Wireless extensions have the unfortunate problem that events
are multicast netlink messages, and are not independent of
pointer size. Thus, currently 32-bit tasks on 64-bit platforms
cannot properly receive events and fail with all kinds of
strange problems, for instance wpa_supplicant never notices
disassociations, due to the way the 64-bit event looks (to a
32-bit process), the fact that the address is all zeroes is
lost, it thinks instead it is 00:00:00:00:01:00.
The same problem existed with the ioctls, until David Miller
fixed those some time ago in an heroic effort.
A different problem caused by this is that we cannot send the
ASSOCREQIE/ASSOCRESPIE events because sending them causes a
32-bit wpa_supplicant on a 64-bit system to overwrite its
internal information, which is worse than it not getting the
information at all -- so we currently resort to sending a
custom string event that it then parses. This, however, has a
severe size limitation we are frequently hitting with modern
access points; this limitation would can be lifted after this
patch by sending the correct binary, not custom, event.
A similar problem apparently happens for some other netlink
users on x86_64 with 32-bit tasks due to the alignment for
64-bit quantities.
In order to fix these problems, I have implemented a way to
send compat messages to tasks. When sending an event, we send
the non-compat event data together with a compat event data in
skb_shinfo(main_skb)->frag_list. Then, when the event is read
from the socket, the netlink code makes sure to pass out only
the skb that is compatible with the task. This approach was
suggested by David Miller, my original approach required
always sending two skbs but that had various small problems.
To determine whether compat is needed or not, I have used the
MSG_CMSG_COMPAT flag, and adjusted the call path for recv and
recvfrom to include it, even if those calls do not have a cmsg
parameter.
I have not solved one small part of the problem, and I don't
think it is necessary to: if a 32-bit application uses read()
rather than any form of recvmsg() it will still get the wrong
(64-bit) event. However, neither do applications actually do
this, nor would it be a regression.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current function for sending events first allocates the
event stream buffer, and then an skb to copy the event stream
into. This can be done in one go. Also, the current function
leaks kernel data to userspace in a 4 uninitialised bytes,
initialise those explicitly. Finally also add a few useful
comments, as opposed to the current comments.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This makes wireless extensions netns aware. The
tasklet sending the events is converted to a work
struct so that we can rtnl_lock() in it.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is never changed by the function, so can be marked const.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently, wext drivers cannot return NULL for stats even though
that would make the ioctl return -EOPNOTSUPP because that would
mean they are no longer listed in /proc/net/wireless. This patch
changes the wext core's behaviour to list them if they have any
wireless_handlers, but only show their stats when available, so
that drivers can start returning NULL if stats are currently not
available, reducing confusion for e.g. IBSS.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The requirement for wireless stats to be atomic is now mostly
artificial since we hold the rtnl _and_ the dev_base_lock for
iterating the device list. Doing that is not required, just the
rtnl is sufficient (and the rtnl is required for other reasons
outlined in commit "wext: fix get_wireless_stats locking").
This will fix http://bugzilla.kernel.org/show_bug.cgi?id=13344
and make things easier for drivers.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Another design flaw in wireless extensions (is anybody
surprised?) in the way it handles the iw_encode_ext
structure: The structure is part of the 'extra' memory
but contains the key length explicitly, instead of it
just being the length of the extra buffer - size of
the struct and using the explicit key length only for
the get operation (which only writes it).
Therefore, we have this layout:
extra: +-------------------------+
| struct iw_encode_ext { |
| ... |
| u16 key_len; |
| u8 key[0]; |
| }; |
+-------------------------+
| key material |
+-------------------------+
Now, all drivers I checked use ext->key_len without
checking that both key_len and the struct fit into the
extra buffer that has been copied from userspace. This
leads to a buffer overrun while reading that buffer,
depending on the driver it may be possible to specify
arbitrary key_len or it may need to be a proper length
for the key algorithm specified.
Thankfully, this is only exploitable by root, but root
can actually cause a segfault or use kernel memory as
a key (which you can even get back with siocgiwencode
or siocgiwencodeext from the key buffer).
Fix this by verifying that key_len fits into the buffer
along with struct iw_encode_ext.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Even though they are true, they cause sparse to complain
because it doesn't see the __acquires(dev_base_lock) on
dev_seq_start() because it is only added to the function
in net/core/dev.c, not the header file. To keep track of
the nesting correctly we should probably annotate those
functions publically, but for now let's just remove the
annotation I added to wext.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Currently, get_wireless_stats is racy by _design_. This is
because it returns a buffer, which needs to be statically
allocated since it cannot be freed if it was allocated
dynamically. Also, SIOCGIWSTATS and /proc/net/wireless use
no common lock, and /proc/net/wireless accesses are not
synchronised against each other. This is a design flaw in
get_wireless_stats since the beginning.
This patch fixes it by wrapping /proc/net/wireless accesses
with the RTNL so they are protected against each other and
SIOCGIWSTATS. The more correct method of fixing this would
be to pass in the buffer instead of returning it and have
the caller take care of synchronisation of the buffer, but
even then most drivers probably assume that their callback
is protected by the RTNL like all other wext callbacks.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fix incorrect use of loose in wext.c
It should be 'lose', not 'loose'.
Signed-off-by: Nick Andrew <nick@nick-andrew.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the minimal the wireless extensions oughta send at least
the name in addition to the ifindex.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without CONFIG_NET_NS, namespace is always &init_net.
Compiler will be able to omit namespace comparisons with this patch.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Next we can kill the hacks in fs/compat_ioctl.c and also
dispatch compat ioctls down into the driver and 80211 protocol
helper layers in order to handle iw_point objects embedded in
stream replies which need to be translated.
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce per-net_device inlines: dev_net(), dev_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
As event_type_pk_size[] is not used, Remove it.
Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
After this patch none of the netlink callback support anything
except the initial network namespace but the rtnetlink infrastructure
now handles multiple network namespaces.
Changes from v2:
- IPv6 addrlabel processing
Changes from v1:
- no need for special rtnl_unlock handling
- fixed IPv6 ndisc
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On 64-bit systems sizeof(struct ifreq) is 8 bytes larger than
sizeof(struct iwreq).
For GET calls, the wireless extension code copies back into userspace
using sizeof(struct ifreq) but userspace and elsewhere only allocates
a "struct iwreq". Thus, this copy writes past the end of the iwreq
object and corrupts whatever sits after it in memory.
Fix the copy_to_user() length.
This particularly hurts the compat case because the wireless compat
code uses compat_alloc_userspace() and right after this allocated
buffer is the current bottom of the user stack, and that's what gets
overwritten by the copy_to_user() call.
Signed-off-by: David S. Miller <davem@davemloft.net>
The problem: proc_net files remember which network namespace the are
against but do not remember hold a reference count (as that would pin
the network namespace). So we currently have a small window where
the reference count on a network namespace may be incremented when opening
a /proc file when it has already gone to zero.
To fix this introduce maybe_get_net and get_proc_net.
maybe_get_net increments the network namespace reference count only if it is
greater then zero, ensuring we don't increment a reference count after it
has gone to zero.
get_proc_net handles all of the magic to go from a proc inode to the network
namespace instance and call maybe_get_net on it.
PROC_NET the old accessor is removed so that we don't get confused and use
the wrong helper function.
Then I fix up the callers to use get_proc_net and handle the case case
where get_proc_net returns NULL. In that case I return -ENXIO because
effectively the network namespace has already gone away so the files
we are trying to access don't exist anymore.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes most of the generic device layer network
namespace safe. This patch makes dev_base_head a
network namespace variable, and then it picks up
a few associated variables. The functions:
dev_getbyhwaddr
dev_getfirsthwbytype
dev_get_by_flags
dev_get_by_name
__dev_get_by_name
dev_get_by_index
__dev_get_by_index
dev_ioctl
dev_ethtool
dev_load
wireless_process_ioctl
were modified to take a network namespace argument, and
deal with it.
vlan_ioctl_set and brioctl_set were modified so their
hooks will receive a network namespace argument.
So basically anthing in the core of the network stack that was
affected to by the change of dev_base was modified to handle
multiple network namespaces. The rest of the network stack was
simply modified to explicitly use &init_net the initial network
namespace. This can be fixed when those components of the network
stack are modified to handle multiple network namespaces.
For now the ifindex generator is left global.
Fundametally ifindex numbers are per namespace, or else
we will have corner case problems with migration when
we get that far.
At the same time there are assumptions in the network stack
that the ifindex of a network device won't change. Making
the ifindex number global seems a good compromise until
the network stack can cope with ifindex changes when
you change namespaces, and the like.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes /proc/net per network namespace. It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.
Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Makes use of the type safe netlink interface and adds a warning
if the message is too big for NLMSG_DEFAULT_SIZE to help debug.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Just a few things that didn't fit in with the other patches.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes a bunch of inline abuse from wext. Most functions
that were marked inline are only used once so the compiler will inline
them anyway, others are used multiple times but there's no requirement
for them to be inline since they aren't in any fast paths.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
EXPORT_SYMBOL statements are supposed to go together with the symbol
they're exporting. This patch moves them accordingly.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes the code in wireless_process_ioctl somewhat more
readable.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch kills the two options in wext that are required to be
enabled anyway because they influence the userspace API.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch kills a whole bunch of code that can only ever be used by
defining some things in wext.c. Also, the things that are printed are
mostly useless since the API is fairly well-tested.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch cleans up the call paths from the core code into wext.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch moves dev/core/wireless.c to net/wireless/wext.c.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
