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advcap.c revision 1.1 
      1 /*
      2  * Copyright (c) 1983 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 #ifndef lint
     36 #if 0
     37 static char sccsid[] = "@(#)remcap.c	5.5 (Berkeley) 2/2/91";
     38 #else
     39 __RCSID("@(#)remcap.c	5.5 (Berkeley) 2/2/91");
     40 #endif
     41 #endif /* not lint */
     42 
     43 /*
     44  * remcap - routines for dealing with the remote host data base
     45  *
     46  * derived from termcap
     47  */
     48 #include <sys/types.h>
     49 #include <sys/uio.h>
     50 #include <unistd.h>
     51 #include <fcntl.h>
     52 #include <ctype.h>
     53 #include <stdlib.h>
     54 #include <stdio.h>
     55 #include <syslog.h>
     56 #include <errno.h>
     57 #include <string.h>
     58 #include "pathnames.h"
     59 
     60 #ifndef BUFSIZ
     61 #define	BUFSIZ		1024
     62 #endif
     63 #define MAXHOP		32		/* max number of tc= indirections */
     64 
     65 #define	tgetent		agetent
     66 #define	tnchktc		anchktc
     67 #define	tnamatch	anamatch
     68 #define	tgetnum		agetnum
     69 #define	tgetflag	agetflag
     70 #define	tgetstr		agetstr
     71 
     72 #if 0
     73 #define V_TERMCAP	"REMOTE"
     74 #define V_TERM		"HOST"
     75 #endif
     76 
     77 char	*RM;
     78 
     79 /*
     80  * termcap - routines for dealing with the terminal capability data base
     81  *
     82  * BUG:		Should use a "last" pointer in tbuf, so that searching
     83  *		for capabilities alphabetically would not be a n**2/2
     84  *		process when large numbers of capabilities are given.
     85  * Note:	If we add a last pointer now we will screw up the
     86  *		tc capability. We really should compile termcap.
     87  *
     88  * Essentially all the work here is scanning and decoding escapes
     89  * in string capabilities.  We don't use stdio because the editor
     90  * doesn't, and because living w/o it is not hard.
     91  */
     92 
     93 static	char *tbuf;
     94 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
     95 
     96 static	char *remotefile;
     97 
     98 extern char *conffile;
     99 
    100 int tgetent __P((char *, char *));
    101 int getent __P((char *, char *, char *));
    102 int tnchktc __P((void));
    103 int tnamatch __P((char *));
    104 static char *tskip __P((char *));
    105 int tgetnum __P((char *));
    106 int tgetflag __P((char *));
    107 char *tgetstr __P((char *, char **));
    108 static char *tdecode __P((char *, char **));
    109 
    110 /*
    111  * Get an entry for terminal name in buffer bp,
    112  * from the termcap file.  Parse is very rudimentary;
    113  * we just notice escaped newlines.
    114  */
    115 int
    116 tgetent(bp, name)
    117 	char *bp, *name;
    118 {
    119 	char *cp;
    120 
    121 	remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
    122 	return (getent(bp, name, cp));
    123 }
    124 
    125 int
    126 getent(bp, name, cp)
    127 	char *bp, *name, *cp;
    128 {
    129 	register int c;
    130 	register int i = 0, cnt = 0;
    131 	char ibuf[BUFSIZ];
    132 	int tf;
    133 
    134 	tbuf = bp;
    135 	tf = 0;
    136 	/*
    137 	 * TERMCAP can have one of two things in it. It can be the
    138 	 * name of a file to use instead of /etc/termcap. In this
    139 	 * case it better start with a "/". Or it can be an entry to
    140 	 * use so we don't have to read the file. In this case it
    141 	 * has to already have the newlines crunched out.
    142 	 */
    143 	if (cp && *cp) {
    144 		tf = open(RM = cp, O_RDONLY);
    145 	}
    146 	if (tf < 0) {
    147 		syslog(LOG_WARNING,
    148 		       "<%s> open: %s", __FUNCTION__, strerror(errno));
    149 		return (-2);
    150 	}
    151 	for (;;) {
    152 		cp = bp;
    153 		for (;;) {
    154 			if (i == cnt) {
    155 				cnt = read(tf, ibuf, BUFSIZ);
    156 				if (cnt <= 0) {
    157 					close(tf);
    158 					return (0);
    159 				}
    160 				i = 0;
    161 			}
    162 			c = ibuf[i++];
    163 			if (c == '\n') {
    164 				if (cp > bp && cp[-1] == '\\') {
    165 					cp--;
    166 					continue;
    167 				}
    168 				break;
    169 			}
    170 			if (cp >= bp+BUFSIZ) {
    171 				write(2,"Remcap entry too long\n", 23);
    172 				break;
    173 			} else
    174 				*cp++ = c;
    175 		}
    176 		*cp = 0;
    177 
    178 		/*
    179 		 * The real work for the match.
    180 		 */
    181 		if (tnamatch(name)) {
    182 			close(tf);
    183 			return (tnchktc());
    184 		}
    185 	}
    186 }
    187 
    188 /*
    189  * tnchktc: check the last entry, see if it's tc=xxx. If so,
    190  * recursively find xxx and append that entry (minus the names)
    191  * to take the place of the tc=xxx entry. This allows termcap
    192  * entries to say "like an HP2621 but doesn't turn on the labels".
    193  * Note that this works because of the left to right scan.
    194  */
    195 int
    196 tnchktc()
    197 {
    198 	register char *p, *q;
    199 	char tcname[16];	/* name of similar terminal */
    200 	char tcbuf[BUFSIZ];
    201 	char *holdtbuf = tbuf;
    202 	int l;
    203 
    204 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
    205 	while (*--p != ':')
    206 		if (p<tbuf) {
    207 			write(2, "Bad remcap entry\n", 18);
    208 			return (0);
    209 		}
    210 	p++;
    211 	/* p now points to beginning of last field */
    212 	if (p[0] != 't' || p[1] != 'c')
    213 		return (1);
    214 	strcpy(tcname, p+3);
    215 	q = tcname;
    216 	while (*q && *q != ':')
    217 		q++;
    218 	*q = 0;
    219 	if (++hopcount > MAXHOP) {
    220 		write(2, "Infinite tc= loop\n", 18);
    221 		return (0);
    222 	}
    223 	if (getent(tcbuf, tcname, remotefile) != 1) {
    224 		return (0);
    225 	}
    226 	for (q = tcbuf; *q++ != ':'; )
    227 		;
    228 	l = p - holdtbuf + strlen(q);
    229 	if (l > BUFSIZ) {
    230 		write(2, "Remcap entry too long\n", 23);
    231 		q[BUFSIZ - (p-holdtbuf)] = 0;
    232 	}
    233 	strcpy(p, q);
    234 	tbuf = holdtbuf;
    235 	return (1);
    236 }
    237 
    238 /*
    239  * Tnamatch deals with name matching.  The first field of the termcap
    240  * entry is a sequence of names separated by |'s, so we compare
    241  * against each such name.  The normal : terminator after the last
    242  * name (before the first field) stops us.
    243  */
    244 int
    245 tnamatch(np)
    246 	char *np;
    247 {
    248 	register char *Np, *Bp;
    249 
    250 	Bp = tbuf;
    251 	if (*Bp == '#')
    252 		return (0);
    253 	for (;;) {
    254 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
    255 			continue;
    256 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
    257 			return (1);
    258 		while (*Bp && *Bp != ':' && *Bp != '|')
    259 			Bp++;
    260 		if (*Bp == 0 || *Bp == ':')
    261 			return (0);
    262 		Bp++;
    263 	}
    264 }
    265 
    266 /*
    267  * Skip to the next field.  Notice that this is very dumb, not
    268  * knowing about \: escapes or any such.  If necessary, :'s can be put
    269  * into the termcap file in octal.
    270  */
    271 static char *
    272 tskip(bp)
    273 	register char *bp;
    274 {
    275 	int dquote;
    276 
    277 	dquote = 0;
    278 	while (*bp) {
    279 		switch (*bp) {
    280 		case ':':
    281 			if (!dquote)
    282 				goto breakbreak;
    283 			else
    284 				bp++;
    285 			break;
    286 		case '\\':
    287 			bp++;
    288 			if (isdigit(*bp)) {
    289 				while (isdigit(*bp++))
    290 					;
    291 			} else
    292 				bp++;
    293 		case '"':
    294 			dquote = (dquote ? 1 : 0);
    295 			bp++;
    296 			break;
    297 		default:
    298 			bp++;
    299 			break;
    300 		}
    301 	}
    302 breakbreak:
    303 	if (*bp == ':')
    304 		bp++;
    305 	return (bp);
    306 }
    307 
    308 /*
    309  * Return the (numeric) option id.
    310  * Numeric options look like
    311  *	li#80
    312  * i.e. the option string is separated from the numeric value by
    313  * a # character.  If the option is not found we return -1.
    314  * Note that we handle octal numbers beginning with 0.
    315  */
    316 int
    317 tgetnum(id)
    318 	char *id;
    319 {
    320 	register long int i;
    321 	register int base;
    322 	register char *bp = tbuf;
    323 
    324 	for (;;) {
    325 		bp = tskip(bp);
    326 		if (*bp == 0)
    327 			return (-1);
    328 		if (strncmp(bp, id, strlen(id)) != 0)
    329 			continue;
    330 		bp += strlen(id);
    331 		if (*bp == '@')
    332 			return (-1);
    333 		if (*bp != '#')
    334 			continue;
    335 		bp++;
    336 		base = 10;
    337 		if (*bp == '0')
    338 			base = 8;
    339 		i = 0;
    340 		while (isdigit(*bp))
    341 			i *= base, i += *bp++ - '0';
    342 		return (i);
    343 	}
    344 }
    345 
    346 /*
    347  * Handle a flag option.
    348  * Flag options are given "naked", i.e. followed by a : or the end
    349  * of the buffer.  Return 1 if we find the option, or 0 if it is
    350  * not given.
    351  */
    352 int
    353 tgetflag(id)
    354 	char *id;
    355 {
    356 	register char *bp = tbuf;
    357 
    358 	for (;;) {
    359 		bp = tskip(bp);
    360 		if (!*bp)
    361 			return (0);
    362 		if (strncmp(bp, id, strlen(id)) == 0) {
    363 			bp += strlen(id);
    364 			if (!*bp || *bp == ':')
    365 				return (1);
    366 			else if (*bp == '@')
    367 				return (0);
    368 		}
    369 	}
    370 }
    371 
    372 /*
    373  * Get a string valued option.
    374  * These are given as
    375  *	cl=^Z
    376  * Much decoding is done on the strings, and the strings are
    377  * placed in area, which is a ref parameter which is updated.
    378  * No checking on area overflow.
    379  */
    380 char *
    381 tgetstr(id, area)
    382 	char *id, **area;
    383 {
    384 	register char *bp = tbuf;
    385 
    386 	for (;;) {
    387 		bp = tskip(bp);
    388 		if (!*bp)
    389 			return (0);
    390 		if (strncmp(bp, id, strlen(id)) != 0)
    391 			continue;
    392 		bp += strlen(id);
    393 		if (*bp == '@')
    394 			return (0);
    395 		if (*bp != '=')
    396 			continue;
    397 		bp++;
    398 		return (tdecode(bp, area));
    399 	}
    400 }
    401 
    402 /*
    403  * Tdecode does the grung work to decode the
    404  * string capability escapes.
    405  */
    406 static char *
    407 tdecode(str, area)
    408 	register char *str;
    409 	char **area;
    410 {
    411 	register char *cp;
    412 	register int c;
    413 	register char *dp;
    414 	int i;
    415 	char term;
    416 
    417 	term = ':';
    418 	cp = *area;
    419 again:
    420 	if (*str == '"') {
    421 		term = '"';
    422 		str++;
    423 	}
    424 	while ((c = *str++) && c != term) {
    425 		switch (c) {
    426 
    427 		case '^':
    428 			c = *str++ & 037;
    429 			break;
    430 
    431 		case '\\':
    432 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
    433 			c = *str++;
    434 nextc:
    435 			if (*dp++ == c) {
    436 				c = *dp++;
    437 				break;
    438 			}
    439 			dp++;
    440 			if (*dp)
    441 				goto nextc;
    442 			if (isdigit(c)) {
    443 				c -= '0', i = 2;
    444 				do
    445 					c <<= 3, c |= *str++ - '0';
    446 				while (--i && isdigit(*str));
    447 			}
    448 			break;
    449 		}
    450 		*cp++ = c;
    451 	}
    452 	if (c == term && term != ':') {
    453 		term = ':';
    454 		goto again;
    455 	}
    456 	*cp++ = 0;
    457 	str = *area;
    458 	*area = cp;
    459 	return (str);
    460 }
    461