freebsd-skq/sys/net/if_loop.c
Andre Oppermann 97d8d152c2 Introduce tcp_hostcache and remove the tcp specific metrics from
the routing table.  Move all usage and references in the tcp stack
from the routing table metrics to the tcp hostcache.

It caches measured parameters of past tcp sessions to provide better
initial start values for following connections from or to the same
source or destination.  Depending on the network parameters to/from
the remote host this can lead to significant speedups for new tcp
connections after the first one because they inherit and shortcut
the learning curve.

tcp_hostcache is designed for multiple concurrent access in SMP
environments with high contention and is hash indexed by remote
ip address.

It removes significant locking requirements from the tcp stack with
regard to the routing table.

Reviewed by:	sam (mentor), bms
Reviewed by:	-net, -current, core@kame.net (IPv6 parts)
Approved by:	re (scottl)
2003-11-20 20:07:39 +00:00

396 lines
8.9 KiB
C

/*
* Copyright (c) 1982, 1986, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*
* @(#)if_loop.c 8.2 (Berkeley) 1/9/95
* $FreeBSD$
*/
/*
* Loopback interface driver for protocol testing and timing.
*/
#include "opt_atalk.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipx.h"
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#endif
#ifdef IPX
#include <netipx/ipx.h>
#include <netipx/ipx_if.h>
#endif
#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#endif
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#endif
#ifdef TINY_LOMTU
#define LOMTU (1024+512)
#elif defined(LARGE_LOMTU)
#define LOMTU 131072
#else
#define LOMTU 16384
#endif
#define LONAME "lo"
struct lo_softc {
struct ifnet sc_if; /* network-visible interface */
LIST_ENTRY(lo_softc) sc_next;
};
int loioctl(struct ifnet *, u_long, caddr_t);
static void lortrequest(int, struct rtentry *, struct rt_addrinfo *);
int looutput(struct ifnet *ifp, struct mbuf *m,
struct sockaddr *dst, struct rtentry *rt);
int lo_clone_create(struct if_clone *, int);
void lo_clone_destroy(struct ifnet *);
struct ifnet *loif = NULL; /* Used externally */
static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface");
static LIST_HEAD(lo_list, lo_softc) lo_list;
struct if_clone lo_cloner = IF_CLONE_INITIALIZER(LONAME,
lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT);
void
lo_clone_destroy(ifp)
struct ifnet *ifp;
{
struct lo_softc *sc;
sc = ifp->if_softc;
/* XXX: destroying lo0 will lead to panics. */
KASSERT(loif != ifp, ("%s: destroying lo0", __func__));
bpfdetach(ifp);
if_detach(ifp);
LIST_REMOVE(sc, sc_next);
free(sc, M_LO);
}
int
lo_clone_create(ifc, unit)
struct if_clone *ifc;
int unit;
{
struct lo_softc *sc;
MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO);
if_initname(&sc->sc_if, ifc->ifc_name, unit);
sc->sc_if.if_mtu = LOMTU;
sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST;
sc->sc_if.if_ioctl = loioctl;
sc->sc_if.if_output = looutput;
sc->sc_if.if_type = IFT_LOOP;
sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen;
sc->sc_if.if_softc = sc;
if_attach(&sc->sc_if);
bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int));
LIST_INSERT_HEAD(&lo_list, sc, sc_next);
if (loif == NULL)
loif = &sc->sc_if;
return (0);
}
static int
loop_modevent(module_t mod, int type, void *data)
{
switch (type) {
case MOD_LOAD:
LIST_INIT(&lo_list);
if_clone_attach(&lo_cloner);
break;
case MOD_UNLOAD:
printf("loop module unload - not possible for this module type\n");
return EINVAL;
}
return 0;
}
static moduledata_t loop_mod = {
"loop",
loop_modevent,
0
};
DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
int
looutput(ifp, m, dst, rt)
struct ifnet *ifp;
register struct mbuf *m;
struct sockaddr *dst;
register struct rtentry *rt;
{
M_ASSERTPKTHDR(m); /* check if we have the packet header */
if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
m_freem(m);
return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
}
ifp->if_opackets++;
ifp->if_obytes += m->m_pkthdr.len;
#if 1 /* XXX */
switch (dst->sa_family) {
case AF_INET:
case AF_INET6:
case AF_IPX:
case AF_APPLETALK:
break;
default:
printf("looutput: af=%d unexpected\n", dst->sa_family);
m_freem(m);
return (EAFNOSUPPORT);
}
#endif
return(if_simloop(ifp, m, dst->sa_family, 0));
}
/*
* if_simloop()
*
* This function is to support software emulation of hardware loopback,
* i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
* hear their own broadcasts, we create a copy of the packet that we
* would normally receive via a hardware loopback.
*
* This function expects the packet to include the media header of length hlen.
*/
int
if_simloop(ifp, m, af, hlen)
struct ifnet *ifp;
struct mbuf *m;
int af;
int hlen;
{
int isr;
M_ASSERTPKTHDR(m);
m_tag_delete_nonpersistent(m);
m->m_pkthdr.rcvif = ifp;
/* BPF write needs to be handled specially */
if (af == AF_UNSPEC) {
KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len"));
af = *(mtod(m, int *));
m->m_len -= sizeof(int);
m->m_pkthdr.len -= sizeof(int);
m->m_data += sizeof(int);
}
/* Let BPF see incoming packet */
if (ifp->if_bpf) {
struct mbuf m0, *n = m;
if (ifp->if_bpf->bif_dlt == DLT_NULL) {
/*
* We need to prepend the address family as
* a four byte field. Cons up a dummy header
* to pacify bpf. This is safe because bpf
* will only read from the mbuf (i.e., it won't
* try to free it or keep a pointer a to it).
*/
m0.m_next = m;
m0.m_len = 4;
m0.m_data = (char *)&af;
n = &m0;
}
BPF_MTAP(ifp, n);
}
/* Strip away media header */
if (hlen > 0) {
m_adj(m, hlen);
#if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__)
/* The alpha doesn't like unaligned data.
* We move data down in the first mbuf */
if (mtod(m, vm_offset_t) & 3) {
KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
bcopy(m->m_data,
(char *)(mtod(m, vm_offset_t)
- (mtod(m, vm_offset_t) & 3)),
m->m_len);
mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3);
}
#endif
}
/* Deliver to upper layer protocol */
switch (af) {
#ifdef INET
case AF_INET:
isr = NETISR_IP;
break;
#endif
#ifdef INET6
case AF_INET6:
m->m_flags |= M_LOOP;
isr = NETISR_IPV6;
break;
#endif
#ifdef IPX
case AF_IPX:
isr = NETISR_IPX;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
isr = NETISR_ATALK2;
break;
#endif
default:
printf("if_simloop: can't handle af=%d\n", af);
m_freem(m);
return (EAFNOSUPPORT);
}
ifp->if_ipackets++;
ifp->if_ibytes += m->m_pkthdr.len;
netisr_queue(isr, m);
return (0);
}
/* ARGSUSED */
static void
lortrequest(cmd, rt, info)
int cmd;
struct rtentry *rt;
struct rt_addrinfo *info;
{
RT_LOCK_ASSERT(rt);
if (rt)
rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
}
/*
* Process an ioctl request.
*/
/* ARGSUSED */
int
loioctl(ifp, cmd, data)
register struct ifnet *ifp;
u_long cmd;
caddr_t data;
{
register struct ifaddr *ifa;
register struct ifreq *ifr = (struct ifreq *)data;
register int error = 0;
switch (cmd) {
case SIOCSIFADDR:
ifp->if_flags |= IFF_UP | IFF_RUNNING;
ifa = (struct ifaddr *)data;
ifa->ifa_rtrequest = lortrequest;
/*
* Everything else is done at a higher level.
*/
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if (ifr == 0) {
error = EAFNOSUPPORT; /* XXX */
break;
}
switch (ifr->ifr_addr.sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
#ifdef INET6
case AF_INET6:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
case SIOCSIFMTU:
ifp->if_mtu = ifr->ifr_mtu;
break;
case SIOCSIFFLAGS:
break;
default:
error = EINVAL;
}
return (error);
}