xref: /dragonfly/usr.sbin/rtadvd/advcap.c (revision 9bb2a92d) 
1 /*	$KAME: advcap.c,v 1.5 2001/02/01 09:12:08 jinmei Exp $	*/
2 
3 /*
4  * Copyright (c) 1983 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD: src/usr.sbin/rtadvd/advcap.c,v 1.1.2.2 2001/07/03 11:02:13 ume Exp $
36  * $DragonFly: src/usr.sbin/rtadvd/advcap.c,v 1.3 2003/11/03 19:31:42 eirikn Exp $
37  */
38 
39 /*
40  * remcap - routines for dealing with the remote host data base
41  *
42  * derived from termcap
43  */
44 #include <sys/types.h>
45 #include <sys/uio.h>
46 #include <unistd.h>
47 #include <fcntl.h>
48 #include <ctype.h>
49 #include <stdlib.h>
50 #include <stdio.h>
51 #include <syslog.h>
52 #include <errno.h>
53 #include <string.h>
54 #include "pathnames.h"
55 
56 #ifndef BUFSIZ
57 #define	BUFSIZ		1024
58 #endif
59 #define MAXHOP		32		/* max number of tc= indirections */
60 
61 #define	tgetent		agetent
62 #define	tnchktc		anchktc
63 #define	tnamatch	anamatch
64 #define	tgetnum		agetnum
65 #define	tgetflag	agetflag
66 #define	tgetstr		agetstr
67 
68 #if 0
69 #define V_TERMCAP	"REMOTE"
70 #define V_TERM		"HOST"
71 #endif
72 
73 char	*RM;
74 
75 /*
76  * termcap - routines for dealing with the terminal capability data base
77  *
78  * BUG:		Should use a "last" pointer in tbuf, so that searching
79  *		for capabilities alphabetically would not be a n**2/2
80  *		process when large numbers of capabilities are given.
81  * Note:	If we add a last pointer now we will screw up the
82  *		tc capability. We really should compile termcap.
83  *
84  * Essentially all the work here is scanning and decoding escapes
85  * in string capabilities.  We don't use stdio because the editor
86  * doesn't, and because living w/o it is not hard.
87  */
88 
89 static	char *tbuf;
90 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
91 
92 static	char *remotefile;
93 
94 extern char *conffile;
95 
96 int tgetent(char *, char *);
97 int getent(char *, char *, char *);
98 int tnchktc(void);
99 int tnamatch(char *);
100 static char *tskip(char *);
101 long long tgetnum(char *);
102 int tgetflag(char *);
103 char *tgetstr(char *, char **);
104 static char *tdecode(char *, char **);
105 
106 /*
107  * Get an entry for terminal name in buffer bp,
108  * from the termcap file.  Parse is very rudimentary;
109  * we just notice escaped newlines.
110  */
111 int
112 tgetent(bp, name)
113 	char *bp, *name;
114 {
115 	char *cp;
116 
117 	remotefile = cp = conffile ? conffile : _PATH_RTADVDCONF;
118 	return (getent(bp, name, cp));
119 }
120 
121 int
122 getent(bp, name, cp)
123 	char *bp, *name, *cp;
124 {
125 	register int c;
126 	register int i = 0, cnt = 0;
127 	char ibuf[BUFSIZ];
128 	int tf;
129 
130 	tbuf = bp;
131 	tf = 0;
132 	/*
133 	 * TERMCAP can have one of two things in it. It can be the
134 	 * name of a file to use instead of /etc/termcap. In this
135 	 * case it better start with a "/". Or it can be an entry to
136 	 * use so we don't have to read the file. In this case it
137 	 * has to already have the newlines crunched out.
138 	 */
139 	if (cp && *cp) {
140 		tf = open(RM = cp, O_RDONLY);
141 	}
142 	if (tf < 0) {
143 		syslog(LOG_INFO,
144 		       "<%s> open: %s", __FUNCTION__, strerror(errno));
145 		return (-2);
146 	}
147 	for (;;) {
148 		cp = bp;
149 		for (;;) {
150 			if (i == cnt) {
151 				cnt = read(tf, ibuf, BUFSIZ);
152 				if (cnt <= 0) {
153 					close(tf);
154 					return (0);
155 				}
156 				i = 0;
157 			}
158 			c = ibuf[i++];
159 			if (c == '\n') {
160 				if (cp > bp && cp[-1] == '\\') {
161 					cp--;
162 					continue;
163 				}
164 				break;
165 			}
166 			if (cp >= bp+BUFSIZ) {
167 				write(2,"Remcap entry too long\n", 23);
168 				break;
169 			} else
170 				*cp++ = c;
171 		}
172 		*cp = 0;
173 
174 		/*
175 		 * The real work for the match.
176 		 */
177 		if (tnamatch(name)) {
178 			close(tf);
179 			return (tnchktc());
180 		}
181 	}
182 }
183 
184 /*
185  * tnchktc: check the last entry, see if it's tc=xxx. If so,
186  * recursively find xxx and append that entry (minus the names)
187  * to take the place of the tc=xxx entry. This allows termcap
188  * entries to say "like an HP2621 but doesn't turn on the labels".
189  * Note that this works because of the left to right scan.
190  */
191 int
192 tnchktc()
193 {
194 	register char *p, *q;
195 	char tcname[16];	/* name of similar terminal */
196 	char tcbuf[BUFSIZ];
197 	char *holdtbuf = tbuf;
198 	int l;
199 
200 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
201 	while (*--p != ':')
202 		if (p<tbuf) {
203 			write(2, "Bad remcap entry\n", 18);
204 			return (0);
205 		}
206 	p++;
207 	/* p now points to beginning of last field */
208 	if (p[0] != 't' || p[1] != 'c')
209 		return (1);
210 	strcpy(tcname, p+3);
211 	q = tcname;
212 	while (*q && *q != ':')
213 		q++;
214 	*q = 0;
215 	if (++hopcount > MAXHOP) {
216 		write(2, "Infinite tc= loop\n", 18);
217 		return (0);
218 	}
219 	if (getent(tcbuf, tcname, remotefile) != 1) {
220 		return (0);
221 	}
222 	for (q = tcbuf; *q++ != ':'; )
223 		;
224 	l = p - holdtbuf + strlen(q);
225 	if (l > BUFSIZ) {
226 		write(2, "Remcap entry too long\n", 23);
227 		q[BUFSIZ - (p-holdtbuf)] = 0;
228 	}
229 	strcpy(p, q);
230 	tbuf = holdtbuf;
231 	return (1);
232 }
233 
234 /*
235  * Tnamatch deals with name matching.  The first field of the termcap
236  * entry is a sequence of names separated by |'s, so we compare
237  * against each such name.  The normal : terminator after the last
238  * name (before the first field) stops us.
239  */
240 int
241 tnamatch(np)
242 	char *np;
243 {
244 	register char *Np, *Bp;
245 
246 	Bp = tbuf;
247 	if (*Bp == '#')
248 		return (0);
249 	for (;;) {
250 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
251 			continue;
252 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
253 			return (1);
254 		while (*Bp && *Bp != ':' && *Bp != '|')
255 			Bp++;
256 		if (*Bp == 0 || *Bp == ':')
257 			return (0);
258 		Bp++;
259 	}
260 }
261 
262 /*
263  * Skip to the next field.  Notice that this is very dumb, not
264  * knowing about \: escapes or any such.  If necessary, :'s can be put
265  * into the termcap file in octal.
266  */
267 static char *
268 tskip(bp)
269 	register char *bp;
270 {
271 	int dquote;
272 
273 	dquote = 0;
274 	while (*bp) {
275 		switch (*bp) {
276 		case ':':
277 			if (!dquote)
278 				goto breakbreak;
279 			else
280 				bp++;
281 			break;
282 		case '\\':
283 			bp++;
284 			if (isdigit(*bp)) {
285 				while (isdigit(*bp++))
286 					;
287 			} else
288 				bp++;
289 		case '"':
290 			dquote = (dquote ? 1 : 0);
291 			bp++;
292 			break;
293 		default:
294 			bp++;
295 			break;
296 		}
297 	}
298 breakbreak:
299 	if (*bp == ':')
300 		bp++;
301 	return (bp);
302 }
303 
304 /*
305  * Return the (numeric) option id.
306  * Numeric options look like
307  *	li#80
308  * i.e. the option string is separated from the numeric value by
309  * a # character.  If the option is not found we return -1.
310  * Note that we handle octal numbers beginning with 0.
311  */
312 long long
313 tgetnum(id)
314 	char *id;
315 {
316 	register long long i;
317 	register int base;
318 	register char *bp = tbuf;
319 
320 	for (;;) {
321 		bp = tskip(bp);
322 		if (*bp == 0)
323 			return (-1);
324 		if (strncmp(bp, id, strlen(id)) != 0)
325 			continue;
326 		bp += strlen(id);
327 		if (*bp == '@')
328 			return (-1);
329 		if (*bp != '#')
330 			continue;
331 		bp++;
332 		base = 10;
333 		if (*bp == '0')
334 			base = 8;
335 		i = 0;
336 		while (isdigit(*bp))
337 			i *= base, i += *bp++ - '0';
338 		return (i);
339 	}
340 }
341 
342 /*
343  * Handle a flag option.
344  * Flag options are given "naked", i.e. followed by a : or the end
345  * of the buffer.  Return 1 if we find the option, or 0 if it is
346  * not given.
347  */
348 int
349 tgetflag(id)
350 	char *id;
351 {
352 	register char *bp = tbuf;
353 
354 	for (;;) {
355 		bp = tskip(bp);
356 		if (!*bp)
357 			return (0);
358 		if (strncmp(bp, id, strlen(id)) == 0) {
359 			bp += strlen(id);
360 			if (!*bp || *bp == ':')
361 				return (1);
362 			else if (*bp == '@')
363 				return (0);
364 		}
365 	}
366 }
367 
368 /*
369  * Get a string valued option.
370  * These are given as
371  *	cl=^Z
372  * Much decoding is done on the strings, and the strings are
373  * placed in area, which is a ref parameter which is updated.
374  * No checking on area overflow.
375  */
376 char *
377 tgetstr(id, area)
378 	char *id, **area;
379 {
380 	register char *bp = tbuf;
381 
382 	for (;;) {
383 		bp = tskip(bp);
384 		if (!*bp)
385 			return (0);
386 		if (strncmp(bp, id, strlen(id)) != 0)
387 			continue;
388 		bp += strlen(id);
389 		if (*bp == '@')
390 			return (0);
391 		if (*bp != '=')
392 			continue;
393 		bp++;
394 		return (tdecode(bp, area));
395 	}
396 }
397 
398 /*
399  * Tdecode does the grung work to decode the
400  * string capability escapes.
401  */
402 static char *
403 tdecode(str, area)
404 	register char *str;
405 	char **area;
406 {
407 	register char *cp;
408 	register int c;
409 	register char *dp;
410 	int i;
411 	char term;
412 
413 	term = ':';
414 	cp = *area;
415 again:
416 	if (*str == '"') {
417 		term = '"';
418 		str++;
419 	}
420 	while ((c = *str++) && c != term) {
421 		switch (c) {
422 
423 		case '^':
424 			c = *str++ & 037;
425 			break;
426 
427 		case '\\':
428 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
429 			c = *str++;
430 nextc:
431 			if (*dp++ == c) {
432 				c = *dp++;
433 				break;
434 			}
435 			dp++;
436 			if (*dp)
437 				goto nextc;
438 			if (isdigit(c)) {
439 				c -= '0', i = 2;
440 				do
441 					c <<= 3, c |= *str++ - '0';
442 				while (--i && isdigit(*str));
443 			}
444 			break;
445 		}
446 		*cp++ = c;
447 	}
448 	if (c == term && term != ':') {
449 		term = ':';
450 		goto again;
451 	}
452 	*cp++ = 0;
453 	str = *area;
454 	*area = cp;
455 	return (str);
456 }
457