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 *
101 * Return:
102 * The amount of bytes placed in the buffer without terminating NUL. If the
103 * output was truncated, then the return value is the number of bytes
104 * (excluding the terminating NUL) which would have been written to the final
105 * string if enough space had been available.
106 */
107int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
108		       char *linebuf, size_t linebuflen, bool ascii)
109{
110	const u8 *ptr = buf;
111	int ngroups;
112	u8 ch;
113	int j, lx = 0;
114	int ascii_column;
115	int ret;
116
117	if (rowsize != 16 && rowsize != 32)
118		rowsize = 16;
119
120	if (len > rowsize)		/* limit to one line at a time */
121		len = rowsize;
122	if (!is_power_of_2(groupsize) || groupsize > 8)
123		groupsize = 1;
124	if ((len % groupsize) != 0)	/* no mixed size output */
125		groupsize = 1;
126
127	ngroups = len / groupsize;
128	ascii_column = rowsize * 2 + rowsize / groupsize + 1;
129
130	if (!linebuflen)
131		goto overflow1;
132
133	if (!len)
134		goto nil;
135
136	if (groupsize == 8) {
137		const u64 *ptr8 = buf;
138
139		for (j = 0; j < ngroups; j++) {
140			ret = snprintf(linebuf + lx, linebuflen - lx,
141				       "%s%16.16llx", j ? " " : "",
142				       (unsigned long long)*(ptr8 + j));
143			if (ret >= linebuflen - lx)
144				goto overflow1;
145			lx += ret;
146		}
147	} else if (groupsize == 4) {
148		const u32 *ptr4 = buf;
149
150		for (j = 0; j < ngroups; j++) {
151			ret = snprintf(linebuf + lx, linebuflen - lx,
152				       "%s%8.8x", j ? " " : "",
153				       *(ptr4 + j));
154			if (ret >= linebuflen - lx)
155				goto overflow1;
156			lx += ret;
157		}
158	} else if (groupsize == 2) {
159		const u16 *ptr2 = buf;
160
161		for (j = 0; j < ngroups; j++) {
162			ret = snprintf(linebuf + lx, linebuflen - lx,
163				       "%s%4.4x", j ? " " : "",
164				       *(ptr2 + j));
165			if (ret >= linebuflen - lx)
166				goto overflow1;
167			lx += ret;
168		}
169	} else {
170		for (j = 0; j < len; j++) {
171			if (linebuflen < lx + 3)
172				goto overflow2;
173			ch = ptr[j];
174			linebuf[lx++] = hex_asc_hi(ch);
175			linebuf[lx++] = hex_asc_lo(ch);
176			linebuf[lx++] = ' ';
177		}
178		if (j)
179			lx--;
180	}
181	if (!ascii)
182		goto nil;
183
184	while (lx < ascii_column) {
185		if (linebuflen < lx + 2)
186			goto overflow2;
187		linebuf[lx++] = ' ';
188	}
189	for (j = 0; j < len; j++) {
190		if (linebuflen < lx + 2)
191			goto overflow2;
192		ch = ptr[j];
193		linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
194	}
195nil:
196	linebuf[lx] = '\0';
197	return lx;
198overflow2:
199	linebuf[lx++] = '\0';
200overflow1:
201	return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
202}
203EXPORT_SYMBOL(hex_dump_to_buffer);
204
205#ifdef CONFIG_PRINTK
206/**
207 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
208 * @level: kernel log level (e.g. KERN_DEBUG)
209 * @prefix_str: string to prefix each line with;
210 *  caller supplies trailing spaces for alignment if desired
211 * @prefix_type: controls whether prefix of an offset, address, or none
212 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
213 * @rowsize: number of bytes to print per line; must be 16 or 32
214 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
215 * @buf: data blob to dump
216 * @len: number of bytes in the @buf
217 * @ascii: include ASCII after the hex output
218 *
219 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
220 * to the kernel log at the specified kernel log level, with an optional
221 * leading prefix.
222 *
223 * print_hex_dump() works on one "line" of output at a time, i.e.,
224 * 16 or 32 bytes of input data converted to hex + ASCII output.
225 * print_hex_dump() iterates over the entire input @buf, breaking it into
226 * "line size" chunks to format and print.
227 *
228 * E.g.:
229 *   print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
230 *		    16, 1, frame->data, frame->len, true);
231 *
232 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
233 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
234 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
235 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
236 */
237void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
238		    int rowsize, int groupsize,
239		    const void *buf, size_t len, bool ascii)
240{
241	const u8 *ptr = buf;
242	int i, linelen, remaining = len;
243	unsigned char linebuf[32 * 3 + 2 + 32 + 1];
244
245	if (rowsize != 16 && rowsize != 32)
246		rowsize = 16;
247
248	for (i = 0; i < len; i += rowsize) {
249		linelen = min(remaining, rowsize);
250		remaining -= rowsize;
251
252		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
253				   linebuf, sizeof(linebuf), ascii);
254
255		switch (prefix_type) {
256		case DUMP_PREFIX_ADDRESS:
257			printk("%s%s%p: %s\n",
258			       level, prefix_str, ptr + i, linebuf);
259			break;
260		case DUMP_PREFIX_OFFSET:
261			printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
262			break;
263		default:
264			printk("%s%s%s\n", level, prefix_str, linebuf);
265			break;
266		}
267	}
268}
269EXPORT_SYMBOL(print_hex_dump);
270
271#if !defined(CONFIG_DYNAMIC_DEBUG)
272/**
273 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
274 * @prefix_str: string to prefix each line with;
275 *  caller supplies trailing spaces for alignment if desired
276 * @prefix_type: controls whether prefix of an offset, address, or none
277 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
278 * @buf: data blob to dump
279 * @len: number of bytes in the @buf
280 *
281 * Calls print_hex_dump(), with log level of KERN_DEBUG,
282 * rowsize of 16, groupsize of 1, and ASCII output included.
283 */
284void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
285			  const void *buf, size_t len)
286{
287	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
288		       buf, len, true);
289}
290EXPORT_SYMBOL(print_hex_dump_bytes);
291#endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
292#endif /* defined(CONFIG_PRINTK) */
293