Merge branch 'mptcp-next'

Mat Martineau says:

====================
mptcp: Protocol in-use tracking and code cleanup

Here's a collection of commits from the MPTCP tree:

Patches 1-4 and 6 contain miscellaneous code cleanup for more consistent
use of helper functions, existing local variables, and better naming.

Patches 5, 7, and 9 add sock_prot_inuse tracking for MPTCP and an
associated self test.

Patch 8 modifies the mptcp_connect self test tool to exit on SIGUSR1
when in "slow mode".
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mptcp/options.c

@@ -1594,8 +1594,7 @@ void mptcp_write_options(struct tcphdr *th, __be32 *ptr, struct tcp_sock *tp,
 				      TCPOLEN_MPTCP_PRIO,
 				      opts->backup, TCPOPT_NOP);
 
-		MPTCP_INC_STATS(sock_net((const struct sock *)tp),
-				MPTCP_MIB_MPPRIOTX);
+		MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_MPPRIOTX);
 	}
 
 mp_capable_done:

net/mptcp/pm_netlink.c

@@ -1143,7 +1143,7 @@ void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ss
 			if (!tcp_rtx_and_write_queues_empty(ssk)) {
 				subflow->stale = 1;
 				__mptcp_retransmit_pending_data(sk);
-				MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_SUBFLOWSTALE);
+				MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
 			}
 			unlock_sock_fast(ssk, slow);
 
@@ -1903,8 +1903,7 @@ static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	if (token)
-		return mptcp_userspace_pm_set_flags(sock_net(skb->sk),
-						    token, &addr, &remote, bkup);
+		return mptcp_userspace_pm_set_flags(net, token, &addr, &remote, bkup);
 
 	spin_lock_bh(&pernet->lock);
 	entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);

net/mptcp/protocol.c

@@ -923,9 +923,8 @@ static void mptcp_check_for_eof(struct mptcp_sock *msk)
 static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_context *subflow;
-	struct sock *sk = (struct sock *)msk;
 
-	sock_owned_by_me(sk);
+	msk_owned_by_me(msk);
 
 	mptcp_for_each_subflow(msk, subflow) {
 		if (READ_ONCE(subflow->data_avail))
@@ -1408,7 +1407,7 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
 	u64 linger_time;
 	long tout = 0;
 
-	sock_owned_by_me(sk);
+	msk_owned_by_me(msk);
 
 	if (__mptcp_check_fallback(msk)) {
 		if (!msk->first)
@@ -1890,7 +1889,7 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
 	u32 time, advmss = 1;
 	u64 rtt_us, mstamp;
 
-	sock_owned_by_me(sk);
+	msk_owned_by_me(msk);
 
 	if (copied <= 0)
 		return;
@@ -2217,7 +2216,7 @@ static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
 	struct mptcp_subflow_context *subflow;
 	int min_stale_count = INT_MAX;
 
-	sock_owned_by_me((const struct sock *)msk);
+	msk_owned_by_me(msk);
 
 	if (__mptcp_check_fallback(msk))
 		return NULL;
@@ -2724,8 +2723,8 @@ static int mptcp_init_sock(struct sock *sk)
 	mptcp_ca_reset(sk);
 
 	sk_sockets_allocated_inc(sk);
-	sk->sk_rcvbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_rmem[1]);
-	sk->sk_sndbuf = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_wmem[1]);
+	sk->sk_rcvbuf = READ_ONCE(net->ipv4.sysctl_tcp_rmem[1]);
+	sk->sk_sndbuf = READ_ONCE(net->ipv4.sysctl_tcp_wmem[1]);
 
 	return 0;
 }
@@ -2892,6 +2891,12 @@ static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
 	return EPOLLIN | EPOLLRDNORM;
 }
 
+static void mptcp_listen_inuse_dec(struct sock *sk)
+{
+	if (inet_sk_state_load(sk) == TCP_LISTEN)
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+}
+
 bool __mptcp_close(struct sock *sk, long timeout)
 {
 	struct mptcp_subflow_context *subflow;
@@ -2901,6 +2906,7 @@ bool __mptcp_close(struct sock *sk, long timeout)
 	sk->sk_shutdown = SHUTDOWN_MASK;
 
 	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) {
+		mptcp_listen_inuse_dec(sk);
 		inet_sk_state_store(sk, TCP_CLOSE);
 		goto cleanup;
 	}
@@ -3001,6 +3007,7 @@ static int mptcp_disconnect(struct sock *sk, int flags)
 	if (msk->fastopening)
 		return 0;
 
+	mptcp_listen_inuse_dec(sk);
 	inet_sk_state_store(sk, TCP_CLOSE);
 
 	mptcp_stop_timer(sk);
@@ -3639,12 +3646,13 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 static int mptcp_listen(struct socket *sock, int backlog)
 {
 	struct mptcp_sock *msk = mptcp_sk(sock->sk);
+	struct sock *sk = sock->sk;
 	struct socket *ssock;
 	int err;
 
 	pr_debug("msk=%p", msk);
 
-	lock_sock(sock->sk);
+	lock_sock(sk);
 	ssock = __mptcp_nmpc_socket(msk);
 	if (!ssock) {
 		err = -EINVAL;
@@ -3652,18 +3660,20 @@ static int mptcp_listen(struct socket *sock, int backlog)
 	}
 
 	mptcp_token_destroy(msk);
-	inet_sk_state_store(sock->sk, TCP_LISTEN);
-	sock_set_flag(sock->sk, SOCK_RCU_FREE);
+	inet_sk_state_store(sk, TCP_LISTEN);
+	sock_set_flag(sk, SOCK_RCU_FREE);
 
 	err = ssock->ops->listen(ssock, backlog);
-	inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
-	if (!err)
-		mptcp_copy_inaddrs(sock->sk, ssock->sk);
+	inet_sk_state_store(sk, inet_sk_state_load(ssock->sk));
+	if (!err) {
+		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
+		mptcp_copy_inaddrs(sk, ssock->sk);
+	}
 
 	mptcp_event_pm_listener(ssock->sk, MPTCP_EVENT_LISTENER_CREATED);
 
 unlock:
-	release_sock(sock->sk);
+	release_sock(sk);
 	return err;
 }
 

net/mptcp/protocol.h

@@ -754,7 +754,7 @@ static inline void mptcp_token_init_request(struct request_sock *req)
 
 int mptcp_token_new_request(struct request_sock *req);
 void mptcp_token_destroy_request(struct request_sock *req);
-int mptcp_token_new_connect(struct sock *sk);
+int mptcp_token_new_connect(struct sock *ssk);
 void mptcp_token_accept(struct mptcp_subflow_request_sock *r,
 			struct mptcp_sock *msk);
 bool mptcp_token_exists(u32 token);

net/mptcp/sockopt.c

@@ -18,7 +18,7 @@
 
 static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk)
 {
-	sock_owned_by_me((const struct sock *)msk);
+	msk_owned_by_me(msk);
 
 	if (likely(!__mptcp_check_fallback(msk)))
 		return NULL;

net/mptcp/token.c

@@ -134,7 +134,7 @@ int mptcp_token_new_request(struct request_sock *req)
 
 /**
  * mptcp_token_new_connect - create new key/idsn/token for subflow
- * @sk: the socket that will initiate a connection
+ * @ssk: the socket that will initiate a connection
  *
  * This function is called when a new outgoing mptcp connection is
  * initiated.
@@ -148,11 +148,12 @@ int mptcp_token_new_request(struct request_sock *req)
  *
  * returns 0 on success.
  */
-int mptcp_token_new_connect(struct sock *sk)
+int mptcp_token_new_connect(struct sock *ssk)
 {
-	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
+	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
 	int retries = MPTCP_TOKEN_MAX_RETRIES;
+	struct sock *sk = subflow->conn;
 	struct token_bucket *bucket;
 
 again:
@@ -169,12 +170,13 @@ int mptcp_token_new_connect(struct sock *sk)
 	}
 
 	pr_debug("ssk=%p, local_key=%llu, token=%u, idsn=%llu\n",
-		 sk, subflow->local_key, subflow->token, subflow->idsn);
+		 ssk, subflow->local_key, subflow->token, subflow->idsn);
 
 	WRITE_ONCE(msk->token, subflow->token);
 	__sk_nulls_add_node_rcu((struct sock *)msk, &bucket->msk_chain);
 	bucket->chain_len++;
 	spin_unlock_bh(&bucket->lock);
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	return 0;
 }
 
@@ -190,8 +192,10 @@ void mptcp_token_accept(struct mptcp_subflow_request_sock *req,
 			struct mptcp_sock *msk)
 {
 	struct mptcp_subflow_request_sock *pos;
+	struct sock *sk = (struct sock *)msk;
 	struct token_bucket *bucket;
 
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 	bucket = token_bucket(req->token);
 	spin_lock_bh(&bucket->lock);
 
@@ -370,12 +374,14 @@ void mptcp_token_destroy_request(struct request_sock *req)
  */
 void mptcp_token_destroy(struct mptcp_sock *msk)
 {
+	struct sock *sk = (struct sock *)msk;
 	struct token_bucket *bucket;
 	struct mptcp_sock *pos;
 
 	if (sk_unhashed((struct sock *)msk))
 		return;
 
+	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 	bucket = token_bucket(msk->token);
 	spin_lock_bh(&bucket->lock);
 	pos = __token_lookup_msk(bucket, msk->token);

net/mptcp/token_test.c

@@ -57,6 +57,9 @@ static struct mptcp_sock *build_msk(struct kunit *test)
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, msk);
 	refcount_set(&((struct sock *)msk)->sk_refcnt, 1);
 	sock_net_set((struct sock *)msk, &init_net);
+
+	/* be sure the token helpers can dereference sk->sk_prot */
+	((struct sock *)msk)->sk_prot = &tcp_prot;
 	return msk;
 }
 

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

@@ -17,6 +17,11 @@ flush_pids()
 	sleep 1.1
 
 	ip netns pids "${ns}" | xargs --no-run-if-empty kill -SIGUSR1 &>/dev/null
+
+	for _ in $(seq 10); do
+		[ -z "$(ip netns pids "${ns}")" ] && break
+		sleep 0.1
+	done
 }
 
 cleanup()
@@ -37,15 +42,20 @@ if [ $? -ne 0 ];then
 	exit $ksft_skip
 fi
 
+get_msk_inuse()
+{
+	ip netns exec $ns cat /proc/net/protocols | awk '$1~/^MPTCP$/{print $3}'
+}
+
 __chk_nr()
 {
-	local condition="$1"
+	local command="$1"
 	local expected=$2
 	local msg nr
 
 	shift 2
 	msg=$*
-	nr=$(ss -inmHMN $ns | $condition)
+	nr=$(eval $command)
 
 	printf "%-50s" "$msg"
 	if [ $nr != $expected ]; then
@@ -57,9 +67,17 @@ __chk_nr()
 	test_cnt=$((test_cnt+1))
 }
 
+__chk_msk_nr()
+{
+	local condition=$1
+	shift 1
+
+	__chk_nr "ss -inmHMN $ns | $condition" $*
+}
+
 chk_msk_nr()
 {
-	__chk_nr "grep -c token:" $*
+	__chk_msk_nr "grep -c token:" $*
 }
 
 wait_msk_nr()
@@ -97,12 +115,12 @@ wait_msk_nr()
 
 chk_msk_fallback_nr()
 {
-		__chk_nr "grep -c fallback" $*
+		__chk_msk_nr "grep -c fallback" $*
 }
 
 chk_msk_remote_key_nr()
 {
-		__chk_nr "grep -c remote_key" $*
+		__chk_msk_nr "grep -c remote_key" $*
 }
 
 __chk_listen()
@@ -142,6 +160,26 @@ chk_msk_listen()
 	nr=$(ss -Ml $filter | wc -l)
 }
 
+chk_msk_inuse()
+{
+	local expected=$1
+	local listen_nr
+
+	shift 1
+
+	listen_nr=$(ss -N "${ns}" -Ml | grep -c LISTEN)
+	expected=$((expected + listen_nr))
+
+	for _ in $(seq 10); do
+		if [ $(get_msk_inuse) -eq $expected ];then
+			break
+		fi
+		sleep 0.1
+	done
+
+	__chk_nr get_msk_inuse $expected $*
+}
+
 # $1: ns, $2: port
 wait_local_port_listen()
 {
@@ -195,8 +233,10 @@ wait_connected $ns 10000
 chk_msk_nr 2 "after MPC handshake "
 chk_msk_remote_key_nr 2 "....chk remote_key"
 chk_msk_fallback_nr 0 "....chk no fallback"
+chk_msk_inuse 2 "....chk 2 msk in use"
 flush_pids
 
+chk_msk_inuse 0 "....chk 0 msk in use after flush"
 
 echo "a" | \
 	timeout ${timeout_test} \
@@ -211,8 +251,11 @@ echo "b" | \
 				127.0.0.1 >/dev/null &
 wait_connected $ns 10001
 chk_msk_fallback_nr 1 "check fallback"
+chk_msk_inuse 1 "....chk 1 msk in use"
 flush_pids
 
+chk_msk_inuse 0 "....chk 0 msk in use after flush"
+
 NR_CLIENTS=100
 for I in `seq 1 $NR_CLIENTS`; do
 	echo "a" | \
@@ -232,6 +275,9 @@ for I in `seq 1 $NR_CLIENTS`; do
 done
 
 wait_msk_nr $((NR_CLIENTS*2)) "many msk socket present"
+chk_msk_inuse $((NR_CLIENTS*2)) "....chk many msk in use"
 flush_pids
 
+chk_msk_inuse 0 "....chk 0 msk in use after flush"
+
 exit $ret

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

@@ -627,7 +627,7 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd,
 		char rbuf[8192];
 		ssize_t len;
 
-		if (fds.events == 0)
+		if (fds.events == 0 || quit)
 			break;
 
 		switch (poll(&fds, 1, poll_timeout)) {
@@ -733,7 +733,7 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd,
 	}
 
 	/* leave some time for late join/announce */
-	if (cfg_remove)
+	if (cfg_remove && !quit)
 		usleep(cfg_wait);
 
 	return 0;