Commit 36c82963 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'rt6_pmtu' 

Martin KaFai Lau says:

====================
ipv6: Stop /128 route from disappearing after pmtu update

The series is separated from another patch series,
'ipv6: Only create RTF_CACHE route after encountering pmtu exception',
which can be found here:
http://thread.gmane.org/gmane.linux.network/359140

This series focus on fixing the /128 route issues.  It is currently targeted
for net-next due to the number of code churn but it is also applicable
to net (should be without conflict).  The original reported problem can be
found here:
http://thread.gmane.org/gmane.linux.network/348138



Patch 01 and 02 are to prepare the fib6 search to expect both the
RTF_CACHE clone and its original route exist at the same fib6_node.

Patch 03 fixes the /128 route disappearing bug.

Patch 04 and 05 stop rt6_info from using the inet_peer's metrics to
avoid the /128 routes (like the /128 clone and its original route)
from stepping on each others' metrics.

The second patch is by 'Steffen Klassert <steffen.klassert@secunet.com>'
which I pulled off from netdev.  The third patch is also mostly by
Steffen with one minor optimization.

Many thanks to Hannes Frederic Sowa <hannes@stressinduktion.org> on
reviewing the patches and giving advice.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 355b590c afc4eef8

include/net/dst.h

+0 −6
Original line number Diff line number Diff line
@@ -109,7 +109,6 @@ u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); 
extern const u32 dst_default_metrics[];



#define DST_METRICS_READ_ONLY		0x1UL

#define DST_METRICS_FORCE_OVERWRITE	0x2UL

#define DST_METRICS_FLAGS		0x3UL

#define __DST_METRICS_PTR(Y)	\

	((u32 *)((Y) & ~DST_METRICS_FLAGS))
@@ -120,11 +119,6 @@ static inline bool dst_metrics_read_only(const struct dst_entry *dst) 
	return dst->_metrics & DST_METRICS_READ_ONLY;

}



static inline void dst_metrics_set_force_overwrite(struct dst_entry *dst)

{

	dst->_metrics |= DST_METRICS_FORCE_OVERWRITE;

}



void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);



static inline void dst_destroy_metrics_generic(struct dst_entry *dst)

include/net/ip6_fib.h

+1 −40
Original line number Diff line number Diff line
@@ -121,44 +121,14 @@ struct rt6_info { 
	struct rt6key			rt6i_prefsrc;



	struct inet6_dev		*rt6i_idev;

	unsigned long			_rt6i_peer;



	u32				rt6i_metric;

	u32				rt6i_pmtu;

	/* more non-fragment space at head required */

	unsigned short			rt6i_nfheader_len;

	u8				rt6i_protocol;

};



static inline struct inet_peer *rt6_peer_ptr(struct rt6_info *rt)

{

	return inetpeer_ptr(rt->_rt6i_peer);

}



static inline bool rt6_has_peer(struct rt6_info *rt)

{

	return inetpeer_ptr_is_peer(rt->_rt6i_peer);

}



static inline void __rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)

{

	__inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);

}



static inline bool rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)

{

	return inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);

}



static inline void rt6_init_peer(struct rt6_info *rt, struct inet_peer_base *base)

{

	inetpeer_init_ptr(&rt->_rt6i_peer, base);

}



static inline void rt6_transfer_peer(struct rt6_info *rt, struct rt6_info *ort)

{

	inetpeer_transfer_peer(&rt->_rt6i_peer, &ort->_rt6i_peer);

}



static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)

{

	return ((struct rt6_info *)dst)->rt6i_idev;
@@ -189,15 +159,6 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 
	rt0->rt6i_flags |= RTF_EXPIRES;

}



static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)

{

	struct dst_entry *new = (struct dst_entry *) from;



	rt->rt6i_flags &= ~RTF_EXPIRES;

	dst_hold(new);

	rt->dst.from = new;

}



static inline void ip6_rt_put(struct rt6_info *rt)

{

	/* dst_release() accepts a NULL parameter.

net/ipv6/addrconf.c

+2 −0
Original line number Diff line number Diff line
@@ -2121,6 +2121,8 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx, 
	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0);

	if (!fn)

		goto out;



	noflags |= RTF_CACHE;

	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {

		if (rt->dst.dev->ifindex != dev->ifindex)

			continue;

net/ipv6/route.c

+91 −85
Original line number Diff line number Diff line
@@ -92,6 +92,7 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 
					   struct sk_buff *skb, u32 mtu);

static void		rt6_do_redirect(struct dst_entry *dst, struct sock *sk,

					struct sk_buff *skb);

static void		rt6_dst_from_metrics_check(struct rt6_info *rt);

static int rt6_score_route(struct rt6_info *rt, int oif, int strict);



#ifdef CONFIG_IPV6_ROUTE_INFO
@@ -104,65 +105,14 @@ static struct rt6_info *rt6_get_route_info(struct net *net, 
					   const struct in6_addr *gwaddr, int ifindex);

#endif



static void rt6_bind_peer(struct rt6_info *rt, int create)

{

	struct inet_peer_base *base;

	struct inet_peer *peer;



	base = inetpeer_base_ptr(rt->_rt6i_peer);

	if (!base)

		return;



	peer = inet_getpeer_v6(base, &rt->rt6i_dst.addr, create);

	if (peer) {

		if (!rt6_set_peer(rt, peer))

			inet_putpeer(peer);

	}

}



static struct inet_peer *__rt6_get_peer(struct rt6_info *rt, int create)

{

	if (rt6_has_peer(rt))

		return rt6_peer_ptr(rt);



	rt6_bind_peer(rt, create);

	return (rt6_has_peer(rt) ? rt6_peer_ptr(rt) : NULL);

}



static struct inet_peer *rt6_get_peer_create(struct rt6_info *rt)

{

	return __rt6_get_peer(rt, 1);

}



static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)

{

	struct rt6_info *rt = (struct rt6_info *)dst;

	struct inet_peer *peer;

	u32 *p = NULL;



	if (!(rt->dst.flags & DST_HOST))

	if (rt->rt6i_flags & RTF_CACHE)

		return NULL;

	else

		return dst_cow_metrics_generic(dst, old);



	peer = rt6_get_peer_create(rt);

	if (peer) {

		u32 *old_p = __DST_METRICS_PTR(old);

		unsigned long prev, new;



		p = peer->metrics;

		if (inet_metrics_new(peer) ||

		    (old & DST_METRICS_FORCE_OVERWRITE))

			memcpy(p, old_p, sizeof(u32) * RTAX_MAX);



		new = (unsigned long) p;

		prev = cmpxchg(&dst->_metrics, old, new);



		if (prev != old) {

			p = __DST_METRICS_PTR(prev);

			if (prev & DST_METRICS_READ_ONLY)

				p = NULL;

		}

	}

	return p;

}



static inline const void *choose_neigh_daddr(struct rt6_info *rt,
@@ -311,7 +261,6 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net, 
		struct dst_entry *dst = &rt->dst;



		memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));

		rt6_init_peer(rt, table ? &table->tb6_peers : net->ipv6.peers);

		INIT_LIST_HEAD(&rt->rt6i_siblings);

	}

	return rt;
@@ -323,7 +272,6 @@ static void ip6_dst_destroy(struct dst_entry *dst) 
	struct inet6_dev *idev = rt->rt6i_idev;

	struct dst_entry *from = dst->from;



	if (!(rt->dst.flags & DST_HOST))

	dst_destroy_metrics_generic(dst);



	if (idev) {
@@ -333,11 +281,6 @@ static void ip6_dst_destroy(struct dst_entry *dst) 


	dst->from = NULL;

	dst_release(from);



	if (rt6_has_peer(rt)) {

		struct inet_peer *peer = rt6_peer_ptr(rt);

		inet_putpeer(peer);

	}

}



static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
@@ -652,15 +595,33 @@ static struct rt6_info *find_rr_leaf(struct fib6_node *fn, 
				     u32 metric, int oif, int strict,

				     bool *do_rr)

{

	struct rt6_info *rt, *match;

	struct rt6_info *rt, *match, *cont;

	int mpri = -1;



	match = NULL;

	for (rt = rr_head; rt && rt->rt6i_metric == metric;

	     rt = rt->dst.rt6_next)

	cont = NULL;

	for (rt = rr_head; rt; rt = rt->dst.rt6_next) {

		if (rt->rt6i_metric != metric) {

			cont = rt;

			break;

		}



		match = find_match(rt, oif, strict, &mpri, match, do_rr);

	for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric;

	     rt = rt->dst.rt6_next)

	}



	for (rt = fn->leaf; rt && rt != rr_head; rt = rt->dst.rt6_next) {

		if (rt->rt6i_metric != metric) {

			cont = rt;

			break;

		}



		match = find_match(rt, oif, strict, &mpri, match, do_rr);

	}



	if (match || !cont)

		return match;



	for (rt = cont; rt; rt = rt->dst.rt6_next)

		match = find_match(rt, oif, strict, &mpri, match, do_rr);



	return match;
@@ -959,7 +920,7 @@ redo_rt6_select: 


	if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)))

		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);

	else if (!(rt->dst.flags & DST_HOST))

	else if (!(rt->dst.flags & DST_HOST) || !(rt->dst.flags & RTF_LOCAL))

		nrt = rt6_alloc_clone(rt, &fl6->daddr);

	else

		goto out2;
@@ -985,6 +946,7 @@ redo_rt6_select: 
	goto redo_fib6_lookup_lock;



out2:

	rt6_dst_from_metrics_check(rt);

	rt->dst.lastuse = jiffies;

	rt->dst.__use++;
@@ -1059,7 +1021,6 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori 
		new = &rt->dst;



		memset(new + 1, 0, sizeof(*rt) - sizeof(*new));

		rt6_init_peer(rt, net->ipv6.peers);



		new->__use = 1;

		new->input = dst_discard;
@@ -1093,6 +1054,13 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori 
 *	Destination cache support functions

 */



static void rt6_dst_from_metrics_check(struct rt6_info *rt)

{

	if (rt->dst.from &&

	    dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(rt->dst.from))

		dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true);

}



static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)

{

	struct rt6_info *rt;
@@ -1109,6 +1077,8 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 
	if (rt6_check_expired(rt))

		return NULL;



	rt6_dst_from_metrics_check(rt);



	return dst;

}
@@ -1154,14 +1124,14 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 
	struct rt6_info *rt6 = (struct rt6_info *)dst;



	dst_confirm(dst);

	if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) {

	if (mtu < dst_mtu(dst) && (rt6->rt6i_flags & RTF_CACHE)) {

		struct net *net = dev_net(dst->dev);



		rt6->rt6i_flags |= RTF_MODIFIED;

		if (mtu < IPV6_MIN_MTU)

			mtu = IPV6_MIN_MTU;



		dst_metric_set(dst, RTAX_MTU, mtu);

		rt6->rt6i_pmtu = mtu;

		rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires);

	}

}
@@ -1341,9 +1311,14 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst) 


static unsigned int ip6_mtu(const struct dst_entry *dst)

{

	const struct rt6_info *rt = (const struct rt6_info *)dst;

	unsigned int mtu = rt->rt6i_pmtu;

	struct inet6_dev *idev;

	unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);



	if (mtu)

		goto out;



	mtu = dst_metric_raw(dst, RTAX_MTU);

	if (mtu)

		goto out;
@@ -1590,10 +1565,8 @@ int ip6_route_add(struct fib6_config *cfg) 


	ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);

	rt->rt6i_dst.plen = cfg->fc_dst_len;

	if (rt->rt6i_dst.plen == 128) {

	if (rt->rt6i_dst.plen == 128)

		rt->dst.flags |= DST_HOST;

		dst_metrics_set_force_overwrite(&rt->dst);

	}



#ifdef CONFIG_IPV6_SUBTREES

	ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len);
@@ -1785,6 +1758,9 @@ static int ip6_route_del(struct fib6_config *cfg) 


	if (fn) {

		for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {

			if ((rt->rt6i_flags & RTF_CACHE) &&

			    !(cfg->fc_flags & RTF_CACHE))

				continue;

			if (cfg->fc_ifindex &&

			    (!rt->dst.dev ||

			     rt->dst.dev->ifindex != cfg->fc_ifindex))
@@ -1926,11 +1902,26 @@ out: 
 *	Misc support functions

 */



static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)

{

	BUG_ON(from->dst.from);



	rt->rt6i_flags &= ~RTF_EXPIRES;

	dst_hold(&from->dst);

	rt->dst.from = &from->dst;

	dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true);

}



static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,

				    const struct in6_addr *dest)

{

	struct net *net = dev_net(ort->dst.dev);

	struct rt6_info *rt = ip6_dst_alloc(net, ort->dst.dev, 0,

	struct rt6_info *rt;



	if (ort->rt6i_flags & RTF_CACHE)

		ort = (struct rt6_info *)ort->dst.from;



	rt = ip6_dst_alloc(net, ort->dst.dev, 0,

			   ort->rt6i_table);



	if (rt) {
@@ -1940,7 +1931,6 @@ static struct rt6_info *ip6_rt_copy(struct rt6_info *ort, 


		rt->rt6i_dst.addr = *dest;

		rt->rt6i_dst.plen = 128;

		dst_copy_metrics(&rt->dst, &ort->dst);

		rt->dst.error = ort->dst.error;

		rt->rt6i_idev = ort->rt6i_idev;

		if (rt->rt6i_idev)
@@ -2372,12 +2362,21 @@ static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 
	   PMTU discouvery.

	 */

	if (rt->dst.dev == arg->dev &&

	    !dst_metric_locked(&rt->dst, RTAX_MTU) &&

	    (dst_mtu(&rt->dst) >= arg->mtu ||

	    !dst_metric_locked(&rt->dst, RTAX_MTU)) {

		if (rt->rt6i_flags & RTF_CACHE) {

			/* For RTF_CACHE with rt6i_pmtu == 0

			 * (i.e. a redirected route),

			 * the metrics of its rt->dst.from has already

			 * been updated.

			 */

			if (rt->rt6i_pmtu && rt->rt6i_pmtu > arg->mtu)

				rt->rt6i_pmtu = arg->mtu;

		} else if (dst_mtu(&rt->dst) >= arg->mtu ||

			   (dst_mtu(&rt->dst) < arg->mtu &&

	      dst_mtu(&rt->dst) == idev->cnf.mtu6))) {

			    dst_mtu(&rt->dst) == idev->cnf.mtu6)) {

			dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu);

		}

	}

	return 0;

}
@@ -2433,6 +2432,9 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 
	if (rtm->rtm_type == RTN_LOCAL)

		cfg->fc_flags |= RTF_LOCAL;



	if (rtm->rtm_flags & RTM_F_CLONED)

		cfg->fc_flags |= RTF_CACHE;



	cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid;

	cfg->fc_nlinfo.nlh = nlh;

	cfg->fc_nlinfo.nl_net = sock_net(skb->sk);
@@ -2603,6 +2605,7 @@ static int rt6_fill_node(struct net *net, 
			 int iif, int type, u32 portid, u32 seq,

			 int prefix, int nowait, unsigned int flags)

{

	u32 metrics[RTAX_MAX];

	struct rtmsg *rtm;

	struct nlmsghdr *nlh;

	long expires;
@@ -2716,7 +2719,10 @@ static int rt6_fill_node(struct net *net, 
			goto nla_put_failure;

	}



	if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)

	memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics));

	if (rt->rt6i_pmtu)

		metrics[RTAX_MTU - 1] = rt->rt6i_pmtu;

	if (rtnetlink_put_metrics(skb, metrics) < 0)

		goto nla_put_failure;



	if (rt->rt6i_flags & RTF_GATEWAY) {

net/ipv6/xfrm6_policy.c

+0 −14
Original line number Diff line number Diff line
@@ -71,13 +71,6 @@ static int xfrm6_get_tos(const struct flowi *fl) 
	return 0;

}



static void xfrm6_init_dst(struct net *net, struct xfrm_dst *xdst)

{

	struct rt6_info *rt = (struct rt6_info *)xdst;



	rt6_init_peer(rt, net->ipv6.peers);

}



static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,

			   int nfheader_len)

{
@@ -106,8 +99,6 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 
		return -ENODEV;

	}



	rt6_transfer_peer(&xdst->u.rt6, rt);



	/* Sheit... I remember I did this right. Apparently,

	 * it was magically lost, so this code needs audit */

	xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
@@ -255,10 +246,6 @@ static void xfrm6_dst_destroy(struct dst_entry *dst) 
	if (likely(xdst->u.rt6.rt6i_idev))

		in6_dev_put(xdst->u.rt6.rt6i_idev);

	dst_destroy_metrics_generic(dst);

	if (rt6_has_peer(&xdst->u.rt6)) {

		struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6);

		inet_putpeer(peer);

	}

	xfrm_dst_destroy(xdst);

}
@@ -308,7 +295,6 @@ static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 
	.get_saddr =		xfrm6_get_saddr,

	.decode_session =	_decode_session6,

	.get_tos =		xfrm6_get_tos,

	.init_dst =		xfrm6_init_dst,

	.init_path =		xfrm6_init_path,

	.fill_dst =		xfrm6_fill_dst,

	.blackhole_route =	ip6_blackhole_route,

CRA Git | Maintained and supported by SUSTech CRA and CCSE