network: return 1 on start and 0 if ipv4ll is already started

Instead of -EBUSY, return 0 from sd_ipv4ll_start() if it's already started,
and change successful start return value to 1.

This matches sd_ndisc_start() behavior; 1 indicates successful start, and
0 indicates already started.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
index aa1ece41d2..4f4d9ebe87 100644
--- a/src/libsystemd-network/sd-ipv4ll.c
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -252,12 +252,14 @@ static int ipv4ll_start_internal(sd_ipv4ll *ll, bool reset_generation) {
                 return r;
         }
 
-        return 0;
+        return 1;
 }
 
 int sd_ipv4ll_start(sd_ipv4ll *ll) {
         assert_return(ll, -EINVAL);
-        assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);
+
+        if (sd_ipv4ll_is_running(ll))
+                return 0;
 
         return ipv4ll_start_internal(ll, true);
 }