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) */ 293