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 "%16.16llx ", (unsigned long long)*(ptr8 + j)); 69 ascii_column = 17 * ngroups + 2; 70 break; 71 } 72 73 case 4: { 74 const u32 *ptr4 = buf; 75 int ngroups = len / groupsize; 76 77 for (j = 0; j < ngroups; j++) 78 lx += scnprintf(linebuf + lx, linebuflen - lx, 79 "%8.8x ", *(ptr4 + j)); 80 ascii_column = 9 * ngroups + 2; 81 break; 82 } 83 84 case 2: { 85 const u16 *ptr2 = buf; 86 int ngroups = len / groupsize; 87 88 for (j = 0; j < ngroups; j++) 89 lx += scnprintf(linebuf + lx, linebuflen - lx, 90 "%4.4x ", *(ptr2 + j)); 91 ascii_column = 5 * ngroups + 2; 92 break; 93 } 94 95 default: 96 for (j = 0; (j < rowsize) && (j < len) && (lx + 4) < linebuflen; 97 j++) { 98 ch = ptr[j]; 99 linebuf[lx++] = hex_asc_hi(ch); 100 linebuf[lx++] = hex_asc_lo(ch); 101 linebuf[lx++] = ' '; 102 } 103 ascii_column = 3 * rowsize + 2; 104 break; 105 } 106 if (!ascii) 107 goto nil; 108 109 while (lx < (linebuflen - 1) && lx < (ascii_column - 1)) 110 linebuf[lx++] = ' '; 111 for (j = 0; (j < rowsize) && (j < len) && (lx + 2) < linebuflen; j++) 112 linebuf[lx++] = (isascii(ptr[j]) && isprint(ptr[j])) ? ptr[j] 113 : '.'; 114 nil: 115 linebuf[lx++] = '\0'; 116 } 117 EXPORT_SYMBOL(hex_dump_to_buffer); 118 119 /** 120 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 121 * @level: kernel log level (e.g. KERN_DEBUG) 122 * @prefix_str: string to prefix each line with; 123 * caller supplies trailing spaces for alignment if desired 124 * @prefix_type: controls whether prefix of an offset, address, or none 125 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 126 * @rowsize: number of bytes to print per line; must be 16 or 32 127 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 128 * @buf: data blob to dump 129 * @len: number of bytes in the @buf 130 * @ascii: include ASCII after the hex output 131 * 132 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 133 * to the kernel log at the specified kernel log level, with an optional 134 * leading prefix. 135 * 136 * print_hex_dump() works on one "line" of output at a time, i.e., 137 * 16 or 32 bytes of input data converted to hex + ASCII output. 138 * print_hex_dump() iterates over the entire input @buf, breaking it into 139 * "line size" chunks to format and print. 140 * 141 * E.g.: 142 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 143 * 16, 1, frame->data, frame->len, 1); 144 * 145 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 146 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 147 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 148 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 149 */ 150 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 151 int rowsize, int groupsize, 152 const void *buf, size_t len, bool ascii) 153 { 154 const u8 *ptr = buf; 155 int i, linelen, remaining = len; 156 unsigned char linebuf[200]; 157 158 if (rowsize != 16 && rowsize != 32) 159 rowsize = 16; 160 161 for (i = 0; i < len; i += rowsize) { 162 linelen = min(remaining, rowsize); 163 remaining -= rowsize; 164 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 165 linebuf, sizeof(linebuf), ascii); 166 167 switch (prefix_type) { 168 case DUMP_PREFIX_ADDRESS: 169 printk("%s%s%*p: %s\n", level, prefix_str, 170 (int)(2 * sizeof(void *)), ptr + i, linebuf); 171 break; 172 case DUMP_PREFIX_OFFSET: 173 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 174 break; 175 default: 176 printk("%s%s%s\n", level, prefix_str, linebuf); 177 break; 178 } 179 } 180 } 181 EXPORT_SYMBOL(print_hex_dump); 182 183 /** 184 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params 185 * @prefix_str: string to prefix each line with; 186 * caller supplies trailing spaces for alignment if desired 187 * @prefix_type: controls whether prefix of an offset, address, or none 188 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 189 * @buf: data blob to dump 190 * @len: number of bytes in the @buf 191 * 192 * Calls print_hex_dump(), with log level of KERN_DEBUG, 193 * rowsize of 16, groupsize of 1, and ASCII output included. 194 */ 195 void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 196 const void *buf, size_t len) 197 { 198 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1, 199 buf, len, 1); 200 } 201 EXPORT_SYMBOL(print_hex_dump_bytes); 202