The group ID used by xt_pknock is configurable, but pknlusr hard-codes
it. Modify pknlusr to accept an optional ID from the command line.
Group IDs range from 1 to 32 and each ID appears in the group bitmask
at position `group_id - 1`.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
A return-value of zero is not an error, so there is no point calling
perror, but since we have not requested and do not expect a zero-length
datagram, we treat it as EOF and exit.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Use struct initialization and drop memset. We do not need to set the port
ID, since the kernel will do it for us.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
We only need to specify the address at our end, and given that we are
receiving messages, not sending them, calling it `src_addr` is
misleading.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
pknlusr.c: In function "main":
pknlusr.c:81:25: warning: cast to pointer from integer of different size
pknlusr.c:81:7: warning: cast to pointer from integer of different size
