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