Line data Source code
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 : */
26 0 : int hex_to_bin(char ch)
27 : {
28 0 : if ((ch >= '0') && (ch <= '9'))
29 0 : return ch - '0';
30 0 : ch = tolower(ch);
31 0 : if ((ch >= 'a') && (ch <= 'f'))
32 0 : 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 : */
45 0 : int hex2bin(u8 *dst, const char *src, size_t count)
46 : {
47 0 : while (count--) {
48 0 : int hi = hex_to_bin(*src++);
49 0 : int lo = hex_to_bin(*src++);
50 :
51 0 : if ((hi < 0) || (lo < 0))
52 : return -EINVAL;
53 :
54 0 : *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 : */
66 0 : char *bin2hex(char *dst, const void *src, size_t count)
67 : {
68 0 : const unsigned char *_src = src;
69 :
70 0 : while (count--)
71 0 : dst = hex_byte_pack(dst, *_src++);
72 0 : 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 : */
106 0 : 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 0 : const u8 *ptr = buf;
110 0 : int ngroups;
111 0 : u8 ch;
112 0 : int j, lx = 0;
113 0 : int ascii_column;
114 0 : int ret;
115 :
116 0 : if (rowsize != 16 && rowsize != 32)
117 0 : rowsize = 16;
118 :
119 0 : if (len > rowsize) /* limit to one line at a time */
120 : len = rowsize;
121 0 : if (!is_power_of_2(groupsize) || groupsize > 8)
122 0 : groupsize = 1;
123 0 : if ((len % groupsize) != 0) /* no mixed size output */
124 0 : groupsize = 1;
125 :
126 0 : ngroups = len / groupsize;
127 0 : ascii_column = rowsize * 2 + rowsize / groupsize + 1;
128 :
129 0 : if (!linebuflen)
130 0 : goto overflow1;
131 :
132 0 : if (!len)
133 0 : goto nil;
134 :
135 0 : if (groupsize == 8) {
136 0 : const u64 *ptr8 = buf;
137 :
138 0 : for (j = 0; j < ngroups; j++) {
139 0 : ret = snprintf(linebuf + lx, linebuflen - lx,
140 : "%s%16.16llx", j ? " " : "",
141 0 : get_unaligned(ptr8 + j));
142 0 : if (ret >= linebuflen - lx)
143 0 : goto overflow1;
144 0 : lx += ret;
145 : }
146 0 : } else if (groupsize == 4) {
147 0 : const u32 *ptr4 = buf;
148 :
149 0 : for (j = 0; j < ngroups; j++) {
150 0 : ret = snprintf(linebuf + lx, linebuflen - lx,
151 : "%s%8.8x", j ? " " : "",
152 0 : get_unaligned(ptr4 + j));
153 0 : if (ret >= linebuflen - lx)
154 0 : goto overflow1;
155 0 : lx += ret;
156 : }
157 0 : } else if (groupsize == 2) {
158 0 : const u16 *ptr2 = buf;
159 :
160 0 : for (j = 0; j < ngroups; j++) {
161 0 : ret = snprintf(linebuf + lx, linebuflen - lx,
162 : "%s%4.4x", j ? " " : "",
163 0 : get_unaligned(ptr2 + j));
164 0 : if (ret >= linebuflen - lx)
165 0 : goto overflow1;
166 0 : lx += ret;
167 : }
168 : } else {
169 0 : for (j = 0; j < len; j++) {
170 0 : if (linebuflen < lx + 2)
171 0 : goto overflow2;
172 0 : ch = ptr[j];
173 0 : linebuf[lx++] = hex_asc_hi(ch);
174 0 : if (linebuflen < lx + 2)
175 0 : goto overflow2;
176 0 : linebuf[lx++] = hex_asc_lo(ch);
177 0 : if (linebuflen < lx + 2)
178 0 : goto overflow2;
179 0 : linebuf[lx++] = ' ';
180 : }
181 0 : if (j)
182 0 : lx--;
183 : }
184 0 : if (!ascii)
185 0 : goto nil;
186 :
187 0 : while (lx < ascii_column) {
188 0 : if (linebuflen < lx + 2)
189 0 : goto overflow2;
190 0 : linebuf[lx++] = ' ';
191 : }
192 0 : for (j = 0; j < len; j++) {
193 0 : if (linebuflen < lx + 2)
194 0 : goto overflow2;
195 0 : ch = ptr[j];
196 0 : linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
197 : }
198 0 : nil:
199 0 : linebuf[lx] = '\0';
200 0 : return lx;
201 0 : overflow2:
202 0 : linebuf[lx++] = '\0';
203 0 : overflow1:
204 0 : 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 : */
240 0 : 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 0 : const u8 *ptr = buf;
245 0 : int i, linelen, remaining = len;
246 0 : unsigned char linebuf[32 * 3 + 2 + 32 + 1];
247 :
248 0 : if (rowsize != 16 && rowsize != 32)
249 0 : rowsize = 16;
250 :
251 0 : for (i = 0; i < len; i += rowsize) {
252 0 : linelen = min(remaining, rowsize);
253 0 : remaining -= rowsize;
254 :
255 0 : hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
256 : linebuf, sizeof(linebuf), ascii);
257 :
258 0 : switch (prefix_type) {
259 0 : case DUMP_PREFIX_ADDRESS:
260 0 : printk("%s%s%p: %s\n",
261 : level, prefix_str, ptr + i, linebuf);
262 0 : break;
263 0 : case DUMP_PREFIX_OFFSET:
264 0 : printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
265 0 : break;
266 0 : default:
267 0 : printk("%s%s%s\n", level, prefix_str, linebuf);
268 0 : break;
269 : }
270 : }
271 0 : }
272 : EXPORT_SYMBOL(print_hex_dump);
273 :
274 : #endif /* defined(CONFIG_PRINTK) */
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