util: Make ns_enter() a void function and report setns() errors

ns_enter() returns an integer... but it's always zero.  If we actually fail
the function doesn't return.  Therefore it makes more sense for this to be
a function returning void, and we can remove the cases where we pointlessly
checked its return value.

In addition ns_enter() is usually called from an ephemeral thread created
by NS_CALL().  That means that the exit(EXIT_FAILURE) there usually won't
be reported (since NS_CALL() doesn't wait() for the thread).  So, use die()
instead to print out some information in the unlikely event that our
setns() here does fail.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 2 insertions, 4 deletions

diff --git a/udp.c b/udp.c
index f749f5f..5a852fb 100644
--- a/udp.c
+++ b/udp.c
@@ -473,8 +473,7 @@ static int udp_splice_new_ns(void *arg)
 
 	a = (struct udp_splice_new_ns_arg *)arg;
 
-	if (ns_enter(a->c))
-		return 0;
+	ns_enter(a->c);
 
 	a->s = udp_splice_new(a->c, a->v6, a->src, true);
 
@@ -1064,8 +1063,7 @@ int udp_sock_init_ns(void *arg)
 	struct ctx *c = (struct ctx *)arg;
 	unsigned dst;
 
-	if (ns_enter(c))
-		return 0;
+	ns_enter(c);
 
 	for (dst = 0; dst < NUM_PORTS; dst++) {
 		if (!bitmap_isset(c->udp.fwd_out.f.map, dst))