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author | Paolo Abeni <pabeni@redhat.com> | 2020-05-15 19:22:15 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-05-15 12:30:13 -0700 |
commit | 90bf45134d55d626ae2713cac50cda10c6c8b0c2 (patch) | |
tree | 03acba9e0f9f038350654ad942bca2dfafe2d970 /net/mptcp | |
parent | ca1c933bcee9393d8a83c6be1093471e0c3b655d (diff) | |
download | linux-stable-90bf45134d55d626ae2713cac50cda10c6c8b0c2.tar.gz linux-stable-90bf45134d55d626ae2713cac50cda10c6c8b0c2.tar.bz2 linux-stable-90bf45134d55d626ae2713cac50cda10c6c8b0c2.zip |
mptcp: add new sock flag to deal with join subflows
MP_JOIN subflows must not land into the accept queue.
Currently tcp_check_req() calls an mptcp specific helper
to detect such scenario.
Such helper leverages the subflow context to check for
MP_JOIN subflows. We need to deal also with MP JOIN
failures, even when the subflow context is not available
due allocation failure.
A possible solution would be changing the syn_recv_sock()
signature to allow returning a more descriptive action/
error code and deal with that in tcp_check_req().
Since the above need is MPTCP specific, this patch instead
uses a TCP request socket hole to add a MPTCP specific flag.
Such flag is used by the MPTCP syn_recv_sock() to tell
tcp_check_req() how to deal with the request socket.
This change is a no-op for !MPTCP build, and makes the
MPTCP code simpler. It allows also the next patch to deal
correctly with MP JOIN failure.
v1 -> v2:
- be more conservative on drop_req initialization (Mat)
RFC -> v1:
- move the drop_req bit inside tcp_request_sock (Eric)
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r-- | net/mptcp/protocol.c | 7 | ||||
-rw-r--r-- | net/mptcp/subflow.c | 3 |
2 files changed, 3 insertions, 7 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e1f23016ed3f..a61e60e94137 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1638,13 +1638,6 @@ bool mptcp_finish_join(struct sock *sk) return ret; } -bool mptcp_sk_is_subflow(const struct sock *sk) -{ - struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - - return subflow->mp_join == 1; -} - static bool mptcp_memory_free(const struct sock *sk, int wake) { struct mptcp_sock *msk = mptcp_sk(sk); diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 009d5c478062..5e03ed8ae899 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -470,6 +470,8 @@ create_child: if (child && *own_req) { struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(child); + tcp_rsk(req)->drop_req = false; + /* we need to fallback on ctx allocation failure and on pre-reqs * checking above. In the latter scenario we additionally need * to reset the context to non MPTCP status. @@ -512,6 +514,7 @@ create_child: goto close_child; SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX); + tcp_rsk(req)->drop_req = true; } } |