deal with fallback: we must reset sk callback to the TCP one. Use the cached ptr in the old ctx. Signed-off-by: Paolo Abeni <pabeni(a)redhat.com&gt; --- net/mptcp/protocol.h | 13 ++++++++++++- net/mptcp/subflow.c | 11 ++++++++--- 2 files changed, 20 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index e4fce9f0ad65..7f3cc7952227 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -121,7 +121,10 @@ struct mptcp_subflow_context { struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ const struct inet_connection_sock_af_ops *icsk_af_ops; - void (*tcp_sk_data_ready)(struct sock *sk); + void (*tcp_data_ready)(struct sock *sk); + void (*tcp_state_change)(struct sock *sk); + void (*tcp_write_space)(struct sock *sk); + struct rcu_head rcu; }; @@ -159,6 +162,14 @@ bool mptcp_subflow_data_available(struct sock *sk); void mptcp_subflow_init(void); int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock); +static inline void mptcp_subflow_tcp_fallback(struct sock *sk, + struct mptcp_subflow_context *ctx) +{ + sk->sk_data_ready = ctx->tcp_data_ready; + sk->sk_state_change = ctx->tcp_state_change; + sk->sk_write_space = ctx->tcp_write_space; +} + extern const struct inet_connection_sock_af_ops ipv4_specific; #if IS_ENABLED(CONFIG_MPTCP_IPV6) extern const struct inet_connection_sock_af_ops ipv6_specific; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 48bf0b1d8d28..3ac1764f276b 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -504,7 +504,7 @@ static void subflow_data_ready(struct sock *sk) struct sock *parent = subflow->conn; if (!parent || !subflow->mp_capable) { - subflow->tcp_sk_data_ready(sk); + subflow->tcp_data_ready(sk); if (parent) parent->sk_data_ready(parent); @@ -652,7 +652,9 @@ static int subflow_ulp_init(struct sock *sk) if (sk->sk_family == AF_INET6) icsk->icsk_af_ops = &subflow_v6_specific; #endif - ctx->tcp_sk_data_ready = sk->sk_data_ready; + ctx->tcp_data_ready = sk->sk_data_ready; + ctx->tcp_state_change = sk->sk_state_change; + ctx->tcp_write_space = sk->sk_write_space; sk->sk_data_ready = subflow_data_ready; sk->sk_write_space = subflow_write_space; sk->sk_state_change = subflow_state_change; @@ -683,6 +685,7 @@ static void subflow_ulp_clone(const struct request_sock *req, if (!subflow_req->mp_capable || (new_ctx = subflow_create_ctx(newsk, priority)) == NULL) { + mptcp_subflow_tcp_fallback(newsk, old_ctx); tcp_sk(newsk)->is_mptcp = 0; return; } @@ -690,7 +693,9 @@ static void subflow_ulp_clone(const struct request_sock *req, new_ctx->conn = NULL; new_ctx->conn_finished = 1; new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; - new_ctx->tcp_sk_data_ready = old_ctx->tcp_sk_data_ready; + 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->mp_capable = 1; new_ctx->fourth_ack = 1; new_ctx->remote_key = subflow_req->remote_key; -- 2.21.0