tcp_hostcache.c revision 193731
11556Srgrimes/*- 21556Srgrimes * Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG 31556Srgrimes * All rights reserved. 41556Srgrimes * 51556Srgrimes * Redistribution and use in source and binary forms, with or without 61556Srgrimes * modification, are permitted provided that the following conditions 71556Srgrimes * are met: 81556Srgrimes * 1. Redistributions of source code must retain the above copyright 91556Srgrimes * notice, this list of conditions and the following disclaimer. 101556Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111556Srgrimes * notice, this list of conditions and the following disclaimer in the 121556Srgrimes * documentation and/or other materials provided with the distribution. 131556Srgrimes * 3. The name of the author may not be used to endorse or promote 141556Srgrimes * products derived from this software without specific prior written 151556Srgrimes * permission. 161556Srgrimes * 171556Srgrimes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 181556Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191556Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201556Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 211556Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221556Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231556Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241556Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251556Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261556Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271556Srgrimes * SUCH DAMAGE. 281556Srgrimes */ 291556Srgrimes 301556Srgrimes/* 311556Srgrimes * The tcp_hostcache moves the tcp-specific cached metrics from the routing 321556Srgrimes * table to a dedicated structure indexed by the remote IP address. It keeps 331556Srgrimes * information on the measured TCP parameters of past TCP sessions to allow 341556Srgrimes * better initial start values to be used with later connections to/from the 351556Srgrimes * same source. Depending on the network parameters (delay, bandwidth, max 361556Srgrimes * MTU, congestion window) between local and remote sites, this can lead to 371556Srgrimes * significant speed-ups for new TCP connections after the first one. 381556Srgrimes * 3920420Ssteve * Due to the tcp_hostcache, all TCP-specific metrics information in the 401556Srgrimes * routing table have been removed. The inpcb no longer keeps a pointer to 411556Srgrimes * the routing entry, and protocol-initiated route cloning has been removed 421556Srgrimes * as well. With these changes, the routing table has gone back to being 431556Srgrimes * more lightwight and only carries information related to packet forwarding. 441556Srgrimes * 4535773Scharnier * tcp_hostcache is designed for multiple concurrent access in SMP 4636007Scharnier * environments and high contention. All bucket rows have their own lock and 4735773Scharnier * thus multiple lookups and modifies can be done at the same time as long as 4835773Scharnier * they are in different bucket rows. If a request for insertion of a new 4948026Sgreen * record can't be satisfied, it simply returns an empty structure. Nobody 501556Srgrimes * and nothing outside of tcp_hostcache.c will ever point directly to any 511556Srgrimes * entry in the tcp_hostcache. All communication is done in an 521556Srgrimes * object-oriented way and only functions of tcp_hostcache will manipulate 531556Srgrimes * hostcache entries. Otherwise, we are unable to achieve good behaviour in 541556Srgrimes * concurrent access situations. Since tcp_hostcache is only caching 551556Srgrimes * information, there are no fatal consequences if we either can't satisfy 561556Srgrimes * any particular request or have to drop/overwrite an existing entry because 571556Srgrimes * of bucket limit memory constrains. 581556Srgrimes */ 591556Srgrimes 6019720Sphk/* 611556Srgrimes * Many thanks to jlemon for basic structure of tcp_syncache which is being 621556Srgrimes * followed here. 631556Srgrimes */ 641556Srgrimes 651556Srgrimes#include <sys/cdefs.h> 661556Srgrimes__FBSDID("$FreeBSD: head/sys/netinet/tcp_hostcache.c 193731 2009-06-08 17:15:40Z zec $"); 671556Srgrimes 681556Srgrimes#include "opt_inet6.h" 691556Srgrimes 701556Srgrimes#include <sys/param.h> 711556Srgrimes#include <sys/systm.h> 721556Srgrimes#include <sys/kernel.h> 731556Srgrimes#include <sys/lock.h> 741556Srgrimes#include <sys/mutex.h> 751556Srgrimes#include <sys/malloc.h> 761556Srgrimes#include <sys/socket.h> 7748051Sgreen#include <sys/socketvar.h> 7848051Sgreen#include <sys/sysctl.h> 791556Srgrimes#include <sys/vimage.h> 8048051Sgreen 8148051Sgreen#include <net/if.h> 821556Srgrimes 831556Srgrimes#include <netinet/in.h> 841556Srgrimes#include <netinet/in_systm.h> 851556Srgrimes#include <netinet/ip.h> 861556Srgrimes#include <netinet/in_var.h> 871556Srgrimes#include <netinet/in_pcb.h> 881556Srgrimes#include <netinet/ip_var.h> 8919720Sphk#ifdef INET6 901556Srgrimes#include <netinet/ip6.h> 911556Srgrimes#include <netinet6/ip6_var.h> 921556Srgrimes#endif 931556Srgrimes#include <netinet/tcp.h> 941556Srgrimes#include <netinet/tcp_var.h> 951556Srgrimes#include <netinet/tcp_hostcache.h> 961556Srgrimes#include <netinet/vinet.h> 971556Srgrimes#ifdef INET6 981556Srgrimes#include <netinet6/tcp6_var.h> 991556Srgrimes#endif 1001556Srgrimes 1011556Srgrimes#include <vm/uma.h> 1021556Srgrimes 1031556Srgrimes/* Arbitrary values */ 1041556Srgrimes#define TCP_HOSTCACHE_HASHSIZE 512 1051556Srgrimes#define TCP_HOSTCACHE_BUCKETLIMIT 30 1061556Srgrimes#define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ 1071556Srgrimes#define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ 1081556Srgrimes 10919720Sphk#ifdef VIMAGE_GLOBALS 1101556Srgrimesstatic struct tcp_hostcache tcp_hostcache; 1111556Srgrimesstatic struct callout tcp_hc_callout; 1121556Srgrimes#endif 1131556Srgrimes 1141556Srgrimesstatic struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); 11548051Sgreenstatic struct hc_metrics *tcp_hc_insert(struct in_conninfo *); 11648026Sgreenstatic int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); 1171556Srgrimesstatic void tcp_hc_purge(void *); 1181556Srgrimes 1191556SrgrimesSYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, 1201556Srgrimes "TCP Host cache"); 1211556Srgrimes 1221556SrgrimesSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, cachelimit, 1231556Srgrimes CTLFLAG_RDTUN, tcp_hostcache.cache_limit, 0, 1241556Srgrimes "Overall entry limit for hostcache"); 1251556Srgrimes 1261556SrgrimesSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, hashsize, 1271556Srgrimes CTLFLAG_RDTUN, tcp_hostcache.hashsize, 0, 1281556Srgrimes "Size of TCP hostcache hashtable"); 1291556Srgrimes 1301556SrgrimesSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, bucketlimit, 1311556Srgrimes CTLFLAG_RDTUN, tcp_hostcache.bucket_limit, 0, 1321556Srgrimes "Per-bucket hash limit for hostcache"); 1331556Srgrimes 1341556SrgrimesSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, count, 1351556Srgrimes CTLFLAG_RD, tcp_hostcache.cache_count, 0, 1361556Srgrimes "Current number of entries in hostcache"); 1371556Srgrimes 13848026SgreenSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, expire, 1391556Srgrimes CTLFLAG_RW, tcp_hostcache.expire, 0, 1401556Srgrimes "Expire time of TCP hostcache entries"); 1411556Srgrimes 14248026SgreenSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, prune, 1431556Srgrimes CTLFLAG_RW, tcp_hostcache.prune, 0, "Time between purge runs"); 1441556Srgrimes 1451556SrgrimesSYSCTL_V_INT(V_NET, vnet_inet, _net_inet_tcp_hostcache, OID_AUTO, purge, 1461556Srgrimes CTLFLAG_RW, tcp_hostcache.purgeall, 0, 1471556Srgrimes "Expire all entires on next purge run"); 1481556Srgrimes 1491556SrgrimesSYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, 1501556Srgrimes CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, 1511556Srgrimes sysctl_tcp_hc_list, "A", "List of all hostcache entries"); 1521556Srgrimes 1531556Srgrimes 1541556Srgrimesstatic MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); 1551556Srgrimes 15648051Sgreen#define HOSTCACHE_HASH(ip) \ 15748051Sgreen (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ 1581556Srgrimes V_tcp_hostcache.hashmask) 1591556Srgrimes 1601556Srgrimes/* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ 1611556Srgrimes#define HOSTCACHE_HASH6(ip6) \ 1621556Srgrimes (((ip6)->s6_addr32[0] ^ \ 1631556Srgrimes (ip6)->s6_addr32[1] ^ \ 1641556Srgrimes (ip6)->s6_addr32[2] ^ \ 1651556Srgrimes (ip6)->s6_addr32[3]) & \ 1661556Srgrimes V_tcp_hostcache.hashmask) 1671556Srgrimes 1681556Srgrimes#define THC_LOCK(lp) mtx_lock(lp) 1691556Srgrimes#define THC_UNLOCK(lp) mtx_unlock(lp) 1701556Srgrimes 1711556Srgrimesvoid 17220420Sstevetcp_hc_init(void) 17348026Sgreen{ 1741556Srgrimes INIT_VNET_INET(curvnet); 1751556Srgrimes int i; 1761556Srgrimes 1771556Srgrimes /* 1781556Srgrimes * Initialize hostcache structures. 1791556Srgrimes */ 18046073Simp V_tcp_hostcache.cache_count = 0; 18146073Simp V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; 1821556Srgrimes V_tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; 1835702Sache V_tcp_hostcache.cache_limit = 1841556Srgrimes V_tcp_hostcache.hashsize * V_tcp_hostcache.bucket_limit; 1851556Srgrimes V_tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; 1861556Srgrimes V_tcp_hostcache.prune = TCP_HOSTCACHE_PRUNE; 1875702Sache 1881556Srgrimes TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", 1891556Srgrimes &V_tcp_hostcache.hashsize); 1901556Srgrimes TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", 19146073Simp &V_tcp_hostcache.cache_limit); 1921556Srgrimes TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", 1935702Sache &V_tcp_hostcache.bucket_limit); 1941556Srgrimes if (!powerof2(V_tcp_hostcache.hashsize)) { 1951556Srgrimes printf("WARNING: hostcache hash size is not a power of 2.\n"); 1961556Srgrimes V_tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; /* default */ 1975702Sache } 1981556Srgrimes V_tcp_hostcache.hashmask = V_tcp_hostcache.hashsize - 1; 1991556Srgrimes 2001556Srgrimes /* 20146073Simp * Allocate the hash table. 2021556Srgrimes */ 2035701Sache V_tcp_hostcache.hashbase = (struct hc_head *) 2045702Sache malloc(V_tcp_hostcache.hashsize * sizeof(struct hc_head), 2055701Sache M_HOSTCACHE, M_WAITOK | M_ZERO); 2065701Sache 2075702Sache /* 2085702Sache * Initialize the hash buckets. 2095701Sache */ 2105702Sache for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 2115701Sache TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket); 2125701Sache V_tcp_hostcache.hashbase[i].hch_length = 0; 2135702Sache mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", 2145702Sache NULL, MTX_DEF); 2155701Sache } 2165701Sache 21746073Simp /* 21819720Sphk * Allocate the hostcache entries. 21919720Sphk */ 2201556Srgrimes V_tcp_hostcache.zone = 2211556Srgrimes uma_zcreate("hostcache", sizeof(struct hc_metrics), 2221556Srgrimes NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 2231556Srgrimes uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit); 2241556Srgrimes 2251556Srgrimes /* 2261556Srgrimes * Set up periodic cache cleanup. 2271556Srgrimes */ 2281556Srgrimes callout_init(&V_tcp_hc_callout, CALLOUT_MPSAFE); 2291556Srgrimes callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 2301556Srgrimes tcp_hc_purge, curvnet); 2311556Srgrimes} 2321556Srgrimes 2331556Srgrimes#ifdef VIMAGE 2341556Srgrimesvoid 2351556Srgrimestcp_hc_destroy(void) 2361556Srgrimes{ 2371556Srgrimes INIT_VNET_INET(curvnet); 2381556Srgrimes 2391556Srgrimes /* XXX TODO walk the hashtable and free all entries */ 24048026Sgreen 2411556Srgrimes callout_drain(&V_tcp_hc_callout); 24228430Sjlemon} 2431556Srgrimes#endif 2441556Srgrimes 2451556Srgrimes/* 2461556Srgrimes * Internal function: look up an entry in the hostcache or return NULL. 24728430Sjlemon * 2481556Srgrimes * If an entry has been returned, the caller becomes responsible for 2491556Srgrimes * unlocking the bucket row after he is done reading/modifying the entry. 25048026Sgreen */ 25128430Sjlemonstatic struct hc_metrics * 2521556Srgrimestcp_hc_lookup(struct in_conninfo *inc) 2531556Srgrimes{ 2541556Srgrimes INIT_VNET_INET(curvnet); 25548026Sgreen int hash; 2561556Srgrimes struct hc_head *hc_head; 2571556Srgrimes struct hc_metrics *hc_entry; 2581556Srgrimes 2591556Srgrimes KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); 2601556Srgrimes 2611556Srgrimes /* 2621556Srgrimes * Hash the foreign ip address. 2631556Srgrimes */ 26448026Sgreen if (inc->inc_flags & INC_ISIPV6) 2651556Srgrimes hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 2661556Srgrimes else 2671556Srgrimes hash = HOSTCACHE_HASH(&inc->inc_faddr); 2681556Srgrimes 26928430Sjlemon hc_head = &V_tcp_hostcache.hashbase[hash]; 2701556Srgrimes 2711556Srgrimes /* 2721556Srgrimes * Acquire lock for this bucket row; we release the lock if we don't 2731556Srgrimes * find an entry, otherwise the caller has to unlock after he is 2741556Srgrimes * done. 2751556Srgrimes */ 2761556Srgrimes THC_LOCK(&hc_head->hch_mtx); 2771556Srgrimes 2781556Srgrimes /* 2791556Srgrimes * Iterate through entries in bucket row looking for a match. 2801556Srgrimes */ 2811556Srgrimes TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { 2821556Srgrimes if (inc->inc_flags & INC_ISIPV6) { 2831556Srgrimes if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, 2841556Srgrimes sizeof(inc->inc6_faddr)) == 0) 2851556Srgrimes return hc_entry; 2861556Srgrimes } else { 2871556Srgrimes if (memcmp(&inc->inc_faddr, &hc_entry->ip4, 2881556Srgrimes sizeof(inc->inc_faddr)) == 0) 2891556Srgrimes return hc_entry; 2901556Srgrimes } 2911556Srgrimes } 2921556Srgrimes 2931556Srgrimes /* 2941556Srgrimes * We were unsuccessful and didn't find anything. 2951556Srgrimes */ 2961556Srgrimes THC_UNLOCK(&hc_head->hch_mtx); 2971556Srgrimes return NULL; 2981556Srgrimes} 2991556Srgrimes 3001556Srgrimes/* 3011556Srgrimes * Internal function: insert an entry into the hostcache or return NULL if 3021556Srgrimes * unable to allocate a new one. 3031556Srgrimes * 3041556Srgrimes * If an entry has been returned, the caller becomes responsible for 3051556Srgrimes * unlocking the bucket row after he is done reading/modifying the entry. 3061556Srgrimes */ 3071556Srgrimesstatic struct hc_metrics * 3081556Srgrimestcp_hc_insert(struct in_conninfo *inc) 3091556Srgrimes{ 3101556Srgrimes INIT_VNET_INET(curvnet); 3111556Srgrimes int hash; 3121556Srgrimes struct hc_head *hc_head; 3131556Srgrimes struct hc_metrics *hc_entry; 3141556Srgrimes 3151556Srgrimes KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); 3161556Srgrimes 3171556Srgrimes /* 3181556Srgrimes * Hash the foreign ip address. 3191556Srgrimes */ 32032324Sjoerg if (inc->inc_flags & INC_ISIPV6) 3211556Srgrimes hash = HOSTCACHE_HASH6(&inc->inc6_faddr); 3221556Srgrimes else 3231556Srgrimes hash = HOSTCACHE_HASH(&inc->inc_faddr); 3241556Srgrimes 3251556Srgrimes hc_head = &V_tcp_hostcache.hashbase[hash]; 3261556Srgrimes 3271556Srgrimes /* 3281556Srgrimes * Acquire lock for this bucket row; we release the lock if we don't 3291556Srgrimes * find an entry, otherwise the caller has to unlock after he is 3301556Srgrimes * done. 3311556Srgrimes */ 3321556Srgrimes THC_LOCK(&hc_head->hch_mtx); 3331556Srgrimes 3341556Srgrimes /* 3351556Srgrimes * If the bucket limit is reached, reuse the least-used element. 3361556Srgrimes */ 3371556Srgrimes if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit || 3381556Srgrimes V_tcp_hostcache.cache_count >= V_tcp_hostcache.cache_limit) { 3391556Srgrimes hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); 3401556Srgrimes /* 3411556Srgrimes * At first we were dropping the last element, just to 3421556Srgrimes * reacquire it in the next two lines again, which isn't very 3431556Srgrimes * efficient. Instead just reuse the least used element. 3441556Srgrimes * We may drop something that is still "in-use" but we can be 34528430Sjlemon * "lossy". 34628430Sjlemon * Just give up if this bucket row is empty and we don't have 34728430Sjlemon * anything to replace. 34828430Sjlemon */ 34928430Sjlemon if (hc_entry == NULL) { 3501556Srgrimes THC_UNLOCK(&hc_head->hch_mtx); 3511556Srgrimes return NULL; 35230312Sjoerg } 3531556Srgrimes TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); 3541556Srgrimes V_tcp_hostcache.hashbase[hash].hch_length--; 3551556Srgrimes V_tcp_hostcache.cache_count--; 3561556Srgrimes TCPSTAT_INC(tcps_hc_bucketoverflow); 3571556Srgrimes#if 0 3581556Srgrimes uma_zfree(V_tcp_hostcache.zone, hc_entry); 3591556Srgrimes#endif 3601556Srgrimes } else { 36148051Sgreen /* 36248026Sgreen * Allocate a new entry, or balk if not possible. 3631556Srgrimes */ 3641556Srgrimes hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT); 3651556Srgrimes if (hc_entry == NULL) { 3661556Srgrimes THC_UNLOCK(&hc_head->hch_mtx); 3671556Srgrimes return NULL; 3681556Srgrimes } 3691556Srgrimes } 3701556Srgrimes 3711556Srgrimes /* 3721556Srgrimes * Initialize basic information of hostcache entry. 3731556Srgrimes */ 3741556Srgrimes bzero(hc_entry, sizeof(*hc_entry)); 3751556Srgrimes if (inc->inc_flags & INC_ISIPV6) 3761556Srgrimes bcopy(&inc->inc6_faddr, &hc_entry->ip6, sizeof(hc_entry->ip6)); 3771556Srgrimes else 3781556Srgrimes hc_entry->ip4 = inc->inc_faddr; 3791556Srgrimes hc_entry->rmx_head = hc_head; 3801556Srgrimes hc_entry->rmx_expire = V_tcp_hostcache.expire; 3811556Srgrimes 3821556Srgrimes /* 3831556Srgrimes * Put it upfront. 38430312Sjoerg */ 38530312Sjoerg TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); 38630312Sjoerg V_tcp_hostcache.hashbase[hash].hch_length++; 38730312Sjoerg V_tcp_hostcache.cache_count++; 38830312Sjoerg TCPSTAT_INC(tcps_hc_added); 38930312Sjoerg 39030312Sjoerg return hc_entry; 39130312Sjoerg} 39230312Sjoerg 39330312Sjoerg/* 39430312Sjoerg * External function: look up an entry in the hostcache and fill out the 39530312Sjoerg * supplied TCP metrics structure. Fills in NULL when no entry was found or 39630312Sjoerg * a value is not set. 39730312Sjoerg */ 39830312Sjoergvoid 39930312Sjoergtcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) 40048051Sgreen{ 40148051Sgreen INIT_VNET_INET(curvnet); 40248051Sgreen struct hc_metrics *hc_entry; 40348051Sgreen 40430312Sjoerg /* 40530312Sjoerg * Find the right bucket. 40630312Sjoerg */ 40730312Sjoerg hc_entry = tcp_hc_lookup(inc); 40830312Sjoerg 40930312Sjoerg /* 41030312Sjoerg * If we don't have an existing object. 41130312Sjoerg */ 41230312Sjoerg if (hc_entry == NULL) { 41330312Sjoerg bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); 4141556Srgrimes return; 4151556Srgrimes } 4161556Srgrimes hc_entry->rmx_hits++; 4171556Srgrimes hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 4181556Srgrimes 4191556Srgrimes hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; 4201556Srgrimes hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; 4211556Srgrimes hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; 4221556Srgrimes hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; 4231556Srgrimes hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; 4241556Srgrimes hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; 4251556Srgrimes hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; 4261556Srgrimes hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; 4271556Srgrimes 4281556Srgrimes /* 4291556Srgrimes * Unlock bucket row. 4301556Srgrimes */ 4311556Srgrimes THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 4321556Srgrimes} 4331556Srgrimes 4341556Srgrimes/* 4351556Srgrimes * External function: look up an entry in the hostcache and return the 43648051Sgreen * discovered path MTU. Returns NULL if no entry is found or value is not 4371556Srgrimes * set. 4381556Srgrimes */ 43948051Sgreenu_long 4401556Srgrimestcp_hc_getmtu(struct in_conninfo *inc) 4411556Srgrimes{ 4421556Srgrimes INIT_VNET_INET(curvnet); 4431556Srgrimes struct hc_metrics *hc_entry; 4441556Srgrimes u_long mtu; 4451556Srgrimes 4461556Srgrimes hc_entry = tcp_hc_lookup(inc); 4471556Srgrimes if (hc_entry == NULL) { 4481556Srgrimes return 0; 4491556Srgrimes } 450 hc_entry->rmx_hits++; 451 hc_entry->rmx_expire = V_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 */ 462void 463tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) 464{ 465 INIT_VNET_INET(curvnet); 466 struct hc_metrics *hc_entry; 467 468 /* 469 * Find the right bucket. 470 */ 471 hc_entry = tcp_hc_lookup(inc); 472 473 /* 474 * If we don't have an existing object, try to insert a new one. 475 */ 476 if (hc_entry == NULL) { 477 hc_entry = tcp_hc_insert(inc); 478 if (hc_entry == NULL) 479 return; 480 } 481 hc_entry->rmx_updates++; 482 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 483 484 hc_entry->rmx_mtu = mtu; 485 486 /* 487 * Put it upfront so we find it faster next time. 488 */ 489 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 490 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 491 492 /* 493 * Unlock bucket row. 494 */ 495 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 496} 497 498/* 499 * External function: update the TCP metrics of an entry in the hostcache. 500 * Creates a new entry if none was found. 501 */ 502void 503tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) 504{ 505 INIT_VNET_INET(curvnet); 506 struct hc_metrics *hc_entry; 507 508 hc_entry = tcp_hc_lookup(inc); 509 if (hc_entry == NULL) { 510 hc_entry = tcp_hc_insert(inc); 511 if (hc_entry == NULL) 512 return; 513 } 514 hc_entry->rmx_updates++; 515 hc_entry->rmx_expire = V_tcp_hostcache.expire; /* start over again */ 516 517 if (hcml->rmx_rtt != 0) { 518 if (hc_entry->rmx_rtt == 0) 519 hc_entry->rmx_rtt = hcml->rmx_rtt; 520 else 521 hc_entry->rmx_rtt = 522 (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; 523 TCPSTAT_INC(tcps_cachedrtt); 524 } 525 if (hcml->rmx_rttvar != 0) { 526 if (hc_entry->rmx_rttvar == 0) 527 hc_entry->rmx_rttvar = hcml->rmx_rttvar; 528 else 529 hc_entry->rmx_rttvar = 530 (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; 531 TCPSTAT_INC(tcps_cachedrttvar); 532 } 533 if (hcml->rmx_ssthresh != 0) { 534 if (hc_entry->rmx_ssthresh == 0) 535 hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; 536 else 537 hc_entry->rmx_ssthresh = 538 (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; 539 TCPSTAT_INC(tcps_cachedssthresh); 540 } 541 if (hcml->rmx_bandwidth != 0) { 542 if (hc_entry->rmx_bandwidth == 0) 543 hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; 544 else 545 hc_entry->rmx_bandwidth = 546 (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; 547 /* TCPSTAT_INC(tcps_cachedbandwidth); */ 548 } 549 if (hcml->rmx_cwnd != 0) { 550 if (hc_entry->rmx_cwnd == 0) 551 hc_entry->rmx_cwnd = hcml->rmx_cwnd; 552 else 553 hc_entry->rmx_cwnd = 554 (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; 555 /* TCPSTAT_INC(tcps_cachedcwnd); */ 556 } 557 if (hcml->rmx_sendpipe != 0) { 558 if (hc_entry->rmx_sendpipe == 0) 559 hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; 560 else 561 hc_entry->rmx_sendpipe = 562 (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; 563 /* TCPSTAT_INC(tcps_cachedsendpipe); */ 564 } 565 if (hcml->rmx_recvpipe != 0) { 566 if (hc_entry->rmx_recvpipe == 0) 567 hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; 568 else 569 hc_entry->rmx_recvpipe = 570 (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; 571 /* TCPSTAT_INC(tcps_cachedrecvpipe); */ 572 } 573 574 TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 575 TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); 576 THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); 577} 578 579/* 580 * Sysctl function: prints the list and values of all hostcache entries in 581 * unsorted order. 582 */ 583static int 584sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) 585{ 586 INIT_VNET_INET(curvnet); 587 int bufsize; 588 int linesize = 128; 589 char *p, *buf; 590 int len, i, error; 591 struct hc_metrics *hc_entry; 592#ifdef INET6 593 char ip6buf[INET6_ADDRSTRLEN]; 594#endif 595 596 bufsize = linesize * (V_tcp_hostcache.cache_count + 1); 597 598 p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); 599 600 len = snprintf(p, linesize, 601 "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " 602 " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); 603 p += len; 604 605#define msec(u) (((u) + 500) / 1000) 606 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 607 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 608 TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket, 609 rmx_q) { 610 len = snprintf(p, linesize, 611 "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " 612 "%4lu %4lu %4i\n", 613 hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : 614#ifdef INET6 615 ip6_sprintf(ip6buf, &hc_entry->ip6), 616#else 617 "IPv6?", 618#endif 619 hc_entry->rmx_mtu, 620 hc_entry->rmx_ssthresh, 621 msec(hc_entry->rmx_rtt * 622 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 623 msec(hc_entry->rmx_rttvar * 624 (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), 625 hc_entry->rmx_bandwidth * 8, 626 hc_entry->rmx_cwnd, 627 hc_entry->rmx_sendpipe, 628 hc_entry->rmx_recvpipe, 629 hc_entry->rmx_hits, 630 hc_entry->rmx_updates, 631 hc_entry->rmx_expire); 632 p += len; 633 } 634 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 635 } 636#undef msec 637 error = SYSCTL_OUT(req, buf, p - buf); 638 free(buf, M_TEMP); 639 return(error); 640} 641 642/* 643 * Expire and purge (old|all) entries in the tcp_hostcache. Runs 644 * periodically from the callout. 645 */ 646static void 647tcp_hc_purge(void *arg) 648{ 649 CURVNET_SET((struct vnet *) arg); 650 INIT_VNET_INET(curvnet); 651 struct hc_metrics *hc_entry, *hc_next; 652 int all = 0; 653 int i; 654 655 if (V_tcp_hostcache.purgeall) { 656 all = 1; 657 V_tcp_hostcache.purgeall = 0; 658 } 659 660 for (i = 0; i < V_tcp_hostcache.hashsize; i++) { 661 THC_LOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 662 TAILQ_FOREACH_SAFE(hc_entry, 663 &V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) { 664 if (all || hc_entry->rmx_expire <= 0) { 665 TAILQ_REMOVE(&V_tcp_hostcache.hashbase[i].hch_bucket, 666 hc_entry, rmx_q); 667 uma_zfree(V_tcp_hostcache.zone, hc_entry); 668 V_tcp_hostcache.hashbase[i].hch_length--; 669 V_tcp_hostcache.cache_count--; 670 } else 671 hc_entry->rmx_expire -= V_tcp_hostcache.prune; 672 } 673 THC_UNLOCK(&V_tcp_hostcache.hashbase[i].hch_mtx); 674 } 675 676 callout_reset(&V_tcp_hc_callout, V_tcp_hostcache.prune * hz, 677 tcp_hc_purge, arg); 678 CURVNET_RESTORE(); 679} 680