linux/include
David Ahern 5c9f7c1dfc ipv4: Add helpers for neigh lookup for nexthop
A common theme in the output path is looking up a neigh entry for a
nexthop, either the gateway in an rtable or a fallback to the daddr
in the skb:

        nexthop = (__force u32)rt_nexthop(rt, ip_hdr(skb)->daddr);
        neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
        if (unlikely(!neigh))
                neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);

To allow the nexthop to be an IPv6 address we need to consider the
family of the nexthop and then call __ipv{4,6}_neigh_lookup_noref based
on it.

To make this simpler, add a ip_neigh_gw4 helper similar to ip_neigh_gw6
added in an earlier patch which handles:

        neigh = __ipv4_neigh_lookup_noref(dev, nexthop);
        if (unlikely(!neigh))
                neigh = __neigh_create(&arp_tbl, &nexthop, dev, false);

And then add a second one, ip_neigh_for_gw, that calls either
ip_neigh_gw4 or ip_neigh_gw6 based on the address family of the gateway.

Update the output paths in the VRF driver and core v4 code to use
ip_neigh_for_gw simplifying the family based lookup and making both
ready for a v6 nexthop.

ipv4_neigh_lookup has a different need - the potential to resolve a
passed in address in addition to any gateway in the rtable or skb. Since
this is a one-off, add ip_neigh_gw4 and ip_neigh_gw6 diectly. The
difference between __neigh_create used by the helpers and neigh_create
called by ipv4_neigh_lookup is taking a refcount, so add rcu_read_lock_bh
and bump the refcnt on the neigh entry.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-08 15:22:41 -07:00
..
acpi ACPI: use different default debug value than ACPICA 2019-03-25 10:45:59 +01:00
asm-generic kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
clocksource
crypto
drm drm i915, amdgpu, qxl and etnaviv fixes 2019-03-15 13:58:35 -07:00
dt-bindings We have a fairly balanced mix of clk driver updates and clk framework 2019-03-14 08:46:17 -07:00
keys Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-03-10 17:32:04 -07:00
kvm ARM: some cleanups, direct physical timer assignment, cache sanitization 2019-03-15 15:00:28 -07:00
linux net: phy: improve link partner capability detection 2019-04-08 15:18:00 -07:00
math-emu
media media: include: fix several typos 2019-03-01 09:45:52 -05:00
memory
misc auxdisplay: charlcd: Introduce charlcd_free() helper 2019-03-17 08:48:16 +01:00
net ipv4: Add helpers for neigh lookup for nexthop 2019-04-08 15:22:41 -07:00
pcmcia
ras
rdma
scsi scsi: kill command serial number 2019-02-27 09:19:24 -05:00
soc IOMMU Updates for Linux v5.1 2019-03-10 12:29:52 -07:00
sound sound fixes for 5.1-rc1 2019-03-15 14:05:00 -07:00
target
trace net: Replace nhc_has_gw with nhc_gw_family 2019-04-08 15:22:40 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-05 14:14:19 -07:00
video media updates for v5.1-rc1 2019-03-09 14:45:54 -08:00
xen