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     Change History (most recent first):
  18
  19 $Log: ExampleClientApp.c,v $
  20 Revision 1.14  2006/08/14 23:24:46  cheshire
  21 Re-licensed mDNSResponder daemon source code under Apache License, Version 2.0
  22
  23 Revision 1.13  2006/02/23 23:38:43  cheshire
  24 <rdar://problem/4427969> On FreeBSD 4 "arpa/inet.h" requires "netinet/in.h" be included first
  25
  26 Revision 1.12  2004/11/30 22:37:00  cheshire
  27 Update copyright dates and add "Mode: C; tab-width: 4" headers
  28
  29 Revision 1.11  2004/09/17 01:08:53  cheshire
  30 Renamed mDNSClientAPI.h to mDNSEmbeddedAPI.h
  31   The name "mDNSClientAPI.h" is misleading to new developers looking at this code. The interfaces
  32   declared in that file are ONLY appropriate to single-address-space embedded applications.
  33   For clients on general-purpose computers, the interfaces defined in dns_sd.h should be used.
  34
  35 Revision 1.10  2004/09/16 01:58:22  cheshire
  36 Fix compiler warnings
  37
  38 Revision 1.9  2003/08/12 19:56:26  cheshire
  39 Update to APSL 2.0
  40
  41 Revision 1.8  2003/07/02 21:19:58  cheshire
  42 <rdar://problem/3313413> Update copyright notices, etc., in source code comments
  43
  44 Revision 1.7  2003/06/18 05:48:41  cheshire
  45 Fix warnings
  46
  47 Revision 1.6  2003/03/31 22:44:36  cheshire
  48 Add log header
  49
  50  */
  51
  52 #include <stdio.h>                      // For printf()
  53 #include <stdlib.h>                     // For exit() etc.
  54 #include <string.h>                     // For strlen() etc.
  55 #include <unistd.h>                     // For select()
  56 #include <errno.h>                      // For errno, EINTR
  57 #include <netinet/in.h>         // For INADDR_NONE
  58 #include <arpa/inet.h>          // For inet_addr()
  59 #include <netdb.h>                      // For gethostbyname()
  60 #include <signal.h>                     // For SIGINT, etc.
  61
  62 #include "mDNSEmbeddedAPI.h"  // Defines the interface to the client layer above
  63 #include "mDNSPosix.h"      // Defines the specific types needed to run mDNS on this platform
  64
  65 //*******************************************************************************************
  66 // Main
  67
  68 static volatile mDNSBool StopNow;
  69
  70 mDNSlocal void HandleSIG(int signal)
  71         {
  72         (void)signal;   // Unused
  73         debugf("%s","");
  74         debugf("HandleSIG");
  75         StopNow = mDNStrue;
  76         }
  77
  78 mDNSexport void ExampleClientEventLoop(mDNS *const m)
  79         {
  80         signal(SIGINT, HandleSIG);      // SIGINT is what you get for a Ctrl-C
  81         signal(SIGTERM, HandleSIG);
  82
  83         while (!StopNow)
  84                 {
  85                 int nfds = 0;
  86                 fd_set readfds;
  87                 struct timeval timeout;
  88                 int result;
  89
  90                 // 1. Set up the fd_set as usual here.
  91                 // This example client has no file descriptors of its own,
  92                 // but a real application would call FD_SET to add them to the set here
  93                 FD_ZERO(&readfds);
  94
  95                 // 2. Set up the timeout.
  96                 // This example client has no other work it needs to be doing,
  97                 // so we set an effectively infinite timeout
  98                 timeout.tv_sec = 0x3FFFFFFF;
  99                 timeout.tv_usec = 0;
 100
 101                 // 3. Give the mDNSPosix layer a chance to add its information to the fd_set and timeout
 102                 mDNSPosixGetFDSet(m, &nfds, &readfds, &timeout);
 103
 104                 // 4. Call select as normal
 105                 verbosedebugf("select(%d, %d.%06d)", nfds, timeout.tv_sec, timeout.tv_usec);
 106                 result = select(nfds, &readfds, NULL, NULL, &timeout);
 107
 108                 if (result < 0)
 109                         {
 110                         verbosedebugf("select() returned %d errno %d", result, errno);
 111                         if (errno != EINTR) StopNow = mDNStrue;
 112                         }
 113                 else
 114                         {
 115                         // 5. Call mDNSPosixProcessFDSet to let the mDNSPosix layer do its work
 116                         mDNSPosixProcessFDSet(m, &readfds);
 117
 118                         // 6. This example client has no other work it needs to be doing,
 119                         // but a real client would do its work here
 120                         // ... (do work) ...
 121                         }
 122                 }
 123
 124         debugf("Exiting");
 125         }