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Message-Id: <20110324.181415.149842651.davem@davemloft.net>
Date: Thu, 24 Mar 2011 18:14:15 -0700 (PDT)
From: David Miller <davem@...emloft.net>
To: netdev@...r.kernel.org
CC: ja@....bg
Subject: [PATCH 1/2] ipv4: Invalidate nexthop cache nh_saddr more correctly.
Any operation that:
1) Brings up an interface
2) Adds an IP address to an interface
3) Deletes an IP address from an interface
can potentially invalidate the nh_saddr value, requiring
it to be recomputed.
Perform the recomputation lazily using a generation ID.
Reported-by: Julian Anastasov <ja@....bg>
Signed-off-by: David S. Miller <davem@...emloft.net>
---
include/net/ip_fib.h | 12 ++++++++++--
include/net/netns/ipv4.h | 1 +
net/ipv4/fib_frontend.c | 11 +++++++----
net/ipv4/fib_semantics.c | 32 +++++++++++---------------------
net/ipv4/route.c | 6 ++++--
5 files changed, 33 insertions(+), 29 deletions(-)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index a1a8580..cd92b92 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -62,6 +62,7 @@ struct fib_nh {
int nh_oif;
__be32 nh_gw;
__be32 nh_saddr;
+ int nh_saddr_genid;
};
/*
@@ -141,12 +142,19 @@ struct fib_result_nl {
#endif /* CONFIG_IP_ROUTE_MULTIPATH */
-#define FIB_RES_SADDR(res) (FIB_RES_NH(res).nh_saddr)
+extern __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
+
+#define FIB_RES_SADDR(net, res) \
+ ((FIB_RES_NH(res).nh_saddr_genid == \
+ atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
+ FIB_RES_NH(res).nh_saddr : \
+ fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
#define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
#define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
#define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
-#define FIB_RES_PREFSRC(res) ((res).fi->fib_prefsrc ? : FIB_RES_SADDR(res))
+#define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
+ FIB_RES_SADDR(net, res))
struct fib_table {
struct hlist_node tb_hlist;
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index e2e2ef5..542195d 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -55,6 +55,7 @@ struct netns_ipv4 {
int current_rt_cache_rebuild_count;
atomic_t rt_genid;
+ atomic_t dev_addr_genid;
#ifdef CONFIG_IP_MROUTE
#ifndef CONFIG_IP_MROUTE_MULTIPLE_TABLES
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 02c3ba6..f116ce8 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -228,7 +228,7 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
if (res.type != RTN_LOCAL || !accept_local)
goto e_inval;
}
- *spec_dst = FIB_RES_PREFSRC(res);
+ *spec_dst = FIB_RES_PREFSRC(net, res);
fib_combine_itag(itag, &res);
dev_match = false;
@@ -258,7 +258,7 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
ret = 0;
if (fib_lookup(net, &fl4, &res) == 0) {
if (res.type == RTN_UNICAST) {
- *spec_dst = FIB_RES_PREFSRC(res);
+ *spec_dst = FIB_RES_PREFSRC(net, res);
ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
}
}
@@ -960,6 +960,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
{
struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
struct net_device *dev = ifa->ifa_dev->dev;
+ struct net *net = dev_net(dev);
switch (event) {
case NETDEV_UP:
@@ -967,12 +968,12 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event,
#ifdef CONFIG_IP_ROUTE_MULTIPATH
fib_sync_up(dev);
#endif
- fib_update_nh_saddrs(dev);
+ atomic_inc(&net->ipv4.dev_addr_genid);
rt_cache_flush(dev_net(dev), -1);
break;
case NETDEV_DOWN:
fib_del_ifaddr(ifa, NULL);
- fib_update_nh_saddrs(dev);
+ atomic_inc(&net->ipv4.dev_addr_genid);
if (ifa->ifa_dev->ifa_list == NULL) {
/* Last address was deleted from this interface.
* Disable IP.
@@ -990,6 +991,7 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
{
struct net_device *dev = ptr;
struct in_device *in_dev = __in_dev_get_rtnl(dev);
+ struct net *net = dev_net(dev);
if (event == NETDEV_UNREGISTER) {
fib_disable_ip(dev, 2, -1);
@@ -1007,6 +1009,7 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo
#ifdef CONFIG_IP_ROUTE_MULTIPATH
fib_sync_up(dev);
#endif
+ atomic_inc(&net->ipv4.dev_addr_genid);
rt_cache_flush(dev_net(dev), -1);
break;
case NETDEV_DOWN:
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 75b9fb5..2d4bebc 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -695,6 +695,16 @@ static void fib_info_hash_move(struct hlist_head *new_info_hash,
fib_info_hash_free(old_laddrhash, bytes);
}
+__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
+{
+ nh->nh_saddr = inet_select_addr(nh->nh_dev,
+ nh->nh_gw,
+ nh->nh_cfg_scope);
+ nh->nh_saddr_genid = atomic_read(&net->ipv4.dev_addr_genid);
+
+ return nh->nh_saddr;
+}
+
struct fib_info *fib_create_info(struct fib_config *cfg)
{
int err;
@@ -855,9 +865,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
change_nexthops(fi) {
nexthop_nh->nh_cfg_scope = cfg->fc_scope;
- nexthop_nh->nh_saddr = inet_select_addr(nexthop_nh->nh_dev,
- nexthop_nh->nh_gw,
- nexthop_nh->nh_cfg_scope);
+ fib_info_update_nh_saddr(net, nexthop_nh);
} endfor_nexthops(fi)
link_it:
@@ -1128,24 +1136,6 @@ out:
return;
}
-void fib_update_nh_saddrs(struct net_device *dev)
-{
- struct hlist_head *head;
- struct hlist_node *node;
- struct fib_nh *nh;
- unsigned int hash;
-
- hash = fib_devindex_hashfn(dev->ifindex);
- head = &fib_info_devhash[hash];
- hlist_for_each_entry(nh, node, head, nh_hash) {
- if (nh->nh_dev != dev)
- continue;
- nh->nh_saddr = inet_select_addr(nh->nh_dev,
- nh->nh_gw,
- nh->nh_cfg_scope);
- }
-}
-
#ifdef CONFIG_IP_ROUTE_MULTIPATH
/*
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 34921b0..4b0c811 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1718,7 +1718,7 @@ void ip_rt_get_source(u8 *addr, struct rtable *rt)
rcu_read_lock();
if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
- src = FIB_RES_PREFSRC(res);
+ src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
else
src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
RT_SCOPE_UNIVERSE);
@@ -2615,7 +2615,7 @@ static struct rtable *ip_route_output_slow(struct net *net,
fib_select_default(&res);
if (!fl4.saddr)
- fl4.saddr = FIB_RES_PREFSRC(res);
+ fl4.saddr = FIB_RES_PREFSRC(net, res);
dev_out = FIB_RES_DEV(res);
fl4.flowi4_oif = dev_out->ifindex;
@@ -3219,6 +3219,8 @@ static __net_init int rt_genid_init(struct net *net)
{
get_random_bytes(&net->ipv4.rt_genid,
sizeof(net->ipv4.rt_genid));
+ get_random_bytes(&net->ipv4.dev_addr_genid,
+ sizeof(net->ipv4.dev_addr_genid));
return 0;
}
--
1.7.4.1
--
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