PATTERNMATCH

The PATTERNMATCH structure defines pattern elements used to evaluate a frame.

typedef struct _PATTERNMATCH {
  DWORD Flags;
  BYTE OffsetBasis;
  GENERIC_PORT Port;
  WORD Offset;
  WORD Length;
  BYTE PatternToMatch[MAX_PATTERN_LENGTH];
} PATTERNMATCH, 
 *LPPATTERNMATCH;

Members

• Flags
  Pattern match flags:

  Value	Meaning
  PATTERN_MATCH_FLAGS_NOT 0x00000001	When set, this flag retains frames that lack the specified pattern in the proper spot.
  PATTERN_MATCH_FLAGS_PORT_SPECIFIED 0x00000008	Seeks a port number value.

• OffsetBasis
  Types of offset, which can be one of the following:

  Value	Meaning
  OFFSET_BASIS_RELATIVE_TO_FRAME	Sets an offset, in bytes, relative to start of the frame.
  OFFSET_BASIS_RELATIVE_TO_EFFECTIVE_PROTOCOL	Sets an offset, in bytes, relative to the start of the referenced protocol.
  OFFSET_BASIS_RELATIVE_TO_IPX	Sets an offset, in bytes, only relative to IPX.
  OFFSET_BASIS_RELATIVE_TO_IP	Sets an offset, in bytes, only relative to IP.

• Port
  Port value, if specified.

• Offset
  The offset, in bytes, relative to the OffsetBasis.

• Length
  Length of the matched pattern.

• PatternToMatch
  Pattern to match.

Remarks

This structure is used to construct a capture filter. For more information about implementing this structure, see Capture Filters.

A capture filter can contain up to four PATTERNMATCH structures.

Requirements

See Also

CAPTUREFILTER