A previous patch added l3mdev flow update making these hooks
redundant. Remove them.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Flip the IPv4 output path to use the l3mdev tx out hook. The VRF dst
is not returned on the first FIB lookup. Instead, the dst on the
skb is switched at the beginning of the IPv4 output processing to
send the packet to the VRF driver on xmit.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow an L3 master device to act as the loopback for that L3 domain.
For IPv4 the device can also have the address 127.0.0.1.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Today mpls iptunnel lwtunnel_output redirect expects the tunnel
output function to handle fragmentation. This is ok but can be
avoided if we did not do the mpls output redirect too early.
ie we could wait until ip fragmentation is done and then call
mpls output for each ip fragment.

To make this work we will need,
1) the lwtunnel state to carry encap headroom
2) and do the redirect to the encap output handler on the ip fragment
(essentially do the output redirect after fragmentation)

This patch adds tunnel headroom in lwtstate to make sure we
account for tunnel data in mtu calculations during fragmentation
and adds new xmit redirect handler to redirect to lwtunnel xmit func
after ip fragmentation.

This includes IPV6 and some mtu fixes and testing from David Ahern.
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow udp and raw sockets to send by oif that is an enslaved interface
versus the l3mdev/VRF device. For example, this allows BFD to use ifindex
from IP_PKTINFO on a receive to send a response without the need to
convert to the VRF index. It also allows ping and ping6 to work when
specifying an enslaved interface (e.g., ping -I swp1 <ip>) which is
a natural use case.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename IP_INC_STATS_BH() to __IP_INC_STATS(), to
better express this is used in non preemptible context.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For local routes that require a particular output interface we do not want
to cache the result.  Caching the result causes incorrect behaviour when
there are multiple source addresses on the interface.  The end result
being that if the intended recipient is waiting on that interface for the
packet he won't receive it because it will be delivered on the loopback
interface and the IP_PKTINFO ipi_ifindex will be set to the loopback
interface as well.

This can be tested by running a program such as "dhcp_release" which
attempts to inject a packet on a particular interface so that it is
received by another program on the same board.  The receiving process
should see an IP_PKTINFO ipi_ifndex value of the source interface
(e.g., eth1) instead of the loopback interface (e.g., lo).  The packet
will still appear on the loopback interface in tcpdump but the important
aspect is that the CMSG info is correct.

Sample dhcp_release command line:

   dhcp_release eth1 192.168.204.222 02:11:33:22:44:66
Signed-off-by: NAllain Legacy <allain.legacy@windriver.com>
Signed off-by: Chris Friesen <chris.friesen@windriver.com>
Reviewed-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vivek reported a kernel exception deleting a VRF with an active
connection through it. The root cause is that the socket has a cached
reference to a dst that is destroyed. Converting the dst_destroy to
dst_release and letting proper reference counting kick in does not
work as the dst has a reference to the device which needs to be released
as well.

I talked to Hannes about this at netdev and he pointed out the ipv4 and
ipv6 dst handling has dst_ifdown for just this scenario. Rather than
continuing with the reinvented dst wheel in VRF just remove it and
leverage the ipv4 and ipv6 versions.

Fixes: 193125db ("net: Introduce VRF device driver")
Fixes: 35402e31 ("net: Add IPv6 support to VRF device")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the gc of ipv4 route was removed, the route cached would has
no chance to be removed, and even it has been timeout, it still could
be used, cause no code to check it's expires.

Fix this issue by checking  and removing route cache when we get route.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit deaa0a6a ("net: Lookup actual route when oif is VRF device")
exposed a bug in __ip_route_output_key_hash for VRF devices: on FIB lookup
failure if the oif is specified the current logic drops to make_route on
the assumption that the route tables are wrong. For VRF/L3 master devices
this leads to wrong dst entries and route lookups. For example:
    $ ip route ls table vrf-red
    unreachable default
    broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
    10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
    local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
    broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2

    $ ip route get oif vrf-red 1.1.1.1
    1.1.1.1 dev vrf-red  src 10.0.0.2
        cache

With this patch:
    $  ip route get oif vrf-red 1.1.1.1
    RTNETLINK answers: No route to host

which is the correct response based on the default route
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The network namespace is already passed into dst_output pass it into
dst->output lwt->output and friends.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For consistency with the other similar methods in the kernel pass a
struct sock into the dst_ops .local_out method.

Simplifying the socket passing case is needed a prequel to passing a
struct net reference into .local_out.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the user specifies a VRF device in a get route query the custom route
pointing to the VRF device is returned:

    $ ip route ls table vrf-red
    unreachable default
    broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
    10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
    local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
    broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev vrf-red
        cache

Add the flags to skip the custom route and go directly to the FIB. With
this patch the actual route is returned:

    $ ip route get oif vrf-red 10.2.1.40
    10.2.1.40 dev eth1  src 10.2.1.2
        cache
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VRF device needs the same path selection following lookup to set source
address. Rather than duplicating code, move existing code into a
function that is exported to modules.

Code move only; no functional change.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ICMP packets are inspected to let them route together with the flow they
belong to, minimizing the chance that a problematic path will affect flows
on other paths, and so that anycast environments can work with ECMP.
Signed-off-by: NPeter Nørlund <pch@ordbogen.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replaces the per-packet multipath with a hash-based multipath using
source and destination address.
Signed-off-by: NPeter Nørlund <pch@ordbogen.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The fib_table_lookup tracepoint found 2 places where the flowi4_flags is
not initialized.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace calls to vrf_dev_get_rth with l3mdev_get_rtable.
The check on the flow flags is handled in the l3mdev operation.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace calls to vrf_master_ifindex_rcu and vrf_master_ifindex with either
l3mdev_master_ifindex_rcu or l3mdev_master_ifindex.

The pattern:
    oif = vrf_master_ifindex(dev) ? : dev->ifindex;
is replaced with
    oif = l3mdev_fib_oif(dev);

And remove the now unused vrf macros.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename IFF_VRF_MASTER to IFF_L3MDEV_MASTER and update the name of the
netif_is_vrf and netif_index_is_vrf macros.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

err is initialized to -EINVAL when it is declared. It is not reset until
fib_lookup which is well after the 3 users of the martian_source jump. So
resetting err to -EINVAL at martian_source label is not needed.

Removing that line obviates the need for the martian_source_keep_err label
so delete it.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch just swaps the ordering of one of the conditional tests in
ip_route_input_mc.  Specifically it swaps the testing for the source
address to see if it is loopback, and the test to see if we allow a
loopback source address.

The reason for swapping these two tests is because it is much faster to
test if an address is loopback than it is to dereference several pointers
to get at the net structure to see if the use of loopback is allowed.
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Very soon, TCP stack might call inet_csk_route_req(), which
calls inet_csk_route_req() with an unlocked listener socket,
so we need to make sure ip_route_output_flow() is not trying to
change any field from its socket argument.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Man page of ip-route(8) says following about route types:

  unreachable - these destinations are unreachable.  Packets are dis‐
  carded and the ICMP message host unreachable is generated.  The local
  senders get an EHOSTUNREACH error.

  blackhole - these destinations are unreachable.  Packets are dis‐
  carded silently.  The local senders get an EINVAL error.

  prohibit - these destinations are unreachable.  Packets are discarded
  and the ICMP message communication administratively prohibited is
  generated.  The local senders get an EACCES error.

In the inet6 address family, this was correct, except the local senders
got ENETUNREACH error instead of EHOSTUNREACH in case of unreachable route.
In the inet address family, all three route types generated ICMP message
net unreachable, and the local senders got ENETUNREACH error.

In both address families all three route types now behave consistently
with documentation.
Signed-off-by: NNikola Forró <nforro@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sergey, Richard and Fabio reported an oops in ip_route_input_noref. e.g., from Richard:

[    0.877040] BUG: unable to handle kernel NULL pointer dereference at 0000000000000056
[    0.877597] IP: [<ffffffff8155b5e2>] ip_route_input_noref+0x1a2/0xb00
[    0.877597] PGD 3fa14067 PUD 3fa6e067 PMD 0
[    0.877597] Oops: 0000 [#1] SMP
[    0.877597] Modules linked in: virtio_net virtio_pci virtio_ring virtio
[    0.877597] CPU: 1 PID: 119 Comm: ifconfig Not tainted 4.2.0+ #1
[    0.877597] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    0.877597] task: ffff88003fab0bc0 ti: ffff88003faa8000 task.ti: ffff88003faa8000
[    0.877597] RIP: 0010:[<ffffffff8155b5e2>]  [<ffffffff8155b5e2>] ip_route_input_noref+0x1a2/0xb00
[    0.877597] RSP: 0018:ffff88003ed03ba0  EFLAGS: 00010202
[    0.877597] RAX: 0000000000000046 RBX: 00000000ffffff8f RCX: 0000000000000020
[    0.877597] RDX: ffff88003fab50b8 RSI: 0000000000000200 RDI: ffffffff8152b4b8
[    0.877597] RBP: ffff88003ed03c50 R08: 0000000000000000 R09: 0000000000000000
[    0.877597] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88003fab6f00
[    0.877597] R13: ffff88003fab5000 R14: 0000000000000000 R15: ffffffff81cb5600
[    0.877597] FS:  00007f6de5751700(0000) GS:ffff88003ed00000(0000) knlGS:0000000000000000
[    0.877597] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.877597] CR2: 0000000000000056 CR3: 000000003fa6d000 CR4: 00000000000006e0
[    0.877597] Stack:
[    0.877597]  0000000000000000 0000000000000046 ffff88003fffa600 ffff88003ed03be0
[    0.877597]  ffff88003f9e2c00 697da8c0017da8c0 ffff880000000000 000000000007fd00
[    0.877597]  0000000000000000 0000000000000046 0000000000000000 0000000400000000
[    0.877597] Call Trace:
[    0.877597]  <IRQ>
[    0.877597]  [<ffffffff812bfa1f>] ? cpumask_next_and+0x2f/0x40
[    0.877597]  [<ffffffff8158e13c>] arp_process+0x39c/0x690
[    0.877597]  [<ffffffff8158e57e>] arp_rcv+0x13e/0x170
[    0.877597]  [<ffffffff8151feec>] __netif_receive_skb_core+0x60c/0xa00
[    0.877597]  [<ffffffff81515795>] ? __build_skb+0x25/0x100
[    0.877597]  [<ffffffff81515795>] ? __build_skb+0x25/0x100
[    0.877597]  [<ffffffff81521ff6>] __netif_receive_skb+0x16/0x70
[    0.877597]  [<ffffffff81522078>] netif_receive_skb_internal+0x28/0x90
[    0.877597]  [<ffffffff8152288f>] napi_gro_receive+0x7f/0xd0
[    0.877597]  [<ffffffffa0017906>] virtnet_receive+0x256/0x910 [virtio_net]
[    0.877597]  [<ffffffffa0017fd8>] virtnet_poll+0x18/0x80 [virtio_net]
[    0.877597]  [<ffffffff815234cd>] net_rx_action+0x1dd/0x2f0
[    0.877597]  [<ffffffff81053228>] __do_softirq+0x98/0x260
[    0.877597]  [<ffffffff8164969c>] do_softirq_own_stack+0x1c/0x30

The root cause is use of res.table uninitialized.

Thanks to Nikolay for noticing the uninitialized use amongst the maze of
gotos.

As Nikolay pointed out the second initialization is not required to fix
the oops, but rather to fix a related problem where a valid lookup should
be invalidated before creating the rth entry.

Fixes: b7503e0c ("net: Add FIB table id to rtable")
Reported-by: NSergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Reported-by: NRichard Alpe <richard.alpe@ericsson.com>
Reported-by: NFabio Estevam <festevam@gmail.com>
Tested-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Tested-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rt_fill_info which is called for 'route get' requests hardcodes the
table id as RT_TABLE_MAIN which is not correct when multiple tables
are used. Use the newly added table id in the rtable to send back
the correct table similar to what is done for IPv6.

To maintain current ABI a new request flag, RTM_F_LOOKUP_TABLE, is
added to indicate the actual table is wanted versus the hardcoded
response.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the FIB table id to rtable to make the information available for
IPv4 as it is for IPv6.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All callers to rt_dst_alloc have nearly the same initialization following
a successful allocation. Consolidate it into rt_dst_alloc.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The mode field holds a single bit of information only (whether the
ip_tunnel_info struct is for rx or tx). Change the mode field to bit flags.
This allows more mode flags to be added.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Acked-by: NThomas Graf <tgraf@suug.ch>
Acked-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

inetpeer caches based on address only, so duplicate IP addresses within
a namespace return the same cached entry. Enhance the ipv4 address key
to contain both the IPv4 address and VRF device index.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, the lwtunnel state resides in per-protocol data. This is
a problem if we encapsulate ipv6 traffic in an ipv4 tunnel (or vice versa).
The xmit function of the tunnel does not know whether the packet has been
routed to it by ipv4 or ipv6, yet it needs the lwtstate data. Moving the
lwtstate data to dst_entry makes such inter-protocol tunneling possible.

As a bonus, this brings a nice diffstat.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the capability to redirect dst input in the same way
that dst output is redirected by LWT.

Also, save the original dst.input and and dst.out when setting up
lwtunnel redirection. These can be called by the client as a pass-
through.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As with ingress use the index of VRF master device for route lookups on
egress. However, the oif should only be used to direct the lookups to a
specific table. Routes in the table are not based on the VRF device but
rather interfaces that are part of the VRF so do not consider the oif for
lookups within the table. The FLOWI_FLAG_VRFSRC is used to control this
latter part.
Signed-off-by: NShrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On ingress use index of VRF master device for route lookups if real device
is enslaved. Rules are expected to be installed for the VRF device to
direct lookups to a specific table.
Signed-off-by: NShrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lwtunnel encap is applied for forwarded packets, but not for
locally-generated packets. This is because the output function is not
overridden in __mkroute_output, unlike it is in __mkroute_input.

The lwtunnel state is correctly set on the rth through the call to
rt_set_nexthop, so all that needs to be done is to override the dst
output function to be lwtunnel_output if there is lwtunnel state
present and it requires output redirection.
Signed-off-by: NRobert Shearman <rshearma@brocade.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It saves some lines and simplify a bit the code when the state is returning
by this function. It's also useful to handle a NULL entry.

To avoid too long lines, I've also renamed lwtunnel_state_get() and
lwtunnel_state_put() to lwtstate_get() and lwtstate_put().

CC: Thomas Graf <tgraf@suug.ch>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: NThomas Graf <tgraf@suug.ch>
Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_select_default considers alternative routes only when
res->fi is for the first alias in res->fa_head. In the
common case this can happen only when the initial lookup
matches the first alias with highest TOS value. This
prevents the alternative routes to require specific TOS.

This patch solves the problem as follows:

- routes that require specific TOS should be returned by
fib_select_default only when TOS matches, as already done
in fib_table_lookup. This rule implies that depending on the
TOS we can have many different lists of alternative gateways
and we have to keep the last used gateway (fa_default) in first
alias for the TOS instead of using single tb_default value.

- as the aliases are ordered by many keys (TOS desc,
fib_priority asc), we restrict the possible results to
routes with matching TOS and lowest metric (fib_priority)
and routes that match any TOS, again with lowest metric.

For example, packet with TOS 8 can not use gw3 (not lowest
metric), gw4 (different TOS) and gw6 (not lowest metric),
all other gateways can be used:

tos 8 via gw1 metric 2 <--- res->fa_head and res->fi
tos 8 via gw2 metric 2
tos 8 via gw3 metric 3
tos 4 via gw4
tos 0 via gw5
tos 0 via gw6 metric 1
Reported-by: NHagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This introduces a new IP tunnel lightweight tunnel type which allows
to specify IP tunnel instructions per route. Only IPv4 is supported
at this point.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new flowi_tunnel structure which is a subset of ip_tunnel_key to
allow routes to match on tunnel metadata. For now, the tunnel id is
added to flowi_tunnel which allows for routes to be bound to specific
virtual tunnels.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>