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 into a dedicated structure indexed by the remote IP address. It 35 * keeps information on the measured tcp parameters of past tcp sessions 36 * to have better initial start values for following connections from the 37 * same source. Depending on the network parameters (delay, bandwidth, max 38 * MTU, congestion window) between local and remote site this can lead to 39 * significant speedups for new tcp connections after the first one. 40 * 41 * Due to this new tcp_hostcache all tcp specific metrics information in 42 * the routing table has been removed. The INPCB no longer keeps a pointer 43 * to the routing entry and protocol initiated route cloning has been 44 * removed as well. With these changes the routing table has gone back 45 * to being more lightwight and only carries information related to packet 46 * forwarding. 47 * 48 * Tcp_hostcache is designed for multiple concurrent access in SMP 49 * environments and high contention. All bucket rows have their own 50 * lock and thus multiple lookups and modifies can be done at the same 51 * time as long as they are in different bucket rows. If a request for 52 * insertion of a new record can't be satisfied it simply returns an 53 * empty structure. Nobody and nothing shall ever point directly to 54 * any entry in tcp_hostcache. All communication is done in an object 55 * oriented way and only funtions of tcp_hostcache will manipulate hostcache 56 * entries. Otherwise we are unable to achieve good behaviour in concurrent 57 * access situations. Since tcp_hostcache is only caching information there 58 * are no fatal consequences if we either can't satisfy any particular request 59 * or have to drop/overwrite an existing entry because of bucket limit 60 * memory constrains. 61 */ 62 63 /* 64 * Many thanks to jlemon for basic structure of tcp_syncache which is being 65 * followed here. 66 */ 67 68 #include "opt_inet6.h" 69 70 #include <sys/param.h> 71 #include <sys/systm.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/mutex.h> 75 #include <sys/malloc.h> 76 #include <sys/socket.h> 77 #include <sys/socketvar.h> 78 #include <sys/sysctl.h> 79 80 #include <net/if.h> 81 82 #include <netinet/in.h> 83 #include <netinet/in_systm.h> 84 #include <netinet/ip.h> 85 #include <netinet/in_var.h> 86 #include <netinet/in_pcb.h> 87 #include <netinet/ip_var.h> 88 #ifdef INET6 89 #include <netinet/ip6.h> 90 #include <netinet6/ip6_var.h> 91 #endif 92 #include <netinet/tcp.h> 93 #include <netinet/tcp_var.h> 94 #ifdef INET6 95 #include <netinet6/tcp6_var.h> 96 #endif 97 98 #include <vm/uma.h> 99 100 101 TAILQ_HEAD(hc_qhead, hc_metrics); 102 103 struct hc_head { 104 struct hc_qhead hch_bucket; 105 u_int hch_length; 106 struct mtx hch_mtx; 107 }; 108 109 struct hc_metrics { 110 /* housekeeping */ 111 TAILQ_ENTRY(hc_metrics) rmx_q; 112 struct hc_head *rmx_head; /* head of bucket tail queue */ 113 struct in_addr ip4; /* IP address */ 114 struct in6_addr ip6; /* IP6 address */ 115 /* endpoint specific values for tcp */ 116 u_long rmx_mtu; /* MTU for this path */ 117 u_long rmx_ssthresh; /* outbound gateway buffer limit */ 118 u_long rmx_rtt; /* estimated round trip time */ 119 u_long rmx_rttvar; /* estimated rtt variance */ 120 u_long rmx_bandwidth; /* estimated bandwidth */ 121 u_long rmx_cwnd; /* congestion window */ 122 u_long rmx_sendpipe; /* outbound delay-bandwidth product */ 123 u_long rmx_recvpipe; /* inbound delay-bandwidth product */ 124 /* tcp hostcache internal data */ 125 int rmx_expire; /* lifetime for object */ 126 u_long rmx_hits; /* number of hits */ 127 u_long rmx_updates; /* number of updates */ 128 }; 129 130 /* Arbitrary values */ 131 #define TCP_HOSTCACHE_HASHSIZE 512 132 #define TCP_HOSTCACHE_BUCKETLIMIT 30 133 #define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 134 #define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 135 136 struct tcp_hostcache { 137 struct hc_head *hashbase; 138 uma_zone_t zone; 139 u_int hashsize; 140 u_int hashmask; 141 u_int bucket_limit; 142 u_int cache_count; 143 u_int cache_limit; 144 int expire; 145 int purgeall; 146 }; 147 static struct tcp_hostcache tcp_hostcache; 148 149 static struct callout tcp_hc_callout; 150 151 static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 152 static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 153 static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 154 static void tcp_hc_purge(void *); 155 156 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, "TCP Host cache"); 157 158 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_RDTUN, 159 &tcp_hostcache.cache_limit, 0, "Overall entry limit for hostcache"); 160 161 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_RDTUN, 162 &tcp_hostcache.hashsize, 0, "Size of TCP hostcache hashtable"); 163 164 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, CTLFLAG_RDTUN, 165 &tcp_hostcache.bucket_limit, 0, "Per-bucket hash limit for hostcache"); 166 167 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_RD, 168 &tcp_hostcache.cache_count, 0, "Current number of entries in hostcache"); 169 170 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_RW, 171 &tcp_hostcache.expire, 0, "Expire time of TCP hostcache entries"); 172 173 SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_RW, 174 &tcp_hostcache.purgeall, 0, "Expire all entires on next purge run"); 175 176 SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 177 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 178 sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 179 180 181 static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 182 183 #define HOSTCACHE_HASH(ip) \ 184 (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 185 tcp_hostcache.hashmask) 186 187 /* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 188 #define HOSTCACHE_HASH6(ip6) \ 189 (((ip6)->s6_addr32[0] ^ \ 190 (ip6)->s6_addr32[1] ^ \ 191 (ip6)->s6_addr32[2] ^ \ 192 (ip6)->s6_addr32[3]) & \ 193 tcp_hostcache.hashmask) 194 195 #define THC_LOCK(lp) mtx_lock(lp) 196 #define THC_UNLOCK(lp) mtx_unlock(lp) 197 198 void 199 tcp_hc_init(void) 200 { 201 int i; 202 203 /* 204 * Initialize hostcache structures 205 */ 206 tcp_hostcache.cache_count = 0; 207 tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 208 tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 209 tcp_hostcache.cache_limit = 210 tcp_hostcache.hashsize * tcp_hostcache.bucket_limit; 211 tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 212 213 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 214 &tcp_hostcache.hashsize); 215 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 216 &tcp_hostcache.cache_limit); 217 TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 218 &tcp_hostcache.bucket_limit); 219 if (!powerof2(tcp_hostcache.hashsize)) { 220 printf("WARNING: hostcache hash size is not a power of 2.\n"); 221 tcp_hostcache.hashsize = 512; /* safe default */ 222 } 223 tcp_hostcache.hashmask = tcp_hostcache.hashsize - 1; 224 225 /* 226 * Allocate the hash table 227 */ 228 tcp_hostcache.hashbase = (struct hc_head *) 229 malloc(tcp_hostcache.hashsize * sizeof(struct hc_head), 230 M_HOSTCACHE, M_WAITOK | M_ZERO); 231 232 /* 233 * Initialize the hash buckets 234 */ 235 for (i = 0; i < tcp_hostcache.hashsize; i++) { 236 TAILQ_INIT(&tcp_hostcache.hashbase[i].hch_bucket); 237 tcp_hostcache.hashbase[i].hch_length = 0; 238 mtx_init(&tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 239 NULL, MTX_DEF); 240 } 241 242 /* 243 * Allocate the hostcache entries. 244 */ 245 tcp_hostcache.zone = uma_zcreate("hostcache", sizeof(struct hc_metrics), 246 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 247 uma_zone_set_max(tcp_hostcache.zone, tcp_hostcache.cache_limit); 248 249 /* 250 * Set up periodic cache cleanup. 251 */ 252 callout_init(&tcp_hc_callout, CALLOUT_MPSAFE); 253 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 254 } 255 256 /* 257 * Internal function: lookup an entry in the hostcache or return NULL. 258 * 259 * If an entry has been returned, the caller becomes responsible for 260 * unlocking the bucket row after he is done reading/modifying the entry. 261 */ 262 static struct hc_metrics * 263 tcp_hc_lookup(struct in_conninfo *inc) 264 { 265 int hash; 266 struct hc_head *hc_head; 267 struct hc_metrics *hc_entry; 268 269 KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 270 271 /* 272 * Hash the foreign ip address. 273 */ 274 if (inc->inc_isipv6) 275 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 276 else 277 hash = HOSTCACHE_HASH(&inc->inc_faddr); 278 279 hc_head = &tcp_hostcache.hashbase[hash]; 280 281 /* 282 * aquire lock for this bucket row 283 * we release the lock if we don't find an entry, 284 * otherwise the caller has to unlock after he is done 285 */ 286 THC_LOCK(&hc_head->hch_mtx); 287 288 /* 289 * circle through entries in bucket row looking for a match 290 */ 291 TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 292 if (inc->inc_isipv6) { 293 if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 294 sizeof(inc->inc6_faddr)) == 0) 295 return hc_entry; 296 } else { 297 if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 298 sizeof(inc->inc_faddr)) == 0) 299 return hc_entry; 300 } 301 } 302 303 /* 304 * We were unsuccessful and didn't find anything 305 */ 306 THC_UNLOCK(&hc_head->hch_mtx); 307 return NULL; 308 } 309 310 /* 311 * Internal function: insert an entry into the hostcache or return NULL 312 * if unable to allocate a new one. 313 * 314 * If an entry has been returned, the caller becomes responsible for 315 * unlocking the bucket row after he is done reading/modifying the entry. 316 */ 317 static struct hc_metrics * 318 tcp_hc_insert(struct in_conninfo *inc) 319 { 320 int hash; 321 struct hc_head *hc_head; 322 struct hc_metrics *hc_entry; 323 324 KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 325 326 /* 327 * Hash the foreign ip address 328 */ 329 if (inc->inc_isipv6) 330 hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 331 else 332 hash = HOSTCACHE_HASH(&inc->inc_faddr); 333 334 hc_head = &tcp_hostcache.hashbase[hash]; 335 336 /* 337 * aquire lock for this bucket row 338 * we release the lock if we don't find an entry, 339 * otherwise the caller has to unlock after he is done 340 */ 341 THC_LOCK(&hc_head->hch_mtx); 342 343 /* 344 * If the bucket limit is reached reuse the least used element 345 */ 346 if (hc_head->hch_length >= tcp_hostcache.bucket_limit || 347 tcp_hostcache.cache_count >= tcp_hostcache.cache_limit) { 348 hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 349 /* 350 * At first we were dropping the last element, just to 351 * reaquire it in the next two lines again which ain't 352 * very efficient. Instead just reuse the least used element. 353 * Maybe we drop something that is still "in-use" but we can 354 * be "lossy". 355 */ 356 TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 357 tcp_hostcache.hashbase[hash].hch_length--; 358 tcp_hostcache.cache_count--; 359 tcpstat.tcps_hc_bucketoverflow++; 360 #if 0 361 uma_zfree(tcp_hostcache.zone, hc_entry); 362 #endif 363 } else { 364 /* 365 * Allocate a new entry, or balk if not possible 366 */ 367 hc_entry = uma_zalloc(tcp_hostcache.zone, M_NOWAIT); 368 if (hc_entry == NULL) { 369 THC_UNLOCK(&hc_head->hch_mtx); 370 return NULL; 371 } 372 } 373 374 /* 375 * Initialize basic information of hostcache entry 376 */ 377 bzero(hc_entry, sizeof(*hc_entry)); 378 if (inc->inc_isipv6) 379 bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 380 else 381 hc_entry->ip4 = inc->inc_faddr; 382 hc_entry->rmx_head = hc_head; 383 hc_entry->rmx_expire = tcp_hostcache.expire; 384 385 /* 386 * Put it upfront 387 */ 388 TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 389 tcp_hostcache.hashbase[hash].hch_length++; 390 tcp_hostcache.cache_count++; 391 tcpstat.tcps_hc_added++; 392 393 return hc_entry; 394 } 395 396 /* 397 * External function: lookup an entry in the hostcache and fill out the 398 * supplied tcp metrics structure. Fills in null when no entry was found 399 * or a value is not set. 400 */ 401 void 402 tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 403 { 404 struct hc_metrics *hc_entry; 405 406 /* 407 * Find the right bucket 408 */ 409 hc_entry = tcp_hc_lookup(inc); 410 411 /* 412 * If we don't have an existing object 413 */ 414 if (hc_entry == NULL) { 415 bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 416 return; 417 } 418 hc_entry->rmx_hits++; 419 hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ 420 421 hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 422 hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 423 hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 424 hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 425 hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 426 hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 427 hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 428 hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 429 430 /* 431 * unlock bucket row 432 */ 433 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 434 } 435 436 /* 437 * External function: lookup an entry in the hostcache and return the 438 * discovered path mtu. Returns null if no entry found or value not is 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; 589 590 bufsize = linesize * (tcp_hostcache.cache_count + 1); 591 592 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 593 594 len = snprintf(p, linesize, 595 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 596 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 597 p += len; 598 599 #define msec(u) (((u) + 500) / 1000) 600 for (i = 0; i < tcp_hostcache.hashsize; i++) { 601 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 602 TAILQ_FOREACH(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 603 rmx_q) { 604 len = snprintf(p, linesize, 605 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 606 "%4lu %4lu %4i\n", 607 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 608 #ifdef INET6 609 ip6_sprintf(&hc_entry->ip6), 610 #else 611 "IPv6?", 612 #endif 613 hc_entry->rmx_mtu, 614 hc_entry->rmx_ssthresh, 615 msec(hc_entry->rmx_rtt * 616 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 617 msec(hc_entry->rmx_rttvar * 618 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 619 hc_entry->rmx_bandwidth * 8, 620 hc_entry->rmx_cwnd, 621 hc_entry->rmx_sendpipe, 622 hc_entry->rmx_recvpipe, 623 hc_entry->rmx_hits, 624 hc_entry->rmx_updates, 625 hc_entry->rmx_expire); 626 p += len; 627 } 628 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 629 } 630 #undef msec 631 error = SYSCTL_OUT(req, buf, p - buf); 632 free(buf, M_TEMP); 633 return(error); 634 } 635 636 /* 637 * Expire and purge (old|all) entries in the tcp_hostcache. Runs periodically 638 * from the callout. 639 */ 640 static void 641 tcp_hc_purge(void *arg) 642 { 643 struct hc_metrics *hc_entry, *hc_next; 644 int all = (intptr_t)arg; 645 int i; 646 647 if (tcp_hostcache.purgeall) { 648 all = 1; 649 tcp_hostcache.purgeall = 0; 650 } 651 652 for (i = 0; i < tcp_hostcache.hashsize; i++) { 653 THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); 654 TAILQ_FOREACH_SAFE(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, 655 rmx_q, hc_next) { 656 if (all || hc_entry->rmx_expire <= 0) { 657 TAILQ_REMOVE(&tcp_hostcache.hashbase[i].hch_bucket, 658 hc_entry, rmx_q); 659 uma_zfree(tcp_hostcache.zone, hc_entry); 660 tcp_hostcache.hashbase[i].hch_length--; 661 tcp_hostcache.cache_count--; 662 } else 663 hc_entry->rmx_expire -= TCP_HOSTCACHE_PRUNE; 664 } 665 THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); 666 } 667 callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); 668 } 669