networkd: link - (de)serialize IPv4LL and DHCPv4 addresses

This initializes the clients to try rebinding the preexisting
addresses before doing anything else.

3 files changed, 73 insertions, 11 deletions

diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
index 05a16f4033..b58fc5808c 100644
--- a/src/network/networkd-dhcp4.c
+++ b/src/network/networkd-dhcp4.c
@@ -533,9 +533,11 @@ int dhcp4_configure(Link *link) {
         assert(link->network);
         assert(link->network->dhcp & ADDRESS_FAMILY_IPV4);
 
-        r = sd_dhcp_client_new(&link->dhcp_client);
-        if (r < 0)
-                return r;
+        if (!link->dhcp_client) {
+                r = sd_dhcp_client_new(&link->dhcp_client);
+                if (r < 0)
+                        return r;
+        }
 
         r = sd_dhcp_client_attach_event(link->dhcp_client, NULL, 0);
         if (r < 0)
diff --git a/src/network/networkd-ipv4ll.c b/src/network/networkd-ipv4ll.c
index 59abb1e8d4..ed0d861e7a 100644
--- a/src/network/networkd-ipv4ll.c
+++ b/src/network/networkd-ipv4ll.c
@@ -208,9 +208,11 @@ int ipv4ll_configure(Link *link) {
         assert(link->network);
         assert(link->network->link_local & ADDRESS_FAMILY_IPV4);
 
-        r = sd_ipv4ll_new(&link->ipv4ll);
-        if (r < 0)
-                return r;
+        if (!link->ipv4ll) {
+                r = sd_ipv4ll_new(&link->ipv4ll);
+                if (r < 0)
+                        return r;
+        }
 
         if (link->udev_device) {
                 r = net_get_unique_predictable_data(link->udev_device, seed);
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 4243f8cba9..5dcd862c21 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -2133,7 +2133,11 @@ int link_initialized(Link *link, struct udev_device *device) {
 }
 
 static int link_load(Link *link) {
-        _cleanup_free_ char *network_file = NULL, *addresses = NULL;
+        _cleanup_free_ char *network_file = NULL,
+                            *addresses = NULL,
+                            *dhcp4_address = NULL,
+                            *ipv4ll_address = NULL;
+        union in_addr_union address;
         int r;
 
         assert(link);
@@ -2141,6 +2145,8 @@ static int link_load(Link *link) {
         r = parse_env_file(link->state_file, NEWLINE,
                            "NETWORK_FILE", &network_file,
                            "ADDRESSES", &addresses,
+                           "DHCP4_ADDRESS", &dhcp4_address,
+                           "IPV4LL_ADDRESS", &ipv4ll_address,
                            NULL);
         if (r < 0 && r != -ENOENT)
                 return log_link_error_errno(link, r, "Failed to read %s: %m", link->state_file);
@@ -2182,7 +2188,6 @@ network_file_fail:
                         char *prefixlen_str;
                         int family;
                         unsigned char prefixlen;
-                        union in_addr_union address;
 
                         prefixlen_str = strchr(*address_str, '/');
                         if (!prefixlen_str) {
@@ -2210,6 +2215,42 @@ network_file_fail:
                 }
         }
 
+        if (dhcp4_address) {
+                r = in_addr_from_string(AF_INET, dhcp4_address, &address);
+                if (r < 0) {
+                        log_link_debug_errno(link, r, "Falied to parse DHCPv4 address %s: %m", dhcp4_address);
+                        goto dhcp4_address_fail;
+                }
+
+                r = sd_dhcp_client_new(&link->dhcp_client);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Falied to create DHCPv4 client: %m");
+
+                r = sd_dhcp_client_set_request_address(link->dhcp_client, &address.in);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Falied to set inital DHCPv4 address %s: %m", dhcp4_address);
+        }
+
+dhcp4_address_fail:
+
+        if (ipv4ll_address) {
+                r = in_addr_from_string(AF_INET, ipv4ll_address, &address);
+                if (r < 0) {
+                        log_link_debug_errno(link, r, "Falied to parse IPv4LL address %s: %m", ipv4ll_address);
+                        goto ipv4ll_address_fail;
+                }
+
+                r = sd_ipv4ll_new(&link->ipv4ll);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Falied to create IPv4LL client: %m");
+
+                r = sd_ipv4ll_set_address(link->ipv4ll, &address.in);
+                if (r < 0)
+                        return log_link_error_errno(link, r, "Falied to set inital IPv4LL address %s: %m", ipv4ll_address);
+        }
+
+ipv4ll_address_fail:
+
         return 0;
 }
 
@@ -2696,15 +2737,21 @@ int link_save(Link *link) {
         }
 
         if (link->dhcp_lease) {
+                struct in_addr address;
                 const char *tz = NULL;
 
+                assert(link->network);
+
                 r = sd_dhcp_lease_get_timezone(link->dhcp_lease, &tz);
                 if (r >= 0)
                         fprintf(f, "TIMEZONE=%s\n", tz);
-        }
 
-        if (link->dhcp_lease) {
-                assert(link->network);
+                r = sd_dhcp_lease_get_address(link->dhcp_lease, &address);
+                if (r >= 0) {
+                        fputs("DHCP4_ADDRESS=", f);
+                        serialize_in_addrs(f, &address, 1);
+                        fputc('\n', f);
+                }
 
                 r = dhcp_lease_save(link->dhcp_lease, link->lease_file);
                 if (r < 0)
@@ -2716,6 +2763,17 @@ int link_save(Link *link) {
         } else
                 unlink(link->lease_file);
 
+        if (link->ipv4ll) {
+                struct in_addr address;
+
+                r = sd_ipv4ll_get_address(link->ipv4ll, &address);
+                if (r >= 0) {
+                        fputs("IPV4LL_ADDRESS=", f);
+                        serialize_in_addrs(f, &address, 1);
+                        fputc('\n', f);
+                }
+        }
+
         if (link->lldp) {
                 assert(link->network);