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: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2011-07-19 20:18:36 +00:00 committed by David S. Miller
parent 61463a30f6
commit 21efcfa0ff
1 changed files with 20 additions and 13 deletions

View File

@ -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;
@ -907,7 +909,10 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
new->input = dst_discard;
new->output = dst_discard;
dst_copy_metrics(new, &ort->dst);
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)
in6_dev_hold(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