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, 13 insertions, 12 deletions

diff --git a/test/perf/pasta_udp b/test/perf/pasta_udp
index 9fed62e..544bf17 100644
--- a/test/perf/pasta_udp
+++ b/test/perf/pasta_udp
@@ -14,6 +14,9 @@
 htools	bc head ip sleep iperf3 udp_rr jq sed
 nstools	ip sleep iperf3 udp_rr jq sed
 
+set	MAP_HOST4 192.0.2.1
+set	MAP_HOST6 2001:db8:9a55::1
+
 test	pasta: throughput and latency (local traffic)
 
 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
@@ -133,8 +136,6 @@ te
 
 test	pasta: throughput and latency (traffic 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'
 
 info	Throughput in Gbps, latency in µs, one thread at __FREQ__ GHz
@@ -146,13 +147,13 @@ tr	UDP throughput over IPv6: ns to host
 iperf3s	host 10003
 # (datagram size) = (packet size) - 48: 40 bytes of IPv6 header, 8 of UDP header
 
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -b 8G -l 1472
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -b 8G -l 1472
 bw	__BW__ 0.3 0.5
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -b 12G -l 3972
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -b 12G -l 3972
 bw	__BW__ 0.5 0.8
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -b 20G -l 16356
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -b 20G -l 16356
 bw	__BW__ 3.0 4.0
-iperf3	BW ns __GW6__%__IFNAME__ 10003 __TIME__ __OPTS__ -b 30G -l 65472
+iperf3	BW ns __MAP_HOST6__ 10003 __TIME__ __OPTS__ -b 30G -l 65472
 bw	__BW__ 6.0 7.0
 
 iperf3k	host
@@ -162,7 +163,7 @@ lat	-
 lat	-
 lat	-
 hostb	udp_rr --nolog -P 10003 -C 10013 -6
-nsout	LAT udp_rr --nolog -P 10003 -C 10013 -6 -c -H __GW6__%__IFNAME__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT udp_rr --nolog -P 10003 -C 10013 -6 -c -H __MAP_HOST6__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 200 150
 
@@ -171,13 +172,13 @@ tr	UDP throughput over IPv4: ns to host
 iperf3s	host 10003
 # (datagram size) = (packet size) - 28: 20 bytes of IPv4 header, 8 of UDP header
 
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -b 8G -l 1472
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -b 8G -l 1472
 bw	__BW__ 0.3 0.5
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -b 12G -l 3972
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -b 12G -l 3972
 bw	__BW__ 0.5 0.8
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -b 20G -l 16356
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -b 20G -l 16356
 bw	__BW__ 3.0 4.0
-iperf3	BW ns __GW__ 10003 __TIME__ __OPTS__ -b 30G -l 65492
+iperf3	BW ns __MAP_HOST4__ 10003 __TIME__ __OPTS__ -b 30G -l 65492
 bw	__BW__ 6.0 7.0
 
 iperf3k	host
@@ -187,7 +188,7 @@ lat	-
 lat	-
 lat	-
 hostb	udp_rr --nolog -P 10003 -C 10013 -4
-nsout	LAT udp_rr --nolog -P 10003 -C 10013 -4 -c -H __GW__ | sed -n 's/^throughput=\(.*\)/\1/p'
+nsout	LAT udp_rr --nolog -P 10003 -C 10013 -4 -c -H __MAP_HOST4__ | sed -n 's/^throughput=\(.*\)/\1/p'
 hostw
 lat	__LAT__ 200 150