Commit c7640f8346 was meant to fix a sign compare warning
in clang because NLMSG_NEXT internally compares the length
with nlmsghdr->nlmsg_len which is a u32. The problem is the
NLMSG_NEXT can underflow an unsigned value, hence why it
expects an int type to be passed in.
To work around this we can instead pass a larger sized
int64_t which the compiler allows since it can upgrade the
unsigned nlmsghdr->nlmsg_len. There is no underflow risk
with an int64_t either because the buffer used is much
smaller than what can fit in an int64_t.
Fixes: c7640f8346 ("monitor: fix integer comparison error (clang)")
To help understand scanning results a bit better and cut down on scan
output add an option to not print the contents of the IEs. Only the
SSID IE will be printed.
