xref: /netbsd-src/lib/libc/gen/vis.c (revision df0caa2637da0538ecdf6b878c4d08e684b43d8f)
1 /*	$NetBSD: vis.c,v 1.33 2005/05/28 13:11:14 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1999, 2005 The NetBSD Foundation, Inc.
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *        This product includes software developed by the NetBSD
47  *        Foundation, Inc. and its contributors.
48  * 4. Neither the name of The NetBSD Foundation nor the names of its
49  *    contributors may be used to endorse or promote products derived
50  *    from this software without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
53  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
54  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
55  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
56  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
57  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
58  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
59  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
60  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
61  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
62  * POSSIBILITY OF SUCH DAMAGE.
63  */
64 
65 #include <sys/cdefs.h>
66 #if defined(LIBC_SCCS) && !defined(lint)
67 __RCSID("$NetBSD: vis.c,v 1.33 2005/05/28 13:11:14 lukem Exp $");
68 #endif /* LIBC_SCCS and not lint */
69 
70 #include "namespace.h"
71 #include <sys/types.h>
72 
73 #include <assert.h>
74 #include <vis.h>
75 #include <stdlib.h>
76 
77 #ifdef __weak_alias
78 __weak_alias(strsvis,_strsvis)
79 __weak_alias(strsvisx,_strsvisx)
80 __weak_alias(strvis,_strvis)
81 __weak_alias(strvisx,_strvisx)
82 __weak_alias(svis,_svis)
83 __weak_alias(vis,_vis)
84 #endif
85 
86 #if !HAVE_VIS || !HAVE_SVIS
87 #include <ctype.h>
88 #include <limits.h>
89 #include <stdio.h>
90 #include <string.h>
91 
92 #undef BELL
93 #define BELL '\a'
94 
95 #define isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
96 #define iswhite(c)	(c == ' ' || c == '\t' || c == '\n')
97 #define issafe(c)	(c == '\b' || c == BELL || c == '\r')
98 #define xtoa(c)		"0123456789abcdef"[c]
99 
100 #define MAXEXTRAS	5
101 
102 
103 #define MAKEEXTRALIST(flag, extra, orig)				      \
104 do {									      \
105 	const char *o = orig;						      \
106 	char *e;							      \
107 	while (*o++)							      \
108 		continue;						      \
109 	extra = malloc((size_t)((o - orig) + MAXEXTRAS));		      \
110 	if (!extra) break;						      \
111 	for (o = orig, e = extra; (*e++ = *o++) != '\0';)		      \
112 		continue;						      \
113 	e--;								      \
114 	if (flag & VIS_SP) *e++ = ' ';					      \
115 	if (flag & VIS_TAB) *e++ = '\t';				      \
116 	if (flag & VIS_NL) *e++ = '\n';					      \
117 	if ((flag & VIS_NOSLASH) == 0) *e++ = '\\';			      \
118 	*e = '\0';							      \
119 } while (/*CONSTCOND*/0)
120 
121 
122 /*
123  * This is HVIS, the macro of vis used to HTTP style (RFC 1808)
124  */
125 #define HVIS(dst, c, flag, nextc, extra)				      \
126 do									      \
127 	if (!isascii(c) || !isalnum(c) || strchr("$-_.+!*'(),", c) != NULL) { \
128 		*dst++ = '%';						      \
129 		*dst++ = xtoa(((unsigned int)c >> 4) & 0xf);		      \
130 		*dst++ = xtoa((unsigned int)c & 0xf);			      \
131 	} else {							      \
132 		SVIS(dst, c, flag, nextc, extra);			      \
133 	}								      \
134 while (/*CONSTCOND*/0)
135 
136 /*
137  * This is SVIS, the central macro of vis.
138  * dst:	      Pointer to the destination buffer
139  * c:	      Character to encode
140  * flag:      Flag word
141  * nextc:     The character following 'c'
142  * extra:     Pointer to the list of extra characters to be
143  *	      backslash-protected.
144  */
145 #define SVIS(dst, c, flag, nextc, extra)				      \
146 do {									      \
147 	int isextra;							      \
148 	isextra = strchr(extra, c) != NULL;				      \
149 	if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||	      \
150 	    ((flag & VIS_SAFE) && issafe(c)))) {			      \
151 		*dst++ = c;						      \
152 		break;							      \
153 	}								      \
154 	if (flag & VIS_CSTYLE) {					      \
155 		switch (c) {						      \
156 		case '\n':						      \
157 			*dst++ = '\\'; *dst++ = 'n';			      \
158 			continue;					      \
159 		case '\r':						      \
160 			*dst++ = '\\'; *dst++ = 'r';			      \
161 			continue;					      \
162 		case '\b':						      \
163 			*dst++ = '\\'; *dst++ = 'b';			      \
164 			continue;					      \
165 		case BELL:						      \
166 			*dst++ = '\\'; *dst++ = 'a';			      \
167 			continue;					      \
168 		case '\v':						      \
169 			*dst++ = '\\'; *dst++ = 'v';			      \
170 			continue;					      \
171 		case '\t':						      \
172 			*dst++ = '\\'; *dst++ = 't';			      \
173 			continue;					      \
174 		case '\f':						      \
175 			*dst++ = '\\'; *dst++ = 'f';			      \
176 			continue;					      \
177 		case ' ':						      \
178 			*dst++ = '\\'; *dst++ = 's';			      \
179 			continue;					      \
180 		case '\0':						      \
181 			*dst++ = '\\'; *dst++ = '0';			      \
182 			if (isoctal(nextc)) {				      \
183 				*dst++ = '0';				      \
184 				*dst++ = '0';				      \
185 			}						      \
186 			continue;					      \
187 		default:						      \
188 			if (isgraph(c)) {				      \
189 				*dst++ = '\\'; *dst++ = c;		      \
190 				continue;				      \
191 			}						      \
192 		}							      \
193 	}								      \
194 	if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {	      \
195 		*dst++ = '\\';						      \
196 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';    \
197 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';    \
198 		*dst++ =			     (c	      & 07) + '0';    \
199 	} else {							      \
200 		if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';		      \
201 		if (c & 0200) {						      \
202 			c &= 0177; *dst++ = 'M';			      \
203 		}							      \
204 		if (iscntrl(c)) {					      \
205 			*dst++ = '^';					      \
206 			if (c == 0177)					      \
207 				*dst++ = '?';				      \
208 			else						      \
209 				*dst++ = c + '@';			      \
210 		} else {						      \
211 			*dst++ = '-'; *dst++ = c;			      \
212 		}							      \
213 	}								      \
214 } while (/*CONSTCOND*/0)
215 
216 
217 /*
218  * svis - visually encode characters, also encoding the characters
219  *	  pointed to by `extra'
220  */
221 char *
222 svis(char *dst, int c, int flag, int nextc, const char *extra)
223 {
224 	char *nextra = NULL;
225 
226 	_DIAGASSERT(dst != NULL);
227 	_DIAGASSERT(extra != NULL);
228 	MAKEEXTRALIST(flag, nextra, extra);
229 	if (!nextra) {
230 		*dst = '\0';		/* can't create nextra, return "" */
231 		return dst;
232 	}
233 	if (flag & VIS_HTTPSTYLE)
234 		HVIS(dst, c, flag, nextc, nextra);
235 	else
236 		SVIS(dst, c, flag, nextc, nextra);
237 	free(nextra);
238 	*dst = '\0';
239 	return dst;
240 }
241 
242 
243 /*
244  * strsvis, strsvisx - visually encode characters from src into dst
245  *
246  *	Extra is a pointer to a \0-terminated list of characters to
247  *	be encoded, too. These functions are useful e. g. to
248  *	encode strings in such a way so that they are not interpreted
249  *	by a shell.
250  *
251  *	Dst must be 4 times the size of src to account for possible
252  *	expansion.  The length of dst, not including the trailing NULL,
253  *	is returned.
254  *
255  *	Strsvisx encodes exactly len bytes from src into dst.
256  *	This is useful for encoding a block of data.
257  */
258 int
259 strsvis(char *dst, const char *csrc, int flag, const char *extra)
260 {
261 	int c;
262 	char *start;
263 	char *nextra = NULL;
264 	const unsigned char *src = (const unsigned char *)csrc;
265 
266 	_DIAGASSERT(dst != NULL);
267 	_DIAGASSERT(src != NULL);
268 	_DIAGASSERT(extra != NULL);
269 	MAKEEXTRALIST(flag, nextra, extra);
270 	if (!nextra) {
271 		*dst = '\0';		/* can't create nextra, return "" */
272 		return 0;
273 	}
274 	if (flag & VIS_HTTPSTYLE) {
275 		for (start = dst; (c = *src++) != '\0'; /* empty */)
276 			HVIS(dst, c, flag, *src, nextra);
277 	} else {
278 		for (start = dst; (c = *src++) != '\0'; /* empty */)
279 			SVIS(dst, c, flag, *src, nextra);
280 	}
281 	free(nextra);
282 	*dst = '\0';
283 	return (dst - start);
284 }
285 
286 
287 int
288 strsvisx(char *dst, const char *csrc, size_t len, int flag, const char *extra)
289 {
290 	unsigned char c;
291 	char *start;
292 	char *nextra = NULL;
293 	const unsigned char *src = (const unsigned char *)csrc;
294 
295 	_DIAGASSERT(dst != NULL);
296 	_DIAGASSERT(src != NULL);
297 	_DIAGASSERT(extra != NULL);
298 	MAKEEXTRALIST(flag, nextra, extra);
299 	if (! nextra) {
300 		*dst = '\0';		/* can't create nextra, return "" */
301 		return 0;
302 	}
303 
304 	if (flag & VIS_HTTPSTYLE) {
305 		for (start = dst; len > 0; len--) {
306 			c = *src++;
307 			HVIS(dst, c, flag, len ? *src : '\0', nextra);
308 		}
309 	} else {
310 		for (start = dst; len > 0; len--) {
311 			c = *src++;
312 			SVIS(dst, c, flag, len ? *src : '\0', nextra);
313 		}
314 	}
315 	free(nextra);
316 	*dst = '\0';
317 	return (dst - start);
318 }
319 #endif
320 
321 #if !HAVE_VIS
322 /*
323  * vis - visually encode characters
324  */
325 char *
326 vis(char *dst, int c, int flag, int nextc)
327 {
328 	char *extra = NULL;
329 	unsigned char uc = (unsigned char)c;
330 
331 	_DIAGASSERT(dst != NULL);
332 
333 	MAKEEXTRALIST(flag, extra, "");
334 	if (! extra) {
335 		*dst = '\0';		/* can't create extra, return "" */
336 		return dst;
337 	}
338 	if (flag & VIS_HTTPSTYLE)
339 		HVIS(dst, uc, flag, nextc, extra);
340 	else
341 		SVIS(dst, uc, flag, nextc, extra);
342 	free(extra);
343 	*dst = '\0';
344 	return dst;
345 }
346 
347 
348 /*
349  * strvis, strvisx - visually encode characters from src into dst
350  *
351  *	Dst must be 4 times the size of src to account for possible
352  *	expansion.  The length of dst, not including the trailing NULL,
353  *	is returned.
354  *
355  *	Strvisx encodes exactly len bytes from src into dst.
356  *	This is useful for encoding a block of data.
357  */
358 int
359 strvis(char *dst, const char *src, int flag)
360 {
361 	char *extra = NULL;
362 	int rv;
363 
364 	MAKEEXTRALIST(flag, extra, "");
365 	if (!extra) {
366 		*dst = '\0';		/* can't create extra, return "" */
367 		return 0;
368 	}
369 	rv = strsvis(dst, src, flag, extra);
370 	free(extra);
371 	return rv;
372 }
373 
374 
375 int
376 strvisx(char *dst, const char *src, size_t len, int flag)
377 {
378 	char *extra = NULL;
379 	int rv;
380 
381 	MAKEEXTRALIST(flag, extra, "");
382 	if (!extra) {
383 		*dst = '\0';		/* can't create extra, return "" */
384 		return 0;
385 	}
386 	rv = strsvisx(dst, src, len, flag, extra);
387 	free(extra);
388 	return rv;
389 }
390 #endif
391