (hc_entry == NULL) { 416 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 417 return; 418 } 419 hc_entry->rmx_hits++; 420 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 421 422 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 423 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 424 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 425 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 426 hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 427 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 428 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 429 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 430 431 /* 432 * unlock bucket row 433 */ 434 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 435 } 436 437 /* 438 * External function: lookup an entry in the hostcache and return the 439 * discovered path mtu. Returns null if no entry is found or value is not 440 * set. 441 */ 442 u_long 443 tcp_hc_getmtu(struct in_conninfo *inc) 444 { 445 struct hc_metrics *hc_entry; 446 u_long mtu; 447 448 hc_entry = tcp_hc_lookup(inc); 449 if (hc_entry == NULL) { 450 return 0; 451 } 452 hc_entry->rmx_hits++; 453 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 454 455 mtu = hc_entry->rmx_mtu; 456 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 457 return mtu; 458 } 459 460 /* 461 * External function: lookup an entry in the hostcache and fill out the 462 * supplied t/tcp tao structure. Fills in null when no entry was found 463 * or a value is not set. 464 */ 465 void 466 tcp_hc_gettao(struct in_conninfo *inc, struct rmxp_tao *tao) 467 { 468 struct hc_metrics *hc_entry; 469 470 hc_entry = tcp_hc_lookup(inc); 471 if (hc_entry == NULL) { 472 bzero(tao, sizeof(*tao)); 473 return; 474 } 475 hc_entry->rmx_hits++; 476 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 477 478 bcopy(&hc_entry->rmx_tao, tao, sizeof(*tao)); 479 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 480 } 481 482 /* 483 * External function: update the mtu value of an entry in the hostcache. 484 * Creates a new entry if none was found. 485 */ 486 void 487 tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) 488 { 489 struct hc_metrics *hc_entry; 490 491 /* 492 * Find the right bucket 493 */ 494 hc_entry = tcp_hc_lookup(inc); 495 496 /* 497 * If we don't have an existing object try to insert a new one 498 */ 499 if (hc_entry == NULL) { 500 hc_entry = tcp_hc_insert(inc); 501 if (hc_entry == NULL) 502 return; 503 } 504 hc_entry->rmx_updates++; 505 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 506 507 hc_entry->rmx_mtu = mtu; 508 509 /* 510 * put it upfront so we find it faster next time 511 */ 512 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 513 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 514 515 /* 516 * unlock bucket row 517 */ 518 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 519 } 520 521 /* 522 * External function: update the tcp metrics of an entry in the hostcache. 523 * Creates a new entry if none was found. 524 */ 525 void 526 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 527 { 528 struct hc_metrics *hc_entry; 529 530 hc_entry = tcp_hc_lookup(inc); 531 if (hc_entry == NULL) { 532 hc_entry = tcp_hc_insert(inc); 533 if (hc_entry == NULL) 534 return; 535 } 536 hc_entry->rmx_updates++; 537 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 538 539 if (hcml->rmx_rtt != 0) { 540 if (hc_entry->rmx_rtt == 0) 541 hc_entry->rmx_rtt = hcml->rmx_rtt; 542 else 543 hc_entry->rmx_rtt = 544 (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; 545 tcpstat.tcps_cachedrtt++; 546 } 547 if (hcml->rmx_rttvar != 0) { 548 if (hc_entry->rmx_rttvar == 0) 549 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 550 else 551 hc_entry->rmx_rttvar = 552 (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; 553 tcpstat.tcps_cachedrttvar++; 554 } 555 if (hcml->rmx_ssthresh != 0) { 556 if (hc_entry->rmx_ssthresh == 0) 557 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 558 else 559 hc_entry->rmx_ssthresh = 560 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 561 tcpstat.tcps_cachedssthresh++; 562 } 563 if (hcml->rmx_bandwidth != 0) { 564 if (hc_entry->rmx_bandwidth == 0) 565 hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; 566 else 567 hc_entry->rmx_bandwidth = 568 (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; 569 /* tcpstat.tcps_cachedbandwidth++; */ 570 } 571 if (hcml->rmx_cwnd != 0) { 572 if (hc_entry->rmx_cwnd == 0) 573 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 574 else 575 hc_entry->rmx_cwnd = 576 (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; 577 /* tcpstat.tcps_cachedcwnd++; */ 578 } 579 if (hcml->rmx_sendpipe != 0) { 580 if (hc_entry->rmx_sendpipe == 0) 581 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 582 else 583 hc_entry->rmx_sendpipe = 584 (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; 585 /* tcpstat.tcps_cachedsendpipe++; */ 586 } 587 if (hcml->rmx_recvpipe != 0) { 588 if (hc_entry->rmx_recvpipe == 0) 589 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 590 else 591 hc_entry->rmx_recvpipe = 592 (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; 593 /* tcpstat.tcps_cachedrecvpipe++; */ 594 } 595 596 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 597 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 598 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 599 } 600 601 /* 602 * External function: update the t/tcp tao of an entry in the hostcache. 603 * Creates a new entry if none was found. 604 */ 605 void 606 tcp_hc_updatetao(struct in_conninfo *inc, int field, tcp_cc ccount, u_short mss) 607 { 608 struct hc_metrics *hc_entry; 609 610 hc_entry = tcp_hc_lookup(inc); 611 if (hc_entry == NULL) { 612 hc_entry = tcp_hc_insert(inc); 613 if (hc_entry == NULL) 614 return; 615 } 616 hc_entry->rmx_updates++; 617 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 618 619 switch(field) { 620 case TCP_HC_TAO_CC: 621 hc_entry->rmx_tao.tao_cc = ccount; 622 break; 623 624 case TCP_HC_TAO_CCSENT: 625 hc_entry->rmx_tao.tao_ccsent = ccount; 626 break; 627 628 case TCP_HC_TAO_MSSOPT: 629 hc_entry->rmx_tao.tao_mssopt = mss; 630 break; 631 } 632 633 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 634 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 635 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 636 } 637 638 /* 639 * Sysctl function: prints the list and values of all hostcache entries in 640 * unsorted order. 641 */ 642 static int 643 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 644 { 645 int bufsize; 646 int linesize = 128; 647 char *p, *buf; 648 int len, i, error; 649 struct hc_metrics *hc_entry; 650 651 bufsize = linesize * (tcp_hostcache.cache_count + 1); 652 653 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 654 655 len = snprintf(p, linesize, 656 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 657 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 658 p += len; 659 660 #define msec(u) (((u) + 500) / 1000) 661 for (i = 0; i < tcp_hostcache.hashsize; i++) { 662 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 663 TAILQ_FOREACH(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 664 rmx_q) { 665 len = snprintf(p, linesize, 666 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 667 "%4lu %4lu %4i\n", 668 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 669 #ifdef INET6 670 ip6_sprintf(&hc_entry->ip6), 671 #else 672 "IPv6?", 673 #endif 674 hc_entry->rmx_mtu, 675 hc_entry->rmx_ssthresh, 676 msec(hc_entry->rmx_rtt * 677 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 678 msec(hc_entry->rmx_rttvar * 679 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 680 hc_entry->rmx_bandwidth * 8, 681 hc_entry->rmx_cwnd, 682 hc_entry->rmx_sendpipe, 683 hc_entry->rmx_recvpipe, 684 hc_entry->rmx_hits, 685 hc_entry->rmx_updates, 686 hc_entry->rmx_expire); 687 p += len; 688 } 689 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 690 } 691 #undef msec 692 error = SYSCTL_OUT(req, buf, p - buf); 693 free(buf, M_TEMP); 694 return(error); 695 } 696 697 /* 698 * Expire and purge (old|all) entries in the tcp_hostcache. Runs periodically 699 * from the callout. 700 */ 701 static void 702 tcp_hc_purge(void *arg) 703 { 704 struct hc_metrics *hc_entry, *hc_next; 705 int all = (intptr_t)arg; 706 int i; 707 708 if (tcp_hostcache.purgeall) { 709 all = 1; 710 tcp_hostcache.purgeall = 0; 711 } 712 713 for (i = 0; i < tcp_hostcache.hashsize; i++) { 714 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 715 TAILQ_FOREACH_SAFE(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 716 rmx_q, hc_next) { 717 if (all || hc_entry->rmx_expire <= 0) { 718 TAILQ_REMOVE(&tcp_hostcache.hashbase[i].hch_bucket, 719 hc_entry, rmx_q); 720 uma_zfree(tcp_hostcache.zone, hc_entry); 721 tcp_hostcache.hashbase[i].hch_length--; 722 tcp_hostcache.cache_count--; 723 } else 724 hc_entry->rmx_expire -= TCP_HOSTCACHE_PRUNE; 725 } 726 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 727 } 728 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 729 }
Cache object: e395d6deba0e92c79556cd0ab5d1803a
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