TCP sendto removal + error when UDP for hostnames

- UDP inet_pton(remote_ip)'s result is not checked -> the server ends up
  sending packets to the null address when a hostname is given instead
of a IPv4 address. A error is now raised

- TCP is using sendto() instead of send(). We can thus remove a useless
inet_pton() call (which moreover differs from the gethostbyaddr used in
setup_port() - possible issues when using hostnames)

Signed-off-by: Benoit Maurin <[email protected]>

src/mavsdk/core/tcp_client_connection.cpp

@@ -163,16 +163,11 @@ bool TcpClientConnection::send_message(const mavlink_message_t& message)
  auto flags = MSG_NOSIGNAL;
 #endif
 
- const auto send_len = sendto(
- _socket_fd.get(),
- reinterpret_cast<char*>(buffer),
- buffer_len,
- flags,
- reinterpret_cast<const sockaddr*>(&dest_addr),
- sizeof(dest_addr));
+ const auto send_len =
+ send(_socket_fd.get(), reinterpret_cast<const char*>(buffer), buffer_len, flags);
 
  if (send_len != buffer_len) {
- LogErr() << "sendto failure: " << GET_ERROR(errno);
+ LogErr() << "send failure: " << GET_ERROR(errno);
  _is_ok = false;
  return false;
  }

src/mavsdk/core/udp_connection.cpp

@@ -77,7 +77,10 @@ ConnectionResult UdpConnection::setup_port()
 
  struct sockaddr_in addr {};
  addr.sin_family = AF_INET;
- inet_pton(AF_INET, _local_ip.c_str(), &(addr.sin_addr));
+ if (inet_pton(AF_INET, _local_ip.c_str(), &(addr.sin_addr)) != 1) {
+ LogErr() << "inet_pton failure for address: " << _local_ip;
+ return ConnectionResult::SocketError;
+ }
  addr.sin_port = htons(_local_port_number);
 
  if (bind(_socket_fd.get(), reinterpret_cast<sockaddr*>(&addr), sizeof(addr)) != 0) {
@@ -129,7 +132,11 @@ bool UdpConnection::send_message(const mavlink_message_t& message)
  struct sockaddr_in dest_addr {};
  dest_addr.sin_family = AF_INET;
 
- inet_pton(AF_INET, remote.ip.c_str(), &dest_addr.sin_addr.s_addr);
+ if (inet_pton(AF_INET, remote.ip.c_str(), &dest_addr.sin_addr.s_addr) != 1) {
+ LogErr() << "inet_pton failure for address: " << remote.ip;
+ send_successful = false;
+ continue;
+ }
  dest_addr.sin_port = htons(remote.port_number);
 
  uint8_t buffer[MAVLINK_MAX_PACKET_LEN];