Commit Graph

134 Commits

Author SHA1 Message Date
Linus Torvalds
1c8c5a9d38 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Add Maglev hashing scheduler to IPVS, from Inju Song.

 2) Lots of new TC subsystem tests from Roman Mashak.

 3) Add TCP zero copy receive and fix delayed acks and autotuning with
    SO_RCVLOWAT, from Eric Dumazet.

 4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard
    Brouer.

 5) Add ttl inherit support to vxlan, from Hangbin Liu.

 6) Properly separate ipv6 routes into their logically independant
    components. fib6_info for the routing table, and fib6_nh for sets of
    nexthops, which thus can be shared. From David Ahern.

 7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP
    messages from XDP programs. From Nikita V. Shirokov.

 8) Lots of long overdue cleanups to the r8169 driver, from Heiner
    Kallweit.

 9) Add BTF ("BPF Type Format"), from Martin KaFai Lau.

10) Add traffic condition monitoring to iwlwifi, from Luca Coelho.

11) Plumb extack down into fib_rules, from Roopa Prabhu.

12) Add Flower classifier offload support to igb, from Vinicius Costa
    Gomes.

13) Add UDP GSO support, from Willem de Bruijn.

14) Add documentation for eBPF helpers, from Quentin Monnet.

15) Add TLS tx offload to mlx5, from Ilya Lesokhin.

16) Allow applications to be given the number of bytes available to read
    on a socket via a control message returned from recvmsg(), from
    Soheil Hassas Yeganeh.

17) Add x86_32 eBPF JIT compiler, from Wang YanQing.

18) Add AF_XDP sockets, with zerocopy support infrastructure as well.
    From Björn Töpel.

19) Remove indirect load support from all of the BPF JITs and handle
    these operations in the verifier by translating them into native BPF
    instead. From Daniel Borkmann.

20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha.

21) Allow XDP programs to do lookups in the main kernel routing tables
    for forwarding. From David Ahern.

22) Allow drivers to store hardware state into an ELF section of kernel
    dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy.

23) Various RACK and loss detection improvements in TCP, from Yuchung
    Cheng.

24) Add TCP SACK compression, from Eric Dumazet.

25) Add User Mode Helper support and basic bpfilter infrastructure, from
    Alexei Starovoitov.

26) Support ports and protocol values in RTM_GETROUTE, from Roopa
    Prabhu.

27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard
    Brouer.

28) Add lots of forwarding selftests, from Petr Machata.

29) Add generic network device failover driver, from Sridhar Samudrala.

* ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits)
  strparser: Add __strp_unpause and use it in ktls.
  rxrpc: Fix terminal retransmission connection ID to include the channel
  net: hns3: Optimize PF CMDQ interrupt switching process
  net: hns3: Fix for VF mailbox receiving unknown message
  net: hns3: Fix for VF mailbox cannot receiving PF response
  bnx2x: use the right constant
  Revert "net: sched: cls: Fix offloading when ingress dev is vxlan"
  net: dsa: b53: Fix for brcm tag issue in Cygnus SoC
  enic: fix UDP rss bits
  netdev-FAQ: clarify DaveM's position for stable backports
  rtnetlink: validate attributes in do_setlink()
  mlxsw: Add extack messages for port_{un, }split failures
  netdevsim: Add extack error message for devlink reload
  devlink: Add extack to reload and port_{un, }split operations
  net: metrics: add proper netlink validation
  ipmr: fix error path when ipmr_new_table fails
  ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds
  net: hns3: remove unused hclgevf_cfg_func_mta_filter
  netfilter: provide udp*_lib_lookup for nf_tproxy
  qed*: Utilize FW 8.37.2.0
  ...
2018-06-06 18:39:49 -07:00
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
Christoph Hellwig
c350637227 proc: introduce proc_create_net{,_data}
Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-05-16 07:24:30 +02:00
David Ahern
138118ec96 net/ipv6: Add fib6_lookup
Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules,
but returns a FIB entry, fib6_info, rather than a dst based rt6_info.
fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled)
to 60% faster than any of the dst based lookup methods (without custom
rules) and 25% faster with custom rules (e.g., l3mdev rule).

Since the lookup function has a completely different signature,
fib6_rule_action is split into 2 paths: the existing one is
renamed __fib6_rule_action and a new one for the fib6_info path
is added. fib6_rule_action decides which to call based on the
lookup_ptr. If it is fib6_table_lookup then the new path is taken.

Caller must hold rcu lock as no reference is taken on the returned
fib entry.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:10:56 +02:00
David Ahern
1d053da910 net/ipv6: Extract table lookup from ip6_pol_route
ip6_pol_route is used for ingress and egress FIB lookups. Refactor it
moving the table lookup into a separate fib6_table_lookup that can be
invoked separately and export the new function.

ip6_pol_route now calls fib6_table_lookup and uses the result to generate
a dst based rt6_info.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:10:56 +02:00
David Ahern
3b290a31bb net/ipv6: Rename rt6_multipath_select
Rename rt6_multipath_select to fib6_multipath_select and export it.
A later patch wants access to it similar to IPv4's fib_select_path.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:10:56 +02:00
David Ahern
6454743bc1 net/ipv6: Rename fib6_lookup to fib6_node_lookup
Rename fib6_lookup to fib6_node_lookup to better reflect what it
returns. The fib6_lookup name will be used in a later patch for
an IPv6 equivalent to IPv4's fib_lookup.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:10:56 +02:00
David Ahern
8fb11a9a8d net/ipv6: rename rt6_next to fib6_next
This slipped through the cracks in the followup set to the fib6_info flip.
Rename rt6_next to fib6_next.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-04 19:54:52 -04:00
David Ahern
a68886a691 net/ipv6: Make from in rt6_info rcu protected
When a dst entry is created from a fib entry, the 'from' in rt6_info
is set to the fib entry. The 'from' reference is used most notably for
cookie checking - making sure stale dst entries are updated if the
fib entry is changed.

When a fib entry is deleted, the pcpu routes on it are walked releasing
the fib6_info reference. This is needed for the fib6_info cleanup to
happen and to make sure all device references are released in a timely
manner.

There is a race window when a FIB entry is deleted and the 'from' on the
pcpu route is dropped and the pcpu route hits a cookie check. Handle
this race using rcu on from.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21 16:06:14 -04:00
David Ahern
a87b7dc9f7 net/ipv6: Move rcu locking to callers of fib6_get_cookie_safe
A later patch protects 'from' in rt6_info and this simplifies the
locking needed by it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21 16:06:13 -04:00
David Ahern
a269f1a764 net/ipv6: Rename rt6_get_cookie_safe
rt6_get_cookie_safe takes a fib6_info and checks the sernum of
the node. Update the name to reflect its purpose.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21 16:06:13 -04:00
David Ahern
6a3e030f08 net/ipv6: Clean up rt expires helpers
rt6_clean_expires and rt6_set_expires are no longer used. Removed them.
rt6_update_expires has 1 caller in route.c, so move it from the header.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-21 16:06:13 -04:00
David Ahern
dcd1f57295 net/ipv6: Remove fib6_idev
fib6_idev can be obtained from __in6_dev_get on the nexthop device
rather than caching it in the fib6_info. Remove it.

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
9ee8cbb2fd net/ipv6: Remove aca_idev
aca_idev has only 1 user - inet6_fill_ifacaddr - and it only
wants the device index which can be extracted from the fib6_info
nexthop.

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
77634cc67d net/ipv6: Remove unused code and variables for rt6_info
Drop unneeded elements from rt6_info struct and rearrange layout to
something more relevant for the data path.

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
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
a64efe142f net/ipv6: introduce fib6_info struct and helpers
Add fib6_info struct and alloc, destroy, hold and release helpers.

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
3b6761d18b net/ipv6: Move dst flags to booleans in fib entries
Continuing to wean FIB paths off of dst_entry, use a bool to hold
requests for certain dst settings. Add a helper to convert the
flags to DST flags when a FIB entry is converted to a dst_entry.

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
14895687d3 net/ipv6: move expires into rt6_info
Add expires to rt6_info for FIB entries, and add fib6 helpers to
manage it. Data path use of dst.expires remains.

The transition is fairly straightforward: when working with fib entries,
rt->dst.expires is just rt->expires, rt6_clean_expires is replaced with
fib6_clean_expires, rt6_set_expires becomes fib6_set_expires, and
rt6_check_expired becomes fib6_check_expired, where the fib6 versions
are added by this patch.

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
d4ead6b34b net/ipv6: move metrics from dst to rt6_info
Similar to IPv4, add fib metrics to the fib struct, which at the moment
is rt6_info. Will be moved to fib6_info in a later patch. Copy metrics
into dst by reference using refcount.

To make the transition:
- add dst_metrics to rt6_info. Default to dst_default_metrics if no
  metrics are passed during route add. No need for a separate pmtu
  entry; it can reference the MTU slot in fib6_metrics

- ip6_convert_metrics allocates memory in the FIB entry and uses
  ip_metrics_convert to copy from netlink attribute to metrics entry

- the convert metrics call is done in ip6_route_info_create simplifying
  the route add path
  + fib6_commit_metrics and fib6_copy_metrics and the temporary
    mx6_config are no longer needed

- add fib6_metric_set helper to change the value of a metric in the
  fib entry since dst_metric_set can no longer be used

- cow_metrics for IPv6 can drop to dst_cow_metrics_generic

- rt6_dst_from_metrics_check is no longer needed

- rt6_fill_node needs the FIB entry and dst as separate arguments to
  keep compatibility with existing output. Current dst address is
  renamed to dest.
  (to be consistent with IPv4 rt6_fill_node really should be split
  into 2 functions similar to fib_dump_info and rt_fill_info)

- rt6_fill_node no longer needs the temporary metrics variable

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
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
e8478e80e5 net/ipv6: Save route type in rt6_info
The RTN_ type for IPv6 FIB entries is currently embedded in rt6i_flags
and dst.error. Since dst is going to be removed, it can no longer be
relied on for FIB dumps so save the route type as fib6_type.

fc_type is set in current users based on the algorithm in rt6_fill_node:
  - rt6i_flags contains RTF_LOCAL: fc_type = RTN_LOCAL
  - rt6i_flags contains RTF_ANYCAST: fc_type = RTN_ANYCAST
  - else fc_type = RTN_UNICAST

Similarly, fib6_type is set in the rt6_info templates based on the
RTF_REJECT section of rt6_fill_node converting dst.error to RTN type.

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
7aef6859ee net/ipv6: Pass net to fib6_update_sernum
Pass net namespace to fib6_update_sernum. It can not be marked const
as fib6_new_sernum will change ipv6.fib6_sernum.

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
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
Ido Schimmel
398958ae48 ipv6: Add support for non-equal-cost multipath
The use of hash-threshold instead of modulo-N makes it trivial to add
support for non-equal-cost multipath.

Instead of dividing the multipath hash function's output space equally
between the nexthops, each nexthop is assigned a region size which is
proportional to its weight.

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
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
4a8e56ee2c ipv6: Export sernum update function
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: 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
a2c554d3f8 ipv6: Add explicit flush indication to routes
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: 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
David Miller
3a2232e92e ipv6: Move dst->from into struct rt6_info.
The dst->from value is only used by ipv6 routes to track where
a route "came from".

Any time we clone or copy a core ipv6 route in the ipv6 routing
tables, we have the copy/clone's ->from point to the base route.

This is used to handle route expiration properly.

Only ipv6 uses this mechanism, and only ipv6 code references
it.  So it is safe to move it into rt6_info.

Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30 09:54:26 -05:00
David Miller
071fb37ec4 ipv6: Move rt6_next from dst_entry into ipv6 route structure.
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30 09:54:25 -05:00
Wei Wang
81eb8447da ipv6: take care of rt6_stats
Currently, most of the rt6_stats are not hooked up correctly. As the
last part of this patch series, hook up all existing rt6_stats and add
one new stat fib_rt_uncache to indicate the number of routes in the
uncached list.
For details of the stats, please refer to the comments added in
include/net/ip6_fib.h.

Note: fib_rt_alloc and fib_rt_uncache are not guaranteed to be modified
under a lock. So atomic_t is used for them.

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 21:22:58 +01:00
Wei Wang
66f5d6ce53 ipv6: replace rwlock with rcu and spinlock in fib6_table
With all the preparation work before, we are now ready to replace rwlock
with rcu and spinlock in fib6_table.
That means now all fib6_node in fib6_table are protected by rcu. And
when freeing fib6_node, call_rcu() is used to wait for the rcu grace
period before releasing the memory.
When accessing fib6_node, corresponding rcu APIs need to be used.
And all previous sessions protected by the write lock will now be
protected by the spin lock per table.
All previous sessions protected by read lock will now be protected by
rcu_read_lock().

A couple of things to note here:
1. As part of the work of replacing rwlock with rcu, the linked list of
fn->leaf now has to be rcu protected as well. So both fn->leaf and
rt->dst.rt6_next are now __rcu tagged and corresponding rcu APIs are
used when manipulating them.

2. For fn->rr_ptr, first of all, it also needs to be rcu protected now
and is tagged with __rcu and rcu APIs are used in corresponding places.
Secondly, fn->rr_ptr is changed in rt6_select() which is a reader
thread. This makes the issue a bit complicated. We think a valid
solution for it is to let rt6_select() grab the tb6_lock if it decides
to change it. As it is not in the normal operation and only happens when
there is no valid neighbor cache for the route, we think the performance
impact should be low.

3. fib6_walk_continue() has to be called with tb6_lock held even in the
route dumping related functions, e.g. inet6_dump_fib(),
fib6_tables_dump() and ipv6_route_seq_ops. It is because
fib6_walk_continue() makes modifications to the walker structure, and so
are fib6_repair_tree() and fib6_del_route(). In order to do proper
syncing between them, we need to let fib6_walk_continue() hold the lock.
We may be able to do further improvement on the way we do the tree walk
to get rid of the need for holding the spin lock. But not for now.

4. When fib6_del_route() removes a route from the tree, we no longer
mark rt->dst.rt6_next to NULL to make simultaneous reader be able to
further traverse the list with rcu. However, rt->dst.rt6_next is only
valid within this same rcu period. No one should access it later.

5. All the operation of atomic_inc(rt->rt6i_ref) is changed to be
performed before we publish this route (either by linking it to fn->leaf
or insert it in the list pointed by fn->leaf) just to be safe because as
soon as we publish the route, some read thread will be able to access it.

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 21:22:58 +01:00
Wei Wang
bbd63f06d1 ipv6: update fn_sernum after route is inserted to tree
fib6_add() logic currently calls fib6_add_1() to figure out what node
should be used for the newly added route and then call
fib6_add_rt2node() to insert the route to the node.
And during the call of fib6_add_1(), fn_sernum is updated for all nodes
that share the same prefix as the new route.
This does not have issue in the current code because reader thread will
not be able to access the tree while writer thread is inserting new
route to it. However, it is not the case once we transition to use RCU.
Reader thread could potentially see the new fn_sernum before the new
route is inserted. As a result, reader thread's route lookup will return
a stale route with the new fn_sernum.

In order to solve this issue, we remove all the update of fn_sernum in
fib6_add_1(), and instead, introduce a new function that updates fn_sernum
for all related nodes and call this functions once the route is
successfully inserted to the tree.
Also, smp_wmb() is used after a route is successfully inserted into the
fib tree and right before the updated of fn->sernum. And smp_rmb() is
used right after fn->sernum is accessed in rt6_get_cookie_safe(). This
is to guarantee that when the reader thread sees the new fn->sernum, the
new route is already inserted in the tree in memory.

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 21:22:58 +01:00
Wei Wang
2b760fcf5c ipv6: hook up exception table to store dst cache
This commit makes use of the exception hash table implementation to
store dst caches created by pmtu discovery and ip redirect into the hash
table under the rt_info and no longer inserts these routes into fib6
tree.
This makes the fib6 tree only contain static configured routes and could
now be protected by rcu instead of a rw lock.
With this change, in the route lookup related functions, after finding
the rt6_info with the longest prefix, we also need to search for the
exception table before doing backtracking.
In the route delete function, if the route being deleted is not a dst
cache, deletion of this route also need to flush the whole hash table
under it. If it is a dst cache, then only delete the cached dst in the
hash table.

Note: for fib6_walk_continue() function, w->root now is always pointing
to a root node considering that fib6_prune_clones() is removed from the
code. So we add a WARN_ON() msg to make sure w->root always points to a
root node and also removed the update of w->root in fib6_repair_tree().
This is a prerequisite for later patch because we don't need to make
w->root as rcu protected when replacing rwlock with RCU.
Also, we remove all prune related variables as it is no longer used.

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
38fbeeeecc ipv6: prepare fib6_locate() for exception table
fib6_locate() is used to find the fib6_node according to the passed in
prefix address key. It currently tries to find the fib6_node with the
exact match of the passed in key. However, when we move cached routes
into the exception table, fib6_locate() will fail to find the fib6_node
for it as the cached routes will be stored in the exception table under
the fib6_node with the longest prefix match of the cache's dst addr key.
This commit adds a new parameter to let the caller specify if it needs
exact match or longest prefix match.
Right now, all callers still does exact match when calling
fib6_locate(). It will be changed in later commit where exception table
is hooked up to store cached routes.

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
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
Wei Wang
180ca444b9 ipv6: introduce a new function fib6_update_sernum()
This function takes a route as input and tries to update the sernum in
the fib6_node this route is associated with. It will be used in later
commit when adding a cached route into the exception table under that
route.

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
David S. Miller
6026e043d0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01 17:42:05 -07:00
Wei Wang
4e587ea71b ipv6: fix sparse warning on rt6i_node
Commit c5cff8561d adds rcu grace period before freeing fib6_node. This
generates a new sparse warning on rt->rt6i_node related code:
  net/ipv6/route.c:1394:30: error: incompatible types in comparison
  expression (different address spaces)
  ./include/net/ip6_fib.h:187:14: error: incompatible types in comparison
  expression (different address spaces)

This commit adds "__rcu" tag for rt6i_node and makes sure corresponding
rcu API is used for it.
After this fix, sparse no longer generates the above warning.

Fixes: c5cff8561d ("ipv6: add rcu grace period before freeing fib6_node")
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-28 15:34:40 -07:00
Wei Wang
c5cff8561d ipv6: add rcu grace period before freeing fib6_node
We currently keep rt->rt6i_node pointing to the fib6_node for the route.
And some functions make use of this pointer to dereference the fib6_node
from rt structure, e.g. rt6_check(). However, as there is neither
refcount nor rcu taken when dereferencing rt->rt6i_node, it could
potentially cause crashes as rt->rt6i_node could be set to NULL by other
CPUs when doing a route deletion.
This patch introduces an rcu grace period before freeing fib6_node and
makes sure the functions that dereference it takes rcu_read_lock().

Note: there is no "Fixes" tag because this bug was there in a very
early stage.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22 11:03:19 -07:00
Ido Schimmel
fe40079995 ipv6: fib: Provide offload indication using nexthop flags
IPv6 routes currently lack nexthop flags as in IPv4. This has several
implications.

In the forwarding path, it requires us to check the carrier state of the
nexthop device and potentially ignore a linkdown route, instead of
checking for RTNH_F_LINKDOWN.

It also requires capable drivers to use the user facing IPv6-specific
route flags to provide offload indication, instead of using the nexthop
flags as in IPv4.

Add nexthop flags to IPv6 routes in the 40 bytes hole and use it to
provide offload indication instead of the RTF_OFFLOAD flag, which is
removed while it's still not part of any official kernel release.

In the near future we would like to use the field for the
RTNH_F_{LINKDOWN,DEAD} flags, but this change is more involved and might
not be ready in time for the current cycle.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15 17:05:03 -07:00
Ido Schimmel
a460aa8396 ipv6: fib: Add helpers to hold / drop a reference on rt6_info
Similar to commit 1c677b3d28 ("ipv4: fib: Add fib_info_hold() helper")
and commit b423cb1080 ("ipv4: fib: Export free_fib_info()") add an
helper to hold a reference on rt6_info and export rt6_release() to drop
it and potentially release the route.

This is needed so that drivers capable of FIB offload could hold a
reference on the route before queueing it for offload and drop it after
the route has been programmed to the device's tables.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
e1ee0a5ba3 ipv6: fib: Dump tables during registration to FIB chain
Dump all the FIB tables in each net namespace upon registration to the
FIB notification chain so that the callee will have a complete view of
the tables.

The integrity of the dump is ensured by a per-table sequence counter
that is incremented (under write lock) whenever a route is added or
deleted from the table.

All the sequence counters are read (under each table's read lock) and
summed, prior and after the dump. In case the counters differ, then the
dump is either restarted or the registration fails.

While it's possible for a table to be modified after its counter has
been read, this isn't really a problem. In case it happened before it
was read the second time, then the comparison at the end will fail. If
it happened afterwards, then we're guaranteed to be notified about the
change, as the notification block is registered prior to the second
read.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
dcb18f762f ipv6: fib_rules: Dump rules during registration to FIB chain
Allow users of the FIB notification chain to receive a complete view of
the IPv6 FIB rules upon registration to the chain.

The integrity of the dump is ensured by a per-family sequence counter
that is incremented (under RTNL) whenever a rule is added or deleted.

All the sequence counters are read (under RTNL) and summed, prior and
after the dump. In case the counters differ, then the dump is either
restarted or the registration fails.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
df77fe4d98 ipv6: fib: Add in-kernel notifications for route add / delete
As with IPv4, allow listeners of the FIB notification chain to receive
notifications whenever a route is added, replaced or deleted. This is
done by placing calls to the FIB notification chain in the two lowest
level functions that end up performing these operations - namely,
fib6_add_rt2node() and fib6_del_route().

Unlike IPv4, APPEND notifications aren't sent as the kernel doesn't
distinguish between "append" (NLM_F_CREATE|NLM_F_APPEND) and "prepend"
(NLM_F_CREATE). If NLM_F_EXCL isn't set, duplicate routes are always
added after the existing duplicate routes.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:36:00 -07:00
Ido Schimmel
16ab6d7d4d ipv6: fib: Add FIB notifiers callbacks
We're about to add IPv6 FIB offload support, so implement the necessary
callbacks in IPv6 code, which will later allow us to add routes and
rules notifications.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 15:35:59 -07:00