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snl.h File Reference

An user friendly multi threaded network library. More...

Go to the source code of this file.

Defines
#define	SNL_LISTEN_CALLBACK(CB)   void (CB)(unsigned short port, int error, int fd, void *data)
	Macro to shorten the listen callback function prototype. More...
#define	SNL_READ_CALLBACK(CB)   void (CB)(int fd, int error, void *buf, int len, void *data)
	Read callback function prototype macro. More...
#define	SNL_ERR_OK   0
	no error.
#define	SNL_ERR_OPEN   -1
	could'nt open socket.
#define	SNL_ERR_LISTEN   -2
	error while listening to socket.
#define	SNL_ERR_CONNECT   -3
	connecting to socket failed.
#define	SNL_ERR_BIND   -4
	couldn't bind to socket.
#define	SNL_ERR_ACCEPT   -5
	error while accepting connection.
#define	SNL_ERR_READ   -6
	error while reading from socket.
#define	SNL_ERR_WRITE   -7
	failed to write to socket.
#define	SNL_ERR_CLOSED   -8
	peer closed connection.
#define	SNL_ERR_BUFFER   -9
	out of memory (buffer allocation error).
#define	SNL_ERR_ADDRESS   -10
	could not get address from hostname.
#define	NULL   ((void *)0)
	NULL is defined in a somehow save manner.
#define	FALSE   (0)
	FALSE is equal to 0.
#define	TRUE   (!FALSE)
	TRUE is not equal to FALSE.
Functions
int	snl_write (int fd, void *buf, unsigned long int len)
	Send a datagram over the socket connection. More...
int	snl_read (int fd, SNL_READ_CALLBACK(*cb), void *data)
	Start a seperate thread to handle exact one socket connection. More...
int	snl_listen (const char *name, unsigned short port, SNL_LISTEN_CALLBACK(*cb), void *data)
	Start a thread to listen for incoming connections. More...
int	snl_connect (const char *name, unsigned short port)
	Connect to a listening socket. More...

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Detailed Description

An user friendly multi threaded network library.

Author:

Clemens Kirchgatterer <clemens@thf.ath.cx>

Version:

V1.1.1

Date:

2002-03-30

This is a very user friendly library to hide all complicating things about network programming behind a neat api. It starts the threads on incoming connections, sends and receives data over a socket and takes care of large enough buffers. This way, a buffer overflow is definitly impossible to happen, as long as only library functions are used to read from and write to the socket filedescriptors.

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Define Documentation

#define SNL_LISTEN_CALLBACK (  CB    )     void (CB)(unsigned short port, int error, int fd, void *data)

Macro to shorten the listen callback function prototype. The SNL_LISTEN_CALLBACK() macro expands the callback function to its full prototype to make the sourcecode more readable.

#define SNL_READ_CALLBACK (  CB    )     void (CB)(int fd, int error, void *buf, int len, void *data)

Read callback function prototype macro. The SNL_READ_CALLBACK() macro expands the callback function to its full prototype to make the sourcecode more readable.

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Function Documentation

int snl_connect (  const char *    name, unsigned short    port )

Connect to a listening socket. Parameters: name  <const char *> hostname, ip address or unix socket to connect port  <unsigned short> the port the server is listening on Returns: a filedescriptor on success or a negative error code Note: if port is 0, then a UNIX DOMAIN SOCKET is used For connecting to a snl server, one has to call this fuction. The first paramter can be a hostname, an ipaddress or a unix socket name, depending on the second parameter. If port == 0, then name is interpreted as an unix socket file name (i.g. "/tmp/socket").

int snl_listen (  const char *    name, unsigned short    port, SNL_LISTEN_CALLBACK *    cb, void *    data )

Start a thread to listen for incoming connections. Parameters: name  <const char *> unix socket name for local connections port  <unsigned short> port number the server should listen on cb  <void (*)()> a pointer to the callback function data  <void *> user specific data Returns: 0 on success or a negative error code Note: if port is 0, then a UNIX DOMAIN SOCKET is used To start the listening thread, this function must be used. Its interface is similar to the one of the read function.

int snl_read (  int    fd, SNL_READ_CALLBACK *    cb, void *    data )

Start a seperate thread to handle exact one socket connection. Parameters: fd  <int> filedescriptor for this connection cb  <void (*)()> a pointer to the callback function data  <void *> user specific data Returns: 0 on success or a negative error code The read function registers a callback function, that will get called, when a complete datagram has been received. It also takes an additional parameter, a void pointer, that one can use for its own purpose.

int snl_write (  int    fd, void *    buf, unsigned long int    len )

Send a datagram over the socket connection. Parameters: fd  <int> filedescriptor for this connection buf  <void *> pointer to the data to send len  <int> length of that data Returns: 0 on success or a negative error code This function is used to send a datagram over the network connection. Thereby the library ensures, that the hole datagram will get sent at once and that the other side receives all data correctly.

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