Filter
Top Products
A-4 APPENDIX A: PACKET FILTER OPCODES, EXAMPLES, AND SYNTAX ERRORS
pushSPGM
Description:
Pushes the source port group mask (SPGM) onto the top of the stack. The SPGM
is a bitmap representing the groups to which the source port of a packet
belongs. This instruction pushes 4 bytes on to the stack.
Each port group mask is represented by a single bit in the SPGM bitmap. Port
group masks are assigned to the bitmap in sequence, starting with port group
mask 1 as the least significant bit through port group mask 32 as the most
significant bit.
Storage Needed:
1 byte
pushDPGM
Description:
Pushes the destination port group mask (DPGM) onto the top of the stack. The
DPGM is a bitmap representing the groups to which the destination port of a
packet belongs. This instruction pushes 4 bytes on to the stack.
Each port group mask is represented by a single bit in the DPGM bitmap. Port
group masks are assigned to the bitmap in sequence, starting with port group
mask 1 as the least significant bit through port group mask 32 as the most
significant bit.
Storage Needed:
1 byte
eq (equal)
Description:
Pops two values from the stack and compares them. If they are equal, a byte
containing the value non-zero is pushed onto the stack; otherwise, a byte
containing 0 is pushed. The size of the operands is determined by the contents
of the stack.
Storage Needed:
1 byte