Commit Graph

231 Commits

Author SHA1 Message Date
Duan Jiong
be7a010d6f ipv6: update Destination Cache entries when gateway turn into host
RFC 4861 states in 7.2.5:

	The IsRouter flag in the cache entry MUST be set based on the
         Router flag in the received advertisement.  In those cases
         where the IsRouter flag changes from TRUE to FALSE as a result
         of this update, the node MUST remove that router from the
         Default Router List and update the Destination Cache entries
         for all destinations using that neighbor as a router as
         specified in Section 7.3.3.  This is needed to detect when a
         node that is used as a router stops forwarding packets due to
         being configured as a host.

Currently, when dealing with NA Message which IsRouter flag changes from
TRUE to FALSE, the kernel only removes router from the Default Router List,
and don't update the Destination Cache entries.

Now in order to update those Destination Cache entries, i introduce
function rt6_clean_tohost().

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-15 23:26:27 -04:00
Jiri Pirko
73af614aed neigh: use tbl->family to distinguish ipv4 from ipv6
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09 20:56:12 -05:00
Jiri Pirko
cb5b09c17f neigh: wrap proc dointvec functions
This will be needed later on to provide better management of default values.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09 20:56:12 -05:00
Jiri Pirko
1f9248e560 neigh: convert parms to an array
This patch converts the neigh param members to an array. This allows easier
manipulation which will be needed later on to provide better management of
default values.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-09 20:56:12 -05:00
Duan Jiong
30e56918dd ipv6: judge the accept_ra_defrtr before calling rt6_route_rcv
when dealing with a RA message, if accept_ra_defrtr is false,
the kernel will not add the default route, and then deal with
the following route information options. Unfortunately, those
options maybe contain default route, so let's judge the
accept_ra_defrtr before calling rt6_route_rcv.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-02 16:00:38 -05:00
Fabio Estevam
bcd081a3ae net: ipv6: ndisc: Fix warning when CONFIG_SYSCTL=n
When CONFIG_SYSCTL=n the following build warning happens:

net/ipv6/ndisc.c:1730:1: warning: label 'out' defined but not used [-Wunused-label]

The 'out' label is only used when CONFIG_SYSCTL=y, so move it inside the
'ifdef CONFIG_SYSCTL' block.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-18 14:49:16 -05:00
Michal Kubeček
2c861cc65e ipv6: don't call fib6_run_gc() until routing is ready
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 <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-11 17:04:09 -04:00
David S. Miller
06c54055be Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
	net/bridge/br_multicast.c
	net/ipv6/sit.c

The conflicts were minor:

1) sit.c changes overlap with change to ip_tunnel_xmit() signature.

2) br_multicast.c had an overlap between computing max_delay using
   msecs_to_jiffies and turning MLDV2_MRC() into an inline function
   with a name using lowercase instead of uppercase letters.

3) stmmac had two overlapping changes, one which conditionally allocated
   and hooked up a dma_cfg based upon the presence of the pbl OF property,
   and another one handling store-and-forward DMA made.  The latter of
   which should not go into the new of_find_property() basic block.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05 14:58:52 -04:00
Duan Jiong
b55b76b221 ipv6:introduce function to find route for redirect
RFC 4861 says that the IP source address of the Redirect is the
same as the current first-hop router for the specified ICMP
Destination Address, so the gateway should be taken into
consideration when we find the route for redirect.

There was once a check in commit
a6279458c5 ("NDISC: Search over
all possible rules on receipt of redirect.") and the check
went away in commit b94f1c0904
("ipv6: Use icmpv6_notify() to propagate redirect, instead of
rt6_redirect()").

The bug is only "exploitable" on layer-2 because the source
address of the redirect is checked to be a valid link-local
address but it makes spoofing a lot easier in the same L2
domain nonetheless.

Thanks very much for Hannes's help.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05 12:44:31 -04:00
Thomas Graf
25a6e6b84f ipv6: Don't depend on per socket memory for neighbour discovery messages
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 <tgraf@suug.ch>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Fabio Estevam <festevam@gmail.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-04 14:37:41 -04:00
Tim Gardner
3e25c65ed0 net: neighbour: Remove CONFIG_ARPD
This config option is superfluous in that it only guards a call
to neigh_app_ns(). Enabling CONFIG_ARPD by default has no
change in behavior. There will now be call to __neigh_notify()
for each ARP resolution, which has no impact unless there is a
user space daemon waiting to receive the notification, i.e.,
the case for which CONFIG_ARPD was designed anyways.

Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Cc: Joe Perches <joe@perches.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-03 21:41:43 -04:00
Cong Wang
f564f45c45 vxlan: add ipv6 proxy support
This patch adds the IPv6 version of "arp_reduce", ndisc_send_na()
will be needed.

Cc: David S. Miller <davem@davemloft.net>
Cc: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31 22:30:01 -04:00
Thomas Graf
816c5b5b01 ipv6: Remove redundant sk variable
A sk variable initialized to ndisc_sk is already available outside
of the branch.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-30 17:18:59 -04:00
Hannes Frederic Sowa
b800c3b966 ipv6: drop fragmented ndisc packets by default (RFC 6980)
This patch implements RFC6980: Drop fragmented ndisc packets by
default. If a fragmented ndisc packet is received the user is informed
that it is possible to disable the check.

Cc: Fernando Gont <fernando@gont.com.ar>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29 15:32:08 -04:00
Duan Jiong
c92a59eca8 ipv6: handle Redirect ICMP Message with no Redirected Header option
rfc 4861 says the Redirected Header option is optional, so
the kernel should not drop the Redirect Message that has no
Redirected Header option. In this patch, the function
ip6_redirect_no_header() is introduced to deal with that
condition.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
2013-08-22 20:08:21 -07:00
Michal Kubeček
2ac3ac8f86 ipv6: prevent fib6_run_gc() contention
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 <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-01 14:16:20 -07:00
Daniel Baluta
f2f79cca13 ndisc: bool initializations should use true and false
Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-16 12:13:31 -07:00
David S. Miller
d98cae64e4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/wireless/ath/ath9k/Kconfig
	drivers/net/xen-netback/netback.c
	net/batman-adv/bat_iv_ogm.c
	net/wireless/nl80211.c

The ath9k Kconfig conflict was a change of a Kconfig option name right
next to the deletion of another option.

The xen-netback conflict was overlapping changes involving the
handling of the notify list in xen_netbk_rx_action().

Batman conflict resolution provided by Antonio Quartulli, basically
keep everything in both conflict hunks.

The nl80211 conflict is a little more involved.  In 'net' we added a
dynamic memory allocation to nl80211_dump_wiphy() to fix a race that
Linus reported.  Meanwhile in 'net-next' the handlers were converted
to use pre and post doit handlers which use a flag to determine
whether to hold the RTNL mutex around the operation.

However, the dump handlers to not use this logic.  Instead they have
to explicitly do the locking.  There were apparent bugs in the
conversion of nl80211_dump_wiphy() in that we were not dropping the
RTNL mutex in all the return paths, and it seems we very much should
be doing so.  So I fixed that whilst handling the overlapping changes.

To simplify the initial returns, I take the RTNL mutex after we try
to allocate 'tb'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-19 16:49:39 -07:00
Matthias Schiffer
33be081a81 ipv6: ndisc: fix ndisc_send_redirect writing to the wrong skb
Since some refactoring in 5f5a011, ndisc_send_redirect called
ndisc_fill_redirect_hdr_option on the wrong skb, leading to data corruption or
in the worst case a panic when the skb_put failed.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-17 22:59:12 -07:00
Simon Horman
29a3cad5c6 ipv6: Correct comparisons and calculations using skb->tail and skb-transport_header
This corrects an regression introduced by "net: Use 16bits for *_headers
fields of struct skbuff" when NET_SKBUFF_DATA_USES_OFFSET is not set. In
that case skb->tail will be a pointer whereas skb->transport_header
will be an offset from head. This is corrected by using wrappers that
ensure that comparisons and calculations are always made using pointers.

Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-28 23:49:07 -07:00
Jiri Pirko
351638e7de net: pass info struct via netdevice notifier
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>

v2->v3: fix typo on simeth
	shortened dev_getter
	shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-28 13:11:01 -07:00
Thomas Graf
80580d4b20 ipv6: ndisc: remove redundant check for !dev->addr_len
send_sllao is already initialized with the value of dev->addr_len

Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-08 12:29:22 -05:00
YOSHIFUJI Hideaki / 吉藤英明
4d5c152e86 ndisc: Use compound literals to build redirect message.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:18 -05:00
YOSHIFUJI Hideaki / 吉藤英明
1cb3fe513f ndisc: Break down ndisc_build_skb() and build message directly.
Construct NS/NA/RS message directly using C99 compound literals.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:18 -05:00
YOSHIFUJI Hideaki / 吉藤英明
b44b5f4ae9 ndisc: Break down __ndisc_send().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:17 -05:00
YOSHIFUJI Hideaki / 吉藤英明
7b3d9b06d8 ndisc: Fill in ICMPv6 checksum and IPv6 header in ndisc_send_skb().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:17 -05:00
YOSHIFUJI Hideaki / 吉藤英明
f4de84c64e ndisc: Use ndisc_send_skb() for redirect.
Reuse dst if one is attached with skb.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:17 -05:00
YOSHIFUJI Hideaki / 吉藤英明
aa4bdd4b3f ndisc: Remove icmp6h argument from ndisc_send_skb().
skb_transport_header() (thus icmp6_hdr()) is available here,
use it.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:17 -05:00
YOSHIFUJI Hideaki / 吉藤英明
5f5a011563 ndisc: Make ndisc_fill_xxx_option() for sk_buff.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:16 -05:00
YOSHIFUJI Hideaki / 吉藤英明
2ce1357614 ndisc: Calculate message body length and option length separately.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:16 -05:00
YOSHIFUJI Hideaki / 吉藤英明
5135e633f9 ndisc: Reset skb->trasport_headner inside ndisc_alloc_send_skb().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:16 -05:00
YOSHIFUJI Hideaki / 吉藤英明
527a150fb2 ndisc: Defer building IPv6 header.
Build ICMPv6 message first and make buffer management easier;
we can use skb->len when filling checksum in ICMPv6 header,
and then build IP header with length field.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:16 -05:00
YOSHIFUJI Hideaki / 吉藤英明
af9a997629 ndisc: Remove dev argument for ndisc_send_skb().
Since we have skb->dev, use it.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:15 -05:00
YOSHIFUJI Hideaki / 吉藤英明
f382d03ad0 ndisc: Set skb->dev and skb->protocol inside ndisc_alloc_skb().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:15 -05:00
YOSHIFUJI Hideaki / 吉藤英明
c8d6c380d9 ndisc: Simplify arguments for ip6_nd_hdr().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:15 -05:00
YOSHIFUJI Hideaki / 吉藤英明
2576f17dfa ipv6: Unshare ip6_nd_hdr() and change return type to void.
- move ip6_nd_hdr() to its users' source files.
  In net/ipv6/mcast.c, it will be called ip6_mc_hdr().
- make return type to void since this function never fails.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:15 -05:00
YOSHIFUJI Hideaki / 吉藤英明
de09334b93 ndisc: Introduce ndisc_alloc_skb() helper.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:15 -05:00
YOSHIFUJI Hideaki / 吉藤英明
9c86dafe94 ndisc: Introduce ndisc_fill_redirect_hdr_option().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:14 -05:00
YOSHIFUJI Hideaki / 吉藤英明
6bce6b4e16 ndisc: Use skb_linearize() instead of pskb_may_pull(skb, skb->len).
Suggested by Eric Dumazet <edumazet@google.com>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:14 -05:00
YOSHIFUJI Hideaki / 吉藤英明
c558e9fca8 ndisc: Move ndisc_opt_addr_space() to include/net/ndisc.h.
This also makes ndisc_opt_addr_data() and ndisc_fill_addr_option()
use ndisc_opt_addr_space().

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:14 -05:00
YOSHIFUJI Hideaki / 吉藤英明
315ff09dba ndisc: Reduce number of arguments for ndisc_fill_addr_option().
Add pointer to struct net_device (dev) and remove
data_len (= dev->addr_len) and addr_type (= dev->type).

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-21 13:33:14 -05:00
YOSHIFUJI Hideaki / 吉藤英明
fb568637e5 ndisc: Make several arguments for ndisc_send_na() boolean.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-20 22:29:49 -05:00
YOSHIFUJI Hideaki / 吉藤英明
ca97a644d7 ipv6: Introduce ipv6_addr_is_solict_mult() to check Solicited Node Multicast Addresses.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-20 22:29:49 -05:00
YOSHIFUJI Hideaki / 吉藤英明
115b0aa6b4 ndisc: Check NS message length before access.
Check message length before accessing "target" field,
as we do for other types.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-18 14:41:13 -05:00
YOSHIFUJI Hideaki / 吉藤英明
12fd84f438 ipv6: Remove unused neigh argument for icmp6_dst_alloc() and its callers.
Because of rt->n removal, we do not need neigh argument any more.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-18 14:41:13 -05:00
YOSHIFUJI Hideaki / 吉藤英明
71bcdba06d ndisc: Use struct rd_msg for redirect message.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-06 21:08:38 -08:00
YOSHIFUJI Hideaki / 吉藤英明
b7dc8c3959 ndisc: Remove unused space at tail of skb for ndisc messages. (TAKE 3)
Currently, the size of skb allocated for NDISC is MAX_HEADER +
LL_RESERVED_SPACE(dev) + packet length + dev->needed_tailroom,
but only LL_RESERVED_SPACE(dev) bytes is "reserved" for headers.
As a result, the skb looks like this (after construction of the
message):

head       data                   tail                       end
+--------------------------------------------------------------+
+           |                      |          |                |
+--------------------------------------------------------------+
|<-hlen---->|<---ipv6 packet------>|<--tlen-->|<--MAX_HEADER-->|
    =LL_                               = dev
     RESERVED_                           ->needed_
     SPACE(dev)                            tailroom

As the name implies, "MAX_HEADER" is used for headers, and should
be "reserved" in prior to packet construction.  Or, if some space
is really required at the tail of ther skb, it should be
explicitly documented.

We have several option after construction of NDISC message:

Option 1:

head       data                   tail       end
+---------------------------------------------+
+           |                      |          |
+---------------------------------------------+
|<-hlen---->|<---ipv6 packet------>|<--tlen-->|
   =LL_                                = dev
    RESERVED_                           ->needed_
    SPACE(dev)                            tailroom

Option 2:

head            data                   tail       end
+--------------------------------------------------+
+                |                      |          |
+--------------------------------------------------+
|<--MAX_HEADER-->|<---ipv6 packet------>|<--tlen-->|
                                            = dev
                                             ->needed_
                                               tailroom

Option 3:

head                        data                   tail       end
+--------------------------------------------------------------+
+                |           |                      |          |
+--------------------------------------------------------------+
|<--MAX_HEADER-->|<-hlen---->|<---ipv6 packet------>|<--tlen-->|
                    =LL_                                = dev
                     RESERVED_                          ->needed_
                     SPACE(dev)                           tailroom

Our tunnel drivers try expanding headroom and the space for tunnel
encapsulation was not a mandatory space -- so we are not seeing
bugs here --, but just for optimization for performance critial
situations.

Since NDISC messages are not performance critical unlike TCP,
and as we know outgoing device, LL_RESERVED_SPACE(dev) should be
just enough for the device in most (if not all) cases:
  LL_RESERVED_SPACE(dev) <= LL_MAX_HEADER <= MAX_HEADER
Note that LL_RESERVED_SPACE(dev) is also enough for NDISC over
SIT (e.g., ISATAP).

So, I think Option 1 is just fine here.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-04 15:16:44 -08:00
Duan Jiong
093d04d42f ipv6: Change skb->data before using icmpv6_notify() to propagate redirect
In function ndisc_redirect_rcv(), the skb->data points to the transport
header, but function icmpv6_notify() need the skb->data points to the
inner IP packet. So before using icmpv6_notify() to propagate redirect,
change skb->data to point the inner IP packet that triggered the sending
of the Redirect, and introduce struct rd_msg to make it easy.

Signed-off-by: Duan Jiong <djduanjiong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-14 13:14:07 -05:00
YOSHIFUJI Hideaki / 吉藤英明
7bdc1b4aba ndisc: Fix padding error in link-layer address option.
If a natural number n exists where 2 + data_len <= 8n < 2 + data_len + pad,
post padding is not initialized correctly.

(Un)fortunately, the only type that requires pad is Infiniband,
whose pad is 2 and data_len is 20, and this logical error has not
become obvious, but it is better to fix.

Note that ndisc_opt_addr_space() handles the situation described
above correctly.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-13 12:58:11 -05:00
YOSHIFUJI Hideaki
fd0ea7dbfa ndisc: Unexport ndisc_{build,send}_skb().
These symbols were exported for bonding device by commit 305d552a
("bonding: send IPv6 neighbor advertisement on failover").

It bacame obsolete by commit 7c899432 ("bonding, ipv4, ipv6, vlan: Handle
NETDEV_BONDING_FAILOVER like NETDEV_NOTIFY_PEERS") and removed by
commit 4f5762ec ("bonding: Remove obsolete source file 'bond_ipv6.c'").

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-12-12 12:42:29 -05:00