core/ipv4/dhcp: Set hostname for DISCOVER packets

If the hostname is not set in the DISCOVER packet, then some servers might
issue an OFFER with that it will reject when the hostname is presented in
the REQUEST packet.

Signed-off-by: Logan Gunthorpe <[email protected]>
Signed-off-by: xueyunfei <[email protected]>

Author: lsgunth

src/core/ipv4/dhcp.c

@@ -1057,6 +1057,12 @@ dhcp_discover(struct netif *netif)
     options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
     options_out_len = dhcp_option_short(options_out_len, msg_out->options, DHCP_MAX_MSG_LEN(netif));
 
+#if ESP_DHCP
+#if LWIP_NETIF_HOSTNAME
+    options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
+#endif /* LWIP NETIF HOSTNAME */
+#endif /* ESP_DHCP */
+
     options_out_len = dhcp_option(options_out_len, msg_out->options, DHCP_OPTION_PARAMETER_REQUEST_LIST, LWIP_ARRAYSIZE(dhcp_discover_request_options));
     for (i = 0; i < LWIP_ARRAYSIZE(dhcp_discover_request_options); i++) {
       options_out_len = dhcp_option_byte(options_out_len, msg_out->options, dhcp_discover_request_options[i]);