Hardware-based packet editor

• US 9,118,618 B2
• Filed: 03/29/2012
• Issued: 08/25/2015
• Est. Priority Date: 03/29/2012
• Status: Active Grant

• Current Assignee: A10 Networks Incorporated
• Original Assignee: A10 Networks Incorporated
• Inventors: Davis, Ian E.
• Primary Examiner(s): Mejia, Anthony
• Application Number:
  US13/433,290
• Publication Number:
  US 20130262702A1
• Time in Patent Office: 1,244 Days
• Field of Search: 709/200, 709/246
• US Class Current: 1/1
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields

Abstract

Hardware-based packet editor receives a packet editing script which includes script entries indicating modifications to a data packet and a data block with data for the modified data packet. For a script entry in the packet editing script, the packet editor copies data in the data block at a block location and with a block length identified in the script entry into a packet buffer. The packet editor repeats the copying for the remaining script entries for the modified data packet. The packet editor then generates the modified data packet with the data in the packet buffer. The packet editing script is generated such that a script entry is created for data to be included in the modified data packet and data to be inserted into the modified data packet. Creation of a script entry is omitted for data to be removed.

Claims

1. A method for modifying a data packet by a hardware-based packet editor comprising:

receiving, by the packet editor, a packet editing script comprising one or more script entries indicating modifications to be applied to the data packet and a data block comprising data for the modified packet;

for each given script entry in the packet editing script, copying, by the packet editor, data in the data block at a location and a size identified in the given script entry into a packet buffer;

generating, by the packet editor, a modified data packet with the data in the packet buffer,

wherein the copying comprises;

retrieving the given script entry of the packet editing script;

determining whether the given script entry is a first script entry for the modified data packet;

in response to determining that the given script entry is the first script entry for the modified data packet, reserving the packet buffer for the modified data packet;

copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer;

determining whether the given script entry is a last script entry for the modified data packet; and

in response to determining that the given script entry is not the last script entry for the modified data packet, performing the copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer and the determining whether the given script entry is a last script entry for the next given script entry of the packet editing script.

2. The method of claim 1 wherein the determining whether the given script entry is the first script entry comprises:

determining whether a start of packet (SOP) indicator in the given script entry indicates that the given script entry is the first script entry for the modified data packet.

3. The method of claim 1 wherein the determining whether the given script entry is a last script entry comprises:

determining whether an end of packet (EOP) indicator in the given script entry indicates that the given script entry is the last script entry for the modified data packet.

4. The method of claim 1 wherein the reserving and the copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer comprises:

setting a packet buffer marker at a beginning of the packet buffer;

appending a copy of the data in the data block at the block location and with the block length identified in the given editing script to the packet buffer at the packet buffer marker; and

modifying the packet buffer marker by the block length identified in the given editing script.

5. The method of claim 1 wherein the generating comprises:

in response to determining that the given script entry is the last script entry for the modified data packet, generating the modified data packet with the data in the packet buffer.

6. The method of claim 5 wherein the generating the modified data packet with the data in the packet buffer further comprises:

determining whether the given script entry is the last script entry in the packet editing script; and

in response to determining that the given script entry is not the last script entry in the packet editing script, repeating the retrieving, the determining whether the given script entry is a first script entry, the reserving, the copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer, the determining whether the given script entry is a last script entry, the performing, and the generating the modified data packet with the data in the packet buffer for a next given script entry in the packet editing script.

7. The method of claim 6 wherein the determining whether the given script entry is the last script entry in the packet editing script comprises:

determining whether an end of table (EOT) indicator in the given script entry indicates that the given script entry is the last script entry in the packet editing script.

8. A system, comprising:

a packet buffer; and

a hardware-based packet editor comprising a control memory and a control module,

wherein the packet editor;

receives a packet editing script comprising one or more script entries indicating modifications to be applied to a data packet and a data block comprising data for the modified packet; and

stores the packet editing script in the control memory, wherein the control module;

retrieves each given script entry stored in the control memory;

copies data in the data block at a location and a size identified in the given script entry into the packet buffer; and

generates a modified data packet with the data in the packet buffer,

wherein copying (4) the data in the data block at the location and the size identified in the given script entry into the packet buffer, the control module;

determines whether the given script entry is a first script entry for the modified data packet; and

in response to determining that the given script entry is the first script entry for the modified data packet, reserves the packet buffer for the modified data packet;

copies the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer;

determines whether the given script entry is a last script entry for the modified data packet; and

in response to determining that the given script entry is not the last script entry for the modified data packet, performs, for the next given script entry of the packet editing script, the copying of the data in the data block at the block location and with the block length identified in the given script entry into the packet buffer and the determining whether the given script entry is a last script entry for the modified data packet for the next given script entry of the packet editing script.

9. The system of claim 8, wherein in determining whether the given script entry is the first script entry for the modified data packet, the control module:

determines whether a start of packet (SOP) indicator in the given script entry indicates that the given script entry is the first script entry for the modified data packet.

10. The system of claim 8 wherein in determining whether the given script entry is the last script entry for the modified data packet, the control module:

determines whether an end of packet (EOP) indicator in the given script entry indicates that the given script entry is the last script entry for the modified data packet.

11. The system of claim 8 wherein in reserving the packet buffer for the modified data packet and in copying the data in the data block at the block location and with the block length identified in the given script entry into the packet buffer, the control module:

sets a packet buffer marker at a beginning of the packet buffer;

appends a copy of the data in the data block at the block location and with the block length identified in the given editing script to the packet buffer at the packet buffer marker; and

modifies the packet buffer marker by the block length identified in the given editing script.

12. The system of claim 8 wherein in generating the modified data packet with the data in the packet buffer, the control module:

in response to determining that the given script entry is the last script entry for the modified data packet, generates the modified data packet with the data in the packet buffer.

13. The system of claim 12 wherein in generating the modified data packet with the data in the packet buffer, the control module further:

determines whether the given script entry is the last script entry in the packet editing script; and

in response to determining that the given script entry is not the last script entry in the packet editing script, repeating the retrieving, the determining whether the given script entry is a first script entry for the modified data packet, the reserving, the copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer, the determining whether the given script entry is a last script entry for the modified data packet, the performing, and the generating the modified data packet with the data in the packet buffer for a next given script entry in the packet editing script.

14. The system of claim 13 wherein the determining whether the given script entry is the last script entry in the packet editing script, the control module:

determines whether an end of table (EOT) indicator in the given script entry indicates that the given script entry is the last script entry in the packet editing script.

15. A non-transitory computer-readable storage medium having embodied thereon a program, the program being executable by a processor to perform a method, the method comprising:

receiving a packet editing script comprising one or more script entries indicating modifications to be applied to a data packet and a data block comprising data for the modified packet;

for each given script entry in the packet editing script, copying data in the data block at a location and a size identified in the given script entry into a packet buffer; and

generating a modified data packet with the data in the packet buffer, wherein copying data in the data block at a location and a size identified in the given script entry into a packet buffer comprises;

retrieving the given script entry of the packet editing script;

determining whether the given script entry is a first script entry for the modified data packet;

in response to determining that the given script entry is the first script entry for the modified data packet, reserving the packet buffer for the modified data packet;

copying the data in the data block at a block location and with a block length identified in the given editing script into the packet buffer;

determining whether the given script entry is a last script entry for the modified data packet; and

in response to determining that the given script entry is not the last script entry for the modified data packet, performing the copy of the data in the data block at a block location and with a block length identified in the given editing script into the packet buffer and the determining whether the given script entry is a last script entry for the modified data packet for the next given script entry of the packet editing script.

16. The storage medium of claim 15 wherein the determining whether the given script entry is a first script entry for the modified data packet comprises:

determining whether a start of packet (SOP) indicator in the given script entry indicates that the given script entry is the first script entry for the modified data packet.

17. The storage medium of claim 15 wherein the determining whether the given script entry is a last script entry for the modified data packet comprises:

determining whether an end of packet (EOP) indicator in the given script entry indicates that the given script entry is the last script entry for the modified data packet.

18. The storage medium of claim 15 wherein the reserving and the copying the data in the data block at a block location and with a block length identified in the given editing script into the packet buffer are configured to:

set a packet buffer marker at a beginning of the packet buffer;

append a copy of the data in the data block at the block location and with the block length identified in the given editing script to the packet buffer at the packet buffer marker; and

modify the packet buffer marker by the block length identified in the given editing script.

19. The storage medium of claim 15 wherein the generating comprises:

in response to determining that the given script entry is the last script entry for the modified data packet, generating the modified data packet with the data in the packet buffer.

20. The storage medium of claim 19 wherein the generating further comprises:

determining whether the given script entry is the last script entry in the packet editing script; and

in response to determining that the given script entry is not the last script entry in the packet editing script, repeat the retrieving, the determining whether the given script entry is a first script entry, the reserving, the copying the data in the data block at a block location and with a block length identified in the given script entry into the packet buffer, the

determining whether the given script entry is a last script entry, the performing, and generating the modified data packet with the data in the packet buffer for a next given script entry in the packet editing script.

21. The storage medium of claim 20 wherein the determine is configured to:

determine whether an end of table (EOT) indicator in the given script entry indicates that the given script entry is the last script entry in the packet editing script.