Accelerating Service Processing Using Fast Path TCP

• US 20130136139A1
• Filed: 08/06/2012
• Published: 05/30/2013
• Est. Priority Date: 11/29/2011
• Status: Active Grant

• Current Assignee: A10 Networks Incorporated
• Original Assignee: A10 Networks Incorporated
• Inventors: Zheng, Wei, Han, Liang
• Granted Patent: US 9,386,088 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 67/1014 based on the content of a request
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields

Abstract

A service gateway includes a fast path module for processing data packets without using packet buffers and a normal path module for processing data packets using packet buffers. The fast path module receives a service request data packet from a client side session, determines that the service request data packet cannot be processed by the fast path module, and in response, sends the service request data packet to the normal path module. After receiving the service request data packet, the normal path module retrieves a first proxy session record created by the fast path module, where the first proxy session record is associated with a client session record for the client side session, creates a second proxy session record based on the service request data packet and the client session record, and processes the service request data packet according to the second proxy session record.

Claims

1. A service gateway, comprising:

a fast path module for processing data packets without using packet buffers; and

a normal path module for processing data packets using one or more packet buffers,

wherein the fast path module;

receives a service request data packet from a client side session between a client and the service gateway;

determines that the service request data packet cannot be processed by the fast path module; and

in response to determining that the service request data packet cannot be processed by the fast path module, sends the service request data packet to the normal path module,

wherein in response to receiving the service request data packet from the fast path module, the normal path module;

retrieves a first proxy session record created by the fast path module, wherein the first proxy session record is associated with a client session record for the client side session;

creates a second proxy session record based on the service request data packet and the client session record associated with the first proxy session record; and

processes the service request data packet according to the second proxy session record.

2. The service gateway of claim 1, wherein in determining that the service request data packet cannot be processed by the fast path module, the fast path module:

determines that the service request data packet;

does not contain a complete HTTP header;

contains only a partial URI;

contains only partial HTTP header field;

contains only a partial HTTP cookie field;

indicates an IP packet fragment;

contains an unexpected URI;

does not contain an expected cookie field;

or

does not contain an expected HTTP header attribute.

3. The service gateway of claim 1, wherein in creating the second proxy session record, the normal path module:

creates a second client session record based on the client session record associated with the first proxy session record and the service request data packet; and

associates the second client session record with the second proxy session record.

4. The service gateway of claim 3, wherein the client side session comprises a TCP session, wherein in creating the second proxy session record, the normal path module further:

obtains a client session receiving initial sequence number and a client session sending initial sequence number from the client session record associated with the first proxy session record;

creates one or more TCP session state variables and one or more packet buffers for the client side session; and

stores the client session receiving initial sequence number, the client session sending initial sequence number, and the one or more TCP session state variables in the second client session record.

5. The service gateway of claim 1, wherein the fast path module further:

determines that the service request data packet can be processed by the fast path module;

in response to determining that the service request data packet can be processed by the fast path module, adjusts sequence numbers in the service request data packet using a calculated client session sequence number adjustment stored in the first proxy session record; and

sends the adjusted service request data packet over a server side session between a server and the service gateway.

6. The service gateway of claim 5, wherein in adjusting the sequence numbers in the service request data packet, the fast path module:

adjusts a sequence number in the service request data packet by the calculated client session sequence number adjustment; and

adjusts an acknowledgement number in the service request data packet by the calculated client session sequence number adjustment.

7. A method for processing HTTP packets by a service gateway implemented by a processor, comprising:

(a) receiving, by a fast path module of the service gateway implemented by the processor, a service request data packet from a client side session between a client and the service gateway, wherein the fast path module processes data packets without using packet buffers;

(b) determining that the service request data packet cannot be processed by the fast path module;

(c) in response to determining that the service request data packet cannot be processed by the fast path module, sending the service request data packet from the fast path module to a normal path module of the service gateway implemented by the processor, wherein the normal path module processes data packets using one or more packet buffers;

(d) in response to receiving the service request data packet from the fast path module, retrieving by the normal path module a first proxy session record created by the fast path module, wherein the first proxy session record is associated with a client session record for the client side session;

(e) creating by the normal path module a second proxy session record based on the service request data packet and the client session record associated with the first proxy session record; and

(f) processing the service request data packet by the normal path module according to the second proxy session record.

8. The method of claim 7, wherein the determining (b) comprises:

(b1) determining that the service request data packet;

does not contain a complete HTTP header;

contains only a partial URI;

contains only partial HTTP header field;

contains only a partial HTTP cookie field;

indicates an IP packet fragment;

contains an unexpected URI;

does not contain an expected cookie field;

or

does not contain an expected HTTP header attribute.

9. The method of claim 7, wherein the creating (e) comprises:

(e1) creating a second client session record by the normal path module based on the client session record associated with the first proxy session record and the service request data packet; and

(e2) associating the second client session record with the second proxy session record.

10. The method of claim 9, wherein the client side session comprises a TCP session, wherein the creating (e1) comprises:

(e1i) obtaining by the normal path module a client session receiving initial sequence number and a client session sending initial sequence number from the client session record associated with the first proxy session record;

(e1ii) creating one or more TCP session state variables and one or more packet buffers for the client side session; and

(e1iii) storing the client session receiving initial sequence number, the client session sending initial sequence number, and the one or more TCP session state variables in the second client session record.

11. The method of claim 7, further comprising:

(g) determining that the service request data packet can be processed by the fast path module;

(h) in response to determining that the service request data packet can be processed by the fast path module, adjusting sequence numbers in the service request data packet using a calculated client session sequence number adjustment stored in the first proxy session record; and

(i) sending the adjusted service request data packet over a server side session between a server and the service gateway.

12. The method of claim 11, wherein the adjusting (h) comprises:

(h1) adjusting a sequence number in the service request data packet by the calculated client session sequence number adjustment; and

(h2) adjusting an acknowledgement number in the service request data packet by the calculated client session sequence number adjustment.

13. A system, comprising:

a processor; and

a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to;

(a) receive, by a fast path module of the service gateway implemented by the processor, a service request data packet from a client side session between a client and the service gateway, wherein the fast path module processes data packets without using packet buffers;

(b) determine that the service request data packet cannot be processed by the fast path module;

(c) in response to determining that the service request data packet cannot be processed by the fast path module, send the service request data packet from the fast path module to a normal path module of the service gateway implemented by the processor, wherein the normal path module processes data packets using one or more packet buffers;

(d) in response to receiving the service request data packet from the fast path module, retrieve by the normal path module a first proxy session record created by the fast path module, wherein the first proxy session record is associated with a client session record for the client side session;

(e) create by the normal path module a second proxy session record based on the service request data packet and the client session record associated with the first proxy session record; and

(f) process the service request data packet by the normal path module according to the second proxy session record.

14. The system of claim 13, wherein the computer readable program code configured to determine (b) is further configured to:

(b1) determine that the service request data packet;

does not contain a complete HTTP header;

contains only a partial URI;

contains only partial HTTP header field;

contains only a partial HTTP cookie field;

indicates an IP packet fragment;

contains an unexpected URI;

does not contain an expected cookie field;

or

does not contain an expected HTTP header attribute.

15. The system of claim 13, wherein the computer readable program code configured to create (e) is further configured to:

(e1) create a second client session record by the normal path module based on the client session record associated with the first proxy session record and the service request data packet; and

(e2) associate the second client session record with the second proxy session record.

16. The system of claim 15, wherein the client side session comprises a TCP session, wherein the computer readable program code configured to create (e1) is further configured to:

(e1i) obtain by the normal path module a client session receiving initial sequence number and a client session sending initial sequence number from the client session record associated with the first proxy session record;

(e1ii) create one or more TCP session state variables and one or more packet buffers for the client side session; and

(e1iii) store the client session receiving initial sequence number, the client session sending initial sequence number, and the one or more TCP session state variables in the second client session record.

17. The system of claim 13, wherein the computer readable program code is further configured to:

(g) determine that the service request data packet can be processed by the fast path module;

(h) in response to determining that the service request data packet can be processed by the fast path module, adjust sequence numbers in the service request data packet using a calculated client session sequence number adjustment stored in the first proxy session record; and

(i) send the adjusted service request data packet over a server side session between a server and the service gateway.

18. The method of claim 17, wherein computer readable program code configured to adjust (h) is further configured to:

(h1) adjust a sequence number in the service request data packet by the calculated client session sequence number adjustment; and

(h2) adjust an acknowledgement number in the service request data packet by the calculated client session sequence number adjustment.