xref: /freebsd/usr.sbin/rtadvd/advcap.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /*	$FreeBSD$	*/
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. 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 int64_t 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 	int c;
124 	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", __func__, 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(STDERR_FILENO, "Remcap entry too long\n",
166 				      23);
167 				break;
168 			} else
169 				*cp++ = c;
170 		}
171 		*cp = 0;
172 
173 		/*
174 		 * The real work for the match.
175 		 */
176 		if (tnamatch(name)) {
177 			close(tf);
178 			return (tnchktc());
179 		}
180 	}
181 }
182 
183 /*
184  * tnchktc: check the last entry, see if it's tc=xxx. If so,
185  * recursively find xxx and append that entry (minus the names)
186  * to take the place of the tc=xxx entry. This allows termcap
187  * entries to say "like an HP2621 but doesn't turn on the labels".
188  * Note that this works because of the left to right scan.
189  */
190 int
191 tnchktc()
192 {
193 	char *p, *q;
194 	char tcname[16];	/* name of similar terminal */
195 	char tcbuf[BUFSIZ];
196 	char *holdtbuf = tbuf;
197 	int l;
198 
199 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
200 	while (*--p != ':')
201 		if (p < tbuf) {
202 			write(STDERR_FILENO, "Bad remcap entry\n", 18);
203 			return (0);
204 		}
205 	p++;
206 	/* p now points to beginning of last field */
207 	if (p[0] != 't' || p[1] != 'c')
208 		return (1);
209 	strlcpy(tcname, p + 3, sizeof tcname);
210 	q = tcname;
211 	while (*q && *q != ':')
212 		q++;
213 	*q = 0;
214 	if (++hopcount > MAXHOP) {
215 		write(STDERR_FILENO, "Infinite tc= loop\n", 18);
216 		return (0);
217 	}
218 	if (getent(tcbuf, tcname, remotefile) != 1) {
219 		return (0);
220 	}
221 	for (q = tcbuf; *q++ != ':'; )
222 		;
223 	l = p - holdtbuf + strlen(q);
224 	if (l > BUFSIZ) {
225 		write(STDERR_FILENO, "Remcap entry too long\n", 23);
226 		q[BUFSIZ - (p-holdtbuf)] = 0;
227 	}
228 	strcpy(p, q);
229 	tbuf = holdtbuf;
230 	return (1);
231 }
232 
233 /*
234  * Tnamatch deals with name matching.  The first field of the termcap
235  * entry is a sequence of names separated by |'s, so we compare
236  * against each such name.  The normal : terminator after the last
237  * name (before the first field) stops us.
238  */
239 int
240 tnamatch(np)
241 	char *np;
242 {
243 	char *Np, *Bp;
244 
245 	Bp = tbuf;
246 	if (*Bp == '#')
247 		return (0);
248 	for (;;) {
249 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
250 			continue;
251 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
252 			return (1);
253 		while (*Bp && *Bp != ':' && *Bp != '|')
254 			Bp++;
255 		if (*Bp == 0 || *Bp == ':')
256 			return (0);
257 		Bp++;
258 	}
259 }
260 
261 /*
262  * Skip to the next field.  Notice that this is very dumb, not
263  * knowing about \: escapes or any such.  If necessary, :'s can be put
264  * into the termcap file in octal.
265  */
266 static char *
267 tskip(bp)
268 	char *bp;
269 {
270 	int dquote;
271 
272 	dquote = 0;
273 	while (*bp) {
274 		switch (*bp) {
275 		case ':':
276 			if (!dquote)
277 				goto breakbreak;
278 			else
279 				bp++;
280 			break;
281 		case '\\':
282 			bp++;
283 			if (isdigit(*bp)) {
284 				while (isdigit(*bp++))
285 					;
286 			} else
287 				bp++;
288 		case '"':
289 			dquote = (dquote ? 1 : 0);
290 			bp++;
291 			break;
292 		default:
293 			bp++;
294 			break;
295 		}
296 	}
297 breakbreak:
298 	if (*bp == ':')
299 		bp++;
300 	return (bp);
301 }
302 
303 /*
304  * Return the (numeric) option id.
305  * Numeric options look like
306  *	li#80
307  * i.e. the option string is separated from the numeric value by
308  * a # character.  If the option is not found we return -1.
309  * Note that we handle octal numbers beginning with 0.
310  */
311 int64_t
312 tgetnum(id)
313 	char *id;
314 {
315 	int64_t i;
316 	int base;
317 	char *bp = tbuf;
318 
319 	for (;;) {
320 		bp = tskip(bp);
321 		if (*bp == 0)
322 			return (-1);
323 		if (strncmp(bp, id, strlen(id)) != 0)
324 			continue;
325 		bp += strlen(id);
326 		if (*bp == '@')
327 			return (-1);
328 		if (*bp != '#')
329 			continue;
330 		bp++;
331 		base = 10;
332 		if (*bp == '0')
333 			base = 8;
334 		i = 0;
335 		while (isdigit(*bp))
336 			i *= base, i += *bp++ - '0';
337 		return (i);
338 	}
339 }
340 
341 /*
342  * Handle a flag option.
343  * Flag options are given "naked", i.e. followed by a : or the end
344  * of the buffer.  Return 1 if we find the option, or 0 if it is
345  * not given.
346  */
347 int
348 tgetflag(id)
349 	char *id;
350 {
351 	char *bp = tbuf;
352 
353 	for (;;) {
354 		bp = tskip(bp);
355 		if (!*bp)
356 			return (0);
357 		if (strncmp(bp, id, strlen(id)) == 0) {
358 			bp += strlen(id);
359 			if (!*bp || *bp == ':')
360 				return (1);
361 			else if (*bp == '@')
362 				return (0);
363 		}
364 	}
365 }
366 
367 /*
368  * Get a string valued option.
369  * These are given as
370  *	cl=^Z
371  * Much decoding is done on the strings, and the strings are
372  * placed in area, which is a ref parameter which is updated.
373  * No checking on area overflow.
374  */
375 char *
376 tgetstr(id, area)
377 	char *id, **area;
378 {
379 	char *bp = tbuf;
380 
381 	for (;;) {
382 		bp = tskip(bp);
383 		if (!*bp)
384 			return (0);
385 		if (strncmp(bp, id, strlen(id)) != 0)
386 			continue;
387 		bp += strlen(id);
388 		if (*bp == '@')
389 			return (0);
390 		if (*bp != '=')
391 			continue;
392 		bp++;
393 		return (tdecode(bp, area));
394 	}
395 }
396 
397 /*
398  * Tdecode does the grung work to decode the
399  * string capability escapes.
400  */
401 static char *
402 tdecode(str, area)
403 	char *str;
404 	char **area;
405 {
406 	char *cp;
407 	int c;
408 	char *dp;
409 	int i;
410 	char term;
411 
412 	term = ':';
413 	cp = *area;
414 again:
415 	if (*str == '"') {
416 		term = '"';
417 		str++;
418 	}
419 	while ((c = *str++) && c != term) {
420 		switch (c) {
421 
422 		case '^':
423 			c = *str++ & 037;
424 			break;
425 
426 		case '\\':
427 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
428 			c = *str++;
429 nextc:
430 			if (*dp++ == c) {
431 				c = *dp++;
432 				break;
433 			}
434 			dp++;
435 			if (*dp)
436 				goto nextc;
437 			if (isdigit(c)) {
438 				c -= '0', i = 2;
439 				do
440 					c <<= 3, c |= *str++ - '0';
441 				while (--i && isdigit(*str));
442 			}
443 			break;
444 		}
445 		*cp++ = c;
446 	}
447 	if (c == term && term != ':') {
448 		term = ':';
449 		goto again;
450 	}
451 	*cp++ = 0;
452 	str = *area;
453 	*area = cp;
454 	return (str);
455 }
456