Commit e9b12edc authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

tcp: record received TOS value in the request socket 



A new field is added to the request sock to record the TOS value
received on the listening socket during 3WHS:
When not under syn flood, it is recording the TOS value sent in SYN.
When under syn flood, it is recording the TOS value sent in the ACK.
This is a preparation patch in order to do TOS reflection in the later
commit.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3a8c4ad1

include/linux/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ struct tcp_request_sock { 
						  * FastOpen it's the seq#

						  * after data-in-SYN.

						  */

	u8				syn_tos;

};



static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)

net/ipv4/syncookies.c

+3 −3
Original line number Diff line number Diff line
@@ -286,11 +286,10 @@ 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

	struct tcp_request_sock *treq;



	if (sk_is_mptcp(sk))

		ops = &mptcp_subflow_request_sock_ops;

#endif
@@ -299,8 +298,9 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, 
	if (!req)

		return NULL;



#if IS_ENABLED(CONFIG_MPTCP)

	treq = tcp_rsk(req);

	treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;

#if IS_ENABLED(CONFIG_MPTCP)

	treq->is_mptcp = sk_is_mptcp(sk);

	if (treq->is_mptcp) {

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

net/ipv4/tcp_input.c

+1 −0
Original line number Diff line number Diff line
@@ -6834,6 +6834,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, 


	tcp_rsk(req)->snt_isn = isn;

	tcp_rsk(req)->txhash = net_tx_rndhash();

	tcp_rsk(req)->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;

	tcp_openreq_init_rwin(req, sk, dst);

	sk_rx_queue_set(req_to_sk(req), skb);

	if (!want_cookie) {