1 d13b044d 2023-08-07 op /*	$OpenBSD: vis.c,v 1.26 2022/05/04 18:57:50 deraadt Exp $ */
  2 d13b044d 2023-08-07 op /*-
  3 d13b044d 2023-08-07 op  * Copyright (c) 1989, 1993
  4 d13b044d 2023-08-07 op  *	The Regents of the University of California.  All rights reserved.
  5 d13b044d 2023-08-07 op  *
  6 d13b044d 2023-08-07 op  * Redistribution and use in source and binary forms, with or without
  7 d13b044d 2023-08-07 op  * modification, are permitted provided that the following conditions
  8 d13b044d 2023-08-07 op  * are met:
  9 d13b044d 2023-08-07 op  * 1. Redistributions of source code must retain the above copyright
 10 d13b044d 2023-08-07 op  *    notice, this list of conditions and the following disclaimer.
 11 d13b044d 2023-08-07 op  * 2. Redistributions in binary form must reproduce the above copyright
 12 d13b044d 2023-08-07 op  *    notice, this list of conditions and the following disclaimer in the
 13 d13b044d 2023-08-07 op  *    documentation and/or other materials provided with the distribution.
 14 d13b044d 2023-08-07 op  * 3. Neither the name of the University nor the names of its contributors
 15 d13b044d 2023-08-07 op  *    may be used to endorse or promote products derived from this software
 16 d13b044d 2023-08-07 op  *    without specific prior written permission.
 17 d13b044d 2023-08-07 op  *
 18 d13b044d 2023-08-07 op  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 19 d13b044d 2023-08-07 op  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 20 d13b044d 2023-08-07 op  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 21 d13b044d 2023-08-07 op  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 22 d13b044d 2023-08-07 op  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 23 d13b044d 2023-08-07 op  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 24 d13b044d 2023-08-07 op  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 25 d13b044d 2023-08-07 op  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 26 d13b044d 2023-08-07 op  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 27 d13b044d 2023-08-07 op  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 28 d13b044d 2023-08-07 op  * SUCH DAMAGE.
 29 d13b044d 2023-08-07 op  */
 30 d13b044d 2023-08-07 op 
 31 d13b044d 2023-08-07 op #include <sys/types.h>
 32 d13b044d 2023-08-07 op #include <errno.h>
 33 d13b044d 2023-08-07 op #include <ctype.h>
 34 d13b044d 2023-08-07 op #include <limits.h>
 35 d13b044d 2023-08-07 op #include <string.h>
 36 d13b044d 2023-08-07 op #include <stdlib.h>
 37 d13b044d 2023-08-07 op #include <vis.h>
 38 d13b044d 2023-08-07 op 
 39 d13b044d 2023-08-07 op static int
 40 d13b044d 2023-08-07 op isoctal(int c)
 41 d13b044d 2023-08-07 op {
 42 d13b044d 2023-08-07 op 	u_char uc = c;
 43 d13b044d 2023-08-07 op 
 44 d13b044d 2023-08-07 op 	return uc >= '0' && uc <= '7';
 45 d13b044d 2023-08-07 op }
 46 d13b044d 2023-08-07 op 
 47 d13b044d 2023-08-07 op static int
 48 d13b044d 2023-08-07 op isvisible(int c, int flag)
 49 d13b044d 2023-08-07 op {
 50 d13b044d 2023-08-07 op 	int vis_sp = flag & VIS_SP;
 51 d13b044d 2023-08-07 op 	int vis_tab = flag & VIS_TAB;
 52 d13b044d 2023-08-07 op 	int vis_nl = flag & VIS_NL;
 53 d13b044d 2023-08-07 op 	int vis_safe = flag & VIS_SAFE;
 54 d13b044d 2023-08-07 op 	int vis_glob = flag & VIS_GLOB;
 55 d13b044d 2023-08-07 op 	int vis_all = flag & VIS_ALL;
 56 d13b044d 2023-08-07 op 	u_char uc = c;
 57 d13b044d 2023-08-07 op 
 58 d13b044d 2023-08-07 op 	if (c == '\\' || !vis_all) {
 59 d13b044d 2023-08-07 op 		if ((u_int)c <= UCHAR_MAX && isascii(uc) &&
 60 d13b044d 2023-08-07 op 		    ((c != '*' && c != '?' && c != '[' && c != '#') || !vis_glob) &&
 61 d13b044d 2023-08-07 op 		    isgraph(uc))
 62 d13b044d 2023-08-07 op 			return 1;
 63 d13b044d 2023-08-07 op 		if (!vis_sp && c == ' ')
 64 d13b044d 2023-08-07 op 			return 1;
 65 d13b044d 2023-08-07 op 		if (!vis_tab && c == '\t')
 66 d13b044d 2023-08-07 op 			return 1;
 67 d13b044d 2023-08-07 op 		if (!vis_nl && c == '\n')
 68 d13b044d 2023-08-07 op 			return 1;
 69 d13b044d 2023-08-07 op 		if (vis_safe && (c == '\b' || c == '\007' || c == '\r' || isgraph(uc)))
 70 d13b044d 2023-08-07 op 			return 1;
 71 d13b044d 2023-08-07 op 	}
 72 d13b044d 2023-08-07 op 	return 0;
 73 d13b044d 2023-08-07 op }
 74 d13b044d 2023-08-07 op 
 75 d13b044d 2023-08-07 op /*
 76 d13b044d 2023-08-07 op  * vis - visually encode characters
 77 d13b044d 2023-08-07 op  */
 78 d13b044d 2023-08-07 op char *
 79 d13b044d 2023-08-07 op vis(char *dst, int c, int flag, int nextc)
 80 d13b044d 2023-08-07 op {
 81 d13b044d 2023-08-07 op 	int vis_dq = flag & VIS_DQ;
 82 d13b044d 2023-08-07 op 	int vis_noslash = flag & VIS_NOSLASH;
 83 d13b044d 2023-08-07 op 	int vis_cstyle = flag & VIS_CSTYLE;
 84 d13b044d 2023-08-07 op 	int vis_octal = flag & VIS_OCTAL;
 85 d13b044d 2023-08-07 op 	int vis_glob = flag & VIS_GLOB;
 86 d13b044d 2023-08-07 op 
 87 d13b044d 2023-08-07 op 	if (isvisible(c, flag)) {
 88 d13b044d 2023-08-07 op 		if ((c == '"' && vis_dq) ||
 89 d13b044d 2023-08-07 op 		    (c == '\\' && !vis_noslash))
 90 d13b044d 2023-08-07 op 			*dst++ = '\\';
 91 d13b044d 2023-08-07 op 		*dst++ = c;
 92 d13b044d 2023-08-07 op 		*dst = '\0';
 93 d13b044d 2023-08-07 op 		return (dst);
 94 d13b044d 2023-08-07 op 	}
 95 d13b044d 2023-08-07 op 
 96 d13b044d 2023-08-07 op 	if (vis_cstyle) {
 97 d13b044d 2023-08-07 op 		switch (c) {
 98 d13b044d 2023-08-07 op 		case '\n':
 99 d13b044d 2023-08-07 op 			*dst++ = '\\';
100 d13b044d 2023-08-07 op 			*dst++ = 'n';
101 d13b044d 2023-08-07 op 			goto done;
102 d13b044d 2023-08-07 op 		case '\r':
103 d13b044d 2023-08-07 op 			*dst++ = '\\';
104 d13b044d 2023-08-07 op 			*dst++ = 'r';
105 d13b044d 2023-08-07 op 			goto done;
106 d13b044d 2023-08-07 op 		case '\b':
107 d13b044d 2023-08-07 op 			*dst++ = '\\';
108 d13b044d 2023-08-07 op 			*dst++ = 'b';
109 d13b044d 2023-08-07 op 			goto done;
110 d13b044d 2023-08-07 op 		case '\a':
111 d13b044d 2023-08-07 op 			*dst++ = '\\';
112 d13b044d 2023-08-07 op 			*dst++ = 'a';
113 d13b044d 2023-08-07 op 			goto done;
114 d13b044d 2023-08-07 op 		case '\v':
115 d13b044d 2023-08-07 op 			*dst++ = '\\';
116 d13b044d 2023-08-07 op 			*dst++ = 'v';
117 d13b044d 2023-08-07 op 			goto done;
118 d13b044d 2023-08-07 op 		case '\t':
119 d13b044d 2023-08-07 op 			*dst++ = '\\';
120 d13b044d 2023-08-07 op 			*dst++ = 't';
121 d13b044d 2023-08-07 op 			goto done;
122 d13b044d 2023-08-07 op 		case '\f':
123 d13b044d 2023-08-07 op 			*dst++ = '\\';
124 d13b044d 2023-08-07 op 			*dst++ = 'f';
125 d13b044d 2023-08-07 op 			goto done;
126 d13b044d 2023-08-07 op 		case ' ':
127 d13b044d 2023-08-07 op 			*dst++ = '\\';
128 d13b044d 2023-08-07 op 			*dst++ = 's';
129 d13b044d 2023-08-07 op 			goto done;
130 d13b044d 2023-08-07 op 		case '\0':
131 d13b044d 2023-08-07 op 			*dst++ = '\\';
132 d13b044d 2023-08-07 op 			*dst++ = '0';
133 d13b044d 2023-08-07 op 			if (isoctal(nextc)) {
134 d13b044d 2023-08-07 op 				*dst++ = '0';
135 d13b044d 2023-08-07 op 				*dst++ = '0';
136 d13b044d 2023-08-07 op 			}
137 d13b044d 2023-08-07 op 			goto done;
138 d13b044d 2023-08-07 op 		}
139 d13b044d 2023-08-07 op 	}
140 d13b044d 2023-08-07 op 	if (((c & 0177) == ' ') || vis_octal ||
141 d13b044d 2023-08-07 op 	    (vis_glob && (c == '*' || c == '?' || c == '[' || c == '#'))) {
142 d13b044d 2023-08-07 op 		*dst++ = '\\';
143 d13b044d 2023-08-07 op 		*dst++ = ((u_char)c >> 6 & 07) + '0';
144 d13b044d 2023-08-07 op 		*dst++ = ((u_char)c >> 3 & 07) + '0';
145 d13b044d 2023-08-07 op 		*dst++ = ((u_char)c & 07) + '0';
146 d13b044d 2023-08-07 op 		goto done;
147 d13b044d 2023-08-07 op 	}
148 d13b044d 2023-08-07 op 	if (!vis_noslash)
149 d13b044d 2023-08-07 op 		*dst++ = '\\';
150 d13b044d 2023-08-07 op 	if (c & 0200) {
151 d13b044d 2023-08-07 op 		c &= 0177;
152 d13b044d 2023-08-07 op 		*dst++ = 'M';
153 d13b044d 2023-08-07 op 	}
154 d13b044d 2023-08-07 op 	if (iscntrl((u_char)c)) {
155 d13b044d 2023-08-07 op 		*dst++ = '^';
156 d13b044d 2023-08-07 op 		if (c == 0177)
157 d13b044d 2023-08-07 op 			*dst++ = '?';
158 d13b044d 2023-08-07 op 		else
159 d13b044d 2023-08-07 op 			*dst++ = c + '@';
160 d13b044d 2023-08-07 op 	} else {
161 d13b044d 2023-08-07 op 		*dst++ = '-';
162 d13b044d 2023-08-07 op 		*dst++ = c;
163 d13b044d 2023-08-07 op 	}
164 d13b044d 2023-08-07 op done:
165 d13b044d 2023-08-07 op 	*dst = '\0';
166 d13b044d 2023-08-07 op 	return (dst);
167 d13b044d 2023-08-07 op }
168 d13b044d 2023-08-07 op 
169 d13b044d 2023-08-07 op /*
170 d13b044d 2023-08-07 op  * strvis, strnvis, strvisx - visually encode characters from src into dst
171 d13b044d 2023-08-07 op  *	
172 d13b044d 2023-08-07 op  *	Dst must be 4 times the size of src to account for possible
173 d13b044d 2023-08-07 op  *	expansion.  The length of dst, not including the trailing NULL,
174 d13b044d 2023-08-07 op  *	is returned. 
175 d13b044d 2023-08-07 op  *
176 d13b044d 2023-08-07 op  *	Strnvis will write no more than siz-1 bytes (and will NULL terminate).
177 d13b044d 2023-08-07 op  *	The number of bytes needed to fully encode the string is returned.
178 d13b044d 2023-08-07 op  *
179 d13b044d 2023-08-07 op  *	Strvisx encodes exactly len bytes from src into dst.
180 d13b044d 2023-08-07 op  *	This is useful for encoding a block of data.
181 d13b044d 2023-08-07 op  */
182 d13b044d 2023-08-07 op int
183 d13b044d 2023-08-07 op strvis(char *dst, const char *src, int flag)
184 d13b044d 2023-08-07 op {
185 d13b044d 2023-08-07 op 	char c;
186 d13b044d 2023-08-07 op 	char *start;
187 d13b044d 2023-08-07 op 
188 d13b044d 2023-08-07 op 	for (start = dst; (c = *src);)
189 d13b044d 2023-08-07 op 		dst = vis(dst, c, flag, *++src);
190 d13b044d 2023-08-07 op 	*dst = '\0';
191 d13b044d 2023-08-07 op 	return (dst - start);
192 d13b044d 2023-08-07 op }
193 d13b044d 2023-08-07 op 
194 d13b044d 2023-08-07 op int
195 d13b044d 2023-08-07 op strnvis(char *dst, const char *src, size_t siz, int flag)
196 d13b044d 2023-08-07 op {
197 d13b044d 2023-08-07 op 	int vis_dq = flag & VIS_DQ;
198 d13b044d 2023-08-07 op 	int vis_noslash = flag & VIS_NOSLASH;
199 d13b044d 2023-08-07 op 	char *start, *end;
200 d13b044d 2023-08-07 op 	char tbuf[5];
201 d13b044d 2023-08-07 op 	int c, i;
202 d13b044d 2023-08-07 op 
203 d13b044d 2023-08-07 op 	i = 0;
204 d13b044d 2023-08-07 op 	for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
205 d13b044d 2023-08-07 op 		if (isvisible(c, flag)) {
206 d13b044d 2023-08-07 op 			if ((c == '"' && vis_dq) ||
207 d13b044d 2023-08-07 op 			    (c == '\\' && !vis_noslash)) {
208 d13b044d 2023-08-07 op 				/* need space for the extra '\\' */
209 d13b044d 2023-08-07 op 				if (dst + 1 >= end) {
210 d13b044d 2023-08-07 op 					i = 2;
211 d13b044d 2023-08-07 op 					break;
212 d13b044d 2023-08-07 op 				}
213 d13b044d 2023-08-07 op 				*dst++ = '\\';
214 d13b044d 2023-08-07 op 			}
215 d13b044d 2023-08-07 op 			i = 1;
216 d13b044d 2023-08-07 op 			*dst++ = c;
217 d13b044d 2023-08-07 op 			src++;
218 d13b044d 2023-08-07 op 		} else {
219 d13b044d 2023-08-07 op 			i = vis(tbuf, c, flag, *++src) - tbuf;
220 d13b044d 2023-08-07 op 			if (dst + i <= end) {
221 d13b044d 2023-08-07 op 				memcpy(dst, tbuf, i);
222 d13b044d 2023-08-07 op 				dst += i;
223 d13b044d 2023-08-07 op 			} else {
224 d13b044d 2023-08-07 op 				src--;
225 d13b044d 2023-08-07 op 				break;
226 d13b044d 2023-08-07 op 			}
227 d13b044d 2023-08-07 op 		}
228 d13b044d 2023-08-07 op 	}
229 d13b044d 2023-08-07 op 	if (siz > 0)
230 d13b044d 2023-08-07 op 		*dst = '\0';
231 d13b044d 2023-08-07 op 	if (dst + i > end) {
232 d13b044d 2023-08-07 op 		/* adjust return value for truncation */
233 d13b044d 2023-08-07 op 		while ((c = *src))
234 d13b044d 2023-08-07 op 			dst += vis(tbuf, c, flag, *++src) - tbuf;
235 d13b044d 2023-08-07 op 	}
236 d13b044d 2023-08-07 op 	return (dst - start);
237 d13b044d 2023-08-07 op }
238 d13b044d 2023-08-07 op 
239 d13b044d 2023-08-07 op int
240 d13b044d 2023-08-07 op stravis(char **outp, const char *src, int flag)
241 d13b044d 2023-08-07 op {
242 d13b044d 2023-08-07 op 	char *buf;
243 d13b044d 2023-08-07 op 	int len, serrno;
244 d13b044d 2023-08-07 op 
245 d13b044d 2023-08-07 op 	buf = reallocarray(NULL, 4, strlen(src) + 1);
246 d13b044d 2023-08-07 op 	if (buf == NULL)
247 d13b044d 2023-08-07 op 		return -1;
248 d13b044d 2023-08-07 op 	len = strvis(buf, src, flag);
249 d13b044d 2023-08-07 op 	serrno = errno;
250 d13b044d 2023-08-07 op 	*outp = realloc(buf, len + 1);
251 d13b044d 2023-08-07 op 	if (*outp == NULL) {
252 d13b044d 2023-08-07 op 		*outp = buf;
253 d13b044d 2023-08-07 op 		errno = serrno;
254 d13b044d 2023-08-07 op 	}
255 d13b044d 2023-08-07 op 	return (len);
256 d13b044d 2023-08-07 op }
257 d13b044d 2023-08-07 op 
258 d13b044d 2023-08-07 op int
259 d13b044d 2023-08-07 op strvisx(char *dst, const char *src, size_t len, int flag)
260 d13b044d 2023-08-07 op {
261 d13b044d 2023-08-07 op 	char c;
262 d13b044d 2023-08-07 op 	char *start;
263 d13b044d 2023-08-07 op 
264 d13b044d 2023-08-07 op 	for (start = dst; len > 1; len--) {
265 d13b044d 2023-08-07 op 		c = *src;
266 d13b044d 2023-08-07 op 		dst = vis(dst, c, flag, *++src);
267 d13b044d 2023-08-07 op 	}
268 d13b044d 2023-08-07 op 	if (len)
269 d13b044d 2023-08-07 op 		dst = vis(dst, *src, flag, '\0');
270 d13b044d 2023-08-07 op 	*dst = '\0';
271 d13b044d 2023-08-07 op 	return (dst - start);
272 d13b044d 2023-08-07 op }