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authorPaolo Abeni <pabeni@redhat.com>2020-05-15 19:22:15 +0200
committerDavid S. Miller <davem@davemloft.net>2020-05-15 12:30:13 -0700
commit90bf45134d55d626ae2713cac50cda10c6c8b0c2 (patch)
tree03acba9e0f9f038350654ad942bca2dfafe2d970 /net/mptcp
parentca1c933bcee9393d8a83c6be1093471e0c3b655d (diff)
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.c7
-rw-r--r--net/mptcp/subflow.c3
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;
}
}