KR102169717B1 - Method for caching of contents and cache apparatus therefor - Google Patents

Abstract

The present invention relates to a content caching method, and more particularly, prior to caching of content delivered from a content providing server to a terminal, it is determined whether the address information of the content providing server is valid, and the content is cached only when it is valid. It relates to a content caching method and a cache device for the same.
For this, in a cache device located between a content providing server that provides content and a terminal that requests and receives the content according to an embodiment of the present invention, the cache device is transmitted from the content providing server to the terminal. Detecting content; Checking address information of the content providing server that provided the content; And when the identified address information of the content providing server is included in valid address information that can be cached, caching the content.

Description

Content caching method and cache device therefor {METHOD FOR CACHING OF CONTENTS AND CACHE APPARATUS THEREFOR}

The present invention relates to a content caching method, and more particularly, prior to caching of content delivered from a content providing server to a terminal, it is determined whether the address information of the content providing server is valid, and the content is cached only when it is valid. It relates to a content caching method and a cache device for the same.

The content described in this section merely provides background information on the present embodiment and does not constitute the prior art.

Recently, with the improvement of the performance of user terminals such as smart phones and the development of mobile communication technology, users can access a web server provided by a content provider (CP) through a user terminal anytime, anywhere to take photos and videos. , Audio, applications, and other various contents can be used.

However, while the number of web servers provided by the content provider (CP) is limited, the number of users who want to access the web server is increasing rapidly, resulting in various problems such as data loss, bottlenecks, transmission delays, instability such as data loss. Occurred.

A CDN (Contents Delivery Network) service was introduced to solve this problem.

CDN service is a service for stably delivering various types of content such as photos, movies, music videos, etc. to the user terminal. The capacity concentrated on the web server of the content provider far away from the user terminal is large or the user's request is required. After copying and storing some or all of the frequent contents in a cache device distributed in a number of ISP (Internet Service Provider) Point of Presence (PoP), especially a cache device distributed in the vicinity of the user terminal, the user When there is a request for, it refers to a service that returns the path of the cache device located closest to the user, so that the user terminal can access the cache device through the returned path and then receive the content.

Such a CDN service has an advantage in that a cache device located in the closest location to the user provides content to the user terminal, thereby improving a response speed to a content request from the user terminal and providing more stable content.

In order to provide such a CDN service, the cache device detects the content delivered to the user terminal from the web server of the content provider, caches the content, and then provides the cached content in response to the next content request. However, until now, the cache device cannot determine whether the content request from the user terminal is a malicious request, so by caching the content requested by the malicious user terminal and providing it to another user terminal, malicious content There is a problem that caching cannot be prevented.

Korean Patent Laid-Open Patent No. 10-2014-0066267, published on June 2, 2014 (Name: game server including content data caching method and caching system in mobile game, and mobile terminal)

The present invention has been proposed to solve the above-described conventional problems. In particular, when a cache device wants to cache content delivered from a content providing server to a terminal, it is possible to selectively cache the content after determining whether the content is valid. An object of the present invention is to provide a content caching method and a cache device therefor.

In particular, the present invention selectively caches only when the content delivered from the content providing server to the terminal is detected by the cache device and the address information of the content providing server prior to caching the content corresponds to valid address information, An object of the present invention is to provide a content caching method capable of preventing in advance caching of malicious content generated by a user's request, and a cache device for the same.

However, the object of the present invention is not limited to the above object, and other objects that are not mentioned will be clearly understood from the following description.

A content caching method according to an embodiment of the present invention for achieving the above object is a cache device located between a content providing server that provides content and a terminal that requests and receives the content, wherein the cache device comprises: Detecting the content delivered to the terminal from the content providing server; Checking address information of the content providing server that provided the content; And when the identified address information of the content providing server is included in valid address information that can be cached, caching the content.

In this case, before the step of detecting the content, detecting a content request transmitted by the terminal to the content providing server; And when the content request is detected, periodically querying and receiving valid address information corresponding to the content providing server to a domain name server, and then storing the information.

In addition, prior to the step of detecting the content, detecting a content request transmitted by the terminal to the content providing server; Determining whether the terminal is caching the requested content when the content request is detected; And, as a result of the determination, when the content requested by the terminal is being cached, the cached content is controlled to be transmitted to the terminal on behalf of the content providing server, and when not caching, the content request is transmitted to the content providing server. Controlling to be performed; may be achieved by further including.

In this case, before the step of detecting the content, storing a list of content providing servers for managing valid address information; And periodically querying and receiving valid address information corresponding to the stored content providing server to a domain name server, and then storing the information.

In addition, after the step of checking the address information of the content providing server, if the identified address information of the content providing server is not included in the valid address information that can be cached, it is transmitted from the content providing server to the terminal. The content may be determined as abnormal content and the content may not be cached.

Additionally, the present invention can provide a computer-readable recording medium in which a program for executing the content caching method described above is recorded.

A cache device according to an embodiment of the present invention for achieving the above object includes: a communication unit supporting transmission and reception of information between a terminal and a content providing server; A storage unit for caching and storing contents; And when content delivered from the content providing server to any one terminal is detected through the communication unit, after checking the address information of the content providing server that provided the content, the address information of the content providing server can be cached. When included in the effective address information, a control unit for controlling to be delivered to the terminal after caching the content in the storage unit; may include.

In this case, when the address information of the content providing server is not included in the effective address information, the control unit may determine the content delivered from the content providing server to the terminal as abnormal content, and may not cache the content. .

According to the content caching method and the cache device therefor of the present invention, when the cache device attempts to cache the content delivered from the content providing server to the terminal, it is possible to selectively cache the content after determining whether the content is valid.

In particular, the present invention selectively caches only when the content delivered from the content providing server to the terminal is detected by the cache device and the address information of the content providing server prior to caching the content corresponds to valid address information, There is an effect that can prevent in advance the caching of malicious content caused by the user's request.

In addition, various effects other than the above-described effects may be directly or implicitly disclosed in the detailed description according to an embodiment of the present invention to be described later.

1 is a schematic configuration diagram of a content providing system according to an embodiment of the present invention.
2 is a block diagram showing a main configuration of a cache device according to an embodiment of the present invention.
3 is a flowchart illustrating a content caching method according to an embodiment of the present invention.
4 is a data flow diagram illustrating a content caching method in a cache device according to an embodiment of the present invention.
5 is a data flow diagram illustrating a content caching method in a cache device according to another embodiment of the present invention.
6 is a flowchart illustrating a process of collecting valid address information for content caching in a cache device according to an embodiment of the present invention.

In order to clarify the features and advantages of the problem solving means of the present invention, the present invention will be described in more detail with reference to specific embodiments of the present invention shown in the accompanying drawings.

However, in the following description and the accompanying drawings, detailed descriptions of known functions or configurations that may obscure the subject matter of the present invention will be omitted. In addition, it should be noted that the same components are indicated by the same reference numerals as possible throughout the drawings.

The terms or words used in the following description and drawings should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms for describing his or her invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, and thus various alternatives that can be substituted for them at the time of application It should be understood that there may be equivalents and variations.

In addition, terms including ordinal numbers such as first and second are used to describe various elements, and are only used for the purpose of distinguishing one element from other elements, and to limit the elements. Not used. For example, without departing from the scope of the present invention, a second component may be referred to as a first component, and similarly, a first component may be referred to as a second component.

In addition, when a component is referred to as being "connected" or "connected" to another component, it means that it is logically or physically connected or can be connected. In other words, it should be understood that a component may be directly connected or connected to another component, but another component may exist in the middle, or may be indirectly connected or connected.

In addition, terms used in the present specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In addition, terms such as "comprises" or "have" described herein are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification. It is to be understood that the above other features, or the possibility of the presence or addition of numbers, steps, actions, components, parts, or combinations thereof, are not preliminarily excluded.

In addition, embodiments within the scope of the present invention include computer-readable media having or transferring computer-executable instructions or data structures stored in the computer-readable media. Such computer-readable media may be any available media accessible by a general purpose or special purpose computer system. By way of example, such computer readable media may be in the form of RAM, ROM, EPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or computer executable instructions, computer readable instructions, or data structures. It may include, but is not limited to, physical storage media such as any other media that may be used to store or deliver certain program code means, and may be accessed by a general purpose or special purpose computer system. .

In the description and claims that follow, a “network” or “communication network” is defined as one or more data links that enable the transfer of electronic data between computer systems and/or modules. When information is transmitted or provided to a computer system through a network or other (wired, wireless, or a combination of wired or wireless) communication connection, this connection can be understood as a computer-readable medium. Computer-readable instructions include, for example, instructions and data that cause a general purpose computer system or a special purpose computer system to perform a specific function or group of functions. Computer-executable instructions may be, for example, assembly language, or even binary, intermediate format instructions such as source code.

In addition, the present invention relates to a personal computer, a laptop computer, a handheld device, a multiprocessor system, a microprocessor-based or programmable consumer electronics, a network PC, a minicomputer, a mainframe computer, a mobile phone, a PDA, a pager. It can be implemented in a network computing environment having various types of computer system configurations including (pager) and the like.

The invention may also be practiced in a distributed system environment where both local and remote computer systems linked through a network with a wired data link, a wireless data link, or a combination of wired and wireless data links perform tasks. In a distributed system environment, program modules may be located in local and remote memory storage devices.

In addition, the terminal described in the specification of the present invention can be implemented in various forms. For example, mobile terminals such as smart phones, tablet PCs, personal digital assistants (PDAs), portable multimedia players (PMPs), and MP3 players, as well as smart TVs and desktop computers A fixed terminal such as, for example, may be used, and any terminal can be applied as the terminal of the present invention as long as it is a terminal that can request and receive and use content from a content providing server through a network.

In addition, the content providing server described in the specification of the present invention is for providing various types of content, such as photos, videos, audio, and applications, to a user terminal, and at least one content provider (CP) It is possible to receive and manage the contents of the terminal and transmit the corresponding contents according to the request of the terminal, and preferably, the contents contracted with the communication service provider providing the CDN service is provided. Such a content providing device may be a web server of a content provider or a web application server (WAS).

In addition, any content of the present invention may be included in the content of the present invention as long as it can be expressed by a specific address (eg, URL) on the network. For example, when the entire web site is also expressed by one URL, it may be distributed as one content through a CDN service.

Now, a main configuration of a content providing system according to an embodiment of the present invention will be described.

1 is a schematic configuration diagram of a content providing system according to an embodiment of the present invention.

Referring to FIG. 1, a content providing system 1000 according to an embodiment of the present invention may include a terminal 100, a plurality of cache devices 400, and a content providing server 200, and a DNS server It may be configured to further include 500.

First, the terminal 100 may request specific content from the content providing server 200 through the communication network 300 according to a user's request, and receive and use the content provided from the content providing server 200.

More specifically, the terminal 100 confirms a request for specific content from a user. The request for the specific content may be made by inputting a URL (Uniform Resource Locator) that requests specific content from a user through a browser or the like. Thereafter, the terminal 100 accesses the DNS server 500 to obtain address information (IP address) of the content providing server 200 that provides the corresponding content. Then, the terminal 100 may request and receive and use the content from the corresponding content providing server 200.

The content providing server 200 is for providing various contents such as photos, videos, audio, applications, etc. to the terminal 100, and receives at least one content from a content provider (CP). It manages and provides contents to a plurality of terminals 100 through the communication network 300.

A plurality of cache devices 400 distributed over the communication network 300 serves to control the flow of content between the terminal 100 and the content providing server 200. At this time, the plurality of cache devices 400 may be located between an access network (not shown) and a core network (not shown) in the communication network 300, and control the flow of content between the terminal 100 and the content providing server 200. It may be distributed and disposed on the communication network 300 in various forms that can be controlled. Here, the cache device 400 is preferably located near the terminal 100 to support faster content provision than the content providing server 200 located in a remote location.

The cache device 400 stores some or all of the content serviced from the content providing server 200 in advance according to a preset content distribution policy. Thereafter, when a content response (eg, HTTP RESPONSE message) to a content request (eg, HTTP GET message) requested by the user terminal transmitted from the content providing server 200 is detected, the corresponding content response message among the plurality of cache devices 400 The cache device 400 that caches the included content transmits the content to the terminal 100 on behalf of the content providing server 200. Here, the cache device 400 may be determined based on the URL address information of the content providing server 200 included in the content request or content response message.

In addition, the cache device 400 according to an embodiment of the present invention may divide and store content in block data units. For example, the cache device 400 according to an embodiment of the present invention may divide and store content divided into a plurality of chunk data units according to an HTTP Live Streaming (HLS) method. In addition, the cache device 400 according to an embodiment of the present invention is divided into a plurality of assets and a plurality of media processing units (MPUs) constituting each asset according to an MPEG Media Transport (MMT) method. It is also possible to divide and store the resulting content by MPU unit. The cache device 400 of the present invention may store and manage some or all of the content provided by the content providing server 200 according to various methods.

In particular, the cache device 400 according to an embodiment of the present invention detects a request for a specific content to the content providing server 200 by the terminal 100, and when the content is not cached by the terminal 100, the terminal 100 It is possible to support so that the content request of is transmitted to the content providing server 200 as it is. Thereafter, the cache device 400 detects the content according to the content response transmitted from the content providing server 200 to the terminal 100 in response to the content request, the content providing server 200 included in the content response After checking the address information of the content providing server 200, the content included in the content response is cached only when the address information of the content providing server 200 is included in the effective address information that can be cached. Thereafter, when a request for the same content occurs, the cache device 400 can provide the corresponding content on behalf of the content providing server 200. To this end, when a content request transmitted from the terminal 100 to the content providing server 200 is detected, the cache device 400 of the present invention schedules a list of valid address information corresponding to the content providing server 200. It is possible to query the DNS server 500 on a periodic basis to receive and manage it.

A more detailed operation method of the cache device 400 according to an embodiment of the present invention will be described later.

In addition, the content providing system 1000 according to an embodiment of the present invention may further include a cache controller (not shown) capable of controlling the plurality of cache devices 400. A cache controller (not shown) may manage a plurality of cache devices 400 that are distributedly arranged and control a content delivery process by the plurality of cache devices 400. When a cache hit occurs in any one of the cache devices 400, such a cache controller (not shown) blocks a message transmitted to the terminal 100 or to the content providing server 200, and the corresponding cache device 400 ) May support delivery of content to the terminal 100 on behalf of the content providing server 200.

As described above, the cache device 400 according to an embodiment of the present invention detects the content delivered by the content providing server 200 to the terminal 100, and before caching it, the content providing server ( 200), and by supporting caching of the content only when the address information corresponds to valid address information, the caching of content generated in response to the request of the malicious terminal 100 can be prevented in advance. There is.

A more specific configuration and operation method of the cache device 400 will be described later, and the communication network 300 in which the plurality of cache devices 400 of the present invention are distributedly arranged at major points includes the terminal 100 and the content providing server ( 200) refers to a communication network for transmitting and receiving information between, and in particular, a combination of communication networks implemented using various types of wired and wireless communication technologies such as intranet networks, mobile communication networks, satellite communication networks, etc. rather than a single communication network type. Can be

Here, the communication network 300 is connected to a mobile network including a plurality of wired/wireless access networks (not shown) and a core network (not shown), and may be configured to include an external network, for example, an Internet network (not shown). Here, the wired/wireless access network (not shown) constituting the mobile network is an access network that performs wired/wireless communication with the terminal 100, for example, a number of such as BS (Base Station), BTS (Base Transceiver Station), NodeB, eNodeB, etc. It may be implemented by a base station controller such as a base station controller (BSC) and a radio network controller (RNC).

In another method, the digital signal processing unit and the wireless signal processing unit, which were integrally implemented in the base station, are divided into a digital unit (hereinafter referred to as DU and a radio unit (hereinafter referred to as RU)). A plurality of RUs (not shown) may be installed in each of the regions, and a plurality of RUs (not shown) may be connected to a centralized DU (not shown).

In addition, a core network (not shown) constituting a mobile network together with a wired/wireless access network (not shown) serves to connect a wired/wireless access network (not shown) and an external network, for example, an Internet network (not shown).

As described above, such a core network (not shown) is a network system that performs main functions for mobile communication services such as mobility control and switching between wired and wireless access networks (not shown), and circuit switching or packet switching ( packet switching) and manages and controls the packet flow in the mobile network. In addition, the core network (not shown) manages the mobility between frequencies, and plays a role for interworking with traffic in the access network (not shown) and the core network (not shown) and other networks, such as the Internet network (not shown). May be. In addition to the above-described configuration, the core network (not shown) may further include a Mobile Switching Center (MSC), a Home Location Register (HLR), a Mobile Mobility Entity (MME), and a Home Subscriber Server (HSS).

In addition, the Internet network (not shown) refers to a common open communication network, that is, a public network in which information is exchanged according to the TCP/IP protocol, and is connected to the content providing server 200 and from the content providing server 200. The provided content may be provided to the terminal 100 through a core network (not shown) and a wired/wireless access network (not shown), or may be provided to a plurality of cache devices 400 according to a preset distribution policy.

In addition, mobile packets transmitted and received on a mobile network may be transmitted through a GTP (GPRS Tunneling Protocol) tunnel differently from an Internet network (not shown). For example, when the terminal 100 transmits a content request message requesting content provided by the content providing server 200, the source address information (IP address of the terminal 100) and the destination of the terminal 100 When an IP packet including address information (IP information of the content providing server 200) is transmitted to an access network (not shown), a base station (e.g., eNodeB) of the access network (not shown) sends a GTP header and a UDP header to the IP packet. , The IP header for GTP tunneling is converted into a mobile packet to which the additional IP header is added, and transmitted to the core network (not shown). In this case, the GTP header may include tunneling identification information (TEID; Tunneling End poing ID) allocated to the terminal 100. The core network (not shown) removes the GTP header, the UDP header, and the IP header for GTP tunneling, and transfers the original IP packet transmitted by the terminal 100 to the content providing server 200 through the Internet network (not shown). Can be transmitted.

As described above, the structure of the communication network 300 of the present invention has been briefly described, and the communication network 300 is combined with the cache device 400 to store computing resources such as hardware and software, and correspond to the computing resources required by the client. It may include a cloud computing network that can be provided to a terminal. Here, cloud computing refers to a computer environment in which information is permanently stored on a server on the Internet and temporarily stored on client terminals such as desktops, tablet computers, notebooks, netbooks, and smartphones, and cloud computing stores all user information. It means a computer environment access network that stores the information on a server on the Internet and makes this information available anytime, anywhere through various IT devices. The communication network 300 is not only a closed network such as a local area network (LAN), a wide area network (WAN), an open network such as the Internet, but also a code division multiple access (CDMA), wideband code division (WCDMA). Multiple Access), GSM (Global System for Mobile Communications), LTE (Long Term Evolution), and EPC (Evolved Packet Core), which are recently attracting attention, as well as next-generation networks and cloud computing networks to be implemented in the future.

Hereinafter, a main configuration and operation method of the cache device 400 according to an embodiment of the present invention will be described with reference to FIG. 2.

2 is a block diagram showing a main configuration of a cache device according to an embodiment of the present invention.

1 and 2, a cache device 400 according to an embodiment of the present invention may include a communication unit 410, a control unit 420, and a storage unit 430.

First, the communication unit 410 monitors various pieces of information transmitted and received through the communication network 300 and performs a role of transmitting and receiving necessary information under the control of the controller 420. In particular, the communication unit 410 of the present invention may serve to receive various information generated between the terminal 100 and the content providing server 200 in which a session is established, and transmit the information to the control unit 420. In addition, the communication unit 410 of the present invention may perform a role of delivering the content stored in the storage unit 430 to the terminal 100 on behalf of the content providing server 200 under the control of the control unit 420. In this case, the communication unit 410 of the present invention may sequentially provide the content divided into blocks to the terminal 100 under the control of the controller 420.

To perform the above-described process, the communication unit 410 of the present invention may include a mirroring module and an injection module, although not shown in the drawings. The mirroring module copies data transmitted through a core network (not shown) or an Internet network (not shown) and transfers the data to the control unit 420. The injection module serves to transmit the data received from the controller 420 to the terminal 100 through a core network (not shown) or an Internet network (not shown). Accordingly, the communication unit 410 of the present invention monitors information transmitted and received between the terminal 100 and the content providing server 200, and detects a content request transmitted from the terminal 100 to the content providing server 200, or The providing server 200 may detect the content transmitted to the terminal 100 in response to the content request.

The controller 420 plays a role of controlling the overall operation of the cache device 400 according to an embodiment of the present invention. The control unit 420 of the present invention may include a monitoring module 421, an effective address management module 422, and a caching control module 423.

First, the monitoring module 421 receives and monitors various information generated between the terminal 100 and the content providing server 200 in which a session is established, from the communication unit 410. In particular, the monitoring module 421 of the present invention may receive a content request or a content response through the communication unit 410. Here, the content request transmitted by the terminal 100 to the content providing server 200 may be delivered in the form of, for example, an HTTP GET/REQUEST message, and the content providing server 200 delivers it to the terminal 100 in response thereto. The content response may be delivered in the form of an HTTP RESPONSE message, for example. The monitoring module 421 of the present invention monitors information generated between the terminal 100 and the content providing server 200, and serves to transmit a content request and a content response to the caching control module 423.

Before describing the effective address management module 422, first, the caching control module 423 will be described. The caching control module 423 of the present invention receives a content request and a content response from the monitoring module 421. When a content request is transmitted from the monitoring module 421, the caching control module 23 may first determine whether the corresponding content is stored in the storage unit 430. The determination process may be performed in units of blocks, for example, and if it is determined that the initial block data for the content is stored in the storage unit 430, the caching control module 423 provides the content stored in the storage unit 430 It can be controlled to be transmitted to the terminal 100 on behalf of the server 200. In this case, the caching control module 423 may control a part or all of the content composed of a plurality of blocks to be sequentially delivered to the terminal 100 through the communication unit 410 in a streaming method.

On the other hand, if it is determined that the caching control module 423 is not stored in the storage unit 430, the content request is bypassed so that the content request is transmitted to the content providing server 200 as it is.

In addition, when a content response transmitted from the content providing server 200 to the terminal 100 is detected in response to the content request, the caching control module 423 controls the content to be delivered to the terminal 100 and at the same time. The content included in the content response may be controlled to be stored in the storage unit 430. At this time, the caching control module 423 of the present invention does not unconditionally cache the content delivered to the terminal 100 by the content providing server 200, but checks the source information of the corresponding content through a content response, that is, provides the content. After checking the address information of the server 200, the content is cached only when the address information of the verified content providing server 200 is included in the valid address information that can be cached.

In more detail, it is assumed that the URL of the content providing server 200 is'www.sk.com'. When the terminal 100 requests a content from the content providing server 200, for example,'HTTP:get/sk.com/a.jpg', the caching control module 423 stores the content corresponding to the URL. You can check whether it is stored in 430. As a result of the confirmation, if the cache device 400 is not cached in the storage unit 430, the cache device 400 cannot provide the content on behalf of the content providing server 200, and thus the content request is bypassed as it is. And, when the content is delivered to the terminal 100 in response to the content request from the content providing server 200, the caching control module 423 detects it, caches the content in the storage unit 430, and later You can prepare for content requests that occur. At this time, the caching control module 423 of the present invention checks the address information of the content, that is, the IP address information, and then the verified IP address information corresponds to the valid address information previously established in response to the content providing server 200 You can determine whether or not. In other words, even though the content provided by the content providing server 200 uses the same URL, a plurality of IP address information may exist. In the above example, IP address information corresponding to'a.jpg' may exist from '200.200.239.01' to '200.200.239.99'. The caching control module 423 of the present invention checks the IP address information of the content delivered from the content providing server 200 in a state in which such valid IP address information is previously established, and the verified IP address information is the content providing server If it is included in the IP address information built in advance corresponding to 200, it is determined that the content is normally provided, and the content is cached.

On the other hand, if the content delivered by the content providing server 200 to the terminal 100 is not included in the valid IP address information, the caching control module 423 determines this as providing abnormal content and does not cache the corresponding content. . That is, the ULR address information is normal, but the terminal 100 is requested by a malicious user or by a malicious code by changing the host file to a malicious host file when requesting the content from the content providing server 200. The content request for which the host file is changed has the same URL, but the content is received from a malicious content providing server other than the normal content providing server 200.

In the case of a conventional cache device, it is not possible to determine whether the request of the terminal 100 is a malicious request, and thus, there is a problem that the content delivered according to the request of the changed host file is cached as it is. The present invention is to solve this problem, and when a list of valid IP address information is built in advance in response to the content providing server 200, and when content is transmitted from the content providing server 200 to the terminal 100, the IP address of the corresponding content It is possible to cache the information in the storage unit 430 only when the information corresponds to valid IP address information.

In addition, when the content provided by the content providing server 200 to the terminal 100 is not included in the valid IP address information, the caching control module 423 of the present invention determines that it is abnormal content provision and caches the corresponding content. I can't. In another embodiment, the caching control module 423 may block the abnormal content from being delivered to the terminal 100, and even if the content is delivered to the terminal 100, the terminal 100 additionally sends a guide message to inform the abnormal content. It can also be provided.

In order to perform the above-described process, the effective address management module 422 of the present invention may perform a role of storing and managing effective address information corresponding to the content providing server 200. At this time, the effective address management module 422 of the present invention interlocks with the DNS server 500 from the point when the content request transmitted from the terminal 100 to the content providing server 200 is detected. ) Can be collected by inquiring about valid address information at regular intervals. On the other hand, the effective address management module 422 of the present invention is in a state in which information on the content providing server 200 to manage effective address information is registered in advance by an administrator, and address information for the content providing server 200 May be received by periodically querying the DNS server 500.

The storage unit 430 may copy and store some or all of the content transmitted from the at least one content providing server 200 to the at least one terminal 100. In this case, the content may be divided and stored in block data units having a predetermined size, and only a part of the content may be stored. In addition, the block data may be stored in correspondence with identification information. In addition, the storage unit 430 of the present invention may store and manage the effective address information 431 in advance corresponding to the content providing server 200.

The main configuration and operation process of the cache device 400 according to the embodiment of the present invention have been described above.

The cache device 400 according to an embodiment of the present invention may have the same configuration as a typical web server or network server in terms of hardware. However, in terms of software, a program module implemented through a language such as C, C++, Java, Visual Basic, and Visual C is included.

Meanwhile, a memory mounted in each device of the present invention stores information within the device. In one implementation, the memory is a computer-readable medium. In one implementation, the memory may be a volatile memory unit, and in another implementation, the memory may be a non-volatile memory unit. In one implementation, the storage device is a computer-readable medium. In various different implementations, the storage device may include, for example, a hard disk device, an optical disk device, or some other mass storage device.

In addition, the term'~module' used in an embodiment of the present invention refers to a software component, and'~module' performs certain roles. As an example,'~module' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, and sub It includes routines, segments of program code, drivers, data, databases, data structures, tables, arrays, and variables. In addition, the components and functions provided in the'~modules' may be combined into a smaller number of components and'~modules' or further separated into additional components and'~modules'.

Although the present specification and drawings describe exemplary device configurations, the functional operations and implementations of the subject described in this specification may be implemented with other types of digital electronic circuits, or the structures disclosed herein and structural equivalents thereof. It may be implemented with computer software, firmware, or hardware, or may be implemented by a combination of one or more of them. Implementations of the subject matter described in this specification are one or more computer program products, that is, one relating to computer program instructions encoded on a tangible program storage medium for execution by or for controlling the operation of a device according to the invention. It can be implemented as the above module. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of materials that affect a machine-readable radio wave signal, or a combination of one or more of them.

Hereinafter, a content caching method according to an embodiment of the present invention will be described.

3 is a flowchart illustrating a content caching method according to an embodiment of the present invention.

1 and 3, a content caching method according to an embodiment of the present invention is performed by a cache device located between a content providing server 200 that provides content and a terminal 100 that requests and receives the content. It can be done.

The cache device 400 of the present invention detects the content delivered to the terminal 100 by the content providing server 200 according to the request of the terminal 100 (S101).

The content detection may be detected as the content providing server 200 monitors and detects a content response message transmitted to the terminal 100.

Then, the cache device 400 checks the address information of the content providing server 200 that provided the content (S105). The address information of the content providing server 200 may be checked by checking the source information of the content. Thereafter, the cache device 400 determines whether the verified address information of the content providing server 200 is included in the effective address information of the content providing server 200 stored in advance corresponding to the corresponding content URL (S105), Only when included, the cache device 400 caches the content (S107), so that only valid content can be selectively cached in response to a malicious content request.

The above-described content caching method in the cache device 400 of the present invention will be described in more detail.

4 is a data flow diagram illustrating a content caching method in a cache device according to an embodiment of the present invention.

Referring to FIG. 4, first, a session connection for content transmission and reception between the terminal 100 and the content providing server 200 must be established. Here, the session connection may be made in various known ways. For example, the terminal 100 may include a procedure for accessing the communication network 500, and access the communication network 500 to query the DNS server 500 for address information (IP address) of the content providing server (S201 ), it may include a process of receiving it (S203). In addition, the terminal 100 may perform an overall procedure for requesting content from the content providing server 200 according to the address information of the content providing server provided from the DNS server 500.

The cache device 400 of the present invention located between the terminal 100 and the content providing server 200 may monitor information transmitted and received between the terminal 100 and the content providing server 200 (S205). In this state, the cache device 400 of the present invention may monitor and detect a content request transmitted from the terminal 100 to the content providing server 200 (S207). In this case, the cache device 400 of the present invention may detect a content request message (HTTP GET/REQUEST message) by the terminal 100 to the content providing server 200. When a content request is detected, the cache device 400 of the present invention may first determine whether the corresponding content is cached in its storage unit (S211). Whether to caching may be determined based on URL information of the content.

In addition, when the cache device 400 is caching the corresponding content, the cached content is provided to the terminal 100 on behalf of the content providing server 200 (S213). At this time, the cache device 400 of the present invention may block a content request transmitted from the terminal 100 to the content providing server 200, and guide the content request to the content providing server 200, but You can also guide you to provide.

Through this process, the terminal 100 of the present invention can receive and use the content from the cache device 400 located in a short distance from itself on behalf of the content providing server 200 in a remote location, so that more rapid and stable content use is possible. Is done.

Meanwhile, if the cache device 400 is not caching the corresponding content in step S207, the process of FIG. 5 may be performed.

5 is a data flow diagram illustrating a content caching method in a cache device according to another embodiment of the present invention.

Referring to FIG. 5, the cache device 400 according to an embodiment of the present invention performs the step of FIG. 5 when it is determined in step S207 of FIG. 4 that the corresponding content is not cached, that is, the terminal ( 100) is controlled so that the content request transmitted to the content providing server 200 is transmitted as it is (S301).

In addition, the cache device 400 interworks with the DNS server 500 until the corresponding content request is transmitted to the content providing server 200 and a response thereto is received from the content providing server 200, and the content providing server Valid address information for 200 may be queried, and a procedure for collecting and storing it may be performed (S303 to S307). Here, a procedure for querying, collecting, and storing valid address information may be performed periodically, and even if a corresponding content request is not transmitted from the terminal 100, it may be performed periodically according to a preset condition. In addition, the effective address information of the present invention refers to a list of valid IP address information that can be stored in correspondence with URL information in content. In other words, although the content provided by the content providing server 200 uses the same URL, a plurality of IP address information may exist. For example, a valid IP corresponding to the'a.jpg' content provided by the content providing server 200 Address information may exist from '200.200.239.01' to '200.200.239.99'. In a state in which the cache device 400 of the present invention pre-builds and stores valid IP address information corresponding to the content of a specific URL through a query process with the DNS server 500, the content request from the content providing server 200 When it is detected that the content is delivered in response to (S309 to S311), the delivered content is controlled to be delivered to the terminal 100 (S311), and the cache device 400 is the content delivered from the content providing server 200 Address information, that is, IP address information of the content providing server 200 is confirmed by using (S313). The confirmation may be confirmed through source information included in the content response. In addition, when the verified address information is included in the valid address information (S315), the cache device 400 may cache the corresponding content. Otherwise, the cache device 400 may terminate the procedure without caching the corresponding content.

That is, the URL address information of the content is normal, but the terminal 100, which has been sensitized by a malicious user or by a malicious code, changes the host file to a malicious host file when requesting the content to the content providing server 200 and requests it. , The content request for which the host file is changed has the same URL, but the content is received from a malicious content providing server other than the normal content providing server 200.

In the case of a conventional cache device, it is not possible to determine whether the request of the terminal 100 is a malicious request, and thus, there is a problem that the content delivered according to the request of the changed host file is cached as it is. The present invention is to solve this problem, and when a list of valid IP address information is built in advance in response to the content providing server 200, and when content is transmitted from the content providing server 200 to the terminal 100, the IP address of the corresponding content By controlling to cache only when the information corresponds to valid IP address information, only normal content cached to the corresponding terminal 100 can be provided when another content request occurs in the future.

The cache device 400 according to an embodiment of the present invention provides content by interworking with the DNS server 500 after a content request is generated from the terminal 100 to the content providing server 200 in steps S303 to S307. The description was made focusing on the configuration of securing valid address information for the server 200.

However, the present invention is not limited thereto, and the cache device 400 of the present invention collects and manages effective address information for the content providing server 200 in advance in a predetermined period, even if a content request from the terminal 100 is not generated. May be.

This will be described with reference to FIG. 6.

6 is a flowchart illustrating a process of collecting valid address information for content caching in a cache device according to an embodiment of the present invention.

Referring to FIG. 6, the cache device 400 of the present invention may receive information on a predetermined number of content providing servers 200 by an administrator who manages the cache device 400 in advance (S401). The process may be accomplished by receiving information on the content providing server 200 from the terminal of the administrator.

Upon passing through such a process, the cache device 400 of the present invention queries the DNS server 500 in a certain periodic unit, and obtains a list of valid IP address information corresponding to the content providing server 200. It can be done (S403).

In this state, as described above, when content delivered from the content providing server 200 to the terminal 100 is detected, the cache device 400 checks the address information of the content providing server that provided the content, and then confirmed. By comparing the address information with the valid address information constructed in step S403, it is possible to check whether the source IP address of the content is a normal source IP address. In addition, in order to further increase the accuracy of the determination, the cache device 400 of the present invention stores valid address information on the content providing server 200 in advance in step S403, and the terminal 100 As soon as a content request delivered to) is detected, valid address information of the additional content providing server 200 may be obtained by interworking with the DNS server 500.

In the above, a content caching method according to an embodiment of the present invention has been described.

The content caching method of the present invention as described above may be provided in the form of a computer-readable medium suitable for storing computer program instructions and data. In a program recorded on a recording medium for implementing a content caching method according to an embodiment of the present invention, the step of detecting content transmitted from the content providing server to the terminal, address information of the content providing server that provided the content If the identified address information of the content providing server is included in valid address information that can be cached, a step of caching the content may be performed.

At this time, the program recorded on the recording medium can be read, installed, and executed by a computer to execute the above-described functions.

Here, in order for the computer to read the program recorded on the recording medium and execute the functions implemented as the program, the above-described program is C, C++, which can be read by the computer's processor (CPU) through the computer's device interface. It may include code coded in a computer language such as JAVA and machine language.

This code may include a functional code related to a function defining the above-described functions, and may include a control code related to an execution procedure necessary for the processor of the computer to execute the above-described functions according to a predetermined procedure. In addition, these codes may further include additional information necessary for the processor of the computer to execute the above-described functions, or code related to a memory reference to which location (address address) of the internal or external memory of the computer should be referenced. . In addition, when the computer's processor needs to communicate with any other computer or server in a remote in order to execute the above-described functions, the code is used by the computer's processor using the computer's communication module. It may further include a communication-related code for how to communicate with other computers or servers, and what information or media should be transmitted and received during communication.

Such computer-readable media suitable for storing computer program commands and data include, for example, magnetic media such as hard disks, floppy disks, and magnetic tapes, and compact disk read only memory (CD-ROM). , Optical Media such as DVD (Digital Video Disk), Magneto-Optical Media such as Floptical Disk, and ROM (Read Only Memory), RAM (RAM) , Random Access Memory), flash memory, EPROM (Erasable Programmable ROM), and EEPROM (Electrically Erasable Programmable ROM). The processor and memory can be supplemented by special purpose logic circuits or incorporated into it.

In addition, the computer-readable recording medium is distributed over a computer system connected through a network, so that computer-readable codes can be stored and executed in a distributed manner. In addition, a functional program for implementing the present invention, and related codes and code segments, etc., are programmers in the technical field to which the present invention pertains in consideration of the system environment of a computer that reads the recording medium and executes the program. May be easily inferred or modified by

While this specification includes details of a number of specific implementations, these should not be construed as limiting to the scope of any invention or claim, but rather as a description of features that may be peculiar to a particular embodiment of a particular invention. It must be understood. Certain features described herein in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination. Furthermore, although features operate in a particular combination and may be initially described as so claimed, one or more features from a claimed combination may in some cases be excluded from the combination, and the claimed combination may be a subcombination. Or sub-combination variations.

Likewise, although operations are depicted in the drawings in a specific order, it should not be understood that such operations must be performed in that particular order or sequential order shown, or that all illustrated operations must be performed in order to obtain a desired result. In certain cases, multitasking and parallel processing can be advantageous. In addition, separation of the various system components of the above-described embodiments should not be understood as requiring such separation in all embodiments, and the program components and systems described are generally integrated together into a single software product or packaged in multiple software products. You should understand that you can.

The present invention relates to a content caching method, and more particularly, prior to caching of content delivered from a content providing server to a terminal, it is determined whether the address information of the content providing server is valid, and the content is cached only when it is valid. It relates to a content caching method and a cache device for the same.

According to the present invention, when a cache device attempts to cache content delivered from a content providing server to a terminal, it determines whether the content is valid and then selectively caches the content, thereby generating malicious content caused by a request from a malicious user. There is an effect of preventing caching in advance, and the present invention can contribute to the development of the CDN service industry through this.

In addition, the present invention is not only sufficiently commercially available or commercially possible, but also has industrial applicability because it can be implemented clearly in reality.

100: terminal 200: content providing server
300: network 400: cache device
410: communication unit 420: control unit
421: monitoring module 422: effective address management module
423: caching control module 430: storage
431: valid address information 500: DNS server
1000: content providing system

Claims (8)

In the content caching method using a cache device located between a content providing server that provides content and a terminal that requests and receives the content,
The cache device,
Detecting the content delivered to the terminal from the content providing server;
Checking address information of the content providing server that provided the content; And
When the verified address information of the content providing server is included in valid address information that can be cached, the content is cached, and the address information of the identified content providing server is not included in the effective address information that can be cached. If not, determining the content delivered from the content providing server to the terminal as abnormal content and not caching the content;
Content caching method comprising a. The method of claim 1,
Before the step of detecting the content,
Detecting, by the terminal, a content request transmitted to the content providing server; And
When the content request is detected, periodically querying and receiving valid address information corresponding to the content providing server to a domain name server, and then storing it;
Content caching method comprising a further. The method of claim 1,
Before the step of detecting the content,
Detecting, by the terminal, a content request transmitted to the content providing server;
Determining whether the terminal is caching the requested content when the content request is detected; And
As a result of the determination, when the content requested by the terminal is being cached, the cached content is controlled to be transmitted to the terminal on behalf of the content providing server, and when not caching, the content request is transmitted to the content providing server. Controlling;
Content caching method comprising a further. The method of claim 1,
Before the step of detecting the content,
Storing a list of content providing servers for managing valid address information; And
Periodically querying and receiving valid address information corresponding to the stored content providing server to a domain name server and storing the information;
Content caching method comprising a further. delete A computer-readable recording medium on which a program for executing the content caching method according to any one of claims 1 to 4 is recorded. A communication unit supporting transmission and reception of information between a terminal and a content providing server;
A storage unit for caching and storing contents; And
When content delivered from the content providing server to any one terminal is detected through the communication unit, after checking the address information of the content providing server that provided the content, the address information of the content providing server can be cached. When included in the address information, a control unit for controlling the content to be delivered to the terminal after caching the content in the storage unit; Including,
The control unit
When the address information of the content providing server is not included in the valid address information, the content delivered from the content providing server to the terminal is determined as abnormal content, and the content is not cached. delete

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