1 // SPDX-License-Identifier: GPL-2.0-only
20  * hex_to_bin - convert a hex digit to its real value
21  * @ch: ascii character represents hex digit
23  * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
30  * (ch - '9' - 1) is negative if ch <= '9'
31  * ('0' - 1 - ch) is negative if ch >= '0'
32  * we "and" these two values, so the result is negative if ch is in the range
34  * we are only interested in the sign, so we do a shift ">> 8"; note that right
35  *	shift of a negative value is implementation-defined, so we cast the
36  *	value to (unsigned) before the shift --- we have 0xffffff if ch is in
38  * we "and" this value with (ch - '0' + 1) --- we have a value 1 ... 10 if ch is
40  * we add this value to -1 --- we have a value 0 ... 9 if ch is in the range '0'
41  *	... '9', -1 otherwise
43  *	uppercase and lowercase letters, so we use (ch & 0xdf), which converts
46 int hex_to_bin(unsigned char ch)  in hex_to_bin()  argument
48 	unsigned char cu = ch & 0xdf;  in hex_to_bin()
49 	return -1 +  in hex_to_bin()
50 		((ch - '0' +  1) & (unsigned)((ch - '9' - 1) & ('0' - 1 - ch)) >> 8) +  in hex_to_bin()
51 		((cu - 'A' + 11) & (unsigned)((cu - 'F' - 1) & ('A' - 1 - cu)) >> 8);  in hex_to_bin()
56  * hex2bin - convert an ascii hexadecimal string to its binary representation
61  * Return 0 on success, -EINVAL in case of bad input.
65 	while (count--) {  in hex2bin()
70 			return -EINVAL;  in hex2bin()
73 			return -EINVAL;  in hex2bin()
82  * bin2hex - convert binary data to an ascii hexadecimal string
91 	while (count--)  in bin2hex()
98  * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
102  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
112  * The converted output is always NUL-terminated.
115  *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
132 	u8 ch;  in hex_dump_to_buffer()  local
142 	if (!is_power_of_2(groupsize) || groupsize > 8)  in hex_dump_to_buffer()
156 	if (groupsize == 8) {  in hex_dump_to_buffer()
160 			ret = snprintf(linebuf + lx, linebuflen - lx,  in hex_dump_to_buffer()
163 			if (ret >= linebuflen - lx)  in hex_dump_to_buffer()
171 			ret = snprintf(linebuf + lx, linebuflen - lx,  in hex_dump_to_buffer()
174 			if (ret >= linebuflen - lx)  in hex_dump_to_buffer()
182 			ret = snprintf(linebuf + lx, linebuflen - lx,  in hex_dump_to_buffer()
185 			if (ret >= linebuflen - lx)  in hex_dump_to_buffer()
193 			ch = ptr[j];  in hex_dump_to_buffer()
194 			linebuf[lx++] = hex_asc_hi(ch);  in hex_dump_to_buffer()
197 			linebuf[lx++] = hex_asc_lo(ch);  in hex_dump_to_buffer()
203 			lx--;  in hex_dump_to_buffer()
216 		ch = ptr[j];  in hex_dump_to_buffer()
217 		linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';  in hex_dump_to_buffer()
225 	return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;  in hex_dump_to_buffer()
231  * print_hex_dump - print a text hex dump to syslog for a binary blob of data
238  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
254  *		    16, 1, frame->data, frame->len, true);
256  * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
258  * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
274 		remaining -= rowsize;  in print_hex_dump()
285 			printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);  in print_hex_dump()