[PATCHv2 net 1/2] ipv4: fix to not remove local route on link down
From: Julian Anastasov <ja@ssi.bg>
Date: 2015-10-26 21:59:43
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
When fib_netdev_event calls fib_disable_ip on NETDEV_DOWN event
we should not delete the local routes if the local address
is still present. The confusion comes from the fact that both
fib_netdev_event and fib_inetaddr_event use the NETDEV_DOWN
constant. Fix it by returning back the variable 'force'.
Steps to reproduce:
modprobe dummy
ifconfig dummy0 192.168.168.1 up
ifconfig dummy0 down
ip route list table local | grep dummy | grep host
local 192.168.168.1 dev dummy0 proto kernel scope host src 192.168.168.1
Fixes: 8a3d03166f19 ("net: track link-status of ipv4 nexthops")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
---
include/net/ip_fib.h | 2 +-
net/ipv4/fib_frontend.c | 13 +++++++------
net/ipv4/fib_semantics.c | 11 ++++++++---
3 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 727d6e9..654aec1 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h@@ -317,7 +317,7 @@ void fib_flush_external(struct net *net); /* Exported by fib_semantics.c */ int ip_fib_check_default(__be32 gw, struct net_device *dev); -int fib_sync_down_dev(struct net_device *dev, unsigned long event); +int fib_sync_down_dev(struct net_device *dev, unsigned long event, int force); int fib_sync_down_addr(struct net *net, __be32 local); int fib_sync_up(struct net_device *dev, unsigned int nh_flags); void fib_select_multipath(struct fib_result *res);
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 690bcbc..4826a22 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c@@ -1110,9 +1110,10 @@ static void nl_fib_lookup_exit(struct net *net) net->ipv4.fibnl = NULL; } -static void fib_disable_ip(struct net_device *dev, unsigned long event) +static void fib_disable_ip(struct net_device *dev, unsigned long event, + int force) { - if (fib_sync_down_dev(dev, event)) + if (fib_sync_down_dev(dev, event, force)) fib_flush(dev_net(dev)); rt_cache_flush(dev_net(dev)); arp_ifdown(dev);
@@ -1140,7 +1141,7 @@ static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, /* Last address was deleted from this interface. * Disable IP. */ - fib_disable_ip(dev, event); + fib_disable_ip(dev, event, 1); } else { rt_cache_flush(dev_net(dev)); }
@@ -1157,7 +1158,7 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo unsigned int flags; if (event == NETDEV_UNREGISTER) { - fib_disable_ip(dev, event); + fib_disable_ip(dev, event, 2); rt_flush_dev(dev); return NOTIFY_DONE; }
@@ -1178,14 +1179,14 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo rt_cache_flush(net); break; case NETDEV_DOWN: - fib_disable_ip(dev, event); + fib_disable_ip(dev, event, 0); break; case NETDEV_CHANGE: flags = dev_get_flags(dev); if (flags & (IFF_RUNNING | IFF_LOWER_UP)) fib_sync_up(dev, RTNH_F_LINKDOWN); else - fib_sync_down_dev(dev, event); + fib_sync_down_dev(dev, event, 0); /* fall through */ case NETDEV_CHANGEMTU: rt_cache_flush(net);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 064bd3c..f493eff 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c@@ -1281,7 +1281,13 @@ int fib_sync_down_addr(struct net *net, __be32 local) return ret; } -int fib_sync_down_dev(struct net_device *dev, unsigned long event) +/* Event force Flags Description + * NETDEV_CHANGE 0 LINKDOWN Carrier OFF, not for scope host + * NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host + * NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed + * NETDEV_UNREGISTER 2 LINKDOWN|DEAD Device removed + */ +int fib_sync_down_dev(struct net_device *dev, unsigned long event, int force) { int ret = 0; int scope = RT_SCOPE_NOWHERE;
@@ -1290,8 +1296,7 @@ int fib_sync_down_dev(struct net_device *dev, unsigned long event) struct hlist_head *head = &fib_info_devhash[hash]; struct fib_nh *nh; - if (event == NETDEV_UNREGISTER || - event == NETDEV_DOWN) + if (force) scope = -1; hlist_for_each_entry(nh, head, nh_hash) {
--
1.9.3