[ Upstream commit e6b45241c5 ]
Eric Dumazet found that commit 813b3b5db8
(ipv4: Use caller's on-stack flowi as-is in output
route lookups.) that comes in 3.0 added a regression.
The problem appears to be that resulting flowi4_oif is
used incorrectly as input parameter to some routing lookups.
The result is that when connecting to local port without
listener if the IP address that is used is not on a loopback
interface we incorrectly assign RTN_UNICAST to the output
route because no route is matched by oif=lo. The RST packet
can not be sent immediately by tcp_v4_send_reset because
it expects RTN_LOCAL.
So, change ip_route_connect and ip_route_newports to
update the flowi4 fields that are input parameters because
we do not want unnecessary binding to oif.
To make it clear what are the input parameters that
can be modified during lookup and to show which fields of
floiw4 are reused add a new function to update the flowi4
structure: flowi4_update_output.
Thanks to Yurij M. Plotnikov for providing a bug report including a
program to reproduce the problem.
Thanks to Eric Dumazet for tracking the problem down to
tcp_v4_send_reset and providing initial fix.
Reported-by: Yurij M. Plotnikov <Yurij.Plotnikov@oktetlabs.ru>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit aa1c366e4f upstream.
With the conversion of struct flowi to a union of AF-specific structs, some
operations on the flow cache need to account for the exact size of the key.
Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On-stack initialization via assignment of flow structures are
expensive because GCC emits a memset() to clear the entire
structure out no matter what.
Add a helper for ipv4 output flow key setup which we can use to avoid
the memset.
Signed-off-by: David S. Miller <davem@davemloft.net>
To start doing these conversions, we need to add some temporary
flow4_* macros which will eventually go away when all the protocol
code paths are changed to work on AF specific flowi objects.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is just a shorthand which will help in passing around AF
specific flow structures as generic ones.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now we have struct flowi4, flowi6, and flowidn for each address
family. And struct flowi is just a union of them all.
It might have been troublesome to convert flow_cache_uli_match() but
as it turns out this function is completely unused and therefore can
be simply removed.
Signed-off-by: David S. Miller <davem@davemloft.net>
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*
This will let us to create AF optimal flow instances.
It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.
Signed-off-by: David S. Miller <davem@davemloft.net>
I intend to turn struct flowi into a union of AF specific flowi
structs. There will be a common structure that each variant includes
first, much like struct sock_common.
This is the first step to move in that direction.
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP is going to record metrics for the connection,
so pre-COW the route metrics at route cache entry
creation time.
This avoids several atomic operations that have to
occur if we COW the metrics after the entry reaches
global visibility.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 4465b46900.
Conflicts:
net/ipv4/fib_frontend.c
As reported by Ben Greear, this causes regressions:
> Change 4465b46900 caused rules
> to stop matching the input device properly because the
> FLOWI_FLAG_MATCH_ANY_IIF is always defined in ip_dev_find().
>
> This breaks rules such as:
>
> ip rule add pref 512 lookup local
> ip rule del pref 0 lookup local
> ip link set eth2 up
> ip -4 addr add 172.16.0.102/24 broadcast 172.16.0.255 dev eth2
> ip rule add to 172.16.0.102 iif eth2 lookup local pref 10
> ip rule add iif eth2 lookup 10001 pref 20
> ip route add 172.16.0.0/24 dev eth2 table 10001
> ip route add unreachable 0/0 table 10001
>
> If you had a second interface 'eth0' that was on a different
> subnet, pinging a system on that interface would fail:
>
> [root@ct503-60 ~]# ping 192.168.100.1
> connect: Invalid argument
Reported-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The GRE Key field is intended to be used for identifying an individual
traffic flow within a tunnel. It is useful to be able to have XFRM
policy selector matches to have different policies for different
GRE tunnels.
Signed-off-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows a host to be configured to respond to any address in
a specified range as if it were local, without actually needing to
configure the address on an interface. This is done through routing
table configuration. For instance, to configure a host to respond
to any address in 10.1/16 received on eth0 as a local address we can do:
ip rule add from all iif eth0 lookup 200
ip route add local 10.1/16 dev lo proto kernel scope host src 127.0.0.1 table 200
This host is now reachable by any 10.1/16 address (route lookup on
input for packets received on eth0 can find the route). On output, the
rule will not be matched so that this host can still send packets to
10.1/16 (not sent on loopback). Presumably, external routing can be
configured to make sense out of this.
To make this work, we needed to modify the logic in finding the
interface which is assigned a given source address for output
(dev_ip_find). We perform a normal fib_lookup instead of just a
lookup on the local table, and in the lookup we ignore the input
interface for matching.
This patch is useful to implement IP-anycast for subnets of virtual
addresses.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
