selftests/mptcp: add diag interface tests

basic functional test, triggering the msk diag interface
code. Require appropriate iproute2 support, skip elsewhere.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/mptcp/Makefile

@@ -5,7 +5,7 @@ KSFT_KHDR_INSTALL := 1
 
 CFLAGS =  -Wall -Wl,--no-as-needed -O2 -g  -I$(top_srcdir)/usr/include
 
-TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh
+TEST_PROGS := mptcp_connect.sh pm_netlink.sh mptcp_join.sh diag.sh
 
 TEST_GEN_FILES = mptcp_connect pm_nl_ctl
 

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

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+rndh=$(printf %x $sec)-$(mktemp -u XXXXXX)
+ns="ns1-$rndh"
+ksft_skip=4
+test_cnt=1
+ret=0
+pids=()
+
+flush_pids()
+{
+	# mptcp_connect in join mode will sleep a bit before completing,
+	# give it some time
+	sleep 1.1
+
+	for pid in ${pids[@]}; do
+		[ -d /proc/$pid ] && kill -SIGUSR1 $pid >/dev/null 2>&1
+	done
+	pids=()
+}
+
+cleanup()
+{
+	ip netns del $ns
+	for pid in ${pids[@]}; do
+		[ -d /proc/$pid ] && kill -9 $pid >/dev/null 2>&1
+	done
+}
+
+ip -Version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+	echo "SKIP: Could not run test without ip tool"
+	exit $ksft_skip
+fi
+ss -h | grep -q MPTCP
+if [ $? -ne 0 ];then
+	echo "SKIP: ss tool does not support MPTCP"
+	exit $ksft_skip
+fi
+
+__chk_nr()
+{
+	local condition="$1"
+	local expected=$2
+	local msg nr
+
+	shift 2
+	msg=$*
+	nr=$(ss -inmHMN $ns | $condition)
+
+	printf "%-50s" "$msg"
+	if [ $nr != $expected ]; then
+		echo "[ fail ] expected $expected found $nr"
+		ret=$test_cnt
+	else
+		echo "[  ok  ]"
+	fi
+	test_cnt=$((test_cnt+1))
+}
+
+chk_msk_nr()
+{
+	__chk_nr "grep -c token:" $*
+}
+
+chk_msk_fallback_nr()
+{
+		__chk_nr "grep -c fallback" $*
+}
+
+chk_msk_remote_key_nr()
+{
+		__chk_nr "grep -c remote_key" $*
+}
+
+
+trap cleanup EXIT
+ip netns add $ns
+ip -n $ns link set dev lo up
+
+echo "a" | ip netns exec $ns ./mptcp_connect -p 10000 -l 0.0.0.0 -t 100 >/dev/null &
+sleep 0.1
+pids[0]=$!
+chk_msk_nr 0 "no msk on netns creation"
+
+echo "b" | ip netns exec $ns ./mptcp_connect -p 10000 127.0.0.1 -j -t 100 >/dev/null &
+sleep 0.1
+pids[1]=$!
+chk_msk_nr 2 "after MPC handshake "
+chk_msk_remote_key_nr 2 "....chk remote_key"
+chk_msk_fallback_nr 0 "....chk no fallback"
+flush_pids
+
+
+echo "a" | ip netns exec $ns ./mptcp_connect -p 10001 -s TCP -l 0.0.0.0 -t 100 >/dev/null &
+pids[0]=$!
+sleep 0.1
+echo "b" | ip netns exec $ns ./mptcp_connect -p 10001 127.0.0.1 -j -t 100 >/dev/null &
+pids[1]=$!
+sleep 0.1
+chk_msk_fallback_nr 1 "check fallback"
+flush_pids
+
+NR_CLIENTS=100
+for I in `seq 1 $NR_CLIENTS`; do
+	echo "a" | ip netns exec $ns ./mptcp_connect -p $((I+10001)) -l 0.0.0.0 -t 100 -w 10 >/dev/null  &
+	pids[$((I*2))]=$!
+done
+sleep 0.1
+
+for I in `seq 1 $NR_CLIENTS`; do
+	echo "b" | ip netns exec $ns ./mptcp_connect -p $((I+10001)) 127.0.0.1 -t 100 -w 10 >/dev/null &
+	pids[$((I*2 + 1))]=$!
+done
+sleep 1.5
+
+chk_msk_nr $((NR_CLIENTS*2)) "many msk socket present"
+flush_pids
+
+exit $ret

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

@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <strings.h>
+#include <signal.h>
 #include <unistd.h>
 
 #include <sys/poll.h>
@@ -36,6 +37,7 @@ extern int optind;
 
 static int  poll_timeout = 10 * 1000;
 static bool listen_mode;
+static bool quit;
 
 enum cfg_mode {
 	CFG_MODE_POLL,
@@ -52,11 +54,12 @@ static int pf = AF_INET;
 static int cfg_sndbuf;
 static int cfg_rcvbuf;
 static bool cfg_join;
+static int cfg_wait;
 
 static void die_usage(void)
 {
 	fprintf(stderr, "Usage: mptcp_connect [-6] [-u] [-s MPTCP|TCP] [-p port] [-m mode]"
-		"[-l] connect_address\n");
+		"[-l] [-w sec] connect_address\n");
 	fprintf(stderr, "\t-6 use ipv6\n");
 	fprintf(stderr, "\t-t num -- set poll timeout to num\n");
 	fprintf(stderr, "\t-S num -- set SO_SNDBUF to num\n");
@@ -65,9 +68,15 @@ static void die_usage(void)
 	fprintf(stderr, "\t-m [MPTCP|TCP] -- use tcp or mptcp sockets\n");
 	fprintf(stderr, "\t-s [mmap|poll] -- use poll (default) or mmap\n");
 	fprintf(stderr, "\t-u -- check mptcp ulp\n");
+	fprintf(stderr, "\t-w num -- wait num sec before closing the socket\n");
 	exit(1);
 }
 
+static void handle_signal(int nr)
+{
+	quit = true;
+}
+
 static const char *getxinfo_strerr(int err)
 {
 	if (err == EAI_SYSTEM)
@@ -418,8 +427,8 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd)
 	}
 
 	/* leave some time for late join/announce */
-	if (cfg_join)
-		usleep(400000);
+	if (cfg_wait)
+		usleep(cfg_wait);
 
 	close(peerfd);
 	return 0;
@@ -812,11 +821,12 @@ static void parse_opts(int argc, char **argv)
 {
 	int c;
 
-	while ((c = getopt(argc, argv, "6jlp:s:hut:m:S:R:")) != -1) {
+	while ((c = getopt(argc, argv, "6jlp:s:hut:m:S:R:w:")) != -1) {
 		switch (c) {
 		case 'j':
 			cfg_join = true;
 			cfg_mode = CFG_MODE_POLL;
+			cfg_wait = 400000;
 			break;
 		case 'l':
 			listen_mode = true;
@@ -850,6 +860,9 @@ static void parse_opts(int argc, char **argv)
 		case 'R':
 			cfg_rcvbuf = parse_int(optarg);
 			break;
+		case 'w':
+			cfg_wait = atoi(optarg)*1000000;
+			break;
 		}
 	}
 
@@ -865,6 +878,7 @@ int main(int argc, char *argv[])
 {
 	init_rng();
 
+	signal(SIGUSR1, handle_signal);
 	parse_opts(argc, argv);
 
 	if (tcpulp_audit)