From 331c7a402358de6206232f6aab7aa48ec6c1088a Mon Sep 17 00:00:00 2001 From: David Ahern Date: Wed, 27 Mar 2019 20:53:47 -0700 Subject: [PATCH] ipv4: Move IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN to helper in_dev lookup followed by IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN check is called in several places, some with the rcu lock and others with the rtnl held. Move the check to a helper similar to what IPv6 has. Since the helper can be invoked from either context use rcu_dereference_rtnl to dereference ip_ptr. Signed-off-by: David Ahern Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller --- include/linux/inetdevice.h | 14 ++++++++++++++ net/ipv4/fib_semantics.c | 31 +++++++------------------------ net/ipv4/fib_trie.c | 4 +--- 3 files changed, 22 insertions(+), 27 deletions(-) diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index a64f21a97369..367dc2a0f84a 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h @@ -237,6 +237,20 @@ static inline struct in_device *__in_dev_get_rtnl(const struct net_device *dev) return rtnl_dereference(dev->ip_ptr); } +/* called with rcu_read_lock or rtnl held */ +static inline bool ip_ignore_linkdown(const struct net_device *dev) +{ + struct in_device *in_dev; + bool rc = false; + + in_dev = rcu_dereference_rtnl(dev->ip_ptr); + if (in_dev && + IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) + rc = true; + + return rc; +} + static inline struct neigh_parms *__in_dev_arp_parms_get_rcu(const struct net_device *dev) { struct in_device *in_dev = __in_dev_get_rcu(dev); diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index b5dbbdfd1e49..78631eb255f7 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -558,7 +558,6 @@ static void fib_rebalance(struct fib_info *fi) { int total; int w; - struct in_device *in_dev; if (fi->fib_nhs < 2) return; @@ -568,10 +567,7 @@ static void fib_rebalance(struct fib_info *fi) if (nh->nh_flags & RTNH_F_DEAD) continue; - in_dev = __in_dev_get_rtnl(nh->nh_dev); - - if (in_dev && - IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && + if (ip_ignore_linkdown(nh->nh_dev) && nh->nh_flags & RTNH_F_LINKDOWN) continue; @@ -582,12 +578,9 @@ static void fib_rebalance(struct fib_info *fi) change_nexthops(fi) { int upper_bound; - in_dev = __in_dev_get_rtnl(nexthop_nh->nh_dev); - if (nexthop_nh->nh_flags & RTNH_F_DEAD) { upper_bound = -1; - } else if (in_dev && - IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && + } else if (ip_ignore_linkdown(nexthop_nh->nh_dev) && nexthop_nh->nh_flags & RTNH_F_LINKDOWN) { upper_bound = -1; } else { @@ -1325,12 +1318,8 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, nla_put_u32(skb, RTA_OIF, fi->fib_nh->nh_oif)) goto nla_put_failure; if (fi->fib_nh->nh_flags & RTNH_F_LINKDOWN) { - struct in_device *in_dev; - rcu_read_lock(); - in_dev = __in_dev_get_rcu(fi->fib_nh->nh_dev); - if (in_dev && - IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) + if (ip_ignore_linkdown(fi->fib_nh->nh_dev)) rtm->rtm_flags |= RTNH_F_DEAD; rcu_read_unlock(); } @@ -1361,12 +1350,8 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event, rtnh->rtnh_flags = nh->nh_flags & 0xFF; if (nh->nh_flags & RTNH_F_LINKDOWN) { - struct in_device *in_dev; - rcu_read_lock(); - in_dev = __in_dev_get_rcu(nh->nh_dev); - if (in_dev && - IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev)) + if (ip_ignore_linkdown(nh->nh_dev)) rtnh->rtnh_flags |= RTNH_F_DEAD; rcu_read_unlock(); } @@ -1433,7 +1418,7 @@ int fib_sync_down_addr(struct net_device *dev, __be32 local) static int call_fib_nh_notifiers(struct fib_nh *fib_nh, enum fib_event_type event_type) { - struct in_device *in_dev = __in_dev_get_rtnl(fib_nh->nh_dev); + bool ignore_link_down = ip_ignore_linkdown(fib_nh->nh_dev); struct fib_nh_notifier_info info = { .fib_nh = fib_nh, }; @@ -1442,14 +1427,12 @@ static int call_fib_nh_notifiers(struct fib_nh *fib_nh, case FIB_EVENT_NH_ADD: if (fib_nh->nh_flags & RTNH_F_DEAD) break; - if (IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && - fib_nh->nh_flags & RTNH_F_LINKDOWN) + if (ignore_link_down && fib_nh->nh_flags & RTNH_F_LINKDOWN) break; return call_fib4_notifiers(dev_net(fib_nh->nh_dev), event_type, &info.info); case FIB_EVENT_NH_DEL: - if ((in_dev && IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && - fib_nh->nh_flags & RTNH_F_LINKDOWN) || + if ((ignore_link_down && fib_nh->nh_flags & RTNH_F_LINKDOWN) || (fib_nh->nh_flags & RTNH_F_DEAD)) return call_fib4_notifiers(dev_net(fib_nh->nh_dev), event_type, &info.info); diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 1704f432de1f..656d3d19f112 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -1471,12 +1471,10 @@ found: continue; for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) { const struct fib_nh *nh = &fi->fib_nh[nhsel]; - struct in_device *in_dev = __in_dev_get_rcu(nh->nh_dev); if (nh->nh_flags & RTNH_F_DEAD) continue; - if (in_dev && - IN_DEV_IGNORE_ROUTES_WITH_LINKDOWN(in_dev) && + if (ip_ignore_linkdown(nh->nh_dev) && nh->nh_flags & RTNH_F_LINKDOWN && !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE)) continue;