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/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <linux/if_tun.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/uio.h>
#include "kern_constants.h"
#include "os.h"
#include "tuntap.h"
#include "user.h"
static int tuntap_user_init(void *data, void *dev)
{
struct tuntap_data *pri = data;
pri->dev = dev;
return 0;
}
static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct tuntap_data *pri = data;
tap_check_ips(pri->gate_addr, addr);
if ((pri->fd == -1) || pri->fixed_config)
return;
open_addr(addr, netmask, pri->dev_name);
}
static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct tuntap_data *pri = data;
if ((pri->fd == -1) || pri->fixed_config)
return;
close_addr(addr, netmask, pri->dev_name);
}
struct tuntap_pre_exec_data {
int stdout;
int close_me;
};
static void tuntap_pre_exec(void *arg)
{
struct tuntap_pre_exec_data *data = arg;
dup2(data->stdout, 1);
close(data->close_me);
}
static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
char *buffer, int buffer_len, int *used_out)
{
struct tuntap_pre_exec_data data;
char version_buf[sizeof("nnnnn\0")];
char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
NULL };
char buf[CMSG_SPACE(sizeof(*fd_out))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
int pid, n, err;
sprintf(version_buf, "%d", UML_NET_VERSION);
data.stdout = remote;
data.close_me = me;
pid = run_helper(tuntap_pre_exec, &data, argv);
if (pid < 0)
return -pid;
close(remote);
msg.msg_name = NULL;
msg.msg_namelen = 0;
if (buffer != NULL) {
iov = ((struct iovec) { buffer, buffer_len });
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
}
else {
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
}
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
msg.msg_flags = 0;
n = recvmsg(me, &msg, 0);
*used_out = n;
if (n < 0) {
err = -errno;
printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
"errno = %d\n", errno);
return err;
}
CATCH_EINTR(waitpid(pid, NULL, 0));
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL) {
printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
"message\n");
return -EINVAL;
}
if ((cmsg->cmsg_level != SOL_SOCKET) ||
(cmsg->cmsg_type != SCM_RIGHTS)) {
printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
"descriptor\n");
return -EINVAL;
}
*fd_out = ((int *) CMSG_DATA(cmsg))[0];
os_set_exec_close(*fd_out);
return 0;
}
static int tuntap_open(void *data)
{
struct ifreq ifr;
struct tuntap_data *pri = data;
char *output, *buffer;
int err, fds[2], len, used;
err = tap_open_common(pri->dev, pri->gate_addr);
if (err < 0)
return err;
if (pri->fixed_config) {
pri->fd = os_open_file("/dev/net/tun",
of_cloexec(of_rdwr(OPENFLAGS())), 0);
if (pri->fd < 0) {
printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
"err = %d\n", -pri->fd);
return pri->fd;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
if (ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0) {
err = -errno;
printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
errno);
close(pri->fd);
return err;
}
}
else {
err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
if (err) {
err = -errno;
printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
"errno = %d\n", errno);
return err;
}
buffer = get_output_buffer(&len);
if (buffer != NULL)
len--;
used = 0;
err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
fds[1], buffer, len, &used);
output = buffer;
if (err < 0) {
printk("%s", output);
free_output_buffer(buffer);
printk(UM_KERN_ERR "tuntap_open_tramp failed - "
"err = %d\n", -err);
return err;
}
pri->dev_name = uml_strdup(buffer);
output += IFNAMSIZ;
printk("%s", output);
free_output_buffer(buffer);
close(fds[0]);
iter_addresses(pri->dev, open_addr, pri->dev_name);
}
return pri->fd;
}
static void tuntap_close(int fd, void *data)
{
struct tuntap_data *pri = data;
if (!pri->fixed_config)
iter_addresses(pri->dev, close_addr, pri->dev_name);
close(fd);
pri->fd = -1;
}
const struct net_user_info tuntap_user_info = {
.init = tuntap_user_init,
.open = tuntap_open,
.close = tuntap_close,
.remove = NULL,
.add_address = tuntap_add_addr,
.delete_address = tuntap_del_addr,
.mtu = ETH_MAX_PACKET,
.max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
};
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