1 3d179b77 2021-12-15 op /*	$OpenBSD: vis.c,v 1.25 2015/09/13 11:32:51 guenther Exp $ */
  2 3d179b77 2021-12-15 op /*-
  3 3d179b77 2021-12-15 op  * Copyright (c) 1989, 1993
  4 3d179b77 2021-12-15 op  *	The Regents of the University of California.  All rights reserved.
  5 3d179b77 2021-12-15 op  *
  6 3d179b77 2021-12-15 op  * Redistribution and use in source and binary forms, with or without
  7 3d179b77 2021-12-15 op  * modification, are permitted provided that the following conditions
  8 3d179b77 2021-12-15 op  * are met:
  9 3d179b77 2021-12-15 op  * 1. Redistributions of source code must retain the above copyright
 10 3d179b77 2021-12-15 op  *    notice, this list of conditions and the following disclaimer.
 11 3d179b77 2021-12-15 op  * 2. Redistributions in binary form must reproduce the above copyright
 12 3d179b77 2021-12-15 op  *    notice, this list of conditions and the following disclaimer in the
 13 3d179b77 2021-12-15 op  *    documentation and/or other materials provided with the distribution.
 14 3d179b77 2021-12-15 op  * 3. Neither the name of the University nor the names of its contributors
 15 3d179b77 2021-12-15 op  *    may be used to endorse or promote products derived from this software
 16 3d179b77 2021-12-15 op  *    without specific prior written permission.
 17 3d179b77 2021-12-15 op  *
 18 3d179b77 2021-12-15 op  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 19 3d179b77 2021-12-15 op  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 20 3d179b77 2021-12-15 op  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 21 3d179b77 2021-12-15 op  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 22 3d179b77 2021-12-15 op  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 23 3d179b77 2021-12-15 op  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 24 3d179b77 2021-12-15 op  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 25 3d179b77 2021-12-15 op  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 26 3d179b77 2021-12-15 op  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 27 3d179b77 2021-12-15 op  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 28 3d179b77 2021-12-15 op  * SUCH DAMAGE.
 29 3d179b77 2021-12-15 op  */
 30 3d179b77 2021-12-15 op 
 31 3d179b77 2021-12-15 op #include "compat.h"
 32 3d179b77 2021-12-15 op 
 33 3d179b77 2021-12-15 op #include <sys/types.h>
 34 3d179b77 2021-12-15 op #include <errno.h>
 35 3d179b77 2021-12-15 op #include <ctype.h>
 36 3d179b77 2021-12-15 op #include <limits.h>
 37 3d179b77 2021-12-15 op #include <string.h>
 38 3d179b77 2021-12-15 op #include <stdlib.h>
 39 3d179b77 2021-12-15 op 
 40 3d179b77 2021-12-15 op #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
 41 3d179b77 2021-12-15 op #define	isvisible(c,flag)						\
 42 3d179b77 2021-12-15 op 	(((c) == '\\' || (flag & VIS_ALL) == 0) &&			\
 43 3d179b77 2021-12-15 op 	(((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) &&		\
 44 3d179b77 2021-12-15 op 	(((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') ||	\
 45 3d179b77 2021-12-15 op 		(flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) ||	\
 46 3d179b77 2021-12-15 op 	((flag & VIS_SP) == 0 && (c) == ' ') ||				\
 47 3d179b77 2021-12-15 op 	((flag & VIS_TAB) == 0 && (c) == '\t') ||			\
 48 3d179b77 2021-12-15 op 	((flag & VIS_NL) == 0 && (c) == '\n') ||			\
 49 3d179b77 2021-12-15 op 	((flag & VIS_SAFE) && ((c) == '\b' ||				\
 50 3d179b77 2021-12-15 op 		(c) == '\007' || (c) == '\r' ||				\
 51 3d179b77 2021-12-15 op 		isgraph((u_char)(c))))))
 52 3d179b77 2021-12-15 op 
 53 3d179b77 2021-12-15 op /*
 54 3d179b77 2021-12-15 op  * vis - visually encode characters
 55 3d179b77 2021-12-15 op  */
 56 3d179b77 2021-12-15 op char *
 57 3d179b77 2021-12-15 op vis(char *dst, int c, int flag, int nextc)
 58 3d179b77 2021-12-15 op {
 59 3d179b77 2021-12-15 op 	if (isvisible(c, flag)) {
 60 3d179b77 2021-12-15 op 		if ((c == '"' && (flag & VIS_DQ) != 0) ||
 61 3d179b77 2021-12-15 op 		    (c == '\\' && (flag & VIS_NOSLASH) == 0))
 62 3d179b77 2021-12-15 op 			*dst++ = '\\';
 63 3d179b77 2021-12-15 op 		*dst++ = c;
 64 3d179b77 2021-12-15 op 		*dst = '\0';
 65 3d179b77 2021-12-15 op 		return (dst);
 66 3d179b77 2021-12-15 op 	}
 67 3d179b77 2021-12-15 op 
 68 3d179b77 2021-12-15 op 	if (flag & VIS_CSTYLE) {
 69 3d179b77 2021-12-15 op 		switch(c) {
 70 3d179b77 2021-12-15 op 		case '\n':
 71 3d179b77 2021-12-15 op 			*dst++ = '\\';
 72 3d179b77 2021-12-15 op 			*dst++ = 'n';
 73 3d179b77 2021-12-15 op 			goto done;
 74 3d179b77 2021-12-15 op 		case '\r':
 75 3d179b77 2021-12-15 op 			*dst++ = '\\';
 76 3d179b77 2021-12-15 op 			*dst++ = 'r';
 77 3d179b77 2021-12-15 op 			goto done;
 78 3d179b77 2021-12-15 op 		case '\b':
 79 3d179b77 2021-12-15 op 			*dst++ = '\\';
 80 3d179b77 2021-12-15 op 			*dst++ = 'b';
 81 3d179b77 2021-12-15 op 			goto done;
 82 3d179b77 2021-12-15 op 		case '\a':
 83 3d179b77 2021-12-15 op 			*dst++ = '\\';
 84 3d179b77 2021-12-15 op 			*dst++ = 'a';
 85 3d179b77 2021-12-15 op 			goto done;
 86 3d179b77 2021-12-15 op 		case '\v':
 87 3d179b77 2021-12-15 op 			*dst++ = '\\';
 88 3d179b77 2021-12-15 op 			*dst++ = 'v';
 89 3d179b77 2021-12-15 op 			goto done;
 90 3d179b77 2021-12-15 op 		case '\t':
 91 3d179b77 2021-12-15 op 			*dst++ = '\\';
 92 3d179b77 2021-12-15 op 			*dst++ = 't';
 93 3d179b77 2021-12-15 op 			goto done;
 94 3d179b77 2021-12-15 op 		case '\f':
 95 3d179b77 2021-12-15 op 			*dst++ = '\\';
 96 3d179b77 2021-12-15 op 			*dst++ = 'f';
 97 3d179b77 2021-12-15 op 			goto done;
 98 3d179b77 2021-12-15 op 		case ' ':
 99 3d179b77 2021-12-15 op 			*dst++ = '\\';
100 3d179b77 2021-12-15 op 			*dst++ = 's';
101 3d179b77 2021-12-15 op 			goto done;
102 3d179b77 2021-12-15 op 		case '\0':
103 3d179b77 2021-12-15 op 			*dst++ = '\\';
104 3d179b77 2021-12-15 op 			*dst++ = '0';
105 3d179b77 2021-12-15 op 			if (isoctal(nextc)) {
106 3d179b77 2021-12-15 op 				*dst++ = '0';
107 3d179b77 2021-12-15 op 				*dst++ = '0';
108 3d179b77 2021-12-15 op 			}
109 3d179b77 2021-12-15 op 			goto done;
110 3d179b77 2021-12-15 op 		}
111 3d179b77 2021-12-15 op 	}
112 3d179b77 2021-12-15 op 	if (((c & 0177) == ' ') || (flag & VIS_OCTAL) ||
113 3d179b77 2021-12-15 op 	    ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) {
114 3d179b77 2021-12-15 op 		*dst++ = '\\';
115 3d179b77 2021-12-15 op 		*dst++ = ((u_char)c >> 6 & 07) + '0';
116 3d179b77 2021-12-15 op 		*dst++ = ((u_char)c >> 3 & 07) + '0';
117 3d179b77 2021-12-15 op 		*dst++ = ((u_char)c & 07) + '0';
118 3d179b77 2021-12-15 op 		goto done;
119 3d179b77 2021-12-15 op 	}
120 3d179b77 2021-12-15 op 	if ((flag & VIS_NOSLASH) == 0)
121 3d179b77 2021-12-15 op 		*dst++ = '\\';
122 3d179b77 2021-12-15 op 	if (c & 0200) {
123 3d179b77 2021-12-15 op 		c &= 0177;
124 3d179b77 2021-12-15 op 		*dst++ = 'M';
125 3d179b77 2021-12-15 op 	}
126 3d179b77 2021-12-15 op 	if (iscntrl((u_char)c)) {
127 3d179b77 2021-12-15 op 		*dst++ = '^';
128 3d179b77 2021-12-15 op 		if (c == 0177)
129 3d179b77 2021-12-15 op 			*dst++ = '?';
130 3d179b77 2021-12-15 op 		else
131 3d179b77 2021-12-15 op 			*dst++ = c + '@';
132 3d179b77 2021-12-15 op 	} else {
133 3d179b77 2021-12-15 op 		*dst++ = '-';
134 3d179b77 2021-12-15 op 		*dst++ = c;
135 3d179b77 2021-12-15 op 	}
136 3d179b77 2021-12-15 op done:
137 3d179b77 2021-12-15 op 	*dst = '\0';
138 3d179b77 2021-12-15 op 	return (dst);
139 3d179b77 2021-12-15 op }
140 3d179b77 2021-12-15 op 
141 3d179b77 2021-12-15 op /*
142 3d179b77 2021-12-15 op  * strvis, strnvis, strvisx - visually encode characters from src into dst
143 3d179b77 2021-12-15 op  *	
144 3d179b77 2021-12-15 op  *	Dst must be 4 times the size of src to account for possible
145 3d179b77 2021-12-15 op  *	expansion.  The length of dst, not including the trailing NULL,
146 3d179b77 2021-12-15 op  *	is returned. 
147 3d179b77 2021-12-15 op  *
148 3d179b77 2021-12-15 op  *	Strnvis will write no more than siz-1 bytes (and will NULL terminate).
149 3d179b77 2021-12-15 op  *	The number of bytes needed to fully encode the string is returned.
150 3d179b77 2021-12-15 op  *
151 3d179b77 2021-12-15 op  *	Strvisx encodes exactly len bytes from src into dst.
152 3d179b77 2021-12-15 op  *	This is useful for encoding a block of data.
153 3d179b77 2021-12-15 op  */
154 3d179b77 2021-12-15 op int
155 3d179b77 2021-12-15 op strvis(char *dst, const char *src, int flag)
156 3d179b77 2021-12-15 op {
157 3d179b77 2021-12-15 op 	char c;
158 3d179b77 2021-12-15 op 	char *start;
159 3d179b77 2021-12-15 op 
160 3d179b77 2021-12-15 op 	for (start = dst; (c = *src);)
161 3d179b77 2021-12-15 op 		dst = vis(dst, c, flag, *++src);
162 3d179b77 2021-12-15 op 	*dst = '\0';
163 3d179b77 2021-12-15 op 	return (dst - start);
164 3d179b77 2021-12-15 op }
165 3d179b77 2021-12-15 op 
166 3d179b77 2021-12-15 op int
167 3d179b77 2021-12-15 op strnvis(char *dst, const char *src, size_t siz, int flag)
168 3d179b77 2021-12-15 op {
169 3d179b77 2021-12-15 op 	char *start, *end;
170 3d179b77 2021-12-15 op 	char tbuf[5];
171 3d179b77 2021-12-15 op 	int c, i;
172 3d179b77 2021-12-15 op 
173 3d179b77 2021-12-15 op 	i = 0;
174 3d179b77 2021-12-15 op 	for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
175 3d179b77 2021-12-15 op 		if (isvisible(c, flag)) {
176 3d179b77 2021-12-15 op 			if ((c == '"' && (flag & VIS_DQ) != 0) ||
177 3d179b77 2021-12-15 op 			    (c == '\\' && (flag & VIS_NOSLASH) == 0)) {
178 3d179b77 2021-12-15 op 				/* need space for the extra '\\' */
179 3d179b77 2021-12-15 op 				if (dst + 1 >= end) {
180 3d179b77 2021-12-15 op 					i = 2;
181 3d179b77 2021-12-15 op 					break;
182 3d179b77 2021-12-15 op 				}
183 3d179b77 2021-12-15 op 				*dst++ = '\\';
184 3d179b77 2021-12-15 op 			}
185 3d179b77 2021-12-15 op 			i = 1;
186 3d179b77 2021-12-15 op 			*dst++ = c;
187 3d179b77 2021-12-15 op 			src++;
188 3d179b77 2021-12-15 op 		} else {
189 3d179b77 2021-12-15 op 			i = vis(tbuf, c, flag, *++src) - tbuf;
190 3d179b77 2021-12-15 op 			if (dst + i <= end) {
191 3d179b77 2021-12-15 op 				memcpy(dst, tbuf, i);
192 3d179b77 2021-12-15 op 				dst += i;
193 3d179b77 2021-12-15 op 			} else {
194 3d179b77 2021-12-15 op 				src--;
195 3d179b77 2021-12-15 op 				break;
196 3d179b77 2021-12-15 op 			}
197 3d179b77 2021-12-15 op 		}
198 3d179b77 2021-12-15 op 	}
199 3d179b77 2021-12-15 op 	if (siz > 0)
200 3d179b77 2021-12-15 op 		*dst = '\0';
201 3d179b77 2021-12-15 op 	if (dst + i > end) {
202 3d179b77 2021-12-15 op 		/* adjust return value for truncation */
203 3d179b77 2021-12-15 op 		while ((c = *src))
204 3d179b77 2021-12-15 op 			dst += vis(tbuf, c, flag, *++src) - tbuf;
205 3d179b77 2021-12-15 op 	}
206 3d179b77 2021-12-15 op 	return (dst - start);
207 3d179b77 2021-12-15 op }
208 3d179b77 2021-12-15 op 
209 3d179b77 2021-12-15 op int
210 3d179b77 2021-12-15 op stravis(char **outp, const char *src, int flag)
211 3d179b77 2021-12-15 op {
212 3d179b77 2021-12-15 op 	char *buf;
213 3d179b77 2021-12-15 op 	int len, serrno;
214 3d179b77 2021-12-15 op 
215 3d179b77 2021-12-15 op 	buf = reallocarray(NULL, 4, strlen(src) + 1);
216 3d179b77 2021-12-15 op 	if (buf == NULL)
217 3d179b77 2021-12-15 op 		return -1;
218 3d179b77 2021-12-15 op 	len = strvis(buf, src, flag);
219 3d179b77 2021-12-15 op 	serrno = errno;
220 3d179b77 2021-12-15 op 	*outp = realloc(buf, len + 1);
221 3d179b77 2021-12-15 op 	if (*outp == NULL) {
222 3d179b77 2021-12-15 op 		*outp = buf;
223 3d179b77 2021-12-15 op 		errno = serrno;
224 3d179b77 2021-12-15 op 	}
225 3d179b77 2021-12-15 op 	return (len);
226 3d179b77 2021-12-15 op }
227 3d179b77 2021-12-15 op 
228 3d179b77 2021-12-15 op int
229 3d179b77 2021-12-15 op strvisx(char *dst, const char *src, size_t len, int flag)
230 3d179b77 2021-12-15 op {
231 3d179b77 2021-12-15 op 	char c;
232 3d179b77 2021-12-15 op 	char *start;
233 3d179b77 2021-12-15 op 
234 3d179b77 2021-12-15 op 	for (start = dst; len > 1; len--) {
235 3d179b77 2021-12-15 op 		c = *src;
236 3d179b77 2021-12-15 op 		dst = vis(dst, c, flag, *++src);
237 3d179b77 2021-12-15 op 	}
238 3d179b77 2021-12-15 op 	if (len)
239 3d179b77 2021-12-15 op 		dst = vis(dst, *src, flag, '\0');
240 3d179b77 2021-12-15 op 	*dst = '\0';
241 3d179b77 2021-12-15 op 	return (dst - start);
242 3d179b77 2021-12-15 op }