libsystemd-network: add support for "Client FQDN" DHCP option

This adds support for the Client Fully Qualified Domain Name (FQDN)
option [RFC 4702] to libsystemd-network. The option can be used to
exchange information about a DHCPv4 client's fully qualified domain
name and about responsibility for updating the DNS RR related to the
client's address assignment.

Other popular DHCP clients (dhclient, dhcpcd) support this option and
it would be useful to have it in networkd too.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/libsystemd-network/dhcp-protocol.h b/src/libsystemd-network/dhcp-protocol.h
index 88a81d2866..5cf4e9e306 100644
--- a/src/libsystemd-network/dhcp-protocol.h
+++ b/src/libsystemd-network/dhcp-protocol.h
@@ -137,6 +137,7 @@ enum {
         DHCP_OPTION_REBINDING_T2_TIME           = 59,
         DHCP_OPTION_VENDOR_CLASS_IDENTIFIER     = 60,
         DHCP_OPTION_CLIENT_IDENTIFIER           = 61,
+        DHCP_OPTION_FQDN                        = 81,
         DHCP_OPTION_NEW_POSIX_TIMEZONE          = 100,
         DHCP_OPTION_NEW_TZDB_TIMEZONE           = 101,
         DHCP_OPTION_CLASSLESS_STATIC_ROUTE      = 121,
@@ -144,3 +145,12 @@ enum {
         DHCP_OPTION_PRIVATE_LAST                = 254,
         DHCP_OPTION_END                         = 255,
 };
+
+#define DHCP_MAX_FQDN_LENGTH 255
+
+enum {
+        DHCP_FQDN_FLAG_S = (1 << 0),
+        DHCP_FQDN_FLAG_O = (1 << 1),
+        DHCP_FQDN_FLAG_E = (1 << 2),
+        DHCP_FQDN_FLAG_N = (1 << 3),
+};