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  * Return:
 102  * The amount of bytes placed in the buffer without terminating NUL. If the
 103  * output was truncated, then the return value is the number of bytes
 104  * (excluding the terminating NUL) which would have been written to the final
 105  * string if enough space had been available.
 106  */
 107 int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
 108                        char *linebuf, size_t linebuflen, bool ascii)
 109 {
 110         const u8 *ptr = buf;
 111         int ngroups;
 112         u8 ch;
 113         int j, lx = 0;
 114         int ascii_column;
 115         int ret;
 116
 117         if (rowsize != 16 && rowsize != 32)
 118                 rowsize = 16;
 119
 120         if (len > rowsize)              /* limit to one line at a time */
 121                 len = rowsize;
 122         if (!is_power_of_2(groupsize) || groupsize > 8)
 123                 groupsize = 1;
 124         if ((len % groupsize) != 0)     /* no mixed size output */
 125                 groupsize = 1;
 126
 127         ngroups = len / groupsize;
 128         ascii_column = rowsize * 2 + rowsize / groupsize + 1;
 129
 130         if (!linebuflen)
 131                 goto overflow1;
 132
 133         if (!len)
 134                 goto nil;
 135
 136         if (groupsize == 8) {
 137                 const u64 *ptr8 = buf;
 138
 139                 for (j = 0; j < ngroups; j++) {
 140                         ret = snprintf(linebuf + lx, linebuflen - lx,
 141                                        "%s%16.16llx", j ? " " : "",
 142                                        (unsigned long long)*(ptr8 + j));
 143                         if (ret >= linebuflen - lx)
 144                                 goto overflow1;
 145                         lx += ret;
 146                 }
 147         } else if (groupsize == 4) {
 148                 const u32 *ptr4 = buf;
 149
 150                 for (j = 0; j < ngroups; j++) {
 151                         ret = snprintf(linebuf + lx, linebuflen - lx,
 152                                        "%s%8.8x", j ? " " : "",
 153                                        *(ptr4 + j));
 154                         if (ret >= linebuflen - lx)
 155                                 goto overflow1;
 156                         lx += ret;
 157                 }
 158         } else if (groupsize == 2) {
 159                 const u16 *ptr2 = buf;
 160
 161                 for (j = 0; j < ngroups; j++) {
 162                         ret = snprintf(linebuf + lx, linebuflen - lx,
 163                                        "%s%4.4x", j ? " " : "",
 164                                        *(ptr2 + j));
 165                         if (ret >= linebuflen - lx)
 166                                 goto overflow1;
 167                         lx += ret;
 168                 }
 169         } else {
 170                 for (j = 0; j < len; j++) {
 171                         if (linebuflen < lx + 3)
 172                                 goto overflow2;
 173                         ch = ptr[j];
 174                         linebuf[lx++] = hex_asc_hi(ch);
 175                         linebuf[lx++] = hex_asc_lo(ch);
 176                         linebuf[lx++] = ' ';
 177                 }
 178                 if (j)
 179                         lx--;
 180         }
 181         if (!ascii)
 182                 goto nil;
 183
 184         while (lx < ascii_column) {
 185                 if (linebuflen < lx + 2)
 186                         goto overflow2;
 187                 linebuf[lx++] = ' ';
 188         }
 189         for (j = 0; j < len; j++) {
 190                 if (linebuflen < lx + 2)
 191                         goto overflow2;
 192                 ch = ptr[j];
 193                 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
 194         }
 195 nil:
 196         linebuf[lx] = '\0';
 197         return lx;
 198 overflow2:
 199         linebuf[lx++] = '\0';
 200 overflow1:
 201         return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
 202 }
 203 EXPORT_SYMBOL(hex_dump_to_buffer);
 204
 205 #ifdef CONFIG_PRINTK
 206 /**
 207  * print_hex_dump - print a text hex dump to syslog for a binary blob of data
 208  * @level: kernel log level (e.g. KERN_DEBUG)
 209  * @prefix_str: string to prefix each line with;
 210  *  caller supplies trailing spaces for alignment if desired
 211  * @prefix_type: controls whether prefix of an offset, address, or none
 212  *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 213  * @rowsize: number of bytes to print per line; must be 16 or 32
 214  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 215  * @buf: data blob to dump
 216  * @len: number of bytes in the @buf
 217  * @ascii: include ASCII after the hex output
 218  *
 219  * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
 220  * to the kernel log at the specified kernel log level, with an optional
 221  * leading prefix.
 222  *
 223  * print_hex_dump() works on one "line" of output at a time, i.e.,
 224  * 16 or 32 bytes of input data converted to hex + ASCII output.
 225  * print_hex_dump() iterates over the entire input @buf, breaking it into
 226  * "line size" chunks to format and print.
 227  *
 228  * E.g.:
 229  *   print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS,
 230  *                  16, 1, frame->data, frame->len, true);
 231  *
 232  * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
 233  * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 234  * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
 235  * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
 236  */
 237 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
 238                     int rowsize, int groupsize,
 239                     const void *buf, size_t len, bool ascii)
 240 {
 241         const u8 *ptr = buf;
 242         int i, linelen, remaining = len;
 243         unsigned char linebuf[32 * 3 + 2 + 32 + 1];
 244
 245         if (rowsize != 16 && rowsize != 32)
 246                 rowsize = 16;
 247
 248         for (i = 0; i < len; i += rowsize) {
 249                 linelen = min(remaining, rowsize);
 250                 remaining -= rowsize;
 251
 252                 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
 253                                    linebuf, sizeof(linebuf), ascii);
 254
 255                 switch (prefix_type) {
 256                 case DUMP_PREFIX_ADDRESS:
 257                         printk("%s%s%p: %s\n",
 258                                level, prefix_str, ptr + i, linebuf);
 259                         break;
 260                 case DUMP_PREFIX_OFFSET:
 261                         printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
 262                         break;
 263                 default:
 264                         printk("%s%s%s\n", level, prefix_str, linebuf);
 265                         break;
 266                 }
 267         }
 268 }
 269 EXPORT_SYMBOL(print_hex_dump);
 270
 271 #if !defined(CONFIG_DYNAMIC_DEBUG)
 272 /**
 273  * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 274  * @prefix_str: string to prefix each line with;
 275  *  caller supplies trailing spaces for alignment if desired
 276  * @prefix_type: controls whether prefix of an offset, address, or none
 277  *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 278  * @buf: data blob to dump
 279  * @len: number of bytes in the @buf
 280  *
 281  * Calls print_hex_dump(), with log level of KERN_DEBUG,
 282  * rowsize of 16, groupsize of 1, and ASCII output included.
 283  */
 284 void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
 285                           const void *buf, size_t len)
 286 {
 287         print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
 288                        buf, len, true);
 289 }
 290 EXPORT_SYMBOL(print_hex_dump_bytes);
 291 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
 292 #endif /* defined(CONFIG_PRINTK) */