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 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory 63 * @buf: data blob to dump 64 * @len: number of bytes in the @buf 65 * @rowsize: number of bytes to print per line; must be 16 or 32 66 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 67 * @linebuf: where to put the converted data 68 * @linebuflen: total size of @linebuf, including space for terminating NUL 69 * @ascii: include ASCII after the hex output 70 * 71 * hex_dump_to_buffer() works on one "line" of output at a time, i.e., 72 * 16 or 32 bytes of input data converted to hex + ASCII output. 73 * 74 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data 75 * to a hex + ASCII dump at the supplied memory location. 76 * The converted output is always NUL-terminated. 77 * 78 * E.g.: 79 * hex_dump_to_buffer(frame->data, frame->len, 16, 1, 80 * linebuf, sizeof(linebuf), true); 81 * 82 * example output buffer: 83 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 84 */ 85 void hex_dump_to_buffer(const void *buf, size_t len, int rowsize, 86 int groupsize, char *linebuf, size_t linebuflen, 87 bool ascii) 88 { 89 const u8 *ptr = buf; 90 u8 ch; 91 int j, lx = 0; 92 int ascii_column; 93 94 if (rowsize != 16 && rowsize != 32) 95 rowsize = 16; 96 97 if (!len) 98 goto nil; 99 if (len > rowsize) /* limit to one line at a time */ 100 len = rowsize; 101 if ((len % groupsize) != 0) /* no mixed size output */ 102 groupsize = 1; 103 104 switch (groupsize) { 105 case 8: { 106 const u64 *ptr8 = buf; 107 int ngroups = len / groupsize; 108 109 for (j = 0; j < ngroups; j++) 110 lx += scnprintf(linebuf + lx, linebuflen - lx, 111 "%s%16.16llx", j ? " " : "", 112 (unsigned long long)*(ptr8 + j)); 113 ascii_column = 17 * ngroups + 2; 114 break; 115 } 116 117 case 4: { 118 const u32 *ptr4 = buf; 119 int ngroups = len / groupsize; 120 121 for (j = 0; j < ngroups; j++) 122 lx += scnprintf(linebuf + lx, linebuflen - lx, 123 "%s%8.8x", j ? " " : "", *(ptr4 + j)); 124 ascii_column = 9 * ngroups + 2; 125 break; 126 } 127 128 case 2: { 129 const u16 *ptr2 = buf; 130 int ngroups = len / groupsize; 131 132 for (j = 0; j < ngroups; j++) 133 lx += scnprintf(linebuf + lx, linebuflen - lx, 134 "%s%4.4x", j ? " " : "", *(ptr2 + j)); 135 ascii_column = 5 * ngroups + 2; 136 break; 137 } 138 139 default: 140 for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) { 141 ch = ptr[j]; 142 linebuf[lx++] = hex_asc_hi(ch); 143 linebuf[lx++] = hex_asc_lo(ch); 144 linebuf[lx++] = ' '; 145 } 146 if (j) 147 lx--; 148 149 ascii_column = 3 * rowsize + 2; 150 break; 151 } 152 if (!ascii) 153 goto nil; 154 155 while (lx < (linebuflen - 1) && lx < (ascii_column - 1)) 156 linebuf[lx++] = ' '; 157 for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) { 158 ch = ptr[j]; 159 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.'; 160 } 161 nil: 162 linebuf[lx++] = '\0'; 163 } 164 EXPORT_SYMBOL(hex_dump_to_buffer); 165 166 #ifdef CONFIG_PRINTK 167 /** 168 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 169 * @level: kernel log level (e.g. KERN_DEBUG) 170 * @prefix_str: string to prefix each line with; 171 * caller supplies trailing spaces for alignment if desired 172 * @prefix_type: controls whether prefix of an offset, address, or none 173 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 174 * @rowsize: number of bytes to print per line; must be 16 or 32 175 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 176 * @buf: data blob to dump 177 * @len: number of bytes in the @buf 178 * @ascii: include ASCII after the hex output 179 * 180 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 181 * to the kernel log at the specified kernel log level, with an optional 182 * leading prefix. 183 * 184 * print_hex_dump() works on one "line" of output at a time, i.e., 185 * 16 or 32 bytes of input data converted to hex + ASCII output. 186 * print_hex_dump() iterates over the entire input @buf, breaking it into 187 * "line size" chunks to format and print. 188 * 189 * E.g.: 190 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 191 * 16, 1, frame->data, frame->len, true); 192 * 193 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 194 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 195 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 196 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 197 */ 198 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 199 int rowsize, int groupsize, 200 const void *buf, size_t len, bool ascii) 201 { 202 const u8 *ptr = buf; 203 int i, linelen, remaining = len; 204 unsigned char linebuf[32 * 3 + 2 + 32 + 1]; 205 206 if (rowsize != 16 && rowsize != 32) 207 rowsize = 16; 208 209 for (i = 0; i < len; i += rowsize) { 210 linelen = min(remaining, rowsize); 211 remaining -= rowsize; 212 213 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 214 linebuf, sizeof(linebuf), ascii); 215 216 switch (prefix_type) { 217 case DUMP_PREFIX_ADDRESS: 218 printk("%s%s%p: %s\n", 219 level, prefix_str, ptr + i, linebuf); 220 break; 221 case DUMP_PREFIX_OFFSET: 222 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 223 break; 224 default: 225 printk("%s%s%s\n", level, prefix_str, linebuf); 226 break; 227 } 228 } 229 } 230 EXPORT_SYMBOL(print_hex_dump); 231 232 #if !defined(CONFIG_DYNAMIC_DEBUG) 233 /** 234 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params 235 * @prefix_str: string to prefix each line with; 236 * caller supplies trailing spaces for alignment if desired 237 * @prefix_type: controls whether prefix of an offset, address, or none 238 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 239 * @buf: data blob to dump 240 * @len: number of bytes in the @buf 241 * 242 * Calls print_hex_dump(), with log level of KERN_DEBUG, 243 * rowsize of 16, groupsize of 1, and ASCII output included. 244 */ 245 void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 246 const void *buf, size_t len) 247 { 248 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1, 249 buf, len, true); 250 } 251 EXPORT_SYMBOL(print_hex_dump_bytes); 252 #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */ 253 #endif /* defined(CONFIG_PRINTK) */ 254