common_connect: add support for getting multiple IPv6 addresses

examples/common_components/protocol_examples_common/Kconfig.projbuild

@@ -175,9 +175,44 @@ menu "Example Connection Configuration"
     endif
 
     config EXAMPLE_CONNECT_IPV6
-        bool "Obtain IPv6 link-local address"
+        bool "Obtain IPv6 address"
         default y
         help
-            By default, examples will wait until IPv4 and IPv6 addresses are obtained.
+            By default, examples will wait until IPv4 and IPv6 local link addresses are obtained.
             Disable this option if the network does not support IPv6.
+            Choose the preferred IPv6 address type if the connection code should wait until other than
+            the local link address gets assigned.
+
+    if EXAMPLE_CONNECT_IPV6
+        choice EXAMPLE_CONNECT_PREFERRED_IPV6
+            prompt "Preferred IPv6 Type"
+            default EXAMPLE_CONNECT_IPV6_PREF_LOCAL_LINK
+            help
+                Select which kind of IPv6 address the connect logic waits for.
+
+            config EXAMPLE_CONNECT_IPV6_PREF_LOCAL_LINK
+                bool "Local Link Address"
+                help
+                    Blocks until Local link address assigned.
+
+            config EXAMPLE_CONNECT_IPV6_PREF_GLOBAL
+                bool "Global Address"
+                help
+                    Blocks until Global address assigned.
+
+            config EXAMPLE_CONNECT_IPV6_PREF_SITE_LOCAL
+                bool "Site Local Address"
+                help
+                    Blocks until Site link address assigned.
+
+            config EXAMPLE_CONNECT_IPV6_PREF_UNIQUE_LOCAL
+                bool "Unique Local Link Address"
+                help
+                    Blocks until Unique local address assigned.
+
+        endchoice
+
+    endif
+
+
 endmenu

examples/common_components/protocol_examples_common/connect.c

@@ -30,6 +30,17 @@
 
 #ifdef CONFIG_EXAMPLE_CONNECT_IPV6
 #define CONNECTED_BITS (GOT_IPV4_BIT | GOT_IPV6_BIT)
+
+#if defined(CONFIG_EXAMPLE_CONNECT_IPV6_PREF_LOCAL_LINK)
+#define EXAMPLE_CONNECT_PREFERRED_IPV6_TYPE ESP_IP6_ADDR_IS_LINK_LOCAL
+#elif defined(CONFIG_EXAMPLE_CONNECT_IPV6_PREF_GLOBAL)
+#define EXAMPLE_CONNECT_PREFERRED_IPV6_TYPE ESP_IP6_ADDR_IS_GLOBAL
+#elif defined(CONFIG_EXAMPLE_CONNECT_IPV6_PREF_SITE_LOCAL)
+#define EXAMPLE_CONNECT_PREFERRED_IPV6_TYPE ESP_IP6_ADDR_IS_SITE_LOCAL
+#elif defined(CONFIG_EXAMPLE_CONNECT_IPV6_PREF_UNIQUE_LOCAL)
+#define EXAMPLE_CONNECT_PREFERRED_IPV6_TYPE ESP_IP6_ADDR_IS_UNIQUE_LOCAL
+#endif // if-elif CONFIG_EXAMPLE_CONNECT_IPV6_PREF_...
+
 #else
 #define CONNECTED_BITS (GOT_IPV4_BIT)
 #endif
@@ -41,6 +52,16 @@ static esp_netif_t *s_example_esp_netif = NULL;
 
 #ifdef CONFIG_EXAMPLE_CONNECT_IPV6
 static esp_ip6_addr_t s_ipv6_addr;
+
+/* types of ipv6 addresses to be displayed on ipv6 events */
+static const char *s_ipv6_addr_types[] = {
+    "ESP_IP6_ADDR_IS_UNKNOWN",
+    "ESP_IP6_ADDR_IS_GLOBAL",
+    "ESP_IP6_ADDR_IS_LINK_LOCAL",
+    "ESP_IP6_ADDR_IS_SITE_LOCAL",
+    "ESP_IP6_ADDR_IS_UNIQUE_LOCAL",
+    "ESP_IP6_ADDR_IS_IPV4_MAPPED_IPV6"
+    };
 #endif
 
 static const char *TAG = "example_connect";
@@ -70,11 +91,12 @@ static void on_got_ipv6(void *arg, esp_event_base_t event_base,
         ESP_LOGD(TAG, "Got IPv6 from another netif: ignored");
         return;
     }
-    ESP_LOGI(TAG, "Got IPv6 event!");
+    esp_ip6_addr_type_t ipv6_type = esp_netif_ip6_get_addr_type(&event->ip6_info.ip);
+    ESP_LOGI(TAG, "Got IPv6 address: " IPV6STR ", type: %s", IPV62STR(event->ip6_info.ip), s_ipv6_addr_types[ipv6_type]);
+    if (ipv6_type == EXAMPLE_CONNECT_PREFERRED_IPV6_TYPE) {
         memcpy(&s_ipv6_addr, &event->ip6_info.ip, sizeof(s_ipv6_addr));
         xEventGroupSetBits(s_connect_event_group, GOT_IPV6_BIT);
-    ESP_LOGI(TAG, "IPv6 address: " IPV6STR ", index: %d, type: %d", IPV62STR(s_ipv6_addr), event->ip_index, esp_ip6_get_addr_type(&s_ipv6_addr));
-
+    }
 }
 
 #endif // CONFIG_EXAMPLE_CONNECT_IPV6

examples/protocols/sockets/README.md

@@ -71,6 +71,26 @@ IP_VERSION = 'IPv4'
 IPV4 = '192.168.0.167'
 IPV6 = 'FE80::32AE:A4FF:FE80:5288'
 ```
+### Note about IPv6 addresses
+
+Examples are configured to obtain multiple IPv6 addresses. The actual behavior may differ depending on the local network, typically the ESP gets assigned these two addresses
+
+* Local Link address
+
+* Unique Local address
+
+The value and type of the IPv6 address is displayed in the terminal, for example:
+
+Please make sure that when using the Local Link address, an interface id is included in the configuration:
+
+* In the embedded code
+```
+    dest_addr.sin6_scope_id = esp_netif_get_netif_impl_index(esp_netif_instance);
+```
+* On the host
+
+   - Interface name suffix is present when passing the address as a string, for example `fe80::260a:XXX:XXX:XXX%en0`
+   - The interface id is present when passing the endpoint as tupple, for example `socket.connect(('fd00::260a:XXXX:XXXX:XXXX', 3333, 0, 3))`
 
 ## Hardware Required