names.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

#include "precomp.h"

#define NDEBUG
#include <debug.h>

static BOOL DnsIntNameContainsDots( LPCWSTR Name ) {
  return wcschr( Name, '.' ) ? TRUE : FALSE;
}

static BOOL DnsIntTwoConsecutiveDots( LPCWSTR Name ) {
  return wcsstr( Name, L".." ) ? TRUE : FALSE;
}

static BOOL DnsIntContainsUnderscore( LPCWSTR Name ) {
  return wcschr( Name, '_' ) ? TRUE : FALSE;
}

/* DnsValidateName *********************
 * Use some different algorithms to validate the given name as suitable for
 * use with DNS.
 *
 * Name      -- The name to evaluate.
 * Format    -- Format to use:
 *               DnsNameDomain
 *               DnsNameDomainLabel
 *               DnsNameHostnameFull
 *               DnsNameHostnameLabel
 *               DnsNameWildcard
 *               DnsNameSrvRecord
 * RETURNS:
 * ERROR_SUCCESS                -- All good
 * ERROR_INVALID_NAME           --
 *  Name greater than 255 chars.
 *  Label greater than 63 chars.
 *  Two consecutive dots, or starts with dot.
 *  Contains a dot, but a Label check was specified.
 * DNS_ERROR_INVALID_NAME_CHAR
 *  Contains any invalid char: " {|}~[\]^':;<=>?@!"#$%^`()+/,"
 *  Contains an *, except when it is the first label and Wildcard was
 *  specified.
 * DNS_ERROR_NUMERIC_NAME
 *  Set if the name contains only numerics, unless Domain is specified.
 * DNS_ERROR_NON_RFC_NAME
 *  If the name contains underscore.
 *  If there is an underscore in any position but the first in the SrvRecord
 *   case.
 *  If the name contains a non-ascii character.
 */

DNS_STATUS WINAPI DnsValidateName_W
( LPCWSTR Name,
  DNS_NAME_FORMAT Format )  {
  BOOL AllowDot = FALSE;
  BOOL AllowLeadingAst = FALSE;
  BOOL AllowLeadingUnderscore = FALSE;
  BOOL AllowAllDigits = FALSE;
  const WCHAR *NextLabel, *CurrentLabel, *CurrentChar;
  
  switch( Format ) {
  case DnsNameDomain:
    AllowAllDigits = TRUE;
    AllowDot = TRUE;
    break;
  case DnsNameDomainLabel:
    AllowAllDigits = TRUE;
    break;
  case DnsNameHostnameFull:
    AllowDot = TRUE;
    break;
  case DnsNameHostnameLabel:
    break;
  case DnsNameWildcard:
    AllowLeadingAst = TRUE;
    AllowDot = TRUE;
    break;
  case DnsNameSrvRecord:
    AllowLeadingUnderscore = TRUE;
    break;
  default:
    break;
  }

  /* Preliminary checks */
  if( Name[0] == 0 ) return ERROR_INVALID_NAME; /* XXX arty: Check this */

  /* Name too long */
  if( wcslen( Name ) > 255 ) {
    return ERROR_INVALID_NAME;
  }
  
  /* Violations about dots */
  if( (!AllowDot && DnsIntNameContainsDots( Name )) ||
      Name[0] == '.' || DnsIntTwoConsecutiveDots( Name ) ) 
    return ERROR_INVALID_NAME;
  
  /* Check component sizes */
  CurrentLabel = Name;
  do {
    NextLabel = CurrentLabel;
    while( *NextLabel && *NextLabel != '.' ) NextLabel++;

    if( NextLabel - CurrentLabel > 63 ) 
      return ERROR_INVALID_NAME;

    CurrentLabel = NextLabel;
  } while( *CurrentLabel );

  CurrentChar = Name;

  while( *CurrentChar ) {
    if( wcschr(L" {|}~[\\]^':;<=>?@!\"#$%^`()+/,",*CurrentChar) )
      return DNS_ERROR_INVALID_NAME_CHAR;
    CurrentChar++;
  }

  if( (!AllowLeadingAst && Name[0] == '*') ||
      (AllowLeadingAst && Name[0] == '*' && Name[1] && Name[1] != '.') )
    return DNS_ERROR_INVALID_NAME_CHAR;

  if( wcschr( Name + 1, '*' ) ) 
    return DNS_ERROR_INVALID_NAME_CHAR;

  CurrentChar = Name;
  while( !AllowAllDigits && *CurrentChar ) {
    if( *CurrentChar == '.' || (*CurrentChar >= '0' && *CurrentChar <= '9') )
      return DNS_ERROR_NUMERIC_NAME;
  }

  if( ((AllowLeadingUnderscore && Name[0] == '_') || Name[0] != '_') &&
      !DnsIntContainsUnderscore( Name + 1 ) ) 
    return DNS_ERROR_NON_RFC_NAME;

  return ERROR_SUCCESS;
}

DNS_STATUS WINAPI DnsValidateName_UTF8
( LPCSTR Name,
  DNS_NAME_FORMAT Format ) {
  PWCHAR Buffer;
  int StrLenWc;
  DNS_STATUS Status;

  StrLenWc = mbstowcs( NULL, Name, 0 );
  Buffer = RtlAllocateHeap( GetProcessHeap(), 0, 
			    sizeof( WCHAR ) * (StrLenWc + 1) );
  mbstowcs( Buffer, Name, StrLenWc + 1 );
  Status = DnsValidateName_W( Buffer, Format );
  RtlFreeHeap( GetProcessHeap(), 0, Buffer );
  
  return Status;
}

DNS_STATUS WINAPI DnsValidateName_A
( LPCSTR Name,
  DNS_NAME_FORMAT Format ) {
  return DnsValidateName_UTF8( Name, Format );
}

/* DnsNameCompare **********************
 * Return TRUE if the names are identical.
 *
 * Name1 & Name2 -- Names.
 */

BOOL WINAPI DnsNameCompare_W
( LPWSTR Name1,
  LPWSTR Name2 ) {
  int offset = 0;

  while( Name1[offset] && Name2[offset] && 
	 towupper( Name1[offset] ) == towupper( Name2[offset] ) ) offset++;
  return 
    (!Name1[offset] && !Name2[offset]) ||
    (!Name1[offset] && !wcscmp( Name2 + offset, L"." )) ||
    (!Name2[offset] && !wcscmp( Name1 + offset, L"." ));
}

BOOL WINAPI DnsNameCompare_UTF8
( LPCSTR Name1,
  LPCSTR Name2 ) {
  int offset = 0;
  
  while( Name1[offset] && Name2[offset] &&
	 toupper( Name1[offset] ) == toupper( Name2[offset] ) ) offset++;
  return
    (!Name1[offset] && !Name2[offset]) ||
    (!Name1[offset] && !strcmp( Name2 + offset, ".")) ||
    (!Name2[offset] && !strcmp( Name1 + offset, "."));
}

BOOL WINAPI DnsNameCompare_A
( LPSTR Name1,
  LPSTR Name2 ) {
  return DnsNameCompare_UTF8( Name1, Name2 );
}