"[errno 1] Operation Not Permitted" When Creating Socket

I am trying to use the program DigiKey have made for their Amazon Dash Button hack to monitor for when the button is pressed and then send a HTTP GET to IFTTT. I am using a Raspber

Solution 1:

Since you wish to receive and parse ARP packets (which are on a link layer, OSI layer 2, below IP level you receive with AF_INET), you'll have to use the low-level packet interface, AF_PACKET.

From man packet (for AF_PACKET sockets):

The socket_type is either SOCK_RAW for raw packets including the link-level header or SOCK_DGRAM for cooked packets with the link-level header removed. The link-level header information is available in a common format in a sockaddr_ll structure. protocol is the IEEE 802.3 protocol number in network byte order. See the <linux/if_ether.h> include file for a list of allowed protocols. When protocol is set to htons(ETH_P_ALL), then all protocols are received. All incoming packets of that protocol type will be passed to the packet socket before they are passed to the protocols implemented in the kernel.

So, for sniffing ARP packets, you must use SOCK_RAW socket type. However, to use it, from man 7 raw:

Only processes with an effective user ID of 0 or the CAP_NET_RAW capability are allowed to open raw sockets.

therefore, you'll have to run your program with sudo.

For socket protocol (third parameter) you might choose 0x0003 as you already have, which means ETH_P_ALL, receiving all packages, or probably better, ETH_P_ARP which has a value of 0x0806 (see your /usr/include/linux/if_ether.h) to receive only ARP packages.

All taken together, this looks like this:

rawSocket = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(0x0806))

whileTrue:
    packet = rawSocket.recvfrom(2048)
    # no need to filter-out ARP# less load on user program