RFC1228 日本語訳
1228 SNMP-DPI: Simple Network Management Protocol Distributed ProgramInterface. G. Carpenter, B. Wijnen. May 1991. (Format: TXT=96972 bytes) (Obsoleted by RFC1592) (Status: EXPERIMENTAL)
プログラムでの自動翻訳です。
RFC一覧
英語原文
Network Working Group G. Carpenter
Request for Comments: 1228 B. Wijnen
T.J. Watson Research Center, IBM Corp.
May 1991
コメントを求めるワーキンググループG.大工要求をネットワークでつないでください: 1228B.Wijnen T.J.ワトソン研究所、IBM社の1991年5月
SNMP-DPI
Simple Network Management Protocol
Distributed Program Interface
SNMP-dpiの簡単なネットワーク管理プロトコル分配されたプログラムインタフェース
Status of this Memo
このMemoの状態
This RFC describes a protocol that International Business Machines Corporation (IBM) has been implementing in most of its SNMP agents to allow dynamic extension of supported MIBs. This is an Experimental Protocol for the Internet community. Discussion and suggestions for improvement are requested. Please refer to the current edition of the "IAB Official Protocol Standards" for the standardization state and status of this protocol. Distribution of this memo is unlimited.
このRFCはIBM社(IBM)がサポートしているMIBsのダイナミックな拡大を許すためにSNMPエージェントの大部分で実装しているプロトコルについて説明します。 これはインターネットコミュニティのためのExperimentalプロトコルです。 議論と改善提案は要求されています。 このプロトコルの標準化状態と状態の「IABの公式のプロトコル標準」の現行版を参照してください。 このメモの分配は無制限です。
ABSTRACT
要約
The Simple Network Management Protocol (SNMP) [1] Distributed Program Interface (DPI) is an extension to SNMP agents that permits end-users to dynamically add, delete or replace management variables in the local Management Information Base without requiring recompilation of the SNMP agent. This is achieved by writing a so-called sub-agent that communicates with the agent via the SNMP-DPI.
Simple Network Managementプロトコル(SNMP)[1]の分配されたProgram Interface(DPI)はSNMPエージェントへのエンドユーザがダイナミックにSNMPエージェントを「再-編集」に要求しないで地方のManagement Information基地の中の管理変数を加えるか、削除するか、または置き換えることを許可する拡張子です。 これは、SNMP-DPIを通してエージェントとコミュニケートするいわゆるサブエージェントに書くことによって、達成されます。
For the author of a sub-agent, the SNMP-DPI eliminates the need to know the details of ASN.1 [2] or SNMP PDU (Protocol Data Unit) encoding/decoding [1, 3].
サブエージェントの作者に関しては、SNMP-DPIは、[1、3]をコード化するか、または解読しながら、ASN.1[2]の詳細を知る必要性かSNMP PDU(プロトコルData Unit)を排除します。
This protocol has been in use within IBM since 1989 and is included in the SNMP agents for VM, MVS and OS/2.
このプロトコルは、1989年以来IBMの中で使用中であり、VM、MVS、およびOS/2のためのSNMPエージェントに含まれています。
Potentially useful sample sub-agent code and implementation examples are available for anonymous FTP from the University of Toronto.
潜在的に役に立つサンプルサブエージェントコードと実装の例はトロント大学からの公開FTPに利用可能です。
MOTIVATION
動機
The Simple Network Management Protocol [1] defines a protocol that permits operations on a collection of variables. This set of variables is called the Management Information Base (MIB) and a core set of variables has previously been defined [4, 5]; however, the design of the MIB makes provision for extension of this core set. Thus, an enterprise or individual can define variables of their own which represent information of use to them. An example of a
Simple Network Managementプロトコル[1]は変数の収集のときに操作を可能にするプロトコルを定義します。 このセットの変数はManagement Information基地(MIB)と呼ばれます、そして、1人の巻き癖の変数は以前に、定義されました[4、5]。 しかしながら、MIBのデザインはこの巻き癖の拡大に備えます。 したがって、企業か個人がそれらの役に立つ情報を表すそれら自身の変数を定義できます。 aに関する例
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potentially interesting variable which is not in the core MIB would be CPU utilization (percent busy). Unfortunately, conventional SNMP agent implementations provide no means for an end-user to make available new variables.
コアMIBにない潜在的におもしろい変数はCPU使用率(パーセント忙しい)でしょう。 残念ながら、従来のSNMPエージェント実装はエンドユーザが利用可能な新しい変数を作る手段を全く提供しません。
The SNMP DPI addresses this issue by providing a light-weight mechanism by which a process can register the existence of a MIB variable with the SNMP agent. When requests for the variable are received by the SNMP agent, it will pass the query on to the process acting as a sub-agent. This sub-agent then returns an appropriate answer to the SNMP agent. The SNMP agent eventually packages an SNMP response packet and sends the answer back to the remote network management station that initiated the request.
SNMP DPIは、SNMPエージェントと共にプロセスが登録されることができる軽量のメカニズムを提供するのによるこの問題がMIB変数の存在であると扱います。 変数を求める要求がSNMPエージェントによって受け取られるとき、それはサブエージェントとして務めるプロセスに質問を通過するでしょう。 そして、このサブエージェントはSNMPエージェントの適切な答えを返します。 SNMPエージェントは、結局、SNMP応答パケットをパッケージして、要求を開始した遠く離れたネットワークマネージメントステーションに答えを送り返します。
None of the remote network management stations have any knowledge that the SNMP agent calls on other processes to obtain an answer. As far as they can tell, there is only one network management application running on the host.
遠く離れたネットワークマネージメントステーションのいずれにはも、SNMPエージェントが、他のプロセスが答えを得るよう呼びかけるという少しの知識もありません。 彼らが判断できる限り、ホストで動く1つのネットワークマネージメント利用しかありません。
THEORY OF OPERATION
動作理論
CONNECTION ESTABLISHMENT
コネクション確立
Communication between the SNMP Agent and its clients (sub-agents) takes place over a stream connection. This is typically a TCP connection, but other stream-oriented transport mechanisms can be used. As an example, the VM SNMP agent allows DPI connections over IUCV (Inter-User Communications Vehicle) [6, 7]. Other than the connection establishment procedure, the protocol used is identical in these environments.
SNMPエージェントとそのクライアント(サブエージェント)とのコミュニケーションはストリーム接続の上で行われます。 これは通常TCP接続ですが、他のストリーム指向の移送機構を使用できます。 例として、VM SNMPエージェントはIUCV(相互User Communications Vehicle)[6、7]の上のDPI接続を許します。 コネクション確立手順を除いて、使用されるプロトコルはこれらの環境が同じです。
REGISTRATION
登録
Regardless of the connection-oriented transport mechanism used, after establishing a connection to the SNMP agent, the sub-agent registers the set of variables it supports. Finally, when all the variable classes have been registered, the sub-agent then waits for requests from the SNMP agent or generates traps as required.
SNMPエージェントに取引関係を築いた後に使用された接続指向の移送機構にかかわらず、サブエージェントはそれがサポートする変数のセットを登録します。 すべての可変クラスが示されたとき、最終的に、サブエージェントは、次に、SNMPエージェントからの要求を待っているか、または必要に応じて罠を生成します。
DPI ARCHITECTURE
dpiアーキテクチャ
There are three requests that can be initiated by the SNMP agent: GET, GET-NEXT and SET. These correspond directly to the three SNMP requests that a network management station can make. The sub-agent responds to a request with a RESPONSE packet.
SNMPエージェントが開始できる3つの要求があります: 得てください、そして、気付いてください、そして、セットしてください。 これらは直接ネットワークマネージメントステーションがすることができる3つのSNMP要求に対応しています。 サブエージェントはRESPONSEパケットで要求に応じます。
There are currently two requests that can be initiated by a sub- agent: REGISTER and TRAP.
現在、サブエージェントが開始できる2つの要求があります: 登録してください、そして、捕らえてください。
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------------------------------------------------------------------------
------------------------------------------------------------------------
*---------------------------------*
| SNMP Network |
| Management Station |
| |
|---------------------------------|
| SNMP Protocol |
*---------------------------------*
A | Get A
| | GetNext | GetResponse
Trap | | Set |
| V |
*---------------------------------* *----------------------*
| SNMP Protocol | | DPI Interface |
|---------------------------------| Reply | *-----------------|
| | |<-----------| | |
| SNMP Agent | | | | Client |
| A *-----------+-> | MIB query | | |
| | | Get/Set | |----------->| | or |
| Trap| | info | SNMP | | | |
|-----+------+-------* | | trap | | SNMP |
| | V | | DPI |<-----------| | Sub-Agent |
| TCP/IP layers, | | | | | |
| Kernel | | |<-----------| | |
*---------------------------------* Register *----------------------*
*---------------------------------* | SNMPネットワーク| | 管理局| | | |---------------------------------| | SNMPプロトコル| *---------------------------------* A| Aを手に入れてください。| | GetNext| GetResponse罠| | セットします。| | V| *---------------------------------* *----------------------* | SNMPプロトコル| | dpiインタフェース| |---------------------------------| 返信| *-----------------| | | | <、-、-、-、-、-、-、-、-、-、--、|、|、|、| SNMPエージェント| | | | クライアント| | *-----------+->。| MIB質問| | | | | | /を設定させてください。| |、-、-、-、-、-、-、-、-、-、--、>|、| または| | 罠| | インフォメーション| SNMP| | | | |-----+------+-------* | | 罠| | SNMP| | | V| | dpi| <、-、-、-、-、-、-、-、-、-、--、|、| サブエージェント| | TCP/IPは層にされます。| | | | | | | カーネル| | | <、-、-、-、-、-、-、-、-、-、--、|、|、| *---------------------------------* *を登録してください。----------------------*
------------------------------------------------------------------------ Figure 1. SNMP DPI overview
------------------------------------------------------------------------ 図1。 SNMP DPI概要
Remarks for Figure 1:
図1のための所見:
o The SNMP agent communicates with the SNMP manager via the
standard SNMP protocol.
o The SNMP agent communicates with the TCP/IP layers and kernel
(operating system) in an implementation-dependent manner. It
potentially implements the standard MIB view in this way.
o An SNMP sub-agent, running as a separate process (potentially
even on another machine), can register objects with the SNMP
agent.
o The SNMP agent will decode SNMP Packets. If such a packet
contains a Get/GetNext or Set request for an object registered
by a sub-agent, it will send the request to the sub-agent via
the corresponding query packet.
o The SNMP sub-agent sends responses back via a RESPONSE packet.
o The SNMP agent then encodes the reply into an SNMP packet and
sends it back to the requesting SNMP manager.
o If the sub-agent wants to report an important state change, it
o SNMPエージェントは標準のSNMPプロトコルでSNMPマネージャとコミュニケートします。○ SNMPエージェントはTCP/IP層とカーネル(オペレーティングシステム)で実装依存する方法で交信します。 それは潜在的にこのように標準のMIB視点を実装します。別々のプロセス(別のマシンで潜在的に同等の)として稼働して、o An SNMPサブエージェントはSNMPエージェントにオブジェクトを登録できます。○ SNMPエージェントはSNMP Packetsを解読するでしょう。 そのようなパケットがサブエージェントによって登録されたオブジェクトを求めるGet/GetNextかSet要求を含んでいると、それは対応する質問パケットを通してサブエージェントに要求を送るでしょう。○ SNMPサブエージェントはRESPONSEパケットを通して応答を返送します。○ SNMPエージェントは、次に、SNMPパケットに回答をコード化して、要求しているSNMPマネージャにそれを送り返します。○ サブエージェントのIfは重要な州の変化を報告したがっています、それ
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sends a TRAP packet to the SNMP agent, which will encode it
into an SNMP trap packet and send it to the manager(s).
TRAPパケットをSNMPエージェントに送ります。(そのエージェントは、SNMP罠パケットにそれをコード化して、それをマネージャに送るでしょう)。
SNMP DPI PROTOCOL
SNMP dpiプロトコル
This section describes the actual protocol used between the SNMP agent and sub-agents. This information has not previously been published.
このセクションはSNMPエージェントとサブエージェントの間で使用される実際のプロトコルについて説明します。 この情報は以前に、発表されていません。
CONNECTION ESTABLISHMENT
コネクション確立
In a TCP/IP environment, the SNMP agent listens on an arbitrary TCP port for a connection request from a sub-agent. It is important to realize that a well-known port is not used: every invocation of the SNMP agent will potentially result in a different TCP port being used.
TCP/IP環境で、SNMPエージェントはサブエージェントからの接続要求のために任意のTCPポートの上で聴きます。 ウェルノウンポートが使用されていないとわかるのは重要です: SNMPエージェントのあらゆる実施が潜在的に使用される異なったTCPポートをもたらすでしょう。
A sub-agent needs to determine this port number to establish a connection. The sub-agent learns the port number from the agent by sending it one conventional SNMP get-request PDU. The port number is maintained by the SNMP agent as the object whose identifier is 1.3.6.1.4.1.2.2.1.1.0; this variable is registered under the IBM enterprise-specific tree. The SNMP agent replies with a conventional SNMP response PDU that contains the port number to be used. This response is examined by the sub-agent and the port number is extracted. The sub-agent then establishes the connection to the specified port.
サブエージェントは、取引関係を築くことをこのポートナンバーに決定する必要があります。 サブエージェントは、エージェントから1要求を得ている従来のSNMP PDUをそれに送ることによって、ポートナンバーを学びます。 ポートナンバーが識別子が1.3であるオブジェクトとしてSNMPエージェントによって維持される、.6、.1、.4、.1、.2、.2、.1、.1、.0。 この変数はIBMの企業特有の木の下に示されます。 SNMPエージェントは使用されるべきポートナンバーを含む従来のSNMP応答PDUと共に返答します。 この応答はサブエージェントによって調べられます、そして、ポートナンバーは抽出されます。 そして、サブエージェントは指定されたポートに接続を確立します。
On the surface, this procedure appears to mean that the sub-agent must be able to create and parse SNMP packets, but this is not the case. The DPI Application Program Interface (API) has a library routine, query_DPI_port(), which can be used to generate and parse the required SNMP packets. This routine is very small (under 100 lines of C), so it does not greatly increase the size of any sub- agent).
表面では、この手順がサブエージェントがSNMPパケットを作成して、分析できなければならないことを意味するように見えますが、これはそうではありません。 DPI Application Program Interface(API)はライブラリ・ルーチン、必要なSNMPパケットを生成して、分析するのに使用できる質問_DPI_ポート()を持っています。 このルーチンは非常に小さいです(C)の100未満の系列によって、それはどんなサブエージェントのサイズも大いに増強しません)。
For completeness, byte-by-byte descriptions of the packets generated by the SNMP DPI API routine query_DPI_port() are provided below. This is probably of little interest to most readers and reading the source to query_DPI_port() provides much of the same information.
完全性において、バイトごとのSNMP DPI APIの通常の質問_DPI_ポート()のそばで発生しているパケットの記述を以下に提供します。 これはたぶんほとんどの読者へのわずかの関心のものです、そして、_DPI_ポート()について質問するためにソースを読むと、同じ情報の多くが提供されます。
SNMP PDU TO GET THE AGENT'S DPI PORT
エージェントのdpiポートを手に入れるSNMP PDU
As noted, before a TCP connection to the SNMP agent can be made, the sub-agent must learn which TCP port that the agent is listening on. To do so, it can issue an SNMP GET for an IBM enterprise-specific variable 1.3.6.1.4.1.2.2.1.1.0.
注意されるように、SNMPエージェントとのTCP接続を作ることができる前にサブエージェントはエージェントが聴いているどのTCPポートを学ばなければならないか。 そうするために、それはIBMの企業特有の可変1.3のためにSNMP GETを発行できます。.6 .1 .4 .1 .2 .2 .1 .1 .0。
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NOTE: the object instance of ".0" is included for clarity in this document.
以下に注意してください。 「」 0インチのオブジェクトインスタンスは明快ために本書では含まれています。
The SNMP PDU can be constructed as shown below. This PDU must be sent to UDP port 161 on the host where the agent runs (probably the same host where the sub-agent runs).
以下に示すようにSNMP PDUを組み立てることができます。 ホストの上のエージェントが走るUDPポート161(たぶんサブエージェントが走る同じホスト)にこのPDUを送らなければなりません。
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+----------------------------------------------------------------------+ | Table 1. SNMP PDU for GET DPI_port. This is the layout of an SNMP | | PDU for GET DPI_port | +-----------------+-----------------+----------------------------------+ | OFFSET | VALUE | FIELD | +-----------------+-----------------+----------------------------------+ | 0 | 0x30 | ASN.1 header | +-----------------+-----------------+----------------------------------+ | 1 | 34 + len | pdu_length, see formula below | +-----------------+-----------------+----------------------------------+ | 2 | 0x02 0x01 0x00 | version (integer, length=1, | | | 0x04 | value=0), community name | | | | (string) | +-----------------+-----------------+----------------------------------+ | 6 | len | length of community name | +-----------------+-----------------+----------------------------------+ | 7 | community name | | +-----------------+-----------------+----------------------------------+ | 7 + len | 0xa0 0x1b | SNMP GET request: | | | | request_type=0xa0, length=0x1b | +-----------------+-----------------+----------------------------------+ | 7 + len + 2 | 0x02 0x01 0x01 | SNMP request ID: integer, | | | | length=1, ID=1 | +-----------------+-----------------+----------------------------------+ | 7 + len + 5 | 0x02 0x01 0x00 | SNMP error status: integer, | | | | length=1, error=0 | +-----------------+-----------------+----------------------------------+ | 7 + len + 8 | 0x02 0x01 0x00 | SNMP index: integer, length=1, | | | | index=0 | +-----------------+-----------------+----------------------------------+ | 7 + len + 11 | 0x30 0x10 | Varbind list, length=0x10 | +-----------------+-----------------+----------------------------------+ | 7 + len + 13 | 0x30 0x0e | Varbind, length=0x0e | +-----------------+-----------------+----------------------------------+ | 7 + len + 15 | 0x06 0x0a | Object ID, length=0x0a | +-----------------+-----------------+----------------------------------+ | 7 + len + 17 | 0x2b 0x06 0x01 | Object instance: | | | 0x04 0x01 0x02 | 1.3.6.1.4.1.2.2.1.1.0 | | | 0x02 0x01 0x01 | | | | 0x00 | | +-----------------+-----------------+----------------------------------+ | 7 + len + 27 | 0x05 0x00 | null value, length=0 | +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 1を見送ってください。 SNMP PDU、dpi_ポートを手に入れてください。 これはSNMPのレイアウトです。| | PDU、dpi_ポートを手に入れてください。| +-----------------+-----------------+----------------------------------+ | 相殺されます。| 値| 分野| +-----------------+-----------------+----------------------------------+ | 0 | 0×30| ASN.1ヘッダー| +-----------------+-----------------+----------------------------------+ | 1 | 34 + len| _長さをpduして、公式を見ます。| +-----------------+-----------------+----------------------------------+ | 2 | 0×02 0×01 0×00| バージョン(整数、長さ=1| | | 0×04| =0を評価する)、共同体名| | | | (ストリング) | +-----------------+-----------------+----------------------------------+ | 6 | len| 共同体名の長さ| +-----------------+-----------------+----------------------------------+ | 7 | 共同体名| | +-----------------+-----------------+----------------------------------+ | 7 + len| 0xa0 0x1b| SNMP GETは以下を要求します。 | | | | _タイプが0xa0と等しいよう要求してください、そして、長さは0x1bと等しいです。| +-----------------+-----------------+----------------------------------+ | 7+len+2| 0×02 0×01 0×01| SNMPはIDを要求します: 整数| | | | 長さは1、ID=1と等しいです。| +-----------------+-----------------+----------------------------------+ | 7+len+5| 0×02 0×01 0×00| SNMPエラー状況: 整数| | | | 1、長さ=誤り=0| +-----------------+-----------------+----------------------------------+ | 7+len+8| 0×02 0×01 0×00| SNMPは索引をつけます: 整数、長さ=1| | | | インデックス=0| +-----------------+-----------------+----------------------------------+ | 7+len+11| 0×30 0×10| Varbindリスト、長さ=0×10| +-----------------+-----------------+----------------------------------+ | 7+len+13| 0×30 0x0e| Varbind、長さ=0x0e| +-----------------+-----------------+----------------------------------+ | 7+len+15| 0×06 0x0a| オブジェクトID、長さ=の0x0a| +-----------------+-----------------+----------------------------------+ | 7+len+17| 0x2b0x06 0×01| オブジェクトインスタンス: | | | 0×04 0×01 0×02| 1.3.6.1.4.1.2.2.1.1.0 | | | 0×02 0×01 0×01| | | | 0×00| | +-----------------+-----------------+----------------------------------+ | 7+len+27| 0×05 0×00| ヌル値、長さ=0| +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
The formula to calculate the length field "pdu_length" is as follows:
長さの分野「pdu_長さ」について計算する公式は以下の通りです:
pdu_length = length of version field and string tag (4 bytes)
pdu_長さはバージョン分野とストリングタグの長さと等しいです。(4バイト)
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+ length of community length field (1 byte)
+ length of community name (depends...)
+ length of SNMP GET request (29 bytes)
+ 共同体名(よる)の共同体長さの分野(1バイト)+長さの長さ + SNMP GET要求の長さ(29バイト)
= 34 + length of community name
= 34 + 共同体名の長さ
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SNMP PDU CONTAINING THE RESPONSE TO THE GET
SNMP PDU、応答を含んでいる、得る。
Assuming that no errors occured, then the port is returned in the last 2 octets of the received packet. The format of the packet is shown below:
誤りが全くoccuredされなかったと仮定する場合、容認されたパケットの最後の2つの八重奏でポートを返します。 パケットの書式は以下に示されます:
+----------------------------------------------------------------------+ | Table 2. SNMP RESPONSE PDU for GET of Agent's DPI port. This is the | | layout of an SNMP RESPONSE PDU for GET DPI_port | +-----------------+-----------------+----------------------------------+ | OFFSET | VALUE | FIELD | +-----------------+-----------------+----------------------------------+ | 0 | 0x30 | ASN.1 header | +-----------------+-----------------+----------------------------------+ | 1 | 36 + len | length, see formula below | +-----------------+-----------------+----------------------------------+ | 2 | 0x02 0x01 0x00 | version (integer, length=1, | | | 0x04 | value=0), community name | | | | (string) | +-----------------+-----------------+----------------------------------+ | 6 | len | length of community name | +-----------------+-----------------+----------------------------------+ | 7 | community name | | +-----------------+-----------------+----------------------------------+ | 7 + len | 0xa2 0x1d | SNMP RESPONSE: | | | | request_type=0xa2, length=0x1d | +-----------------+-----------------+----------------------------------+ | 7 + len + 2 | 0x02 0x01 0x01 | SNMP request ID: integer, | | | | length=1, ID=1 | +-----------------+-----------------+----------------------------------+ | 7 + len + 5 | 0x02 0x01 0x00 | SNMP error status: integer, | | | | length=1, error=0 | +-----------------+-----------------+----------------------------------+ | 7 + len + 8 | 0x02 0x01 0x00 | SNMP index: integer, length=1, | | | | index=0 | +-----------------+-----------------+----------------------------------+ | 7 + len + 11 | 0x30 0x12 | Varbind list, length=0x12 | +-----------------+-----------------+----------------------------------+ | 7 + len + 13 | 0x30 0x10 | Varbind, length=0x10 | +-----------------+-----------------+----------------------------------+ | 7 + len + 15 | 0x06 0x0a | Object ID, length=0x0a | +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 2を見送ってください。 エージェントのDPIポートのGETのためのSNMP RESPONSE PDU。 これはそうです。| | GET DPI_ポートへのSNMP RESPONSE PDUのレイアウト| +-----------------+-----------------+----------------------------------+ | 相殺されます。| 値| 分野| +-----------------+-----------------+----------------------------------+ | 0 | 0×30| ASN.1ヘッダー| +-----------------+-----------------+----------------------------------+ | 1 | 36 + len| 長さ、以下の公式を見てください。| +-----------------+-----------------+----------------------------------+ | 2 | 0×02 0×01 0×00| バージョン(整数、長さ=1| | | 0×04| =0を評価する)、共同体名| | | | (ストリング) | +-----------------+-----------------+----------------------------------+ | 6 | len| 共同体名の長さ| +-----------------+-----------------+----------------------------------+ | 7 | 共同体名| | +-----------------+-----------------+----------------------------------+ | 7 + len| 0xa2 0x1d| SNMP応答: | | | | _タイプが0xa2と等しいよう要求してください、そして、長さは0x1dと等しいです。| +-----------------+-----------------+----------------------------------+ | 7+len+2| 0×02 0×01 0×01| SNMPはIDを要求します: 整数| | | | 長さは1、ID=1と等しいです。| +-----------------+-----------------+----------------------------------+ | 7+len+5| 0×02 0×01 0×00| SNMPエラー状況: 整数| | | | 1、長さ=誤り=0| +-----------------+-----------------+----------------------------------+ | 7+len+8| 0×02 0×01 0×00| SNMPは索引をつけます: 整数、長さ=1| | | | インデックス=0| +-----------------+-----------------+----------------------------------+ | 7+len+11| 0×30 0×12| Varbindリスト、長さ=0×12| +-----------------+-----------------+----------------------------------+ | 7+len+13| 0×30 0×10| Varbind、長さ=0×10| +-----------------+-----------------+----------------------------------+ | 7+len+15| 0×06 0x0a| オブジェクトID、長さ=の0x0a| +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 8] RFC 1228 SNMP-DPI May 1991
大工とWijnen[8ページ]RFC1228SNMP-dpi1991年5月
+----------------------------------------------------------------------+ | Table 2. SNMP RESPONSE PDU for GET of Agent's DPI port. This is the | | layout of an SNMP RESPONSE PDU for GET DPI_port | +-----------------+-----------------+----------------------------------+ | OFFSET | VALUE | FIELD | +-----------------+-----------------+----------------------------------+ | 7 + len + 17 | 0x2b 0x06 0x01 | Object instance: | | | 0x04 0x01 0x02 | 1.3.6.1.4.1.2.2.1.1.0 | | | 0x02 0x01 0x01 | | | | 0x00 | | +-----------------+-----------------+----------------------------------+ | 7 + len + 27 | 0x02 0x02 | integer, length=2 | +-----------------+-----------------+----------------------------------+ | 7 + len + 29 | msb lsb | port number (msb, lsb) | +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 2を見送ってください。 エージェントのDPIポートのGETのためのSNMP RESPONSE PDU。 これはそうです。| | GET DPI_ポートへのSNMP RESPONSE PDUのレイアウト| +-----------------+-----------------+----------------------------------+ | 相殺されます。| 値| 分野| +-----------------+-----------------+----------------------------------+ | 7+len+17| 0x2b0x06 0×01| オブジェクトインスタンス: | | | 0×04 0×01 0×02| 1.3.6.1.4.1.2.2.1.1.0 | | | 0×02 0×01 0×01| | | | 0×00| | +-----------------+-----------------+----------------------------------+ | 7+len+27| 0×02 0×02| 整数、長さ=2| +-----------------+-----------------+----------------------------------+ | 7+len+29| msb lsb| ポートナンバー(msb、lsb)| +-----------------+-----------------+----------------------------------+ +----------------------------------------------------------------------+
The formula to calculate the length field "pdu_length" is as follows:
長さの分野「pdu_長さ」について計算する公式は以下の通りです:
pdu_length = length of version field and string tag (4 bytes)
+ length of community length field (1 byte)
+ length of community name (depends...)
+ length of SNMP RESPONSE (31 bytes)
pdu_長さは共同体名(よる)の共同体長さの分野(1バイト)+長さのバージョン分野とストリングタグ(4バイト)+長さの長さと等しいです。 + SNMP RESPONSEの長さ(31バイト)
= 36 + length of community name
= 36 + 共同体名の長さ
SNMP DPI PACKET FORMATS
SNMP dpiパケット・フォーマット
Each request to or response from the agent is constructed as a "packet" and is written to the stream.
エージェントからの各要求か応答が、「パケット」として構成されて、ストリームに書かれています。
Each packet is prefaced with the length of the data remaining in the packet. The length is stored in network byte order (most significant byte first, least significant last). The receiving side will read the packet by doing something similar to:
データの長さがパケットに残っていて、各パケットは前書きされます。 長さがネットワークバイトオーダーで保存される、(最も重要なバイト、1番目、最も重要でない最終) 受信側は、以下のことのために何か同様のことをすることによって、パケットを読むでしょう。
unsigned char len_bfr[2];
char *bfr;
int len;
未署名の炭のlen_bfr[2]。 *bfrを炭にしてください。 int len。
read(fd,len_bfr,2);
len = len_bfr[0] * 256 + len_bfr[1];
bfr = malloc(len);
read(fd,bfr,len);
(fd、len_bfr、2)は読みます。 lenはlen_bfr[0]*256+len_bfr[1]と等しいです。 bfrはmalloc(len)と等しいです。 (fd、bfr、len)は読みます。
NOTE: the above example makes no provisions for error handling or a read returning less than the requested amount of data. This is not a suggested coding style.
以下に注意してください。 上記の例は要求されたデータ量ほど戻らないエラー処理か読書に備えません。 これは提案されたコード化スタイルではありません。
Carpenter & Wijnen [Page 9] RFC 1228 SNMP-DPI May 1991
大工とWijnen[9ページ]RFC1228SNMP-dpi1991年5月
The first part of every packet identifies the application protocol being used, as well as some version information. The protocol major version is intended to indicate in broad terms what version of the protocol is used. The protocol minor version is intended to identify major incompatible versions of the protocol. The protocol release is intended to indicate incremental modifications to the protocol. The constants that are valid for these fields are defined in Table 10 on page 18.
あらゆるパケットの最初の一部が何らかのバージョン情報と同様に使用されるアプリケーション・プロトコルを特定します。 プロトコルの主要なバージョンが、プロトコルのどんなバージョンが使用されているかを大きく見ると示すことを意図します。 プロトコルの小さい方のバージョンがプロトコルの主要な両立しないバージョンを特定することを意図します。 プロトコルリリースがプロトコルへの増加の変更を示すことを意図します。 これらの分野に、有効な定数は18ページのTable10で定義されます。
The next (common) field in all packets is the packet type. This field indicates what kind of packet we're dealing with (SNMP DPI GET, GET-NEXT, SET, TRAP, RESPONSE or REGISTER). The permitted values for this field are defined in Table 11 on page 18.
すべてのパケットの次の(一般的)の分野はパケットタイプです。 この分野は、私たちがどういうパケットに対処しているかを(SNMP DPI GET、GET-ネクスト、SET、TRAP、RESPONSEまたはREGISTER)示します。 この分野への受入れられた値は18ページのTable11で定義されます。
+----------------------------------------------------------------------+ | Table 3. SNMP DPI packet header. This header is present in all | | packets. | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type | +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 3を見送ってください。 SNMP DPIパケットのヘッダー。 このヘッダーは全部で出席しています。| | パケット。 | +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプ| +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
>From this point onwards, the contents of the packet are defined by the protocol being used. The remainder of this section describes:
これからの>は前方へ指して、パケットの内容は使用されるプロトコルによって定義されます。 このセクションの残りは以下について説明します。
o the structure of packets for the SNMP DPI protocol, version 1.0.
o SNMP DPIプロトコルのためのパケットの構造、バージョン1.0。
o The constants as defined with this version of the protocol.
o プロトコルのこのバージョンで定義される定数。
Carpenter & Wijnen [Page 10] RFC 1228 SNMP-DPI May 1991
大工とWijnen[10ページ]RFC1228SNMP-dpi1991年5月
REGISTER
レジスタ
In order to register a branch in the MIB tree, an SNMP sub-agent sends an SNMP DPI REGISTER packet to the agent.
MIB木にブランチを登録するために、SNMPサブエージェントはSNMP DPI REGISTERパケットをエージェントに送ります。
Such a packet contains the standard SNMP DPI header plus REGISTER- specific data, which basically is a null terminated string representing the object ID in dotted ASN.1 notation (with a trailing dot!).
そのようなパケットは標準のSNMP DPIヘッダーとREGISTERの特定のデータを含んでいます。(基本的に、データは点を打たされたASN.1記法(引きずっているドットがある!)でオブジェクトIDを表すヌル終えられたストリングです)。
+----------------------------------------------------------------------+ | Table 4. SNMP DPI REGISTER packet. This is the layout of an SNMP | | DPI REGISTER packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type = SNMP_DPI_REGISTER | +-------------+--------------------------------------------------------+ | 6 | null terminated object ID | +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 4を見送ってください。 SNMP DPI REGISTERパケット。 これはSNMPのレイアウトです。| | DPI REGISTERパケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプはSNMP_DPI_REGISTERと等しいです。| +-------------+--------------------------------------------------------+ | 6 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 11] RFC 1228 SNMP-DPI May 1991
大工とWijnen[11ページ]RFC1228SNMP-dpi1991年5月
GET
得てください。
When the SNMP agent receives a PDU containing an SNMP GET request for a variable that a sub-agent registered with the agent, it passes an SNMP DPI GET packet to the sub-agent.
SNMPエージェントが変数を求めるサブエージェントがエージェントとともに記名したというSNMP GET要求を含むPDUを受け取るとき、それはSNMP DPI GETパケットをサブエージェントに渡します。
Such a packet contains the standard SNMP DPI header plus GET-specific data, which is basically a null terminated string representing the object ID in dotted ASN.1 notation.
そのようなパケットは標準のSNMP DPIヘッダーとGET特有のデータを含んでいます。(データは基本的に点を打たされたASN.1記法でオブジェクトIDを表すヌル終えられたストリングです)。
+----------------------------------------------------------------------+ | Table 5. SNMP DPI GET packet. This is the layout of an SNMP DPI GET | | packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type = SNMP_DPI_GET | +-------------+--------------------------------------------------------+ | 6 | null terminated object ID | +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 5を見送ってください。 SNMP DPI GETパケット。 これはSNMP DPI GETのレイアウトです。| | パケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプはSNMP_DPI_GETと等しいです。| +-------------+--------------------------------------------------------+ | 6 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 12] RFC 1228 SNMP-DPI May 1991
大工とWijnen[12ページ]RFC1228SNMP-dpi1991年5月
GET-NEXT
気付いてください。
When the SNMP agent receives a PDU containing an SNMP GET-NEXT request for a variable for which a sub-agent may be authoritative, it passes an SNMP DPI GET-NEXT packet to the sub-agent.
SNMPエージェントがサブエージェントが正式であるかもしれない変数を求めるSNMP GET-ネクスト要求を含むPDUを受け取るとき、それはSNMP DPI GET-ネクストパケットをサブエージェントに渡します。
Such a packet contains the standard SNMP DPI header plus GET-NEXT- specific data. These data take the form of two null terminated strings. The first string represents the object ID in dotted ASN.1 notation; the second string represents the group ID in dotted ASN.1 notation.
そのようなパケットは標準のSNMP DPIヘッダーとGET-ネクスト特有のデータを含んでいます。 これらのデータは2個のヌル終えられたストリングの形を取ります。 最初のストリングは点を打たされたASN.1記法でオブジェクトIDを表します。 2番目のストリングは点を打たされたASN.1記法でグループIDを表します。
+----------------------------------------------------------------------+ | Table 6. SNMP DPI GET NEXT packet. This is the layout of an SNMP | | DPI GET NEXT packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type = SNMP_DPI_GET_NEXT | +-------------+--------------------------------------------------------+ | 6 | null terminated object ID | +-------------+--------------------------------------------------------+ | 6 + len | null terminated group ID | +-------------+--------------------------------------------------------+ | NOTE: len=strlen(object ID)+1 | +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 6を見送ってください。 SNMP DPI GET NEXTパケット。 これはSNMPのレイアウトです。| | DPI GET NEXTパケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプはSNMP_DPI_GET_ネクストと等しいです。| +-------------+--------------------------------------------------------+ | 6 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ | 6 + len| ヌル終えられたグループID| +-------------+--------------------------------------------------------+ | 以下に注意してください。 len=strlen(オブジェクトID)+1| +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 13] RFC 1228 SNMP-DPI May 1991
大工とWijnen[13ページ]RFC1228SNMP-dpi1991年5月
SET
セットします。
When the SNMP agent receives a PDU containing an SNMP SET request for a variable that a sub-agent registered with the agent, it passes an SNMP DPI SET packet to the sub-agent.
SNMPエージェントが変数を求めるサブエージェントがエージェントとともに記名したというSNMP SET要求を含むPDUを受け取るとき、それはSNMP DPI SETパケットをサブエージェントに渡します。
Such a packet contains the standard SNMP DPI header plus SET specific data, which is basically a null terminated string representing the object ID in ASN.1 notation, with the type, value length and value to be set. The permitted types for the type field are defined in Table 12 on page 19. Integer values are sent as 4-byte elements in network byte order (most significant byte first, least significant byte last).
そのようなパケットは標準のSNMP DPIヘッダーとSETの特定のデータを含んでいます。(データは基本的に設定されるためにタイプ、値の長さ、および値でASN.1記法でオブジェクトIDを表すヌル終えられたストリングです)。 タイプ分野のための受入れられたタイプは19ページのTable12で定義されます。 4バイトの要素としてネットワークバイトオーダー(最初に最も重要でないバイトが持続する中で最も重要なバイト)で整数値を送ります。
+----------------------------------------------------------------------+ | Table 7. SNMP DPI SET packet. This is the layout of an SNMP DPI SET | | packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type = SNMP_DPI_SET | +-------------+--------------------------------------------------------+ | 6 | null terminated object ID | +-------------+--------------------------------------------------------+ | 6 + len | SNMP Variable Type Value | +-------------+--------------------------------------------------------+ | 6 + len + 1 | Length of value (MSB) | +-------------+--------------------------------------------------------+ | 6 + len + 2 | Length of value (LSB) | +-------------+--------------------------------------------------------+ | 6 + len + 3 | Value | +-------------+--------------------------------------------------------+ | NOTE: len=strlen(object ID)+1 | +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 7を見送ってください。 SNMP DPI SETパケット。 これはSNMP DPI SETのレイアウトです。| | パケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプはSNMP_DPI_SETと等しいです。| +-------------+--------------------------------------------------------+ | 6 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ | 6 + len| SNMPの可変タイプ価値| +-------------+--------------------------------------------------------+ | 6+len+1| 価値(MSB)の長さ| +-------------+--------------------------------------------------------+ | 6+len+2| 価値(LSB)の長さ| +-------------+--------------------------------------------------------+ | 6+len+3| 値| +-------------+--------------------------------------------------------+ | 以下に注意してください。 len=strlen(オブジェクトID)+1| +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 14] RFC 1228 SNMP-DPI May 1991
大工とWijnen[14ページ]RFC1228SNMP-dpi1991年5月
RESPONSE
応答
An SNMP sub-agent must respond to a GET, GET_NEXT or SET request that it has received from the agent (unless it fails or has a bug). To do so, it sends an SNMP DPI RESPONSE packet to the agent.
SNMPサブエージェントはエージェントから受信したという(バグを失敗するか、または持っていない場合)GET、GET_ネクストまたはSET要求に応じなければなりません。 そうするために、それはSNMP DPI RESPONSEパケットをエージェントに送ります。
Such a packet contains the standard SNMP DPI header plus RESPONSE specific data, which basically is an error_code plus (if there was no error), the name/type/value tuple representing the returned object. This is described as by a string representing the object ID in ASN.1 notation, plus the type, value length and value of the object that was manipulated. The permitted types for the type field are defined in Table 12 on page 19. Integer values are sent as 4-byte elements in network byte order (most significant byte first, least significant byte last).
そのようなパケットは標準のSNMP DPIヘッダーとRESPONSEの特定のデータを含んでいます。(基本的に、データは誤り_コードプラス(誤りが全くなかったなら)(返されたオブジェクトを表す名前/タイプ/値のtuple)です)。 これは操作されたオブジェクトのASN.1記法でオブジェクトIDを表すストリング、タイプ、値の長さ、および値のように説明されます。 タイプ分野のための受入れられたタイプは19ページのTable12で定義されます。 4バイトの要素としてネットワークバイトオーダー(最初に最も重要でないバイトが持続する中で最も重要なバイト)で整数値を送ります。
Carpenter & Wijnen [Page 15] RFC 1228 SNMP-DPI May 1991
大工とWijnen[15ページ]RFC1228SNMP-dpi1991年5月
+----------------------------------------------------------------------+ | Table 8. SNMP DPI RESPONSE packet. This is the layout of an SNMP | | DPI RESPONSE packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type = SNMP_DPI_RESPONSE | +-------------+--------------------------------------------------------+ | 6 | SNMP error code | +-------------+--------------------------------------------------------+ | 7 | null terminated object ID | +-------------+--------------------------------------------------------+ | 7 + len | SNMP Variable Type Value | +-------------+--------------------------------------------------------+ | 7 + len + 1 | Length of value (MSB) | +-------------+--------------------------------------------------------+ | 7 + len + 2 | Length of value (LSB) | +-------------+--------------------------------------------------------+ | 7 + len + 3 | Value | +-------------+--------------------------------------------------------+ | NOTE: len=strlen(object ID)+1 | +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 8を見送ってください。 SNMP DPI RESPONSEパケット。 これはSNMPのレイアウトです。| | DPI RESPONSEパケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプはSNMP_DPI_RESPONSEと等しいです。| +-------------+--------------------------------------------------------+ | 6 | SNMPエラーコード| +-------------+--------------------------------------------------------+ | 7 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ | 7 + len| SNMPの可変タイプ価値| +-------------+--------------------------------------------------------+ | 7+len+1| 価値(MSB)の長さ| +-------------+--------------------------------------------------------+ | 7+len+2| 価値(LSB)の長さ| +-------------+--------------------------------------------------------+ | 7+len+3| 値| +-------------+--------------------------------------------------------+ | 以下に注意してください。 len=strlen(オブジェクトID)+1| +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
TRAP
罠
An SNMP sub-agent can request the agent to generate a TRAP by sending an SNMP DPI TRAP packet to the agent.
SNMPサブエージェントは、SNMP DPI TRAPパケットをエージェントに送ることによってTRAPを生成するようエージェントに要求できます。
Such a packet contains the standard SNMP DPI header plus TRAP specific data, which is basically the generic and specific trap code, plus a name/type/value tuple. The tuple is described by a string representing the object ID in ASN.1 notation, plus the type, value length and value of the object that is being sent in the trap. The permitted types for the type field are defined in Table 12 on page 19. Integer values are sent as 4-byte elements in network byte order (most significant byte first, least significant byte last).
そのようなパケットは標準のSNMP DPIヘッダーとTRAPの特定のデータを含んでいます。(データは、基本的にジェネリックと、特定の罠コードと、名前/タイプ/値のtupleです)。 tupleは罠で送られるオブジェクトのASN.1記法でオブジェクトIDを表すストリング、タイプ、値の長さ、および値によって説明されます。 タイプ分野のための受入れられたタイプは19ページのTable12で定義されます。 4バイトの要素としてネットワークバイトオーダー(最初に最も重要でないバイトが持続する中で最も重要なバイト)で整数値を送ります。
Carpenter & Wijnen [Page 16] RFC 1228 SNMP-DPI May 1991
大工とWijnen[16ページ]RFC1228SNMP-dpi1991年5月
+----------------------------------------------------------------------+ | Table 9. SNMP DPI TRAP packet. This is the layout of an SNMP DPI | | TRAP packet | +-------------+--------------------------------------------------------+ | OFFSET | FIELD | +-------------+--------------------------------------------------------+ | 0 | packet length to follow (MSB) | +-------------+--------------------------------------------------------+ | 1 | packet length to follow (LSB) | +-------------+--------------------------------------------------------+ | 2 | protocol major version | +-------------+--------------------------------------------------------+ | 3 | protocol minor version | +-------------+--------------------------------------------------------+ | 4 | protocol release | +-------------+--------------------------------------------------------+ | 5 | packet type - SNMP_DPI_TRAP | +-------------+--------------------------------------------------------+ | 6 | SNMP generic trap code | +-------------+--------------------------------------------------------+ | 7 | SNMP specific trap code | +-------------+--------------------------------------------------------+ | 8 | null terminated object ID | +-------------+--------------------------------------------------------+ | 8 + len | SNMP Variable Type Value | +-------------+--------------------------------------------------------+ | 8 + len + 1 | Length of value (MSB) | +-------------+--------------------------------------------------------+ | 8 + len + 2 | Length of value (LSB) | +-------------+--------------------------------------------------------+ | 8 + len + 3 | Value | +-------------+--------------------------------------------------------+ | NOTE: len=strlen(object ID)+1 | +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 9を見送ってください。 SNMP DPI TRAPパケット。 これはSNMP DPIのレイアウトです。| | TRAPパケット| +-------------+--------------------------------------------------------+ | 相殺されます。| 分野| +-------------+--------------------------------------------------------+ | 0 | 続くパケット長(MSB)| +-------------+--------------------------------------------------------+ | 1 | 続くパケット長(LSB)| +-------------+--------------------------------------------------------+ | 2 | 主要なバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 3 | 小さい方のバージョンについて議定書の中で述べてください。| +-------------+--------------------------------------------------------+ | 4 | プロトコルリリース| +-------------+--------------------------------------------------------+ | 5 | パケットタイプ--SNMP_DPI_TRAP| +-------------+--------------------------------------------------------+ | 6 | SNMPジェネリック罠コード| +-------------+--------------------------------------------------------+ | 7 | SNMPの特定の罠コード| +-------------+--------------------------------------------------------+ | 8 | ヌル終えられたオブジェクトID| +-------------+--------------------------------------------------------+ | 8 + len| SNMPの可変タイプ価値| +-------------+--------------------------------------------------------+ | 8+len+1| 価値(MSB)の長さ| +-------------+--------------------------------------------------------+ | 8+len+2| 価値(LSB)の長さ| +-------------+--------------------------------------------------------+ | 8+len+3| 値| +-------------+--------------------------------------------------------+ | 以下に注意してください。 len=strlen(オブジェクトID)+1| +----------------------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 17] RFC 1228 SNMP-DPI May 1991
大工とWijnen[17ページ]RFC1228SNMP-dpi1991年5月
CONSTANTS AND VALUES
定数と値
This section describes the constants that have been defined for this version of the SNMP DPI Protocol.
このセクションはSNMP DPIプロトコルのこのバージョンのために定義された定数について説明します。
PROTOCOL VERSION AND RELEASE VALUES
プロトコルバージョンANDリリース値
+----------------------------------------------------------------------+ | Table 10. Protocol version and release values | +-----------------------------------+----------------------------------+ | FIELD | VALUE | +-----------------------------------+----------------------------------+ | protocol major version | 2 (SNMP DPI protocol) | +-----------------------------------+----------------------------------+ | protocol minor version | 1 (version 1) | +-----------------------------------+----------------------------------+ | protocol release | 0 (release 0) | +-----------------------------------+----------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 10を見送ってください。 プロトコルバージョンとリリース値| +-----------------------------------+----------------------------------+ | 分野| 値| +-----------------------------------+----------------------------------+ | 主要なバージョンについて議定書の中で述べてください。| 2 (SNMP DPIプロトコル)| +-----------------------------------+----------------------------------+ | 小さい方のバージョンについて議定書の中で述べてください。| 1 (バージョン1)| +-----------------------------------+----------------------------------+ | プロトコルリリース| 0 (リリース0)| +-----------------------------------+----------------------------------+ +----------------------------------------------------------------------+
Any other values are currently undefined.
いかなる他の値も現在、未定義です。
PACKET TYPE VALUES
パケットタイプ値
The packet type field can have the following values:
パケットタイプ分野は以下の値を持つことができます:
+----------------------------------------------------------------------+ | Table 11. Valid values for the packet type field | +-------+--------------------------------------------------------------+ | VALUE | PACKET TYPE | +-------+--------------------------------------------------------------+ | 1 | SNMP_DPI_GET | +-------+--------------------------------------------------------------+ | 2 | SNMP_DPI_GET_NEXT | +-------+--------------------------------------------------------------+ | 3 | SNMP_DPI_SET | +-------+--------------------------------------------------------------+ | 4 | SNMP_DPI_TRAP | +-------+--------------------------------------------------------------+ | 5 | SNMP_DPI_RESPONSE | +-------+--------------------------------------------------------------+ | 6 | SNMP_DPI_REGISTER | +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 11を見送ってください。 パケットタイプ分野への有効値| +-------+--------------------------------------------------------------+ | 値| パケットタイプ| +-------+--------------------------------------------------------------+ | 1 | dpi_が手に入れるSNMP_| +-------+--------------------------------------------------------------+ | 2 | SNMP_dpi_は次に、_を手に入れます。| +-------+--------------------------------------------------------------+ | 3 | SNMP_dpi_はセットしました。| +-------+--------------------------------------------------------------+ | 4 | SNMP_dpi_罠| +-------+--------------------------------------------------------------+ | 5 | SNMP_dpi_応答| +-------+--------------------------------------------------------------+ | 6 | SNMP_dpi_は登録されます。| +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
Carpenter & Wijnen [Page 18] RFC 1228 SNMP-DPI May 1991
大工とWijnen[18ページ]RFC1228SNMP-dpi1991年5月
VARIABLE TYPE VALUES
可変タイプ値
The variable type field can have the following values:
可変タイプ分野は以下の値を持つことができます:
+----------------------------------------------------------------------+ | Table 12. Valid values for the Value Type field | +-------+--------------------------------------------------------------+ | VALUE | VALUE TYPE | +-------+--------------------------------------------------------------+ | 0 | text representation | +-------+--------------------------------------------------------------+ | 129 | number (integer) | +-------+--------------------------------------------------------------+ | 2 | octet string | +-------+--------------------------------------------------------------+ | 3 | object identifier | +-------+--------------------------------------------------------------+ | 4 | empty (no value) | +-------+--------------------------------------------------------------+ | 133 | internet address | +-------+--------------------------------------------------------------+ | 134 | counter (unsigned) | +-------+--------------------------------------------------------------+ | 135 | gauge (unsigned) | +-------+--------------------------------------------------------------+ | 136 | time ticks (1/100ths seconds) | +-------+--------------------------------------------------------------+ | 9 | display string | +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | 12を見送ってください。 Value Type分野への有効値| +-------+--------------------------------------------------------------+ | 値| 値のタイプ| +-------+--------------------------------------------------------------+ | 0 | テキスト表現| +-------+--------------------------------------------------------------+ | 129 | 数(整数)| +-------+--------------------------------------------------------------+ | 2 | 八重奏ストリング| +-------+--------------------------------------------------------------+ | 3 | オブジェクト識別子| +-------+--------------------------------------------------------------+ | 4 | (値がありません)を空にしてください。| +-------+--------------------------------------------------------------+ | 133 | インターネットアドレス| +-------+--------------------------------------------------------------+ | 134 | 反対してください(未署名の)。| +-------+--------------------------------------------------------------+ | 135 | ゲージ(未署名の)| +-------+--------------------------------------------------------------+ | 136 | タイム・チック(1/100ths秒)| +-------+--------------------------------------------------------------+ | 9 | ディスプレイストリング| +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
NOTE: Fields which represent values that are stored as a 4-byte integer are indicated by ORing their base type value with 128.
以下に注意してください。 4バイトの整数として保存される値を表す分野はORingによって示されて、それらのベースが128で値をタイプするということです。
Error Code Values for SNMP Agent Detected Errors
エラーコードはSNMPエージェントのために検出された誤りを評価します。
The error code can have one of the following values:
エラーコードは以下の値の1つを持つことができます:
Carpenter & Wijnen [Page 19] RFC 1228 SNMP-DPI May 1991
大工とWijnen[19ページ]RFC1228SNMP-dpi1991年5月
+----------------------------------------------------------------------+ | Table 13. Valid values for the SNMP Agent Minor Error Code field | +-------+--------------------------------------------------------------+ | VALUE | SNMP AGENT ERROR CODE | +-------+--------------------------------------------------------------+ | 0 | no error | +-------+--------------------------------------------------------------+ | 1 | too big | +-------+--------------------------------------------------------------+ | 2 | no such name | +-------+--------------------------------------------------------------+ | 3 | bad value | +-------+--------------------------------------------------------------+ | 4 | read only | +-------+--------------------------------------------------------------+ | 5 | general error | +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
+----------------------------------------------------------------------+ | Table 13. Valid values for the SNMP Agent Minor Error Code field | +-------+--------------------------------------------------------------+ | VALUE | SNMP AGENT ERROR CODE | +-------+--------------------------------------------------------------+ | 0 | no error | +-------+--------------------------------------------------------------+ | 1 | too big | +-------+--------------------------------------------------------------+ | 2 | no such name | +-------+--------------------------------------------------------------+ | 3 | bad value | +-------+--------------------------------------------------------------+ | 4 | read only | +-------+--------------------------------------------------------------+ | 5 | general error | +-------+--------------------------------------------------------------+ +----------------------------------------------------------------------+
SNMP DPI APPLICATION PROGRAM INTERFACE
SNMP DPI APPLICATION PROGRAM INTERFACE
This section documents an API that implements the SNMP DPI. This information has been previously published [6, 8], but the information provided below is more current as of May 14, 1991.
This section documents an API that implements the SNMP DPI. This information has been previously published [6, 8], but the information provided below is more current as of May 14, 1991.
OVERVIEW OF REQUEST PROCESSING
OVERVIEW OF REQUEST PROCESSING
GET PROCESSING
GET PROCESSING
A GET request is the easiest to process. When the DPI packet is parsed, the parse tree holds the object ID of the variable being requested.
A GET request is the easiest to process. When the DPI packet is parsed, the parse tree holds the object ID of the variable being requested.
If the specified object is not supported by the sub-agent, it would return an error indication of "no such name". No name/type/value information would be returned.
If the specified object is not supported by the sub-agent, it would return an error indication of "no such name". No name/type/value information would be returned.
unsigned char *cp;
unsigned char *cp;
cp = mkDPIresponse(SNMP_NO_SUCH_NAME,0);
cp = mkDPIresponse(SNMP_NO_SUCH_NAME,0);
If the object is recognized, then the sub-agent creates a parse tree representing the name/type/value of the object in question (using the DPI API routine mkDPIset()), and returns no error indication. This is demonstrated below (a string is being returned).
If the object is recognized, then the sub-agent creates a parse tree representing the name/type/value of the object in question (using the DPI API routine mkDPIset()), and returns no error indication. This is demonstrated below (a string is being returned).
Carpenter & Wijnen [Page 20] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 20] RFC 1228 SNMP-DPI May 1991
char *obj_id;
char *obj_id;
unsigned char *cp;
struct dpi_set_packet *ret_value;
char *data;
unsigned char *cp; struct dpi_set_packet *ret_value; char *data;
/* obj_id = object ID of variable, like 1.3.6.1.2.1.1.1 */
/* should be identical to object ID sent in get request */
data = "a string to be returned";
ret_value = mkDPIset(obj_id,SNMP_TYPE_STRING,
strlen(data)+1,data);
cp = mkDPIresponse(0,ret_value);
/* obj_id = object ID of variable, like 1.3.6.1.2.1.1.1 */ /* should be identical to object ID sent in get request */ data = "a string to be returned"; ret_value = mkDPIset(obj_id,SNMP_TYPE_STRING, strlen(data)+1,data); cp = mkDPIresponse(0,ret_value);
SET PROCESSING
SET PROCESSING
Processing a SET request is only slightly more difficult than a GET request. In this case, additional information is made available in the parse tree, namely the type, length and value to be set.
Processing a SET request is only slightly more difficult than a GET request. In this case, additional information is made available in the parse tree, namely the type, length and value to be set.
The sub-agent may return an error indication of "no such name" if the variable is unrecognized, just as in a GET request. If the variable is recognized, but cannot be set, an error indication of "no such name" should be also be returned, although it is tempting to return a "read only" error.
The sub-agent may return an error indication of "no such name" if the variable is unrecognized, just as in a GET request. If the variable is recognized, but cannot be set, an error indication of "no such name" should be also be returned, although it is tempting to return a "read only" error.
GET NEXT PROCESSING
GET NEXT PROCESSING
GET-NEXT requests are the most complicated requests to process. After parsing a GET-NEXT request, the parse tree will contain two parameters. One is the object ID on which the GET-NEXT operation is being performed. The semantics of the operation are that the sub- agent is to return the name/type/value of the next variable it supports whose name lexicographically follows the passed object ID.
GET-NEXT requests are the most complicated requests to process. After parsing a GET-NEXT request, the parse tree will contain two parameters. One is the object ID on which the GET-NEXT operation is being performed. The semantics of the operation are that the sub- agent is to return the name/type/value of the next variable it supports whose name lexicographically follows the passed object ID.
It is important to realize that a given sub-agent may support several discontiguous sections of the MIB tree. In such a situation it would be incorrect to jump from one section to another. This problem is correctly handled by examining the second parameter which is passed. This parameter represents the "reason" why the sub-agent is being called. It holds the prefix of the tree that the sub-agent had indicated it supported.
It is important to realize that a given sub-agent may support several discontiguous sections of the MIB tree. In such a situation it would be incorrect to jump from one section to another. This problem is correctly handled by examining the second parameter which is passed. This parameter represents the "reason" why the sub-agent is being called. It holds the prefix of the tree that the sub-agent had indicated it supported.
If the next variable supported by the sub-agent does not begin with that prefix, the sub-agent must return an error indication of "no such name". If required, the SNMP agent will call upon the sub-agent again, but pass it a different group prefix. This is illustrated in the discussion below:
If the next variable supported by the sub-agent does not begin with that prefix, the sub-agent must return an error indication of "no such name". If required, the SNMP agent will call upon the sub-agent again, but pass it a different group prefix. This is illustrated in the discussion below:
Carpenter & Wijnen [Page 21] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 21] RFC 1228 SNMP-DPI May 1991
Assume there are two sub-agents. The first sub-agent registers two distinct sections of the tree, A and C. In reality, the sub-agent supports variables A.1 and A.2, but it correctly registers the minimal prefix required to uniquely identify the variable class it supports.
Assume there are two sub-agents. The first sub-agent registers two distinct sections of the tree, A and C. In reality, the sub-agent supports variables A.1 and A.2, but it correctly registers the minimal prefix required to uniquely identify the variable class it supports.
The second sub-agent registers a different section, B, which appears between the two sections registered by the first agent.
The second sub-agent registers a different section, B, which appears between the two sections registered by the first agent.
If a remote management station begins dumping the MIB, starting from A, the following sequence of queries would be performed:
If a remote management station begins dumping the MIB, starting from A, the following sequence of queries would be performed:
Sub-agent 1 gets called:
get-next(A,A) == A.1
get-next(A.1,A) = A.2
get-next(A.2,A) = error(no such name)
Sub-agent 1 gets called: get-next(A,A) == A.1 get-next(A.1,A) = A.2 get-next(A.2,A) = error(no such name)
Sub-agent 2 is then called:
get-next(A.2,B) = B.1
get-next(B.1,B) = error(no such name)
Sub-agent 2 is then called: get-next(A.2,B) = B.1 get-next(B.1,B) = error(no such name)
Sub-agent 1 gets called again:
get-next(B.1,C) = C.1
Sub-agent 1 gets called again: get-next(B.1,C) = C.1
REGISTER REQUESTS
REGISTER REQUESTS
A sub-agent must register the variables it supports with the SNMP agent. The appropriate packets may be created using the DPI API library routine mkDPIregister().
A sub-agent must register the variables it supports with the SNMP agent. The appropriate packets may be created using the DPI API library routine mkDPIregister().
unsigned char *cp;
unsigned char *cp;
cp = mkDPIregister("1.3.6.1.2.1.1.2.");
cp = mkDPIregister("1.3.6.1.2.1.1.2.");
NOTE: object IDs are registered with a trailing dot (".").
NOTE: object IDs are registered with a trailing dot (".").
TRAP REQUESTS
TRAP REQUESTS
A sub-agent can request that the SNMP agent generate a trap for it. The sub-agent must provide the desired values for the generic and specific parameters of the trap. It may optionally provide a name/type/value parameter that will be included in the trap packet. The DPI API library routine mkDPItrap() can be used to generate the required packet.
A sub-agent can request that the SNMP agent generate a trap for it. The sub-agent must provide the desired values for the generic and specific parameters of the trap. It may optionally provide a name/type/value parameter that will be included in the trap packet. The DPI API library routine mkDPItrap() can be used to generate the required packet.
Carpenter & Wijnen [Page 22] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 22] RFC 1228 SNMP-DPI May 1991
DPI API LIBRARY ROUTINES
DPI API LIBRARY ROUTINES
This section documents Application Program Interfaces to the DPI.
This section documents Application Program Interfaces to the DPI.
QUERY_DPI_PORT()
QUERY_DPI_PORT()
int port;
char *hostname, *community_name;
int port; char *hostname, *community_name;
port = query_DPI_port(hostname, community_name);
port = query_DPI_port(hostname, community_name);
The query_DPI_port() function is used by a DPI client to determine what TCP port number is associated with the DPI. This port number is needed to connect() to the SNMP agent. If the port cannot be determined, -1 is returned.
The query_DPI_port() function is used by a DPI client to determine what TCP port number is associated with the DPI. This port number is needed to connect() to the SNMP agent. If the port cannot be determined, -1 is returned.
The function is passed two arguments: a string representing the host's name or IP address and the community name to be used when making the request.
The function is passed two arguments: a string representing the host's name or IP address and the community name to be used when making the request.
This function enables a DPI client to "bootstrap" itself. The port number is obtained via an SNMP GET request, but the DPI client does not have to be able to create and parse SNMP packets--this is all done by the query_DPI_port() function.
This function enables a DPI client to "bootstrap" itself. The port number is obtained via an SNMP GET request, but the DPI client does not have to be able to create and parse SNMP packets--this is all done by the query_DPI_port() function.
NOTE: the query_DPI_port() function assumes that the community name does not contain any null characters. If this is not the case, use the _query_DPI_port() function which takes a third parameter, the length of the community name.
NOTE: the query_DPI_port() function assumes that the community name does not contain any null characters. If this is not the case, use the _query_DPI_port() function which takes a third parameter, the length of the community name.
MKDPIREGISTER
MKDPIREGISTER
#include "snmp_dpi.h"
#include "snmp_dpi.h"
unsigned char *packet;
int len;
unsigned char *packet; int len;
/* register sysDescr variable */
packet = mkDPIregister("1.3.6.1.2.1.1.1.");
/* register sysDescr variable */ packet = mkDPIregister("1.3.6.1.2.1.1.1.");
len = *packet * 256 + *(packet + 1);
len += 2; /* include length bytes */
len = *packet * 256 + *(packet + 1); len += 2; /* include length bytes */
The mkDPIregister() function creates the necessary register-request packet and returns a pointer to a static buffer holding the packet contents. The null pointer (0) is returned if there is an error detected during the creation of the packet.
The mkDPIregister() function creates the necessary register-request packet and returns a pointer to a static buffer holding the packet contents. The null pointer (0) is returned if there is an error detected during the creation of the packet.
Carpenter & Wijnen [Page 23] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 23] RFC 1228 SNMP-DPI May 1991
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
NOTE: object identifiers are registered with a trailing dot (".").
NOTE: object identifiers are registered with a trailing dot (".").
MKDPISET
MKDPISET
#include "snmp_dpi.h"
#include "snmp_dpi.h"
struct dpi_set_packet *set_value;
struct dpi_set_packet *set_value;
char *obj_id;
int type, length;
char *value;
char *obj_id; int type, length; char *value;
set_value = mkDPIset(obj_id, type, length, value);
set_value = mkDPIset(obj_id, type, length, value);
The mkDPIset() function can be used to create the portion of a parse tree that represents a name/value pair (as would be normally be returned in a response packet). It returns a pointer to a dynamically allocated parse tree representing the name/type/value information. If there is an error detected while creating the parse tree, the null pointer (0) is returned.
The mkDPIset() function can be used to create the portion of a parse tree that represents a name/value pair (as would be normally be returned in a response packet). It returns a pointer to a dynamically allocated parse tree representing the name/type/value information. If there is an error detected while creating the parse tree, the null pointer (0) is returned.
The value of type can be one of the following (which are defined in the include file "snmp_dpi.h"):
The value of type can be one of the following (which are defined in the include file "snmp_dpi.h"):
o SNMP_TYPE_NUMBER
o SNMP_TYPE_STRING
o SNMP_TYPE_OBJECT
o SNMP_TYPE_INTERNET
o SNMP_TYPE_COUNTER
o SNMP_TYPE_GAUGE
o SNMP_TYPE_TICKS
o SNMP_TYPE_NUMBER o SNMP_TYPE_STRING o SNMP_TYPE_OBJECT o SNMP_TYPE_INTERNET o SNMP_TYPE_COUNTER o SNMP_TYPE_GAUGE o SNMP_TYPE_TICKS
The value parameter is always a pointer to the first byte of the object's value.
The value parameter is always a pointer to the first byte of the object's value.
NOTE: the parse tree is dynamically allocated and copies are made of the passed parameters. After a successful call to mkDPIset(), they can be disposed of in any manner the application chooses without affecting the parse tree contents.
NOTE: the parse tree is dynamically allocated and copies are made of the passed parameters. After a successful call to mkDPIset(), they can be disposed of in any manner the application chooses without affecting the parse tree contents.
MKDPIRESPONSE
MKDPIRESPONSE
#include "snmp_dpi.h"
#include "snmp_dpi.h"
unsigned char *packet;
unsigned char *packet;
Carpenter & Wijnen [Page 24] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 24] RFC 1228 SNMP-DPI May 1991
int error_code;
struct dpi_set_packet *ret_value;
int error_code; struct dpi_set_packet *ret_value;
packet = mkDPIresponse(error_code, ret_value);
packet = mkDPIresponse(error_code, ret_value);
len = *packet * 256 + *(packet + 1);
len += 2; /* include length bytes */
len = *packet * 256 + *(packet + 1); len += 2; /* include length bytes */
The mkDPIresponse() function creates an appropriate response packet. It takes two parameters. The first is the error code to be returned. It may be 0 (indicating no error) or one of the following (which are defined in the include file "snmp_dpi.h"):
The mkDPIresponse() function creates an appropriate response packet. It takes two parameters. The first is the error code to be returned. It may be 0 (indicating no error) or one of the following (which are defined in the include file "snmp_dpi.h"):
o SNMP_NO_ERROR
o SNMP_TOO_BIG
o SNMP_NO_SUCH_NAME
o SNMP_BAD_VALUE
o SNMP_READ_ONLY
o SNMP_GEN_ERR
o SNMP_NO_ERROR o SNMP_TOO_BIG o SNMP_NO_SUCH_NAME o SNMP_BAD_VALUE o SNMP_READ_ONLY o SNMP_GEN_ERR
If the error code indicates no error, then the second parameter is a pointer to a parse tree (created by mkDPIset()) which represents the name/type/value information being returned. If an error is indicated, the second parameter is passed as a null pointer (0).
If the error code indicates no error, then the second parameter is a pointer to a parse tree (created by mkDPIset()) which represents the name/type/value information being returned. If an error is indicated, the second parameter is passed as a null pointer (0).
If the packet can be created, a pointer to a static buffer containing the packet contents is returned. This is the same buffer used by mkDPIregister(). If an error is encountered while creating the packet, the null pointer (0) is returned.
If the packet can be created, a pointer to a static buffer containing the packet contents is returned. This is the same buffer used by mkDPIregister(). If an error is encountered while creating the packet, the null pointer (0) is returned.
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
NOTE: mkDPIresponse() always frees the passed parse tree.
NOTE: mkDPIresponse() always frees the passed parse tree.
MKDPITRAP
MKDPITRAP
#include "snmp_dpi.h"
#include "snmp_dpi.h"
unsigned char *packet;
unsigned char *packet;
int generic, specific;
struct dpi_set_packet *ret_value;
int generic, specific; struct dpi_set_packet *ret_value;
packet = mkDPItrap(generic, specific, ret_value);
packet = mkDPItrap(generic, specific, ret_value);
len = *packet * 256 + *(packet + 1);
len += 2; /* include length bytes */
len = *packet * 256 + *(packet + 1); len += 2; /* include length bytes */
Carpenter & Wijnen [Page 25] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 25] RFC 1228 SNMP-DPI May 1991
The mkDPItrap() function creates an appropriate trap request packet. The first two parameters correspond to to value of the generic and specific fields in the SNMP trap packet. The third field can be used to pass a name/value pair to be provided in the SNMP trap packet. This information is passed as the set-packet portion of the parse tree. As an example, a linkDown trap for interface 3 might be generated by the following:
The mkDPItrap() function creates an appropriate trap request packet. The first two parameters correspond to to value of the generic and specific fields in the SNMP trap packet. The third field can be used to pass a name/value pair to be provided in the SNMP trap packet. This information is passed as the set-packet portion of the parse tree. As an example, a linkDown trap for interface 3 might be generated by the following:
struct dpi_set_packet *if_index_value;
unsigned long data;
unsigned char *packet;
int len;
struct dpi_set_packet *if_index_value; unsigned long data; unsigned char *packet; int len;
data = 3; /* interface number = 3 */
if_index_value = mkDPIset("1.3.6.1.2.1.2.2.1.1", SNMP_TYPE_NUMBER,
sizeof(unsigned long), &data);
packet = mkDPItrap(2, 0, if_index_value);
len = *packet * 256 + *(packet + 1);
len += 2; /* include length bytes */
write(fd,packet,len);
data = 3; /* interface number = 3 */ if_index_value = mkDPIset("1.3.6.1.2.1.2.2.1.1", SNMP_TYPE_NUMBER, sizeof(unsigned long), &data); packet = mkDPItrap(2, 0, if_index_value); len = *packet * 256 + *(packet + 1); len += 2; /* include length bytes */ write(fd,packet,len);
If the packet can be created, a pointer to a static buffer containing the packet contents is returned. This is the same buffer used by mkDPIregister(). If an error is encountered while creating the packet, the null pointer (0) is returned.
If the packet can be created, a pointer to a static buffer containing the packet contents is returned. This is the same buffer used by mkDPIregister(). If an error is encountered while creating the packet, the null pointer (0) is returned.
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
The length of the remainder packet is stored in the first two bytes of the packet, as demonstrated in the example above.
NOTE: mkDPItrap() always frees the passed parse tree.
NOTE: mkDPItrap() always frees the passed parse tree.
PDPIPACKET
PDPIPACKET
#include "snmp_dpi.h"
#include "snmp_dpi.h"
unsigned char *packet;
unsigned char *packet;
struct snmp_dpi_hdr *hdr;
struct snmp_dpi_hdr *hdr;
hdr = pDPIpacket(packet)
hdr = pDPIpacket(packet)
The pDPIpacket() function parses a DPI packet and returns a parse tree representing its contents. The parse tree is dynamically allocated and contains copies of the information within the DPI packet. After a successful call to pDPIpacket(), the packet may be disposed of in any manner the application chooses without affecting the contents of the parse tree. If an error is encountered during the parse, the null pointer (0) is returned.
The pDPIpacket() function parses a DPI packet and returns a parse tree representing its contents. The parse tree is dynamically allocated and contains copies of the information within the DPI packet. After a successful call to pDPIpacket(), the packet may be disposed of in any manner the application chooses without affecting the contents of the parse tree. If an error is encountered during the parse, the null pointer (0) is returned.
Carpenter & Wijnen [Page 26] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 26] RFC 1228 SNMP-DPI May 1991
NOTE: the relevant parse tree structures are defined in the include file "snmp_dpi.h", and that file remains the definitive reference.
NOTE: the relevant parse tree structures are defined in the include file "snmp_dpi.h", and that file remains the definitive reference.
The root of the parse tree is represented by a snmp_dpi_hdr structure:
The root of the parse tree is represented by a snmp_dpi_hdr structure:
struct snmp_dpi_hdr {
unsigned char proto_major;
unsigned char proto_minor;
unsigned char proto_release;
struct snmp_dpi_hdr { unsigned char proto_major; unsigned char proto_minor; unsigned char proto_release;
unsigned char packet_type;
union {
struct dpi_get_packet *dpi_get;
struct dpi_next_packet *dpi_next;
struct dpi_set_packet *dpi_set;
struct dpi_resp_packet *dpi_response;
struct dpi_trap_packet *dpi_trap;
} packet_body;
};
unsigned char packet_type; union { struct dpi_get_packet *dpi_get; struct dpi_next_packet *dpi_next; struct dpi_set_packet *dpi_set; struct dpi_resp_packet *dpi_response; struct dpi_trap_packet *dpi_trap; } packet_body; };
The field of immediate interest is packet_type. This field can have one of the following values (which are defined in the include file "snmp_dpi.h"):
The field of immediate interest is packet_type. This field can have one of the following values (which are defined in the include file "snmp_dpi.h"):
o SNMP_DPI_GET
o SNMP_DPI_GET_NEXT
o SNMP_DPI_SET
o SNMP_DPI_GET o SNMP_DPI_GET_NEXT o SNMP_DPI_SET
The packet_type field indicates what request is being made of the DPI client. For each of these requests, the remainder of the packet_body will be different.
The packet_type field indicates what request is being made of the DPI client. For each of these requests, the remainder of the packet_body will be different.
If a get request is indicated, the object ID of the desired variable is passed in a dpi_get_packet structure:
If a get request is indicated, the object ID of the desired variable is passed in a dpi_get_packet structure:
struct dpi_get_packet {
char *object_id;
};
struct dpi_get_packet { char *object_id; };
A get-next request is similar, but the dpi_next_packet structure also contains the object ID prefix of the group that is currently being traversed:
A get-next request is similar, but the dpi_next_packet structure also contains the object ID prefix of the group that is currently being traversed:
struct dpi_next_packet {
char *object_id;
char *group_id;
};
struct dpi_next_packet { char *object_id; char *group_id; };
Carpenter & Wijnen [Page 27] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 27] RFC 1228 SNMP-DPI May 1991
If the next object whose object ID lexicographically follows the object ID indicated by object_id does not begin with the suffix indicated by group_id, the DPI client must return an error indication of SNMP_NO_SUCH_NAME.
If the next object whose object ID lexicographically follows the object ID indicated by object_id does not begin with the suffix indicated by group_id, the DPI client must return an error indication of SNMP_NO_SUCH_NAME.
A set request has the most amount of data associated with it and this is contained in a dpi_set_packet structure:
A set request has the most amount of data associated with it and this is contained in a dpi_set_packet structure:
struct dpi_set_packet {
char *object_id;
unsigned char type;
unsigned short value_len;
char *value;
};
struct dpi_set_packet { char *object_id; unsigned char type; unsigned short value_len; char *value; };
The object ID of the variable to be modified is indicated by object_id The type of the variable is provided in type and may have one of the following values:
The object ID of the variable to be modified is indicated by object_id The type of the variable is provided in type and may have one of the following values:
o SNMP_TYPE_NUMBER
o SNMP_TYPE_STRING
o SNMP_TYPE_OBJECT
o SNMP_TYPE_EMPTY
o SNMP_TYPE_INTERNET
o SNMP_TYPE_COUNTER
o SNMP_TYPE_GAUGE
o SNMP_TYPE_TICKS
o SNMP_TYPE_NUMBER o SNMP_TYPE_STRING o SNMP_TYPE_OBJECT o SNMP_TYPE_EMPTY o SNMP_TYPE_INTERNET o SNMP_TYPE_COUNTER o SNMP_TYPE_GAUGE o SNMP_TYPE_TICKS
The length of the value to be set is stored in value_len and value contains a pointer to the value.
The length of the value to be set is stored in value_len and value contains a pointer to the value.
NOTE: the storage pointed to by value will be reclaimed when the parse tree is freed. The DPI client must make provision for copying the value contents.
NOTE: the storage pointed to by value will be reclaimed when the parse tree is freed. The DPI client must make provision for copying the value contents.
FDPIPARSE
FDPIPARSE
#include "snmp_dpi.h"
#include "snmp_dpi.h"
struct snmp_dpi_hdr *hdr;
struct snmp_dpi_hdr *hdr;
fDPIparse(hdr);
fDPIparse(hdr);
The routine fDPIparse() frees a parse tree previously created by a call to pDPIpacket This routine is declared as void--it has no return value.
The routine fDPIparse() frees a parse tree previously created by a call to pDPIpacket This routine is declared as void--it has no return value.
NOTE: after calling fDPIparse(), no further references to the parse
NOTE: after calling fDPIparse(), no further references to the parse
Carpenter & Wijnen [Page 28] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 28] RFC 1228 SNMP-DPI May 1991
tree can be made.
tree can be made.
AGENT IMPLEMENTATION ISSUES
AGENT IMPLEMENTATION ISSUES
Although the SNMP DPI protocol is completely documented in this paper, the document itself is somewhat biased towards clearly defining the interface provided to sub-agents (i.e., it provides a specification of a C language API). This detailed coverage is possible because the client side of the interface is completely self-contained.
Although the SNMP DPI protocol is completely documented in this paper, the document itself is somewhat biased towards clearly defining the interface provided to sub-agents (i.e., it provides a specification of a C language API). This detailed coverage is possible because the client side of the interface is completely self-contained.
The agent side of the interface has to be integrated into individual vendor implementations, many of which may have a unique organizational structure in an attempt to address various performance and storage constraints. This makes it infeasible to provide much more than suggestions for SNMP agent implementers. Unfortunately, this leaves room for a large amount of interpretation which can lead to implementations that don't necessarily work they way they should- -too much ambiguity can be a bad thing.
The agent side of the interface has to be integrated into individual vendor implementations, many of which may have a unique organizational structure in an attempt to address various performance and storage constraints. This makes it infeasible to provide much more than suggestions for SNMP agent implementers. Unfortunately, this leaves room for a large amount of interpretation which can lead to implementations that don't necessarily work they way they should- -too much ambiguity can be a bad thing.
The following characteristics of an agent implementation are to be considered mandatory:
The following characteristics of an agent implementation are to be considered mandatory:
DUPLICATE REGISTRATIONS
DUPLICATE REGISTRATIONS
With this release of the protocol, order of registration is significant. The last sub-agent to register a variable is the one that is deemed to be authoritative. Variables implemented by the base SNMP agent are considered to have been registered prior to any sub-agent registrations. Thus sub-agents may re-implement support for variables that were incorrectly implemented by a vendor.
With this release of the protocol, order of registration is significant. The last sub-agent to register a variable is the one that is deemed to be authoritative. Variables implemented by the base SNMP agent are considered to have been registered prior to any sub-agent registrations. Thus sub-agents may re-implement support for variables that were incorrectly implemented by a vendor.
AUTOMATIC DEREGISTRATION ON CLOSE
AUTOMATIC DEREGISTRATION ON CLOSE
All SNMP DPI connections are carried over a stream connection. When the connection is closed by the client (no matter what the cause), the agent must automatically unregister all of the variables that were registered by the sub-agent.
All SNMP DPI connections are carried over a stream connection. When the connection is closed by the client (no matter what the cause), the agent must automatically unregister all of the variables that were registered by the sub-agent.
TIMELY RESPONSE CONSTRAINTS
TIMELY RESPONSE CONSTRAINTS
A sub-agent must respond to a request in a timely fashion. In this version of the protocol, we specify that a sub-agent must respond to a request by the SNMP agent within 5 seconds. If the sub-agent does not respond in time, the SNMP agent should terminate the connection and unregister all of the variables that were previously registered by the sub-agent in question.
A sub-agent must respond to a request in a timely fashion. In this version of the protocol, we specify that a sub-agent must respond to a request by the SNMP agent within 5 seconds. If the sub-agent does not respond in time, the SNMP agent should terminate the connection and unregister all of the variables that were previously registered by the sub-agent in question.
Carpenter & Wijnen [Page 29] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 29] RFC 1228 SNMP-DPI May 1991
NOTE: agent implementations that do not have access to a timer may not be able to implement this. In that case, they leave themselves open to being placed in a state where they are blocked forever if the sub-agent malfunctions.
NOTE: agent implementations that do not have access to a timer may not be able to implement this. In that case, they leave themselves open to being placed in a state where they are blocked forever if the sub-agent malfunctions.
SUPPORT FOR MULTIPLE MIB VIEWS
SUPPORT FOR MULTIPLE MIB VIEWS
Some agents allow different MIB views to be selected based on the community name used. It is not the intention of this document to pass judgement on the various approaches that have been proposed or implemented, but instead merely to recognize the existence of implementations that support this feature.
Some agents allow different MIB views to be selected based on the community name used. It is not the intention of this document to pass judgement on the various approaches that have been proposed or implemented, but instead merely to recognize the existence of implementations that support this feature.
The point of this discussion is to specify clearly that objects supported by an SNMP DPI sub-agent are to be registered under the MIB view that was selected by the community name used in the SNMP GET request that obtained the DPI_port value.
The point of this discussion is to specify clearly that objects supported by an SNMP DPI sub-agent are to be registered under the MIB view that was selected by the community name used in the SNMP GET request that obtained the DPI_port value.
The SNMP DPI does not specify a reserved port, but instead sub-agents bootstrap themselves by making an SNMP GET request for the DPI_port variable. This variable represents the TCP port to which the sub- agent should connect. It should be understood that there is no reason why the SNMP agent cannot have several listens (passive opens) active, each corresponding to a distinct MIB view. The port number returned then would be different based on the community name used in the SNMP GET request for the DPI_port variable.
The SNMP DPI does not specify a reserved port, but instead sub-agents bootstrap themselves by making an SNMP GET request for the DPI_port variable. This variable represents the TCP port to which the sub- agent should connect. It should be understood that there is no reason why the SNMP agent cannot have several listens (passive opens) active, each corresponding to a distinct MIB view. The port number returned then would be different based on the community name used in the SNMP GET request for the DPI_port variable.
CONSIDERATIONS FOR THE NEXT RELEASE
CONSIDERATIONS FOR THE NEXT RELEASE
The SNMP DPI protocol makes provision for extension and parallel use of potentially incompatible releases. The discussion above documents the protocol as it is currently in use and has not discussed features of interest that should be considered for a future revision.
The SNMP DPI protocol makes provision for extension and parallel use of potentially incompatible releases. The discussion above documents the protocol as it is currently in use and has not discussed features of interest that should be considered for a future revision.
UNREGISTER
UNREGISTER
For closure, an UNREGISTER request could be of use.
For closure, an UNREGISTER request could be of use.
SUPPORT FOR ATOMIC SETS
SUPPORT FOR ATOMIC SETS
The SNMP protocol [1] specifies that:
The SNMP protocol [1] specifies that:
Each variable assignment specified by the SetRequest-PDU should be
effected as if simultaneously set with respect to all other
assignments specified in the same message.
Each variable assignment specified by the SetRequest-PDU should be effected as if simultaneously set with respect to all other assignments specified in the same message.
The SNMP DPI has no provision for backing out a successfully processed SET request if one of the subsequent variable assignments
The SNMP DPI has no provision for backing out a successfully processed SET request if one of the subsequent variable assignments
Carpenter & Wijnen [Page 30] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 30] RFC 1228 SNMP-DPI May 1991
fails. This omission is a reflection of several biases:
fails. This omission is a reflection of several biases:
o the SNMP DPI was intended to be light-weight.
o the SNMP DPI was intended to be light-weight.
o a belief that the SNMP RFC prescribes semantics which are infeasible
to implement unless the range of applications is restricted.
o a belief that the SNMP RFC prescribes semantics which are infeasible to implement unless the range of applications is restricted.
It has been suggested that a new request, TEST_SET, be added to the DPI protocol. Processing of a SET request would then be performed as follows:
It has been suggested that a new request, TEST_SET, be added to the DPI protocol. Processing of a SET request would then be performed as follows:
o all variables would be processed using TEST_SET unless any error
occurred. The subagents would verify that they could process the
request.
o all variables would be processed using TEST_SET unless any error occurred. The subagents would verify that they could process the request.
o if no error occurred, each of the variables would be reprocessed,
this time with a SET request.
o if no error occurred, each of the variables would be reprocessed, this time with a SET request.
A problem with such an approach is that it relies on the TEST_SET operation to make an assertion that the request can be successfully performed. If this is not possible, then it cannot be asserted that the prescribed semantics will be provided. Such situations do exist, for example, a SET request that causes the far-end channel service unit to be looped up--one does not know if the operation will be successful until it is performed.
A problem with such an approach is that it relies on the TEST_SET operation to make an assertion that the request can be successfully performed. If this is not possible, then it cannot be asserted that the prescribed semantics will be provided. Such situations do exist, for example, a SET request that causes the far-end channel service unit to be looped up--one does not know if the operation will be successful until it is performed.
SAMPLE SNMP DPI API IMPLEMENTATION
SAMPLE SNMP DPI API IMPLEMENTATION
The following C language sources show an example implementation of the SNMP DPI Application Programming Interface as it would be exposed to the sub-agents.
The following C language sources show an example implementation of the SNMP DPI Application Programming Interface as it would be exposed to the sub-agents.
SAMPLE SNMP DPI INCLUDE FILE
SAMPLE SNMP DPI INCLUDE FILE
/* SNMP distributed program interface */
/* SNMP distributed program interface */
#define SNMP_DPI_GET 1 #define SNMP_DPI_GET_NEXT 2 #define SNMP_DPI_SET 3 #define SNMP_DPI_TRAP 4 #define SNMP_DPI_RESPONSE 5 #define SNMP_DPI_REGISTER 6
#define SNMP_DPI_GET 1 #define SNMP_DPI_GET_NEXT 2 #define SNMP_DPI_SET 3 #define SNMP_DPI_TRAP 4 #define SNMP_DPI_RESPONSE 5 #define SNMP_DPI_REGISTER 6
#define SNMP_DPI_PROTOCOL 2 #define SNMP_DPI_VERSION 1 #define SNMP_DPI_RELEASE 0
#define SNMP_DPI_PROTOCOL 2 #define SNMP_DPI_VERSION 1 #define SNMP_DPI_RELEASE 0
/* SNMP error codes from RFC 1098 (1067) */
/* SNMP error codes from RFC 1098 (1067) */
Carpenter & Wijnen [Page 31] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 31] RFC 1228 SNMP-DPI May 1991
#define SNMP_NO_ERROR 0 #define SNMP_TOO_BIG 1 #define SNMP_NO_SUCH_NAME 2 #define SNMP_BAD_VALUE 3 #define SNMP_READ_ONLY 4 #define SNMP_GEN_ERR 5
#define SNMP_NO_ERROR 0 #define SNMP_TOO_BIG 1 #define SNMP_NO_SUCH_NAME 2 #define SNMP_BAD_VALUE 3 #define SNMP_READ_ONLY 4 #define SNMP_GEN_ERR 5
/* variable types */ #define SNMP_TYPE_TEXT 0 /* textual representation */ #define SNMP_TYPE_NUMBER (128|1) /* number */ #define SNMP_TYPE_STRING 2 /* text string */ #define SNMP_TYPE_OBJECT 3 /* object identifier */ #define SNMP_TYPE_EMPTY 4 /* no value */ #define SNMP_TYPE_INTERNET (128|5) /* internet address */ #define SNMP_TYPE_COUNTER (128|6) /* counter */ #define SNMP_TYPE_GAUGE (128|7) /* gauge */ #define SNMP_TYPE_TICKS (128|8) /* time ticks (1/100th sec) */ #define SNMP_TYPE_MASK 0x7f /* mask for type */
/* variable types */ #define SNMP_TYPE_TEXT 0 /* textual representation */ #define SNMP_TYPE_NUMBER (128|1) /* number */ #define SNMP_TYPE_STRING 2 /* text string */ #define SNMP_TYPE_OBJECT 3 /* object identifier */ #define SNMP_TYPE_EMPTY 4 /* no value */ #define SNMP_TYPE_INTERNET (128|5) /* internet address */ #define SNMP_TYPE_COUNTER (128|6) /* counter */ #define SNMP_TYPE_GAUGE (128|7) /* gauge */ #define SNMP_TYPE_TICKS (128|8) /* time ticks (1/100th sec) */ #define SNMP_TYPE_MASK 0x7f /* mask for type */
struct dpi_get_packet {
char *object_id;
};
struct dpi_get_packet { char *object_id; };
struct dpi_next_packet {
char *object_id;
char *group_id;
};
struct dpi_next_packet { char *object_id; char *group_id; };
struct dpi_set_packet {
char *object_id;
unsigned char type;
unsigned short value_len;
char *value;
};
struct dpi_set_packet { char *object_id; unsigned char type; unsigned short value_len; char *value; };
struct dpi_resp_packet {
unsigned char ret_code;
struct dpi_set_packet *ret_data;
};
struct dpi_resp_packet { unsigned char ret_code; struct dpi_set_packet *ret_data; };
struct dpi_trap_packet {
unsigned char generic;
unsigned char specific;
struct dpi_set_packet *info;
};
struct dpi_trap_packet { unsigned char generic; unsigned char specific; struct dpi_set_packet *info; };
struct snmp_dpi_hdr {
struct snmp_dpi_hdr {
Carpenter & Wijnen [Page 32] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 32] RFC 1228 SNMP-DPI May 1991
unsigned char proto_major;
unsigned char proto_minor;
unsigned char proto_release;
unsigned char proto_major; unsigned char proto_minor; unsigned char proto_release;
unsigned char packet_type;
union {
struct dpi_get_packet *dpi_get;
struct dpi_next_packet *dpi_next;
struct dpi_set_packet *dpi_set;
struct dpi_resp_packet *dpi_response;
struct dpi_trap_packet *dpi_trap;
} packet_body;
};
unsigned char packet_type; union { struct dpi_get_packet *dpi_get; struct dpi_next_packet *dpi_next; struct dpi_set_packet *dpi_set; struct dpi_resp_packet *dpi_response; struct dpi_trap_packet *dpi_trap; } packet_body; };
extern struct snmp_dpi_hdr *pDPIpacket(); extern void fDPIparse(); extern unsigned char *mkMIBquery(); extern unsigned char *mkDPIregister(); extern unsigned char *mkDPIresponse(); extern unsigned char *mkDPItrap(); extern struct dpi_set_packet *mkDPIset();
extern struct snmp_dpi_hdr *pDPIpacket(); extern void fDPIparse(); extern unsigned char *mkMIBquery(); extern unsigned char *mkDPIregister(); extern unsigned char *mkDPIresponse(); extern unsigned char *mkDPItrap(); extern struct dpi_set_packet *mkDPIset();
SAMPLE QUERY_DPI_PORT() FUNCTION
SAMPLE QUERY_DPI_PORT() FUNCTION
#ifdef VM
#ifdef VM
#include <manifest.h> #include <snmp_vm.h> #include <bsdtime.h> #include <bsdtypes.h> #include <socket.h> #include <in.h> #include <netdb.h> #include <inet.h>
#include <manifest.h> #include <snmp_vm.h> #include <bsdtime.h> #include <bsdtypes.h> #include <socket.h> #include <in.h> #include <netdb.h> #include <inet.h>
#else
#else
#include <sys/time.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/inet.h>
#include <sys/time.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/inet.h>
#endif
#endif
static unsigned char asn1_hdr[] = {0x30};
static unsigned char asn1_hdr[] = {0x30};
Carpenter & Wijnen [Page 33] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 33] RFC 1228 SNMP-DPI May 1991
/* insert length of remaining packet, not including this */
static unsigned char version[] = {0x02, 0x01, 0x00, 0x04};
/* insert length of remaining packet, not including this */ static unsigned char version[] = {0x02, 0x01, 0x00, 0x04};
/* integer, len=1, value=0, string */
/* insert community name length and community name */
static unsigned char request[] = {
0xa0, 0x1b, /* get request, len=0x1b */
0x02, 0x01, 0x01, /* integer, len=1,request_id = 1 */
0x02, 0x01, 0x00, /* integer, len=1, error_status = 0 */
0x02, 0x01, 0x00, /* integer, len=1, error_index = 0 */
0x30, 0x10, /* varbind list, len=0x10 */
0x30, 0x0e, /* varbind , len=0x0e */
0x06, 0x0a, /* object ID, len=0x0a */
0x2b, 0x06, 0x01, 0x04, 0x01, 0x02, 0x02, 0x01, 0x01, 0x00,
0x05, 0x00 /* value, len = 0 */
};
/* integer, len=1, value=0, string */ /* insert community name length and community name */ static unsigned char request[] = { 0xa0, 0x1b, /* get request, len=0x1b */ 0x02, 0x01, 0x01, /* integer, len=1,request_id = 1 */ 0x02, 0x01, 0x00, /* integer, len=1, error_status = 0 */ 0x02, 0x01, 0x00, /* integer, len=1, error_index = 0 */ 0x30, 0x10, /* varbind list, len=0x10 */ 0x30, 0x0e, /* varbind , len=0x0e */ 0x06, 0x0a, /* object ID, len=0x0a */ 0x2b, 0x06, 0x01, 0x04, 0x01, 0x02, 0x02, 0x01, 0x01, 0x00, 0x05, 0x00 /* value, len = 0 */ };
static extract_DPI_port();
static extract_DPI_port();
query_DPI_port(hostname, community_name)
char *hostname;
char *community_name;
{
int community_len;
int rc;
query_DPI_port(hostname, community_name) char *hostname; char *community_name; { int community_len; int rc;
community_len = strlen(community_name);
community_len = strlen(community_name);
rc = _query_DPI_port(hostname, community_name, community_len);
return (rc);
}
rc = _query_DPI_port(hostname, community_name, community_len); return (rc); }
/* use if community_name has embedded nulls */
/* use if community_name has embedded nulls */
_query_DPI_port(hostname, community_name, community_len)
char *hostname;
char *community_name;
int community_len;
{
unsigned char packet[1024];
int packet_len;
int remaining_len;
int fd, rc, sock_len;
struct sockaddr_in sock, dest_sock;
struct timeval timeout;
unsigned long host_addr, read_mask;
int tries;
_query_DPI_port(hostname, community_name, community_len) char *hostname; char *community_name; int community_len; { unsigned char packet[1024]; int packet_len; int remaining_len; int fd, rc, sock_len; struct sockaddr_in sock, dest_sock; struct timeval timeout; unsigned long host_addr, read_mask; int tries;
Carpenter & Wijnen [Page 34] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 34] RFC 1228 SNMP-DPI May 1991
host_addr = lookup_host(hostname);
packet_len = 0;
bcopy(asn1_hdr, packet, sizeof(asn1_hdr));
packet_len += sizeof(asn1_hdr);
host_addr = lookup_host(hostname); packet_len = 0; bcopy(asn1_hdr, packet, sizeof(asn1_hdr)); packet_len += sizeof(asn1_hdr);
remaining_len = sizeof(version) + 1 +
community_len + sizeof(request);
remaining_len = sizeof(version) + 1 + community_len + sizeof(request);
packet[packet_len++] = remaining_len & 0xff;
bcopy(version, packet + packet_len, sizeof(version));
packet_len += sizeof(version);
packet[packet_len++] = community_len & 0xff;
bcopy(community_name, packet + packet_len, community_len);
packet_len += community_len;
bcopy(request, packet + packet_len, sizeof(request));
packet_len += sizeof(request);
packet[packet_len++] = remaining_len & 0xff; bcopy(version, packet + packet_len, sizeof(version)); packet_len += sizeof(version); packet[packet_len++] = community_len & 0xff; bcopy(community_name, packet + packet_len, community_len); packet_len += community_len; bcopy(request, packet + packet_len, sizeof(request)); packet_len += sizeof(request);
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
return (-1);
}
bzero(&sock, sizeof(sock));
sock.sin_family = AF_INET;
sock.sin_port = 0;
sock.sin_addr.s_addr = 0;
rc = bind(fd, &sock, sizeof(sock));
if (rc < 0)
return (-1);
timeout.tv_sec = 3;
timeout.tv_usec = 0;
bzero(&dest_sock, sizeof(dest_sock));
dest_sock.sin_family = AF_INET;
dest_sock.sin_port = htons(161);
dest_sock.sin_addr.s_addr = host_addr;
fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd < 0) { return (-1); } bzero(&sock, sizeof(sock)); sock.sin_family = AF_INET; sock.sin_port = 0; sock.sin_addr.s_addr = 0; rc = bind(fd, &sock, sizeof(sock)); if (rc < 0) return (-1); timeout.tv_sec = 3; timeout.tv_usec = 0; bzero(&dest_sock, sizeof(dest_sock)); dest_sock.sin_family = AF_INET; dest_sock.sin_port = htons(161); dest_sock.sin_addr.s_addr = host_addr;
tries = 0;
while (++tries < 4) {
rc = sendto(fd, packet, packet_len, 0, &dest_sock,
sizeof(dest_sock));
read_mask = 1 << fd;
rc = select(read_mask + 1, &read_mask, 0, 0, &timeout);
if (rc <= 0)
continue;
sock_len = sizeof(dest_sock);
packet_len = recvfrom(fd, packet, sizeof(packet), 0,
&dest_sock, &sock_len);
if (packet_len <= 0) {
return (-1);
tries = 0; while (++tries < 4) { rc = sendto(fd, packet, packet_len, 0, &dest_sock, sizeof(dest_sock)); read_mask = 1 << fd; rc = select(read_mask + 1, &read_mask, 0, 0, &timeout); if (rc <= 0) continue; sock_len = sizeof(dest_sock); packet_len = recvfrom(fd, packet, sizeof(packet), 0, &dest_sock, &sock_len); if (packet_len <= 0) { return (-1);
Carpenter & Wijnen [Page 35] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 35] RFC 1228 SNMP-DPI May 1991
}
rc = extract_DPI_port(packet, packet_len);
return (rc);
}
return (-1);
}
} rc = extract_DPI_port(packet, packet_len); return (rc); } return (-1); }
static extract_DPI_port(packet, len) unsigned char packet[]; int len;
static extract_DPI_port(packet, len) unsigned char packet[]; int len;
{
int offset;
int port;
{ int offset; int port;
/* should do error checking (like for noSuchName) */
offset = len - 2;
port = (packet[offset] << 8) + packet[offset + 1];
return (port);
}
/* should do error checking (like for noSuchName) */ offset = len - 2; port = (packet[offset] << 8) + packet[offset + 1]; return (port); }
SAMPLE DPI FUNCTIONS
SAMPLE DPI FUNCTIONS
/* DPI parser */
/* DPI parser */
#ifdef VM #include "manifest.h" #endif
#ifdef VM #include "manifest.h" #endif
#include "snmp_dpi.h"
#include "snmp_dpi.h"
static struct dpi_get_packet *pDPIget(); static struct dpi_next_packet *pDPInext(); static struct dpi_set_packet *pDPIset(); static struct dpi_trap_packet *pDPItrap(); static struct dpi_resp_packet *pDPIresponse();
static struct dpi_get_packet *pDPIget(); static struct dpi_next_packet *pDPInext(); static struct dpi_set_packet *pDPIset(); static struct dpi_trap_packet *pDPItrap(); static struct dpi_resp_packet *pDPIresponse();
static void fDPIget(); static void fDPInext(); static void fDPIset(); static void fDPItrap(); static void fDPIresponse();
static void fDPIget(); static void fDPInext(); static void fDPIset(); static void fDPItrap(); static void fDPIresponse();
static int cDPIget(); static int cDPInext(); static int cDPIset(); static int cDPItrap(); static int cDPIresponse();
static int cDPIget(); static int cDPInext(); static int cDPIset(); static int cDPItrap(); static int cDPIresponse();
Carpenter & Wijnen [Page 36] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 36] RFC 1228 SNMP-DPI May 1991
static struct snmp_dpi_hdr *mkDPIhdr(); static struct dpi_get_packet *mkDPIget(); static struct dpi_next_packet *mkDPInext(); struct dpi_set_packet *mkDPIset();
static struct snmp_dpi_hdr *mkDPIhdr(); static struct dpi_get_packet *mkDPIget(); static struct dpi_next_packet *mkDPInext(); struct dpi_set_packet *mkDPIset();
extern char *malloc();
extern char *malloc();
static unsigned char new_packet[1024]; static int packet_len;
static unsigned char new_packet[1024]; static int packet_len;
struct snmp_dpi_hdr *pDPIpacket(packet)
unsigned char *packet;
{
struct snmp_dpi_hdr *hdr;
int len, offset;
struct snmp_dpi_hdr *pDPIpacket(packet) unsigned char *packet; { struct snmp_dpi_hdr *hdr; int len, offset;
hdr = (struct snmp_dpi_hdr *) malloc(sizeof(struct snmp_dpi_hdr));
if (hdr == 0)
return (0);
hdr = (struct snmp_dpi_hdr *) malloc(sizeof(struct snmp_dpi_hdr)); if (hdr == 0) return (0);
len = (packet[0] << 8) + packet[1];
len += 2;
offset = 2;
hdr->proto_major = packet[offset++];
hdr->proto_minor = packet[offset++];
hdr->proto_release = packet[offset++];
hdr->packet_type = packet[offset++];
switch (hdr->packet_type) {
case SNMP_DPI_GET:
case SNMP_DPI_REGISTER:
hdr->packet_body.dpi_get =
pDPIget(packet + offset, len - offset);
break;
case SNMP_DPI_GET_NEXT:
hdr->packet_body.dpi_next =
pDPInext(packet + offset, len - offset);
break;
case SNMP_DPI_SET:
hdr->packet_body.dpi_set =
pDPIset(packet + offset, len - offset);
break;
case SNMP_DPI_TRAP:
hdr->packet_body.dpi_trap =
pDPItrap(packet + offset, len - offset);
break;
case SNMP_DPI_RESPONSE:
len = (packet[0] << 8) + packet[1]; len += 2; offset = 2; hdr->proto_major = packet[offset++]; hdr->proto_minor = packet[offset++]; hdr->proto_release = packet[offset++]; hdr->packet_type = packet[offset++]; switch (hdr->packet_type) { case SNMP_DPI_GET: case SNMP_DPI_REGISTER: hdr->packet_body.dpi_get = pDPIget(packet + offset, len - offset); break; case SNMP_DPI_GET_NEXT: hdr->packet_body.dpi_next = pDPInext(packet + offset, len - offset); break; case SNMP_DPI_SET: hdr->packet_body.dpi_set = pDPIset(packet + offset, len - offset); break; case SNMP_DPI_TRAP: hdr->packet_body.dpi_trap = pDPItrap(packet + offset, len - offset); break; case SNMP_DPI_RESPONSE:
Carpenter & Wijnen [Page 37] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 37] RFC 1228 SNMP-DPI May 1991
hdr->packet_body.dpi_response =
pDPIresponse(packet + offset, len - offset);
break;
}
return (hdr);
}
hdr->packet_body.dpi_response = pDPIresponse(packet + offset, len - offset); break; } return (hdr); }
static struct dpi_get_packet *pDPIget(packet, len)
unsigned char *packet;
int len;
{
struct dpi_get_packet *get;
int l;
static struct dpi_get_packet *pDPIget(packet, len) unsigned char *packet; int len; { struct dpi_get_packet *get; int l;
get = (struct dpi_get_packet *)
malloc(sizeof(struct dpi_get_packet));
if (get == 0)
return (0);
l = strlen(packet) + 1;
get->object_id = malloc(l);
strcpy(get->object_id, packet);
return (get);
}
get = (struct dpi_get_packet *) malloc(sizeof(struct dpi_get_packet)); if (get == 0) return (0); l = strlen(packet) + 1; get->object_id = malloc(l); strcpy(get->object_id, packet); return (get); }
static struct dpi_next_packet *pDPInext(packet, len)
unsigned char *packet;
int len;
{
struct dpi_next_packet *next;
int l;
unsigned char *cp;
static struct dpi_next_packet *pDPInext(packet, len) unsigned char *packet; int len; { struct dpi_next_packet *next; int l; unsigned char *cp;
next = (struct dpi_next_packet *)
malloc(sizeof(struct dpi_next_packet));
if (next == 0)
return (0);
cp = packet;
l = strlen(cp) + 1;
next->object_id = malloc(l);
strcpy(next->object_id, cp);
cp += l;
l = strlen(cp) + 1;
next->group_id = malloc(l);
strcpy(next->group_id, cp);
return (next);
}
next = (struct dpi_next_packet *) malloc(sizeof(struct dpi_next_packet)); if (next == 0) return (0); cp = packet; l = strlen(cp) + 1; next->object_id = malloc(l); strcpy(next->object_id, cp); cp += l; l = strlen(cp) + 1; next->group_id = malloc(l); strcpy(next->group_id, cp); return (next); }
static struct dpi_set_packet *pDPIset(packet, len)
static struct dpi_set_packet *pDPIset(packet, len)
Carpenter & Wijnen [Page 38] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 38] RFC 1228 SNMP-DPI May 1991
unsigned char *packet;
int len;
{
struct dpi_set_packet *set;
int l;
unsigned char *cp;
unsigned char *packet; int len; { struct dpi_set_packet *set; int l; unsigned char *cp;
if (len == 0)
return (0); /* nothing to parse */
set = (struct dpi_set_packet *)
malloc(sizeof(struct dpi_set_packet));
if (set == 0)
return (0);
if (len == 0) return (0); /* nothing to parse */ set = (struct dpi_set_packet *) malloc(sizeof(struct dpi_set_packet)); if (set == 0) return (0);
cp = packet;
l = strlen(cp) + 1;
set->object_id = malloc(l);
strcpy(set->object_id, cp);
cp += l;
set->type = *(cp++);
l = (*(cp++) << 8);
l += *(cp++);
set->value_len = l;
set->value = malloc(l);
bcopy(cp, set->value, l);
return (set);
}
cp = packet; l = strlen(cp) + 1; set->object_id = malloc(l); strcpy(set->object_id, cp); cp += l; set->type = *(cp++); l = (*(cp++) << 8); l += *(cp++); set->value_len = l; set->value = malloc(l); bcopy(cp, set->value, l); return (set); }
static struct dpi_trap_packet *pDPItrap(packet, len)
unsigned char *packet;
int len;
{
struct dpi_trap_packet *trap;
static struct dpi_trap_packet *pDPItrap(packet, len) unsigned char *packet; int len; { struct dpi_trap_packet *trap;
trap = (struct dpi_trap_packet *)
malloc(sizeof(struct dpi_trap_packet));
if (trap == 0)
return (0);
trap = (struct dpi_trap_packet *) malloc(sizeof(struct dpi_trap_packet)); if (trap == 0) return (0);
trap->generic = *packet;
trap->specific = *(packet + 1);
trap->info = pDPIset(packet + 2, len - 2);
return (trap);
}
trap->generic = *packet; trap->specific = *(packet + 1); trap->info = pDPIset(packet + 2, len - 2); return (trap); }
static struct dpi_resp_packet *pDPIresponse(packet, len) unsigned char *packet; int len;
static struct dpi_resp_packet *pDPIresponse(packet, len) unsigned char *packet; int len;
Carpenter & Wijnen [Page 39] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 39] RFC 1228 SNMP-DPI May 1991
{
struct dpi_resp_packet *resp;
{ struct dpi_resp_packet *resp;
resp = (struct dpi_resp_packet *)
malloc(sizeof(struct dpi_resp_packet));
if (resp == 0)
return (0);
resp = (struct dpi_resp_packet *) malloc(sizeof(struct dpi_resp_packet)); if (resp == 0) return (0);
resp->ret_code = *packet;
resp->ret_data = pDPIset(packet + 1, len - 1);
return (resp);
}
resp->ret_code = *packet; resp->ret_data = pDPIset(packet + 1, len - 1); return (resp); }
void fDPIparse(hdr)
struct snmp_dpi_hdr *hdr;
{
if (hdr == 0)
return;
switch (hdr->packet_type) {
case SNMP_DPI_GET:
case SNMP_DPI_REGISTER:
fDPIget(hdr);
break;
case SNMP_DPI_GET_NEXT:
fDPInext(hdr);
break;
case SNMP_DPI_SET:
fDPIset(hdr);
break;
case SNMP_DPI_TRAP:
fDPItrap(hdr);
break;
case SNMP_DPI_RESPONSE:
fDPIresponse(hdr);
break;
}
free(hdr);
}
void fDPIparse(hdr) struct snmp_dpi_hdr *hdr; { if (hdr == 0) return; switch (hdr->packet_type) { case SNMP_DPI_GET: case SNMP_DPI_REGISTER: fDPIget(hdr); break; case SNMP_DPI_GET_NEXT: fDPInext(hdr); break; case SNMP_DPI_SET: fDPIset(hdr); break; case SNMP_DPI_TRAP: fDPItrap(hdr); break; case SNMP_DPI_RESPONSE: fDPIresponse(hdr); break; } free(hdr); }
static void fDPIget(hdr)
struct snmp_dpi_hdr *hdr;
{
struct dpi_get_packet *get;
static void fDPIget(hdr) struct snmp_dpi_hdr *hdr; { struct dpi_get_packet *get;
get = hdr->packet_body.dpi_get;
if (get == 0)
return;
if (get->object_id)
get = hdr->packet_body.dpi_get; if (get == 0) return; if (get->object_id)
Carpenter & Wijnen [Page 40] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 40] RFC 1228 SNMP-DPI May 1991
free(get->object_id);
free(get);
}
free(get->object_id); free(get); }
static void fDPInext(hdr)
struct snmp_dpi_hdr *hdr;
{
struct dpi_next_packet *next;
static void fDPInext(hdr) struct snmp_dpi_hdr *hdr; { struct dpi_next_packet *next;
next = hdr->packet_body.dpi_next;
if (next == 0)
return;
if (next->object_id)
free(next->object_id);
if (next->group_id)
free(next->group_id);
free(next);
}
next = hdr->packet_body.dpi_next; if (next == 0) return; if (next->object_id) free(next->object_id); if (next->group_id) free(next->group_id); free(next); }
static void fDPIset(hdr)
struct snmp_dpi_hdr *hdr;
{
struct dpi_set_packet *set;
static void fDPIset(hdr) struct snmp_dpi_hdr *hdr; { struct dpi_set_packet *set;
set = hdr->packet_body.dpi_set;
if (set == 0)
return;
if (set->object_id)
free(set->object_id);
if (set->value)
free(set->value);
free(set);
}
set = hdr->packet_body.dpi_set; if (set == 0) return; if (set->object_id) free(set->object_id); if (set->value) free(set->value); free(set); }
static void fDPItrap(hdr)
struct snmp_dpi_hdr *hdr;
{
struct dpi_trap_packet *trap;
struct dpi_set_packet *set;
static void fDPItrap(hdr) struct snmp_dpi_hdr *hdr; { struct dpi_trap_packet *trap; struct dpi_set_packet *set;
trap = hdr->packet_body.dpi_trap;
if (trap == 0)
return;
trap = hdr->packet_body.dpi_trap; if (trap == 0) return;
set = trap->info;
if (set != 0) {
if (set->object_id)
free(set->object_id);
set = trap->info; if (set != 0) { if (set->object_id) free(set->object_id);
Carpenter & Wijnen [Page 41] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 41] RFC 1228 SNMP-DPI May 1991
if (set->value)
free(set->value);
free(set);
}
free(trap);
}
if (set->value) free(set->value); free(set); } free(trap); }
static void fDPIresponse(hdr)
struct snmp_dpi_hdr *hdr;
{
struct dpi_resp_packet *resp;
struct dpi_set_packet *set;
static void fDPIresponse(hdr) struct snmp_dpi_hdr *hdr; { struct dpi_resp_packet *resp; struct dpi_set_packet *set;
resp = hdr->packet_body.dpi_response;
if (resp == 0)
return;
resp = hdr->packet_body.dpi_response; if (resp == 0) return;
set = resp->ret_data;
if (set != 0) {
if (set->object_id)
free(set->object_id);
if (set->value)
free(set->value);
free(set);
}
free(resp);
}
set = resp->ret_data; if (set != 0) { if (set->object_id) free(set->object_id); if (set->value) free(set->value); free(set); } free(resp); }
unsigned char *cDPIpacket(hdr)
struct snmp_dpi_hdr *hdr;
{
int rc, len;
if (hdr == 0) {
return (0);
}
packet_len = 2;
new_packet[packet_len++] = hdr->proto_major;
new_packet[packet_len++] = hdr->proto_minor;
new_packet[packet_len++] = hdr->proto_release;
new_packet[packet_len++] = hdr->packet_type;
switch (hdr->packet_type) {
case SNMP_DPI_GET:
case SNMP_DPI_REGISTER:
rc = cDPIget(hdr->packet_body.dpi_get);
break;
case SNMP_DPI_GET_NEXT:
rc = cDPInext(hdr->packet_body.dpi_next);
break;
unsigned char *cDPIpacket(hdr) struct snmp_dpi_hdr *hdr; { int rc, len; if (hdr == 0) { return (0); } packet_len = 2; new_packet[packet_len++] = hdr->proto_major; new_packet[packet_len++] = hdr->proto_minor; new_packet[packet_len++] = hdr->proto_release; new_packet[packet_len++] = hdr->packet_type; switch (hdr->packet_type) { case SNMP_DPI_GET: case SNMP_DPI_REGISTER: rc = cDPIget(hdr->packet_body.dpi_get); break; case SNMP_DPI_GET_NEXT: rc = cDPInext(hdr->packet_body.dpi_next); break;
Carpenter & Wijnen [Page 42] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 42] RFC 1228 SNMP-DPI May 1991
case SNMP_DPI_SET:
rc = cDPIset(hdr->packet_body.dpi_set);
break;
case SNMP_DPI_TRAP:
rc = cDPItrap(hdr->packet_body.dpi_trap);
break;
case SNMP_DPI_RESPONSE:
rc = cDPIresponse(hdr->packet_body.dpi_response);
break;
}
if (rc == -1)
return (0);
len = packet_len - 2;
new_packet[1] = len & 0xff;
len >>= 8;
new_packet[0] = len & 0xff;
return (new_packet);
}
case SNMP_DPI_SET: rc = cDPIset(hdr->packet_body.dpi_set); break; case SNMP_DPI_TRAP: rc = cDPItrap(hdr->packet_body.dpi_trap); break; case SNMP_DPI_RESPONSE: rc = cDPIresponse(hdr->packet_body.dpi_response); break; } if (rc == -1) return (0); len = packet_len - 2; new_packet[1] = len & 0xff; len >>= 8; new_packet[0] = len & 0xff; return (new_packet); }
static int cDPIget(get)
struct dpi_get_packet *get;
{
if (get->object_id == 0)
return (-1);
static int cDPIget(get) struct dpi_get_packet *get; { if (get->object_id == 0) return (-1);
strcpy(&new_packet[packet_len], get->object_id);
packet_len += strlen(get->object_id) + 1;
return (0);
}
strcpy(&new_packet[packet_len], get->object_id); packet_len += strlen(get->object_id) + 1; return (0); }
static int cDPInext(next)
struct dpi_next_packet *next;
{
if (next->object_id == 0)
return (-1);
if (next->group_id == 0)
return (-1);
static int cDPInext(next) struct dpi_next_packet *next; { if (next->object_id == 0) return (-1); if (next->group_id == 0) return (-1);
strcpy(&new_packet[packet_len], next->object_id);
packet_len += strlen(next->object_id) + 1;
strcpy(&new_packet[packet_len], next->group_id);
packet_len += strlen(next->group_id) + 1;
return (0);
}
strcpy(&new_packet[packet_len], next->object_id); packet_len += strlen(next->object_id) + 1; strcpy(&new_packet[packet_len], next->group_id); packet_len += strlen(next->group_id) + 1; return (0); }
static int cDPIset(set)
struct dpi_set_packet *set;
{
static int cDPIset(set) struct dpi_set_packet *set; {
Carpenter & Wijnen [Page 43] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 43] RFC 1228 SNMP-DPI May 1991
int len;
int len;
if (set->object_id == 0)
return (-1);
if ((set->value == 0) && (set->value_len != 0))
return (-1);
if (set->object_id == 0) return (-1); if ((set->value == 0) && (set->value_len != 0)) return (-1);
strcpy(&new_packet[packet_len], set->object_id);
packet_len += strlen(set->object_id) + 1;
new_packet[packet_len++] = set->type;
len = set->value_len >> 8;
new_packet[packet_len++] = len & 0xff;
new_packet[packet_len++] = set->value_len & 0xff;
bcopy(set->value, &new_packet[packet_len], set->value_len);
packet_len += set->value_len;
return (0);
}
strcpy(&new_packet[packet_len], set->object_id); packet_len += strlen(set->object_id) + 1; new_packet[packet_len++] = set->type; len = set->value_len >> 8; new_packet[packet_len++] = len & 0xff; new_packet[packet_len++] = set->value_len & 0xff; bcopy(set->value, &new_packet[packet_len], set->value_len); packet_len += set->value_len; return (0); }
static int cDPIresponse(resp)
struct dpi_resp_packet *resp;
{
int rc;
static int cDPIresponse(resp) struct dpi_resp_packet *resp; { int rc;
if (resp == 0)
return (-1);
if (resp == 0) return (-1);
new_packet[packet_len++] = resp->ret_code;
if (resp->ret_data != 0) {
rc = cDPIset(resp->ret_data);
} else
rc = 0;
return (rc);
}
new_packet[packet_len++] = resp->ret_code; if (resp->ret_data != 0) { rc = cDPIset(resp->ret_data); } else rc = 0; return (rc); }
static int cDPItrap(trap)
struct dpi_trap_packet *trap;
{
int rc;
static int cDPItrap(trap) struct dpi_trap_packet *trap; { int rc;
new_packet[packet_len++] = trap->generic;
new_packet[packet_len++] = trap->specific;
if (trap->info != 0)
rc = cDPIset(trap->info);
else
rc = 0;
return (rc);
}
new_packet[packet_len++] = trap->generic; new_packet[packet_len++] = trap->specific; if (trap->info != 0) rc = cDPIset(trap->info); else rc = 0; return (rc); }
Carpenter & Wijnen [Page 44] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 44] RFC 1228 SNMP-DPI May 1991
unsigned char *mkMIBquery(cmd, oid_name, group_oid, type, len, value)
int cmd;
char *oid_name, *group_oid;
int type, len;
char *value;
{
struct snmp_dpi_hdr *hdr;
unsigned char *cp;
unsigned char *mkMIBquery(cmd, oid_name, group_oid, type, len, value) int cmd; char *oid_name, *group_oid; int type, len; char *value; { struct snmp_dpi_hdr *hdr; unsigned char *cp;
hdr = mkDPIhdr(cmd);
if (hdr == 0)
return (0);
switch (hdr->packet_type) {
case SNMP_DPI_GET:
case SNMP_DPI_REGISTER:
hdr->packet_body.dpi_get = mkDPIget(oid_name);
break;
case SNMP_DPI_GET_NEXT:
hdr->packet_body.dpi_next = mkDPInext(oid_name, group_oid);
break;
case SNMP_DPI_SET:
hdr->packet_body.dpi_set =
mkDPIset(oid_name, type, len, value);
break;
}
cp = cDPIpacket(hdr);
fDPIparse(hdr);
return (cp);
}
hdr = mkDPIhdr(cmd); if (hdr == 0) return (0); switch (hdr->packet_type) { case SNMP_DPI_GET: case SNMP_DPI_REGISTER: hdr->packet_body.dpi_get = mkDPIget(oid_name); break; case SNMP_DPI_GET_NEXT: hdr->packet_body.dpi_next = mkDPInext(oid_name, group_oid); break; case SNMP_DPI_SET: hdr->packet_body.dpi_set = mkDPIset(oid_name, type, len, value); break; } cp = cDPIpacket(hdr); fDPIparse(hdr); return (cp); }
unsigned char *mkDPIregister(oid_name)
char *oid_name;
{
return (mkMIBquery(SNMP_DPI_REGISTER, oid_name));
}
unsigned char *mkDPIregister(oid_name) char *oid_name; { return (mkMIBquery(SNMP_DPI_REGISTER, oid_name)); }
unsigned char *mkDPIresponse(ret_code, value_list)
int ret_code;
struct dpi_set_packet *value_list;
{
struct snmp_dpi_hdr *hdr;
struct dpi_resp_packet *resp;
unsigned char *cp;
unsigned char *mkDPIresponse(ret_code, value_list) int ret_code; struct dpi_set_packet *value_list; { struct snmp_dpi_hdr *hdr; struct dpi_resp_packet *resp; unsigned char *cp;
hdr = mkDPIhdr(SNMP_DPI_RESPONSE);
resp = (struct dpi_resp_packet *)
malloc(sizeof(struct dpi_resp_packet));
if (resp == 0) {
hdr = mkDPIhdr(SNMP_DPI_RESPONSE); resp = (struct dpi_resp_packet *) malloc(sizeof(struct dpi_resp_packet)); if (resp == 0) {
Carpenter & Wijnen [Page 45] RFC 1228 SNMP-DPI May 1991
Carpenter & Wijnen [Page 45] RFC 1228 SNMP-DPI May 1991
free(hdr);
return (0);
}
hdr->packet_body.dpi_response = resp;
resp->ret_code = ret_code;
resp->ret_data = value_list;
cp = cDPIpacket(hdr);
fDPIparse(hdr);
return (cp);
}
(hdr)を解放してください。 リターン(0)。 hdr>のパケット_body.dpi_応答はrespと等しいです。 resp->は_コードを浸水させます。= _コードを浸水させてください。 resp->は_データ=値_リストを浸水させます。 cpはcDPIpacket(hdr)と等しいです。 fDPIparse(hdr)。 戻ってください(cp)。 }
unsigned char *mkDPItrap(generic, specific, value_list)
int generic, specific;
struct dpi_set_packet *value_list;
{
struct snmp_dpi_hdr *hdr;
struct dpi_trap_packet *trap;
unsigned char *cp;
未署名の炭*mkDPItrap(ジェネリック、特定の値の_リスト)intジェネリックで、特定。 struct dpi_セット_パケット*値の_は記載します。 struct snmp_dpi_hdr*hdr; struct dpi_罠_パケット*は捕らえられます; 未署名の炭*cp
hdr = mkDPIhdr(SNMP_DPI_TRAP);
trap = (struct dpi_trap_packet *)
malloc(sizeof(struct dpi_trap_packet));
if (trap == 0) {
free(hdr);
return (0);
}
hdr->packet_body.dpi_trap = trap;
trap->generic = generic;
trap->specific = specific;
trap->info = value_list;
cp = cDPIpacket(hdr);
fDPIparse(hdr);
return (cp);
}
hdrはmkDPIhdr(SNMP_DPI_TRAP)と等しいです。 =(struct dpi_罠_パケット*)malloc(sizeof(struct dpi_罠_パケット))を捕らえてください。 (罠=0)がhdr->を解放するなら(hdr); リターン(0);、パケット_body.dpi_罠は罠と等しいです。 >を捕らえているジェネリックはジェネリックと等しいです。 >を捕らえている詳細は詳細と等しいです。 >を捕らえているインフォメーションは値_リストと等しいです。 cpはcDPIpacket(hdr)と等しいです。 fDPIparse(hdr)。 戻ってください(cp)。 }
static struct snmp_dpi_hdr *mkDPIhdr(type)
int type;
{
静的なstruct snmp_dpi_hdr*mkDPIhdr(タイプする)intタイプ。 {
struct snmp_dpi_hdr *hdr;
_struct snmp_dpi hdr*hdr。
hdr = (struct snmp_dpi_hdr *) malloc(sizeof(struct snmp_dpi_hdr));
if (hdr == 0)
return (0);
hdr->proto_major = SNMP_DPI_PROTOCOL;
hdr->proto_minor = SNMP_DPI_VERSION;
hdr->proto_release = SNMP_DPI_RELEASE;
hdr->packet_type = type;
hdr=(_struct snmp_dpi hdr*)malloc(sizeof(_struct snmp_dpi hdr))。 (hdr=0)が(0)を返すなら。 hdr>のproto_主要な=SNMP_DPI_プロトコル。 hdr>のproto_小さい方の=SNMP_DPI_バージョン。 proto_がリリースするhdr->はSNMP_DPI_RELEASEと等しいです。 パケット_がタイプと等しいのをタイプするhdr->。
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大工とWijnen[46ページ]RFC1228SNMP-dpi1991年5月
return (hdr);
}
戻ってください(hdr)。 }
static struct dpi_get_packet *mkDPIget(oid_name)
char *oid_name;
{
struct dpi_get_packet *get;
int l;
静的なstruct dpi_は_パケット*mkDPIget(oid_名前)炭*oid_名を得ます。 struct dpi_は_*が得るパケットを得ます; int l
get = (struct dpi_get_packet *)
malloc(sizeof(struct dpi_get_packet));
if (get == 0)
return (0);
=(struct dpi_は_パケット*を得る)malloc(sizeof(struct dpi_は_パケットを得る))を手に入れてください。 (=0を得ます)リターン(0)であるなら。
l = strlen(oid_name) + 1;
get->object_id = malloc(l);
strcpy(get->object_id, oid_name);
return (get);
}
lはstrlen(oid_名前)+1と等しいです。 >オブジェクト_イド=malloc(l)を手に入れます。 strcpy(>オブジェクト_イド、oid_名を得ている)。 戻ってください(得ます)。 }
static struct dpi_next_packet *mkDPInext(oid_name, group_oid)
char *oid_name;
char *group_oid;
{
struct dpi_next_packet *next;
int l;
次の_パケット*mkDPInext(oid_名前、グループ_oid)炭*oid_が命名する静的なstruct dpi_。 *グループ_oidを炭にしてください。 struct dpi_次の次の_パケット*; int l。
next = (struct dpi_next_packet *)
malloc(sizeof(struct dpi_next_packet));
if (next == 0)
return (0);
l = strlen(oid_name) + 1;
next->object_id = malloc(l);
strcpy(next->object_id, oid_name);
l = strlen(group_oid) + 1;
next->group_id = malloc(l);
strcpy(next->group_id, group_oid);
return (next);
}
次の=(struct dpi_次_パケット*)malloc(sizeof(struct dpi_次_パケット))。 (次の=0)が(0)を返すなら。 lはstrlen(oid_名前)+1と等しいです。 次の>のオブジェクト_イドはmalloc(l)と等しいです。 strcpy(次の>のオブジェクト_イド、oid_名)。 lはstrlen(グループ_oid)+1と等しいです。 次の>のグループ_イドはmalloc(l)と等しいです。 strcpy(次の>のグループ_イド、グループ_oid)。 戻ってください(次の)。 }
struct dpi_set_packet *mkDPIset(oid_name, type, len, value)
char *oid_name;
int type;
int len;
char *value;
{
struct dpi_set_packet *set;
int l;
struct dpi_は_パケット*mkDPIset(_名、タイプ、lenが評価するoid)炭*oid_名を設定します。 intタイプ。 int len。 *値を炭にしてください。 struct dpi_セット_パケット*はセットしました; int l
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大工とWijnen[47ページ]RFC1228SNMP-dpi1991年5月
set = (struct dpi_set_packet *)
malloc(sizeof(struct dpi_set_packet));
if (set == 0)
return (0);
=(struct dpi_は_パケット*を設定する)malloc(sizeof(struct dpi_は_パケットを設定する))を設定してください。 (セット=0)が(0)を返すなら。
l = strlen(oid_name) + 1;
set->object_id = malloc(l);
strcpy(set->object_id, oid_name);
set->type = type;
set->value_len = len;
set->value = malloc(len);
bcopy(value, set->value, len);
return (set);
}
lはstrlen(oid_名前)+1と等しいです。 >を設定しているオブジェクト_イドはmalloc(l)と等しいです。 strcpy(>を設定しているオブジェクト_イド、oid_名)。 >を設定しているタイプはタイプと等しいです。 >を設定している値_lenはlenと等しいです。 >を設定している値はmalloc(len)と等しいです。 bcopy(値、>を設定している値、len)。 戻ってください(設定します)。 }
SAMPLE SOURCES FOR ANONYMOUS FTP
アノニマスFTPのためのサンプルソース
The complete source to two SNMP DPI-related programs is available for anonymous ftp from the University of Toronto. The host name to use is "vm.utcs.utoronto.ca" (128.100.100.2). The files are in the "anonymou.204" minidisk, so one must issue a "cd anonymou.204" after having logged in. Don't forget to use the binary transmission mode.
2つのSNMP DPI関連のプログラムへの完全なソースはトロント大学からのアノニマスFTPに手があいています。 使用するホスト名が"vm.utcs.utoronto.ca"である、(128.100 .100 .2)。 ファイルがある、「anonymouの0.204インチのミニディスク、「ログインした0.204インチ後のcd anonymou」を発行しなければならないそう 2進の転送方式を使用するのを忘れないでください。
The Ping Engine
ピングエンジン
This program is an SNMP DPI sub-agent which allows network management stations to perform remote PINGs. The source to this applications is in the file "ping_eng.tarbin". The source to the SNMP DPI API is also contained within the archive.
このプログラムはSNMP DPIサブエージェントです(ネットワークマネージメントステーションはリモートPINGsを実行できます)。 このアプリケーションへのソースが「ピング_eng.tarbin」というファイルにあります。 また、SNMP DPI APIへのソースはアーカイブの中に含まれています。
The DPI->SMUX daemon
DPI->、SMUXデーモン
This program illustrates what is required to include the SNMP DPI in an SNMP agent. This is actually a SMUX-based agent that works with the ISODE SNMP agent and provides an interface for SNMP DPI sub- agents. The source to this program is in the file "dpid.tarbin". ISODE 6.7, or later, is a prerequisite.
このプログラムは、何がSNMPエージェントにSNMP DPIを含むのに必要であるかを例証します。 これは実際にISODE SNMPエージェントと共に働いて、SNMP DPIサブエージェントにインタフェースを提供するSMUXベースのエージェントです。 このプログラムへのソースが"dpid.tarbin"というファイルにあります。 ISODE6.7以降は前提条件です。
References
参照
[1] Case, J., Fedor, M., Schoffstall, M., and J. Davin, "Simple
Network Management Protocol", RFC 1157, SNMP Research,
Performance Systems International, Performance Systems
International, MIT Laboratory for Computer Science, May 1990.
[1] SNMPが研究するケース、J.、ヒョードル、M.、Schoffstall、M.、およびJ.デーヴィン、「簡単なネットワーク管理プロトコル」、RFC1157、国際言語運用機構、国際言語運用機構(MITコンピュータサイエンス研究所)は1990がそうするかもしれません。
[2] Information processing systems - Open Systems Interconnection,
"Specification of Abstract Syntax Notation One (ASN.1)",
[2]情報処理システム--オープン・システム・インターコネクション、「抽象構文記法1(ASN.1)の仕様」
Carpenter & Wijnen [Page 48] RFC 1228 SNMP-DPI May 1991
大工とWijnen[48ページ]RFC1228SNMP-dpi1991年5月
International Organization for Standardization, International
Standard 8824, December 1987.
国際標準化機構、国際規格8824、1987年12月。
[3] Information processing systems - Open Systems Interconnection,
"Specification of Basic Encoding Rules for Abstract Syntax
Notation One (ASN.1)", International Organization for
Standardization, International Standard 8825, December 1987.
[3]情報処理システム--オープン・システム・インターコネクション、「基本的なコード化の仕様は抽象構文記法1(ASN.1)のために統治されます」、国際標準化機構、国際規格8825、1987年12月。
[4] McCloghrie K., and M. Rose, "Management Information Base for
Network Management of TCP/IP-based internets", RFC 1156,
Performance Systems International and Hughes LAN Systems, May
1990.
[4]McCloghrie K.、M.ローズ、「TCP/IPベースのインターネットのNetwork Managementのための管理Information基地」、RFC1156、国際パフォーマンスSystems、およびヒューズLAN Systems(1990年5月)。
[5] Rose, M., and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based internets", RFC 1155,
Performance Systems International and Hughes LAN Systems, May
1990.
[5] ローズ、M.、K.McCloghrie、「TCP/IPベースのインターネットのためのManagement情報の構造とIdentification」、RFC1155、国際パフォーマンスSystems、およびヒューズLAN Systems(1990年5月)。
[6] International Business Machines, Inc., "TCP/IP for VM:
Programmer's Reference", SC31-6084-0, 1990.
[6] インターナショナル・ビジネス・マシーンズInc.、「VMのためのTCP/IP:」 「プログラマの参照」、SC31-6084-0、1990。
[7] International Business Machines, Inc., "Virtual Machine System
Facilities for Programming, Release 6", SC24-5288-01, 1988.
[7] インターナショナル・ビジネス・マシーンズInc.、「SC24-5288-01、1988をリリース6インチプログラムするための仮想計算機システム施設。」
[8] International Business Machines, Inc., "TCP/IP Version 1.1 for
OS/2 EE: Programmer's Reference", SC31-6077-1, 1990.
[8] インターナショナル・ビジネス・マシーンズInc.、「OS/2EEのためのTCP/IPバージョン1.1:」 「プログラマの参照」、SC31-6077-1、1990。
Security Considerations
セキュリティ問題
Security issues are not discussed in this memo.
このメモで安全保障問題について議論しません。
Carpenter & Wijnen [Page 49] RFC 1228 SNMP-DPI May 1991
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Authors' Addresses
作者のアドレス
Geoffrey C. Carpenter IBM T. J. Watson Research Center P. O. Box 218 Yorktown Heights, NY 10598
ニューヨーク ジェフリーC.大工IBM T.J.ワトソン研究所私書箱218ヨークタウンの高さ、10598
Phone: (914) 945-1970
以下に電話をしてください。 (914) 945-1970
Email: gcc@watson.ibm.com
メール: gcc@watson.ibm.com
Bert Wijnen IBM International Operations Watsonweg 2 1423 ND Uithoorn The Netherlands
バートのWijnen IBMの国際経営活動Watsonweg2 1423第オイトホルンオランダ
Phone: +31-2975-53316
以下に電話をしてください。 +31-2975-53316
Email: wijnen@uitvm2.iinus1.ibm.com
メール: wijnen@uitvm2.iinus1.ibm.com
Carpenter & Wijnen [Page 50]
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