lwip: Support IPv6 only mode

examples/protocols/coap_client/README.md

@@ -107,3 +107,5 @@ optional `path`, and begins with `coap://`, `coaps://`, `coap+tcp://` or `coaps+
 * CoAP logging can be enabled by running 'idf.py menuconfig -> Component config -> CoAP Configuration -> Enable CoAP debugging'
 and setting appropriate log level.  If Mbed TLS logging is required, this needs to be configured separately under mbedTLS
 Component Configuration and the CoAP logging level set to mbedTLS.
+
+* CoAP library does not support IPv6 only configuration, so it is necessary to enable `LWIP_IPv4`

examples/protocols/coap_client/main/Kconfig.projbuild

@@ -1,5 +1,11 @@
 menu "Example CoAP Client Configuration"
 
+    # Hidden option that selects IPv4
+    config EXAMPLE_COAP_NEEDS_IPV4
+        bool
+        default true
+        select LWIP_IPV4
+
     config EXAMPLE_TARGET_DOMAIN_URI
         string "Target Uri"
         default "coaps://californium.eclipseprojects.io"

examples/protocols/coap_server/README.md

@@ -92,3 +92,5 @@ fetches `/.well-known/core`
 * CoAP logging can be enabled by running 'idf.py menuconfig -> Component config -> CoAP Configuration -> Enable CoAP debugging'
 and setting appropriate log level.  If Mbed TLS logging is required, this needs to be configured separately under mbedTLS
 Component Configuration and the CoAP logging level set to mbedTLS.
+
+* CoAP library does not support IPv6 only configuration, so it is necessary to enable `LWIP_IPv4`

examples/protocols/coap_server/main/Kconfig.projbuild

@@ -1,5 +1,11 @@
 menu "Example CoAP Server Configuration"
 
+    # Hidden option that selects IPv4
+    config EXAMPLE_COAP_NEEDS_IPV4
+        bool
+        default true
+        select LWIP_IPV4
+
     config EXAMPLE_COAP_PSK_KEY
         string "Preshared Key (PSK) to used in the connection from the CoAP client"
         depends on COAP_MBEDTLS_PSK

examples/protocols/esp_local_ctrl/README.md

@@ -9,6 +9,8 @@ See the `esp_local_ctrl` component documentation for details.
 
 Before using the example, run `idf.py menuconfig` (or `idf.py menuconfig` if using CMake build system) to configure Wi-Fi or Ethernet. See "Establishing Wi-Fi or Ethernet Connection" section in [examples/protocols/README.md](../README.md) for more details.
 
+Note, that this example in not supported for IPv6-only configuration.
+
 ## Client Side Implementation
 
 A python test script `scripts/esp_local_ctrl.py` has been provided for as a client side application for controlling the device over the same Wi-Fi network. The script relies on a pre-generated `main/certs/rootCA.pem` to verify the server certificate. The server side private key and certificate can also be found under `main/certs`, namely `prvtkey.pem` and `cacert.pem`.

examples/protocols/http_server/simple/sdkconfig.ci.ipv6_only

@@ -0,0 +1,5 @@
+CONFIG_EXAMPLE_WIFI_SSID_PWD_FROM_STDIN=y
+CONFIG_EXAMPLE_CONNECT_IPV4=n
+CONFIG_EXAMPLE_CONNECT_IPV6=y
+CONFIG_LWIP_IPV4=n
+CONFIG_LWIP_IPV6=y

examples/protocols/sockets/tcp_server/main/Kconfig.projbuild

@@ -3,6 +3,7 @@ menu "Example Configuration"
     config EXAMPLE_IPV4
         bool "IPV4"
         default y
+        depends on LWIP_IPV4
 
     config EXAMPLE_IPV6
         bool "IPV6"

examples/protocols/sockets/tcp_server/main/tcp_server.c

@@ -73,6 +73,7 @@ static void tcp_server_task(void *pvParameters)
     int keepCount = KEEPALIVE_COUNT;
     struct sockaddr_storage dest_addr;
 
+#ifdef CONFIG_EXAMPLE_IPV4
     if (addr_family == AF_INET) {
         struct sockaddr_in *dest_addr_ip4 = (struct sockaddr_in *)&dest_addr;
         dest_addr_ip4->sin_addr.s_addr = htonl(INADDR_ANY);
@@ -80,8 +81,9 @@ static void tcp_server_task(void *pvParameters)
         dest_addr_ip4->sin_port = htons(PORT);
         ip_protocol = IPPROTO_IP;
     }
+#endif
 #ifdef CONFIG_EXAMPLE_IPV6
-    else if (addr_family == AF_INET6) {
+    if (addr_family == AF_INET6) {
         struct sockaddr_in6 *dest_addr_ip6 = (struct sockaddr_in6 *)&dest_addr;
         bzero(&dest_addr_ip6->sin6_addr.un, sizeof(dest_addr_ip6->sin6_addr.un));
         dest_addr_ip6->sin6_family = AF_INET6;
@@ -138,11 +140,13 @@ static void tcp_server_task(void *pvParameters)
         setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL, &keepInterval, sizeof(int));
         setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT, &keepCount, sizeof(int));
         // Convert ip address to string
+#ifdef CONFIG_EXAMPLE_IPV4
         if (source_addr.ss_family == PF_INET) {
             inet_ntoa_r(((struct sockaddr_in *)&source_addr)->sin_addr, addr_str, sizeof(addr_str) - 1);
         }
+#endif
 #ifdef CONFIG_EXAMPLE_IPV6
-        else if (source_addr.ss_family == PF_INET6) {
+        if (source_addr.ss_family == PF_INET6) {
             inet6_ntoa_r(((struct sockaddr_in6 *)&source_addr)->sin6_addr, addr_str, sizeof(addr_str) - 1);
         }
 #endif

examples/protocols/sockets/tcp_server/sdkconfig.ci.ipv6_only

@@ -0,0 +1,6 @@
+CONFIG_EXAMPLE_WIFI_SSID_PWD_FROM_STDIN=y
+CONFIG_EXAMPLE_IPV4=n
+CONFIG_EXAMPLE_IPV6=y
+CONFIG_EXAMPLE_CONNECT_IPV6=y
+CONFIG_LWIP_IPV4=n
+CONFIG_LWIP_IPV6=y