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authorMichael Tokarev <mjt@tls.msk.ru>2010-06-02 14:33:01 -0300
committerAnthony Liguori <aliguori@us.ibm.com>2010-06-22 15:15:30 -0500
commit91ca60e01277da2184d9c3f992c440cb5aa264c4 (patch)
treee86d8211635f69f90b6bbbeec9856cbbb6807cc1 /net
parent49b586a922c1818cbd9f576600f72bff182bc257 (diff)
give some useful error messages when tap open
In net/tap-linux.c, when manipulation of /dev/net/tun fails, it prints (with fprintf) something like this: warning: could not open /dev/net/tun: no virtual network emulation this has 2 issues: 1) it is not a warning really, it's a fatal error (kvm exits after that), 2) there's no indication as of what's actually wrong: printing errno there is helpful. The patch below removes the "warning" prefix, uses %m (since it's linux, %m is available as format modifier), and changes fprintf() to %qemu_error(). Now it prints something like this instead: could not configure /dev/net/tun: Device or resource busy (there are 2 messages like that in the same function) This fixes Debian bug #578154, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578154 Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'net')
-rw-r--r--net/tap-linux.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 03b83012f8..c92983cb53 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -33,14 +33,16 @@
#include "qemu-common.h"
#include "qemu-error.h"
+#define PATH_NET_TUN "/dev/net/tun"
+
int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
{
struct ifreq ifr;
int fd, ret;
- TFR(fd = open("/dev/net/tun", O_RDWR));
+ TFR(fd = open(PATH_NET_TUN, O_RDWR));
if (fd < 0) {
- fprintf(stderr, "warning: could not open /dev/net/tun: no virtual network emulation\n");
+ error_report("could not open %s: %m", PATH_NET_TUN);
return -1;
}
memset(&ifr, 0, sizeof(ifr));
@@ -71,7 +73,7 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required
pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
if (ret != 0) {
- fprintf(stderr, "warning: could not configure /dev/net/tun: no virtual network emulation\n");
+ error_report("could not configure %s (%s): %m", PATH_NET_TUN, ifr.ifr_name);
close(fd);
return -1;
}