commands.c

linux下c语言编写的telnet客户端程序

    }
    if (!connected && needconnect) {
	printf("?Need to be connected first.\r\n");
	printf("'send ?' for help\r\n");
	return 0;
    }
    /* Now, do we have enough room? */
    if (NETROOM() < count) {
	printf("There is not enough room in the buffer TO the network\r\n");
	printf("to process your request.  Nothing will be done.\r\n");
	printf("('send synch' will throw away most data in the network\r\n");
	printf("buffer, if this might help.)\r\n");
	return 0;
    }
    /* OK, they are all OK, now go through again and actually send */
    count = 0;
    for (i = 1; i < argc; i++) {
	if ((s = GETSEND(argv[i])) == 0) {
	    fprintf(stderr, "Telnet 'send' error - argument disappeared!\r\n");
	    (void) quit();
	    /*NOTREACHED*/
	}
	if (s->handler) {
	    count++;
#if 0	/* XXX no command takes more than 1 arg */
	    success += (*s->handler)((s->narg > 0) ? argv[i+1] : 0,
				  (s->narg > 1) ? argv[i+2] : 0);
#else
	    success += (*s->handler)((s->narg > 0) ? argv[i+1] : NULL);
#endif
	    i += s->narg;
	} else {
	    NET2ADD(IAC, s->what);
	    printoption("SENT", IAC, s->what);
	}
    }
    return (count == success);
}

typedef	void (*tncmd_handler_t)	P((int, int));

	static int
send_tncmd(tncmd_handler_t func, const char *cmd, const char *name);

    static int
send_esc(const char *arg)
{
   (void)arg;
    NETADD(escape);
    return 1;
}

    static int
send_docmd(const char *name)
{
    return(send_tncmd(send_do, "do", name));
}

    static int
send_dontcmd(const char *name)
{
    return(send_tncmd(send_dont, "dont", name));
}
    static int
send_willcmd(const char *name)
{
    return(send_tncmd(send_will, "will", name));
}
    static int
send_wontcmd(const char *name)
{
    return(send_tncmd(send_wont, "wont", name));
}

extern char *telopts[];

    int
send_tncmd(tncmd_handler_t func, const char *cmd, const char *name)
{
    char **cpp;
    int val = 0;

    if (isprefix(name, "help") || isprefix(name, "?")) {
	int col, len;

	printf("Usage: send %s <value|option>\r\n", cmd);
	printf("\"value\" must be from 0 to 255\r\n");
	printf("Valid options are:\r\n\t");

	col = 8;
	for (cpp = telopts; *cpp; cpp++) {
	    len = strlen(*cpp) + 3;
	    if (col + len > 65) {
		printf("\r\n\t");
		col = 8;
	    }
	    printf(" \"%s\"", *cpp);
	    col += len;
	}
	printf("\r\n");
	return 0;
    }
    cpp = (char **)genget(name, telopts, sizeof(char *));
    if (Ambiguous(cpp)) {
	fprintf(stderr,"'%s': ambiguous argument ('send %s ?' for help).\r\n",
					name, cmd);
	return 0;
    }
    if (cpp) {
	val = cpp - telopts;
    } else {
	const char *cp = name;

	while (*cp >= '0' && *cp <= '9') {
	    val *= 10;
	    val += *cp - '0';
	    cp++;
	}
	if (*cp != 0) {
	    fprintf(stderr, "'%s': unknown argument ('send %s ?' for help).\r\n",
					name, cmd);
	    return 0;
	} else if (val < 0 || val > 255) {
	    fprintf(stderr, "'%s': bad value ('send %s ?' for help).\r\n",
					name, cmd);
	    return 0;
	}
    }
    if (!connected) {
	printf("?Need to be connected first.\r\n");
	return 0;
    }
    (*func)(val, 1);
    return 1;
}

    static int
send_help(const char *arg)
{
    struct sendlist *s;	/* pointer to current command */
    (void)arg;
    for (s = Sendlist; s->name; s++) {
	if (s->help)
	    printf("%-15s %s\r\n", s->name, s->help);
    }
    return(0);
}

/*
 * The following are the routines and data structures referred
 * to by the arguments to the "toggle" command.
 */

    static int
lclchars(int arg)
{
    (void)arg;
    donelclchars = 1;
    return 1;
}

    static int
togdebug(int arg)
{
    (void)arg;
#ifndef	NOT43
    if (net > 0 &&
	(SetSockOpt(net, SOL_SOCKET, SO_DEBUG, debug)) < 0) {
	    perror("setsockopt (SO_DEBUG)");
    }
#else	/* NOT43 */
    if (debug) {
	if (net > 0 && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
	    perror("setsockopt (SO_DEBUG)");
    } else
	printf("Cannot turn off socket debugging\r\n");
#endif	/* NOT43 */
    return 1;
}


    static int
togcrlf(int arg)
{
    (void)arg;
    if (crlf) {
	printf("Will send carriage returns as telnet <CR><LF>.\r\n");
    } else {
	printf("Will send carriage returns as telnet <CR><NUL>.\r\n");
    }
    return 1;
}

int binmode;

    static int
togbinary(int val)
{
    donebinarytoggle = 1;

    if (val >= 0) {
	binmode = val;
    } else {
	if (my_want_state_is_will(TELOPT_BINARY) &&
				my_want_state_is_do(TELOPT_BINARY)) {
	    binmode = 1;
	} else if (my_want_state_is_wont(TELOPT_BINARY) &&
				my_want_state_is_dont(TELOPT_BINARY)) {
	    binmode = 0;
	}
	val = binmode ? 0 : 1;
    }

    if (val == 1) {
	if (my_want_state_is_will(TELOPT_BINARY) &&
					my_want_state_is_do(TELOPT_BINARY)) {
	    printf("Already operating in binary mode with remote host.\r\n");
	} else {
	    printf("Negotiating binary mode with remote host.\r\n");
	    tel_enter_binary(3);
	}
    } else {
	if (my_want_state_is_wont(TELOPT_BINARY) &&
					my_want_state_is_dont(TELOPT_BINARY)) {
	    printf("Already in network ascii mode with remote host.\r\n");
	} else {
	    printf("Negotiating network ascii mode with remote host.\r\n");
	    tel_leave_binary(3);
	}
    }
    return 1;
}

    static int
togrbinary(int val)
{
    donebinarytoggle = 1;

    if (val == -1)
	val = my_want_state_is_do(TELOPT_BINARY) ? 0 : 1;

    if (val == 1) {
	if (my_want_state_is_do(TELOPT_BINARY)) {
	    printf("Already receiving in binary mode.\r\n");
	} else {
	    printf("Negotiating binary mode on input.\r\n");
	    tel_enter_binary(1);
	}
    } else {
	if (my_want_state_is_dont(TELOPT_BINARY)) {
	    printf("Already receiving in network ascii mode.\r\n");
	} else {
	    printf("Negotiating network ascii mode on input.\r\n");
	    tel_leave_binary(1);
	}
    }
    return 1;
}

    static int
togxbinary(int val)
{
    donebinarytoggle = 1;

    if (val == -1)
	val = my_want_state_is_will(TELOPT_BINARY) ? 0 : 1;

    if (val == 1) {
	if (my_want_state_is_will(TELOPT_BINARY)) {
	    printf("Already transmitting in binary mode.\r\n");
	} else {
	    printf("Negotiating binary mode on output.\r\n");
	    tel_enter_binary(2);
	}
    } else {
	if (my_want_state_is_wont(TELOPT_BINARY)) {
	    printf("Already transmitting in network ascii mode.\r\n");
	} else {
	    printf("Negotiating network ascii mode on output.\r\n");
	    tel_leave_binary(2);
	}
    }
    return 1;
}


static int togglehelp P((int));
#if	defined(AUTHENTICATION)
extern int auth_togdebug P((int));
#endif
#if    defined(ENCRYPTION)
extern int EncryptAutoEnc P((int));
extern int EncryptAutoDec P((int));
extern int EncryptDebug P((int));
extern int EncryptVerbose P((int));
#endif


typedef int (*toggle_handler_t)	P((int));
struct togglelist {
    const char	*name;		/* name of toggle */
    const char	*help;		/* help message */
    toggle_handler_t handler;	/* routine to do actual setting */
    int		*variable;
    char	*actionexplanation;
    int		needconnect;	/* Need to be connected */
};

static struct togglelist Togglelist[] = {
    { "autoflush",
	"flushing of output when sending interrupt characters",
	    0,
		&autoflush,
		    "flush output when sending interrupt characters", 0 },
    { "autosynch",
	"automatic sending of interrupt characters in urgent mode",
	    0,