Assign different subnets to different network interfaces

common_examples/tcp_client/README.md

@@ -6,15 +6,29 @@ This example provides a basic implementation of TCP client for ESP32 with driver
 TCP client is designed to periodically transmit to the server, and accept responses, which are printed to the console.
 
 ## Configuring the example
-Configure the example using `idf.py menuconfig`, according to your setup, provide settings for Ethernet initialization. Next, go to `Example options` and input the IP address of your PC in the local network to which ESP32 is connected. If you want to connect this to another ESP32 device running `tcp_server` example, make sure to the the `Server IP address` to 196.168.1.1
+Configure the example using `idf.py menuconfig`, according to your setup, provide settings for Ethernet initialization. Next, go to `Example options` and set the `Server IP address`.
+
+### Determining the server IP address
+If you are running a TCP server on your PC using `tcp_server.py` - run a command to see your IP:
+* Windows - `ipconfig /all`
+* macOS/Linux - `ifconfig`
+
+If you are running a TCP server on another ESP32 along with a DHCP server - see the output of your server for lines such as:
+```
+I (6349) tcp_server: --------
+I (6359) tcp_server: Network Interface 0: 192.168.0.1
+I (6359) tcp_server: Network Interface 1: 192.168.1.1
+I (6369) tcp_server: --------
+```
+It will list all your network interfaces and the IP address assigned to it. Depending on the interface you are connected to - set the `Server IP address` accordingly.
 
 ## Running the example
 
-After you obtain an IP address you will see a message reading `TCP client is started, waiting for the server to accept a connection.`. 
+After you obtain an IP address you will see a message reading `TCP client is started, waiting for the server to accept a connection.`
 
 If you are connecting the device to a PC - start the server with `tcp_server.py`. The command to do so is `tcp_server.py IP` to start listening on the specified IP address.
 
 **Important**: use the IP address of your PC in the local network to which ESP32 is connected. It **must** match the IP address you've set in the `Example options`.
 
 
-You will see incoming messages in ESP32 console or as an as output of `tcp_server.py` if you have ran it.
+You will see incoming messages in the ESP32 console or as an output of `tcp_server.py` if you are connecting the ESP32 to your PC and running a TCP server using a script.

common_examples/tcp_server/README.md

@@ -7,7 +7,7 @@ TCP server is designed to accept transmissions from the client, print them to th
 
 ## Configuring the example
 Configure the example using `idf.py menuconfig`, according to your setup, provide settings for Ethernet initialization. If you want to connect to another ESP32, set the 
-`Act as DHCP server` option in the `Example options`, the IP address of the device will be 192.168.1.1.
+`Act as DHCP server` option in the `Example options`, each IP addres will be assigned an IP 192.168.n.1, where `n` is the number of the interface.
 
 ## Running the example
 To transmit data between your PC and ESP32 you need to wait until it obtains an IP address from DHCP server and run tcp client script.

common_examples/tcp_server/main/tcp_server.c

@@ -13,23 +13,11 @@
 #define SOCKET_MAX_LENGTH   128
 static const char *TAG = "tcp_server";
 
-esp_netif_ip_info_t ip_info = {
-    .ip = {.addr = ESP_IP4TOADDR(192, 168, 1, 1)},
-    .netmask = {.addr =  ESP_IP4TOADDR(255, 255, 255, 0)},
-    .gw = {.addr = ESP_IP4TOADDR(192, 168, 1, 1)}
-};
-
-static void start_dhcp_server_at_connection(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)
-{
-    esp_netif_dhcpc_stop(esp_netif);
-    esp_netif_set_ip_info(esp_netif, &ip_info);
-    esp_netif_dhcps_start(esp_netif);
-}
-
-
 void app_main(void)
 {
     uint8_t eth_port_cnt = 0;
+    char if_key_str[10];
+    char if_desc_str[10];
     esp_eth_handle_t *eth_handles;
     esp_netif_config_t cfg;
     esp_netif_inherent_config_t eth_netif_cfg;
@@ -38,27 +26,55 @@ void app_main(void)
     ethernet_init_all(&eth_handles, &eth_port_cnt);
 
 #if CONFIG_EXAMPLE_ACT_AS_DHCP_SERVER
-    // Config for ESP32 to act as DHCP server
+    esp_netif_ip_info_t *ip_infos;
+
+    ip_infos = calloc(eth_port_cnt, sizeof(esp_netif_ip_info_t));
+
     eth_netif_cfg = (esp_netif_inherent_config_t) {
         .get_ip_event = IP_EVENT_ETH_GOT_IP,
         .lost_ip_event = 0,
         .flags = ESP_NETIF_DHCP_SERVER,
-        .ip_info = &ip_info,
-        .if_key = "ETH_DHCPS",
-        .if_desc = "eth",
         .route_prio = 50
     };
+    cfg = (esp_netif_config_t) {
+        .base = &eth_netif_cfg,
+        .stack = ESP_NETIF_NETSTACK_DEFAULT_ETH
+    };
+
+    for (uint8_t i = 0; i < eth_port_cnt; i++) {
+        sprintf(if_key_str, "ETH_S%d", i);
+        sprintf(if_desc_str, "eth%d", i);
+
+        esp_netif_ip_info_t ip_info_i = {
+            .ip = {.addr = ESP_IP4TOADDR(192, 168, i, 1)},
+            .netmask = {.addr =  ESP_IP4TOADDR(255, 255, 255, 0)},
+            .gw = {.addr = ESP_IP4TOADDR(192, 168, i, 1)}
+        };
+        ip_infos[i] = ip_info_i;
+
+        eth_netif_cfg.if_key = if_key_str;
+        eth_netif_cfg.if_desc = if_desc_str;
+        eth_netif_cfg.route_prio -= i * 5;
+        eth_netif_cfg.ip_info = &(ip_infos[i]);
+        esp_netif_t *eth_netif = esp_netif_new(&cfg);
+        ESP_ERROR_CHECK(esp_netif_attach(eth_netif, esp_eth_new_netif_glue(eth_handles[i])));
+        esp_eth_start(eth_handles[i]);
+        esp_netif_dhcpc_stop(eth_netif);
+        esp_netif_dhcps_start(eth_netif);
+    }
+    ESP_LOGI(TAG, "--------");
+    for (uint8_t i = 0; i < eth_port_cnt; i++) {
+        ESP_LOGI(TAG, "Network Interface %d: " IPSTR, i, IP2STR(&ip_infos[i].ip));
+    }
+    ESP_LOGI(TAG, "--------");
 #else
     if (eth_port_cnt == 1) {
         // Use default config when using one interface
         eth_netif_cfg = *(ESP_NETIF_BASE_DEFAULT_ETH);
     } else {
-        // Set behavioral config to support multiple interfaces
+        // Set config to support multiple interfaces
         eth_netif_cfg = (esp_netif_inherent_config_t) ESP_NETIF_INHERENT_DEFAULT_ETH();
     }
-#endif
-    char if_key_str[10];
-    char if_desc_str[10];
     cfg = (esp_netif_config_t) {
         .base = &eth_netif_cfg,
         .stack = ESP_NETIF_NETSTACK_DEFAULT_ETH
@@ -71,13 +87,10 @@ void app_main(void)
         eth_netif_cfg.route_prio -= i * 5;
         esp_netif_t *eth_netif = esp_netif_new(&cfg);
         ESP_ERROR_CHECK(esp_netif_attach(eth_netif, esp_eth_new_netif_glue(eth_handles[i])));
-
-#if CONFIG_EXAMPLE_ACT_AS_DHCP_SERVER
-        esp_event_handler_register(ETH_EVENT, ETHERNET_EVENT_CONNECTED, start_dhcp_server_at_connection, eth_netif);
-#endif
-
         esp_eth_start(eth_handles[i]);
     }
+#endif
+
     int server_fd, client_fd;
     struct sockaddr_in server, client;
     char rxbuffer[SOCKET_MAX_LENGTH] = {0};