Virtual network mechanism to access well known port application programs running on a single host system

• US 5,636,371 A
• Filed: 06/07/1995
• Issued: 06/03/1997
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Original Assignee: Bull HN Information Systems Incorporated (Atos SE)
• Inventors: Yu, Kin C.
• Primary Examiner(s): Tesh, Kevin
• Assistant Examiner(s): PHAN, THAI Q
• Application Number:
  US08/473,476
• Time in Patent Office: 727 Days
• Field of Search: 395/182.09, 395/200, 395/200.02, 395/200.13, 395/200.2, 395/500, 395/413, 370/60, 370/60.1, 370/94.1, 370/85.14, 370/94.3, 340/825.52, 340/825.07
• US Class Current: 703/26
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/162 involving adaptations of sockets based mechanisms secure socket layer H04L63/168
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/32 Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
• CPC Class Codes: H04L 69/326 in the transport layer [OSI layer 4] H04L69/16 takes precedence
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A local host data processing system operating under the control of a local host operating system includes components of a hosted operating system. The host operating system further include a TCP/IP network protocol stack which couples to the communications facilities of the host system connected to a local area network for communicating with a number of remote host systems. Host and hosted operating systems share the same TCP/IP network protocol stack. A virtual network mechanism is configured within the local host system to be operatively coupled to the host network protocol stack and provide access to well-known port application programs. When so configured, the mechanism functions as another LAN to which the hosted operating system is attached. The mechanism transforms the well-known port identifier of each inbound packet into a non-well-known port identifier in addition to other station address identifier fields. It then redirects the transformed packet back to the IP layer of the stack for transfer to the appropriate well-known port application program of the hosted operating system. It reverses this operation for each reply packet which is also redirected back to the IP layer for forwarding to the remote system. This eliminates the need to specify additional protocol stacks and to provide additional communication hardware facilities for handling multiple instances of well-known port applications programs.

Claims

1. A method which allows a local host system to share a communications network software facility of the local host system operating system between a number of data communications application servers operating under the host operating system and a corresponding number of data communications application servers operating under components of a hosted operating system running under control of the local host operating system, the local host system being coupled to at least one remote host system through a local area network (LAN) and an internetwork, the network software facility being coupled to a communications network interface unit which includes interfacing hardware and software for connecting the local host system to the LAN for communicating with the remote host system using a standard communications network protocol which is characterized by assigning different station address identifier values to each host system requiring that the local host system and hosted operating system be assigned different station address identifier values and well-known services function identifier values to the different data communications application servers associated with local host system and hosted operating systems so that servers performing the same service function are assigned the same well-known services function identifier value for directing incoming packets sent by the remote host system to the appropriate application server, said method comprising the steps of:

(a) configuring a virtual network mechanism within the local host operating system to be operatively coupled to the host operating system communication network software facility and to function as if an another LAN connected to a virtual host system running the hosted operating system and operating as if it contained its own communications network software facility;

(b) mapping predetermined portions of each incoming packet by the virtual network mechanism sent by the remote host system and received from the local host communications network software facility by (1) changing the station address identifier value of each incoming packet to specify the local host system as a destination and the virtual network mechanism as a source of the packet for returning any reply packet thereto and (2) changing the well-known services identifier value to a virtual identifier value so that the mapped incoming packet received from the virtual network mechanism is directed by the host operating system communications network software facility to the appropriate communications application server of the hosted operating system for processing; and

;

(c) remapping the predetermined portions of each outgoing reply packet sent by the hosted system communications application server through the communications network software facility to the virtual network interface mechanism by restoring the remote host station address identifier and well-known service identifier values so each outgoing reply packet sent by the virtual network mechanism to the internetwork appears to the remote host system as a reply packet to the communication between the remote host system and the hosted system communications application server as if the server had been reached through the LAN using the originally sent station address assigned to the hosted operating system and well-known services identifier value.

2. The method of claim 1 wherein the virtual network mechanism includes interfacing software similar to the network interface unit for minimizing the amount of software required to be added to the local host operating system and for utilizing the network routing capabilities of the communications network software facility.

3. The method of claim 2 wherein the communications network software facility includes a TCP/IP protocol stack containing TCP and IP layers and the virtual network mechanism utilizes the network routing capabilities of the IP layer.

4. The method of claim 1 wherein the standard communications network protocol is the TCP/IP protocol, the station address identifier value corresponds to an IP address containing IP source and IP destination addresses and the well-known service function identifier value corresponds to a TCP well-known port number value containing TCP source and TCP destination port numbers.

5. The method of claim 1 wherein configuring step (a) of the method includes the step of:

(d) performing an initialization operation by the virtual network mechanism which setups and builds a predetermined types of control data structures for enabling processing of each incoming and outgoing packet through the interfacing software included in the virtual network mechanism.

6. The method of claim 5 wherein the predetermined types of control data structures includes a first structure which defines the existence of the virtual network mechanism to the network software facility and a second structure which defines the virtual network mechanism.

7. The method of claim 6 wherein the first structure is an interface network structure utilized by the host operating system and the second structure is a software control structure which is used to manage packet processing for each of the client application programs running on the remote host system.

8. The method of claim 7 wherein the second structure contains a predetermined number of fields, a first field for storing the state of the virtual network mechanism, a second field for maintaining a count of the number of different client entries being managed by the virtual network mechanism, third and fourth fields for storing the local host and virtual host station address identifier values wherein the virtual host station value is generated by performing an arithmetic operation on the local host station address identifier value and a fifth field for storing a client pointer value for accessing the first client table structure generated by the virtual network mechanism.

9. The method of claim 6 wherein the predetermined types of control data structures includes a number of client table structures, each client table structure being associated with a different client application program of the remote host system which has established communication with the local host system.

10. The method of claim 9 wherein a new client table is assigned by the virtual network mechanism each time a connection packet is sent by a different client application program running on the remote host system.

11. The method of claim 10 wherein the remote host system establishes connection with the hosted operating system data communication services application servers by configuring the remote host to have the local host system function as a "gateway" so that the local host system communications network software facility automatically routes incoming packets sent by the remote host system to the virtual network mechanism.

12. The method of claim 10 wherein the client table includes a predetermined number of fields, a first field for storing the station address identifier value of the remote system client application program, a second field defining the operational state of the client table, third and fourth fields for defining different client application program port identifier values and a fifth field for storing a timer count value defining client application program activity.

13. The method of claim 1 wherein each mapping step of the method of claim 1 further includes the step of:

(e) regenerating the checksum for each incoming and outgoing packet for enabling the network software facility of the local host system to correctly process said each incoming and outgoing packet by standard protocol procedures.

14. The method of claim 1 wherein the method further includes the step of:

(f) saving the station address identifier value of the remote host system and the well-known services identifier value contained in each incoming packet in a client table structure generated by the virtual network mechanism which can be indexed through the virtual identifier in response to having received an initial connection packet from a client application program running on the remote host system for enabling the subsequent mapping of each reply packet.

15. The method of claim 1 wherein the mapping step (a) of the method includes the step of mapping the well-known services identifier value to a non-well-known services identifier value containing the well-known services identifier value.

16. The mechanism of claim 15 wherein each of said first and second mapping components includes means for regenerating checksum for each inbound and outbound packet for enabling the network software facility of the lock host system to correctly process said each inbound and outbound packet by standard protocol procedures.

17. A virtual network mechanism which allows a local host system to share a communications network software facility of the local host system operating system between a number of data communications application servers operating under the host operating system and a corresponding number of application servers operating under components of a hosted operating system running under control of the local host operating system, the local host system being coupled to at least one remote host system through a local area network (LAN) and an internetwork, the network software facility being operatively coupled to a network interface unit which includes interfacing hardware and a software for connecting the local host system to the LAN for communicating with the remote host system using a standard communications network protocol which is characterized by assigning different station address identifier values to each host system such that the local host system and hosted system are assigned different station addresses and well-known services function identifier values to the different data communications applications servers associated with local host system and hosted operating systems so that servers performing the same service function are assigned the same well-known services function identifier value for directing incoming communications data packets sent by the remote host system to the appropriate communications application server running on the hosted system, said mechanism comprising:

(a) an interface component configured within the local host operating system to operatively couple the virtual network mechanism to the host operating system communications network software facility as if an another LAN which connects to a virtual host system, the interface component serving as the equivalent of the components of the hosted operating system;

(b) a first mapping component coupled to the interface component for mapping predetermined portions of each incoming packet sent by the remote host system and received from the interface component through the local host communications network software facility so that the station address identifier value of each incoming packet is changed to specify the local host system as a destination and the virtual network interface mechanism as a source of the packet for receiving for processing each reply packet sent by a hosted communications application server and the well-known services identifier value is changed to a virtual identifier value so that the packet is directed by the communications network software facility to the appropriate communications application server of the hosted operating system for processing; and

,

(c) a second mapping component for mapping the predetermined portions of each outgoing reply packet sent by a hosted system communications application server to the interface component by restoring the remote host station address identifier and well-known service identifier values so each outgoing reply packet appears to the remote host system as a reply packet to the communication initiated by a client application program running on the remote host system and the hosted system communications application server as if the server had been accessed through the LAN using the station address assigned to the hosted system and well-known service identifier value previously established for designating that service function.

18. The mechanism of claim 17 wherein the mechanism further includes an initialization component for setting up and building predetermined types of control data structures for enabling processing of each incoming and outgoing packet received from the interface component.

19. The mechanism of claim 18 wherein the predetermined types of structures include a first structure which defines the existence of the virtual network mechanism to the network software facility and a second structure which defines the virtual host system.

20. The mechanism of claim 18 wherein the first structure is an interface network structure utilized by the host operating system and the second structure is a software control structure which is used to manage packet processing for each of the client application programs running on the remote host system, the software control structure containing a predetermined number of fields, a first field for storing the state of the virtual network mechanism, a second field for maintaining a count of the number of different client entries being managed by the virtual network mechanism, third and fourth fields for storing the local host and virtual host station address identifier values wherein the virtual host station value is generated by performing an arithmetic operation on the local host station address identifier value and a fifth field for storing a client pointer value for accessing the first client table structure generated by the virtual network mechanism.