2013-04-06 16:48:33 +02:00

404 lines
8.9 KiB
C

/* $NetBSD: if_virt.c,v 1.27 2012/09/14 16:29:22 pooka Exp $ */
/*
* Copyright (c) 2008 Antti Kantee. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.27 2012/09/14 16:29:22 pooka Exp $");
#include <sys/param.h>
#include <sys/condvar.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kmem.h>
#include <sys/kthread.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/sockio.h>
#include <sys/socketvar.h>
#include <sys/cprng.h>
#include <net/bpf.h>
#include <net/if.h>
#include <net/if_ether.h>
#include <net/if_tap.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <rump/rump.h>
#include <rump/rumpuser.h>
#include "rump_private.h"
#include "rump_net_private.h"
/*
* Virtual interface for userspace purposes. Uses tap(4) to
* interface with the kernel and just simply shovels data
* to/from /dev/tap.
*/
#define VIRTIF_BASE "virt"
static int virtif_init(struct ifnet *);
static int virtif_ioctl(struct ifnet *, u_long, void *);
static void virtif_start(struct ifnet *);
static void virtif_stop(struct ifnet *, int);
struct virtif_sc {
struct ethercom sc_ec;
int sc_tapfd;
bool sc_dying;
struct lwp *sc_l_snd, *sc_l_rcv;
kmutex_t sc_mtx;
kcondvar_t sc_cv;
};
static void virtif_receiver(void *);
static void virtif_sender(void *);
static int virtif_clone(struct if_clone *, int);
static int virtif_unclone(struct ifnet *);
struct if_clone virtif_cloner =
IF_CLONE_INITIALIZER(VIRTIF_BASE, virtif_clone, virtif_unclone);
int
rump_virtif_create(int num)
{
struct virtif_sc *sc;
struct ifnet *ifp;
uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 };
char tapdev[16];
int fd, error = 0;
if (num >= 0x100)
return E2BIG;
snprintf(tapdev, sizeof(tapdev), "/dev/tap%d", num);
fd = rumpuser_open(tapdev, RUMPUSER_OPEN_RDWR, &error);
if (fd == -1) {
printf("virtif_create: can't open /dev/tap%d: %d\n",
num, error);
return error;
}
enaddr[2] = cprng_fast32() & 0xff;
enaddr[5] = num;
sc = kmem_zalloc(sizeof(*sc), KM_SLEEP);
sc->sc_dying = false;
sc->sc_tapfd = fd;
mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE);
cv_init(&sc->sc_cv, "virtsnd");
ifp = &sc->sc_ec.ec_if;
sprintf(ifp->if_xname, "%s%d", VIRTIF_BASE, num);
ifp->if_softc = sc;
if (rump_threads) {
if ((error = kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
virtif_receiver, ifp, &sc->sc_l_rcv, "virtifr")) != 0)
goto out;
if ((error = kthread_create(PRI_NONE,
KTHREAD_MUSTJOIN | KTHREAD_MPSAFE, NULL,
virtif_sender, ifp, &sc->sc_l_snd, "virtifs")) != 0)
goto out;
} else {
printf("WARNING: threads not enabled, receive NOT working\n");
}
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_init = virtif_init;
ifp->if_ioctl = virtif_ioctl;
ifp->if_start = virtif_start;
ifp->if_stop = virtif_stop;
IFQ_SET_READY(&ifp->if_snd);
if_attach(ifp);
ether_ifattach(ifp, enaddr);
out:
if (error) {
virtif_unclone(ifp);
}
return error;
}
static int
virtif_clone(struct if_clone *ifc, int unit)
{
return rump_virtif_create(unit);
}
static int
virtif_unclone(struct ifnet *ifp)
{
struct virtif_sc *sc = ifp->if_softc;
mutex_enter(&sc->sc_mtx);
if (sc->sc_dying) {
mutex_exit(&sc->sc_mtx);
return EINPROGRESS;
}
sc->sc_dying = true;
cv_broadcast(&sc->sc_cv);
mutex_exit(&sc->sc_mtx);
virtif_stop(ifp, 1);
if_down(ifp);
if (sc->sc_l_snd) {
kthread_join(sc->sc_l_snd);
sc->sc_l_snd = NULL;
}
if (sc->sc_l_rcv) {
kthread_join(sc->sc_l_rcv);
sc->sc_l_rcv = NULL;
}
rumpuser_close(sc->sc_tapfd, NULL);
mutex_destroy(&sc->sc_mtx);
cv_destroy(&sc->sc_cv);
kmem_free(sc, sizeof(*sc));
ether_ifdetach(ifp);
if_detach(ifp);
return 0;
}
static int
virtif_init(struct ifnet *ifp)
{
struct virtif_sc *sc = ifp->if_softc;
ifp->if_flags |= IFF_RUNNING;
mutex_enter(&sc->sc_mtx);
cv_broadcast(&sc->sc_cv);
mutex_exit(&sc->sc_mtx);
return 0;
}
static int
virtif_ioctl(struct ifnet *ifp, u_long cmd, void *data)
{
int s, rv;
s = splnet();
rv = ether_ioctl(ifp, cmd, data);
if (rv == ENETRESET)
rv = 0;
splx(s);
return rv;
}
/* just send everything in-context */
static void
virtif_start(struct ifnet *ifp)
{
struct virtif_sc *sc = ifp->if_softc;
mutex_enter(&sc->sc_mtx);
ifp->if_flags |= IFF_OACTIVE;
cv_broadcast(&sc->sc_cv);
mutex_exit(&sc->sc_mtx);
}
static void
virtif_stop(struct ifnet *ifp, int disable)
{
struct virtif_sc *sc = ifp->if_softc;
ifp->if_flags &= ~IFF_RUNNING;
mutex_enter(&sc->sc_mtx);
cv_broadcast(&sc->sc_cv);
mutex_exit(&sc->sc_mtx);
}
#define POLLTIMO_MS 1
static void
virtif_receiver(void *arg)
{
struct ifnet *ifp = arg;
struct virtif_sc *sc = ifp->if_softc;
struct mbuf *m;
size_t plen = ETHER_MAX_LEN_JUMBO+1;
struct pollfd pfd;
ssize_t n;
int error, rv;
pfd.fd = sc->sc_tapfd;
pfd.events = POLLIN;
for (;;) {
m = m_gethdr(M_WAIT, MT_DATA);
MEXTMALLOC(m, plen, M_WAIT);
again:
/* poll, but periodically check if we should die */
rv = rumpuser_poll(&pfd, 1, POLLTIMO_MS, &error);
if (sc->sc_dying) {
m_freem(m);
break;
}
if (rv == 0)
goto again;
n = rumpuser_read(sc->sc_tapfd, mtod(m, void *), plen, &error);
KASSERT(n < ETHER_MAX_LEN_JUMBO);
if (__predict_false(n < 0)) {
if (n == -1 && error == EAGAIN) {
goto again;
}
printf("%s: read from /dev/tap failed. host is down?\n",
ifp->if_xname);
mutex_enter(&sc->sc_mtx);
/* could check if need go, done soon anyway */
cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz);
mutex_exit(&sc->sc_mtx);
goto again;
}
/* tap sometimes returns EOF. don't sweat it and plow on */
if (__predict_false(n == 0))
goto again;
/* discard if we're not up */
if ((ifp->if_flags & IFF_RUNNING) == 0)
goto again;
m->m_len = m->m_pkthdr.len = n;
m->m_pkthdr.rcvif = ifp;
bpf_mtap(ifp, m);
ether_input(ifp, m);
}
kthread_exit(0);
}
/* lazy bum stetson-harrison magic value */
#define LB_SH 32
static void
virtif_sender(void *arg)
{
struct ifnet *ifp = arg;
struct virtif_sc *sc = ifp->if_softc;
struct mbuf *m, *m0;
struct rumpuser_iovec io[LB_SH];
int i, error;
mutex_enter(&sc->sc_mtx);
KERNEL_LOCK(1, NULL);
while (!sc->sc_dying) {
if (!(ifp->if_flags & IFF_RUNNING)) {
cv_wait(&sc->sc_cv, &sc->sc_mtx);
continue;
}
IF_DEQUEUE(&ifp->if_snd, m0);
if (!m0) {
ifp->if_flags &= ~IFF_OACTIVE;
cv_wait(&sc->sc_cv, &sc->sc_mtx);
continue;
}
mutex_exit(&sc->sc_mtx);
m = m0;
for (i = 0; i < LB_SH && m; i++) {
io[i].iov_base = mtod(m, void *);
io[i].iov_len = m->m_len;
m = m->m_next;
}
if (i == LB_SH)
panic("lazy bum");
bpf_mtap(ifp, m0);
KERNEL_UNLOCK_LAST(curlwp);
rumpuser_writev(sc->sc_tapfd, io, i, &error);
KERNEL_LOCK(1, NULL);
m_freem(m0);
mutex_enter(&sc->sc_mtx);
}
KERNEL_UNLOCK_LAST(curlwp);
mutex_exit(&sc->sc_mtx);
kthread_exit(0);
}
/*
* dummyif is a nada-interface.
* As it requires nothing external, it can be used for testing
* interface configuration.
*/
static int dummyif_init(struct ifnet *);
static void dummyif_start(struct ifnet *);
void
rump_dummyif_create()
{
struct ifnet *ifp;
struct ethercom *ec;
uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 };
enaddr[2] = cprng_fast32() & 0xff;
enaddr[5] = cprng_fast32() & 0xff;
ec = kmem_zalloc(sizeof(*ec), KM_SLEEP);
ifp = &ec->ec_if;
strlcpy(ifp->if_xname, "dummy0", sizeof(ifp->if_xname));
ifp->if_softc = ifp;
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_init = dummyif_init;
ifp->if_ioctl = virtif_ioctl;
ifp->if_start = dummyif_start;
if_attach(ifp);
ether_ifattach(ifp, enaddr);
}
static int
dummyif_init(struct ifnet *ifp)
{
ifp->if_flags |= IFF_RUNNING;
return 0;
}
static void
dummyif_start(struct ifnet *ifp)
{
}