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Date: Thu, 12 Dec 2013 08:18:25 +0100
From: Petr Písař <ppisar@...hat.com>
To: <netdev@...r.kernel.org>
Cc: Stephen Hemminger <stephen@...workplumber.org>,
Petr Písař <ppisar@...hat.com>
Subject: [PATCH] Do not listen if rtnl_send() fails in ip link iplink_have_newlink() test
If rtnl_send() fails in iplink_have_newlink() test, listening for
response will result in indefinite hang. This can be demonstrated by
"ip link show" while SELinux preventing from sending the RTM_NEWLINK
over netlink.
This patch checks for the return value as is done at all other
rtnl_send() calls. It falls back to IOCTL in case of failure.
Signed-off-by: Petr Písař <ppisar@...hat.com>
---
ip/iplink.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/ip/iplink.c b/ip/iplink.c
index 58b6c20..5132868 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -178,8 +178,13 @@ static int iplink_have_newlink(void)
req.n.nlmsg_type = RTM_NEWLINK;
req.i.ifi_family = AF_UNSPEC;
- rtnl_send(&rth, &req.n, req.n.nlmsg_len);
- rtnl_listen(&rth, accept_msg, NULL);
+ if (rtnl_send(&rth, &req.n, req.n.nlmsg_len) < 0) {
+ perror("Could not check for "
+ "link configuration over netlink support");
+ have_rtnl_newlink = 0;
+ } else {
+ rtnl_listen(&rth, accept_msg, NULL);
+ }
}
return have_rtnl_newlink;
}
--
1.8.3.1
--
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