Packet data modification processor command instruction set
A command instruction set for a packet data modification processor has a format in which a packet address, if present, specifies an encapsulated layer within the packet and a location within this encapsulated layer. The at least one command within the command instruction set specifies deriving at least a portion of a first packet from data taken from a second packet or the command.
1. A computer readable medium encoded with processor executable instructions comprising a command for a packet data modification processor,
the command specifying a packet address for a first packet, the packet address comprising a first portion representing a pointer to a beginning of a layer of the first packet and a second portion representing an offset from the pointer, the second portion specifying a location within the layer of the first packet; and
the command specifying forming, modifying or replacing a portion of the first packet, at the location specified by the second portion, based on or using data derived from a second packet distinct from the command or the command.
2. The computer readable medium of claim 1 wherein the command specifies forming, modifying or replacing the portion of the first packet based on unmodified data, the unmodified data comprising data taken without modification from the second packet or the command.
3. The computer readable medium of claim 2 wherein the command specifies inserting the unmodified data into the first packet without overwriting existing packet data.
4. The computer readable medium of claim 2 wherein the command specifies replacing existing data in the first packet with the unmodified data.
5. The computer readable medium of claim 2 wherein the unmodified data forms a fragment of the first packet.
6. The computer readable medium of claim 5 wherein the fragment has a predetermined granularity.
7. The computer readable medium of claim 5 wherein the fragment is one of several fragments forming the first packet.
8. The computer readable medium of claim 1 wherein the command specifies forming, modifying or replacing the portion of the first packet based on data taken from the second packet or the command, and then modified through one or more modifications.
9. The computer readable medium of claim 8 wherein the one or more modifications comprises masking the data with a mask.
10. The computer readable medium of claim 8 wherein the one or more modifications comprises incrementing the data.
11. The processor readable medium of claim 8 wherein the one or more modifications comprises decrementing the data.
12. The computer readable medium of claim 8 wherein the one or more modifications comprises one or more arithmetic operations.
13. The computer readable medium of claim 8 wherein the one or more modifications comprises one or more logical operations.
14. The computer readable medium of claim 8 wherein the one or more modifications comprises deleting a portion of the data.
15. The computer readable medium of claim 8 wherein the command specifies inserting the data as modified into the first packet without overwriting existing packet data.
16. The computer readable medium of claim 8 wherein the command specifies replacing existing data in the first packet with the unmodified data.
17. The computer readable medium of claim 8 wherein the data as modified forms a fragment of the first packet.
18. The computer readable medium of claim 17 wherein the fragment has a predetermined granularity.
19. The computer readable medium of claim 17 wherein the fragment is one of several fragments forming the first packet.
20. The computer readable medium of claim 1 wherein the first and second packets are the same.
21. The computer readable medium of claim 1 wherein the first and second packets are different.
22. The computer readable medium of claim 1 wherein the command is a TTL decrement command.
23. The computer readable medium of claim 1 wherein the command is a TC increment command.
24. The computer readable medium of claim 1 wherein the command is a macro.
25. The computer readable medium of claim 24 wherein the macro is a replace MAC DA/replace MAC SA/replace VLAN macro.
26. The computer readable medium of claim 24 wherein the macro is a replace MAC DA/replace MAC SA/strip VLAN macro.
27. The computer readable medium of claim 1 encoded with processor readable instructions comprising a plurality of the commands of claim 1 for the packet data modification processor.
28. The computer readable medium of claim 1 , wherein the second portion specifies the location relative to the first portion.