telnetd/libtelnet/getent.c

#ifndef __GNO__

/*-
 * Copyright (c) 1991, 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 <sys/cdefs.h>



#ifndef lint
#if 0
static char sccsid[] = "@(#)getent.c	8.2 (Berkeley) 12/15/93";
#endif
#endif /* not lint */

#include <stdlib.h>
#include <string.h>

#include "misc-proto.h"

static char *area;
static char gettytab[] = "/etc/gettytab";

/*ARGSUSED*/
int
getent(char *cp __unused, const char *name)
{
	int retval;
	char *tempnam, *dba[2] = { gettytab, NULL };

	tempnam = strdup(name);
	retval =  cgetent(&area, dba, tempnam) == 0 ? 1 : 0;
	free(tempnam);
	return(retval);
}

/*ARGSUSED*/
char *
Getstr(const char *id, char **cpp __unused)
{
	int retval;
	char *answer, *tempid;

	tempid = strdup(id);
	retval = cgetstr(area, tempid, &answer);
	free(tempid);
	return((retval > 0) ? answer : NULL);
}

#else

/* On GNO, use code for this taken from GNO's getty. */

/*
 * Copyright (c) 1983 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.
 */

#ifndef __GNO__
#ifndef lint
static char sccsid[] = "@(#)gettytab.c  5.5 (Berkeley) 2/25/91";
#endif /* not lint */
#endif

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <paths.h>

#ifndef _PATH_GETTYTAB
#define _PATH_GETTYTAB	"/etc/gettytab"
#endif

#define TABBUFSIZ   512

static  char *tbuf;
int hopcount;   /* detect infinite loops in termcap, init 0 */

int nchktc(void);
int namatch(char *np);

static char *	skip (register char *bp);
static char *	decode (register char *str, char **area);

/*
 * Get an entry for terminal name in buffer bp,
 * from the termcap file.  Parse is very rudimentary;
 * we just notice escaped newlines.
 */
int
getent(char *bp, char *name)
{
    register char *cp;
    register int c;
    register int i = 0, cnt = 0;
    static char ibuf[TABBUFSIZ];
    char *cp2;
    int tf;

    tbuf = bp;
    tf = open(_PATH_GETTYTAB, O_RDONLY);
    if (tf < 0)
        return (-1);
    for (;;) {
        cp = bp;
        for (;;) {
            if (i == cnt) {
                cnt = read(tf, ibuf, TABBUFSIZ);
                if (cnt <= 0) {
                    close(tf);
                    return (0);
                }
                i = 0;
            }
            c = ibuf[i++];
            if (c == '\n' || c == '\r') {
                if (cp > bp && cp[-1] == '\\'){
                    cp--;
                    continue;
                }
                break;
            }
            if (cp >= bp+TABBUFSIZ) {
                write(STDERR_FILENO,"Gettytab entry too long\n", 24);
                break;
            } else
                *cp++ = c;
        }
        *cp = 0;

        /*
         * The real work for the match.
         */
        if (namatch(name)) {
            close(tf);
            return(nchktc());
        }
    }
}

/*
 * tnchktc: check the last entry, see if it's tc=xxx. If so,
 * recursively find xxx and append that entry (minus the names)
 * to take the place of the tc=xxx entry. This allows termcap
 * entries to say "like an HP2621 but doesn't turn on the labels".
 * Note that this works because of the left to right scan.
 */
#define MAXHOP  32
int
nchktc(void)
{
    register char *p, *q;
    char tcname[16];    /* name of similar terminal */
    char *tcbuf;
    /*char tcbuf[TABBUFSIZ];*/
    char *holdtbuf = tbuf;
    int l;

    tcbuf = malloc(TABBUFSIZ);
    p = tbuf + strlen(tbuf) - 2;    /* before the last colon */
    while (*--p != ':')
        if (p<tbuf) {
            write(STDERR_FILENO, "Bad gettytab entry\n", 19);
            free(tcbuf);
            return (0);
        }
    p++;
    /* p now points to beginning of last field */
    if (p[0] != 't' || p[1] != 'c') {
    	free(tcbuf);
        return(1);
    }
    strcpy(tcname,p+3);
    q = tcname;
    while (q && *q != ':')
        q++;
    *q = 0;
    if (++hopcount > MAXHOP) {
        write(STDERR_FILENO, "Getty: infinite tc= loop\n", 25);
        free(tcbuf);
        return (0);
    }
    if (getent(tcbuf, tcname) != 1) {
        free(tcbuf);
        return(0);
    }
    for (q=tcbuf; *q != ':'; q++)
        ;
    l = p - holdtbuf + strlen(q);
    if (l > TABBUFSIZ) {
        write(STDERR_FILENO, "Gettytab entry too long\n", 24);
        q[TABBUFSIZ - (p-tbuf)] = 0;
    }
    strcpy(p, q+1);
    tbuf = holdtbuf;
    free(tcbuf);
    return(1);
}

/*
 * Tnamatch deals with name matching.  The first field of the termcap
 * entry is a sequence of names separated by |'s, so we compare
 * against each such name.  The normal : terminator after the last
 * name (before the first field) stops us.
 */
int
namatch(char *np)
{
    register char *Np, *Bp;

    Bp = tbuf;
    if (*Bp == '#')
        return(0);
    for (;;) {
        for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
            continue;
        if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
            return (1);
        while (*Bp && *Bp != ':' && *Bp != '|')
            Bp++;
        if (*Bp == 0 || *Bp == ':')
            return (0);
        Bp++;
    }
}

/*
 * Skip to the next field.  Notice that this is very dumb, not
 * knowing about \: escapes or any such.  If necessary, :'s can be put
 * into the termcap file in octal.
 */
static char *
skip(register char *bp)
{

    while (*bp && *bp != ':')
        bp++;
    if (*bp == ':')
        bp++;
    return (bp);
}

/*
 * Return the (numeric) option id.
 * Numeric options look like
 *  li#80
 * i.e. the option string is separated from the numeric value by
 * a # character.  If the option is not found we return -1.
 * Note that we handle octal numbers beginning with 0.
 */
long
getnum(char *id)
{
    register long i, base;
    register char *bp = tbuf;

    for (;;) {
        bp = skip(bp);
        if (*bp == 0)
            return (-1);
        if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
            continue;
        if (*bp == '@')
            return(-1);
        if (*bp != '#')
            continue;
        bp++;
        base = 10;
        if (*bp == '0')
            base = 8;
        i = 0;
        while (isdigit(*bp))
            i *= base, i += *bp++ - '0';
        return (i);
    }
}

/*
 * Handle a flag option.
 * Flag options are given "naked", i.e. followed by a : or the end
 * of the buffer.  Return 1 if we find the option, or 0 if it is
 * not given.
 */
int
getflag (char *id)
{
    register char *bp = tbuf;

    for (;;) {
        bp = skip(bp);
        if (!*bp)
            return (-1);
        if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
            if (!*bp || *bp == ':')
                return (1);
            else if (*bp == '!')
                return (0);
            else if (*bp == '@')
                return(-1);
        }
    }
}

/*
 * Get a string valued option.
 * These are given as
 *  cl=^Z
 * Much decoding is done on the strings, and the strings are
 * placed in area, which is a ref parameter which is updated.
 * No checking on area overflow.
 */
char *
Getstr(char *id, char **area)
{
    register char *bp = tbuf;

    for (;;) {
        bp = skip(bp);
        if (!*bp)
            return (0);
        if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
            continue;
        if (*bp == '@')
            return(0);
        if (*bp != '=')
            continue;
        bp++;
        return (decode(bp, area));
    }
}

/*
 * Tdecode does the grung work to decode the
 * string capability escapes.
 */
static char *
decode(register char *str, char **area)
{
    register char *cp;
    register int c;
    register char *dp;
    int i;

    cp = *area;
    while ((c = *str++) && c != ':') {
        switch (c) {

        case '^':
            c = *str++ & 037;
            break;

        case '\\':
            dp = "E\033^^\\\\::n\nr\rt\tb\bf\f";
            c = *str++;
nextc:
            if (*dp++ == c) {
                c = *dp++;
                break;
            }
            dp++;
            if (*dp)
                goto nextc;
            if (isdigit(c)) {
                c -= '0', i = 2;
                do
                    c <<= 3, c |= *str++ - '0';
                while (--i && isdigit(*str));
            }
            break;
        }
        *cp++ = c;
    }
    *cp++ = 0;
    str = *area;
    *area = cp;
    return (str);
}

#endif