diff --git a/test/passt/udp b/test/passt/udp
index 0253a86..7d444b8 100644
--- a/test/passt/udp
+++ b/test/passt/udp
@@ -11,42 +11,41 @@
 # Copyright (c) 2021 Red Hat GmbH
 # Author: Stefano Brivio <sbrivio@redhat.com>
 
-gtools	socat tee grep cat ip jq md5sum cut
-htools	printf dd socat tee grep cat ip jq md5sum cut
+gtools	socat ip jq md5sum cut
+htools	dd socat jq md5sum cut
 
 test	UDP/IPv4: host to guest
 set	TEMP __STATEDIR__/data
-set	SC_PID __STATEDIR__/socat.pid
-guestb	(socat -u UDP4-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
+guestb	socat -u UDP4-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
 sleep	1
-host	dd if=/dev/urandom bs=1k count=5 > __TEMP__ && printf "\nEND_OF_TEST\n" >> __TEMP__
-host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10001
+host	dd if=/dev/urandom bs=1k count=5 > __TEMP__
+host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10001,shut-null
 guestw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__HOST_MD5__" ]
 
 test	UDP/IPv4: guest to host
-hostb	(socat -u UDP4-LISTEN:10003,bind=127.0.0.1 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP4-LISTEN:10003,bind=127.0.0.1,null-eof OPEN:__TEMP__,create,trunc
 gout	GW ip -j -4 route show|jq -rM '.[] | select(.dst == "default").gateway'
-guest	socat -u OPEN:test.bin UDP4:__GW__:10003
+guest	socat -u OPEN:test.bin UDP4:__GW__:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__HOST_MD5__" ]
 
 test	UDP/IPv6: host to guest
-guestb	(socat -u UDP6-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
+guestb	socat -u UDP6-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
 sleep	1
-host	socat -u OPEN:__TEMP__ UDP6:[::1]:10001
+host	socat -u OPEN:__TEMP__ UDP6:[::1]:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__HOST_MD5__" ]
 
 test	UDP/IPv6: guest to host
-hostb	(socat -u UDP6-LISTEN:10003,bind=[::1] STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP6-LISTEN:10003,bind=[::1],null-eof OPEN:__TEMP__,create,trunc
 gout	GW6 ip -j -6 route show|jq -rM '.[] | select(.dst == "default").gateway'
 gout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
-guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10003
+guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__HOST_MD5__" ]
diff --git a/test/passt_in_ns/udp b/test/passt_in_ns/udp
index 3b1e521..5f01cbf 100644
--- a/test/passt_in_ns/udp
+++ b/test/passt_in_ns/udp
@@ -11,17 +11,16 @@
 # Copyright (c) 2021 Red Hat GmbH
 # Author: Stefano Brivio <sbrivio@redhat.com>
 
-gtools	socat tee grep cat ip jq md5sum cut
-nstools	socat tee grep cat ip jq md5sum cut
-htools	printf dd socat tee grep cat ip jq md5sum cut
+gtools	socat ip jq md5sum cut
+nstools	socat ip jq md5sum cut
+htools	dd socat ip jq md5sum cut
 
 test	UDP/IPv4: host to guest
 set	TEMP __STATEDIR__/data
-set	SC_PID __STATEDIR__/socat.pid
-guestb	(socat -u UDP4-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
+guestb	socat -u UDP4-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
 sleep	1
-host	dd if=/dev/urandom bs=1k count=5 > __TEMP__ && printf "\nEND_OF_TEST\n" >> __TEMP__
-host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10001
+host	dd if=/dev/urandom bs=1k count=5 > __TEMP__
+host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10001,shut-null
 guestw
 hout	MD5 md5sum __TEMP__ | cut -d' ' -f1
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
@@ -29,114 +28,114 @@ check	[ "__GUEST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: host to ns
 set	TEMP_NS __STATEDIR__/data_ns
-nsb	(socat -u UDP4-LISTEN:10002 STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10002
+nsb	socat -u UDP4-LISTEN:10002,null-eof OPEN:__TEMP_NS__,create,trunc
+host	socat -u OPEN:__TEMP__ UDP4:127.0.0.1:10002,shut-null
 nsw
 nsout	NS_MD5 md5sum __TEMP_NS__ | cut -d' ' -f1
 check	[ "__NS_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: guest to host
-hostb	(socat -u UDP4-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP4-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
 gout	GW ip -j -4 route show|jq -rM '.[] | select(.dst == "default").gateway'
-guest	socat -u OPEN:test.bin UDP4:__GW__:10003
+guest	socat -u OPEN:test.bin UDP4:__GW__:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: guest to ns
-nsb	(socat -u UDP4-LISTEN:10002 STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-guest	socat -u OPEN:test.bin UDP4:__GW__:10002
+nsb	socat -u UDP4-LISTEN:10002,null-eof OPEN:__TEMP_NS__,create,trunc
+guest	socat -u OPEN:test.bin UDP4:__GW__:10002,shut-null
 nsw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to host (recvmmsg/sendmmsg)
 sleep	1
-hostb	(socat -u UDP4-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-ns	socat -u OPEN:__TEMP_NS__ UDP4:127.0.0.1:10003
+hostb	socat -u UDP4-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
+ns	socat -u OPEN:__TEMP_NS__ UDP4:127.0.0.1:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to host (via tap)
-hostb	(socat -u UDP4-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-ns	socat -u OPEN:__TEMP_NS__ UDP4:__GW__:10003
+hostb	socat -u UDP4-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
+ns	socat -u OPEN:__TEMP_NS__ UDP4:__GW__:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to guest (using loopback address)
-guestb	(socat -u UDP4-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
-ns	socat -u OPEN:__TEMP_NS__ UDP4:127.0.0.1:10001
+guestb	socat -u UDP4-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
+ns	socat -u OPEN:__TEMP_NS__ UDP4:127.0.0.1:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to guest (using namespace address)
-guestb	(socat -u UDP4-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
+guestb	socat -u UDP4-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
 nsout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
 nsout	ADDR ip -j -4 addr show|jq -rM '.[] | select(.ifname == "__IFNAME__").addr_info[0].local'
-ns	socat -u OPEN:__TEMP_NS__ UDP4:__ADDR__:10001
+ns	socat -u OPEN:__TEMP_NS__ UDP4:__ADDR__:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: host to guest
-guestb	(socat -u UDP6-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
-host	socat -u OPEN:__TEMP__ UDP6:[::1]:10001
+guestb	socat -u UDP6-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
+host	socat -u OPEN:__TEMP__ UDP6:[::1]:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: host to ns
-nsb	(socat -u UDP6-LISTEN:10002 STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-host	socat -u OPEN:__TEMP__ UDP6:[::1]:10002
+nsb	socat -u UDP6-LISTEN:10002,null-eof OPEN:__TEMP_NS__,create,trunc
+host	socat -u OPEN:__TEMP__ UDP6:[::1]:10002,shut-null
 nsw
 nsout	NS_MD5 md5sum __TEMP_NS__ | cut -d' ' -f1
 check	[ "__NS_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: guest to host
-hostb	(socat -u UDP6-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP6-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
 gout	GW6 ip -j -6 route show|jq -rM '.[] | select(.dst == "default").gateway'
 gout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
-guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10003
+guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: guest to ns
-nsb	(socat -u UDP6-LISTEN:10002 STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10002
+nsb	socat -u UDP6-LISTEN:10002,null-eof OPEN:__TEMP_NS__,create,trunc
+guest	socat -u OPEN:test.bin UDP6:[__GW6__%__IFNAME__]:10002,shut-null
 nsw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to host (recvmmsg/sendmmsg)
-hostb	(socat -u UDP6-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10003
+hostb	socat -u UDP6-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to host (via tap)
-hostb	(socat -u UDP6-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP6-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
 nsout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[__GW6__%__IFNAME__]:10003
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[__GW6__%__IFNAME__]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to guest (using loopback address)
-guestb	(socat -u UDP6-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10001
+guestb	socat -u UDP6-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to guest (using namespace address)
-guestb	(socat -u UDP6-LISTEN:10001 STDOUT & echo $! > sc.pid) | tee test.bin | (grep -qm1 "END_OF_TEST" && kill $(cat sc.pid))
+guestb	socat -u UDP6-LISTEN:10001,null-eof OPEN:test.bin,create,trunc
 nsout	ADDR6 ip -j -6 addr show|jq -rM '.[] | select(.ifname == "__IFNAME__").addr_info[0].local'
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[__ADDR6__]:10001
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[__ADDR6__]:10001,shut-null
 guestw
 gout	GUEST_MD5 md5sum test.bin | cut -d' ' -f1
 check	[ "__GUEST_MD5__" = "__MD5__" ]
diff --git a/test/pasta/udp b/test/pasta/udp
index 74148e3..fc6bf0a 100644
--- a/test/pasta/udp
+++ b/test/pasta/udp
@@ -11,59 +11,58 @@
 # Copyright (c) 2021 Red Hat GmbH
 # Author: Stefano Brivio <sbrivio@redhat.com>
 
-nstools	socat tee grep cat ip jq md5sum cut
-htools	printf dd socat tee grep cat ip jq md5sum cut
+nstools	socat ip jq md5sum cut
+htools	dd socat ip jq md5sum cut
 
 test	UDP/IPv4: host to ns
 set	TEMP __STATEDIR__/data
 set	TEMP_NS __STATEDIR__/data_ns
-set	SC_PID __STATEDIR__/socat.pid
-nsb	(socat -u UDP4-LISTEN:10002,bind=127.0.0.1 STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-host	dd if=/dev/urandom bs=1k count=5 > __TEMP__ && printf "\nEND_OF_TEST\n" >> __TEMP__
+nsb	socat -u UDP4-LISTEN:10002,bind=127.0.0.1,null-eof OPEN:__TEMP_NS__,create,trunc
+host	dd if=/dev/urandom bs=1k count=5 > __TEMP__
 
-host	socat OPEN:__TEMP__ UDP4:127.0.0.1:10002
+host	socat OPEN:__TEMP__ UDP4:127.0.0.1:10002,shut-null
 nsw
 hout	MD5 md5sum __TEMP__ | cut -d' ' -f1
 nsout	NS_MD5 md5sum __TEMP_NS__ | cut -d' ' -f1
 check	[ "__NS_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to host (recvmmsg/sendmmsg)
-hostb	(socat -u UDP4-LISTEN:10003,bind=127.0.0.1 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP4-LISTEN:10003,bind=127.0.0.1,null-eof OPEN:__TEMP__,create,trunc
 sleep	1
-ns	socat OPEN:__TEMP_NS__ UDP4:127.0.0.1:10003
+ns	socat OPEN:__TEMP_NS__ UDP4:127.0.0.1:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv4: ns to host (via tap)
-hostb	(socat -u UDP4-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP4-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
 nsout	GW ip -j -4 route show|jq -rM '.[] | select(.dst == "default").gateway'
-ns	socat -u OPEN:__TEMP_NS__ UDP4:__GW__:10003
+ns	socat -u OPEN:__TEMP_NS__ UDP4:__GW__:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: host to ns
-nsb	(socat -u UDP6-LISTEN:10002,bind=[::1] STDOUT & echo $! > __SC_PID__) | tee __TEMP_NS__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
-host	socat -u OPEN:__TEMP__ UDP6:[::1]:10002
+nsb	socat -u UDP6-LISTEN:10002,bind=[::1],null-eof OPEN:__TEMP_NS__,create,trunc
+host	socat -u OPEN:__TEMP__ UDP6:[::1]:10002,shut-null
 nsw
 hout	MD5 md5sum __TEMP__ | cut -d' ' -f1
 nsout	NS_MD5 md5sum __TEMP_NS__ | cut -d' ' -f1
 check	[ "__NS_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to host (recvmmsg/sendmmsg)
-hostb	(socat -u UDP6-LISTEN:10003,bind=[::1] STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP6-LISTEN:10003,bind=[::1],null-eof OPEN:__TEMP__,create,trunc
 sleep	1
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10003
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[::1]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]
 
 test	UDP/IPv6: ns to host (via tap)
-hostb	(socat -u UDP6-LISTEN:10003 STDOUT & echo $! > __SC_PID__) | tee __TEMP__ | (grep -qm1 "END_OF_TEST" && kill $(cat __SC_PID__))
+hostb	socat -u UDP6-LISTEN:10003,null-eof OPEN:__TEMP__,create,trunc
 nsout	GW6 ip -j -6 route show|jq -rM '.[] | select(.dst == "default").gateway'
 nsout	IFNAME ip -j link show | jq -rM '.[] | select(.link_type == "ether").ifname'
-ns	socat -u OPEN:__TEMP_NS__ UDP6:[__GW6__%__IFNAME__]:10003
+ns	socat -u OPEN:__TEMP_NS__ UDP6:[__GW6__%__IFNAME__]:10003,shut-null
 hostw
 hout	HOST_MD5 md5sum __TEMP__ | cut -d' ' -f1
 check	[ "__HOST_MD5__" = "__MD5__" ]