Multiple memory handling fixes

Based on valgrind reports running on unit tests following changes were introduced:
* TLSSocketWrapper frees allocated cert buffer in case of errors from mbedtls,
* nsapi_addr has a mem_init() function, initializing all of its memory during construction.

Author: michalpasztamobica

features/netsocket/InternetSocket.cpp

@@ -21,6 +21,7 @@ using namespace mbed;
 
 InternetSocket::InternetSocket()
     : _stack(0), _socket(0), _timeout(osWaitForever),
+      _remote_peer(),
       _readers(0), _writers(0),
       _factory_allocated(false)
 {

features/netsocket/SocketAddress.cpp

@@ -26,32 +26,43 @@
 
 SocketAddress::SocketAddress(nsapi_addr_t addr, uint16_t port)
 {
+    mem_init();
     _ip_address = NULL;
     set_addr(addr);
     set_port(port);
 }
 
 SocketAddress::SocketAddress(const char *addr, uint16_t port)
 {
+    mem_init();
     _ip_address = NULL;
     set_ip_address(addr);
     set_port(port);
 }
 
 SocketAddress::SocketAddress(const void *bytes, nsapi_version_t version, uint16_t port)
 {
+    mem_init();
     _ip_address = NULL;
     set_ip_bytes(bytes, version);
     set_port(port);
 }
 
 SocketAddress::SocketAddress(const SocketAddress &addr)
 {
+    mem_init();
     _ip_address = NULL;
     set_addr(addr.get_addr());
     set_port(addr.get_port());
 }
 
+void SocketAddress::mem_init(void)
+{
+    _addr.version = NSAPI_UNSPEC;
+    memset(_addr.bytes, 0, NSAPI_IP_BYTES);
+    _port = 0;
+}
+
 bool SocketAddress::set_ip_address(const char *addr)
 {
     delete[] _ip_address;

features/netsocket/SocketAddress.h

@@ -178,6 +178,9 @@ class SocketAddress {
 private:
     void _SocketAddress(NetworkStack *iface, const char *host, uint16_t port);
 
+    /** Initialize memory */
+    void mem_init(void);
+
     mutable char *_ip_address;
     nsapi_addr_t _addr;
     uint16_t _port;

features/netsocket/TLSSocketWrapper.cpp

@@ -99,6 +99,8 @@ nsapi_error_t TLSSocketWrapper::set_root_ca_cert(const void *root_ca, size_t len
     if ((ret = mbedtls_x509_crt_parse(crt, static_cast<const unsigned char *>(root_ca),
                                       len)) != 0) {
         print_mbedtls_error("mbedtls_x509_crt_parse", ret);
+        mbedtls_x509_crt_free(crt);
+        delete crt;
         return NSAPI_ERROR_PARAMETER;
     }
     set_ca_chain(crt);
@@ -130,12 +132,16 @@ nsapi_error_t TLSSocketWrapper::set_client_cert_key(const void *client_cert, siz
     if ((ret = mbedtls_x509_crt_parse(crt, static_cast<const unsigned char *>(client_cert),
                                       client_cert_len)) != 0) {
         print_mbedtls_error("mbedtls_x509_crt_parse", ret);
+        mbedtls_x509_crt_free(crt);
+        delete crt;
         return NSAPI_ERROR_PARAMETER;
     }
     mbedtls_pk_init(&_pkctx);
     if ((ret = mbedtls_pk_parse_key(&_pkctx, static_cast<const unsigned char *>(client_private_key_pem),
                                     client_private_key_len, NULL, 0)) != 0) {
         print_mbedtls_error("mbedtls_pk_parse_key", ret);
+        mbedtls_x509_crt_free(crt);
+        delete crt;
         return NSAPI_ERROR_PARAMETER;
     }
     set_own_cert(crt);