lib/hexdump.c

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