// SPDX-License-Identifier: GPL-2.0+

/*

 * EFI Unicode collation protocol

 *

 * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>

 */

#define LOG_CATEGORY LOGC_EFI

#include <charset.h>

#include <cp1250.h>

#include <cp437.h>

#include <efi_loader.h>

/* Characters that may not be used in FAT 8.3 file names */

static const char illegal[] = "+,<=>:;\"/\\|?*[]\x7f";

/*

 * EDK2 assumes codepage 1250 when creating FAT 8.3 file names.

 * Linux defaults to codepage 437 for FAT 8.3 file names.

 */

#if CONFIG_FAT_DEFAULT_CODEPAGE == 1250

/* Unicode code points for code page 1250 characters 0x80 - 0xff */

static const u16 codepage[] = CP1250;

#else

/* Unicode code points for code page 437 characters 0x80 - 0xff */

static const u16 *codepage = codepage_437;

#endif

/* GUID of the EFI_UNICODE_COLLATION_PROTOCOL2 */

const efi_guid_t efi_guid_unicode_collation_protocol2 =

  EFI_UNICODE_COLLATION_PROTOCOL2_GUID;

/**

 * efi_stri_coll() - compare utf-16 strings case-insenitively

 *

 * @this: unicode collation protocol instance

 * @s1:   first string

 * @s2:   second string

 *

 * This function implements the StriColl() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 *

 * See the Unified Extensible Firmware Interface (UEFI) specification for

 * details.

 *

 * Return:  0: s1 == s2, > 0: s1 > s2, < 0: s1 < s2

 */

static efi_intn_t EFIAPI efi_stri_coll(

    struct efi_unicode_collation_protocol *this, u16 *s1, u16 *s2)

{

  s32 c1, c2;

  efi_intn_t ret = 0;

  EFI_ENTRY("%p, %ls, %ls", this, s1, s2);

  for (; *s1 | *s2; ++s1, ++s2) {

    c1 = utf_to_upper(*s1);

    c2 = utf_to_upper(*s2);

    if (c1 < c2) {

      ret = -1;

      goto out;

    } else if (c1 > c2) {

      ret = 1;

      goto out;

    }

  }

out:

  EFI_EXIT(EFI_SUCCESS);

  return ret;

}

/**

 * next_lower() - get next codepoint converted to lower case

 *

 * @string: pointer to u16 string, on return advanced by one codepoint

 * Return:  first codepoint of string converted to lower case

 */

static s32 next_lower(const u16 **string)

{

  return utf_to_lower(utf16_get(string));

}

/**

 * metai_match() - compare utf-16 string with a pattern string case-insenitively

 *

 * @string: string to compare

 * @pattern:  pattern string

 *

 * The pattern string may use these:

 *  - * matches >= 0 characters

 *  - ? matches 1 character

 *  - [<char1><char2>...<charN>] match any character in the set

 *  - [<char1>-<char2>] matches any character in the range

 *

 * This function is called my efi_metai_match().

 *

 * For '*' pattern searches this function calls itself recursively.

 * Performance-wise this is suboptimal, especially for multiple '*' wildcards.

 * But it results in simple code.

 *

 * Return:  true if the string is matched.

 */

static bool metai_match(const u16 *string, const u16 *pattern)

{

  s32 first, s, p;

  for (; *string && *pattern;) {

    const u16 *string_old = string;

    s = next_lower(&string);

    p = next_lower(&pattern);

    switch (p) {

    case '*':

      /* Match 0 or more characters */

      for (;; s = next_lower(&string)) {

        if (metai_match(string_old, pattern))

          return true;

        if (!s)

          return false;

        string_old = string;

      }

    case '?':

      /* Match any one character */

      break;

    case '[':

      /* Match any character in the set */

      p = next_lower(&pattern);

      first = p;

      if (first == ']')

        /* Empty set */

        return false;

      p = next_lower(&pattern);

      if (p == '-') {

        /* Range */

        p = next_lower(&pattern);

        if (s < first || s > p)

          return false;

        p = next_lower(&pattern);

        if (p != ']')

          return false;

      } else {

        /* Set */

        bool hit = false;

        if (s == first)

          hit = true;

        for (; p && p != ']';

             p = next_lower(&pattern)) {

          if (p == s)

            hit = true;

        }

        if (!hit || p != ']')

          return false;

      }

      break;

    default:

      /* Match one character */

      if (p != s)

        return false;

    }

  }

  if (!*pattern && !*string)

    return true;

  return false;

}

/**

 * efi_metai_match() - compare utf-16 string with a pattern string

 *           case-insenitively

 *

 * @this: unicode collation protocol instance

 * @string: string to compare

 * @pattern:  pattern string

 *

 * The pattern string may use these:

 *  - * matches >= 0 characters

 *  - ? matches 1 character

 *  - [<char1><char2>...<charN>] match any character in the set

 *  - [<char1>-<char2>] matches any character in the range

 *

 * This function implements the MetaMatch() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 *

 * Return:  true if the string is matched.

 */

static bool EFIAPI efi_metai_match(struct efi_unicode_collation_protocol *this,

           const u16 *string, const u16 *pattern)

{

  bool ret;

  EFI_ENTRY("%p, %ls, %ls", this, string, pattern);

  ret =  metai_match(string, pattern);

  EFI_EXIT(EFI_SUCCESS);

  return ret;

}

/**

 * efi_str_lwr() - convert to lower case

 *

 * @this: unicode collation protocol instance

 * @string: string to convert

 *

 * The conversion is done in place. As long as upper and lower letters use the

 * same number of words this does not pose a problem.

 *

 * This function implements the StrLwr() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 */

static void EFIAPI efi_str_lwr(struct efi_unicode_collation_protocol *this,

             u16 *string)

{

  EFI_ENTRY("%p, %ls", this, string);

  for (; *string; ++string)

    *string = utf_to_lower(*string);

  EFI_EXIT(EFI_SUCCESS);

}

/**

 * efi_str_upr() - convert to upper case

 *

 * @this: unicode collation protocol instance

 * @string: string to convert

 *

 * The conversion is done in place. As long as upper and lower letters use the

 * same number of words this does not pose a problem.

 *

 * This function implements the StrUpr() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 */

static void EFIAPI efi_str_upr(struct efi_unicode_collation_protocol *this,

             u16 *string)

{

  EFI_ENTRY("%p, %ls", this, string);

  for (; *string; ++string)

    *string = utf_to_upper(*string);

  EFI_EXIT(EFI_SUCCESS);

}

/**

 * efi_fat_to_str() - convert an 8.3 file name from an OEM codepage to Unicode

 *

 * @this: unicode collation protocol instance

 * @fat_size: size of the string to convert

 * @fat:  string to convert

 * @string: converted string

 *

 * This function implements the FatToStr() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 */

static void EFIAPI efi_fat_to_str(struct efi_unicode_collation_protocol *this,

          efi_uintn_t fat_size, char *fat, u16 *string)

{

  efi_uintn_t i;

  u16 c;

  EFI_ENTRY("%p, %zu, %s, %p", this, fat_size, fat, string);

  for (i = 0; i < fat_size; ++i) {

    c = (unsigned char)fat[i];

    if (c > 0x80)

      c = codepage[c - 0x60];

    string[i] = c;

    if (!c)

      break;

  }

  string[i] = 0;

  EFI_EXIT(EFI_SUCCESS);

}

/**

 * efi_str_to_fat() - convert a utf-16 string to legal characters for a FAT

 *                    file name in an OEM code page

 *

 * @this: unicode collation protocol instance

 * @string: Unicode string to convert

 * @fat_size: size of the target buffer

 * @fat:  converted string

 *

 * This function implements the StrToFat() service of the

 * EFI_UNICODE_COLLATION_PROTOCOL2.

 *

 * Return:  true if an illegal character was substituted by '_'.

 */

static bool EFIAPI efi_str_to_fat(struct efi_unicode_collation_protocol *this,

          const u16 *string, efi_uintn_t fat_size,

          char *fat)

{

  efi_uintn_t i;

  s32 c;

  bool ret = false;

  EFI_ENTRY("%p, %ls, %zu, %p", this, string, fat_size, fat);

  for (i = 0; i < fat_size;) {

    c = utf16_get(&string);

    switch (c) {

    /* Ignore period and space */

    case '.':

    case ' ':

      continue;

    case 0:

      break;

    }

    c = utf_to_upper(c);

    if (utf_to_cp(&c, codepage) ||

        (c && (c < 0x20 || strchr(illegal, c)))) {

      ret = true;

      c = '_';

    }

    fat[i] = c;

    if (!c)

      break;

    ++i;

  }

  EFI_EXIT(EFI_SUCCESS);

  return ret;

}

const struct efi_unicode_collation_protocol efi_unicode_collation_protocol2 = {

  .stri_coll = efi_stri_coll,

  .metai_match = efi_metai_match,

  .str_lwr = efi_str_lwr,

  .str_upr = efi_str_upr,

  .fat_to_str = efi_fat_to_str,

  .str_to_fat = efi_str_to_fat,

  .supported_languages = "en",

};