WO2019052058A1

WO2019052058A1 - Domain name redirecting method and system

Info

Publication number: WO2019052058A1
Application number: PCT/CN2017/116429
Authority: WO
Inventors: 赵冲
Original assignee: 上海斐讯数据通信技术有限公司
Priority date: 2017-09-14
Filing date: 2017-12-15
Publication date: 2019-03-21
Also published as: CN107613037A; CN107613037B

Abstract

Disclosed are a domain name redirecting method and system. The method comprises the following steps: S10, obtaining an Internet Protocol (IP) address; S20, parsing a data packet in a link layer, and intercepting a designated domain name request; and S30, redirecting the designated domain name request to the IP address. By means of the present invention, a user simply needs to remember a domain name and can directly access a network by means of the domain name, and thus the method is more friendly. In addition, the present invention expands the interception range of DNS request data packets, and can perform identical interception and redirection on DNS requests not passing an IP layer, thereby ensuring the integrity of data and ensuring the comprehensiveness of device management; for service providers, some network devices that cannot be managed by accessing fixed IP addresses can be managed by the method by accessing fixed IP addresses, and thus the network management is more convenient and more standardized.

Description

Domain name redirection method and system

Technical field

The present invention relates to the field of Internet, and in particular, to a domain name redirection method and system.

Background technique

DNS (Domain Name System) is a system that converts an access domain address into a corresponding IP address (Internet Protocol Address, also known as an Internet Protocol Address). It acts as a domain name and an IP address on the Internet. A distributed database that provides domain name to IP address translation, which makes it easier for users to access the Internet without having to remember the IP number string that can be directly read by the machine. Usually the URL we input is a domain name. The process of obtaining the IP address corresponding to the host name by the host name is called domain name resolution (or host name resolution). DNS is a system for domain name resolution. The DNS protocol runs on top of the UDP protocol and uses port number 53.

At present, in the process of domain name resolution for DNS requests, most network devices need to redirect specific DNS requests for various purposes, such as to implement management of specific domain names or provide data support for project development and internal testing. DNS redirection is used in the Internet to facilitate the selection of cache servers based on DNS resolution mechanisms. These technologies are widely used by various CDN companies.

The patent document disclosed in the publication No. CN102014173B discloses "a domain name redirection control method, module and system". The method indicates that the domain name redirection control module receives the domain name obtained and sent by the DNS server from the user request when responding to the user domain name request. And determining, according to the saved redirected domain name information, whether the received domain name information is available for redirection, and if it is determined that the domain name requested by the user is available for redirection, redirecting the domain name accessed by the user to the corresponding IP address. The redirected domain name information is stored in a redirected domain name list, and the redirected domain name list records a domain name that is not available for redirecting. However, the method only points out that the DNS server obtains and sends the domain name when responding to the user domain name request, and does not indicate where to intercept. The location of the interception directly affects the success of the interception, and the acquisition process of the corresponding IP address. , did not propose a more practical approach.

Another example is the patent document published as CN101505323B, which discloses "based on content under massive data. Analysis of the domain name resolution redirection method, the method includes the method of obtaining the domain name, the determination of the correct domain name error domain name, and the analysis and processing method of the incorrect domain name. When the user inputs the wrong domain name, instead of directly returning to the blank page, the domain name input to the user The content is analyzed, and according to the content of the domain name, the information most needed by the user is returned, and the helplessness of the user to open the blank page is avoided, and the service can be provided to the customer more intelligently.

Regarding the specific DNS request redirection method, the general implementation scheme after induction is roughly as follows: First, the domain name is modified by adding the binary combination of the domain name and the IP address in the application layer by modifying the /etc/hosts file. Hijacking; add the form as follows 192.168.1.103www.sohu.com, where 192.168.1.103 is the local server IP, www.sohu.com is the domain name to be hijacked. The second is to intercept the DNS packets through the IP layer of the network protocol stack, and re-group a DNS return packet to send to the specified IP address. For simpler applications, by adding a binary combination of domain name and IP address in the application layer /etc/hosts file, you can easily redirect to a specified IP for a certain domain name or domain name; but for relatively complex In terms of application requirements, basically all of them will choose to intercept the DNS request packet at the IP layer.

However, after some network devices on the market receive the DNS request from the client, they will not send the DNS request to the IP layer of the network device network protocol stack. The above two implementation solutions cannot be used without the IP layer. The DNS request packet is intercepted, causing a blind spot in the management of the network device.

It can be seen that it is desirable to provide a solution to avoid the above problems and defects.

Summary of the invention

The technical problem to be solved by the present invention is to address the shortcomings of the above prior art, and provide a domain name redirection capable of intercepting and redirecting a DNS request packet that does not go through the IP layer but only at the link layer to the corresponding IP address. Methods and systems.

In order to achieve the above object, the technical solution adopted by the present invention is:

A domain name redirection method, the method comprising the following steps:

S10: Obtain an internet protocol address;

S20: Parsing the data packet in the link layer and intercepting the specified domain name request;

S30: Redirect the specified domain name request to the internet protocol address.

Further, the step S20 includes:

S21: Parsing a data packet in the link layer, and determining whether the data packet is a domain name packet data packet;

S22: If the domain name packet data packet, continue to parse the domain name packet data packet to obtain a domain name;

S23: Determine whether the domain name is a designated domain name, and if yes, perform step S30.

Further, the step S30 includes:

S31: Construct a domain name return packet, and redirect the domain name return packet to the internet protocol address.

Further, the step S10 includes:

S11: Obtain an internet protocol address from the corresponding server according to the dynamic host configuration protocol.

Further, the step S10 and the step S20 include: determining whether the internet protocol address is successfully obtained. If successful, performing step S20. If not, step S20 is not performed.

Further, the step S20 includes: establishing a hook function, and hooking all link layer data packets to the hook function.

Further, the hook function execution step includes:

S21: Parsing the data packet, and determining whether the data packet is a domain name message data packet;

A domain name redirection system, the system comprising:

An internet protocol address module for obtaining an internet protocol address;

Parsing an interception module for parsing data packets in the link layer and intercepting the specified domain name request;

And a redirection module, configured to redirect the specified domain name request to the internet protocol address.

Further, the parsing intercepting module includes:

a first determining unit, configured to determine whether the data packet is a domain name packet data packet, after the data packet in the link layer is parsed;

An obtaining unit, configured to acquire a domain name when continuing to parse the domain name message data packet if the first determining unit determines that the domain name message data packet is

The second determining unit is configured to determine whether the domain name obtained by the acquiring unit is a specified domain name.

Further, the redirection module includes:

A construction unit that constructs a domain name return package.

After adopting the above technical solution, the beneficial effects of the present invention are:

(1) Since the Internet Protocol address is mostly dynamically allocated by the server, there is uncertainty, After the corresponding Internet Protocol address is obtained in the device, the request to intercept the specified domain name is parsed, so that the parsing process is not used as much as possible, and the network resources are not wasted;

(2) By parsing the data packets in the link layer and intercepting the specified domain name request, all DNS requests can be intercepted including DNS requests without IP layer, so that more clients can get more convenient and smooth Internet access. Experience, but also provides convenience for service providers to better manage network services through a better domain name;

(3) obtaining the domain name by first determining whether the link layer data packet is a domain name packet data packet, and acquiring the domain name, instead of acquiring the key field in the link layer data packet To facilitate accurate domain name acquisition while reducing the total amount of link layer packet parsing tasks;

(4) By establishing a hook function, all link layer data packets are hooked to the hook function, and all link layer data packets can be obtained simply and quickly, and all DNS requests can be processed according to a unified parsing interception method. , provides conditions for redirecting all specified domain names without flaws.

In general, the above implementation scheme adopts a way of directly accessing the network by remembering the domain name, which is easier for the user to remember and more friendly; the same for the service provider, some network devices that cannot be managed by accessing a fixed IP address. The above scheme can be used to manage the network device by setting a fixed domain name by using a fixed domain name; in addition, the above technical solution expands the interception range of the DNS request packet, and can perform the same for the DNS request without the IP layer. Interception and redirection ensure data integrity and ensure the comprehensiveness of device management.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the prior art, the drawings are as follows:

FIG. 1 is a flowchart of a domain name redirection method according to Embodiment 1 of the present invention;

2 is a flowchart of a domain name redirection method according to Embodiment 2 of the present invention;

FIG. 3 is a flowchart of a domain name redirection method according to Embodiment 3 of the present invention;

FIG. 4 is a structural diagram of a domain name redirection system according to Embodiment 4 of the present invention.

Detailed ways

The technical solutions of the present invention are further described below with reference to the accompanying drawings, but the present invention is not limited to the embodiments.

With the rapid development of wireless networks, we can experience the efficiency and convenience of WLAN (also known as the WIFI network) for our lives anytime, anywhere. In recent years, WIFI devices have emerged in an endless stream, and WIFI devices have a variety of ways to establish network connections. Different WIFI devices under different connection modes perform their respective functions due to different needs.

DNS (Domain Name System) is one of the ways to establish a network connection. In the process of DNS request execution, in order to implement the management of a specific domain name or provide data support for project development and internal testing, a specific DNS is required. Request a redirect. In most of the existing redirection operations, DNS requests are intercepted in some places of the IP layer, and it is impossible to intercept request packets that do not pass through the IP layer, and cannot manage some network devices by using a fixed domain name. Demand. Therefore, it is necessary to perform packet interception somewhere in the link layer.

In order to solve the above problems, the present invention provides a solution for conveniently accessing and managing some network devices such as a repeater or a WIFI expander connected to a main router through a wireless bridge, or a user accessing these devices through a domain name. When the DNS request sent by the terminal does not actively go to the IP layer of these devices, the DNS request interception is performed somewhere in the link layer in advance, and is redirected to the IP of these devices.

The scheme implements a hook structure by establishing a kernel module, intercepts the DNS request in the link layer, and constructs a corresponding return packet to redirect the DNS request to the device IP. Among them, when the kernel module is started, how to perform the redirection and timely execution are all issues to be considered when designing this solution.

Example 1

As shown in FIG. 1 , this embodiment provides a domain name redirection method, where the method includes the following steps:

S10: Obtain an internet protocol address (IP address);

In this step, the router or Repeater first finds the IP address used by the device to connect to the network, and saves the IP address information field, such as 192.168.18.25. Then trigger the next step to start the packet parsing of the link layer. Since the existing IP address is mostly a dynamic IP address allocated by the server, instead of a fixed IP address, the IP address is first obtained in this step, and then the process of parsing the data packet in the link layer is started, which can reduce unnecessary data parsing and save network resources. , purify the network connection process.

S20: Parsing a data packet in the link layer and intercepting a specified domain name (DNS) request;

In this step, after obtaining the IP address, the router or the Repeater actively triggers the process of parsing the data packet in the link layer, parses all the data packets in the link layer, and intercepts the DNS request specified by the service provider. After the interception is completed, the next step is performed. If the specified DNS request is set to e.to, the DNS request of e.to will be found in this step and intercepted for use; all DNS requests include DNS requests that do not go through the IP layer. Can be intercepted, so that more clients get more convenient and smooth access or online experience, and also provide convenience for service providers through a better domain name, a wider range of management routers or Repeater network devices;

S30: Redirect the specified domain name (DNS) request to the internet protocol address (IP address).

In this step, after the router or Repeater intercepts the DNS request specified by the service provider, the DNS request is redirected to the previously obtained IP address, that is, after obtaining 192.168.18.25 and e.to successively, e.to Specifies that the DNS request is redirected to the IP address 192.168.18.25. In this way, the function of accessing the router or the Repeater through the DNS is realized, which is convenient for the user to memorize and smoothly establish the network connection, and also facilitates the service provider to manage the network device such as the router or the Repeater by accessing the fixed DNS.

The domain name redirection method provided in this embodiment implements accessing and managing some network devices that do not actively send DNS requests to their own IP layers through DNS. These network devices may be WIFI expanders, Repeaters, and the like.

Example 2

As shown in FIG. 2, the difference between this embodiment and the previous embodiment is that the present embodiment provides a more detailed domain name redirection method, and the step S20 specifically includes:

S21: Parsing a data packet in the link layer, and determining whether the data packet is a DNS packet data packet;

In this step, after obtaining the IP address, the router or the Repeater first parses all the data packets received in the link layer one by one, finds the DNS packet data packet, and determines whether the DNS packet is a monitoring packet. Whether it is from port 53 of the UPD protocol.

S22: If it is a DNS packet data packet, continue to parse the DNS packet data packet to obtain a DNS;

In this step, if it is determined that the data packet is indeed from port 53 of the UPD protocol, then the packet data packet is continuously parsed to obtain the DNS in the packet.

S23: Determine whether the DNS is a designated DNS, and if yes, execute step S30.

In this step, the DNS obtained is matched with the DNS set by the service provider, for example, a hypothetical service. If the specified DNS is e.to, it is determined whether the obtained DNS is e.to. If the judgment result is yes, the router or Repeater will redirect the e.to DNS request to the previously obtained IP address, and finally It realizes the function that can be accessed through DNS.

In summary, by first determining whether the data packet is a DNS packet data packet, and then obtaining the DNS, and finally confirming whether it is the parsing and intercepting sequence of the specified DNS, the total number of link layer data packet parsing tasks can be reduced, and the device can be accurate. Get DNS and complete DNS access.

Optionally, the step S30 includes:

S31: Construct a DNS return packet and redirect the DNS return packet to the IP address.

In this step, the router or the Repeater and other devices confirm that the DNS request sent by the client is indeed the specified e.to, which is recognized by itself, and then constructs an e.to according to the packet encoding type identifiable by the device. The packet data packet (referred to as the DNS return packet), for example, e.to is www.baidu.com, which is constructed according to the packet encoding type identifiable by the device, and is 3www5baidu3com. After the DNS return packet is constructed, the DNS return packet is returned. Redirecting to the IP address, the IP address is an IP address obtained before the device parses the data packet in the link layer.

Optionally, the step S10 includes:

S11: Obtain an IP address from the corresponding server according to the DHCP protocol.

Repeater devices generally connect to the primary router through wireless bridging. When the Repeater successfully bridges the primary router through WIFI, the Repeater uses the network with the primary router. The IP address of the primary router is a dynamic IP address, which arrives with the lease term. The IP address may be changed, with uncertainty, and the way to save a unique IP address obviously does not satisfy the access requirements. In this step, the udhcpc process is obtained by using the udhcpc process. The udhcpc process obtains the IP address from the DHCP server of the primary router through the DHCP protocol. The IP address is obtained according to the IP address allocation principle. The obtained IP address is more realistic and more accurate. accurate.

It should be noted that the step S10 and the step S20 include: determining whether the IP address is successfully obtained. If successful, performing step S20. If not, step S20 is not performed. That is to say, only when the process of obtaining an IP address successfully obtains an IP address that meets the access requirement, the packet in the link layer is parsed and the specified DNS request process is intercepted. Reduce unnecessary parsing interception process, purify the network, and save resources.

The domain name redirection method provided in this embodiment helps the network device adopting the method to be more intelligent. Complete the DNS access process and more accurately guarantee DNS access.

Example 3

As shown in FIG. 3, the difference between this embodiment and the embodiment 2 is that the embodiment provides a detailed method for realizing domain name redirection in the Linux kernel, and the Repeater is taken as an example. In this embodiment, if only the Repeater obtains the current After the IP address of the network connection, the Repeater loads the DNS interception process through the Insmod tool, that is, the corresponding processes of steps S20 and S30 are started to implement DNS redirection.

During the programming process, the corresponding processes mentioned in steps S20 and S30 are written to the same dns_redirect.ko kernel module. If and only after the Repeater obtains the IP address (redirect_ip) under the current network connection, the Insmod tool will be dns_redirect. The ko kernel module is loaded into the Linux kernel, and finally the specified DNS redirection is implemented. It is not difficult to understand that DNS and redirect_ip are two parameters when loading the dns_redirect.ko kernel module.

Specifically, the step S20 includes:

A hook function is created to hook all link layer packets to the hook function.

A hook function is a program segment that processes a message and hooks it into the system through a system call. Whenever a specific message is sent, the hook program first captures the message before it reaches the destination window, that is, the hook function first obtains control, providing conditions for subsequent processing of the message. In this step, a hook function is established, which can hang all link layer data packets into the same processing segment of the message, perform the same processing process, and complete DNS interception and redirection without any problem, thereby establishing a method to A bridge for specific program implementation.

Specifically, the hook function execution step includes:

S21: Parsing the data packet, and determining whether the data packet is a DNS packet data packet;

The execution procedure of the hook function here is the same as the specific implementation process of step S20 in Embodiment 2, and will not be described again.

In addition, some program implementations are defined as follows:

Static struct packet_type all_packet_type__read_mostly={

.type=cpu_to_be16(ETH_P_ALL),

.func=ip_skb_recv, /*ip receive method*/

};

Among them, the general idea is to first implement a packet_type kernel structure, parse the data packet of type ETH_P_ALL, and execute the hook function ip_skb_recv.

Static int__init dns_redirect_init(void)

{

If(dns){

D_len=strlen(dns);

}

Dev_add_pack(&all_packet_type);

Return 0;

}

Insmod dns_redirect.ko, hooks the all_packet_type instance to the path that the packet must pass through a dev_add_pack function. In this way, the hook function of ip_skb_recv is established, and all link layer data packets are implemented by the ip_skb_recv function to implement the hook process.

This embodiment provides a practical program design, hooking all link layer data packets to the hook function, and can easily and quickly obtain all link layer data packets, and can process all according to a unified parsing interception method. The DNS request provides conditions for redirecting all specified DNS. In general, users and service providers can access and manage only network devices that do not actively send DNS requests to their own IP layer through domain names.

Example 4

As shown in FIG. 4, this embodiment provides a domain name redirection system, where the system includes:

The IP address module 100 is configured to obtain an IP address.

The parsing intercepting module 200 is configured to parse the data packet in the link layer and intercept the specified DNS request;

The redirecting module 300 is configured to redirect the specified DNS request to the IP address.

Further, the parsing intercepting module 200 includes:

The first determining unit 210 is configured to: after parsing the data packet in the link layer, determine whether the data packet is a DNS packet data packet;

The obtaining unit 220 is configured to: if the first determining unit 210 determines that it is a DNS packet data packet, Obtaining DNS when resolving the DNS packet data packet;

The second determining unit 230 is configured to determine whether the DNS acquired by the obtaining unit 220 is a designated DNS.

Further, the redirection module 300 includes:

The construction unit 310 is configured to construct a DNS return packet.

Taking a router as an example, the system works as follows: The IP address module 100 of the router obtains a dynamic IP address backup from the DHCP server, such as 192.168.15.28. Then, the parsing interception module 200 of the router parses the data packet in the link layer, and the first determining unit 210 determines whether the data packet is a DNS packet data packet, and if the result is not, the process ends, and if the result is yes, the process starts. The obtaining unit 220 intercepts the acquisition of the DNS when the DNS packet data packet is continuously parsed; the second determining unit 230 determines whether the DNS acquired by the obtaining unit 220 is a designated DNS, such as e.to. If not, the process is terminated. If so, the construction unit 310 starts to start constructing the e.to return packet, and the redirection module 300 of the router redirects the e.to return packet to the IP address 192.168.15.28.

The domain name redirection system provided in this implementation expands the interception range of DNS request packets, and can perform the same interception and redirection for some DNS requests that do not pass through the IP layer, thereby ensuring data integrity and ensuring comprehensiveness of device management. .

The specific embodiments described herein are merely illustrative of the spirit of the invention. A person skilled in the art can make various modifications or additions to the specific embodiments described or in a similar manner, without departing from the spirit of the invention or as defined by the appended claims. The scope.

Claims

A domain name redirection method, characterized in that the method comprises the following steps:

S10: Obtain an internet protocol address;

S20: Parsing the data packet in the link layer and intercepting the specified domain name request;

S30: Redirect the specified domain name request to the internet protocol address.
The domain name redirection method according to claim 1, wherein the step S20 includes:

S21: Parsing a data packet in the link layer, and determining whether the data packet is a domain name packet data packet;

S22: If the domain name packet data packet, continue to parse the domain name packet data packet to obtain a domain name;

S23: Determine whether the domain name is a designated domain name, and if yes, perform step S30.
The domain name redirection method according to claim 1 or 2, wherein the step S30 includes:

S31: Construct a domain name return packet, and redirect the domain name return packet to the internet protocol address.
The domain name redirection method according to claim 1, wherein the step S10 comprises:

S11: Obtain an internet protocol address from the corresponding server according to the dynamic host configuration protocol.
The domain name redirection method according to claim 1, wherein the step S10 and the step S20 include: determining whether the internet protocol address is successfully obtained, and if successful, performing step S20, if not successful , step S20 is not performed.
The domain name redirection method according to claim 1, wherein the step S20 comprises: establishing a hook function, and hooking all link layer data packets to the hook function.
The domain name redirection method according to claim 6, wherein the hook function execution step comprises:

S21: Parsing the data packet, and determining whether the data packet is a domain name message data packet;

S22: If the domain name packet data packet, continue to parse the domain name packet data packet to obtain a domain name;

S23: Determine whether the domain name is a designated domain name, and if yes, perform step S30.
A domain name redirection system, characterized in that the system comprises:

An internet protocol address module for obtaining an internet protocol address;

Parsing an interception module for parsing data packets in the link layer and intercepting the specified domain name request;

And a redirection module, configured to redirect the specified domain name request to the internet protocol address.
The domain name redirection system according to claim 8, wherein the parsing intercepting module comprises:

a first determining unit, configured to determine whether the data packet is a domain name packet data packet, after the data packet in the link layer is parsed;

An obtaining unit, configured to acquire a domain name when continuing to parse the domain name message data packet if the first determining unit determines that the domain name message data packet is

The second determining unit is configured to determine whether the domain name obtained by the acquiring unit is a specified domain name.
The domain name redirection system according to claim 8, wherein the redirection module comprises:

A construction unit that constructs a domain name return package.