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) */ 299