1/*
2 * lib/hexdump.c
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation. See README and COPYING for
7 * more details.
8 */
9
10#include <linux/types.h>
11#include <linux/ctype.h>
12#include <linux/kernel.h>
13#include <linux/export.h>
14
15const char hex_asc[] = "0123456789abcdef";
16EXPORT_SYMBOL(hex_asc);
17const char hex_asc_upper[] = "0123456789ABCDEF";
18EXPORT_SYMBOL(hex_asc_upper);
19
20/**
21 * hex_to_bin - convert a hex digit to its real value
22 * @ch: ascii character represents hex digit
23 *
24 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
25 * input.
26 */
27int hex_to_bin(char ch)
28{
29	if ((ch >= '0') && (ch <= '9'))
30		return ch - '0';
31	ch = tolower(ch);
32	if ((ch >= 'a') && (ch <= 'f'))
33		return ch - 'a' + 10;
34	return -1;
35}
36EXPORT_SYMBOL(hex_to_bin);
37
38/**
39 * hex2bin - convert an ascii hexadecimal string to its binary representation
40 * @dst: binary result
41 * @src: ascii hexadecimal string
42 * @count: result length
43 *
44 * Return 0 on success, -1 in case of bad input.
45 */
46int hex2bin(u8 *dst, const char *src, size_t count)
47{
48	while (count--) {
49		int hi = hex_to_bin(*src++);
50		int lo = hex_to_bin(*src++);
51
52		if ((hi < 0) || (lo < 0))
53			return -1;
54
55		*dst++ = (hi << 4) | lo;
56	}
57	return 0;
58}
59EXPORT_SYMBOL(hex2bin);
60
61/**
62 * bin2hex - convert binary data to an ascii hexadecimal string
63 * @dst: ascii hexadecimal result
64 * @src: binary data
65 * @count: binary data length
66 */
67char *bin2hex(char *dst, const void *src, size_t count)
68{
69	const unsigned char *_src = src;
70
71	while (count--)
72		dst = hex_byte_pack(dst, *_src++);
73	return dst;
74}
75EXPORT_SYMBOL(bin2hex);
76
77/**
78 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
79 * @buf: data blob to dump
80 * @len: number of bytes in the @buf
81 * @rowsize: number of bytes to print per line; must be 16 or 32
82 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
83 * @linebuf: where to put the converted data
84 * @linebuflen: total size of @linebuf, including space for terminating NUL
85 * @ascii: include ASCII after the hex output
86 *
87 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
88 * 16 or 32 bytes of input data converted to hex + ASCII output.
89 *
90 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
91 * to a hex + ASCII dump at the supplied memory location.
92 * The converted output is always NUL-terminated.
93 *
94 * E.g.:
95 *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
96 *			linebuf, sizeof(linebuf), true);
97 *
98 * example output buffer:
99 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
100 */
101void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
102			int groupsize, char *linebuf, size_t linebuflen,
103			bool ascii)
104{
105	const u8 *ptr = buf;
106	u8 ch;
107	int j, lx = 0;
108	int ascii_column;
109
110	if (rowsize != 16 && rowsize != 32)
111		rowsize = 16;
112
113	if (!len)
114		goto nil;
115	if (len > rowsize)		/* limit to one line at a time */
116		len = rowsize;
117	if ((len % groupsize) != 0)	/* no mixed size output */
118		groupsize = 1;
119
120	switch (groupsize) {
121	case 8: {
122		const u64 *ptr8 = buf;
123		int ngroups = len / groupsize;
124
125		for (j = 0; j < ngroups; j++)
126			lx += scnprintf(linebuf + lx, linebuflen - lx,
127					"%s%16.16llx", j ? " " : "",
128					(unsigned long long)*(ptr8 + j));
129		ascii_column = 17 * ngroups + 2;
130		break;
131	}
132
133	case 4: {
134		const u32 *ptr4 = buf;
135		int ngroups = len / groupsize;
136
137		for (j = 0; j < ngroups; j++)
138			lx += scnprintf(linebuf + lx, linebuflen - lx,
139					"%s%8.8x", j ? " " : "", *(ptr4 + j));
140		ascii_column = 9 * ngroups + 2;
141		break;
142	}
143
144	case 2: {
145		const u16 *ptr2 = buf;
146		int ngroups = len / groupsize;
147
148		for (j = 0; j < ngroups; j++)
149			lx += scnprintf(linebuf + lx, linebuflen - lx,
150					"%s%4.4x", j ? " " : "", *(ptr2 + j));
151		ascii_column = 5 * ngroups + 2;
152		break;
153	}
154
155	default:
156		for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) {
157			ch = ptr[j];
158			linebuf[lx++] = hex_asc_hi(ch);
159			linebuf[lx++] = hex_asc_lo(ch);
160			linebuf[lx++] = ' ';
161		}
162		if (j)
163			lx--;
164
165		ascii_column = 3 * rowsize + 2;
166		break;
167	}
168	if (!ascii)
169		goto nil;
170
171	while (lx < (linebuflen - 1) && lx < (ascii_column - 1))
172		linebuf[lx++] = ' ';
173	for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) {
174		ch = ptr[j];
175		linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
176	}
177nil:
178	linebuf[lx++] = '\0';
179}
180EXPORT_SYMBOL(hex_dump_to_buffer);
181
182#ifdef CONFIG_PRINTK
183/**
184 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
185 * @level: kernel log level (e.g. KERN_DEBUG)
186 * @prefix_str: string to prefix each line with;
187 *  caller supplies trailing spaces for alignment if desired
188 * @prefix_type: controls whether prefix of an offset, address, or none
189 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
190 * @rowsize: number of bytes to print per line; must be 16 or 32
191 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
192 * @buf: data blob to dump
193 * @len: number of bytes in the @buf
194 * @ascii: include ASCII after the hex output
195 *
196 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
197 * to the kernel log at the specified kernel log level, with an optional
198 * leading prefix.
199 *
200 * print_hex_dump() works on one "line" of output at a time, i.e.,
201 * 16 or 32 bytes of input data converted to hex + ASCII output.
202 * print_hex_dump() iterates over the entire input @buf, breaking it into
203 * "line size" chunks to format and print.
204 *
205 * E.g.:
206 *   print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
207 *		    16, 1, frame->data, frame->len, true);
208 *
209 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
210 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
211 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
212 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
213 */
214void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
215		    int rowsize, int groupsize,
216		    const void *buf, size_t len, bool ascii)
217{
218	const u8 *ptr = buf;
219	int i, linelen, remaining = len;
220	unsigned char linebuf[32 * 3 + 2 + 32 + 1];
221
222	if (rowsize != 16 && rowsize != 32)
223		rowsize = 16;
224
225	for (i = 0; i < len; i += rowsize) {
226		linelen = min(remaining, rowsize);
227		remaining -= rowsize;
228
229		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
230				   linebuf, sizeof(linebuf), ascii);
231
232		switch (prefix_type) {
233		case DUMP_PREFIX_ADDRESS:
234			printk("%s%s%p: %s\n",
235			       level, prefix_str, ptr + i, linebuf);
236			break;
237		case DUMP_PREFIX_OFFSET:
238			printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
239			break;
240		default:
241			printk("%s%s%s\n", level, prefix_str, linebuf);
242			break;
243		}
244	}
245}
246EXPORT_SYMBOL(print_hex_dump);
247
248#if !defined(CONFIG_DYNAMIC_DEBUG)
249/**
250 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
251 * @prefix_str: string to prefix each line with;
252 *  caller supplies trailing spaces for alignment if desired
253 * @prefix_type: controls whether prefix of an offset, address, or none
254 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
255 * @buf: data blob to dump
256 * @len: number of bytes in the @buf
257 *
258 * Calls print_hex_dump(), with log level of KERN_DEBUG,
259 * rowsize of 16, groupsize of 1, and ASCII output included.
260 */
261void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
262			  const void *buf, size_t len)
263{
264	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
265		       buf, len, true);
266}
267EXPORT_SYMBOL(print_hex_dump_bytes);
268#endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
269#endif /* defined(CONFIG_PRINTK) */
270