/*
   * lib/hexdump.c
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation. See README and COPYING for
   * more details.
   */
  
  #include <linux/types.h>
  #include <linux/ctype.h>
  #include <linux/kernel.h>

  #include <linux/export.h>

  #include <asm/unaligned.h>

  const char hex_asc[] = "0123456789abcdef";
  EXPORT_SYMBOL(hex_asc);

  const char hex_asc_upper[] = "0123456789ABCDEF";
  EXPORT_SYMBOL(hex_asc_upper);

  /**

   * 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.
   */
  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;
  }
  EXPORT_SYMBOL(hex_to_bin);
  
  /**

   * 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.

   */

  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;

  }
  EXPORT_SYMBOL(hex2bin);
  
  /**

   * bin2hex - convert binary data to an ascii hexadecimal string
   * @dst: ascii hexadecimal result
   * @src: binary data
   * @count: binary data length
   */
  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;
  }
  EXPORT_SYMBOL(bin2hex);
  
  /**

   * 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)

  {
  	const u8 *ptr = buf;

  	int ngroups;

  	u8 ch;
  	int j, lx = 0;

  	int ascii_column;

  	int ret;

  	if (rowsize != 16 && rowsize != 32)
  		rowsize = 16;

  	if (len > rowsize)		/* limit to one line at a time */
  		len = rowsize;

  	if (!is_power_of_2(groupsize) || groupsize > 8)
  		groupsize = 1;

  	if ((len % groupsize) != 0)	/* no mixed size output */
  		groupsize = 1;

  	ngroups = len / groupsize;
  	ascii_column = rowsize * 2 + rowsize / groupsize + 1;

  
  	if (!linebuflen)
  		goto overflow1;
  
  	if (!len)
  		goto nil;

  	if (groupsize == 8) {

  		const u64 *ptr8 = buf;

  		for (j = 0; j < ngroups; j++) {
  			ret = snprintf(linebuf + lx, linebuflen - lx,
  				       "%s%16.16llx", j ? " " : "",

  				       get_unaligned(ptr8 + j));

  			if (ret >= linebuflen - lx)
  				goto overflow1;
  			lx += ret;
  		}

  	} else if (groupsize == 4) {

  		const u32 *ptr4 = buf;

  		for (j = 0; j < ngroups; j++) {
  			ret = snprintf(linebuf + lx, linebuflen - lx,
  				       "%s%8.8x", j ? " " : "",

  				       get_unaligned(ptr4 + j));

  			if (ret >= linebuflen - lx)
  				goto overflow1;
  			lx += ret;
  		}

  	} else if (groupsize == 2) {

  		const u16 *ptr2 = buf;

  		for (j = 0; j < ngroups; j++) {
  			ret = snprintf(linebuf + lx, linebuflen - lx,
  				       "%s%4.4x", j ? " " : "",

  				       get_unaligned(ptr2 + j));

  			if (ret >= linebuflen - lx)
  				goto overflow1;
  			lx += ret;
  		}

  	} else {

  		for (j = 0; j < len; j++) {

  			if (linebuflen < lx + 2)

  				goto overflow2;

  			ch = ptr[j];

  			linebuf[lx++] = hex_asc_hi(ch);

  			if (linebuflen < lx + 2)
  				goto overflow2;

  			linebuf[lx++] = hex_asc_lo(ch);

  			if (linebuflen < lx + 2)
  				goto overflow2;

  			linebuf[lx++] = ' ';

  		}

  		if (j)
  			lx--;

  	}

  	if (!ascii)
  		goto nil;

  	while (lx < ascii_column) {
  		if (linebuflen < lx + 2)
  			goto overflow2;

  		linebuf[lx++] = ' ';

  	}
  	for (j = 0; j < len; j++) {
  		if (linebuflen < lx + 2)
  			goto overflow2;

  		ch = ptr[j];
  		linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
  	}

  nil:

  	linebuf[lx] = '\0';
  	return lx;
  overflow2:

  	linebuf[lx++] = '\0';

  overflow1:
  	return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;

  }
  EXPORT_SYMBOL(hex_dump_to_buffer);

  #ifdef CONFIG_PRINTK

  /**
   * print_hex_dump - print a text hex dump to syslog for a binary blob of data
   * @level: kernel log level (e.g. KERN_DEBUG)

   * @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 (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)

   * @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 kernel log at the specified kernel log level, 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(KERN_DEBUG, "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 *level, const char *prefix_str, int prefix_type,

  		    int rowsize, int groupsize,
  		    const void *buf, size_t len, bool ascii)

  {

  	const u8 *ptr = buf;

  	int i, linelen, remaining = len;

  	unsigned char linebuf[32 * 3 + 2 + 32 + 1];

  	if (rowsize != 16 && rowsize != 32)
  		rowsize = 16;
  
  	for (i = 0; i < len; i += rowsize) {
  		linelen = min(remaining, rowsize);
  		remaining -= rowsize;

  		hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,

  				   linebuf, sizeof(linebuf), ascii);

  
  		switch (prefix_type) {
  		case DUMP_PREFIX_ADDRESS:

  			printk("%s%s%p: %s
  ",
  			       level, prefix_str, ptr + i, linebuf);

  			break;
  		case DUMP_PREFIX_OFFSET:

  			printk("%s%s%.8x: %s
  ", level, prefix_str, i, linebuf);

  			break;
  		default:

  			printk("%s%s%s
  ", level, prefix_str, linebuf);

  			break;
  		}
  	}
  }
  EXPORT_SYMBOL(print_hex_dump);

  #if !defined(CONFIG_DYNAMIC_DEBUG)

  /**
   * 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 (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
   * @buf: data blob to dump
   * @len: number of bytes in the @buf
   *
   * Calls print_hex_dump(), with log level of KERN_DEBUG,
   * 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)

  {
  	print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,

  		       buf, len, true);

  }
  EXPORT_SYMBOL(print_hex_dump_bytes);

  #endif /* !defined(CONFIG_DYNAMIC_DEBUG) */
  #endif /* defined(CONFIG_PRINTK) */