1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32/* 33 * The tcp_hostcache moves the tcp-specific cached metrics from the routing 34 * table to a dedicated structure indexed by the remote IP address. It keeps 35 * information on the measured TCP parameters of past TCP sessions to allow 36 * better initial start values to be used with later connections to/from the 37 * same source. Depending on the network parameters (delay, max MTU, 38 * congestion window) between local and remote sites, this can lead to 39 * significant speed-ups for new TCP connections after the first one. 40 * 41 * Due to the tcp_hostcache, all TCP-specific metrics information in the 42 * routing table have been removed. The inpcb no longer keeps a pointer to 43 * the routing entry, and protocol-initiated route cloning has been removed 44 * as well. With these changes, the routing table has gone back to being 45 * more lightwight and only carries information related to packet forwarding. 46 * 47 * tcp_hostcache is designed for multiple concurrent access in SMP 48 * environments and high contention. All bucket rows have their own lock and 49 * thus multiple lookups and modifies can be done at the same time as long as 50 * they are in different bucket rows. If a request for insertion of a new 51 * record can't be satisfied, it simply returns an empty structure. Nobody 52 * and nothing outside of tcp_hostcache.c will ever point directly to any 53 * entry in the tcp_hostcache. All communication is done in an 54 * object-oriented way and only functions of tcp_hostcache will manipulate 55 * hostcache entries. Otherwise, we are unable to achieve good behaviour in 56 * concurrent access situations. Since tcp_hostcache is only caching 57 * information, there are no fatal consequences if we either can't satisfy 58 * any particular request or have to drop/overwrite an existing entry because 59 * of bucket limit memory constrains. 60 */ 61 62/* 63 * Many thanks to jlemon for basic structure of tcp_syncache which is being 64 * followed here. 65 */ 66 67#include <sys/cdefs.h> 68__FBSDID("$FreeBSD$"); 69 70#include "opt_inet6.h" 71 72#include <sys/param.h> 73#include <sys/systm.h> 74#include <sys/hash.h> 75#include <sys/jail.h> 76#include <sys/kernel.h> 77#include <sys/lock.h> 78#include <sys/mutex.h> 79#include <sys/malloc.h> 80#include <sys/proc.h> 81#include <sys/sbuf.h> 82#include <sys/socket.h> 83#include <sys/socketvar.h> 84#include <sys/sysctl.h> 85 86#include <net/if.h> 87#include <net/if_var.h> 88#include <net/route.h> 89#include <net/vnet.h> 90 91#include <netinet/in.h> 92#include <netinet/in_systm.h> 93#include <netinet/ip.h> 94#include <netinet/in_var.h> 95#include <netinet/in_pcb.h> 96#include <netinet/ip_var.h> 97#ifdef INET6 98#include <netinet/ip6.h> 99#include <netinet6/ip6_var.h> 100#endif 101#include <netinet/tcp.h> 102#include <netinet/tcp_var.h> 103#include <netinet/tcp_hostcache.h> 104#ifdef INET6 105#include <netinet6/tcp6_var.h> 106#endif 107 108#include <vm/uma.h> 109 110/* Arbitrary values */ 111#define TCP_HOSTCACHE_HASHSIZE 512 112#define TCP_HOSTCACHE_BUCKETLIMIT 30 113#define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 114#define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 115 116VNET_DEFINE_STATIC(struct tcp_hostcache, tcp_hostcache); 117#define V_tcp_hostcache VNET(tcp_hostcache) 118 119VNET_DEFINE_STATIC(struct callout, tcp_hc_callout); 120#define V_tcp_hc_callout VNET(tcp_hc_callout) 121 122static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 123static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 124static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 125static int sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS); 126static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS); 127static void tcp_hc_purge_internal(int); 128static void tcp_hc_purge(void *); 129 130static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, 131 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 132 "TCP Host cache"); 133 134VNET_DEFINE(int, tcp_use_hostcache) = 1; 135#define V_tcp_use_hostcache VNET(tcp_use_hostcache) 136SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW, 137 &VNET_NAME(tcp_use_hostcache), 0, 138 "Enable the TCP hostcache"); 139 140SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN, 141 &VNET_NAME(tcp_hostcache.cache_limit), 0, 142 "Overall entry limit for hostcache"); 143 144SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN, 145 &VNET_NAME(tcp_hostcache.hashsize), 0, 146 "Size of TCP hostcache hashtable"); 147 148SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 149 CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, 150 "Per-bucket hash limit for hostcache"); 151 152SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_VNET | CTLFLAG_RD, 153 &VNET_NAME(tcp_hostcache.cache_count), 0, 154 "Current number of entries in hostcache"); 155 156SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_VNET | CTLFLAG_RW, 157 &VNET_NAME(tcp_hostcache.expire), 0, 158 "Expire time of TCP hostcache entries"); 159 160SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_VNET | CTLFLAG_RW, 161 &VNET_NAME(tcp_hostcache.prune), 0, 162 "Time between purge runs"); 163 164SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_VNET | CTLFLAG_RW, 165 &VNET_NAME(tcp_hostcache.purgeall), 0, 166 "Expire all entires on next purge run"); 167 168SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 169 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_MPSAFE, 170 0, 0, sysctl_tcp_hc_list, "A", 171 "List of all hostcache entries"); 172 173SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, histo, 174 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_MPSAFE, 175 0, 0, sysctl_tcp_hc_histo, "A", 176 "Print a histogram of hostcache hashbucket utilization"); 177 178SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow, 179 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 180 NULL, 0, sysctl_tcp_hc_purgenow, "I", 181 "Immediately purge all entries"); 182 183static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 184 185/* Use jenkins_hash32(), as in other parts of the tcp stack */ 186#define HOSTCACHE_HASH(ip) \ 187 (jenkins_hash32((uint32_t *)(ip), 1, V_tcp_hostcache.hashsalt) & \ 188 V_tcp_hostcache.hashmask) 189 190#define HOSTCACHE_HASH6(ip6) \ 191 (jenkins_hash32((uint32_t *)&((ip6)->s6_addr32[0]), 4, \ 192 V_tcp_hostcache.hashsalt) & \ 193 V_tcp_hostcache.hashmask) 194 195#define THC_LOCK(lp) mtx_lock(lp) 196#define THC_UNLOCK(lp) mtx_unlock(lp) 197 198void 199tcp_hc_init(void) 200{ 201 u_int cache_limit; 202 int i; 203 204 /* 205 * Initialize hostcache structures. 206 */ 207 atomic_store_int(&V_tcp_hostcache.cache_count, 0); 208 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 209 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 210 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 211 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 212 V_tcp_hostcache.hashsalt = arc4random(); 213 214 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 215 &V_tcp_hostcache.hashsize); 216 if (!powerof2(V_tcp_hostcache.hashsize)) { 217 printf("WARNING: hostcache hash size is not a power of 2.\n"); 218 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 219 } 220 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 221 222 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 223 &V_tcp_hostcache.bucket_limit); 224 225 cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 226 V_tcp_hostcache.cache_limit = cache_limit; 227 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 228 &V_tcp_hostcache.cache_limit); 229 if (V_tcp_hostcache.cache_limit > cache_limit) 230 V_tcp_hostcache.cache_limit = cache_limit; 231 232 /* 233 * Allocate the hash table. 234 */ 235 V_tcp_hostcache.hashbase = (struct hc_head *) 236 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 237 M_HOSTCACHE, M_WAITOK | M_ZERO); 238 239 /* 240 * Initialize the hash buckets. 241 */ 242 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 243 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 244 V_tcp_hostcache.hashbase[i].hch_length = 0; 245 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 246 NULL, MTX_DEF); 247 } 248 249 /* 250 * Allocate the hostcache entries. 251 */ 252 V_tcp_hostcache.zone = 253 uma_zcreate("hostcache", sizeof(struct hc_metrics), 254 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 255 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 256 257 /* 258 * Set up periodic cache cleanup. 259 */ 260 callout_init(&V_tcp_hc_callout, 1); 261 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 262 tcp_hc_purge, curvnet); 263} 264 265#ifdef VIMAGE 266void 267tcp_hc_destroy(void) 268{ 269 int i; 270 271 callout_drain(&V_tcp_hc_callout); 272 273 /* Purge all hc entries. */ 274 tcp_hc_purge_internal(1); 275 276 /* Free the uma zone and the allocated hash table. */ 277 uma_zdestroy(V_tcp_hostcache.zone); 278 279 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 280 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 281 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 282} 283#endif 284 285/* 286 * Internal function: look up an entry in the hostcache or return NULL. 287 * 288 * If an entry has been returned, the caller becomes responsible for 289 * unlocking the bucket row after he is done reading/modifying the entry. 290 */ 291static struct hc_metrics * 292tcp_hc_lookup(struct in_conninfo *inc) 293{ 294 int hash; 295 struct hc_head *hc_head; 296 struct hc_metrics *hc_entry; 297 298 if (!V_tcp_use_hostcache) 299 return NULL; 300 301 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 302 303 /* 304 * Hash the foreign ip address. 305 */ 306 if (inc->inc_flags & INC_ISIPV6) 307 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 308 else 309 hash = HOSTCACHE_HASH(&inc->inc_faddr); 310 311 hc_head = &V_tcp_hostcache.hashbase[hash]; 312 313 /* 314 * Acquire lock for this bucket row; we release the lock if we don't 315 * find an entry, otherwise the caller has to unlock after he is 316 * done. 317 */ 318 THC_LOCK(&hc_head->hch_mtx); 319 320 /* 321 * Iterate through entries in bucket row looking for a match. 322 */ 323 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 324 if (inc->inc_flags & INC_ISIPV6) { 325 /* XXX: check ip6_zoneid */ 326 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 327 sizeof(inc->inc6_faddr)) == 0) 328 return hc_entry; 329 } else { 330 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 331 sizeof(inc->inc_faddr)) == 0) 332 return hc_entry; 333 } 334 } 335 336 /* 337 * We were unsuccessful and didn't find anything. 338 */ 339 THC_UNLOCK(&hc_head->hch_mtx); 340 return NULL; 341} 342 343/* 344 * Internal function: insert an entry into the hostcache or return NULL if 345 * unable to allocate a new one. 346 * 347 * If an entry has been returned, the caller becomes responsible for 348 * unlocking the bucket row after he is done reading/modifying the entry. 349 */ 350static struct hc_metrics * 351tcp_hc_insert(struct in_conninfo *inc) 352{ 353 int hash; 354 struct hc_head *hc_head; 355 struct hc_metrics *hc_entry; 356 357 if (!V_tcp_use_hostcache) 358 return NULL; 359 360 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 361 362 /* 363 * Hash the foreign ip address. 364 */ 365 if (inc->inc_flags & INC_ISIPV6) 366 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 367 else 368 hash = HOSTCACHE_HASH(&inc->inc_faddr); 369 370 hc_head = &V_tcp_hostcache.hashbase[hash]; 371 372 /* 373 * Acquire lock for this bucket row; we release the lock if we don't 374 * find an entry, otherwise the caller has to unlock after he is 375 * done. 376 */ 377 THC_LOCK(&hc_head->hch_mtx); 378 379 /* 380 * If the bucket limit is reached, reuse the least-used element. 381 */ 382 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 383 atomic_load_int(&V_tcp_hostcache.cache_count) >= V_tcp_hostcache.cache_limit) { 384 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 385 /* 386 * At first we were dropping the last element, just to 387 * reacquire it in the next two lines again, which isn't very 388 * efficient. Instead just reuse the least used element. 389 * We may drop something that is still "in-use" but we can be 390 * "lossy". 391 * Just give up if this bucket row is empty and we don't have 392 * anything to replace. 393 */ 394 if (hc_entry == NULL) { 395 THC_UNLOCK(&hc_head->hch_mtx); 396 return NULL; 397 } 398 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 399 KASSERT(V_tcp_hostcache.hashbase[hash].hch_length > 0 && 400 V_tcp_hostcache.hashbase[hash].hch_length <= 401 V_tcp_hostcache.bucket_limit, 402 ("tcp_hostcache: bucket length range violated at %u: %u", 403 hash, V_tcp_hostcache.hashbase[hash].hch_length)); 404 V_tcp_hostcache.hashbase[hash].hch_length--; 405 atomic_subtract_int(&V_tcp_hostcache.cache_count, 1); 406 TCPSTAT_INC(tcps_hc_bucketoverflow); 407#if 0 408 uma_zfree(V_tcp_hostcache.zone, hc_entry); 409#endif 410 } else { 411 /* 412 * Allocate a new entry, or balk if not possible. 413 */ 414 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 415 if (hc_entry == NULL) { 416 THC_UNLOCK(&hc_head->hch_mtx); 417 return NULL; 418 } 419 } 420 421 /* 422 * Initialize basic information of hostcache entry. 423 */ 424 bzero(hc_entry, sizeof(*hc_entry)); 425 if (inc->inc_flags & INC_ISIPV6) { 426 hc_entry->ip6 = inc->inc6_faddr; 427 hc_entry->ip6_zoneid = inc->inc6_zoneid; 428 } else 429 hc_entry->ip4 = inc->inc_faddr; 430 hc_entry->rmx_head = hc_head; 431 hc_entry->rmx_expire = V_tcp_hostcache.expire; 432 433 /* 434 * Put it upfront. 435 */ 436 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 437 V_tcp_hostcache.hashbase[hash].hch_length++; 438 KASSERT(V_tcp_hostcache.hashbase[hash].hch_length < 439 V_tcp_hostcache.bucket_limit, 440 ("tcp_hostcache: bucket length too high at %u: %u", 441 hash, V_tcp_hostcache.hashbase[hash].hch_length)); 442 atomic_add_int(&V_tcp_hostcache.cache_count, 1); 443 TCPSTAT_INC(tcps_hc_added); 444 445 return hc_entry; 446} 447 448/* 449 * External function: look up an entry in the hostcache and fill out the 450 * supplied TCP metrics structure. Fills in NULL when no entry was found or 451 * a value is not set. 452 */ 453void 454tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 455{ 456 struct hc_metrics *hc_entry; 457 458 if (!V_tcp_use_hostcache) { 459 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 460 return; 461 } 462 463 /* 464 * Find the right bucket. 465 */ 466 hc_entry = tcp_hc_lookup(inc); 467 468 /* 469 * If we don't have an existing object. 470 */ 471 if (hc_entry == NULL) { 472 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 473 return; 474 } 475 hc_entry->rmx_hits++; 476 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 477 478 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 479 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 480 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 481 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 482 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 483 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 484 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 485 486 /* 487 * Unlock bucket row. 488 */ 489 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 490} 491 492/* 493 * External function: look up an entry in the hostcache and return the 494 * discovered path MTU. Returns 0 if no entry is found or value is not 495 * set. 496 */ 497uint32_t 498tcp_hc_getmtu(struct in_conninfo *inc) 499{ 500 struct hc_metrics *hc_entry; 501 uint32_t mtu; 502 503 if (!V_tcp_use_hostcache) 504 return 0; 505 506 hc_entry = tcp_hc_lookup(inc); 507 if (hc_entry == NULL) { 508 return 0; 509 } 510 hc_entry->rmx_hits++; 511 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 512 513 mtu = hc_entry->rmx_mtu; 514 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 515 return mtu; 516} 517 518/* 519 * External function: update the MTU value of an entry in the hostcache. 520 * Creates a new entry if none was found. 521 */ 522void 523tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu) 524{ 525 struct hc_metrics *hc_entry; 526 527 if (!V_tcp_use_hostcache) 528 return; 529 530 /* 531 * Find the right bucket. 532 */ 533 hc_entry = tcp_hc_lookup(inc); 534 535 /* 536 * If we don't have an existing object, try to insert a new one. 537 */ 538 if (hc_entry == NULL) { 539 hc_entry = tcp_hc_insert(inc); 540 if (hc_entry == NULL) 541 return; 542 } 543 hc_entry->rmx_updates++; 544 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 545 546 hc_entry->rmx_mtu = mtu; 547 548 /* 549 * Put it upfront so we find it faster next time. 550 */ 551 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 552 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 553 554 /* 555 * Unlock bucket row. 556 */ 557 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 558} 559 560/* 561 * External function: update the TCP metrics of an entry in the hostcache. 562 * Creates a new entry if none was found. 563 */ 564void 565tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 566{ 567 struct hc_metrics *hc_entry; 568 569 if (!V_tcp_use_hostcache) 570 return; 571 572 hc_entry = tcp_hc_lookup(inc); 573 if (hc_entry == NULL) { 574 hc_entry = tcp_hc_insert(inc); 575 if (hc_entry == NULL) 576 return; 577 } 578 hc_entry->rmx_updates++; 579 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 580 581 if (hcml->rmx_rtt != 0) { 582 if (hc_entry->rmx_rtt == 0) 583 hc_entry->rmx_rtt = hcml->rmx_rtt; 584 else 585 hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt + 586 (uint64_t)hcml->rmx_rtt) / 2; 587 TCPSTAT_INC(tcps_cachedrtt); 588 } 589 if (hcml->rmx_rttvar != 0) { 590 if (hc_entry->rmx_rttvar == 0) 591 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 592 else 593 hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar + 594 (uint64_t)hcml->rmx_rttvar) / 2; 595 TCPSTAT_INC(tcps_cachedrttvar); 596 } 597 if (hcml->rmx_ssthresh != 0) { 598 if (hc_entry->rmx_ssthresh == 0) 599 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 600 else 601 hc_entry->rmx_ssthresh = 602 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 603 TCPSTAT_INC(tcps_cachedssthresh); 604 } 605 if (hcml->rmx_cwnd != 0) { 606 if (hc_entry->rmx_cwnd == 0) 607 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 608 else 609 hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd + 610 (uint64_t)hcml->rmx_cwnd) / 2; 611 /* TCPSTAT_INC(tcps_cachedcwnd); */ 612 } 613 if (hcml->rmx_sendpipe != 0) { 614 if (hc_entry->rmx_sendpipe == 0) 615 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 616 else 617 hc_entry->rmx_sendpipe = 618 ((uint64_t)hc_entry->rmx_sendpipe + 619 (uint64_t)hcml->rmx_sendpipe) /2; 620 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 621 } 622 if (hcml->rmx_recvpipe != 0) { 623 if (hc_entry->rmx_recvpipe == 0) 624 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 625 else 626 hc_entry->rmx_recvpipe = 627 ((uint64_t)hc_entry->rmx_recvpipe + 628 (uint64_t)hcml->rmx_recvpipe) /2; 629 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 630 } 631 632 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 633 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 634 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 635} 636 637/* 638 * Sysctl function: prints the list and values of all hostcache entries in 639 * unsorted order. 640 */ 641static int 642sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 643{ 644 const int linesize = 128; 645 struct sbuf sb; 646 int i, error, len; 647 struct hc_metrics *hc_entry; 648 char ip4buf[INET_ADDRSTRLEN]; 649#ifdef INET6 650 char ip6buf[INET6_ADDRSTRLEN]; 651#endif 652 653 if (jailed_without_vnet(curthread->td_ucred) != 0) 654 return (EPERM); 655 656 /* Optimize Buffer length query by sbin/sysctl */ 657 if (req->oldptr == NULL) { 658 len = (atomic_load_int(&V_tcp_hostcache.cache_count) + 1) * 659 linesize; 660 return (SYSCTL_OUT(req, NULL, len)); 661 } 662 663 error = sysctl_wire_old_buffer(req, 0); 664 if (error != 0) { 665 return(error); 666 } 667 668 /* Use a buffer sized for one full bucket */ 669 sbuf_new_for_sysctl(&sb, NULL, V_tcp_hostcache.bucket_limit * 670 linesize, req); 671 672 sbuf_printf(&sb, 673 "\nIP address MTU SSTRESH RTT RTTVAR " 674 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 675 sbuf_drain(&sb); 676 677#define msec(u) (((u) + 500) / 1000) 678 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 679 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 680 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 681 rmx_q) { 682 sbuf_printf(&sb, 683 "%-15s %5u %8u %6lums %6lums %8u %8u %8u %4lu " 684 "%4lu %4i\n", 685 hc_entry->ip4.s_addr ? 686 inet_ntoa_r(hc_entry->ip4, ip4buf) : 687#ifdef INET6 688 ip6_sprintf(ip6buf, &hc_entry->ip6), 689#else 690 "IPv6?", 691#endif 692 hc_entry->rmx_mtu, 693 hc_entry->rmx_ssthresh, 694 msec((u_long)hc_entry->rmx_rtt * 695 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 696 msec((u_long)hc_entry->rmx_rttvar * 697 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), 698 hc_entry->rmx_cwnd, 699 hc_entry->rmx_sendpipe, 700 hc_entry->rmx_recvpipe, 701 hc_entry->rmx_hits, 702 hc_entry->rmx_updates, 703 hc_entry->rmx_expire); 704 } 705 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 706 sbuf_drain(&sb); 707 } 708#undef msec 709 error = sbuf_finish(&sb); 710 sbuf_delete(&sb); 711 return(error); 712} 713 714/* 715 * Sysctl function: prints a histogram of the hostcache hashbucket 716 * utilization. 717 */ 718static int 719sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS) 720{ 721 const int linesize = 50; 722 struct sbuf sb; 723 int i, error; 724 int *histo; 725 u_int hch_length; 726 727 if (jailed_without_vnet(curthread->td_ucred) != 0) 728 return (EPERM); 729 730 histo = (int *)malloc(sizeof(int) * (V_tcp_hostcache.bucket_limit + 1), 731 M_TEMP, M_NOWAIT|M_ZERO); 732 if (histo == NULL) 733 return(ENOMEM); 734 735 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 736 hch_length = V_tcp_hostcache.hashbase[i].hch_length; 737 KASSERT(hch_length <= V_tcp_hostcache.bucket_limit, 738 ("tcp_hostcache: bucket limit exceeded at %u: %u", 739 i, hch_length)); 740 histo[hch_length]++; 741 } 742 743 /* Use a buffer for 16 lines */ 744 sbuf_new_for_sysctl(&sb, NULL, 16 * linesize, req); 745 746 sbuf_printf(&sb, "\nLength\tCount\n"); 747 for (i = 0; i <= V_tcp_hostcache.bucket_limit; i++) { 748 sbuf_printf(&sb, "%u\t%u\n", i, histo[i]); 749 } 750 error = sbuf_finish(&sb); 751 sbuf_delete(&sb); 752 free(histo, M_TEMP); 753 return(error); 754} 755 756/* 757 * Caller has to make sure the curvnet is set properly. 758 */ 759static void 760tcp_hc_purge_internal(int all) 761{ 762 struct hc_metrics *hc_entry, *hc_next; 763 int i; 764 765 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 766 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 767 TAILQ_FOREACH_SAFE(hc_entry, 768 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 769 KASSERT(V_tcp_hostcache.hashbase[i].hch_length > 0 && 770 V_tcp_hostcache.hashbase[i].hch_length <= 771 V_tcp_hostcache.bucket_limit, 772 ("tcp_hostcache: bucket length out of range at %u: %u", 773 i, V_tcp_hostcache.hashbase[i].hch_length)); 774 if (all || hc_entry->rmx_expire <= 0) { 775 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 776 hc_entry, rmx_q); 777 uma_zfree(V_tcp_hostcache.zone, hc_entry); 778 V_tcp_hostcache.hashbase[i].hch_length--; 779 atomic_subtract_int(&V_tcp_hostcache.cache_count, 1); 780 } else 781 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 782 } 783 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 784 } 785} 786 787/* 788 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 789 * periodically from the callout. 790 */ 791static void 792tcp_hc_purge(void *arg) 793{ 794 CURVNET_SET((struct vnet *) arg); 795 int all = 0; 796 797 if (V_tcp_hostcache.purgeall) { 798 if (V_tcp_hostcache.purgeall == 2) 799 V_tcp_hostcache.hashsalt = arc4random(); 800 all = 1; 801 V_tcp_hostcache.purgeall = 0; 802 } 803 804 tcp_hc_purge_internal(all); 805 806 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 807 tcp_hc_purge, arg); 808 CURVNET_RESTORE(); 809} 810 811/* 812 * Expire and purge all entries in hostcache immediately. 813 */ 814static int 815sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS) 816{ 817 int error, val; 818 819 val = 0; 820 error = sysctl_handle_int(oidp, &val, 0, req); 821 if (error || !req->newptr) 822 return (error); 823 824 if (val == 2) 825 V_tcp_hostcache.hashsalt = arc4random(); 826 tcp_hc_purge_internal(1); 827 828 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 829 tcp_hc_purge, curvnet); 830 831 return (0); 832} 833