[libvirt] [PATCH] macvtap: log an error if on failure to connect to netlink socket

[Laine Stump]

A bug in libnl (see https://bugzilla.redhat.com/show_bug.cgi?id=677724
and https://bugzilla.redhat.com/show_bug.cgi?id=677725) makes it very
easy to create a failure to connect to the netlink socket when trying
to open a macvtap network device ("type='direct'" in domain interface
XML). When that error occurred, there was no log message, leading
virsh (for example) to report "unknown error".

This patch logs a message which will hopefully be more useful. (All
other error exits from the same function were already logging a
message).
---
 src/util/macvtap.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/src/util/macvtap.c b/src/util/macvtap.c
index a71db86..66bdc73 100644
--- a/src/util/macvtap.c
+++ b/src/util/macvtap.c
@@ -127,6 +127,8 @@ int nlComm(struct nl_msg *nl_msg,
         return -1;
 
     if (nl_connect(nlhandle, NETLINK_ROUTE) < 0) {
+        virReportSystemError(errno,
+                             "%s", _("cannot connect to netlink socket"));
         rc = -1;
         goto err_exit;
     }
-- 
1.7.3.4