Re: Help with UDP data handler

I can't tell you what you might doing wrong, but I can offer
some suggestions based on how I did something similar.
I did not use the callback feature. It seems to me there are
too many messages flying around to use this feature reliably.
 
I open several UDP sockets listening for broadcast messages.
 
 for(i=0;i<UDP_SOCKETS;i++){
   udp_extopen(&udpcon[i].socket,
                 IF_DEFAULT,
                 UDP_BROADCAST_PORT,
                 -1,-1,NULL,0,0);
 }

 
In the main loop I call a function that checks each socket for
a received message. If a message with data is found, the data
is copied to a buffer and passed to a paring routine.
 
// Look for incoming packets. for( s=0;s<UDP_SOCKETS;s++) { if( !udp_peek( &udpcon[s].socket, NULL) ) { continue;// No packets... } numBytes=udp_recvfrom( &udpcon[s].socket, udpcon[s].buf, sizeof(udpcon[s].buf), &udpcon[s].ip, &udpcon[s].port); if( numBytes<1) { continue;// No data... } udpcon[s].buf[numBytes]=NUL; 
UdpParse( &udpcon[s]); 
}
 
Occasionally, my program sends its own broadcast status. 
When it does, it opens a UDP port, sends the message, then
closes the port.
 
// Open a Broadcast socket if( !udp_extopen( &udpsock.socket, IF_DEFAULT, UDP_BROADCAST_PORT-1, -1, UDP_BROADCAST_PORT, NULL, 0, 0) ) return;// Oops! // Build a status message FormatUDPStatusMsg( udpsock.buf); // Send it... udp_send( &udpsock.socket, udpsock.buf, strlen(udpsock.buf) ); udp_close( &udpsock.socket); 
 
This works well in our system.
 
 
 
>From: Jeff Powell <jrpinjapan-/[email protected]>
>To: [email protected] 
>Sent: Monday, July 30, 2012 8:57 AM
>Subject: [rabbit-semi] Help with UDP data handler
>
>
>  
>I posted this as part of a different question and nobody answered so I 
>will try again as it's own topic.
>
>I have opened a udp socket with a datahandler.
>I opened a second udp socket for sending multicast data when values change.
>I get a connection, read from client, write back to client.
>I get another connection. It does not go to the datahandler.
>The main loop runs and multicast data continues to send properly.
>
>What am I missing?
>
>-- code --
>if (!udp_open(&tsock, LOCAL_PORT, 0, 0, dataHandler))
>{
>printf("udp_lst_open failed!\n");
>exit(0);
>}
>else
>{
>printf("Listener %s:%d\n",MY_IP_ADDRESS,LOCAL_PORT);
>}
>if (!udp_open(&usock, MBUS_PORT, resolve(MBUS_ADDRESS), MBUS_PORT, 
>NULL))
>{
>printf("udp_open failed!\n");
>exit(0);
>}
>
>...
>
>while (1)
>{
>idleProcessing(); // where values are processed and 
>multicast data is sent as needed.
>tcp_tick(NULL);
>}
>
>...
>
>int dataHandler(int event, udp_Socket *s, ll_Gather *g, 
>_udp_datagram_info *udi)
>{
>int status;
>char cip[20];
>CARDMSG_S *pkt;
>if(handleUdp) // stops recursion, does not effect 
>handler death
>return 1;
>handleUdp=1;
>if(event == UDP_DH_ICMPMSG) // from the example
>{
>return 1;
>}
>memset(&replyMsg, 0, sizeof (REPLYMSG_S));
>xmem2root(pktbuf, g->data2, g->len2);
>if(g->len3>0)
>xmem2root(pktbuf+g->len2, g->data3, g->len3);
>pkt=(CARDMSG_S*) &pktbuf;
>inet_ntoa( cip, udi->remip);
>printf("%s:%u Slot %d Type %d Device %d Offset %x Width %x Data %lx 
>%lx\n", cip, udi->remport, pkt->cSlot, pkt->cOperation, pkt->cDevice, 
>pkt->cOffset, pkt->cDataWidth, pkt->sData.longs[1], pkt->sData.longs[0] );
>status = process_packet(pktbuf);
>replyMsg.eStatus = status;
>printf("Status: %x\n", status);
>udp_sendto(s, (char*) &replyMsg, sizeof(REPLYMSG_S), udi->remip, 
>udi->remport); // straight from the
>// even tried this but it does not help either. Returns 1 for NULL or 
>bytes recv'd for the incoming socket.
>printf("Sent response %u\n", tcp_tick(NULL));
>handleUdp=0;
>return 1;
>}
>
>
>
>
>