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tag: 20121227
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/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2009 Red Hat, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "net/tap.h"
#include "config-host.h"
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <net/if.h>
#include "net.h"
#include "sysemu.h"
#include "qemu-char.h"
#include "qemu-common.h"
#include "qemu-error.h"
#include "net/tap-linux.h"
#include "hw/vhost_net.h"
/* Maximum GSO packet size (64k) plus plenty of room for
* the ethernet and virtio_net headers
*/
#define TAP_BUFSIZE (4096 + 65536)
typedef struct TAPState {
VLANClientState nc;
int fd;
char down_script[1024];
char down_script_arg[128];
uint8_t buf[TAP_BUFSIZE];
unsigned int read_poll : 1;
unsigned int write_poll : 1;
unsigned int using_vnet_hdr : 1;
unsigned int has_ufo: 1;
VHostNetState *vhost_net;
unsigned host_vnet_hdr_len;
} TAPState;
static int launch_script(const char *setup_script, const char *ifname, int fd);
static int tap_can_send(void *opaque);
static void tap_send(void *opaque);
static void tap_writable(void *opaque);
static void tap_update_fd_handler(TAPState *s)
{
qemu_set_fd_handler2(s->fd,
s->read_poll ? tap_can_send : NULL,
s->read_poll ? tap_send : NULL,
s->write_poll ? tap_writable : NULL,
s);
}
static void tap_read_poll(TAPState *s, int enable)
{
s->read_poll = !!enable;
tap_update_fd_handler(s);
}
static void tap_write_poll(TAPState *s, int enable)
{
s->write_poll = !!enable;
tap_update_fd_handler(s);
}
static void tap_writable(void *opaque)
{
TAPState *s = opaque;
tap_write_poll(s, 0);
qemu_flush_queued_packets(&s->nc);
}
static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt)
{
ssize_t len;
do {
len = writev(s->fd, iov, iovcnt);
} while (len == -1 && errno == EINTR);
if (len == -1 && errno == EAGAIN) {
tap_write_poll(s, 1);
return 0;
}
return len;
}
static ssize_t tap_receive_iov(VLANClientState *nc, const struct iovec *iov,
int iovcnt)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
const struct iovec *iovp = iov;
struct iovec iov_copy[iovcnt + 1];
struct virtio_net_hdr_mrg_rxbuf hdr = { };
if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
iov_copy[0].iov_base = &hdr;
iov_copy[0].iov_len = s->host_vnet_hdr_len;
memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov));
iovp = iov_copy;
iovcnt++;
}
return tap_write_packet(s, iovp, iovcnt);
}
static ssize_t tap_receive_raw(VLANClientState *nc, const uint8_t *buf, size_t size)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
struct iovec iov[2];
int iovcnt = 0;
struct virtio_net_hdr_mrg_rxbuf hdr = { };
if (s->host_vnet_hdr_len) {
iov[iovcnt].iov_base = &hdr;
iov[iovcnt].iov_len = s->host_vnet_hdr_len;
iovcnt++;
}
iov[iovcnt].iov_base = (char *)buf;
iov[iovcnt].iov_len = size;
iovcnt++;
return tap_write_packet(s, iov, iovcnt);
}
static ssize_t tap_receive(VLANClientState *nc, const uint8_t *buf, size_t size)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
struct iovec iov[1];
if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
return tap_receive_raw(nc, buf, size);
}
iov[0].iov_base = (char *)buf;
iov[0].iov_len = size;
return tap_write_packet(s, iov, 1);
}
static int tap_can_send(void *opaque)
{
TAPState *s = opaque;
return qemu_can_send_packet(&s->nc);
}
#ifndef __sun__
ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)
{
return read(tapfd, buf, maxlen);
}
#endif
static void tap_send_completed(VLANClientState *nc, ssize_t len)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
tap_read_poll(s, 1);
}
static void tap_send(void *opaque)
{
TAPState *s = opaque;
int size;
do {
uint8_t *buf = s->buf;
size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
if (size <= 0) {
break;
}
if (s->host_vnet_hdr_len && !s->using_vnet_hdr) {
buf += s->host_vnet_hdr_len;
size -= s->host_vnet_hdr_len;
}
size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed);
if (size == 0) {
tap_read_poll(s, 0);
}
} while (size > 0 && qemu_can_send_packet(&s->nc));
}
int tap_has_ufo(VLANClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
return s->has_ufo;
}
int tap_has_vnet_hdr(VLANClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
return !!s->host_vnet_hdr_len;
}
int tap_has_vnet_hdr_len(VLANClientState *nc, int len)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
return tap_probe_vnet_hdr_len(s->fd, len);
}
void tap_set_vnet_hdr_len(VLANClientState *nc, int len)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) ||
len == sizeof(struct virtio_net_hdr));
tap_fd_set_vnet_hdr_len(s->fd, len);
s->host_vnet_hdr_len = len;
}
void tap_using_vnet_hdr(VLANClientState *nc, int using_vnet_hdr)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
using_vnet_hdr = using_vnet_hdr != 0;
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
s->using_vnet_hdr = using_vnet_hdr;
}
void tap_set_offload(VLANClientState *nc, int csum, int tso4,
int tso6, int ecn, int ufo)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
if (s->fd < 0) {
return;
}
tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo);
}
static void tap_cleanup(VLANClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
if (s->vhost_net) {
vhost_net_cleanup(s->vhost_net);
s->vhost_net = NULL;
}
qemu_purge_queued_packets(nc);
if (s->down_script[0])
launch_script(s->down_script, s->down_script_arg, s->fd);
tap_read_poll(s, 0);
tap_write_poll(s, 0);
close(s->fd);
s->fd = -1;
}
static void tap_poll(VLANClientState *nc, bool enable)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
tap_read_poll(s, enable);
tap_write_poll(s, enable);
}
int tap_get_fd(VLANClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
return s->fd;
}
/* fd support */
static NetClientInfo net_tap_info = {
.type = NET_CLIENT_TYPE_TAP,
.size = sizeof(TAPState),
.receive = tap_receive,
.receive_raw = tap_receive_raw,
.receive_iov = tap_receive_iov,
.poll = tap_poll,
.cleanup = tap_cleanup,
};
static TAPState *net_tap_fd_init(VLANState *vlan,
const char *model,
const char *name,
int fd,
int vnet_hdr)
{
VLANClientState *nc;
TAPState *s;
nc = qemu_new_net_client(&net_tap_info, vlan, NULL, model, name);
s = DO_UPCAST(TAPState, nc, nc);
s->fd = fd;
s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0;
s->using_vnet_hdr = 0;
s->has_ufo = tap_probe_has_ufo(s->fd);
tap_set_offload(&s->nc, 0, 0, 0, 0, 0);
tap_read_poll(s, 1);
s->vhost_net = NULL;
return s;
}
static int launch_script(const char *setup_script, const char *ifname, int fd)
{
sigset_t oldmask, mask;
int pid, status;
char *args[3];
char **parg;
sigemptyset(&mask);
sigaddset(&mask, SIGCHLD);
sigprocmask(SIG_BLOCK, &mask, &oldmask);
/* try to launch network script */
pid = fork();
if (pid == 0) {
int open_max = sysconf(_SC_OPEN_MAX), i;
for (i = 0; i < open_max; i++) {
if (i != STDIN_FILENO &&
i != STDOUT_FILENO &&
i != STDERR_FILENO &&
i != fd) {
close(i);
}
}
parg = args;
*parg++ = (char *)setup_script;
*parg++ = (char *)ifname;
*parg = NULL;
execv(setup_script, args);
_exit(1);
} else if (pid > 0) {
while (waitpid(pid, &status, 0) != pid) {
/* loop */
}
sigprocmask(SIG_SETMASK, &oldmask, NULL);
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
return 0;
}
}
fprintf(stderr, "%s: could not launch network script\n", setup_script);
return -1;
}
static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
{
int fd, vnet_hdr_required;
char ifname[128] = {0,};
const char *setup_script;
if (qemu_opt_get(opts, "ifname")) {
pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname"));
}
*vnet_hdr = qemu_opt_get_bool(opts, "vnet_hdr", 1);
if (qemu_opt_get(opts, "vnet_hdr")) {
vnet_hdr_required = *vnet_hdr;
} else {
vnet_hdr_required = 0;
}
TFR(fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required));
if (fd < 0) {
return -1;
}
setup_script = qemu_opt_get(opts, "script");
if (setup_script &&
setup_script[0] != '\0' &&
strcmp(setup_script, "no") != 0 &&
launch_script(setup_script, ifname, fd)) {
close(fd);
return -1;
}
qemu_opt_set(opts, "ifname", ifname);
return fd;
}
int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan)
{
TAPState *s;
int fd, vnet_hdr = 0;
if (qemu_opt_get(opts, "fd")) {
if (qemu_opt_get(opts, "ifname") ||
qemu_opt_get(opts, "script") ||
qemu_opt_get(opts, "downscript") ||
qemu_opt_get(opts, "vnet_hdr")) {
error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
return -1;
}
fd = net_handle_fd_param(mon, qemu_opt_get(opts, "fd"));
if (fd == -1) {
return -1;
}
fcntl(fd, F_SETFL, O_NONBLOCK);
vnet_hdr = tap_probe_vnet_hdr(fd);
} else {
if (!qemu_opt_get(opts, "script")) {
qemu_opt_set(opts, "script", DEFAULT_NETWORK_SCRIPT);
}
if (!qemu_opt_get(opts, "downscript")) {
qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT);
}
fd = net_tap_init(opts, &vnet_hdr);
if (fd == -1) {
return -1;
}
}
s = net_tap_fd_init(vlan, "tap", name, fd, vnet_hdr);
if (!s) {
close(fd);
return -1;
}
if (tap_set_sndbuf(s->fd, opts) < 0) {
return -1;
}
if (qemu_opt_get(opts, "fd")) {
snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
} else {
const char *ifname, *script, *downscript;
ifname = qemu_opt_get(opts, "ifname");
script = qemu_opt_get(opts, "script");
downscript = qemu_opt_get(opts, "downscript");
snprintf(s->nc.info_str, sizeof(s->nc.info_str),
"ifname=%s,script=%s,downscript=%s",
ifname, script, downscript);
if (strcmp(downscript, "no") != 0) {
snprintf(s->down_script, sizeof(s->down_script), "%s", downscript);
snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname);
}
}
if (qemu_opt_get_bool(opts, "vhost", !!qemu_opt_get(opts, "vhostfd") ||
qemu_opt_get_bool(opts, "vhostforce", false))) {
int vhostfd, r;
bool force = qemu_opt_get_bool(opts, "vhostforce", false);
if (qemu_opt_get(opts, "vhostfd")) {
r = net_handle_fd_param(mon, qemu_opt_get(opts, "vhostfd"));
if (r == -1) {
return -1;
}
vhostfd = r;
} else {
vhostfd = -1;
}
s->vhost_net = vhost_net_init(&s->nc, vhostfd, force);
if (!s->vhost_net) {
error_report("vhost-net requested but could not be initialized");
return -1;
}
} else if (qemu_opt_get(opts, "vhostfd")) {
error_report("vhostfd= is not valid without vhost");
return -1;
}
return 0;
}
VHostNetState *tap_get_vhost_net(VLANClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
assert(nc->info->type == NET_CLIENT_TYPE_TAP);
return s->vhost_net;
}
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