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  1. 09 1月, 2018 20 次提交
  3. 08 1月, 2018 20 次提交
    • D
      Merge branch 'ipv6-ipv4-nexthop-align' · f66faae2
      由 David S. Miller 提交于 
      Ido Schimmel says:

====================
ipv6: Align nexthop behaviour with IPv4

This set tries to eliminate some differences between IPv4's and IPv6's
treatment of nexthops. These differences are most likely a side effect
of IPv6's data structures (specifically 'rt6_info') that incorporate
both the route and the nexthop and the late addition of ECMP support in
commit 51ebd318 ("ipv6: add support of equal cost multipath
(ECMP)").

IPv4 and IPv6 do not react the same to certain netdev events. For
example, upon carrier change affected IPv4 nexthops are marked using the
RTNH_F_LINKDOWN flag and the nexthop group is rebalanced accordingly.
IPv6 on the other hand, does nothing which forces us to perform a
carrier check during route lookup and dump. This makes it difficult to
introduce features such as non-equal-cost multipath that are built on
top of this set [1].

In addition, when a netdev is put administratively down IPv4 nexthops
are marked using the RTNH_F_DEAD flag, whereas IPv6 simply flushes all
the routes using these nexthops. To be consistent with IPv4, multipath
routes should only be flushed when all nexthops in the group are
considered dead.

The first 12 patches introduce non-functional changes that store the
RTNH_F_DEAD and RTNH_F_LINKDOWN flags in IPv6 routes based on netdev
events, in a similar fashion to IPv4. This allows us to remove the
carrier check performed during route lookup and dump.

The next three patches make sure we only flush a multipath route when
all of its nexthops are dead.

Last three patches add test cases for IPv4/IPv6 FIB. These verify that
both address families react similarly to netdev events.

Finally, this series also serves as a good first step towards David
Ahern's goal of treating nexthops as standalone objects [2], as it makes
the code more in line with IPv4 where the nexthop and the nexthop group
are separate objects from the route itself.

1. https://github.com/idosch/linux/tree/ipv6-nexthops
2. http://vger.kernel.org/netconf2017_files/nexthop-objects.pdf

Changes since RFC (feedback from David Ahern):
* Remove redundant declaration of rt6_ifdown() in patch 4 and adjust
comment referencing it accordingly
* Drop patch to flush multipath routes upon NETDEV_UNREGISTER. Reword
cover letter accordingly
* Use a temporary variable to make code more readable in patch 15
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f66faae2
    • I
      selftests: fib_tests: Add test cases for netdev carrier change · 82e45b6f
      由 Ido Schimmel 提交于 
      Check that IPv4 and IPv6 react the same when the carrier of a netdev is
toggled. Local routes should not be affected by this, whereas unicast
routes should.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      82e45b6f
    • I
      selftests: fib_tests: Add test cases for netdev down · 5adb7683
      由 Ido Schimmel 提交于 
      Check that IPv4 and IPv6 react the same when a netdev is being put
administratively down.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5adb7683
    • I
      selftests: fib_tests: Add test cases for IPv4/IPv6 FIB · 607bd2e5
      由 Ido Schimmel 提交于 
      Add test cases to check that IPv4 and IPv6 react to a netdev being
unregistered as expected.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      607bd2e5
    • I
      ipv6: Flush multipath routes when all siblings are dead · 1de178ed
      由 Ido Schimmel 提交于 
      By default, IPv6 deletes nexthops from a multipath route when the
nexthop device is put administratively down. This differs from IPv4
where the nexthops are kept, but marked with the RTNH_F_DEAD flag. A
multipath route is flushed when all of its nexthops become dead.

Align IPv6 with IPv4 and have it conform to the same guidelines.

In case the multipath route needs to be flushed, its siblings are
flushed one by one. Otherwise, the nexthops are marked with the
appropriate flags and the tree walker is instructed to skip all the
siblings.

As explained in previous patches, care is taken to update the sernum of
the affected tree nodes, so as to prevent the use of wrong dst entries.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1de178ed
    • I
      ipv6: Take table lock outside of sernum update function · 922c2ac8
      由 Ido Schimmel 提交于 
      The next patch is going to allow dead routes to remain in the FIB tree
in certain situations.

When this happens we need to be sure to bump the sernum of the nodes
where these are stored so that potential copies cached in sockets are
invalidated.

The function that performs this update assumes the table lock is not
taken when it is invoked, but that will not be the case when it is
invoked by the tree walker.

Have the function assume the lock is taken and make the single caller
take the lock itself.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      922c2ac8
    • I
      ipv6: Export sernum update function · 4a8e56ee
      由 Ido Schimmel 提交于 
      We are going to allow dead routes to stay in the FIB tree (e.g., when
they are part of a multipath route, directly connected route with no
carrier) and revive them when their nexthop device gains carrier or when
it is put administratively up.

This is equivalent to the addition of the route to the FIB tree and we
should therefore take care of updating the sernum of all the parent
nodes of the node where the route is stored. Otherwise, we risk sockets
caching and using sub-optimal dst entries.

Export the function that performs the above, so that it could be invoked
from fib6_ifup() later on.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4a8e56ee
    • I
      ipv6: Teach tree walker to skip multipath routes · b5cb5a75
      由 Ido Schimmel 提交于 
      As explained in previous patch, fib6_ifdown() needs to consider the
state of all the sibling routes when a multipath route is traversed.

This is done by evaluating all the siblings when the first sibling in a
multipath route is traversed. If the multipath route does not need to be
flushed (e.g., not all siblings are dead), then we should just skip the
multipath route as our work is done.

Have the tree walker jump to the last sibling when it is determined that
the multipath route needs to be skipped.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b5cb5a75
    • I
      ipv6: Add explicit flush indication to routes · a2c554d3
      由 Ido Schimmel 提交于 
      When routes that are a part of a multipath route are evaluated by
fib6_ifdown() in response to NETDEV_DOWN and NETDEV_UNREGISTER events
the state of their sibling routes is not considered.

This will change in subsequent patches in order to align IPv6 with
IPv4's behavior. For example, when the last sibling in a multipath route
becomes dead, the entire multipath route needs to be removed.

To prevent the tree walker from re-evaluating all the sibling routes
each time, we can simply evaluate them once - when the first sibling is
traversed.

If we determine the entire multipath route needs to be removed, then the
'should_flush' bit is set in all the siblings, which will cause the
walker to flush them when it traverses them.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a2c554d3
    • I
      ipv6: Report dead flag during route dump · f9d882ea
      由 Ido Schimmel 提交于 
      Up until now the RTNH_F_DEAD flag was only reported in route dump when
the 'ignore_routes_with_linkdown' sysctl was set. This is expected as
dead routes were flushed otherwise.

The reliance on this sysctl is going to be removed, so we need to report
the flag regardless of the sysctl's value.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f9d882ea
    • I
      ipv6: Ignore dead routes during lookup · 8067bb8c
      由 Ido Schimmel 提交于 
      Currently, dead routes are only present in the routing tables in case
the 'ignore_routes_with_linkdown' sysctl is set. Otherwise, they are
flushed.

Subsequent patches are going to remove the reliance on this sysctl and
make IPv6 more consistent with IPv4.

Before this is done, we need to make sure dead routes are skipped during
route lookup, so as to not cause packet loss.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8067bb8c
    • I
      ipv6: Check nexthop flags in route dump instead of carrier · 44c9f2f2
      由 Ido Schimmel 提交于 
      Similar to previous patch, there is no need to check for the carrier of
the nexthop device when dumping the route and we can instead check for
the presence of the RTNH_F_LINKDOWN flag.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      44c9f2f2
    • I
      ipv6: Check nexthop flags during route lookup instead of carrier · 14c5206c
      由 Ido Schimmel 提交于 
      Now that the RTNH_F_LINKDOWN flag is set in nexthops, we can avoid the
need to dereference the nexthop device and check its carrier and instead
check for the presence of the flag.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      14c5206c
    • I
      ipv6: Set nexthop flags during route creation · 5609b80a
      由 Ido Schimmel 提交于 
      It is valid to install routes with a nexthop device that does not have a
carrier, so we need to make sure they're marked accordingly.

As explained in the previous patch, host and anycast routes are never
marked with the 'linkdown' flag.

Note that reject routes are unaffected, as these use the loopback device
which always has a carrier.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5609b80a
    • I
      ipv6: Set nexthop flags upon carrier change · 27c6fa73
      由 Ido Schimmel 提交于 
      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 4832c30d ("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: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      27c6fa73
    • I
      ipv6: Prepare to handle multiple netdev events · 4c981e28
      由 Ido Schimmel 提交于 
      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: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4c981e28
    • I
      ipv6: Clear nexthop flags upon netdev up · 2127d95a
      由 Ido Schimmel 提交于 
      Previous patch marked nexthops with the 'dead' and 'linkdown' flags.
Clear these flags when the netdev comes back up.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2127d95a
    • I
      ipv6: Mark dead nexthops with appropriate flags · 2b241361
      由 Ido Schimmel 提交于 
      When a netdev is put administratively down or unregistered all the
nexthops using it as their nexthop device should be marked with the
'dead' and 'linkdown' flags.

Currently, when a route is dumped its nexthop device is tested and the
flags are set accordingly. A similar check is performed during route
lookup.

Instead, we can simply mark the nexthops based on netdev events and
avoid checking the netdev's state during route dump and lookup.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2b241361
    • I
      ipv6: Remove redundant route flushing during namespace dismantle · 9fcb0714
      由 Ido Schimmel 提交于 
      By the time fib6_net_exit() is executed all the netdevs in the namespace
have been either unregistered or pushed back to the default namespace.
That is because pernet subsys operations are always ordered before
pernet device operations and therefore invoked after them during
namespace dismantle.

Thus, all the routing tables in the namespace are empty by the time
fib6_net_exit() is invoked and the call to rt6_ifdown() can be removed.

This allows us to simplify the condition in fib6_ifdown() as it's only
ever called with an actual netdev.
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9fcb0714
    • D
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next · 7f0b8000
      由 David S. Miller 提交于 
      Daniel Borkmann says:

====================
pull-request: bpf-next 2018-01-07

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

The main changes are:

1) Add a start of a framework for extending struct xdp_buff without
   having the overhead of populating every data at runtime. Idea
   is to have a new per-queue struct xdp_rxq_info that holds read
   mostly data (currently that is, queue number and a pointer to
   the corresponding netdev) which is set up during rxqueue config
   time. When a XDP program is invoked, struct xdp_buff holds a
   pointer to struct xdp_rxq_info that the BPF program can then
   walk. The user facing BPF program that uses struct xdp_md for
   context can use these members directly, and the verifier rewrites
   context access transparently by walking the xdp_rxq_info and
   net_device pointers to load the data, from Jesper.

2) Redo the reporting of offload device information to user space
   such that it works in combination with network namespaces. The
   latter is reported through a device/inode tuple as similarly
   done in other subsystems as well (e.g. perf) in order to identify
   the namespace. For this to work, ns_get_path() has been generalized
   such that the namespace can be retrieved not only from a specific
   task (perf case), but also from a callback where we deduce the
   netns (ns_common) from a netdevice. bpftool support using the new
   uapi info and extensive test cases for test_offload.py in BPF
   selftests have been added as well, from Jakub.

3) Add two bpftool improvements: i) properly report the bpftool
   version such that it corresponds to the version from the kernel
   source tree. So pick the right linux/version.h from the source
   tree instead of the installed one. ii) fix bpftool and also
   bpf_jit_disasm build with bintutils >= 2.9. The reason for the
   build breakage is that binutils library changed the function
   signature to select the disassembler. Given this is needed in
   multiple tools, add a proper feature detection to the
   tools/build/features infrastructure, from Roman.

4) Implement the BPF syscall command BPF_MAP_GET_NEXT_KEY for the
   stacktrace map. It is currently unimplemented, but there are
   use cases where user space needs to walk all stacktrace map
   entries e.g. for dumping or deleting map entries w/o having to
   close and recreate the map. Add BPF selftests along with it,
   from Yonghong.

5) Few follow-up cleanups for the bpftool cgroup code: i) rename
   the cgroup 'list' command into 'show' as we have it for other
   subcommands as well, ii) then alias the 'show' command such that
   'list' is accepted which is also common practice in iproute2,
   and iii) remove couple of newlines from error messages using
   p_err(), from Jakub.

6) Two follow-up cleanups to sockmap code: i) remove the unused
   bpf_compute_data_end_sk_skb() function and ii) only build the
   sockmap infrastructure when CONFIG_INET is enabled since it's
   only aware of TCP sockets at this time, from John.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7f0b8000