networkd: dhcp add vendor class indentifier option 60

Vendor Class Identifier be used by DHCP clients to identify
their vendor type and configuration. When using this option,
vendors can define their own specific identifier values, such
as to convey a particular hardware or operating system
configuration or other identifying information.

Vendor-specified DHCP options—features that let administrators assign
separate options to clients with similar configuration requirements.
For example, if DHCP-aware clients for example we want to separate
different gateway and option for different set of people
(dev/test/hr/finance) in a org or devices for example web/database
servers or let's say in a embedded device etc and require a different
default gateway or DNS server than the rest of clients.

Author: Susant Sahani

man/systemd.network.xml

@@ -446,6 +446,12 @@
                                                 if, say, the root filesystem relies on this connection. Defaults to false.</para>
                                         </listitem>
                                 </varlistentry>
+                                    <varlistentry>
+                                        <term><varname>VendorClassIdentifier=</varname></term>
+                                        <listitem>
+                                                <para>The vendor class identifier used to identify vendor type and configuration.</para>
+                                        </listitem>
+                                </varlistentry>
                        </variablelist>
 
         </refsect1>

src/libsystemd-network/dhcp-protocol.h

@@ -131,6 +131,7 @@ enum {
         DHCP_OPTION_MAXIMUM_MESSAGE_SIZE        = 57,
         DHCP_OPTION_RENEWAL_T1_TIME             = 58,
         DHCP_OPTION_REBINDING_T2_TIME           = 59,
+        DHCP_OPTION_VENDOR_CLASS_IDENTIFIER     = 60,
         DHCP_OPTION_CLIENT_IDENTIFIER           = 61,
         DHCP_OPTION_CLASSLESS_STATIC_ROUTE      = 121,
         DHCP_OPTION_END                         = 255,

src/libsystemd-network/sd-dhcp-client.c

@@ -57,6 +57,7 @@ struct sd_dhcp_client {
                 struct ether_addr mac_addr;
         } _packed_ client_id;
         char *hostname;
+        char *vendor_class_identifier;
         uint32_t xid;
         usec_t start_time;
         uint16_t secs;
@@ -200,6 +201,23 @@ int sd_dhcp_client_set_hostname(sd_dhcp_client *client,
         return 0;
 }
 
+int sd_dhcp_client_set_vendor_class_identifier(sd_dhcp_client *client,
+                                               const char *vci) {
+        char *new_vci = NULL;
+
+        assert_return(client, -EINVAL);
+
+        new_vci = strdup(vci);
+        if (!new_vci)
+                return -ENOMEM;
+
+        free(client->vendor_class_identifier);
+
+        client->vendor_class_identifier = new_vci;
+
+        return 0;
+}
+
 int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret) {
         assert_return(client, -EINVAL);
         assert_return(ret, -EINVAL);
@@ -419,6 +437,15 @@ static int client_send_discover(sd_dhcp_client *client) {
                         return r;
         }
 
+        if (client->vendor_class_identifier) {
+                r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
+                                       DHCP_OPTION_VENDOR_CLASS_IDENTIFIER,
+                                       strlen(client->vendor_class_identifier),
+                                       client->vendor_class_identifier);
+                if (r < 0)
+                        return r;
+        }
+
         r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
                                DHCP_OPTION_END, 0, NULL);
         if (r < 0)
@@ -1406,6 +1433,7 @@ sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) {
 
                 free(client->req_opts);
                 free(client->hostname);
+                free(client->vendor_class_identifier);
                 free(client);
         }
 

src/network/networkd-link.c

@@ -2023,6 +2023,13 @@ static int link_configure(Link *link) {
                                         return r;
                         }
                 }
+
+                if (link->network->dhcp_vendor_class_identifier) {
+                        r = sd_dhcp_client_set_vendor_class_identifier(link->dhcp_client,
+                                                                       link->network->dhcp_vendor_class_identifier);
+                        if (r < 0)
+                                return r;
+                }
         }
 
         if (link->network->dhcp_server) {

src/network/networkd-network-gperf.gperf

@@ -51,6 +51,7 @@ DHCP.UseDomainName,          config_parse_bool,                  0,
 DHCP.UseRoutes,              config_parse_bool,                  0,                             offsetof(Network, dhcp_routes)
 DHCP.SendHostname,           config_parse_bool,                  0,                             offsetof(Network, dhcp_sendhost)
 DHCP.CriticalConnection,     config_parse_bool,                  0,                             offsetof(Network, dhcp_critical)
+DHCP.VendorClassIdentifier,  config_parse_string,                0,                             offsetof(Network, dhcp_vendor_class_identifier)
 /* backwards compatibility: do not add new entries to this section */
 DHCPv4.UseDNS,               config_parse_bool,                  0,                             offsetof(Network, dhcp_dns)
 DHCPv4.UseMTU,               config_parse_bool,                  0,                             offsetof(Network, dhcp_mtu)

src/network/networkd-network.c

@@ -166,6 +166,7 @@ void network_free(Network *network) {
         free(network->match_name);
 
         free(network->description);
+        free(network->dhcp_vendor_class_identifier);
 
         while ((address = network->ntp)) {
                 LIST_REMOVE(addresses, network->ntp, address);

src/network/networkd.h

@@ -175,6 +175,8 @@ struct Network {
         char *match_driver;
         char *match_type;
         char *match_name;
+        char *dhcp_vendor_class_identifier;
+
         Condition *match_host;
         Condition *match_virt;
         Condition *match_kernel;

src/systemd/sd-dhcp-client.h

@@ -52,6 +52,7 @@ int sd_dhcp_client_set_index(sd_dhcp_client *client, int interface_index);
 int sd_dhcp_client_set_mac(sd_dhcp_client *client,
                            const struct ether_addr *addr);
 int sd_dhcp_client_set_hostname(sd_dhcp_client *client, const char *hostname);
+int sd_dhcp_client_set_vendor_class_identifier(sd_dhcp_client *client, const char *vci);
 int sd_dhcp_client_get_lease(sd_dhcp_client *client, sd_dhcp_lease **ret);
 
 int sd_dhcp_client_stop(sd_dhcp_client *client);