mptcp: subflow: split subflow_init_req

When syncookie support is added, we will need to add a variant of
subflow_init_req() helper.  It will do almost same thing except
that it will not compute/add a token to the mptcp token tree.

To avoid excess copy&paste, this commit splits away part of the
code into a new helper, __subflow_init_req, that can then be re-used
from the 'no insert' function added in a followup change.

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 9feb878..091e305 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -91,17 +91,9 @@ static struct mptcp_sock *subflow_token_join_request(struct request_sock *req,
        return msk;
 }
 
-static void subflow_init_req(struct request_sock *req,
-                            const struct sock *sk_listener,
-                            struct sk_buff *skb)
+static int __subflow_init_req(struct request_sock *req, const struct sock *sk_listener)
 {
-       struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
        struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
-       struct mptcp_options_received mp_opt;
-
-       pr_debug("subflow_req=%p, listener=%p", subflow_req, listener);
-
-       mptcp_get_options(skb, &mp_opt);
 
        subflow_req->mp_capable = 0;
        subflow_req->mp_join = 0;
@@ -113,9 +105,29 @@ static void subflow_init_req(struct request_sock *req,
         * TCP option space.
         */
        if (rcu_access_pointer(tcp_sk(sk_listener)->md5sig_info))
-               return;
+               return -EINVAL;
 #endif
 
+       return 0;
+}
+
+static void subflow_init_req(struct request_sock *req,
+                            const struct sock *sk_listener,
+                            struct sk_buff *skb)
+{
+       struct mptcp_subflow_context *listener = mptcp_subflow_ctx(sk_listener);
+       struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req);
+       struct mptcp_options_received mp_opt;
+       int ret;
+
+       pr_debug("subflow_req=%p, listener=%p", subflow_req, listener);
+
+       ret = __subflow_init_req(req, sk_listener);
+       if (ret)
+               return;
+
+       mptcp_get_options(skb, &mp_opt);
+
        if (mp_opt.mp_capable) {
                SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MPCAPABLEPASSIVE);