Fix compile errors on freebsd

makefile

@@ -103,7 +103,7 @@ linux:git_version
 	${cc_local}   -o ${NAME}_$@          -I. ${SOURCES} ${PCAP} ${FLAGS} -lrt -ggdb -static -O2 ${MP}
 
 freebsd:git_version
-	${cc_local}   -o ${NAME}_$@        -I. ${SOURCES} ${PCAP} ${FLAGS} -lrt -ggdb -static -O2 ${MP}
+	${cc_local}   -o ${NAME}_$@        -I. ${SOURCES} ${PCAP} ${FLAGS} -lrt -ggdb -static -libverbs -O2 ${MP}
 
 mac:git_version
 	${cc_local}   -o ${NAME}_$@        -I. ${SOURCES} ${PCAP} ${FLAGS} -ggdb -O2 ${MP}