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 * $FreeBSD$ 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, bandwidth, max 38 * MTU, 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 has 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 "opt_inet6.h" 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/kernel.h> 72 #include <sys/lock.h> 73 #include <sys/mutex.h> 74 #include <sys/malloc.h> 75 #include <sys/socket.h> 76 #include <sys/socketvar.h> 77 #include <sys/sysctl.h> 78 79 #include <net/if.h> 80 81 #include <netinet/in.h> 82 #include <netinet/in_systm.h> 83 #include <netinet/ip.h> 84 #include <netinet/in_var.h> 85 #include <netinet/in_pcb.h> 86 #include <netinet/ip_var.h> 87 #ifdef INET6 88 #include <netinet/ip6.h> 89 #include <netinet6/ip6_var.h> 90 #endif 91 #include <netinet/tcp.h> 92 #include <netinet/tcp_var.h> 93 #ifdef INET6 94 #include <netinet6/tcp6_var.h> 95 #endif 96 97 #include <vm/uma.h> 98 99 100 TAILQ_HEAD(hc_qhead, hc_metrics); 101 102 struct hc_head { 103 struct hc_qhead hch_bucket; 104 u_int hch_length; 105 struct mtx hch_mtx; 106 }; 107 108 struct hc_metrics { 109 /* housekeeping */ 110 TAILQ_ENTRY(hc_metrics) rmx_q; 111 struct hc_head *rmx_head; /* head of bucket tail queue */ 112 struct in_addr ip4; /* IP address */ 113 struct in6_addr ip6; /* IP6 address */ 114 /* endpoint specific values for TCP */ 115 u_long rmx_mtu; /* MTU for this path */ 116 u_long rmx_ssthresh; /* outbound gateway buffer limit */ 117 u_long rmx_rtt; /* estimated round trip time */ 118 u_long rmx_rttvar; /* estimated rtt variance */ 119 u_long rmx_bandwidth; /* estimated bandwidth */ 120 u_long rmx_cwnd; /* congestion window */ 121 u_long rmx_sendpipe; /* outbound delay-bandwidth product */ 122 u_long rmx_recvpipe; /* inbound delay-bandwidth product */ 123 /* TCP hostcache internal data */ 124 int rmx_expire; /* lifetime for object */ 125 u_long rmx_hits; /* number of hits */ 126 u_long rmx_updates; /* number of updates */ 127 }; 128 129 /* Arbitrary values */ 130 #define TCP_HOSTCACHE_HASHSIZE 512 131 #define TCP_HOSTCACHE_BUCKETLIMIT 30 132 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 133 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 134 135 struct tcp_hostcache { 136 struct hc_head *hashbase; 137 uma_zone_t zone; 138 u_int hashsize; 139 u_int hashmask; 140 u_int bucket_limit; 141 u_int cache_count; 142 u_int cache_limit; 143 int expire; 144 int purgeall; 145 }; 146 static struct tcp_hostcache tcp_hostcache; 147 148 static struct callout tcp_hc_callout; 149 150 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 151 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 152 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 153 static void tcp_hc_purge(void *); 154 155 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, "TCP Host cache"); 156 157 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_RDTUN, 158 &tcp_hostcache.cache_limit, 0, "Overall entry limit for hostcache"); 159 160 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_RDTUN, 161 &tcp_hostcache.hashsize, 0, "Size of TCP hostcache hashtable"); 162 163 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, CTLFLAG_RDTUN, 164 &tcp_hostcache.bucket_limit, 0, "Per-bucket hash limit for hostcache"); 165 166 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_RD, 167 &tcp_hostcache.cache_count, 0, "Current number of entries in hostcache"); 168 169 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_RW, 170 &tcp_hostcache.expire, 0, "Expire time of TCP hostcache entries"); 171 172 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_RW, 173 &tcp_hostcache.purgeall, 0, "Expire all entires on next purge run"); 174 175 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 176 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 177 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 178 179 180 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 181 182 #define HOSTCACHE_HASH(ip) \ 183 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 184 tcp_hostcache.hashmask) 185 186 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 187 #define HOSTCACHE_HASH6(ip6) \ 188 (((ip6)->s6_addr32[0] ^ \ 189 (ip6)->s6_addr32[1] ^ \ 190 (ip6)->s6_addr32[2] ^ \ 191 (ip6)->s6_addr32[3]) & \ 192 tcp_hostcache.hashmask) 193 194 #define THC_LOCK(lp) mtx_lock(lp) 195 #define THC_UNLOCK(lp) mtx_unlock(lp) 196 197 void 198 tcp_hc_init(void) 199 { 200 int i; 201 202 /* 203 * Initialize hostcache structures. 204 */ 205 tcp_hostcache.cache_count = 0; 206 tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 207 tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 208 tcp_hostcache.cache_limit = 209 tcp_hostcache.hashsize * tcp_hostcache.bucket_limit; 210 tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 211 212 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 213 &tcp_hostcache.hashsize); 214 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 215 &tcp_hostcache.cache_limit); 216 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 217 &tcp_hostcache.bucket_limit); 218 if (!powerof2(tcp_hostcache.hashsize)) { 219 printf("WARNING: hostcache hash size is not a power of 2.\n"); 220 tcp_hostcache.hashsize = 512; /* safe default */ 221 } 222 tcp_hostcache.hashmask = tcp_hostcache.hashsize - 1; 223 224 /* 225 * Allocate the hash table. 226 */ 227 tcp_hostcache.hashbase = (struct hc_head *) 228 malloc(tcp_hostcache.hashsize * sizeof(struct hc_head), 229 M_HOSTCACHE, M_WAITOK | M_ZERO); 230 231 /* 232 * Initialize the hash buckets. 233 */ 234 for (i = 0; i < tcp_hostcache.hashsize; i++) { 235 TAILQ_INIT(&tcp_hostcache.hashbase[i].hch_bucket); 236 tcp_hostcache.hashbase[i].hch_length = 0; 237 mtx_init(&tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 238 NULL, MTX_DEF); 239 } 240 241 /* 242 * Allocate the hostcache entries. 243 */ 244 tcp_hostcache.zone = uma_zcreate("hostcache", sizeof(struct hc_metrics), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_zone_set_max(tcp_hostcache.zone, tcp_hostcache.cache_limit); 247 248 /* 249 * Set up periodic cache cleanup. 250 */ 251 callout_init(&tcp_hc_callout, CALLOUT_MPSAFE); 252 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 253 } 254 255 /* 256 * Internal function: look up an entry in the hostcache or return NULL. 257 * 258 * If an entry has been returned, the caller becomes responsible for 259 * unlocking the bucket row after he is done reading/modifying the entry. 260 */ 261 static struct hc_metrics * 262 tcp_hc_lookup(struct in_conninfo *inc) 263 { 264 int hash; 265 struct hc_head *hc_head; 266 struct hc_metrics *hc_entry; 267 268 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 269 270 /* 271 * Hash the foreign ip address. 272 */ 273 if (inc->inc_isipv6) 274 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 275 else 276 hash = HOSTCACHE_HASH(&inc->inc_faddr); 277 278 hc_head = &tcp_hostcache.hashbase[hash]; 279 280 /* 281 * Acquire lock for this bucket row; we release the lock if we don't 282 * find an entry, otherwise the caller has to unlock after he is 283 * done. 284 */ 285 THC_LOCK(&hc_head->hch_mtx); 286 287 /* 288 * Iterate through entries in bucket row looking for a match. 289 */ 290 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 291 if (inc->inc_isipv6) { 292 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 293 sizeof(inc->inc6_faddr)) == 0) 294 return hc_entry; 295 } else { 296 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 297 sizeof(inc->inc_faddr)) == 0) 298 return hc_entry; 299 } 300 } 301 302 /* 303 * We were unsuccessful and didn't find anything. 304 */ 305 THC_UNLOCK(&hc_head->hch_mtx); 306 return NULL; 307 } 308 309 /* 310 * Internal function: insert an entry into the hostcache or return NULL if 311 * unable to allocate a new one. 312 * 313 * If an entry has been returned, the caller becomes responsible for 314 * unlocking the bucket row after he is done reading/modifying the entry. 315 */ 316 static struct hc_metrics * 317 tcp_hc_insert(struct in_conninfo *inc) 318 { 319 int hash; 320 struct hc_head *hc_head; 321 struct hc_metrics *hc_entry; 322 323 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 324 325 /* 326 * Hash the foreign ip address. 327 */ 328 if (inc->inc_isipv6) 329 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 330 else 331 hash = HOSTCACHE_HASH(&inc->inc_faddr); 332 333 hc_head = &tcp_hostcache.hashbase[hash]; 334 335 /* 336 * Acquire lock for this bucket row; we release the lock if we don't 337 * find an entry, otherwise the caller has to unlock after he is 338 * done. 339 */ 340 THC_LOCK(&hc_head->hch_mtx); 341 342 /* 343 * If the bucket limit is reached, reuse the least-used element. 344 */ 345 if (hc_head->hch_length >= tcp_hostcache.bucket_limit || 346 tcp_hostcache.cache_count >= tcp_hostcache.cache_limit) { 347 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 348 /* 349 * At first we were dropping the last element, just to 350 * reacquire it in the next two lines again, which isn't very 351 * efficient. Instead just reuse the least used element. 352 * We may drop something that is still "in-use" but we can be 353 * "lossy". 354 */ 355 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 356 tcp_hostcache.hashbase[hash].hch_length--; 357 tcp_hostcache.cache_count--; 358 tcpstat.tcps_hc_bucketoverflow++; 359 #if 0 360 uma_zfree(tcp_hostcache.zone, hc_entry); 361 #endif 362 } else { 363 /* 364 * Allocate a new entry, or balk if not possible. 365 */ 366 hc_entry = uma_zalloc(tcp_hostcache.zone, M_NOWAIT); 367 if (hc_entry == NULL) { 368 THC_UNLOCK(&hc_head->hch_mtx); 369 return NULL; 370 } 371 } 372 373 /* 374 * Initialize basic information of hostcache entry. 375 */ 376 bzero(hc_entry, sizeof(*hc_entry)); 377 if (inc->inc_isipv6) 378 bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 379 else 380 hc_entry->ip4 = inc->inc_faddr; 381 hc_entry->rmx_head = hc_head; 382 hc_entry->rmx_expire = tcp_hostcache.expire; 383 384 /* 385 * Put it upfront. 386 */ 387 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 388 tcp_hostcache.hashbase[hash].hch_length++; 389 tcp_hostcache.cache_count++; 390 tcpstat.tcps_hc_added++; 391 392 return hc_entry; 393 } 394 395 /* 396 * External function: look up an entry in the hostcache and fill out the 397 * supplied TCP metrics structure. Fills in NULL when no entry was found or 398 * a value is not set. 399 */ 400 void 401 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 402 { 403 struct hc_metrics *hc_entry; 404 405 /* 406 * Find the right bucket. 407 */ 408 hc_entry = tcp_hc_lookup(inc); 409 410 /* 411 * If we don't have an existing object. 412 */ 413 if (hc_entry == NULL) { 414 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 415 return; 416 } 417 hc_entry->rmx_hits++; 418 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 419 420 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 421 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 422 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 423 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 424 hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 425 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 426 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 427 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 428 429 /* 430 * Unlock bucket row. 431 */ 432 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 433 } 434 435 /* 436 * External function: look up an entry in the hostcache and return the 437 * discovered path MTU. Returns NULL if no entry is found or value is not 438 * set. 439 */ 440 u_long 441 tcp_hc_getmtu(struct in_conninfo *inc) 442 { 443 struct hc_metrics *hc_entry; 444 u_long mtu; 445 446 hc_entry = tcp_hc_lookup(inc); 447 if (hc_entry == NULL) { 448 return 0; 449 } 450 hc_entry->rmx_hits++; 451 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 452 453 mtu = hc_entry->rmx_mtu; 454 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 455 return mtu; 456 } 457 458 /* 459 * External function: update the MTU value of an entry in the hostcache. 460 * Creates a new entry if none was found. 461 */ 462 void 463 tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) 464 { 465 struct hc_metrics *hc_entry; 466 467 /* 468 * Find the right bucket. 469 */ 470 hc_entry = tcp_hc_lookup(inc); 471 472 /* 473 * If we don't have an existing object, try to insert a new one. 474 */ 475 if (hc_entry == NULL) { 476 hc_entry = tcp_hc_insert(inc); 477 if (hc_entry == NULL) 478 return; 479 } 480 hc_entry->rmx_updates++; 481 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 482 483 hc_entry->rmx_mtu = mtu; 484 485 /* 486 * Put it upfront so we find it faster next time. 487 */ 488 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 489 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 490 491 /* 492 * Unlock bucket row. 493 */ 494 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 495 } 496 497 /* 498 * External function: update the TCP metrics of an entry in the hostcache. 499 * Creates a new entry if none was found. 500 */ 501 void 502 tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 503 { 504 struct hc_metrics *hc_entry; 505 506 hc_entry = tcp_hc_lookup(inc); 507 if (hc_entry == NULL) { 508 hc_entry = tcp_hc_insert(inc); 509 if (hc_entry == NULL) 510 return; 511 } 512 hc_entry->rmx_updates++; 513 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 514 515 if (hcml->rmx_rtt != 0) { 516 if (hc_entry->rmx_rtt == 0) 517 hc_entry->rmx_rtt = hcml->rmx_rtt; 518 else 519 hc_entry->rmx_rtt = 520 (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; 521 tcpstat.tcps_cachedrtt++; 522 } 523 if (hcml->rmx_rttvar != 0) { 524 if (hc_entry->rmx_rttvar == 0) 525 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 526 else 527 hc_entry->rmx_rttvar = 528 (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; 529 tcpstat.tcps_cachedrttvar++; 530 } 531 if (hcml->rmx_ssthresh != 0) { 532 if (hc_entry->rmx_ssthresh == 0) 533 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 534 else 535 hc_entry->rmx_ssthresh = 536 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 537 tcpstat.tcps_cachedssthresh++; 538 } 539 if (hcml->rmx_bandwidth != 0) { 540 if (hc_entry->rmx_bandwidth == 0) 541 hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; 542 else 543 hc_entry->rmx_bandwidth = 544 (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; 545 /* tcpstat.tcps_cachedbandwidth++; */ 546 } 547 if (hcml->rmx_cwnd != 0) { 548 if (hc_entry->rmx_cwnd == 0) 549 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 550 else 551 hc_entry->rmx_cwnd = 552 (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; 553 /* tcpstat.tcps_cachedcwnd++; */ 554 } 555 if (hcml->rmx_sendpipe != 0) { 556 if (hc_entry->rmx_sendpipe == 0) 557 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 558 else 559 hc_entry->rmx_sendpipe = 560 (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; 561 /* tcpstat.tcps_cachedsendpipe++; */ 562 } 563 if (hcml->rmx_recvpipe != 0) { 564 if (hc_entry->rmx_recvpipe == 0) 565 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 566 else 567 hc_entry->rmx_recvpipe = 568 (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; 569 /* tcpstat.tcps_cachedrecvpipe++; */ 570 } 571 572 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 573 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 574 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 575 } 576 577 /* 578 * Sysctl function: prints the list and values of all hostcache entries in 579 * unsorted order. 580 */ 581 static int 582 sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 583 { 584 int bufsize; 585 int linesize = 128; 586 char *p, *buf; 587 int len, i, error; 588 struct hc_metrics *hc_entry; 589 #ifdef INET6 590 char ip6buf[INET6_ADDRSTRLEN]; 591 #endif 592 593 bufsize = linesize * (tcp_hostcache.cache_count + 1); 594 595 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 596 597 len = snprintf(p, linesize, 598 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 599 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 600 p += len; 601 602 #define msec(u) (((u) + 500) / 1000) 603 for (i = 0; i < tcp_hostcache.hashsize; i++) { 604 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 605 TAILQ_FOREACH(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 606 rmx_q) { 607 len = snprintf(p, linesize, 608 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 609 "%4lu %4lu %4i\n", 610 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 611 #ifdef INET6 612 ip6_sprintf(ip6buf, &hc_entry->ip6), 613 #else 614 "IPv6?", 615 #endif 616 hc_entry->rmx_mtu, 617 hc_entry->rmx_ssthresh, 618 msec(hc_entry->rmx_rtt * 619 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 620 msec(hc_entry->rmx_rttvar * 621 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 622 hc_entry->rmx_bandwidth * 8, 623 hc_entry->rmx_cwnd, 624 hc_entry->rmx_sendpipe, 625 hc_entry->rmx_recvpipe, 626 hc_entry->rmx_hits, 627 hc_entry->rmx_updates, 628 hc_entry->rmx_expire); 629 p += len; 630 } 631 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 632 } 633 #undef msec 634 error = SYSCTL_OUT(req, buf, p - buf); 635 free(buf, M_TEMP); 636 return(error); 637 } 638 639 /* 640 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 641 * periodically from the callout. 642 */ 643 static void 644 tcp_hc_purge(void *arg) 645 { 646 struct hc_metrics *hc_entry, *hc_next; 647 int all = (intptr_t)arg; 648 int i; 649 650 if (tcp_hostcache.purgeall) { 651 all = 1; 652 tcp_hostcache.purgeall = 0; 653 } 654 655 for (i = 0; i < tcp_hostcache.hashsize; i++) { 656 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 657 TAILQ_FOREACH_SAFE(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 658 rmx_q, hc_next) { 659 if (all || hc_entry->rmx_expire <= 0) { 660 TAILQ_REMOVE(&tcp_hostcache.hashbase[i].hch_bucket, 661 hc_entry, rmx_q); 662 uma_zfree(tcp_hostcache.zone, hc_entry); 663 tcp_hostcache.hashbase[i].hch_length--; 664 tcp_hostcache.cache_count--; 665 } else 666 hc_entry->rmx_expire -= TCP_HOSTCACHE_PRUNE; 667 } 668 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 669 } 670 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 671 } 672