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, max MTU, 36 * 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/sbuf.h> 77 #include <sys/socket.h> 78 #include <sys/socketvar.h> 79 #include <sys/sysctl.h> 80 81 #include <net/if.h> 82 #include <net/if_var.h> 83 #include <net/route.h> 84 #include <net/vnet.h> 85 86 #include <netinet/in.h> 87 #include <netinet/in_systm.h> 88 #include <netinet/ip.h> 89 #include <netinet/in_var.h> 90 #include <netinet/in_pcb.h> 91 #include <netinet/ip_var.h> 92 #ifdef INET6 93 #include <netinet/ip6.h> 94 #include <netinet6/ip6_var.h> 95 #endif 96 #include <netinet/tcp.h> 97 #include <netinet/tcp_var.h> 98 #include <netinet/tcp_hostcache.h> 99 #ifdef INET6 100 #include <netinet6/tcp6_var.h> 101 #endif 102 103 #include <vm/uma.h> 104 105 /* Arbitrary values */ 106 #define TCP_HOSTCACHE_HASHSIZE 512 107 #define TCP_HOSTCACHE_BUCKETLIMIT 30 108 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 109 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 110 111 static VNET_DEFINE(struct tcp_hostcache, tcp_hostcache); 112 #define V_tcp_hostcache VNET(tcp_hostcache) 113 114 static VNET_DEFINE(struct callout, tcp_hc_callout); 115 #define V_tcp_hc_callout VNET(tcp_hc_callout) 116 117 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 118 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 119 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 120 static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS); 121 static void tcp_hc_purge_internal(int); 122 static void tcp_hc_purge(void *); 123 124 static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, 125 "TCP Host cache"); 126 127 VNET_DEFINE(int, tcp_use_hostcache) = 1; 128 #define V_tcp_use_hostcache VNET(tcp_use_hostcache) 129 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW, 130 &VNET_NAME(tcp_use_hostcache), 0, 131 "Enable the TCP hostcache"); 132 133 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN, 134 &VNET_NAME(tcp_hostcache.cache_limit), 0, 135 "Overall entry limit for hostcache"); 136 137 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN, 138 &VNET_NAME(tcp_hostcache.hashsize), 0, 139 "Size of TCP hostcache hashtable"); 140 141 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 142 CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, 143 "Per-bucket hash limit for hostcache"); 144 145 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_VNET | CTLFLAG_RD, 146 &VNET_NAME(tcp_hostcache.cache_count), 0, 147 "Current number of entries in hostcache"); 148 149 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_VNET | CTLFLAG_RW, 150 &VNET_NAME(tcp_hostcache.expire), 0, 151 "Expire time of TCP hostcache entries"); 152 153 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_VNET | CTLFLAG_RW, 154 &VNET_NAME(tcp_hostcache.prune), 0, 155 "Time between purge runs"); 156 157 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_VNET | CTLFLAG_RW, 158 &VNET_NAME(tcp_hostcache.purgeall), 0, 159 "Expire all entires on next purge run"); 160 161 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 162 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 163 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 164 165 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow, 166 CTLTYPE_INT | CTLFLAG_RW, NULL, 0, 167 sysctl_tcp_hc_purgenow, "I", "Immediately purge all entries"); 168 169 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 170 171 #define HOSTCACHE_HASH(ip) \ 172 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 173 V_tcp_hostcache.hashmask) 174 175 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 176 #define HOSTCACHE_HASH6(ip6) \ 177 (((ip6)->s6_addr32[0] ^ \ 178 (ip6)->s6_addr32[1] ^ \ 179 (ip6)->s6_addr32[2] ^ \ 180 (ip6)->s6_addr32[3]) & \ 181 V_tcp_hostcache.hashmask) 182 183 #define THC_LOCK(lp) mtx_lock(lp) 184 #define THC_UNLOCK(lp) mtx_unlock(lp) 185 186 void 187 tcp_hc_init(void) 188 { 189 u_int cache_limit; 190 int i; 191 192 /* 193 * Initialize hostcache structures. 194 */ 195 V_tcp_hostcache.cache_count = 0; 196 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 197 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 198 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 199 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 200 201 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 202 &V_tcp_hostcache.hashsize); 203 if (!powerof2(V_tcp_hostcache.hashsize)) { 204 printf("WARNING: hostcache hash size is not a power of 2.\n"); 205 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 206 } 207 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 208 209 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 210 &V_tcp_hostcache.bucket_limit); 211 212 cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 213 V_tcp_hostcache.cache_limit = cache_limit; 214 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 215 &V_tcp_hostcache.cache_limit); 216 if (V_tcp_hostcache.cache_limit > cache_limit) 217 V_tcp_hostcache.cache_limit = cache_limit; 218 219 /* 220 * Allocate the hash table. 221 */ 222 V_tcp_hostcache.hashbase = (struct hc_head *) 223 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 224 M_HOSTCACHE, M_WAITOK | M_ZERO); 225 226 /* 227 * Initialize the hash buckets. 228 */ 229 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 230 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 231 V_tcp_hostcache.hashbase[i].hch_length = 0; 232 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 233 NULL, MTX_DEF); 234 } 235 236 /* 237 * Allocate the hostcache entries. 238 */ 239 V_tcp_hostcache.zone = 240 uma_zcreate("hostcache", sizeof(struct hc_metrics), 241 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 242 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 243 244 /* 245 * Set up periodic cache cleanup. 246 */ 247 callout_init(&V_tcp_hc_callout, 1); 248 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 249 tcp_hc_purge, curvnet); 250 } 251 252 #ifdef VIMAGE 253 void 254 tcp_hc_destroy(void) 255 { 256 int i; 257 258 callout_drain(&V_tcp_hc_callout); 259 260 /* Purge all hc entries. */ 261 tcp_hc_purge_internal(1); 262 263 /* Free the uma zone and the allocated hash table. */ 264 uma_zdestroy(V_tcp_hostcache.zone); 265 266 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 267 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 268 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 269 } 270 #endif 271 272 /* 273 * Internal function: look up an entry in the hostcache or return NULL. 274 * 275 * If an entry has been returned, the caller becomes responsible for 276 * unlocking the bucket row after he is done reading/modifying the entry. 277 */ 278 static struct hc_metrics * 279 tcp_hc_lookup(struct in_conninfo *inc) 280 { 281 int hash; 282 struct hc_head *hc_head; 283 struct hc_metrics *hc_entry; 284 285 if (!V_tcp_use_hostcache) 286 return NULL; 287 288 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 289 290 /* 291 * Hash the foreign ip address. 292 */ 293 if (inc->inc_flags & INC_ISIPV6) 294 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 295 else 296 hash = HOSTCACHE_HASH(&inc->inc_faddr); 297 298 hc_head = &V_tcp_hostcache.hashbase[hash]; 299 300 /* 301 * Acquire lock for this bucket row; we release the lock if we don't 302 * find an entry, otherwise the caller has to unlock after he is 303 * done. 304 */ 305 THC_LOCK(&hc_head->hch_mtx); 306 307 /* 308 * Iterate through entries in bucket row looking for a match. 309 */ 310 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 311 if (inc->inc_flags & INC_ISIPV6) { 312 /* XXX: check ip6_zoneid */ 313 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 314 sizeof(inc->inc6_faddr)) == 0) 315 return hc_entry; 316 } else { 317 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 318 sizeof(inc->inc_faddr)) == 0) 319 return hc_entry; 320 } 321 } 322 323 /* 324 * We were unsuccessful and didn't find anything. 325 */ 326 THC_UNLOCK(&hc_head->hch_mtx); 327 return NULL; 328 } 329 330 /* 331 * Internal function: insert an entry into the hostcache or return NULL if 332 * unable to allocate a new one. 333 * 334 * If an entry has been returned, the caller becomes responsible for 335 * unlocking the bucket row after he is done reading/modifying the entry. 336 */ 337 static struct hc_metrics * 338 tcp_hc_insert(struct in_conninfo *inc) 339 { 340 int hash; 341 struct hc_head *hc_head; 342 struct hc_metrics *hc_entry; 343 344 if (!V_tcp_use_hostcache) 345 return NULL; 346 347 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 348 349 /* 350 * Hash the foreign ip address. 351 */ 352 if (inc->inc_flags & INC_ISIPV6) 353 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 354 else 355 hash = HOSTCACHE_HASH(&inc->inc_faddr); 356 357 hc_head = &V_tcp_hostcache.hashbase[hash]; 358 359 /* 360 * Acquire lock for this bucket row; we release the lock if we don't 361 * find an entry, otherwise the caller has to unlock after he is 362 * done. 363 */ 364 THC_LOCK(&hc_head->hch_mtx); 365 366 /* 367 * If the bucket limit is reached, reuse the least-used element. 368 */ 369 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 370 V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { 371 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 372 /* 373 * At first we were dropping the last element, just to 374 * reacquire it in the next two lines again, which isn't very 375 * efficient. Instead just reuse the least used element. 376 * We may drop something that is still "in-use" but we can be 377 * "lossy". 378 * Just give up if this bucket row is empty and we don't have 379 * anything to replace. 380 */ 381 if (hc_entry == NULL) { 382 THC_UNLOCK(&hc_head->hch_mtx); 383 return NULL; 384 } 385 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 386 V_tcp_hostcache.hashbase[hash].hch_length--; 387 V_tcp_hostcache.cache_count--; 388 TCPSTAT_INC(tcps_hc_bucketoverflow); 389 #if 0 390 uma_zfree(V_tcp_hostcache.zone, hc_entry); 391 #endif 392 } else { 393 /* 394 * Allocate a new entry, or balk if not possible. 395 */ 396 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 397 if (hc_entry == NULL) { 398 THC_UNLOCK(&hc_head->hch_mtx); 399 return NULL; 400 } 401 } 402 403 /* 404 * Initialize basic information of hostcache entry. 405 */ 406 bzero(hc_entry, sizeof(*hc_entry)); 407 if (inc->inc_flags & INC_ISIPV6) { 408 hc_entry->ip6 = inc->inc6_faddr; 409 hc_entry->ip6_zoneid = inc->inc6_zoneid; 410 } else 411 hc_entry->ip4 = inc->inc_faddr; 412 hc_entry->rmx_head = hc_head; 413 hc_entry->rmx_expire = V_tcp_hostcache.expire; 414 415 /* 416 * Put it upfront. 417 */ 418 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 419 V_tcp_hostcache.hashbase[hash].hch_length++; 420 V_tcp_hostcache.cache_count++; 421 TCPSTAT_INC(tcps_hc_added); 422 423 return hc_entry; 424 } 425 426 /* 427 * External function: look up an entry in the hostcache and fill out the 428 * supplied TCP metrics structure. Fills in NULL when no entry was found or 429 * a value is not set. 430 */ 431 void 432 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 433 { 434 struct hc_metrics *hc_entry; 435 436 if (!V_tcp_use_hostcache) 437 return; 438 439 /* 440 * Find the right bucket. 441 */ 442 hc_entry = tcp_hc_lookup(inc); 443 444 /* 445 * If we don't have an existing object. 446 */ 447 if (hc_entry == NULL) { 448 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 449 return; 450 } 451 hc_entry->rmx_hits++; 452 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 453 454 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 455 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 456 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 457 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 458 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 459 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 460 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 461 462 /* 463 * Unlock bucket row. 464 */ 465 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 466 } 467 468 /* 469 * External function: look up an entry in the hostcache and return the 470 * discovered path MTU. Returns 0 if no entry is found or value is not 471 * set. 472 */ 473 uint32_t 474 tcp_hc_getmtu(struct in_conninfo *inc) 475 { 476 struct hc_metrics *hc_entry; 477 uint32_t mtu; 478 479 if (!V_tcp_use_hostcache) 480 return 0; 481 482 hc_entry = tcp_hc_lookup(inc); 483 if (hc_entry == NULL) { 484 return 0; 485 } 486 hc_entry->rmx_hits++; 487 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 488 489 mtu = hc_entry->rmx_mtu; 490 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 491 return mtu; 492 } 493 494 /* 495 * External function: update the MTU value of an entry in the hostcache. 496 * Creates a new entry if none was found. 497 */ 498 void 499 tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu) 500 { 501 struct hc_metrics *hc_entry; 502 503 if (!V_tcp_use_hostcache) 504 return; 505 506 /* 507 * Find the right bucket. 508 */ 509 hc_entry = tcp_hc_lookup(inc); 510 511 /* 512 * If we don't have an existing object, try to insert a new one. 513 */ 514 if (hc_entry == NULL) { 515 hc_entry = tcp_hc_insert(inc); 516 if (hc_entry == NULL) 517 return; 518 } 519 hc_entry->rmx_updates++; 520 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 521 522 hc_entry->rmx_mtu = mtu; 523 524 /* 525 * Put it upfront so we find it faster next time. 526 */ 527 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 528 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 529 530 /* 531 * Unlock bucket row. 532 */ 533 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 534 } 535 536 /* 537 * External function: update the TCP metrics of an entry in the hostcache. 538 * Creates a new entry if none was found. 539 */ 540 void 541 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 542 { 543 struct hc_metrics *hc_entry; 544 545 if (!V_tcp_use_hostcache) 546 return; 547 548 hc_entry = tcp_hc_lookup(inc); 549 if (hc_entry == NULL) { 550 hc_entry = tcp_hc_insert(inc); 551 if (hc_entry == NULL) 552 return; 553 } 554 hc_entry->rmx_updates++; 555 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 556 557 if (hcml->rmx_rtt != 0) { 558 if (hc_entry->rmx_rtt == 0) 559 hc_entry->rmx_rtt = hcml->rmx_rtt; 560 else 561 hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt + 562 (uint64_t)hcml->rmx_rtt) / 2; 563 TCPSTAT_INC(tcps_cachedrtt); 564 } 565 if (hcml->rmx_rttvar != 0) { 566 if (hc_entry->rmx_rttvar == 0) 567 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 568 else 569 hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar + 570 (uint64_t)hcml->rmx_rttvar) / 2; 571 TCPSTAT_INC(tcps_cachedrttvar); 572 } 573 if (hcml->rmx_ssthresh != 0) { 574 if (hc_entry->rmx_ssthresh == 0) 575 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 576 else 577 hc_entry->rmx_ssthresh = 578 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 579 TCPSTAT_INC(tcps_cachedssthresh); 580 } 581 if (hcml->rmx_cwnd != 0) { 582 if (hc_entry->rmx_cwnd == 0) 583 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 584 else 585 hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd + 586 (uint64_t)hcml->rmx_cwnd) / 2; 587 /* TCPSTAT_INC(tcps_cachedcwnd); */ 588 } 589 if (hcml->rmx_sendpipe != 0) { 590 if (hc_entry->rmx_sendpipe == 0) 591 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 592 else 593 hc_entry->rmx_sendpipe = 594 ((uint64_t)hc_entry->rmx_sendpipe + 595 (uint64_t)hcml->rmx_sendpipe) /2; 596 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 597 } 598 if (hcml->rmx_recvpipe != 0) { 599 if (hc_entry->rmx_recvpipe == 0) 600 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 601 else 602 hc_entry->rmx_recvpipe = 603 ((uint64_t)hc_entry->rmx_recvpipe + 604 (uint64_t)hcml->rmx_recvpipe) /2; 605 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 606 } 607 608 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 609 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 610 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 611 } 612 613 /* 614 * Sysctl function: prints the list and values of all hostcache entries in 615 * unsorted order. 616 */ 617 static int 618 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 619 { 620 const int linesize = 128; 621 struct sbuf sb; 622 int i, error; 623 struct hc_metrics *hc_entry; 624 #ifdef INET6 625 char ip6buf[INET6_ADDRSTRLEN]; 626 #endif 627 628 sbuf_new(&sb, NULL, linesize * (V_tcp_hostcache.cache_count + 1), 629 SBUF_INCLUDENUL); 630 631 sbuf_printf(&sb, 632 "\nIP address MTU SSTRESH RTT RTTVAR " 633 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 634 635 #define msec(u) (((u) + 500) / 1000) 636 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 637 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 638 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 639 rmx_q) { 640 sbuf_printf(&sb, 641 "%-15s %5u %8u %6lums %6lums %8u %8u %8u %4lu " 642 "%4lu %4i\n", 643 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 644 #ifdef INET6 645 ip6_sprintf(ip6buf, &hc_entry->ip6), 646 #else 647 "IPv6?", 648 #endif 649 hc_entry->rmx_mtu, 650 hc_entry->rmx_ssthresh, 651 msec((u_long)hc_entry->rmx_rtt * 652 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 653 msec((u_long)hc_entry->rmx_rttvar * 654 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), 655 hc_entry->rmx_cwnd, 656 hc_entry->rmx_sendpipe, 657 hc_entry->rmx_recvpipe, 658 hc_entry->rmx_hits, 659 hc_entry->rmx_updates, 660 hc_entry->rmx_expire); 661 } 662 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 663 } 664 #undef msec 665 error = sbuf_finish(&sb); 666 if (error == 0) 667 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 668 sbuf_delete(&sb); 669 return(error); 670 } 671 672 /* 673 * Caller has to make sure the curvnet is set properly. 674 */ 675 static void 676 tcp_hc_purge_internal(int all) 677 { 678 struct hc_metrics *hc_entry, *hc_next; 679 int i; 680 681 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 682 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 683 TAILQ_FOREACH_SAFE(hc_entry, 684 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 685 if (all || hc_entry->rmx_expire <= 0) { 686 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 687 hc_entry, rmx_q); 688 uma_zfree(V_tcp_hostcache.zone, hc_entry); 689 V_tcp_hostcache.hashbase[i].hch_length--; 690 V_tcp_hostcache.cache_count--; 691 } else 692 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 693 } 694 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 695 } 696 } 697 698 /* 699 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 700 * periodically from the callout. 701 */ 702 static void 703 tcp_hc_purge(void *arg) 704 { 705 CURVNET_SET((struct vnet *) arg); 706 int all = 0; 707 708 if (V_tcp_hostcache.purgeall) { 709 all = 1; 710 V_tcp_hostcache.purgeall = 0; 711 } 712 713 tcp_hc_purge_internal(all); 714 715 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 716 tcp_hc_purge, arg); 717 CURVNET_RESTORE(); 718 } 719 720 /* 721 * Expire and purge all entries in hostcache immediately. 722 */ 723 static int 724 sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS) 725 { 726 int error, val; 727 728 val = 0; 729 error = sysctl_handle_int(oidp, &val, 0, req); 730 if (error || !req->newptr) 731 return (error); 732 733 tcp_hc_purge_internal(1); 734 735 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 736 tcp_hc_purge, curvnet); 737 738 return (0); 739 } 740