mDNSPosix/ExampleClientApp.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  */
  17
  18 #include <stdio.h>          // For printf()
  19 #include <stdlib.h>         // For exit() etc.
  20 #include <string.h>         // For strlen() etc.
  21 #include <unistd.h>         // For select()
  22 #include <errno.h>          // For errno, EINTR
  23 #include <netinet/in.h>     // For INADDR_NONE
  24 #include <arpa/inet.h>      // For inet_addr()
  25 #include <netdb.h>          // For gethostbyname()
  26 #include <signal.h>         // For SIGINT, etc.
  27
  28 #include "mDNSEmbeddedAPI.h"  // Defines the interface to the client layer above
  29 #include "mDNSPosix.h"      // Defines the specific types needed to run mDNS on this platform
  30
  31 //*******************************************************************************************
  32 // Main
  33
  34 static volatile mDNSBool StopNow;
  35
  36 mDNSlocal void HandleSIG(int signal)
  37 {
  38     (void)signal;   // Unused
  39     debugf("%s","");
  40     debugf("HandleSIG");
  41     StopNow = mDNStrue;
  42 }
  43
  44 mDNSexport void ExampleClientEventLoop(mDNS *const m)
  45 {
  46     signal(SIGINT, HandleSIG);  // SIGINT is what you get for a Ctrl-C
  47     signal(SIGTERM, HandleSIG);
  48
  49     while (!StopNow)
  50     {
  51         int nfds = 0;
  52         fd_set readfds;
  53         fd_set writefds;
  54         struct timeval timeout;
  55         int result;
  56
  57         // 1. Set up the fd_set as usual here.
  58         // This example client has no file descriptors of its own,
  59         // but a real application would call FD_SET to add them to the set here
  60         FD_ZERO(&readfds);
  61         FD_ZERO(&writefds);
  62
  63         // 2. Set up the timeout.
  64         // This example client has no other work it needs to be doing,
  65         // so we set an effectively infinite timeout
  66         timeout.tv_sec = FutureTime;
  67         timeout.tv_usec = 0;
  68
  69         // 3. Give the mDNSPosix layer a chance to add its information to the fd_set and timeout
  70         mDNSPosixGetFDSet(m, &nfds, &readfds, &writefds, &timeout);
  71
  72         // 4. Call select as normal
  73         verbosedebugf("select(%d, %d.%06d)", nfds, timeout.tv_sec, timeout.tv_usec);
  74         result = select(nfds, &readfds, &writefds, NULL, &timeout);
  75
  76         if (result < 0)
  77         {
  78             verbosedebugf("select() returned %d errno %d", result, errno);
  79             if (errno != EINTR) StopNow = mDNStrue;
  80         }
  81         else
  82         {
  83             // 5. Call mDNSPosixProcessFDSet to let the mDNSPosix layer do its work
  84             mDNSPosixProcessFDSet(m, &readfds, &writefds);
  85
  86             // 6. This example client has no other work it needs to be doing,
  87             // but a real client would do its work here
  88             // ... (do work) ...
  89         }
  90     }
  91
  92     debugf("Exiting");
  93 }