linux-stable.git/net/ipv6, branch v3.5.6

ipv6: addrconf: Avoid calling netdevice notifiers with RCU read-side lock

2012-10-02T17:38:40+00:00

[ Upstream commit 4acd4945cd1e1f92b20d14e349c6c6a52acbd42d ]

Cong Wang reports that lockdep detected suspicious RCU usage while
enabling IPV6 forwarding:

 [ 1123.310275] ===============================
 [ 1123.442202] [ INFO: suspicious RCU usage. ]
 [ 1123.558207] 3.6.0-rc1+ #109 Not tainted
 [ 1123.665204] -------------------------------
 [ 1123.768254] include/linux/rcupdate.h:430 Illegal context switch in RCU read-side critical section!
 [ 1123.992320]
 [ 1123.992320] other info that might help us debug this:
 [ 1123.992320]
 [ 1124.307382]
 [ 1124.307382] rcu_scheduler_active = 1, debug_locks = 0
 [ 1124.522220] 2 locks held by sysctl/5710:
 [ 1124.648364]  #0:  (rtnl_mutex){+.+.+.}, at: [] rtnl_trylock+0x15/0x17
 [ 1124.882211]  #1:  (rcu_read_lock){.+.+.+}, at: [] rcu_lock_acquire+0x0/0x29
 [ 1125.085209]
 [ 1125.085209] stack backtrace:
 [ 1125.332213] Pid: 5710, comm: sysctl Not tainted 3.6.0-rc1+ #109
 [ 1125.441291] Call Trace:
 [ 1125.545281]  [] lockdep_rcu_suspicious+0x109/0x112
 [ 1125.667212]  [] rcu_preempt_sleep_check+0x45/0x47
 [ 1125.781838]  [] __might_sleep+0x1e/0x19b
[...]
 [ 1127.445223]  [] call_netdevice_notifiers+0x4a/0x4f
[...]
 [ 1127.772188]  [] dev_disable_lro+0x32/0x6b
 [ 1127.885174]  [] dev_forward_change+0x30/0xcb
 [ 1128.013214]  [] addrconf_forward_change+0x85/0xc5
[...]

addrconf_forward_change() uses RCU iteration over the netdev list,
which is unnecessary since it already holds the RTNL lock.  We also
cannot reasonably require netdevice notifier functions not to sleep.

Reported-by: Cong Wang 
Signed-off-by: Ben Hutchings 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: heed result of security_inet_conn_request() in tcp_v6_conn_request()

2012-06-25T23:05:19+00:00

If security_inet_conn_request() returns non-zero then TCP/IPv6 should
drop the request, just as in TCP/IPv4 and DCCP in both IPv4 and IPv6.

Signed-off-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv6: fib: fix fib dump restart

2012-06-25T22:37:19+00:00

Commit 2bec5a369ee79576a3 (ipv6: fib: fix crash when changing large fib
while dumping it) introduced ability to restart the dump at tree root,
but failed to skip correctly a count of already dumped entries. Code
didn't match Patrick intent.

We must skip exactly the number of already dumped entries.

Note that like other /proc/net files or netlink producers, we could
still dump some duplicates entries.

Reported-by: Debabrata Banerjee 
Reported-by: Josh Hunt 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv6: Move ipv6 proc file registration to end of init order

2012-06-19T01:38:50+00:00

/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.

This opens up a short time frame to access fib_table_hash with its pants
down.

Move the registration of the proc files to a later point in the init
order to avoid the race.

Tested :-)

Signed-off-by: Thomas Graf 
Signed-off-by: David S. Miller

Revert "ipv6: Prevent access to uninitialized fib_table_hash via /proc/net/ipv6_route"

2012-06-16T08:12:19+00:00

This reverts commit 2a0c451ade8e1783c5d453948289e4a978d417c9.

It causes crashes, because now ip6_null_entry is used before
it is initialized.

Signed-off-by: David S. Miller

ipv6: Prevent access to uninitialized fib_table_hash via /proc/net/ipv6_route

2012-06-15T22:30:15+00:00

/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.

This opens up a short time frame to access fib_table_hash with its pants
down.

fib6_init() as a whole can't be moved to an earlier position as it also
registers the rtnetlink message handlers which should be registered at
the end. Therefore split it into fib6_init() which is run early and
fib6_init_late() to register the rtnetlink message handlers.

Signed-off-by: Thomas Graf 
Reviewed-by: Neil Horman 
Signed-off-by: David S. Miller

snmp: fix OutOctets counter to include forwarded datagrams

2012-06-07T21:50:56+00:00

RFC 4293 defines ipIfStatsOutOctets (similar definition for
ipSystemStatsOutOctets):

   The total number of octets in IP datagrams delivered to the lower
   layers for transmission.  Octets from datagrams counted in
   ipIfStatsOutTransmits MUST be counted here.

And ipIfStatsOutTransmits:

   The total number of IP datagrams that this entity supplied to the
   lower layers for transmission.  This includes datagrams generated
   locally and those forwarded by this entity.

Therefore, IPSTATS_MIB_OUTOCTETS must be incremented when incrementing
IPSTATS_MIB_OUTFORWDATAGRAMS.

IP_UPD_PO_STATS is not used since ipIfStatsOutRequests must not
include forwarded datagrams:

   The total number of IP datagrams that local IP user-protocols
   (including ICMP) supplied to IP in requests for transmission.  Note
   that this counter does not include any datagrams counted in
   ipIfStatsOutForwDatagrams.

Signed-off-by: Vincent Bernat 
Signed-off-by: David S. Miller

ipv6: fib: Restore NTF_ROUTER exception in fib6_age()

2012-06-07T20:02:21+00:00

Commit 5339ab8b1dd82 (ipv6: fib: Convert fib6_age() to
dst_neigh_lookup().) seems to have mistakenly inverted the
exception for cached NTF_ROUTER routes.

Signed-off-by: Thomas Graf 
Signed-off-by: David S. Miller

tcp: reflect SYN queue_mapping into SYNACK packets

2012-06-01T18:22:11+00:00

While testing how linux behaves on SYNFLOOD attack on multiqueue device
(ixgbe), I found that SYNACK messages were dropped at Qdisc level
because we send them all on a single queue.

Obvious choice is to reflect incoming SYN packet @queue_mapping to
SYNACK packet.

Under stress, my machine could only send 25.000 SYNACK per second (for
200.000 incoming SYN per second). NIC : ixgbe with 16 rx/tx queues.

After patch, not a single SYNACK is dropped.

Signed-off-by: Eric Dumazet 
Cc: Hans Schillstrom 
Cc: Jesper Dangaard Brouer 
Cc: Neal Cardwell 
Cc: Tom Herbert 
Signed-off-by: David S. Miller

ipv6: fix incorrect ipsec fragment

2012-05-27T05:11:22+00:00

Since commit ad0081e43a
"ipv6: Fragment locally generated tunnel-mode IPSec6 packets as needed"
the fragment of packets is incorrect.
because tunnel mode needs IPsec headers and trailer for all fragments,
while on transport mode it is sufficient to add the headers to the
first fragment and the trailer to the last.

so modify mtu and maxfraglen base on ipsec mode and if fragment is first
or last.

with my test,it work well(every fragment's size is the mtu)
and does not trigger slow fragment path.

Changes from v1:
	though optimization, mtu_prev and maxfraglen_prev can be delete.
	replace xfrm mode codes with dst_entry's new frag DST_XFRM_TUNNEL.
	add fuction ip6_append_data_mtu to make codes clearer.

Signed-off-by: Gao feng 
Signed-off-by: David S. Miller