telnet.c File Reference

#include <errno.h>
#include <poll.h>
#include <unistd.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include "lite.h"

Include dependency graph for telnet.c:

Macros
#define	EXPECT_DEBUG   0
#define	EXPECT_POLL_TIMEOUT   3000 /* 3 sec timeout waiting for server. */
#define	TELL(fmt, args...)

Functions
sdbuf_t *	telnet_open (int addr, short port)
	Open telnet connection to addr:port and connect. More...
int	telnet_close (sdbuf_t *ctx)
	Close a telnet session previously opened with telnet_open() More...
int	telnet_expect (sdbuf_t *ctx, char *script[], FILE *output)
	Poor man's telnet expect. More...
int	telnet_session (int addr, short port, char *script[], FILE *output)
	Very simple expect-like implementation for telnet. More...

Detailed Description

Author

Joachim Wiberg

Date

2010-2021

Copyright

ISC License

Function Documentation

telnet_close()

int telnet_close

(

sdbuf_t *

ctx

)

Close a telnet session previously opened with telnet_open()

Parameters

ctx	An sdbuf_t socket buffer context

Returns

Always returns POSIX OK(0).

telnet_expect()

int telnet_expect	(	sdbuf_t *	ctx,
		char *	script[],
		FILE *	output
	)

Poor man's telnet expect.

Parameters

ctx	Telnet session context from telnet_open()
script	NULL terminated list of expect and response strings
output	Optional output from session

Issues script sequence on telnet session specified in ctx, with optional output from session.

The script consists of strings of expect and response pairs. For example, expect "ogin: " followed by response "root\n", expect "assword: "with response "secret\n", concluded by NULL.

Returns

POSIX OK(0) or non-zero on error.

telnet_open()

sdbuf_t* telnet_open	(	int	addr,
		short	port
	)

Open telnet connection to addr:port and connect.

Parameters

addr	Integer encoded IPv4 address in network byte order
port	Internet port number in network byte order

Returns

An sdbuf_t socket buffer context.

telnet_session()

int telnet_session	(	int	addr,
		short	port,
		char *	script[],
		FILE *	output
	)

Very simple expect-like implementation for telnet.

Parameters

addr	Integer encoded IPv4 address, in network byte order, use htonl().
port	Internet port to connect to, in network byte order, use htons().
script	Expect like script of paired 'expect', 'response' strings.
output	A FILE pointer to a tempfile() for output from the last command.

This is a very simple expect-like implementation for querying and operating daemons remotely over telnet.

The script is a query-response type of list of strings leading up to a final command, which output is then written to the given output file.

Returns

POSIX OK(0), or non-zero with errno set on error.