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mptcp: reset subflow when MP_FAIL doesn't respond

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This patch adds a new msk->flags bit MPTCP_FAIL_NO_RESPONSE, then reuses
sk_timer to trigger a check if we have not received a response from the
peer after sending MP_FAIL. If the peer doesn't respond properly, reset
the subflow.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Geliang Tang 2022-04-26 14:57:15 -07:00 committed by David S. Miller
parent 9c81be0dbc
commit 49fa1919d6
4 changed files with 68 additions and 0 deletions
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8
net/mptcp/pm.c
View File

@ -287,6 +287,7 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
struct mptcp_sock *msk = mptcp_sk(subflow->conn);
struct sock *s = (struct sock *)msk;
pr_debug("fail_seq=%llu", fail_seq);
@ -299,6 +300,13 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
subflow->send_mp_fail = 1;
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX);
subflow->send_infinite_map = 1;
} else if (s && inet_sk_state_load(s) != TCP_CLOSE) {
pr_debug("MP_FAIL response received");
mptcp_data_lock(s);
if (inet_sk_state_load(s) != TCP_CLOSE)
sk_stop_timer(s, &s->sk_timer);
mptcp_data_unlock(s);
}
}

48
net/mptcp/protocol.c
View File

@ -2169,10 +2169,38 @@ static void mptcp_retransmit_timer(struct timer_list *t)
sock_put(sk);
}
static struct mptcp_subflow_context *
mp_fail_response_expect_subflow(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow, *ret = NULL;
mptcp_for_each_subflow(msk, subflow) {
if (READ_ONCE(subflow->mp_fail_response_expect)) {
ret = subflow;
break;
}
}
return ret;
}
static void mptcp_check_mp_fail_response(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
struct sock *sk = (struct sock *)msk;
bh_lock_sock(sk);
subflow = mp_fail_response_expect_subflow(msk);
if (subflow)
__set_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags);
bh_unlock_sock(sk);
}
static void mptcp_timeout_timer(struct timer_list *t)
{
struct sock *sk = from_timer(sk, t, sk_timer);
mptcp_check_mp_fail_response(mptcp_sk(sk));
mptcp_schedule_work(sk);
sock_put(sk);
}
@ -2499,6 +2527,23 @@ reset_timer:
mptcp_data_unlock(sk);
}
static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
{
struct mptcp_subflow_context *subflow;
struct sock *ssk;
bool slow;
subflow = mp_fail_response_expect_subflow(msk);
if (subflow) {
pr_debug("MP_FAIL doesn't respond, reset the subflow");
ssk = mptcp_subflow_tcp_sock(subflow);
slow = lock_sock_fast(ssk);
mptcp_subflow_reset(ssk);
unlock_sock_fast(ssk, slow);
}
}
static void mptcp_worker(struct work_struct *work)
{
struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
@ -2539,6 +2584,9 @@ static void mptcp_worker(struct work_struct *work)
if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags))
__mptcp_retrans(sk);
if (test_and_clear_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags))
mptcp_mp_fail_no_response(msk);
unlock:
release_sock(sk);
sock_put(sk);

1
net/mptcp/protocol.h
View File

@ -116,6 +116,7 @@
#define MPTCP_WORK_EOF 3
#define MPTCP_FALLBACK_DONE 4
#define MPTCP_WORK_CLOSE_SUBFLOW 5
#define MPTCP_FAIL_NO_RESPONSE 6
/* MPTCP socket release cb flags */
#define MPTCP_PUSH_PENDING 1

11
net/mptcp/subflow.c
View File

@ -968,6 +968,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
bool csum_reqd = READ_ONCE(msk->csum_enabled);
struct sock *sk = (struct sock *)msk;
struct mptcp_ext *mpext;
struct sk_buff *skb;
u16 data_len;
@ -1009,6 +1010,12 @@ static enum mapping_status get_mapping_status(struct sock *ssk,
pr_debug("infinite mapping received");
MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX);
subflow->map_data_len = 0;
if (sk && inet_sk_state_load(sk) != TCP_CLOSE) {
mptcp_data_lock(sk);
if (inet_sk_state_load(sk) != TCP_CLOSE)
sk_stop_timer(sk, &sk->sk_timer);
mptcp_data_unlock(sk);
}
return MAPPING_INVALID;
}
@ -1219,6 +1226,10 @@ fallback:
sk_eat_skb(ssk, skb);
} else {
WRITE_ONCE(subflow->mp_fail_response_expect, true);
/* The data lock is acquired in __mptcp_move_skbs() */
sk_reset_timer((struct sock *)msk,
&((struct sock *)msk)->sk_timer,
jiffies + TCP_RTO_MAX);
}
WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA);
return true;