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Commit 21efcfa0 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
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ipv6: unshare inetpeers 



We currently cow metrics a bit too soon in IPv6 case : All routes are
tied to a single inetpeer entry.

Change ip6_rt_copy() to get destination address as second argument, so
that we fill rt6i_dst before the dst_copy_metrics() call.

icmp6_dst_alloc() must set rt6i_dst before calling dst_metric_set(), or
else the cow is done while rt6i_dst is still NULL.

If orig route points to readonly metrics, we can share the pointer
instead of performing the memory allocation and copy.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 61463a30

net/ipv6/route.c

+20 −13
Original line number Diff line number Diff line
@@ -72,7 +72,8 @@ 
#define RT6_TRACE(x...) do { ; } while (0)

#endif



static struct rt6_info * ip6_rt_copy(struct rt6_info *ort);

static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,

				    const struct in6_addr *dest);

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

static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);

static unsigned int	 ip6_default_mtu(const struct dst_entry *dst);
@@ -690,7 +691,8 @@ int ip6_ins_rt(struct rt6_info *rt) 
	return __ip6_ins_rt(rt, &info);

}



static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, const struct in6_addr *daddr,

static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort,

				      const struct in6_addr *daddr,

				      const struct in6_addr *saddr)

{

	struct rt6_info *rt;
@@ -699,7 +701,7 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, const struct in6_add 
	 *	Clone the route.

	 */



	rt = ip6_rt_copy(ort);

	rt = ip6_rt_copy(ort, daddr);



	if (rt) {

		struct neighbour *neigh;
@@ -707,12 +709,11 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, const struct in6_add 


		if (!(rt->rt6i_flags&RTF_GATEWAY)) {

			if (rt->rt6i_dst.plen != 128 &&

			    ipv6_addr_equal(&rt->rt6i_dst.addr, daddr))

			    ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))

				rt->rt6i_flags |= RTF_ANYCAST;

			ipv6_addr_copy(&rt->rt6i_gateway, daddr);

		}



		ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);

		rt->rt6i_dst.plen = 128;

		rt->rt6i_flags |= RTF_CACHE;

		rt->dst.flags |= DST_HOST;
@@ -759,11 +760,12 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, const struct in6_add 
	return rt;

}



static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, const struct in6_addr *daddr)

static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort,

					const struct in6_addr *daddr)

{

	struct rt6_info *rt = ip6_rt_copy(ort);

	struct rt6_info *rt = ip6_rt_copy(ort, daddr);



	if (rt) {

		ipv6_addr_copy(&rt->rt6i_dst.addr, daddr);

		rt->rt6i_dst.plen = 128;

		rt->rt6i_flags |= RTF_CACHE;

		rt->dst.flags |= DST_HOST;
@@ -907,6 +909,9 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori 
		new->input = dst_discard;

		new->output = dst_discard;



		if (dst_metrics_read_only(&ort->dst))

			new->_metrics = ort->dst._metrics;

		else

			dst_copy_metrics(new, &ort->dst);

		rt->rt6i_idev = ort->rt6i_idev;

		if (rt->rt6i_idev)
@@ -1067,6 +1072,7 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 
	rt->rt6i_idev     = idev;

	dst_set_neighbour(&rt->dst, neigh);

	atomic_set(&rt->dst.__refcnt, 1);

	ipv6_addr_copy(&rt->rt6i_dst.addr, addr);

	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);

	rt->dst.output  = ip6_output;
@@ -1584,7 +1590,7 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src, 
	if (neigh == dst_get_neighbour(&rt->dst))

		goto out;



	nrt = ip6_rt_copy(rt);

	nrt = ip6_rt_copy(rt, dest);

	if (nrt == NULL)

		goto out;
@@ -1592,7 +1598,6 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src, 
	if (on_link)

		nrt->rt6i_flags &= ~RTF_GATEWAY;



	ipv6_addr_copy(&nrt->rt6i_dst.addr, dest);

	nrt->rt6i_dst.plen = 128;

	nrt->dst.flags |= DST_HOST;
@@ -1730,7 +1735,8 @@ void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *sad 
 *	Misc support functions

 */



static struct rt6_info * ip6_rt_copy(struct rt6_info *ort)

static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort,

				    const struct in6_addr *dest)

{

	struct net *net = dev_net(ort->rt6i_dev);

	struct rt6_info *rt = ip6_dst_alloc(&net->ipv6.ip6_dst_ops,
@@ -1740,6 +1746,8 @@ static struct rt6_info * ip6_rt_copy(struct rt6_info *ort) 
		rt->dst.input = ort->dst.input;

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



		ipv6_addr_copy(&rt->rt6i_dst.addr, dest);

		rt->rt6i_dst.plen = ort->rt6i_dst.plen;

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

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

		rt->rt6i_idev = ort->rt6i_idev;
@@ -1752,7 +1760,6 @@ static struct rt6_info * ip6_rt_copy(struct rt6_info *ort) 
		rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES;

		rt->rt6i_metric = 0;



		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));

#ifdef CONFIG_IPV6_SUBTREES

		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));

#endif