1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * lib/hexdump.c 4 */ 5 6 #include <linux/types.h> 7 #include <linux/ctype.h> 8 #include <linux/errno.h> 9 #include <linux/kernel.h> 10 #include <linux/minmax.h> 11 #include <linux/export.h> 12 #include <asm/unaligned.h> 13 14 const char hex_asc[] = "0123456789abcdef"; 15 EXPORT_SYMBOL(hex_asc); 16 const char hex_asc_upper[] = "0123456789ABCDEF"; 17 EXPORT_SYMBOL(hex_asc_upper); 18 19 /** 20 * hex_to_bin - convert a hex digit to its real value 21 * @ch: ascii character represents hex digit 22 * 23 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad 24 * input. 25 */ 26 int hex_to_bin(char ch) 27 { 28 if ((ch >= '0') && (ch <= '9')) 29 return ch - '0'; 30 ch = tolower(ch); 31 if ((ch >= 'a') && (ch <= 'f')) 32 return ch - 'a' + 10; 33 return -1; 34 } 35 EXPORT_SYMBOL(hex_to_bin); 36 37 /** 38 * hex2bin - convert an ascii hexadecimal string to its binary representation 39 * @dst: binary result 40 * @src: ascii hexadecimal string 41 * @count: result length 42 * 43 * Return 0 on success, -EINVAL in case of bad input. 44 */ 45 int hex2bin(u8 *dst, const char *src, size_t count) 46 { 47 while (count--) { 48 int hi = hex_to_bin(*src++); 49 int lo = hex_to_bin(*src++); 50 51 if ((hi < 0) || (lo < 0)) 52 return -EINVAL; 53 54 *dst++ = (hi << 4) | lo; 55 } 56 return 0; 57 } 58 EXPORT_SYMBOL(hex2bin); 59 60 /** 61 * bin2hex - convert binary data to an ascii hexadecimal string 62 * @dst: ascii hexadecimal result 63 * @src: binary data 64 * @count: binary data length 65 */ 66 char *bin2hex(char *dst, const void *src, size_t count) 67 { 68 const unsigned char *_src = src; 69 70 while (count--) 71 dst = hex_byte_pack(dst, *_src++); 72 return dst; 73 } 74 EXPORT_SYMBOL(bin2hex); 75 76 /** 77 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory 78 * @buf: data blob to dump 79 * @len: number of bytes in the @buf 80 * @rowsize: number of bytes to print per line; must be 16 or 32 81 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 82 * @linebuf: where to put the converted data 83 * @linebuflen: total size of @linebuf, including space for terminating NUL 84 * @ascii: include ASCII after the hex output 85 * 86 * hex_dump_to_buffer() works on one "line" of output at a time, i.e., 87 * 16 or 32 bytes of input data converted to hex + ASCII output. 88 * 89 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data 90 * to a hex + ASCII dump at the supplied memory location. 91 * The converted output is always NUL-terminated. 92 * 93 * E.g.: 94 * hex_dump_to_buffer(frame->data, frame->len, 16, 1, 95 * linebuf, sizeof(linebuf), true); 96 * 97 * example output buffer: 98 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 99 * 100 * Return: 101 * The amount of bytes placed in the buffer without terminating NUL. If the 102 * output was truncated, then the return value is the number of bytes 103 * (excluding the terminating NUL) which would have been written to the final 104 * string if enough space had been available. 105 */ 106 int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize, 107 char *linebuf, size_t linebuflen, bool ascii) 108 { 109 const u8 *ptr = buf; 110 int ngroups; 111 u8 ch; 112 int j, lx = 0; 113 int ascii_column; 114 int ret; 115 116 if (rowsize != 16 && rowsize != 32) 117 rowsize = 16; 118 119 if (len > rowsize) /* limit to one line at a time */ 120 len = rowsize; 121 if (!is_power_of_2(groupsize) || groupsize > 8) 122 groupsize = 1; 123 if ((len % groupsize) != 0) /* no mixed size output */ 124 groupsize = 1; 125 126 ngroups = len / groupsize; 127 ascii_column = rowsize * 2 + rowsize / groupsize + 1; 128 129 if (!linebuflen) 130 goto overflow1; 131 132 if (!len) 133 goto nil; 134 135 if (groupsize == 8) { 136 const u64 *ptr8 = buf; 137 138 for (j = 0; j < ngroups; j++) { 139 ret = snprintf(linebuf + lx, linebuflen - lx, 140 "%s%16.16llx", j ? " " : "", 141 get_unaligned(ptr8 + j)); 142 if (ret >= linebuflen - lx) 143 goto overflow1; 144 lx += ret; 145 } 146 } else if (groupsize == 4) { 147 const u32 *ptr4 = buf; 148 149 for (j = 0; j < ngroups; j++) { 150 ret = snprintf(linebuf + lx, linebuflen - lx, 151 "%s%8.8x", j ? " " : "", 152 get_unaligned(ptr4 + j)); 153 if (ret >= linebuflen - lx) 154 goto overflow1; 155 lx += ret; 156 } 157 } else if (groupsize == 2) { 158 const u16 *ptr2 = buf; 159 160 for (j = 0; j < ngroups; j++) { 161 ret = snprintf(linebuf + lx, linebuflen - lx, 162 "%s%4.4x", j ? " " : "", 163 get_unaligned(ptr2 + j)); 164 if (ret >= linebuflen - lx) 165 goto overflow1; 166 lx += ret; 167 } 168 } else { 169 for (j = 0; j < len; j++) { 170 if (linebuflen < lx + 2) 171 goto overflow2; 172 ch = ptr[j]; 173 linebuf[lx++] = hex_asc_hi(ch); 174 if (linebuflen < lx + 2) 175 goto overflow2; 176 linebuf[lx++] = hex_asc_lo(ch); 177 if (linebuflen < lx + 2) 178 goto overflow2; 179 linebuf[lx++] = ' '; 180 } 181 if (j) 182 lx--; 183 } 184 if (!ascii) 185 goto nil; 186 187 while (lx < ascii_column) { 188 if (linebuflen < lx + 2) 189 goto overflow2; 190 linebuf[lx++] = ' '; 191 } 192 for (j = 0; j < len; j++) { 193 if (linebuflen < lx + 2) 194 goto overflow2; 195 ch = ptr[j]; 196 linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.'; 197 } 198 nil: 199 linebuf[lx] = '\0'; 200 return lx; 201 overflow2: 202 linebuf[lx++] = '\0'; 203 overflow1: 204 return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1; 205 } 206 EXPORT_SYMBOL(hex_dump_to_buffer); 207 208 #ifdef CONFIG_PRINTK 209 /** 210 * print_hex_dump - print a text hex dump to syslog for a binary blob of data 211 * @level: kernel log level (e.g. KERN_DEBUG) 212 * @prefix_str: string to prefix each line with; 213 * caller supplies trailing spaces for alignment if desired 214 * @prefix_type: controls whether prefix of an offset, address, or none 215 * is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE) 216 * @rowsize: number of bytes to print per line; must be 16 or 32 217 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1) 218 * @buf: data blob to dump 219 * @len: number of bytes in the @buf 220 * @ascii: include ASCII after the hex output 221 * 222 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump 223 * to the kernel log at the specified kernel log level, with an optional 224 * leading prefix. 225 * 226 * print_hex_dump() works on one "line" of output at a time, i.e., 227 * 16 or 32 bytes of input data converted to hex + ASCII output. 228 * print_hex_dump() iterates over the entire input @buf, breaking it into 229 * "line size" chunks to format and print. 230 * 231 * E.g.: 232 * print_hex_dump(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, 233 * 16, 1, frame->data, frame->len, true); 234 * 235 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode: 236 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO 237 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode: 238 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c pqrstuvwxyz{|}~. 239 */ 240 void print_hex_dump(const char *level, const char *prefix_str, int prefix_type, 241 int rowsize, int groupsize, 242 const void *buf, size_t len, bool ascii) 243 { 244 const u8 *ptr = buf; 245 int i, linelen, remaining = len; 246 unsigned char linebuf[32 * 3 + 2 + 32 + 1]; 247 248 if (rowsize != 16 && rowsize != 32) 249 rowsize = 16; 250 251 for (i = 0; i < len; i += rowsize) { 252 linelen = min(remaining, rowsize); 253 remaining -= rowsize; 254 255 hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, 256 linebuf, sizeof(linebuf), ascii); 257 258 switch (prefix_type) { 259 case DUMP_PREFIX_ADDRESS: 260 printk("%s%s%p: %s\n", 261 level, prefix_str, ptr + i, linebuf); 262 break; 263 case DUMP_PREFIX_OFFSET: 264 printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf); 265 break; 266 default: 267 printk("%s%s%s\n", level, prefix_str, linebuf); 268 break; 269 } 270 } 271 } 272 EXPORT_SYMBOL(print_hex_dump); 273 274 #endif /* defined(CONFIG_PRINTK) */ 275