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/errno.h>
  13 #include <linux/kernel.h>
  14 #include <linux/export.h>
  15 #include <asm/unaligned.h>
  16
  17 const char hex_asc[] = "0123456789abcdef";
  18 EXPORT_SYMBOL(hex_asc);
  19 const char hex_asc_upper[] = "0123456789ABCDEF";
  20 EXPORT_SYMBOL(hex_asc_upper);
  21
  22 /**
  23  * hex_to_bin - convert a hex digit to its real value
  24  * @ch: ascii character represents hex digit
  25  *
  26  * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
  27  * input.
  28  */
  29 int hex_to_bin(char ch)
  30 {
  31         if ((ch >= '0') && (ch <= '9'))
  32                 return ch - '0';
  33         ch = tolower(ch);
  34         if ((ch >= 'a') && (ch <= 'f'))
  35                 return ch - 'a' + 10;
  36         return -1;
  37 }
  38 EXPORT_SYMBOL(hex_to_bin);
  39
  40 /**
  41  * hex2bin - convert an ascii hexadecimal string to its binary representation
  42  * @dst: binary result
  43  * @src: ascii hexadecimal string
  44  * @count: result length
  45  *
  46  * Return 0 on success, -EINVAL in case of bad input.
  47  */
  48 int hex2bin(u8 *dst, const char *src, size_t count)
  49 {
  50         while (count--) {
  51                 int hi = hex_to_bin(*src++);
  52                 int lo = hex_to_bin(*src++);
  53
  54                 if ((hi < 0) || (lo < 0))
  55                         return -EINVAL;
  56
  57                 *dst++ = (hi << 4) | lo;
  58         }
  59         return 0;
  60 }
  61 EXPORT_SYMBOL(hex2bin);
  62
  63 /**
  64  * bin2hex - convert binary data to an ascii hexadecimal string
  65  * @dst: ascii hexadecimal result
  66  * @src: binary data
  67  * @count: binary data length
  68  */
  69 char *bin2hex(char *dst, const void *src, size_t count)
  70 {
  71         const unsigned char *_src = src;
  72
  73         while (count--)
  74                 dst = hex_byte_pack(dst, *_src++);
  75         return dst;
  76 }
  77 EXPORT_SYMBOL(bin2hex);
  78
  79 /**
  80  * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
  81  * @buf: data blob to dump
  82  * @len: number of bytes in the @buf
  83  * @rowsize: number of bytes to print per line; must be 16 or 32
  84  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
  85  * @linebuf: where to put the converted data
  86  * @linebuflen: total size of @linebuf, including space for terminating NUL
  87  * @ascii: include ASCII after the hex output
  88  *
  89  * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
  90  * 16 or 32 bytes of input data converted to hex + ASCII output.
  91  *
  92  * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
  93  * to a hex + ASCII dump at the supplied memory location.
  94  * The converted output is always NUL-terminated.
  95  *
  96  * E.g.:
  97  *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
  98  *                      linebuf, sizeof(linebuf), true);
  99  *
 100  * example output buffer:
 101  * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 102  *
 103  * Return:
 104  * The amount of bytes placed in the buffer without terminating NUL. If the
 105  * output was truncated, then the return value is the number of bytes
 106  * (excluding the terminating NUL) which would have been written to the final
 107  * string if enough space had been available.
 108  */
 109 int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
 110                        char *linebuf, size_t linebuflen, bool ascii)
 111 {
 112         const u8 *ptr = buf;
 113         int ngroups;
 114         u8 ch;
 115         int j, lx = 0;
 116         int ascii_column;
 117         int ret;
 118
 119         if (rowsize != 16 && rowsize != 32)
 120                 rowsize = 16;
 121
 122         if (len > rowsize)              /* limit to one line at a time */
 123                 len = rowsize;
 124         if (!is_power_of_2(groupsize) || groupsize > 8)
 125                 groupsize = 1;
 126         if ((len % groupsize) != 0)     /* no mixed size output */
 127                 groupsize = 1;
 128
 129         ngroups = len / groupsize;
 130         ascii_column = rowsize * 2 + rowsize / groupsize + 1;
 131
 132         if (!linebuflen)
 133                 goto overflow1;
 134
 135         if (!len)
 136                 goto nil;
 137
 138         if (groupsize == 8) {
 139                 const u64 *ptr8 = buf;
 140
 141                 for (j = 0; j < ngroups; j++) {
 142                         ret = snprintf(linebuf + lx, linebuflen - lx,
 143                                        "%s%16.16llx", j ? " " : "",
 144                                        get_unaligned(ptr8 + j));
 145                         if (ret >= linebuflen - lx)
 146                                 goto overflow1;
 147                         lx += ret;
 148                 }
 149         } else if (groupsize == 4) {
 150                 const u32 *ptr4 = buf;
 151
 152                 for (j = 0; j < ngroups; j++) {
 153                         ret = snprintf(linebuf + lx, linebuflen - lx,
 154                                        "%s%8.8x", j ? " " : "",
 155                                        get_unaligned(ptr4 + j));
 156                         if (ret >= linebuflen - lx)
 157                                 goto overflow1;
 158                         lx += ret;
 159                 }
 160         } else if (groupsize == 2) {
 161                 const u16 *ptr2 = buf;
 162
 163                 for (j = 0; j < ngroups; j++) {
 164                         ret = snprintf(linebuf + lx, linebuflen - lx,
 165                                        "%s%4.4x", j ? " " : "",
 166                                        get_unaligned(ptr2 + j));
 167                         if (ret >= linebuflen - lx)
 168                                 goto overflow1;
 169                         lx += ret;
 170                 }
 171         } else {
 172                 for (j = 0; j < len; j++) {
 173                         if (linebuflen < lx + 2)
 174                                 goto overflow2;
 175                         ch = ptr[j];
 176                         linebuf[lx++] = hex_asc_hi(ch);
 177                         if (linebuflen < lx + 2)
 178                                 goto overflow2;
 179                         linebuf[lx++] = hex_asc_lo(ch);
 180                         if (linebuflen < lx + 2)
 181                                 goto overflow2;
 182                         linebuf[lx++] = ' ';
 183                 }
 184                 if (j)
 185                         lx--;
 186         }
 187         if (!ascii)
 188                 goto nil;
 189
 190         while (lx < ascii_column) {
 191                 if (linebuflen < lx + 2)
 192                         goto overflow2;
 193                 linebuf[lx++] = ' ';
 194         }
 195         for (j = 0; j < len; j++) {
 196                 if (linebuflen < lx + 2)
 197                         goto overflow2;
 198                 ch = ptr[j];
 199                 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
 200         }
 201 nil:
 202         linebuf[lx] = '\0';
 203         return lx;
 204 overflow2:
 205         linebuf[lx++] = '\0';
 206 overflow1:
 207         return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
 208 }
 209 EXPORT_SYMBOL(hex_dump_to_buffer);
 210
 211 #ifdef CONFIG_PRINTK
 212 /**
 213  * print_hex_dump - print a text hex dump to syslog for a binary blob of data
 214  * @level: kernel log level (e.g. KERN_DEBUG)
 215  * @prefix_str: string to prefix each line with;
 216  *  caller supplies trailing spaces for alignment if desired
 217  * @prefix_type: controls whether prefix of an offset, address, or none
 218  *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 219  * @rowsize: number of bytes to print per line; must be 16 or 32
 220  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 221  * @buf: data blob to dump
 222  * @len: number of bytes in the @buf
 223  * @ascii: include ASCII after the hex output
 224  *
 225  * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
 226  * to the kernel log at the specified kernel log level, with an optional
 227  * leading prefix.
 228  *
 229  * print_hex_dump() works on one "line" of output at a time, i.e.,
 230  * 16 or 32 bytes of input data converted to hex + ASCII output.
 231  * print_hex_dump() iterates over the entire input @buf, breaking it into
 232  * "line size" chunks to format and print.
 233  *
 234  * E.g.:
 235  *   print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
 236  *                  16, 1, frame->data, frame->len, true);
 237  *
 238  * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
 239  * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 240  * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
 241  * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
 242  */
 243 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
 244                     int rowsize, int groupsize,
 245                     const void *buf, size_t len, bool ascii)
 246 {
 247         const u8 *ptr = buf;
 248         int i, linelen, remaining = len;
 249         unsigned char linebuf[32 * 3 + 2 + 32 + 1];
 250
 251         if (rowsize != 16 && rowsize != 32)
 252                 rowsize = 16;
 253
 254         for (i = 0; i < len; i += rowsize) {
 255                 linelen = min(remaining, rowsize);
 256                 remaining -= rowsize;
 257
 258                 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
 259                                    linebuf, sizeof(linebuf), ascii);
 260
 261                 switch (prefix_type) {
 262                 case DUMP_PREFIX_ADDRESS:
 263                         printk("%s%s%p: %s\n",
 264                                level, prefix_str, ptr + i, linebuf);
 265                         break;
 266                 case DUMP_PREFIX_OFFSET:
 267                         printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
 268                         break;
 269                 default:
 270                         printk("%s%s%s\n", level, prefix_str, linebuf);
 271                         break;
 272                 }
 273         }
 274 }
 275 EXPORT_SYMBOL(print_hex_dump);
 276
 277 #if !defined(CONFIG_DYNAMIC_DEBUG)
 278 /**
 279  * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 280  * @prefix_str: string to prefix each line with;
 281  *  caller supplies trailing spaces for alignment if desired
 282  * @prefix_type: controls whether prefix of an offset, address, or none
 283  *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 284  * @buf: data blob to dump
 285  * @len: number of bytes in the @buf
 286  *
 287  * Calls print_hex_dump(), with log level of KERN_DEBUG,
 288  * rowsize of 16, groupsize of 1, and ASCII output included.
 289  */
 290 void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 291                           const void *buf, size_t len)
 292 {
 293         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
 294                        buf, len, true);
 295 }
 296 EXPORT_SYMBOL(print_hex_dump_bytes);
 297 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
 298 #endif /* defined(CONFIG_PRINTK) */