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advcap.c revision 1.5 
      1 /*	$NetBSD: advcap.c,v 1.5 2000/05/23 11:37:58 itojun Exp $	*/
      2 /*	$KAME: advcap.c,v 1.4 2000/05/23 11:17:40 itojun Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 1983 The Regents of the University of California.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 /*
     38  * remcap - routines for dealing with the remote host data base
     39  *
     40  * derived from termcap
     41  */
     42 #include <sys/types.h>
     43 #include <sys/uio.h>
     44 #include <unistd.h>
     45 #include <fcntl.h>
     46 #include <ctype.h>
     47 #include <stdlib.h>
     48 #include <stdio.h>
     49 #include <syslog.h>
     50 #include <errno.h>
     51 #include <string.h>
     52 #include "pathnames.h"
     53 
     54 #ifndef BUFSIZ
     55 #define	BUFSIZ		1024
     56 #endif
     57 #define MAXHOP		32		/* max number of tc= indirections */
     58 
     59 #define	tgetent		agetent
     60 #define	tnchktc		anchktc
     61 #define	tnamatch	anamatch
     62 #define	tgetnum		agetnum
     63 #define	tgetflag	agetflag
     64 #define	tgetstr		agetstr
     65 
     66 #if 0
     67 #define V_TERMCAP	"REMOTE"
     68 #define V_TERM		"HOST"
     69 #endif
     70 
     71 char	*RM;
     72 
     73 /*
     74  * termcap - routines for dealing with the terminal capability data base
     75  *
     76  * BUG:		Should use a "last" pointer in tbuf, so that searching
     77  *		for capabilities alphabetically would not be a n**2/2
     78  *		process when large numbers of capabilities are given.
     79  * Note:	If we add a last pointer now we will screw up the
     80  *		tc capability. We really should compile termcap.
     81  *
     82  * Essentially all the work here is scanning and decoding escapes
     83  * in string capabilities.  We don't use stdio because the editor
     84  * doesn't, and because living w/o it is not hard.
     85  */
     86 
     87 static	char *tbuf;
     88 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
     89 
     90 static	char *remotefile;
     91 
     92 extern char *conffile;
     93 
     94 int tgetent __P((char *, char *));
     95 int getent __P((char *, char *, char *));
     96 int tnchktc __P((void));
     97 int tnamatch __P((char *));
     98 static char *tskip __P((char *));
     99 int tgetnum __P((char *));
    100 int tgetflag __P((char *));
    101 char *tgetstr __P((char *, char **));
    102 static char *tdecode __P((char *, char **));
    103 
    104 /*
    105  * Get an entry for terminal name in buffer bp,
    106  * from the termcap file.  Parse is very rudimentary;
    107  * we just notice escaped newlines.
    108  */
    109 int
    110 tgetent(bp, name)
    111 	char *bp, *name;
    112 {
    113 	char *cp;
    114 
    115 	remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
    116 	return (getent(bp, name, cp));
    117 }
    118 
    119 int
    120 getent(bp, name, cp)
    121 	char *bp, *name, *cp;
    122 {
    123 	register int c;
    124 	register int i = 0, cnt = 0;
    125 	char ibuf[BUFSIZ];
    126 	int tf;
    127 
    128 	tbuf = bp;
    129 	tf = 0;
    130 	/*
    131 	 * TERMCAP can have one of two things in it. It can be the
    132 	 * name of a file to use instead of /etc/termcap. In this
    133 	 * case it better start with a "/". Or it can be an entry to
    134 	 * use so we don't have to read the file. In this case it
    135 	 * has to already have the newlines crunched out.
    136 	 */
    137 	if (cp && *cp) {
    138 		tf = open(RM = cp, O_RDONLY);
    139 	}
    140 	if (tf < 0) {
    141 		syslog(LOG_INFO,
    142 		       "<%s> open: %s", __FUNCTION__, strerror(errno));
    143 		return (-2);
    144 	}
    145 	for (;;) {
    146 		cp = bp;
    147 		for (;;) {
    148 			if (i == cnt) {
    149 				cnt = read(tf, ibuf, BUFSIZ);
    150 				if (cnt <= 0) {
    151 					close(tf);
    152 					return (0);
    153 				}
    154 				i = 0;
    155 			}
    156 			c = ibuf[i++];
    157 			if (c == '\n') {
    158 				if (cp > bp && cp[-1] == '\\') {
    159 					cp--;
    160 					continue;
    161 				}
    162 				break;
    163 			}
    164 			if (cp >= bp+BUFSIZ) {
    165 				write(2,"Remcap entry too long\n", 23);
    166 				break;
    167 			} else
    168 				*cp++ = c;
    169 		}
    170 		*cp = 0;
    171 
    172 		/*
    173 		 * The real work for the match.
    174 		 */
    175 		if (tnamatch(name)) {
    176 			close(tf);
    177 			return (tnchktc());
    178 		}
    179 	}
    180 }
    181 
    182 /*
    183  * tnchktc: check the last entry, see if it's tc=xxx. If so,
    184  * recursively find xxx and append that entry (minus the names)
    185  * to take the place of the tc=xxx entry. This allows termcap
    186  * entries to say "like an HP2621 but doesn't turn on the labels".
    187  * Note that this works because of the left to right scan.
    188  */
    189 int
    190 tnchktc()
    191 {
    192 	register char *p, *q;
    193 	char tcname[16];	/* name of similar terminal */
    194 	char tcbuf[BUFSIZ];
    195 	char *holdtbuf = tbuf;
    196 	int l;
    197 
    198 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
    199 	while (*--p != ':')
    200 		if (p<tbuf) {
    201 			write(2, "Bad remcap entry\n", 18);
    202 			return (0);
    203 		}
    204 	p++;
    205 	/* p now points to beginning of last field */
    206 	if (p[0] != 't' || p[1] != 'c')
    207 		return (1);
    208 	strcpy(tcname, p+3);
    209 	q = tcname;
    210 	while (*q && *q != ':')
    211 		q++;
    212 	*q = 0;
    213 	if (++hopcount > MAXHOP) {
    214 		write(2, "Infinite tc= loop\n", 18);
    215 		return (0);
    216 	}
    217 	if (getent(tcbuf, tcname, remotefile) != 1) {
    218 		return (0);
    219 	}
    220 	for (q = tcbuf; *q++ != ':'; )
    221 		;
    222 	l = p - holdtbuf + strlen(q);
    223 	if (l > BUFSIZ) {
    224 		write(2, "Remcap entry too long\n", 23);
    225 		q[BUFSIZ - (p-holdtbuf)] = 0;
    226 	}
    227 	strcpy(p, q);
    228 	tbuf = holdtbuf;
    229 	return (1);
    230 }
    231 
    232 /*
    233  * Tnamatch deals with name matching.  The first field of the termcap
    234  * entry is a sequence of names separated by |'s, so we compare
    235  * against each such name.  The normal : terminator after the last
    236  * name (before the first field) stops us.
    237  */
    238 int
    239 tnamatch(np)
    240 	char *np;
    241 {
    242 	register char *Np, *Bp;
    243 
    244 	Bp = tbuf;
    245 	if (*Bp == '#')
    246 		return (0);
    247 	for (;;) {
    248 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
    249 			continue;
    250 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
    251 			return (1);
    252 		while (*Bp && *Bp != ':' && *Bp != '|')
    253 			Bp++;
    254 		if (*Bp == 0 || *Bp == ':')
    255 			return (0);
    256 		Bp++;
    257 	}
    258 }
    259 
    260 /*
    261  * Skip to the next field.  Notice that this is very dumb, not
    262  * knowing about \: escapes or any such.  If necessary, :'s can be put
    263  * into the termcap file in octal.
    264  */
    265 static char *
    266 tskip(bp)
    267 	register char *bp;
    268 {
    269 	int dquote;
    270 
    271 	dquote = 0;
    272 	while (*bp) {
    273 		switch (*bp) {
    274 		case ':':
    275 			if (!dquote)
    276 				goto breakbreak;
    277 			else
    278 				bp++;
    279 			break;
    280 		case '\\':
    281 			bp++;
    282 			if (isdigit(*bp)) {
    283 				while (isdigit(*bp++))
    284 					;
    285 			} else
    286 				bp++;
    287 		case '"':
    288 			dquote = (dquote ? 1 : 0);
    289 			bp++;
    290 			break;
    291 		default:
    292 			bp++;
    293 			break;
    294 		}
    295 	}
    296 breakbreak:
    297 	if (*bp == ':')
    298 		bp++;
    299 	return (bp);
    300 }
    301 
    302 /*
    303  * Return the (numeric) option id.
    304  * Numeric options look like
    305  *	li#80
    306  * i.e. the option string is separated from the numeric value by
    307  * a # character.  If the option is not found we return -1.
    308  * Note that we handle octal numbers beginning with 0.
    309  */
    310 int
    311 tgetnum(id)
    312 	char *id;
    313 {
    314 	register long int i;
    315 	register int base;
    316 	register char *bp = tbuf;
    317 
    318 	for (;;) {
    319 		bp = tskip(bp);
    320 		if (*bp == 0)
    321 			return (-1);
    322 		if (strncmp(bp, id, strlen(id)) != 0)
    323 			continue;
    324 		bp += strlen(id);
    325 		if (*bp == '@')
    326 			return (-1);
    327 		if (*bp != '#')
    328 			continue;
    329 		bp++;
    330 		base = 10;
    331 		if (*bp == '0')
    332 			base = 8;
    333 		i = 0;
    334 		while (isdigit(*bp))
    335 			i *= base, i += *bp++ - '0';
    336 		return (i);
    337 	}
    338 }
    339 
    340 /*
    341  * Handle a flag option.
    342  * Flag options are given "naked", i.e. followed by a : or the end
    343  * of the buffer.  Return 1 if we find the option, or 0 if it is
    344  * not given.
    345  */
    346 int
    347 tgetflag(id)
    348 	char *id;
    349 {
    350 	register char *bp = tbuf;
    351 
    352 	for (;;) {
    353 		bp = tskip(bp);
    354 		if (!*bp)
    355 			return (0);
    356 		if (strncmp(bp, id, strlen(id)) == 0) {
    357 			bp += strlen(id);
    358 			if (!*bp || *bp == ':')
    359 				return (1);
    360 			else if (*bp == '@')
    361 				return (0);
    362 		}
    363 	}
    364 }
    365 
    366 /*
    367  * Get a string valued option.
    368  * These are given as
    369  *	cl=^Z
    370  * Much decoding is done on the strings, and the strings are
    371  * placed in area, which is a ref parameter which is updated.
    372  * No checking on area overflow.
    373  */
    374 char *
    375 tgetstr(id, area)
    376 	char *id, **area;
    377 {
    378 	register char *bp = tbuf;
    379 
    380 	for (;;) {
    381 		bp = tskip(bp);
    382 		if (!*bp)
    383 			return (0);
    384 		if (strncmp(bp, id, strlen(id)) != 0)
    385 			continue;
    386 		bp += strlen(id);
    387 		if (*bp == '@')
    388 			return (0);
    389 		if (*bp != '=')
    390 			continue;
    391 		bp++;
    392 		return (tdecode(bp, area));
    393 	}
    394 }
    395 
    396 /*
    397  * Tdecode does the grung work to decode the
    398  * string capability escapes.
    399  */
    400 static char *
    401 tdecode(str, area)
    402 	register char *str;
    403 	char **area;
    404 {
    405 	register char *cp;
    406 	register int c;
    407 	register char *dp;
    408 	int i;
    409 	char term;
    410 
    411 	term = ':';
    412 	cp = *area;
    413 again:
    414 	if (*str == '"') {
    415 		term = '"';
    416 		str++;
    417 	}
    418 	while ((c = *str++) && c != term) {
    419 		switch (c) {
    420 
    421 		case '^':
    422 			c = *str++ & 037;
    423 			break;
    424 
    425 		case '\\':
    426 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
    427 			c = *str++;
    428 nextc:
    429 			if (*dp++ == c) {
    430 				c = *dp++;
    431 				break;
    432 			}
    433 			dp++;
    434 			if (*dp)
    435 				goto nextc;
    436 			if (isdigit(c)) {
    437 				c -= '0', i = 2;
    438 				do
    439 					c <<= 3, c |= *str++ - '0';
    440 				while (--i && isdigit(*str));
    441 			}
    442 			break;
    443 		}
    444 		*cp++ = c;
    445 	}
    446 	if (c == term && term != ':') {
    447 		term = ':';
    448 		goto again;
    449 	}
    450 	*cp++ = 0;
    451 	str = *area;
    452 	*area = cp;
    453 	return (str);
    454 }
    455