CN113992626A - Method, device and storage medium for realizing DNS - Google Patents

Abstract

The present application discloses a method, device, and storage medium for implementing DNS. The method includes: a programmable switch receives a message sent by a host, and determines whether the message is a DNS request message of a domain name system; if so, querying a chip hardware table Whether there is an IP address queried by the DNS request message in the item, the chip hardware entry is stored in the switch; if so, return the IP address to the host; if not, use the DNS The request message is uploaded to the local domain name server for query; the DNS response message including the IP address returned by the local domain name server is received; the DNS response message is parsed, and the DNS response message is parsed according to the IP address obtained by the analysis The mapping relationship between the domain name included in the request message and the IP address is stored in the chip hardware entry, and the IP address is returned to the host.

Description

A method, device and storage medium for implementing DNS

technical field

The present application relates to the field of domain name resolution, and in particular, to a method, device and storage medium for implementing DNS.

Background technique

IP addresses identify end users in the computer Internet. End users will use domain name access instead of IP address. In order to achieve domain name access, domain name resolution is required between the two.

Domain Name System (DNS) is the link connecting the entire Internet application layer and the network layer. Its main function is to realize the conversion between IP addresses and domain names to locate and identify Internet resources. mail, etc.) to function properly.

However, in the existing domain name resolution, problems such as slow response speed of visiting websites often occur due to the small network bandwidth and the large number of user visits, which affects the user experience.

SUMMARY OF THE INVENTION

The present application provides a method for implementing DNS, which solves the technical problem of slow response speed of visiting websites due to a large number of user visits.

A method for realizing DNS acceleration of a domain name system, comprising:

The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system;

If yes, query whether the IP address queried by the DNS request message exists in the chip hardware table entry, and the chip hardware table entry is stored in the switch;

If so, return the IP address to the host;

If not, upload the DNS request message to the local domain name server for query;

receiving a DNS response message including the IP address returned by the local domain name server;

The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware table entry. Return to the host.

In an embodiment of the present application, the judging whether the message is a domain name system DNS request message specifically includes: receiving a message sent by a host from a port of a programmable switch; parsing the message; The parsed message is sent to the logical processing unit to match the defined rules; the message that can match the defined rule is identified as a DNS request message of the domain name system.

In an embodiment of the present application, the querying whether there is an IP address corresponding to the IP address queried by the DNS request message in the chip hardware entry specifically includes: querying whether there is an IP address in the chip hardware entry A DNS domain name consistent with the DNS domain name included in the DNS request message; if so, query the IP address corresponding to the DNS domain name; determine that the state of the corresponding IP address is valid; return the IP address to the host.

In an embodiment of the present application, uploading the DNS request message to a local DNS server for query specifically includes: if the local domain name server locally queries the IP corresponding to the domain name included in the DNS request message address, reply the message carrying the IP address to the programmable server; if the local domain name server does not find the IP address corresponding to the domain name locally, query the IP address from the upper-level domain name server; If the upper-level domain name server does not query the corresponding IP address, then continue to query the upper-level domain name server of the upper-level domain name server of the local domain name server, and perform recursive query until the IP corresponding to the domain name is queried. address; when the IP address corresponding to the domain name is queried, pass it back to the local domain name server recursively through the domain name server level by level; receive the IP message corresponding to the domain name queried by the local domain name server through the programmable switch , and store the IP address corresponding to the domain name in the chip hardware entry.

In an embodiment of the present application, the parsing of the packet specifically includes: parsing to obtain the source mac address and source IP address in the packet, so as to determine the host sending the packet; parsing Obtain the vlan information in the message to determine the forwarding path of the message; parse and obtain the DNS data segment in the message to determine that the message is a DNS message; parse and obtain the DNS message The flag bit in to determine whether the DNS message is a DNS request message or a DNS response message; Parse to obtain the identification bit in the DNS message, to assist the programmable switch to determine the DNS request message and the DNS response message consistency.

In an embodiment of the present application, after storing the mapping relationship between the domain name included in the DNS request packet and the IP address in the chip hardware entry, the method further includes: if the domain name server When the stored mapping relationship between the domain name and the IP address is changed, the IP address in the chip hardware table entry is refreshed.

In an embodiment of the present application, when the IP address included in the DNS response message received by the host is invalid, a signal indicating that the IP address is invalid is sent to the programmable switch; The switch sends the DNS request message; after receiving the DNS request, the programmable switch forwards the DNS request message to the local domain name server.

In an embodiment of the present application, before receiving the message sent by the host, the method further includes: running a DNS server program on the programmable switch; The default is the main configuration file, and the generated root.z file is used to configure related records.

The embodiment of the present application also provides a device for implementing the domain name system DNS, including:

at least one processor; and,

a memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system;

If yes, query whether the IP address queried by the DNS request message exists in the chip hardware table entry, and the chip hardware table entry is stored in the switch;

If so, return the IP address to the host;

If not, upload the DNS request message to the local domain name server for query;

receiving a DNS response message including the IP address returned by the local domain name server;

The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware table entry. Return to the host.

Embodiments of the present application further provide a non-volatile storage medium storing computer-executable instructions, wherein the computer-executable instructions are set to:

The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system;

If yes, query whether the IP address queried by the DNS request message exists in the chip hardware table entry, and the chip hardware table entry is stored in the switch;

If so, return the IP address to the host;

If not, upload the DNS request message to the local domain name server for query;

receiving a DNS response message including the IP address returned by the local domain name server;

The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware table entry. Return to the host.

The present application provides a method for implementing DNS, which at least includes the following beneficial effects: when a terminal user accesses a domain name, by using a programmable switch as a local DNS server, the query of the domain name corresponding to the host can be accelerated, and the network bandwidth is small and user access is effectively avoided. It can improve the response speed of users visiting the website. By recording the domain name whose IP address is queried for the first time, a learning is realized, and subsequent DNS requests of the same domain name can be automatically replied multiple times without going through multi-level domain name servers for query, which speeds up the DNS process. Inquire. Accelerates DNS domain name resolution through the acceleration of DNS node access at the hardware level of programmable switches. At the same time, it implements lightweight DNS server deployment to meet the DNS server deployment requirements of small networks and save user costs.

Description of drawings

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the attached image:

1 is a schematic diagram of steps for implementing a DNS method provided by an embodiment of the present application;

2 is a schematic diagram of a programmable switch implementing a DNS system provided by an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a device for implementing DNS according to an embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described clearly and completely below with reference to the specific embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

The Internet Protocol (IP) addresses interconnected between networks identify end users in the computer Internet. End users will use domain name access instead of IP address. In order to achieve domain name access, domain name resolution is required between the two. Because the design of the domain name system is a distributed database of Transmission Control Protocol/Internet Protocol (Transmission Control Protocol/Internet Protocol, TCP/IP) applications. Then when accessing a domain name, if the corresponding IP address cannot be obtained in the cache record of the host's local Domain Name System (DNS) resolver, it will recursively go to the next DNS recursive server to query, and finally get the corresponding domain name IP address.

Domain Name System (DNS) is the link connecting the entire Internet application layer and the network layer. Its main function is to realize the conversion between IP addresses and domain names to locate and identify Internet resources. mail, etc.) to function properly.

However, in the existing domain name resolution, problems such as slow response speed of visiting websites often occur due to the small network bandwidth and the large number of user visits, which affects the user experience.

A method for implementing DNS provided by this application, when a terminal user accesses a domain name, by using a programmable switch as a local DNS server, the query of the corresponding domain name of the host can be accelerated, and the network bandwidth is small, the user access volume is large, and the distribution of the network points is not effectively avoided. Equalize the problem and improve the response speed of users visiting the website. A specific description will be given below.

1 is a schematic diagram of steps for implementing a DNS method provided by an embodiment of the present application, which may include the following steps:

S101: Receive a message sent by the host, and determine whether the message is a DNS request message of the domain name system.

In the process of accessing the network, the host needs to query the IP address corresponding to the accessed network. First, the host sends a DNS request message to the programmable switch. When the programmable switch queries the corresponding IP address, it generates a DNS response message and returns it. host. As shown in Figure 2, DNS queries can be accelerated through a system of established programmable switches. After the programmable switch receives the DNS request message from the host, it processes the message through the CPU. If the corresponding IP address is queried in the programmable chip of the programmable switch, it will reply the DNS response message to the host. If it is not queried in the programmable chip P4, the DNS request message is forwarded to the upper-level DNS server for query. When the upper-level DNS server finds the corresponding IP address, it returns a DNS response message to the programmable switch.

In an embodiment of the present application, before receiving the message sent by the host, run a DNS server (DNS server) program on the programmable switch; according to the running DNS server program, the generated sr.conf is configured as the main configuration by default file, the generated root.z file is used to configure related records. DNS server is an application program that can support the host to find the IP address corresponding to the domain name through the programmable switch.

Specifically, in order to run the DNS server program well on the programmable switch, the operating system on the programmable switch can be a Linux operating system, and the installed software is dnspod-sr to support the DNS server program running on the programmable switch. dnspod-sr is a high-performance recursive DNS server software running on the Linux operating system. It has the advantages of high performance, high load, and easy expansion. Its characteristics are stable, which can effectively reduce the failure rate of parsing. It can actively refresh the cache and respond to high speed.

There will be three configuration files in the unpacked root directory: records.z, root.z, sr.conf, sr.conf is the main configuration file by default, and the content of the configuration file will be automatically read at startup. The root.z configuration file is used to configure related records.

In an embodiment of the present application, the packet sent by the host enters through the port of the programmable switch, and then the packet is parsed by the programmable chip in the programmable switch. The packet generally includes the host's source mac address, source IP address, vlan information, and DNS data segments. The source mac address and source IP address in the packet are obtained through parsing to determine the host sending the packet; the vlan information in the packet is obtained through parsing to determine the forwarding path of the packet; the DNS data segment in the packet is obtained through parsing to determine the forwarding path of the packet. It is determined that the message is a DNS message, and the DNS traffic is identified at the data level; the flag bits in the DNS message are obtained by parsing to determine whether the DNS message is a DNS request message or a DNS response message; The flag is used to assist the programmable switch in determining the consistency between the DNS request message and the DNS response message.

The parsed message is sent to the logic processing unit for matching of defined rules. The content of the data segment obtained by parsing can be identified as DNS request data according to the defined rule matching, and then the message is executed next. deal with accordingly.

S102: If yes, query whether the IP address queried by the DNS request message exists in the chip hardware entry, where the chip hardware entry is stored in the switch.

In an embodiment of the present application, when the programmable switch receives and recognizes that the message sent by the host is a DNS request message, it firstly queries the chip hardware entry in the programmable switch whether there is a message related to the DNS request message. The DNS domain name included in this article is the same as the DNS domain name, and the format of the chip hardware table entry is shown in the following table.

S103: If yes, return the IP address to the host.

If it exists, query whether the DNS domain name has a corresponding IP address in the chip hardware table entry; if so, query whether the status of the corresponding IP address is valid; if so, return the IP address to the host.

DNS domain name Domain name corresponds to IP address state www.****.com x.x.x.x efficient

S104: If no, upload the DNS request message to the local domain name server for query.

In an embodiment of the present application, when the programmable switch does not locally query the IP address corresponding to the DNS request message, then according to the preferred DNS server (usually the local domain name server) set in the TCP/IP parameters, The local domain name server forwards the DNS request message. When the local domain name server receives the query request, if it detects that the domain name to be queried is contained in the local domain name server's local configuration area resources, that is, if the local domain name server finds the query locally The IP address corresponding to the domain name contained in the DNS request message will reply the resolution result to the programmable server, that is, the message carrying the IP address, to complete the domain name resolution. If the domain name is not resolved on the local domain name server, but the mapping relationship between the domain name and the IP address is cached on the local domain name server, the domain name resolution is completed.

If the local domain name server does not query the IP address corresponding to the domain name locally, it will query the IP address of the upper-level domain name server; The upper-level domain name server of the upper-level domain name server performs a query, and performs a recursive query until the IP address corresponding to the domain name is queried; when the IP address corresponding to the domain name is queried, it is recursively transmitted back to the local domain name server through the domain name server level by level; The programmable switch receives the IP packet corresponding to the domain name queried by the local domain name server, and stores the IP address corresponding to the domain name in the chip hardware table entry.

Specifically, if both the local domain name server and the cache resolution fail, the query is performed according to the settings of the local domain name server, and the local domain name server will forward the DNS request message to the upper-level domain name server, which will be parsed by the upper-level server. The upper-level domain name server of the domain name server is generally the root domain name server. If the root domain name server cannot be resolved, the root domain name server will then forward the forwarding request to its upper-level domain name server. The upper-level domain name server of the root domain name server is generally Top-level domain name servers for recursive queries. When the IP address corresponding to the domain name is queried, it is recursively passed back to the local domain name server through the domain name server. The root domain name server is passed back to the local domain name server, which is then passed back to the programmable switch by the local domain name server, and then returned to the host by the programmable switch.

S105: Receive a DNS response message including a corresponding IP address returned by the local domain name server.

When the local domain name server sends a DNS response message, the programmable switch receives the returned DNS response message containing the corresponding IP address.

S106: Parse the DNS response message, store the mapping relationship between the domain name and the IP address contained in the DNS request message in the chip hardware table entry according to the IP address obtained by the parsing, and return the IP address to the host.

When the programmable switch receives the IP packet corresponding to the domain name queried by the local domain name server, it parses the packet and stores the IP address corresponding to the domain name in the chip hardware table entry. By storing the mapping relationship between the domain name and the IP address in the chip hardware table entry, one-time learning is realized, and the IP address requested by the domain name is automatically replied many times, thus realizing the accelerated query of DNS.

In an embodiment of the present application, after the mapping relationship between the domain name and the IP address contained in the DNS request message is stored in the chip hardware table entry, in order to prevent the cached mapping relationship from invalidating, when the domain name stored in the domain name server and the IP address are stored in the When the mapping relationship of the IP address is invalid or changed, the IP address in the hardware table entry of the chip is refreshed.

In an embodiment of the present application, the programmable switch returns the corresponding IP address to the host according to the mapping relationship stored in the chip hardware entry. When the IP address included in the DNS response packet received by the host is invalid, the host If the interface cannot see the page information of the visited website, it means that the IP address received by the host is invalid. At this time, the host can send a signal that the IP address is invalid to the programmable switch, to inform the programmable switch that the IP address stored in the switch is invalid. If the corresponding website is not accessed, the user will click the refresh button in the interface, and the host will send the DNS request message to the programmable switch again; the programmable switch will forward the DNS request message to the local domain name server after receiving the DNS request. , the local domain name server will query the IP address corresponding to the URL, and then return the IP address to the host in a recursive way.

A method for implementing DNS provided by an embodiment of the present application is provided above. Based on the same inventive idea, an embodiment of the present application also provides a corresponding device for implementing DNS, as shown in FIG. 3 .

This embodiment provides a device for implementing DNS, including:

at least one processor; and,

a memory communicatively coupled to the at least one processor; wherein,

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system;

If yes, query whether there is an IP address queried by the DNS request message in the chip hardware table entry. The chip hardware table entry is stored in the switch;

If so, return the IP address to the host;

If not, upload the DNS request message to the local domain name server for query;

Receive the DNS response message containing the IP address returned by the local domain name server;

The DNS response message is parsed, and the mapping relationship between the domain name and the IP address contained in the DNS request message is stored in the chip hardware table entry according to the IP address obtained by the resolution, and the IP address is returned to the host.

Based on the same idea, some embodiments of the present application also provide a medium corresponding to the above method.

Some embodiments of the present application provide a non-volatile storage medium for implementing DNS, which stores computer-executable instructions, and the computer-executable instructions are set to:

The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system;

If yes, query whether there is an IP address queried by the DNS request message in the chip hardware table entry. The chip hardware table entry is stored in the switch;

If so, return the IP address to the host;

If not, upload the DNS request message to the local domain name server for query;

Receive the DNS response message containing the IP address returned by the local domain name server;

The DNS response message is parsed, and the mapping relationship between the domain name and the IP address contained in the DNS request message is stored in the chip hardware table entry according to the IP address obtained by the resolution, and the IP address is returned to the host.

The present application provides a method for implementing DNS, which at least includes the following beneficial effects: when a terminal user accesses a domain name, by using a programmable switch as a local DNS server, the query of the domain name corresponding to the host can be accelerated, and the network bandwidth is small and user access is effectively avoided. It can improve the response speed of users visiting the website.

Each embodiment in this application is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method and medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and reference may be made to some descriptions of the method embodiments for related parts.

The methods and media provided in the embodiments of the present application are in a one-to-one correspondence with the methods. Therefore, the methods and media also have similar beneficial technical effects to their corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, therefore, The beneficial technical effects of the method and medium will not be repeated here.

It should also be noted that the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, commodity or method that includes a list of elements includes not only those elements, but also includes not explicitly Other elements listed, or that are inherent to the commodity or method of the process. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process method article or method that includes the element.

The above descriptions are merely examples of the present application, and are not intended to limit the present application. Various modifications and variations of this application are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims (10)

1. a method for realizing Domain Name System DNS, is characterized in that, comprises: The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system; If yes, query whether the IP address queried by the DNS request message exists in the chip hardware table entry, and the chip hardware table entry is stored in the switch; If so, return the IP address to the host; If not, upload the DNS request message to the local domain name server for query; receiving a DNS response message including the IP address returned by the local domain name server; The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware table entry. Return to the host. 2. The method according to claim 1, wherein the judging whether the message is a domain name system DNS request message specifically comprises: Receive the message sent by the host from the port of the programmable switch; parsing the message; Send the parsed message to the logic processing unit for matching of defined rules; The packets that can match the defined rules are identified as DNS request packets of the Domain Name System. 3. The method according to claim 1, wherein whether there is an IP address corresponding to the IP address queried by the DNS request message in the query chip hardware table entry, specifically comprising: Query whether there is a DNS domain name consistent with the DNS domain name included in the DNS request message in the chip hardware table entry; If so, query the IP address corresponding to the DNS domain name; determining that the status of the corresponding IP address is valid; Return the IP address to the host. 4. The method according to claim 1, wherein the described DNS request message is uploaded to a local DNS server for query, specifically comprising: If the local domain name server locally queries the IP address corresponding to the domain name included in the DNS request message, it will reply to the programmable server with a message carrying the IP address; If the local domain name server does not locally query the IP address corresponding to the domain name, query the IP address from the upper-level domain name server; If the upper-level domain name server of the local domain name server does not query the corresponding IP address, continue to query the upper-level domain name server of the upper-level domain name server of the local domain name server, and perform recursive query until the query The IP address corresponding to the domain name; When the IP address corresponding to the domain name is queried, it is recursively transmitted back to the local domain name server through the domain name server; The programmable switch receives the IP message corresponding to the domain name queried by the local domain name server, and stores the IP address corresponding to the domain name in the chip hardware entry. 5. The method according to claim 2, wherein the parsing of the message specifically comprises: Obtain the source mac address and source IP address in the message by parsing, to determine the host sending the message; Obtain the vlan information in the message by parsing to determine the forwarding path of the message; Parsing to obtain the DNS data segment in the message, to determine that the message is a DNS message; The flag bit in the DNS message is obtained by parsing, to determine whether the DNS message is a DNS request message or a DNS response message; The identification bit in the DNS message is obtained by parsing, so as to assist the programmable switch in determining the consistency between the DNS request message and the DNS response message. 6. The method according to claim 1, wherein after storing the mapping relationship between the domain name and the IP address contained in the DNS request message in the chip hardware table entry, the method further comprises: : If the mapping relationship between the domain name and the IP address stored in the domain name server is changed, the IP address in the chip hardware table entry is refreshed. 7. The method according to claim 1, wherein before receiving the message sent by the host, the method further comprises: Run the DNS server program on the programmable switch; According to the running DNS server program, the generated sr.conf is used as the main configuration file by default, and the generated root.z file is used to configure related records. 8. The method of claim 1, wherein the method further comprises: When the IP address contained in the DNS response message received by the host is invalid, it sends a signal that the IP address is invalid to the programmable switch; Based on the user's refresh operation, the host re-sends the DNS request message to the programmable switch; After receiving the DNS request, the programmable switch forwards the DNS request message to the local domain name server. 9. A device for realizing Domain Name System DNS, characterized in that, comprising: at least one processor; and, a memory communicatively coupled to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to: The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system; If so, query whether there is an IP address queried by the DNS request message in the chip hardware entry, and the chip hardware entry is stored in the switch; If so, return the IP address to the host; If not, upload the DNS request message to the local domain name server for query; receiving a DNS response message including the IP address returned by the local domain name server; The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware entry. Return to the host. 10. A non-volatile storage medium storing computer-executable instructions, wherein the computer-executable instructions are set to: The programmable switch receives the message sent by the host, and determines whether the message is a DNS request message of the domain name system; If so, query whether there is an IP address queried by the DNS request message in the chip hardware entry, and the chip hardware entry is stored in the switch; If so, return the IP address to the host; If not, upload the DNS request message to the local domain name server for query; receiving a DNS response message including the IP address returned by the local domain name server; The DNS response message is parsed, and the mapping relationship between the domain name included in the DNS request message and the IP address is stored in the chip hardware entry according to the IP address obtained by the analysis, and the IP address is stored in the chip hardware entry. Return to the host.

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