Commit Graph

157 Commits

Author SHA1 Message Date
Tim Stallard 03e2a984b6 net: ipv6: do not consider routes via gateways for anycast address check
The behaviour for what is considered an anycast address changed in
commit 45e4fd2668 ("ipv6: Only create RTF_CACHE routes after
encountering pmtu exception"). This now considers the first
address in a subnet where there is a route via a gateway
to be an anycast address.

This breaks path MTU discovery and traceroutes when a host in a
remote network uses the address at the start of a prefix
(eg 2600:: advertised as 2600::/48 in the DFZ) as ICMP errors
will not be sent to anycast addresses.

This patch excludes any routes with a gateway, or via point to
point links, like the behaviour previously from
rt6_is_gw_or_nonexthop in net/ipv6/route.c.

This can be tested with:
ip link add v1 type veth peer name v2
ip netns add test
ip netns exec test ip link set lo up
ip link set v2 netns test
ip link set v1 up
ip netns exec test ip link set v2 up
ip addr add 2001:db8::1/64 dev v1 nodad
ip addr add 2001:db8:100:: dev lo nodad
ip netns exec test ip addr add 2001:db8::2/64 dev v2 nodad
ip netns exec test ip route add unreachable 2001:db8:1::1
ip netns exec test ip route add 2001:db8:100::/64 via 2001:db8::1
ip netns exec test sysctl net.ipv6.conf.all.forwarding=1
ip route add 2001:db8:1::1 via 2001:db8::2
ping -I 2001:db8::1 2001:db8:1::1 -c1
ping -I 2001:db8:100:: 2001:db8:1::1 -c1
ip addr delete 2001:db8:100:: dev lo
ip netns delete test

Currently the first ping will get back a destination unreachable ICMP
error, but the second will never get a response, with "icmp6_send:
acast source" logged. After this patch, both get destination
unreachable ICMP replies.

Fixes: 45e4fd2668 ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception")
Signed-off-by: Tim Stallard <code@timstallard.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-07 18:26:52 -07:00
Gustavo A. R. Silva 207644f513 net: ip6_route: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-29 21:52:20 -08:00
David S. Miller d96ff269a0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
The new route handling in ip_mc_finish_output() from 'net' overlapped
with the new support for returning congestion notifications from BPF
programs.

In order to handle this I had to take the dev_loopback_xmit() calls
out of the switch statement.

The aquantia driver conflicts were simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-27 21:06:39 -07:00
Nicolas Dichtel 9b1c1ef13b ipv6: constify rt6_nexthop()
There is no functional change in this patch, it only prepares the next one.

rt6_nexthop() will be used by ip6_dst_lookup_neigh(), which uses const
variables.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-26 13:26:08 -07:00
Stefano Brivio 1e47b4837f ipv6: Dump route exceptions if requested
Since commit 2b760fcf5c ("ipv6: hook up exception table to store dst
cache"), route exceptions reside in a separate hash table, and won't be
found by walking the FIB, so they won't be dumped to userspace on a
RTM_GETROUTE message.

This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to
have no function anymore:

 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium
 # ip -6 route list cache
 # ip -6 route flush cache
 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium

because iproute2 lists cached routes using RTM_GETROUTE, and flushes them
by listing all the routes, and deleting them with RTM_DELROUTE one by one.

If cached routes are requested using the RTM_F_CLONED flag together with
strict checking, or if no strict checking is requested (and hence we can't
consistently apply filters), look up exceptions in the hash table
associated with the current fib6_info in rt6_dump_route(), and, if present
and not expired, add them to the dump.

We might be unable to dump all the entries for a given node in a single
message, so keep track of how many entries were handled for the current
node in fib6_walker, and skip that amount in case we start from the same
partially dumped node.

When a partial dump restarts, as the starting node might change when
'sernum' changes, we have no guarantee that we need to skip the same
amount of in-node entries. Therefore, we need two counters, and we need to
zero the in-node counter if the node from which the dump is resumed
differs.

Note that, with the current version of iproute2, this only fixes the
'ip -6 route list cache': on a flush command, iproute2 doesn't pass
RTM_F_CLONED and, due to this inconsistency, 'ip -6 route flush cache' is
still unable to fetch the routes to be flushed. This will be addressed in
a patch for iproute2.

To flush cached routes, a procfs entry could be introduced instead: that's
how it works for IPv4. We already have a rt6_flush_exception() function
ready to be wired to it. However, this would not solve the issue for
listing.

Versions of iproute2 and kernel tested:

                    iproute2
kernel             4.14.0   4.15.0   4.19.0   5.0.0   5.1.0    5.1.0, patched
 3.18    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.4     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.9     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.14    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.15    list
         flush
 4.19    list
         flush
 5.0     list
         flush
 5.1     list
         flush
 with    list        +        +        +        +       +            +
 fix     flush       +        +        +                             +

v7:
  - Explain usage of "skip" counters in commit message (suggested by
    David Ahern)

v6:
  - Rebase onto net-next, use recently introduced nexthop walker
  - Make rt6_nh_dump_exceptions() a separate function (suggested by David
    Ahern)

v5:
  - Use dump_routes and dump_exceptions from filter, ignore NLM_F_MATCH,
    update test results (flushing works with iproute2 < 5.0.0 now)

v4:
  - Split NLM_F_MATCH and strict check handling in separate patches
  - Filter routes using RTM_F_CLONED: if it's not set, only return
    non-cached routes, and if it's set, only return cached routes:
    change requested by David Ahern and Martin Lau. This implies that
    iproute2 needs a separate patch to be able to flush IPv6 cached
    routes. This is not ideal because we can't fix the breakage caused
    by 2b760fcf5c entirely in kernel. However, two years have passed
    since then, and this makes it more tolerable

v3:
  - More descriptive comment about expired exceptions in rt6_dump_route()
  - Swap return values of rt6_dump_route() (suggested by Martin Lau)
  - Don't zero skip_in_node in case we don't dump anything in a given pass
    (also suggested by Martin Lau)
  - Remove check on RTM_F_CLONED altogether: in the current UAPI semantic,
    it's just a flag to indicate the route was cloned, not to filter on
    routes

v2: Add tracking of number of entries to be skipped in current node after
    a partial dump. As we restart from the same node, if not all the
    exceptions for a given node fit in a single message, the dump will
    not terminate, as suggested by Martin Lau. This is a concrete
    possibility, setting up a big number of exceptions for the same route
    actually causes the issue, suggested by David Ahern.

Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-24 10:18:49 -07:00
Wei Wang 7d9e5f4221 ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF
For tx path, in most cases, we still have to take refcnt on the dst
cause the caller is caching the dst somewhere. But it still is
beneficial to make use of RT6_LOOKUP_F_DST_NOREF flag while doing the
route lookup. It is cause this flag prevents manipulating refcnt on
net->ipv6.ip6_null_entry when doing fib6_rule_lookup() to traverse each
routing table. The null_entry is a shared object and constant updates on
it cause false sharing.

We converted the current major lookup function ip6_route_output_flags()
to make use of RT6_LOOKUP_F_DST_NOREF.

Together with the change in the rx path, we see noticable performance
boost:
I ran synflood tests between 2 hosts under the same switch. Both hosts
have 20G mlx NIC, and 8 tx/rx queues.
Sender sends pure SYN flood with random src IPs and ports using trafgen.
Receiver has a simple TCP listener on the target port.
Both hosts have multiple custom rules:
- For incoming packets, only local table is traversed.
- For outgoing packets, 3 tables are traversed to find the route.
The packet processing rate on the receiver is as follows:
- Before the fix: 3.78Mpps
- After the fix:  5.50Mpps

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Wei Wang d64a1f574a ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic
This patch specifically converts the rule lookup logic to honor this
flag and not release refcnt when traversing each rule and calling
lookup() on each routing table.
Similar to previous patch, we also need some special handling of dst
entries in uncached list because there is always 1 refcnt taken for them
even if RT6_LOOKUP_F_DST_NOREF flag is set.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
Wei Wang 0e09edcce7 ipv6: introduce RT6_LOOKUP_F_DST_NOREF flag in ip6_pol_route()
This new flag is to instruct the route lookup function to not take
refcnt on the dst entry. The user which does route lookup with this flag
must properly use rcu protection.
ip6_pol_route() is the major route lookup function for both tx and rx
path.
In this function:
Do not take refcnt on dst if RT6_LOOKUP_F_DST_NOREF flag is set, and
directly return the route entry. The caller should be holding rcu lock
when using this flag, and decide whether to take refcnt or not.

One note on the dst cache in the uncached_list:
As uncached_list does not consume refcnt, one refcnt is always returned
back to the caller even if RT6_LOOKUP_F_DST_NOREF flag is set.
Uncached dst is only possible in the output path. So in such call path,
caller MUST check if the dst is in the uncached_list before assuming
that there is no refcnt taken on the returned dst.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-23 13:24:17 -07:00
David Ahern f88d8ea67f ipv6: Plumb support for nexthop object in a fib6_info
Add struct nexthop and nh_list list_head to fib6_info. nh_list is the
fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info
referencing a nexthop object can not have 'sibling' entries (the old way
of doing multipath routes), the nh_list is a union with fib6_siblings.

Add f6i_list list_head to 'struct nexthop' to track fib6_info entries
using a nexthop instance. Update __remove_nexthop_fib to walk f6_list
and delete fib entries using the nexthop.

Add a few nexthop helpers for use when a nexthop is added to fib6_info:
- nexthop_fib6_nh - return first fib6_nh in a nexthop object
- fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh
  if the fib6_info references a nexthop object
- nexthop_path_fib6_result - similar to ipv4, select a path within a
  multipath nexthop object. If the nexthop is a blackhole, set
  fib6_result type to RTN_BLACKHOLE, and set the REJECT flag

Update the fib6_info references to check for nh and take a different path
as needed:
- rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT
  be coalesced with other fib entries into a multipath route
- rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references
  a nexthop
- addrconf (host routes), RA's and info entries (anything configured via
  ndisc) does not use nexthop objects
- fib6_info_destroy_rcu - put reference to nexthop object
- fib6_purge_rt - drop fib6_info from f6i_list
- fib6_select_path - update to use the new nexthop_path_fib6_result when
  fib entry uses a nexthop object
- rt6_device_match - update to catch use of nexthop object as a blackhole
  and set fib6_type and flags.
- ip6_route_info_create - don't add space for fib6_nh if fib entry is
  going to reference a nexthop object, take a reference to nexthop object,
  disallow use of source routing
- rt6_nlmsg_size - add space for RTA_NH_ID
- add rt6_fill_node_nexthop to add nexthop data on a dump

As with ipv4, most of the changes push existing code into the else branch
of whether the fib entry uses a nexthop object.

Update the nexthop code to walk f6i_list on a nexthop deleted to remove
fib entries referencing it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-04 19:26:50 -07:00
David Ahern 1cf844c747 ipv6: Make fib6_nh optional at the end of fib6_info
Move fib6_nh to the end of fib6_info and make it an array of
size 0. Pass a flag to fib6_info_alloc indicating if the
allocation needs to add space for a fib6_nh.

The current code path always has a fib6_nh allocated with a
fib6_info; with nexthop objects they will be separate.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-24 13:26:44 -07:00
David Ahern ecc5663cce net: Change nhc_flags to unsigned char
nhc_flags holds the RTNH_F flags for a given nexthop (fib{6}_nh).
All of the RTNH_F_ flags fit in an unsigned char, and since the API to
userspace (rtnh_flags and lower byte of rtm_flags) is 1 byte it can not
grow. Make nhc_flags in fib_nh_common an unsigned char and shrink the
size of the struct by 8, from 56 to 48 bytes.

Update the flags arguments for up netdevice events and fib_nexthop_info
which determines the RTNH_F flags to return on a dump/event. The RTNH_F
flags are passed in the lower byte of rtm_flags which is an unsigned int
so use a temp variable for the flags to fib_nexthop_info and combine
with rtm_flags in the caller.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-23 19:44:18 -07:00
David Ahern be659b8d3c ipv6: Restore RTF_ADDRCONF check in rt6_qualify_for_ecmp
The RTF_ADDRCONF flag filters out routes added by RA's in determining
which routes can be appended to an existing one to create a multipath
route. Restore the flag check and add a comment to document the RA piece.

Fixes: 4e54507ab1 ("ipv6: Simplify rt6_qualify_for_ecmp")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-21 19:44:16 -07:00
David Ahern 4e54507ab1 ipv6: Simplify rt6_qualify_for_ecmp
After commit c7a1ce397a ("ipv6: Change addrconf_f6i_alloc to use
ip6_route_info_create"), the gateway is no longer filled in for fib6_nh
structs in a prefix route. Accordingly, the RTF_ADDRCONF flag check can
be dropped from the 'rt6_qualify_for_ecmp'.

Further, RTF_DYNAMIC is only set in rt6_info instances, so it can be
removed from the check as well.

This reduces rt6_qualify_for_ecmp and the mlxsw version to just checking
if the nexthop has a gateway which is the real indication of whether
entries can be coalesced into a multipath route.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-21 10:39:52 -07:00
David Ahern b748f26092 ipv6: Pass fib6_result to ip6_mtu_from_fib6 and fib6_mtu
Change ip6_mtu_from_fib6 and fib6_mtu to take a fib6_result over a
fib6_info. Update both to use the fib6_nh from fib6_result.

Since the signature of ip6_mtu_from_fib6 is already changing, add const
to daddr and saddr.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-17 23:10:46 -07:00
David Ahern bdf0046771 net: Replace nhc_has_gw with nhc_gw_family
Allow the gateway in a fib_nh_common to be from a different address
family than the outer fib{6}_nh. To that end, replace nhc_has_gw with
nhc_gw_family and update users of nhc_has_gw to check nhc_gw_family.
Now nhc_family is used to know if the nh_common is part of a fib_nh
or fib6_nh (used for container_of to get to route family specific data),
and nhc_gw_family represents the address family for the gateway.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-08 15:22:40 -07:00
David Ahern ad1601ae02 ipv6: Rename fib6_nh entries
Rename fib6_nh entries that will be moved to a fib_nh_common struct.
Specifically, the device, gateway, flags, and lwtstate are common
with all nexthop definitions. In some places new temporary variables
are declared or local variables renamed to maintain line lengths.

Rename only; no functional change intended.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-29 10:48:04 -07:00
David Ahern 2b2450ca4a ipv6: Move gateway checks to a fib6_nh setting
The gateway setting is not per fib6_info entry but per-fib6_nh. Add a new
fib_nh_has_gw flag to fib6_nh and convert references to RTF_GATEWAY to
the new flag. For IPv6 address the flag is cheaper than checking that
nh_gw is non-0 like IPv4 does.

While this increases fib6_nh by 8-bytes, the effective allocation size of
a fib6_info is unchanged. The 8 bytes is recovered later with a
fib_nh_common change.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-29 10:48:03 -07:00
David Ahern 4724676d55 net: Add struct for fib dump filter
Add struct fib_dump_filter for options on limiting which routes are
returned in a dump request. The current list is table id, protocol,
route type, rtm_flags and nexthop device index. struct net is needed
to lookup the net_device from the index.

Declare the filter for each route dump handler and plumb the new
arguments from dump handlers to ip_valid_fib_dump_req.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-16 00:13:12 -07:00
Maciej Żenczykowski d456336d16 net: remove 1 always zero parameter from ip6_redirect_no_header()
(the parameter in question is mark)

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-02 16:12:40 -07:00
David Ahern 33bd5ac54d net/ipv6: Revert attempt to simplify route replace and append
NetworkManager likes to manage linklocal prefix routes and does so with
the NLM_F_APPEND flag, breaking attempts to simplify the IPv6 route
code and by extension enable multipath routes with device only nexthops.

Revert f34436a430 and these followup patches:
6eba08c362 ("ipv6: Only emit append events for appended routes").
ce45bded64 ("mlxsw: spectrum_router: Align with new route replace logic")
53b562df8c ("mlxsw: spectrum_router: Allow appending to dev-only routes")

Update the fib_tests cases to reflect the old behavior.

Fixes: f34436a430 ("net/ipv6: Simplify route replace and appending into multipath route")
Signed-off-by: David Ahern <dsahern@gmail.com>
2018-07-04 15:22:13 +09:00
David S. Miller 90fed9c946 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2018-05-24

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc).

2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers.

3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit.

4) Jiong Wang adds support for indirect and arithmetic shifts to NFP

5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible.

6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing
   to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions.

7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT.

8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events.

9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24 22:20:51 -04:00
David Ahern f34436a430 net/ipv6: Simplify route replace and appending into multipath route
Bring consistency to ipv6 route replace and append semantics.

Remove rt6_qualify_for_ecmp which is just guess work. It fails in 2 cases:
1. can not replace a route with a reject route. Existing code appends
   a new route instead of replacing the existing one.

2. can not have a multipath route where a leg uses a dev only nexthop

Existing use cases affected by this change:
1. adding a route with existing prefix and metric using NLM_F_CREATE
   without NLM_F_APPEND or NLM_F_EXCL (ie., what iproute2 calls
   'prepend'). Existing code auto-determines that the new nexthop can
   be appended to an existing route to create a multipath route. This
   change breaks that by requiring the APPEND flag for the new route
   to be added to an existing one. Instead the prepend just adds another
   route entry.

2. route replace. Existing code replaces first matching multipath route
   if new route is multipath capable and fallback to first matching
   non-ECMP route (reject or dev only route) in case one isn't available.
   New behavior replaces first matching route. (Thanks to Ido for spotting
   this one)

Note: Newer iproute2 is needed to display multipath routes with a dev-only
      nexthop. This is due to a bug in iproute2 and parsing nexthops.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-22 14:44:18 -04:00
David Ahern 901731b882 net/ipv6: Add helper to return path MTU based on fib result
Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.

Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-22 10:51:09 +02:00
David S. Miller 90278871d4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for your net-next
tree, more relevant updates in this batch are:

1) Add Maglev support to IPVS. Moreover, store lastest server weight in
   IPVS since this is needed by maglev, patches from from Inju Song.

2) Preparation works to add iptables flowtable support, patches
   from Felix Fietkau.

3) Hand over flows back to conntrack slow path in case of TCP RST/FIN
   packet is seen via new teardown state, also from Felix.

4) Add support for extended netlink error reporting for nf_tables.

5) Support for larger timeouts that 23 days in nf_tables, patch from
   Florian Westphal.

6) Always set an upper limit to dynamic sets, also from Florian.

7) Allow number generator to make map lookups, from Laura Garcia.

8) Use hash_32() instead of opencode hashing in IPVS, from Vicent Bernat.

9) Extend ip6tables SRH match to support previous, next and last SID,
   from Ahmed Abdelsalam.

10) Move Passive OS fingerprint nf_osf.c, from Fernando Fernandez.

11) Expose nf_conntrack_max through ctnetlink, from Florent Fourcot.

12) Several housekeeping patches for xt_NFLOG, x_tables and ebtables,
   from Taehee Yoo.

13) Unify meta bridge with core nft_meta, then make nft_meta built-in.
   Make rt and exthdr built-in too, again from Florian.

14) Missing initialization of tbl->entries in IPVS, from Cong Wang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-06 21:51:37 -04:00
Felix Fietkau 07cb9623ee ipv6: make ip6_dst_mtu_forward inline
Just like ip_dst_mtu_maybe_forward(), to avoid a dependency with ipv6.ko.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-04-21 19:20:04 +02:00
David Ahern 647d4c1363 net/ipv6: Remove compare of fib6_idev from rt6_duplicate_nexthop
After 4832c30d54 ("net: ipv6: put host and anycast routes on device
with address") the comparison of idev does not add value since it
correlates to the nexthop device which is already compared. Remove
the idev comparison.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-19 15:40:13 -04:00
David Ahern 6fe7494144 net/ipv6: Change ip6_route_get_saddr to get dev from route
Prior to 4832c30d54 ("net: ipv6: put host and anycast routes on device
with address") host routes and anycast routes were installed with the
device set to loopback (or VRF device once that feature was added). In the
older code dst.dev was set to loopback (needed for packet tx) and rt6i_idev
was used to denote the actual interface.

Commit 4832c30d54 changed the code to have dst.dev pointing to the real
device with the switch to lo or vrf device done on dst clones. As a
consequence of this change ip6_route_get_saddr can just pass the nexthop
device to ipv6_dev_get_saddr.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-19 15:40:13 -04:00
David Ahern 360a9887c8 net/ipv6: Rename addrconf_dst_alloc
addrconf_dst_alloc now returns a fib6_info. Update the name
and its users to reflect the change.

Rename only; no functional change intended.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-19 15:40:13 -04:00
David Ahern 93c2fb253d net/ipv6: Rename fib6_info struct elements
Change the prefix for fib6_info struct elements from rt6i_ to fib6_.
rt6i_pcpu and rt6i_exception_bucket are left as is given that they
point to rt6_info entries.

Rename only; not functional change intended.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-19 15:40:12 -04:00
David Ahern 8d1c802b28 net/ipv6: Flip FIB entries to fib6_info
Convert all code paths referencing a FIB entry from
rt6_info to fib6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:18 -04:00
David Ahern 93531c6743 net/ipv6: separate handling of FIB entries from dst based routes
Last step before flipping the data type for FIB entries:
- use fib6_info_alloc to create FIB entries in ip6_route_info_create
  and addrconf_dst_alloc
- use fib6_info_release in place of dst_release, ip6_rt_put and
  rt6_release
- remove the dst_hold before calling __ip6_ins_rt or ip6_del_rt
- when purging routes, drop per-cpu routes
- replace inc and dec of rt6i_ref with fib6_info_hold and fib6_info_release
- use rt->from since it points to the FIB entry
- drop references to exception bucket, fib6_metrics and per-cpu from
  dst entries (those are relevant for fib entries only)

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:17 -04:00
David Ahern 23fb93a4d3 net/ipv6: Cleanup exception and cache route handling
IPv6 FIB will only contain FIB entries with exception routes added to
the FIB entry. Once this transformation is complete, FIB lookups will
return a fib6_info with the lookup functions still returning a dst
based rt6_info. The current code uses rt6_info for both paths and
overloads the rt6_info variable usually called 'rt'.

This patch introduces a new 'f6i' variable name for the result of the FIB
lookup and keeps 'rt' as the dst based return variable. 'f6i' becomes a
fib6_info in a later patch which is why it is introduced as f6i now;
avoids the additional churn in the later patch.

In addition, remove RTF_CACHE and dst checks from fib6 add and delete
since they can not happen now and will never happen after the data
type flip.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:17 -04:00
David Ahern acb54e3cba net/ipv6: Add gfp_flags to route add functions
Most FIB entries can be added using memory allocated with GFP_KERNEL.
Add gfp_flags to ip6_route_add and addrconf_dst_alloc. Code paths that
can be reached from the packet path (e.g., ndisc and autoconfig) or
atomic notifiers use GFP_ATOMIC; paths from user context (adding
addresses and routes) use GFP_KERNEL.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:17 -04:00
David Ahern f8a1b43b70 net/ipv6: Create a neigh_lookup for FIB entries
The router discovery code has a FIB entry and wants to validate the
gateway has a neighbor entry. Refactor the existing dst_neigh_lookup
for IPv6 and create a new function that takes the gateway and device
and returns a neighbor entry. Use the new function in
ndisc_router_discovery to validate the gateway.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:17 -04:00
David Ahern 5e670d844b net/ipv6: Move nexthop data to fib6_nh
Introduce fib6_nh structure and move nexthop related data from
rt6_info and rt6_info.dst to fib6_nh. References to dev, gateway or
lwtstate from a FIB lookup perspective are converted to use fib6_nh;
datapath references to dst version are left as is.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:16 -04:00
David Ahern afb1d4b593 net/ipv6: Pass net namespace to route functions
Pass network namespace reference into route add, delete and get
functions.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 23:41:16 -04:00
Alexey Kodanev 7d6850f7c6 ipv6: add a wrapper for ip6_dst_store() with flowi6 checks
Move commonly used pattern of ip6_dst_store() usage to a separate
function - ip6_sk_dst_store_flow(), which will check the addresses
for equality using the flow information, before saving them.

There is no functional changes in this patch. In addition, it will
be used in the next patch, in ip6_sk_dst_lookup_flow().

Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04 11:31:57 -04:00
David S. Miller 03fe2debbb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Fun set of conflict resolutions here...

For the mac80211 stuff, these were fortunately just parallel
adds.  Trivially resolved.

In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the
function phy_disable_interrupts() earlier in the file, whilst in
'net-next' the phy_error() call from this function was removed.

In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the
'rt_table_id' member of rtable collided with a bug fix in 'net' that
added a new struct member "rt_mtu_locked" which needs to be copied
over here.

The mlxsw driver conflict consisted of net-next separating
the span code and definitions into separate files, whilst
a 'net' bug fix made some changes to that moved code.

The mlx5 infiniband conflict resolution was quite non-trivial,
the RDMA tree's merge commit was used as a guide here, and
here are their notes:

====================

    Due to bug fixes found by the syzkaller bot and taken into the for-rc
    branch after development for the 4.17 merge window had already started
    being taken into the for-next branch, there were fairly non-trivial
    merge issues that would need to be resolved between the for-rc branch
    and the for-next branch.  This merge resolves those conflicts and
    provides a unified base upon which ongoing development for 4.17 can
    be based.

    Conflicts:
            drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f95
            (IB/mlx5: Fix cleanup order on unload) added to for-rc and
            commit b5ca15ad7e (IB/mlx5: Add proper representors support)
            add as part of the devel cycle both needed to modify the
            init/de-init functions used by mlx5.  To support the new
            representors, the new functions added by the cleanup patch
            needed to be made non-static, and the init/de-init list
            added by the representors patch needed to be modified to
            match the init/de-init list changes made by the cleanup
            patch.
    Updates:
            drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function
            prototypes added by representors patch to reflect new function
            names as changed by cleanup patch
            drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init
            stage list to match new order from cleanup patch
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 11:31:58 -04:00
David Ahern b4bac172e9 net/ipv6: Add support for path selection using hash of 5-tuple
Some operators prefer IPv6 path selection to use a standard 5-tuple
hash rather than just an L3 hash with the flow the label. To that end
add support to IPv6 for multipath hash policy similar to bf4e0a3db9
("net: ipv4: add support for ECMP hash policy choice"). The default
is still L3 which covers source and destination addresses along with
flow label and IPv6 protocol.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-04 13:04:23 -05:00
David Ahern b75cc8f90f net/ipv6: Pass skb to route lookup
IPv6 does path selection for multipath routes deep in the lookup
functions. The next patch adds L4 hash option and needs the skb
for the forward path. To get the skb to the relevant FIB lookup
functions it needs to go through the fib rules layer, so add a
lookup_data argument to the fib_lookup_arg struct.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-04 13:04:22 -05:00
Roopa Prabhu 5e5d6fed37 ipv6: route: dissect flow in input path if fib rules need it
Dissect flow in fwd path if fib rules require it. Controlled by
a flag to avoid penatly for the common case. Flag is set when fib
rules with sport, dport and proto match that require flow dissect
are installed. Also passes the dissected hash keys to the multipath
hash function when applicable to avoid dissecting the flow again.
icmp packets will continue to use inner header for hash
calculations.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-28 22:44:44 -05:00
Xin Long 510c321b55 xfrm: reuse uncached_list to track xdsts
In early time, when freeing a xdst, it would be inserted into
dst_garbage.list first. Then if it's refcnt was still held
somewhere, later it would be put into dst_busy_list in
dst_gc_task().

When one dev was being unregistered, the dev of these dsts in
dst_busy_list would be set with loopback_dev and put this dev.
So that this dev's removal wouldn't get blocked, and avoid the
kmsg warning:

  kernel:unregister_netdevice: waiting for veth0 to become \
  free. Usage count = 2

However after Commit 52df157f17 ("xfrm: take refcnt of dst
when creating struct xfrm_dst bundle"), the xdst will not be
freed with dst gc, and this warning happens.

To fix it, we need to find these xdsts that are still held by
others when removing the dev, and free xdst's dev and set it
with loopback_dev.

But unfortunately after flow_cache for xfrm was deleted, no
list tracks them anymore. So we need to save these xdsts
somewhere to release the xdst's dev later.

To make this easier, this patch is to reuse uncached_list to
track xdsts, so that the dev refcnt can be released in the
event NETDEV_UNREGISTER process of fib_netdev_notifier.

Thanks to Florian, we could move forward this fix quickly.

Fixes: 52df157f17 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle")
Reported-by: Jianlin Shi <jishi@redhat.com>
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Tested-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2018-02-16 07:03:33 +01:00
Ido Schimmel d7dedee184 ipv6: Calculate hash thresholds for IPv6 nexthops
Before we convert IPv6 to use hash-threshold instead of modulo-N, we
first need each nexthop to store its region boundary in the hash
function's output space.

The boundary is calculated by dividing the output space equally between
the different active nexthops. That is, nexthops that are not dead or
linkdown.

The boundaries are rebalanced whenever a nexthop is added or removed to
a multipath route and whenever a nexthop becomes active or inactive.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-10 15:14:44 -05:00
Ido Schimmel 27c6fa73f9 ipv6: Set nexthop flags upon carrier change
Similar to IPv4, when the carrier of a netdev changes we should toggle
the 'linkdown' flag on all the nexthops using it as their nexthop
device.

This will later allow us to test for the presence of this flag during
route lookup and dump.

Up until commit 4832c30d54 ("net: ipv6: put host and anycast routes on
device with address") host and anycast routes used the loopback netdev
as their nexthop device and thus were not marked with the 'linkdown'
flag. The patch preserves this behavior and allows one to ping the local
address even when the nexthop device does not have a carrier and the
'ignore_routes_with_linkdown' sysctl is set.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-07 21:29:40 -05:00
Ido Schimmel 4c981e28d3 ipv6: Prepare to handle multiple netdev events
To make IPv6 more in line with IPv4 we need to be able to respond
differently to different netdev events. For example, when a netdev is
unregistered all the routes using it as their nexthop device should be
flushed, whereas when the netdev's carrier changes only the 'linkdown'
flag should be toggled.

Currently, this is not possible, as the function that traverses the
routing tables is not aware of the triggering event.

Propagate the triggering event down, so that it could be used in later
patches.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-07 21:29:40 -05:00
Ido Schimmel 2127d95aef ipv6: Clear nexthop flags upon netdev up
Previous patch marked nexthops with the 'dead' and 'linkdown' flags.
Clear these flags when the netdev comes back up.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-07 21:29:39 -05:00
David S. Miller 2a171788ba Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-04 09:26:51 +09:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Wei Wang c757faa8bf ipv6: prepare fib6_age() for exception table
If all dst cache entries are stored in the exception table under the
main route, we have to go through them during fib6_age() when doing
garbage collecting.
Introduce a new function rt6_age_exception() which goes through all dst
entries in the exception table and remove those entries that are expired.
This function is called in fib6_age() so that all dst caches are also
garbage collected.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07 21:22:57 +01:00
Wei Wang 35732d01fe ipv6: introduce a hash table to store dst cache
Add a hash table into struct rt6_info in order to store dst caches
created by pmtu discovery and ip redirect in ipv6 routing code.
APIs to add dst cache, delete dst cache, find dst cache and update
dst cache in the hash table are implemented and will be used in later
commits.
This is a preparation work to move all cache routes into the exception
table instead of getting inserted into the fib6 tree.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07 21:22:57 +01:00