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/module.h> 14 15 const char hex_asc[] = "0123456789abcdef"; 16 EXPORT_SYMBOL(hex_asc); 17 18 /** 19 * hex_to_bin - convert a hex digit to its real value 20 * @ch: ascii character represents hex digit 21 * 22 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad 23 * input. 24 */ 25 int hex_to_bin(char ch) 26 { 27 if ((ch >= '0') && (ch <= '9')) 28 return ch - '0'; 29 ch = tolower(ch); 30 if ((ch >= 'a') && (ch <= 'f')) 31 return ch - 'a' + 10; 32 return -1; 33 } 34 EXPORT_SYMBOL(hex_to_bin); 35 36 /** 37 * hex2bin - convert an ascii hexadecimal string to its binary representation 38 * @dst: binary result 39 * @src: ascii hexadecimal string 40 * @count: result length 41 */ 42 void hex2bin(u8 *dst, const char *src, size_t count) 43 { 44 while (count--) { 45 *dst = hex_to_bin(*src++) << 4; 46 *dst += hex_to_bin(*src++); 47 dst++; 48 } 49 } 50 EXPORT_SYMBOL(hex2bin); 51 52 /** 53 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory 54 * @buf: data blob to dump 55 * @len: number of bytes in the @buf 56 * @rowsize: number of bytes to print per line; must be 16 or 32 57 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 58 * @linebuf: where to put the converted data 59 * @linebuflen: total size of @linebuf, including space for terminating NUL 60 * @ascii: include ASCII after the hex output 61 * 62 * hex_dump_to_buffer() works on one "line" of output at a time, i.e., 63 * 16 or 32 bytes of input data converted to hex + ASCII output. 64 * 65 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data 66 * to a hex + ASCII dump at the supplied memory location. 67 * The converted output is always NUL-terminated. 68 * 69 * E.g.: 70 * hex_dump_to_buffer(frame->data, frame->len, 16, 1, 71 * linebuf, sizeof(linebuf), true); 72 * 73 * example output buffer: 74 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 75 */ 76 void hex_dump_to_buffer(const void *buf, size_t len, int rowsize, 77 int groupsize, char *linebuf, size_t linebuflen, 78 bool ascii) 79 { 80 const u8 *ptr = buf; 81 u8 ch; 82 int j, lx = 0; 83 int ascii_column; 84 85 if (rowsize != 16 && rowsize != 32) 86 rowsize = 16; 87 88 if (!len) 89 goto nil; 90 if (len > rowsize) /* limit to one line at a time */ 91 len = rowsize; 92 if ((len % groupsize) != 0) /* no mixed size output */ 93 groupsize = 1; 94 95 switch (groupsize) { 96 case 8: { 97 const u64 *ptr8 = buf; 98 int ngroups = len / groupsize; 99 100 for (j = 0; j < ngroups; j++) 101 lx += scnprintf(linebuf + lx, linebuflen - lx, 102 "%s%16.16llx", j ? " " : "", 103 (unsigned long long)*(ptr8 + j)); 104 ascii_column = 17 * ngroups + 2; 105 break; 106 } 107 108 case 4: { 109 const u32 *ptr4 = buf; 110 int ngroups = len / groupsize; 111 112 for (j = 0; j < ngroups; j++) 113 lx += scnprintf(linebuf + lx, linebuflen - lx, 114 "%s%8.8x", j ? " " : "", *(ptr4 + j)); 115 ascii_column = 9 * ngroups + 2; 116 break; 117 } 118 119 case 2: { 120 const u16 *ptr2 = buf; 121 int ngroups = len / groupsize; 122 123 for (j = 0; j < ngroups; j++) 124 lx += scnprintf(linebuf + lx, linebuflen - lx, 125 "%s%4.4x", j ? " " : "", *(ptr2 + j)); 126 ascii_column = 5 * ngroups + 2; 127 break; 128 } 129 130 default: 131 for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) { 132 ch = ptr[j]; 133 linebuf[lx++] = hex_asc_hi(ch); 134 linebuf[lx++] = hex_asc_lo(ch); 135 linebuf[lx++] = ' '; 136 } 137 if (j) 138 lx--; 139 140 ascii_column = 3 * rowsize + 2; 141 break; 142 } 143 if (!ascii) 144 goto nil; 145 146 while (lx < (linebuflen - 1) && lx < (ascii_column - 1)) 147 linebuf[lx++] = ' '; 148 for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) { 149 ch = ptr[j]; 150 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.'; 151 } 152 nil: 153 linebuf[lx++] = '\0'; 154 } 155 EXPORT_SYMBOL(hex_dump_to_buffer); 156 157 /** 158 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 159 * @level: kernel log level (e.g. KERN_DEBUG) 160 * @prefix_str: string to prefix each line with; 161 * caller supplies trailing spaces for alignment if desired 162 * @prefix_type: controls whether prefix of an offset, address, or none 163 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 164 * @rowsize: number of bytes to print per line; must be 16 or 32 165 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 166 * @buf: data blob to dump 167 * @len: number of bytes in the @buf 168 * @ascii: include ASCII after the hex output 169 * 170 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 171 * to the kernel log at the specified kernel log level, with an optional 172 * leading prefix. 173 * 174 * print_hex_dump() works on one "line" of output at a time, i.e., 175 * 16 or 32 bytes of input data converted to hex + ASCII output. 176 * print_hex_dump() iterates over the entire input @buf, breaking it into 177 * "line size" chunks to format and print. 178 * 179 * E.g.: 180 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 181 * 16, 1, frame->data, frame->len, true); 182 * 183 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 184 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 185 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 186 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 187 */ 188 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 189 int rowsize, int groupsize, 190 const void *buf, size_t len, bool ascii) 191 { 192 const u8 *ptr = buf; 193 int i, linelen, remaining = len; 194 unsigned char linebuf[32 * 3 + 2 + 32 + 1]; 195 196 if (rowsize != 16 && rowsize != 32) 197 rowsize = 16; 198 199 for (i = 0; i < len; i += rowsize) { 200 linelen = min(remaining, rowsize); 201 remaining -= rowsize; 202 203 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 204 linebuf, sizeof(linebuf), ascii); 205 206 switch (prefix_type) { 207 case DUMP_PREFIX_ADDRESS: 208 printk("%s%s%p: %s\n", 209 level, prefix_str, ptr + i, linebuf); 210 break; 211 case DUMP_PREFIX_OFFSET: 212 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 213 break; 214 default: 215 printk("%s%s%s\n", level, prefix_str, linebuf); 216 break; 217 } 218 } 219 } 220 EXPORT_SYMBOL(print_hex_dump); 221 222 /** 223 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params 224 * @prefix_str: string to prefix each line with; 225 * caller supplies trailing spaces for alignment if desired 226 * @prefix_type: controls whether prefix of an offset, address, or none 227 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 228 * @buf: data blob to dump 229 * @len: number of bytes in the @buf 230 * 231 * Calls print_hex_dump(), with log level of KERN_DEBUG, 232 * rowsize of 16, groupsize of 1, and ASCII output included. 233 */ 234 void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 235 const void *buf, size_t len) 236 { 237 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1, 238 buf, len, true); 239 } 240 EXPORT_SYMBOL(print_hex_dump_bytes); 241