System, method and apparatus for use in monitoring or controlling internet access

• US 7,590,716 B2
• Filed: 09/28/2004
• Issued: 09/15/2009
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Forcepoint LLC (Francisco Partners Management LLC)
• Original Assignee: Websense UK Ltd. (Francisco Partners Management LLC)
• Inventors: Pettener, Ian James, Nash, Allstair H., Sinclair, John W.
• Primary Examiner(s): Dalencourt; Yves
• Assistant Examiner(s): Lai; Michael C
• Application Number:
  US10/952,626
• Publication Number:
  US 20060075072A1
• Time in Patent Office: 1,813 Days
• Field of Search: 709223-229, 707/101
• US Class Current: 709/223
• CPC Class Codes: G11B 20/00847 wherein the usage restriction is defined by a licence file
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 63/0435 wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06
• CPC Class Codes: H04L 63/102 Entity profiles
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

An apparatus method and system are described for categorizing Uniform Resource Locators (URLs) when accessing the Internet from a client. A request message is generated to request categorization of a specified URL, and a category is provided in a reply message. The specified URL and the category are added to a category cache. In a second or subsequent instance of a URL request referring to the specified URL, the category is determined from the category cache. This reduces communication traffic in a network such as the Internet.

Claims

1. A method of categorizing Uniform Resource Locators (URLs) to control Internet access, comprising:

receiving a URL request denoting a specified URL;

generating a request message to request categorization of the specified URL;

receiving a reply message denoting a category for the specified URL amongst a predetermined set of categories;

adding the specified URL and the category to a category cache,

wherein the category cache comprises;

a hash array wherein a host portion of the specified URL is hashed to identify a corresponding index element in the hash array; and

a combined host tree and age list stored at the identified corresponding index element in the hash array associated with the host portion of the specified URL,

wherein each tree node of the host tree comprises URL data representing a specified URL and a corresponding category, and each tree node further comprises a next pointer and a previous pointer which refer to a next older tree node and a previous newer tree node, respectively, to form an age list, and

wherein adding the specified URL and the category to the category cache comprises;

identifying the corresponding index element in the hash array;

storing the URL data at the head of the age list; and

removing an oldest tree node from the tail of the age list when the category cache has reached a predetermined maximum size;

wherein in response to receiving a second or subsequent instance of a URL request with respect to the specified URL, the method further comprises;

determining the category of the specified URL from the category cache;

moving the URL data representing the specified URL to the head of the age list; and

processing the second or subsequent URL request based on the category of the specified URL from the category cache.

2. The method of claim 1, comprising adding new tree nodes to the head of the age list.

3. The method of claim 1, wherein the hash array has a predetermined length.

4. The method of claim 3, wherein the predetermined length of the hash array is set by a variable which is input from a control panel during use.

5. The method of claim 1, comprising:

searching the category cache for the specified URL; and

returning a category code for the specified URL from the category cache, or else generating the request message to request categorization of the specified URL.

6. The method of claim 1, wherein each specified URL comprises a host portion and a path portion, and each tree node comprises a host string holding the host portion, and an array of one or more page strings each representing a path portion depending from the host portion.

7. The method of claim 6, comprising:

extracting a URL host portion and a URL path portion from the specified URL,

hashing the host portion to determine an index element in the hash array,

searching the host tree identified by the index element to locate a tree node matching the host portion,

matching a URL path portion with a page string in the array, and

returning a stored category associated with the specified URL.

8. The method of claim 6, wherein the category cache comprises, within each tree node, a children flag which identifies whether category codes are available for children of a specified URL host or URL path.

9. The method of claim 1, further comprising providing a custom cache alongside the category cache, wherein the custom cache records a customized list of stored URLs and associated category codes.

10. The method of claim 9, wherein the custom cache comprises:

a hash array wherein the host portion of a specified URL is hashed to produce an index element in the hash array; and

a host tree wherein each tree node of the host tree comprises URL data representing a specified URL and a corresponding category code.

11. The method of claim 9, comprising, in order, the steps of

searching a specified URL in the custom cache and returning a category code,

or else searching the specified URL in the category cache and returning a category code,

or else generating a request message to request categorization of the specified URL and receiving a reply message returning a category code.

12. The method of claim 1, further comprising:

receiving a second specified URL;

searching the category cache using the second specified URL as a search key, and returning a category code associated with the second specified URL when a match is found for the second specified URL; and

generating a request message to request a category code for the second specified URL, when a match is not found for the second specified URL.

13. The method of claim 12, comprising the steps of:

receiving the second specified URL from a client software function, and

passing the category code to the client software function in return.

14. The method of claim 12, comprising:

sending the request message to a remote categorization service;

receiving a reply message from the remote categorization service denoting a category code for the second specified URL amongst a predetermined set of categories.

15. The method of claim 14, further comprising:

adding the second specified URL and the category code to the category cache.

16. The method of claim 12, wherein the method comprises:

hashing at least part of the second specified URL to reference an index element for a hash array within the category cache; and

searching the combined host tree and age list for a tree node containing URL data which matches the second specified URL.

17. The method of claim 16, wherein each tree node comprises a host string holding a host portion of a URL and an associated category code, and a page array of zero or more page strings each page string holding a page portion and an associated category code, and the method comprises selecting a tree node by a host portion of the second specified URL, and selecting a page string in the page array matching all or part of a page portion of a specified URL, to thereby retrieve a category code for the second specified URL.

18. The method of claim 17, wherein each page string further comprises a children flag indicating whether category codes are available for children of a stored path portion.

19. The method of claim 16, comprising the steps of

determining an oldest tree node at the tail of the age list and

removing the oldest tree node when the category cache has reached a predetermined maximum size.

20. The method of claim 19, comprising the steps of

adding a new tree node and

updating the age list to place the new tree node at the head of the age list.

21. The method of claim 16, comprising, when the searching step determines a tree node matching the second specified URL, updating to place the matched tree node at the head of the age list.

30. A program storage medium having computer executable instructions stored thereon for performing the method of claim 1.

22. A system for use in controlling or monitoring of Internet access by categorizing Uniform Resource Locators (URLs), comprising:

a client device arranged to monitor or control Internet access according to a category code of a specified URL, and including a categorization module to provide the category code for the specified URL from a category cache stored at the client device or else generate a request message to request categorization of the specified URL, the client device comprising a memory configured to store a category cache; and

a categorization server coupled to communicate with the client device and arranged to receive the request message and to send a reply message identifying a category code for the specified URL,

wherein a processor of said client device is configured to;

receive a URL request denoting the specified URL;

generate a request message to request categorization of the specified URL by the categorization server;

receive a reply message from the categorization server denoting a category for the specified URL amongst a predetermined set of categories; and

add the specified URL and the category to the category cache,

wherein the category cache comprises;

a hash array wherein a host portion of the specified URL is hashed to identify a corresponding index element in the hash array; and

a combined host tree and age list stored at the identified corresponding index element in the hash array associated with the host portion of the specified URL,

wherein each tree node of the host tree comprises URL data representing a specified URL and a corresponding category, and each tree node further comprises a next pointer and a previous pointer which refer to a next older tree node and a previous newer tree node, respectively, to form an age list, and

wherein to add the specified URL and the category to the category cache, the processor of the client device is further configured to;

identify the corresponding index element in the hash array;

store the URL data at the head of the age list; and

remove an oldest tree node from the tail of the age list when the category cache has reached a predetermined maximum size;

wherein in response to receiving a second or subsequent instance of a URL request with respect to the specified URL, the client device is configured to;

determine the category of the specified URL from the category cache;

move the URL data representing the specified URL to the head of the age list; and

process the second or subsequent URL request based on the category of the specified URL from the category cache.

23. The system of claim 22, wherein the client device and the categorization server communicate over the Internet.

24. The system of claim 22, wherein the client device comprises a user machine to provide a human-oriented user interface, and a client internet gateway appliance to couple the user machine to the Internet through an Internet Service Provider (ISP).

25. The system of claim 24, wherein the user machine and the client internet gateway appliance are formed within a single integrated device.

26. The system of claim 24, wherein the user machine and the client internet gateway appliance are separate devices arranged to communicate over a local network.

27. The system of claim 22, wherein the client device and the categorization sever are arranged to communicate over a local area network.

28. A client device, comprising:

a computer readable medium having stored thereon instructions that when executed by a processor of the client device provide;

an interface module arranged to present a URL categorization function, wherein the interface module receives a specified URL from a client software module executed by the processor and returns a category code of the specified URL;

a category cache module storing a plurality of URLs and associated category codes, such that matching the specified URL against one of the stored URLs provides the category code; and

a communication module arranged to send an outgoing request message to a categorization server when there is no match in the category cache and to receive and buffer incoming data including a corresponding reply message, wherein the request message comprises the specified URL and the reply message comprises the category code,

wherein the category cache module is configured to store the specified URL and the category code to a category cache, the category cache comprising;

a hash array wherein a host portion of the specified URL is hashed to identify a corresponding index element in the hash array; and

a combined host tree and age list stored at the identified corresponding index element in the hash array associated with the host portion of the specified URL,

wherein each tree node of the host tree comprises URL data representing a specified URL and a corresponding category, and each tree node further comprises a next pointer and a previous pointer which refer to a next older tree node and a previous newer tree node, respectively, to form an age list, and

wherein to store the specified URL and the category, the category cache module is configured is to;

identify the corresponding index element in the hash array;

store the URL data at the head of the age list; and

remove an oldest tree node from the tail of the age list when the category cache has reached a predetermined maximum size; and

wherein, in response to receiving a second or subsequent instance of a URL request by the interface module with respect to the specified URL, the category cache module is configured to;

determine the category of the specified URL from the category cache; and

move the URL data representing the specified URL to the head of the age list.

29. The client device of claim 28, further comprising:

a custom cache which holds a customized list of stored URLs and associated category codes, such that the custom cache is searchable.