linux-stable.git/net/ipv6/ndisc.c, branch linux-3.4.y

ipv6: don't call fib6_run_gc() until routing is ready

2016-10-26T15:15:43+00:00

commit 2c861cc65ef4604011a0082e4dcdba2819aa191a upstream.

When loading the ipv6 module, ndisc_init() is called before
ip6_route_init(). As the former registers a handler calling
fib6_run_gc(), this opens a window to run the garbage collector
before necessary data structures are initialized. If a network
device is initialized in this window, adding MAC address to it
triggers a NETDEV_CHANGEADDR event, leading to a crash in
fib6_clean_all().

Take the event handler registration out of ndisc_init() into a
separate function ndisc_late_init() and move it after
ip6_route_init().

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller 
Signed-off-by: Zefan Li

ipv6: prevent fib6_run_gc() contention

2016-03-21T01:17:57+00:00

commit 2ac3ac8f86f2fe065d746d9a9abaca867adec577 upstream.

On a high-traffic router with many processors and many IPv6 dst
entries, soft lockup in fib6_run_gc() can occur when number of
entries reaches gc_thresh.

This happens because fib6_run_gc() uses fib6_gc_lock to allow
only one thread to run the garbage collector but ip6_dst_gc()
doesn't update net->ipv6.ip6_rt_last_gc until fib6_run_gc()
returns. On a system with many entries, this can take some time
so that in the meantime, other threads pass the tests in
ip6_dst_gc() (ip6_rt_last_gc is still not updated) and wait for
the lock. They then have to run the garbage collector one after
another which blocks them for quite long.

Resolve this by replacing special value ~0UL of expire parameter
to fib6_run_gc() by explicit "force" parameter to choose between
spin_lock_bh() and spin_trylock_bh() and call fib6_run_gc() with
force=false if gc_thresh is reached but not max_size.

Signed-off-by: Michal Kubecek 
Signed-off-by: David S. Miller 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

ipv6: Don't depend on per socket memory for neighbour discovery messages

2013-09-14T13:02:10+00:00

[ Upstream commit 25a6e6b84fba601eff7c28d30da8ad7cfbef0d43 ]

Allocating skbs when sending out neighbour discovery messages
currently uses sock_alloc_send_skb() based on a per net namespace
socket and thus share a socket wmem buffer space.

If a netdevice is temporarily unable to transmit due to carrier
loss or for other reasons, the queued up ndisc messages will cosnume
all of the wmem space and will thus prevent from any more skbs to
be allocated even for netdevices that are able to transmit packets.

The number of neighbour discovery messages sent is very limited,
use of alloc_skb() bypasses the socket wmem buffer size enforcement
while the manual call to skb_set_owner_w() maintains the socket
reference needed for the IPv6 output path.

This patch has orginally been posted by Eric Dumazet in a modified
form.

Signed-off-by: Thomas Graf 
Cc: Eric Dumazet 
Cc: Hannes Frederic Sowa 
Cc: Stephen Warren 
Cc: Fabio Estevam 
Tested-by: Fabio Estevam 
Tested-by: Stephen Warren 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: send unsolicited neighbour advertisements to all-nodes

2012-11-17T21:16:21+00:00

[ Upstream commit 60713a0ca7fd6651b951cc1b4dbd528d1fc0281b ]

As documented in RFC4861 (Neighbor Discovery for IP version 6) 7.2.6.,
unsolicited neighbour advertisements should be sent to the all-nodes
multicast address.

Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix problem with expired dst cache

2012-04-13T16:58:29+00:00

If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet.
this dst cache will not check expire because it has no RTF_EXPIRES flag.
So this dst cache will always be used until the dst gc run.

Change the struct dst_entry,add a union contains new pointer from and expires.
When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use.
we can use this field to point to where the dst cache copy from.
The dst.from is only used in IPV6.

rt6_check_expired check if rt6_info.dst.from is expired.

ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.

ip6_dst_destroy release the ort.

Add some functions to operate the RTF_EXPIRES flag and expires(from) together.
and change the code to use these new adding functions.

Changes from v5:
modify ip6_route_add and ndisc_router_discovery to use new adding functions.

Only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.

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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2012-02-27T02:55:51+00:00

Conflicts:
	drivers/net/ethernet/sfc/rx.c

Overlapping changes in drivers/net/ethernet/sfc/rx.c, one to change
the rx_buf->is_page boolean into a set of u16 flags, and another to
adjust how ->ip_summed is initialized.

Signed-off-by: David S. Miller

ipv6: ip6_route_output() never returns NULL.

2012-02-22T20:30:14+00:00

ip6_route_output() never returns NULL, so it is wrong to
check if the return value is NULL.

Signed-off-by: RongQing.Li 
Signed-off-by: David S. Miller

ipv6: Remove neigh argument from ndisc_send_redirect()

2012-01-28T02:00:08+00:00

Instead, compute it as-needed inside of that function using
dst_neigh_lookup().

Signed-off-by: David S. Miller

ipv6: ndisc: Convert to dst_neigh_lookup()

2012-01-28T02:00:08+00:00

Now all code paths grab a local reference to the neigh, so if neigh
is not NULL we unconditionally release it at the end.  The old logic
would only release if we didn't have a non-NULL 'rt'.

Signed-off-by: David S. Miller

ipv6: Check RA for sllao when configuring optimistic ipv6 address (v2)

2012-01-04T20:53:20+00:00

Recently Dave noticed that a test we did in ipv6_add_addr to see if we next hop
route for the interface we're adding an addres to was wrong (see commit
7ffbcecbeed91e5874e9a1cfc4c0cbb07dac3069).  for one, it never triggers, and two,
it was completely wrong to begin with.  This test was meant to cover this
section of RFC 4429:

3.3 Modifications to RFC 2462 Stateless Address Autoconfiguration

   * (modifies section 5.5) A host MAY choose to configure a new address
        as an Optimistic Address.  A host that does not know the SLLAO
        of its router SHOULD NOT configure a new address as Optimistic.
        A router SHOULD NOT configure an Optimistic Address.

This patch should bring us into proper compliance with the above clause.  Since
we only add a SLAAC address after we've received a RA which may or may not
contain a source link layer address option, we can pass a pointer to that option
to addrconf_prefix_rcv (which may be null if the option is not present), and
only set the optimistic flag if the option was found in the RA.

Change notes:
(v2) modified the new parameter to addrconf_prefix_rcv to be a bool rather than
a pointer to make its use more clear as per request from davem.

Signed-off-by: Neil Horman 
CC: "David S. Miller" 
CC: Hideaki YOSHIFUJI 
Signed-off-by: David S. Miller