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authorEd Maste <emaste@freebsd.org>2015-10-23 11:53:55 -0400
committerMichael Tokarev <mjt@tls.msk.ru>2015-11-06 15:42:38 +0300
commitbd54a9f9435c85de190a82019faef16c5ecf8e46 (patch)
tree8c5c06154146e8cda32837ae6d3ad7a3e74009a1 /net/tap-bsd.c
parenta2f31f180499593b5edb8ac5ab8ac1b92f0abcd4 (diff)
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tap-bsd: use user-specified tap device if it already exists
Acked-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Ed Maste <emaste@freebsd.org> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Diffstat (limited to 'net/tap-bsd.c')
-rw-r--r--net/tap-bsd.c38
1 files changed, 33 insertions, 5 deletions
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 7028d9b..0103a97 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -109,8 +109,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
#define PATH_NET_TAP "/dev/tap"
-int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
- int vnet_hdr_required, int mq_required, Error **errp)
+static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
{
int fd, s, ret;
struct ifreq ifr;
@@ -126,7 +125,8 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
if (ret < 0) {
error_setg_errno(errp, errno, "could not get tap interface name");
- goto error;
+ close(fd);
+ return -1;
}
if (ifname[0] != '\0') {
@@ -135,19 +135,47 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
if (s < 0) {
error_setg_errno(errp, errno,
"could not open socket to set interface name");
- goto error;
+ close(fd);
+ return -1;
}
ifr.ifr_data = ifname;
ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
close(s);
if (ret < 0) {
error_setg(errp, "could not set tap interface name");
- goto error;
+ close(fd);
+ return -1;
}
} else {
pstrcpy(ifname, ifname_size, ifr.ifr_name);
}
+ return fd;
+}
+
+int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
+ int vnet_hdr_required, int mq_required, Error **errp)
+{
+ int fd = -1;
+
+ /* If the specified tap device already exists just use it. */
+ if (ifname[0] != '\0') {
+ char dname[100];
+ snprintf(dname, sizeof dname, "/dev/%s", ifname);
+ TFR(fd = open(dname, O_RDWR));
+ if (fd < 0 && errno != ENOENT) {
+ error_setg_errno(errp, errno, "could not open %s", dname);
+ return -1;
+ }
+ }
+
+ if (fd < 0) {
+ /* Tap device not specified or does not exist. */
+ if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
+ return -1;
+ }
+ }
+
if (*vnet_hdr) {
/* BSD doesn't have IFF_VNET_HDR */
*vnet_hdr = 0;