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