sd-netlink: drop sd_genl_family_t and introduce GenericNetlinkFamily

Kernel manages each genl family by its name, e.g. "nlctrl" or WG_GENL_NAME,
and its ID (used for nlmsg_type) is determined dynamically when the
corresponding module is loaded.

This commit makes sd-netlink follow the same way; now, sd_genl_family_t
is dropped, and sd_genl_message_new() takes a genl family name. Each
genl family is resolved when it is used first time, and its information
is stored in GenericNetlinkFamily.

src/network/netdev/batadv.c

@@ -122,7 +122,7 @@ static int netdev_batadv_post_create(NetDev *netdev, Link *link, sd_netlink_mess
         b = BATADV(netdev);
         assert(b);
 
-        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_BATADV, BATADV_CMD_SET_MESH, &message);
+        r = sd_genl_message_new(netdev->manager->genl, BATADV_NL_NAME, BATADV_CMD_SET_MESH, &message);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r, "Failed to allocate generic netlink message: %m");
 

src/network/netdev/fou-tunnel.c

@@ -36,7 +36,7 @@ static int netdev_fill_fou_tunnel_message(NetDev *netdev, sd_netlink_message **r
 
         assert(t);
 
-        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_FOU, FOU_CMD_ADD, &m);
+        r = sd_genl_message_new(netdev->manager->genl, FOU_GENL_NAME, FOU_CMD_ADD, &m);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r, "Failed to allocate generic netlink message: %m");
 

src/network/netdev/l2tp-tunnel.c

@@ -104,7 +104,7 @@ static int netdev_l2tp_fill_message_tunnel(NetDev *netdev, union in_addr_union *
 
         assert(t);
 
-        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_L2TP, L2TP_CMD_TUNNEL_CREATE, &m);
+        r = sd_genl_message_new(netdev->manager->genl, L2TP_GENL_NAME, L2TP_CMD_TUNNEL_CREATE, &m);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r, "Failed to create generic netlink message: %m");
 
@@ -195,7 +195,7 @@ static int netdev_l2tp_fill_message_session(NetDev *netdev, L2tpSession *session
         assert(session);
         assert(session->tunnel);
 
-        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_L2TP, L2TP_CMD_SESSION_CREATE, &m);
+        r = sd_genl_message_new(netdev->manager->genl, L2TP_GENL_NAME, L2TP_CMD_SESSION_CREATE, &m);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r, "Failed to create generic netlink message: %m");
 

src/network/netdev/macsec.c

@@ -224,7 +224,7 @@ static int netdev_macsec_fill_message(NetDev *netdev, int command, sd_netlink_me
         assert(netdev);
         assert(netdev->ifindex > 0);
 
-        r = sd_genl_message_new(netdev->manager->genl, SD_GENL_MACSEC, command, &m);
+        r = sd_genl_message_new(netdev->manager->genl, MACSEC_GENL_NAME, command, &m);
         if (r < 0)
                 return log_netdev_error_errno(netdev, r, "Failed to create generic netlink message: %m");
 

src/network/netdev/wireguard.c

@@ -229,7 +229,7 @@ static int wireguard_set_interface(NetDev *netdev) {
 
                 message = sd_netlink_message_unref(message);
 
-                r = sd_genl_message_new(netdev->manager->genl, SD_GENL_WIREGUARD, WG_CMD_SET_DEVICE, &message);
+                r = sd_genl_message_new(netdev->manager->genl, WG_GENL_NAME, WG_CMD_SET_DEVICE, &message);
                 if (r < 0)
                         return log_netdev_error_errno(netdev, r, "Failed to allocate generic netlink message: %m");