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