Merge branch 'mptcp-more-selftest-coverage-and-code-cleanup-for-net-next'

Mat Martineau says:

====================
mptcp: More selftest coverage and code cleanup for net-next

Patches 1-5 and 7-8 add selftest coverage (and an associated subflow
counter in the kernel) to validate the recently-updated handling of
subflows with ID 0.

Patch 6 renames a label in the userspace path manager for clarity.

Patches 9-11 and 13-15 factor out common selftest code by moving certain
functions to mptcp_lib.sh

Patch 12 makes sure the random data file generated for selftest
payloads has the intended size.

v3: https://lore.kernel.org/r/20231115-send-net-next-2023107-v3-0-1ef58145a882@kernel.org
v2: https://lore.kernel.org/r/20231114-send-net-next-2023107-v2-0-b650a477362c@kernel.org
v1: https://lore.kernel.org/r/20231027-send-net-next-2023107-v1-0-03eff9452957@kernel.org
====================

Link: https://lore.kernel.org/r/20231128-send-net-next-2023107-v4-0-8d6b94150f6b@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/uapi/linux/mptcp.h

@@ -57,6 +57,7 @@ struct mptcp_info {
 	__u64	mptcpi_bytes_sent;
 	__u64	mptcpi_bytes_received;
 	__u64	mptcpi_bytes_acked;
+	__u8	mptcpi_subflows_total;
 };
 
 /* MPTCP Reset reason codes, rfc8684 */

net/mptcp/pm_userspace.c

@@ -276,12 +276,12 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 
 	if (!mptcp_pm_is_userspace(msk)) {
 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
-		goto remove_err;
+		goto out;
 	}
 
 	if (id_val == 0) {
 		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
-		goto remove_err;
+		goto out;
 	}
 
 	lock_sock(sk);
@@ -296,7 +296,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	if (!match) {
 		GENL_SET_ERR_MSG(info, "address with specified id not found");
 		release_sock(sk);
-		goto remove_err;
+		goto out;
 	}
 
 	list_move(&match->list, &free_list);
@@ -310,7 +310,7 @@ int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	err = 0;
- remove_err:
+out:
 	sock_put(sk);
 	return err;
 }

net/mptcp/protocol.h

@@ -1072,6 +1072,15 @@ static inline void __mptcp_do_fallback(struct mptcp_sock *msk)
 	set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
 }
 
+static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk)
+{
+	struct sock *ssk = READ_ONCE(msk->first);
+
+	return ssk && ((1 << inet_sk_state_load(ssk)) &
+		       (TCPF_ESTABLISHED | TCPF_SYN_SENT |
+			TCPF_SYN_RECV | TCPF_LISTEN));
+}
+
 static inline void mptcp_do_fallback(struct sock *ssk)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);

net/mptcp/sockopt.c

@@ -938,6 +938,8 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
 	info->mptcpi_bytes_sent = msk->bytes_sent;
 	info->mptcpi_bytes_received = msk->bytes_received;
 	info->mptcpi_bytes_retrans = msk->bytes_retrans;
+	info->mptcpi_subflows_total = info->mptcpi_subflows +
+		__mptcp_has_initial_subflow(msk);
 	unlock_sock_fast(sk, slow);
 }
 EXPORT_SYMBOL_GPL(mptcp_diag_fill_info);

tools/testing/selftests/net/mptcp/diag.sh

@@ -182,23 +182,6 @@ chk_msk_inuse()
 	__chk_nr get_msk_inuse $expected "$msg" 0
 }
 
-# $1: ns, $2: port
-wait_local_port_listen()
-{
-	local listener_ns="${1}"
-	local port="${2}"
-
-	local port_hex i
-
-	port_hex="$(printf "%04X" "${port}")"
-	for i in $(seq 10); do
-		ip netns exec "${listener_ns}" cat /proc/net/tcp | \
-			awk "BEGIN {rc=1} {if (\$2 ~ /:${port_hex}\$/ && \$4 ~ /0A/) {rc=0; exit}} END {exit rc}" &&
-			break
-		sleep 0.1
-	done
-}
-
 wait_connected()
 {
 	local listener_ns="${1}"
@@ -222,7 +205,7 @@ echo "a" | \
 		ip netns exec $ns \
 			./mptcp_connect -p 10000 -l -t ${timeout_poll} -w 20 \
 				0.0.0.0 >/dev/null &
-wait_local_port_listen $ns 10000
+mptcp_lib_wait_local_port_listen $ns 10000
 chk_msk_nr 0 "no msk on netns creation"
 chk_msk_listen 10000
 
@@ -245,7 +228,7 @@ echo "a" | \
 		ip netns exec $ns \
 			./mptcp_connect -p 10001 -l -s TCP -t ${timeout_poll} -w 20 \
 				0.0.0.0 >/dev/null &
-wait_local_port_listen $ns 10001
+mptcp_lib_wait_local_port_listen $ns 10001
 echo "b" | \
 	timeout ${timeout_test} \
 		ip netns exec $ns \
@@ -266,7 +249,7 @@ for I in `seq 1 $NR_CLIENTS`; do
 				./mptcp_connect -p $((I+10001)) -l -w 20 \
 					-t ${timeout_poll} 0.0.0.0 >/dev/null &
 done
-wait_local_port_listen $ns $((NR_CLIENTS + 10001))
+mptcp_lib_wait_local_port_listen $ns $((NR_CLIENTS + 10001))
 
 for I in `seq 1 $NR_CLIENTS`; do
 	echo "b" | \

tools/testing/selftests/net/mptcp/mptcp_connect.sh

@@ -254,31 +254,6 @@ else
 	set_ethtool_flags "$ns4" ns4eth3 "$ethtool_args"
 fi
 
-print_file_err()
-{
-	ls -l "$1" 1>&2
-	echo "Trailing bytes are: "
-	tail -c 27 "$1"
-}
-
-check_transfer()
-{
-	local in=$1
-	local out=$2
-	local what=$3
-
-	cmp "$in" "$out" > /dev/null 2>&1
-	if [ $? -ne 0 ] ;then
-		echo "[ FAIL ] $what does not match (in, out):"
-		print_file_err "$in"
-		print_file_err "$out"
-
-		return 1
-	fi
-
-	return 0
-}
-
 check_mptcp_disabled()
 {
 	local disabled_ns="ns_disabled-$rndh"
@@ -310,12 +285,6 @@ check_mptcp_disabled()
 	return 0
 }
 
-# $1: IP address
-is_v6()
-{
-	[ -z "${1##*:*}" ]
-}
-
 do_ping()
 {
 	local listener_ns="$1"
@@ -324,7 +293,7 @@ do_ping()
 	local ping_args="-q -c 1"
 	local rc=0
 
-	if is_v6 "${connect_addr}"; then
+	if mptcp_lib_is_v6 "${connect_addr}"; then
 		$ipv6 || return 0
 		ping_args="${ping_args} -6"
 	fi
@@ -341,38 +310,6 @@ do_ping()
 	return 0
 }
 
-# $1: ns, $2: MIB counter
-get_mib_counter()
-{
-	local listener_ns="${1}"
-	local mib="${2}"
-
-	# strip the header
-	ip netns exec "${listener_ns}" \
-		nstat -z -a "${mib}" | \
-			tail -n+2 | \
-			while read a count c rest; do
-				echo $count
-			done
-}
-
-# $1: ns, $2: port
-wait_local_port_listen()
-{
-	local listener_ns="${1}"
-	local port="${2}"
-
-	local port_hex i
-
-	port_hex="$(printf "%04X" "${port}")"
-	for i in $(seq 10); do
-		ip netns exec "${listener_ns}" cat /proc/net/tcp* | \
-			awk "BEGIN {rc=1} {if (\$2 ~ /:${port_hex}\$/ && \$4 ~ /0A/) {rc=0; exit}} END {exit rc}" &&
-			break
-		sleep 0.1
-	done
-}
-
 do_transfer()
 {
 	local listener_ns="$1"
@@ -441,12 +378,12 @@ do_transfer()
 			nstat -n
 	fi
 
-	local stat_synrx_last_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
-	local stat_ackrx_last_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
-	local stat_cookietx_last=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesSent")
-	local stat_cookierx_last=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv")
-	local stat_csum_err_s=$(get_mib_counter "${listener_ns}" "MPTcpExtDataCsumErr")
-	local stat_csum_err_c=$(get_mib_counter "${connector_ns}" "MPTcpExtDataCsumErr")
+	local stat_synrx_last_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
+	local stat_ackrx_last_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
+	local stat_cookietx_last=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesSent")
+	local stat_cookierx_last=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesRecv")
+	local stat_csum_err_s=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtDataCsumErr")
+	local stat_csum_err_c=$(mptcp_lib_get_counter "${connector_ns}" "MPTcpExtDataCsumErr")
 
 	timeout ${timeout_test} \
 		ip netns exec ${listener_ns} \
@@ -454,7 +391,7 @@ do_transfer()
 				$extra_args $local_addr < "$sin" > "$sout" &
 	local spid=$!
 
-	wait_local_port_listen "${listener_ns}" "${port}"
+	mptcp_lib_wait_local_port_listen "${listener_ns}" "${port}"
 
 	local start
 	start=$(date +%s%3N)
@@ -504,16 +441,16 @@ do_transfer()
 		return 1
 	fi
 
-	check_transfer $sin $cout "file received by client"
+	mptcp_lib_check_transfer $sin $cout "file received by client"
 	retc=$?
-	check_transfer $cin $sout "file received by server"
+	mptcp_lib_check_transfer $cin $sout "file received by server"
 	rets=$?
 
-	local stat_synrx_now_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
-	local stat_ackrx_now_l=$(get_mib_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
-	local stat_cookietx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesSent")
-	local stat_cookierx_now=$(get_mib_counter "${listener_ns}" "TcpExtSyncookiesRecv")
-	local stat_ooo_now=$(get_mib_counter "${listener_ns}" "TcpExtTCPOFOQueue")
+	local stat_synrx_now_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableSYNRX")
+	local stat_ackrx_now_l=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtMPCapableACKRX")
+	local stat_cookietx_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesSent")
+	local stat_cookierx_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtSyncookiesRecv")
+	local stat_ooo_now=$(mptcp_lib_get_counter "${listener_ns}" "TcpExtTCPOFOQueue")
 
 	expect_synrx=$((stat_synrx_last_l))
 	expect_ackrx=$((stat_ackrx_last_l))
@@ -542,8 +479,8 @@ do_transfer()
 	fi
 
 	if $checksum; then
-		local csum_err_s=$(get_mib_counter "${listener_ns}" "MPTcpExtDataCsumErr")
-		local csum_err_c=$(get_mib_counter "${connector_ns}" "MPTcpExtDataCsumErr")
+		local csum_err_s=$(mptcp_lib_get_counter "${listener_ns}" "MPTcpExtDataCsumErr")
+		local csum_err_c=$(mptcp_lib_get_counter "${connector_ns}" "MPTcpExtDataCsumErr")
 
 		local csum_err_s_nr=$((csum_err_s - stat_csum_err_s))
 		if [ $csum_err_s_nr -gt 0 ]; then
@@ -613,9 +550,8 @@ make_file()
 	ksize=$((SIZE / 1024))
 	rem=$((SIZE - (ksize * 1024)))
 
-	dd if=/dev/urandom of="$name" bs=1024 count=$ksize 2> /dev/null
-	dd if=/dev/urandom conv=notrunc of="$name" bs=1 count=$rem 2> /dev/null
-	echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "$name"
+	mptcp_lib_make_file $name 1024 $ksize
+	dd if=/dev/urandom conv=notrunc of="$name" oflag=append bs=1 count=$rem 2> /dev/null
 
 	echo "Created $name (size $(du -b "$name")) containing data sent by $who"
 }
@@ -635,12 +571,12 @@ run_tests_lo()
 	fi
 
 	# skip if we don't want v6
-	if ! $ipv6 && is_v6 "${connect_addr}"; then
+	if ! $ipv6 && mptcp_lib_is_v6 "${connect_addr}"; then
 		return 0
 	fi
 
 	local local_addr
-	if is_v6 "${connect_addr}"; then
+	if mptcp_lib_is_v6 "${connect_addr}"; then
 		local_addr="::"
 	else
 		local_addr="0.0.0.0"
@@ -708,7 +644,7 @@ run_test_transparent()
 	TEST_GROUP="${msg}"
 
 	# skip if we don't want v6
-	if ! $ipv6 && is_v6 "${connect_addr}"; then
+	if ! $ipv6 && mptcp_lib_is_v6 "${connect_addr}"; then
 		return 0
 	fi
 
@@ -741,7 +677,7 @@ EOF
 	fi
 
 	local local_addr
-	if is_v6 "${connect_addr}"; then
+	if mptcp_lib_is_v6 "${connect_addr}"; then
 		local_addr="::"
 		r6flag="-6"
 	else

tools/testing/selftests/net/mptcp/mptcp_lib.sh

@@ -207,3 +207,94 @@ mptcp_lib_result_print_all_tap() {
 		printf "%s\n" "${subtest}"
 	done
 }
+
+# get the value of keyword $1 in the line marked by keyword $2
+mptcp_lib_get_info_value() {
+	grep "${2}" | sed -n 's/.*\('"${1}"':\)\([0-9a-f:.]*\).*$/\2/p;q'
+}
+
+# $1: info name ; $2: evts_ns ; $3: event type
+mptcp_lib_evts_get_info() {
+	mptcp_lib_get_info_value "${1}" "^type:${3:-1}," < "${2}"
+}
+
+# $1: PID
+mptcp_lib_kill_wait() {
+	[ "${1}" -eq 0 ] && return 0
+
+	kill -SIGUSR1 "${1}" > /dev/null 2>&1
+	kill "${1}" > /dev/null 2>&1
+	wait "${1}" 2>/dev/null
+}
+
+# $1: IP address
+mptcp_lib_is_v6() {
+	[ -z "${1##*:*}" ]
+}
+
+# $1: ns, $2: MIB counter
+mptcp_lib_get_counter() {
+	local ns="${1}"
+	local counter="${2}"
+	local count
+
+	count=$(ip netns exec "${ns}" nstat -asz "${counter}" |
+		awk 'NR==1 {next} {print $2}')
+	if [ -z "${count}" ]; then
+		mptcp_lib_fail_if_expected_feature "${counter} counter"
+		return 1
+	fi
+
+	echo "${count}"
+}
+
+mptcp_lib_make_file() {
+	local name="${1}"
+	local bs="${2}"
+	local size="${3}"
+
+	dd if=/dev/urandom of="${name}" bs="${bs}" count="${size}" 2> /dev/null
+	echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "${name}"
+}
+
+# $1: file
+mptcp_lib_print_file_err() {
+	ls -l "${1}" 1>&2
+	echo "Trailing bytes are: "
+	tail -c 27 "${1}"
+}
+
+# $1: input file ; $2: output file ; $3: what kind of file
+mptcp_lib_check_transfer() {
+	local in="${1}"
+	local out="${2}"
+	local what="${3}"
+
+	if ! cmp "$in" "$out" > /dev/null 2>&1; then
+		echo "[ FAIL ] $what does not match (in, out):"
+		mptcp_lib_print_file_err "$in"
+		mptcp_lib_print_file_err "$out"
+
+		return 1
+	fi
+
+	return 0
+}
+
+# $1: ns, $2: port
+mptcp_lib_wait_local_port_listen() {
+	local listener_ns="${1}"
+	local port="${2}"
+
+	local port_hex
+	port_hex="$(printf "%04X" "${port}")"
+
+	local _
+	for _ in $(seq 10); do
+		ip netns exec "${listener_ns}" cat /proc/net/tcp* | \
+			awk "BEGIN {rc=1} {if (\$2 ~ /:${port_hex}\$/ && \$4 ~ /0A/) \
+			     {rc=0; exit}} END {exit rc}" &&
+			break
+		sleep 0.1
+	done
+}

tools/testing/selftests/net/mptcp/mptcp_sockopt.sh

@@ -135,38 +135,6 @@ check_mark()
 	return 0
 }
 
-print_file_err()
-{
-	ls -l "$1" 1>&2
-	echo "Trailing bytes are: "
-	tail -c 27 "$1"
-}
-
-check_transfer()
-{
-	local in=$1
-	local out=$2
-	local what=$3
-
-	cmp "$in" "$out" > /dev/null 2>&1
-	if [ $? -ne 0 ] ;then
-		echo "[ FAIL ] $what does not match (in, out):"
-		print_file_err "$in"
-		print_file_err "$out"
-		ret=1
-
-		return 1
-	fi
-
-	return 0
-}
-
-# $1: IP address
-is_v6()
-{
-	[ -z "${1##*:*}" ]
-}
-
 do_transfer()
 {
 	local listener_ns="$1"
@@ -183,7 +151,7 @@ do_transfer()
 	local mptcp_connect="./mptcp_connect -r 20"
 
 	local local_addr ip
-	if is_v6 "${connect_addr}"; then
+	if mptcp_lib_is_v6 "${connect_addr}"; then
 		local_addr="::"
 		ip=ipv6
 	else
@@ -238,7 +206,7 @@ do_transfer()
 		check_mark $connector_ns 4 || retc=1
 	fi
 
-	check_transfer $cin $sout "file received by server"
+	mptcp_lib_check_transfer $cin $sout "file received by server"
 	rets=$?
 
 	mptcp_lib_result_code "${retc}" "mark ${ip}"
@@ -257,8 +225,7 @@ make_file()
 	local who=$2
 	local size=$3
 
-	dd if=/dev/urandom of="$name" bs=1024 count=$size 2> /dev/null
-	echo -e "\nMPTCP_TEST_FILE_END_MARKER" >> "$name"
+	mptcp_lib_make_file $name 1024 $size
 
 	echo "Created $name (size $size KB) containing data sent by $who"
 }

tools/testing/selftests/net/mptcp/simult_flows.sh

@@ -123,23 +123,6 @@ setup()
 	grep -q ' kmemleak_init$\| lockdep_init$\| kasan_init$\| prove_locking$' /proc/kallsyms && slack=$((slack+550))
 }
 
-# $1: ns, $2: port
-wait_local_port_listen()
-{
-	local listener_ns="${1}"
-	local port="${2}"
-
-	local port_hex i
-
-	port_hex="$(printf "%04X" "${port}")"
-	for i in $(seq 10); do
-		ip netns exec "${listener_ns}" cat /proc/net/tcp* | \
-			awk "BEGIN {rc=1} {if (\$2 ~ /:${port_hex}\$/ && \$4 ~ /0A/) {rc=0; exit}} END {exit rc}" &&
-			break
-		sleep 0.1
-	done
-}
-
 do_transfer()
 {
 	local cin=$1
@@ -179,7 +162,7 @@ do_transfer()
 				0.0.0.0 < "$sin" > "$sout" &
 	local spid=$!
 
-	wait_local_port_listen "${ns3}" "${port}"
+	mptcp_lib_wait_local_port_listen "${ns3}" "${port}"
 
 	timeout ${timeout_test} \
 		ip netns exec ${ns1} \