Build and send packet from Riot node

Hello everyone, i explain my project. I have 3 OpenMote. A node has installed gnrc_border_router application, another gnrc_networking application and another has installed sniffer application, precisely this sniffer:

The sniffer sniff the packet that border router and networking send and receive each other. I have also a raspberry which has installed a Bro Intrusion Detection System. My idea is that when a sniffer sniff a packet build another packet with some field, e.g ipv6 source address, ipv6 dest addr, mac addr source and mac addr dest then send this packet to raspberry so that Bro process this message or send a packet to border router. I state that sniffer works with a OpenBattery and then i have not a control from shell. How do i this things (build and send)?

Thank you, Alberto.