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 30 /* 31 * The tcp_hostcache moves the tcp-specific cached metrics from the routing 32 * table to a dedicated structure indexed by the remote IP address. It keeps 33 * information on the measured TCP parameters of past TCP sessions to allow 34 * better initial start values to be used with later connections to/from the 35 * same source. Depending on the network parameters (delay, bandwidth, max 36 * MTU, congestion window) between local and remote sites, this can lead to 37 * significant speed-ups for new TCP connections after the first one. 38 * 39 * Due to the tcp_hostcache, all TCP-specific metrics information in the 40 * routing table have been removed. The inpcb no longer keeps a pointer to 41 * the routing entry, and protocol-initiated route cloning has been removed 42 * as well. With these changes, the routing table has gone back to being 43 * more lightwight and only carries information related to packet forwarding. 44 * 45 * tcp_hostcache is designed for multiple concurrent access in SMP 46 * environments and high contention. All bucket rows have their own lock and 47 * thus multiple lookups and modifies can be done at the same time as long as 48 * they are in different bucket rows. If a request for insertion of a new 49 * record can't be satisfied, it simply returns an empty structure. Nobody 50 * and nothing outside of tcp_hostcache.c will ever point directly to any 51 * entry in the tcp_hostcache. All communication is done in an 52 * object-oriented way and only functions of tcp_hostcache will manipulate 53 * hostcache entries. Otherwise, we are unable to achieve good behaviour in 54 * concurrent access situations. Since tcp_hostcache is only caching 55 * information, there are no fatal consequences if we either can't satisfy 56 * any particular request or have to drop/overwrite an existing entry because 57 * of bucket limit memory constrains. 58 */ 59 60 /* 61 * Many thanks to jlemon for basic structure of tcp_syncache which is being 62 * followed here. 63 */ 64 65 #include <sys/cdefs.h> 66 __FBSDID("$FreeBSD$"); 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 #include <net/route.h> 82 #include <net/vnet.h> 83 84 #include <netinet/in.h> 85 #include <netinet/in_systm.h> 86 #include <netinet/ip.h> 87 #include <netinet/in_var.h> 88 #include <netinet/in_pcb.h> 89 #include <netinet/ip_var.h> 90 #ifdef INET6 91 #include <netinet/ip6.h> 92 #include <netinet6/ip6_var.h> 93 #endif 94 #include <netinet/tcp.h> 95 #include <netinet/tcp_var.h> 96 #include <netinet/tcp_hostcache.h> 97 #ifdef INET6 98 #include <netinet6/tcp6_var.h> 99 #endif 100 101 #include <vm/uma.h> 102 103 /* Arbitrary values */ 104 #define TCP_HOSTCACHE_HASHSIZE 512 105 #define TCP_HOSTCACHE_BUCKETLIMIT 30 106 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 107 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 108 109 static VNET_DEFINE(struct tcp_hostcache, tcp_hostcache); 110 #define V_tcp_hostcache VNET(tcp_hostcache) 111 112 static VNET_DEFINE(struct callout, tcp_hc_callout); 113 #define V_tcp_hc_callout VNET(tcp_hc_callout) 114 115 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 116 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 117 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 118 static void tcp_hc_purge_internal(int); 119 static void tcp_hc_purge(void *); 120 121 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, 122 "TCP Host cache"); 123 124 SYSCTL_VNET_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_RDTUN, 125 &VNET_NAME(tcp_hostcache.cache_limit), 0, 126 "Overall entry limit for hostcache"); 127 128 SYSCTL_VNET_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_RDTUN, 129 &VNET_NAME(tcp_hostcache.hashsize), 0, 130 "Size of TCP hostcache hashtable"); 131 132 SYSCTL_VNET_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 133 CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, 134 "Per-bucket hash limit for hostcache"); 135 136 SYSCTL_VNET_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_RD, 137 &VNET_NAME(tcp_hostcache.cache_count), 0, 138 "Current number of entries in hostcache"); 139 140 SYSCTL_VNET_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_RW, 141 &VNET_NAME(tcp_hostcache.expire), 0, 142 "Expire time of TCP hostcache entries"); 143 144 SYSCTL_VNET_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_RW, 145 &VNET_NAME(tcp_hostcache.prune), 0, 146 "Time between purge runs"); 147 148 SYSCTL_VNET_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_RW, 149 &VNET_NAME(tcp_hostcache.purgeall), 0, 150 "Expire all entires on next purge run"); 151 152 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 153 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 154 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 155 156 157 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 158 159 #define HOSTCACHE_HASH(ip) \ 160 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 161 V_tcp_hostcache.hashmask) 162 163 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 164 #define HOSTCACHE_HASH6(ip6) \ 165 (((ip6)->s6_addr32[0] ^ \ 166 (ip6)->s6_addr32[1] ^ \ 167 (ip6)->s6_addr32[2] ^ \ 168 (ip6)->s6_addr32[3]) & \ 169 V_tcp_hostcache.hashmask) 170 171 #define THC_LOCK(lp) mtx_lock(lp) 172 #define THC_UNLOCK(lp) mtx_unlock(lp) 173 174 void 175 tcp_hc_init(void) 176 { 177 int i; 178 179 /* 180 * Initialize hostcache structures. 181 */ 182 V_tcp_hostcache.cache_count = 0; 183 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 184 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 185 V_tcp_hostcache.cache_limit = 186 V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 187 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 188 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 189 190 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 191 &V_tcp_hostcache.hashsize); 192 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 193 &V_tcp_hostcache.cache_limit); 194 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 195 &V_tcp_hostcache.bucket_limit); 196 if (!powerof2(V_tcp_hostcache.hashsize)) { 197 printf("WARNING: hostcache hash size is not a power of 2.\n"); 198 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 199 } 200 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 201 202 /* 203 * Allocate the hash table. 204 */ 205 V_tcp_hostcache.hashbase = (struct hc_head *) 206 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 207 M_HOSTCACHE, M_WAITOK | M_ZERO); 208 209 /* 210 * Initialize the hash buckets. 211 */ 212 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 213 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 214 V_tcp_hostcache.hashbase[i].hch_length = 0; 215 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 216 NULL, MTX_DEF); 217 } 218 219 /* 220 * Allocate the hostcache entries. 221 */ 222 V_tcp_hostcache.zone = 223 uma_zcreate("hostcache", sizeof(struct hc_metrics), 224 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 225 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 226 227 /* 228 * Set up periodic cache cleanup. 229 */ 230 callout_init(&V_tcp_hc_callout, CALLOUT_MPSAFE); 231 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 232 tcp_hc_purge, curvnet); 233 } 234 235 #ifdef VIMAGE 236 void 237 tcp_hc_destroy(void) 238 { 239 int i; 240 241 callout_drain(&V_tcp_hc_callout); 242 243 /* Purge all hc entries. */ 244 tcp_hc_purge_internal(1); 245 246 /* Free the uma zone and the allocated hash table. */ 247 uma_zdestroy(V_tcp_hostcache.zone); 248 249 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 250 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 251 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 252 } 253 #endif 254 255 /* 256 * Internal function: look up an entry in the hostcache or return NULL. 257 * 258 * If an entry has been returned, the caller becomes responsible for 259 * unlocking the bucket row after he is done reading/modifying the entry. 260 */ 261 static struct hc_metrics * 262 tcp_hc_lookup(struct in_conninfo *inc) 263 { 264 int hash; 265 struct hc_head *hc_head; 266 struct hc_metrics *hc_entry; 267 268 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 269 270 /* 271 * Hash the foreign ip address. 272 */ 273 if (inc->inc_flags & INC_ISIPV6) 274 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 275 else 276 hash = HOSTCACHE_HASH(&inc->inc_faddr); 277 278 hc_head = &V_tcp_hostcache.hashbase[hash]; 279 280 /* 281 * Acquire lock for this bucket row; we release the lock if we don't 282 * find an entry, otherwise the caller has to unlock after he is 283 * done. 284 */ 285 THC_LOCK(&hc_head->hch_mtx); 286 287 /* 288 * Iterate through entries in bucket row looking for a match. 289 */ 290 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 291 if (inc->inc_flags & INC_ISIPV6) { 292 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 293 sizeof(inc->inc6_faddr)) == 0) 294 return hc_entry; 295 } else { 296 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 297 sizeof(inc->inc_faddr)) == 0) 298 return hc_entry; 299 } 300 } 301 302 /* 303 * We were unsuccessful and didn't find anything. 304 */ 305 THC_UNLOCK(&hc_head->hch_mtx); 306 return NULL; 307 } 308 309 /* 310 * Internal function: insert an entry into the hostcache or return NULL if 311 * unable to allocate a new one. 312 * 313 * If an entry has been returned, the caller becomes responsible for 314 * unlocking the bucket row after he is done reading/modifying the entry. 315 */ 316 static struct hc_metrics * 317 tcp_hc_insert(struct in_conninfo *inc) 318 { 319 int hash; 320 struct hc_head *hc_head; 321 struct hc_metrics *hc_entry; 322 323 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 324 325 /* 326 * Hash the foreign ip address. 327 */ 328 if (inc->inc_flags & INC_ISIPV6) 329 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 330 else 331 hash = HOSTCACHE_HASH(&inc->inc_faddr); 332 333 hc_head = &V_tcp_hostcache.hashbase[hash]; 334 335 /* 336 * Acquire lock for this bucket row; we release the lock if we don't 337 * find an entry, otherwise the caller has to unlock after he is 338 * done. 339 */ 340 THC_LOCK(&hc_head->hch_mtx); 341 342 /* 343 * If the bucket limit is reached, reuse the least-used element. 344 */ 345 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 346 V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { 347 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 348 /* 349 * At first we were dropping the last element, just to 350 * reacquire it in the next two lines again, which isn't very 351 * efficient. Instead just reuse the least used element. 352 * We may drop something that is still "in-use" but we can be 353 * "lossy". 354 * Just give up if this bucket row is empty and we don't have 355 * anything to replace. 356 */ 357 if (hc_entry == NULL) { 358 THC_UNLOCK(&hc_head->hch_mtx); 359 return NULL; 360 } 361 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 362 V_tcp_hostcache.hashbase[hash].hch_length--; 363 V_tcp_hostcache.cache_count--; 364 TCPSTAT_INC(tcps_hc_bucketoverflow); 365 #if 0 366 uma_zfree(V_tcp_hostcache.zone, hc_entry); 367 #endif 368 } else { 369 /* 370 * Allocate a new entry, or balk if not possible. 371 */ 372 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 373 if (hc_entry == NULL) { 374 THC_UNLOCK(&hc_head->hch_mtx); 375 return NULL; 376 } 377 } 378 379 /* 380 * Initialize basic information of hostcache entry. 381 */ 382 bzero(hc_entry, sizeof(*hc_entry)); 383 if (inc->inc_flags & INC_ISIPV6) 384 bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 385 else 386 hc_entry->ip4 = inc->inc_faddr; 387 hc_entry->rmx_head = hc_head; 388 hc_entry->rmx_expire = V_tcp_hostcache.expire; 389 390 /* 391 * Put it upfront. 392 */ 393 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 394 V_tcp_hostcache.hashbase[hash].hch_length++; 395 V_tcp_hostcache.cache_count++; 396 TCPSTAT_INC(tcps_hc_added); 397 398 return hc_entry; 399 } 400 401 /* 402 * External function: look up an entry in the hostcache and fill out the 403 * supplied TCP metrics structure. Fills in NULL when no entry was found or 404 * a value is not set. 405 */ 406 void 407 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 408 { 409 struct hc_metrics *hc_entry; 410 411 /* 412 * Find the right bucket. 413 */ 414 hc_entry = tcp_hc_lookup(inc); 415 416 /* 417 * If we don't have an existing object. 418 */ 419 if (hc_entry == NULL) { 420 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 421 return; 422 } 423 hc_entry->rmx_hits++; 424 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 425 426 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 427 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 428 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 429 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 430 hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 431 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 432 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 433 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 434 435 /* 436 * Unlock bucket row. 437 */ 438 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 439 } 440 441 /* 442 * External function: look up an entry in the hostcache and return the 443 * discovered path MTU. Returns NULL if no entry is found or value is not 444 * set. 445 */ 446 u_long 447 tcp_hc_getmtu(struct in_conninfo *inc) 448 { 449 struct hc_metrics *hc_entry; 450 u_long mtu; 451 452 hc_entry = tcp_hc_lookup(inc); 453 if (hc_entry == NULL) { 454 return 0; 455 } 456 hc_entry->rmx_hits++; 457 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 458 459 mtu = hc_entry->rmx_mtu; 460 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 461 return mtu; 462 } 463 464 /* 465 * External function: update the MTU value of an entry in the hostcache. 466 * Creates a new entry if none was found. 467 */ 468 void 469 tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) 470 { 471 struct hc_metrics *hc_entry; 472 473 /* 474 * Find the right bucket. 475 */ 476 hc_entry = tcp_hc_lookup(inc); 477 478 /* 479 * If we don't have an existing object, try to insert a new one. 480 */ 481 if (hc_entry == NULL) { 482 hc_entry = tcp_hc_insert(inc); 483 if (hc_entry == NULL) 484 return; 485 } 486 hc_entry->rmx_updates++; 487 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 488 489 hc_entry->rmx_mtu = mtu; 490 491 /* 492 * Put it upfront so we find it faster next time. 493 */ 494 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 495 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 496 497 /* 498 * Unlock bucket row. 499 */ 500 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 501 } 502 503 /* 504 * External function: update the TCP metrics of an entry in the hostcache. 505 * Creates a new entry if none was found. 506 */ 507 void 508 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 509 { 510 struct hc_metrics *hc_entry; 511 512 hc_entry = tcp_hc_lookup(inc); 513 if (hc_entry == NULL) { 514 hc_entry = tcp_hc_insert(inc); 515 if (hc_entry == NULL) 516 return; 517 } 518 hc_entry->rmx_updates++; 519 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 520 521 if (hcml->rmx_rtt != 0) { 522 if (hc_entry->rmx_rtt == 0) 523 hc_entry->rmx_rtt = hcml->rmx_rtt; 524 else 525 hc_entry->rmx_rtt = 526 (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; 527 TCPSTAT_INC(tcps_cachedrtt); 528 } 529 if (hcml->rmx_rttvar != 0) { 530 if (hc_entry->rmx_rttvar == 0) 531 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 532 else 533 hc_entry->rmx_rttvar = 534 (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; 535 TCPSTAT_INC(tcps_cachedrttvar); 536 } 537 if (hcml->rmx_ssthresh != 0) { 538 if (hc_entry->rmx_ssthresh == 0) 539 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 540 else 541 hc_entry->rmx_ssthresh = 542 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 543 TCPSTAT_INC(tcps_cachedssthresh); 544 } 545 if (hcml->rmx_bandwidth != 0) { 546 if (hc_entry->rmx_bandwidth == 0) 547 hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; 548 else 549 hc_entry->rmx_bandwidth = 550 (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; 551 /* TCPSTAT_INC(tcps_cachedbandwidth); */ 552 } 553 if (hcml->rmx_cwnd != 0) { 554 if (hc_entry->rmx_cwnd == 0) 555 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 556 else 557 hc_entry->rmx_cwnd = 558 (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; 559 /* TCPSTAT_INC(tcps_cachedcwnd); */ 560 } 561 if (hcml->rmx_sendpipe != 0) { 562 if (hc_entry->rmx_sendpipe == 0) 563 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 564 else 565 hc_entry->rmx_sendpipe = 566 (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; 567 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 568 } 569 if (hcml->rmx_recvpipe != 0) { 570 if (hc_entry->rmx_recvpipe == 0) 571 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 572 else 573 hc_entry->rmx_recvpipe = 574 (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; 575 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 576 } 577 578 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 579 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 580 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 581 } 582 583 /* 584 * Sysctl function: prints the list and values of all hostcache entries in 585 * unsorted order. 586 */ 587 static int 588 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 589 { 590 int bufsize; 591 int linesize = 128; 592 char *p, *buf; 593 int len, i, error; 594 struct hc_metrics *hc_entry; 595 #ifdef INET6 596 char ip6buf[INET6_ADDRSTRLEN]; 597 #endif 598 599 bufsize = linesize * (V_tcp_hostcache.cache_count + 1); 600 601 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 602 603 len = snprintf(p, linesize, 604 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 605 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 606 p += len; 607 608 #define msec(u) (((u) + 500) / 1000) 609 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 610 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 611 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 612 rmx_q) { 613 len = snprintf(p, linesize, 614 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 615 "%4lu %4lu %4i\n", 616 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 617 #ifdef INET6 618 ip6_sprintf(ip6buf, &hc_entry->ip6), 619 #else 620 "IPv6?", 621 #endif 622 hc_entry->rmx_mtu, 623 hc_entry->rmx_ssthresh, 624 msec(hc_entry->rmx_rtt * 625 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 626 msec(hc_entry->rmx_rttvar * 627 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 628 hc_entry->rmx_bandwidth * 8, 629 hc_entry->rmx_cwnd, 630 hc_entry->rmx_sendpipe, 631 hc_entry->rmx_recvpipe, 632 hc_entry->rmx_hits, 633 hc_entry->rmx_updates, 634 hc_entry->rmx_expire); 635 p += len; 636 } 637 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 638 } 639 #undef msec 640 error = SYSCTL_OUT(req, buf, p - buf); 641 free(buf, M_TEMP); 642 return(error); 643 } 644 645 /* 646 * Caller has to make sure the curvnet is set properly. 647 */ 648 static void 649 tcp_hc_purge_internal(int all) 650 { 651 struct hc_metrics *hc_entry, *hc_next; 652 int i; 653 654 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 655 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 656 TAILQ_FOREACH_SAFE(hc_entry, 657 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 658 if (all || hc_entry->rmx_expire <= 0) { 659 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 660 hc_entry, rmx_q); 661 uma_zfree(V_tcp_hostcache.zone, hc_entry); 662 V_tcp_hostcache.hashbase[i].hch_length--; 663 V_tcp_hostcache.cache_count--; 664 } else 665 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 666 } 667 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 668 } 669 } 670 671 /* 672 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 673 * periodically from the callout. 674 */ 675 static void 676 tcp_hc_purge(void *arg) 677 { 678 CURVNET_SET((struct vnet *) arg); 679 int all = 0; 680 681 if (V_tcp_hostcache.purgeall) { 682 all = 1; 683 V_tcp_hostcache.purgeall = 0; 684 } 685 686 tcp_hc_purge_internal(all); 687 688 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 689 tcp_hc_purge, arg); 690 CURVNET_RESTORE(); 691 } 692