ipc: harden message receive
ipc: harden message receive

Currently, IPC does not check received messages for invalid data
and passes them to user code unchanged. This may result in buffer
overruns on reading message data. Fix this by checking the message
length and fd number on receive, and discard any messages that
are not valid.

Fixes: bacaa2754017 ("eal: add channel for multi-process communication")
Cc: stable@dpdk.org

Signed-off-by: Anatoly Burakov <814e00d8f6e4e81b7ccc7e3e5a0bfec0078f0203@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk