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/errno.h>
13#include <linux/kernel.h>
14#include <linux/export.h>
15#include <asm/unaligned.h>
16
17const char hex_asc[] = "0123456789abcdef";
18EXPORT_SYMBOL(hex_asc);
19const char hex_asc_upper[] = "0123456789ABCDEF";
20EXPORT_SYMBOL(hex_asc_upper);
21
22/**
23 * hex_to_bin - convert a hex digit to its real value
24 * @ch: ascii character represents hex digit
25 *
26 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
27 * input.
28 */
29int hex_to_bin(char ch)
30{
31 if ((ch >= '0') && (ch <= '9'))
32 return ch - '0';
33 ch = tolower(ch);
34 if ((ch >= 'a') && (ch <= 'f'))
35 return ch - 'a' + 10;
36 return -1;
37}
38EXPORT_SYMBOL(hex_to_bin);
39
40/**
41 * hex2bin - convert an ascii hexadecimal string to its binary representation
42 * @dst: binary result
43 * @src: ascii hexadecimal string
44 * @count: result length
45 *
46 * Return 0 on success, -EINVAL in case of bad input.
47 */
48int hex2bin(u8 *dst, const char *src, size_t count)
49{
50 while (count--) {
51 int hi = hex_to_bin(*src++);
52 int lo = hex_to_bin(*src++);
53
54 if ((hi < 0) || (lo < 0))
55 return -EINVAL;
56
57 *dst++ = (hi << 4) | lo;
58 }
59 return 0;
60}
61EXPORT_SYMBOL(hex2bin);
62
63/**
64 * bin2hex - convert binary data to an ascii hexadecimal string
65 * @dst: ascii hexadecimal result
66 * @src: binary data
67 * @count: binary data length
68 */
69char *bin2hex(char *dst, const void *src, size_t count)
70{
71 const unsigned char *_src = src;
72
73 while (count--)
74 dst = hex_byte_pack(dst, *_src++);
75 return dst;
76}
77EXPORT_SYMBOL(bin2hex);
78
79/**
80 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
81 * @buf: data blob to dump
82 * @len: number of bytes in the @buf
83 * @rowsize: number of bytes to print per line; must be 16 or 32
84 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
85 * @linebuf: where to put the converted data
86 * @linebuflen: total size of @linebuf, including space for terminating NUL
87 * @ascii: include ASCII after the hex output
88 *
89 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
90 * 16 or 32 bytes of input data converted to hex + ASCII output.
91 *
92 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
93 * to a hex + ASCII dump at the supplied memory location.
94 * The converted output is always NUL-terminated.
95 *
96 * E.g.:
97 * hex_dump_to_buffer(frame->data, frame->len, 16, 1,
98 * linebuf, sizeof(linebuf), true);
99 *
100 * example output buffer:
101 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
102 *
103 * Return:
104 * The amount of bytes placed in the buffer without terminating NUL. If the
105 * output was truncated, then the return value is the number of bytes
106 * (excluding the terminating NUL) which would have been written to the final
107 * string if enough space had been available.
108 */
109int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
110 char *linebuf, size_t linebuflen, bool ascii)
111{
112 const u8 *ptr = buf;
113 int ngroups;
114 u8 ch;
115 int j, lx = 0;
116 int ascii_column;
117 int ret;
118
119 if (rowsize != 16 && rowsize != 32)
120 rowsize = 16;
121
122 if (len > rowsize) /* limit to one line at a time */
123 len = rowsize;
124 if (!is_power_of_2(groupsize) || groupsize > 8)
125 groupsize = 1;
126 if ((len % groupsize) != 0) /* no mixed size output */
127 groupsize = 1;
128
129 ngroups = len / groupsize;
130 ascii_column = rowsize * 2 + rowsize / groupsize + 1;
131
132 if (!linebuflen)
133 goto overflow1;
134
135 if (!len)
136 goto nil;
137
138 if (groupsize == 8) {
139 const u64 *ptr8 = buf;
140
141 for (j = 0; j < ngroups; j++) {
142 ret = snprintf(linebuf + lx, linebuflen - lx,
143 "%s%16.16llx", j ? " " : "",
144 get_unaligned(ptr8 + j));
145 if (ret >= linebuflen - lx)
146 goto overflow1;
147 lx += ret;
148 }
149 } else if (groupsize == 4) {
150 const u32 *ptr4 = buf;
151
152 for (j = 0; j < ngroups; j++) {
153 ret = snprintf(linebuf + lx, linebuflen - lx,
154 "%s%8.8x", j ? " " : "",
155 get_unaligned(ptr4 + j));
156 if (ret >= linebuflen - lx)
157 goto overflow1;
158 lx += ret;
159 }
160 } else if (groupsize == 2) {
161 const u16 *ptr2 = buf;
162
163 for (j = 0; j < ngroups; j++) {
164 ret = snprintf(linebuf + lx, linebuflen - lx,
165 "%s%4.4x", j ? " " : "",
166 get_unaligned(ptr2 + j));
167 if (ret >= linebuflen - lx)
168 goto overflow1;
169 lx += ret;
170 }
171 } else {
172 for (j = 0; j < len; j++) {
173 if (linebuflen < lx + 2)
174 goto overflow2;
175 ch = ptr[j];
176 linebuf[lx++] = hex_asc_hi(ch);
177 if (linebuflen < lx + 2)
178 goto overflow2;
179 linebuf[lx++] = hex_asc_lo(ch);
180 if (linebuflen < lx + 2)
181 goto overflow2;
182 linebuf[lx++] = ' ';
183 }
184 if (j)
185 lx--;
186 }
187 if (!ascii)
188 goto nil;
189
190 while (lx < ascii_column) {
191 if (linebuflen < lx + 2)
192 goto overflow2;
193 linebuf[lx++] = ' ';
194 }
195 for (j = 0; j < len; j++) {
196 if (linebuflen < lx + 2)
197 goto overflow2;
198 ch = ptr[j];
199 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
200 }
201nil:
202 linebuf[lx] = '\0';
203 return lx;
204overflow2:
205 linebuf[lx++] = '\0';
206overflow1:
207 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
208}
209EXPORT_SYMBOL(hex_dump_to_buffer);
210
211#ifdef CONFIG_PRINTK
212/**
213 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
214 * @level: kernel log level (e.g. KERN_DEBUG)
215 * @prefix_str: string to prefix each line with;
216 * caller supplies trailing spaces for alignment if desired
217 * @prefix_type: controls whether prefix of an offset, address, or none
218 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
219 * @rowsize: number of bytes to print per line; must be 16 or 32
220 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
221 * @buf: data blob to dump
222 * @len: number of bytes in the @buf
223 * @ascii: include ASCII after the hex output
224 *
225 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
226 * to the kernel log at the specified kernel log level, with an optional
227 * leading prefix.
228 *
229 * print_hex_dump() works on one "line" of output at a time, i.e.,
230 * 16 or 32 bytes of input data converted to hex + ASCII output.
231 * print_hex_dump() iterates over the entire input @buf, breaking it into
232 * "line size" chunks to format and print.
233 *
234 * E.g.:
235 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
236 * 16, 1, frame->data, frame->len, true);
237 *
238 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
239 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
240 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
241 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
242 */
243void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
244 int rowsize, int groupsize,
245 const void *buf, size_t len, bool ascii)
246{
247 const u8 *ptr = buf;
248 int i, linelen, remaining = len;
249 unsigned char linebuf[32 * 3 + 2 + 32 + 1];
250
251 if (rowsize != 16 && rowsize != 32)
252 rowsize = 16;
253
254 for (i = 0; i < len; i += rowsize) {
255 linelen = min(remaining, rowsize);
256 remaining -= rowsize;
257
258 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
259 linebuf, sizeof(linebuf), ascii);
260
261 switch (prefix_type) {
262 case DUMP_PREFIX_ADDRESS:
263 printk("%s%s%p: %s\n",
264 level, prefix_str, ptr + i, linebuf);
265 break;
266 case DUMP_PREFIX_OFFSET:
267 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
268 break;
269 default:
270 printk("%s%s%s\n", level, prefix_str, linebuf);
271 break;
272 }
273 }
274}
275EXPORT_SYMBOL(print_hex_dump);
276
277#if !defined(CONFIG_DYNAMIC_DEBUG)
278/**
279 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
280 * @prefix_str: string to prefix each line with;
281 * caller supplies trailing spaces for alignment if desired
282 * @prefix_type: controls whether prefix of an offset, address, or none
283 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
284 * @buf: data blob to dump
285 * @len: number of bytes in the @buf
286 *
287 * Calls print_hex_dump(), with log level of KERN_DEBUG,
288 * rowsize of 16, groupsize of 1, and ASCII output included.
289 */
290void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
291 const void *buf, size_t len)
292{
293 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
294 buf, len, true);
295}
296EXPORT_SYMBOL(print_hex_dump_bytes);
297#endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
298#endif /* defined(CONFIG_PRINTK) */
299