NetBSD/sys/net/if_loop.c

511 lines
12 KiB
C

/* $NetBSD: if_loop.c,v 1.118 2022/09/04 23:34:51 thorpej Exp $ */
/*
* 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, 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.
*
* @(#)if_loop.c 8.2 (Berkeley) 1/9/95
*/
/*
* Loopback interface driver for protocol testing and timing.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.118 2022/09/04 23:34:51 thorpej Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
#include "opt_atalk.h"
#include "opt_mbuftrace.h"
#include "opt_mpls.h"
#include "opt_net_mpsafe.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/device.h>
#include <sys/module.h>
#include <sys/cpu.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/in_offload.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#endif
#ifdef INET6
#ifndef INET
#include <netinet/in.h>
#endif
#include <netinet6/in6_var.h>
#include <netinet6/in6_offload.h>
#include <netinet/ip6.h>
#endif
#ifdef MPLS
#include <netmpls/mpls.h>
#include <netmpls/mpls_var.h>
#endif
#ifdef NETATALK
#include <netatalk/at.h>
#include <netatalk/at_var.h>
#endif
#include <net/bpf.h>
#if defined(LARGE_LOMTU)
#define LOMTU (131072 + MHLEN + MLEN)
#define LOMTU_MAX LOMTU
#else
#define LOMTU (32768 + MHLEN + MLEN)
#define LOMTU_MAX (65536 + MHLEN + MLEN)
#endif
#ifdef ALTQ
static void lostart(struct ifnet *);
#endif
static int loop_clone_create(struct if_clone *, int);
static int loop_clone_destroy(struct ifnet *);
static void loop_rtrequest(int, struct rtentry *, const struct rt_addrinfo *);
static struct if_clone loop_cloner =
IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
void
loopattach(int n)
{
#ifndef _MODULE
loop_clone_create(&loop_cloner, 0); /* lo0 always exists */
#endif
}
void
loopinit(void)
{
if (lo0ifp != NULL) /* can happen in rump kernel */
return;
#ifdef _MODULE
loop_clone_create(&loop_cloner, 0); /* lo0 always exists */
#endif
if_clone_attach(&loop_cloner);
}
static int
loopdetach(void)
{
/* no detach for now; we don't allow lo0 to be deleted */
return EBUSY;
}
static int
loop_clone_create(struct if_clone *ifc, int unit)
{
struct ifnet *ifp;
ifp = if_alloc(IFT_LOOP);
if_initname(ifp, ifc->ifc_name, unit);
ifp->if_mtu = LOMTU;
ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
#ifdef NET_MPSAFE
ifp->if_extflags = IFEF_MPSAFE;
#endif
ifp->if_ioctl = loioctl;
ifp->if_output = looutput;
#ifdef ALTQ
ifp->if_start = lostart;
#endif
ifp->if_type = IFT_LOOP;
ifp->if_hdrlen = 0;
ifp->if_addrlen = 0;
ifp->if_dlt = DLT_NULL;
IFQ_SET_READY(&ifp->if_snd);
if (unit == 0)
lo0ifp = ifp;
if_initialize(ifp);
ifp->if_link_state = LINK_STATE_UP;
if_alloc_sadl(ifp);
bpf_attach(ifp, DLT_NULL, sizeof(u_int));
#ifdef MBUFTRACE
ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
M_WAITOK | M_ZERO);
strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
sizeof(ifp->if_mowner->mo_name));
MOWNER_ATTACH(ifp->if_mowner);
#endif
ifp->if_flags |= IFF_RUNNING;
if_register(ifp);
return (0);
}
static int
loop_clone_destroy(struct ifnet *ifp)
{
if (ifp == lo0ifp)
return (EPERM);
ifp->if_flags &= ~IFF_RUNNING;
#ifdef MBUFTRACE
MOWNER_DETACH(ifp->if_mowner);
free(ifp->if_mowner, M_DEVBUF);
#endif
bpf_detach(ifp);
if_detach(ifp);
if_free(ifp);
return (0);
}
int
looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
const struct rtentry *rt)
{
pktqueue_t *pktq = NULL;
int s;
int csum_flags;
int error = 0;
size_t pktlen;
MCLAIM(m, ifp->if_mowner);
KERNEL_LOCK_UNLESS_NET_MPSAFE();
if ((m->m_flags & M_PKTHDR) == 0)
panic("looutput: no header mbuf");
if (ifp->if_flags & IFF_LOOPBACK)
bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
m_set_rcvif(m, ifp);
if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
m_freem(m);
error = (rt->rt_flags & RTF_BLACKHOLE ? 0 :
rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
goto out;
}
pktlen = m->m_pkthdr.len;
if_statadd2(ifp, if_opackets, 1, if_obytes, pktlen);
#ifdef ALTQ
/*
* ALTQ on the loopback interface is just for debugging. It's
* used only for loopback interfaces, not for a simplex interface.
*/
if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
ifp->if_start == lostart) {
/*
* If the queueing discipline needs packet classification,
* do it before prepending the link headers.
*/
IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
if (m == NULL) {
if_statinc(ifp, if_oerrors);
error = ENOBUFS;
goto out;
}
*(mtod(m, uint32_t *)) = dst->sa_family;
error = if_transmit_lock(ifp, m);
goto out;
}
#endif /* ALTQ */
m_tag_delete_chain(m);
#ifdef MPLS
bool is_mpls = false;
if (rt != NULL && rt_gettag(rt) != NULL &&
rt_gettag(rt)->sa_family == AF_MPLS &&
(m->m_flags & (M_MCAST | M_BCAST)) == 0) {
union mpls_shim msh;
msh.s_addr = MPLS_GETSADDR(rt);
if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
is_mpls = true;
pktq = mpls_pktq;
}
}
if (!is_mpls)
#endif
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
csum_flags = m->m_pkthdr.csum_flags;
KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
in_undefer_cksum(m, 0, csum_flags);
m->m_pkthdr.csum_flags = 0;
} else {
/*
* Do nothing. Pass M_CSUM_IPv4 and M_CSUM_UDPv4 as
* they are to tell those are calculated and good.
*/
}
pktq = ip_pktq;
break;
#endif
#ifdef INET6
case AF_INET6:
csum_flags = m->m_pkthdr.csum_flags;
KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
if (csum_flags != 0 &&
IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
in6_undefer_cksum(m, 0, csum_flags);
m->m_pkthdr.csum_flags = 0;
} else {
/*
* Do nothing. Pass M_CSUM_UDPv6 as
* they are to tell those are calculated and good.
*/
}
m->m_flags |= M_LOOP;
pktq = ip6_pktq;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
pktq = at_pktq2;
break;
#endif
default:
printf("%s: can't handle af%d\n", ifp->if_xname,
dst->sa_family);
m_freem(m);
error = EAFNOSUPPORT;
goto out;
}
KASSERT(pktq != NULL);
error = 0;
s = splnet();
if (__predict_true(pktq_enqueue(pktq, m, 0))) {
if_statadd2(ifp, if_ipackets, 1, if_ibytes, pktlen);
} else {
m_freem(m);
if_statinc(ifp, if_oerrors);
error = ENOBUFS;
}
splx(s);
out:
KERNEL_UNLOCK_UNLESS_NET_MPSAFE();
return error;
}
#ifdef ALTQ
static void
lostart(struct ifnet *ifp)
{
for (;;) {
pktqueue_t *pktq = NULL;
struct mbuf *m;
size_t pktlen;
uint32_t af;
int s;
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == NULL)
return;
af = *(mtod(m, uint32_t *));
m_adj(m, sizeof(uint32_t));
switch (af) {
#ifdef INET
case AF_INET:
pktq = ip_pktq;
break;
#endif
#ifdef INET6
case AF_INET6:
m->m_flags |= M_LOOP;
pktq = ip6_pktq;
break;
#endif
#ifdef NETATALK
case AF_APPLETALK:
pktq = at_pktq2;
break;
#endif
default:
printf("%s: can't handle af%d\n", ifp->if_xname, af);
m_freem(m);
return;
}
pktlen = m->m_pkthdr.len;
KASSERT(pktq != NULL);
s = splnet();
if (__predict_false(pktq_enqueue(pktq, m, 0))) {
m_freem(m);
splx(s);
return;
}
if_statadd2(ifp, if_ipackets, 1, if_ibytes, pktlen);
splx(s);
}
}
#endif /* ALTQ */
/* ARGSUSED */
static void
loop_rtrequest(int cmd, struct rtentry *rt,
const struct rt_addrinfo *info)
{
if (rt)
rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
}
/*
* Process an ioctl request.
*/
/* ARGSUSED */
int
loioctl(struct ifnet *ifp, u_long cmd, void *data)
{
struct ifaddr *ifa;
struct ifreq *ifr = data;
int error = 0;
switch (cmd) {
case SIOCINITIFADDR:
ifp->if_flags |= IFF_UP;
ifa = (struct ifaddr *)data;
if (ifa != NULL)
ifa->ifa_rtrequest = loop_rtrequest;
/*
* Everything else is done at a higher level.
*/
break;
case SIOCSIFMTU:
if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
error = EINVAL;
else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){
error = 0;
}
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
if (ifr == NULL) {
error = EAFNOSUPPORT; /* XXX */
break;
}
switch (ifreq_getaddr(cmd, ifr)->sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
#ifdef INET6
case AF_INET6:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
default:
error = ifioctl_common(ifp, cmd, data);
}
return (error);
}
/*
* Module infrastructure
*/
#include "if_module.h"
IF_MODULE(MODULE_CLASS_DRIVER, loop, NULL)