xref: /freebsd/crypto/heimdal/lib/roken/unvis.c (revision 0a36787e4c1fa0cf77dcf83be0867178476e372b)
1 /*	$NetBSD: unvis.c,v 1.19 2000/01/22 22:19:13 mycroft 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 #if 1
33 #include <config.h>
34 #include "roken.h"
35 #ifndef _DIAGASSERT
36 #define _DIAGASSERT(X)
37 #endif
38 #else
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 #if 0
42 static char sccsid[] = "@(#)unvis.c	8.1 (Berkeley) 6/4/93";
43 #else
44 __RCSID("$NetBSD: unvis.c,v 1.19 2000/01/22 22:19:13 mycroft Exp $");
45 #endif
46 #endif /* LIBC_SCCS and not lint */
47 
48 #define __LIBC12_SOURCE__
49 
50 #include "namespace.h"
51 #endif
52 #include <sys/types.h>
53 
54 #include <assert.h>
55 #include <ctype.h>
56 #include <stdio.h>
57 #include <vis.h>
58 
59 #if 0
60 #ifdef __weak_alias
61 __weak_alias(strunvis,_strunvis)
62 __weak_alias(unvis,_unvis)
63 #endif
64 
65 __warn_references(unvis,
66     "warning: reference to compatibility unvis(); include <vis.h> for correct reference")
67 #endif
68 
69 /*
70  * decode driven by state machine
71  */
72 #define	S_GROUND	0	/* haven't seen escape char */
73 #define	S_START		1	/* start decoding special sequence */
74 #define	S_META		2	/* metachar started (M) */
75 #define	S_META1		3	/* metachar more, regular char (-) */
76 #define	S_CTRL		4	/* control char started (^) */
77 #define	S_OCTAL2	5	/* octal digit 2 */
78 #define	S_OCTAL3	6	/* octal digit 3 */
79 
80 #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
81 
82 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
83 	rk_strunvis (char *, const char *);
84 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
85 	rk_unvis (char *, int, int *, int);
86 
87 /*
88  * unvis - decode characters previously encoded by vis
89  */
90 
91 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
92 rk_unvis(char *cp, int c, int *astate, int flag)
93 {
94 
95 	_DIAGASSERT(cp != NULL);
96 	_DIAGASSERT(astate != NULL);
97 
98 	if (flag & UNVIS_END) {
99 		if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
100 			*astate = S_GROUND;
101 			return (UNVIS_VALID);
102 		}
103 		return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
104 	}
105 
106 	switch (*astate) {
107 
108 	case S_GROUND:
109 		*cp = 0;
110 		if (c == '\\') {
111 			*astate = S_START;
112 			return (0);
113 		}
114 		*cp = c;
115 		return (UNVIS_VALID);
116 
117 	case S_START:
118 		switch(c) {
119 		case '\\':
120 			*cp = c;
121 			*astate = S_GROUND;
122 			return (UNVIS_VALID);
123 		case '0': case '1': case '2': case '3':
124 		case '4': case '5': case '6': case '7':
125 			*cp = (c - '0');
126 			*astate = S_OCTAL2;
127 			return (0);
128 		case 'M':
129 			*cp = (u_char)0200;
130 			*astate = S_META;
131 			return (0);
132 		case '^':
133 			*astate = S_CTRL;
134 			return (0);
135 		case 'n':
136 			*cp = '\n';
137 			*astate = S_GROUND;
138 			return (UNVIS_VALID);
139 		case 'r':
140 			*cp = '\r';
141 			*astate = S_GROUND;
142 			return (UNVIS_VALID);
143 		case 'b':
144 			*cp = '\b';
145 			*astate = S_GROUND;
146 			return (UNVIS_VALID);
147 		case 'a':
148 			*cp = '\007';
149 			*astate = S_GROUND;
150 			return (UNVIS_VALID);
151 		case 'v':
152 			*cp = '\v';
153 			*astate = S_GROUND;
154 			return (UNVIS_VALID);
155 		case 't':
156 			*cp = '\t';
157 			*astate = S_GROUND;
158 			return (UNVIS_VALID);
159 		case 'f':
160 			*cp = '\f';
161 			*astate = S_GROUND;
162 			return (UNVIS_VALID);
163 		case 's':
164 			*cp = ' ';
165 			*astate = S_GROUND;
166 			return (UNVIS_VALID);
167 		case 'E':
168 			*cp = '\033';
169 			*astate = S_GROUND;
170 			return (UNVIS_VALID);
171 		case '\n':
172 			/*
173 			 * hidden newline
174 			 */
175 			*astate = S_GROUND;
176 			return (UNVIS_NOCHAR);
177 		case '$':
178 			/*
179 			 * hidden marker
180 			 */
181 			*astate = S_GROUND;
182 			return (UNVIS_NOCHAR);
183 		}
184 		*astate = S_GROUND;
185 		return (UNVIS_SYNBAD);
186 
187 	case S_META:
188 		if (c == '-')
189 			*astate = S_META1;
190 		else if (c == '^')
191 			*astate = S_CTRL;
192 		else {
193 			*astate = S_GROUND;
194 			return (UNVIS_SYNBAD);
195 		}
196 		return (0);
197 
198 	case S_META1:
199 		*astate = S_GROUND;
200 		*cp |= c;
201 		return (UNVIS_VALID);
202 
203 	case S_CTRL:
204 		if (c == '?')
205 			*cp |= 0177;
206 		else
207 			*cp |= c & 037;
208 		*astate = S_GROUND;
209 		return (UNVIS_VALID);
210 
211 	case S_OCTAL2:	/* second possible octal digit */
212 		if (isoctal(c)) {
213 			/*
214 			 * yes - and maybe a third
215 			 */
216 			*cp = (*cp << 3) + (c - '0');
217 			*astate = S_OCTAL3;
218 			return (0);
219 		}
220 		/*
221 		 * no - done with current sequence, push back passed char
222 		 */
223 		*astate = S_GROUND;
224 		return (UNVIS_VALIDPUSH);
225 
226 	case S_OCTAL3:	/* third possible octal digit */
227 		*astate = S_GROUND;
228 		if (isoctal(c)) {
229 			*cp = (*cp << 3) + (c - '0');
230 			return (UNVIS_VALID);
231 		}
232 		/*
233 		 * we were done, push back passed char
234 		 */
235 		return (UNVIS_VALIDPUSH);
236 
237 	default:
238 		/*
239 		 * decoder in unknown state - (probably uninitialized)
240 		 */
241 		*astate = S_GROUND;
242 		return (UNVIS_SYNBAD);
243 	}
244 }
245 
246 /*
247  * strunvis - decode src into dst
248  *
249  *	Number of chars decoded into dst is returned, -1 on error.
250  *	Dst is null terminated.
251  */
252 
253 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
254 rk_strunvis(char *dst, const char *src)
255 {
256 	char c;
257 	char *start = dst;
258 	int state = 0;
259 
260 	_DIAGASSERT(src != NULL);
261 	_DIAGASSERT(dst != NULL);
262 
263 	while ((c = *src++) != '\0') {
264 	again:
265 		switch (rk_unvis(dst, (unsigned char)c, &state, 0)) {
266 		case UNVIS_VALID:
267 			dst++;
268 			break;
269 		case UNVIS_VALIDPUSH:
270 			dst++;
271 			goto again;
272 		case 0:
273 		case UNVIS_NOCHAR:
274 			break;
275 		default:
276 			return (-1);
277 		}
278 	}
279 	if (unvis(dst, (unsigned char)c, &state, UNVIS_END) == UNVIS_VALID)
280 		dst++;
281 	*dst = '\0';
282 	return (dst - start);
283 }
284