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| − | == About == | + | == Resources == |
| | XINU implements UDP as per RFC 768 | | XINU implements UDP as per RFC 768 |
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| − | == Sending data over UDP ==
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| − | '''Step 1: Allocate a new UDP device.'''
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| − | :Use udpAlloc to get a device number for a udp device. If allocation fails, the device number returned will be SYSERR.
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| − | dev = tcpAlloc())
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| − | '''Step 2: Get the local ip address'''
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| − | :Use netLookup to find our local ip address.
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| − | :If interface is NULL, then we don't have a valid network interface.
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| − | This usually happens when a user forgets to run the netup command.
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| − | interface = netLookup((ethertab[0].dev)->num);
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| − | localhost = &(interface->ip);
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| − | '''Step3: Open the UDP device'''
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| − | :To open the device simply call open( ) with the following arguments:
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| − | #The UDP device number
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| − | #Our local ip address
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| − | #The destination's ip address
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| − | #The local port to use
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| − | #The remote port to connect to
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| − | open(dev, localIP, dstIP, localPort, remotePort)
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| − | Again if open fails, SYSERR is returned.
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| − | '''Step 4: Send the packet'''
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| − | :To actually send the data, use write( ) with the device, buffer, and length arguments.
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| − | :The actual data you want to send will be written to the buffer. The length arg is the length of the buffer.
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| − | write(dev, buf, MSG_MAX_LEN)
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| − | As usual, write returns SYSERR if it fails.
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| − | '''Step 5: Close the connection'''
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| − | :Once the device is finish being used, be responsible and call close to return the device.
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| − | close(dev);
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