Commit 6fc8c827 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

tcp: syncookies: create mptcp request socket for ACK cookies with MPTCP option 



If SYN packet contains MP_CAPABLE option, keep it enabled.
Syncokie validation and cookie-based socket creation is changed to
instantiate an mptcp request sockets if the ACK contains an MPTCP
connection request.

Rather than extend both cookie_v4/6_check, add a common helper to create
the (mp)tcp request socket.

Suggested-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c83a47e5

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -469,6 +469,8 @@ struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, 
int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th,

		      u32 cookie);

struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb);

struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops,

					    struct sock *sk, struct sk_buff *skb);

#ifdef CONFIG_SYN_COOKIES



/* Syncookies use a monotonic timer which increments every 60 seconds.

net/ipv4/syncookies.c

+34 −4
Original line number Diff line number Diff line
@@ -276,6 +276,39 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, 
}

EXPORT_SYMBOL(cookie_ecn_ok);



struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops,

					    struct sock *sk,

					    struct sk_buff *skb)

{

	struct tcp_request_sock *treq;

	struct request_sock *req;



#ifdef CONFIG_MPTCP

	if (sk_is_mptcp(sk))

		ops = &mptcp_subflow_request_sock_ops;

#endif



	req = inet_reqsk_alloc(ops, sk, false);

	if (!req)

		return NULL;



#if IS_ENABLED(CONFIG_MPTCP)

	treq = tcp_rsk(req);

	treq->is_mptcp = sk_is_mptcp(sk);

	if (treq->is_mptcp) {

		int err = mptcp_subflow_init_cookie_req(req, sk, skb);



		if (err) {

			reqsk_free(req);

			return NULL;

		}

	}

#endif



	return req;

}

EXPORT_SYMBOL_GPL(cookie_tcp_reqsk_alloc);



/* On input, sk is a listener.

 * Output is listener if incoming packet would not create a child

 *           NULL if memory could not be allocated.
@@ -326,7 +359,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 
		goto out;



	ret = NULL;

	req = inet_reqsk_alloc(&tcp_request_sock_ops, sk, false); /* for safety */

	req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops, sk, skb);

	if (!req)

		goto out;
@@ -350,9 +383,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 
	treq->snt_synack	= 0;

	treq->tfo_listener	= false;



	if (IS_ENABLED(CONFIG_MPTCP))

		treq->is_mptcp = 0;



	if (IS_ENABLED(CONFIG_SMC))

		ireq->smc_ok = 0;

net/ipv4/tcp_input.c

+0 −3
Original line number Diff line number Diff line
@@ -6701,9 +6701,6 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, 


	af_ops->init_req(req, sk, skb);



	if (IS_ENABLED(CONFIG_MPTCP) && want_cookie)

		tcp_rsk(req)->is_mptcp = 0;



	if (security_inet_conn_request(sk, skb, req))

		goto drop_and_free;

net/ipv6/syncookies.c

+1 −4
Original line number Diff line number Diff line
@@ -170,7 +170,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
		goto out;



	ret = NULL;

	req = inet_reqsk_alloc(&tcp6_request_sock_ops, sk, false);

	req = cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops, sk, skb);

	if (!req)

		goto out;
@@ -178,9 +178,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	treq = tcp_rsk(req);

	treq->tfo_listener = false;



	if (IS_ENABLED(CONFIG_MPTCP))

		treq->is_mptcp = 0;



	if (security_inet_conn_request(sk, skb, req))

		goto out_free;