diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2020-03-13 16:52:41 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-03-15 00:19:03 -0700 |
| commit | 58b09919626bf9067345289212ec030c61eb1034 (patch) | |
| tree | 88a92c876cccfbad9904f97e4afd5e2e607fb25b /net/mptcp/protocol.c | |
| parent | 7a1d0e61f11676f066dc3571543b8e104ff0d055 (diff) | |
mptcp: create msk early
This change moves the mptcp socket allocation from mptcp_accept() to
subflow_syn_recv_sock(), so that subflow->conn is now always set
for the non fallback scenario.
It allows cleaning up a bit mptcp_accept() reducing the additional
locking and will allow fourther cleanup in the next patch.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/protocol.c')
| -rw-r--r-- | net/mptcp/protocol.c | 83 |
1 files changed, 45 insertions, 38 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index c0cef07f4382..04c3caed92df 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -820,9 +820,12 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) } #endif -static struct sock *mptcp_sk_clone_lock(const struct sock *sk) +struct sock *mptcp_sk_clone(const struct sock *sk, struct request_sock *req) { + struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); + struct mptcp_sock *msk; + u64 ack_seq; if (!nsk) return NULL; @@ -832,6 +835,36 @@ static struct sock *mptcp_sk_clone_lock(const struct sock *sk) inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); #endif + __mptcp_init_sock(nsk); + + msk = mptcp_sk(nsk); + msk->local_key = subflow_req->local_key; + msk->token = subflow_req->token; + msk->subflow = NULL; + + if (unlikely(mptcp_token_new_accept(subflow_req->token, nsk))) { + bh_unlock_sock(nsk); + + /* we can't call into mptcp_close() here - possible BH context + * free the sock directly + */ + nsk->sk_prot->destroy(nsk); + sk_free(nsk); + return NULL; + } + + msk->write_seq = subflow_req->idsn + 1; + if (subflow_req->remote_key_valid) { + msk->can_ack = true; + msk->remote_key = subflow_req->remote_key; + mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); + ack_seq++; + msk->ack_seq = ack_seq; + } + bh_unlock_sock(nsk); + + /* keep a single reference */ + __sock_put(nsk); return nsk; } @@ -859,40 +892,26 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, struct mptcp_subflow_context *subflow; struct sock *new_mptcp_sock; struct sock *ssk = newsk; - u64 ack_seq; subflow = mptcp_subflow_ctx(newsk); - lock_sock(sk); + new_mptcp_sock = subflow->conn; - local_bh_disable(); - new_mptcp_sock = mptcp_sk_clone_lock(sk); - if (!new_mptcp_sock) { - *err = -ENOBUFS; - local_bh_enable(); - release_sock(sk); - mptcp_subflow_shutdown(newsk, SHUT_RDWR + 1, 0, 0); - tcp_close(newsk, 0); - return NULL; + /* is_mptcp should be false if subflow->conn is missing, see + * subflow_syn_recv_sock() + */ + if (WARN_ON_ONCE(!new_mptcp_sock)) { + tcp_sk(newsk)->is_mptcp = 0; + return newsk; } - __mptcp_init_sock(new_mptcp_sock); + /* acquire the 2nd reference for the owning socket */ + sock_hold(new_mptcp_sock); + local_bh_disable(); + bh_lock_sock(new_mptcp_sock); msk = mptcp_sk(new_mptcp_sock); - msk->local_key = subflow->local_key; - msk->token = subflow->token; - msk->subflow = NULL; msk->first = newsk; - mptcp_token_update_accept(newsk, new_mptcp_sock); - - msk->write_seq = subflow->idsn + 1; - if (subflow->can_ack) { - msk->can_ack = true; - msk->remote_key = subflow->remote_key; - mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); - ack_seq++; - msk->ack_seq = ack_seq; - } newsk = new_mptcp_sock; mptcp_copy_inaddrs(newsk, ssk); list_add(&subflow->node, &msk->conn_list); @@ -903,18 +922,6 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV); bh_unlock_sock(new_mptcp_sock); local_bh_enable(); - release_sock(sk); - - /* the subflow can already receive packet, avoid racing with - * the receive path and process the pending ones - */ - lock_sock(ssk); - subflow->rel_write_seq = 1; - subflow->tcp_sock = ssk; - subflow->conn = new_mptcp_sock; - if (unlikely(!skb_queue_empty(&ssk->sk_receive_queue))) - mptcp_subflow_data_available(ssk); - release_sock(ssk); } return newsk; |