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 + 3) 173 goto overflow2; 174 ch = ptr[j]; 175 linebuf[lx++] = hex_asc_hi(ch); 176 linebuf[lx++] = hex_asc_lo(ch); 177 linebuf[lx++] = ' '; 178 } 179 if (j) 180 lx--; 181 } 182 if (!ascii) 183 goto nil; 184 185 while (lx < ascii_column) { 186 if (linebuflen < lx + 2) 187 goto overflow2; 188 linebuf[lx++] = ' '; 189 } 190 for (j = 0; j < len; j++) { 191 if (linebuflen < lx + 2) 192 goto overflow2; 193 ch = ptr[j]; 194 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.'; 195 } 196 nil: 197 linebuf[lx] = '\0'; 198 return lx; 199 overflow2: 200 linebuf[lx++] = '\0'; 201 overflow1: 202 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1; 203 } 204 EXPORT_SYMBOL(hex_dump_to_buffer); 205 206 #ifdef CONFIG_PRINTK 207 /** 208 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 209 * @level: kernel log level (e.g. KERN_DEBUG) 210 * @prefix_str: string to prefix each line with; 211 * caller supplies trailing spaces for alignment if desired 212 * @prefix_type: controls whether prefix of an offset, address, or none 213 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 214 * @rowsize: number of bytes to print per line; must be 16 or 32 215 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 216 * @buf: data blob to dump 217 * @len: number of bytes in the @buf 218 * @ascii: include ASCII after the hex output 219 * 220 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 221 * to the kernel log at the specified kernel log level, with an optional 222 * leading prefix. 223 * 224 * print_hex_dump() works on one "line" of output at a time, i.e., 225 * 16 or 32 bytes of input data converted to hex + ASCII output. 226 * print_hex_dump() iterates over the entire input @buf, breaking it into 227 * "line size" chunks to format and print. 228 * 229 * E.g.: 230 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 231 * 16, 1, frame->data, frame->len, true); 232 * 233 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 234 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 235 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 236 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 237 */ 238 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 239 int rowsize, int groupsize, 240 const void *buf, size_t len, bool ascii) 241 { 242 const u8 *ptr = buf; 243 int i, linelen, remaining = len; 244 unsigned char linebuf[32 * 3 + 2 + 32 + 1]; 245 246 if (rowsize != 16 && rowsize != 32) 247 rowsize = 16; 248 249 for (i = 0; i < len; i += rowsize) { 250 linelen = min(remaining, rowsize); 251 remaining -= rowsize; 252 253 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 254 linebuf, sizeof(linebuf), ascii); 255 256 switch (prefix_type) { 257 case DUMP_PREFIX_ADDRESS: 258 printk("%s%s%p: %s\n", 259 level, prefix_str, ptr + i, linebuf); 260 break; 261 case DUMP_PREFIX_OFFSET: 262 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 263 break; 264 default: 265 printk("%s%s%s\n", level, prefix_str, linebuf); 266 break; 267 } 268 } 269 } 270 EXPORT_SYMBOL(print_hex_dump); 271 272 #if !defined(CONFIG_DYNAMIC_DEBUG) 273 /** 274 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params 275 * @prefix_str: string to prefix each line with; 276 * caller supplies trailing spaces for alignment if desired 277 * @prefix_type: controls whether prefix of an offset, address, or none 278 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 279 * @buf: data blob to dump 280 * @len: number of bytes in the @buf 281 * 282 * Calls print_hex_dump(), with log level of KERN_DEBUG, 283 * rowsize of 16, groupsize of 1, and ASCII output included. 284 */ 285 void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 286 const void *buf, size_t len) 287 { 288 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1, 289 buf, len, true); 290 } 291 EXPORT_SYMBOL(print_hex_dump_bytes); 292 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */ 293 #endif /* defined(CONFIG_PRINTK) */ 294