networkd: tighten parsing of Tunnel addresses

When assigning addresses, we'd set the family, and later
verify that the address on the other end has the same family.
But when the address was specified as "any", we'd simply unset
the family. Instead, only unset the family if both addresses
are wiped.

Also, don't bother setting family = AF_UNSPEC, since it's the default (0).

1 files changed, 26 insertions, 15 deletions

diff --git a/src/network/netdev/tunnel.c b/src/network/netdev/tunnel.c
index b1f1b5a425..2ce55a84b6 100644
--- a/src/network/netdev/tunnel.c
+++ b/src/network/netdev/tunnel.c
@@ -432,26 +432,40 @@ int config_parse_tunnel_address(const char *unit,
         assert(rvalue);
         assert(data);
 
+        /* This is used to parse addresses on both local and remote ends of the tunnel.
+         * Address families must match.
+         *
+         * "any" is a special value which means that the address is unspecified.
+         */
+
         if (streq(rvalue, "any")) {
-                t->family = 0;
+                *addr = IN_ADDR_NULL;
+
+                /* As a special case, if both the local and remote addresses are
+                 * unspecified, also clear the address family.
+                 */
+                if (t->family != AF_UNSPEC &&
+                    in_addr_is_null(t->family, &t->local) &&
+                    in_addr_is_null(t->family, &t->remote))
+                        t->family = AF_UNSPEC;
                 return 0;
-        } else {
+        }
 
-                r = in_addr_from_string_auto(rvalue, &f, &buffer);
-                if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, r, "Tunnel address is invalid, ignoring assignment: %s", rvalue);
-                        return 0;
-                }
+        r = in_addr_from_string_auto(rvalue, &f, &buffer);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Tunnel address \"%s\" invalid, ignoring assignment: %m", rvalue);
+                return 0;
+        }
 
-                if (t->family != AF_UNSPEC && t->family != f) {
-                        log_syntax(unit, LOG_ERR, filename, line, 0, "Tunnel addresses incompatible, ignoring assignment: %s", rvalue);
-                        return 0;
-                }
+        if (t->family != AF_UNSPEC && t->family != f) {
+                log_syntax(unit, LOG_ERR, filename, line, 0,
+                           "Tunnel addresses incompatible, ignoring assignment: %s", rvalue);
+                return 0;
         }
 
         t->family = f;
         *addr = buffer;
-
         return 0;
 }
 
@@ -579,7 +593,6 @@ static void ipip_init(NetDev *n) {
         assert(t);
 
         t->pmtudisc = true;
-        t->family = AF_UNSPEC;
 }
 
 static void sit_init(NetDev *n) {
@@ -589,7 +602,6 @@ static void sit_init(NetDev *n) {
         assert(t);
 
         t->pmtudisc = true;
-        t->family = AF_UNSPEC;
 }
 
 static void vti_init(NetDev *n) {
@@ -620,7 +632,6 @@ static void gre_init(NetDev *n) {
         assert(t);
 
         t->pmtudisc = true;
-        t->family = AF_UNSPEC;
 }
 
 static void ip6gre_init(NetDev *n) {