KR100666948B1 - Apparatus and method for processing ipv6 packet - Google Patents

Abstract

The present invention is for processing an IPv6 packet, and generates an extension header including information required for packet filtering or QoS function, and adds it immediately after the IPv6 basic header, thereby providing information required for packet processing without cumbersome information retrieval process. The present invention relates to an IPv6 packet processing apparatus and a method for easily searching.

Internet Protocol version 6 (IPv6), packet processing, forwarding, extension headers, classification header

Description

IP version 6 packet processing apparatus and method {APPARATUS AND METHOD FOR PROCESSING IPV6 PACKET}             

1 is a diagram illustrating a header format of a general Internet Protocol Version 6 (IPv6) packet.

2 illustrates the format of a routing extension header among extension headers of a typical IPv6 packet.

3 illustrates an example of using a next header for identification of a packet.

4 illustrates the format of an original packet that a sender intends to transmit.

FIG. 5 is a diagram illustrating a format of divided packets in which an original packet of the type shown in FIG. 4 is divided into MTU units, the size of which is larger than a maximum transmission unit (MTU). FIG.

6 illustrates a basic format of a classification extension header.

FIG. 7 illustrates the format of a classification extension header for Transmission Control Protocol (TCP). FIG.

8 illustrates the format of a classification extension header for UDP (User Datagram Protocol).

9 illustrates the format of a classification extension header for the ICMP (Internet Control Message Protocol).

10A illustrates a packet format before modifications have been made in accordance with the present invention.

FIG. 10B is a diagram illustrating the creation of the extension header 1000 and the addition process of the generated extension header according to the present invention. FIG.

FIG. 10C illustrates a packet format that includes a legacy extension header, in accordance with the present invention. FIG.

FIG. 11 illustrates the format of a packet including a legacy header extension that may be received by a network component in accordance with the present invention. FIG.

The present invention relates to an IPv6 packet processing apparatus and method for performing IPv6 packet processing in a network component, and more particularly, to an IPv6 packet processing apparatus for facilitating retrieval of information required for processing an IPv6 packet. And to a method.

Network components that process IPv6 packets, particularly those that perform picket filtering or quality of service (QoS) functions (for example, routers, firewalls, etc.), typically receive packets received for processing packets. The following information is retrieved from each protocol header of.

In the IPv6 basic header, a source IPv6 address, a destination IPv6 address, a traffic class, and a flow label information are retrieved. ICMP (Internet Control Message Protocol) headers retrieve ICMP type values. In the TCP / UDP header, a source port value, a destination port value, and a TCP control bit value are retrieved. Finally, the presence or absence of a fragment extension header is searched to determine whether the packet is a fragmented packet.

In order to describe the retrieval of such information, the configuration of the header of the IPv6 packet will first be described. The format of the IPv6 header described below is defined in RFC 2460.

1 is a diagram illustrating a basic header format of a general Internet Protocol Version 6 (IPv6) packet.

As shown in FIG. 1, the header 100 of an IPv6 packet includes a version field 102, a traffic class field 104, a flow label field 106, and a payload length. (payload length) field 108, next header field 110, hop limit field 112, source address field 114 and destination address field ( 116). These fields are described in detail as follows.

The version field 102 indicates the protocol version of the packet. In the case of IPv6, the version field 102 indicates "6". Traffic classification field 104 and flow label field 106 are both fields for providing QoS. Because the traffic classification field 104 can be set or read at the upper layer, the application layer of the upper layer such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) is applied to the lower transport layer by the IP layer. Can be used if required. The flow label field 106 takes the value of the traffic classification field 104 and specifies it to be satisfied at all routers from sender to receiver. Of course, the RSVP (ReSerVation Protocol) or the like should scan the flow of all routers in advance and set the flow label. In other words, once the flow label is set, it means that a virtual path that satisfies a predetermined QoS has been created.

The payload length field 108 means the number of bytes of all payloads following the IPv6 header, i.e. the IPv6 basic header. Note that an option field or extension field value that may be added after the destination address field 116 is also considered a payload. In other words, all headers and data except the IPv6 header are payloads.

The next header field 110 determines the type of the optional header that follows the destination address field 116. For example, if the value of the next header field 110 is "0", then the IPv6 header is followed by the Hop-by-Hop option extension header, and the "1" is followed by the ICMP (Internet Control Message Protocol) extension. The value of the Next header field indicating that the header is "6" is the value of the Next header field indicating that the following header is a Transmission Control Protocol (TCP) header. The next header types indicated by the next header field 110 may be summarized as shown in Table 1 below.

Header type value Explanation Hop-by-hop options 0 Notice that the following header is a Hop-by-Hop option. The Hop-by-Hop option should be checked by all routers going through the sender to the receiver. IP (Internet Protocol) 4 Notice that the header that follows is an IPv4 header. This value allows you to send and receive IPv4 packets as IPv6 packets. Transmission Control Protocol (TCP) 6 Notice that the following header is a TCP header. User Datagram Protocol (UDP) 17 Notice that the header that follows is a UDP header. IPv6 41 Notice that the following header is an IPv6 header Used when sending IPv6 over IPv6. Routing 43 Notice that the header that follows is a routing header. The routing header implements Loose Source Routing (specifying which router must pass through the path from sender to receiver) in IPv4. Fragment 44 Use when packet is truncated due to small Path-MTU. Inter-Domain Routing 45 The routing protocol header is coming. RSVP (Reservation Protocol) 46 If you use RSVP. Encapsulating Security Payload (ESP) 50 For security purposes. Defined in IPSec. Authentication Header (AH) 51 For security purposes. Defined in IPSec. Internet Control Message Protocol (ICMP) 58 Notice that the header that follows is an ICMP header. 59 Notice that there is no following header. Recipient Options 60 Option that only recipients should check.

The hop limit field 112 is a value that decreases by one for each pass through the router, which is similar to the time to live (TTL) value of IPv4. When the value of the hop limit field 112 becomes 0, the "ICMP Time Exceeded" message is generated in the corresponding router.

The source address field 114 and the destination address field 116 indicate the source address and the destination address of the packet.

Above, the IPv6 header shown in FIG. 1 is specifically referred to as an "IPv6 basic header", and extension headers may be added after the basic header. Hereinafter, an extension header will be described with reference to the accompanying drawings.

2 is a diagram illustrating a format of an IPv6 routing extension header.

As illustrated in FIG. 2, the IPv6 routing extension header 200 may include a next header field 202, a header length field 204, a routing type field 206, a segment left field 208, and a specific data field according to a type. 210 may be configured to include. Other extension headers may also be configured in a format similar to the format shown in FIG. 2, wherein the routing type field 206 and the specific data field 210 according to the type are configured differently according to the corresponding protocol. Description of each of the above fields will be omitted.

Extended headers that can be located after the current IPv6 default header include the Hop-by-Hop Options header, the Routing header, the Fragment header, the Destination Options header, and the Authentication. (Authentication) header, Encapsulating Security Payload header, etc. There are no special restrictions on the number of extension headers that can be added after the IPv6 basic header. These extension headers commonly use the first 8 bits of the header as the next header field to indicate the type of extension header or other protocol header immediately following it.

However, when a packet (IPv6 packet, hereinafter referred to as a "packet") includes a plurality of extension headers, network components transmitting the packet sequentially process the next header fields of the headers for processing the packet. You should check and find the header you want. This will be described with reference to FIG. 3.

3 is a diagram illustrating an example of using a next header for packet identification.

When the network component receives a packet having the configuration shown in FIG. 3, the network component may retrieve the IPv6 basic header 100, the hop-by-hop option A header 300, and hops to retrieve information in the TCP header 306. The next header field of the bi-hop option B header 302 and the routing A header 304 must be sequentially searched. Such conventional header information retrieval deteriorates the efficiency of packet processing since the header information retrieval needs to be searched even for headers that are not directly needed.

On the other hand, if the length of the generated packet is larger than the minimum MTU value of the links to be passed to the destination, the host system that transmits the packet is transmitted by fragmenting the packet to a size smaller than the minimum MTU value. When splitting a packet, extension headers included in each packet may be a bigger problem. Prior to describing the problem due to the division, the division of the packet will be described first.

4 is a diagram illustrating a format of an original packet to be transmitted by a sender.

As shown in Fig. 4, the packet may be considered as the non-dividable portion 400 and the dividable portion 410 at the time of dividing. The non-dividable portion 400 is an essential part in transmitting a packet through network systems. The splittable portion 410 is a portion that is considered only by the sender or receiver, and examples of the non-dividable portion 400 in the packet include the basic header 100 and the extended header 200, and the splittable portion 410. Examples include the TCP header 400 and the data 412. The packet division will be described with reference to the accompanying drawings. Hereinafter, the packet before the division is referred to as the "original packet", and the packet after the division is referred to as "the original packet". Divided packet ".

FIG. 5 is a diagram illustrating a format of divided packets in which an original packet of the type shown in FIG. 4 is divided into MTU units, the size of which is larger than a maximum transmission unit (MTU).

The nondividable portion 400 should be included in every divided packet. In FIG. 5, the IPv6 basic header 100 and the routing header 200 are non-dividable portions 400. In addition, the divided packet should include a fragment header 500 including fragment information. The split header may include information such as which packet is the original packet of the split packet, and what part of the original packet is the split packet.

The problem caused by the extension headers when the packet is split is described as follows. For example, TCP header 400 is included in splittable portion 410. TCP header 400 is included only in the first divided packet and not in subsequent divided packets. Therefore, the network component processes the packet by applying two rules for processing the divided packet, or by storing the information obtained from the first divided packet internally and applying it to other divided packets. Doing. However, the method of applying the two rules can cause the problem that the rule can be applied to the wrong packet, and the method of storing the acquired information internally must always manage the header information internally and store the divided packets one by one. Comparing the information to the information may cause a decrease in performance.

Accordingly, an object of the present invention is to provide an apparatus and method for processing an IPv6 packet, which enables a network component to easily retrieve information required for processing an IPv6 packet from an IPv6 packet.

Another object of the present invention is to provide an apparatus and method for processing an IPv6 packet to enable a network component to easily retrieve information required for processing a divided IPv6 packet.

The present invention to achieve these objects; 1. An IPv6 packet processing apparatus, comprising: a packet generation unit for generating an IPv6 packet to be transmitted, and a protocol extension header including a protocol field located after a basic header and extension headers and including information required for processing an IPv6 packet And a packet transmission unit for generating a header generation unit for generating a packet and a packet transmission unit including the generated legacy header extension header immediately after the basic header of the IPv6 packet.

In addition, the present invention; An IPv6 packet processing apparatus, comprising: an information retrieval unit for retrieving information included in the expansion extension header if the received IPv6 packet is a packet including a extension header, and the information retrieved by the information retrieval unit; An IPv6 packet processing apparatus comprising a packet processing unit for processing the received packet is proposed.                         

In addition, the present invention; An IPv6 packet processing method, comprising: a first step of generating an IPv6 packet to be transmitted, a second step of generating a extension header including information required for processing the IPv6 packet, and the generated procedure The present invention proposes an IPv6 packet transmission method comprising a third process of including an extension header immediately after the basic header of the IPv6 packet.

In another aspect, the present invention; An IPv6 packet processing method, comprising: a first process of receiving an IPv6 packet, determining whether the received IPv6 packet is a packet including a legacy header extension, and receiving the packet, wherein the received packet includes a legacy header extension And a second step of searching for information included in the extension header and a third step of processing the received packet using information retrieved from the extension header. We propose a packet processing method.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention described below is characterized by adding a new header including information required for processing the packet immediately after the IPv6 basic header. Hereinafter, a header used for the present invention, a transmission apparatus for transmitting an IPv6 packet including the header from a sender to a receiver, and a transmission method thereof will be described. Transmission of the IPv6 packet including the header includes at least the generation of the header and the extraction of information using the header.

First, a new header (hereinafter referred to as "classification extension header") used for the present invention will be described.

6 is a diagram illustrating a basic format of a collision extension header.

As shown in FIG. 6, the collision extension header according to the present invention may have a format in which the format of the extension header defined in RFC2460 is applied.

Table 2 below describes each field shown in FIG. 6.

The collision extension header should be located immediately after the IPv6 basic header.

Referring to the expansion extension header of the basic form shown in Figure 6 will be described in the format of the expansion extension according to some embodiments as follows.

FIG. 7 is a diagram illustrating a format of a collision extension header for TCP.

Table 3 below describes each field of the protocol extension header shown in FIG. 7 when the protocol value is 6, that is, for the TCP protocol.

8 is a diagram illustrating a format of a legacy extension header for UDP.

Table 4 below describes each field of the protocol extension header when the protocol value is 17, that is, shown in FIG. 8, that is, for the UDP protocol.

9 is a diagram illustrating the format of a legacy extension header for ICMP.

Table 5 below describes each field of the protocol extension header when the protocol value is 1, that is, shown in FIG. 9, that is, for the ICMP protocol.

Next, the packet processing using the above-mentioned collision extension header according to the present invention will be described. Packet processing according to the present invention can be described in four categories according to the type of network elements. The classification of the type of network component according to the present invention may include a sender, a network component that performs packet filtering or QoS, a network component that does not perform packet filtering, or QoS, and a sender.

First, the sender will be described. The sender is a network component that generates and transmits packets.

① The sender creates a packet to send.

(2) The sender generates a collision extension header according to the present invention. In this case, the collision extension header is made according to the header and type located after the IPv6 basic header and the extension headers.

3. The sender copies the contents of the header located after the IPv6 default headers and extension headers into the newly created collision extension header.

(4) The sender places the generated legacy extension header immediately after the IPv6 default header.

These processes are shown in FIGS. 10A-10C. FIG. 10A is a packet format before modification according to the present invention, and FIG. 10B is a diagram illustrating a process of generating a extension header 1000 and adding a generated extension header according to the present invention. FIG. 10C is a diagram illustrating a packet format including a legacy extension header, in accordance with the present invention. FIG.

To this end, the sender may include at least a packet generator configured to generate a packet to be transmitted, a header generator configured to generate the extension header 1000 with reference to the generated packet, and a packet transmitter configured to transmit a packet including the generated header. It may include.

Second, a description will be given of network components that perform packet filtering or QoS.

FIG. 11 is a diagram illustrating a format of a packet including a legacy header extension that may be received by a network component according to the present invention.

Receiving a packet of the form as shown in FIG. 11, the network component performing packet filtering or QoS retrieves the necessary information in the IPv6 basic header 100, and in the extension header 1000. The required information is retrieved according to the value of the protocol field 604, and the packet processing required (for example, permit / drop, performance of QoS function, etc.) is compared by internally searching filtering or collision rules and the retrieved information. ). To this end, when a network component that performs packet filtering or QoS receives a packet including the extension header 1000, the network component retrieves information for processing the packet from the extension header 1000. And an information retrieval unit and a packet processing unit for processing the corresponding packet according to the retrieved information.

Third, network components that do not perform packet filtering or QoS will be described. Such a system only serves to forward the packet between the sender and the receiver. This network component will ignore the extension header 1000 of the received packet and search for the next extended header.

Finally, let's talk about the receiver. The receiver corresponds to the destination of the packet. When the receiver receives the packet, the receiver compares the value of the protocol specific data 610 stored in the extension header 1000 with the value in the corresponding protocol header. If it is not the same, the receiver drops the packet. The reason why the receiver does this is to prevent the sender from deliberately modifying the extension header 1000 for the purpose of not being constrained by the packet filtering or QoS functionality provided by the firewall or router.

The present invention facilitates the retrieval of information required for packet processing such as packet filtering or QoS function.

Claims (10)

In the IPv6 packet processing apparatus, A packet generator for generating an IPv6 packet to be transmitted, A header generation unit which is located after the basic headers and the extension headers, and generates the extension header including a protocol field including information required for processing the IPv6 packet; IPv6 packet processing apparatus including a packet transmission unit for including the generated transmission extension header immediately after the basic header of the IPv6 packet. delete The method of claim 1, The header located after the basic header and the extension headers of the IPv6 packet is one of a Transmission Control Protocol (TCP) header, a User Datagram Protocol (UDP) header, and an Internep Control Message Protocol (ICMP) header. The IPv6 packet processing apparatus of claim 1, wherein the packet processing requesting information included in the extension header is a packet filtering or a quality of service (QoS) function. In the IPv6 packet processing apparatus, An information retrieval unit for retrieving information included in the extension header if the received IPv6 packet is a packet including the extension header; And a packet processing unit for processing the received packet using the information retrieved by the information retrieval unit. The method of claim 5, The packet processing unit performed by the packet processing unit is a packet filtering or QoS function IPv6 packet processing apparatus. In the IPv6 packet processing method, Generating a IPv6 packet for transmission; A second process of generating a extension header including information required for processing the IPv6 packet; And a third step of including the generated legacy header extension header immediately after the basic header of the IPv6 packet. The method of claim 7, wherein The protocol header includes a protocol type of a header located after the base header and extension headers of the IPv6 packet and information according to the protocol type. The method of claim 8, wherein the packet processing requesting the information included in the extension header is a packet filtering or a quality of service (QoS) function. In the IPv6 packet processing method, A first step of receiving an IPv6 packet, A second step of determining whether the received IPv6 packet is a packet including a extension header; and, And a third step of processing the received packet using information retrieved from the collision extension header.

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