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