Added version to nsapi get host by name

Author: Mika Leppänen

features/net/FEATURE_IPV4/lwip-interface/lwip_stack.c

@@ -525,23 +525,38 @@ static int lwip_err_remap(err_t err) {
 }
 
 /* LWIP network stack implementation */
-static int lwip_gethostbyname(nsapi_stack_t *stack, const char *host, nsapi_addr_t *addr)
+static int lwip_gethostbyname(nsapi_stack_t *stack, const char *host, nsapi_addr_t *addr, nsapi_version_t version)
 {
     ip_addr_t lwip_addr;
 
 #if LWIP_IPV4 && LWIP_IPV6
     u8_t addr_type;
-    const ip_addr_t *ip_addr;
-    ip_addr = lwip_get_ip_addr(true, &lwip_netif);
-    if (IP_IS_V6(ip_addr)) {
-        addr_type = NETCONN_DNS_IPV6;
-    } else {
+    if (version == NSAPI_UNSPEC) {
+        const ip_addr_t *ip_addr;
+        ip_addr = lwip_get_ip_addr(true, &lwip_netif);
+        if (IP_IS_V6(ip_addr)) {
+            addr_type = NETCONN_DNS_IPV6;
+        } else {
+            addr_type = NETCONN_DNS_IPV4;
+        }
+    } else if (version == NSAPI_IPv4) {
         addr_type = NETCONN_DNS_IPV4;
+    } else if (version == NSAPI_IPv6) {
+        addr_type = NETCONN_DNS_IPV6;
     }
     err_t err = netconn_gethostbyname_addrtype(host, &lwip_addr, addr_type);
-#else
+#elif LWIP_IPV4
+    if (version != NSAPI_IPv4 && version != NSAPI_UNSPEC) {
+        return NSAPI_ERROR_DNS_FAILURE;
+    }
+    err_t err = netconn_gethostbyname(host, &lwip_addr);
+#elif LWIP_IPV6
+    if (version != NSAPI_IPv6 && version != NSAPI_UNSPEC) {
+        return NSAPI_ERROR_DNS_FAILURE;
+    }
     err_t err = netconn_gethostbyname(host, &lwip_addr);
 #endif
+
     if (err != ERR_OK) {
         return NSAPI_ERROR_DNS_FAILURE;
     }

features/net/network-socket/NetworkStack.cpp

@@ -107,7 +107,19 @@ class NetworkStackWrapper : public NetworkStack
         }
 
         nsapi_addr_t addr = {NSAPI_IPv4, 0};
-        int err = _stack_api()->gethostbyname(_stack(), name, &addr);
+        int err = _stack_api()->gethostbyname(_stack(), name, &addr, NSAPI_UNSPEC);
+        address->set_addr(addr);
+        return err;
+    }
+
+    virtual int gethostbyname(const char *name, SocketAddress *address, nsapi_version_t version)
+    {
+        if (!_stack_api()->gethostbyname) {
+            return NetworkStack::gethostbyname(name, address, version);
+        }
+
+        nsapi_addr_t addr = {NSAPI_IPv4, 0};
+        int err = _stack_api()->gethostbyname(_stack(), name, &addr, version);
         address->set_addr(addr);
         return err;
     }

features/net/network-socket/nsapi_types.h

@@ -85,15 +85,16 @@ typedef enum nsapi_error {
  *  @enum nsapi_version_t
  */
 typedef enum nsapi_version {
-    NSAPI_IPv4, /*!< Address is IPv4 */
-    NSAPI_IPv6, /*!< Address is IPv6 */
+    NSAPI_IPv4,   /*!< Address is IPv4 */
+    NSAPI_IPv6,   /*!< Address is IPv6 */
+    NSAPI_UNSPEC  /*!< Address is unspecified */
 } nsapi_version_t;
 
 /** IP address structure for passing IP addresses by value
  */
 typedef struct nsapi_addr {
     /** IP version
-     *  NSAPI_IPv4 or NSAPI_IPv6
+     *  NSAPI_IPv4 or NSAPI_IPv6 (NSAPI_UNSPEC not currently supported)
      */
     nsapi_version_t version;
 
@@ -197,9 +198,10 @@ typedef struct nsapi_stack_api
      *  @param stack    Stack handle
      *  @param addr     Destination for the host IP address
      *  @param host     Hostname to resolve
+     *  @param version  Address family
      *  @return         0 on success, negative error code on failure
      */
-    int (*gethostbyname)(nsapi_stack_t *stack, const char *host, nsapi_addr_t *addr);
+    int (*gethostbyname)(nsapi_stack_t *stack, const char *host, nsapi_addr_t *addr, nsapi_version_t version);
 
     /** Add a domain name server to list of servers to query
      *