1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * lib/hexdump.c
4 */
5
6 #include <linux/types.h>
7 #include <linux/ctype.h>
8 #include <linux/errno.h>
9 #include <linux/kernel.h>
10 #include <linux/minmax.h>
11 #include <linux/export.h>
12 #include <asm/unaligned.h>
13
14 const char hex_asc[] = "0123456789abcdef";
15 EXPORT_SYMBOL(hex_asc);
16 const char hex_asc_upper[] = "0123456789ABCDEF";
17 EXPORT_SYMBOL(hex_asc_upper);
18
19 /**
20 * hex_to_bin - convert a hex digit to its real value
21 * @ch: ascii character represents hex digit
22 *
23 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
24 * input.
25 */
hex_to_bin(char ch)26 int hex_to_bin(char ch)
27 {
28 if ((ch >= '0') && (ch <= '9'))
29 return ch - '0';
30 ch = tolower(ch);
31 if ((ch >= 'a') && (ch <= 'f'))
32 return ch - 'a' + 10;
33 return -1;
34 }
35 EXPORT_SYMBOL(hex_to_bin);
36
37 /**
38 * hex2bin - convert an ascii hexadecimal string to its binary representation
39 * @dst: binary result
40 * @src: ascii hexadecimal string
41 * @count: result length
42 *
43 * Return 0 on success, -EINVAL in case of bad input.
44 */
hex2bin(u8 * dst,const char * src,size_t count)45 int hex2bin(u8 *dst, const char *src, size_t count)
46 {
47 while (count--) {
48 int hi = hex_to_bin(*src++);
49 int lo = hex_to_bin(*src++);
50
51 if ((hi < 0) || (lo < 0))
52 return -EINVAL;
53
54 *dst++ = (hi << 4) | lo;
55 }
56 return 0;
57 }
58 EXPORT_SYMBOL(hex2bin);
59
60 /**
61 * bin2hex - convert binary data to an ascii hexadecimal string
62 * @dst: ascii hexadecimal result
63 * @src: binary data
64 * @count: binary data length
65 */
bin2hex(char * dst,const void * src,size_t count)66 char *bin2hex(char *dst, const void *src, size_t count)
67 {
68 const unsigned char *_src = src;
69
70 while (count--)
71 dst = hex_byte_pack(dst, *_src++);
72 return dst;
73 }
74 EXPORT_SYMBOL(bin2hex);
75
76 /**
77 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
78 * @buf: data blob to dump
79 * @len: number of bytes in the @buf
80 * @rowsize: number of bytes to print per line; must be 16 or 32
81 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
82 * @linebuf: where to put the converted data
83 * @linebuflen: total size of @linebuf, including space for terminating NUL
84 * @ascii: include ASCII after the hex output
85 *
86 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
87 * 16 or 32 bytes of input data converted to hex + ASCII output.
88 *
89 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
90 * to a hex + ASCII dump at the supplied memory location.
91 * The converted output is always NUL-terminated.
92 *
93 * E.g.:
94 * hex_dump_to_buffer(frame->data, frame->len, 16, 1,
95 * linebuf, sizeof(linebuf), true);
96 *
97 * example output buffer:
98 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
99 *
100 * Return:
101 * The amount of bytes placed in the buffer without terminating NUL. If the
102 * output was truncated, then the return value is the number of bytes
103 * (excluding the terminating NUL) which would have been written to the final
104 * string if enough space had been available.
105 */
hex_dump_to_buffer(const void * buf,size_t len,int rowsize,int groupsize,char * linebuf,size_t linebuflen,bool ascii)106 int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
107 char *linebuf, size_t linebuflen, bool ascii)
108 {
109 const u8 *ptr = buf;
110 int ngroups;
111 u8 ch;
112 int j, lx = 0;
113 int ascii_column;
114 int ret;
115
116 if (rowsize != 16 && rowsize != 32)
117 rowsize = 16;
118
119 if (len > rowsize) /* limit to one line at a time */
120 len = rowsize;
121 if (!is_power_of_2(groupsize) || groupsize > 8)
122 groupsize = 1;
123 if ((len % groupsize) != 0) /* no mixed size output */
124 groupsize = 1;
125
126 ngroups = len / groupsize;
127 ascii_column = rowsize * 2 + rowsize / groupsize + 1;
128
129 if (!linebuflen)
130 goto overflow1;
131
132 if (!len)
133 goto nil;
134
135 if (groupsize == 8) {
136 const u64 *ptr8 = buf;
137
138 for (j = 0; j < ngroups; j++) {
139 ret = snprintf(linebuf + lx, linebuflen - lx,
140 "%s%16.16llx", j ? " " : "",
141 get_unaligned(ptr8 + j));
142 if (ret >= linebuflen - lx)
143 goto overflow1;
144 lx += ret;
145 }
146 } else if (groupsize == 4) {
147 const u32 *ptr4 = buf;
148
149 for (j = 0; j < ngroups; j++) {
150 ret = snprintf(linebuf + lx, linebuflen - lx,
151 "%s%8.8x", j ? " " : "",
152 get_unaligned(ptr4 + j));
153 if (ret >= linebuflen - lx)
154 goto overflow1;
155 lx += ret;
156 }
157 } else if (groupsize == 2) {
158 const u16 *ptr2 = buf;
159
160 for (j = 0; j < ngroups; j++) {
161 ret = snprintf(linebuf + lx, linebuflen - lx,
162 "%s%4.4x", j ? " " : "",
163 get_unaligned(ptr2 + j));
164 if (ret >= linebuflen - lx)
165 goto overflow1;
166 lx += ret;
167 }
168 } else {
169 for (j = 0; j < len; j++) {
170 if (linebuflen < lx + 2)
171 goto overflow2;
172 ch = ptr[j];
173 linebuf[lx++] = hex_asc_hi(ch);
174 if (linebuflen < lx + 2)
175 goto overflow2;
176 linebuf[lx++] = hex_asc_lo(ch);
177 if (linebuflen < lx + 2)
178 goto overflow2;
179 linebuf[lx++] = ' ';
180 }
181 if (j)
182 lx--;
183 }
184 if (!ascii)
185 goto nil;
186
187 while (lx < ascii_column) {
188 if (linebuflen < lx + 2)
189 goto overflow2;
190 linebuf[lx++] = ' ';
191 }
192 for (j = 0; j < len; j++) {
193 if (linebuflen < lx + 2)
194 goto overflow2;
195 ch = ptr[j];
196 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
197 }
198 nil:
199 linebuf[lx] = '\0';
200 return lx;
201 overflow2:
202 linebuf[lx++] = '\0';
203 overflow1:
204 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
205 }
206 EXPORT_SYMBOL(hex_dump_to_buffer);
207
208 #ifdef CONFIG_PRINTK
209 /**
210 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
211 * @level: kernel log level (e.g. KERN_DEBUG)
212 * @prefix_str: string to prefix each line with;
213 * caller supplies trailing spaces for alignment if desired
214 * @prefix_type: controls whether prefix of an offset, address, or none
215 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
216 * @rowsize: number of bytes to print per line; must be 16 or 32
217 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
218 * @buf: data blob to dump
219 * @len: number of bytes in the @buf
220 * @ascii: include ASCII after the hex output
221 *
222 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
223 * to the kernel log at the specified kernel log level, with an optional
224 * leading prefix.
225 *
226 * print_hex_dump() works on one "line" of output at a time, i.e.,
227 * 16 or 32 bytes of input data converted to hex + ASCII output.
228 * print_hex_dump() iterates over the entire input @buf, breaking it into
229 * "line size" chunks to format and print.
230 *
231 * E.g.:
232 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
233 * 16, 1, frame->data, frame->len, true);
234 *
235 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
236 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
237 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
238 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
239 */
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)240 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
241 int rowsize, int groupsize,
242 const void *buf, size_t len, bool ascii)
243 {
244 const u8 *ptr = buf;
245 int i, linelen, remaining = len;
246 unsigned char linebuf[32 * 3 + 2 + 32 + 1];
247
248 if (rowsize != 16 && rowsize != 32)
249 rowsize = 16;
250
251 for (i = 0; i < len; i += rowsize) {
252 linelen = min(remaining, rowsize);
253 remaining -= rowsize;
254
255 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
256 linebuf, sizeof(linebuf), ascii);
257
258 switch (prefix_type) {
259 case DUMP_PREFIX_ADDRESS:
260 printk("%s%s%p: %s\n",
261 level, prefix_str, ptr + i, linebuf);
262 break;
263 case DUMP_PREFIX_OFFSET:
264 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
265 break;
266 default:
267 printk("%s%s%s\n", level, prefix_str, linebuf);
268 break;
269 }
270 }
271 }
272 EXPORT_SYMBOL(print_hex_dump);
273
274 #endif /* defined(CONFIG_PRINTK) */
275