commands.c

linux下c语言编写的telnet客户端程序

/*	$OpenBSD: commands.c,v 1.34 2000/11/08 21:49:44 aaron Exp $	*/
/*	$NetBSD: commands.c,v 1.14 1996/03/24 22:03:48 jtk Exp $	*/

/*
 * Copyright (c) 1988, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "telnet_locl.h"
#include <err.h>

#if	defined(IPPROTO_IP) && defined(IP_TOS)
int tos = -1;
#endif	/* defined(IPPROTO_IP) && defined(IP_TOS) */

char	*hostname;
static char _hostname[MAXHOSTNAMELEN];

typedef int (*intrtn_t) __P((int, char**));
static int call __P((intrtn_t, ...));

typedef	int (*cmd_handler_t) P((int, char **));
typedef struct {
	char	*name;		/* command name */
	char	*help;		/* help string (NULL for no help) */
	cmd_handler_t	handler;	/* routine which executes command */
	int	needconnect;	/* Do we need to be connected to execute? */
} Command;

static char line[256];
static char saveline[256];
static int margc;
static char *margv[20];

#if	defined(SKEY)
#include <sys/wait.h>
#define PATH_SKEY	"/usr/bin/skey"
    int
skey_calc(int argc, char *argv[])
{
	int status;

	if(argc != 3) {
		printf("usage: %s sequence challenge\n", argv[0]);
		return 0;
	}

	switch(fork()) {
	case 0:
		execv(PATH_SKEY, argv);
		exit (1);
	case -1:
		err(1, "fork");
		break;
	default:
		(void) wait(&status);
		if (WIFEXITED(status))
			return (WEXITSTATUS(status));
		return (0);
	}
}
#endif
   	


    static void
makeargv(void)
{
    char *cp, *cp2, c;
    char **argp = margv;

    margc = 0;
    cp = line;
    if (*cp == '!') {		/* Special case shell escape */
	strcpy(saveline, line);	/* save for shell command */
	*argp++ = "!";		/* No room in string to get this */
	margc++;
	cp++;
    }
    while ((c = *cp)) {
	int inquote = 0;
	while (isspace(c))
	    c = *++cp;
	if (c == '\0')
	    break;
	*argp++ = cp;
	margc += 1;
	for (cp2 = cp; c != '\0'; c = *++cp) {
	    if (inquote) {
		if (c == inquote) {
		    inquote = 0;
		    continue;
		}
	    } else {
		if (c == '\\') {
		    if ((c = *++cp) == '\0')
			break;
		} else if (c == '"') {
		    inquote = '"';
		    continue;
		} else if (c == '\'') {
		    inquote = '\'';
		    continue;
		} else if (isspace(c))
		    break;
	    }
	    *cp2++ = c;
	}
	*cp2 = '\0';
	if (c == '\0')
	    break;
	cp++;
    }
    *argp++ = 0;
}

/*
 * Make a character string into a number.
 *
 * Todo:  1.  Could take random integers (12, 0x12, 012, 0b1).
 */

	static char
special(char *s)
{
	char c;
	char b;

	switch (*s) {
	case '^':
		b = *++s;
		if (b == '?') {
		    c = b | 0x40;		/* DEL */
		} else {
		    c = b & 0x1f;
		}
		break;
	default:
		c = *s;
		break;
	}
	return c;
}

/*
 * Construct a control character sequence
 * for a special character.
 */
	static char *
control(cc_t c)
{
	static char buf[5];
	/*
	 * The only way I could get the Sun 3.5 compiler
	 * to shut up about
	 *	if ((unsigned int)c >= 0x80)
	 * was to assign "c" to an unsigned int variable...
	 * Arggg....
	 */
	unsigned int uic = (unsigned int)c;

	if (uic == 0x7f)
		return ("^?");
	if (c == (cc_t)_POSIX_VDISABLE) {
		return "off";
	}
	if (uic >= 0x80) {
		buf[0] = '\\';
		buf[1] = ((c>>6)&07) + '0';
		buf[2] = ((c>>3)&07) + '0';
		buf[3] = (c&07) + '0';
		buf[4] = 0;
	} else if (uic >= 0x20) {
		buf[0] = c;
		buf[1] = 0;
	} else {
		buf[0] = '^';
		buf[1] = '@'+c;
		buf[2] = 0;
	}
	return (buf);
}



/*
 *	The following are data structures and routines for
 *	the "send" command.
 *
 */

typedef	int (*send_handler_t) P((const char *));
struct sendlist {
    const char	*name;		/* How user refers to it (case independent) */
    const char	*help;		/* Help information (0 ==> no help) */
    int		needconnect;	/* Need to be connected */
    int		narg;		/* Number of arguments */
    send_handler_t handler;	/* Routine to perform (for special ops) */
    int		nbyte;		/* Number of bytes to send this command */
    int		what;		/* Character to be sent (<0 ==> special) */
};


static int
	send_esc P((const char *)),
	send_help P((const char *)),
	send_docmd P((const char *)),
	send_dontcmd P((const char *)),
	send_willcmd P((const char *)),
	send_wontcmd P((const char *));

static struct sendlist Sendlist[] = {
    { "ao",	"Send Telnet Abort output",		1, 0, 0, 2, AO },
    { "ayt",	"Send Telnet 'Are You There'",		1, 0, 0, 2, AYT },
    { "brk",	"Send Telnet Break",			1, 0, 0, 2, BREAK },
    { "break",	0,					1, 0, 0, 2, BREAK },
    { "ec",	"Send Telnet Erase Character",		1, 0, 0, 2, EC },
    { "el",	"Send Telnet Erase Line",		1, 0, 0, 2, EL },
    { "escape",	"Send current escape character",	1, 0, send_esc, 1, 0 },
    { "ga",	"Send Telnet 'Go Ahead' sequence",	1, 0, 0, 2, GA },
    { "ip",	"Send Telnet Interrupt Process",	1, 0, 0, 2, IP },
    { "intp",	0,					1, 0, 0, 2, IP },
    { "interrupt", 0,					1, 0, 0, 2, IP },
    { "intr",	0,					1, 0, 0, 2, IP },
    { "nop",	"Send Telnet 'No operation'",		1, 0, 0, 2, NOP },
    { "eor",	"Send Telnet 'End of Record'",		1, 0, 0, 2, EOR },
    { "abort",	"Send Telnet 'Abort Process'",		1, 0, 0, 2, ABORT },
    { "susp",	"Send Telnet 'Suspend Process'",	1, 0, 0, 2, SUSP },
    { "eof",	"Send Telnet End of File Character",	1, 0, 0, 2, xEOF },
    { "synch",	"Perform Telnet 'Synch operation'",	1, 0, (send_handler_t)dosynch, 2, 0 },
    { "getstatus", "Send request for STATUS",		1, 0, (send_handler_t)get_status, 6, 0 },
    { "?",	"Display send options",			0, 0, send_help, 0, 0 },
    { "help",	0,					0, 0, send_help, 0, 0 },
    { "do",	0,					0, 1, send_docmd, 3, 0 },
    { "dont",	0,					0, 1, send_dontcmd, 3, 0 },
    { "will",	0,					0, 1, send_willcmd, 3, 0 },
    { "wont",	0,					0, 1, send_wontcmd, 3, 0 },
    { NULL, NULL, 0, 0, NULL, 0, 0 }
};

#define	GETSEND(name) ((struct sendlist *) genget(name, (char **) Sendlist, \
				sizeof(struct sendlist)))

    static int
sendcmd(int argc, char *argv[])
{
    int count;		/* how many bytes we are going to need to send */
    int i;
    struct sendlist *s;	/* pointer to current command */
    int success = 0;
    int needconnect = 0;

    if (argc < 2) {
	printf("need at least one argument for 'send' command\r\n");
	printf("'send ?' for help\r\n");
	return 0;
    }
    /*
     * First, validate all the send arguments.
     * In addition, we see how much space we are going to need, and
     * whether or not we will be doing a "SYNCH" operation (which
     * flushes the network queue).
     */
    count = 0;
    for (i = 1; i < argc; i++) {
	s = GETSEND(argv[i]);
	if (s == 0) {
	    printf("Unknown send argument '%s'\r\n'send ?' for help.\r\n",
			argv[i]);
	    return 0;
	} else if (Ambiguous(s)) {
	    printf("Ambiguous send argument '%s'\r\n'send ?' for help.\r\n",
			argv[i]);
	    return 0;
	}
	if (i + s->narg >= argc) {
	    fprintf(stderr,
	    "Need %d argument%s to 'send %s' command.  'send %s ?' for help.\r\n",
		s->narg, s->narg == 1 ? "" : "s", s->name, s->name);
	    return 0;
	}
	count += s->nbyte;
	if (s->handler == send_help) {
	    send_help(NULL);
	    return 0;
	}

	i += s->narg;
	needconnect += s->needconnect;