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advcap.c revision 1.9 
      1 /*	$NetBSD: advcap.c,v 1.9 2003/08/07 11:25:42 agc Exp $	*/
      2 /*	$KAME: advcap.c,v 1.9 2002/05/29 14:28:35 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. Neither the name of the University nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * remcap - routines for dealing with the remote host data base
     35  *
     36  * derived from termcap
     37  */
     38 #include <sys/types.h>
     39 #include <sys/uio.h>
     40 #include <unistd.h>
     41 #include <fcntl.h>
     42 #include <ctype.h>
     43 #include <stdlib.h>
     44 #include <stdio.h>
     45 #include <syslog.h>
     46 #include <errno.h>
     47 #include <string.h>
     48 #include "pathnames.h"
     49 
     50 #ifndef BUFSIZ
     51 #define	BUFSIZ		1024
     52 #endif
     53 #define MAXHOP		32		/* max number of tc= indirections */
     54 
     55 #define	tgetent		agetent
     56 #define	tnchktc		anchktc
     57 #define	tnamatch	anamatch
     58 #define	tgetnum		agetnum
     59 #define	tgetflag	agetflag
     60 #define	tgetstr		agetstr
     61 
     62 #if 0
     63 #define V_TERMCAP	"REMOTE"
     64 #define V_TERM		"HOST"
     65 #endif
     66 
     67 char	*RM;
     68 
     69 /*
     70  * termcap - routines for dealing with the terminal capability data base
     71  *
     72  * BUG:		Should use a "last" pointer in tbuf, so that searching
     73  *		for capabilities alphabetically would not be a n**2/2
     74  *		process when large numbers of capabilities are given.
     75  * Note:	If we add a last pointer now we will screw up the
     76  *		tc capability. We really should compile termcap.
     77  *
     78  * Essentially all the work here is scanning and decoding escapes
     79  * in string capabilities.  We don't use stdio because the editor
     80  * doesn't, and because living w/o it is not hard.
     81  */
     82 
     83 static	char *tbuf;
     84 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
     85 
     86 static	char *remotefile;
     87 
     88 extern char *conffile;
     89 
     90 int tgetent __P((char *, char *));
     91 int getent __P((char *, char *, char *));
     92 int tnchktc __P((void));
     93 int tnamatch __P((char *));
     94 static char *tskip __P((char *));
     95 int64_t tgetnum __P((char *));
     96 int tgetflag __P((char *));
     97 char *tgetstr __P((char *, char **));
     98 static char *tdecode __P((char *, char **));
     99 
    100 /*
    101  * Get an entry for terminal name in buffer bp,
    102  * from the termcap file.  Parse is very rudimentary;
    103  * we just notice escaped newlines.
    104  */
    105 int
    106 tgetent(bp, name)
    107 	char *bp, *name;
    108 {
    109 	char *cp;
    110 
    111 	remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
    112 	return (getent(bp, name, cp));
    113 }
    114 
    115 int
    116 getent(bp, name, cp)
    117 	char *bp, *name, *cp;
    118 {
    119 	int c;
    120 	int i = 0, cnt = 0;
    121 	char ibuf[BUFSIZ];
    122 	int tf;
    123 
    124 	tbuf = bp;
    125 	tf = 0;
    126 	/*
    127 	 * TERMCAP can have one of two things in it. It can be the
    128 	 * name of a file to use instead of /etc/termcap. In this
    129 	 * case it better start with a "/". Or it can be an entry to
    130 	 * use so we don't have to read the file. In this case it
    131 	 * has to already have the newlines crunched out.
    132 	 */
    133 	if (cp && *cp) {
    134 		tf = open(RM = cp, O_RDONLY);
    135 	}
    136 	if (tf < 0) {
    137 		syslog(LOG_INFO,
    138 		       "<%s> open: %s", __func__, strerror(errno));
    139 		return (-2);
    140 	}
    141 	for (;;) {
    142 		cp = bp;
    143 		for (;;) {
    144 			if (i == cnt) {
    145 				cnt = read(tf, ibuf, BUFSIZ);
    146 				if (cnt <= 0) {
    147 					close(tf);
    148 					return (0);
    149 				}
    150 				i = 0;
    151 			}
    152 			c = ibuf[i++];
    153 			if (c == '\n') {
    154 				if (cp > bp && cp[-1] == '\\') {
    155 					cp--;
    156 					continue;
    157 				}
    158 				break;
    159 			}
    160 			if (cp >= bp + BUFSIZ) {
    161 				write(2,"Remcap entry too long\n", 23);
    162 				break;
    163 			} else
    164 				*cp++ = c;
    165 		}
    166 		*cp = 0;
    167 
    168 		/*
    169 		 * The real work for the match.
    170 		 */
    171 		if (tnamatch(name)) {
    172 			close(tf);
    173 			return (tnchktc());
    174 		}
    175 	}
    176 }
    177 
    178 /*
    179  * tnchktc: check the last entry, see if it's tc=xxx. If so,
    180  * recursively find xxx and append that entry (minus the names)
    181  * to take the place of the tc=xxx entry. This allows termcap
    182  * entries to say "like an HP2621 but doesn't turn on the labels".
    183  * Note that this works because of the left to right scan.
    184  */
    185 int
    186 tnchktc()
    187 {
    188 	char *p, *q;
    189 	char tcname[16];	/* name of similar terminal */
    190 	char tcbuf[BUFSIZ];
    191 	char *holdtbuf = tbuf;
    192 	int l;
    193 
    194 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
    195 	while (*--p != ':')
    196 		if (p < tbuf) {
    197 			write(2, "Bad remcap entry\n", 18);
    198 			return (0);
    199 		}
    200 	p++;
    201 	/* p now points to beginning of last field */
    202 	if (p[0] != 't' || p[1] != 'c')
    203 		return (1);
    204 	strlcpy(tcname, p + 3, sizeof tcname);
    205 	q = tcname;
    206 	while (*q && *q != ':')
    207 		q++;
    208 	*q = 0;
    209 	if (++hopcount > MAXHOP) {
    210 		write(2, "Infinite tc= loop\n", 18);
    211 		return (0);
    212 	}
    213 	if (getent(tcbuf, tcname, remotefile) != 1) {
    214 		return (0);
    215 	}
    216 	for (q = tcbuf; *q++ != ':'; )
    217 		;
    218 	l = p - holdtbuf + strlen(q);
    219 	if (l > BUFSIZ) {
    220 		write(2, "Remcap entry too long\n", 23);
    221 		q[BUFSIZ - (p-holdtbuf)] = 0;
    222 	}
    223 	strcpy(p, q);
    224 	tbuf = holdtbuf;
    225 	return (1);
    226 }
    227 
    228 /*
    229  * Tnamatch deals with name matching.  The first field of the termcap
    230  * entry is a sequence of names separated by |'s, so we compare
    231  * against each such name.  The normal : terminator after the last
    232  * name (before the first field) stops us.
    233  */
    234 int
    235 tnamatch(np)
    236 	char *np;
    237 {
    238 	char *Np, *Bp;
    239 
    240 	Bp = tbuf;
    241 	if (*Bp == '#')
    242 		return (0);
    243 	for (;;) {
    244 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
    245 			continue;
    246 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
    247 			return (1);
    248 		while (*Bp && *Bp != ':' && *Bp != '|')
    249 			Bp++;
    250 		if (*Bp == 0 || *Bp == ':')
    251 			return (0);
    252 		Bp++;
    253 	}
    254 }
    255 
    256 /*
    257  * Skip to the next field.  Notice that this is very dumb, not
    258  * knowing about \: escapes or any such.  If necessary, :'s can be put
    259  * into the termcap file in octal.
    260  */
    261 static char *
    262 tskip(bp)
    263 	char *bp;
    264 {
    265 	int dquote;
    266 
    267 	dquote = 0;
    268 	while (*bp) {
    269 		switch (*bp) {
    270 		case ':':
    271 			if (!dquote)
    272 				goto breakbreak;
    273 			else
    274 				bp++;
    275 			break;
    276 		case '\\':
    277 			bp++;
    278 			if (isdigit(*bp)) {
    279 				while (isdigit(*bp++))
    280 					;
    281 			} else
    282 				bp++;
    283 		case '"':
    284 			dquote = (dquote ? 1 : 0);
    285 			bp++;
    286 			break;
    287 		default:
    288 			bp++;
    289 			break;
    290 		}
    291 	}
    292 breakbreak:
    293 	if (*bp == ':')
    294 		bp++;
    295 	return (bp);
    296 }
    297 
    298 /*
    299  * Return the (numeric) option id.
    300  * Numeric options look like
    301  *	li#80
    302  * i.e. the option string is separated from the numeric value by
    303  * a # character.  If the option is not found we return -1.
    304  * Note that we handle octal numbers beginning with 0.
    305  */
    306 int64_t
    307 tgetnum(id)
    308 	char *id;
    309 {
    310 	int64_t i;
    311 	int base;
    312 	char *bp = tbuf;
    313 
    314 	for (;;) {
    315 		bp = tskip(bp);
    316 		if (*bp == 0)
    317 			return (-1);
    318 		if (strncmp(bp, id, strlen(id)) != 0)
    319 			continue;
    320 		bp += strlen(id);
    321 		if (*bp == '@')
    322 			return (-1);
    323 		if (*bp != '#')
    324 			continue;
    325 		bp++;
    326 		base = 10;
    327 		if (*bp == '0')
    328 			base = 8;
    329 		i = 0;
    330 		while (isdigit(*bp))
    331 			i *= base, i += *bp++ - '0';
    332 		return (i);
    333 	}
    334 }
    335 
    336 /*
    337  * Handle a flag option.
    338  * Flag options are given "naked", i.e. followed by a : or the end
    339  * of the buffer.  Return 1 if we find the option, or 0 if it is
    340  * not given.
    341  */
    342 int
    343 tgetflag(id)
    344 	char *id;
    345 {
    346 	char *bp = tbuf;
    347 
    348 	for (;;) {
    349 		bp = tskip(bp);
    350 		if (!*bp)
    351 			return (0);
    352 		if (strncmp(bp, id, strlen(id)) == 0) {
    353 			bp += strlen(id);
    354 			if (!*bp || *bp == ':')
    355 				return (1);
    356 			else if (*bp == '@')
    357 				return (0);
    358 		}
    359 	}
    360 }
    361 
    362 /*
    363  * Get a string valued option.
    364  * These are given as
    365  *	cl=^Z
    366  * Much decoding is done on the strings, and the strings are
    367  * placed in area, which is a ref parameter which is updated.
    368  * No checking on area overflow.
    369  */
    370 char *
    371 tgetstr(id, area)
    372 	char *id, **area;
    373 {
    374 	char *bp = tbuf;
    375 
    376 	for (;;) {
    377 		bp = tskip(bp);
    378 		if (!*bp)
    379 			return (0);
    380 		if (strncmp(bp, id, strlen(id)) != 0)
    381 			continue;
    382 		bp += strlen(id);
    383 		if (*bp == '@')
    384 			return (0);
    385 		if (*bp != '=')
    386 			continue;
    387 		bp++;
    388 		return (tdecode(bp, area));
    389 	}
    390 }
    391 
    392 /*
    393  * Tdecode does the grung work to decode the
    394  * string capability escapes.
    395  */
    396 static char *
    397 tdecode(str, area)
    398 	char *str;
    399 	char **area;
    400 {
    401 	char *cp;
    402 	int c;
    403 	char *dp;
    404 	int i;
    405 	char term;
    406 
    407 	term = ':';
    408 	cp = *area;
    409 again:
    410 	if (*str == '"') {
    411 		term = '"';
    412 		str++;
    413 	}
    414 	while ((c = *str++) && c != term) {
    415 		switch (c) {
    416 
    417 		case '^':
    418 			c = *str++ & 037;
    419 			break;
    420 
    421 		case '\\':
    422 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
    423 			c = *str++;
    424 nextc:
    425 			if (*dp++ == c) {
    426 				c = *dp++;
    427 				break;
    428 			}
    429 			dp++;
    430 			if (*dp)
    431 				goto nextc;
    432 			if (isdigit(c)) {
    433 				c -= '0', i = 2;
    434 				do
    435 					c <<= 3, c |= *str++ - '0';
    436 				while (--i && isdigit(*str));
    437 			}
    438 			break;
    439 		}
    440 		*cp++ = c;
    441 	}
    442 	if (c == term && term != ':') {
    443 		term = ':';
    444 		goto again;
    445 	}
    446 	*cp++ = 0;
    447 	str = *area;
    448 	*area = cp;
    449 	return (str);
    450 }
    451