xref: /freebsd/usr.sbin/rtadvd/advcap.c (revision 4f29da19bd44f0e99f021510460a81bf754c21d2)
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  * 4. 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(STDERR_FILENO, "Remcap entry too long\n",
162 				      23);
163 				break;
164 			} else
165 				*cp++ = c;
166 		}
167 		*cp = 0;
168 
169 		/*
170 		 * The real work for the match.
171 		 */
172 		if (tnamatch(name)) {
173 			close(tf);
174 			return (tnchktc());
175 		}
176 	}
177 }
178 
179 /*
180  * tnchktc: check the last entry, see if it's tc=xxx. If so,
181  * recursively find xxx and append that entry (minus the names)
182  * to take the place of the tc=xxx entry. This allows termcap
183  * entries to say "like an HP2621 but doesn't turn on the labels".
184  * Note that this works because of the left to right scan.
185  */
186 int
187 tnchktc()
188 {
189 	char *p, *q;
190 	char tcname[16];	/* name of similar terminal */
191 	char tcbuf[BUFSIZ];
192 	char *holdtbuf = tbuf;
193 	int l;
194 
195 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
196 	while (*--p != ':')
197 		if (p < tbuf) {
198 			write(STDERR_FILENO, "Bad remcap entry\n", 18);
199 			return (0);
200 		}
201 	p++;
202 	/* p now points to beginning of last field */
203 	if (p[0] != 't' || p[1] != 'c')
204 		return (1);
205 	strlcpy(tcname, p + 3, sizeof tcname);
206 	q = tcname;
207 	while (*q && *q != ':')
208 		q++;
209 	*q = 0;
210 	if (++hopcount > MAXHOP) {
211 		write(STDERR_FILENO, "Infinite tc= loop\n", 18);
212 		return (0);
213 	}
214 	if (getent(tcbuf, tcname, remotefile) != 1) {
215 		return (0);
216 	}
217 	for (q = tcbuf; *q++ != ':'; )
218 		;
219 	l = p - holdtbuf + strlen(q);
220 	if (l > BUFSIZ) {
221 		write(STDERR_FILENO, "Remcap entry too long\n", 23);
222 		q[BUFSIZ - (p-holdtbuf)] = 0;
223 	}
224 	strcpy(p, q);
225 	tbuf = holdtbuf;
226 	return (1);
227 }
228 
229 /*
230  * Tnamatch deals with name matching.  The first field of the termcap
231  * entry is a sequence of names separated by |'s, so we compare
232  * against each such name.  The normal : terminator after the last
233  * name (before the first field) stops us.
234  */
235 int
236 tnamatch(np)
237 	char *np;
238 {
239 	char *Np, *Bp;
240 
241 	Bp = tbuf;
242 	if (*Bp == '#')
243 		return (0);
244 	for (;;) {
245 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
246 			continue;
247 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
248 			return (1);
249 		while (*Bp && *Bp != ':' && *Bp != '|')
250 			Bp++;
251 		if (*Bp == 0 || *Bp == ':')
252 			return (0);
253 		Bp++;
254 	}
255 }
256 
257 /*
258  * Skip to the next field.  Notice that this is very dumb, not
259  * knowing about \: escapes or any such.  If necessary, :'s can be put
260  * into the termcap file in octal.
261  */
262 static char *
263 tskip(bp)
264 	char *bp;
265 {
266 	int dquote;
267 
268 	dquote = 0;
269 	while (*bp) {
270 		switch (*bp) {
271 		case ':':
272 			if (!dquote)
273 				goto breakbreak;
274 			else
275 				bp++;
276 			break;
277 		case '\\':
278 			bp++;
279 			if (isdigit(*bp)) {
280 				while (isdigit(*bp++))
281 					;
282 			} else
283 				bp++;
284 		case '"':
285 			dquote = (dquote ? 1 : 0);
286 			bp++;
287 			break;
288 		default:
289 			bp++;
290 			break;
291 		}
292 	}
293 breakbreak:
294 	if (*bp == ':')
295 		bp++;
296 	return (bp);
297 }
298 
299 /*
300  * Return the (numeric) option id.
301  * Numeric options look like
302  *	li#80
303  * i.e. the option string is separated from the numeric value by
304  * a # character.  If the option is not found we return -1.
305  * Note that we handle octal numbers beginning with 0.
306  */
307 int64_t
308 tgetnum(id)
309 	char *id;
310 {
311 	int64_t i;
312 	int base;
313 	char *bp = tbuf;
314 
315 	for (;;) {
316 		bp = tskip(bp);
317 		if (*bp == 0)
318 			return (-1);
319 		if (strncmp(bp, id, strlen(id)) != 0)
320 			continue;
321 		bp += strlen(id);
322 		if (*bp == '@')
323 			return (-1);
324 		if (*bp != '#')
325 			continue;
326 		bp++;
327 		base = 10;
328 		if (*bp == '0')
329 			base = 8;
330 		i = 0;
331 		while (isdigit(*bp))
332 			i *= base, i += *bp++ - '0';
333 		return (i);
334 	}
335 }
336 
337 /*
338  * Handle a flag option.
339  * Flag options are given "naked", i.e. followed by a : or the end
340  * of the buffer.  Return 1 if we find the option, or 0 if it is
341  * not given.
342  */
343 int
344 tgetflag(id)
345 	char *id;
346 {
347 	char *bp = tbuf;
348 
349 	for (;;) {
350 		bp = tskip(bp);
351 		if (!*bp)
352 			return (0);
353 		if (strncmp(bp, id, strlen(id)) == 0) {
354 			bp += strlen(id);
355 			if (!*bp || *bp == ':')
356 				return (1);
357 			else if (*bp == '@')
358 				return (0);
359 		}
360 	}
361 }
362 
363 /*
364  * Get a string valued option.
365  * These are given as
366  *	cl=^Z
367  * Much decoding is done on the strings, and the strings are
368  * placed in area, which is a ref parameter which is updated.
369  * No checking on area overflow.
370  */
371 char *
372 tgetstr(id, area)
373 	char *id, **area;
374 {
375 	char *bp = tbuf;
376 
377 	for (;;) {
378 		bp = tskip(bp);
379 		if (!*bp)
380 			return (0);
381 		if (strncmp(bp, id, strlen(id)) != 0)
382 			continue;
383 		bp += strlen(id);
384 		if (*bp == '@')
385 			return (0);
386 		if (*bp != '=')
387 			continue;
388 		bp++;
389 		return (tdecode(bp, area));
390 	}
391 }
392 
393 /*
394  * Tdecode does the grung work to decode the
395  * string capability escapes.
396  */
397 static char *
398 tdecode(str, area)
399 	char *str;
400 	char **area;
401 {
402 	char *cp;
403 	int c;
404 	char *dp;
405 	int i;
406 	char term;
407 
408 	term = ':';
409 	cp = *area;
410 again:
411 	if (*str == '"') {
412 		term = '"';
413 		str++;
414 	}
415 	while ((c = *str++) && c != term) {
416 		switch (c) {
417 
418 		case '^':
419 			c = *str++ & 037;
420 			break;
421 
422 		case '\\':
423 			dp = "E\033^^\\\\::n\nr\rt\tb\bf\f\"\"";
424 			c = *str++;
425 nextc:
426 			if (*dp++ == c) {
427 				c = *dp++;
428 				break;
429 			}
430 			dp++;
431 			if (*dp)
432 				goto nextc;
433 			if (isdigit(c)) {
434 				c -= '0', i = 2;
435 				do
436 					c <<= 3, c |= *str++ - '0';
437 				while (--i && isdigit(*str));
438 			}
439 			break;
440 		}
441 		*cp++ = c;
442 	}
443 	if (c == term && term != ':') {
444 		term = ':';
445 		goto again;
446 	}
447 	*cp++ = 0;
448 	str = *area;
449 	*area = cp;
450 	return (str);
451 }
452