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
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>
16 const char hex_asc[] = "0123456789abcdef";
17 EXPORT_SYMBOL(hex_asc);
18 const char hex_asc_upper[] = "0123456789ABCDEF";
19 EXPORT_SYMBOL(hex_asc_upper);
22 * hex_to_bin - convert a hex digit to its real value
23 * @ch: ascii character represents hex digit
25 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
28 * This function is used to load cryptographic keys, so it is coded in such a
29 * way that there are no conditions or memory accesses that depend on data.
31 * Explanation of the logic:
32 * (ch - '9' - 1) is negative if ch <= '9'
33 * ('0' - 1 - ch) is negative if ch >= '0'
34 * we "and" these two values, so the result is negative if ch is in the range
36 * we are only interested in the sign, so we do a shift ">> 8"; note that right
37 * shift of a negative value is implementation-defined, so we cast the
38 * value to (unsigned) before the shift --- we have 0xffffff if ch is in
39 * the range '0' ... '9', 0 otherwise
40 * we "and" this value with (ch - '0' + 1) --- we have a value 1 ... 10 if ch is
41 * in the range '0' ... '9', 0 otherwise
42 * we add this value to -1 --- we have a value 0 ... 9 if ch is in the range '0'
43 * ... '9', -1 otherwise
44 * the next line is similar to the previous one, but we need to decode both
45 * uppercase and lowercase letters, so we use (ch & 0xdf), which converts
46 * lowercase to uppercase
48 int hex_to_bin(unsigned char ch)
50 unsigned char cu = ch & 0xdf;
52 ((ch - '0' + 1) & (unsigned)((ch - '9' - 1) & ('0' - 1 - ch)) >> 8) +
53 ((cu - 'A' + 11) & (unsigned)((cu - 'F' - 1) & ('A' - 1 - cu)) >> 8);
55 EXPORT_SYMBOL(hex_to_bin);
58 * hex2bin - convert an ascii hexadecimal string to its binary representation
60 * @src: ascii hexadecimal string
61 * @count: result length
63 * Return 0 on success, -1 in case of bad input.
65 int hex2bin(u8 *dst, const char *src, size_t count)
70 hi = hex_to_bin(*src++);
73 lo = hex_to_bin(*src++);
77 *dst++ = (hi << 4) | lo;
81 EXPORT_SYMBOL(hex2bin);
84 * bin2hex - convert binary data to an ascii hexadecimal string
85 * @dst: ascii hexadecimal result
87 * @count: binary data length
89 char *bin2hex(char *dst, const void *src, size_t count)
91 const unsigned char *_src = src;
94 dst = hex_byte_pack(dst, *_src++);
97 EXPORT_SYMBOL(bin2hex);
100 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
101 * @buf: data blob to dump
102 * @len: number of bytes in the @buf
103 * @rowsize: number of bytes to print per line; must be 16 or 32
104 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
105 * @linebuf: where to put the converted data
106 * @linebuflen: total size of @linebuf, including space for terminating NUL
107 * @ascii: include ASCII after the hex output
109 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
110 * 16 or 32 bytes of input data converted to hex + ASCII output.
112 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
113 * to a hex + ASCII dump at the supplied memory location.
114 * The converted output is always NUL-terminated.
117 * hex_dump_to_buffer(frame->data, frame->len, 16, 1,
118 * linebuf, sizeof(linebuf), true);
120 * example output buffer:
121 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
124 * The amount of bytes placed in the buffer without terminating NUL. If the
125 * output was truncated, then the return value is the number of bytes
126 * (excluding the terminating NUL) which would have been written to the final
127 * string if enough space had been available.
129 int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
130 char *linebuf, size_t linebuflen, bool ascii)
139 if (rowsize != 16 && rowsize != 32)
142 if (len > rowsize) /* limit to one line at a time */
144 if (!is_power_of_2(groupsize) || groupsize > 8)
146 if ((len % groupsize) != 0) /* no mixed size output */
149 ngroups = len / groupsize;
150 ascii_column = rowsize * 2 + rowsize / groupsize + 1;
158 if (groupsize == 8) {
159 const u64 *ptr8 = buf;
161 for (j = 0; j < ngroups; j++) {
162 ret = snprintf(linebuf + lx, linebuflen - lx,
163 "%s%16.16llx", j ? " " : "",
164 get_unaligned(ptr8 + j));
165 if (ret >= linebuflen - lx)
169 } else if (groupsize == 4) {
170 const u32 *ptr4 = buf;
172 for (j = 0; j < ngroups; j++) {
173 ret = snprintf(linebuf + lx, linebuflen - lx,
174 "%s%8.8x", j ? " " : "",
175 get_unaligned(ptr4 + j));
176 if (ret >= linebuflen - lx)
180 } else if (groupsize == 2) {
181 const u16 *ptr2 = buf;
183 for (j = 0; j < ngroups; j++) {
184 ret = snprintf(linebuf + lx, linebuflen - lx,
185 "%s%4.4x", j ? " " : "",
186 get_unaligned(ptr2 + j));
187 if (ret >= linebuflen - lx)
192 for (j = 0; j < len; j++) {
193 if (linebuflen < lx + 2)
196 linebuf[lx++] = hex_asc_hi(ch);
197 if (linebuflen < lx + 2)
199 linebuf[lx++] = hex_asc_lo(ch);
200 if (linebuflen < lx + 2)
210 while (lx < ascii_column) {
211 if (linebuflen < lx + 2)
215 for (j = 0; j < len; j++) {
216 if (linebuflen < lx + 2)
219 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
225 linebuf[lx++] = '\0';
227 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
229 EXPORT_SYMBOL(hex_dump_to_buffer);
233 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
234 * @level: kernel log level (e.g. KERN_DEBUG)
235 * @prefix_str: string to prefix each line with;
236 * caller supplies trailing spaces for alignment if desired
237 * @prefix_type: controls whether prefix of an offset, address, or none
238 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
239 * @rowsize: number of bytes to print per line; must be 16 or 32
240 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
241 * @buf: data blob to dump
242 * @len: number of bytes in the @buf
243 * @ascii: include ASCII after the hex output
245 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
246 * to the kernel log at the specified kernel log level, with an optional
249 * print_hex_dump() works on one "line" of output at a time, i.e.,
250 * 16 or 32 bytes of input data converted to hex + ASCII output.
251 * print_hex_dump() iterates over the entire input @buf, breaking it into
252 * "line size" chunks to format and print.
255 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
256 * 16, 1, frame->data, frame->len, true);
258 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
259 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
260 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
261 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
263 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
264 int rowsize, int groupsize,
265 const void *buf, size_t len, bool ascii)
268 int i, linelen, remaining = len;
269 unsigned char linebuf[32 * 3 + 2 + 32 + 1];
271 if (rowsize != 16 && rowsize != 32)
274 for (i = 0; i < len; i += rowsize) {
275 linelen = min(remaining, rowsize);
276 remaining -= rowsize;
278 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
279 linebuf, sizeof(linebuf), ascii);
281 switch (prefix_type) {
282 case DUMP_PREFIX_ADDRESS:
283 printk("%s%s%p: %s\n",
284 level, prefix_str, ptr + i, linebuf);
286 case DUMP_PREFIX_OFFSET:
287 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
290 printk("%s%s%s\n", level, prefix_str, linebuf);
295 EXPORT_SYMBOL(print_hex_dump);
297 #if !defined(CONFIG_DYNAMIC_DEBUG)
299 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
300 * @prefix_str: string to prefix each line with;
301 * caller supplies trailing spaces for alignment if desired
302 * @prefix_type: controls whether prefix of an offset, address, or none
303 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
304 * @buf: data blob to dump
305 * @len: number of bytes in the @buf
307 * Calls print_hex_dump(), with log level of KERN_DEBUG,
308 * rowsize of 16, groupsize of 1, and ASCII output included.
310 void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
311 const void *buf, size_t len)
313 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
316 EXPORT_SYMBOL(print_hex_dump_bytes);
317 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
318 #endif /* defined(CONFIG_PRINTK) */