libsystemd-dhcp: expose received DNS server

[elogind.git] / src / libsystemd-dhcp / dhcp-client.c

diff --git a/src/libsystemd-dhcp/dhcp-client.c b/src/libsystemd-dhcp/dhcp-client.c
index b9492a5a680d349781f2c3e4b03b2dfd850e6830..dbec869816532fc93ebef5e1f199bf0284ae7610 100644 (file)
--- a/src/libsystemd-dhcp/dhcp-client.c
+++ b/src/libsystemd-dhcp/dhcp-client.c
@@ -41,6 +41,7 @@ struct DHCPLease {
         be32_t server_address;
         be32_t subnet_mask;
         be32_t router;
+        be32_t dns;
 };
 
 typedef struct DHCPLease DHCPLease;
@@ -209,6 +210,33 @@ int sd_dhcp_client_get_netmask(sd_dhcp_client *client, struct in_addr *addr)
         return 0;
 }
 
+int sd_dhcp_client_get_dns(sd_dhcp_client *client, struct in_addr *addr)
+{
+        assert_return(client, -EINVAL);
+        assert_return(addr, -EINVAL);
+
+        switch (client->state) {
+        case DHCP_STATE_INIT:
+        case DHCP_STATE_SELECTING:
+        case DHCP_STATE_INIT_REBOOT:
+        case DHCP_STATE_REBOOTING:
+        case DHCP_STATE_REQUESTING:
+                return -EADDRNOTAVAIL;
+
+        case DHCP_STATE_BOUND:
+        case DHCP_STATE_RENEWING:
+        case DHCP_STATE_REBINDING:
+                if (client->lease->dns)
+                        addr->s_addr = client->lease->dns;
+                else
+                        return -ENOENT;
+
+                break;
+        }
+
+        return 0;
+}
+
 int sd_dhcp_client_prefixlen(const struct in_addr *addr)
 {
         int len = 0;
@@ -260,8 +288,6 @@ static int client_notify(sd_dhcp_client *client, int event)
 static int client_stop(sd_dhcp_client *client, int error)
 {
         assert_return(client, -EINVAL);
-        assert_return(client->state != DHCP_STATE_INIT &&
-                      client->state != DHCP_STATE_INIT_REBOOT, -EALREADY);
 
         client->receive_message =
                 sd_event_source_unref(client->receive_message);
@@ -729,6 +755,12 @@ static int client_parse_offer(uint8_t code, uint8_t len, const uint8_t *option,
 
                 break;
 
+        case DHCP_OPTION_DOMAIN_NAME_SERVER:
+                if (len >= 4)
+                        memcpy(&lease->dns, option, 4);
+
+                break;
+
         case DHCP_OPTION_RENEWAL_T1_TIME:
                 if (len == 4) {
                         memcpy(&val, option, 4);