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advcap.c revision 1.12.42.1 
      1 /*	$NetBSD: advcap.c,v 1.12.42.1 2012/04/17 00:09:53 yamt Exp $	*/
      2 /*	$KAME: advcap.c,v 1.11 2003/05/19 09:46:50 keiichi 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(char *, char *);
     91 int getent(char *, char *, char *);
     92 int tnchktc(void);
     93 int tnamatch(char *);
     94 static char *tskip(char *);
     95 int64_t tgetnum(char *);
     96 int tgetflag(char *);
     97 char *tgetstr(char *, char **);
     98 static char *tdecode(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(char *bp, char *name)
    107 {
    108 	char *cp;
    109 
    110 	remotefile = cp = conffile ? conffile : __UNCONST(_PATH_RTADVDCONF);
    111 	return (getent(bp, name, cp));
    112 }
    113 
    114 int
    115 getent(char *bp, char *name, char *cp)
    116 {
    117 	int c;
    118 	int i = 0, cnt = 0;
    119 	char ibuf[BUFSIZ];
    120 	int tf;
    121 
    122 	tbuf = bp;
    123 	tf = 0;
    124 	/*
    125 	 * TERMCAP can have one of two things in it. It can be the
    126 	 * name of a file to use instead of /etc/termcap. In this
    127 	 * case it better start with a "/". Or it can be an entry to
    128 	 * use so we don't have to read the file. In this case it
    129 	 * has to already have the newlines crunched out.
    130 	 */
    131 	if (cp && *cp) {
    132 		tf = open(RM = cp, O_RDONLY);
    133 	}
    134 	if (tf < 0) {
    135 		syslog(LOG_INFO,
    136 		       "<%s> open: %s", __func__, strerror(errno));
    137 		return (-2);
    138 	}
    139 	for (;;) {
    140 		cp = bp;
    141 		for (;;) {
    142 			if (i == cnt) {
    143 				cnt = read(tf, ibuf, BUFSIZ);
    144 				if (cnt <= 0) {
    145 					close(tf);
    146 					return (0);
    147 				}
    148 				i = 0;
    149 			}
    150 			c = ibuf[i++];
    151 			if (c == '\n') {
    152 				if (cp > bp && cp[-1] == '\\') {
    153 					cp--;
    154 					continue;
    155 				}
    156 				break;
    157 			}
    158 			if (cp >= bp + BUFSIZ) {
    159 				write(2,"Remcap entry too long\n", 23);
    160 				break;
    161 			} else
    162 				*cp++ = c;
    163 		}
    164 		*cp = 0;
    165 
    166 		/*
    167 		 * The real work for the match.
    168 		 */
    169 		if (tnamatch(name)) {
    170 			close(tf);
    171 			return (tnchktc());
    172 		}
    173 	}
    174 }
    175 
    176 /*
    177  * tnchktc: check the last entry, see if it's tc=xxx. If so,
    178  * recursively find xxx and append that entry (minus the names)
    179  * to take the place of the tc=xxx entry. This allows termcap
    180  * entries to say "like an HP2621 but doesn't turn on the labels".
    181  * Note that this works because of the left to right scan.
    182  */
    183 int
    184 tnchktc(void)
    185 {
    186 	char *p, *q;
    187 	char tcname[16];	/* name of similar terminal */
    188 	char tcbuf[BUFSIZ];
    189 	char *holdtbuf = tbuf;
    190 	int l;
    191 
    192 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
    193 	while (*--p != ':')
    194 		if (p < tbuf) {
    195 			write(2, "Bad remcap entry\n", 18);
    196 			return (0);
    197 		}
    198 	p++;
    199 	/* p now points to beginning of last field */
    200 	if (p[0] != 't' || p[1] != 'c')
    201 		return (1);
    202 	strlcpy(tcname, p + 3, sizeof tcname);
    203 	q = tcname;
    204 	while (*q && *q != ':')
    205 		q++;
    206 	*q = 0;
    207 	if (++hopcount > MAXHOP) {
    208 		write(2, "Infinite tc= loop\n", 18);
    209 		return (0);
    210 	}
    211 	if (getent(tcbuf, tcname, remotefile) != 1) {
    212 		return (0);
    213 	}
    214 	for (q = tcbuf; *q++ != ':'; )
    215 		;
    216 	l = p - holdtbuf + strlen(q);
    217 	if (l > BUFSIZ) {
    218 		write(2, "Remcap entry too long\n", 23);
    219 		q[BUFSIZ - (p-holdtbuf)] = 0;
    220 	}
    221 	strcpy(p, q);
    222 	tbuf = holdtbuf;
    223 	return (1);
    224 }
    225 
    226 /*
    227  * Tnamatch deals with name matching.  The first field of the termcap
    228  * entry is a sequence of names separated by |'s, so we compare
    229  * against each such name.  The normal : terminator after the last
    230  * name (before the first field) stops us.
    231  */
    232 int
    233 tnamatch(char *np)
    234 {
    235 	char *Np, *Bp;
    236 
    237 	Bp = tbuf;
    238 	if (*Bp == '#')
    239 		return (0);
    240 	for (;;) {
    241 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
    242 			continue;
    243 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
    244 			return (1);
    245 		while (*Bp && *Bp != ':' && *Bp != '|')
    246 			Bp++;
    247 		if (*Bp == 0 || *Bp == ':')
    248 			return (0);
    249 		Bp++;
    250 	}
    251 }
    252 
    253 /*
    254  * Skip to the next field.  Notice that this is very dumb, not
    255  * knowing about \: escapes or any such.  If necessary, :'s can be put
    256  * into the termcap file in octal.
    257  */
    258 static char *
    259 tskip(char *bp)
    260 {
    261 	int dquote;
    262 
    263 	dquote = 0;
    264 	while (*bp) {
    265 		switch (*bp) {
    266 		case ':':
    267 			if (!dquote)
    268 				goto breakbreak;
    269 			else
    270 				bp++;
    271 			break;
    272 		case '\\':
    273 			bp++;
    274 			if (isdigit((unsigned char)*bp)) {
    275 				while (isdigit((unsigned char)*bp++))
    276 					;
    277 			} else
    278 				bp++;
    279 		case '"':
    280 			dquote = (dquote ? 0 : 1);
    281 			bp++;
    282 			break;
    283 		default:
    284 			bp++;
    285 			break;
    286 		}
    287 	}
    288 breakbreak:
    289 	if (*bp == ':')
    290 		bp++;
    291 	return (bp);
    292 }
    293 
    294 /*
    295  * Return the (numeric) option id.
    296  * Numeric options look like
    297  *	li#80
    298  * i.e. the option string is separated from the numeric value by
    299  * a # character.  If the option is not found we return -1.
    300  * Note that we handle octal numbers beginning with 0.
    301  */
    302 int64_t
    303 tgetnum(char *id)
    304 {
    305 	int64_t i;
    306 	int base;
    307 	char *bp = tbuf;
    308 
    309 	for (;;) {
    310 		bp = tskip(bp);
    311 		if (*bp == 0)
    312 			return (-1);
    313 		if (strncmp(bp, id, strlen(id)) != 0)
    314 			continue;
    315 		bp += strlen(id);
    316 		if (*bp == '@')
    317 			return (-1);
    318 		if (*bp != '#')
    319 			continue;
    320 		bp++;
    321 		base = 10;
    322 		if (*bp == '0')
    323 			base = 8;
    324 		i = 0;
    325 		while (isdigit((unsigned char)*bp))
    326 			i *= base, i += *bp++ - '0';
    327 		return (i);
    328 	}
    329 }
    330 
    331 /*
    332  * Handle a flag option.
    333  * Flag options are given "naked", i.e. followed by a : or the end
    334  * of the buffer.  Return 1 if we find the option, or 0 if it is
    335  * not given.
    336  */
    337 int
    338 tgetflag(char *id)
    339 {
    340 	char *bp = tbuf;
    341 
    342 	for (;;) {
    343 		bp = tskip(bp);
    344 		if (!*bp)
    345 			return (0);
    346 		if (strncmp(bp, id, strlen(id)) == 0) {
    347 			bp += strlen(id);
    348 			if (!*bp || *bp == ':')
    349 				return (1);
    350 			else if (*bp == '@')
    351 				return (0);
    352 		}
    353 	}
    354 }
    355 
    356 /*
    357  * Get a string valued option.
    358  * These are given as
    359  *	cl=^Z
    360  * Much decoding is done on the strings, and the strings are
    361  * placed in area, which is a ref parameter which is updated.
    362  * No checking on area overflow.
    363  */
    364 char *
    365 tgetstr(char *id, char **area)
    366 {
    367 	char *bp = tbuf;
    368 
    369 	for (;;) {
    370 		bp = tskip(bp);
    371 		if (!*bp)
    372 			return (0);
    373 		if (strncmp(bp, id, strlen(id)) != 0)
    374 			continue;
    375 		bp += strlen(id);
    376 		if (*bp == '@')
    377 			return (0);
    378 		if (*bp != '=')
    379 			continue;
    380 		bp++;
    381 		return (tdecode(bp, area));
    382 	}
    383 }
    384 
    385 /*
    386  * Tdecode does the grung work to decode the
    387  * string capability escapes.
    388  */
    389 static char *
    390 tdecode(char *str, char **area)
    391 {
    392 	char *cp;
    393 	int c;
    394 	const char *dps = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"", *dp;
    395 	int i;
    396 	char term;
    397 
    398 	term = ':';
    399 	cp = *area;
    400 again:
    401 	if (*str == '"') {
    402 		term = '"';
    403 		str++;
    404 	}
    405 	while ((c = *str++) && c != term) {
    406 		switch (c) {
    407 
    408 		case '^':
    409 			c = *str++ & 037;
    410 			break;
    411 
    412 		case '\\':
    413 			dp = dps;
    414 			c = *str++;
    415 nextc:
    416 			if (*dp++ == c) {
    417 				c = *dp++;
    418 				break;
    419 			}
    420 			dp++;
    421 			if (*dp)
    422 				goto nextc;
    423 			if (isdigit((unsigned char)c)) {
    424 				c -= '0', i = 2;
    425 				do
    426 					c <<= 3, c |= *str++ - '0';
    427 				while (--i && isdigit((unsigned char)*str));
    428 			}
    429 			break;
    430 		}
    431 		*cp++ = c;
    432 	}
    433 	if (c == term && term != ':') {
    434 		term = ':';
    435 		goto again;
    436 	}
    437 	*cp++ = 0;
    438 	str = *area;
    439 	*area = cp;
    440 	return (str);
    441 }
    442