IWL5300 realtime csi gathering about csikit

[Gi-z]

Hi, that code is functional but incomplete. My only test system using IWL5300 encounters a buffer overflow after reading CSI in real-time for longer than 1 minute. I am inexperienced with Linux sockets and as such haven't been able to effectively debug this issue. For now there may be better solutions for this elsewhere, but I may be able to investigate this again soon.

[tweigel-dev]

with the following snipped you can try to use the realtime capture:

def print_and_fill(csiEntry):
    print(csiEntry)
    global entrys
    entrys.append(csiEntry)



reader = IWLBeamformReader()
entrys = []
reader.read_log(print_and_fill)

[tweigel-dev]

Are you sure that a buffer overflow happend? Because currently I am using the https://github.com/pgawlowicz/linux-80211n-csitool-supplementary/blob/master/python/netlink.py code to extract csi at real time and have no problems.
this code seems to be very close to yours.

a few times the driver crashes after collecting much data but I had this behavior also with the log_to_file.
a simple restart of the iwl with ifconfig w1p1s0 down && ifconfig w1p1s0 up fix the issue of the broken driver.

[tweigel-dev]

i try to merge your code with the code by pgawlowicz.
Did the following function I found in your code work?

def read_bf_entry(self, data):
        """
            This function parses a CSI payload not associated with a file (for example: those extracted via netlink).
            Parameters:
                data (bytes): The total bytes returned by the kernel for a CSI frame.
            Returns:
                csi_block (dict): Individual parsed CSI block.
        """

        csi_header = struct.unpack("<LHHBBBBBbBBHH", data[4:25])
        all_data = [x[0] for x in struct.Struct(">B").iter_unpack(data[25:])]

        csi_block = self.read_bfee(csi_header, all_data)

        return csi_block

Because I get an exception if i want to fit the udp payload into this function
csi_header = struct.unpack("<LHHBBBBBbBBHH", data[4:25]) struct.error: unpack requires a buffer of 20 bytes.

the code diff at netlink.py is only:

CN_NETLINK_USERS = 11 #his
CN_NETLINK_USERS = 10 #yours

and the return of the payload :

payload = data        # his
payload = data[32:] #yours

it seems that if the CN_NETLINK_USERS = 10 is set, then the socket is never receiving datagramms. therefore i think the 11 is right. but which datapart has to be passed to the read_bf_entry? Both variants caused the same error

Here you can find the current code state:
https://github.com/tweigel-dev/CSIKit/tree/feature/realtime

[tweigel-dev]

I noticed that data[4:25] gives a length of 21, but the struct.unpack needs 20. There is the source of the issue I think

[tweigel-dev]

Hi, that code is functional but incomplete. My only test system using IWL5300 encounters a buffer overflow after reading CSI in real-time for longer than 1 minute. I am inexperienced with Linux sockets and as such haven't been able to effectively debug this issue. For now there may be better solutions for this elsewhere, but I may be able to investigate this again soon.

Look here maybe this helps you to fix the issue
dhalperi/linux-80211n-csitool-supplementary#175

[Gi-z]

Thank you, I will attempt this solution once I've also had time to merge your PR!