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, 14 deletions

diff --git a/test/perf/pasta_tcp b/test/perf/pasta_tcp
index a443f5a..d1ccf7d 100644
--- a/test/perf/pasta_tcp
+++ b/test/perf/pasta_tcp
@@ -14,6 +14,9 @@
 htools	head ip seq bc sleep iperf3 tcp_rr tcp_crr jq sed
 nstools	/sbin/sysctl nproc ip seq sleep iperf3 tcp_rr tcp_crr jq sed
 
+set	MAP_HOST4 192.0.2.1
+set	MAP_HOST6 2001:db8:9a55::1
+
 test	pasta: throughput and latency (local connections)
 
 ns	/sbin/sysctl -w net.ipv4.tcp_rmem="131072 524288 134217728"
@@ -122,8 +125,6 @@ te
 
 test	pasta: throughput and latency (connections via tap)
 
-nsout	GW ip -j -4 route show|jq -rM '.[] | select(.dst == "default").gateway'
-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'
 set	THREADS 2
 set	OPTS -Z -P __THREADS__ -i1 -O__OMIT__
@@ -137,16 +138,16 @@ tr	TCP throughput over IPv6: ns to host
 iperf3s	host 10003
 
 ns	ip link set dev __IFNAME__ mtu 1500
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -w 512k
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -w 512k
 bw	__BW__ 0.2 0.4
 ns	ip link set dev __IFNAME__ mtu 4000
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -w 1M
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -w 1M
 bw	__BW__ 0.3 0.5
 ns	ip link set dev __IFNAME__ mtu 16384
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -w 8M
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -w 8M
 bw	__BW__ 1.5 2.0
 ns	ip link set dev __IFNAME__ mtu 65520
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -w 8M
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -w 8M
 bw	__BW__ 2.0 2.5
 
 iperf3k	host
@@ -156,7 +157,7 @@ lat	-
 lat	-
 lat	-
 hostb	tcp_rr --nolog -P 10003 -C 10013 -6
-nsout	LAT tcp_rr --nolog -l1 -P 10003 -C 10013 -6 -c -H __GW6__%__IFNAME__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT tcp_rr --nolog -l1 -P 10003 -C 10013 -6 -c -H __MAP_HOST6__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 150 100
 
@@ -165,7 +166,7 @@ lat	-
 lat	-
 lat	-
 hostb	tcp_crr --nolog -P 10003 -C 10013 -6
-nsout	LAT tcp_crr --nolog -l1 -P 10003 -C 10013 -6 -c -H __GW6__%__IFNAME__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT tcp_crr --nolog -l1 -P 10003 -C 10013 -6 -c -H __MAP_HOST6__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 1500 500
 
@@ -174,16 +175,16 @@ tr	TCP throughput over IPv4: ns to host
 iperf3s	host 10003
 
 ns	ip link set dev __IFNAME__ mtu 1500
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -w 512k
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -w 512k
 bw	__BW__ 0.2 0.4
 ns	ip link set dev __IFNAME__ mtu 4000
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -w 1M
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -w 1M
 bw	__BW__ 0.3 0.5
 ns	ip link set dev __IFNAME__ mtu 16384
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -w 8M
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -w 8M
 bw	__BW__ 1.5 2.0
 ns	ip link set dev __IFNAME__ mtu 65520
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -w 8M
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -w 8M
 bw	__BW__ 2.0 2.5
 
 iperf3k	host
@@ -193,7 +194,7 @@ lat	-
 lat	-
 lat	-
 hostb	tcp_rr --nolog -P 10003 -C 10013 -4
-nsout	LAT tcp_rr --nolog -l1 -P 10003 -C 10013 -4 -c -H __GW__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT tcp_rr --nolog -l1 -P 10003 -C 10013 -4 -c -H __MAP_HOST4__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 150 100
 
@@ -202,7 +203,7 @@ lat	-
 lat	-
 lat	-
 hostb	tcp_crr --nolog -P 10003 -C 10013 -4
-nsout	LAT tcp_crr --nolog -l1 -P 10003 -C 10013 -4 -c -H __GW__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT tcp_crr --nolog -l1 -P 10003 -C 10013 -4 -c -H __MAP_HOST4__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 1500 500