Merge pull request #29442 from yuwata/network-dhcp4-preferred-address

network: introduce [DHCPv4] PreferredAddress= setting

src/network/networkd-dhcp4.c

@@ -1383,15 +1383,15 @@ static int dhcp4_set_client_identifier(Link *link) {
         return 0;
 }
 
-static int dhcp4_set_request_address(Link *link) {
+static int dhcp4_find_dynamic_address(Link *link, struct in_addr *ret) {
         Address *a;
 
         assert(link);
         assert(link->network);
-        assert(link->dhcp_client);
+        assert(ret);
 
         if (!FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP))
-                return 0;
+                return false;
 
         SET_FOREACH(a, link->addresses) {
                 if (a->source != NETWORK_CONFIG_SOURCE_FOREIGN)
@@ -1403,11 +1403,29 @@ static int dhcp4_set_request_address(Link *link) {
         }
 
         if (!a)
+                return false;
+
+        *ret = a->in_addr.in;
+        return true;
+}
+
+static int dhcp4_set_request_address(Link *link) {
+        struct in_addr a;
+
+        assert(link);
+        assert(link->network);
+        assert(link->dhcp_client);
+
+        a = link->network->dhcp_request_address;
+
+        if (in4_addr_is_null(&a))
+                (void) dhcp4_find_dynamic_address(link, &a);
+
+        if (in4_addr_is_null(&a))
                 return 0;
 
-        log_link_debug(link, "DHCPv4 CLIENT: requesting " IPV4_ADDRESS_FMT_STR, IPV4_ADDRESS_FMT_VAL(a->in_addr.in));
-
-        return sd_dhcp_client_set_request_address(link->dhcp_client, &a->in_addr.in);
+        log_link_debug(link, "DHCPv4 CLIENT: requesting %s.", IN4_ADDR_TO_STRING(&a));
+        return sd_dhcp_client_set_request_address(link->dhcp_client, &a);
 }
 
 static bool link_needs_dhcp_broadcast(Link *link) {
@@ -1487,6 +1505,10 @@ static int dhcp4_configure(Link *link) {
         }
 
         if (!link->network->dhcp_anonymize) {
+                r = dhcp4_set_request_address(link);
+                if (r < 0)
+                        return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to set initial DHCPv4 address: %m");
+
                 if (link->network->dhcp_use_mtu) {
                         r = sd_dhcp_client_set_request_option(link->dhcp_client, SD_DHCP_OPTION_MTU_INTERFACE);
                         if (r < 0)
@@ -1616,10 +1638,6 @@ static int dhcp4_configure(Link *link) {
                         return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed set to lease lifetime: %m");
         }
 
-        r = dhcp4_set_request_address(link);
-        if (r < 0)
-                return log_link_debug_errno(link, r, "DHCPv4 CLIENT: Failed to set initial DHCPv4 address: %m");
-
         return dhcp4_set_client_identifier(link);
 }
 

src/network/networkd-network-gperf.gperf

@@ -214,6 +214,7 @@ NextHop.Family,                              config_parse_nexthop_family,
 NextHop.OnLink,                              config_parse_nexthop_onlink,                              0,                             0
 NextHop.Blackhole,                           config_parse_nexthop_blackhole,                           0,                             0
 NextHop.Group,                               config_parse_nexthop_group,                               0,                             0
+DHCPv4.RequestAddress,                       config_parse_in_addr_non_null,                            AF_INET,                       offsetof(Network, dhcp_request_address)
 DHCPv4.ClientIdentifier,                     config_parse_dhcp_client_identifier,                      0,                             offsetof(Network, dhcp_client_identifier)
 DHCPv4.UseDNS,                               config_parse_dhcp_use_dns,                                AF_INET,                       0
 DHCPv4.RoutesToDNS,                          config_parse_bool,                                        0,                             offsetof(Network, dhcp_routes_to_dns)

src/network/networkd-network.h

@@ -114,6 +114,7 @@ struct Network {
 
         /* DHCP Client Support */
         AddressFamily dhcp;
+        struct in_addr dhcp_request_address;
         DHCPClientIdentifier dhcp_client_identifier;
         DUID dhcp_duid;
         uint32_t dhcp_iaid;