CN104539586A - Session management method and device - Google Patents

Abstract

The invention provides a session management method and device. It involves the Internet field; it solves the problem of resource shortage of firewall sessions. The method includes: establishing a unique Transmission Control Protocol TCP session for each DNS client; receiving a Domain Name System DNS query request carried in the User Datagram Protocol UDP session; confirming the TCP session of the DNS client corresponding to the UDP session, and passing the The TCP session forwards the DNS query request to the DNS server. The technical solution provided by the invention is applicable to the DNS query process, and realizes the aggregation of multiple UDP sessions into one TCP session on the firewall.

Description

Session management method and device

technical field

The invention relates to the Internet field, in particular to a session management method and device.

Background technique

With the explosive development of the Internet, especially with more and more internal and external links and pictures on the webpage, there are more and more Domain Name System (DNS, Domain Name System) messages on the network, and each DNS query will occupy a session of the firewall. And if the DNS query is mostly carried on the User Datagram Protocol (UDP, User Datagram Protocol), the session cannot be actively released after the query ends, and a large number of firewall sessions will be wasted. According to current calculations, DNS has already accounted for 20% of the number of sessions in the entire network, and the number of sessions on the firewall is increasingly tight.

Contents of the invention

The invention provides a session management method and device, which solves the problem of shortage of firewall session number resources.

A session management method comprising:

Establish a unique Transmission Control Protocol TCP session for each DNS client;

receiving a domain name system DNS query request carried in a UDP session;

Confirm the TCP session of the DNS client corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session.

Preferably, the establishment of a unique TCP session for each DNS client includes:

When receiving the DNS query message sent by the user for the first time, establish a TCP session according to the five-tuple carried by the DNS query message. The five-tuple includes: DNS client address, DNS server address, local allocation Port number, port 53 and PROTO.TCP;

A mapping table of the TCP session is established with the DNS client address, the DNS server address and the query request number TransID as indexes.

Preferably, confirming the TCP session of the DNS client corresponding to the UDP session, forwarding the DNS query request to the DNS server through the TCP session includes:

Extract the DNS client address, DNS server address and TransID of the received DNS query request;

The mapping table is queried according to the DNS client address, the DNS server address, and the TransID requested by the DNS query, and a corresponding TCP session is determined.

Preferably, the method also includes:

Receive the DNS response message carried by the TCP session sent by the DNS server;

Search the mapping table according to the DNS client address, DNS server address and TransID of the DNS response message, and find the belonging UDP session;

Carry the DNS response message in the UDP session to which it belongs, and send it to the DNS client.

The present invention also provides a session management device, including:

A TCP session establishment module, used to establish a unique TCP session for each DNS client;

A request receiving module, configured to receive a DNS query request carried in a UDP session;

The bearer conversion module is configured to confirm the TCP session of the DNS client corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session.

Preferably, the TCP session establishment module includes:

The session creation unit is configured to, when receiving the DNS query message sent by the user for the first time, according to the DNS client address, DNS server address, locally assigned port number, port 53 and PROTO. TCP establishes a TCP session for the five-tuple;

The mapping management unit is configured to use DNS client address, DNS server address and TransID as indexes to establish the mapping table of the TCP session.

Preferably, the bearer conversion module includes:

An information extraction unit, configured to extract the DNS client address, DNS server address and TransID of the DNS query request received;

A query unit, configured to query the mapping table according to the DNS client address, DNS server address and TransID requested by the DNS query, and determine the corresponding TCP session;

A conversion unit, configured to carry the DNS query request on the corresponding TCP session and send it to the DNS server.

Preferably, the device also includes:

A response receiving module, configured to receive a DNS response message sent by a DNS server and carried in a TCP session;

The UDP session query module is used to search the mapping table according to the DNS client address, DNS server address, and TransID of the DNS response message, and find the belonging UDP session;

A message forwarding module, configured to carry the DNS response message in the UDP session to which it belongs, and send it to the DNS client.

The present invention provides a session management method and device, which establishes a unique TCP session for each user, receives the DNS carried in the UDP session, confirms the TCP session of the DNS client corresponding to the UDP session, and reports to DNS through the TCP session. The server forwards the DNS query request. It realizes the convergence of multiple UDP sessions into one TCP session on the firewall, reduces resource occupation, and solves the problem of resource shortage of firewall sessions.

Description of drawings

FIG. 1 is a flowchart of a session management method provided by Embodiment 1 of the present invention;

Fig. 2 is a flow chart of DNS session aggregation;

Fig. 3 is a DNS session reverse mapping flow chart;

FIG. 4 is a schematic structural diagram of a session management device provided by Embodiment 2 of the present invention;

Fig. 5 is a schematic structural diagram of a TCP session establishment module in Fig. 4;

FIG. 6 is a schematic structural diagram of the bearer conversion module 403 in FIG. 4 .

Detailed ways

Each DNS query will occupy a session of the firewall, and if the DNS query is mostly carried on UDP, the session cannot be actively released after the query is completed, and a large number of firewall sessions will be wasted.

In order to solve the above problems, embodiments of the present invention provide a session management method and device. The DNS aggregation function is implemented in the user plane functional entity (SAE-GW, System Architecture Evolution Gateway). Using a mapping method, multiple DNS UDP sessions initiated by a user are aggregated into one TCP session and sent to the DNS server to reduce PDN. side session count purposes.

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined arbitrarily with each other.

The method described in the present invention is to realize the aggregation of DNS UDP sessions on the SAE-GW, so that the DNS UDP sessions initiated by a user are aggregated into a TCP session with the DNS server.

First, Embodiment 1 of the present invention will be described with reference to the accompanying drawings.

The embodiment of the present invention provides a session management method. During a web access process initiated by a user, there are multiple DNS queries (see FIG. 1 ), and each query port number is different. When SAE-GW receives the first UDP query, SAE-GW establishes a TCP session with the DNS server, and sends the content of the query to the DNS server on the TCP session, and saves the content on the SAE-GW at the same time. UDP session information queried by the user this time. After SAE-GW receives the query result, it maps back to the user's UDP session and sends it to the user. Subsequent DNS queries all go through the same TCP session.

According to the DNS protocol, the query request number (TransID) in the DNS message is allocated by the DNS client, and one is allocated for each query. Therefore, a DNS can be uniquely determined by establishing a mapping table with the DNS client address + DNS server address + TransID as the index. UDP session, realize the many-to-one mapping from UDP session to TCP session.

The specific implementation method is:

Fig. 1 is the DNS session aggregation interactive figure of the embodiment of the present invention, comprises the following steps:

Step 101, the DNS client initiates a DNS query, and establishes a DNS UDP session 1.

Step 102, SAE-GW uses "DNS client address, DNS server address, locally assigned port number 1, port 53, PROTO.TCP" to establish a TCP session 1 with the DNS server for the quintuple, wherein port 53 is for DNS Port reserved for service packet transmission, PROTO.TCP indicates that the session type is a TCP session. In the embodiment of the present invention, a unique TCP session is established for each user, and UDP sessions from the same user are aggregated into the same TCP session. When receiving the DNS query message sent by the user for the first time, according to the DNS client address, DNS server address, locally assigned port number, port 53, and PROTO.TCP carried by the DNS query message, the five-tuple is established A TCP session; establishing a mapping table of the TCP session with DNS client address, DNS server address, and TransID as indexes.

Step 103, SAE-GW carries the query request of DNS UDP session 1 on TCP session 1, sends it to the DNS server, and saves DNS UDP session 1 at the same time.

After the creation of the TCP session is completed, the SAE-GW can carry the DNS query request received in the UDP session to the TCP session of the user corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session . When a DNS query request is received, extract the DNS client address, DNS server address, and TransID of the DNS query request received, and then query the DNS client address, DNS server address, and TransID according to the DNS query request. The mapping table determines the corresponding TCP session, carries the DNS query request on the corresponding TCP session, and sends it to the DNS server.

In step 104, the SAE-GW receives the response message on the bearer TCP session 1, and reversely maps it to the UDP session 1.

When receiving the DNS response message sent by the DNS server and carried in the TCP session, the mapping table can also be searched according to the DNS client address, DNS server address, and TransID of the DNS response message to find the UDP session to which it belongs. , carrying the DNS response message in the belonging UDP session, and sending it to the DNS client.

Step 105, the SAE-GW sends the UDP session 1 carried by the DNS response to the DNS client.

Step 106, the DNS client sends a new DNS query, and establishes a DNS UDP session 2.

Step 107, SAE-GW carries the query request of DNS UDP session 2 on TCP session 1, sends it to the DNS server, and saves DNS UDP session 2 at the same time.

In step 108, the SAE-GW receives the response message on bearer TCP session 1, and reversely maps it to UDP session 2.

Step 109, the SAE-GW sends the UDP session 2 carried by the DNS response to the DNS client.

Figure 2 is a flowchart of DNS session aggregation, including the following steps:

In step 201, the SAE-GW receives a DNS query message and triggers a DNS session aggregation process.

Step 202, judging whether the TCP session has been established, if established, proceed to step 204, and if not established, proceed to step 203.

Step 203: Establish a TCP session with (DNS client address, DNS server address, locally assigned port number, 53, PROTO.TCP) as a quintuple.

Step 204: Establish a mapping table with (DNS client address, DNS server address, TransID) as an index.

Step 205, the DNS query message is carried on the TCP session and sent to the DNS server.

Figure 3 is a flow chart of DNS session reverse mapping, including the following steps:

In step 301, the SAE-GW receives a DNS response message and triggers a DNS session reverse mapping process.

Step 302, look up the mapping table with (DNS client address, DNS server address, TransID) as an index, and find the belonging UDP session.

Step 303, the DNS response message is carried on the original UDP session and sent to the DNS client.

Embodiment 2 of the present invention will be described below with reference to the accompanying drawings.

An embodiment of the present invention provides a session management device, the structure of which is shown in Figure 4, including:

A TCP session establishment module 401, configured to set up a unique TCP session for each user;

A request receiving module 402, configured to receive a DNS query request carried in a UDP session;

The bearer conversion module 403 is configured to confirm the TCP session of the DNS client corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session.

Preferably, the structure of the TCP session establishment module 401 is as shown in Figure 5, including:

The session creation unit 4011 is configured to, when receiving the DNS query message sent by the user for the first time, according to the DNS client address, DNS server address, locally assigned port number, port 53, PROTO .TCP establishes a TCP session for the five-tuple;

The mapping management unit 4012 is configured to use the DNS client address, DNS server address, and TransID as indexes to create a mapping table for the TCP session.

Preferably, the structure of the bearer conversion module 403 is as shown in Figure 6, including:

An information extraction unit 4031, configured to extract the DNS client address, DNS server address, and TransID of the DNS query request received;

The query unit 4032 is configured to query the mapping table according to the DNS client address, DNS server address, and TransID requested by the DNS query, and determine the corresponding TCP session;

The conversion unit 4033 is configured to carry the DNS query request on the corresponding TCP session and send it to the DNS server.

Preferably, the device also includes:

A response receiving module 404, configured to receive a DNS response message sent by the DNS server and carried in the TCP session;

The UDP session query module 405 is used to search the mapping table according to the DNS client address, DNS server address, and TransID of the DNS response message, and find the belonging UDP session;

A message forwarding module 406, configured to carry the DNS response message in the UDP session to which it belongs, and send it to the DNS client.

The above session management device can be integrated in the SAE-GW, and the SAE-GW can complete corresponding functions.

The embodiment of the present invention provides a session management method and device, which establishes a unique TCP session for each user, receives the DNS carried in the UDP session, confirms the TCP session of the DNS client corresponding to the UDP session, and passes the TCP The session forwards the DNS query request to the DNS server. It realizes the convergence of multiple UDP sessions into one TCP session on the firewall, reduces resource occupation, and solves the problem of resource shortage of firewall sessions.

Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned embodiments can be implemented using a computer program flow, the computer program can be stored in a computer-readable storage medium, and the computer program can be run on a corresponding hardware platform (such as system, device, device, device, etc.), and when executed, includes one or a combination of the steps of the method embodiment.

Optionally, all or part of the steps in the above embodiments can also be implemented using integrated circuits, and these steps can be fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module accomplish. As such, the present invention is not limited to any specific combination of hardware and software.

The devices/functional modules/functional units in the above embodiments can be realized by general-purpose computing devices, and they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices.

When each device/functional module/functional unit in the above-mentioned embodiments is realized in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. The computer-readable storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, and the like.

Anyone skilled in the art within the technical scope disclosed in the present invention can easily think of changes or substitutions, which should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope described in the claims.

Claims (8)

1. A session management method, characterized in that, comprising: Establish a unique Transmission Control Protocol TCP session for each DNS client; receiving a domain name system DNS query request carried in a UDP session; Confirm the TCP session of the DNS client corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session. 2. The session management method according to claim 1, wherein said setting up a unique TCP session for each DNS client comprises: When receiving the DNS query message sent by the user for the first time, establish a TCP session according to the five-tuple carried by the DNS query message. The five-tuple includes: DNS client address, DNS server address, local allocation Port number, port 53 and PROTO.TCP; A mapping table of the TCP session is established with the DNS client address, the DNS server address and the query request number TransID as indexes. 3. The session management method according to claim 2, wherein confirming the TCP session of the DNS client corresponding to the UDP session, forwarding the DNS query request to the DNS server through the TCP session comprises: Extract the DNS client address, DNS server address and TransID of the received DNS query request; The mapping table is queried according to the DNS client address, the DNS server address, and the TransID requested by the DNS query, and a corresponding TCP session is determined. 4. The session management method according to claim 2, further comprising: Receive the DNS response message carried by the TCP session sent by the DNS server; Search the mapping table according to the DNS client address, DNS server address and TransID of the DNS response message, and find the belonging UDP session; Carry the DNS response message in the UDP session to which it belongs, and send it to the DNS client. 5. A session management device, comprising: A TCP session establishment module, used to establish a unique TCP session for each DNS client; A request receiving module, configured to receive a DNS query request carried in a UDP session; The bearer conversion module is configured to confirm the TCP session of the DNS client corresponding to the UDP session, and forward the DNS query request to the DNS server through the TCP session. 6. The session management device according to claim 5, wherein the TCP session establishment module comprises: The session creation unit is configured to, when receiving the DNS query message sent by the user for the first time, according to the DNS client address, DNS server address, locally assigned port number, port 53 and PROTO. TCP establishes a TCP session for the five-tuple; The mapping management unit is configured to use DNS client address, DNS server address and TransID as indexes to establish the mapping table of the TCP session. 7. The session management device according to claim 6, wherein the bearer conversion module comprises: An information extraction unit, configured to extract the DNS client address, DNS server address and TransID of the DNS query request received; A query unit, configured to query the mapping table according to the DNS client address, DNS server address and TransID requested by the DNS query, and determine the corresponding TCP session; A conversion unit, configured to carry the DNS query request on the corresponding TCP session and send it to the DNS server. 8. The session management device according to claim 6, further comprising: A response receiving module, configured to receive a DNS response message sent by a DNS server and carried in a TCP session; The UDP session query module is used to search the mapping table according to the DNS client address, DNS server address, and TransID of the DNS response message, and find the belonging UDP session; A message forwarding module, configured to carry the DNS response message in the UDP session to which it belongs, and send it to the DNS client.