xref: /netbsd-src/sys/lib/libkern/hexdump.c (revision 489063e9bc954dec6cf273a7913f6a1ddfda4956)
1 /*-
2  * Copyright (c) 2017 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Christos Zoulas.
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: hexdump.c,v 1.4 2017/12/09 00:51:52 christos Exp $");
31 
32 #ifdef DEBUG_HEXDUMP
33 #include <stdio.h>
34 #include <ctype.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #define RET int
38 static const char hexdigits[] = "0123456789abcdef";
39 #else
40 #define RET void
41 #include <lib/libkern/libkern.h>
42 #include <sys/systm.h>
43 #endif
44 
45 #define MID (3 * 8)
46 #define BAR ((3 * 16) + 1)
47 #define ASC (BAR + 2)
48 #define NL (BAR + 18)
49 
50 void
51 hexdump(RET (*pr)(const char *, ...) __printflike(1, 2), const char *msg,
52     const void *ptr, size_t len)
53 {
54 	size_t i, p, q;
55 	const unsigned char *u = ptr;
56 	char buf[NL + 2];
57 
58 	if (msg)
59 		(*pr)("%s: %zu bytes @ %p\n", msg, len, ptr);
60 
61 	buf[BAR] = '|';
62 	buf[BAR + 1] = ' ';
63 	buf[NL] = '\n';
64 	buf[NL + 1] = '\0';
65         for (q = p = i = 0; i < len; i++) {
66 		unsigned char c = u[i];
67 		buf[p++] = hexdigits[(c >> 4) & 0xf];
68 		buf[p++] = hexdigits[(c >> 0) & 0xf];
69 		buf[p++] = ' ';
70                 if (q == 7)
71 		       buf[p++] = ' ';
72 
73 		buf[ASC + q++] = isprint(c) ? c : '.';
74 
75 		if (q == 16) {
76 			q = p = 0;
77 			(*pr)("%s", buf);
78 		}
79         }
80 	if (q) {
81 		while (p < BAR)
82 			buf[p++] = ' ';
83 		buf[ASC + q++] = '\n';
84 		buf[ASC + q] = '\0';
85 		(*pr)("%s", buf);
86 	}
87 }
88 
89 #ifdef DEBUG_HEXDUMP
90 int
main(int argc,char * argv[])91 main(int argc, char *argv[])
92 {
93 	hexdump(printf, "foo", main, atoi(argv[1]));
94 	return 0;
95 }
96 #endif
97