ipv4: Make neigh lookup keys for loopback/point-to-point devices be INADDR_ANY (cd9ff4de) · Commits · 戴 / test

Map all lookup neigh keys to INADDR_ANY for loopback/point-to-point devices to avoid making an entry for every remote ip the device needs to talk to. This used the be the old behavior but became broken in (ipv4: Make neigh lookups directly in output packet path) and later removed in (ipv4: Fix neigh lookup keying over loopback/point-to-point devices) because it was broken. Signed-off-by:

Jim Westfall <jwestfall@surrealistic.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/arp.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,9 @@ static inline u32 arp_hashfn(const void pkey, const struct net_device dev, u32

		static inline struct neighbour __ipv4_neigh_lookup_noref(struct net_device dev, u32 key)
		{
		if (dev->flags & (IFF_LOOPBACK \| IFF_POINTOPOINT))
		key = INADDR_ANY;

		return ___neigh_lookup_noref(&arp_tbl, neigh_key_eq32, arp_hashfn, &key, dev);
		}

net/ipv4/arp.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -223,11 +223,16 @@ static bool arp_key_eq(const struct neighbour neigh, const void pkey)

		static int arp_constructor(struct neighbour *neigh)
		{
		__be32 addr = (__be32 )neigh->primary_key;
		__be32 addr;
		struct net_device *dev = neigh->dev;
		struct in_device *in_dev;
		struct neigh_parms *parms;
		u32 inaddr_any = INADDR_ANY;

		if (dev->flags & (IFF_LOOPBACK \| IFF_POINTOPOINT))
		memcpy(neigh->primary_key, &inaddr_any, arp_tbl.key_len);

		addr = (__be32 )neigh->primary_key;
		rcu_read_lock();
		in_dev = __in_dev_get_rcu(dev);
		if (!in_dev) {

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