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authorPaolo Abeni <pabeni@redhat.com>2020-11-16 10:48:09 +0100
committerJakub Kicinski <kuba@kernel.org>2020-11-16 19:46:07 +0100
commite16163b6e2b720fb74e5af758546f6dad27e6c9e (patch)
tree85e5123bc59744f1fd1a3110f5b517b5baa5f356 /net
parentmptcp: introduce MPTCP snd_nxt (diff)
downloadlinux-e16163b6e2b720fb74e5af758546f6dad27e6c9e.tar.xz
linux-e16163b6e2b720fb74e5af758546f6dad27e6c9e.zip
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>
Diffstat (limited to 'net')
-rw-r--r--net/mptcp/options.c2
-rw-r--r--net/mptcp/pm_netlink.c6
-rw-r--r--net/mptcp/protocol.c340
-rw-r--r--net/mptcp/protocol.h13
-rw-r--r--net/mptcp/subflow.c22
5 files changed, 273 insertions, 110 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index a6b57021b6d0..1be272d2bd95 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -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;
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 446ef8f07734..f8a9d82a0ea8 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -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--;
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 2b0fd08b03f9..daa51e657db8 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -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);
+ 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 {
- /* incoming subflow */
- tcp_close(ssk, timeout);
+ /* 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 @@ reset_unlock:
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, *tmp;
+ struct mptcp_subflow_context *subflow;
struct mptcp_sock *msk = mptcp_sk(sk);
- LIST_HEAD(conn_list);
- lock_sock(sk);
- sk->sk_shutdown = SHUTDOWN_MASK;
+ 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);
- if (sk->sk_state == TCP_LISTEN) {
+ /* 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);
- goto cleanup;
- } else if (sk->sk_state == TCP_CLOSE) {
- goto cleanup;
+ mptcp_close_wake_up(sk);
}
- 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_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, SHUTDOWN_MASK);
- }
+ mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN);
}
+}
- sk_stream_wait_close(sk, timeout);
+static void __mptcp_wr_shutdown(struct sock *sk)
+{
+ struct mptcp_sock *msk = mptcp_sk(sk);
-update_state:
- inet_sk_state_store(sk, TCP_CLOSE);
+ 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);
+
+ pr_debug("msk=%p", msk);
-cleanup:
/* be sure to always acquire the join list lock, to sync vs
* mptcp_finish_join().
*/
@@ -2018,19 +2131,74 @@ cleanup:
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);
+}
+
+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;
+ }
- sk_common_release(sk);
+ 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;
}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 946319cf9cca..fd9c666aed7f 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -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);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index ac4a1fe3550b..42581ffb0c7e 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -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 @@ out:
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,