linux.git/net/bridge/netfilter, branch v2.6.23

[NETFILTER]: Fix/improve deadlock condition on module removal netfilter

2007-09-11T09:28:26+00:00

So I've had a deadlock reported to me.  I've found that the sequence of
events goes like this:

1) process A (modprobe) runs to remove ip_tables.ko

2) process B (iptables-restore) runs and calls setsockopt on a netfilter socket,
increasing the ip_tables socket_ops use count

3) process A acquires a file lock on the file ip_tables.ko, calls remove_module
in the kernel, which in turn executes the ip_tables module cleanup routine,
which calls nf_unregister_sockopt

4) nf_unregister_sockopt, seeing that the use count is non-zero, puts the
calling process into uninterruptible sleep, expecting the process using the
socket option code to wake it up when it exits the kernel

4) the user of the socket option code (process B) in do_ipt_get_ctl, calls
ipt_find_table_lock, which in this case calls request_module to load
ip_tables_nat.ko

5) request_module forks a copy of modprobe (process C) to load the module and
blocks until modprobe exits.

6) Process C. forked by request_module process the dependencies of
ip_tables_nat.ko, of which ip_tables.ko is one.

7) Process C attempts to lock the request module and all its dependencies, it
blocks when it attempts to lock ip_tables.ko (which was previously locked in
step 3)

Theres not really any great permanent solution to this that I can see, but I've
developed a two part solution that corrects the problem

Part 1) Modifies the nf_sockopt registration code so that, instead of using a
use counter internal to the nf_sockopt_ops structure, we instead use a pointer
to the registering modules owner to do module reference counting when nf_sockopt
calls a modules set/get routine.  This prevents the deadlock by preventing set 4
from happening.

Part 2) Enhances the modprobe utilty so that by default it preforms non-blocking
remove operations (the same way rmmod does), and add an option to explicity
request blocking operation.  So if you select blocking operation in modprobe you
can still cause the above deadlock, but only if you explicity try (and since
root can do any old stupid thing it would like....  :)  ).

Signed-off-by: Neil Horman 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: Clean up duplicate includes in net/bridge/

2007-07-24T22:30:30+00:00

This patch cleans up duplicate includes in
	net/bridge/

Signed-off-by: Jesper Juhl 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: Fix logging regression

2007-07-24T22:29:55+00:00

Loading one of the LOG target fails if a different target has already
registered itself as backend for the same family. This can affect the
ipt_LOG and ipt_ULOG modules when both are loaded.

Reported and tested by: 

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: Lower *tables printk severity

2007-07-15T03:46:15+00:00

Lower ip6tables, arptables and ebtables printk severity similar to
Dan Aloni's patch for iptables.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETLINK]: Switch cb_lock spinlock to mutex and allow to override it

2007-04-26T05:29:03+00:00

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 
Signed-off-by: David S. Miller

[NETFILTER]: {eb,ip6,ip}t_LOG: remove remains of LOG target overloading

2007-04-26T05:29:00+00:00

All LOG targets always use their internal logging function nowadays, so
remove the incorrect error message and handle real errors (!= -EEXIST)
by failing to load.

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: ebt_arp: add gratuitous arp filtering

2007-04-26T05:28:58+00:00

The attached patch adds gratuitous arp filtering, more precisely: it
allows checking that the IPv4 source address matches the IPv4
destination address inside the ARP header. It also adds a check for the
hardware address type when matching MAC addresses (nothing critical,
just for better consistency).

Signed-off-by: Bart De Schuymer 
Acked-by: Carl-Daniel Hailfinger 
Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NETFILTER]: Use setup_timer

2007-04-26T05:27:43+00:00

Signed-off-by: Patrick McHardy 
Signed-off-by: David S. Miller

[NET]: convert network timestamps to ktime_t

2007-04-26T05:23:34+00:00

We currently use a special structure (struct skb_timeval) and plain
'struct timeval' to store packet timestamps in sk_buffs and struct
sock.

This has some drawbacks :
- Fixed resolution of micro second.
- Waste of space on 64bit platforms where sizeof(struct timeval)=16

I suggest using ktime_t that is a nice abstraction of high resolution
time services, currently capable of nanosecond resolution.

As sizeof(ktime_t) is 8 bytes, using ktime_t in 'struct sock' permits
a 8 byte shrink of this structure on 64bit architectures. Some other
structures also benefit from this size reduction (struct ipq in
ipv4/ip_fragment.c, struct frag_queue in ipv6/reassembly.c, ...)

Once this ktime infrastructure adopted, we can more easily provide
nanosecond resolution on top of it. (ioctl SIOCGSTAMPNS and/or
SO_TIMESTAMPNS/SCM_TIMESTAMPNS)

Note : this patch includes a bug correction in
compat_sock_get_timestamp() where a "err = 0;" was missing (so this
syscall returned -ENOENT instead of 0)

Signed-off-by: Eric Dumazet 
CC: Stephen Hemminger 
CC: John find 
Signed-off-by: David S. Miller

[PATCH] Convert highest_possible_processor_id to nr_cpu_ids

2007-02-21T01:10:13+00:00

We frequently need the maximum number of possible processors in order to
allocate arrays for all processors.  So far this was done using
highest_possible_processor_id().  However, we do need the number of
processors not the highest id.  Moreover the number was so far dynamically
calculated on each invokation.  The number of possible processors does not
change when the system is running.  We can therefore calculate that number
once.

Signed-off-by: Christoph Lameter 
Cc: Frederik Deweerdt 
Cc: Neil Brown 
Cc: Trond Myklebust 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds