networkd: refuse to use .network files with missing Address/Gateway key

These keys are mandatory in [Address]/[Route] sections. Otherwise, we
hit an assert:

ens3: setting addresses
Assertion 'address->family == 2 || address->family == 10' failed at /build/amd64-generic/tmp/portage/sys-apps/systemd-9999-r1/work/systemd-9999/src/network/networkd-address.c:137, function address_configure(). Aborting.

Reported-by: Alex Polvi <alex.polvi@coreos.com>

At the same time make sure Route's Destination and Gateway uses the same address family.

4 files changed, 31 insertions, 7 deletions

diff --git a/man/systemd-networkd.service.xml b/man/systemd-networkd.service.xml
index 57be3358fe..de45d10a78 100644
--- a/man/systemd-networkd.service.xml
+++ b/man/systemd-networkd.service.xml
@@ -206,7 +206,7 @@
                                 <varlistentry>
                                         <term><varname>Address</varname></term>
                                         <listitem>
-                                                <para>As in the <literal>[Network]</literal> section.</para>
+                                                <para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
                                         </listitem>
                                 </varlistentry>
                                 <varlistentry>
@@ -223,7 +223,7 @@
                                 <varlistentry>
                                         <term><varname>Gateway</varname></term>
                                         <listitem>
-                                                <para>As in the <literal>[Network]</literal> section.</para>
+                                                <para>As in the <literal>[Network]</literal> section. This key is mandatory.</para>
                                         </listitem>
                                 </varlistentry>
                                 <varlistentry>
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 3cbc9aba26..0326fe675b 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -29,6 +29,8 @@
 static int network_load_one(Manager *manager, const char *filename) {
         _cleanup_network_free_ Network *network = NULL;
         _cleanup_fclose_ FILE *file = NULL;
+        Route *route;
+        Address *address;
         int r;
 
         assert(manager);
@@ -71,6 +73,29 @@ static int network_load_one(Manager *manager, const char *filename) {
         }
 
         LIST_PREPEND(networks, manager->networks, network);
+
+        LIST_FOREACH(static_routes, route, network->static_routes) {
+                if (!route->family) {
+                        log_warning("Route section without Gateway field configured in %s. "
+                                    "Ignoring", filename);
+                        return 0;
+                }
+
+                if (route->dst_family && route->family != route->dst_family) {
+                        log_warning("Route section with conflicting Gateway and Destination address "
+                                    "family configured in %s. Ignoring", filename);
+                        return 0;
+                }
+        }
+
+        LIST_FOREACH(static_addresses, address, network->static_addresses) {
+                if (!address->family) {
+                        log_warning("Address section without Address field configured in %s. "
+                                    "Ignoring", filename);
+                        return 0;
+                }
+        }
+
         network = NULL;
 
         return 0;
@@ -109,8 +134,6 @@ void network_free(Network *network) {
         if (!network)
                 return;
 
-        assert(network->manager);
-
         free(network->filename);
 
         free(network->match_mac);
@@ -130,7 +153,7 @@ void network_free(Network *network) {
         hashmap_free(network->addresses_by_section);
         hashmap_free(network->routes_by_section);
 
-        if (network->manager->networks)
+        if (network->manager && network->manager->networks)
                 LIST_REMOVE(networks, network->manager->networks, network);
 
         free(network);
diff --git a/src/network/networkd-route.c b/src/network/networkd-route.c
index 488d3f5013..83dad655db 100644
--- a/src/network/networkd-route.c
+++ b/src/network/networkd-route.c
@@ -231,7 +231,7 @@ int config_parse_destination(const char *unit,
                         return log_oom();
         }
 
-        r = net_parse_inaddr(address, &n->family, &n->dst_addr);
+        r = net_parse_inaddr(address, &n->dst_family, &n->dst_addr);
         if (r < 0) {
                 log_syntax(unit, LOG_ERR, filename, line, EINVAL,
                            "Destination is invalid, ignoring assignment: %s", address);
@@ -252,7 +252,7 @@ int config_parse_destination(const char *unit,
 
                 n->dst_prefixlen = (unsigned char) i;
         } else {
-                switch (n->family) {
+                switch (n->dst_family) {
                         case AF_INET:
                                 n->dst_prefixlen = 32;
                                 break;
diff --git a/src/network/networkd.h b/src/network/networkd.h
index 3b2908090f..75309a9b85 100644
--- a/src/network/networkd.h
+++ b/src/network/networkd.h
@@ -119,6 +119,7 @@ struct Route {
         uint64_t section;
 
         unsigned char family;
+        unsigned char dst_family;
         unsigned char dst_prefixlen;
 
         union {