fix(sta2eth): Make some Ethernet options configurable

examples/network/sta2eth/main/Kconfig.projbuild

@@ -86,4 +86,26 @@ menu "Example Configuration"
             the reconfiguration mode, i.e. to restart provisioning
             or manual configuration of Wi-Fi settings (ssid, password)
 
+    if EXAMPLE_WIRED_INTERFACE_IS_ETHERNET
+
+        config EXAMPLE_MODIFY_DHCP_MESSAGES
+            bool "Modify DHCP messages"
+            default y
+            help
+                This is needed if the client uses 61 option and the DHCP server applies strict rules
+                on assigning addresses.
+                Set this to 'n' if you don't need DHCP or you're using simplified DHCP workflow
+                without HW address options in DHCP messages.
+
+        config EXAMPLE_ETHERNET_USE_PROMISCUOUS
+            bool "Enable promiscuous mode on Ethernet interface"
+            default n
+            help
+                Enable promiscuous mode on the Ethernet interface.
+                Note: Enabling promiscuous mode results in better throughput as MAC addresses
+                in frames are not rewritten with the Ethernet interface's actual MAC address.
+                Note: Enabling promiscuous mode may cause ARP conflicts if the PC
+                is also connected to the same network with another NIC.
+    endif
+
 endmenu

examples/network/sta2eth/main/ethernet_iface.c

@@ -20,13 +20,13 @@
  *  - this results in better throughput
  *  - might cause ARP conflicts if the PC is also connected to the same AP with another NIC
  */
-#define ETH_BRIDGE_PROMISCUOUS  0
+#define ETH_BRIDGE_PROMISCUOUS  CONFIG_EXAMPLE_ETHERNET_USE_PROMISCUOUS
 
 /**
  * Set this to 1 to runtime update HW addresses in DHCP messages
  * (this is needed if the client uses 61 option and the DHCP server applies strict rules on assigning addresses)
  */
-#define MODIFY_DHCP_MSGS        0
+#define MODIFY_DHCP_MSGS        CONFIG_EXAMPLE_MODIFY_DHCP_MESSAGES
 
 static const char *TAG = "example_wired_ethernet";
 static esp_eth_handle_t s_eth_handle = NULL;