97 lines
4.4 KiB
Plaintext
97 lines
4.4 KiB
Plaintext
/***********************************************************************
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*
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* Copyright (C) 2006 Novell, Inc. All Rights Reserved.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; version 2.1
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* of the License.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, Novell, Inc.
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*
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* To contact Novell about this file by physical or electronic mail,
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* you may find current contact information at www.novell.com.
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*
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* Author: Juan Carlos Luciani <jluciani@novell.com>
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*
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***********************************************************************/
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/***********************************************************************
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*
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* README for IpcLibs
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*
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***********************************************************************/
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INTRODUCTION
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IpcLibs provides an IPC infrastructure that can be linked into client and server
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applications.
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IpcLibs provides IPC communications over TCP or DOMAIN sockets. It does this in a scalable
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and un-serialized manner. The infrastructure can make use of multiple communication channels
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between a client and a server and is capabled of concurrently serving multiple requests over
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the different channels.
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The IpcLib APIs are very simple to utilize and support multi-threaded applications.
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SERVER APPLICATION PROGRAMMING NOTES
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The IPC API for server applications is defined in casa_s_ipc.h. This API is provided by
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libcasa_s_ipc.so.
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To utilize the IPC server services, an application must first initialize the infrastructure by
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calling IpcServerInit() which is then followed by the desired IpcServerSetXXAddress() call.
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After the Ipc server is initialized and the server address is set, then the application calls
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IpcServerStart() to start the engine (This causes the engine to start to accept connections and
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receive requests from clients).
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To start servicing requests, the application executesIpcServerGetRequest(); this calls blocks until
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a request is ready to be serviced at which time it returns with an ID which is associated with the
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request that needs to be serviced. The returned ID is then used by the application to retrieve the
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request data via the IpcServerGetRequestData(), once the application processes the request, it
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completes it by executing IpcServerCompleteRequest() with the ID and any data that it may want to
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send back to the client.
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Note that a server application can call IpcServerGetRequest() from multiple threads to make itself
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more scalable.
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For an example server application that utilizes the IPC API for servers, see file
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linux/server/test/testServer.c.
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CLIENT APPLICATION PROGRAMMING NOTES
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The IPC API for client applications is defined in casa_c_ipc.h. This API is provided by
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libcasa_c_ipc.so.
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To utilize the IPC client services, an application must first initialize the infrastructure by
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calling IpcClientInit(). Once the IPC client is initialized, then the application needs to open
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endpoints for the servers that it wishes to submit requests. Endpoints are opened by calling the
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appropriate IpcClientOpenXXRemoteEndPoint() with information about the server listen address.
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IpcClientOpenXXRemoteEndpoint() calls return a handles that are associated with the opened
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endpoints. This endpoint handles are then utilized by the application to specify the target of
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IPC requests.
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To submit a request to a particular endpoint, the application executes IpcClientSubmitReq() with
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the endpoint handle and the request data. Calls to IpcClientSubmitReq() block until the requests
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is processed by the server at which time it returns the reply data.
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For an example client application that utilizes the IPC API for clients, see file
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linux/client/test/testClient.c.
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SECURITY CONSIDERATIONS
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IpcLibs does not provide any security features beyond what is provided by the protocol stacks for
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tcp/ip and Domain sockets communications. IpcLibs does not directly perform any uid/gid checks
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when Domain socket communications are performed.
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By leveraging the File System Access Control features, you can scope communications that occur over
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Domain sockets to specific or groups of users.
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