Root/lib/hexdump.c

Source at commit b386be689295730688885552666ea40b2e639b14 created 8 years 11 months ago.
By Maarten ter Huurne, Revert "MIPS: JZ4740: reset: Initialize hibernate wakeup counters."
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
15const char hex_asc[] = "0123456789abcdef";
16EXPORT_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 */
25int 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}
34EXPORT_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 *
42 * Return 0 on success, -1 in case of bad input.
43 */
44int hex2bin(u8 *dst, const char *src, size_t count)
45{
46    while (count--) {
47        int hi = hex_to_bin(*src++);
48        int lo = hex_to_bin(*src++);
49
50        if ((hi < 0) || (lo < 0))
51            return -1;
52
53        *dst++ = (hi << 4) | lo;
54    }
55    return 0;
56}
57EXPORT_SYMBOL(hex2bin);
58
59/**
60 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
61 * @buf: data blob to dump
62 * @len: number of bytes in the @buf
63 * @rowsize: number of bytes to print per line; must be 16 or 32
64 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
65 * @linebuf: where to put the converted data
66 * @linebuflen: total size of @linebuf, including space for terminating NUL
67 * @ascii: include ASCII after the hex output
68 *
69 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
70 * 16 or 32 bytes of input data converted to hex + ASCII output.
71 *
72 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
73 * to a hex + ASCII dump at the supplied memory location.
74 * The converted output is always NUL-terminated.
75 *
76 * E.g.:
77 * hex_dump_to_buffer(frame->data, frame->len, 16, 1,
78 * linebuf, sizeof(linebuf), true);
79 *
80 * example output buffer:
81 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
82 */
83void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
84            int groupsize, char *linebuf, size_t linebuflen,
85            bool ascii)
86{
87    const u8 *ptr = buf;
88    u8 ch;
89    int j, lx = 0;
90    int ascii_column;
91
92    if (rowsize != 16 && rowsize != 32)
93        rowsize = 16;
94
95    if (!len)
96        goto nil;
97    if (len > rowsize) /* limit to one line at a time */
98        len = rowsize;
99    if ((len % groupsize) != 0) /* no mixed size output */
100        groupsize = 1;
101
102    switch (groupsize) {
103    case 8: {
104        const u64 *ptr8 = buf;
105        int ngroups = len / groupsize;
106
107        for (j = 0; j < ngroups; j++)
108            lx += scnprintf(linebuf + lx, linebuflen - lx,
109                    "%s%16.16llx", j ? " " : "",
110                    (unsigned long long)*(ptr8 + j));
111        ascii_column = 17 * ngroups + 2;
112        break;
113    }
114
115    case 4: {
116        const u32 *ptr4 = buf;
117        int ngroups = len / groupsize;
118
119        for (j = 0; j < ngroups; j++)
120            lx += scnprintf(linebuf + lx, linebuflen - lx,
121                    "%s%8.8x", j ? " " : "", *(ptr4 + j));
122        ascii_column = 9 * ngroups + 2;
123        break;
124    }
125
126    case 2: {
127        const u16 *ptr2 = buf;
128        int ngroups = len / groupsize;
129
130        for (j = 0; j < ngroups; j++)
131            lx += scnprintf(linebuf + lx, linebuflen - lx,
132                    "%s%4.4x", j ? " " : "", *(ptr2 + j));
133        ascii_column = 5 * ngroups + 2;
134        break;
135    }
136
137    default:
138        for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) {
139            ch = ptr[j];
140            linebuf[lx++] = hex_asc_hi(ch);
141            linebuf[lx++] = hex_asc_lo(ch);
142            linebuf[lx++] = ' ';
143        }
144        if (j)
145            lx--;
146
147        ascii_column = 3 * rowsize + 2;
148        break;
149    }
150    if (!ascii)
151        goto nil;
152
153    while (lx < (linebuflen - 1) && lx < (ascii_column - 1))
154        linebuf[lx++] = ' ';
155    for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) {
156        ch = ptr[j];
157        linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
158    }
159nil:
160    linebuf[lx++] = '\0';
161}
162EXPORT_SYMBOL(hex_dump_to_buffer);
163
164#ifdef CONFIG_PRINTK
165/**
166 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
167 * @level: kernel log level (e.g. KERN_DEBUG)
168 * @prefix_str: string to prefix each line with;
169 * caller supplies trailing spaces for alignment if desired
170 * @prefix_type: controls whether prefix of an offset, address, or none
171 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
172 * @rowsize: number of bytes to print per line; must be 16 or 32
173 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
174 * @buf: data blob to dump
175 * @len: number of bytes in the @buf
176 * @ascii: include ASCII after the hex output
177 *
178 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
179 * to the kernel log at the specified kernel log level, with an optional
180 * leading prefix.
181 *
182 * print_hex_dump() works on one "line" of output at a time, i.e.,
183 * 16 or 32 bytes of input data converted to hex + ASCII output.
184 * print_hex_dump() iterates over the entire input @buf, breaking it into
185 * "line size" chunks to format and print.
186 *
187 * E.g.:
188 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
189 * 16, 1, frame->data, frame->len, true);
190 *
191 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
192 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO
193 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
194 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~.
195 */
196void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
197            int rowsize, int groupsize,
198            const void *buf, size_t len, bool ascii)
199{
200    const u8 *ptr = buf;
201    int i, linelen, remaining = len;
202    unsigned char linebuf[32 * 3 + 2 + 32 + 1];
203
204    if (rowsize != 16 && rowsize != 32)
205        rowsize = 16;
206
207    for (i = 0; i < len; i += rowsize) {
208        linelen = min(remaining, rowsize);
209        remaining -= rowsize;
210
211        hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
212                   linebuf, sizeof(linebuf), ascii);
213
214        switch (prefix_type) {
215        case DUMP_PREFIX_ADDRESS:
216            printk("%s%s%p: %s\n",
217                   level, prefix_str, ptr + i, linebuf);
218            break;
219        case DUMP_PREFIX_OFFSET:
220            printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
221            break;
222        default:
223            printk("%s%s%s\n", level, prefix_str, linebuf);
224            break;
225        }
226    }
227}
228EXPORT_SYMBOL(print_hex_dump);
229
230/**
231 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
232 * @prefix_str: string to prefix each line with;
233 * caller supplies trailing spaces for alignment if desired
234 * @prefix_type: controls whether prefix of an offset, address, or none
235 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
236 * @buf: data blob to dump
237 * @len: number of bytes in the @buf
238 *
239 * Calls print_hex_dump(), with log level of KERN_DEBUG,
240 * rowsize of 16, groupsize of 1, and ASCII output included.
241 */
242void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
243              const void *buf, size_t len)
244{
245    print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
246               buf, len, true);
247}
248EXPORT_SYMBOL(print_hex_dump_bytes);
249#endif
250

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