NetBSD/sys/netinet6/in6_pcb.c

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/* $NetBSD: in6_pcb.c,v 1.139 2015/04/27 10:14:44 ozaki-r Exp $ */
/* $KAME: in6_pcb.c,v 1.84 2001/02/08 18:02:08 itojun Exp $ */
1999-07-04 01:24:45 +04:00
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*/
/*
* Copyright (c) 1982, 1986, 1991, 1993
* The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)in_pcb.c 8.2 (Berkeley) 1/4/94
*/
2001-11-13 03:56:55 +03:00
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: in6_pcb.c,v 1.139 2015/04/27 10:14:44 ozaki-r Exp $");
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#include "opt_inet.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/ioctl.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/proc.h>
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#include <sys/kauth.h>
#include <sys/domain.h>
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#include <sys/once.h>
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip6.h>
#include <netinet/portalgo.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include "faith.h"
#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#include <netipsec/key.h>
#endif /* IPSEC */
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
#include <netinet/tcp_vtw.h>
const struct in6_addr zeroin6_addr;
#define IN6PCBHASH_PORT(table, lport) \
&(table)->inpt_porthashtbl[ntohs(lport) & (table)->inpt_porthash]
#define IN6PCBHASH_BIND(table, laddr, lport) \
&(table)->inpt_bindhashtbl[ \
(((laddr)->s6_addr32[0] ^ (laddr)->s6_addr32[1] ^ \
(laddr)->s6_addr32[2] ^ (laddr)->s6_addr32[3]) + ntohs(lport)) & \
(table)->inpt_bindhash]
#define IN6PCBHASH_CONNECT(table, faddr, fport, laddr, lport) \
&(table)->inpt_bindhashtbl[ \
((((faddr)->s6_addr32[0] ^ (faddr)->s6_addr32[1] ^ \
(faddr)->s6_addr32[2] ^ (faddr)->s6_addr32[3]) + ntohs(fport)) + \
(((laddr)->s6_addr32[0] ^ (laddr)->s6_addr32[1] ^ \
(laddr)->s6_addr32[2] ^ (laddr)->s6_addr32[3]) + \
ntohs(lport))) & (table)->inpt_bindhash]
int ip6_anonportmin = IPV6PORT_ANONMIN;
int ip6_anonportmax = IPV6PORT_ANONMAX;
int ip6_lowportmin = IPV6PORT_RESERVEDMIN;
int ip6_lowportmax = IPV6PORT_RESERVEDMAX;
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static struct pool in6pcb_pool;
static int
in6pcb_poolinit(void)
{
pool_init(&in6pcb_pool, sizeof(struct in6pcb), 0, 0, 0, "in6pcbpl",
NULL, IPL_SOFTNET);
return 0;
}
void
in6_pcbinit(struct inpcbtable *table, int bindhashsize, int connecthashsize)
{
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static ONCE_DECL(control);
in_pcbinit(table, bindhashsize, connecthashsize);
table->inpt_lastport = (u_int16_t)ip6_anonportmax;
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RUN_ONCE(&control, in6pcb_poolinit);
}
int
in6_pcballoc(struct socket *so, void *v)
{
struct inpcbtable *table = v;
struct in6pcb *in6p;
int s;
s = splnet();
in6p = pool_get(&in6pcb_pool, PR_NOWAIT);
splx(s);
if (in6p == NULL)
return (ENOBUFS);
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memset((void *)in6p, 0, sizeof(*in6p));
in6p->in6p_af = AF_INET6;
in6p->in6p_table = table;
in6p->in6p_socket = so;
in6p->in6p_hops = -1; /* use kernel default */
in6p->in6p_icmp6filt = NULL;
in6p->in6p_portalgo = PORTALGO_DEFAULT;
in6p->in6p_bindportonsend = false;
#if defined(IPSEC)
if (ipsec_enabled) {
int error = ipsec_init_pcbpolicy(so, &in6p->in6p_sp);
if (error != 0) {
s = splnet();
pool_put(&in6pcb_pool, in6p);
splx(s);
return error;
}
}
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#endif /* IPSEC */
s = splnet();
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TAILQ_INSERT_HEAD(&table->inpt_queue, (struct inpcb_hdr*)in6p,
inph_queue);
LIST_INSERT_HEAD(IN6PCBHASH_PORT(table, in6p->in6p_lport),
&in6p->in6p_head, inph_lhash);
in6_pcbstate(in6p, IN6P_ATTACHED);
splx(s);
if (ip6_v6only)
in6p->in6p_flags |= IN6P_IPV6_V6ONLY;
so->so_pcb = (void *)in6p;
return (0);
}
/*
* Bind address from sin6 to in6p.
*/
static int
in6_pcbbind_addr(struct in6pcb *in6p, struct sockaddr_in6 *sin6, struct lwp *l)
{
int error;
/*
* We should check the family, but old programs
* incorrectly fail to intialize it.
*/
if (sin6->sin6_family != AF_INET6)
return (EAFNOSUPPORT);
#ifndef INET
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
return (EADDRNOTAVAIL);
#endif
if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
return (error);
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
return (EINVAL);
if (sin6->sin6_addr.s6_addr32[3]) {
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
bcopy(&sin6->sin6_addr.s6_addr32[3],
&sin.sin_addr, sizeof(sin.sin_addr));
if (!IN_MULTICAST(sin.sin_addr.s_addr) &&
ifa_ifwithaddr((struct sockaddr *)&sin) == 0)
return EADDRNOTAVAIL;
}
} else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
// succeed
} else if (!IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
struct ifaddr *ia = NULL;
if ((in6p->in6p_flags & IN6P_FAITH) == 0 &&
(ia = ifa_ifwithaddr((struct sockaddr *)sin6)) == 0)
return (EADDRNOTAVAIL);
/*
* bind to an anycast address might accidentally
* cause sending a packet with an anycast source
* address, so we forbid it.
*
* We should allow to bind to a deprecated address,
* since the application dare to use it.
* But, can we assume that they are careful enough
* to check if the address is deprecated or not?
* Maybe, as a safeguard, we should have a setsockopt
* flag to control the bind(2) behavior against
* deprecated addresses (default: forbid bind(2)).
*/
if (ia &&
((struct in6_ifaddr *)ia)->ia6_flags &
(IN6_IFF_ANYCAST|IN6_IFF_NOTREADY|IN6_IFF_DETACHED))
return (EADDRNOTAVAIL);
}
in6p->in6p_laddr = sin6->sin6_addr;
return (0);
}
/*
* Bind port from sin6 to in6p.
*/
static int
in6_pcbbind_port(struct in6pcb *in6p, struct sockaddr_in6 *sin6, struct lwp *l)
{
struct inpcbtable *table = in6p->in6p_table;
struct socket *so = in6p->in6p_socket;
int wild = 0, reuseport = (so->so_options & SO_REUSEPORT);
int error;
if ((so->so_options & (SO_REUSEADDR|SO_REUSEPORT)) == 0 &&
((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
(so->so_options & SO_ACCEPTCONN) == 0))
wild = 1;
if (sin6->sin6_port != 0) {
enum kauth_network_req req;
#ifndef IPNOPRIVPORTS
if (ntohs(sin6->sin6_port) < IPV6PORT_RESERVED)
req = KAUTH_REQ_NETWORK_BIND_PRIVPORT;
else
#endif /* IPNOPRIVPORTS */
req = KAUTH_REQ_NETWORK_BIND_PORT;
error = kauth_authorize_network(l->l_cred, KAUTH_NETWORK_BIND,
req, so, sin6, NULL);
if (error)
return (EACCES);
}
if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
/*
* Treat SO_REUSEADDR as SO_REUSEPORT for multicast;
* allow compepte duplication of binding if
* SO_REUSEPORT is set, or if SO_REUSEADDR is set
* and a multicast address is bound on both
* new and duplicated sockets.
*/
if (so->so_options & (SO_REUSEADDR | SO_REUSEPORT))
reuseport = SO_REUSEADDR|SO_REUSEPORT;
}
if (sin6->sin6_port != 0) {
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
#ifdef INET
struct inpcb *t;
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
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struct vestigial_inpcb vestige;
t = in_pcblookup_port(table,
*(struct in_addr *)&sin6->sin6_addr.s6_addr32[3],
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
sin6->sin6_port, wild, &vestige);
if (t && (reuseport & t->inp_socket->so_options) == 0)
return (EADDRINUSE);
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
if (!t
&& vestige.valid
&& !(reuseport && vestige.reuse_port))
return EADDRINUSE;
#else
return (EADDRNOTAVAIL);
#endif
}
{
struct in6pcb *t;
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
struct vestigial_inpcb vestige;
t = in6_pcblookup_port(table, &sin6->sin6_addr,
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
sin6->sin6_port, wild, &vestige);
if (t && (reuseport & t->in6p_socket->so_options) == 0)
return (EADDRINUSE);
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
if (!t
&& vestige.valid
&& !(reuseport && vestige.reuse_port))
return EADDRINUSE;
}
}
if (sin6->sin6_port == 0) {
int e;
e = in6_pcbsetport(sin6, in6p, l);
if (e != 0)
return (e);
} else {
in6p->in6p_lport = sin6->sin6_port;
in6_pcbstate(in6p, IN6P_BOUND);
}
LIST_REMOVE(&in6p->in6p_head, inph_lhash);
LIST_INSERT_HEAD(IN6PCBHASH_PORT(table, in6p->in6p_lport),
&in6p->in6p_head, inph_lhash);
return (0);
}
int
in6_pcbbind(void *v, struct sockaddr_in6 *sin6, struct lwp *l)
{
struct in6pcb *in6p = v;
struct sockaddr_in6 lsin6;
int error;
if (in6p->in6p_af != AF_INET6)
return (EINVAL);
/*
* If we already have a local port or a local address it means we're
* bounded.
*/
if (in6p->in6p_lport || !(IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) ||
(IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) &&
2010-08-20 20:38:16 +04:00
in6p->in6p_laddr.s6_addr32[3] == 0)))
return (EINVAL);
if (NULL != sin6) {
/* We were provided a sockaddr_in6 to use. */
if (sin6->sin6_len != sizeof(*sin6))
return (EINVAL);
} else {
/* We always bind to *something*, even if it's "anything". */
lsin6 = *((const struct sockaddr_in6 *)
in6p->in6p_socket->so_proto->pr_domain->dom_sa_any);
sin6 = &lsin6;
}
/* Bind address. */
error = in6_pcbbind_addr(in6p, sin6, l);
if (error)
return (error);
/* Bind port. */
error = in6_pcbbind_port(in6p, sin6, l);
if (error) {
/*
* Reset the address here to "any" so we don't "leak" the
* in6pcb.
*/
in6p->in6p_laddr = in6addr_any;
return (error);
}
2003-09-06 07:12:51 +04:00
#if 0
in6p->in6p_flowinfo = 0; /* XXX */
#endif
return (0);
}
/*
* Connect from a socket to a specified address.
* Both address and port must be specified in argument sin6.
* If don't have a local address for this socket yet,
* then pick one.
*/
int
in6_pcbconnect(void *v, struct mbuf *nam, struct lwp *l)
{
struct in6pcb *in6p = v;
struct in6_addr *in6a = NULL;
struct sockaddr_in6 *sin6 = mtod(nam, struct sockaddr_in6 *);
struct ifnet *ifp = NULL; /* outgoing interface */
int error = 0;
int scope_ambiguous = 0;
#ifdef INET
struct in6_addr mapped;
#endif
struct sockaddr_in6 tmp;
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
struct vestigial_inpcb vestige;
(void)&in6a; /* XXX fool gcc */
if (in6p->in6p_af != AF_INET6)
return (EINVAL);
if (nam->m_len != sizeof(*sin6))
return (EINVAL);
if (sin6->sin6_len != sizeof(*sin6))
return (EINVAL);
if (sin6->sin6_family != AF_INET6)
return (EAFNOSUPPORT);
if (sin6->sin6_port == 0)
return (EADDRNOTAVAIL);
if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr) &&
in6p->in6p_socket->so_type == SOCK_STREAM)
return EADDRNOTAVAIL;
if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
scope_ambiguous = 1;
if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
return(error);
/* sanity check for mapped address case */
if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
return EINVAL;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
in6p->in6p_laddr.s6_addr16[5] = htons(0xffff);
if (!IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr))
return EINVAL;
} else
{
if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr))
return EINVAL;
}
/* protect *sin6 from overwrites */
tmp = *sin6;
sin6 = &tmp;
/* Source address selection. */
if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) &&
in6p->in6p_laddr.s6_addr32[3] == 0) {
#ifdef INET
struct sockaddr_in sin, *sinp;
2009-03-18 19:00:08 +03:00
memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(sin);
sin.sin_family = AF_INET;
memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr32[3],
sizeof(sin.sin_addr));
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
sinp = in_selectsrc(&sin, &in6p->in6p_route,
in6p->in6p_socket->so_options, NULL, &error);
if (sinp == 0) {
if (error == 0)
error = EADDRNOTAVAIL;
return (error);
}
2009-03-18 19:00:08 +03:00
memset(&mapped, 0, sizeof(mapped));
mapped.s6_addr16[5] = htons(0xffff);
memcpy(&mapped.s6_addr32[3], &sinp->sin_addr, sizeof(sinp->sin_addr));
in6a = &mapped;
#else
return EADDRNOTAVAIL;
#endif
} else {
/*
* XXX: in6_selectsrc might replace the bound local address
* with the address specified by setsockopt(IPV6_PKTINFO).
* Is it the intended behavior?
*/
in6a = in6_selectsrc(sin6, in6p->in6p_outputopts,
in6p->in6p_moptions,
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
&in6p->in6p_route,
&in6p->in6p_laddr, &ifp, &error);
if (ifp && scope_ambiguous &&
(error = in6_setscope(&sin6->sin6_addr, ifp, NULL)) != 0) {
return(error);
}
if (in6a == 0) {
if (error == 0)
error = EADDRNOTAVAIL;
return (error);
}
}
if (ifp != NULL)
in6p->in6p_ip6.ip6_hlim = (u_int8_t)in6_selecthlim(in6p, ifp);
else
in6p->in6p_ip6.ip6_hlim = (u_int8_t)in6_selecthlim_rt(in6p);
if (in6_pcblookup_connect(in6p->in6p_table, &sin6->sin6_addr,
sin6->sin6_port,
IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) ? in6a : &in6p->in6p_laddr,
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
in6p->in6p_lport, 0, &vestige)
|| vestige.valid)
return (EADDRINUSE);
if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) ||
(IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr) &&
in6p->in6p_laddr.s6_addr32[3] == 0))
{
if (in6p->in6p_lport == 0) {
error = in6_pcbbind(in6p, NULL, l);
if (error != 0)
return error;
}
in6p->in6p_laddr = *in6a;
}
in6p->in6p_faddr = sin6->sin6_addr;
in6p->in6p_fport = sin6->sin6_port;
/* Late bind, if needed */
if (in6p->in6p_bindportonsend) {
struct sockaddr_in6 lsin = *((const struct sockaddr_in6 *)
in6p->in6p_socket->so_proto->pr_domain->dom_sa_any);
lsin.sin6_addr = in6p->in6p_laddr;
lsin.sin6_port = 0;
if ((error = in6_pcbbind_port(in6p, &lsin, l)) != 0)
return error;
}
in6_pcbstate(in6p, IN6P_CONNECTED);
2003-09-06 07:12:51 +04:00
in6p->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
if (ip6_auto_flowlabel)
in6p->in6p_flowinfo |=
(htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
#if defined(IPSEC)
if (ipsec_enabled && in6p->in6p_socket->so_type == SOCK_STREAM)
ipsec_pcbconn(in6p->in6p_sp);
#endif
return (0);
}
void
in6_pcbdisconnect(struct in6pcb *in6p)
{
2009-03-18 19:00:08 +03:00
memset((void *)&in6p->in6p_faddr, 0, sizeof(in6p->in6p_faddr));
in6p->in6p_fport = 0;
in6_pcbstate(in6p, IN6P_BOUND);
2003-09-06 07:12:51 +04:00
in6p->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
#if defined(IPSEC)
if (ipsec_enabled)
ipsec_pcbdisconn(in6p->in6p_sp);
#endif
if (in6p->in6p_socket->so_state & SS_NOFDREF)
in6_pcbdetach(in6p);
}
void
in6_pcbdetach(struct in6pcb *in6p)
{
struct socket *so = in6p->in6p_socket;
int s;
if (in6p->in6p_af != AF_INET6)
return;
#if defined(IPSEC)
if (ipsec_enabled)
ipsec6_delete_pcbpolicy(in6p);
#endif
so->so_pcb = NULL;
s = splnet();
in6_pcbstate(in6p, IN6P_ATTACHED);
LIST_REMOVE(&in6p->in6p_head, inph_lhash);
TAILQ_REMOVE(&in6p->in6p_table->inpt_queue, &in6p->in6p_head,
inph_queue);
splx(s);
if (in6p->in6p_options) {
m_freem(in6p->in6p_options);
}
if (in6p->in6p_outputopts != NULL) {
ip6_clearpktopts(in6p->in6p_outputopts, -1);
free(in6p->in6p_outputopts, M_IP6OPT);
}
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
rtcache_free(&in6p->in6p_route);
ip6_freemoptions(in6p->in6p_moptions);
ip_freemoptions(in6p->in6p_v4moptions);
sofree(so); /* drops the socket's lock */
pool_put(&in6pcb_pool, in6p);
mutex_enter(softnet_lock); /* reacquire it */
}
void
in6_setsockaddr(struct in6pcb *in6p, struct sockaddr_in6 *sin6)
{
if (in6p->in6p_af != AF_INET6)
return;
2007-11-10 03:14:31 +03:00
sockaddr_in6_init(sin6, &in6p->in6p_laddr, in6p->in6p_lport, 0, 0);
(void)sa6_recoverscope(sin6); /* XXX: should catch errors */
}
void
in6_setpeeraddr(struct in6pcb *in6p, struct sockaddr_in6 *sin6)
{
if (in6p->in6p_af != AF_INET6)
return;
2007-11-10 03:14:31 +03:00
sockaddr_in6_init(sin6, &in6p->in6p_faddr, in6p->in6p_fport, 0, 0);
(void)sa6_recoverscope(sin6); /* XXX: should catch errors */
}
/*
* Pass some notification to all connections of a protocol
* associated with address dst. The local address and/or port numbers
* may be specified to limit the search. The "usual action" will be
* taken, depending on the ctlinput cmd. The caller must filter any
* cmds that are uninteresting (e.g., no error in the map).
* Call the protocol specific routine (if any) to report
* any errors for each matching socket.
*
* Must be called at splsoftnet.
*
* Note: src (4th arg) carries the flowlabel value on the original IPv6
* header, in sin6_flowinfo member.
*/
int
in6_pcbnotify(struct inpcbtable *table, const struct sockaddr *dst,
u_int fport_arg, const struct sockaddr *src, u_int lport_arg, int cmd,
void *cmdarg, void (*notify)(struct in6pcb *, int))
{
struct rtentry *rt;
2013-11-23 18:20:21 +04:00
struct inpcb_hdr *inph, *ninph;
struct sockaddr_in6 sa6_src;
const struct sockaddr_in6 *sa6_dst;
u_int16_t fport = fport_arg, lport = lport_arg;
int errno;
int nmatch = 0;
u_int32_t flowinfo;
if ((unsigned)cmd >= PRC_NCMDS || dst->sa_family != AF_INET6)
return 0;
sa6_dst = (const struct sockaddr_in6 *)dst;
if (IN6_IS_ADDR_UNSPECIFIED(&sa6_dst->sin6_addr))
return 0;
/*
* note that src can be NULL when we get notify by local fragmentation.
*/
sa6_src = (src == NULL) ? sa6_any : *(const struct sockaddr_in6 *)src;
flowinfo = sa6_src.sin6_flowinfo;
/*
* Redirects go to all references to the destination,
* and use in6_rtchange to invalidate the route cache.
* Dead host indications: also use in6_rtchange to invalidate
* the cache, and deliver the error to all the sockets.
* Otherwise, if we have knowledge of the local port and address,
* deliver only to that socket.
*/
if (PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) {
fport = 0;
lport = 0;
2009-03-18 19:00:08 +03:00
memset((void *)&sa6_src.sin6_addr, 0, sizeof(sa6_src.sin6_addr));
if (cmd != PRC_HOSTDEAD)
notify = in6_rtchange;
}
errno = inet6ctlerrmap[cmd];
2013-11-23 18:20:21 +04:00
TAILQ_FOREACH_SAFE(inph, &table->inpt_queue, inph_queue, ninph) {
struct in6pcb *in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
/*
* Under the following condition, notify of redirects
* to the pcb, without making address matches against inpcb.
* - redirect notification is arrived.
* - the inpcb is unconnected.
* - the inpcb is caching !RTF_HOST routing entry.
* - the ICMPv6 notification is from the gateway cached in the
* inpcb. i.e. ICMPv6 notification is from nexthop gateway
* the inpcb used very recently.
*
* This is to improve interaction between netbsd/openbsd
* redirect handling code, and inpcb route cache code.
* without the clause, !RTF_HOST routing entry (which carries
* gateway used by inpcb right before the ICMPv6 redirect)
* will be cached forever in unconnected inpcb.
*
* There still is a question regarding to what is TRT:
* - On bsdi/freebsd, RTF_HOST (cloned) routing entry will be
* generated on packet output. inpcb will always cache
* RTF_HOST routing entry so there's no need for the clause
* (ICMPv6 redirect will update RTF_HOST routing entry,
* and inpcb is caching it already).
* However, bsdi/freebsd are vulnerable to local DoS attacks
* due to the cloned routing entries.
* - Specwise, "destination cache" is mentioned in RFC2461.
* Jinmei says that it implies bsdi/freebsd behavior, itojun
* is not really convinced.
* - Having hiwat/lowat on # of cloned host route (redirect/
* pmtud) may be a good idea. netbsd/openbsd has it. see
* icmp6_mtudisc_update().
*/
if ((PRC_IS_REDIRECT(cmd) || cmd == PRC_HOSTDEAD) &&
IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
(rt = rtcache_validate(&in6p->in6p_route)) != NULL &&
!(rt->rt_flags & RTF_HOST)) {
const struct sockaddr_in6 *dst6;
dst6 = (const struct sockaddr_in6 *)
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
rtcache_getdst(&in6p->in6p_route);
if (dst6 == NULL)
;
else if (IN6_ARE_ADDR_EQUAL(&dst6->sin6_addr,
&sa6_dst->sin6_addr))
goto do_notify;
}
/*
* If the error designates a new path MTU for a destination
* and the application (associated with this socket) wanted to
* know the value, notify. Note that we notify for all
* disconnected sockets if the corresponding application
* wanted. This is because some UDP applications keep sending
* sockets disconnected.
* XXX: should we avoid to notify the value to TCP sockets?
*/
if (cmd == PRC_MSGSIZE && (in6p->in6p_flags & IN6P_MTU) != 0 &&
(IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) ||
IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &sa6_dst->sin6_addr))) {
ip6_notify_pmtu(in6p, (const struct sockaddr_in6 *)dst,
(u_int32_t *)cmdarg);
}
/*
* Detect if we should notify the error. If no source and
* destination ports are specified, but non-zero flowinfo and
* local address match, notify the error. This is the case
* when the error is delivered with an encrypted buffer
* by ESP. Otherwise, just compare addresses and ports
* as usual.
*/
if (lport == 0 && fport == 0 && flowinfo &&
in6p->in6p_socket != NULL &&
flowinfo == (in6p->in6p_flowinfo & IPV6_FLOWLABEL_MASK) &&
IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &sa6_src.sin6_addr))
goto do_notify;
else if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr,
&sa6_dst->sin6_addr) ||
in6p->in6p_socket == 0 ||
(lport && in6p->in6p_lport != lport) ||
(!IN6_IS_ADDR_UNSPECIFIED(&sa6_src.sin6_addr) &&
!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
&sa6_src.sin6_addr)) ||
(fport && in6p->in6p_fport != fport))
continue;
do_notify:
if (notify)
(*notify)(in6p, errno);
nmatch++;
}
return nmatch;
}
void
in6_pcbpurgeif0(struct inpcbtable *table, struct ifnet *ifp)
{
2013-11-23 18:20:21 +04:00
struct inpcb_hdr *inph, *ninph;
struct ip6_moptions *im6o;
struct in6_multi_mship *imm, *nimm;
2013-11-23 18:20:21 +04:00
TAILQ_FOREACH_SAFE(inph, &table->inpt_queue, inph_queue, ninph) {
struct in6pcb *in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
im6o = in6p->in6p_moptions;
if (im6o) {
/*
* Unselect the outgoing interface if it is being
* detached.
*/
if (im6o->im6o_multicast_ifp == ifp)
im6o->im6o_multicast_ifp = NULL;
/*
* Drop multicast group membership if we joined
* through the interface being detached.
* XXX controversial - is it really legal for kernel
* to force this?
*/
for (imm = im6o->im6o_memberships.lh_first;
imm != NULL; imm = nimm) {
nimm = imm->i6mm_chain.le_next;
if (imm->i6mm_maddr->in6m_ifp == ifp) {
LIST_REMOVE(imm, i6mm_chain);
2001-12-21 11:54:52 +03:00
in6_leavegroup(imm);
}
}
}
in_purgeifmcast(in6p->in6p_v4moptions, ifp);
}
}
void
in6_pcbpurgeif(struct inpcbtable *table, struct ifnet *ifp)
{
struct rtentry *rt;
2013-11-23 18:20:21 +04:00
struct inpcb_hdr *inph, *ninph;
2013-11-23 18:20:21 +04:00
TAILQ_FOREACH_SAFE(inph, &table->inpt_queue, inph_queue, ninph) {
struct in6pcb *in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
if ((rt = rtcache_validate(&in6p->in6p_route)) != NULL &&
rt->rt_ifp == ifp)
in6_rtchange(in6p, 0);
}
}
/*
* Check for alternatives when higher level complains
* about service problems. For now, invalidate cached
* routing information. If the route was created dynamically
* (by a redirect), time to try a default gateway again.
*/
void
in6_losing(struct in6pcb *in6p)
{
struct rtentry *rt;
struct rt_addrinfo info;
if (in6p->in6p_af != AF_INET6)
return;
if ((rt = rtcache_validate(&in6p->in6p_route)) == NULL)
return;
memset(&info, 0, sizeof(info));
info.rti_info[RTAX_DST] = rtcache_getdst(&in6p->in6p_route);
info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
info.rti_info[RTAX_NETMASK] = rt_mask(rt);
rt_missmsg(RTM_LOSING, &info, rt->rt_flags, 0);
if (rt->rt_flags & RTF_DYNAMIC) {
(void)rtrequest(RTM_DELETE, rt_getkey(rt),
rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
}
/*
* A new route can be allocated
* the next time output is attempted.
*/
rtcache_free(&in6p->in6p_route);
}
/*
Here are various changes designed to protect against bad IPv4 routing caused by stale route caches (struct route). Route caches are sprinkled throughout PCBs, the IP fast-forwarding table, and IP tunnel interfaces (gre, gif, stf). Stale IPv6 and ISO route caches will be treated by separate patches. Thank you to Christoph Badura for suggesting the general approach to invalidating route caches that I take here. Here are the details: Add hooks to struct domain for tracking and for invalidating each domain's route caches: dom_rtcache, dom_rtflush, and dom_rtflushall. Introduce helper subroutines, rtflush(ro) for invalidating a route cache, rtflushall(family) for invalidating all route caches in a routing domain, and rtcache(ro) for notifying the domain of a new cached route. Chain together all IPv4 route caches where ro_rt != NULL. Provide in_rtcache() for adding a route to the chain. Provide in_rtflush() and in_rtflushall() for invalidating IPv4 route caches. In in_rtflush(), set ro_rt to NULL, and remove the route from the chain. In in_rtflushall(), walk the chain and remove every route cache. In rtrequest1(), call rtflushall() to invalidate route caches when a route is added. In gif(4), discard the workaround for stale caches that involves expiring them every so often. Replace the pattern 'RTFREE(ro->ro_rt); ro->ro_rt = NULL;' with a call to rtflush(ro). Update ipflow_fastforward() and all other users of route caches so that they expect a cached route, ro->ro_rt, to turn to NULL. Take care when moving a 'struct route' to rtflush() the source and to rtcache() the destination. In domain initializers, use .dom_xxx tags. KNF here and there.
2006-12-09 08:33:04 +03:00
* After a routing change, flush old routing. A new route can be
* allocated the next time output is attempted.
*/
void
in6_rtchange(struct in6pcb *in6p, int errno)
{
if (in6p->in6p_af != AF_INET6)
return;
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
rtcache_free(&in6p->in6p_route);
/*
* A new route can be allocated the next time
* output is attempted.
*/
}
struct in6pcb *
in6_pcblookup_port(struct inpcbtable *table, struct in6_addr *laddr6,
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
u_int lport_arg, int lookup_wildcard, struct vestigial_inpcb *vp)
{
struct inpcbhead *head;
struct inpcb_hdr *inph;
struct in6pcb *in6p, *match = 0;
int matchwild = 3, wildcard;
u_int16_t lport = lport_arg;
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
if (vp)
vp->valid = 0;
head = IN6PCBHASH_PORT(table, lport);
LIST_FOREACH(inph, head, inph_lhash) {
in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
if (in6p->in6p_lport != lport)
continue;
wildcard = 0;
if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr))
wildcard++;
if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (!IN6_IS_ADDR_V4MAPPED(laddr6))
continue;
/* duplicate of IPv4 logic */
wildcard = 0;
if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr) &&
in6p->in6p_faddr.s6_addr32[3])
wildcard++;
if (!in6p->in6p_laddr.s6_addr32[3]) {
if (laddr6->s6_addr32[3])
wildcard++;
} else {
if (!laddr6->s6_addr32[3])
wildcard++;
else {
if (in6p->in6p_laddr.s6_addr32[3] !=
laddr6->s6_addr32[3])
continue;
}
}
} else if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (!IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
} else {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
}
if (IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
else {
if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr,
laddr6))
continue;
}
}
if (wildcard && !lookup_wildcard)
continue;
if (wildcard < matchwild) {
match = in6p;
matchwild = wildcard;
if (matchwild == 0)
break;
}
}
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
if (match && matchwild == 0)
return match;
if (vp && table->vestige && table->vestige->init_ports6) {
struct vestigial_inpcb better;
void *state;
state = (*table->vestige->init_ports6)(laddr6,
lport_arg,
lookup_wildcard);
while (table->vestige
&& (*table->vestige->next_port6)(state, vp)) {
if (vp->lport != lport)
continue;
wildcard = 0;
if (!IN6_IS_ADDR_UNSPECIFIED(&vp->faddr.v6))
wildcard++;
if (IN6_IS_ADDR_UNSPECIFIED(&vp->laddr.v6)) {
if (!IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
} else {
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
if (vp->v6only)
continue;
}
if (IN6_IS_ADDR_UNSPECIFIED(laddr6))
wildcard++;
else {
if (!IN6_ARE_ADDR_EQUAL(&vp->laddr.v6, laddr6))
continue;
}
}
if (wildcard && !lookup_wildcard)
continue;
if (wildcard < matchwild) {
better = *vp;
match = (void*)&better;
matchwild = wildcard;
if (matchwild == 0)
break;
}
}
if (match) {
if (match != (void*)&better)
return match;
else {
*vp = better;
return 0;
}
}
}
return (match);
}
/*
* WARNING: return value (rtentry) could be IPv4 one if in6pcb is connected to
* IPv4 mapped address.
*/
struct rtentry *
in6_pcbrtentry(struct in6pcb *in6p)
{
struct rtentry *rt;
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
struct route *ro;
union {
const struct sockaddr *sa;
const struct sockaddr_in6 *sa6;
#ifdef INET
const struct sockaddr_in *sa4;
#endif
} cdst;
ro = &in6p->in6p_route;
if (in6p->in6p_af != AF_INET6)
return (NULL);
cdst.sa = rtcache_getdst(ro);
if (cdst.sa == NULL)
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
;
#ifdef INET
else if (cdst.sa->sa_family == AF_INET) {
KASSERT(IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr));
if (cdst.sa4->sin_addr.s_addr != in6p->in6p_faddr.s6_addr32[3])
rtcache_free(ro);
}
#endif
else {
if (!IN6_ARE_ADDR_EQUAL(&cdst.sa6->sin6_addr,
&in6p->in6p_faddr))
rtcache_free(ro);
}
if ((rt = rtcache_validate(ro)) == NULL)
rt = rtcache_update(ro, 1);
#ifdef INET
if (rt == NULL && IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
union {
struct sockaddr dst;
struct sockaddr_in dst4;
} u;
struct in_addr addr;
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
addr.s_addr = in6p->in6p_faddr.s6_addr32[3];
sockaddr_in_init(&u.dst4, &addr, 0);
if (rtcache_setdst(ro, &u.dst) != 0)
return NULL;
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
2008-01-10 11:06:11 +03:00
rt = rtcache_init(ro);
} else
#endif
if (rt == NULL && !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
union {
struct sockaddr dst;
struct sockaddr_in6 dst6;
} u;
sockaddr_in6_init(&u.dst6, &in6p->in6p_faddr, 0, 0, 0);
if (rtcache_setdst(ro, &u.dst) != 0)
return NULL;
Eliminate address family-specific route caches (struct route, struct route_in6, struct route_iso), replacing all caches with a struct route. The principle benefit of this change is that all of the protocol families can benefit from route cache-invalidation, which is necessary for correct routing. Route-cache invalidation fixes an ancient PR, kern/3508, at long last; it fixes various other PRs, also. Discussions with and ideas from Joerg Sonnenberger influenced this work tremendously. Of course, all design oversights and bugs are mine. DETAILS 1 I added to each address family a pool of sockaddrs. I have introduced routines for allocating, copying, and duplicating, and freeing sockaddrs: struct sockaddr *sockaddr_alloc(sa_family_t af, int flags); struct sockaddr *sockaddr_copy(struct sockaddr *dst, const struct sockaddr *src); struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags); void sockaddr_free(struct sockaddr *sa); sockaddr_alloc() returns either a sockaddr from the pool belonging to the specified family, or NULL if the pool is exhausted. The returned sockaddr has the right size for that family; sa_family and sa_len fields are initialized to the family and sockaddr length---e.g., sa_family = AF_INET and sa_len = sizeof(struct sockaddr_in). sockaddr_free() puts the given sockaddr back into its family's pool. sockaddr_dup() and sockaddr_copy() work analogously to strdup() and strcpy(), respectively. sockaddr_copy() KASSERTs that the family of the destination and source sockaddrs are alike. The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is passed directly to pool_get(9). 2 I added routines for initializing sockaddrs in each address family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(), etc. They are fairly self-explanatory. 3 structs route_in6 and route_iso are no more. All protocol families use struct route. I have changed the route cache, 'struct route', so that it does not contain storage space for a sockaddr. Instead, struct route points to a sockaddr coming from the pool the sockaddr belongs to. I added a new method to struct route, rtcache_setdst(), for setting the cache destination: int rtcache_setdst(struct route *, const struct sockaddr *); rtcache_setdst() returns 0 on success, or ENOMEM if no memory is available to create the sockaddr storage. It is now possible for rtcache_getdst() to return NULL if, say, rtcache_setdst() failed. I check the return value for NULL everywhere in the kernel. 4 Each routing domain (struct domain) has a list of live route caches, dom_rtcache. rtflushall(sa_family_t af) looks up the domain indicated by 'af', walks the domain's list of route caches and invalidates each one.
2007-05-03 00:40:22 +04:00
2008-01-10 11:06:11 +03:00
rt = rtcache_init(ro);
}
2008-01-10 11:06:11 +03:00
return rt;
}
struct in6pcb *
in6_pcblookup_connect(struct inpcbtable *table, const struct in6_addr *faddr6,
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
u_int fport_arg, const struct in6_addr *laddr6, u_int lport_arg,
int faith,
struct vestigial_inpcb *vp)
{
struct inpcbhead *head;
struct inpcb_hdr *inph;
struct in6pcb *in6p;
u_int16_t fport = fport_arg, lport = lport_arg;
if (vp)
vp->valid = 0;
head = IN6PCBHASH_CONNECT(table, faddr6, fport, laddr6, lport);
LIST_FOREACH(inph, head, inph_hash) {
in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
/* find exact match on both source and dest */
if (in6p->in6p_fport != fport)
continue;
if (in6p->in6p_lport != lport)
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr))
continue;
if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, faddr6))
continue;
if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
continue;
if (!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, laddr6))
continue;
if ((IN6_IS_ADDR_V4MAPPED(laddr6) ||
IN6_IS_ADDR_V4MAPPED(faddr6)) &&
(in6p->in6p_flags & IN6P_IPV6_V6ONLY))
continue;
return in6p;
}
Reduces the resources demanded by TCP sessions in TIME_WAIT-state using methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime Truncation (MSLT). MSLT and VTW were contributed by Coyote Point Systems, Inc. Even after a TCP session enters the TIME_WAIT state, its corresponding socket and protocol control blocks (PCBs) stick around until the TCP Maximum Segment Lifetime (MSL) expires. On a host whose workload necessarily creates and closes down many TCP sockets, the sockets & PCBs for TCP sessions in TIME_WAIT state amount to many megabytes of dead weight in RAM. Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to a class based on the nearness of the peer. Corresponding to each class is an MSL, and a session uses the MSL of its class. The classes are loopback (local host equals remote host), local (local host and remote host are on the same link/subnet), and remote (local host and remote host communicate via one or more gateways). Classes corresponding to nearer peers have lower MSLs by default: 2 seconds for loopback, 10 seconds for local, 60 seconds for remote. Loopback and local sessions expire more quickly when MSLT is used. Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket dead weight with a compact representation of the session, called a "vestigial PCB". VTW data structures are designed to be very fast and memory-efficient: for fast insertion and lookup of vestigial PCBs, the PCBs are stored in a hash table that is designed to minimize the number of cacheline visits per lookup/insertion. The memory both for vestigial PCBs and for elements of the PCB hashtable come from fixed-size pools, and linked data structures exploit this to conserve memory by representing references with a narrow index/offset from the start of a pool instead of a pointer. When space for new vestigial PCBs runs out, VTW makes room by discarding old vestigial PCBs, oldest first. VTW cooperates with MSLT. It may help to think of VTW as a "FIN cache" by analogy to the SYN cache. A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT sessions as fast as it can is approximately 17% idle when VTW is active versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM when VTW is active (approximately 64k vestigial PCBs are created) than when it is inactive.
2011-05-03 22:28:44 +04:00
if (vp && table->vestige) {
if ((*table->vestige->lookup6)(faddr6, fport_arg,
laddr6, lport_arg, vp))
return 0;
}
return NULL;
}
struct in6pcb *
in6_pcblookup_bind(struct inpcbtable *table, const struct in6_addr *laddr6,
u_int lport_arg, int faith)
{
struct inpcbhead *head;
struct inpcb_hdr *inph;
struct in6pcb *in6p;
u_int16_t lport = lport_arg;
#ifdef INET
struct in6_addr zero_mapped;
#endif
head = IN6PCBHASH_BIND(table, laddr6, lport);
LIST_FOREACH(inph, head, inph_hash) {
in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
if (faith && (in6p->in6p_flags & IN6P_FAITH) == 0)
continue;
if (in6p->in6p_fport != 0)
continue;
if (in6p->in6p_lport != lport)
continue;
if (IN6_IS_ADDR_V4MAPPED(laddr6) &&
(in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, laddr6))
goto out;
}
#ifdef INET
if (IN6_IS_ADDR_V4MAPPED(laddr6)) {
memset(&zero_mapped, 0, sizeof(zero_mapped));
zero_mapped.s6_addr16[5] = 0xffff;
head = IN6PCBHASH_BIND(table, &zero_mapped, lport);
LIST_FOREACH(inph, head, inph_hash) {
in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
if (faith && (in6p->in6p_flags & IN6P_FAITH) == 0)
continue;
if (in6p->in6p_fport != 0)
continue;
if (in6p->in6p_lport != lport)
continue;
if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &zero_mapped))
goto out;
}
}
#endif
head = IN6PCBHASH_BIND(table, &zeroin6_addr, lport);
LIST_FOREACH(inph, head, inph_hash) {
in6p = (struct in6pcb *)inph;
if (in6p->in6p_af != AF_INET6)
continue;
if (faith && (in6p->in6p_flags & IN6P_FAITH) == 0)
continue;
if (in6p->in6p_fport != 0)
continue;
if (in6p->in6p_lport != lport)
continue;
if (IN6_IS_ADDR_V4MAPPED(laddr6) &&
(in6p->in6p_flags & IN6P_IPV6_V6ONLY) != 0)
continue;
if (IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &zeroin6_addr))
goto out;
}
return (NULL);
out:
inph = &in6p->in6p_head;
if (inph != LIST_FIRST(head)) {
LIST_REMOVE(inph, inph_hash);
LIST_INSERT_HEAD(head, inph, inph_hash);
}
return in6p;
}
void
in6_pcbstate(struct in6pcb *in6p, int state)
{
if (in6p->in6p_af != AF_INET6)
return;
if (in6p->in6p_state > IN6P_ATTACHED)
LIST_REMOVE(&in6p->in6p_head, inph_hash);
switch (state) {
case IN6P_BOUND:
LIST_INSERT_HEAD(IN6PCBHASH_BIND(in6p->in6p_table,
&in6p->in6p_laddr, in6p->in6p_lport), &in6p->in6p_head,
inph_hash);
break;
case IN6P_CONNECTED:
LIST_INSERT_HEAD(IN6PCBHASH_CONNECT(in6p->in6p_table,
&in6p->in6p_faddr, in6p->in6p_fport,
&in6p->in6p_laddr, in6p->in6p_lport), &in6p->in6p_head,
inph_hash);
break;
}
in6p->in6p_state = state;
}