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-rw-r--r--net/mptcp/pm.c8
-rw-r--r--net/mptcp/protocol.c11
-rw-r--r--net/mptcp/protocol.h7
-rw-r--r--net/mptcp/subflow.c19
4 files changed, 32 insertions, 13 deletions
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index feb01747d7d8..420d416e2603 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -765,8 +765,14 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
pr_debug("fail_seq=%llu\n", fail_seq);
- if (!READ_ONCE(msk->allow_infinite_fallback))
+ /* After accepting the fail, we can't create any other subflows */
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_infinite_fallback) {
+ spin_unlock_bh(&msk->fallback_lock);
return;
+ }
+ msk->allow_subflows = false;
+ spin_unlock_bh(&msk->fallback_lock);
if (!subflow->fail_tout) {
pr_debug("send MP_FAIL response and infinite map\n");
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b08a42fcbb65..bf92cee9b5ce 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -791,7 +791,7 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk)
static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk)
{
mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq);
- WRITE_ONCE(msk->allow_infinite_fallback, false);
+ msk->allow_infinite_fallback = false;
mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC);
}
@@ -803,7 +803,7 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk)
return false;
spin_lock_bh(&msk->fallback_lock);
- if (__mptcp_check_fallback(msk)) {
+ if (!msk->allow_subflows) {
spin_unlock_bh(&msk->fallback_lock);
return false;
}
@@ -2625,7 +2625,7 @@ static void __mptcp_retrans(struct sock *sk)
len = max(copied, len);
tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle,
info.size_goal);
- WRITE_ONCE(msk->allow_infinite_fallback, false);
+ msk->allow_infinite_fallback = false;
}
spin_unlock_bh(&msk->fallback_lock);
@@ -2753,7 +2753,8 @@ static void __mptcp_init_sock(struct sock *sk)
WRITE_ONCE(msk->first, NULL);
inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk)));
- WRITE_ONCE(msk->allow_infinite_fallback, true);
+ msk->allow_infinite_fallback = true;
+ msk->allow_subflows = true;
msk->recovery = false;
msk->subflow_id = 1;
msk->last_data_sent = tcp_jiffies32;
@@ -3549,7 +3550,7 @@ bool mptcp_finish_join(struct sock *ssk)
/* active subflow, already present inside the conn_list */
if (!list_empty(&subflow->node)) {
spin_lock_bh(&msk->fallback_lock);
- if (__mptcp_check_fallback(msk)) {
+ if (!msk->allow_subflows) {
spin_unlock_bh(&msk->fallback_lock);
return false;
}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 2a60c3c71651..6ec245fd2778 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -346,13 +346,15 @@ struct mptcp_sock {
u64 rtt_us; /* last maximum rtt of subflows */
} rcvq_space;
u8 scaling_ratio;
+ bool allow_subflows;
u32 subflow_id;
u32 setsockopt_seq;
char ca_name[TCP_CA_NAME_MAX];
- spinlock_t fallback_lock; /* protects fallback and
- * allow_infinite_fallback
+ spinlock_t fallback_lock; /* protects fallback,
+ * allow_infinite_fallback and
+ * allow_join
*/
};
@@ -1232,6 +1234,7 @@ static inline bool __mptcp_try_fallback(struct mptcp_sock *msk)
return false;
}
+ msk->allow_subflows = false;
set_bit(MPTCP_FALLBACK_DONE, &msk->flags);
spin_unlock_bh(&msk->fallback_lock);
return true;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index a6a35985e551..1802bc5435a1 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1302,20 +1302,29 @@ static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ss
mptcp_schedule_work(sk);
}
-static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
+static bool mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
unsigned long fail_tout;
+ /* we are really failing, prevent any later subflow join */
+ spin_lock_bh(&msk->fallback_lock);
+ if (!msk->allow_infinite_fallback) {
+ spin_unlock_bh(&msk->fallback_lock);
+ return false;
+ }
+ msk->allow_subflows = false;
+ spin_unlock_bh(&msk->fallback_lock);
+
/* graceful failure can happen only on the MPC subflow */
if (WARN_ON_ONCE(ssk != READ_ONCE(msk->first)))
- return;
+ return false;
/* since the close timeout take precedence on the fail one,
* no need to start the latter when the first is already set
*/
if (sock_flag((struct sock *)msk, SOCK_DEAD))
- return;
+ return true;
/* we don't need extreme accuracy here, use a zero fail_tout as special
* value meaning no fail timeout at all;
@@ -1327,6 +1336,7 @@ static void mptcp_subflow_fail(struct mptcp_sock *msk, struct sock *ssk)
tcp_send_ack(ssk);
mptcp_reset_tout_timer(msk, subflow->fail_tout);
+ return true;
}
static bool subflow_check_data_avail(struct sock *ssk)
@@ -1387,12 +1397,11 @@ fallback:
(subflow->mp_join || subflow->valid_csum_seen)) {
subflow->send_mp_fail = 1;
- if (!READ_ONCE(msk->allow_infinite_fallback)) {
+ if (!mptcp_subflow_fail(msk, ssk)) {
subflow->reset_transient = 0;
subflow->reset_reason = MPTCP_RST_EMIDDLEBOX;
goto reset;
}
- mptcp_subflow_fail(msk, ssk);
WRITE_ONCE(subflow->data_avail, true);
return true;
}