include/hexdump.h

/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (C) 2018 Synopsys, Inc. All rights reserved.
 *
 */

#ifndef HEXDUMP_H
#define HEXDUMP_H

#include <linux/ctype.h>
#include <linux/types.h>

enum dump_prefix_t {
	DUMP_PREFIX_NONE,
	DUMP_PREFIX_ADDRESS,
	DUMP_PREFIX_OFFSET
};

extern const char hex_asc[];
#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]

static inline char *hex_byte_pack(char *buf, u8 byte)
{
	*buf++ = hex_asc_hi(byte);
	*buf++ = hex_asc_lo(byte);
	return buf;
}

/**
 * hex_to_bin - convert a hex digit to its real value
 * @ch: ascii character represents hex digit
 *
 * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
 * input.
 */
static inline int hex_to_bin(char ch)
{
	if ((ch >= '0') && (ch <= '9'))
		return ch - '0';
	ch = tolower(ch);
	if ((ch >= 'a') && (ch <= 'f'))
		return ch - 'a' + 10;
	return -1;
}

/**
 * hex2bin - convert an ascii hexadecimal string to its binary representation
 * @dst: binary result
 * @src: ascii hexadecimal string
 * @count: result length
 *
 * Return 0 on success, -1 in case of bad input.
 */
static inline int hex2bin(u8 *dst, const char *src, size_t count)
{
	while (count--) {
		int hi = hex_to_bin(*src++);
		int lo = hex_to_bin(*src++);

		if ((hi < 0) || (lo < 0))
			return -1;

		*dst++ = (hi << 4) | lo;
	}
	return 0;
}

/**
 * bin2hex - convert binary data to an ascii hexadecimal string
 * @dst: ascii hexadecimal result
 * @src: binary data
 * @count: binary data length
 */
static inline char *bin2hex(char *dst, const void *src, size_t count)
{
	const unsigned char *_src = src;

	while (count--)
		dst = hex_byte_pack(dst, *_src++);
	return dst;
}

/**
 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 * @rowsize: number of bytes to print per line; must be 16 or 32
 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 * @linebuf: where to put the converted data
 * @linebuflen: total size of @linebuf, including space for terminating NUL
 * @ascii: include ASCII after the hex output
 *
 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
 * 16 or 32 bytes of input data converted to hex + ASCII output.
 *
 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
 * to a hex + ASCII dump at the supplied memory location.
 * The converted output is always NUL-terminated.
 *
 * E.g.:
 *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
 *			linebuf, sizeof(linebuf), true);
 *
 * example output buffer:
 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 *
 * Return:
 * The amount of bytes placed in the buffer without terminating NUL. If the
 * output was truncated, then the return value is the number of bytes
 * (excluding the terminating NUL) which would have been written to the final
 * string if enough space had been available.
 */
int hex_dump_to_buffer(const void *buf, size_t len, int rowsize, int groupsize,
		       char *linebuf, size_t linebuflen, bool ascii);

/**
 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
 * @prefix_str: string to prefix each line with;
 *  caller supplies trailing spaces for alignment if desired
 * @prefix_type: controls whether prefix of an offset, address, or none
 *  is printed (see enum dump_prefix_t)
 * @rowsize: number of bytes to print per line; must be 16 or 32
 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 * @ascii: include ASCII after the hex output
 *
 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
 * to the stdio, with an optional leading prefix.
 *
 * print_hex_dump() works on one "line" of output at a time, i.e.,
 * 16 or 32 bytes of input data converted to hex + ASCII output.
 * print_hex_dump() iterates over the entire input @buf, breaking it into
 * "line size" chunks to format and print.
 *
 * E.g.:
 *   print_hex_dump("raw data: ", DUMP_PREFIX_ADDRESS, 16, 1, frame->data,
 *                  frame->len, true);
 *
 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
 */
void print_hex_dump(const char *prefix_str, int prefix_type, int rowsize,
		    int groupsize, const void *buf, size_t len, bool ascii);

/**
 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 * @prefix_str: string to prefix each line with;
 *  caller supplies trailing spaces for alignment if desired
 * @prefix_type: controls whether prefix of an offset, address, or none
 *  is printed (see enum dump_prefix_t)
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 *
 * Calls print_hex_dump(), rowsize of 16, groupsize of 1,
 * and ASCII output included.
 */
void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
			  const void *buf, size_t len);

#endif /* HEXDUMP_H */