Commit 7b0f570f authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

tcp: Move TCP-AO bits from cookie_v[46]_check() to tcp_ao_syncookie(). 



We initialise treq->af_specific in cookie_tcp_reqsk_alloc() so that
we can look up a key later in tcp_create_openreq_child().

Initially, that change was added for MD5 by commit ba5a4fdd ("tcp:
make sure treq->af_specific is initialized"), but it has not been used
since commit d0f2b7a9 ("tcp: Disable header prediction for MD5
flow.").

Now, treq->af_specific is used only by TCP-AO, so, we can move that
initialisation into tcp_ao_syncookie().

In addition to that, l3index in cookie_v[46]_check() is only used for
tcp_ao_syncookie(), so let's move it as well.

While at it, we move down tcp_ao_syncookie() in cookie_v4_check() so
that it will be called after security_inet_conn_request() to make
functions order consistent with cookie_v6_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/20231129022924.96156-7-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent efce3d1f

include/net/tcp.h

+0 −1
Original line number Diff line number Diff line
@@ -494,7 +494,6 @@ 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);

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,

					    const struct tcp_request_sock_ops *af_ops,

					    struct sock *sk, struct sk_buff *skb);

#ifdef CONFIG_SYN_COOKIES

include/net/tcp_ao.h

+2 −4
Original line number Diff line number Diff line
@@ -265,8 +265,7 @@ void tcp_ao_established(struct sock *sk); 
void tcp_ao_finish_connect(struct sock *sk, struct sk_buff *skb);

void tcp_ao_connect_init(struct sock *sk);

void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,

		      struct tcp_request_sock *treq,

		      unsigned short int family, int l3index);

		      struct request_sock *req, unsigned short int family);

#else /* CONFIG_TCP_AO */



static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb,
@@ -277,8 +276,7 @@ static inline int tcp_ao_transmit_skb(struct sock *sk, struct sk_buff *skb, 
}



static inline void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,

				    struct tcp_request_sock *treq,

				    unsigned short int family, int l3index)

				    struct request_sock *req, unsigned short int family)

{

}

net/ipv4/syncookies.c

+4 −12
Original line number Diff line number Diff line
@@ -286,9 +286,7 @@ 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,

					    const struct tcp_request_sock_ops *af_ops,

					    struct sock *sk,

					    struct sk_buff *skb)

					    struct sock *sk, struct sk_buff *skb)

{

	struct tcp_request_sock *treq;

	struct request_sock *req;
@@ -303,9 +301,6 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, 


	treq = tcp_rsk(req);



	/* treq->af_specific might be used to perform TCP_MD5 lookup */

	treq->af_specific = af_ops;



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

	treq->req_usec_ts = false;
@@ -345,7 +340,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 
	struct rtable *rt;

	__u8 rcv_wscale;

	u32 tsoff = 0;

	int l3index;



	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||

	    !th->ack || th->rst)
@@ -376,8 +370,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 
	if (!cookie_timestamp_decode(net, &tcp_opt))

		goto out;



	req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops,

				     &tcp_request_sock_ipv4_ops, sk, skb);

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

	if (!req)

		goto out_drop;
@@ -406,9 +399,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 


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



	l3index = l3mdev_master_ifindex_by_index(net, ireq->ir_iif);

	tcp_ao_syncookie(sk, skb, treq, AF_INET, l3index);



	/* 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)

	 */
@@ -417,6 +407,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) 
	if (security_inet_conn_request(sk, skb, req))

		goto out_free;



	tcp_ao_syncookie(sk, skb, req, AF_INET);



	req->num_retrans = 0;



	/*

net/ipv4/tcp_ao.c

+14 −2
Original line number Diff line number Diff line
@@ -844,18 +844,30 @@ static struct tcp_ao_key *tcp_ao_inbound_lookup(unsigned short int family, 
}



void tcp_ao_syncookie(struct sock *sk, const struct sk_buff *skb,

		      struct tcp_request_sock *treq,

		      unsigned short int family, int l3index)

		      struct request_sock *req, unsigned short int family)

{

	struct tcp_request_sock *treq = tcp_rsk(req);

	const struct tcphdr *th = tcp_hdr(skb);

	const struct tcp_ao_hdr *aoh;

	struct tcp_ao_key *key;

	int l3index;



	/* treq->af_specific is used to perform TCP_AO lookup

	 * in tcp_create_openreq_child().

	 */

#if IS_ENABLED(CONFIG_IPV6)

	if (family == AF_INET6)

		treq->af_specific = &tcp_request_sock_ipv6_ops;

	else

#endif

		treq->af_specific = &tcp_request_sock_ipv4_ops;



	treq->maclen = 0;



	if (tcp_parse_auth_options(th, NULL, &aoh) || !aoh)

		return;



	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), inet_rsk(req)->ir_iif);

	key = tcp_ao_inbound_lookup(family, sk, skb, -1, aoh->keyid, l3index);

	if (!key)

		/* Key not found, continue without TCP-AO */

net/ipv6/syncookies.c

+2 −5
Original line number Diff line number Diff line
@@ -142,7 +142,6 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	int full_space, mss;

	__u8 rcv_wscale;

	u32 tsoff = 0;

	int l3index;



	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||

	    !th->ack || th->rst)
@@ -173,8 +172,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	if (!cookie_timestamp_decode(net, &tcp_opt))

		goto out;



	req = cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops,

				     &tcp_request_sock_ipv6_ops, sk, skb);

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

	if (!req)

		goto out_drop;
@@ -218,8 +216,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) 
	treq->ts_off = tsoff;

	treq->txhash = net_tx_rndhash();



	l3index = l3mdev_master_ifindex_by_index(net, ireq->ir_iif);

	tcp_ao_syncookie(sk, skb, treq, AF_INET6, l3index);

	tcp_ao_syncookie(sk, skb, req, AF_INET6);



	if (IS_ENABLED(CONFIG_SMC))

		ireq->smc_ok = 0;