G?khan Alkan:
> I try to develop poc code for postfix content filtering. All i need is read
> the 10025/tcp and send all data which i can read to 10026/tcp. Below is my
> poc code. But i try to send email it doesn't work and postfix show me "451
> 4.3.0 Error: queue file write error".
I recommend that you use netcat.
Wietse
> fcntl(server_sock, F_SETFL, O_NONBLOCK);
What if fcntl() reports an error?
> fcntl(client_sock, F_SETFL, O_NONBLOCK);
client_sock is still zero here.
What if fcntl() reports an error?
> client_sock = accept(server_sock, (struct sockaddr
> *)&client_addr, &addr_len);
What if accept() reports an error? It will always return -1 because
server_sock is non-blocking. Thus, client_sock will always be -1.
> sock_fd = socket(AF_INET, SOCK_STREAM, 0);
What if socket() reports an error?
> while(1) {
> result = recv(client_sock, buff, sizeof(buff),0 );
What if recv() reports an error? At this point, client_sock is
-1 because accept() reported an error. See above.
> inet_pton(AF_INET, REMOTE_IP, &remote_addr.sin_addr);
> connect(sock_fd, (struct sockaddr *)&remote_addr,
> sizeof(remote_addr));
What if connect() reports an error?
> send(sock_fd, buff, (sizeof(buff)-1), 0);
What if send() reports an error?
> }
The above program loops forever in while(1).
> shutdown(client_sock, SHUT_RDWR);
What if shutdown() reports an error? At this point client_sock is -1
because accept() reported an error. See above.
> close(server_sock);
> close(client_sock);
> close(sock_fd);
Wietse
