+static int client_parse_message(sd_dhcp6_client *client,
+ DHCP6Message *message, size_t len,
+ sd_dhcp6_lease *lease) {
+ int r;
+ uint8_t *optval, *option = (uint8_t *)(message + 1), *id = NULL;
+ uint16_t optcode, status;
+ size_t optlen, id_len;
+ bool clientid = false;
+ be32_t iaid_lease;
+
+ while ((r = dhcp6_option_parse(&option, &len, &optcode, &optlen,
+ &optval)) >= 0) {
+ switch (optcode) {
+ case DHCP6_OPTION_CLIENTID:
+ if (clientid) {
+ log_dhcp6_client(client, "%s contains multiple clientids",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ if (optlen != sizeof(client->duid) ||
+ memcmp(&client->duid, optval, optlen) != 0) {
+ log_dhcp6_client(client, "%s DUID does not match",
+ dhcp6_message_type_to_string(message->type));
+
+ return -EINVAL;
+ }
+ clientid = true;
+
+ break;
+
+ case DHCP6_OPTION_SERVERID:
+ r = dhcp6_lease_get_serverid(lease, &id, &id_len);
+ if (r >= 0 && id) {
+ log_dhcp6_client(client, "%s contains multiple serverids",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ r = dhcp6_lease_set_serverid(lease, optval, optlen);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DHCP6_OPTION_PREFERENCE:
+ if (optlen != 1)
+ return -EINVAL;
+
+ r = dhcp6_lease_set_preference(lease, *optval);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case DHCP6_OPTION_STATUS_CODE:
+ if (optlen < 2)
+ return -EINVAL;
+
+ status = optval[0] << 8 | optval[1];
+ if (status) {
+ log_dhcp6_client(client, "%s Status %s",
+ dhcp6_message_type_to_string(message->type),
+ dhcp6_message_status_to_string(status));
+ return -EINVAL;
+ }
+
+ break;
+
+ case DHCP6_OPTION_IA_NA:
+ r = dhcp6_option_parse_ia(&optval, &optlen, optcode,
+ &lease->ia);
+ if (r < 0 && r != -ENOMSG)
+ return r;
+
+ r = dhcp6_lease_get_iaid(lease, &iaid_lease);
+ if (r < 0)
+ return r;
+
+ if (client->ia_na.id != iaid_lease) {
+ log_dhcp6_client(client, "%s has wrong IAID",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ break;
+ }
+ }
+
+ if ((r < 0 && r != -ENOMSG) || !clientid) {
+ log_dhcp6_client(client, "%s has incomplete options",
+ dhcp6_message_type_to_string(message->type));
+ return -EINVAL;
+ }
+
+ r = dhcp6_lease_get_serverid(lease, &id, &id_len);
+ if (r < 0)
+ log_dhcp6_client(client, "%s has no server id",
+ dhcp6_message_type_to_string(message->type));
+
+ return r;
+}
+
+static int client_receive_advertise(sd_dhcp6_client *client,
+ DHCP6Message *advertise, size_t len) {
+ int r;
+ _cleanup_dhcp6_lease_free_ sd_dhcp6_lease *lease = NULL;
+ uint8_t pref_advertise = 0, pref_lease = 0;
+
+ if (advertise->type != DHCP6_ADVERTISE)
+ return -EINVAL;
+
+ r = dhcp6_lease_new(&lease);
+ if (r < 0)
+ return r;
+
+ r = client_parse_message(client, advertise, len, lease);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_lease_get_preference(lease, &pref_advertise);
+ if (r < 0)
+ return r;
+
+ r = dhcp6_lease_get_preference(client->lease, &pref_lease);
+ if (!client->lease || r < 0 || pref_advertise > pref_lease) {
+ sd_dhcp6_lease_unref(client->lease);
+ client->lease = lease;
+ lease = NULL;
+ r = 0;
+ }
+
+ return r;
+}
+