selftests/net: packetdrill: Support single protocol test.

Currently, we cannot write IPv4 or IPv6 specific packetdrill tests
as ksft_runner.sh runs each .pkt file for both protocols.

Let's support single protocol test by checking --ip_version in the
.pkt file.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250819231527.1427361-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/packetdrill/ksft_runner.sh

@@ -3,21 +3,22 @@
 
 source "$(dirname $(realpath $0))/../../kselftest/ktap_helpers.sh"
 
-readonly ipv4_args=('--ip_version=ipv4 '
-		    '--local_ip=192.168.0.1 '
-		    '--gateway_ip=192.168.0.1 '
-		    '--netmask_ip=255.255.0.0 '
-		    '--remote_ip=192.0.2.1 '
-		    '-D CMSG_LEVEL_IP=SOL_IP '
-		    '-D CMSG_TYPE_RECVERR=IP_RECVERR ')
-
-readonly ipv6_args=('--ip_version=ipv6 '
-		    '--mtu=1520 '
-		    '--local_ip=fd3d:0a0b:17d6::1 '
-		    '--gateway_ip=fd3d:0a0b:17d6:8888::1 '
-		    '--remote_ip=fd3d:fa7b:d17d::1 '
-		    '-D CMSG_LEVEL_IP=SOL_IPV6 '
-		    '-D CMSG_TYPE_RECVERR=IPV6_RECVERR ')
+declare -A ip_args=(
+	[ipv4]="--ip_version=ipv4
+		--local_ip=192.168.0.1
+		--gateway_ip=192.168.0.1
+		--netmask_ip=255.255.0.0
+		--remote_ip=192.0.2.1
+		-D CMSG_LEVEL_IP=SOL_IP
+		-D CMSG_TYPE_RECVERR=IP_RECVERR"
+	[ipv6]="--ip_version=ipv6
+		--mtu=1520
+		--local_ip=fd3d:0a0b:17d6::1
+		--gateway_ip=fd3d:0a0b:17d6:8888::1
+		--remote_ip=fd3d:fa7b:d17d::1
+		-D CMSG_LEVEL_IP=SOL_IPV6
+		-D CMSG_TYPE_RECVERR=IPV6_RECVERR"
+)
 
 if [ $# -ne 1 ]; then
 	ktap_exit_fail_msg "usage: $0 <script>"
@@ -38,12 +39,20 @@ if [[ -n "${KSFT_MACHINE_SLOW}" ]]; then
 	failfunc=ktap_test_xfail
 fi
 
+ip_versions=$(grep -E '^--ip_version=' $script | cut -d '=' -f 2)
+if [[ -z $ip_versions ]]; then
+	ip_versions="ipv4 ipv6"
+elif [[ ! "$ip_versions" =~ ^ipv[46]$ ]]; then
+	ktap_exit_fail_msg "Too many or unsupported --ip_version: $ip_versions"
+	exit "$KSFT_FAIL"
+fi
+
 ktap_print_header
 ktap_set_plan 2
 
-unshare -n packetdrill ${ipv4_args[@]} ${optargs[@]} $script > /dev/null \
-	&& ktap_test_pass "ipv4" || $failfunc "ipv4"
-unshare -n packetdrill ${ipv6_args[@]} ${optargs[@]} $script > /dev/null \
-	&& ktap_test_pass "ipv6" || $failfunc "ipv6"
+for ip_version in $ip_versions; do
+	unshare -n packetdrill ${ip_args[$ip_version]} ${optargs[@]} $script > /dev/null \
+	    && ktap_test_pass $ip_version || $failfunc $ip_version
+done
 
 ktap_finished