Cellular: Fix BG96 AT driver for IPv6

Author: Ari Parkkila

features/cellular/framework/targets/QUECTEL/BG96/QUECTEL_BG96.cpp

@@ -57,8 +57,8 @@ static const intptr_t cellular_properties[AT_CellularBase::PROPERTY_MAX] = {
     1,  // AT_CMGF
     1,  // AT_CSDH
     1,  // PROPERTY_IPV4_STACK
-    0,  // PROPERTY_IPV6_STACK
-    0,  // PROPERTY_IPV4V6_STACK
+    1,  // PROPERTY_IPV6_STACK
+    1,  // PROPERTY_IPV4V6_STACK
     1,  // PROPERTY_NON_IP_PDP_TYPE
     1,  // PROPERTY_AT_CGEREP
 };

features/cellular/framework/targets/QUECTEL/BG96/QUECTEL_BG96_CellularStack.cpp

@@ -15,6 +15,7 @@
  * limitations under the License.
  */
 
+#include <string.h>
 #include "QUECTEL/BG96/QUECTEL_BG96_CellularStack.h"
 #include "CellularLog.h"
 
@@ -60,8 +61,10 @@ nsapi_error_t QUECTEL_BG96_CellularStack::socket_connect(nsapi_socket_t handle,
 
     _at.lock();
     if (socket->proto == NSAPI_TCP) {
+        char ipdot[NSAPI_IP_SIZE];
+        ip2dot(address, ipdot);
         _at.at_cmd_discard("+QIOPEN", "=", "%d%d%s%s%d%d%d", _cid, request_connect_id, "TCP",
-                           address.get_ip_address(), address.get_port(), socket->localAddress.get_port(), 0);
+                           ipdot, address.get_port(), socket->localAddress.get_port(), 0);
 
         handle_open_socket_response(modem_connect_id, err);
 
@@ -74,7 +77,7 @@ nsapi_error_t QUECTEL_BG96_CellularStack::socket_connect(nsapi_socket_t handle,
             _at.at_cmd_discard("+QICLOSE", "=", "%d", modem_connect_id);
 
             _at.at_cmd_discard("+QIOPEN", "=", "%d%d%s%s%d%d%d", _cid, request_connect_id, "TCP",
-                               address.get_ip_address(), address.get_port(), socket->localAddress.get_port(), 0);
+                               ipdot, address.get_port(), socket->localAddress.get_port(), 0);
 
             handle_open_socket_response(modem_connect_id, err);
         }
@@ -228,8 +231,10 @@ nsapi_error_t QUECTEL_BG96_CellularStack::create_socket_impl(CellularSocket *soc
             handle_open_socket_response(modem_connect_id, err);
         }
     } else if (socket->proto == NSAPI_UDP && socket->connected) {
+        char ipdot[NSAPI_IP_SIZE];
+        ip2dot(socket->remoteAddress, ipdot);
         _at.at_cmd_discard("+QIOPEN", "=", "%d%d%s%s%d", _cid, request_connect_id, "UDP",
-                           socket->remoteAddress.get_ip_address(), socket->remoteAddress.get_port());
+                           ipdot, socket->remoteAddress.get_port());
 
         handle_open_socket_response(modem_connect_id, err);
 
@@ -241,7 +246,7 @@ nsapi_error_t QUECTEL_BG96_CellularStack::create_socket_impl(CellularSocket *soc
             socket_close_impl(modem_connect_id);
 
             _at.at_cmd_discard("+QIOPEN", "=", "%d%d%s%s%d", _cid, request_connect_id, "UDP",
-                               socket->remoteAddress.get_ip_address(), socket->remoteAddress.get_port());
+                               ipdot, socket->remoteAddress.get_port());
 
             handle_open_socket_response(modem_connect_id, err);
         }
@@ -264,7 +269,9 @@ nsapi_error_t QUECTEL_BG96_CellularStack::create_socket_impl(CellularSocket *soc
 nsapi_size_or_error_t QUECTEL_BG96_CellularStack::socket_sendto_impl(CellularSocket *socket, const SocketAddress &address,
                                                                      const void *data, nsapi_size_t size)
 {
-    if (size > BG96_MAX_SEND_SIZE) {
+    if (size > BG96_MAX_SEND_SIZE ||
+            (_stack_type == IPV4_STACK && address.get_ip_version() != NSAPI_IPv4) ||
+            (_stack_type == IPV6_STACK && address.get_ip_version() != NSAPI_IPv6)) {
         return NSAPI_ERROR_PARAMETER;
     }
 
@@ -277,8 +284,10 @@ nsapi_size_or_error_t QUECTEL_BG96_CellularStack::socket_sendto_impl(CellularSoc
 
     // Send
     if (socket->proto == NSAPI_UDP) {
+        char ipdot[NSAPI_IP_SIZE];
+        ip2dot(address, ipdot);
         _at.cmd_start_stop("+QISEND", "=", "%d%d%s%d", socket->id, size,
-                           address.get_ip_address(), address.get_port());
+                           ipdot, address.get_port());
     } else {
         _at.cmd_start_stop("+QISEND", "=", "%d%d", socket->id, size);
     }
@@ -401,3 +410,21 @@ nsapi_error_t QUECTEL_BG96_CellularStack::gethostbyname_async_cancel(int id)
     return NSAPI_ERROR_OK;
 }
 #endif
+
+void QUECTEL_BG96_CellularStack::ip2dot(const SocketAddress &ip, char *dot)
+{
+    if (ip.get_ip_version() == NSAPI_IPv6) {
+        const uint8_t *bytes = (uint8_t *)ip.get_ip_bytes();
+        char *p = dot;
+        for (int i = 0; i < NSAPI_IPv6_BYTES; i += 2) {
+            if (i != 0) {
+                *dot++ = ':';
+            }
+            dot += sprintf(dot, "%x", (*(bytes + i) << 8 | *(bytes + i + 1)));
+        }
+    } else if (ip.get_ip_version() == NSAPI_IPv4) {
+        strcpy(dot, ip.get_ip_address());
+    } else {
+        *dot = '\0';
+    }
+}

features/cellular/framework/targets/QUECTEL/BG96/QUECTEL_BG96_CellularStack.h

@@ -89,6 +89,14 @@ class QUECTEL_BG96_CellularStack : public AT_CellularStack {
     hostbyname_cb_t _dns_callback;
     nsapi_version_t _dns_version;
 #endif
+    /** Convert IP address to dotted string representation
+     *
+     *  BG96 requires consecutive zeros so can't use get_ip_address or ip6tos directly.
+     *
+     *  @param ip address
+     *  @param dot buffer with size NSAPI_IPv6, where address is written zero terminated
+     */
+    void ip2dot(const SocketAddress &ip, char *dot);
 };
 } // namespace mbed
 #endif /* QUECTEL_BG96_CELLULARSTACK_H_ */