Commit Graph

141 Commits

Author SHA1 Message Date
Eric Dumazet c70eba7453 igmp: fix new sparse errors
Fix following sparse errors :

net/ipv4/igmp.c:1222:25: warning: cast from restricted __be32
net/ipv4/igmp.c🔢31: warning: incorrect type in assignment (different address spaces)
net/ipv4/igmp.c🔢31:    expected struct ip_mc_list [noderef] <asn:4>*next_hash
net/ipv4/igmp.c🔢31:    got struct ip_mc_list *<noident>
net/ipv4/igmp.c:1250:31: warning: incorrect type in assignment (different address spaces)
net/ipv4/igmp.c:1250:31:    expected struct ip_mc_list [noderef] <asn:4>*next_hash
net/ipv4/igmp.c:1250:31:    got struct ip_mc_list *<noident>
net/ipv4/igmp.c:2380:37: warning: cast from restricted __be32

These were added by commit e989707135
("igmp: hash a hash table to speedup ip_check_mc_rcu()")

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-12 14:14:55 -07:00
Shawn Bohrer 946d3bd723 igmp: remove unnecessary in_device member zeroing
ip_mc_init_dev() is passed a freshly kzalloc'd in_device so it is
unnecessary to explicitly zero out the members.

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-12 00:41:15 -07:00
Eric Dumazet e989707135 igmp: hash a hash table to speedup ip_check_mc_rcu()
After IP route cache removal, multicast applications using
a lot of multicast addresses hit a O(N) behavior in ip_check_mc_rcu()

Add a per in_device hash table to get faster lookup.

This hash table is created only if the number of items in mc_list is
above 4.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-12 00:25:23 -07:00
Simon Horman f7c0c2ae84 ipv4: 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
Gao feng ece31ffd53 net: proc: change proc_net_remove to remove_proc_entry
proc_net_remove is only used to remove proc entries
that under /proc/net,it's not a general function for
removing proc entries of netns. if we want to remove
some proc entries which under /proc/net/stat/, we still
need to call remove_proc_entry.

this patch use remove_proc_entry to replace proc_net_remove.
we can remove proc_net_remove after this patch.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Gao feng d4beaa66ad net: proc: change proc_net_fops_create to proc_create
Right now, some modules such as bonding use proc_create
to create proc entries under /proc/net/, and other modules
such as ipv4 use proc_net_fops_create.

It looks a little chaos.this patch changes all of
proc_net_fops_create to proc_create. we can remove
proc_net_fops_create after this patch.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
stephen hemminger 193ba92452 igmp: export symbol ip_mc_leave_group
Needed for VXLAN.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-01 18:39:44 -04:00
Eric Dumazet d679c5324d igmp: avoid drop_monitor false positives
igmp should call consume_skb() for all correctly processed packets,
to avoid false dropwatch/drop_monitor false positives.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-07 14:17:10 -04:00
Eric Dumazet a399a80531 time: jiffies_delta_to_clock_t() helper to the rescue
Various /proc/net files sometimes report crazy timer values, expressed
in clock_t units.

This happens when an expired timer delta (expires - jiffies) is passed
to jiffies_to_clock_t().

This function has an overflow in :

return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);

commit cbbc719fcc (time: Change jiffies_to_clock_t() argument type
to unsigned long) only got around the problem.

As we cant output negative values in /proc/net/tcp without breaking
various tools, I suggest adding a jiffies_delta_to_clock_t() wrapper
that caps the negative delta to a 0 value.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Maciej Żenczykowski <maze@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: hank <pyu@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-09 16:17:03 -07:00
Daniel Baluta 5e73ea1a31 ipv4: fix checkpatch errors
Fix checkpatch errors of the following type:
	* ERROR: "foo * bar" should be "foo *bar"
	* ERROR: "(foo*)" should be "(foo *)"

Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:37:19 -04:00
David S. Miller 06eb4eafbd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-04-10 14:30:45 -04:00
RongQing.Li ce713ee5a1 net: replace continue with break to reduce unnecessary loop in xxx_xmarksources
The conditional which decides to skip inactive filters does not
change with the change of loop index, so it is unnecessary to
check them many times.

Signed-off-by: RongQing.Li <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-05 05:42:18 -04:00
David Howells 9ffc93f203 Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Eric Dumazet cf778b00e9 net: reintroduce missing rcu_assign_pointer() calls
commit a9b3cd7f32 (rcu: convert uses of rcu_assign_pointer(x, NULL) to
RCU_INIT_POINTER) did a lot of incorrect changes, since it did a
complete conversion of rcu_assign_pointer(x, y) to RCU_INIT_POINTER(x,
y).

We miss needed barriers, even on x86, when y is not NULL.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-12 12:26:56 -08:00
Ben Hutchings a8c1f65c79 igmp: Avoid zero delay when receiving odd mixture of IGMP queries
Commit 5b7c840667 ('ipv4: correct IGMP
behavior on v3 query during v2-compatibility mode') added yet another
case for query parsing, which can result in max_delay = 0.  Substitute
a value of 1, as in the usual v3 case.

Reported-by: Simon McVittie <smcv@debian.org>
References: http://bugs.debian.org/654876
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-09 14:06:46 -08:00
Jun Zhao 5eb81e8916 ipv4 : igmp : Delete useless parameter in ip_mc_add1_src()
Need not to used 'delta' flag when add single-source to interface
filter source list.

Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Signed-off-by: David S. Miller <davem@drr.davemloft.net>
2011-11-30 23:10:01 -05:00
David S. Miller 6dec4ac4ee Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv4/inet_diag.c
2011-11-26 14:47:03 -05:00
Jun Zhao 685f94e6db ipv4 : igmp : fix error handle in ip_mc_add_src()
When add sources to interface failure, need to roll back the sfcount[MODE]
to before state. We need to match it corresponding.

Acked-by: David L Stevens <dlstevens@us.ibm.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jun Zhao <mypopydev@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-23 17:31:39 -05:00
Herbert Xu 6608824329 ipv4: Remove all uses of LL_ALLOCATED_SPACE
ipv4: Remove all uses of LL_ALLOCATED_SPACE

The macro LL_ALLOCATED_SPACE was ill-conceived.  It applies the
alignment to the sum of needed_headroom and needed_tailroom.  As
the amount that is then reserved for head room is needed_headroom
with alignment, this means that the tail room left may be too small.

This patch replaces all uses of LL_ALLOCATED_SPACE in net/ipv4
with the macro LL_RESERVED_SPACE and direct reference to
needed_tailroom.

This also fixes the problem with needed_headroom changing between
allocating the skb and reserving the head room.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-18 14:37:08 -05:00
David S. Miller 8decf86879 Merge branch 'master' of github.com:davem330/net
Conflicts:
	MAINTAINERS
	drivers/net/Kconfig
	drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c
	drivers/net/ethernet/broadcom/tg3.c
	drivers/net/wireless/iwlwifi/iwl-pci.c
	drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c
	drivers/net/wireless/rt2x00/rt2800usb.c
	drivers/net/wireless/wl12xx/main.c
2011-09-22 03:23:13 -04:00
Yan, Zheng e05c4ad3ed mcast: Fix source address selection for multicast listener report
Should check use count of include mode filter instead of total number
of include mode filters.

Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-24 17:46:15 -07:00
Jiri Pirko b81693d914 net: remove ndo_set_multicast_list callback
Remove no longer used operation.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-17 20:22:03 -07:00
David S. Miller 19fd61785a Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net 2011-08-07 23:20:26 -07:00
Stephen Hemminger a9b3cd7f32 rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER
When assigning a NULL value to an RCU protected pointer, no barrier
is needed. The rcu_assign_pointer, used to handle that but will soon
change to not handle the special case.

Convert all rcu_assign_pointer of NULL value.

//smpl
@@ expression P; @@

- rcu_assign_pointer(P, NULL)
+ RCU_INIT_POINTER(P, NULL)

// </smpl>

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-02 04:29:23 -07:00
Julia Lawall a1889c0d20 net: adjust array index
Convert array index from the loop bound to the loop index.

A simplified version of the semantic patch that fixes this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e1,e2,ar;
@@

for(e1 = 0; e1 < e2; e1++) { <...
  ar[
- e2
+ e1
  ]
  ...> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-01 02:27:21 -07:00
Veaceslav Falico 24cf3af3fe igmp: call ip_mc_clear_src() only when we have no users of ip_mc_list
In igmp_group_dropped() we call ip_mc_clear_src(), which resets the number
of source filters per mulitcast. However, igmp_group_dropped() is also
called on NETDEV_DOWN, NETDEV_PRE_TYPE_CHANGE and NETDEV_UNREGISTER, which
means that the group might get added back on NETDEV_UP, NETDEV_REGISTER and
NETDEV_POST_TYPE_CHANGE respectively, leaving us with broken source
filters.

To fix that, we must clear the source filters only when there are no users
in the ip_mc_list, i.e. in ip_mc_dec_group() and on device destroy.

Acked-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-24 13:26:12 -04:00
Linus Torvalds 06f4e926d2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1446 commits)
  macvlan: fix panic if lowerdev in a bond
  tg3: Add braces around 5906 workaround.
  tg3: Fix NETIF_F_LOOPBACK error
  macvlan: remove one synchronize_rcu() call
  networking: NET_CLS_ROUTE4 depends on INET
  irda: Fix error propagation in ircomm_lmp_connect_response()
  irda: Kill set but unused variable 'bytes' in irlan_check_command_param()
  irda: Kill set but unused variable 'clen' in ircomm_connect_indication()
  rxrpc: Fix set but unused variable 'usage' in rxrpc_get_transport()
  be2net: Kill set but unused variable 'req' in lancer_fw_download()
  irda: Kill set but unused vars 'saddr' and 'daddr' in irlan_provider_connect_indication()
  atl1c: atl1c_resume() is only used when CONFIG_PM_SLEEP is defined.
  rxrpc: Fix set but unused variable 'usage' in rxrpc_get_peer().
  rxrpc: Kill set but unused variable 'local' in rxrpc_UDP_error_handler()
  rxrpc: Kill set but unused variable 'sp' in rxrpc_process_connection()
  rxrpc: Kill set but unused variable 'sp' in rxrpc_rotate_tx_window()
  pkt_sched: Kill set but unused variable 'protocol' in tc_classify()
  isdn: capi: Use pr_debug() instead of ifdefs.
  tg3: Update version to 3.119
  tg3: Apply rx_discards fix to 5719/5720
  ...

Fix up trivial conflicts in arch/x86/Kconfig and net/mac80211/agg-tx.c
as per Davem.
2011-05-20 13:43:21 -07:00
Lai Jiangshan 10d50e748d net,rcu: convert call_rcu(ip_mc_socklist_reclaim) to kfree_rcu()
The rcu callback ip_mc_socklist_reclaim() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(ip_mc_socklist_reclaim).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-07 22:50:59 -07:00
Lai Jiangshan 7519cce48f net,rcu: convert call_rcu(ip_sf_socklist_reclaim) to kfree_rcu()
The rcu callback ip_sf_socklist_reclaim() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(ip_sf_socklist_reclaim).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-07 22:50:58 -07:00
Lai Jiangshan 42ea299d3f net,rcu: convert call_rcu(ip_mc_list_reclaim) to kfree_rcu()
The rcu callback ip_mc_list_reclaim() just calls a kfree(),
so we use kfree_rcu() instead of the call_rcu(ip_mc_list_reclaim).

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-05-07 22:50:57 -07:00
David S. Miller 492f64ce12 ipv4: Use flowi4's {saddr,daddr} in igmpv3_newpack() and igmp_send_report()
Instead of rt->rt_{src,dst}

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-03 20:53:12 -07:00
David S. Miller 31e4543db2 ipv4: Make caller provide on-stack flow key to ip_route_output_ports().
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-03 20:25:42 -07:00
David S. Miller 2e97e980b5 ipv4: Remove erroneous check in igmpv3_newpack() and igmp_send_report().
Output route resolution never returns a route with rt_src set to zero
(which is INADDR_ANY).

Even if the flow key for the output route lookup specifies INADDR_ANY
for the source address, the output route resolution chooses a real
source address to use in the final route.

This test has existed forever in igmp_send_report() and David Stevens
simply copied over the erroneous test when implementing support for
IGMPv3.

Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
2011-04-27 13:59:05 -07:00
David S. Miller 78fbfd8a65 ipv4: Create and use route lookup helpers.
The idea here is this minimizes the number of places one has to edit
in order to make changes to how flows are defined and used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:42 -08:00
David S. Miller dbdd9a52e3 ipv4: Remove redundant RCU locking in ip_check_mc().
All callers are under rcu_read_lock() protection already.

Rename to ip_check_mc_rcu() to make it even more clear.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10 16:37:26 -08:00
David S. Miller b23dd4fe42 ipv4: Make output route lookup return rtable directly.
Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 14:31:35 -08:00
Eric Dumazet 57e1ab6ead igmp: refine skb allocations
IGMP allocates MTU sized skbs. This may fail for large MTU (order-2
allocations), so add a fallback to try lower sizes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-18 11:02:23 -08:00
Eric Dumazet 866f3b25a2 bonding: IGMP handling cleanup
Instead of iterating in_dev->mc_list from bonding driver, its better
to call a helper function provided by igmp.c
Details of implementation (locking) are private to igmp code.

ip_mc_rejoin_group(struct ip_mc_list *im) becomes
ip_mc_rejoin_groups(struct in_device *in_dev);

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-18 09:33:19 -08:00
Changli Gao 5811662b15 net: use the macros defined for the members of flowi
Use the macros defined for the members of flowi to clean the code up.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 12:27:45 -08:00
David S. Miller d9aa93804e ipv4: Fix build with multicast disabled.
net/ipv4/igmp.c: In function 'ip_mc_inc_group':
net/ipv4/igmp.c:1228: error: implicit declaration of function 'for_each_pmc_rtnl'
net/ipv4/igmp.c:1228: error: expected ';' before '{' token
net/ipv4/igmp.c: In function 'ip_mc_unmap':
net/ipv4/igmp.c:1333: error: expected ';' before 'igmp_group_dropped'
 ...

Move for_each_pmc_rcu and for_each_pmc_rtnl macro definitions
outside of multicast ifdef protection.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-15 08:52:02 -08:00
David S. Miller c25ecd0a21 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-11-14 11:57:05 -08:00
Eric Dumazet 1d7138de87 igmp: RCU conversion of in_dev->mc_list
in_dev->mc_list is protected by one rwlock (in_dev->mc_list_lock).

This can easily be converted to a RCU protection.

Writers hold RTNL, so mc_list_lock is removed, not replaced by a
spinlock.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Cypher Wu <cypher.w@gmail.com>
Cc: Américo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-12 13:18:57 -08:00
David S. Miller c753796769 ipv4: Make rt->fl.iif tests lest obscure.
When we test rt->fl.iif against zero, we're seeing if it's
an output or an input route.

Make that explicit with some helper functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-11 17:07:48 -08:00
Eric Dumazet 18943d292f inet: fix ip_mc_drop_socket()
commit 8723e1b4ad (inet: RCU changes in inetdev_by_index())
forgot one call site in ip_mc_drop_socket()

We should not decrease idev refcount after inetdev_by_index() call,
since refcount is not increased anymore.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-09 08:26:42 -08:00
Eric Dumazet 8723e1b4ad inet: RCU changes in inetdev_by_index()
Convert inetdev_by_index() to not increment in_dev refcount.

Callers hold RCU or RTNL, and should not decrement in_dev refcount.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-19 03:50:48 -07:00
Eric Dumazet 9e917dca74 net: avoid a dev refcount in ip_mc_find_dev()
We hold RTNL in ip_mc_find_dev(), no need to touch device refcount.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-19 03:50:47 -07:00
Flavio Leitner e12b453904 bonding: fix to rejoin multicast groups immediately
The IGMP specs states that if the system receives a
membership report, it shouldn't send another for the
next minute. However, if a link failure happens right
after that, the backup slave and the switch connected
to this slave will not know about the multicast and
the traffic will hang for about a minute.

This patch fixes it to rejoin multicast groups immediately
after a failover restoring the multicast traffic.

Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-05 20:26:57 -07:00
David Stevens 5b7c840667 ipv4: correct IGMP behavior on v3 query during v2-compatibility mode
A recent patch to allow IGMPv2 responses to IGMPv3 queries
bypasses length checks for valid query lengths, incorrectly
resets the v2_seen timer, and does not support IGMPv1.

The following patch responds with a v2 report as required
by IGMPv2 while correcting the other problems introduced
by the patch.

Signed-Off-By: David L Stevens <dlstevens@us.ibm.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-03 21:58:47 -07:00
Bob Arendt 7998156344 ipv4: force_igmp_version ignored when a IGMPv3 query received
After all these years, it turns out that the
    /proc/sys/net/ipv4/conf/*/force_igmp_version
parameter isn't fully implemented.

*Symptom*:
When set force_igmp_version to a value of 2, the kernel should only perform
multicast IGMPv2 operations (IETF rfc2236).  An host-initiated Join message
will be sent as a IGMPv2 Join message.  But if a IGMPv3 query message is
received, the host responds with a IGMPv3 join message.  Per rfc3376 and
rfc2236, a IGMPv2 host should treat a IGMPv3 query as a IGMPv2 query and
respond with an IGMPv2 Join message.

*Consequences*:
This is an issue when a IGMPv3 capable switch is the querier and will only
issue IGMPv3 queries (which double as IGMPv2 querys) and there's an
intermediate switch that is only IGMPv2 capable.  The intermediate switch
processes the initial v2 Join, but fails to recognize the IGMPv3 Join responses
to the Query, resulting in a dropped connection when the intermediate v2-only
switch times it out.

*Identifying issue in the kernel source*:
The issue is in this section of code (in net/ipv4/igmp.c), which is called when
an IGMP query is received  (from mainline 2.6.36-rc3 gitweb):
 ...
A IGMPv3 query has a length >= 12 and no sources.  This routine will exit after
line 880, setting the general query timer (random timeout between 0 and query
response time).  This calls igmp_gq_timer_expire():
...
.. which only sends a v3 response.  So if a v3 query is received, the kernel
always sends a v3 response.

IGMP queries happen once every 60 sec (per vlan), so the traffic is low.  A
IGMPv3 query *is* a strict superset of a IGMPv2 query, so this patch properly
short circuit's the v3 behaviour.

One issue is that this does not address force_igmp_version=1.  Then again, I've
never seen any IGMPv1 multicast equipment in the wild.  However there is a lot
of v2-only equipment. If it's necessary to support the IGMPv1 case as well:

837         if (len == 8 || IGMP_V2_SEEN(in_dev) || IGMP_V1_SEEN(in_dev)) {

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-13 12:56:51 -07:00
Eric Dumazet 4bc2f18ba4 net/ipv4: EXPORT_SYMBOL cleanups
CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-07-12 12:57:54 -07:00