xref: /aosp_15_r20/external/mdnsresponder/mDNSPosix/ExampleClientApp.c (revision 48a54d368dc4fa860885eef7b70b6c53499e7c25)

/* -*- Mode: C; tab-width: 4 -*-
 *
 * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>			// For printf()
#include <stdlib.h>			// For exit() etc.
#include <string.h>			// For strlen() etc.
#include <unistd.h>			// For select()
#include <errno.h>			// For errno, EINTR
#include <netinet/in.h>		// For INADDR_NONE
#include <arpa/inet.h>		// For inet_addr()
#include <netdb.h>			// For gethostbyname()
#include <signal.h>			// For SIGINT, etc.

#include "mDNSEmbeddedAPI.h"  // Defines the interface to the client layer above
#include "mDNSPosix.h"      // Defines the specific types needed to run mDNS on this platform

//*******************************************************************************************
// Main

static volatile mDNSBool StopNow;

mDNSlocal void HandleSIG(int signal)
	{
	(void)signal;	// Unused
	debugf("%s","");
	debugf("HandleSIG");
	StopNow = mDNStrue;
	}

mDNSexport void ExampleClientEventLoop(mDNS *const m)
	{
	signal(SIGINT, HandleSIG);	// SIGINT is what you get for a Ctrl-C
	signal(SIGTERM, HandleSIG);

	while (!StopNow)
		{
		int nfds = 0;
		fd_set readfds;
		struct timeval timeout;
		int result;

		// 1. Set up the fd_set as usual here.
		// This example client has no file descriptors of its own,
		// but a real application would call FD_SET to add them to the set here
		FD_ZERO(&readfds);

		// 2. Set up the timeout.
		// This example client has no other work it needs to be doing,
		// so we set an effectively infinite timeout
		timeout.tv_sec = 0x3FFFFFFF;
		timeout.tv_usec = 0;

		// 3. Give the mDNSPosix layer a chance to add its information to the fd_set and timeout
		mDNSPosixGetFDSet(m, &nfds, &readfds, &timeout);

		// 4. Call select as normal
		verbosedebugf("select(%d, %d.%06d)", nfds, timeout.tv_sec, timeout.tv_usec);
		result = select(nfds, &readfds, NULL, NULL, &timeout);

		if (result < 0)
			{
			verbosedebugf("select() returned %d errno %d", result, errno);
			if (errno != EINTR) StopNow = mDNStrue;
			}
		else
			{
			// 5. Call mDNSPosixProcessFDSet to let the mDNSPosix layer do its work
			mDNSPosixProcessFDSet(m, &readfds);

			// 6. This example client has no other work it needs to be doing,
			// but a real client would do its work here
			// ... (do work) ...
			}
		}

	debugf("Exiting");
	}