Basic TCP Server
From NutWiki
First register network driver and configure interface by using DHCP.
NutRegisterDevice(&DEV_ETHER, 0, 0); if (NutDhcpIfConfig(DEV_ETHER_NAME, 0, 60000)) { /* Error: Cannot configure interface. */ }
There are several alternatives:
- Network Configuration Using Hard Coded Configuration
- Network Configuration Using Stored Configuration
- Network Configuration Using a Configuration Editor
Next, create a socket and wait for client connections at a specified port (8000).
sock = NutTcpCreateSocket(); if (NutTcpAccept(sock, 8000)) { /* Error: Cannot connect server. */ }
To prevent DOS attack, set timeout value for established TCP connection:
uint32_t to = 10000; NutTcpSetSockOpt(sock, SO_RCVTIMEO, &to, sizeof(to));
You may then receive data from the client...
got = NutTcpRecv(sock, buffer, len); if (got <= 0) { /* Error or connection closed by the client. */ }
... or send data to the client.
if (NutTcpSend(sock, buffer, len) != len) { /* Error or connection closed by the client. */ }
When done, close the socket. This will also close the connection if it is still established.
NutTcpCloseSocket(sock);
For more advanced applications you can redirect the connected socket to a file stream and use standard I/O functions like fprintf() or fscanf() for sending and receiving data.
FILE *stream; /* ... more code here ... */ stream = _fdopen((int) sock, "r+b"); /* ... more code here ... */ /* Sending data. */ fprintf(stream, "Welcome!\r\n"); /* ... more code here ... */ /* Receiving data. */ got = fread(buffer, 1, len, stream); /* ... more code here ... */
Do not forget to close the stream with fclose() and socket with NutTcpCloseSocket().
See also
- Network Configuration Using Stored Configuration
- Network Configuration Using Hard Coded Configuration
- Network Configuration Using a Configuration Editor
- Basic TCP Client
- Socket Timeouts
- Discovery Service
- More Nut/OS Examples
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