forked from mirrors/linux
		
	mptcp: refactor shutdown and close
We must not close the subflows before all the MPTCP level data, comprising the DATA_FIN has been acked at the MPTCP level, otherwise we could be unable to retransmit as needed. __mptcp_wr_shutdown() shutdown is responsible to check for the correct status and close all subflows. Is called by the output path after spooling any data and at shutdown/close time. In a similar way, __mptcp_destroy_sock() is responsible to clean-up the MPTCP level status, and is called when the msk transition to TCP_CLOSE. The protocol level close() does not force anymore the TCP_CLOSE status, but orphan the msk socket and all the subflows. Orphaned msk sockets are forciby closed after a timeout or when all MPTCP-level data is acked. There is a caveat about keeping the orphaned subflows around: the TCP stack can asynchronusly call tcp_cleanup_ulp() on them via tcp_close(). To prevent accessing freed memory on later MPTCP level operations, the msk acquires a reference to each subflow socket and prevent subflow_ulp_release() from releasing the subflow context before __mptcp_destroy_sock(). The additional subflow references are released by __mptcp_done() and the async ULP release is detected checking ULP ops. If such field has been already cleared by the ULP release path, the dangling context is freed directly by __mptcp_done(). Co-developed-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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					 5 changed files with 280 additions and 117 deletions
				
			
		|  | @ -492,7 +492,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, | |||
| 	bool ret = false; | ||||
| 
 | ||||
| 	mpext = skb ? mptcp_get_ext(skb) : NULL; | ||||
| 	snd_data_fin_enable = READ_ONCE(msk->snd_data_fin_enable); | ||||
| 	snd_data_fin_enable = mptcp_data_fin_enabled(msk); | ||||
| 
 | ||||
| 	if (!skb || (mpext && mpext->use_map) || snd_data_fin_enable) { | ||||
| 		unsigned int map_size; | ||||
|  |  | |||
|  | @ -416,14 +416,13 @@ void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk) | |||
| 	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { | ||||
| 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | ||||
| 		int how = RCV_SHUTDOWN | SEND_SHUTDOWN; | ||||
| 		long timeout = 0; | ||||
| 
 | ||||
| 		if (msk->pm.rm_id != subflow->remote_id) | ||||
| 			continue; | ||||
| 
 | ||||
| 		spin_unlock_bh(&msk->pm.lock); | ||||
| 		mptcp_subflow_shutdown(sk, ssk, how); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow, timeout); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow); | ||||
| 		spin_lock_bh(&msk->pm.lock); | ||||
| 
 | ||||
| 		msk->pm.add_addr_accepted--; | ||||
|  | @ -452,14 +451,13 @@ void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id) | |||
| 	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { | ||||
| 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | ||||
| 		int how = RCV_SHUTDOWN | SEND_SHUTDOWN; | ||||
| 		long timeout = 0; | ||||
| 
 | ||||
| 		if (rm_id != subflow->local_id) | ||||
| 			continue; | ||||
| 
 | ||||
| 		spin_unlock_bh(&msk->pm.lock); | ||||
| 		mptcp_subflow_shutdown(sk, ssk, how); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow, timeout); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow); | ||||
| 		spin_lock_bh(&msk->pm.lock); | ||||
| 
 | ||||
| 		msk->pm.local_addr_used--; | ||||
|  |  | |||
|  | @ -21,6 +21,7 @@ | |||
| #include <net/transp_v6.h> | ||||
| #endif | ||||
| #include <net/mptcp.h> | ||||
| #include <net/xfrm.h> | ||||
| #include "protocol.h" | ||||
| #include "mib.h" | ||||
| 
 | ||||
|  | @ -41,6 +42,8 @@ struct mptcp_skb_cb { | |||
| 
 | ||||
| static struct percpu_counter mptcp_sockets_allocated; | ||||
| 
 | ||||
| static void __mptcp_destroy_sock(struct sock *sk); | ||||
| 
 | ||||
| /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not
 | ||||
|  * completed yet or has failed, return the subflow socket. | ||||
|  * Otherwise return NULL. | ||||
|  | @ -102,6 +105,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) | |||
| 	msk->subflow = ssock; | ||||
| 	subflow = mptcp_subflow_ctx(ssock->sk); | ||||
| 	list_add(&subflow->node, &msk->conn_list); | ||||
| 	sock_hold(ssock->sk); | ||||
| 	subflow->request_mptcp = 1; | ||||
| 
 | ||||
| 	/* accept() will wait on first subflow sk_wq, and we always wakes up
 | ||||
|  | @ -323,6 +327,19 @@ static void mptcp_stop_timer(struct sock *sk) | |||
| 	mptcp_sk(sk)->timer_ival = 0; | ||||
| } | ||||
| 
 | ||||
| static void mptcp_close_wake_up(struct sock *sk) | ||||
| { | ||||
| 	if (sock_flag(sk, SOCK_DEAD)) | ||||
| 		return; | ||||
| 
 | ||||
| 	sk->sk_state_change(sk); | ||||
| 	if (sk->sk_shutdown == SHUTDOWN_MASK || | ||||
| 	    sk->sk_state == TCP_CLOSE) | ||||
| 		sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); | ||||
| 	else | ||||
| 		sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); | ||||
| } | ||||
| 
 | ||||
| static void mptcp_check_data_fin_ack(struct sock *sk) | ||||
| { | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sk); | ||||
|  | @ -341,20 +358,14 @@ static void mptcp_check_data_fin_ack(struct sock *sk) | |||
| 		switch (sk->sk_state) { | ||||
| 		case TCP_FIN_WAIT1: | ||||
| 			inet_sk_state_store(sk, TCP_FIN_WAIT2); | ||||
| 			sk->sk_state_change(sk); | ||||
| 			break; | ||||
| 		case TCP_CLOSING: | ||||
| 		case TCP_LAST_ACK: | ||||
| 			inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 			sk->sk_state_change(sk); | ||||
| 			break; | ||||
| 		} | ||||
| 
 | ||||
| 		if (sk->sk_shutdown == SHUTDOWN_MASK || | ||||
| 		    sk->sk_state == TCP_CLOSE) | ||||
| 			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); | ||||
| 		else | ||||
| 			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); | ||||
| 		mptcp_close_wake_up(sk); | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
|  | @ -428,7 +439,6 @@ static void mptcp_check_data_fin(struct sock *sk) | |||
| 			break; | ||||
| 		case TCP_FIN_WAIT2: | ||||
| 			inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 			// @@ Close subflows now?
 | ||||
| 			break; | ||||
| 		default: | ||||
| 			/* Other states not expected */ | ||||
|  | @ -445,13 +455,7 @@ static void mptcp_check_data_fin(struct sock *sk) | |||
| 			release_sock(ssk); | ||||
| 		} | ||||
| 
 | ||||
| 		sk->sk_state_change(sk); | ||||
| 
 | ||||
| 		if (sk->sk_shutdown == SHUTDOWN_MASK || | ||||
| 		    sk->sk_state == TCP_CLOSE) | ||||
| 			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); | ||||
| 		else | ||||
| 			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); | ||||
| 		mptcp_close_wake_up(sk); | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
|  | @ -691,6 +695,10 @@ static void mptcp_reset_timer(struct sock *sk) | |||
| 	struct inet_connection_sock *icsk = inet_csk(sk); | ||||
| 	unsigned long tout; | ||||
| 
 | ||||
| 	/* prevent rescheduling on close */ | ||||
| 	if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE)) | ||||
| 		return; | ||||
| 
 | ||||
| 	/* should never be called with mptcp level timer cleared */ | ||||
| 	tout = READ_ONCE(mptcp_sk(sk)->timer_ival); | ||||
| 	if (WARN_ON_ONCE(!tout)) | ||||
|  | @ -734,8 +742,10 @@ static void mptcp_check_for_eof(struct mptcp_sock *msk) | |||
| 
 | ||||
| 	mptcp_for_each_subflow(msk, subflow) | ||||
| 		receivers += !subflow->rx_eof; | ||||
| 	if (receivers) | ||||
| 		return; | ||||
| 
 | ||||
| 	if (!receivers && !(sk->sk_shutdown & RCV_SHUTDOWN)) { | ||||
| 	if (!(sk->sk_shutdown & RCV_SHUTDOWN)) { | ||||
| 		/* hopefully temporary hack: propagate shutdown status
 | ||||
| 		 * to msk, when all subflows agree on it | ||||
| 		 */ | ||||
|  | @ -745,6 +755,19 @@ static void mptcp_check_for_eof(struct mptcp_sock *msk) | |||
| 		set_bit(MPTCP_DATA_READY, &msk->flags); | ||||
| 		sk->sk_data_ready(sk); | ||||
| 	} | ||||
| 
 | ||||
| 	switch (sk->sk_state) { | ||||
| 	case TCP_ESTABLISHED: | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE_WAIT); | ||||
| 		break; | ||||
| 	case TCP_FIN_WAIT1: | ||||
| 		/* fallback sockets skip TCP_CLOSING - TCP will take care */ | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 		break; | ||||
| 	default: | ||||
| 		return; | ||||
| 	} | ||||
| 	mptcp_close_wake_up(sk); | ||||
| } | ||||
| 
 | ||||
| static bool mptcp_ext_cache_refill(struct mptcp_sock *msk) | ||||
|  | @ -1657,6 +1680,13 @@ static void mptcp_retransmit_timer(struct timer_list *t) | |||
| 	sock_put(sk); | ||||
| } | ||||
| 
 | ||||
| static void mptcp_timeout_timer(struct timer_list *t) | ||||
| { | ||||
| 	struct sock *sk = from_timer(sk, t, sk_timer); | ||||
| 
 | ||||
| 	mptcp_schedule_work(sk); | ||||
| } | ||||
| 
 | ||||
| /* Find an idle subflow.  Return NULL if there is unacked data at tcp
 | ||||
|  * level. | ||||
|  * | ||||
|  | @ -1703,20 +1733,43 @@ static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk) | |||
|  * parent socket. | ||||
|  */ | ||||
| void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, | ||||
| 		       struct mptcp_subflow_context *subflow, | ||||
| 		       long timeout) | ||||
| 		       struct mptcp_subflow_context *subflow) | ||||
| { | ||||
| 	struct socket *sock = READ_ONCE(ssk->sk_socket); | ||||
| 	bool dispose_socket = false; | ||||
| 	struct socket *sock; | ||||
| 
 | ||||
| 	list_del(&subflow->node); | ||||
| 
 | ||||
| 	if (sock && sock != sk->sk_socket) { | ||||
| 		/* outgoing subflow */ | ||||
| 		sock_release(sock); | ||||
| 	} else { | ||||
| 		/* incoming subflow */ | ||||
| 		tcp_close(ssk, timeout); | ||||
| 	lock_sock(ssk); | ||||
| 
 | ||||
| 	/* if we are invoked by the msk cleanup code, the subflow is
 | ||||
| 	 * already orphaned | ||||
| 	 */ | ||||
| 	sock = ssk->sk_socket; | ||||
| 	if (sock) { | ||||
| 		dispose_socket = sock != sk->sk_socket; | ||||
| 		sock_orphan(ssk); | ||||
| 	} | ||||
| 
 | ||||
| 	/* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops
 | ||||
| 	 * the ssk has been already destroyed, we just need to release the | ||||
| 	 * reference owned by msk; | ||||
| 	 */ | ||||
| 	if (!inet_csk(ssk)->icsk_ulp_ops) { | ||||
| 		kfree_rcu(subflow, rcu); | ||||
| 	} else { | ||||
| 		/* otherwise ask tcp do dispose of ssk and subflow ctx */ | ||||
| 		subflow->disposable = 1; | ||||
| 		__tcp_close(ssk, 0); | ||||
| 
 | ||||
| 		/* close acquired an extra ref */ | ||||
| 		__sock_put(ssk); | ||||
| 	} | ||||
| 	release_sock(ssk); | ||||
| 	if (dispose_socket) | ||||
| 		iput(SOCK_INODE(sock)); | ||||
| 
 | ||||
| 	sock_put(ssk); | ||||
| } | ||||
| 
 | ||||
| static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) | ||||
|  | @ -1761,10 +1814,29 @@ static void __mptcp_close_subflow(struct mptcp_sock *msk) | |||
| 		if (inet_sk_state_load(ssk) != TCP_CLOSE) | ||||
| 			continue; | ||||
| 
 | ||||
| 		__mptcp_close_ssk((struct sock *)msk, ssk, subflow, 0); | ||||
| 		__mptcp_close_ssk((struct sock *)msk, ssk, subflow); | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| static bool mptcp_check_close_timeout(const struct sock *sk) | ||||
| { | ||||
| 	s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp; | ||||
| 	struct mptcp_subflow_context *subflow; | ||||
| 
 | ||||
| 	if (delta >= TCP_TIMEWAIT_LEN) | ||||
| 		return true; | ||||
| 
 | ||||
| 	/* if all subflows are in closed status don't bother with additional
 | ||||
| 	 * timeout | ||||
| 	 */ | ||||
| 	mptcp_for_each_subflow(mptcp_sk(sk), subflow) { | ||||
| 		if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) != | ||||
| 		    TCP_CLOSE) | ||||
| 			return false; | ||||
| 	} | ||||
| 	return true; | ||||
| } | ||||
| 
 | ||||
| static void mptcp_worker(struct work_struct *work) | ||||
| { | ||||
| 	struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); | ||||
|  | @ -1777,9 +1849,14 @@ static void mptcp_worker(struct work_struct *work) | |||
| 	struct msghdr msg = { | ||||
| 		.msg_flags = MSG_DONTWAIT, | ||||
| 	}; | ||||
| 	int ret; | ||||
| 	int state, ret; | ||||
| 
 | ||||
| 	lock_sock(sk); | ||||
| 	set_bit(MPTCP_WORKER_RUNNING, &msk->flags); | ||||
| 	state = sk->sk_state; | ||||
| 	if (unlikely(state == TCP_CLOSE)) | ||||
| 		goto unlock; | ||||
| 
 | ||||
| 	mptcp_clean_una_wakeup(sk); | ||||
| 	mptcp_check_data_fin_ack(sk); | ||||
| 	__mptcp_flush_join_list(msk); | ||||
|  | @ -1796,6 +1873,18 @@ static void mptcp_worker(struct work_struct *work) | |||
| 
 | ||||
| 	mptcp_check_data_fin(sk); | ||||
| 
 | ||||
| 	/* if the msk data is completely acked, or the socket timedout,
 | ||||
| 	 * there is no point in keeping around an orphaned sk | ||||
| 	 */ | ||||
| 	if (sock_flag(sk, SOCK_DEAD) && | ||||
| 	    (mptcp_check_close_timeout(sk) || | ||||
| 	    (state != sk->sk_state && | ||||
| 	    ((1 << inet_sk_state_load(sk)) & (TCPF_CLOSE | TCPF_FIN_WAIT2))))) { | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 		__mptcp_destroy_sock(sk); | ||||
| 		goto unlock; | ||||
| 	} | ||||
| 
 | ||||
| 	if (!test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) | ||||
| 		goto unlock; | ||||
| 
 | ||||
|  | @ -1844,6 +1933,7 @@ static void mptcp_worker(struct work_struct *work) | |||
| 		mptcp_reset_timer(sk); | ||||
| 
 | ||||
| unlock: | ||||
| 	clear_bit(MPTCP_WORKER_RUNNING, &msk->flags); | ||||
| 	release_sock(sk); | ||||
| 	sock_put(sk); | ||||
| } | ||||
|  | @ -1869,7 +1959,7 @@ static int __mptcp_init_sock(struct sock *sk) | |||
| 
 | ||||
| 	/* re-use the csk retrans timer for MPTCP-level retrans */ | ||||
| 	timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); | ||||
| 
 | ||||
| 	timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0); | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
|  | @ -1914,8 +2004,12 @@ static void mptcp_cancel_work(struct sock *sk) | |||
| { | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sk); | ||||
| 
 | ||||
| 	if (cancel_work_sync(&msk->work)) | ||||
| 		sock_put(sk); | ||||
| 	/* if called by the work itself, do not try to cancel the work, or
 | ||||
| 	 * we will hang. | ||||
| 	 */ | ||||
| 	if (!test_bit(MPTCP_WORKER_RUNNING, &msk->flags) && | ||||
| 	    cancel_work_sync(&msk->work)) | ||||
| 		__sock_put(sk); | ||||
| } | ||||
| 
 | ||||
| void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how) | ||||
|  | @ -1973,42 +2067,61 @@ static int mptcp_close_state(struct sock *sk) | |||
| 	return next & TCP_ACTION_FIN; | ||||
| } | ||||
| 
 | ||||
| static void mptcp_close(struct sock *sk, long timeout) | ||||
| static void __mptcp_check_send_data_fin(struct sock *sk) | ||||
| { | ||||
| 	struct mptcp_subflow_context *subflow; | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sk); | ||||
| 
 | ||||
| 	pr_debug("msk=%p snd_data_fin_enable=%d pending=%d snd_nxt=%llu write_seq=%llu", | ||||
| 		 msk, msk->snd_data_fin_enable, !!mptcp_send_head(sk), | ||||
| 		 msk->snd_nxt, msk->write_seq); | ||||
| 
 | ||||
| 	/* we still need to enqueue subflows or not really shutting down,
 | ||||
| 	 * skip this | ||||
| 	 */ | ||||
| 	if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq || | ||||
| 	    mptcp_send_head(sk)) | ||||
| 		return; | ||||
| 
 | ||||
| 	WRITE_ONCE(msk->snd_nxt, msk->write_seq); | ||||
| 
 | ||||
| 	/* fallback socket will not get data_fin/ack, can move to close now */ | ||||
| 	if (__mptcp_check_fallback(msk) && sk->sk_state == TCP_LAST_ACK) { | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 		mptcp_close_wake_up(sk); | ||||
| 	} | ||||
| 
 | ||||
| 	__mptcp_flush_join_list(msk); | ||||
| 	mptcp_for_each_subflow(msk, subflow) { | ||||
| 		struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); | ||||
| 
 | ||||
| 		mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN); | ||||
| 	} | ||||
| } | ||||
| 
 | ||||
| static void __mptcp_wr_shutdown(struct sock *sk) | ||||
| { | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sk); | ||||
| 
 | ||||
| 	pr_debug("msk=%p snd_data_fin_enable=%d shutdown=%x state=%d pending=%d", | ||||
| 		 msk, msk->snd_data_fin_enable, sk->sk_shutdown, sk->sk_state, | ||||
| 		 !!mptcp_send_head(sk)); | ||||
| 
 | ||||
| 	/* will be ignored by fallback sockets */ | ||||
| 	WRITE_ONCE(msk->write_seq, msk->write_seq + 1); | ||||
| 	WRITE_ONCE(msk->snd_data_fin_enable, 1); | ||||
| 
 | ||||
| 	__mptcp_check_send_data_fin(sk); | ||||
| } | ||||
| 
 | ||||
| static void __mptcp_destroy_sock(struct sock *sk) | ||||
| { | ||||
| 	struct mptcp_subflow_context *subflow, *tmp; | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sk); | ||||
| 	LIST_HEAD(conn_list); | ||||
| 
 | ||||
| 	lock_sock(sk); | ||||
| 	sk->sk_shutdown = SHUTDOWN_MASK; | ||||
| 	pr_debug("msk=%p", msk); | ||||
| 
 | ||||
| 	if (sk->sk_state == TCP_LISTEN) { | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 		goto cleanup; | ||||
| 	} else if (sk->sk_state == TCP_CLOSE) { | ||||
| 		goto cleanup; | ||||
| 	} | ||||
| 
 | ||||
| 	if (__mptcp_check_fallback(msk)) { | ||||
| 		goto update_state; | ||||
| 	} else if (mptcp_close_state(sk)) { | ||||
| 		pr_debug("Sending DATA_FIN sk=%p", sk); | ||||
| 		WRITE_ONCE(msk->write_seq, msk->write_seq + 1); | ||||
| 		WRITE_ONCE(msk->snd_data_fin_enable, 1); | ||||
| 
 | ||||
| 		mptcp_for_each_subflow(msk, subflow) { | ||||
| 			struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); | ||||
| 
 | ||||
| 			mptcp_subflow_shutdown(sk, tcp_sk, SHUTDOWN_MASK); | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	sk_stream_wait_close(sk, timeout); | ||||
| 
 | ||||
| update_state: | ||||
| 	inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 
 | ||||
| cleanup: | ||||
| 	/* be sure to always acquire the join list lock, to sync vs
 | ||||
| 	 * mptcp_finish_join(). | ||||
| 	 */ | ||||
|  | @ -2018,19 +2131,74 @@ static void mptcp_close(struct sock *sk, long timeout) | |||
| 	list_splice_init(&msk->conn_list, &conn_list); | ||||
| 
 | ||||
| 	__mptcp_clear_xmit(sk); | ||||
| 
 | ||||
| 	release_sock(sk); | ||||
| 	sk_stop_timer(sk, &sk->sk_timer); | ||||
| 	msk->pm.status = 0; | ||||
| 
 | ||||
| 	list_for_each_entry_safe(subflow, tmp, &conn_list, node) { | ||||
| 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow, timeout); | ||||
| 		__mptcp_close_ssk(sk, ssk, subflow); | ||||
| 	} | ||||
| 
 | ||||
| 	mptcp_cancel_work(sk); | ||||
| 	sk->sk_prot->destroy(sk); | ||||
| 
 | ||||
| 	__skb_queue_purge(&sk->sk_receive_queue); | ||||
| 	sk_stream_kill_queues(sk); | ||||
| 	xfrm_sk_free_policy(sk); | ||||
| 	sk_refcnt_debug_release(sk); | ||||
| 	sock_put(sk); | ||||
| } | ||||
| 
 | ||||
| 	sk_common_release(sk); | ||||
| static void mptcp_close(struct sock *sk, long timeout) | ||||
| { | ||||
| 	struct mptcp_subflow_context *subflow; | ||||
| 	bool do_cancel_work = false; | ||||
| 
 | ||||
| 	lock_sock(sk); | ||||
| 	sk->sk_shutdown = SHUTDOWN_MASK; | ||||
| 
 | ||||
| 	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) { | ||||
| 		inet_sk_state_store(sk, TCP_CLOSE); | ||||
| 		goto cleanup; | ||||
| 	} | ||||
| 
 | ||||
| 	if (mptcp_close_state(sk)) | ||||
| 		__mptcp_wr_shutdown(sk); | ||||
| 
 | ||||
| 	sk_stream_wait_close(sk, timeout); | ||||
| 
 | ||||
| cleanup: | ||||
| 	/* orphan all the subflows */ | ||||
| 	inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32; | ||||
| 	list_for_each_entry(subflow, &mptcp_sk(sk)->conn_list, node) { | ||||
| 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow); | ||||
| 		bool slow, dispose_socket; | ||||
| 		struct socket *sock; | ||||
| 
 | ||||
| 		slow = lock_sock_fast(ssk); | ||||
| 		sock = ssk->sk_socket; | ||||
| 		dispose_socket = sock && sock != sk->sk_socket; | ||||
| 		sock_orphan(ssk); | ||||
| 		unlock_sock_fast(ssk, slow); | ||||
| 
 | ||||
| 		/* for the outgoing subflows we additionally need to free
 | ||||
| 		 * the associated socket | ||||
| 		 */ | ||||
| 		if (dispose_socket) | ||||
| 			iput(SOCK_INODE(sock)); | ||||
| 	} | ||||
| 	sock_orphan(sk); | ||||
| 
 | ||||
| 	sock_hold(sk); | ||||
| 	pr_debug("msk=%p state=%d", sk, sk->sk_state); | ||||
| 	if (sk->sk_state == TCP_CLOSE) { | ||||
| 		__mptcp_destroy_sock(sk); | ||||
| 		do_cancel_work = true; | ||||
| 	} else { | ||||
| 		sk_reset_timer(sk, &sk->sk_timer, jiffies + TCP_TIMEWAIT_LEN); | ||||
| 	} | ||||
| 	release_sock(sk); | ||||
| 	if (do_cancel_work) | ||||
| 		mptcp_cancel_work(sk); | ||||
| 	sock_put(sk); | ||||
| } | ||||
| 
 | ||||
| static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) | ||||
|  | @ -2183,6 +2351,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, | |||
| 		newsk = new_mptcp_sock; | ||||
| 		mptcp_copy_inaddrs(newsk, ssk); | ||||
| 		list_add(&subflow->node, &msk->conn_list); | ||||
| 		sock_hold(ssk); | ||||
| 
 | ||||
| 		mptcp_rcv_space_init(msk, ssk); | ||||
| 		bh_unlock_sock(new_mptcp_sock); | ||||
|  | @ -2430,9 +2599,9 @@ static void mptcp_sock_graft(struct sock *sk, struct socket *parent) | |||
| 	write_unlock_bh(&sk->sk_callback_lock); | ||||
| } | ||||
| 
 | ||||
| bool mptcp_finish_join(struct sock *sk) | ||||
| bool mptcp_finish_join(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); | ||||
| 	struct sock *parent = (void *)msk; | ||||
| 	struct socket *parent_sock; | ||||
|  | @ -2453,12 +2622,14 @@ bool mptcp_finish_join(struct sock *sk) | |||
| 	/* active connections are already on conn_list, and we can't acquire
 | ||||
| 	 * msk lock here. | ||||
| 	 * use the join list lock as synchronization point and double-check | ||||
| 	 * msk status to avoid racing with mptcp_close() | ||||
| 	 * msk status to avoid racing with __mptcp_destroy_sock() | ||||
| 	 */ | ||||
| 	spin_lock_bh(&msk->join_list_lock); | ||||
| 	ret = inet_sk_state_load(parent) == TCP_ESTABLISHED; | ||||
| 	if (ret && !WARN_ON_ONCE(!list_empty(&subflow->node))) | ||||
| 	if (ret && !WARN_ON_ONCE(!list_empty(&subflow->node))) { | ||||
| 		list_add_tail(&subflow->node, &msk->join_list); | ||||
| 		sock_hold(ssk); | ||||
| 	} | ||||
| 	spin_unlock_bh(&msk->join_list_lock); | ||||
| 	if (!ret) | ||||
| 		return false; | ||||
|  | @ -2467,8 +2638,8 @@ bool mptcp_finish_join(struct sock *sk) | |||
| 	 * at close time | ||||
| 	 */ | ||||
| 	parent_sock = READ_ONCE(parent->sk_socket); | ||||
| 	if (parent_sock && !sk->sk_socket) | ||||
| 		mptcp_sock_graft(sk, parent_sock); | ||||
| 	if (parent_sock && !ssk->sk_socket) | ||||
| 		mptcp_sock_graft(ssk, parent_sock); | ||||
| 	subflow->map_seq = READ_ONCE(msk->ack_seq); | ||||
| 	return true; | ||||
| } | ||||
|  | @ -2704,12 +2875,12 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, | |||
| static int mptcp_shutdown(struct socket *sock, int how) | ||||
| { | ||||
| 	struct mptcp_sock *msk = mptcp_sk(sock->sk); | ||||
| 	struct mptcp_subflow_context *subflow; | ||||
| 	struct sock *sk = sock->sk; | ||||
| 	int ret = 0; | ||||
| 
 | ||||
| 	pr_debug("sk=%p, how=%d", msk, how); | ||||
| 
 | ||||
| 	lock_sock(sock->sk); | ||||
| 	lock_sock(sk); | ||||
| 
 | ||||
| 	how++; | ||||
| 	if ((how & ~SHUTDOWN_MASK) || !how) { | ||||
|  | @ -2718,45 +2889,22 @@ static int mptcp_shutdown(struct socket *sock, int how) | |||
| 	} | ||||
| 
 | ||||
| 	if (sock->state == SS_CONNECTING) { | ||||
| 		if ((1 << sock->sk->sk_state) & | ||||
| 		if ((1 << sk->sk_state) & | ||||
| 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE)) | ||||
| 			sock->state = SS_DISCONNECTING; | ||||
| 		else | ||||
| 			sock->state = SS_CONNECTED; | ||||
| 	} | ||||
| 
 | ||||
| 	/* If we've already sent a FIN, or it's a closed state, skip this. */ | ||||
| 	if (__mptcp_check_fallback(msk)) { | ||||
| 		if (how == SHUT_WR || how == SHUT_RDWR) | ||||
| 			inet_sk_state_store(sock->sk, TCP_FIN_WAIT1); | ||||
| 
 | ||||
| 		mptcp_for_each_subflow(msk, subflow) { | ||||
| 			struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); | ||||
| 
 | ||||
| 			mptcp_subflow_shutdown(sock->sk, tcp_sk, how); | ||||
| 		} | ||||
| 	} else if ((how & SEND_SHUTDOWN) && | ||||
| 		   ((1 << sock->sk->sk_state) & | ||||
| 		    (TCPF_ESTABLISHED | TCPF_SYN_SENT | | ||||
| 		     TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) && | ||||
| 		   mptcp_close_state(sock->sk)) { | ||||
| 		__mptcp_flush_join_list(msk); | ||||
| 
 | ||||
| 		WRITE_ONCE(msk->write_seq, msk->write_seq + 1); | ||||
| 		WRITE_ONCE(msk->snd_data_fin_enable, 1); | ||||
| 
 | ||||
| 		mptcp_for_each_subflow(msk, subflow) { | ||||
| 			struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); | ||||
| 
 | ||||
| 			mptcp_subflow_shutdown(sock->sk, tcp_sk, how); | ||||
| 		} | ||||
| 	} | ||||
| 	sk->sk_shutdown |= how; | ||||
| 	if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk)) | ||||
| 		__mptcp_wr_shutdown(sk); | ||||
| 
 | ||||
| 	/* Wake up anyone sleeping in poll. */ | ||||
| 	sock->sk->sk_state_change(sock->sk); | ||||
| 	sk->sk_state_change(sk); | ||||
| 
 | ||||
| out_unlock: | ||||
| 	release_sock(sock->sk); | ||||
| 	release_sock(sk); | ||||
| 
 | ||||
| 	return ret; | ||||
| } | ||||
|  |  | |||
|  | @ -91,6 +91,7 @@ | |||
| #define MPTCP_WORK_EOF		3 | ||||
| #define MPTCP_FALLBACK_DONE	4 | ||||
| #define MPTCP_WORK_CLOSE_SUBFLOW 5 | ||||
| #define MPTCP_WORKER_RUNNING	6 | ||||
| 
 | ||||
| static inline bool before64(__u64 seq1, __u64 seq2) | ||||
| { | ||||
|  | @ -352,7 +353,8 @@ struct mptcp_subflow_context { | |||
| 		mpc_map : 1, | ||||
| 		backup : 1, | ||||
| 		rx_eof : 1, | ||||
| 		can_ack : 1;	    /* only after processing the remote a key */ | ||||
| 		can_ack : 1,        /* only after processing the remote a key */ | ||||
| 		disposable : 1;	    /* ctx can be free at ulp release time */ | ||||
| 	enum mptcp_data_avail data_avail; | ||||
| 	u32	remote_nonce; | ||||
| 	u64	thmac; | ||||
|  | @ -409,8 +411,7 @@ bool mptcp_subflow_data_available(struct sock *sk); | |||
| void __init mptcp_subflow_init(void); | ||||
| void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how); | ||||
| void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, | ||||
| 		       struct mptcp_subflow_context *subflow, | ||||
| 		       long timeout); | ||||
| 		       struct mptcp_subflow_context *subflow); | ||||
| void mptcp_subflow_reset(struct sock *ssk); | ||||
| 
 | ||||
| /* called with sk socket lock held */ | ||||
|  | @ -452,6 +453,12 @@ bool mptcp_schedule_work(struct sock *sk); | |||
| void mptcp_data_acked(struct sock *sk); | ||||
| void mptcp_subflow_eof(struct sock *sk); | ||||
| bool mptcp_update_rcv_data_fin(struct mptcp_sock *msk, u64 data_fin_seq, bool use_64bit); | ||||
| static inline bool mptcp_data_fin_enabled(const struct mptcp_sock *msk) | ||||
| { | ||||
| 	return READ_ONCE(msk->snd_data_fin_enable) && | ||||
| 	       READ_ONCE(msk->write_seq) == READ_ONCE(msk->snd_nxt); | ||||
| } | ||||
| 
 | ||||
| void mptcp_destroy_common(struct mptcp_sock *msk); | ||||
| 
 | ||||
| void __init mptcp_token_init(void); | ||||
|  |  | |||
|  | @ -1125,6 +1125,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, | |||
| 	if (err && err != -EINPROGRESS) | ||||
| 		goto failed; | ||||
| 
 | ||||
| 	sock_hold(ssk); | ||||
| 	spin_lock_bh(&msk->join_list_lock); | ||||
| 	list_add_tail(&subflow->node, &msk->join_list); | ||||
| 	spin_unlock_bh(&msk->join_list_lock); | ||||
|  | @ -1132,6 +1133,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, | |||
| 	return err; | ||||
| 
 | ||||
| failed: | ||||
| 	subflow->disposable = 1; | ||||
| 	sock_release(sf); | ||||
| 	return err; | ||||
| } | ||||
|  | @ -1254,7 +1256,6 @@ static void subflow_state_change(struct sock *sk) | |||
| 		mptcp_data_ready(parent, sk); | ||||
| 
 | ||||
| 	if (__mptcp_check_fallback(mptcp_sk(parent)) && | ||||
| 	    !(parent->sk_shutdown & RCV_SHUTDOWN) && | ||||
| 	    !subflow->rx_eof && subflow_is_done(sk)) { | ||||
| 		subflow->rx_eof = 1; | ||||
| 		mptcp_subflow_eof(parent); | ||||
|  | @ -1297,17 +1298,26 @@ static int subflow_ulp_init(struct sock *sk) | |||
| 	return err; | ||||
| } | ||||
| 
 | ||||
| static void subflow_ulp_release(struct sock *sk) | ||||
| static void subflow_ulp_release(struct sock *ssk) | ||||
| { | ||||
| 	struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk); | ||||
| 	struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(ssk); | ||||
| 	bool release = true; | ||||
| 	struct sock *sk; | ||||
| 
 | ||||
| 	if (!ctx) | ||||
| 		return; | ||||
| 
 | ||||
| 	if (ctx->conn) | ||||
| 		sock_put(ctx->conn); | ||||
| 	sk = ctx->conn; | ||||
| 	if (sk) { | ||||
| 		/* if the msk has been orphaned, keep the ctx
 | ||||
| 		 * alive, will be freed by mptcp_done() | ||||
| 		 */ | ||||
| 		release = ctx->disposable; | ||||
| 		sock_put(sk); | ||||
| 	} | ||||
| 
 | ||||
| 	kfree_rcu(ctx, rcu); | ||||
| 	if (release) | ||||
| 		kfree_rcu(ctx, rcu); | ||||
| } | ||||
| 
 | ||||
| static void subflow_ulp_clone(const struct request_sock *req, | ||||
|  |  | |||
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		Reference in a new issue
	
	 Paolo Abeni
						Paolo Abeni