networkd: rearrange checks when to write something into sysctl a bit

Move check whether ipv6 is available into link_ipv6_privacy_extensions()
to keep it as internal and early as possible.

Always check if there's a network attached to a link before we apply
sysctls. We do this for most of the sysctl functions already, with this
change we do it for all.

1 files changed, 13 insertions, 4 deletions

diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index a1401cc33f..4a84e49699 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -147,6 +147,10 @@ bool link_ipv6_accept_ra_enabled(Link *link) {
 }
 
 static IPv6PrivacyExtensions link_ipv6_privacy_extensions(Link *link) {
+
+        if (!socket_ipv6_is_supported())
+                return _IPV6_PRIVACY_EXTENSIONS_INVALID;
+
         if (link->flags & IFF_LOOPBACK)
                 return _IPV6_PRIVACY_EXTENSIONS_INVALID;
 
@@ -1896,10 +1900,6 @@ static int link_set_ipv6_privacy_extensions(Link *link) {
         const char *p = NULL;
         int r;
 
-        /* Make this a NOP if IPv6 is not available */
-        if (!socket_ipv6_is_supported())
-                return 0;
-
         s = link_ipv6_privacy_extensions(link);
         if (s < 0)
                 return 0;
@@ -1925,6 +1925,9 @@ static int link_set_ipv6_accept_ra(Link *link) {
         if (link->flags & IFF_LOOPBACK)
                 return 0;
 
+        if (!link->network)
+                return 0;
+
         p = strjoina("/proc/sys/net/ipv6/conf/", link->ifname, "/accept_ra");
 
         /* We handle router advertisments ourselves, tell the kernel to GTFO */
@@ -1947,6 +1950,9 @@ static int link_set_ipv6_dad_transmits(Link *link) {
         if (link->flags & IFF_LOOPBACK)
                 return 0;
 
+        if (!link->network)
+                return 0;
+
         if (link->network->ipv6_dad_transmits < 0)
                 return 0;
 
@@ -1972,6 +1978,9 @@ static int link_set_ipv6_hop_limit(Link *link) {
         if (link->flags & IFF_LOOPBACK)
                 return 0;
 
+        if (!link->network)
+                return 0;
+
         if (link->network->ipv6_hop_limit < 0)
                 return 0;