Cellular: Fix resolving of DNS server IPv4/6 address

Author: Ari Parkkila

UNITTESTS/stubs/AT_CellularContext_stub.cpp

@@ -288,3 +288,7 @@ char *AT_CellularContext::get_interface_name(char *interface_name)
 {
     return NULL;
 }
+
+void AT_CellularContext::is_prefer_ipv6(char *ip, size_t ip_size, char *ip2, size_t ip2_size)
+{
+}

UNITTESTS/stubs/AT_CellularStack_stub.cpp

@@ -94,3 +94,7 @@ void AT_CellularStack::socket_attach(nsapi_socket_t handle, void (*callback)(voi
 {
 }
 
+bool AT_CellularStack::is_addr_stack_compatible(const SocketAddress &addr)
+{
+    return true;
+}

UNITTESTS/target_h/myCellularContext.h

@@ -220,6 +220,9 @@ class myCellularContext : public CellularContext {
     {
     };
 
+    void is_prefer_ipv6(char *ip, size_t ip_size, char *ip2, size_t ip2_size)
+    {
+    };
 };
 
 }

features/cellular/framework/AT/AT_CellularContext.cpp

@@ -841,31 +841,31 @@ nsapi_error_t AT_CellularContext::get_pdpcontext_params(pdpContextList_t &params
 
         _at.read_string(ipv6_and_subnetmask, ipv6_subnet_size);
         separate_ip_addresses(ipv6_and_subnetmask, params->gateway_addr, sizeof(params->gateway_addr), temp, max_ipv6_size);
-        prefer_ipv6(params->gateway_addr, sizeof(params->gateway_addr), temp, max_ipv6_size);
+        is_prefer_ipv6(params->gateway_addr, sizeof(params->gateway_addr), temp, max_ipv6_size);
         ipv6_and_subnetmask[0] = '\0';
         temp[0] = '\0';
 
         _at.read_string(ipv6_and_subnetmask, ipv6_subnet_size);
         separate_ip_addresses(ipv6_and_subnetmask, params->dns_primary_addr, sizeof(params->dns_primary_addr), temp, max_ipv6_size);
-        prefer_ipv6(params->dns_primary_addr, sizeof(params->dns_primary_addr), temp, max_ipv6_size);
+        is_prefer_ipv6(params->dns_primary_addr, sizeof(params->dns_primary_addr), temp, max_ipv6_size);
         ipv6_and_subnetmask[0] = '\0';
         temp[0] = '\0';
 
         _at.read_string(ipv6_and_subnetmask, ipv6_subnet_size);
         separate_ip_addresses(ipv6_and_subnetmask, params->dns_secondary_addr, sizeof(params->dns_secondary_addr), temp, max_ipv6_size);
-        prefer_ipv6(params->dns_secondary_addr, sizeof(params->dns_secondary_addr), temp, max_ipv6_size);
+        is_prefer_ipv6(params->dns_secondary_addr, sizeof(params->dns_secondary_addr), temp, max_ipv6_size);
         ipv6_and_subnetmask[0] = '\0';
         temp[0] = '\0';
 
         _at.read_string(ipv6_and_subnetmask, ipv6_subnet_size);
         separate_ip_addresses(ipv6_and_subnetmask, params->p_cscf_prim_addr, sizeof(params->p_cscf_prim_addr), temp, max_ipv6_size);
-        prefer_ipv6(params->p_cscf_prim_addr, sizeof(params->p_cscf_prim_addr), temp, max_ipv6_size);
+        is_prefer_ipv6(params->p_cscf_prim_addr, sizeof(params->p_cscf_prim_addr), temp, max_ipv6_size);
         ipv6_and_subnetmask[0] = '\0';
         temp[0] = '\0';
 
         _at.read_string(ipv6_and_subnetmask, ipv6_subnet_size);
         separate_ip_addresses(ipv6_and_subnetmask, params->p_cscf_sec_addr, sizeof(params->p_cscf_sec_addr), temp, max_ipv6_size);
-        prefer_ipv6(params->p_cscf_sec_addr, sizeof(params->p_cscf_sec_addr), temp, max_ipv6_size);
+        is_prefer_ipv6(params->p_cscf_sec_addr, sizeof(params->p_cscf_sec_addr), temp, max_ipv6_size);
 
         params->im_signalling_flag = _at.read_int();
         params->lipa_indication = _at.read_int();
@@ -1065,3 +1065,16 @@ void AT_CellularContext::set_disconnect()
     _is_connected = false;
     _device->cellular_callback(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, NSAPI_STATUS_DISCONNECTED, this);
 }
+
+void AT_CellularContext::is_prefer_ipv6(char *ip, size_t ip_size, char *ip2, size_t ip2_size)
+{
+#if NSAPI_PPP_AVAILABLE
+    prefer_ipv6(ip, ip_size, ip2, ip2_size);
+#else
+    AT_CellularStack *stack = static_cast<AT_CellularStack *>(get_stack());
+    SocketAddress addr("127.0.0.1");
+    if (!stack->is_addr_stack_compatible(addr)) {
+        prefer_ipv6(ip, ip_size, ip2, ip2_size);
+    }
+#endif
+}

features/cellular/framework/AT/AT_CellularContext.h

@@ -109,6 +109,7 @@ class AT_CellularContext : public CellularContext, public AT_CellularBase {
     void ppp_status_cb(nsapi_event_t ev, intptr_t ptr);
     void ppp_disconnected();
 #endif // #if NSAPI_PPP_AVAILABLE
+    void is_prefer_ipv6(char *ip, size_t ip_size, char *ip2, size_t ip2_size);
     nsapi_error_t do_activate_context();
     virtual void activate_context();
     nsapi_error_t find_and_activate_context();

features/cellular/framework/AT/AT_CellularStack.cpp

@@ -410,4 +410,3 @@ bool AT_CellularStack::is_addr_stack_compatible(const SocketAddress &addr)
     }
     return true;
 }
-

features/cellular/framework/AT/AT_CellularStack.h

@@ -44,6 +44,14 @@ class AT_CellularStack : public NetworkStack, public AT_CellularBase {
 public: // NetworkStack
 
     virtual const char *get_ip_address();
+
+    /**
+     *  Checks if send to address is valid and if current stack type supports sending to that address type
+     *  @param  addr for nsapi_version_t compatiblity check
+     *  @return true on supported, false otherwise
+     */
+    bool is_addr_stack_compatible(const SocketAddress &addr);
+
 protected: // NetworkStack
 
     /**
@@ -192,11 +200,6 @@ class AT_CellularStack : public NetworkStack, public AT_CellularBase {
      */
     int find_socket_index(nsapi_socket_t handle);
 
-    /**
-     *  Checks if send to address is valid and if current stack type supports sending to that address type
-     */
-    bool is_addr_stack_compatible(const SocketAddress &addr);
-
     // socket container
     CellularSocket **_socket;