tcp_hostcache: use SMR for lookups, mutex(9) for updates.
In certain cases, e.g. a SYN-flood from a limited set of hosts, the TCP hostcache becomes the main contention point. To solve that, this change introduces lockless lookups on the hostcache. The cache remains a hash, however buckets are now CK_SLIST. For updates a bucket mutex is obtained, for read an SMR section is entered. Reviewed by: markj, rscheff Differential revision: https://reviews.freebsd.org/D29729
This commit is contained in:
Gleb Smirnoff
parent
1db08fbe3f
commit
d554522f6e
@ -2,6 +2,7 @@
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (c) 2002 Andre Oppermann, Internet Business Solutions AG
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* Copyright (c) 2021 Gleb Smirnoff <glebius@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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@ -45,18 +46,18 @@
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* more lightwight and only carries information related to packet forwarding.
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*
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* tcp_hostcache is designed for multiple concurrent access in SMP
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* environments and high contention. All bucket rows have their own lock and
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* thus multiple lookups and modifies can be done at the same time as long as
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* they are in different bucket rows. If a request for insertion of a new
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* record can't be satisfied, it simply returns an empty structure. Nobody
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* and nothing outside of tcp_hostcache.c will ever point directly to any
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* entry in the tcp_hostcache. All communication is done in an
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* object-oriented way and only functions of tcp_hostcache will manipulate
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* hostcache entries. Otherwise, we are unable to achieve good behaviour in
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* concurrent access situations. Since tcp_hostcache is only caching
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* information, there are no fatal consequences if we either can't satisfy
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* any particular request or have to drop/overwrite an existing entry because
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* of bucket limit memory constrains.
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* environments and high contention. It is a straight hash. Each bucket row
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* is protected by its own lock for modification. Readers are protected by
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* SMR. This puts certain restrictions on writers, e.g. a writer shall only
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* insert a fully populated entry into a row. Writer can't reuse least used
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* entry if a hash is full. Value updates for an entry shall be atomic.
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*
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* TCP stack(s) communication with tcp_hostcache() is done via KBI functions
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* tcp_hc_*() and the hc_metrics_lite structure.
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*
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* Since tcp_hostcache is only caching information, there are no fatal
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* consequences if we either can't allocate a new entry or have to drop
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* an existing entry, or return somewhat stale information.
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*/
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/*
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@ -79,6 +80,7 @@ __FBSDID("$FreeBSD$");
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/sbuf.h>
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#include <sys/smr.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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@ -92,18 +94,15 @@ __FBSDID("$FreeBSD$");
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#include <vm/uma.h>
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TAILQ_HEAD(hc_qhead, hc_metrics);
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struct hc_head {
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struct hc_qhead hch_bucket;
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CK_SLIST_HEAD(hc_qhead, hc_metrics) hch_bucket;
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u_int hch_length;
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struct mtx hch_mtx;
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};
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struct hc_metrics {
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/* housekeeping */
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TAILQ_ENTRY(hc_metrics) rmx_q;
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struct hc_head *rmx_head; /* head of bucket tail queue */
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CK_SLIST_ENTRY(hc_metrics) rmx_q;
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struct in_addr ip4; /* IP address */
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struct in6_addr ip6; /* IP6 address */
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uint32_t ip6_zoneid; /* IPv6 scope zone id */
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@ -126,6 +125,7 @@ struct hc_metrics {
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struct tcp_hostcache {
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struct hc_head *hashbase;
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uma_zone_t zone;
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smr_t smr;
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u_int hashsize;
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u_int hashmask;
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u_int hashsalt;
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@ -149,8 +149,7 @@ VNET_DEFINE_STATIC(struct tcp_hostcache, tcp_hostcache);
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VNET_DEFINE_STATIC(struct callout, tcp_hc_callout);
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#define V_tcp_hc_callout VNET(tcp_hc_callout)
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static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *, bool);
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static struct hc_metrics *tcp_hc_insert(struct in_conninfo *);
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static struct hc_metrics *tcp_hc_lookup(struct in_conninfo *);
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static int sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS);
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static int sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS);
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static int sysctl_tcp_hc_purgenow(SYSCTL_HANDLER_ARGS);
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@ -213,14 +212,13 @@ SYSCTL_PROC(_net_inet_tcp_hostcache, OID_AUTO, purgenow,
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static MALLOC_DEFINE(M_HOSTCACHE, "hostcache", "TCP hostcache");
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/* Use jenkins_hash32(), as in other parts of the tcp stack */
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#define HOSTCACHE_HASH(ip) \
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(jenkins_hash32((uint32_t *)(ip), 1, V_tcp_hostcache.hashsalt) & \
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V_tcp_hostcache.hashmask)
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#define HOSTCACHE_HASH6(ip6) \
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(jenkins_hash32((uint32_t *)&((ip6)->s6_addr32[0]), 4, \
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V_tcp_hostcache.hashsalt) & \
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V_tcp_hostcache.hashmask)
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#define HOSTCACHE_HASH(inc) \
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((inc)->inc_flags & INC_ISIPV6) ? \
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(jenkins_hash32((inc)->inc6_faddr.s6_addr32, 4, \
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V_tcp_hostcache.hashsalt) & V_tcp_hostcache.hashmask) \
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: \
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(jenkins_hash32(&(inc)->inc_faddr.s_addr, 1, \
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V_tcp_hostcache.hashsalt) & V_tcp_hostcache.hashmask)
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#define THC_LOCK(h) mtx_lock(&(h)->hch_mtx)
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#define THC_UNLOCK(h) mtx_unlock(&(h)->hch_mtx)
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@ -270,7 +268,7 @@ tcp_hc_init(void)
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* Initialize the hash buckets.
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*/
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for (i = 0; i < V_tcp_hostcache.hashsize; i++) {
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TAILQ_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket);
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CK_SLIST_INIT(&V_tcp_hostcache.hashbase[i].hch_bucket);
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V_tcp_hostcache.hashbase[i].hch_length = 0;
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mtx_init(&V_tcp_hostcache.hashbase[i].hch_mtx, "tcp_hc_entry",
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NULL, MTX_DEF);
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@ -281,8 +279,9 @@ tcp_hc_init(void)
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*/
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V_tcp_hostcache.zone =
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uma_zcreate("hostcache", sizeof(struct hc_metrics),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR);
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uma_zone_set_max(V_tcp_hostcache.zone, V_tcp_hostcache.cache_limit);
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V_tcp_hostcache.smr = uma_zone_get_smr(V_tcp_hostcache.zone);
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/*
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* Set up periodic cache cleanup.
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@ -313,169 +312,58 @@ tcp_hc_destroy(void)
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#endif
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/*
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* Internal function: look up an entry in the hostcache or return NULL.
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*
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* If an entry has been returned, the caller becomes responsible for
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* unlocking the bucket row after he is done reading/modifying the entry.
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* Internal function: compare cache entry to a connection.
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*/
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static bool
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tcp_hc_cmp(struct hc_metrics *hc_entry, struct in_conninfo *inc)
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{
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if (inc->inc_flags & INC_ISIPV6) {
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/* XXX: check ip6_zoneid */
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if (memcmp(&inc->inc6_faddr, &hc_entry->ip6,
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sizeof(inc->inc6_faddr)) == 0)
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return (true);
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} else {
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if (memcmp(&inc->inc_faddr, &hc_entry->ip4,
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sizeof(inc->inc_faddr)) == 0)
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return (true);
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}
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return (false);
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}
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/*
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* Internal function: look up an entry in the hostcache for read.
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* On success returns in SMR section.
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*/
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static struct hc_metrics *
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tcp_hc_lookup(struct in_conninfo *inc, bool update)
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tcp_hc_lookup(struct in_conninfo *inc)
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{
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int hash;
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struct hc_head *hc_head;
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struct hc_metrics *hc_entry;
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KASSERT(inc != NULL, ("%s: NULL in_conninfo", __func__));
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/*
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* Hash the foreign ip address.
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*/
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if (inc->inc_flags & INC_ISIPV6)
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hash = HOSTCACHE_HASH6(&inc->inc6_faddr);
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else
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hash = HOSTCACHE_HASH(&inc->inc_faddr);
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hc_head = &V_tcp_hostcache.hashbase[hash];
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/*
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* Acquire lock for this bucket row; we release the lock if we don't
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* find an entry, otherwise the caller has to unlock after he is
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* done.
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*/
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THC_LOCK(hc_head);
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hc_head = &V_tcp_hostcache.hashbase[HOSTCACHE_HASH(inc)];
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/*
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* Iterate through entries in bucket row looking for a match.
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*/
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TAILQ_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) {
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if (inc->inc_flags & INC_ISIPV6) {
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/* XXX: check ip6_zoneid */
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if (memcmp(&inc->inc6_faddr, &hc_entry->ip6,
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sizeof(inc->inc6_faddr)) == 0)
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goto found;
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} else {
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if (memcmp(&inc->inc_faddr, &hc_entry->ip4,
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sizeof(inc->inc_faddr)) == 0)
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goto found;
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}
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}
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smr_enter(V_tcp_hostcache.smr);
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CK_SLIST_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q)
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if (tcp_hc_cmp(hc_entry, inc))
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break;
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/*
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* We were unsuccessful and didn't find anything.
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*/
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THC_UNLOCK(hc_head);
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return (NULL);
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found:
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if (hc_entry != NULL) {
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if (atomic_load_int(&hc_entry->rmx_expire) !=
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V_tcp_hostcache.expire)
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atomic_store_int(&hc_entry->rmx_expire,
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V_tcp_hostcache.expire);
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#ifdef TCP_HC_COUNTERS
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if (update)
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hc_entry->rmx_updates++;
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else
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hc_entry->rmx_hits++;
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#endif
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hc_entry->rmx_expire = V_tcp_hostcache.expire;
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return (hc_entry);
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}
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/*
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* Internal function: insert an entry into the hostcache or return NULL if
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* unable to allocate a new one.
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*
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* If an entry has been returned, the caller becomes responsible for
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* unlocking the bucket row after he is done reading/modifying the entry.
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*/
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static struct hc_metrics *
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tcp_hc_insert(struct in_conninfo *inc)
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{
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int hash;
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struct hc_head *hc_head;
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struct hc_metrics *hc_entry;
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KASSERT(inc != NULL, ("%s: NULL in_conninfo", __func__));
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/*
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* Hash the foreign ip address.
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*/
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if (inc->inc_flags & INC_ISIPV6)
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hash = HOSTCACHE_HASH6(&inc->inc6_faddr);
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else
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hash = HOSTCACHE_HASH(&inc->inc_faddr);
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hc_head = &V_tcp_hostcache.hashbase[hash];
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/*
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* Acquire lock for this bucket row; we release the lock if we don't
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* find an entry, otherwise the caller has to unlock after he is
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* done.
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*/
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THC_LOCK(hc_head);
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/*
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* If the bucket limit is reached, reuse the least-used element.
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*/
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if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit ||
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atomic_load_int(&V_tcp_hostcache.cache_count) >= V_tcp_hostcache.cache_limit) {
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hc_entry = TAILQ_LAST(&hc_head->hch_bucket, hc_qhead);
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/*
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* At first we were dropping the last element, just to
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* reacquire it in the next two lines again, which isn't very
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* efficient. Instead just reuse the least used element.
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* We may drop something that is still "in-use" but we can be
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* "lossy".
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* Just give up if this bucket row is empty and we don't have
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* anything to replace.
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*/
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if (hc_entry == NULL) {
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THC_UNLOCK(hc_head);
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return (NULL);
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}
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TAILQ_REMOVE(&hc_head->hch_bucket, hc_entry, rmx_q);
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KASSERT(V_tcp_hostcache.hashbase[hash].hch_length > 0 &&
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V_tcp_hostcache.hashbase[hash].hch_length <=
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V_tcp_hostcache.bucket_limit,
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("tcp_hostcache: bucket length range violated at %u: %u",
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hash, V_tcp_hostcache.hashbase[hash].hch_length));
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V_tcp_hostcache.hashbase[hash].hch_length--;
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atomic_subtract_int(&V_tcp_hostcache.cache_count, 1);
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TCPSTAT_INC(tcps_hc_bucketoverflow);
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#if 0
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uma_zfree(V_tcp_hostcache.zone, hc_entry);
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#endif
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} else {
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/*
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* Allocate a new entry, or balk if not possible.
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*/
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hc_entry = uma_zalloc(V_tcp_hostcache.zone, M_NOWAIT);
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if (hc_entry == NULL) {
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THC_UNLOCK(hc_head);
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return (NULL);
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}
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}
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/*
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* Initialize basic information of hostcache entry.
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*/
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bzero(hc_entry, sizeof(*hc_entry));
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if (inc->inc_flags & INC_ISIPV6) {
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hc_entry->ip6 = inc->inc6_faddr;
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hc_entry->ip6_zoneid = inc->inc6_zoneid;
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} else
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hc_entry->ip4 = inc->inc_faddr;
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hc_entry->rmx_head = hc_head;
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hc_entry->rmx_expire = V_tcp_hostcache.expire;
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/*
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* Put it upfront.
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*/
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TAILQ_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q);
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V_tcp_hostcache.hashbase[hash].hch_length++;
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KASSERT(V_tcp_hostcache.hashbase[hash].hch_length <=
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V_tcp_hostcache.bucket_limit,
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("tcp_hostcache: bucket length too high at %u: %u",
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hash, V_tcp_hostcache.hashbase[hash].hch_length));
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atomic_add_int(&V_tcp_hostcache.cache_count, 1);
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TCPSTAT_INC(tcps_hc_added);
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smr_exit(V_tcp_hostcache.smr);
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return (hc_entry);
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}
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@ -498,7 +386,7 @@ tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite)
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/*
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* Find the right bucket.
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*/
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hc_entry = tcp_hc_lookup(inc, false);
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hc_entry = tcp_hc_lookup(inc);
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/*
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* If we don't have an existing object.
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@ -508,18 +396,15 @@ tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite)
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return;
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}
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hc_metrics_lite->rmx_mtu = hc_entry->rmx_mtu;
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hc_metrics_lite->rmx_ssthresh = hc_entry->rmx_ssthresh;
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hc_metrics_lite->rmx_rtt = hc_entry->rmx_rtt;
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hc_metrics_lite->rmx_rttvar = hc_entry->rmx_rttvar;
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hc_metrics_lite->rmx_cwnd = hc_entry->rmx_cwnd;
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hc_metrics_lite->rmx_sendpipe = hc_entry->rmx_sendpipe;
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hc_metrics_lite->rmx_recvpipe = hc_entry->rmx_recvpipe;
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hc_metrics_lite->rmx_mtu = atomic_load_32(&hc_entry->rmx_mtu);
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hc_metrics_lite->rmx_ssthresh = atomic_load_32(&hc_entry->rmx_ssthresh);
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hc_metrics_lite->rmx_rtt = atomic_load_32(&hc_entry->rmx_rtt);
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hc_metrics_lite->rmx_rttvar = atomic_load_32(&hc_entry->rmx_rttvar);
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hc_metrics_lite->rmx_cwnd = atomic_load_32(&hc_entry->rmx_cwnd);
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hc_metrics_lite->rmx_sendpipe = atomic_load_32(&hc_entry->rmx_sendpipe);
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hc_metrics_lite->rmx_recvpipe = atomic_load_32(&hc_entry->rmx_recvpipe);
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/*
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* Unlock bucket row.
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*/
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THC_UNLOCK(hc_entry->rmx_head);
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smr_exit(V_tcp_hostcache.smr);
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}
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/*
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@ -536,13 +421,14 @@ tcp_hc_getmtu(struct in_conninfo *inc)
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if (!V_tcp_use_hostcache)
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return (0);
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hc_entry = tcp_hc_lookup(inc, false);
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hc_entry = tcp_hc_lookup(inc);
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if (hc_entry == NULL) {
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return (0);
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}
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mtu = hc_entry->rmx_mtu;
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THC_UNLOCK(hc_entry->rmx_head);
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mtu = atomic_load_32(&hc_entry->rmx_mtu);
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smr_exit(V_tcp_hostcache.smr);
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return (mtu);
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}
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@ -565,75 +451,175 @@ tcp_hc_updatemtu(struct in_conninfo *inc, uint32_t mtu)
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void
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tcp_hc_update(struct in_conninfo *inc, struct hc_metrics_lite *hcml)
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{
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struct hc_metrics *hc_entry;
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struct hc_head *hc_head;
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struct hc_metrics *hc_entry, *hc_prev;
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uint32_t v;
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bool new;
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if (!V_tcp_use_hostcache)
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return;
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hc_entry = tcp_hc_lookup(inc, true);
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if (hc_entry == NULL) {
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hc_entry = tcp_hc_insert(inc);
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if (hc_entry == NULL)
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return;
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hc_head = &V_tcp_hostcache.hashbase[HOSTCACHE_HASH(inc)];
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hc_prev = NULL;
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THC_LOCK(hc_head);
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CK_SLIST_FOREACH(hc_entry, &hc_head->hch_bucket, rmx_q) {
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if (tcp_hc_cmp(hc_entry, inc))
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||||
break;
|
||||
if (CK_SLIST_NEXT(hc_entry, rmx_q) != NULL)
|
||||
hc_prev = hc_entry;
|
||||
}
|
||||
|
||||
if (hc_entry != NULL) {
|
||||
if (atomic_load_int(&hc_entry->rmx_expire) !=
|
||||
V_tcp_hostcache.expire)
|
||||
atomic_store_int(&hc_entry->rmx_expire,
|
||||
V_tcp_hostcache.expire);
|
||||
#ifdef TCP_HC_COUNTERS
|
||||
hc_entry->rmx_updates++;
|
||||
#endif
|
||||
new = false;
|
||||
} else {
|
||||
/*
|
||||
* Try to allocate a new entry. If the bucket limit is
|
||||
* reached, delete the least-used element, located at the end
|
||||
* of the CK_SLIST. During lookup we saved the pointer to
|
||||
* the second to last element, in case if list has at least 2
|
||||
* elements. This will allow to delete last element without
|
||||
* extra traversal.
|
||||
*
|
||||
* Give up if the row is empty.
|
||||
*/
|
||||
if (hc_head->hch_length >= V_tcp_hostcache.bucket_limit ||
|
||||
atomic_load_int(&V_tcp_hostcache.cache_count) >=
|
||||
V_tcp_hostcache.cache_limit) {
|
||||
if (hc_prev != NULL) {
|
||||
hc_entry = CK_SLIST_NEXT(hc_prev, rmx_q);
|
||||
KASSERT(CK_SLIST_NEXT(hc_entry, rmx_q) == NULL,
|
||||
("%s: %p is not one to last",
|
||||
__func__, hc_prev));
|
||||
CK_SLIST_REMOVE_AFTER(hc_prev, rmx_q);
|
||||
} else if ((hc_entry =
|
||||
CK_SLIST_FIRST(&hc_head->hch_bucket)) != NULL) {
|
||||
KASSERT(CK_SLIST_NEXT(hc_entry, rmx_q) == NULL,
|
||||
("%s: %p is not the only element",
|
||||
__func__, hc_entry));
|
||||
CK_SLIST_REMOVE_HEAD(&hc_head->hch_bucket,
|
||||
rmx_q);
|
||||
} else {
|
||||
THC_UNLOCK(hc_head);
|
||||
return;
|
||||
}
|
||||
KASSERT(hc_head->hch_length > 0 &&
|
||||
hc_head->hch_length <= V_tcp_hostcache.bucket_limit,
|
||||
("tcp_hostcache: bucket length violated at %p",
|
||||
hc_head));
|
||||
hc_head->hch_length--;
|
||||
atomic_subtract_int(&V_tcp_hostcache.cache_count, 1);
|
||||
TCPSTAT_INC(tcps_hc_bucketoverflow);
|
||||
uma_zfree_smr(V_tcp_hostcache.zone, hc_entry);
|
||||
}
|
||||
|
||||
/*
|
||||
* Allocate a new entry, or balk if not possible.
|
||||
*/
|
||||
hc_entry = uma_zalloc_smr(V_tcp_hostcache.zone, M_NOWAIT);
|
||||
if (hc_entry == NULL) {
|
||||
THC_UNLOCK(hc_head);
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Initialize basic information of hostcache entry.
|
||||
*/
|
||||
bzero(hc_entry, sizeof(*hc_entry));
|
||||
if (inc->inc_flags & INC_ISIPV6) {
|
||||
hc_entry->ip6 = inc->inc6_faddr;
|
||||
hc_entry->ip6_zoneid = inc->inc6_zoneid;
|
||||
} else
|
||||
hc_entry->ip4 = inc->inc_faddr;
|
||||
hc_entry->rmx_expire = V_tcp_hostcache.expire;
|
||||
new = true;
|
||||
}
|
||||
|
||||
/*
|
||||
* Fill in data. Use atomics, since an existing entry is
|
||||
* accessible by readers in SMR section.
|
||||
*/
|
||||
if (hcml->rmx_mtu != 0) {
|
||||
hc_entry->rmx_mtu = hcml->rmx_mtu;
|
||||
atomic_store_32(&hc_entry->rmx_mtu, hcml->rmx_mtu);
|
||||
}
|
||||
if (hcml->rmx_rtt != 0) {
|
||||
if (hc_entry->rmx_rtt == 0)
|
||||
hc_entry->rmx_rtt = hcml->rmx_rtt;
|
||||
v = hcml->rmx_rtt;
|
||||
else
|
||||
hc_entry->rmx_rtt = ((uint64_t)hc_entry->rmx_rtt +
|
||||
v = ((uint64_t)hc_entry->rmx_rtt +
|
||||
(uint64_t)hcml->rmx_rtt) / 2;
|
||||
atomic_store_32(&hc_entry->rmx_rtt, v);
|
||||
TCPSTAT_INC(tcps_cachedrtt);
|
||||
}
|
||||
if (hcml->rmx_rttvar != 0) {
|
||||
if (hc_entry->rmx_rttvar == 0)
|
||||
hc_entry->rmx_rttvar = hcml->rmx_rttvar;
|
||||
if (hc_entry->rmx_rttvar == 0)
|
||||
v = hcml->rmx_rttvar;
|
||||
else
|
||||
hc_entry->rmx_rttvar = ((uint64_t)hc_entry->rmx_rttvar +
|
||||
v = ((uint64_t)hc_entry->rmx_rttvar +
|
||||
(uint64_t)hcml->rmx_rttvar) / 2;
|
||||
atomic_store_32(&hc_entry->rmx_rttvar, v);
|
||||
TCPSTAT_INC(tcps_cachedrttvar);
|
||||
}
|
||||
if (hcml->rmx_ssthresh != 0) {
|
||||
if (hc_entry->rmx_ssthresh == 0)
|
||||
hc_entry->rmx_ssthresh = hcml->rmx_ssthresh;
|
||||
v = hcml->rmx_ssthresh;
|
||||
else
|
||||
hc_entry->rmx_ssthresh =
|
||||
(hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2;
|
||||
v = (hc_entry->rmx_ssthresh + hcml->rmx_ssthresh) / 2;
|
||||
atomic_store_32(&hc_entry->rmx_ssthresh, v);
|
||||
TCPSTAT_INC(tcps_cachedssthresh);
|
||||
}
|
||||
if (hcml->rmx_cwnd != 0) {
|
||||
if (hc_entry->rmx_cwnd == 0)
|
||||
hc_entry->rmx_cwnd = hcml->rmx_cwnd;
|
||||
v = hcml->rmx_cwnd;
|
||||
else
|
||||
hc_entry->rmx_cwnd = ((uint64_t)hc_entry->rmx_cwnd +
|
||||
v = ((uint64_t)hc_entry->rmx_cwnd +
|
||||
(uint64_t)hcml->rmx_cwnd) / 2;
|
||||
atomic_store_32(&hc_entry->rmx_cwnd, v);
|
||||
/* TCPSTAT_INC(tcps_cachedcwnd); */
|
||||
}
|
||||
if (hcml->rmx_sendpipe != 0) {
|
||||
if (hc_entry->rmx_sendpipe == 0)
|
||||
hc_entry->rmx_sendpipe = hcml->rmx_sendpipe;
|
||||
v = hcml->rmx_sendpipe;
|
||||
else
|
||||
hc_entry->rmx_sendpipe =
|
||||
((uint64_t)hc_entry->rmx_sendpipe +
|
||||
v = ((uint64_t)hc_entry->rmx_sendpipe +
|
||||
(uint64_t)hcml->rmx_sendpipe) /2;
|
||||
atomic_store_32(&hc_entry->rmx_sendpipe, v);
|
||||
/* TCPSTAT_INC(tcps_cachedsendpipe); */
|
||||
}
|
||||
if (hcml->rmx_recvpipe != 0) {
|
||||
if (hc_entry->rmx_recvpipe == 0)
|
||||
hc_entry->rmx_recvpipe = hcml->rmx_recvpipe;
|
||||
v = hcml->rmx_recvpipe;
|
||||
else
|
||||
hc_entry->rmx_recvpipe =
|
||||
((uint64_t)hc_entry->rmx_recvpipe +
|
||||
v = ((uint64_t)hc_entry->rmx_recvpipe +
|
||||
(uint64_t)hcml->rmx_recvpipe) /2;
|
||||
atomic_store_32(&hc_entry->rmx_recvpipe, v);
|
||||
/* TCPSTAT_INC(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);
|
||||
/*
|
||||
* Put it upfront.
|
||||
*/
|
||||
if (new) {
|
||||
CK_SLIST_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q);
|
||||
hc_head->hch_length++;
|
||||
KASSERT(hc_head->hch_length <= V_tcp_hostcache.bucket_limit,
|
||||
("tcp_hostcache: bucket length too high at %p", hc_head));
|
||||
atomic_add_int(&V_tcp_hostcache.cache_count, 1);
|
||||
TCPSTAT_INC(tcps_hc_added);
|
||||
} else if (hc_entry != CK_SLIST_FIRST(&hc_head->hch_bucket)) {
|
||||
KASSERT(CK_SLIST_NEXT(hc_prev, rmx_q) == hc_entry,
|
||||
("%s: %p next is not %p", __func__, hc_prev, hc_entry));
|
||||
CK_SLIST_REMOVE_AFTER(hc_prev, rmx_q);
|
||||
CK_SLIST_INSERT_HEAD(&hc_head->hch_bucket, hc_entry, rmx_q);
|
||||
}
|
||||
THC_UNLOCK(hc_head);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -683,8 +669,8 @@ sysctl_tcp_hc_list(SYSCTL_HANDLER_ARGS)
|
||||
#define msec(u) (((u) + 500) / 1000)
|
||||
for (i = 0; i < V_tcp_hostcache.hashsize; i++) {
|
||||
THC_LOCK(&V_tcp_hostcache.hashbase[i]);
|
||||
TAILQ_FOREACH(hc_entry, &V_tcp_hostcache.hashbase[i].hch_bucket,
|
||||
rmx_q) {
|
||||
CK_SLIST_FOREACH(hc_entry,
|
||||
&V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q) {
|
||||
sbuf_printf(&sb,
|
||||
"%-15s %5u %8u %6lums %6lums %8u %8u %8u "
|
||||
#ifdef TCP_HC_COUNTERS
|
||||
@ -770,29 +756,46 @@ sysctl_tcp_hc_histo(SYSCTL_HANDLER_ARGS)
|
||||
static void
|
||||
tcp_hc_purge_internal(int all)
|
||||
{
|
||||
struct hc_metrics *hc_entry, *hc_next;
|
||||
struct hc_head *head;
|
||||
struct hc_metrics *hc_entry, *hc_next, *hc_prev;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < V_tcp_hostcache.hashsize; i++) {
|
||||
THC_LOCK(&V_tcp_hostcache.hashbase[i]);
|
||||
TAILQ_FOREACH_SAFE(hc_entry,
|
||||
&V_tcp_hostcache.hashbase[i].hch_bucket, rmx_q, hc_next) {
|
||||
KASSERT(V_tcp_hostcache.hashbase[i].hch_length > 0 &&
|
||||
V_tcp_hostcache.hashbase[i].hch_length <=
|
||||
head = &V_tcp_hostcache.hashbase[i];
|
||||
hc_prev = NULL;
|
||||
THC_LOCK(head);
|
||||
CK_SLIST_FOREACH_SAFE(hc_entry, &head->hch_bucket, rmx_q,
|
||||
hc_next) {
|
||||
KASSERT(head->hch_length > 0 && head->hch_length <=
|
||||
V_tcp_hostcache.bucket_limit, ("tcp_hostcache: "
|
||||
"bucket length out of range at %u: %u",
|
||||
i, V_tcp_hostcache.hashbase[i].hch_length));
|
||||
if (all || hc_entry->rmx_expire <= 0) {
|
||||
TAILQ_REMOVE(
|
||||
&V_tcp_hostcache.hashbase[i].hch_bucket,
|
||||
hc_entry, rmx_q);
|
||||
uma_zfree(V_tcp_hostcache.zone, hc_entry);
|
||||
V_tcp_hostcache.hashbase[i].hch_length--;
|
||||
"bucket length out of range at %u: %u", i,
|
||||
head->hch_length));
|
||||
if (all ||
|
||||
atomic_load_int(&hc_entry->rmx_expire) <= 0) {
|
||||
if (hc_prev != NULL) {
|
||||
KASSERT(hc_entry ==
|
||||
CK_SLIST_NEXT(hc_prev, rmx_q),
|
||||
("%s: %p is not next to %p",
|
||||
__func__, hc_entry, hc_prev));
|
||||
CK_SLIST_REMOVE_AFTER(hc_prev, rmx_q);
|
||||
} else {
|
||||
KASSERT(hc_entry ==
|
||||
CK_SLIST_FIRST(&head->hch_bucket),
|
||||
("%s: %p is not first",
|
||||
__func__, hc_entry));
|
||||
CK_SLIST_REMOVE_HEAD(&head->hch_bucket,
|
||||
rmx_q);
|
||||
}
|
||||
uma_zfree_smr(V_tcp_hostcache.zone, hc_entry);
|
||||
head->hch_length--;
|
||||
atomic_subtract_int(&V_tcp_hostcache.cache_count, 1);
|
||||
} else
|
||||
hc_entry->rmx_expire -= V_tcp_hostcache.prune;
|
||||
} else {
|
||||
atomic_subtract_int(&hc_entry->rmx_expire,
|
||||
V_tcp_hostcache.prune);
|
||||
hc_prev = hc_entry;
|
||||
}
|
||||
}
|
||||
THC_UNLOCK(&V_tcp_hostcache.hashbase[i]);
|
||||
THC_UNLOCK(head);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user