conf: Allow address remapped to host to be configured

Because the host and guest share the same IP address with passt/pasta, it's
not possible for the guest to directly address the host.  Therefore we
allow packets from the guest going to a special "NAT to host" address to be
redirected to the host, appearing there as though they have both source and
destination address of loopback.

Currently that special address is always the address of the default
gateway (or none).  That can be a problem if we want that gateway to be
addressable by the guest.  Therefore, allow the special "NAT to host"
address to be overridden on the command line with a new --map-host-loopback
option.

In order to exercise and test it, update the passt_in_ns and perf
tests to use this option and give different mapping addresses for the
two layers of the environment.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 15 insertions, 16 deletions

diff --git a/test/perf/passt_udp b/test/perf/passt_udp
index f25c903..4c66c41 100644
--- a/test/perf/passt_udp
+++ b/test/perf/passt_udp
@@ -15,6 +15,9 @@ gtools	/sbin/sysctl ip jq nproc sleep iperf3 udp_rr # From neper
 nstools	ip jq sleep iperf3 udp_rr
 htools	bc head sed
 
+set	MAP_NS4 192.0.2.2
+set	MAP_NS6 2001:db8:9a55::2
+
 test	passt: throughput and latency
 
 guest	/sbin/sysctl -w net.core.rmem_max=16777216
@@ -22,10 +25,6 @@ guest	/sbin/sysctl -w net.core.wmem_max=16777216
 guest	/sbin/sysctl -w net.core.rmem_default=16777216
 guest	/sbin/sysctl -w net.core.wmem_default=16777216
 
-gout	GW ip -j -4 route show|jq -rM '.[] | select(.dst == "default").gateway'
-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'
-
 hout	FREQ_PROCFS (echo "scale=1"; sed -n 's/cpu MHz.*: \([0-9]*\)\..*$/(\1+10^2\/2)\/10^3/p' /proc/cpuinfo) | bc -l | head -n1
 hout	FREQ_CPUFREQ (echo "scale=1"; printf '( %i + 10^5 / 2 ) / 10^6\n' $(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq) ) | bc -l
 hout	FREQ [ -n "__FREQ_CPUFREQ__" ] && echo __FREQ_CPUFREQ__ || echo __FREQ_PROCFS__
@@ -46,13 +45,13 @@ iperf3s	ns 10002
 
 bw	-
 bw	-
-iperf3	BW guest __GW6__%__IFNAME__ 10002 __TIME__ __OPTS__ -b 3G -l 1232
+iperf3	BW guest __MAP_NS6__ 10002 __TIME__ __OPTS__ -b 3G -l 1232
 bw	__BW__ 0.8 1.2
-iperf3	BW guest __GW6__%__IFNAME__ 10002 __TIME__ __OPTS__ -b 4G -l 1452
+iperf3	BW guest __MAP_NS6__ 10002 __TIME__ __OPTS__ -b 4G -l 1452
 bw	__BW__ 1.0 1.5
-iperf3	BW guest __GW6__%__IFNAME__ 10002 __TIME__ __OPTS__ -b 8G -l 8952
+iperf3	BW guest __MAP_NS6__ 10002 __TIME__ __OPTS__ -b 8G -l 8952
 bw	__BW__ 4.0 5.0
-iperf3	BW guest __GW6__%__IFNAME__ 10002 __TIME__ __OPTS__ -b 15G -l 64372
+iperf3	BW guest __MAP_NS6__ 10002 __TIME__ __OPTS__ -b 15G -l 64372
 bw	__BW__ 4.0 5.0
 
 iperf3k	ns
@@ -64,7 +63,7 @@ lat	-
 lat	-
 lat	-
 nsb	udp_rr --nolog -6
-gout	LAT udp_rr --nolog -6 -c -H __GW6__%__IFNAME__ | sed -n 's/^throughput=\(.*\)/\1/p'
+gout	LAT udp_rr --nolog -6 -c -H __MAP_NS6__ | sed -n 's/^throughput=\(.*\)/\1/p'
 lat	__LAT__ 200 150
 
 
@@ -72,17 +71,17 @@ tr	UDP throughput over IPv4: guest to host
 iperf3s	ns 10002
 # (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
 
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 1G -l 228
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 1G -l 228
 bw	__BW__ 0.0 0.0
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 2G -l 548
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 2G -l 548
 bw	__BW__ 0.4 0.6
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 3G -l 1252
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 3G -l 1252
 bw	__BW__ 0.8 1.2
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 4G -l 1472
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 4G -l 1472
 bw	__BW__ 1.0 1.5
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 8G -l 8972
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 8G -l 8972
 bw	__BW__ 4.0 5.0
-iperf3	BW guest __GW__ 10002 __TIME__ __OPTS__ -b 15G -l 65492
+iperf3	BW guest __MAP_NS4__ 10002 __TIME__ __OPTS__ -b 15G -l 65492
 bw	__BW__ 4.0 5.0
 
 iperf3k	ns
@@ -94,7 +93,7 @@ lat	-
 lat	-
 lat	-
 nsb	udp_rr --nolog -4
-gout	LAT udp_rr --nolog -4 -c -H __GW__ | sed -n 's/^throughput=\(.*\)/\1/p'
+gout	LAT udp_rr --nolog -4 -c -H __MAP_NS4__ | sed -n 's/^throughput=\(.*\)/\1/p'
 lat	__LAT__ 200 150