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.

3 files changed, 7 insertions, 4 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);
 }
diff --git a/src/libsystemd-network/test-ipv4ll.c b/src/libsystemd-network/test-ipv4ll.c
index 2f319bf7d9..6051e65820 100644
--- a/src/libsystemd-network/test-ipv4ll.c
+++ b/src/libsystemd-network/test-ipv4ll.c
@@ -159,10 +159,10 @@ static void test_basic_request(sd_event *e) {
         assert_se(sd_ipv4ll_start(ll) == -EINVAL);
 
         assert_se(sd_ipv4ll_set_ifindex(ll, 1) == 0);
-        assert_se(sd_ipv4ll_start(ll) == 0);
+        assert_se(sd_ipv4ll_start(ll) == 1);
 
         sd_event_run(e, (uint64_t) -1);
-        assert_se(sd_ipv4ll_start(ll) == -EBUSY);
+        assert_se(sd_ipv4ll_start(ll) == 0);
 
         assert_se(sd_ipv4ll_is_running(ll));
 
diff --git a/src/libsystemd-network/test-ndisc-rs.c b/src/libsystemd-network/test-ndisc-rs.c
index c8ee1ec31d..9fc902645c 100644
--- a/src/libsystemd-network/test-ndisc-rs.c
+++ b/src/libsystemd-network/test-ndisc-rs.c
@@ -297,6 +297,7 @@ static void test_rs(void) {
 
         assert_se(sd_ndisc_stop(nd) >= 0);
         assert_se(sd_ndisc_start(nd) >= 0);
+        assert_se(sd_ndisc_start(nd) >= 0);
         assert_se(sd_ndisc_stop(nd) >= 0);
 
         assert_se(sd_ndisc_start(nd) >= 0);