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/jail.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.h> 75 #include <sys/mutex.h> 76 #include <sys/malloc.h> 77 #include <sys/proc.h> 78 #include <sys/sbuf.h> 79 #include <sys/socket.h> 80 #include <sys/socketvar.h> 81 #include <sys/sysctl.h> 82 83 #include <net/if.h> 84 #include <net/if_var.h> 85 #include <net/route.h> 86 #include <net/vnet.h> 87 88 #include <netinet/in.h> 89 #include <netinet/in_systm.h> 90 #include <netinet/ip.h> 91 #include <netinet/in_var.h> 92 #include <netinet/in_pcb.h> 93 #include <netinet/ip_var.h> 94 #ifdef INET6 95 #include <netinet/ip6.h> 96 #include <netinet6/ip6_var.h> 97 #endif 98 #include <netinet/tcp.h> 99 #include <netinet/tcp_var.h> 100 #include <netinet/tcp_hostcache.h> 101 #ifdef INET6 102 #include <netinet6/tcp6_var.h> 103 #endif 104 105 #include <vm/uma.h> 106 107 /* Arbitrary values */ 108 #define TCP_HOSTCACHE_HASHSIZE 512 109 #define TCP_HOSTCACHE_BUCKETLIMIT 30 110 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 111 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 112 113 static VNET_DEFINE(struct tcp_hostcache, tcp_hostcache); 114 #define V_tcp_hostcache VNET(tcp_hostcache) 115 116 static VNET_DEFINE(struct callout, tcp_hc_callout); 117 #define V_tcp_hc_callout VNET(tcp_hc_callout) 118 119 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 120 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 121 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 122 static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS); 123 static void tcp_hc_purge_internal(int); 124 static void tcp_hc_purge(void *); 125 126 static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, 127 "TCP Host cache"); 128 129 VNET_DEFINE(int, tcp_use_hostcache) = 1; 130 #define V_tcp_use_hostcache VNET(tcp_use_hostcache) 131 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW, 132 &VNET_NAME(tcp_use_hostcache), 0, 133 "Enable the TCP hostcache"); 134 135 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN, 136 &VNET_NAME(tcp_hostcache.cache_limit), 0, 137 "Overall entry limit for hostcache"); 138 139 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN, 140 &VNET_NAME(tcp_hostcache.hashsize), 0, 141 "Size of TCP hostcache hashtable"); 142 143 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 144 CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, 145 "Per-bucket hash limit for hostcache"); 146 147 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_VNET | CTLFLAG_RD, 148 &VNET_NAME(tcp_hostcache.cache_count), 0, 149 "Current number of entries in hostcache"); 150 151 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_VNET | CTLFLAG_RW, 152 &VNET_NAME(tcp_hostcache.expire), 0, 153 "Expire time of TCP hostcache entries"); 154 155 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_VNET | CTLFLAG_RW, 156 &VNET_NAME(tcp_hostcache.prune), 0, 157 "Time between purge runs"); 158 159 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_VNET | CTLFLAG_RW, 160 &VNET_NAME(tcp_hostcache.purgeall), 0, 161 "Expire all entires on next purge run"); 162 163 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 164 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 165 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 166 167 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow, 168 CTLTYPE_INT | CTLFLAG_RW, NULL, 0, 169 sysctl_tcp_hc_purgenow, "I", "Immediately purge all entries"); 170 171 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 172 173 #define HOSTCACHE_HASH(ip) \ 174 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 175 V_tcp_hostcache.hashmask) 176 177 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 178 #define HOSTCACHE_HASH6(ip6) \ 179 (((ip6)->s6_addr32[0] ^ \ 180 (ip6)->s6_addr32[1] ^ \ 181 (ip6)->s6_addr32[2] ^ \ 182 (ip6)->s6_addr32[3]) & \ 183 V_tcp_hostcache.hashmask) 184 185 #define THC_LOCK(lp) mtx_lock(lp) 186 #define THC_UNLOCK(lp) mtx_unlock(lp) 187 188 void 189 tcp_hc_init(void) 190 { 191 u_int cache_limit; 192 int i; 193 194 /* 195 * Initialize hostcache structures. 196 */ 197 V_tcp_hostcache.cache_count = 0; 198 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 199 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 200 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 201 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 202 203 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 204 &V_tcp_hostcache.hashsize); 205 if (!powerof2(V_tcp_hostcache.hashsize)) { 206 printf("WARNING: hostcache hash size is not a power of 2.\n"); 207 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 208 } 209 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 210 211 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 212 &V_tcp_hostcache.bucket_limit); 213 214 cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 215 V_tcp_hostcache.cache_limit = cache_limit; 216 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 217 &V_tcp_hostcache.cache_limit); 218 if (V_tcp_hostcache.cache_limit > cache_limit) 219 V_tcp_hostcache.cache_limit = cache_limit; 220 221 /* 222 * Allocate the hash table. 223 */ 224 V_tcp_hostcache.hashbase = (struct hc_head *) 225 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 226 M_HOSTCACHE, M_WAITOK | M_ZERO); 227 228 /* 229 * Initialize the hash buckets. 230 */ 231 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 232 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 233 V_tcp_hostcache.hashbase[i].hch_length = 0; 234 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 235 NULL, MTX_DEF); 236 } 237 238 /* 239 * Allocate the hostcache entries. 240 */ 241 V_tcp_hostcache.zone = 242 uma_zcreate("hostcache", sizeof(struct hc_metrics), 243 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 244 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 245 246 /* 247 * Set up periodic cache cleanup. 248 */ 249 callout_init(&V_tcp_hc_callout, 1); 250 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 251 tcp_hc_purge, curvnet); 252 } 253 254 #ifdef VIMAGE 255 void 256 tcp_hc_destroy(void) 257 { 258 int i; 259 260 callout_drain(&V_tcp_hc_callout); 261 262 /* Purge all hc entries. */ 263 tcp_hc_purge_internal(1); 264 265 /* Free the uma zone and the allocated hash table. */ 266 uma_zdestroy(V_tcp_hostcache.zone); 267 268 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 269 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 270 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 271 } 272 #endif 273 274 /* 275 * Internal function: look up an entry in the hostcache or return NULL. 276 * 277 * If an entry has been returned, the caller becomes responsible for 278 * unlocking the bucket row after he is done reading/modifying the entry. 279 */ 280 static struct hc_metrics * 281 tcp_hc_lookup(struct in_conninfo *inc) 282 { 283 int hash; 284 struct hc_head *hc_head; 285 struct hc_metrics *hc_entry; 286 287 if (!V_tcp_use_hostcache) 288 return NULL; 289 290 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 291 292 /* 293 * Hash the foreign ip address. 294 */ 295 if (inc->inc_flags & INC_ISIPV6) 296 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 297 else 298 hash = HOSTCACHE_HASH(&inc->inc_faddr); 299 300 hc_head = &V_tcp_hostcache.hashbase[hash]; 301 302 /* 303 * Acquire lock for this bucket row; we release the lock if we don't 304 * find an entry, otherwise the caller has to unlock after he is 305 * done. 306 */ 307 THC_LOCK(&hc_head->hch_mtx); 308 309 /* 310 * Iterate through entries in bucket row looking for a match. 311 */ 312 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 313 if (inc->inc_flags & INC_ISIPV6) { 314 /* XXX: check ip6_zoneid */ 315 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 316 sizeof(inc->inc6_faddr)) == 0) 317 return hc_entry; 318 } else { 319 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 320 sizeof(inc->inc_faddr)) == 0) 321 return hc_entry; 322 } 323 } 324 325 /* 326 * We were unsuccessful and didn't find anything. 327 */ 328 THC_UNLOCK(&hc_head->hch_mtx); 329 return NULL; 330 } 331 332 /* 333 * Internal function: insert an entry into the hostcache or return NULL if 334 * unable to allocate a new one. 335 * 336 * If an entry has been returned, the caller becomes responsible for 337 * unlocking the bucket row after he is done reading/modifying the entry. 338 */ 339 static struct hc_metrics * 340 tcp_hc_insert(struct in_conninfo *inc) 341 { 342 int hash; 343 struct hc_head *hc_head; 344 struct hc_metrics *hc_entry; 345 346 if (!V_tcp_use_hostcache) 347 return NULL; 348 349 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 350 351 /* 352 * Hash the foreign ip address. 353 */ 354 if (inc->inc_flags & INC_ISIPV6) 355 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 356 else 357 hash = HOSTCACHE_HASH(&inc->inc_faddr); 358 359 hc_head = &V_tcp_hostcache.hashbase[hash]; 360 361 /* 362 * Acquire lock for this bucket row; we release the lock if we don't 363 * find an entry, otherwise the caller has to unlock after he is 364 * done. 365 */ 366 THC_LOCK(&hc_head->hch_mtx); 367 368 /* 369 * If the bucket limit is reached, reuse the least-used element. 370 */ 371 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 372 V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { 373 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 374 /* 375 * At first we were dropping the last element, just to 376 * reacquire it in the next two lines again, which isn't very 377 * efficient. Instead just reuse the least used element. 378 * We may drop something that is still "in-use" but we can be 379 * "lossy". 380 * Just give up if this bucket row is empty and we don't have 381 * anything to replace. 382 */ 383 if (hc_entry == NULL) { 384 THC_UNLOCK(&hc_head->hch_mtx); 385 return NULL; 386 } 387 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 388 V_tcp_hostcache.hashbase[hash].hch_length--; 389 V_tcp_hostcache.cache_count--; 390 TCPSTAT_INC(tcps_hc_bucketoverflow); 391 #if 0 392 uma_zfree(V_tcp_hostcache.zone, hc_entry); 393 #endif 394 } else { 395 /* 396 * Allocate a new entry, or balk if not possible. 397 */ 398 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 399 if (hc_entry == NULL) { 400 THC_UNLOCK(&hc_head->hch_mtx); 401 return NULL; 402 } 403 } 404 405 /* 406 * Initialize basic information of hostcache entry. 407 */ 408 bzero(hc_entry, sizeof(*hc_entry)); 409 if (inc->inc_flags & INC_ISIPV6) { 410 hc_entry->ip6 = inc->inc6_faddr; 411 hc_entry->ip6_zoneid = inc->inc6_zoneid; 412 } else 413 hc_entry->ip4 = inc->inc_faddr; 414 hc_entry->rmx_head = hc_head; 415 hc_entry->rmx_expire = V_tcp_hostcache.expire; 416 417 /* 418 * Put it upfront. 419 */ 420 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 421 V_tcp_hostcache.hashbase[hash].hch_length++; 422 V_tcp_hostcache.cache_count++; 423 TCPSTAT_INC(tcps_hc_added); 424 425 return hc_entry; 426 } 427 428 /* 429 * External function: look up an entry in the hostcache and fill out the 430 * supplied TCP metrics structure. Fills in NULL when no entry was found or 431 * a value is not set. 432 */ 433 void 434 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 435 { 436 struct hc_metrics *hc_entry; 437 438 if (!V_tcp_use_hostcache) 439 return; 440 441 /* 442 * Find the right bucket. 443 */ 444 hc_entry = tcp_hc_lookup(inc); 445 446 /* 447 * If we don't have an existing object. 448 */ 449 if (hc_entry == NULL) { 450 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 451 return; 452 } 453 hc_entry->rmx_hits++; 454 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 455 456 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 457 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 458 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 459 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 460 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 461 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 462 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 463 464 /* 465 * Unlock bucket row. 466 */ 467 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 468 } 469 470 /* 471 * External function: look up an entry in the hostcache and return the 472 * discovered path MTU. Returns 0 if no entry is found or value is not 473 * set. 474 */ 475 uint32_t 476 tcp_hc_getmtu(struct in_conninfo *inc) 477 { 478 struct hc_metrics *hc_entry; 479 uint32_t mtu; 480 481 if (!V_tcp_use_hostcache) 482 return 0; 483 484 hc_entry = tcp_hc_lookup(inc); 485 if (hc_entry == NULL) { 486 return 0; 487 } 488 hc_entry->rmx_hits++; 489 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 490 491 mtu = hc_entry->rmx_mtu; 492 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 493 return mtu; 494 } 495 496 /* 497 * External function: update the MTU value of an entry in the hostcache. 498 * Creates a new entry if none was found. 499 */ 500 void 501 tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu) 502 { 503 struct hc_metrics *hc_entry; 504 505 if (!V_tcp_use_hostcache) 506 return; 507 508 /* 509 * Find the right bucket. 510 */ 511 hc_entry = tcp_hc_lookup(inc); 512 513 /* 514 * If we don't have an existing object, try to insert a new one. 515 */ 516 if (hc_entry == NULL) { 517 hc_entry = tcp_hc_insert(inc); 518 if (hc_entry == NULL) 519 return; 520 } 521 hc_entry->rmx_updates++; 522 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 523 524 hc_entry->rmx_mtu = mtu; 525 526 /* 527 * Put it upfront so we find it faster next time. 528 */ 529 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 530 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 531 532 /* 533 * Unlock bucket row. 534 */ 535 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 536 } 537 538 /* 539 * External function: update the TCP metrics of an entry in the hostcache. 540 * Creates a new entry if none was found. 541 */ 542 void 543 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 544 { 545 struct hc_metrics *hc_entry; 546 547 if (!V_tcp_use_hostcache) 548 return; 549 550 hc_entry = tcp_hc_lookup(inc); 551 if (hc_entry == NULL) { 552 hc_entry = tcp_hc_insert(inc); 553 if (hc_entry == NULL) 554 return; 555 } 556 hc_entry->rmx_updates++; 557 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 558 559 if (hcml->rmx_rtt != 0) { 560 if (hc_entry->rmx_rtt == 0) 561 hc_entry->rmx_rtt = hcml->rmx_rtt; 562 else 563 hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt + 564 (uint64_t)hcml->rmx_rtt) / 2; 565 TCPSTAT_INC(tcps_cachedrtt); 566 } 567 if (hcml->rmx_rttvar != 0) { 568 if (hc_entry->rmx_rttvar == 0) 569 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 570 else 571 hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar + 572 (uint64_t)hcml->rmx_rttvar) / 2; 573 TCPSTAT_INC(tcps_cachedrttvar); 574 } 575 if (hcml->rmx_ssthresh != 0) { 576 if (hc_entry->rmx_ssthresh == 0) 577 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 578 else 579 hc_entry->rmx_ssthresh = 580 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 581 TCPSTAT_INC(tcps_cachedssthresh); 582 } 583 if (hcml->rmx_cwnd != 0) { 584 if (hc_entry->rmx_cwnd == 0) 585 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 586 else 587 hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd + 588 (uint64_t)hcml->rmx_cwnd) / 2; 589 /* TCPSTAT_INC(tcps_cachedcwnd); */ 590 } 591 if (hcml->rmx_sendpipe != 0) { 592 if (hc_entry->rmx_sendpipe == 0) 593 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 594 else 595 hc_entry->rmx_sendpipe = 596 ((uint64_t)hc_entry->rmx_sendpipe + 597 (uint64_t)hcml->rmx_sendpipe) /2; 598 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 599 } 600 if (hcml->rmx_recvpipe != 0) { 601 if (hc_entry->rmx_recvpipe == 0) 602 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 603 else 604 hc_entry->rmx_recvpipe = 605 ((uint64_t)hc_entry->rmx_recvpipe + 606 (uint64_t)hcml->rmx_recvpipe) /2; 607 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 608 } 609 610 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 611 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 612 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 613 } 614 615 /* 616 * Sysctl function: prints the list and values of all hostcache entries in 617 * unsorted order. 618 */ 619 static int 620 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 621 { 622 const int linesize = 128; 623 struct sbuf sb; 624 int i, error; 625 struct hc_metrics *hc_entry; 626 char ip4buf[INET_ADDRSTRLEN]; 627 #ifdef INET6 628 char ip6buf[INET6_ADDRSTRLEN]; 629 #endif 630 631 if (jailed_without_vnet(curthread->td_ucred) != 0) 632 return (EPERM); 633 634 sbuf_new(&sb, NULL, linesize * (V_tcp_hostcache.cache_count + 1), 635 SBUF_INCLUDENUL); 636 637 sbuf_printf(&sb, 638 "\nIP address MTU SSTRESH RTT RTTVAR " 639 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 640 641 #define msec(u) (((u) + 500) / 1000) 642 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 643 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 644 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 645 rmx_q) { 646 sbuf_printf(&sb, 647 "%-15s %5u %8u %6lums %6lums %8u %8u %8u %4lu " 648 "%4lu %4i\n", 649 hc_entry->ip4.s_addr ? 650 inet_ntoa_r(hc_entry->ip4, ip4buf) : 651 #ifdef INET6 652 ip6_sprintf(ip6buf, &hc_entry->ip6), 653 #else 654 "IPv6?", 655 #endif 656 hc_entry->rmx_mtu, 657 hc_entry->rmx_ssthresh, 658 msec((u_long)hc_entry->rmx_rtt * 659 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 660 msec((u_long)hc_entry->rmx_rttvar * 661 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), 662 hc_entry->rmx_cwnd, 663 hc_entry->rmx_sendpipe, 664 hc_entry->rmx_recvpipe, 665 hc_entry->rmx_hits, 666 hc_entry->rmx_updates, 667 hc_entry->rmx_expire); 668 } 669 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 670 } 671 #undef msec 672 error = sbuf_finish(&sb); 673 if (error == 0) 674 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 675 sbuf_delete(&sb); 676 return(error); 677 } 678 679 /* 680 * Caller has to make sure the curvnet is set properly. 681 */ 682 static void 683 tcp_hc_purge_internal(int all) 684 { 685 struct hc_metrics *hc_entry, *hc_next; 686 int i; 687 688 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 689 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 690 TAILQ_FOREACH_SAFE(hc_entry, 691 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 692 if (all || hc_entry->rmx_expire <= 0) { 693 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 694 hc_entry, rmx_q); 695 uma_zfree(V_tcp_hostcache.zone, hc_entry); 696 V_tcp_hostcache.hashbase[i].hch_length--; 697 V_tcp_hostcache.cache_count--; 698 } else 699 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 700 } 701 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 702 } 703 } 704 705 /* 706 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 707 * periodically from the callout. 708 */ 709 static void 710 tcp_hc_purge(void *arg) 711 { 712 CURVNET_SET((struct vnet *) arg); 713 int all = 0; 714 715 if (V_tcp_hostcache.purgeall) { 716 all = 1; 717 V_tcp_hostcache.purgeall = 0; 718 } 719 720 tcp_hc_purge_internal(all); 721 722 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 723 tcp_hc_purge, arg); 724 CURVNET_RESTORE(); 725 } 726 727 /* 728 * Expire and purge all entries in hostcache immediately. 729 */ 730 static int 731 sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS) 732 { 733 int error, val; 734 735 val = 0; 736 error = sysctl_handle_int(oidp, &val, 0, req); 737 if (error || !req->newptr) 738 return (error); 739 740 tcp_hc_purge_internal(1); 741 742 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 743 tcp_hc_purge, curvnet); 744 745 return (0); 746 } 747