resolved: suppress ifindex info in varlink JSON responses if zero

If we don't have ifindex info, don't set the field for it.

We already do that for parsed IP address replies, let's do it for all
cases: it's a bit nicer to suppress the ifindex prop if it doesn't apply
than to pass it invalid.

This is the other side of #18482, i.e. fixes things so that the parser
doesn't get tripped up by this.

(This too makes a problem go away we should track down properly, i.e.
figure out how the ifindex got lost in
https://github.com/systemd/systemd/pull/17823#issuecomment-742439422 )

diff --git a/src/resolve/resolved-varlink.c b/src/resolve/resolved-varlink.c
index 2fb9d38dfaa897c06c9905005ef59381c8f303ba..9a8a4f3013f6e7717849d1aff842a0b6ebfcac0d 100644 (file)
--- a/src/resolve/resolved-varlink.c
+++ b/src/resolve/resolved-varlink.c
@@ -180,7 +180,7 @@ static void vl_method_resolve_hostname_complete(DnsQuery *q) {
 
                 r = json_build(&entry,
                                JSON_BUILD_OBJECT(
-                                               JSON_BUILD_PAIR("ifindex", JSON_BUILD_INTEGER(ifindex)),
+                                               JSON_BUILD_PAIR_CONDITION(ifindex > 0, "ifindex", JSON_BUILD_INTEGER(ifindex)),
                                                JSON_BUILD_PAIR("family", JSON_BUILD_INTEGER(family)),
                                                JSON_BUILD_PAIR("address", JSON_BUILD_BYTE_ARRAY(p, FAMILY_ADDRESS_SIZE(family)))));
                 if (r < 0)
@@ -408,7 +408,7 @@ static void vl_method_resolve_address_complete(DnsQuery *q) {
 
                 r = json_build(&entry,
                                JSON_BUILD_OBJECT(
-                                               JSON_BUILD_PAIR("ifindex", JSON_BUILD_INTEGER(ifindex)),
+                                               JSON_BUILD_PAIR_CONDITION(ifindex > 0, "ifindex", JSON_BUILD_INTEGER(ifindex)),
                                                JSON_BUILD_PAIR("name", JSON_BUILD_STRING(normalized))));
                 if (r < 0)
                         goto finish;