From: Paolo Abeni pabeni@redhat.com
[ Upstream commit 15cc10453398c22f78f6c2b897119ecce5e5dd89 ]
Currently all errors received on msk subflows are ignored. We need to catch at least the errors on connect() and on fallback sockets.
Use a custom sk_error_report callback at subflow level, and do the real action under the msk socket lock - via the usual sock_owned_by_user()/release_callback() schema.
Fixes: 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks") Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/protocol.c | 7 +++++++ net/mptcp/protocol.h | 4 ++++ net/mptcp/subflow.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 7345df40385a..f588332eebb4 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2958,6 +2958,8 @@ static void mptcp_release_cb(struct sock *sk) mptcp_push_pending(sk, 0); spin_lock_bh(&sk->sk_lock.slock); } + if (test_and_clear_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags)) + __mptcp_error_report(sk);
/* clear any wmem reservation and errors */ __mptcp_update_wmem(sk); @@ -3354,6 +3356,11 @@ static __poll_t mptcp_poll(struct file *file, struct socket *sock, if (sk->sk_shutdown & RCV_SHUTDOWN) mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
+ /* This barrier is coupled with smp_wmb() in tcp_reset() */ + smp_rmb(); + if (sk->sk_err) + mask |= EPOLLERR; + return mask; }
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index c374345ad134..62288836d053 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -96,6 +96,7 @@ #define MPTCP_WORK_CLOSE_SUBFLOW 5 #define MPTCP_PUSH_PENDING 6 #define MPTCP_CLEAN_UNA 7 +#define MPTCP_ERROR_REPORT 8
static inline bool before64(__u64 seq1, __u64 seq2) { @@ -413,6 +414,7 @@ struct mptcp_subflow_context { void (*tcp_data_ready)(struct sock *sk); void (*tcp_state_change)(struct sock *sk); void (*tcp_write_space)(struct sock *sk); + void (*tcp_error_report)(struct sock *sk);
struct rcu_head rcu; }; @@ -478,6 +480,7 @@ static inline void mptcp_subflow_tcp_fallback(struct sock *sk, sk->sk_data_ready = ctx->tcp_data_ready; sk->sk_state_change = ctx->tcp_state_change; sk->sk_write_space = ctx->tcp_write_space; + sk->sk_error_report = ctx->tcp_error_report;
inet_csk(sk)->icsk_af_ops = ctx->icsk_af_ops; } @@ -505,6 +508,7 @@ bool mptcp_finish_join(struct sock *sk); bool mptcp_schedule_work(struct sock *sk); void __mptcp_check_push(struct sock *sk, struct sock *ssk); void __mptcp_data_acked(struct sock *sk); +void __mptcp_error_report(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); void __mptcp_flush_join_list(struct mptcp_sock *msk); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 96e040951cd4..6c0205816a5d 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1054,6 +1054,46 @@ static void subflow_write_space(struct sock *ssk) /* we take action in __mptcp_clean_una() */ }
+void __mptcp_error_report(struct sock *sk) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + int err = sock_error(ssk); + + if (!err) + continue; + + /* only propagate errors on fallen-back sockets or + * on MPC connect + */ + if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(msk)) + continue; + + inet_sk_state_store(sk, inet_sk_state_load(ssk)); + sk->sk_err = -err; + + /* This barrier is coupled with smp_rmb() in mptcp_poll() */ + smp_wmb(); + sk->sk_error_report(sk); + break; + } +} + +static void subflow_error_report(struct sock *ssk) +{ + struct sock *sk = mptcp_subflow_ctx(ssk)->conn; + + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_error_report(sk); + else + set_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags); + mptcp_data_unlock(sk); +} + static struct inet_connection_sock_af_ops * subflow_default_af_ops(struct sock *sk) { @@ -1367,9 +1407,11 @@ static int subflow_ulp_init(struct sock *sk) ctx->tcp_data_ready = sk->sk_data_ready; ctx->tcp_state_change = sk->sk_state_change; ctx->tcp_write_space = sk->sk_write_space; + ctx->tcp_error_report = sk->sk_error_report; sk->sk_data_ready = subflow_data_ready; sk->sk_write_space = subflow_write_space; sk->sk_state_change = subflow_state_change; + sk->sk_error_report = subflow_error_report; out: return err; } @@ -1422,6 +1464,7 @@ static void subflow_ulp_clone(const struct request_sock *req, new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; new_ctx->tcp_state_change = old_ctx->tcp_state_change; new_ctx->tcp_write_space = old_ctx->tcp_write_space; + new_ctx->tcp_error_report = old_ctx->tcp_error_report; new_ctx->rel_write_seq = 1; new_ctx->tcp_sock = newsk;