From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
To: shemminger@vyatta.com
Cc: netdev@vger.kernel.org, junwei.zhang@6wind.com,
bhutchings@solarflare.com,
Nicolas Dichtel <nicolas.dichtel@6wind.com>
Subject: [PATCH iproute2 v2] ipbatch: fix use of 'ip netns exec'
Date: Mon, 8 Jul 2013 11:44:20 +0200 [thread overview]
Message-ID: <1373276660-14088-1-git-send-email-nicolas.dichtel@6wind.com> (raw)
In-Reply-To: <20130705141639.56b47e7e@samsung-9>
From: JunweiZhang <junwei.zhang@6wind.com>
execvp() does not return when the command succeed, hence all commands in the
batch file after the line 'ip netns exec' are not executed.
Let's fork before calling execvp().
Example:
$ cat test.batch
netns add netns1
netns exec netns1 ip l
netns
$ ip -b test.batch
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: sit0: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT
link/sit 0.0.0.0 brd 0.0.0.0
All command after 'netns exec' are never executed.
With the patch:
$ ip -b test.batch
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN mode DEFAULT
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: sit0: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT
link/sit 0.0.0.0 brd 0.0.0.0
netns1
Now, existing netns are displayed.
Signed-off-by: JunweiZhang <junwei.zhang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
v2: keep exit status of the child
add an example in the commit log
ip/ipnetns.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index fa2b681..9f401ca 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -138,6 +138,7 @@ static int netns_exec(int argc, char **argv)
const char *name, *cmd;
char net_path[MAXPATHLEN];
int netns;
+ int pid, status;
if (argc < 1) {
fprintf(stderr, "No netns name specified\n");
@@ -185,10 +186,23 @@ static int netns_exec(int argc, char **argv)
/* Setup bind mounts for config files in /etc */
bind_etc(name);
- if (execvp(cmd, argv + 1) < 0)
- fprintf(stderr, "exec of \"%s\" failed: %s\n",
- cmd, strerror(errno));
- return EXIT_FAILURE;
+ pid = fork();
+ if (pid < 0)
+ return EXIT_FAILURE;
+ else if (pid > 0)
+ waitpid(pid, &status, 0);
+ else {
+ /* Child */
+ if (execvp(cmd, argv + 1) < 0)
+ fprintf(stderr, "exec of \"%s\" failed: %s\n",
+ cmd, strerror(errno));
+ return EXIT_FAILURE;
+ }
+ /* ip must returns the status of the child, but do_cmd() will add a
+ * minus to this returned value, so let's add another one here to
+ * cancel it.
+ */
+ return -WEXITSTATUS(status);
}
static int is_pid(const char *str)
--
1.8.2.1
next parent reply other threads:[~2013-07-08 9:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20130705141639.56b47e7e@samsung-9>
2013-07-08 9:44 ` Nicolas Dichtel [this message]
2013-07-08 23:36 ` [PATCH iproute2 v2] ipbatch: fix use of 'ip netns exec' Ben Hutchings
2013-07-09 10:26 ` [PATCH iproute2 v3] " Nicolas Dichtel
2013-07-09 13:20 ` Eric Dumazet
2013-07-09 15:55 ` [PATCH iproute2 v4] " Nicolas Dichtel
2013-07-09 16:19 ` Ben Hutchings
2013-07-09 16:59 ` Nicolas Dichtel
2013-07-09 18:13 ` Ben Hutchings
2013-07-10 9:52 ` Nicolas Dichtel
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