Commit de5626b9 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

tcp: Factorise cookie-independent fields initialisation in cookie_v[46]_check(). 



We will support arbitrary SYN Cookie with BPF, and then some reqsk fields
are initialised in kfunc, and others are done in cookie_v[46]_check().

This patch factorises the common part as cookie_tcp_reqsk_init() and
calls it in cookie_tcp_reqsk_alloc() to minimise the discrepancy between
cookie_v[46]_check().

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-8-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 7b0f570f

net/ipv4/syncookies.c

+37 −31
Original line number Diff line number Diff line
@@ -285,10 +285,43 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, 
}

EXPORT_SYMBOL(cookie_ecn_ok);



static int cookie_tcp_reqsk_init(struct sock *sk, struct sk_buff *skb,

				 struct request_sock *req)

{

	struct inet_request_sock *ireq = inet_rsk(req);

	struct tcp_request_sock *treq = tcp_rsk(req);

	const struct tcphdr *th = tcp_hdr(skb);



	req->num_retrans = 0;



	ireq->ir_num = ntohs(th->dest);

	ireq->ir_rmt_port = th->source;

	ireq->ir_iif = inet_request_bound_dev_if(sk, skb);

	ireq->ir_mark = inet_request_mark(sk, skb);



	if (IS_ENABLED(CONFIG_SMC))

		ireq->smc_ok = 0;



	treq->snt_synack = 0;

	treq->tfo_listener = false;

	treq->txhash = net_tx_rndhash();

	treq->rcv_isn = ntohl(th->seq) - 1;

	treq->snt_isn = ntohl(th->ack_seq) - 1;

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

	treq->req_usec_ts = false;



#if IS_ENABLED(CONFIG_MPTCP)

	treq->is_mptcp = sk_is_mptcp(sk);

	if (treq->is_mptcp)

		return mptcp_subflow_init_cookie_req(req, sk, skb);

#endif



	return 0;

}



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;



	if (sk_is_mptcp(sk))
@@ -299,22 +332,10 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, 
	if (!req)

		return NULL;



	treq = tcp_rsk(req);



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

	treq->req_usec_ts = false;



#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);



		if (err) {

	if (cookie_tcp_reqsk_init(sk, skb, req)) {

		reqsk_free(req);

		return NULL;

	}

	}

#endif



	return req;

}
@@ -376,28 +397,15 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 


	ireq = inet_rsk(req);

	treq = tcp_rsk(req);

	treq->rcv_isn		= ntohl(th->seq) - 1;

	treq->snt_isn		= ntohl(th->ack_seq) - 1;

	treq->ts_off		= tsoff;

	treq->txhash		= net_tx_rndhash();

	req->mss		= mss;

	ireq->ir_num		= ntohs(th->dest);

	ireq->ir_rmt_port	= th->source;

	sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr);

	sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr);

	ireq->ir_mark		= inet_request_mark(sk, skb);

	ireq->snd_wscale	= tcp_opt.snd_wscale;

	ireq->sack_ok		= tcp_opt.sack_ok;

	ireq->wscale_ok		= tcp_opt.wscale_ok;

	ireq->tstamp_ok		= tcp_opt.saw_tstamp;

	req->ts_recent		= tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;

	treq->snt_synack	= 0;

	treq->tfo_listener	= false;



	if (IS_ENABLED(CONFIG_SMC))

		ireq->smc_ok = 0;



	ireq->ir_iif = inet_request_bound_dev_if(sk, skb);



	/* We throwed the options of the initial SYN away, so we hope

	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
@@ -409,8 +417,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 


	tcp_ao_syncookie(sk, skb, req, AF_INET);



	req->num_retrans = 0;



	/*

	 * We need to lookup the route here to get at the correct

	 * window size. We should better make sure that the window size

net/ipv6/syncookies.c

+0 −14
Original line number Diff line number Diff line
@@ -178,11 +178,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 


	ireq = inet_rsk(req);

	treq = tcp_rsk(req);

	treq->tfo_listener = false;



	req->mss = mss;

	ireq->ir_rmt_port = th->source;

	ireq->ir_num = ntohs(th->dest);

	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;

	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
@@ -196,31 +193,20 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
		ireq->pktopts = skb;

	}



	ireq->ir_iif = inet_request_bound_dev_if(sk, skb);

	/* So that link locals have meaning */

	if (!sk->sk_bound_dev_if &&

	    ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)

		ireq->ir_iif = tcp_v6_iif(skb);



	ireq->ir_mark = inet_request_mark(sk, skb);



	req->num_retrans = 0;

	ireq->snd_wscale	= tcp_opt.snd_wscale;

	ireq->sack_ok		= tcp_opt.sack_ok;

	ireq->wscale_ok		= tcp_opt.wscale_ok;

	ireq->tstamp_ok		= tcp_opt.saw_tstamp;

	req->ts_recent		= tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;

	treq->snt_synack	= 0;

	treq->rcv_isn = ntohl(th->seq) - 1;

	treq->snt_isn = ntohl(th->ack_seq) - 1;

	treq->ts_off = tsoff;

	treq->txhash = net_tx_rndhash();



	tcp_ao_syncookie(sk, skb, req, AF_INET6);



	if (IS_ENABLED(CONFIG_SMC))

		ireq->smc_ok = 0;



	/*

	 * We need to lookup the dst_entry to get the correct window size.

	 * This is taken from tcp_v6_syn_recv_sock.  Somebody please enlighten