dhcp: Set hostname for DISCOVER packets

If the hostname is not set in the DISCOVER packet, then some servers might issue an OFFER with hostname configured and consequently reject the REQUEST with any other hostname. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Co-Authored-By: Simon Goldschmidt <goldsimon@gmx.de>
espressif · May 11, 2023 · 90b2a6b · 90b2a6b
1 parent 5231c8d
commit 90b2a6b
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diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
@@ -1031,6 +1031,10 @@ 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 LWIP_NETIF_HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME
+    options_out_len = dhcp_option_hostname(options_out_len, msg_out->options, netif);
+#endif /* LWIP NETIF HOSTNAME && LWIP_DHCP_DISCOVER_ADD_HOSTNAME */
+
     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]);

diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
@@ -966,6 +966,14 @@
 #if !defined LWIP_DHCP_MAX_DNS_SERVERS || defined __DOXYGEN__
 #define LWIP_DHCP_MAX_DNS_SERVERS       DNS_MAX_SERVERS
 #endif
+
+/** LWIP_DHCP_DISCOVER_ADD_HOSTNAME: Set to 1 to include hostname opt in discover packets.
+ * If the hostname is not set in the DISCOVER packet, then some servers might issue an OFFER with hostname
+ * configured and consequently reject the REQUEST with any other hostname.
+ */
+#if !defined LWIP_DHCP_DISCOVER_ADD_HOSTNAME || defined __DOXYGEN__
+#define LWIP_DHCP_DISCOVER_ADD_HOSTNAME 0
+#endif /* LWIP_DHCP_DISCOVER_ADD_HOSTNAME */
 /**
  * @}
  */