From c8a56512a67076d5e5eb08166532e7081feec437 Mon Sep 17 00:00:00 2001 From: Tobias Brunner Date: Sat, 15 Jun 2013 17:46:25 +0200 Subject: [PATCH] tun-device: Avoid opening /dev/tunX multiple times (e.g. on FreeBSD) --- src/libstrongswan/networking/tun_device.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/libstrongswan/networking/tun_device.c b/src/libstrongswan/networking/tun_device.c index 2191198e2..00de2eddf 100644 --- a/src/libstrongswan/networking/tun_device.c +++ b/src/libstrongswan/networking/tun_device.c @@ -390,14 +390,18 @@ static bool init_tun(private_tun_device_t *this, const char *name_tmpl) /* this works on FreeBSD and might also work on Linux with older TUN * driver versions (no IFF_TUN) */ char devname[IFNAMSIZ]; - int i; + /* the same process is allowed to open a device again, but that's not what + * we want (unless we previously closed a device, which we don't know at + * this point). therefore, this counter is static so we don't accidentally + * open a device twice */ + static int i = -1; if (name_tmpl) { DBG1(DBG_LIB, "arbitrary naming of TUN devices is not supported"); } - for (i = 0; i < 256; i++) + for (; ++i < 256; ) { snprintf(devname, IFNAMSIZ, "/dev/tun%d", i); this->tunfd = open(devname, O_RDWR);