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