Re: [BUG] ipv6: all routes share same inetpeer
From: Eric Dumazet <hidden>
Date: 2011-07-20 06:18:42
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Le mercredi 20 juillet 2011 à 07:29 +0200, Eric Dumazet a écrit :
My first patch had an issue in rt6_alloc_cow(), line 710, where ipv6_addr_equal(&rt->rt6i_dst.addr, daddr) becomes always true. I guess I can replace it by ipv6_addr_equal(&ort->rt6i_dst.addr, daddr)
Here the combo patch I tested : I also had to solve the icmp6_dst_alloc() problem [it uses dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 255);] Note : this is based on net-2.6, but I really tested it on net-next-2.6 (with the frag ident patch applied too) [PATCH] 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 <redacted> --- net/ipv6/route.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0ef1f08..5b5a32d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c@@ -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);
@@ -683,7 +684,8 @@ 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;
@@ -692,7 +694,7 @@ 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;
@@ -700,12 +702,11 @@ 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;
@@ -752,11 +753,12 @@ 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;
@@ -900,7 +902,10 @@ 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);
@@ -1060,6 +1065,7 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev, rt->rt6i_idev = idev; rt->rt6i_nexthop = 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;
@@ -1577,7 +1583,7 @@ void rt6_redirect(const struct in6_addr *dest, const struct in6_addr *src, if (neigh == rt->dst.neighbour) goto out; - nrt = ip6_rt_copy(rt); + nrt = ip6_rt_copy(rt, dest); if (nrt == NULL) goto out;
@@ -1585,7 +1591,6 @@ 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;
@@ -1723,7 +1728,8 @@ 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,
@@ -1733,6 +1739,8 @@ 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;
@@ -1745,7 +1753,6 @@ 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