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/jail.h> 75 #include <sys/kernel.h> 76 #include <sys/lock.h> 77 #include <sys/mutex.h> 78 #include <sys/malloc.h> 79 #include <sys/proc.h> 80 #include <sys/sbuf.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/sysctl.h> 84 85 #include <net/if.h> 86 #include <net/if_var.h> 87 #include <net/route.h> 88 #include <net/vnet.h> 89 90 #include <netinet/in.h> 91 #include <netinet/in_systm.h> 92 #include <netinet/ip.h> 93 #include <netinet/in_var.h> 94 #include <netinet/in_pcb.h> 95 #include <netinet/ip_var.h> 96 #ifdef INET6 97 #include <netinet/ip6.h> 98 #include <netinet6/ip6_var.h> 99 #endif 100 #include <netinet/tcp.h> 101 #include <netinet/tcp_var.h> 102 #ifdef INET6 103 #include <netinet6/tcp6_var.h> 104 #endif 105 106 #include <vm/uma.h> 107 108 TAILQ_HEAD(hc_qhead, hc_metrics); 109 110 struct hc_head { 111 struct hc_qhead hch_bucket; 112 u_int hch_length; 113 struct mtx hch_mtx; 114 }; 115 116 struct hc_metrics { 117 /* housekeeping */ 118 TAILQ_ENTRY(hc_metrics) rmx_q; 119 struct hc_head *rmx_head; /* head of bucket tail queue */ 120 struct in_addr ip4; /* IP address */ 121 struct in6_addr ip6; /* IP6 address */ 122 uint32_t ip6_zoneid; /* IPv6 scope zone id */ 123 /* endpoint specific values for tcp */ 124 uint32_t rmx_mtu; /* MTU for this path */ 125 uint32_t rmx_ssthresh; /* outbound gateway buffer limit */ 126 uint32_t rmx_rtt; /* estimated round trip time */ 127 uint32_t rmx_rttvar; /* estimated rtt variance */ 128 uint32_t rmx_cwnd; /* congestion window */ 129 uint32_t rmx_sendpipe; /* outbound delay-bandwidth product */ 130 uint32_t rmx_recvpipe; /* inbound delay-bandwidth product */ 131 /* TCP hostcache internal data */ 132 int rmx_expire; /* lifetime for object */ 133 u_long rmx_hits; /* number of hits */ 134 u_long rmx_updates; /* number of updates */ 135 }; 136 137 struct tcp_hostcache { 138 struct hc_head *hashbase; 139 uma_zone_t zone; 140 u_int hashsize; 141 u_int hashmask; 142 u_int bucket_limit; 143 u_int cache_count; 144 u_int cache_limit; 145 int expire; 146 int prune; 147 int purgeall; 148 }; 149 150 /* Arbitrary values */ 151 #define TCP_HOSTCACHE_HASHSIZE 512 152 #define TCP_HOSTCACHE_BUCKETLIMIT 30 153 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 154 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 155 156 VNET_DEFINE_STATIC(struct tcp_hostcache, tcp_hostcache); 157 #define V_tcp_hostcache VNET(tcp_hostcache) 158 159 VNET_DEFINE_STATIC(struct callout, tcp_hc_callout); 160 #define V_tcp_hc_callout VNET(tcp_hc_callout) 161 162 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 163 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 164 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 165 static int sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS); 166 static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS); 167 static void tcp_hc_purge_internal(int); 168 static void tcp_hc_purge(void *); 169 170 static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, 171 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 172 "TCP Host cache"); 173 174 VNET_DEFINE(int, tcp_use_hostcache) = 1; 175 #define V_tcp_use_hostcache VNET(tcp_use_hostcache) 176 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, enable, CTLFLAG_VNET | CTLFLAG_RW, 177 &VNET_NAME(tcp_use_hostcache), 0, 178 "Enable the TCP hostcache"); 179 180 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_VNET | CTLFLAG_RDTUN, 181 &VNET_NAME(tcp_hostcache.cache_limit), 0, 182 "Overall entry limit for hostcache"); 183 184 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_VNET | CTLFLAG_RDTUN, 185 &VNET_NAME(tcp_hostcache.hashsize), 0, 186 "Size of TCP hostcache hashtable"); 187 188 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 189 CTLFLAG_VNET | CTLFLAG_RDTUN, &VNET_NAME(tcp_hostcache.bucket_limit), 0, 190 "Per-bucket hash limit for hostcache"); 191 192 SYSCTL_UINT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_VNET | CTLFLAG_RD, 193 &VNET_NAME(tcp_hostcache.cache_count), 0, 194 "Current number of entries in hostcache"); 195 196 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_VNET | CTLFLAG_RW, 197 &VNET_NAME(tcp_hostcache.expire), 0, 198 "Expire time of TCP hostcache entries"); 199 200 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, prune, CTLFLAG_VNET | CTLFLAG_RW, 201 &VNET_NAME(tcp_hostcache.prune), 0, 202 "Time between purge runs"); 203 204 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_VNET | CTLFLAG_RW, 205 &VNET_NAME(tcp_hostcache.purgeall), 0, 206 "Expire all entires on next purge run"); 207 208 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 209 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_MPSAFE, 210 0, 0, sysctl_tcp_hc_list, "A", 211 "List of all hostcache entries"); 212 213 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, histo, 214 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_MPSAFE, 215 0, 0, sysctl_tcp_hc_histo, "A", 216 "Print a histogram of hostcache hashbucket utilization"); 217 218 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow, 219 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 220 NULL, 0, sysctl_tcp_hc_purgenow, "I", 221 "Immediately purge all entries"); 222 223 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 224 225 #define HOSTCACHE_HASH(ip) \ 226 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 227 V_tcp_hostcache.hashmask) 228 229 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 230 #define HOSTCACHE_HASH6(ip6) \ 231 (((ip6)->s6_addr32[0] ^ \ 232 (ip6)->s6_addr32[1] ^ \ 233 (ip6)->s6_addr32[2] ^ \ 234 (ip6)->s6_addr32[3]) & \ 235 V_tcp_hostcache.hashmask) 236 237 #define THC_LOCK(lp) mtx_lock(lp) 238 #define THC_UNLOCK(lp) mtx_unlock(lp) 239 240 void 241 tcp_hc_init(void) 242 { 243 u_int cache_limit; 244 int i; 245 246 /* 247 * Initialize hostcache structures. 248 */ 249 atomic_store_int(&V_tcp_hostcache.cache_count, 0); 250 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 251 V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 252 V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 253 V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 254 255 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 256 &V_tcp_hostcache.hashsize); 257 if (!powerof2(V_tcp_hostcache.hashsize)) { 258 printf("WARNING: hostcache hash size is not a power of 2.\n"); 259 V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 260 } 261 V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 262 263 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 264 &V_tcp_hostcache.bucket_limit); 265 266 cache_limit = V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 267 V_tcp_hostcache.cache_limit = cache_limit; 268 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 269 &V_tcp_hostcache.cache_limit); 270 if (V_tcp_hostcache.cache_limit > cache_limit) 271 V_tcp_hostcache.cache_limit = cache_limit; 272 273 /* 274 * Allocate the hash table. 275 */ 276 V_tcp_hostcache.hashbase = (struct hc_head *) 277 malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 278 M_HOSTCACHE, M_WAITOK | M_ZERO); 279 280 /* 281 * Initialize the hash buckets. 282 */ 283 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 284 TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 285 V_tcp_hostcache.hashbase[i].hch_length = 0; 286 mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 287 NULL, MTX_DEF); 288 } 289 290 /* 291 * Allocate the hostcache entries. 292 */ 293 V_tcp_hostcache.zone = 294 uma_zcreate("hostcache", sizeof(struct hc_metrics), 295 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 296 uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 297 298 /* 299 * Set up periodic cache cleanup. 300 */ 301 callout_init(&V_tcp_hc_callout, 1); 302 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 303 tcp_hc_purge, curvnet); 304 } 305 306 #ifdef VIMAGE 307 void 308 tcp_hc_destroy(void) 309 { 310 int i; 311 312 callout_drain(&V_tcp_hc_callout); 313 314 /* Purge all hc entries. */ 315 tcp_hc_purge_internal(1); 316 317 /* Free the uma zone and the allocated hash table. */ 318 uma_zdestroy(V_tcp_hostcache.zone); 319 320 for (i = 0; i < V_tcp_hostcache.hashsize; i++) 321 mtx_destroy(&V_tcp_hostcache.hashbase[i].hch_mtx); 322 free(V_tcp_hostcache.hashbase, M_HOSTCACHE); 323 } 324 #endif 325 326 /* 327 * Internal function: look up an entry in the hostcache or return NULL. 328 * 329 * If an entry has been returned, the caller becomes responsible for 330 * unlocking the bucket row after he is done reading/modifying the entry. 331 */ 332 static struct hc_metrics * 333 tcp_hc_lookup(struct in_conninfo *inc) 334 { 335 int hash; 336 struct hc_head *hc_head; 337 struct hc_metrics *hc_entry; 338 339 if (!V_tcp_use_hostcache) 340 return NULL; 341 342 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 343 344 /* 345 * Hash the foreign ip address. 346 */ 347 if (inc->inc_flags & INC_ISIPV6) 348 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 349 else 350 hash = HOSTCACHE_HASH(&inc->inc_faddr); 351 352 hc_head = &V_tcp_hostcache.hashbase[hash]; 353 354 /* 355 * Acquire lock for this bucket row; we release the lock if we don't 356 * find an entry, otherwise the caller has to unlock after he is 357 * done. 358 */ 359 THC_LOCK(&hc_head->hch_mtx); 360 361 /* 362 * Iterate through entries in bucket row looking for a match. 363 */ 364 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 365 if (inc->inc_flags & INC_ISIPV6) { 366 /* XXX: check ip6_zoneid */ 367 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 368 sizeof(inc->inc6_faddr)) == 0) 369 return hc_entry; 370 } else { 371 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 372 sizeof(inc->inc_faddr)) == 0) 373 return hc_entry; 374 } 375 } 376 377 /* 378 * We were unsuccessful and didn't find anything. 379 */ 380 THC_UNLOCK(&hc_head->hch_mtx); 381 return NULL; 382 } 383 384 /* 385 * Internal function: insert an entry into the hostcache or return NULL if 386 * unable to allocate a new one. 387 * 388 * If an entry has been returned, the caller becomes responsible for 389 * unlocking the bucket row after he is done reading/modifying the entry. 390 */ 391 static struct hc_metrics * 392 tcp_hc_insert(struct in_conninfo *inc) 393 { 394 int hash; 395 struct hc_head *hc_head; 396 struct hc_metrics *hc_entry; 397 398 if (!V_tcp_use_hostcache) 399 return NULL; 400 401 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 402 403 /* 404 * Hash the foreign ip address. 405 */ 406 if (inc->inc_flags & INC_ISIPV6) 407 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 408 else 409 hash = HOSTCACHE_HASH(&inc->inc_faddr); 410 411 hc_head = &V_tcp_hostcache.hashbase[hash]; 412 413 /* 414 * Acquire lock for this bucket row; we release the lock if we don't 415 * find an entry, otherwise the caller has to unlock after he is 416 * done. 417 */ 418 THC_LOCK(&hc_head->hch_mtx); 419 420 /* 421 * If the bucket limit is reached, reuse the least-used element. 422 */ 423 if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 424 atomic_load_int(&V_tcp_hostcache.cache_count) >= V_tcp_hostcache.cache_limit) { 425 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 426 /* 427 * At first we were dropping the last element, just to 428 * reacquire it in the next two lines again, which isn't very 429 * efficient. Instead just reuse the least used element. 430 * We may drop something that is still "in-use" but we can be 431 * "lossy". 432 * Just give up if this bucket row is empty and we don't have 433 * anything to replace. 434 */ 435 if (hc_entry == NULL) { 436 THC_UNLOCK(&hc_head->hch_mtx); 437 return NULL; 438 } 439 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 440 KASSERT(V_tcp_hostcache.hashbase[hash].hch_length > 0 && 441 V_tcp_hostcache.hashbase[hash].hch_length <= 442 V_tcp_hostcache.bucket_limit, 443 ("tcp_hostcache: bucket length range violated at %u: %u", 444 hash, V_tcp_hostcache.hashbase[hash].hch_length)); 445 V_tcp_hostcache.hashbase[hash].hch_length--; 446 atomic_subtract_int(&V_tcp_hostcache.cache_count, 1); 447 TCPSTAT_INC(tcps_hc_bucketoverflow); 448 #if 0 449 uma_zfree(V_tcp_hostcache.zone, hc_entry); 450 #endif 451 } else { 452 /* 453 * Allocate a new entry, or balk if not possible. 454 */ 455 hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 456 if (hc_entry == NULL) { 457 THC_UNLOCK(&hc_head->hch_mtx); 458 return NULL; 459 } 460 } 461 462 /* 463 * Initialize basic information of hostcache entry. 464 */ 465 bzero(hc_entry, sizeof(*hc_entry)); 466 if (inc->inc_flags & INC_ISIPV6) { 467 hc_entry->ip6 = inc->inc6_faddr; 468 hc_entry->ip6_zoneid = inc->inc6_zoneid; 469 } else 470 hc_entry->ip4 = inc->inc_faddr; 471 hc_entry->rmx_head = hc_head; 472 hc_entry->rmx_expire = V_tcp_hostcache.expire; 473 474 /* 475 * Put it upfront. 476 */ 477 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 478 V_tcp_hostcache.hashbase[hash].hch_length++; 479 KASSERT(V_tcp_hostcache.hashbase[hash].hch_length < 480 V_tcp_hostcache.bucket_limit, 481 ("tcp_hostcache: bucket length too high at %u: %u", 482 hash, V_tcp_hostcache.hashbase[hash].hch_length)); 483 atomic_add_int(&V_tcp_hostcache.cache_count, 1); 484 TCPSTAT_INC(tcps_hc_added); 485 486 return hc_entry; 487 } 488 489 /* 490 * External function: look up an entry in the hostcache and fill out the 491 * supplied TCP metrics structure. Fills in NULL when no entry was found or 492 * a value is not set. 493 */ 494 void 495 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 496 { 497 struct hc_metrics *hc_entry; 498 499 if (!V_tcp_use_hostcache) { 500 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 501 return; 502 } 503 504 /* 505 * Find the right bucket. 506 */ 507 hc_entry = tcp_hc_lookup(inc); 508 509 /* 510 * If we don't have an existing object. 511 */ 512 if (hc_entry == NULL) { 513 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 514 return; 515 } 516 hc_entry->rmx_hits++; 517 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 518 519 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 520 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 521 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 522 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 523 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 524 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 525 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 526 527 /* 528 * Unlock bucket row. 529 */ 530 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 531 } 532 533 /* 534 * External function: look up an entry in the hostcache and return the 535 * discovered path MTU. Returns 0 if no entry is found or value is not 536 * set. 537 */ 538 uint32_t 539 tcp_hc_getmtu(struct in_conninfo *inc) 540 { 541 struct hc_metrics *hc_entry; 542 uint32_t mtu; 543 544 if (!V_tcp_use_hostcache) 545 return 0; 546 547 hc_entry = tcp_hc_lookup(inc); 548 if (hc_entry == NULL) { 549 return 0; 550 } 551 hc_entry->rmx_hits++; 552 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 553 554 mtu = hc_entry->rmx_mtu; 555 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 556 return mtu; 557 } 558 559 /* 560 * External function: update the MTU value of an entry in the hostcache. 561 * Creates a new entry if none was found. 562 */ 563 void 564 tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu) 565 { 566 struct hc_metrics *hc_entry; 567 568 if (!V_tcp_use_hostcache) 569 return; 570 571 /* 572 * Find the right bucket. 573 */ 574 hc_entry = tcp_hc_lookup(inc); 575 576 /* 577 * If we don't have an existing object, try to insert a new one. 578 */ 579 if (hc_entry == NULL) { 580 hc_entry = tcp_hc_insert(inc); 581 if (hc_entry == NULL) 582 return; 583 } 584 hc_entry->rmx_updates++; 585 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 586 587 hc_entry->rmx_mtu = mtu; 588 589 /* 590 * Put it upfront so we find it faster next time. 591 */ 592 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 593 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 594 595 /* 596 * Unlock bucket row. 597 */ 598 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 599 } 600 601 /* 602 * External function: update the TCP metrics of an entry in the hostcache. 603 * Creates a new entry if none was found. 604 */ 605 void 606 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 607 { 608 struct hc_metrics *hc_entry; 609 610 if (!V_tcp_use_hostcache) 611 return; 612 613 hc_entry = tcp_hc_lookup(inc); 614 if (hc_entry == NULL) { 615 hc_entry = tcp_hc_insert(inc); 616 if (hc_entry == NULL) 617 return; 618 } 619 hc_entry->rmx_updates++; 620 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 621 622 if (hcml->rmx_rtt != 0) { 623 if (hc_entry->rmx_rtt == 0) 624 hc_entry->rmx_rtt = hcml->rmx_rtt; 625 else 626 hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt + 627 (uint64_t)hcml->rmx_rtt) / 2; 628 TCPSTAT_INC(tcps_cachedrtt); 629 } 630 if (hcml->rmx_rttvar != 0) { 631 if (hc_entry->rmx_rttvar == 0) 632 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 633 else 634 hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar + 635 (uint64_t)hcml->rmx_rttvar) / 2; 636 TCPSTAT_INC(tcps_cachedrttvar); 637 } 638 if (hcml->rmx_ssthresh != 0) { 639 if (hc_entry->rmx_ssthresh == 0) 640 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 641 else 642 hc_entry->rmx_ssthresh = 643 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 644 TCPSTAT_INC(tcps_cachedssthresh); 645 } 646 if (hcml->rmx_cwnd != 0) { 647 if (hc_entry->rmx_cwnd == 0) 648 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 649 else 650 hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd + 651 (uint64_t)hcml->rmx_cwnd) / 2; 652 /* TCPSTAT_INC(tcps_cachedcwnd); */ 653 } 654 if (hcml->rmx_sendpipe != 0) { 655 if (hc_entry->rmx_sendpipe == 0) 656 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 657 else 658 hc_entry->rmx_sendpipe = 659 ((uint64_t)hc_entry->rmx_sendpipe + 660 (uint64_t)hcml->rmx_sendpipe) /2; 661 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 662 } 663 if (hcml->rmx_recvpipe != 0) { 664 if (hc_entry->rmx_recvpipe == 0) 665 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 666 else 667 hc_entry->rmx_recvpipe = 668 ((uint64_t)hc_entry->rmx_recvpipe + 669 (uint64_t)hcml->rmx_recvpipe) /2; 670 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 671 } 672 673 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 674 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 675 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 676 } 677 678 /* 679 * Sysctl function: prints the list and values of all hostcache entries in 680 * unsorted order. 681 */ 682 static int 683 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 684 { 685 const int linesize = 128; 686 struct sbuf sb; 687 int i, error, len; 688 struct hc_metrics *hc_entry; 689 char ip4buf[INET_ADDRSTRLEN]; 690 #ifdef INET6 691 char ip6buf[INET6_ADDRSTRLEN]; 692 #endif 693 694 if (jailed_without_vnet(curthread->td_ucred) != 0) 695 return (EPERM); 696 697 /* Optimize Buffer length query by sbin/sysctl */ 698 if (req->oldptr == NULL) { 699 len = (atomic_load_int(&V_tcp_hostcache.cache_count) + 1) * 700 linesize; 701 return (SYSCTL_OUT(req, NULL, len)); 702 } 703 704 error = sysctl_wire_old_buffer(req, 0); 705 if (error != 0) { 706 return(error); 707 } 708 709 /* Use a buffer sized for one full bucket */ 710 sbuf_new_for_sysctl(&sb, NULL, V_tcp_hostcache.bucket_limit * 711 linesize, req); 712 713 sbuf_printf(&sb, 714 "\nIP address MTU SSTRESH RTT RTTVAR " 715 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 716 sbuf_drain(&sb); 717 718 #define msec(u) (((u) + 500) / 1000) 719 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 720 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 721 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 722 rmx_q) { 723 sbuf_printf(&sb, 724 "%-15s %5u %8u %6lums %6lums %8u %8u %8u %4lu " 725 "%4lu %4i\n", 726 hc_entry->ip4.s_addr ? 727 inet_ntoa_r(hc_entry->ip4, ip4buf) : 728 #ifdef INET6 729 ip6_sprintf(ip6buf, &hc_entry->ip6), 730 #else 731 "IPv6?", 732 #endif 733 hc_entry->rmx_mtu, 734 hc_entry->rmx_ssthresh, 735 msec((u_long)hc_entry->rmx_rtt * 736 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 737 msec((u_long)hc_entry->rmx_rttvar * 738 (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE))), 739 hc_entry->rmx_cwnd, 740 hc_entry->rmx_sendpipe, 741 hc_entry->rmx_recvpipe, 742 hc_entry->rmx_hits, 743 hc_entry->rmx_updates, 744 hc_entry->rmx_expire); 745 } 746 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 747 sbuf_drain(&sb); 748 } 749 #undef msec 750 error = sbuf_finish(&sb); 751 sbuf_delete(&sb); 752 return(error); 753 } 754 755 /* 756 * Sysctl function: prints a histogram of the hostcache hashbucket 757 * utilization. 758 */ 759 static int 760 sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS) 761 { 762 const int linesize = 50; 763 struct sbuf sb; 764 int i, error; 765 int *histo; 766 u_int hch_length; 767 768 if (jailed_without_vnet(curthread->td_ucred) != 0) 769 return (EPERM); 770 771 histo = (int *)malloc(sizeof(int) * (V_tcp_hostcache.bucket_limit + 1), 772 M_TEMP, M_NOWAIT|M_ZERO); 773 if (histo == NULL) 774 return(ENOMEM); 775 776 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 777 hch_length = V_tcp_hostcache.hashbase[i].hch_length; 778 KASSERT(hch_length <= V_tcp_hostcache.bucket_limit, 779 ("tcp_hostcache: bucket limit exceeded at %u: %u", 780 i, hch_length)); 781 histo[hch_length]++; 782 } 783 784 /* Use a buffer for 16 lines */ 785 sbuf_new_for_sysctl(&sb, NULL, 16 * linesize, req); 786 787 sbuf_printf(&sb, "\nLength\tCount\n"); 788 for (i = 0; i <= V_tcp_hostcache.bucket_limit; i++) { 789 sbuf_printf(&sb, "%u\t%u\n", i, histo[i]); 790 } 791 error = sbuf_finish(&sb); 792 sbuf_delete(&sb); 793 free(histo, M_TEMP); 794 return(error); 795 } 796 797 /* 798 * Caller has to make sure the curvnet is set properly. 799 */ 800 static void 801 tcp_hc_purge_internal(int all) 802 { 803 struct hc_metrics *hc_entry, *hc_next; 804 int i; 805 806 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 807 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 808 TAILQ_FOREACH_SAFE(hc_entry, 809 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 810 KASSERT(V_tcp_hostcache.hashbase[i].hch_length > 0 && 811 V_tcp_hostcache.hashbase[i].hch_length <= 812 V_tcp_hostcache.bucket_limit, 813 ("tcp_hostcache: bucket length out of range at %u: %u", 814 i, V_tcp_hostcache.hashbase[i].hch_length)); 815 if (all || hc_entry->rmx_expire <= 0) { 816 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 817 hc_entry, rmx_q); 818 uma_zfree(V_tcp_hostcache.zone, hc_entry); 819 V_tcp_hostcache.hashbase[i].hch_length--; 820 atomic_subtract_int(&V_tcp_hostcache.cache_count, 1); 821 } else 822 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 823 } 824 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 825 } 826 } 827 828 /* 829 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 830 * periodically from the callout. 831 */ 832 static void 833 tcp_hc_purge(void *arg) 834 { 835 CURVNET_SET((struct vnet *) arg); 836 int all = 0; 837 838 if (V_tcp_hostcache.purgeall) { 839 all = 1; 840 V_tcp_hostcache.purgeall = 0; 841 } 842 843 tcp_hc_purge_internal(all); 844 845 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 846 tcp_hc_purge, arg); 847 CURVNET_RESTORE(); 848 } 849 850 /* 851 * Expire and purge all entries in hostcache immediately. 852 */ 853 static int 854 sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS) 855 { 856 int error, val; 857 858 val = 0; 859 error = sysctl_handle_int(oidp, &val, 0, req); 860 if (error || !req->newptr) 861 return (error); 862 863 tcp_hc_purge_internal(1); 864 865 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 866 tcp_hc_purge, curvnet); 867 868 return (0); 869 } 870