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diff --git a/docs/tutorials/008/page04.html b/docs/tutorials/008/page04.html deleted file mode 100644 index e52d37d19c7..00000000000 --- a/docs/tutorials/008/page04.html +++ /dev/null @@ -1,156 +0,0 @@ -<HTML> -<HEAD> - <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> - <META NAME="GENERATOR" CONTENT="Mozilla/4.05 [en] (WinNT; I) [Netscape]"> - <META NAME="Author" CONTENT="James CE Johnson"> - <TITLE>ACE Tutorial 008</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> - -<CENTER><B><FONT SIZE=+2>ACE Tutorial 008</FONT></B></CENTER> - -<CENTER><B><FONT SIZE=+2>Sending and receiving datagrams</FONT></B></CENTER> - - -<P> -<HR WIDTH="100%"> -<BR> -<BR> In <A HREF="broadcast_client.cpp">broadcast_client.cpp</A> we -find out how to send a single datagram to every host on our (sub)network. -I have to say <I>(sub)network</I> because broadcast datagrams typically -are not passed through routers. So, if your network admin has divided -up your network into subnets, your broadcasts will likey only stay on the -subnet you're a part of. - -<P>I've only commented the parts that are different from the directed_client. - -<P> -<HR WIDTH="100%"> - -<P><TT>#include "ace/SOCK_Dgram_Bcast.h"</TT> -<BR><TT>#include "ace/INET_Addr.h"</TT> - -<P><TT>static const u_short PORT = ACE_DEFAULT_SERVER_PORT;</TT> - -<P><TT>int main(int argc,char *argv[] )</TT> -<BR><TT>{</TT> -<BR><TT> ACE_INET_Addr -local((u_short)0);</TT> - -<P><TT> /*</TT> -<BR><TT> Instead -of creating the ACE_SOCK_Dgram we created last time,</TT> -<BR><TT> we'll -create an ACE_SOCK_Dgram_Bcast. "Bcast" means, of course,</TT> -<BR><TT> "Broadcast". -This ACE object is clever enough to go out to the</TT> -<BR><TT> OS -and find all of the network interfaces. When you send()</TT> -<BR><TT> on -a Dgram_Bcast, it will send the datagram out on all of those</TT> -<BR><TT> interfaces. -This is quiet handy if you do it on a multi-homed</TT> -<BR><TT> host -that plays router...</TT> -<BR><TT> */</TT> -<BR><TT> ACE_SOCK_Dgram_Bcast -dgram;</TT> - -<P><TT> if( dgram.open(local) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "datagram open"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> char buf[512];</TT> - -<P><TT> sprintf(buf, "Hello World!");</TT> - -<P><TT> /*</TT> -<BR><TT> The -only other difference between us and the directed client</TT> -<BR><TT> is -that we don't specify a host to receive the datagram.</TT> -<BR><TT> Instead, -we use the magic value "INADDR_BROADCAST". All hosts</TT> -<BR><TT> are -obliged to respond to datagrams directed to this address</TT> -<BR><TT> the -same as they would to datagrams sent to their hostname.</TT> - -<P><TT> Remember, -the Dgram_Bcast will send a datagram to all interfaces</TT> -<BR><TT> on -the host. That's true even if the address is for a specific</TT> -<BR><TT> host -(and the host address makes sense for the interface).</TT> -<BR><TT> The -real power is in using an INADDR_BROADCAST addressed datagram</TT> -<BR><TT> against -all interfaces.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_INET_Addr -remote(PORT,INADDR_BROADCAST);</TT> - -<P><TT> ACE_DEBUG ((LM_DEBUG, -"(%P|%t) Sending (%s) to the server.\n",buf));</TT> -<BR><TT> </TT> -<BR><TT> if( dgram.send(buf,strlen(buf)+1,remote) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "send"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> if( dgram.recv(buf,sizeof(buf),remote) -== -1 )</TT> -<BR><TT> {</TT> -<BR><TT> -ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "recv"),-1);</TT> -<BR><TT> }</TT> - -<P><TT> ACE_DEBUG ((LM_DEBUG, -"(%P|%t) The server said: %s\n",buf));</TT> - -<P><TT> /*</TT> -<BR><TT> Using -the <I>remote</I> object instance, find out where the server lives.</TT> -<BR><TT> We -could then save this address and use directed datagrams to chat</TT> -<BR><TT> with -the server for a while.</TT> -<BR><TT> */</TT> -<BR><TT> ACE_DEBUG ((LM_DEBUG, -"(%P|%t) The server can be found at: (%s:%d)\n",</TT> -<BR><TT> -remote.get_host_addr(), PORT ));</TT> -<BR><TT> </TT> -<BR><TT> return(0);</TT> -<BR><TT>}</TT> - -<P> -<HR WIDTH="100%"> - -<P> About that subnet thing: -<BLOCKQUOTE>If you run this client on a host that has multiple network -interfaces, the broadcast will go to all of those (sub)networks. -What do you do, though, if you need to get past a router? My advice -is to write a server that will run on hosts on both sides of your router. -When a server on one side of the router receives a broadcast, it would -send a directed datagram to it's counterpart on the other side of the router. -The counterpart would then re-broadcast the original datagram on that sub-net. -Cheap, simple and effective.</BLOCKQUOTE> -One final word of warning: -<BLOCKQUOTE>When creating your broadcast datagrams you may see something -like this: <I>ACE_SOCK_Dgram_Bcast::mk_broadcast: Broadcast is not -enable for this interface.: Unknown error</I>. There are some interfaces -(ppp, slip) that don't support broadcast datagrams. That's what you're -seeing here.</BLOCKQUOTE> - -<HR WIDTH="100%"> -<CENTER>[<A HREF="../online-tutorials.html">Tutorial Index</A>] [<A HREF="page05.html">Continue -This Tutorial</A>]</CENTER> - -</BODY> -</HTML> |