Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages. This patch adds that information to netlink messages
so we can audit who sent netlink messages.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As it stands it's impossible to use any authentication algorithms
with an ID above 31 portably. It just happens to work on x86 but
fails miserably on ppc64.
The reason is that we're using a bit mask to check the algorithm
ID but the mask is only 32 bits wide.
After looking at how this is used in the field, I have concluded
that in the long term we should phase out state matching by IDs
because this is made superfluous by the reqid feature. For current
applications, the best solution IMHO is to allow all algorithms when
the bit masks are all ~0.
The following patch does exactly that.
This bug was identified by IBM when testing on the ppc64 platform
using the NULL authentication algorithm which has an ID of 251.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
When CONFIG_SECURITY_NETWORK_XFRM is undefined the following warnings appears:
net/xfrm/xfrm_user.c: In function 'xfrm_add_pol_expire':
net/xfrm/xfrm_user.c:1576: warning: 'ctx' may be used uninitialized in this function
net/xfrm/xfrm_user.c: In function 'xfrm_get_policy':
net/xfrm/xfrm_user.c:1340: warning: 'ctx' may be used uninitialized in this function
(security_xfrm_policy_alloc is noop for the case).
It seems that they are result of the commit
03e1ad7b5d ("LSM: Make the Labeled IPsec
hooks more stack friendly")
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The xfrm_get_policy() and xfrm_add_pol_expire() put some rather large structs
on the stack to work around the LSM API. This patch attempts to fix that
problem by changing the LSM API to require only the relevant "security"
pointers instead of the entire SPD entry; we do this for all of the
security_xfrm_policy*() functions to keep things consistent.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit df9dcb45 ([IPSEC]: Fix inter address family IPsec tunnel handling)
broke openswan by removing the selector initialization for tunnel mode
in case it is uninitialized.
This patch restores the initialization, fixing openswan, but probably
breaking inter-family tunnels again (unknown since the patch author
disappeared). The correct thing for inter-family tunnels is probably
to simply initialize the selector family explicitly.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change xfrm_policy and xfrm_state walking algorithm from O(n^2) to O(n).
This is achieved adding the entries to one more list which is used
solely for walking the entries.
This also fixes some races where the dump can have duplicate or missing
entries when the SPD/SADB is modified during an ongoing dump.
Dumping SADB with 20000 entries using "time ip xfrm state" the sys
time dropped from 1.012s to 0.080s.
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
When we destory a new policy entry, we need to tell
xfrm_policy_destroy() explicitly that the entry is not
alive yet.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds support for combined mode algorithms with GCM being
the first algorithm supported.
Combined mode algorithms can be added through the xfrm_user interface
using the new algorithm payload type XFRMA_ALG_AEAD. Each algorithms
is identified by its name and the ICV length.
For the purposes of matching algorithms in xfrm_tmpl structures,
combined mode algorithms occupy the same name space as encryption
algorithms. This is in line with how they are negotiated using IKE.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create a specific helper for netlink kernel socket disposal. This just
let the code look better and provides a ground for proper disposal
inside a namespace.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Tested-by: Alexey Dobriyan <adobriyan@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since __xfrm_policy_destroy is used to destory the resources
allocated by xfrm_policy_alloc. So using the name
__xfrm_policy_destroy is not correspond with xfrm_policy_alloc.
Rename it to xfrm_policy_destroy.
And along with some instances that call xfrm_policy_alloc
but not using xfrm_policy_destroy to destroy the resource,
fix them.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently x->lastused is u64 which means that it cannot be
read/written atomically on all architectures. David Miller observed
that the value stored in it is only an unsigned long which is always
atomic.
So based on his suggestion this patch changes the internal
representation from u64 to unsigned long while the user-interface
still refers to it as u64.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
alg_key_len is the length in bits of the key, not in bytes.
Best way to fix this is to move alg_len() function from net/xfrm/xfrm_user.c
to include/net/xfrm.h, and to use it in xfrm_algo_clone()
alg_len() is renamed to xfrm_alg_len() because of its global exposition.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The change 050f009e16
[IPSEC]: Lock state when copying non-atomic fields to user-space
caused a regression.
Ingo Molnar reports that it causes a potential dead-lock found by the
lock validator as it tries to take x->lock within xfrm_state_lock while
numerous other sites take the locks in opposite order.
For 2.6.24, the best fix is to simply remove the added locks as that puts
us back in the same state as we've been in for years. For later kernels
a proper fix would be to reverse the locking order for every xfrm state
user such that if x->lock is taken together with xfrm_state_lock then
it is to be taken within it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced
asynchronious user -> kernel communication.
The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.
Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.
This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.
Kernel -> user path in netlink_unicast remains untouched.
EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds locking so that when we're copying non-atomic fields such as
life-time or coaddr to user-space we don't get a partial result.
For af_key I've changed every instance of pfkey_xfrm_state2msg apart from
expiration notification to include the keys and life-times. This is in-line
with XFRM behaviour.
The actual cases affected are:
* pfkey_getspi: No change as we don't have any keys to copy.
* key_notify_sa:
+ ADD/UPD: This wouldn't work otherwise.
+ DEL: It can't hurt.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Here's a good example of code duplication leading to code rot. The
notification patch did its own netlink message creation for xfrm states.
It duplicated code that was already in dump_one_state. Guess what, the
next time (and the time after) when someone updated dump_one_state the
notification path got zilch.
This patch moves that code from dump_one_state to copy_to_user_state_extra
and uses it in xfrm_notify_sa too. Unfortunately whoever updates this
still needs to update xfrm_sa_len since the notification path wants to
know the exact size for allocation.
At least I've added a comment saying so and if someone still forgest, we'll
have a WARN_ON telling us so.
I also changed the security size calculation to use xfrm_user_sec_ctx since
that's what we actually put into the skb. However it makes no practical
difference since it has the same size as xfrm_sec_ctx.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch moves some common code that conceptually belongs to the xfrm core
from af_key/xfrm_user into xfrm_alloc_spi.
In particular, the spin lock on the state is now taken inside xfrm_alloc_spi.
Previously it also protected the construction of the response PF_KEY/XFRM
messages to user-space. This is inconsistent as other identical constructions
are not protected by the state lock. This is bad because they in fact should
be protected but only in certain spots (so as not to hold the lock for too
long which may cause packet drops).
The SPI byte order conversion has also been moved.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
I was looking at Patrick's fix to inet_diag and it occured
to me that we're using a pointer argument to return values
unnecessarily in netlink_run_queue. Changing it to return
the value will allow the compiler to generate better code
since the value won't have to be memory-backed.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.
This patch updates all of the existing netlink protocols
to only support the initial network namespace. Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.
As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.
The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch modifies the current ipsec audit layer
by breaking it up into purpose driven audit calls.
So far, the only audit calls made are when add/delete
an SA/policy. It had been discussed to give each
key manager it's own calls to do this, but I found
there to be much redundnacy since they did the exact
same things, except for how they got auid and sid, so I
combined them. The below audit calls can be made by any
key manager. Hopefully, this is ok.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These functions are only used once and are a lot easier to understand if
inlined directly into the function.
Fixes by Masahide NAKAMURA.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
nlmsg_parse() puts attributes at array[type] so the indexing
method can be simpilfied by removing the obscuring "- 1".
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds a policy defining the minimal payload lengths for all the attributes
allowing for most attribute validation checks to be removed from in
the middle of the code path. Makes updates more consistent as many format
errors are recognised earlier, before any changes have been attempted.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Uses nlmsg_parse() to parse the attributes. This actually changes
behaviour as unknown attributes (type > MAXTYPE) no longer cause
an error. Instead unknown attributes will be ignored henceforth
to keep older kernels compatible with more recent userspace tools.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Moves all complex message size calculation into own inlined helper
functions and makes use of the type-safe netlink interface.
Using nlmsg_new() simplifies the calculation itself as it takes care
of the netlink header length by itself.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Moves all of the SUB_POLICY ifdefs related to the attribute size
calculation into a function.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds alg_len() to calculate the properly padded length of an
algorithm attribute to simplify the code.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also makes use of copy_sec_ctx() in another place and removes
duplicated code.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the issue we had with template families which
specified the inner families of policies, we need to set
the inner families of states as the main xfrm user Openswan
leaves it as zero.
af_key is unaffected because the inner family is set by it
and not the KM.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we check for permission before deleting entries from SAD and
SPD, (see security_xfrm_policy_delete() security_xfrm_state_delete())
However we are not checking for authorization when flushing the SPD and
the SAD completely. It was perhaps missed in the original security hooks
patch.
This patch adds a security check when flushing entries from the SAD and
SPD. It runs the entire database and checks each entry for a denial.
If the process attempting the flush is unable to remove all of the
entries a denial is logged the the flush function returns an error
without removing anything.
This is particularly useful when a process may need to create or delete
its own xfrm entries used for things like labeled networking but that
same process should not be able to delete other entries or flush the
entire database.
Signed-off-by: Joy Latten<latten@austin.ibm.com>
Signed-off-by: Eric Paris <eparis@parisplace.org>
Signed-off-by: James Morris <jmorris@namei.org>
Aggregate the SPD info TLVs.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Aggregate the SAD info TLVs.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
With this patch you can use iproute2 in user space to efficiently see
how many policies exist in different directions.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This brings the SAD info in sync with net-2.6.22/net-2.6
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
On a system with a lot of SAs, counting SAD entries chews useful
CPU time since you need to dump the whole SAD to user space;
i.e something like ip xfrm state ls | grep -i src | wc -l
I have seen taking literally minutes on a 40K SAs when the system
is swapping.
With this patch, some of the SAD info (that was already being tracked)
is exposed to user space. i.e you do:
ip xfrm state count
And you get the count; you can also pass -s to the command line and
get the hash info.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Spring cleaning time...
There seems to be a lot of places in the network code that have
extra bogus semicolons after conditionals. Most commonly is a
bogus semicolon after: switch() { }
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Switch cb_lock to mutex and allow netlink kernel users to override it
with a subsystem specific mutex for consistent locking in dump callbacks.
All netlink_dump_start users have been audited not to rely on any
side-effects of the previously used spinlock.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that all users of netlink_dump_start() use netlink_run_queue()
to process the receive queue, it is possible to return -EINTR from
netlink_dump_start() directly, therefore simplying the callers.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
The error pointer argument in netlink message handlers is used
to signal the special case where processing has to be interrupted
because a dump was started but no error happened. Instead it is
simpler and more clear to return -EINTR and have netlink_run_queue()
deal with getting the queue right.
nfnetlink passed on this error pointer to its subsystem handlers
but only uses it to signal the start of a netlink dump. Therefore
it can be removed there as well.
This patch also cleans up the error handling in the affected
message handlers to be consistent since it had to be touched anyway.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Changes netlink_rcv_skb() to skip netlink controll messages and don't
pass them on to the message handler.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink_rcv_skb() is changed to skip messages which don't have the
NLM_F_REQUEST bit to avoid every netlink family having to perform this
check on their own.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending a security context of 50+ characters in an ACQUIRE
message, following kernel panic occurred.
kernel BUG in xfrm_send_acquire at net/xfrm/xfrm_user.c:1781!
cpu 0x3: Vector: 700 (Program Check) at [c0000000421bb2e0]
pc: c00000000033b074: .xfrm_send_acquire+0x240/0x2c8
lr: c00000000033b014: .xfrm_send_acquire+0x1e0/0x2c8
sp: c0000000421bb560
msr: 8000000000029032
current = 0xc00000000fce8f00
paca = 0xc000000000464b00
pid = 2303, comm = ping
kernel BUG in xfrm_send_acquire at net/xfrm/xfrm_user.c:1781!
enter ? for help
3:mon> t
[c0000000421bb650] c00000000033538c .km_query+0x6c/0xec
[c0000000421bb6f0] c000000000337374 .xfrm_state_find+0x7f4/0xb88
[c0000000421bb7f0] c000000000332350 .xfrm_tmpl_resolve+0xc4/0x21c
[c0000000421bb8d0] c0000000003326e8 .xfrm_lookup+0x1a0/0x5b0
[c0000000421bba00] c0000000002e6ea0 .ip_route_output_flow+0x88/0xb4
[c0000000421bbaa0] c0000000003106d8 .ip4_datagram_connect+0x218/0x374
[c0000000421bbbd0] c00000000031bc00 .inet_dgram_connect+0xac/0xd4
[c0000000421bbc60] c0000000002b11ac .sys_connect+0xd8/0x120
[c0000000421bbd90] c0000000002d38d0 .compat_sys_socketcall+0xdc/0x214
[c0000000421bbe30] c00000000000869c syscall_exit+0x0/0x40
--- Exception: c00 (System Call) at 0000000007f0ca9c
SP (fc0ef8f0) is in userspace
We are using size of security context from xfrm_policy to determine
how much space to alloc skb and then putting security context from
xfrm_state into skb. Should have been using size of security context
from xfrm_state to alloc skb. Following fix does that
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Turning up the warnings on gcc makes it emit warnings
about the placement of 'inline' in function declarations.
Here's everything that was under net/
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Inside pfkey_delete and xfrm_del_sa the audit hooks were not called if
there was any permission/security failures in attempting to do the del
operation (such as permission denied from security_xfrm_state_delete).
This patch moves the audit hook to the exit path such that all failures
(and successes) will actually get audited.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkat Yekkirala <vyekkirala@trustedcs.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The security hooks to check permissions to remove an xfrm_policy were
actually done after the policy was removed. Since the unlinking and
deletion are done in xfrm_policy_by* functions this moves the hooks
inside those 2 functions. There we have all the information needed to
do the security check and it can be done before the deletion. Since
auditing requires the result of that security check err has to be passed
back and forth from the xfrm_policy_by* functions.
This patch also fixes a bug where a deletion that failed the security
check could cause improper accounting on the xfrm_policy
(xfrm_get_policy didn't have a put on the exit path for the hold taken
by xfrm_policy_by*)
It also fixes the return code when no policy is found in
xfrm_add_pol_expire. In old code (at least back in the 2.6.18 days) err
wasn't used before the return when no policy is found and so the
initialization would cause err to be ENOENT. But since err has since
been used above when we don't get a policy back from the xfrm_policy_by*
function we would always return 0 instead of the intended ENOENT. Also
fixed some white space damage in the same area.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkat Yekkirala <vyekkirala@trustedcs.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
As noted by Kent Yoder, this function will always return an
error. Make sure it returns zero on success.
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure that this function is called correctly, and
add BUG() checking to ensure the arguments are sane.
Based upon a patch by Joy Latten.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add user interface for handling XFRM_MSG_MIGRATE. The message is issued
by user application. When kernel receives the message, procedure of
updating XFRM databases will take place.
Signed-off-by: Shinta Sugimoto <shinta.sugimoto@ericsson.com>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
All ->doit handlers want a struct rtattr **, so pass down the right
type.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
An audit message occurs when an ipsec SA
or ipsec policy is created/deleted.
Signed-off-by: Joy Latten <latten@austin.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we never checked the ->family value of templates
before, many applications simply leave it at zero.
Detect this and fix it up to be the pol->family value.
Also, do not clobber xp->family while reading in templates,
that is not necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
aevents can not uniquely identify an SA. We break the ABI with this
patch, but consensus is that since it is not yet utilized by any
(known) application then it is fine (better do it now than later).
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Diego Beltrami <Diego.Beltrami@hiit.fi>
Signed-off-by: Kazunori Miyazawa <miyazawa@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Might as well make flush notifier prettier when subpolicy used
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
The destination PID is passed directly to netlink_unicast()
respectively netlink_multicast().
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make copy_to_user_policy_type take a type instead a policy and
fix its users to pass the type
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
When application uses XFRM_MSG_GETSA to get state entry through
netlink socket and kernel has no matching one, the application expects
reply message with error status by kernel.
Kernel doesn't send the message back in the case of Mobile IPv6 route
optimization protocols (i.e. routing header or destination options
header). This is caused by incorrect return code "0" from
net/xfrm/xfrm_user.c(xfrm_user_state_lookup) and it makes kernel skip
to acknowledge at net/netlink/af_netlink.c(netlink_rcv_skb).
This patch fix to reply ESRCH to application.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: TAKAMIYA Noriaki <takamiya@po.ntts.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
I actually dont have a test case for these; i just found them by
inspection. Refer to patch "[XFRM]: Sub-policies broke policy events"
for more info
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
XFRM policy events are broken when sub-policy feature is turned on.
A simple test to verify this:
run ip xfrm mon on one window and add then delete a policy on another
window ..
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use memcpy() to move xfrm_address_t objects in and out
of netlink messages. The vast majority of xfrm_user was
doing this properly, except for copy_from_user_state()
and copy_to_user_state().
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently when an IPSec policy rule doesn't specify a security
context, it is assumed to be "unlabeled" by SELinux, and so
the IPSec policy rule fails to match to a flow that it would
otherwise match to, unless one has explicitly added an SELinux
policy rule allowing the flow to "polmatch" to the "unlabeled"
IPSec policy rules. In the absence of such an explicitly added
SELinux policy rule, the IPSec policy rule fails to match and
so the packet(s) flow in clear text without the otherwise applicable
xfrm(s) applied.
The above SELinux behavior violates the SELinux security notion of
"deny by default" which should actually translate to "encrypt by
default" in the above case.
This was first reported by Evgeniy Polyakov and the way James Morris
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.
With this patch applied, SELinux "polmatching" of flows Vs. IPSec
policy rules will only come into play when there's a explicit context
specified for the IPSec policy rule (which also means there's corresponding
SELinux policy allowing appropriate domains/flows to polmatch to this context).
Secondly, when a security module is loaded (in this case, SELinux), the
security_xfrm_policy_lookup() hook can return errors other than access denied,
such as -EINVAL. 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 solution for this 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).
This patch: Fix the selinux side of things.
This makes sure SELinux polmatching of flow contexts to IPSec policy
rules comes into play only when an explicit context is associated
with the IPSec policy rule.
Also, this no longer defaults the context of a socket policy to
the context of the socket since the "no explicit context" case
is now handled properly.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: James Morris <jmorris@namei.org>
This patch introduces the BEET mode (Bound End-to-End Tunnel) with as
specified by the ietf draft at the following link:
http://www.ietf.org/internet-drafts/draft-nikander-esp-beet-mode-06.txt
The patch provides only single family support (i.e. inner family =
outer family).
Signed-off-by: Diego Beltrami <diego.beltrami@gmail.com>
Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Abhinav Pathak <abhinav.pathak@hiit.fi>
Signed-off-by: Jeff Ahrenholz <ahrenholz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sub policy can be used through netlink socket.
PF_KEY uses main only and it is TODO to support sub.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
XFRM_MSG_REPORT is a message as notification of state protocol and
selector from kernel to user-space.
Mobile IPv6 will use it when inbound reject is occurred at route
optimization to make user-space know a binding error requirement.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add Mobile IPv6 route optimization protocols to netlink interface.
Route optimization states carry care-of address.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transformation user interface is not only for IPsec.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
With this patch transformation state is updated last used time
for each sending. Xtime is used for it like other state lifetime
expiration.
Mobile IPv6 enabled nodes will want to know traffic status of each
binding (e.g. judgement to request binding refresh by correspondent node,
or to keep home/care-of nonce alive by mobile node).
The last used timestamp is an important hint about it.
Based on MIPL2 kernel patch.
This patch was also written by: Henrik Petander <petander@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Care-of address is carried by state as a transformation option like
IPsec encryption/authentication algorithm.
Based on MIPL2 kernel patch.
Signed-off-by: Noriaki TAKAMIYA <takamiya@po.ntts.co.jp>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
This is a support to search transformation states by its addresses
by using source address list for Mobile IPv6 usage.
To use it from user-space, it is also added a message type for
source address as a xfrm state option.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It will be added two more transformation protocols (routing header
and destination options header) for Mobile IPv6.
xfrm_id_proto_match() can be handle zero as all, IPSEC_PROTO_ANY as
all IPsec and otherwise as exact one.
Based on MIPL2 kernel patch.
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Transformation mode is used as either IPsec transport or tunnel.
It is required to add two more items, route optimization and inbound trigger
for Mobile IPv6.
Based on MIPL2 kernel patch.
This patch was also written by: Ville Nuorvala <vnuorval@tcs.hut.fi>
Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This defaults the label of socket-specific IPSec policies to be the
same as the socket they are set on.
Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This includes the security context of a security association created
for use by IKE in the acquire messages sent to IKE daemons using
netlink/xfrm_user. This would allow the daemons to include the
security context in the negotiation, so that the resultant association
is unique to that security context.
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a compatibility name field for each IPsec algorithm. This
is needed when parameterised algorithms are used. For example, "md5" will
become "hmac(md5)", and "aes" will become "cbc(aes)".
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The header file linux/crypto.h is only needed by a few files so including
it in net/xfrm.h (which is included by half of the networking stack) is a
waste. This patch moves it out of net/xfrm.h and into the specific header
files that actually need it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch encapsulates the usage of eff_cap (in netlink_skb_params) within
the security framework by extending security_netlink_recv to include a required
capability parameter and converting all direct usage of eff_caps outside
of the lsm modules to use the interface. It also updates the SELinux
implementation of the security_netlink_send and security_netlink_recv
hooks to take advantage of the sid in the netlink_skb_params struct.
This also enables SELinux to perform auditing of netlink capability checks.
Please apply, for 2.6.18 if possible.
Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Assignment used as truth value in xfrm_del_sa()
and xfrm_get_policy().
Wrong argument type declared for security_xfrm_state_delete()
when SELINUX is disabled.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains a fix for the previous patch that adds security
contexts to IPsec policies and security associations. In the previous
patch, no authorization (besides the check for write permissions to
SAD and SPD) is required to delete IPsec policies and security
assocations with security contexts. Thus a user authorized to change
SAD and SPD can bypass the IPsec policy authorization by simply
deleteing policies with security contexts. To fix this security hole,
an additional authorization check is added for removing security
policies and security associations with security contexts.
Note that if no security context is supplied on add or present on
policy to be deleted, the SELinux module allows the change
unconditionally. The hook is called on deletion when no context is
present, which we may want to change. At present, I left it up to the
module.
LSM changes:
The patch adds two new LSM hooks: xfrm_policy_delete and
xfrm_state_delete. The new hooks are necessary to authorize deletion
of IPsec policies that have security contexts. The existing hooks
xfrm_policy_free and xfrm_state_free lack the context to do the
authorization, so I decided to split authorization of deletion and
memory management of security data, as is typical in the LSM
interface.
Use:
The new delete hooks are checked when xfrm_policy or xfrm_state are
deleted by either the xfrm_user interface (xfrm_get_policy,
xfrm_del_sa) or the pfkey interface (pfkey_spddelete, pfkey_delete).
SELinux changes:
The new policy_delete and state_delete functions are added.
Signed-off-by: Catherine Zhang <cxzhang@watson.ibm.com>
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When xfrm_user isn't loaded xfrm_nl is NULL, which makes IPsec crash because
xfrm_aevent_is_on passes the NULL pointer to netlink_has_listeners as socket.
A second problem is that the xfrm_nl pointer is not cleared when the socket
is releases at module unload time.
Protect references of xfrm_nl from outside of xfrm_user by RCU, check
that the socket is present in xfrm_aevent_is_on and set it to NULL
when unloading xfrm_user.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Semaphore to mutex conversion.
The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
First, it warns when PAGE_SIZE >= 64K because the ctx_len
field is 16-bits.
Secondly, if there are any real length limitations it can
be verified by the security layer security_xfrm_state_alloc()
call.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is similar to the SA expire insertion patch - only it inserts
expires for SP.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows a user to insert SA expires. This is useful to
do on an HA backup for the case of byte counts but may not be very
useful for the case of time based expiry.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This introduces a feature similar to the one described in RFC 2367:
"
... the application needing an SA sends a PF_KEY
SADB_ACQUIRE message down to the Key Engine, which then either
returns an error or sends a similar SADB_ACQUIRE message up to one or
more key management applications capable of creating such SAs.
...
...
The third is where an application-layer consumer of security
associations (e.g. an OSPFv2 or RIPv2 daemon) needs a security
association.
Send an SADB_ACQUIRE message from a user process to the kernel.
<base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
proposal>
The kernel returns an SADB_ACQUIRE message to registered
sockets.
<base, address(SD), (address(P),) (identity(SD),) (sensitivity,)
proposal>
The user-level consumer waits for an SADB_UPDATE or SADB_ADD
message for its particular type, and then can use that
association by using SADB_GET messages.
"
An app such as OSPF could then use ipsec KM to get keys
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch provides the core functionality needed for sync events
for ipsec. Derived work of Krisztian KOVACS <hidden@balabit.hu>
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
We often just do an atomic_dec(&x->refcnt) on an xfrm_state object
because we know there is more than 1 reference remaining and thus
we can elide the heavier xfrm_state_put() call.
Do this behind an inline function called __xfrm_state_put() so that is
more obvious and also to allow us to more cleanly add refcount
debugging later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch contains two corrections to the LSM-IPsec Nethooks patches
previously applied.
(1) free a security context on a failed insert via xfrm_user
interface in xfrm_add_policy. Memory leak.
(2) change the authorization of the allocation of a security context
in a xfrm_policy or xfrm_state from both relabelfrom and relabelto
to setcontext.
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch series implements per packet access control via the
extension of the Linux Security Modules (LSM) interface by hooks in
the XFRM and pfkey subsystems that leverage IPSec security
associations to label packets. Extensions to the SELinux LSM are
included that leverage the patch for this purpose.
This patch implements the changes necessary to the XFRM subsystem,
pfkey interface, ipv4/ipv6, and xfrm_user interface to restrict a
socket to use only authorized security associations (or no security
association) to send/receive network packets.
Patch purpose:
The patch is designed to enable access control per packets based on
the strongly authenticated IPSec security association. Such access
controls augment the existing ones based on network interface and IP
address. The former are very coarse-grained, and the latter can be
spoofed. By using IPSec, the system can control access to remote
hosts based on cryptographic keys generated using the IPSec mechanism.
This enables access control on a per-machine basis or per-application
if the remote machine is running the same mechanism and trusted to
enforce the access control policy.
Patch design approach:
The overall approach is that policy (xfrm_policy) entries set by
user-level programs (e.g., setkey for ipsec-tools) are extended with a
security context that is used at policy selection time in the XFRM
subsystem to restrict the sockets that can send/receive packets via
security associations (xfrm_states) that are built from those
policies.
A presentation available at
www.selinux-symposium.org/2005/presentations/session2/2-3-jaeger.pdf
from the SELinux symposium describes the overall approach.
Patch implementation details:
On output, the policy retrieved (via xfrm_policy_lookup or
xfrm_sk_policy_lookup) must be authorized for the security context of
the socket and the same security context is required for resultant
security association (retrieved or negotiated via racoon in
ipsec-tools). This is enforced in xfrm_state_find.
On input, the policy retrieved must also be authorized for the socket
(at __xfrm_policy_check), and the security context of the policy must
also match the security association being used.
The patch has virtually no impact on packets that do not use IPSec.
The existing Netfilter (outgoing) and LSM rcv_skb hooks are used as
before.
Also, if IPSec is used without security contexts, the impact is
minimal. The LSM must allow such policies to be selected for the
combination of socket and remote machine, but subsequent IPSec
processing proceeds as in the original case.
Testing:
The pfkey interface is tested using the ipsec-tools. ipsec-tools have
been modified (a separate ipsec-tools patch is available for version
0.5) that supports assignment of xfrm_policy entries and security
associations with security contexts via setkey and the negotiation
using the security contexts via racoon.
The xfrm_user interface is tested via ad hoc programs that set
security contexts. These programs are also available from me, and
contain programs for setting, getting, and deleting policy for testing
this interface. Testing of sa functions was done by tracing kernel
behavior.
Signed-off-by: Trent Jaeger <tjaeger@cse.psu.edu>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most netlink families make no use of the done() callback, making
it optional gets rid of all unnecessary dummy implementations.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
netlink_broadcast users must initialize NETLINK_CB(skb).dst_groups to the
destination group mask for netlink_recvmsg.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Remove bogus code for compiling netlink as module
- Add module refcounting support for modules implementing a netlink
protocol
- Add support for autoloading modules that implement a netlink protocol
as soon as someone opens a socket for that protocol
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Spotted by, and original patch by, Balazs Scheidler.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds xfrm_init_state which is simply a wrapper that calls
xfrm_get_type and subsequently x->type->init_state. It also gets rid
of the unused args argument.
Abstracting it out allows us to add common initialisation code, e.g.,
to set family-specific flags.
The add_time setting in xfrm_user.c was deleted because it's already
set by xfrm_state_alloc.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jmorris@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch changes the format of the XFRM_MSG_DELSA and
XFRM_MSG_DELPOLICY notification so that the main message
sent is of the same format as that received by the kernel
if the original message was via netlink. This also means
that we won't lose the byid information carried in km_event.
Since this user interface is introduced by Jamal's patch
we can still afford to change it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Small fixup to use netlink macros instead of hardcoding.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Herbert Xu wrote:
> @@ -1254,6 +1326,7 @@ static int pfkey_add(struct sock *sk, st
> if (IS_ERR(x))
> return PTR_ERR(x);
>
> + xfrm_state_hold(x);
This introduces a leak when xfrm_state_add()/xfrm_state_update()
fail. We hold two references (one from xfrm_state_alloc(), one
from xfrm_state_hold()), but only drop one. We need to take the
reference because the reference from xfrm_state_alloc() can
be dropped by __xfrm_state_delete(), so the fix is to drop both
references on error. Same problem in xfrm_user.c.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes XFRM_SAP_* and converts them over to XFRM_MSG_*.
The netlink interface is meant to map directly onto the underlying
xfrm subsystem. Therefore rather than using a new independent
representation for the events we can simply use the existing ones
from xfrm_user.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch fixes policy deletion in xfrm_user so that it sets
km_event.data.byid. This puts xfrm_user on par with what af_key
does in this case.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Heres the final patch.
What this patch provides
- netlink xfrm events
- ability to have events generated by netlink propagated to pfkey
and vice versa.
- fixes the acquire lets-be-happy-with-one-success issue
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We need to verify that the payload contains enough data so that
attach_one_algo can copy alg_key_len bits from the payload.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The variable alg_key_len is in bits and not bytes. The function
attach_one_algo is currently using it as if it were in bytes.
This causes it to read memory which may not be there.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we free up a partially processed packet because it's
skb->len dropped to zero, we need to decrement qlen because
we are dropping out of the top-level loop so it will do
the decrement for us.
Spotted by Herbert Xu.
Signed-off-by: David S. Miller <davem@davemloft.net>
The qlen should continue to decrement, even if we
pop partially processed SKBs back onto the receive queue.
Signed-off-by: David S. Miller <davem@davemloft.net>
Let's recap the problem. The current asynchronous netlink kernel
message processing is vulnerable to these attacks:
1) Hit and run: Attacker sends one or more messages and then exits
before they're processed. This may confuse/disable the next netlink
user that gets the netlink address of the attacker since it may
receive the responses to the attacker's messages.
Proposed solutions:
a) Synchronous processing.
b) Stream mode socket.
c) Restrict/prohibit binding.
2) Starvation: Because various netlink rcv functions were written
to not return until all messages have been processed on a socket,
it is possible for these functions to execute for an arbitrarily
long period of time. If this is successfully exploited it could
also be used to hold rtnl forever.
Proposed solutions:
a) Synchronous processing.
b) Stream mode socket.
Firstly let's cross off solution c). It only solves the first
problem and it has user-visible impacts. In particular, it'll
break user space applications that expect to bind or communicate
with specific netlink addresses (pid's).
So we're left with a choice of synchronous processing versus
SOCK_STREAM for netlink.
For the moment I'm sticking with the synchronous approach as
suggested by Alexey since it's simpler and I'd rather spend
my time working on other things.
However, it does have a number of deficiencies compared to the
stream mode solution:
1) User-space to user-space netlink communication is still vulnerable.
2) Inefficient use of resources. This is especially true for rtnetlink
since the lock is shared with other users such as networking drivers.
The latter could hold the rtnl while communicating with hardware which
causes the rtnetlink user to wait when it could be doing other things.
3) It is still possible to DoS all netlink users by flooding the kernel
netlink receive queue. The attacker simply fills the receive socket
with a single netlink message that fills up the entire queue. The
attacker then continues to call sendmsg with the same message in a loop.
Point 3) can be countered by retransmissions in user-space code, however
it is pretty messy.
In light of these problems (in particular, point 3), we should implement
stream mode netlink at some point. In the mean time, here is a patch
that implements synchronous processing.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Converts xfrm_msg_min and xfrm_dispatch to use c99 designated
initializers to make greping a little bit easier. Also replaces
two hardcoded message type with meaningful names.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric Paris