But is it possible and how, to log the network packages from the auditors IP, but only the text (the queries), not the complete packages?
Sim, é possível:
tcpdump -s0 -i eth0 src host auditors.ip and dst port 3306 -w mysql.pcap
então você pode filtrar apenas as consultas do MySQL rodando:
while read stream; do \
tshark -qz follow,tcp,ascii,$stream -r mysql.pcap; done \
< <(tshark -R "mysql" -T fields -e tcp.stream -r mysql.pcap | sort | uniq)