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-rw-r--r--toys/net/tunctl.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/toys/net/tunctl.c b/toys/net/tunctl.c
index c7bf8927..1aafebfd 100644
--- a/toys/net/tunctl.c
+++ b/toys/net/tunctl.c
@@ -3,21 +3,28 @@
* Copyright 2016 Rob Landley <rob@landley.net>
*
* See http://kernel.org/doc/Documentation/networking/tuntap.txt
+ *
+ * This is useful for things like "kvm -netdev tap" and containers.
+ * See https://landley.net/lxc/02-networking.html for example usage.
+ *
+ * todo: bridge mode
+ * -b bridge daemon (forwards packets between NAME and NAME2 interfaces)
-USE_TUNCTL(NEWTOY(tunctl, "<1>1t|d|u:[!td]", TOYFLAG_USR|TOYFLAG_BIN))
+
+USE_TUNCTL(NEWTOY(tunctl, "<1>1t|d|u:T[!td]", TOYFLAG_USR|TOYFLAG_BIN))
config TUNCTL
bool "tunctl"
default y
help
- usage: tunctl [-dt] [-u USER] NAME
+ usage: tunctl [-dtT] [-u USER] NAME
Create and delete tun/tap virtual ethernet devices.
- A tap device Template for new commands. You don't need this.
- -d Delete tun device
- -t Create tun device
- -u Owner of new device
+ -T Use tap (ethernet frames) instead of tun (ip packets)
+ -d Delete tun/tap device
+ -t Create tun/tap device
+ -u Set owner (user who can read/write device without root access)
*/
#define FOR_tunctl
@@ -34,9 +41,11 @@ void tunctl_main(void)
uid_t u = TT.user ? xgetuid(TT.user) : 0;
int fd = xopen("/dev/net/tun", O_RDWR);
- ifr->ifr_flags = IFF_TAP|IFF_NO_PI;
+ // Associate filehandle with device
+ ifr->ifr_flags = ((toys.optflags&FLAG_T) ? IFF_TUN : IFF_TAP)|IFF_NO_PI;
strncpy(ifr->ifr_name, *toys.optargs, sizeof(ifr->ifr_name));
xioctl(fd, TUNSETIFF, toybuf);
+
if (toys.optflags&FLAG_t) {
xioctl(fd, TUNSETPERSIST, (void *)1);
xioctl(fd, TUNSETOWNER, (void *)(long)u);