2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 06:34:11 +08:00
Commit Graph

60 Commits

Author SHA1 Message Date
Cong Wang
6a662719c9 ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif
As suggested by Julian:

	Simply, flowi4_iif must not contain 0, it does not
	look logical to ignore all ip rules with specified iif.

because in fib_rule_match() we do:

        if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
                goto out;

flowi4_iif should be LOOPBACK_IFINDEX by default.

We need to move LOOPBACK_IFINDEX to include/net/flow.h:

1) It is mostly used by flowi_iif

2) Fix the following compile error if we use it in flow.h
by the patches latter:

In file included from include/linux/netfilter.h:277:0,
                 from include/net/netns/netfilter.h:5,
                 from include/net/net_namespace.h:21,
                 from include/linux/netdevice.h:43,
                 from include/linux/icmpv6.h:12,
                 from include/linux/ipv6.h:61,
                 from include/net/ipv6.h:16,
                 from include/linux/sunrpc/clnt.h:27,
                 from include/linux/nfs_fs.h:30,
                 from init/do_mounts.c:32:
include/net/flow.h: In function ‘flowi4_init_output’:
include/net/flow.h:84:32: error: ‘LOOPBACK_IFINDEX’ undeclared (first use in this function)

Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julian Anastasov <ja@ssi.bg>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-16 15:05:11 -04:00
Steffen Klassert
4a93f5095a flowcache: Fix resource leaks on namespace exit.
We leak an active timer, the hotcpu notifier and all allocated
resources when we exit a namespace. Fix this by introducing a
flow_cache_fini() function where we release the resources before
we exit.

Fixes: ca925cf153 ("flowcache: Make flow cache name space aware")
Reported-by: Jakub Kicinski <moorray3@wp.pl>
Tested-by: Jakub Kicinski <moorray3@wp.pl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-12 15:31:18 -04:00
Fan Du
ca925cf153 flowcache: Make flow cache name space aware
Inserting a entry into flowcache, or flushing flowcache should be based
on per net scope. The reason to do so is flushing operation from fat
netns crammed with flow entries will also making the slim netns with only
a few flow cache entries go away in original implementation.

Since flowcache is tightly coupled with IPsec, so it would be easier to
put flow cache global parameters into xfrm namespace part. And one last
thing needs to do is bumping flow cache genid, and flush flow cache should
also be made in per net style.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-02-12 07:02:11 +01:00
Steffen Klassert
0e0d44ab42 net: Remove FLOWI_FLAG_CAN_SLEEP
FLOWI_FLAG_CAN_SLEEP was used to notify xfrm about the posibility
to sleep until the needed states are resolved. This code is gone,
so FLOWI_FLAG_CAN_SLEEP is not needed anymore.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2013-12-06 07:24:39 +01:00
Joe Perches
4787342c39 flow.h/flow_keys.h: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-20 14:49:33 -04:00
Julian Anastasov
c92b96553a ipv4: Add FLOWI_FLAG_KNOWN_NH
Add flag to request that output route should be
returned with known rt_gateway, in case we want to use
it as nexthop for neighbour resolving.

	The returned route can be cached as follows:

- in NH exception: because the cached routes are not shared
	with other destinations
- in FIB NH: when using gateway because all destinations for
	NH share same gateway

	As last option, to return rt_gateway!=0 we have to
set DST_NOCACHE.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08 17:42:36 -04:00
David S. Miller
ba3f7f04ef ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20 13:36:54 -07:00
David S. Miller
3e12939a2a inet: Kill FLOWI_FLAG_PRECOW_METRICS.
No longer needed.  TCP writes metrics, but now in it's own special
cache that does not dirty the route metrics.  Therefore there is no
longer any reason to pre-cow metrics in this way.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 22:40:12 -07:00
Eric Dumazet
7586eceb0a ipv4: tcp: dont cache output dst for syncookies
Don't cache output dst for syncookies, as this adds pressure on IP route
cache and rcu subsystem for no gain.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-22 21:47:33 -07:00
Julian Anastasov
e6b45241c5 ipv4: reset flowi parameters on route connect
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>
2012-02-04 19:29:48 -05:00
Eric Dumazet
747465ef7a net: fix some sparse errors
make C=2 CF="-D__CHECK_ENDIAN__" M=net

And fix flowi4_init_output() prototype for sport

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-17 10:31:12 -05:00
David S. Miller
abb434cb05 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/bluetooth/l2cap_core.c

Just two overlapping changes, one added an initialization of
a local variable, and another change added a new local variable.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-23 17:13:56 -05:00
Steffen Klassert
c0ed1c14a7 net: Add a flow_cache_flush_deferred function
flow_cach_flush() might sleep but can be called from
atomic context via the xfrm garbage collector. So add
a flow_cache_flush_deferred() function and use this if
the xfrm garbage colector is invoked from within the
packet path.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-21 16:48:08 -05:00
Eric Dumazet
84f9307c5d ipv4: use a 64bit load/store in output path
gcc compiler is smart enough to use a single load/store if we
memcpy(dptr, sptr, 8) on x86_64, regardless of
CONFIG_CC_OPTIMIZE_FOR_SIZE

In IP header, daddr immediately follows saddr, this wont change in the
future. We only need to make sure our flowi4 (saddr,daddr) fields wont
break the rule.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01 13:28:54 -05:00
dpward
aa1c366e4f net: Handle different key sizes between address families in flow cache
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>
2011-09-16 17:47:28 -04:00
David Ward
728871bc05 net: Align AF-specific flowi structs to long
AF-specific flowi structs are now passed to flow_key_compare, which must
also be aligned to a long.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16 17:45:07 -04:00
Arun Sharma
60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
David S. Miller
9b12c75bf4 net: Order ports in same order as addresses in flow objects.
For consistency.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31 18:03:35 -07:00
David S. Miller
83229aa5e2 net: Add helper flowi4_init_output().
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>
2011-03-31 04:52:14 -07:00
David S. Miller
bef55aebd5 decnet: Convert to use flowidn where applicable.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:55 -08:00
David S. Miller
1958b856c1 net: Put fl6_* macros to struct flowi6 and use them again.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:55 -08:00
David S. Miller
9cce96df5b net: Put fl4_* macros to struct flowi4 and use them again.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:54 -08:00
David S. Miller
2032656e76 net: Add flowi6_* member helper macros.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:52 -08:00
David S. Miller
22bd5b9b13 ipv4: Pass ipv4 flow objects into fib_lookup() paths.
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>
2011-03-12 15:08:47 -08:00
David S. Miller
59b1a94c9a net: Add flowiX_to_flowi() shorthands.
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>
2011-03-12 15:08:47 -08:00
David S. Miller
56bb8059e1 net: Break struct flowi out into AF specific instances.
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>
2011-03-12 15:08:46 -08:00
David S. Miller
6281dcc94a net: Make flowi ports AF dependent.
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>
2011-03-12 15:08:46 -08:00
David S. Miller
08704bcbf0 net: Create union flowi_uli
This will be used when we have seperate flowi types.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:45 -08:00
David S. Miller
806566cc78 net: Create struct flowi_common
Pull out the AF independent members of struct flowi into a
new struct flowi_common

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:45 -08:00
David S. Miller
1d28f42c1b net: Put flowi_* prefix on AF independent members of struct flowi
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>
2011-03-12 15:08:44 -08:00
David S. Miller
fbef0a4091 net: Remove unnecessary padding in struct flowi
Move tos, scope, proto, and flags to the beginning of
the structure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:43 -08:00
David S. Miller
5df65e5567 net: Add FLOWI_FLAG_CAN_SLEEP.
And set is in contexts where the route resolution can sleep.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:22:19 -08:00
David S. Miller
dee9f4bceb net: Make flow cache paths use a const struct flowi.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22 18:44:31 -08:00
David S. Miller
0730b9a150 net: Mark flowi arg to flow_cache_uli_match() const.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22 18:27:22 -08:00
David S. Miller
a4daad6b09 net: Pre-COW metrics for TCP.
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>
2011-01-27 22:01:53 -08:00
David S. Miller
17f7f4d9fc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/ipv4/fib_frontend.c
2010-12-26 22:37:05 -08:00
David S. Miller
e058464990 Revert "ipv4: Allow configuring subnets as local addresses"
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>
2010-12-23 12:03:57 -08:00
Timo Teräs
cc9ff19da9 xfrm: use gre key as flow upper protocol info
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>
2010-11-15 10:44:04 -08:00
Tom Herbert
4465b46900 ipv4: Allow configuring subnets as local addresses
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>
2010-09-28 23:38:15 -07:00
Timo Teräs
fe1a5f031e flow: virtualize flow cache entry methods
This allows to validate the cached object before returning it.
It also allows to destruct object properly, if the last reference
was held in flow cache. This is also a prepartion for caching
bundles in the flow cache.

In return for virtualizing the methods, we save on:
- not having to regenerate the whole flow cache on policy removal:
  each flow matching a killed policy gets refreshed as the getter
  function notices it smartly.
- we do not have to call flow_cache_flush from policy gc, since the
  flow cache now properly deletes the object if it had any references

Signed-off-by: Timo Teras <timo.teras@iki.fi>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-07 03:43:18 -07:00
Alexey Dobriyan
52479b623d netns xfrm: lookup in netns
Pass netns to xfrm_lookup()/__xfrm_lookup(). For that pass netns
to flow_cache_lookup() and resolver callback.

Take it from socket or netdevice. Stub DECnet to init_net.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25 17:35:18 -08:00
Julian Anastasov
a210d01ae3 ipv4: Loosen source address check on IPv4 output
ip_route_output() contains a check to make sure that no flows with
non-local source IP addresses are routed. This obviously makes using
such addresses impossible.

This patch introduces a flowi flag which makes omitting this check
possible. The new flag provides a way of handling transparent and
non-transparent connections differently.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 07:28:28 -07:00
Rami Rosen
95c3e8bfcd ipv4: remove unused field in struct flowi (include/net/flow.h).
This patch removes an unused field (flags) from struct flowi; it seems
that this "flags" field was used once in the past for multipath
routing with FLOWI_FLAG_MULTIPATHOLDROUTE flag (which does no longer
exist); however, the "flags" field of struct flowi is not used
anymore.

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-05 01:19:50 -07:00
Rami Rosen
61f1ab41b8 [IPV4]: Remove unused multipath cached routing defintion in net/flow.h
Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:00:20 -08:00
Masahide NAKAMURA
136ebf08b4 [IPV6] MIP6: Kill unnecessary ifdefs.
Kill unnecessary CONFIG_IPV6_MIP6.

o It is redundant for RAW socket to keep MH out with the config then
  it can handle any protocol.
o Clean-up at AH.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-10 22:15:41 -07:00
Masahide NAKAMURA
157bfc2502 [XFRM]: Restrict upper layer information by bundle.
On MIPv6 usage, XFRM sub policy is enabled.
When main (IPsec) and sub (MIPv6) policy selectors have the same
address set but different upper layer information (i.e. protocol
number and its ports or type/code), multiple bundle should be created.
However, currently we have issue to use the same bundle created for
the first time with all flows covered by the case.

It is useful for the bundle to have the upper layer information
to be restructured correctly if it does not match with the flow.

1. Bundle was created by two policies
Selector from another policy is added to xfrm_dst.
If the flow does not match the selector, it goes to slow path to
restructure new bundle by single policy.

2. Bundle was created by one policy
Flow cache is added to xfrm_dst as originated one. If the flow does
not match the cache, it goes to slow path to try searching another
policy.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-30 00:58:09 -07:00
Thomas Graf
47dcf0cb10 [NET]: Rethink mark field in struct flowi
Now that all protocols have been made aware of the mark
field it can be moved out of the union thus simplyfing
its usage.

The config options in the IPv4/IPv6/DECnet subsystems
to enable respectively disable mark based routing only
obfuscate the code with ifdefs, the cost for the
additional comparison in the flow key is insignificant,
and most distributions have all these options enabled
by default anyway. Therefore it makes sense to remove
the config options and enable mark based routing by
default.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:39 -08:00
Al Viro
90bcaf7b4a [IPV6]: flowlabels are net-endian
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02 21:21:21 -08:00
Eric Dumazet
185b1aa122 [NET]: Reduce sizeof(struct flowi) by 20 bytes.
As suggested by David, just kill off some unused fields in dnports to
reduce sizef(struct flowi). If they come back, they should be moved to
nl_u.dn_u in order not to enlarge again struct flowi

[ Modified to really delete this stuff instead of using #if 0. -DaveM ]

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-21 20:24:01 -07:00
James Morris
134b0fc544 IPsec: propagate security module errors up from flow_cache_lookup
When a security module is loaded (in this case, SELinux), the
security_xfrm_policy_lookup() hook can return an access denied permission
(or other error).  We were not handling that correctly, and in fact
inverting the return logic and propagating a false "ok" back up to
xfrm_lookup(), which then allowed packets to pass as if they were not
associated with an xfrm policy.

The way I was seeing the problem was when connecting via IPsec to a
confined service on an SELinux box (vsftpd), which did not have the
appropriate SELinux policy permissions to send packets via IPsec.

The first SYNACK would be blocked, because of an uncached lookup via
flow_cache_lookup(), which would fail to resolve an xfrm policy because
the SELinux policy is checked at that point via the resolver.

However, retransmitted SYNACKs would then find a cached flow entry when
calling into flow_cache_lookup() with a null xfrm policy, which is
interpreted by xfrm_lookup() as the packet not having any associated
policy and similarly to the first case, allowing it to pass without
transformation.

The solution presented here is to first ensure that errno values are
correctly propagated all the way back up through the various call chains
from security_xfrm_policy_lookup(), and handled correctly.

Then, flow_cache_lookup() is modified, so that if the policy resolver
fails (typically a permission denied via the security module), the flow
cache entry is killed rather than having a null policy assigned (which
indicates that the packet can pass freely).  This also forces any future
lookups for the same flow to consult the security module (e.g. SELinux)
for current security policy (rather than, say, caching the error on the
flow cache entry).

Signed-off-by: James Morris <jmorris@namei.org>
2006-10-11 23:59:34 -07:00