diff options
Diffstat (limited to 'sys/netinet/tcp_hostcache.c')
| -rw-r--r-- | sys/netinet/tcp_hostcache.c | 728 |
1 files changed, 728 insertions, 0 deletions
diff --git a/sys/netinet/tcp_hostcache.c b/sys/netinet/tcp_hostcache.c new file mode 100644 index 0000000..461ce85 --- /dev/null +++ b/sys/netinet/tcp_hostcache.c @@ -0,0 +1,728 @@ +/* + * Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +/* + * The tcp_hostcache moves the tcp specific cached metrics from the routing + * table into a dedicated structure indexed by the remote IP address. It + * keeps information on the measured tcp parameters of past tcp sessions + * to have better initial start values for following connections from the + * same source. Depending on the network parameters (delay, bandwidth, max + * MTU, congestion window) between local and remote site this can lead to + * significant speedups for new tcp connections after the first one. + * + * Due to this new tcp_hostcache all tcp specific metrics information in + * the routing table has been removed. The INPCB no longer keeps a pointer + * to the routing entry and protocol initiated route cloning has been + * removed as well. With these changes the routing table has gone back + * to being more lightwight and only carries information related to packet + * forwarding. + * + * Tcp_hostcache is designed for multiple concurrent access in SMP + * environments and high contention. All bucket rows have their own + * lock and thus multiple lookups and modifies can be done at the same + * time as long as they are in different bucket rows. If a request for + * insertion of a new record can't be satisfied it simply returns an + * empty structure. Nobody and nothing shall ever point directly to + * any entry in tcp_hostcache. All communication is done in an object + * oriented way and only funtions of tcp_hostcache will manipulate hostcache + * entries. Otherwise we are unable to achieve good behaviour in concurrent + * access situations. Since tcp_hostcache is only caching information there + * are no fatal consequences if we either can't satisfy any particular request + * or have to drop/overwrite an existing entry because of bucket limit + * memory constrains. + */ + +/* + * Many thanks to jlemon for basic structure of tcp_syncache which is being + * followed here. + */ + +#include "opt_inet6.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/malloc.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/sysctl.h> + +#include <net/if.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <netinet/in_var.h> +#include <netinet/in_pcb.h> +#include <netinet/ip_var.h> +#ifdef INET6 +#include <netinet/ip6.h> +#include <netinet6/ip6_var.h> +#endif +#include <netinet/tcp.h> +#include <netinet/tcp_var.h> +#ifdef INET6 +#include <netinet6/tcp6_var.h> +#endif + +#include <vm/uma.h> + + +TAILQ_HEAD(hc_qhead, hc_metrics); + +struct hc_head { + struct hc_qhead hch_bucket; + u_int hch_length; + struct mtx hch_mtx; +}; + +struct hc_metrics { + /* housekeeping */ + TAILQ_ENTRY(hc_metrics) rmx_q; + struct hc_head *rmx_head; /* head of bucket tail queue */ + struct in_addr ip4; /* IP address */ + struct in6_addr ip6; /* IP6 address */ + /* endpoint specific values for tcp */ + u_long rmx_mtu; /* MTU for this path */ + u_long rmx_ssthresh; /* outbound gateway buffer limit */ + u_long rmx_rtt; /* estimated round trip time */ + u_long rmx_rttvar; /* estimated rtt variance */ + u_long rmx_bandwidth; /* estimated bandwidth */ + u_long rmx_cwnd; /* congestion window */ + u_long rmx_sendpipe; /* outbound delay-bandwidth product */ + u_long rmx_recvpipe; /* inbound delay-bandwidth product */ + struct rmxp_tao rmx_tao; /* TAO cache for T/TCP */ + /* tcp hostcache internal data */ + int rmx_expire; /* lifetime for object */ + u_long rmx_hits; /* number of hits */ + u_long rmx_updates; /* number of updates */ +}; + +/* Arbitrary values */ +#define TCP_HOSTCACHE_HASHSIZE 512 +#define TCP_HOSTCACHE_BUCKETLIMIT 30 +#define TCP_HOSTCACHE_EXPIRE 60*60 /* one hour */ +#define TCP_HOSTCACHE_PRUNE 5*60 /* every 5 minutes */ + +struct tcp_hostcache { + struct hc_head *hashbase; + uma_zone_t zone; + u_int hashsize; + u_int hashmask; + u_int bucket_limit; + u_int cache_count; + u_int cache_limit; + int expire; + int purgeall; +}; +static struct tcp_hostcache tcp_hostcache; + +static struct callout tcp_hc_callout; + +static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *); +static struct hc_metrics *tcp_hc_insert(struct in_conninfo *); +static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS); +static void tcp_hc_purge(void *); + +SYSCTL_NODE(_net_inet_tcp, OID_AUTO, hostcache, CTLFLAG_RW, 0, "TCP Host cache"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, cachelimit, CTLFLAG_RDTUN, + &tcp_hostcache.cache_limit, 0, "Overall entry limit for hostcache"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, hashsize, CTLFLAG_RDTUN, + &tcp_hostcache.hashsize, 0, "Size of TCP hostcache hashtable"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, bucketlimit, CTLFLAG_RDTUN, + &tcp_hostcache.bucket_limit, 0, "Per-bucket hash limit for hostcache"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, count, CTLFLAG_RD, + &tcp_hostcache.cache_count, 0, "Current number of entries in hostcache"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, expire, CTLFLAG_RW, + &tcp_hostcache.expire, 0, "Expire time of TCP hostcache entries"); + +SYSCTL_INT(_net_inet_tcp_hostcache, OID_AUTO, purge, CTLFLAG_RW, + &tcp_hostcache.purgeall, 0, "Expire all entires on next purge run"); + +SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, list, + CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_SKIP, 0, 0, + sysctl_tcp_hc_list, "A", "List of all hostcache entries"); + + +static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache"); + +#define HOSTCACHE_HASH(ip) \ + (((ip)->s_addr ^ ((ip)->s_addr >> 7) ^ ((ip)->s_addr >> 17)) & \ + tcp_hostcache.hashmask) + +/* XXX: What is the recommended hash to get good entropy for IPv6 addresses? */ +#define HOSTCACHE_HASH6(ip6) \ + (((ip6)->s6_addr32[0] ^ \ + (ip6)->s6_addr32[1] ^ \ + (ip6)->s6_addr32[2] ^ \ + (ip6)->s6_addr32[3]) & \ + tcp_hostcache.hashmask) + +#define THC_LOCK(lp) mtx_lock(lp) +#define THC_UNLOCK(lp) mtx_unlock(lp) + +void +tcp_hc_init(void) +{ + int i; + + /* + * Initialize hostcache structures + */ + tcp_hostcache.cache_count = 0; + tcp_hostcache.hashsize = TCP_HOSTCACHE_HASHSIZE; + tcp_hostcache.bucket_limit = TCP_HOSTCACHE_BUCKETLIMIT; + tcp_hostcache.cache_limit = + tcp_hostcache.hashsize * tcp_hostcache.bucket_limit; + tcp_hostcache.expire = TCP_HOSTCACHE_EXPIRE; + + TUNABLE_INT_FETCH("net.inet.tcp.hostcache.hashsize", + &tcp_hostcache.hashsize); + TUNABLE_INT_FETCH("net.inet.tcp.hostcache.cachelimit", + &tcp_hostcache.cache_limit); + TUNABLE_INT_FETCH("net.inet.tcp.hostcache.bucketlimit", + &tcp_hostcache.bucket_limit); + if (!powerof2(tcp_hostcache.hashsize)) { + printf("WARNING: hostcache hash size is not a power of 2.\n"); + tcp_hostcache.hashsize = 512; /* safe default */ + } + tcp_hostcache.hashmask = tcp_hostcache.hashsize - 1; + + /* + * Allocate the hash table + */ + tcp_hostcache.hashbase = (struct hc_head *) + malloc(tcp_hostcache.hashsize * sizeof(struct hc_head), + M_HOSTCACHE, M_WAITOK | M_ZERO); + + /* + * Initialize the hash buckets + */ + for (i = 0; i < tcp_hostcache.hashsize; i++) { + TAILQ_INIT(&tcp_hostcache.hashbase[i].hch_bucket); + tcp_hostcache.hashbase[i].hch_length = 0; + mtx_init(&tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry", + NULL, MTX_DEF); + } + + /* + * Allocate the hostcache entries. + */ + tcp_hostcache.zone = uma_zcreate("hostcache", sizeof(struct hc_metrics), + NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + uma_zone_set_max(tcp_hostcache.zone, tcp_hostcache.cache_limit); + + /* + * Set up periodic cache cleanup. + */ + callout_init(&tcp_hc_callout, CALLOUT_MPSAFE); + callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); +} + +/* + * Internal function: lookup an entry in the hostcache or return NULL. + * + * If an entry has been returned, the caller becomes responsible for + * unlocking the bucket row after he is done reading/modifying the entry. + */ +static struct hc_metrics * +tcp_hc_lookup(struct in_conninfo *inc) +{ + int hash; + struct hc_head *hc_head; + struct hc_metrics *hc_entry; + + KASSERT(inc != NULL, ("tcp_hc_lookup with NULL in_conninfo pointer")); + + /* + * Hash the foreign ip address. + */ + if (inc->inc_isipv6) + hash = HOSTCACHE_HASH6(&inc->inc6_faddr); + else + hash = HOSTCACHE_HASH(&inc->inc_faddr); + + hc_head = &tcp_hostcache.hashbase[hash]; + + /* + * aquire lock for this bucket row + * we release the lock if we don't find an entry, + * otherwise the caller has to unlock after he is done + */ + THC_LOCK(&hc_head->hch_mtx); + + /* + * circle through entries in bucket row looking for a match + */ + TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) { + if (inc->inc_isipv6) { + if (memcmp(&inc->inc6_faddr, &hc_entry->ip6, + sizeof(inc->inc6_faddr)) == 0) + return hc_entry; + } else { + if (memcmp(&inc->inc_faddr, &hc_entry->ip4, + sizeof(inc->inc_faddr)) == 0) + return hc_entry; + } + } + + /* + * We were unsuccessful and didn't find anything + */ + THC_UNLOCK(&hc_head->hch_mtx); + return NULL; +} + +/* + * Internal function: insert an entry into the hostcache or return NULL + * if unable to allocate a new one. + * + * If an entry has been returned, the caller becomes responsible for + * unlocking the bucket row after he is done reading/modifying the entry. + */ +static struct hc_metrics * +tcp_hc_insert(struct in_conninfo *inc) +{ + int hash; + struct hc_head *hc_head; + struct hc_metrics *hc_entry; + + KASSERT(inc != NULL, ("tcp_hc_insert with NULL in_conninfo pointer")); + + /* + * Hash the foreign ip address + */ + if (inc->inc_isipv6) + hash = HOSTCACHE_HASH6(&inc->inc6_faddr); + else + hash = HOSTCACHE_HASH(&inc->inc_faddr); + + hc_head = &tcp_hostcache.hashbase[hash]; + + /* + * aquire lock for this bucket row + * we release the lock if we don't find an entry, + * otherwise the caller has to unlock after he is done + */ + THC_LOCK(&hc_head->hch_mtx); + + /* + * If the bucket limit is reached reuse the least used element + */ + if (hc_head->hch_length >= tcp_hostcache.bucket_limit || + tcp_hostcache.cache_count >= tcp_hostcache.cache_limit) { + hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead); + /* + * At first we were dropping the last element, just to + * reaquire it in the next two lines again which ain't + * very efficient. Instead just reuse the least used element. + * maybe we drop something that is still "in-use" but we can + * be "lossy". + */ +#if 0 + TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q); + uma_zfree(tcp_hostcache.zone, hc_entry); + tcp_hostcache.hashbase[hash].hch_length--; + tcp_hostcache.cache_count--; +#endif + tcpstat.tcps_hc_bucketoverflow++; + } else { + /* + * Allocate a new entry, or balk if not possible + */ + hc_entry = uma_zalloc(tcp_hostcache.zone, M_NOWAIT); + if (hc_entry == NULL) { + THC_UNLOCK(&hc_head->hch_mtx); + return NULL; + } + } + + /* + * Initialize basic information of hostcache entry + */ + bzero(hc_entry, sizeof(*hc_entry)); + if (inc->inc_isipv6) + bcopy(&hc_entry->ip6, &inc->inc6_faddr, sizeof(hc_entry->ip6)); + else + hc_entry->ip4 = inc->inc_faddr; + hc_entry->rmx_head = hc_head; + hc_entry->rmx_expire = tcp_hostcache.expire; + + /* + * Put it upfront + */ + TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q); + tcp_hostcache.hashbase[hash].hch_length++; + tcp_hostcache.cache_count++; + tcpstat.tcps_hc_added++; + + return hc_entry; +} + +/* + * External function: lookup an entry in the hostcache and fill out the + * supplied tcp metrics structure. Fills in null when no entry was found + * or a value is not set. + */ +void +tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite) +{ + struct hc_metrics *hc_entry; + + /* + * Find the right bucket + */ + hc_entry = tcp_hc_lookup(inc); + + /* + * If we don't have an existing object + */ + if (hc_entry == NULL) { + bzero(hc_metrics_lite, sizeof(*hc_metrics_lite)); + return; + } + hc_entry->rmx_hits++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu; + hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh; + hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt; + hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar; + hc_metrics_lite->rmx_bandwidth = hc_entry->rmx_bandwidth; + hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd; + hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe; + hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe; + + /* + * unlock bucket row + */ + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); +} + +/* + * External function: lookup an entry in the hostcache and return the + * discovered path mtu. Returns null if no entry found or value not is set. + */ +u_long +tcp_hc_getmtu(struct in_conninfo *inc) +{ + struct hc_metrics *hc_entry; + u_long mtu; + + hc_entry = tcp_hc_lookup(inc); + if (hc_entry == NULL) { + return 0; + } + hc_entry->rmx_hits++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + mtu = hc_entry->rmx_mtu; + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); + return mtu; +} + +/* + * External function: lookup an entry in the hostcache and fill out the + * supplied t/tcp tao structure. Fills in null when no entry was found + * or a value is not set. + */ +void +tcp_hc_gettao(struct in_conninfo *inc, struct rmxp_tao *tao) +{ + struct hc_metrics *hc_entry; + + hc_entry = tcp_hc_lookup(inc); + if (hc_entry == NULL) { + bzero(tao, sizeof(*tao)); + return; + } + hc_entry->rmx_hits++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + bcopy(tao, &hc_entry->rmx_tao, sizeof(*tao)); + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); +} + +/* + * External function: update the mtu value of an entry in the hostcache. + * Creates a new entry if none was found. + */ +void +tcp_hc_updatemtu(struct in_conninfo *inc, u_long mtu) +{ + struct hc_metrics *hc_entry; + + /* + * Find the right bucket + */ + hc_entry = tcp_hc_lookup(inc); + + /* + * If we don't have an existing object try to insert a new one + */ + if (hc_entry == NULL) { + hc_entry = tcp_hc_insert(inc); + if (hc_entry == NULL) + return; + } + hc_entry->rmx_updates++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + hc_entry->rmx_mtu = mtu; + + /* + * put it upfront so we find it faster next time + */ + TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + + /* + * unlock bucket row + */ + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); +} + +/* + * External function: update the tcp metrics of an entry in the hostcache. + * Creates a new entry if none was found. + */ +void +tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml) +{ + struct hc_metrics *hc_entry; + + hc_entry = tcp_hc_lookup(inc); + if (hc_entry == NULL) { + hc_entry = tcp_hc_insert(inc); + if (hc_entry == NULL) + return; + } + hc_entry->rmx_updates++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + if (hcml->rmx_rtt != 0) { + if (hc_entry->rmx_rtt == 0) + hc_entry->rmx_rtt = hcml->rmx_rtt; + else + hc_entry->rmx_rtt = + (hc_entry->rmx_rtt + hcml->rmx_rtt) / 2; + tcpstat.tcps_cachedrtt++; + } + if (hcml->rmx_rttvar != 0) { + if (hc_entry->rmx_rttvar == 0) + hc_entry->rmx_rttvar = hcml->rmx_rttvar; + else + hc_entry->rmx_rttvar = + (hc_entry->rmx_rttvar + hcml->rmx_rttvar) / 2; + tcpstat.tcps_cachedrttvar++; + } + if (hcml->rmx_ssthresh != 0) { + if (hc_entry->rmx_ssthresh == 0) + hc_entry->rmx_ssthresh = hcml->rmx_ssthresh; + else + hc_entry->rmx_ssthresh = + (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2; + tcpstat.tcps_cachedssthresh++; + } + if (hcml->rmx_bandwidth != 0) { + if (hc_entry->rmx_bandwidth == 0) + hc_entry->rmx_bandwidth = hcml->rmx_bandwidth; + else + hc_entry->rmx_bandwidth = + (hc_entry->rmx_bandwidth + hcml->rmx_bandwidth) / 2; + /* tcpstat.tcps_cachedbandwidth++; */ + } + if (hcml->rmx_cwnd != 0) { + if (hc_entry->rmx_cwnd == 0) + hc_entry->rmx_cwnd = hcml->rmx_cwnd; + else + hc_entry->rmx_cwnd = + (hc_entry->rmx_cwnd + hcml->rmx_cwnd) / 2; + /* tcpstat.tcps_cachedcwnd++; */ + } + if (hcml->rmx_sendpipe != 0) { + if (hc_entry->rmx_sendpipe == 0) + hc_entry->rmx_sendpipe = hcml->rmx_sendpipe; + else + hc_entry->rmx_sendpipe = + (hc_entry->rmx_sendpipe + hcml->rmx_sendpipe) /2; + /* tcpstat.tcps_cachedsendpipe++; */ + } + if (hcml->rmx_recvpipe != 0) { + if (hc_entry->rmx_recvpipe == 0) + hc_entry->rmx_recvpipe = hcml->rmx_recvpipe; + else + hc_entry->rmx_recvpipe = + (hc_entry->rmx_recvpipe + hcml->rmx_recvpipe) /2; + /* tcpstat.tcps_cachedrecvpipe++; */ + } + + TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); +} + +/* + * External function: update the t/tcp tao of an entry in the hostcache. + * Creates a new entry if none was found. + */ +void +tcp_hc_updatetao(struct in_conninfo *inc, int field, tcp_cc ccount, u_short mss) +{ + struct hc_metrics *hc_entry; + + hc_entry = tcp_hc_lookup(inc); + if (hc_entry == NULL) { + hc_entry = tcp_hc_insert(inc); + if (hc_entry == NULL) + return; + } + hc_entry->rmx_updates++; + hc_entry->rmx_expire = tcp_hostcache.expire; /* start over again */ + + switch(field) { + case TCP_HC_TAO_CC: + hc_entry->rmx_tao.tao_cc = ccount; + break; + + case TCP_HC_TAO_CCSENT: + hc_entry->rmx_tao.tao_ccsent = ccount; + break; + + case TCP_HC_TAO_MSSOPT: + hc_entry->rmx_tao.tao_mssopt = mss; + break; + } + + TAILQ_REMOVE(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + TAILQ_INSERT_HEAD(&hc_entry->rmx_head->hch_bucket, hc_entry, rmx_q); + THC_UNLOCK(&hc_entry->rmx_head->hch_mtx); +} + +/* + * Sysctl function: prints the list and values of all hostcache entries in + * unsorted order. + */ +static int +sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS) +{ + int bufsize; + int linesize = 128; + char *p, *buf; + int len, i, error; + struct hc_metrics *hc_entry; + + bufsize = linesize * (tcp_hostcache.cache_count + 1); + + p = buf = (char *)malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO); + + len = snprintf(p, linesize, + "\nIP address MTU SSTRESH RTT RTTVAR BANDWIDTH " + " CWND SENDPIPE RECVPIPE HITS UPD EXP\n"); + p += len; + +#define msec(u) (((u) + 500) / 1000) + for (i = 0; i < tcp_hostcache.hashsize; i++) { + THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); + TAILQ_FOREACH(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, + rmx_q) { + len = snprintf(p, linesize, + "%-15s %5lu %8lu %6lums %6lums %9lu %8lu %8lu %8lu " + "%4lu %4lu %4i\n", + hc_entry->ip4.s_addr ? inet_ntoa(hc_entry->ip4) : +#ifdef INET6 + ip6_sprintf(&hc_entry->ip6), +#else + "IPv6?", +#endif + hc_entry->rmx_mtu, + hc_entry->rmx_ssthresh, + msec(hc_entry->rmx_rtt * + (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), + msec(hc_entry->rmx_rttvar * + (RTM_RTTUNIT / (hz * TCP_RTT_SCALE))), + hc_entry->rmx_bandwidth * hz * 8, + hc_entry->rmx_cwnd, + hc_entry->rmx_sendpipe, + hc_entry->rmx_recvpipe, + hc_entry->rmx_hits, + hc_entry->rmx_updates, + hc_entry->rmx_expire); + p += len; + } + THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); + } +#undef msec + error = SYSCTL_OUT(req, buf, p - buf); + free(buf, M_TEMP); + return(error); +} + +/* + * Expire and purge (old|all) entries in the tcp_hostcache. Runs periodically + * from the callout. + */ +static void +tcp_hc_purge(void *arg) +{ + struct hc_metrics *hc_entry; + int all = (intptr_t)arg; + int i; + + if (tcp_hostcache.purgeall) { + all = 1; + tcp_hostcache.purgeall = 0; + } + + for (i = 0; i < tcp_hostcache.hashsize; i++) { + THC_LOCK(&tcp_hostcache.hashbase[i].hch_mtx); + TAILQ_FOREACH(hc_entry, &tcp_hostcache.hashbase[i].hch_bucket, + rmx_q) { + if (all || hc_entry->rmx_expire <= 0) { + TAILQ_REMOVE(&tcp_hostcache.hashbase[i].hch_bucket, + hc_entry, rmx_q); + uma_zfree(tcp_hostcache.zone, hc_entry); + tcp_hostcache.hashbase[i].hch_length--; + tcp_hostcache.cache_count--; + } else + hc_entry->rmx_expire -= TCP_HOSTCACHE_PRUNE; + } + THC_UNLOCK(&tcp_hostcache.hashbase[i].hch_mtx); + } + callout_reset(&tcp_hc_callout, TCP_HOSTCACHE_PRUNE * hz, tcp_hc_purge, 0); +} |
