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 /** 16 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory 17 * @buf: data blob to dump 18 * @len: number of bytes in the @buf 19 * @rowsize: number of bytes to print per line; must be 16 or 32 20 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 21 * @linebuf: where to put the converted data 22 * @linebuflen: total size of @linebuf, including space for terminating NUL 23 * @ascii: include ASCII after the hex output 24 * 25 * hex_dump_to_buffer() works on one "line" of output at a time, i.e., 26 * 16 or 32 bytes of input data converted to hex + ASCII output. 27 * 28 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data 29 * to a hex + ASCII dump at the supplied memory location. 30 * The converted output is always NUL-terminated. 31 * 32 * E.g.: 33 * hex_dump_to_buffer(frame->data, frame->len, 16, 1, 34 * linebuf, sizeof(linebuf), 1); 35 * 36 * example output buffer: 37 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 38 */ 39 void hex_dump_to_buffer(const void *buf, size_t len, int rowsize, 40 int groupsize, char *linebuf, size_t linebuflen, 41 bool ascii) 42 { 43 const u8 *ptr = buf; 44 u8 ch; 45 int j, lx = 0; 46 int ascii_column; 47 48 if (rowsize != 16 && rowsize != 32) 49 rowsize = 16; 50 51 if (!len) 52 goto nil; 53 if (len > rowsize) /* limit to one line at a time */ 54 len = rowsize; 55 if ((len % groupsize) != 0) /* no mixed size output */ 56 groupsize = 1; 57 58 switch (groupsize) { 59 case 8: { 60 const u64 *ptr8 = buf; 61 int ngroups = len / groupsize; 62 63 for (j = 0; j < ngroups; j++) 64 lx += scnprintf(linebuf + lx, linebuflen - lx, 65 "%16.16llx ", (unsigned long long)*(ptr8 + j)); 66 ascii_column = 17 * ngroups + 2; 67 break; 68 } 69 70 case 4: { 71 const u32 *ptr4 = buf; 72 int ngroups = len / groupsize; 73 74 for (j = 0; j < ngroups; j++) 75 lx += scnprintf(linebuf + lx, linebuflen - lx, 76 "%8.8x ", *(ptr4 + j)); 77 ascii_column = 9 * ngroups + 2; 78 break; 79 } 80 81 case 2: { 82 const u16 *ptr2 = buf; 83 int ngroups = len / groupsize; 84 85 for (j = 0; j < ngroups; j++) 86 lx += scnprintf(linebuf + lx, linebuflen - lx, 87 "%4.4x ", *(ptr2 + j)); 88 ascii_column = 5 * ngroups + 2; 89 break; 90 } 91 92 default: 93 for (j = 0; (j < rowsize) && (j < len) && (lx + 4) < linebuflen; 94 j++) { 95 ch = ptr[j]; 96 linebuf[lx++] = hex_asc(ch >> 4); 97 linebuf[lx++] = hex_asc(ch & 0x0f); 98 linebuf[lx++] = ' '; 99 } 100 ascii_column = 3 * rowsize + 2; 101 break; 102 } 103 if (!ascii) 104 goto nil; 105 106 while (lx < (linebuflen - 1) && lx < (ascii_column - 1)) 107 linebuf[lx++] = ' '; 108 for (j = 0; (j < rowsize) && (j < len) && (lx + 2) < linebuflen; j++) 109 linebuf[lx++] = isprint(ptr[j]) ? ptr[j] : '.'; 110 nil: 111 linebuf[lx++] = '\0'; 112 } 113 EXPORT_SYMBOL(hex_dump_to_buffer); 114 115 /** 116 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 117 * @level: kernel log level (e.g. KERN_DEBUG) 118 * @prefix_str: string to prefix each line with; 119 * caller supplies trailing spaces for alignment if desired 120 * @prefix_type: controls whether prefix of an offset, address, or none 121 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 122 * @rowsize: number of bytes to print per line; must be 16 or 32 123 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 124 * @buf: data blob to dump 125 * @len: number of bytes in the @buf 126 * @ascii: include ASCII after the hex output 127 * 128 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 129 * to the kernel log at the specified kernel log level, with an optional 130 * leading prefix. 131 * 132 * print_hex_dump() works on one "line" of output at a time, i.e., 133 * 16 or 32 bytes of input data converted to hex + ASCII output. 134 * print_hex_dump() iterates over the entire input @buf, breaking it into 135 * "line size" chunks to format and print. 136 * 137 * E.g.: 138 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 139 * 16, 1, frame->data, frame->len, 1); 140 * 141 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 142 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 143 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 144 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 145 */ 146 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 147 int rowsize, int groupsize, 148 const void *buf, size_t len, bool ascii) 149 { 150 const u8 *ptr = buf; 151 int i, linelen, remaining = len; 152 unsigned char linebuf[200]; 153 154 if (rowsize != 16 && rowsize != 32) 155 rowsize = 16; 156 157 for (i = 0; i < len; i += rowsize) { 158 linelen = min(remaining, rowsize); 159 remaining -= rowsize; 160 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 161 linebuf, sizeof(linebuf), ascii); 162 163 switch (prefix_type) { 164 case DUMP_PREFIX_ADDRESS: 165 printk("%s%s%*p: %s\n", level, prefix_str, 166 (int)(2 * sizeof(void *)), ptr + i, linebuf); 167 break; 168 case DUMP_PREFIX_OFFSET: 169 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 170 break; 171 default: 172 printk("%s%s%s\n", level, prefix_str, linebuf); 173 break; 174 } 175 } 176 } 177 EXPORT_SYMBOL(print_hex_dump); 178 179 /** 180 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params 181 * @prefix_str: string to prefix each line with; 182 * caller supplies trailing spaces for alignment if desired 183 * @prefix_type: controls whether prefix of an offset, address, or none 184 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 185 * @buf: data blob to dump 186 * @len: number of bytes in the @buf 187 * 188 * Calls print_hex_dump(), with log level of KERN_DEBUG, 189 * rowsize of 16, groupsize of 1, and ASCII output included. 190 */ 191 void print_hex_dump_bytes(const char *prefix_str, int prefix_type, 192 const void *buf, size_t len) 193 { 194 print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1, 195 buf, len, 1); 196 } 197 EXPORT_SYMBOL(print_hex_dump_bytes); 198