resolved: when answer A or AAAA questions, order responses by whether addresses are link-local or not

2 files changed, 14 insertions, 2 deletions

diff --git a/src/shared/in-addr-util.c b/src/shared/in-addr-util.c
index e9a99177fc..459f846173 100644
--- a/src/shared/in-addr-util.c
+++ b/src/shared/in-addr-util.c
@@ -23,7 +23,7 @@
 
 #include "in-addr-util.h"
 
-int in_addr_null(int family, const union in_addr_union *u) {
+int in_addr_is_null(int family, const union in_addr_union *u) {
         assert(u);
 
         if (family == AF_INET)
@@ -39,6 +39,17 @@ int in_addr_null(int family, const union in_addr_union *u) {
         return -EAFNOSUPPORT;
 }
 
+int in_addr_is_link_local(int family, const union in_addr_union *u) {
+        assert(u);
+
+        if (family == AF_INET)
+                return (be32toh(u->in.s_addr) & 0xFFFF0000) == (169U << 24 | 254U << 16);
+
+        if (family == AF_INET6)
+                return IN6_IS_ADDR_LINKLOCAL(&u->in6);
+
+        return -EAFNOSUPPORT;
+}
 
 int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b) {
         assert(a);
diff --git a/src/shared/in-addr-util.h b/src/shared/in-addr-util.h
index cff2c321ed..7d1d6baa27 100644
--- a/src/shared/in-addr-util.h
+++ b/src/shared/in-addr-util.h
@@ -31,7 +31,8 @@ union in_addr_union {
         struct in6_addr in6;
 };
 
-int in_addr_null(int family, const union in_addr_union *u);
+int in_addr_is_null(int family, const union in_addr_union *u);
+int in_addr_is_link_local(int family, const union in_addr_union *u);
 int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b);
 int in_addr_prefix_intersect(int family, const union in_addr_union *a, unsigned aprefixlen, const union in_addr_union *b, unsigned bprefixlen);
 int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen);