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2016-05-19net: bridge: fix old ioctl unlocked net device walkNikolay Aleksandrov1-2/+3
[ Upstream commit 31ca0458a61a502adb7ed192bf9716c6d05791a5 ] get_bridge_ifindices() is used from the old "deviceless" bridge ioctl calls which aren't called with rtnl held. The comment above says that it is called with rtnl but that is not really the case. Here's a sample output from a test ASSERT_RTNL() which I put in get_bridge_ifindices and executed "brctl show": [ 957.422726] RTNL: assertion failed at net/bridge//br_ioctl.c (30) [ 957.422925] CPU: 0 PID: 1862 Comm: brctl Tainted: G W O 4.6.0-rc4+ #157 [ 957.423009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.1-20150318_183358- 04/01/2014 [ 957.423009] 0000000000000000 ffff880058adfdf0 ffffffff8138dec5 0000000000000400 [ 957.423009] ffffffff81ce8380 ffff880058adfe58 ffffffffa05ead32 0000000000000001 [ 957.423009] 00007ffec1a444b0 0000000000000400 ffff880053c19130 0000000000008940 [ 957.423009] Call Trace: [ 957.423009] [<ffffffff8138dec5>] dump_stack+0x85/0xc0 [ 957.423009] [<ffffffffa05ead32>] br_ioctl_deviceless_stub+0x212/0x2e0 [bridge] [ 957.423009] [<ffffffff81515beb>] sock_ioctl+0x22b/0x290 [ 957.423009] [<ffffffff8126ba75>] do_vfs_ioctl+0x95/0x700 [ 957.423009] [<ffffffff8126c159>] SyS_ioctl+0x79/0x90 [ 957.423009] [<ffffffff8163a4c0>] entry_SYSCALL_64_fastpath+0x23/0xc1 Since it only reads bridge ifindices, we can use rcu to safely walk the net device list. Also remove the wrong rtnl comment above. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2016-02-12bridge: Only call /sbin/bridge-stp for the initial network namespaceHannes Frederic Sowa1-1/+4
[ Upstream commit ff62198553e43cdffa9d539f6165d3e83f8a42bc ] [I stole this patch from Eric Biederman. He wrote:] > There is no defined mechanism to pass network namespace information > into /sbin/bridge-stp therefore don't even try to invoke it except > for bridge devices in the initial network namespace. > > It is possible for unprivileged users to cause /sbin/bridge-stp to be > invoked for any network device name which if /sbin/bridge-stp does not > guard against unreasonable arguments or being invoked twice on the > same network device could cause problems. [Hannes: changed patch using netns_eq] Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-11-14bridge: superfluous skb->nfct check in br_nf_dev_queue_xmitVasily Averin1-2/+2
commit aff09ce303f83bd370772349238482ae422a2341 upstream. Currently bridge can silently drop ipv4 fragments. If node have loaded nf_defrag_ipv4 module but have no nf_conntrack_ipv4, br_nf_pre_routing defragments incoming ipv4 fragments but nfct check in br_nf_dev_queue_xmit does not allow re-fragment combined packet back, and therefore it is dropped in br_dev_queue_push_xmit without incrementing of any failcounters It seems the only way to hit the ip_fragment code in the bridge xmit path is to have a fragment list whose reassembled fragments go over the mtu. This only happens if nf_defrag is enabled. Thanks to Florian Westphal for providing feedback to clarify this. Defragmentation ipv4 is required not only in conntracks but at least in TPROXY target and socket match, therefore #ifdef is changed from NF_CONNTRACK_IPV4 to NF_DEFRAG_IPV4 Signed-off-by: Vasily Averin <vvs@openvz.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-08-27bridge: mdb: fix double add notificationNikolay Aleksandrov1-1/+0
[ Upstream commit 5ebc784625ea68a9570d1f70557e7932988cd1b4 ] Since the mdb add/del code was introduced there have been 2 br_mdb_notify calls when doing br_mdb_add() resulting in 2 notifications on each add. Example: Command: bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent Before patch: root@debian:~# bridge monitor all [MDB]dev br0 port eth1 grp 239.0.0.1 permanent [MDB]dev br0 port eth1 grp 239.0.0.1 permanent After patch: root@debian:~# bridge monitor all [MDB]dev br0 port eth1 grp 239.0.0.1 permanent Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Fixes: cfd567543590 ("bridge: add support of adding and deleting mdb entries") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-08-27bridge: mdb: zero out the local br_ip variable before useNikolay Aleksandrov1-0/+2
[ Upstream commit f1158b74e54f2e2462ba5e2f45a118246d9d5b43 ] Since commit b0e9a30dd669 ("bridge: Add vlan id to multicast groups") there's a check in br_ip_equal() for a matching vlan id, but the mdb functions were not modified to use (or at least zero it) so when an entry was added it would have a garbage vlan id (from the local br_ip variable in __br_mdb_add/del) and this would prevent it from being matched and also deleted. So zero out the whole local ip var to protect ourselves from future changes and also to fix the current bug, since there's no vlan id support in the mdb uapi - use always vlan id 0. Example before patch: root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent RTNETLINK answers: Invalid argument After patch: root@debian:~# bridge mdb add dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb del dev br0 port eth1 grp 239.0.0.1 permanent root@debian:~# bridge mdb Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Fixes: b0e9a30dd669 ("bridge: Add vlan id to multicast groups") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-07-30bridge: fix br_stp_set_bridge_priority race conditionsNikolay Aleksandrov2-3/+3
[ Upstream commit 2dab80a8b486f02222a69daca6859519e05781d9 ] After the ->set() spinlocks were removed br_stp_set_bridge_priority was left running without any protection when used via sysfs. It can race with port add/del and could result in use-after-free cases and corrupted lists. Tested by running port add/del in a loop with stp enabled while setting priority in a loop, crashes are easily reproducible. The spinlocks around sysfs ->set() were removed in commit: 14f98f258f19 ("bridge: range check STP parameters") There's also a race condition in the netlink priority support that is fixed by this change, but it was introduced recently and the fixes tag covers it, just in case it's needed the commit is: af615762e972 ("bridge: add ageing_time, stp_state, priority over netlink") Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Fixes: 14f98f258f19 ("bridge: range check STP parameters") Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-07-30bridge: fix multicast router rlist endless loopNikolay Aleksandrov1-4/+3
[ Upstream commit 1a040eaca1a22f8da8285ceda6b5e4a2cb704867 ] Since the addition of sysfs multicast router support if one set multicast_router to "2" more than once, then the port would be added to the hlist every time and could end up linking to itself and thus causing an endless loop for rlist walkers. So to reproduce just do: echo 2 > multicast_router; echo 2 > multicast_router; in a bridge port and let some igmp traffic flow, for me it hangs up in br_multicast_flood(). Fix this by adding a check in br_multicast_add_router() if the port is already linked. The reason this didn't happen before the addition of multicast_router sysfs entries is because there's a !hlist_unhashed check that prevents it. Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Fixes: 0909e11758bd ("bridge: Add multicast_router sysfs entries") Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2015-06-10bridge: fix parsing of MLDv2 reportsThadeu Lima de Souza Cascardo1-1/+1
[ Upstream commit 47cc84ce0c2fe75c99ea5963c4b5704dd78ead54 ] When more than a multicast address is present in a MLDv2 report, all but the first address is ignored, because the code breaks out of the loop if there has not been an error adding that address. This has caused failures when two guests connected through the bridge tried to communicate using IPv6. Neighbor discoveries would not be transmitted to the other guest when both used a link-local address and a static address. This only happens when there is a MLDv2 querier in the network. The fix will only break out of the loop when there is a failure adding a multicast address. The mdb before the patch: dev ovirtmgmt port vnet0 grp ff02::1:ff7d:6603 temp dev ovirtmgmt port vnet1 grp ff02::1:ff7d:6604 temp dev ovirtmgmt port bond0.86 grp ff02::2 temp After the patch: dev ovirtmgmt port vnet0 grp ff02::1:ff7d:6603 temp dev ovirtmgmt port vnet1 grp ff02::1:ff7d:6604 temp dev ovirtmgmt port bond0.86 grp ff02::fb temp dev ovirtmgmt port bond0.86 grp ff02::2 temp dev ovirtmgmt port bond0.86 grp ff02::d temp dev ovirtmgmt port vnet0 grp ff02::1:ff00:76 temp dev ovirtmgmt port bond0.86 grp ff02::16 temp dev ovirtmgmt port vnet1 grp ff02::1:ff00:77 temp dev ovirtmgmt port bond0.86 grp ff02::1:ff00:def temp dev ovirtmgmt port bond0.86 grp ff02::1:ffa1:40bf temp Fixes: 08b202b67264 ("bridge br_multicast: IPv6 MLD support.") Reported-by: Rik Theys <Rik.Theys@esat.kuleuven.be> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com> Tested-by: Rik Theys <Rik.Theys@esat.kuleuven.be> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-17bridge: Fix br_should_learn to check vlan_enabledVlad Yasevich1-1/+1
[ Upstream commit c095f248e63ada504dd90c90baae673ae10ee3fe ] As Toshiaki Makita pointed out, the BRIDGE_INPUT_SKB_CB will not be initialized in br_should_learn() as that function is called only from br_handle_local_finish(). That is an input handler for link-local ethernet traffic so it perfectly correct to check br->vlan_enabled here. Reported-by: Toshiaki Makita<toshiaki.makita1@gmail.com> Fixes: 20adfa1 bridge: Check if vlan filtering is enabled only once. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-17bridge: Check if vlan filtering is enabled only once.Vlad Yasevich2-4/+14
[ Upstream commit 20adfa1a81af00bf2027644507ad4fa9cd2849cf ] The bridge code checks if vlan filtering is enabled on both ingress and egress. When the state flip happens, it is possible for the bridge to currently be forwarding packets and forwarding behavior becomes non-deterministic. Bridge may drop packets on some interfaces, but not others. This patch solves this by caching the filtered state of the packet into skb_cb on ingress. The skb_cb is guaranteed to not be over-written between the time packet entres bridge forwarding path and the time it leaves it. On egress, we can then check the cached state to see if we need to apply filtering information. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-10-17net: Always untag vlan-tagged traffic on input.Vlad Yasevich1-1/+1
[ Upstream commit 0d5501c1c828fb97d02af50aa9d2b1a5498b94e4 ] Currently the functionality to untag traffic on input resides as part of the vlan module and is build only when VLAN support is enabled in the kernel. When VLAN is disabled, the function vlan_untag() turns into a stub and doesn't really untag the packets. This seems to create an interesting interaction between VMs supporting checksum offloading and some network drivers. There are some drivers that do not allow the user to change tx-vlan-offload feature of the driver. These drivers also seem to assume that any VLAN-tagged traffic they transmit will have the vlan information in the vlan_tci and not in the vlan header already in the skb. When transmitting skbs that already have tagged data with partial checksum set, the checksum doesn't appear to be updated correctly by the card thus resulting in a failure to establish TCP connections. The following is a packet trace taken on the receiver where a sender is a VM with a VLAN configued. The host VM is running on doest not have VLAN support and the outging interface on the host is tg3: 10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294837885 ecr 0,nop,wscale 7], length 0 10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294838888 ecr 0,nop,wscale 7], length 0 This connection finally times out. I've only access to the TG3 hardware in this configuration thus have only tested this with TG3 driver. There are a lot of other drivers that do not permit user changes to vlan acceleration features, and I don't know if they all suffere from a similar issue. The patch attempt to fix this another way. It moves the vlan header stipping code out of the vlan module and always builds it into the kernel network core. This way, even if vlan is not supported on a virtualizatoin host, the virtual machines running on top of such host will still work with VLANs enabled. CC: Patrick McHardy <kaber@trash.net> CC: Nithin Nayak Sujir <nsujir@broadcom.com> CC: Michael Chan <mchan@broadcom.com> CC: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-06-23bridge: Prevent insertion of FDB entry with disallowed vlanToshiaki Makita3-2/+37
[ Upstream commit e0d7968ab6c8bce2437b36fa7f04117e333f196d ] br_handle_local_finish() is allowing us to insert an FDB entry with disallowed vlan. For example, when port 1 and 2 are communicating in vlan 10, and even if vlan 10 is disallowed on port 3, port 3 can interfere with their communication by spoofed src mac address with vlan id 10. Note: Even if it is judged that a frame should not be learned, it should not be dropped because it is destined for not forwarding layer but higher layer. See IEEE 802.1Q-2011 8.13.10. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-29bridge: Handle IFLA_ADDRESS correctly when creating bridge deviceToshiaki Makita1-0/+15
[ Upstream commit 30313a3d5794472c3548d7288e306a5492030370 ] When bridge device is created with IFLA_ADDRESS, we are not calling br_stp_change_bridge_id(), which leads to incorrect local fdb management and bridge id calculation, and prevents us from receiving frames on the bridge device. Reported-by: Tom Gundersen <teg@jklm.no> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-29bridge: Fix double free and memory leak around br_allowed_ingressToshiaki Makita2-4/+5
[ Upstream commit eb7076182d1ae4bc4641534134ed707100d76acc ] br_allowed_ingress() has two problems. 1. If br_allowed_ingress() is called by br_handle_frame_finish() and vlan_untag() in br_allowed_ingress() fails, skb will be freed by both vlan_untag() and br_handle_frame_finish(). 2. If br_allowed_ingress() is called by br_dev_xmit() and br_allowed_ingress() fails, the skb will not be freed. Fix these two problems by freeing the skb in br_allowed_ingress() if it fails. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-05-29netfilter: Can't fail and free after table replacementThomas Graf1-3/+2
commit c58dd2dd443c26d856a168db108a0cd11c285bf3 upstream. All xtables variants suffer from the defect that the copy_to_user() to copy the counters to user memory may fail after the table has already been exchanged and thus exposed. Return an error at this point will result in freeing the already exposed table. Any subsequent packet processing will result in a kernel panic. We can't copy the counters before exposing the new tables as we want provide the counter state after the old table has been unhooked. Therefore convert this into a silent error. Cc: Florian Westphal <fw@strlen.de> Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-04-18bridge: multicast: enable snooping on general queries onlyLinus Lüssing1-3/+5
[ Upstream commit 20a599bec95a52fa72432b2376a2ce47c5bb68fb ] Without this check someone could easily create a denial of service by injecting multicast-specific queries to enable the bridge snooping part if no real querier issuing periodic general queries is present on the link which would result in the bridge wrongly shutting down ports for multicast traffic as the bridge did not learn about these listeners. With this patch the snooping code is enabled upon receiving valid, general queries only. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-04-18bridge: multicast: add sanity check for general query destinationLinus Lüssing1-0/+19
[ Upstream commit 9ed973cc40c588abeaa58aea0683ea665132d11d ] General IGMP and MLD queries are supposed to have the multicast link-local all-nodes address as their destination according to RFC2236 section 9, RFC3376 section 4.1.12/9.1, RFC2710 section 8 and RFC3810 section 5.1.15. Without this check, such malformed IGMP/MLD queries can result in a denial of service: The queries are ignored by most IGMP/MLD listeners therefore they will not respond with an IGMP/MLD report. However, without this patch these malformed MLD queries would enable the snooping part in the bridge code, potentially shutting down the according ports towards these hosts for multicast traffic as the bridge did not learn about these listeners. Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-04-18bridge: multicast: add sanity check for query source addressesLinus Lüssing1-0/+6
[ Upstream commit 6565b9eeef194afbb3beec80d6dd2447f4091f8c ] MLD queries are supposed to have an IPv6 link-local source address according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch adds a sanity check to ignore such broken MLD queries. Without this check, such malformed MLD queries can result in a denial of service: The queries are ignored by any MLD listener therefore they will not respond with an MLD report. However, without this patch these malformed MLD queries would enable the snooping part in the bridge code, potentially shutting down the according ports towards these hosts for multicast traffic as the bridge did not learn about these listeners. Reported-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Linus Lüssing <linus.luessing@web.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-02-26bridge: fix netconsole setup over bridgeCong Wang1-23/+28
[ Upstream commit dbe173079ab58a444e12dbebe96f5aec1e0bed1a ] Commit 93d8bf9fb8f3 ("bridge: cleanup netpoll code") introduced a check in br_netpoll_enable(), but this check is incorrect for br_netpoll_setup(). This patch moves the code after the check into __br_netpoll_enable() and calls it in br_netpoll_setup(). For br_add_if(), the check is still needed. Fixes: 93d8bf9fb8f3 ("bridge: cleanup netpoll code") Cc: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Tested-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
2014-01-16bridge: use spin_lock_bh() in br_multicast_set_hash_maxCurt Brune1-2/+2
[ Upstream commit fe0d692bbc645786bce1a98439e548ae619269f5 ] br_multicast_set_hash_max() is called from process context in net/bridge/br_sysfs_br.c by the sysfs store_hash_max() function. br_multicast_set_hash_max() calls spin_lock(&br->multicast_lock), which can deadlock the CPU if a softirq that also tries to take the same lock interrupts br_multicast_set_hash_max() while the lock is held . This can happen quite easily when any of the bridge multicast timers expire, which try to take the same lock. The fix here is to use spin_lock_bh(), preventing other softirqs from executing on this CPU. Steps to reproduce: 1. Create a bridge with several interfaces (I used 4). 2. Set the "multicast query interval" to a low number, like 2. 3. Enable the bridge as a multicast querier. 4. Repeatedly set the bridge hash_max parameter via sysfs. # brctl addbr br0 # brctl addif br0 eth1 eth2 eth3 eth4 # brctl setmcqi br0 2 # brctl setmcquerier br0 1 # while true ; do echo 4096 > /sys/class/net/br0/bridge/hash_max; done Signed-off-by: Curt Brune <curt@cumulusnetworks.com> Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-16br: fix use of ->rx_handler_data in code executed on non-rx_handler pathJiri Pirko2-1/+11
[ Upstream commit 859828c0ea476b42f3a93d69d117aaba90994b6f ] br_stp_rcv() is reached by non-rx_handler path. That means there is no guarantee that dev is bridge port and therefore simple NULL check of ->rx_handler_data is not enough. There is need to check if dev is really bridge port and since only rcu read lock is held here, do it by checking ->rx_handler pointer. Note that synchronize_net() in netdev_rx_handler_unregister() ensures this approach as valid. Introduced originally by: commit f350a0a87374418635689471606454abc7beaa3a "bridge: use rx_handler_data pointer to store net_bridge_port pointer" Fixed but not in the best way by: commit b5ed54e94d324f17c97852296d61a143f01b227a "bridge: fix RCU races with bridge port" Reintroduced by: commit 716ec052d2280d511e10e90ad54a86f5b5d4dcc2 "bridge: fix NULL pointer deref of br_port_get_rcu" Please apply to stable trees as well. Thanks. RH bugzilla reference: https://bugzilla.redhat.com/show_bug.cgi?id=1025770 Reported-by: Laine Stump <laine@redhat.com> Debugged-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jiri Pirko <jiri@resnulli.us> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08bridge: flush br's address entry in fdb when remove the bridge devDing Tianhong1-0/+2
[ Upstream commit f873042093c0b418d2351fe142222b625c740149 ] When the following commands are executed: brctl addbr br0 ifconfig br0 hw ether <addr> rmmod bridge The calltrace will occur: [ 563.312114] device eth1 left promiscuous mode [ 563.312188] br0: port 1(eth1) entered disabled state [ 563.468190] kmem_cache_destroy bridge_fdb_cache: Slab cache still has objects [ 563.468197] CPU: 6 PID: 6982 Comm: rmmod Tainted: G O 3.12.0-0.7-default+ #9 [ 563.468199] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 563.468200] 0000000000000880 ffff88010f111e98 ffffffff814d1c92 ffff88010f111eb8 [ 563.468204] ffffffff81148efd ffff88010f111eb8 0000000000000000 ffff88010f111ec8 [ 563.468206] ffffffffa062a270 ffff88010f111ed8 ffffffffa063ac76 ffff88010f111f78 [ 563.468209] Call Trace: [ 563.468218] [<ffffffff814d1c92>] dump_stack+0x6a/0x78 [ 563.468234] [<ffffffff81148efd>] kmem_cache_destroy+0xfd/0x100 [ 563.468242] [<ffffffffa062a270>] br_fdb_fini+0x10/0x20 [bridge] [ 563.468247] [<ffffffffa063ac76>] br_deinit+0x4e/0x50 [bridge] [ 563.468254] [<ffffffff810c7dc9>] SyS_delete_module+0x199/0x2b0 [ 563.468259] [<ffffffff814e0922>] system_call_fastpath+0x16/0x1b [ 570.377958] Bridge firewalling registered --------------------------- cut here ------------------------------- The reason is that when the bridge dev's address is changed, the br_fdb_change_mac_address() will add new address in fdb, but when the bridge was removed, the address entry in the fdb did not free, the bridge_fdb_cache still has objects when destroy the cache, Fix this by flushing the bridge address entry when removing the bridge. v2: according to the Toshiaki Makita and Vlad's suggestion, I only delete the vlan0 entry, it still have a leak here if the vlan id is other number, so I need to call fdb_delete_by_port(br, NULL, 1) to flush all entries whose dst is NULL for the bridge. Suggested-by: Toshiaki Makita <toshiaki.makita1@gmail.com> Suggested-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-22Revert "bridge: only expire the mdb entry when query is received"Linus Lüssing3-22/+28
While this commit was a good attempt to fix issues occuring when no multicast querier is present, this commit still has two more issues: 1) There are cases where mdb entries do not expire even if there is a querier present. The bridge will unnecessarily continue flooding multicast packets on the according ports. 2) Never removing an mdb entry could be exploited for a Denial of Service by an attacker on the local link, slowly, but steadily eating up all memory. Actually, this commit became obsolete with "bridge: disable snooping if there is no querier" (b00589af3b) which included fixes for a few more cases. Therefore reverting the following commits (the commit stated in the commit message plus three of its follow up fixes): ==================== Revert "bridge: update mdb expiration timer upon reports." This reverts commit f144febd93d5ee534fdf23505ab091b2b9088edc. Revert "bridge: do not call setup_timer() multiple times" This reverts commit 1faabf2aab1fdaa1ace4e8c829d1b9cf7bfec2f1. Revert "bridge: fix some kernel warning in multicast timer" This reverts commit c7e8e8a8f7a70b343ca1e0f90a31e35ab2d16de1. Revert "bridge: only expire the mdb entry when query is received" This reverts commit 9f00b2e7cf241fa389733d41b615efdaa2cb0f5b. ==================== CC: Cong Wang <amwang@redhat.com> Signed-off-by: Linus Lüssing <linus.luessing@web.de> Reviewed-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19bridge: Fix updating FDB entries when the PVID is appliedToshiaki Makita1-0/+1
We currently set the value that variable vid is pointing, which will be used in FDB later, to 0 at br_allowed_ingress() when we receive untagged or priority-tagged frames, even though the PVID is valid. This leads to FDB updates in such a wrong way that they are learned with VID 0. Update the value to that of PVID if the PVID is applied. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Reviewed-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19bridge: Fix the way the PVID is referencedToshiaki Makita1-3/+1
We are using the VLAN_TAG_PRESENT bit to detect whether the PVID is set or not at br_get_pvid(), while we don't care about the bit in adding/deleting the PVID, which makes it impossible to forward any incomming untagged frame with vlan_filtering enabled. Since vid 0 cannot be used for the PVID, we can use vid 0 to indicate that the PVID is not set, which is slightly more efficient than using the VLAN_TAG_PRESENT. Fix the problem by getting rid of using the VLAN_TAG_PRESENT. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Reviewed-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19bridge: Apply the PVID to priority-tagged framesToshiaki Makita1-7/+20
IEEE 802.1Q says that when we receive priority-tagged (VID 0) frames use the PVID for the port as its VID. (See IEEE 802.1Q-2011 6.9.1 and Table 9-2) Apply the PVID to not only untagged frames but also priority-tagged frames. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Reviewed-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19bridge: Don't use VID 0 and 4095 in vlan filteringToshiaki Makita3-54/+49
IEEE 802.1Q says that: - VID 0 shall not be configured as a PVID, or configured in any Filtering Database entry. - VID 4095 shall not be configured as a PVID, or transmitted in a tag header. This VID value may be used to indicate a wildcard match for the VID in management operations or Filtering Database entries. (See IEEE 802.1Q-2011 6.9.1 and Table 9-2) Don't accept adding these VIDs in the vlan_filtering implementation. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Reviewed-by: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-18bridge: Correctly clamp MAX forward_delay when enabling STPVlad Yasevich1-1/+1
Commit be4f154d5ef0ca147ab6bcd38857a774133f5450 bridge: Clamp forward_delay when enabling STP had a typo when attempting to clamp maximum forward delay. It is possible to set bridge_forward_delay to be higher then permitted maximum when STP is off. When turning STP on, the higher then allowed delay has to be clamed down to max value. CC: Herbert Xu <herbert@gondor.apana.org.au> CC: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com> Reviewed-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-11bridge: update mdb expiration timer upon reports.Vlad Yasevich1-1/+8
commit 9f00b2e7cf241fa389733d41b615efdaa2cb0f5b bridge: only expire the mdb entry when query is received changed the mdb expiration timer to be armed only when QUERY is received. Howerver, this causes issues in an environment where the multicast server socket comes and goes very fast while a client is trying to send traffic to it. The root cause is a race where a sequence of LEAVE followed by REPORT messages can race against QUERY messages generated in response to LEAVE. The QUERY ends up starting the expiration timer, and that timer can potentially expire after the new REPORT message has been received signaling the new join operation. This leads to a significant drop in multicast traffic and possible complete stall. The solution is to have REPORT messages update the expiration timer on entries that already exist. CC: Cong Wang <xiyou.wangcong@gmail.com> CC: Herbert Xu <herbert@gondor.apana.org.au> CC: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-16bridge: fix NULL pointer deref of br_port_get_rcuHong Zhiguo1-4/+1
The NULL deref happens when br_handle_frame is called between these 2 lines of del_nbp: dev->priv_flags &= ~IFF_BRIDGE_PORT; /* --> br_handle_frame is called at this time */ netdev_rx_handler_unregister(dev); In br_handle_frame the return of br_port_get_rcu(dev) is dereferenced without check but br_port_get_rcu(dev) returns NULL if: !(dev->priv_flags & IFF_BRIDGE_PORT) Eric Dumazet pointed out the testing of IFF_BRIDGE_PORT is not necessary here since we're in rcu_read_lock and we have synchronize_net() in netdev_rx_handler_unregister. So remove the testing of IFF_BRIDGE_PORT and by the previous patch, make sure br_port_get_rcu is called in bridging code. Signed-off-by: Hong Zhiguo <zhiguohong@tencent.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-16bridge: use br_port_get_rtnl within rtnl lockHong Zhiguo2-3/+3
current br_port_get_rcu is problematic in bridging path (NULL deref). Change these calls in netlink path first. Signed-off-by: Hong Zhiguo <zhiguohong@tencent.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-13bridge: Clamp forward_delay when enabling STPHerbert Xu3-8/+26
At some point limits were added to forward_delay. However, the limits are only enforced when STP is enabled. This created a scenario where you could have a value outside the allowed range while STP is disabled, which then stuck around even after STP is enabled. This patch fixes this by clamping the value when we enable STP. I had to move the locking around a bit to ensure that there is no window where someone could insert a value outside the range while we're in the middle of enabling STP. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Cheers, Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-13resubmit bridge: fix message_age_timer calculationChris Healy1-1/+1
This changes the message_age_timer calculation to use the BPDU's max age as opposed to the local bridge's max age. This is in accordance with section 8.6.2.3.2 Step 2 of the 802.1D-1998 sprecification. With the current implementation, when running with very large bridge diameters, convergance will not always occur even if a root bridge is configured to have a longer max age. Tested successfully on bridge diameters of ~200. Signed-off-by: Chris Healy <cphealy@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds6-35/+33
Pull networking changes from David Miller: "Noteworthy changes this time around: 1) Multicast rejoin support for team driver, from Jiri Pirko. 2) Centralize and simplify TCP RTT measurement handling in order to reduce the impact of bad RTO seeding from SYN/ACKs. Also, when both timestamps and local RTT measurements are available prefer the later because there are broken middleware devices which scramble the timestamp. From Yuchung Cheng. 3) Add TCP_NOTSENT_LOWAT socket option to limit the amount of kernel memory consumed to queue up unsend user data. From Eric Dumazet. 4) Add a "physical port ID" abstraction for network devices, from Jiri Pirko. 5) Add a "suppress" operation to influence fib_rules lookups, from Stefan Tomanek. 6) Add a networking development FAQ, from Paul Gortmaker. 7) Extend the information provided by tcp_probe and add ipv6 support, from Daniel Borkmann. 8) Use RCU locking more extensively in openvswitch data paths, from Pravin B Shelar. 9) Add SCTP support to openvswitch, from Joe Stringer. 10) Add EF10 chip support to SFC driver, from Ben Hutchings. 11) Add new SYNPROXY netfilter target, from Patrick McHardy. 12) Compute a rate approximation for sending in TCP sockets, and use this to more intelligently coalesce TSO frames. Furthermore, add a new packet scheduler which takes advantage of this estimate when available. From Eric Dumazet. 13) Allow AF_PACKET fanouts with random selection, from Daniel Borkmann. 14) Add ipv6 support to vxlan driver, from Cong Wang" Resolved conflicts as per discussion. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1218 commits) openvswitch: Fix alignment of struct sw_flow_key. netfilter: Fix build errors with xt_socket.c tcp: Add missing braces to do_tcp_setsockopt caif: Add missing braces to multiline if in cfctrl_linkup_request bnx2x: Add missing braces in bnx2x:bnx2x_link_initialize vxlan: Fix kernel panic on device delete. net: mvneta: implement ->ndo_do_ioctl() to support PHY ioctls net: mvneta: properly disable HW PHY polling and ensure adjust_link() works icplus: Use netif_running to determine device state ethernet/arc/arc_emac: Fix huge delays in large file copies tuntap: orphan frags before trying to set tx timestamp tuntap: purge socket error queue on detach qlcnic: use standard NAPI weights ipv6:introduce function to find route for redirect bnx2x: VF RSS support - VF side bnx2x: VF RSS support - PF side vxlan: Notify drivers for listening UDP port changes net: usbnet: update addr_assign_type if appropriate driver/net: enic: update enic maintainers and driver driver/net: enic: Exposing symbols for Cisco's low latency driver ...
2013-09-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller5-93/+240
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>
2013-09-05bridge: apply multicast snooping to IPv6 link-local, tooLinus Lüssing3-14/+6
The multicast snooping code should have matured enough to be safely applicable to IPv6 link-local multicast addresses (excluding the link-local all nodes address, ff02::1), too. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05bridge: prevent flooding IPv6 packets that do not have a listenerLinus Lüssing1-2/+8
Currently if there is no listener for a certain group then IPv6 packets for that group are flooded on all ports, even though there might be no host and router interested in it on a port. With this commit they are only forwarded to ports with a multicast router. Just like commit bd4265fe36 ("bridge: Only flood unregistered groups to routers") did for IPv4, let's do the same for IPv6 with the same reasoning. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05Merge tag 'PTR_RET-for-linus' of ↵Linus Torvalds3-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull PTR_RET() removal patches from Rusty Russell: "PTR_RET() is a weird name, and led to some confusing usage. We ended up with PTR_ERR_OR_ZERO(), and replacing or fixing all the usages. This has been sitting in linux-next for a whole cycle" [ There are still some PTR_RET users scattered about, with some of them possibly being new, but most of them existing in Rusty's tree too. We have that #define PTR_RET(p) PTR_ERR_OR_ZERO(p) thing in <linux/err.h>, so they continue to work for now - Linus ] * tag 'PTR_RET-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: GFS2: Replace PTR_RET with PTR_ERR_OR_ZERO Btrfs: volume: Replace PTR_RET with PTR_ERR_OR_ZERO drm/cma: Replace PTR_RET with PTR_ERR_OR_ZERO sh_veu: Replace PTR_RET with PTR_ERR_OR_ZERO dma-buf: Replace PTR_RET with PTR_ERR_OR_ZERO drivers/rtc: Replace PTR_RET with PTR_ERR_OR_ZERO mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR(). staging/zcache: don't use PTR_RET(). remoteproc: don't use PTR_RET(). pinctrl: don't use PTR_RET(). acpi: Replace weird use of PTR_RET. s390: Replace weird use of PTR_RET. PTR_RET is now PTR_ERR_OR_ZERO(): Replace most. PTR_RET is now PTR_ERR_OR_ZERO
2013-09-04net: ipv6: mld: get rid of MLDV2_MRC and simplify calculationDaniel Borkmann1-1/+2
Get rid of MLDV2_MRC and use our new macros for mantisse and exponent to calculate Maximum Response Delay out of the Maximum Response Code. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-31net: bridge: convert MLDv2 Query MRC into msecs_to_jiffies for max_delayDaniel Borkmann1-1/+2
While looking into MLDv1/v2 code, I noticed that bridging code does not convert it's max delay into jiffies for MLDv2 messages as we do in core IPv6' multicast code. RFC3810, 5.1.3. Maximum Response Code says: The Maximum Response Code field specifies the maximum time allowed before sending a responding Report. The actual time allowed, called the Maximum Response Delay, is represented in units of milliseconds, and is derived from the Maximum Response Code as follows: [...] As we update timers that work with jiffies, we need to convert it. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Linus Lüssing <linus.luessing@web.de> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-30bridge: separate querier and query timer into IGMP/IPv4 and MLD/IPv6 onesLinus Lüssing5-93/+240
Currently we would still potentially suffer multicast packet loss if there is just either an IGMP or an MLD querier: For the former case, we would possibly drop IPv6 multicast packets, for the latter IPv4 ones. This is because we are currently assuming that if either an IGMP or MLD querier is present that the other one is present, too. This patch makes the behaviour and fix added in "bridge: disable snooping if there is no querier" (b00589af3b04) to also work if there is either just an IGMP or an MLD querier on the link: It refines the deactivation of the snooping to be protocol specific by using separate timers for the snooped IGMP and MLD queries as well as separate timers for our internal IGMP and MLD queriers. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-29bridge: inherit slave devices needed_headroomFlorian Fainelli1-0/+3
Some slave devices may have set a dev->needed_headroom value which is different than the default one, most likely in order to prepend a hardware descriptor in front of the Ethernet frame to send. Whenever a new slave is added to a bridge, ensure that we update the needed_headroom value accordingly to account for the slave needed_headroom value. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller3-9/+9
Conflicts: drivers/net/wireless/iwlwifi/pcie/trans.c include/linux/inetdevice.h The inetdevice.h conflict involves moving the IPV4_DEVCONF values into a UAPI header, overlapping additions of some new entries. The iwlwifi conflict is a context overlap. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-21bridge: Use the correct bit length for bitmap functions in the VLAN codeToshiaki Makita3-9/+9
The VLAN code needs to know the length of the per-port VLAN bitmap to perform its most basic operations (retrieving VLAN informations, removing VLANs, forwarding database manipulation, etc). Unfortunately, in the current implementation we are using a macro that indicates the bitmap size in longs in places where the size in bits is expected, which in some cases can cause what appear to be random failures. Use the correct macro. Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-2/+2
2013-08-07bridge: correct the comment for file br_sysfs_br.cWang Sheng-Hui1-1/+1
br_sysfs_if.c is for sysfs attributes of bridge ports, while br_sysfs_br.c is for sysfs attributes of bridge itself. Correct the comment here. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-06bridge: don't try to update timers in case of broken MLD queriesLinus Lüssing1-1/+1
Currently we are reading an uninitialized value for the max_delay variable when snooping an MLD query message of invalid length and would update our timers with that. Fixing this by simply ignoring such broken MLD queries (just like we do for IGMP already). This is a regression introduced by: "bridge: disable snooping if there is no querier" (b00589af3b04) Reported-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-05bridge: fix rcu check warning in multicast port groupstephen hemminger2-2/+3
Use of RCU here with out marked pointer and function doesn't match prototype with sparse. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller4-13/+49
Merge net into net-next to setup some infrastructure Eric Dumazet needs for usbnet changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-01bridge: disable snooping if there is no querierLinus Lüssing4-11/+46
If there is no querier on a link then we won't get periodic reports and therefore won't be able to learn about multicast listeners behind ports, potentially leading to lost multicast packets, especially for multicast listeners that joined before the creation of the bridge. These lost multicast packets can appear since c5c23260594 ("bridge: Add multicast_querier toggle and disable queries by default") in particular. With this patch we are flooding multicast packets if our querier is disabled and if we didn't detect any other querier. A grace period of the Maximum Response Delay of the querier is added to give multicast responses enough time to arrive and to be learned from before disabling the flooding behaviour again. Signed-off-by: Linus Lüssing <linus.luessing@web.de> Signed-off-by: David S. Miller <davem@davemloft.net>