Binding 2 UDP sockets on same port, connected to different destinations, 1 receives

Posted on 16th Feb 2014 07:03 pm by admin

Hello,
My application wants to send/recv data to 2 different UDP ports on a remote computer, using the same source port.
So I bind to the same local port which works, and connect to the remote IP : port which works as well, but then randomly only one of the two sockets will receive data from the stack, even though packets are arriving on the network for both.

In this code, the local UDP port is always 13398; the first time this code is called, the destination is 192.168.13.45:6970 and the second time it's 192.168.13.45:6972.
What would cause only one of the sockets to receive data afterwards? Also it's randomly the first or the second one that receive data, but once both sockets are binded and connected, only that random one will receive data.

Thanks!

SOCKET serverSock = ::socket(AF_INET, SOCK_DGRAM,IPPROTO_UDP);
int i=1;
if ( setsockopt(serverSock, SOL_SOCKET, SO_REUSEADDR, (char *)&i, sizeof(i)) != 0 ) {
logger.warn(_T("Could not set SO_REUSEADDR: %s"), GetWSATextError(WSAGetLastError()));
}

SOCKADDR_IN saServer, dest;
memset(&saServer,0,sizeof(saServer));
saServer.sin_family = AF_INET;
saServer.sin_addr.s_addr = INADDR_ANY; // Since this is a server, any address will do
saServer.sin_port = htons(m_manager->GetLocalUDPPort()); // Convert int to a value for the port field
int ret = bind(serverSock, (struct sockaddr *) &saServer, sizeof(saServer));
if (ret != 0) {
logger.warn(_T("Could not bind to udp port 1: %d, %s"), m_manager->GetLocalUDPPort(), GetWSATextError(WSAGetLastError()));
return false;
}

memset(&dest,0,sizeof(dest));
dest.sin_family=AF_INET;
dest.sin_addr.s_addr=m_deviceIP;
dest.sin_port = htons(m_devicePort1);
ret = connect(serverSock, (sockaddr *) &dest, sizeof(dest));
if (ret != 0) {
logger.warn(_T("Failed to connect to udp 1: %s:%d, %s"), inet_ntoa(dest.sin_addr), m_devicePort1, GetWSATextError(WSAGetLastError()));
return false;
}

Your Answer:

Login to answer

Other forums

Need help with an email blocker for a guessbook
I am new with php and here is a simple guessbook page but I am being hit with spam from a group of t

Issue Parsing XML into table
Hello all,

Im a bit new to php and new to phpfreaks. But thanks in advance for the help!
<

Using CSS to format MySQL query
Hi,

If i want to have a news page on my site, which displays all records of a table in descen

parameter passing issue on function
Well I thought I had created a pretty slick web page, using ?page and $_GET to load pages which wher

Convert .fdf to .pdf
I currently have a web form that uploads the form data to an .fdf file and emails it.

However

 formating when pulling data from a mysql database 
Ok so Im not to sure if this is the right thread to post in but here is my catch 22 issue.

I 
problem with array - multilingual page 
this is my test page :
Code: <?php 
   if(isset($_GET['lang'])) {
      if($_GET['la
Help me with some material on Open Text Overview. 
Hi Experts,

Please help me out with some material on Open Text. I have been supporting AP Workf
getting a website's source code as a variable? How? 
Hey guys, is there any way for me to get the source code of a website as a variable for me to work w
Probably a simple error... 
I'm getting the error -- Parse error: syntax error, unexpected '{' in /home/content/c/s/t/csteffen24