Commit 68d0c6d3 authored by David S. Miller's avatar David S. Miller
Browse files

ipv6: Consolidate route lookup sequences. 



Route lookups follow a general pattern in the ipv6 code wherein
we first find the non-IPSEC route, potentially override the
flow destination address due to ipv6 options settings, and then
finally make an IPSEC search using either xfrm_lookup() or
__xfrm_lookup().

__xfrm_lookup() is used when we want to generate a blackhole route
if the key manager needs to resolve the IPSEC rules (in this case
-EREMOTE is returned and the original 'dst' is left unchanged).

Otherwise plain xfrm_lookup() is used and when asynchronous IPSEC
resolution is necessary, we simply fail the lookup completely.

All of these cases are encapsulated into two routines,
ip6_dst_lookup_flow and ip6_sk_dst_lookup_flow.  The latter of which
handles unconnected UDP datagram sockets.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 903ab86d

include/net/ipv6.h

+8 −3
Original line number Diff line number Diff line
@@ -512,12 +512,17 @@ extern void ip6_flush_pending_frames(struct sock *sk); 
extern int			ip6_dst_lookup(struct sock *sk,

					       struct dst_entry **dst,

					       struct flowi *fl);

extern struct dst_entry *	ip6_dst_lookup_flow(struct sock *sk,

						    struct flowi *fl,

						    const struct in6_addr *final_dst,

						    bool want_blackhole);

extern struct dst_entry *	ip6_sk_dst_lookup_flow(struct sock *sk,

						       struct flowi *fl,

						       const struct in6_addr *final_dst,

						       bool want_blackhole);

extern int			ip6_dst_blackhole(struct sock *sk,

						  struct dst_entry **dst,

						  struct flowi *fl);

extern int			ip6_sk_dst_lookup(struct sock *sk,

						  struct dst_entry **dst,

						  struct flowi *fl);



/*

 *	skb processing functions

net/dccp/ipv6.c

+20 −45
Original line number Diff line number Diff line
@@ -162,15 +162,9 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 
			fl.fl_ip_sport = inet->inet_sport;

			security_sk_classify_flow(sk, &fl);



			err = ip6_dst_lookup(sk, &dst, &fl);

			if (err) {

				sk->sk_err_soft = -err;

				goto out;

			}



			err = xfrm_lookup(net, &dst, &fl, sk, 0);

			if (err < 0) {

				sk->sk_err_soft = -err;

			dst = ip6_dst_lookup_flow(sk, &fl, NULL, false);

			if (IS_ERR(dst)) {

				sk->sk_err_soft = -PTR_ERR(dst);

				goto out;

			}

		} else
@@ -267,16 +261,12 @@ static int dccp_v6_send_response(struct sock *sk, struct request_sock *req, 


	final_p = fl6_update_dst(&fl, opt, &final);



	err = ip6_dst_lookup(sk, &dst, &fl);

	if (err)

		goto done;



	if (final_p)

		ipv6_addr_copy(&fl.fl6_dst, final_p);



	err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0);

	if (err < 0)

	dst = ip6_dst_lookup_flow(sk, &fl, final_p, false);

	if (IS_ERR(dst)) {

		err = PTR_ERR(dst);

		dst = NULL;

		goto done;

	}



	skb = dccp_make_response(sk, dst, req);

	if (skb != NULL) {
@@ -338,15 +328,14 @@ static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb) 
	security_skb_classify_flow(rxskb, &fl);



	/* sk = NULL, but it is safe for now. RST socket required. */

	if (!ip6_dst_lookup(ctl_sk, &dst, &fl)) {

		if (xfrm_lookup(net, &dst, &fl, NULL, 0) >= 0) {

	dst = ip6_dst_lookup_flow(ctl_sk, &fl, NULL, false);

	if (!IS_ERR(dst)) {

		skb_dst_set(skb, dst);

		ip6_xmit(ctl_sk, skb, &fl, NULL);

		DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);

		DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);

		return;

	}

	}



	kfree_skb(skb);

}
@@ -550,13 +539,8 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk, 
		fl.fl_ip_sport = inet_rsk(req)->loc_port;

		security_sk_classify_flow(sk, &fl);



		if (ip6_dst_lookup(sk, &dst, &fl))

			goto out;



		if (final_p)

			ipv6_addr_copy(&fl.fl6_dst, final_p);



		if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)

		dst = ip6_dst_lookup_flow(sk, &fl, final_p, false);

		if (IS_ERR(dst))

			goto out;

	}
@@ -979,18 +963,9 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 


	final_p = fl6_update_dst(&fl, np->opt, &final);



	err = ip6_dst_lookup(sk, &dst, &fl);

	if (err)

		goto failure;



	if (final_p)

		ipv6_addr_copy(&fl.fl6_dst, final_p);



	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);

	if (err < 0) {

		if (err == -EREMOTE)

			err = ip6_dst_blackhole(sk, &dst, &fl);

		if (err < 0)

	dst = ip6_dst_lookup_flow(sk, &fl, final_p, true);

	if (IS_ERR(dst)) {

		err = PTR_ERR(dst);

		goto failure;

	}

net/ipv6/af_inet6.c

+5 −12
Original line number Diff line number Diff line
@@ -644,9 +644,8 @@ EXPORT_SYMBOL(inet6_unregister_protosw); 


int inet6_sk_rebuild_header(struct sock *sk)

{

	int err;

	struct dst_entry *dst;

	struct ipv6_pinfo *np = inet6_sk(sk);

	struct dst_entry *dst;



	dst = __sk_dst_check(sk, np->dst_cookie);
@@ -668,17 +667,11 @@ int inet6_sk_rebuild_header(struct sock *sk) 


		final_p = fl6_update_dst(&fl, np->opt, &final);



		err = ip6_dst_lookup(sk, &dst, &fl);

		if (err) {

		dst = ip6_dst_lookup_flow(sk, &fl, final_p, false);

		if (IS_ERR(dst)) {

			sk->sk_route_caps = 0;

			return err;

		}

		if (final_p)

			ipv6_addr_copy(&fl.fl6_dst, final_p);



		if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {

			sk->sk_err_soft = -err;

			return err;

			sk->sk_err_soft = -PTR_ERR(dst);

			return PTR_ERR(dst);

		}



		__ip6_dst_store(sk, dst, NULL, NULL);

net/ipv6/datagram.c

+4 −11
Original line number Diff line number Diff line
@@ -162,17 +162,10 @@ ipv4_connected: 
	opt = flowlabel ? flowlabel->opt : np->opt;

	final_p = fl6_update_dst(&fl, opt, &final);



	err = ip6_dst_lookup(sk, &dst, &fl);

	if (err)

		goto out;

	if (final_p)

		ipv6_addr_copy(&fl.fl6_dst, final_p);



	err = __xfrm_lookup(sock_net(sk), &dst, &fl, sk, XFRM_LOOKUP_WAIT);

	if (err < 0) {

		if (err == -EREMOTE)

			err = ip6_dst_blackhole(sk, &dst, &fl);

		if (err < 0)

	dst = ip6_dst_lookup_flow(sk, &fl, final_p, true);

	err = 0;

	if (IS_ERR(dst)) {

		err = PTR_ERR(dst);

		goto out;

	}

net/ipv6/inet6_connection_sock.c

+6 −19
Original line number Diff line number Diff line
@@ -74,13 +74,8 @@ struct dst_entry *inet6_csk_route_req(struct sock *sk, 
	fl.fl_ip_sport = inet_rsk(req)->loc_port;

	security_req_classify_flow(req, &fl);



	if (ip6_dst_lookup(sk, &dst, &fl))

		return NULL;



	if (final_p)

		ipv6_addr_copy(&fl.fl6_dst, final_p);



	if ((xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)

	dst = ip6_dst_lookup_flow(sk, &fl, final_p, false);

	if (IS_ERR(dst))

		return NULL;



	return dst;
@@ -234,21 +229,13 @@ int inet6_csk_xmit(struct sk_buff *skb) 
	dst = __inet6_csk_dst_check(sk, np->dst_cookie);



	if (dst == NULL) {

		int err = ip6_dst_lookup(sk, &dst, &fl);



		if (err) {

			sk->sk_err_soft = -err;

			kfree_skb(skb);

			return err;

		}



		if (final_p)

			ipv6_addr_copy(&fl.fl6_dst, final_p);

		dst = ip6_dst_lookup_flow(sk, &fl, final_p, false);



		if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {

		if (IS_ERR(dst)) {

			sk->sk_err_soft = -PTR_ERR(dst);

			sk->sk_route_caps = 0;

			kfree_skb(skb);

			return err;

			return PTR_ERR(dst);

		}



		__inet6_csk_dst_store(sk, dst, NULL, NULL);

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