networkd: store DNS servers configured per-network as parsed addresses

DNS servers must be specified as IP addresses, hence let's store them as that
internally, so that they are guaranteed to be fully normalized always, and
invalid data cannot be stored.

1 files changed, 24 insertions, 11 deletions

diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 0b634572a9..b7743557ec 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -854,28 +854,26 @@ static int address_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userda
 static int link_push_dns_to_dhcp_server(Link *link, sd_dhcp_server *s) {
         _cleanup_free_ struct in_addr *addresses = NULL;
         size_t n_addresses = 0, n_allocated = 0;
-        char **a;
+        unsigned i;
 
         log_debug("Copying DNS server information from %s", link->ifname);
 
         if (!link->network)
                 return 0;
 
-        STRV_FOREACH(a, link->network->dns) {
-                struct in_addr ia;
+        for (i = 0; i < link->network->n_dns; i++) {
 
                 /* Only look for IPv4 addresses */
-                if (inet_pton(AF_INET, *a, &ia) <= 0)
+                if (link->network->dns[i].family != AF_INET)
                         continue;
 
                 if (!GREEDY_REALLOC(addresses, n_allocated, n_addresses + 1))
                         return log_oom();
 
-                addresses[n_addresses++] = ia;
+                addresses[n_addresses++] = link->network->dns[i].address.in;
         }
 
-        if (link->network->dhcp_use_dns &&
-            link->dhcp_lease) {
+        if (link->network->dhcp_use_dns && link->dhcp_lease) {
                 const struct in_addr *da = NULL;
                 int n;
 
@@ -919,8 +917,7 @@ static int link_push_ntp_to_dhcp_server(Link *link, sd_dhcp_server *s) {
                 addresses[n_addresses++] = ia;
         }
 
-        if (link->network->dhcp_use_ntp &&
-            link->dhcp_lease) {
+        if (link->network->dhcp_use_ntp && link->dhcp_lease) {
                 const struct in_addr *da = NULL;
                 int n;
 
@@ -3235,7 +3232,7 @@ int link_save(Link *link) {
         if (r < 0)
                 goto fail;
 
-        fchmod(fileno(f), 0644);
+        (void) fchmod(fileno(f), 0644);
 
         fprintf(f,
                 "# This is private data. Do not parse.\n"
@@ -3248,6 +3245,7 @@ int link_save(Link *link) {
                 sd_dhcp6_lease *dhcp6_lease = NULL;
                 const char *dhcp_domainname = NULL;
                 char **dhcp6_domains = NULL;
+                unsigned j;
 
                 if (link->dhcp6_client) {
                         r = sd_dhcp6_client_get_lease(link->dhcp6_client, &dhcp6_lease);
@@ -3259,7 +3257,22 @@ int link_save(Link *link) {
 
                 fputs("DNS=", f);
                 space = false;
-                fputstrv(f, link->network->dns, NULL, &space);
+
+                for (j = 0; j < link->network->n_dns; j++) {
+                        _cleanup_free_ char *b = NULL;
+
+                        r = in_addr_to_string(link->network->dns[j].family,
+                                              &link->network->dns[j].address,  &b);
+                        if (r < 0) {
+                                log_debug_errno(r, "Failed to format address, ignoring: %m");
+                                continue;
+                        }
+
+                        if (space)
+                                fputc(' ', f);
+                        fputs(b, f);
+                        space = true;
+                }
 
                 if (link->network->dhcp_use_dns &&
                     link->dhcp_lease) {