[PATCH net-next v11 09/13] selftests/vsock: use ss to wait for listeners instead of /proc/net

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Replace /proc/net parsing with ss(8) for detecting listening sockets in
wait_for_listener() functions and add support for TCP, VSOCK, and Unix
socket protocols.

The previous implementation parsed /proc/net/tcp using awk to detect
listening sockets, but this approach could not support vsock because
vsock does not export socket information to /proc/net/.

Instead, use ss so that we can detect listeners on tcp, vsock, and unix.

The protocol parameter is now required for all wait_for_listener family
functions (wait_for_listener, vm_wait_for_listener,
host_wait_for_listener) to explicitly specify which socket type to wait
for.

ss is added to the dependency check in check_deps().

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 tools/testing/selftests/vsock/vmtest.sh | 47 +++++++++++++++++++++------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh
index 1623e4da15e2..e32997db322d 100755
--- a/tools/testing/selftests/vsock/vmtest.sh
+++ b/tools/testing/selftests/vsock/vmtest.sh
@@ -191,7 +191,7 @@ check_args() {
 }
 
 check_deps() {
-	for dep in vng ${QEMU} busybox pkill ssh; do
+	for dep in vng ${QEMU} busybox pkill ssh ss; do
 		if [[ ! -x $(command -v "${dep}") ]]; then
 			echo -e "skip:    dependency ${dep} not found!\n"
 			exit "${KSFT_SKIP}"
@@ -346,21 +346,32 @@ wait_for_listener()
 	local port=$1
 	local interval=$2
 	local max_intervals=$3
-	local protocol=tcp
-	local pattern
+	local protocol=$4
 	local i
 
-	pattern=":$(printf "%04X" "${port}") "
-
-	# for tcp protocol additionally check the socket state
-	[ "${protocol}" = "tcp" ] && pattern="${pattern}0A"
-
 	for i in $(seq "${max_intervals}"); do
-		if awk -v pattern="${pattern}" \
-			'BEGIN {rc=1} $2" "$4 ~ pattern {rc=0} END {exit rc}' \
-			/proc/net/"${protocol}"*; then
+		case "${protocol}" in
+		tcp)
+			if ss --listening --tcp --numeric | grep -q ":${port} "; then
+				break
+			fi
+			;;
+		vsock)
+			if ss --listening --vsock --numeric | grep -q ":${port} "; then
+				break
+			fi
+			;;
+		unix)
+			# For unix sockets, port is actually the socket path
+			if ss --listening --unix | grep -q "${port}"; then
+				break
+			fi
+			;;
+		*)
+			echo "Unknown protocol: ${protocol}" >&2
 			break
-		fi
+			;;
+		esac
 		sleep "${interval}"
 	done
 }
@@ -368,23 +379,25 @@ wait_for_listener()
 vm_wait_for_listener() {
 	local ns=$1
 	local port=$2
+	local protocol=$3
 
 	vm_ssh "${ns}" <<EOF
 $(declare -f wait_for_listener)
-wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
+wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} ${protocol}
 EOF
 }
 
 host_wait_for_listener() {
 	local ns=$1
 	local port=$2
+	local protocol=$3
 
 	if [[ "${ns}" == "init_ns" ]]; then
-		wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}"
+		wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}" "${protocol}"
 	else
 		ip netns exec "${ns}" bash <<-EOF
 			$(declare -f wait_for_listener)
-			wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX}
+			wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} ${protocol}
 		EOF
 	fi
 }
@@ -431,7 +444,7 @@ vm_vsock_test() {
 			return $rc
 		fi
 
-		vm_wait_for_listener "${ns}" "${port}"
+		vm_wait_for_listener "${ns}" "${port}" "tcp"
 		rc=$?
 	fi
 	set +o pipefail
@@ -472,7 +485,7 @@ host_vsock_test() {
 			return $rc
 		fi
 
-		host_wait_for_listener "${ns}" "${port}"
+		host_wait_for_listener "${ns}" "${port}" "tcp"
 		rc=$?
 	fi
 	set +o pipefail

-- 
2.47.3