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 */
hex_to_bin(char ch)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 */
hex2bin(u8 * dst,const char * src,size_t count)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 */
bin2hex(char * dst,const void * src,size_t count)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 */
hex_dump_to_buffer(const void * buf,size_t len,int rowsize,int groupsize,char * linebuf,size_t linebuflen,bool ascii)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 + 2)
173 goto overflow2;
174 ch = ptr[j];
175 linebuf[lx++] = hex_asc_hi(ch);
176 if (linebuflen < lx + 2)
177 goto overflow2;
178 linebuf[lx++] = hex_asc_lo(ch);
179 if (linebuflen < lx + 2)
180 goto overflow2;
181 linebuf[lx++] = ' ';
182 }
183 if (j)
184 lx--;
185 }
186 if (!ascii)
187 goto nil;
188
189 while (lx < ascii_column) {
190 if (linebuflen < lx + 2)
191 goto overflow2;
192 linebuf[lx++] = ' ';
193 }
194 for (j = 0; j < len; j++) {
195 if (linebuflen < lx + 2)
196 goto overflow2;
197 ch = ptr[j];
198 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
199 }
200 nil:
201 linebuf[lx] = '\0';
202 return lx;
203 overflow2:
204 linebuf[lx++] = '\0';
205 overflow1:
206 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
207 }
208 EXPORT_SYMBOL(hex_dump_to_buffer);
209
210 #ifdef CONFIG_PRINTK
211 /**
212 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
213 * @level: kernel log level (e.g. KERN_DEBUG)
214 * @prefix_str: string to prefix each line with;
215 * caller supplies trailing spaces for alignment if desired
216 * @prefix_type: controls whether prefix of an offset, address, or none
217 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
218 * @rowsize: number of bytes to print per line; must be 16 or 32
219 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
220 * @buf: data blob to dump
221 * @len: number of bytes in the @buf
222 * @ascii: include ASCII after the hex output
223 *
224 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
225 * to the kernel log at the specified kernel log level, with an optional
226 * leading prefix.
227 *
228 * print_hex_dump() works on one "line" of output at a time, i.e.,
229 * 16 or 32 bytes of input data converted to hex + ASCII output.
230 * print_hex_dump() iterates over the entire input @buf, breaking it into
231 * "line size" chunks to format and print.
232 *
233 * E.g.:
234 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
235 * 16, 1, frame->data, frame->len, true);
236 *
237 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
238 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
239 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
240 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
241 */
print_hex_dump(const char * level,const char * prefix_str,int prefix_type,int rowsize,int groupsize,const void * buf,size_t len,bool ascii)242 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
243 int rowsize, int groupsize,
244 const void *buf, size_t len, bool ascii)
245 {
246 const u8 *ptr = buf;
247 int i, linelen, remaining = len;
248 unsigned char linebuf[32 * 3 + 2 + 32 + 1];
249
250 if (rowsize != 16 && rowsize != 32)
251 rowsize = 16;
252
253 for (i = 0; i < len; i += rowsize) {
254 linelen = min(remaining, rowsize);
255 remaining -= rowsize;
256
257 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
258 linebuf, sizeof(linebuf), ascii);
259
260 switch (prefix_type) {
261 case DUMP_PREFIX_ADDRESS:
262 printk("%s%s%p: %s\n",
263 level, prefix_str, ptr + i, linebuf);
264 break;
265 case DUMP_PREFIX_OFFSET:
266 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
267 break;
268 default:
269 printk("%s%s%s\n", level, prefix_str, linebuf);
270 break;
271 }
272 }
273 }
274 EXPORT_SYMBOL(print_hex_dump);
275
276 #if !defined(CONFIG_DYNAMIC_DEBUG)
277 /**
278 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
279 * @prefix_str: string to prefix each line with;
280 * caller supplies trailing spaces for alignment if desired
281 * @prefix_type: controls whether prefix of an offset, address, or none
282 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
283 * @buf: data blob to dump
284 * @len: number of bytes in the @buf
285 *
286 * Calls print_hex_dump(), with log level of KERN_DEBUG,
287 * rowsize of 16, groupsize of 1, and ASCII output included.
288 */
print_hex_dump_bytes(const char * prefix_str,int prefix_type,const void * buf,size_t len)289 void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
290 const void *buf, size_t len)
291 {
292 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
293 buf, len, true);
294 }
295 EXPORT_SYMBOL(print_hex_dump_bytes);
296 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
297 #endif /* defined(CONFIG_PRINTK) */
298