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 109static VNET_DEFINE(struct tcp_hostcache, tcp_hostcache); 110#define V_tcp_hostcache VNET(tcp_hostcache) 111 112static VNET_DEFINE(struct callout, tcp_hc_callout); 113#define V_tcp_hc_callout VNET(tcp_hc_callout) 114 115static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 116static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 117static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 118static void tcp_hc_purge_internal(int); 119static void tcp_hc_purge(void *); 120 121static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, 122 "TCP Host cache"); 123 124SYSCTL_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 128SYSCTL_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 132SYSCTL_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 136SYSCTL_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 140SYSCTL_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 144SYSCTL_VNET_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_RW, 145 &VNET_NAME(tcp_hostcache.prune), 0, 146 "Time between purge runs"); 147 148SYSCTL_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 152SYSCTL_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 157static 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 174void 175tcp_hc_init(void) 176{ 177 u_int cache_limit; 178 int i; 179 180 /* 181 * Initialize hostcache structures. 182 */ 183 V_tcp_hostcache.cache_count = 0; 184 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 185 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 186 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 187 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 188 189 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 190 &V_tcp_hostcache.hashsize); 191 if (!powerof2(V_tcp_hostcache.hashsize)) { 192 printf("WARNING: hostcache hash size is not a power of 2.\n"); 193 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 194 } 195 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 196 197 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 198 &V_tcp_hostcache.bucket_limit); 199 200 cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 201 V_tcp_hostcache.cache_limit = cache_limit; 202 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 203 &V_tcp_hostcache.cache_limit); 204 if (V_tcp_hostcache.cache_limit > cache_limit) 205 V_tcp_hostcache.cache_limit = cache_limit; 206 207 /* 208 * Allocate the hash table. 209 */ 210 V_tcp_hostcache.hashbase = (struct hc_head *) 211 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 212 M_HOSTCACHE, M_WAITOK | M_ZERO); 213 214 /* 215 * Initialize the hash buckets. 216 */ 217 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 218 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 219 V_tcp_hostcache.hashbase[i].hch_length = 0; 220 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 221 NULL, MTX_DEF); 222 } 223 224 /* 225 * Allocate the hostcache entries. 226 */ 227 V_tcp_hostcache.zone = 228 uma_zcreate("hostcache", sizeof(struct hc_metrics), 229 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 230 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 231 232 /* 233 * Set up periodic cache cleanup. 234 */ 235 callout_init(&V_tcp_hc_callout, CALLOUT_MPSAFE); 236 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 237 tcp_hc_purge, curvnet); 238} 239 240#ifdef VIMAGE 241void 242tcp_hc_destroy(void) 243{ 244 int i; 245 246 callout_drain(&V_tcp_hc_callout); 247 248 /* Purge all hc entries. */ 249 tcp_hc_purge_internal(1); 250 251 /* Free the uma zone and the allocated hash table. */ 252 uma_zdestroy(V_tcp_hostcache.zone); 253 254 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 255 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 256 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 257} 258#endif 259 260/* 261 * Internal function: look up an entry in the hostcache or return NULL. 262 * 263 * If an entry has been returned, the caller becomes responsible for 264 * unlocking the bucket row after he is done reading/modifying the entry. 265 */ 266static struct hc_metrics * 267tcp_hc_lookup(struct in_conninfo *inc) 268{ 269 int hash; 270 struct hc_head *hc_head; 271 struct hc_metrics *hc_entry; 272 273 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 274 275 /* 276 * Hash the foreign ip address. 277 */ 278 if (inc->inc_flags & INC_ISIPV6) 279 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 280 else 281 hash = HOSTCACHE_HASH(&inc->inc_faddr); 282 283 hc_head = &V_tcp_hostcache.hashbase[hash]; 284 285 /* 286 * Acquire lock for this bucket row; we release the lock if we don't 287 * find an entry, otherwise the caller has to unlock after he is 288 * done. 289 */ 290 THC_LOCK(&hc_head->hch_mtx); 291 292 /* 293 * Iterate through entries in bucket row looking for a match. 294 */ 295 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 296 if (inc->inc_flags & INC_ISIPV6) { 297 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 298 sizeof(inc->inc6_faddr)) == 0) 299 return hc_entry; 300 } else { 301 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 302 sizeof(inc->inc_faddr)) == 0) 303 return hc_entry; 304 } 305 } 306 307 /* 308 * We were unsuccessful and didn't find anything. 309 */ 310 THC_UNLOCK(&hc_head->hch_mtx); 311 return NULL; 312} 313 314/* 315 * Internal function: insert an entry into the hostcache or return NULL if 316 * unable to allocate a new one. 317 * 318 * If an entry has been returned, the caller becomes responsible for 319 * unlocking the bucket row after he is done reading/modifying the entry. 320 */ 321static struct hc_metrics * 322tcp_hc_insert(struct in_conninfo *inc) 323{ 324 int hash; 325 struct hc_head *hc_head; 326 struct hc_metrics *hc_entry; 327 328 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 329 330 /* 331 * Hash the foreign ip address. 332 */ 333 if (inc->inc_flags & INC_ISIPV6) 334 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 335 else 336 hash = HOSTCACHE_HASH(&inc->inc_faddr); 337 338 hc_head = &V_tcp_hostcache.hashbase[hash]; 339 340 /* 341 * Acquire lock for this bucket row; we release the lock if we don't 342 * find an entry, otherwise the caller has to unlock after he is 343 * done. 344 */ 345 THC_LOCK(&hc_head->hch_mtx); 346 347 /* 348 * If the bucket limit is reached, reuse the least-used element. 349 */ 350 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 351 V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { 352 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 353 /* 354 * At first we were dropping the last element, just to 355 * reacquire it in the next two lines again, which isn't very 356 * efficient. Instead just reuse the least used element. 357 * We may drop something that is still "in-use" but we can be 358 * "lossy". 359 * Just give up if this bucket row is empty and we don't have 360 * anything to replace. 361 */ 362 if (hc_entry == NULL) { 363 THC_UNLOCK(&hc_head->hch_mtx); 364 return NULL; 365 } 366 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 367 V_tcp_hostcache.hashbase[hash].hch_length--; 368 V_tcp_hostcache.cache_count--; 369 TCPSTAT_INC(tcps_hc_bucketoverflow); 370#if 0 371 uma_zfree(V_tcp_hostcache.zone, hc_entry); 372#endif 373 } else { 374 /* 375 * Allocate a new entry, or balk if not possible. 376 */ 377 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 378 if (hc_entry == NULL) { 379 THC_UNLOCK(&hc_head->hch_mtx); 380 return NULL; 381 } 382 } 383 384 /* 385 * Initialize basic information of hostcache entry. 386 */ 387 bzero(hc_entry, sizeof(*hc_entry)); 388 if (inc->inc_flags & INC_ISIPV6) 389 bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 390 else 391 hc_entry->ip4 = inc->inc_faddr; 392 hc_entry->rmx_head = hc_head; 393 hc_entry->rmx_expire = V_tcp_hostcache.expire; 394 395 /* 396 * Put it upfront. 397 */ 398 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 399 V_tcp_hostcache.hashbase[hash].hch_length++; 400 V_tcp_hostcache.cache_count++; 401 TCPSTAT_INC(tcps_hc_added); 402 403 return hc_entry; 404} 405 406/* 407 * External function: look up an entry in the hostcache and fill out the 408 * supplied TCP metrics structure. Fills in NULL when no entry was found or 409 * a value is not set. 410 */ 411void 412tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 413{ 414 struct hc_metrics *hc_entry; 415 416 /* 417 * Find the right bucket. 418 */ 419 hc_entry = tcp_hc_lookup(inc); 420 421 /* 422 * If we don't have an existing object. 423 */ 424 if (hc_entry == NULL) { 425 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 426 return; 427 } 428 hc_entry->rmx_hits++; 429 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 430 431 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 432 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 433 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 434 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 435 hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 436 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 437 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 438 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 439 440 /* 441 * Unlock bucket row. 442 */ 443 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 444} 445 446/* 447 * External function: look up an entry in the hostcache and return the 448 * discovered path MTU. Returns NULL if no entry is found or value is not 449 * set. 450 */ 451u_long 452tcp_hc_getmtu(struct in_conninfo *inc) 453{ 454 struct hc_metrics *hc_entry; 455 u_long mtu; 456 457 hc_entry = tcp_hc_lookup(inc); 458 if (hc_entry == NULL) { 459 return 0; 460 } 461 hc_entry->rmx_hits++; 462 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 463 464 mtu = hc_entry->rmx_mtu; 465 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 466 return mtu; 467} 468 469/* 470 * External function: update the MTU value of an entry in the hostcache. 471 * Creates a new entry if none was found. 472 */ 473void 474tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) 475{ 476 struct hc_metrics *hc_entry; 477 478 /* 479 * Find the right bucket. 480 */ 481 hc_entry = tcp_hc_lookup(inc); 482 483 /* 484 * If we don't have an existing object, try to insert a new one. 485 */ 486 if (hc_entry == NULL) { 487 hc_entry = tcp_hc_insert(inc); 488 if (hc_entry == NULL) 489 return; 490 } 491 hc_entry->rmx_updates++; 492 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 493 494 hc_entry->rmx_mtu = mtu; 495 496 /* 497 * Put it upfront so we find it faster next time. 498 */ 499 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 500 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 501 502 /* 503 * Unlock bucket row. 504 */ 505 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 506} 507 508/* 509 * External function: update the TCP metrics of an entry in the hostcache. 510 * Creates a new entry if none was found. 511 */ 512void 513tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 514{ 515 struct hc_metrics *hc_entry; 516 517 hc_entry = tcp_hc_lookup(inc); 518 if (hc_entry == NULL) { 519 hc_entry = tcp_hc_insert(inc); 520 if (hc_entry == NULL) 521 return; 522 } 523 hc_entry->rmx_updates++; 524 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 525 526 if (hcml->rmx_rtt != 0) { 527 if (hc_entry->rmx_rtt == 0) 528 hc_entry->rmx_rtt = hcml->rmx_rtt; 529 else 530 hc_entry->rmx_rtt = 531 (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; 532 TCPSTAT_INC(tcps_cachedrtt); 533 } 534 if (hcml->rmx_rttvar != 0) { 535 if (hc_entry->rmx_rttvar == 0) 536 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 537 else 538 hc_entry->rmx_rttvar = 539 (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; 540 TCPSTAT_INC(tcps_cachedrttvar); 541 } 542 if (hcml->rmx_ssthresh != 0) { 543 if (hc_entry->rmx_ssthresh == 0) 544 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 545 else 546 hc_entry->rmx_ssthresh = 547 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 548 TCPSTAT_INC(tcps_cachedssthresh); 549 } 550 if (hcml->rmx_bandwidth != 0) { 551 if (hc_entry->rmx_bandwidth == 0) 552 hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; 553 else 554 hc_entry->rmx_bandwidth = 555 (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; 556 /* TCPSTAT_INC(tcps_cachedbandwidth); */ 557 } 558 if (hcml->rmx_cwnd != 0) { 559 if (hc_entry->rmx_cwnd == 0) 560 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 561 else 562 hc_entry->rmx_cwnd = 563 (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; 564 /* TCPSTAT_INC(tcps_cachedcwnd); */ 565 } 566 if (hcml->rmx_sendpipe != 0) { 567 if (hc_entry->rmx_sendpipe == 0) 568 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 569 else 570 hc_entry->rmx_sendpipe = 571 (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; 572 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 573 } 574 if (hcml->rmx_recvpipe != 0) { 575 if (hc_entry->rmx_recvpipe == 0) 576 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 577 else 578 hc_entry->rmx_recvpipe = 579 (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; 580 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 581 } 582 583 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 584 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 585 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 586} 587 588/* 589 * Sysctl function: prints the list and values of all hostcache entries in 590 * unsorted order. 591 */ 592static int 593sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 594{ 595 int bufsize; 596 int linesize = 128; 597 char *p, *buf; 598 int len, i, error; 599 struct hc_metrics *hc_entry; 600#ifdef INET6 601 char ip6buf[INET6_ADDRSTRLEN]; 602#endif 603 604 bufsize = linesize * (V_tcp_hostcache.cache_count + 1); 605 606 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 607 608 len = snprintf(p, linesize, 609 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 610 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 611 p += len; 612 613#define msec(u) (((u) + 500) / 1000) 614 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 615 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 616 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 617 rmx_q) { 618 len = snprintf(p, linesize, 619 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 620 "%4lu %4lu %4i\n", 621 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 622#ifdef INET6 623 ip6_sprintf(ip6buf, &hc_entry->ip6), 624#else 625 "IPv6?", 626#endif 627 hc_entry->rmx_mtu, 628 hc_entry->rmx_ssthresh, 629 msec(hc_entry->rmx_rtt * 630 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 631 msec(hc_entry->rmx_rttvar * 632 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), 633 hc_entry->rmx_bandwidth * 8, 634 hc_entry->rmx_cwnd, 635 hc_entry->rmx_sendpipe, 636 hc_entry->rmx_recvpipe, 637 hc_entry->rmx_hits, 638 hc_entry->rmx_updates, 639 hc_entry->rmx_expire); 640 p += len; 641 } 642 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 643 } 644#undef msec 645 error = SYSCTL_OUT(req, buf, p - buf); 646 free(buf, M_TEMP); 647 return(error); 648} 649 650/* 651 * Caller has to make sure the curvnet is set properly. 652 */ 653static void 654tcp_hc_purge_internal(int all) 655{ 656 struct hc_metrics *hc_entry, *hc_next; 657 int i; 658 659 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 660 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 661 TAILQ_FOREACH_SAFE(hc_entry, 662 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 663 if (all || hc_entry->rmx_expire <= 0) { 664 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 665 hc_entry, rmx_q); 666 uma_zfree(V_tcp_hostcache.zone, hc_entry); 667 V_tcp_hostcache.hashbase[i].hch_length--; 668 V_tcp_hostcache.cache_count--; 669 } else 670 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 671 } 672 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 673 } 674} 675 676/* 677 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 678 * periodically from the callout. 679 */ 680static void 681tcp_hc_purge(void *arg) 682{ 683 CURVNET_SET((struct vnet *) arg); 684 int all = 0; 685 686 if (V_tcp_hostcache.purgeall) { 687 all = 1; 688 V_tcp_hostcache.purgeall = 0; 689 } 690 691 tcp_hc_purge_internal(all); 692 693 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 694 tcp_hc_purge, arg); 695 CURVNET_RESTORE(); 696} 697