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[Qemu-devel] [PATCH] Add -tun option for preconfigured interface
From: |
Jean-Christian de Rivaz |
Subject: |
[Qemu-devel] [PATCH] Add -tun option for preconfigured interface |
Date: |
Sun, 13 Feb 2005 03:15:00 +0100 |
User-agent: |
Mozilla Thunderbird 1.0 (X11/20050116) |
I like that the root on the host OS can assign TUN interface to users
and that the root configure it. So the user only use the new -tun
<devname> option to use the preconfigured TUN interface without the need
to execute a trick and unsecure script.
Here is the added desciption:
----------------------------------------------------------------------
-tun devname
Try to use devname while opening a tap/tun host network interface
and use it. If it work, the network init script is not executed for this
interface. If it don't work, the interface will use the name assigned by
the operating system and the network init script is executed.
This option permit the use of preconfigured interface. For
example, as root you can assign a tun interface to a user and configure
it like this:
tunctl -u bob -t tun2
ifconfig tun2 192.168.2.1
Then bob can use this interface with the option "-tun tun2". Note
that option permit the use of a DHCP server on the host to configure the
guest interface.
----------------------------------------------------------------------
I have also patched the qemu-doc.html but cvs diff don't work with it.
I have tryed to be compatible with the -tun-fd option, but this is
untested. Also the tun_open() function for BSD system will probably not
handle this case as expected.
--
Jean-Christian de Rivaz
Index: qemu-doc.texi
===================================================================
RCS file: /cvsroot/qemu/qemu/qemu-doc.texi,v
retrieving revision 1.55
diff -u -r1.55 qemu-doc.texi
--- qemu-doc.texi 10 Feb 2005 21:46:47 -0000 1.55
+++ qemu-doc.texi 13 Feb 2005 01:59:04 -0000
@@ -212,6 +212,22 @@
aa:bb:cc:dd:ee:ff in hexa). The mac address is incremented for each
new network interface.
address@hidden -tun devname
+Try to use @var{devname} while opening a tap/tun host network interface and use
+it. If it work, the network init script is not executed for this
+interface. If it don't work, the interface will use the name assigned
+by the operating system and the network init script is executed.
+
+This option permit the use of preconfigured interface. For example, as
+root you can assign a tun interface to a user and configure it like this:
address@hidden
+tunctl -u bob -t tun2
+ifconfig tun2 192.168.2.1
address@hidden example
+Then bob can use this interface with the option "-tun tun2". Note that
+option permit the use of a DHCP server on the host to configure the
+guest interface.
+
@item -tun-fd fd
Assumes @var{fd} talks to a tap/tun host network interface and use
it. Read @url{http://bellard.org/qemu/tetrinet.html} to have an
Index: vl.c
===================================================================
RCS file: /cvsroot/qemu/qemu/vl.c,v
retrieving revision 1.120
diff -u -r1.120 vl.c
--- vl.c 10 Feb 2005 22:00:06 -0000 1.120
+++ vl.c 13 Feb 2005 01:59:05 -0000
@@ -1600,7 +1600,7 @@
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
- pstrcpy(ifr.ifr_name, IFNAMSIZ, "tun%d");
+ pstrcpy(ifr.ifr_name, IFNAMSIZ, (ifname && *ifname) ? ifname : "tun%d");
ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
if (ret != 0) {
fprintf(stderr, "warning: could not configure /dev/net/tun: no virtual
network emulation\n");
@@ -1626,7 +1626,7 @@
qemu_add_fd_read_handler(nd->fd, fd_can_read, fd_read, opaque);
}
-static int net_tun_init(NetDriverState *nd)
+static int net_tun_init(NetDriverState *nd, int script)
{
int pid, status;
char *args[3];
@@ -1637,7 +1637,7 @@
return -1;
/* try to launch network init script */
- pid = fork();
+ pid = script ? fork() : -1;
if (pid >= 0) {
if (pid == 0) {
parg = args;
@@ -2731,6 +2731,7 @@
"-nics n simulate 'n' network cards [default=1]\n"
"-macaddr addr set the mac address of the first interface\n"
"-n script set tap/tun network init script [default=%s]\n"
+ "-tun devname try to use devname while opening tap/tun
interface\n"
"-tun-fd fd use this fd as already opened tap/tun interface\n"
#ifdef CONFIG_SLIRP
"-user-net use user mode network stack [default if no tap/tun
script]\n"
@@ -2819,6 +2820,7 @@
QEMU_OPTION_nics,
QEMU_OPTION_macaddr,
QEMU_OPTION_n,
+ QEMU_OPTION_tun,
QEMU_OPTION_tun_fd,
QEMU_OPTION_user_net,
QEMU_OPTION_tftp,
@@ -2880,6 +2882,7 @@
{ "nics", HAS_ARG, QEMU_OPTION_nics},
{ "macaddr", HAS_ARG, QEMU_OPTION_macaddr},
{ "n", HAS_ARG, QEMU_OPTION_n },
+ { "tun", HAS_ARG, QEMU_OPTION_tun },
{ "tun-fd", HAS_ARG, QEMU_OPTION_tun_fd },
#ifdef CONFIG_SLIRP
{ "user-net", 0, QEMU_OPTION_user_net },
@@ -2990,7 +2993,7 @@
int cyls, heads, secs, translation;
int start_emulation = 1;
uint8_t macaddr[6];
- int net_if_type, nb_tun_fds, tun_fds[MAX_NICS];
+ int net_if_type, nb_tun, nb_tun_fds, cnt_tun_fds, tun_fds[MAX_NICS];
int optind;
const char *r, *optarg;
CharDriverState *monitor_hd;
@@ -3037,7 +3040,12 @@
parallel_devices[i][0] = '\0';
parallel_device_index = 0;
+ for(i = 0; i < MAX_NICS; i++) {
+ nd_table[i].ifname[0] = '\0';
+ }
+ nb_tun = 0;
nb_tun_fds = 0;
+ cnt_tun_fds = 0;
net_if_type = -1;
nb_nics = 1;
/* default mac address of the first network interface */
@@ -3141,18 +3149,25 @@
case QEMU_OPTION_append:
kernel_cmdline = optarg;
break;
+ case QEMU_OPTION_tun:
+ net_if_type = NET_IF_TUN;
+ if (nb_tun+nb_tun_fds < MAX_NICS) {
+ pstrcpy(nd_table[nb_tun++].ifname, IFNAMSIZ, optarg);
+ }
+ break;
case QEMU_OPTION_tun_fd:
{
const char *p;
int fd;
net_if_type = NET_IF_TUN;
- if (nb_tun_fds < MAX_NICS) {
+ if (nb_tun+nb_tun_fds < MAX_NICS) {
fd = strtol(optarg, (char **)&p, 0);
if (*p != '\0') {
fprintf(stderr, "qemu: invalid fd for network
interface %d\n", nb_tun_fds);
exit(1);
}
tun_fds[nb_tun_fds++] = fd;
+ nb_tun++;
}
}
break;
@@ -3426,12 +3441,20 @@
#endif
#if !defined(_WIN32)
case NET_IF_TUN:
- if (i < nb_tun_fds) {
- net_fd_init(nd, tun_fds[i]);
- } else {
- if (net_tun_init(nd) < 0)
- net_dummy_init(nd);
- }
+ if (nd->ifname && *(nd->ifname)) {
+ if (net_tun_init(nd, 0) < 0) {
+ nd->ifname[0] = '\0';
+ if (net_tun_init(nd, 1) < 0)
+ net_dummy_init(nd);
+ }
+ } else {
+ if (cnt_tun_fds < nb_tun_fds) {
+ net_fd_init(nd, tun_fds[cnt_tun_fds++]);
+ } else {
+ if (net_tun_init(nd, 1) < 0)
+ net_dummy_init(nd);
+ }
+ }
break;
#endif
case NET_IF_DUMMY:
- [Qemu-devel] [PATCH] Add -tun option for preconfigured interface,
Jean-Christian de Rivaz <=