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