Merge branch 'mptcp-refactoring-for-one-selftest-and-csum-validation'

Mat Martineau says:

====================
mptcp: Refactoring for one selftest and csum validation

Patch 1 changes the MPTCP join self tests to depend more on events
rather than delays, so the script runs faster and has more consistent
results.

Patches 2 and 3 get rid of some duplicate code in MPTCP's checksum
validation by modifying and leveraging an existing helper function.
====================

Link: https://lore.kernel.org/r/20220107192524.445137-1-mathew.j.martineau@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 79 insertions, 65 deletions

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 38e34a1fb2dd0a..8ed2d9f4a84d2a 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -1233,7 +1233,7 @@ static void mptcp_set_rwin(const struct tcp_sock *tp)
 		WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
 }
 
-static u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __sum16 sum)
+u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum)
 {
 	struct csum_pseudo_header header;
 	__wsum csum;
@@ -1248,14 +1248,14 @@ static u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __sum1
 	header.data_len = htons(data_len);
 	header.csum = 0;
 
-	csum = csum_partial(&header, sizeof(header), ~csum_unfold(sum));
+	csum = csum_partial(&header, sizeof(header), sum);
 	return (__force u16)csum_fold(csum);
 }
 
 static u16 mptcp_make_csum(const struct mptcp_ext *mpext)
 {
 	return __mptcp_make_csum(mpext->data_seq, mpext->subflow_seq, mpext->data_len,
-				 mpext->csum);
+				 ~csum_unfold(mpext->csum));
 }
 
 void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
@@ -1376,7 +1376,7 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
 					   __mptcp_make_csum(opts->data_seq,
 							     opts->subflow_seq,
 							     opts->data_len,
-							     opts->csum), ptr);
+							     ~csum_unfold(opts->csum)), ptr);
 		} else {
 			put_unaligned_be32(opts->data_len << 16 |
 					   TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a77f512d5ad728..0e6b42c76ea072 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -725,6 +725,7 @@ void mptcp_token_destroy(struct mptcp_sock *msk);
 void mptcp_crypto_key_sha(u64 key, u32 *token, u64 *idsn);
 
 void mptcp_crypto_hmac_sha(u64 key1, u64 key2, u8 *msg, int len, void *hmac);
+u16 __mptcp_make_csum(u64 data_seq, u32 subflow_seq, u16 data_len, __wsum sum);
 
 void __init mptcp_pm_init(void);
 void mptcp_pm_data_init(struct mptcp_sock *msk);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 5bedc7e88977a0..bea47a1180dc2c 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -845,9 +845,8 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 					      bool csum_reqd)
 {
 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
-	struct csum_pseudo_header header;
 	u32 offset, seq, delta;
-	__wsum csum;
+	u16 csum;
 	int len;
 
 	if (!csum_reqd)
@@ -908,13 +907,11 @@ static enum mapping_status validate_data_csum(struct sock *ssk, struct sk_buff *
 	 * while the pseudo header requires the original DSS data len,
 	 * including that
 	 */
-	header.data_seq = cpu_to_be64(subflow->map_seq);
-	header.subflow_seq = htonl(subflow->map_subflow_seq);
-	header.data_len = htons(subflow->map_data_len + subflow->map_data_fin);
-	header.csum = 0;
-
-	csum = csum_partial(&header, sizeof(header), subflow->map_data_csum);
-	if (unlikely(csum_fold(csum))) {
+	csum = __mptcp_make_csum(subflow->map_seq,
+				 subflow->map_subflow_seq,
+				 subflow->map_data_len + subflow->map_data_fin,
+				 subflow->map_data_csum);
+	if (unlikely(csum)) {
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DATACSUMERR);
 		subflow->send_mp_fail = 1;
 		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPFAILTX);
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 3165bd1a43ccd9..27d0eb9afdcaff 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -238,6 +238,45 @@ is_v6()
 	[ -z "${1##*:*}" ]
 }
 
+# $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 ~ /:${port_hex}\$/ && \$4 ~ /0A/) {rc=0; exit}} END {exit rc}" &&
+			break
+		sleep 0.1
+	done
+}
+
+rm_addr_count()
+{
+	ns=${1}
+
+	ip netns exec ${ns} nstat -as | grep MPTcpExtRmAddr | awk '{print $2}'
+}
+
+# $1: ns, $2: old rm_addr counter in $ns
+wait_rm_addr()
+{
+	local ns="${1}"
+	local old_cnt="${2}"
+	local cnt
+	local i
+
+	for i in $(seq 10); do
+		cnt=$(rm_addr_count ${ns})
+		[ "$cnt" = "${old_cnt}" ] || break
+		sleep 0.1
+	done
+}
+
 do_transfer()
 {
 	listener_ns="$1"
@@ -307,7 +346,7 @@ do_transfer()
 	fi
 	spid=$!
 
-	sleep 1
+	wait_local_port_listen "${listener_ns}" "${port}"
 
 	if [ "$test_link_fail" -eq 0 ];then
 		timeout ${timeout_test} \
@@ -324,10 +363,13 @@ do_transfer()
 	fi
 	cpid=$!
 
+	# let the mptcp subflow be established in background before
+	# do endpoint manipulation
+	[ $addr_nr_ns1 = "0" -a $addr_nr_ns2 = "0" ] || sleep 1
+
 	if [ $addr_nr_ns1 -gt 0 ]; then
 		let add_nr_ns1=addr_nr_ns1
 		counter=2
-		sleep 1
 		while [ $add_nr_ns1 -gt 0 ]; do
 			local addr
 			if is_v6 "${connect_addr}"; then
@@ -339,7 +381,6 @@ do_transfer()
 			let counter+=1
 			let add_nr_ns1-=1
 		done
-		sleep 1
 	elif [ $addr_nr_ns1 -lt 0 ]; then
 		let rm_nr_ns1=-addr_nr_ns1
 		if [ $rm_nr_ns1 -lt 8 ]; then
@@ -347,22 +388,19 @@ do_transfer()
 			pos=1
 			dump=(`ip netns exec ${listener_ns} ./pm_nl_ctl dump`)
 			if [ ${#dump[@]} -gt 0 ]; then
-				sleep 1
-
 				while [ $counter -le $rm_nr_ns1 ]
 				do
 					id=${dump[$pos]}
+					rm_addr=$(rm_addr_count ${connector_ns})
 					ip netns exec ${listener_ns} ./pm_nl_ctl del $id
-					sleep 1
+					wait_rm_addr ${connector_ns} ${rm_addr}
 					let counter+=1
 					let pos+=5
 				done
 			fi
 		elif [ $rm_nr_ns1 -eq 8 ]; then
-			sleep 1
 			ip netns exec ${listener_ns} ./pm_nl_ctl flush
 		elif [ $rm_nr_ns1 -eq 9 ]; then
-			sleep 1
 			ip netns exec ${listener_ns} ./pm_nl_ctl del 0 ${connect_addr}
 		fi
 	fi
@@ -373,10 +411,13 @@ do_transfer()
 		addr_nr_ns2=${addr_nr_ns2:9}
 	fi
 
+	# if newly added endpoints must be deleted, give the background msk
+	# some time to created them
+	[ $addr_nr_ns1 -gt 0 -a $addr_nr_ns2 -lt 0 ] && sleep 1
+
 	if [ $addr_nr_ns2 -gt 0 ]; then
 		let add_nr_ns2=addr_nr_ns2
 		counter=3
-		sleep 1
 		while [ $add_nr_ns2 -gt 0 ]; do
 			local addr
 			if is_v6 "${connect_addr}"; then
@@ -388,7 +429,6 @@ do_transfer()
 			let counter+=1
 			let add_nr_ns2-=1
 		done
-		sleep 1
 	elif [ $addr_nr_ns2 -lt 0 ]; then
 		let rm_nr_ns2=-addr_nr_ns2
 		if [ $rm_nr_ns2 -lt 8 ]; then
@@ -396,19 +436,18 @@ do_transfer()
 			pos=1
 			dump=(`ip netns exec ${connector_ns} ./pm_nl_ctl dump`)
 			if [ ${#dump[@]} -gt 0 ]; then
-				sleep 1
-
 				while [ $counter -le $rm_nr_ns2 ]
 				do
+					# rm_addr are serialized, allow the previous one to complete
 					id=${dump[$pos]}
+					rm_addr=$(rm_addr_count ${listener_ns})
 					ip netns exec ${connector_ns} ./pm_nl_ctl del $id
-					sleep 1
+					wait_rm_addr ${listener_ns} ${rm_addr}
 					let counter+=1
 					let pos+=5
 				done
 			fi
 		elif [ $rm_nr_ns2 -eq 8 ]; then
-			sleep 1
 			ip netns exec ${connector_ns} ./pm_nl_ctl flush
 		elif [ $rm_nr_ns2 -eq 9 ]; then
 			local addr
@@ -417,7 +456,6 @@ do_transfer()
 			else
 				addr="10.0.1.2"
 			fi
-			sleep 1
 			ip netns exec ${connector_ns} ./pm_nl_ctl del 0 $addr
 		fi
 	fi
@@ -539,6 +577,14 @@ run_tests()
 	lret=$?
 }
 
+dump_stats()
+{
+	echo Server ns stats
+	ip netns exec $ns1 nstat -as | grep Tcp
+	echo Client ns stats
+	ip netns exec $ns2 nstat -as | grep Tcp
+}
+
 chk_csum_nr()
 {
 	local msg=${1:-""}
@@ -570,12 +616,7 @@ chk_csum_nr()
 	else
 		echo "[ ok ]"
 	fi
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 }
 
 chk_fail_nr()
@@ -607,12 +648,7 @@ chk_fail_nr()
 		echo "[ ok ]"
 	fi
 
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 }
 
 chk_join_nr()
@@ -656,12 +692,7 @@ chk_join_nr()
 	else
 		echo "[ ok ]"
 	fi
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 	if [ $checksum -eq 1 ]; then
 		chk_csum_nr
 		chk_fail_nr 0 0
@@ -823,12 +854,7 @@ chk_add_nr()
 		echo ""
 	fi
 
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 }
 
 chk_rm_nr()
@@ -871,12 +897,7 @@ chk_rm_nr()
 		echo "[ ok ]"
 	fi
 
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 }
 
 chk_prio_nr()
@@ -908,12 +929,7 @@ chk_prio_nr()
 		echo "[ ok ]"
 	fi
 
-	if [ "${dump_stats}" = 1 ]; then
-		echo Server ns stats
-		ip netns exec $ns1 nstat -as | grep MPTcp
-		echo Client ns stats
-		ip netns exec $ns2 nstat -as | grep MPTcp
-	fi
+	[ "${dump_stats}" = 1 ] && dump_stats
 }
 
 chk_link_usage()
@@ -1651,7 +1667,7 @@ add_addr_ports_tests()
 	ip netns exec $ns2 ./pm_nl_ctl limits 1 3
 	ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow
 	ip netns exec $ns2 ./pm_nl_ctl add 10.0.4.2 flags subflow
-	run_tests $ns1 $ns2 10.0.1.1 0 -8 -8 slow
+	run_tests $ns1 $ns2 10.0.1.1 0 -8 -2 slow
 	chk_join_nr "flush subflows and signal with port" 3 3 3
 	chk_add_nr 1 1
 	chk_rm_nr 2 2