mirror of git://anongit.mindrot.org/openssh.git
283 lines
6.2 KiB
C
283 lines
6.2 KiB
C
/*
|
|
* Copyright (c) 2005 Reyk Floeter <reyk@openbsd.org>
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/ioctl.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
#include <netinet/ip.h>
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdarg.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "openbsd-compat/sys-queue.h"
|
|
#include "log.h"
|
|
#include "misc.h"
|
|
#include "sshbuf.h"
|
|
#include "channels.h"
|
|
#include "ssherr.h"
|
|
|
|
/*
|
|
* This is the portable version of the SSH tunnel forwarding, it
|
|
* uses some preprocessor definitions for various platform-specific
|
|
* settings.
|
|
*
|
|
* SSH_TUN_LINUX Use the (newer) Linux tun/tap device
|
|
* SSH_TUN_FREEBSD Use the FreeBSD tun/tap device
|
|
* SSH_TUN_COMPAT_AF Translate the OpenBSD address family
|
|
* SSH_TUN_PREPEND_AF Prepend/remove the address family
|
|
*/
|
|
|
|
/*
|
|
* System-specific tunnel open function
|
|
*/
|
|
|
|
#if defined(SSH_TUN_LINUX)
|
|
#include <linux/if.h>
|
|
#include <linux/if_tun.h>
|
|
|
|
int
|
|
sys_tun_open(int tun, int mode)
|
|
{
|
|
struct ifreq ifr;
|
|
int fd = -1;
|
|
const char *name = NULL;
|
|
|
|
if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
|
|
debug("%s: failed to open tunnel control interface: %s",
|
|
__func__, strerror(errno));
|
|
return (-1);
|
|
}
|
|
|
|
bzero(&ifr, sizeof(ifr));
|
|
|
|
if (mode == SSH_TUNMODE_ETHERNET) {
|
|
ifr.ifr_flags = IFF_TAP;
|
|
name = "tap%d";
|
|
} else {
|
|
ifr.ifr_flags = IFF_TUN;
|
|
name = "tun%d";
|
|
}
|
|
ifr.ifr_flags |= IFF_NO_PI;
|
|
|
|
if (tun != SSH_TUNID_ANY) {
|
|
if (tun > SSH_TUNID_MAX) {
|
|
debug("%s: invalid tunnel id %x: %s", __func__,
|
|
tun, strerror(errno));
|
|
goto failed;
|
|
}
|
|
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
|
|
}
|
|
|
|
if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
|
|
debug("%s: failed to configure tunnel (mode %d): %s", __func__,
|
|
mode, strerror(errno));
|
|
goto failed;
|
|
}
|
|
|
|
if (tun == SSH_TUNID_ANY)
|
|
debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
|
|
else
|
|
debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
|
|
|
|
return (fd);
|
|
|
|
failed:
|
|
close(fd);
|
|
return (-1);
|
|
}
|
|
#endif /* SSH_TUN_LINUX */
|
|
|
|
#ifdef SSH_TUN_FREEBSD
|
|
#include <sys/socket.h>
|
|
#include <net/if.h>
|
|
|
|
#ifdef HAVE_NET_IF_TUN_H
|
|
#include <net/if_tun.h>
|
|
#endif
|
|
|
|
int
|
|
sys_tun_open(int tun, int mode)
|
|
{
|
|
struct ifreq ifr;
|
|
char name[100];
|
|
int fd = -1, sock, flag;
|
|
const char *tunbase = "tun";
|
|
|
|
if (mode == SSH_TUNMODE_ETHERNET) {
|
|
#ifdef SSH_TUN_NO_L2
|
|
debug("%s: no layer 2 tunnelling support", __func__);
|
|
return (-1);
|
|
#else
|
|
tunbase = "tap";
|
|
#endif
|
|
}
|
|
|
|
/* Open the tunnel device */
|
|
if (tun <= SSH_TUNID_MAX) {
|
|
snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
|
|
fd = open(name, O_RDWR);
|
|
} else if (tun == SSH_TUNID_ANY) {
|
|
for (tun = 100; tun >= 0; tun--) {
|
|
snprintf(name, sizeof(name), "/dev/%s%d",
|
|
tunbase, tun);
|
|
if ((fd = open(name, O_RDWR)) >= 0)
|
|
break;
|
|
}
|
|
} else {
|
|
debug("%s: invalid tunnel %u\n", __func__, tun);
|
|
return (-1);
|
|
}
|
|
|
|
if (fd < 0) {
|
|
debug("%s: %s open failed: %s", __func__, name,
|
|
strerror(errno));
|
|
return (-1);
|
|
}
|
|
|
|
/* Turn on tunnel headers */
|
|
flag = 1;
|
|
#if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
|
|
if (mode != SSH_TUNMODE_ETHERNET &&
|
|
ioctl(fd, TUNSIFHEAD, &flag) == -1) {
|
|
debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
|
|
strerror(errno));
|
|
close(fd);
|
|
}
|
|
#endif
|
|
|
|
debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
|
|
|
|
/* Set the tunnel device operation mode */
|
|
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
|
|
if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
|
|
goto failed;
|
|
|
|
if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
|
|
goto failed;
|
|
if ((ifr.ifr_flags & IFF_UP) == 0) {
|
|
ifr.ifr_flags |= IFF_UP;
|
|
if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
|
|
goto failed;
|
|
}
|
|
|
|
close(sock);
|
|
return (fd);
|
|
|
|
failed:
|
|
if (fd >= 0)
|
|
close(fd);
|
|
if (sock >= 0)
|
|
close(sock);
|
|
debug("%s: failed to set %s mode %d: %s", __func__, name,
|
|
mode, strerror(errno));
|
|
return (-1);
|
|
}
|
|
#endif /* SSH_TUN_FREEBSD */
|
|
|
|
/*
|
|
* System-specific channel filters
|
|
*/
|
|
|
|
#if defined(SSH_TUN_FILTER)
|
|
#define OPENBSD_AF_INET 2
|
|
#define OPENBSD_AF_INET6 24
|
|
|
|
int
|
|
sys_tun_infilter(struct Channel *c, char *buf, int len)
|
|
{
|
|
#if defined(SSH_TUN_PREPEND_AF)
|
|
char rbuf[CHAN_RBUF];
|
|
struct ip *iph;
|
|
#endif
|
|
u_int32_t *af;
|
|
char *ptr = buf;
|
|
int r;
|
|
|
|
#if defined(SSH_TUN_PREPEND_AF)
|
|
if (len <= 0 || len > (int)(sizeof(rbuf) - sizeof(*af)))
|
|
return (-1);
|
|
ptr = (char *)&rbuf[0];
|
|
bcopy(buf, ptr + sizeof(u_int32_t), len);
|
|
len += sizeof(u_int32_t);
|
|
af = (u_int32_t *)ptr;
|
|
|
|
iph = (struct ip *)(ptr + sizeof(u_int32_t));
|
|
switch (iph->ip_v) {
|
|
case 6:
|
|
*af = AF_INET6;
|
|
break;
|
|
case 4:
|
|
default:
|
|
*af = AF_INET;
|
|
break;
|
|
}
|
|
#endif
|
|
|
|
#if defined(SSH_TUN_COMPAT_AF)
|
|
if (len < (int)sizeof(u_int32_t))
|
|
return (-1);
|
|
|
|
af = (u_int32_t *)ptr;
|
|
if (*af == htonl(AF_INET6))
|
|
*af = htonl(OPENBSD_AF_INET6);
|
|
else
|
|
*af = htonl(OPENBSD_AF_INET);
|
|
#endif
|
|
|
|
if ((r = sshbuf_put_string(&c->input, ptr, len)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
return (0);
|
|
}
|
|
|
|
u_char *
|
|
sys_tun_outfilter(struct Channel *c, u_char **data, u_int *dlen)
|
|
{
|
|
u_char *buf;
|
|
u_int32_t *af;
|
|
int r;
|
|
size_t xxx_dlen;
|
|
|
|
/* XXX new API is incompatible with this signature. */
|
|
if ((r = sshbuf_get_string(&c->output, data, &xxx_dlen)) != 0)
|
|
fatal("%s: buffer error: %s", __func__, ssh_err(r));
|
|
if (dlen != NULL)
|
|
*dlen = xxx_dlen;
|
|
if (*dlen < sizeof(*af))
|
|
return (NULL);
|
|
buf = *data;
|
|
|
|
#if defined(SSH_TUN_PREPEND_AF)
|
|
*dlen -= sizeof(u_int32_t);
|
|
buf = *data + sizeof(u_int32_t);
|
|
#elif defined(SSH_TUN_COMPAT_AF)
|
|
af = ntohl(*(u_int32_t *)buf);
|
|
if (*af == OPENBSD_AF_INET6)
|
|
*af = htonl(AF_INET6);
|
|
else
|
|
*af = htonl(AF_INET);
|
|
#endif
|
|
|
|
return (buf);
|
|
}
|
|
#endif /* SSH_TUN_FILTER */
|