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2024-02-29netfilter: bridge: confirm multicast packets before passing them up the stackFlorian Westphal
conntrack nf_confirm logic cannot handle cloned skbs referencing the same nf_conn entry, which will happen for multicast (broadcast) frames on bridges. Example: macvlan0 | br0 / \ ethX ethY ethX (or Y) receives a L2 multicast or broadcast packet containing an IP packet, flow is not yet in conntrack table. 1. skb passes through bridge and fake-ip (br_netfilter)Prerouting. -> skb->_nfct now references a unconfirmed entry 2. skb is broad/mcast packet. bridge now passes clones out on each bridge interface. 3. skb gets passed up the stack. 4. In macvlan case, macvlan driver retains clone(s) of the mcast skb and schedules a work queue to send them out on the lower devices. The clone skb->_nfct is not a copy, it is the same entry as the original skb. The macvlan rx handler then returns RX_HANDLER_PASS. 5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb. The Macvlan broadcast worker and normal confirm path will race. This race will not happen if step 2 already confirmed a clone. In that case later steps perform skb_clone() with skb->_nfct already confirmed (in hash table). This works fine. But such confirmation won't happen when eb/ip/nftables rules dropped the packets before they reached the nf_confirm step in postrouting. Pablo points out that nf_conntrack_bridge doesn't allow use of stateful nat, so we can safely discard the nf_conn entry and let inet call conntrack again. This doesn't work for bridge netfilter: skb could have a nat transformation. Also bridge nf prevents re-invocation of inet prerouting via 'sabotage_in' hook. Work around this problem by explicit confirmation of the entry at LOCAL_IN time, before upper layer has a chance to clone the unconfirmed entry. The downside is that this disables NAT and conntrack helpers. Alternative fix would be to add locking to all code parts that deal with unconfirmed packets, but even if that could be done in a sane way this opens up other problems, for example: -m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4 -m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5 For multicast case, only one of such conflicting mappings will be created, conntrack only handles 1:1 NAT mappings. Users should set create a setup that explicitly marks such traffic NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass them, ruleset might have accept rules for untracked traffic already, so user-visible behaviour would change. Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217777 Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-02-16net: bridge: switchdev: Ensure deferred event delivery on unoffloadTobias Waldekranz
When unoffloading a device, it is important to ensure that all relevant deferred events are delivered to it before it disassociates itself from the bridge. Before this change, this was true for the normal case when a device maps 1:1 to a net_bridge_port, i.e. br0 / swp0 When swp0 leaves br0, the call to switchdev_deferred_process() in del_nbp() makes sure to process any outstanding events while the device is still associated with the bridge. In the case when the association is indirect though, i.e. when the device is attached to the bridge via an intermediate device, like a LAG... br0 / lag0 / swp0 ...then detaching swp0 from lag0 does not cause any net_bridge_port to be deleted, so there was no guarantee that all events had been processed before the device disassociated itself from the bridge. Fix this by always synchronously processing all deferred events before signaling completion of unoffloading back to the driver. Fixes: 4e51bf44a03a ("net: bridge: move the switchdev object replay helpers to "push" mode") Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-16net: bridge: switchdev: Skip MDB replays of deferred events on offloadTobias Waldekranz
Before this change, generation of the list of MDB events to replay would race against the creation of new group memberships, either from the IGMP/MLD snooping logic or from user configuration. While new memberships are immediately visible to walkers of br->mdb_list, the notification of their existence to switchdev event subscribers is deferred until a later point in time. So if a replay list was generated during a time that overlapped with such a window, it would also contain a replay of the not-yet-delivered event. The driver would thus receive two copies of what the bridge internally considered to be one single event. On destruction of the bridge, only a single membership deletion event was therefore sent. As a consequence of this, drivers which reference count memberships (at least DSA), would be left with orphan groups in their hardware database when the bridge was destroyed. This is only an issue when replaying additions. While deletion events may still be pending on the deferred queue, they will already have been removed from br->mdb_list, so no duplicates can be generated in that scenario. To a user this meant that old group memberships, from a bridge in which a port was previously attached, could be reanimated (in hardware) when the port joined a new bridge, without the new bridge's knowledge. For example, on an mv88e6xxx system, create a snooping bridge and immediately add a port to it: root@infix-06-0b-00:~$ ip link add dev br0 up type bridge mcast_snooping 1 && \ > ip link set dev x3 up master br0 And then destroy the bridge: root@infix-06-0b-00:~$ ip link del dev br0 root@infix-06-0b-00:~$ mvls atu ADDRESS FID STATE Q F 0 1 2 3 4 5 6 7 8 9 a DEV:0 Marvell 88E6393X 33:33:00:00:00:6a 1 static - - 0 . . . . . . . . . . 33:33:ff:87:e4:3f 1 static - - 0 . . . . . . . . . . ff:ff:ff:ff:ff:ff 1 static - - 0 1 2 3 4 5 6 7 8 9 a root@infix-06-0b-00:~$ The two IPv6 groups remain in the hardware database because the port (x3) is notified of the host's membership twice: once via the original event and once via a replay. Since only a single delete notification is sent, the count remains at 1 when the bridge is destroyed. Then add the same port (or another port belonging to the same hardware domain) to a new bridge, this time with snooping disabled: root@infix-06-0b-00:~$ ip link add dev br1 up type bridge mcast_snooping 0 && \ > ip link set dev x3 up master br1 All multicast, including the two IPv6 groups from br0, should now be flooded, according to the policy of br1. But instead the old memberships are still active in the hardware database, causing the switch to only forward traffic to those groups towards the CPU (port 0). Eliminate the race in two steps: 1. Grab the write-side lock of the MDB while generating the replay list. This prevents new memberships from showing up while we are generating the replay list. But it leaves the scenario in which a deferred event was already generated, but not delivered, before we grabbed the lock. Therefore: 2. Make sure that no deferred version of a replay event is already enqueued to the switchdev deferred queue, before adding it to the replay list, when replaying additions. Fixes: 4f2673b3a2b6 ("net: bridge: add helper to replay port and host-joined mdb entries") Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com> Reviewed-by: Vladimir Oltean <olteanv@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-30bridge: mcast: fix disabled snooping after long uptimeLinus Lüssing
The original idea of the delay_time check was to not apply multicast snooping too early when an MLD querier appears. And to instead wait at least for MLD reports to arrive before switching from flooding to group based, MLD snooped forwarding, to avoid temporary packet loss. However in a batman-adv mesh network it was noticed that after 248 days of uptime 32bit MIPS based devices would start to signal that they had stopped applying multicast snooping due to missing queriers - even though they were the elected querier and still sending MLD queries themselves. While time_is_before_jiffies() generally is safe against jiffies wrap-arounds, like the code comments in jiffies.h explain, it won't be able to track a difference larger than ULONG_MAX/2. With a 32bit large jiffies and one jiffies tick every 10ms (CONFIG_HZ=100) on these MIPS devices running OpenWrt this would result in a difference larger than ULONG_MAX/2 after 248 (= 2^32/100/60/60/24/2) days and time_is_before_jiffies() would then start to return false instead of true. Leading to multicast snooping not being applied to multicast packets anymore. Fix this issue by using a proper timer_list object which won't have this ULONG_MAX/2 difference limitation. Fixes: b00589af3b04 ("bridge: disable snooping if there is no querier") Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20240127175033.9640-1-linus.luessing@c0d3.blue Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-17netfilter: bridge: replace physindev with physinif in nf_bridge_infoPavel Tikhomirov
An skb can be added to a neigh->arp_queue while waiting for an arp reply. Where original skb's skb->dev can be different to neigh's neigh->dev. For instance in case of bridging dnated skb from one veth to another, the skb would be added to a neigh->arp_queue of the bridge. As skb->dev can be reset back to nf_bridge->physindev and used, and as there is no explicit mechanism that prevents this physindev from been freed under us (for instance neigh_flush_dev doesn't cleanup skbs from different device's neigh queue) we can crash on e.g. this stack: arp_process neigh_update skb = __skb_dequeue(&neigh->arp_queue) neigh_resolve_output(..., skb) ... br_nf_dev_xmit br_nf_pre_routing_finish_bridge_slow skb->dev = nf_bridge->physindev br_handle_frame_finish Let's use plain ifindex instead of net_device link. To peek into the original net_device we will use dev_get_by_index_rcu(). Thus either we get device and are safe to use it or we don't get it and drop skb. Fixes: c4e70a87d975 ("netfilter: bridge: rename br_netfilter.c to br_netfilter_hooks.c") Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-12-26bridge: cfm: fix enum typo in br_cc_ccm_tx_parseLin Ma
It appears that there is a typo in the code where the nlattr array is being parsed with policy br_cfm_cc_ccm_tx_policy, but the instance is being accessed via IFLA_BRIDGE_CFM_CC_RDI_INSTANCE, which is associated with the policy br_cfm_cc_rdi_policy. This problem was introduced by commit 2be665c3940d ("bridge: cfm: Netlink SET configuration Interface."). Though it seems like a harmless typo since these two enum owns the exact same value (1 here), it is quite misleading hence fix it by using the correct enum IFLA_BRIDGE_CFM_CC_CCM_TX_INSTANCE here. Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-20bridge: mdb: Add MDB bulk deletion supportIdo Schimmel
Implement MDB bulk deletion support in the bridge driver, allowing MDB entries to be deleted in bulk according to provided parameters. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-05docs: bridge: Add kAPI/uAPI fieldsHangbin Liu
Add kAPI/uAPI field for bridge doc. Update struct net_bridge_vlan comments to fix doc build warning. Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-11-14netfilter: nf_conntrack_bridge: initialize err to 0Linkui Xiao
K2CI reported a problem: consume_skb(skb); return err; [nf_br_ip_fragment() error] uninitialized symbol 'err'. err is not initialized, because returning 0 is expected, initialize err to 0. Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system") Reported-by: k2ci <kernel-bot@kylinos.cn> Signed-off-by: Linkui Xiao <xiaolinkui@kylinos.cn> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-11-08netfilter: add missing module descriptionsFlorian Westphal
W=1 builds warn on missing MODULE_DESCRIPTION, add them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-27net: bridge: fill in MODULE_DESCRIPTION()Nikolay Aleksandrov
Fill in bridge's module description. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27bridge: mcast: Add MDB get supportIdo Schimmel
Implement support for MDB get operation by looking up a matching MDB entry, allocating the skb according to the entry's size and then filling in the response. The operation is performed under the bridge multicast lock to ensure that the entry does not change between the time the reply size is determined and when the reply is filled in. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27bridge: mcast: Rename MDB entry get functionIdo Schimmel
The current name is going to conflict with the upcoming net device operation for the MDB get operation. Rename the function to br_mdb_entry_skb_get(). No functional changes intended. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27bridge: mcast: Factor out a helper for PG entry size calculationIdo Schimmel
Currently, netlink notifications are sent for individual port group entries and not for the entire MDB entry itself. Subsequent patches are going to add MDB get support which will require the bridge driver to reply with an entire MDB entry. Therefore, as a preparation, factor out an helper to calculate the size of an individual port group entry. When determining the size of the reply this helper will be invoked for each port group entry in the MDB entry. No functional changes intended. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27bridge: mcast: Account for missing attributesIdo Schimmel
The 'MDBA_MDB' and 'MDBA_MDB_ENTRY' nest attributes are not accounted for when calculating the size of MDB notifications. Add them along with comments for existing attributes. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27bridge: mcast: Dump MDB entries even when snooping is disabledIdo Schimmel
Currently, the bridge driver does not dump MDB entries when multicast snooping is disabled although the entries are present in the kernel: # bridge mdb add dev br0 port swp1 grp 239.1.1.1 permanent # bridge mdb show dev br0 dev br0 port swp1 grp 239.1.1.1 permanent dev br0 port br0 grp ff02::6a temp dev br0 port br0 grp ff02::1:ff9d:e61b temp # ip link set dev br0 type bridge mcast_snooping 0 # bridge mdb show dev br0 # ip link set dev br0 type bridge mcast_snooping 1 # bridge mdb show dev br0 dev br0 port swp1 grp 239.1.1.1 permanent dev br0 port br0 grp ff02::6a temp dev br0 port br0 grp ff02::1:ff9d:e61b temp This behavior differs from other netlink dump interfaces that dump entries regardless if they are used or not. For example, VLANs are dumped even when VLAN filtering is disabled: # ip link set dev br0 type bridge vlan_filtering 0 # bridge vlan show dev swp1 port vlan-id swp1 1 PVID Egress Untagged Remove the check and always dump MDB entries: # bridge mdb add dev br0 port swp1 grp 239.1.1.1 permanent # bridge mdb show dev br0 dev br0 port swp1 grp 239.1.1.1 permanent dev br0 port br0 grp ff02::6a temp dev br0 port br0 grp ff02::1:ffeb:1a4d temp # ip link set dev br0 type bridge mcast_snooping 0 # bridge mdb show dev br0 dev br0 port swp1 grp 239.1.1.1 permanent dev br0 port br0 grp ff02::6a temp dev br0 port br0 grp ff02::1:ffeb:1a4d temp # ip link set dev br0 type bridge mcast_snooping 1 # bridge mdb show dev br0 dev br0 port swp1 grp 239.1.1.1 permanent dev br0 port br0 grp ff02::6a temp dev br0 port br0 grp ff02::1:ffeb:1a4d temp Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-24br_netfilter: use single forward hook for ip and arpFlorian Westphal
br_netfilter registers two forward hooks, one for ip and one for arp. Just use a common function for both and then call the arp/ip helper as needed. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-18netfilter: bridge: convert br_netfilter to NF_DROP_REASONFlorian Westphal
errno is 0 because these hooks are called from prerouting and forward. There is no socket that the errno would ever be propagated to. Other netfilter modules (e.g. nf_nat, conntrack, ...) can be converted in a similar way. Signed-off-by: Florian Westphal <fw@strlen.de>
2023-10-17net: bridge: Set strict_start_type for br_policyJohannes Nixdorf
Set any new attributes added to br_policy to be parsed strictly, to prevent userspace from passing garbage. Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20231016-fdb_limit-v5-4-32cddff87758@avm.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-17net: bridge: Add netlink knobs for number / max learned FDB entriesJohannes Nixdorf
The previous patch added accounting and a limit for the number of dynamically learned FDB entries per bridge. However it did not provide means to actually configure those bounds or read back the count. This patch does that. Two new netlink attributes are added for the accounting and limit of dynamically learned FDB entries: - IFLA_BR_FDB_N_LEARNED (RO) for the number of entries accounted for a single bridge. - IFLA_BR_FDB_MAX_LEARNED (RW) for the configured limit of entries for the bridge. The new attributes are used like this: # ip link add name br up type bridge fdb_max_learned 256 # ip link add name v1 up master br type veth peer v2 # ip link set up dev v2 # mausezahn -a rand -c 1024 v2 0.01 seconds (90877 packets per second # bridge fdb | grep -v permanent | wc -l 256 # ip -d link show dev br 13: br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 [...] [...] fdb_n_learned 256 fdb_max_learned 256 Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20231016-fdb_limit-v5-3-32cddff87758@avm.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-17net: bridge: Track and limit dynamically learned FDB entriesJohannes Nixdorf
A malicious actor behind one bridge port may spam the kernel with packets with a random source MAC address, each of which will create an FDB entry, each of which is a dynamic allocation in the kernel. There are roughly 2^48 different MAC addresses, further limited by the rhashtable they are stored in to 2^31. Each entry is of the type struct net_bridge_fdb_entry, which is currently 128 bytes big. This means the maximum amount of memory allocated for FDB entries is 2^31 * 128B = 256GiB, which is too much for most computers. Mitigate this by maintaining a per bridge count of those automatically generated entries in fdb_n_learned, and a limit in fdb_max_learned. If the limit is hit new entries are not learned anymore. For backwards compatibility the default setting of 0 disables the limit. User-added entries by netlink or from bridge or bridge port addresses are never blocked and do not count towards that limit. Introduce a new fdb entry flag BR_FDB_DYNAMIC_LEARNED to keep track of whether an FDB entry is included in the count. The flag is enabled for dynamically learned entries, and disabled for all other entries. This should be equivalent to BR_FDB_ADDED_BY_USER and BR_FDB_LOCAL being unset, but contrary to the two flags it can be toggled atomically. Atomicity is required here, as there are multiple callers that modify the flags, but are not under a common lock (br_fdb_update is the exception for br->hash_lock, br_fdb_external_learn_add for RTNL). Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de> Link: https://lore.kernel.org/r/20231016-fdb_limit-v5-2-32cddff87758@avm.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-17net: bridge: Set BR_FDB_ADDED_BY_USER early in fdb_add_entryJohannes Nixdorf
In preparation of the following fdb limit for dynamically learned entries, allow fdb_create to detect that the entry was added by the user. This way it can skip applying the limit in this case. Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de> Link: https://lore.kernel.org/r/20231016-fdb_limit-v5-1-32cddff87758@avm.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-13net: Handle bulk delete policy in bridge driverAmit Cohen
The merge commit 92716869375b ("Merge branch 'br-flush-filtering'") added support for FDB flushing in bridge driver. The following patches will extend VXLAN driver to support FDB flushing as well. The netlink message for bulk delete is shared between the drivers. With the existing implementation, there is no way to prevent user from flushing with attributes that are not supported per driver. For example, when VNI will be added, user will not get an error for flush FDB entries in bridge with VNI, although this attribute is not relevant for bridge. As preparation for support of FDB flush in VXLAN driver, move the policy to be handled in bridge driver, later a new policy for VXLAN will be added in VXLAN driver. Do not pass 'vid' as part of ndo_fdb_del_bulk(), as this field is relevant only for bridge. Signed-off-by: Amit Cohen <amcohen@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01neighbour: fix data-races around n->outputEric Dumazet
n->output field can be read locklessly, while a writer might change the pointer concurrently. Add missing annotations to prevent load-store tearing. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-19net: bridge: use DEV_STATS_INC()Eric Dumazet
syzbot/KCSAN reported data-races in br_handle_frame_finish() [1] This function can run from multiple cpus without mutual exclusion. Adopt SMP safe DEV_STATS_INC() to update dev->stats fields. Handles updates to dev->stats.tx_dropped while we are at it. [1] BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 1: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 run_ksoftirqd+0x17/0x20 kernel/softirq.c:921 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 read-write to 0xffff8881374b2178 of 8 bytes by interrupt on cpu 0: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c9/0x940 net/bridge/br_input.c:417 __netif_receive_skb_core+0xa8a/0x21e0 net/core/dev.c:5417 __netif_receive_skb_one_core net/core/dev.c:5521 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5637 process_backlog+0x21f/0x380 net/core/dev.c:5965 __napi_poll+0x60/0x3b0 net/core/dev.c:6527 napi_poll net/core/dev.c:6594 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6727 __do_softirq+0xc1/0x265 kernel/softirq.c:553 do_softirq+0x5e/0x90 kernel/softirq.c:454 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x1a8/0x1f0 net/batman-adv/translation-table.c:1356 batadv_tt_purge+0x2b/0x630 net/batman-adv/translation-table.c:3560 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00000000000d7190 -> 0x00000000000d7191 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 14848 Comm: kworker/u4:11 Not tainted 6.6.0-rc1-syzkaller-00236-gad8a69f361b9 #0 Fixes: 1c29fc4989bc ("[BRIDGE]: keep track of received multicast packets") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Nikolay Aleksandrov <razor@blackwall.org> Cc: bridge@lists.linux-foundation.org Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20230918091351.1356153-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-29Merge tag 'sysctl-6.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and placings sysctls to their own sybsystem or file to help avoid merge conflicts. Matthew Wilcox pointed out though that if we're going to do that we might as well also *save* space while at it and try to remove the extra last sysctl entry added at the end of each array, a sentintel, instead of bloating the kernel by adding a new sentinel with each array moved. Doing that was not so trivial, and has required slowing down the moves of kernel/sysctl.c arrays and measuring the impact on size by each new move. The complex part of the effort to help reduce the size of each sysctl is being done by the patient work of el señor Don Joel Granados. A lot of this is truly painful code refactoring and testing and then trying to measure the savings of each move and removing the sentinels. Although Joel already has code which does most of this work, experience with sysctl moves in the past shows is we need to be careful due to the slew of odd build failures that are possible due to the amount of random Kconfig options sysctls use. To that end Joel's work is split by first addressing the major housekeeping needed to remove the sentinels, which is part of this merge request. The rest of the work to actually remove the sentinels will be done later in future kernel releases. The preliminary math is showing this will all help reduce the overall build time size of the kernel and run time memory consumed by the kernel by about ~64 bytes per array where we are able to remove each sentinel in the future. That also means there is no more bloating the kernel with the extra ~64 bytes per array moved as no new sentinels are created" * tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: sysctl: Use ctl_table_size as stopping criteria for list macro sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl vrf: Update to register_net_sysctl_sz networking: Update to register_net_sysctl_sz netfilter: Update to register_net_sysctl_sz ax.25: Update to register_net_sysctl_sz sysctl: Add size to register_net_sysctl function sysctl: Add size arg to __register_sysctl_init sysctl: Add size to register_sysctl sysctl: Add a size arg to __register_sysctl_table sysctl: Add size argument to init_header sysctl: Add ctl_table_size to ctl_table_header sysctl: Use ctl_table_header in list_for_each_table_entry sysctl: Prefer ctl_table_header in proc_sysctl
2023-08-22netfilter: ebtables: fix fortify warnings in size_entry_mwt()GONG, Ruiqi
When compiling with gcc 13 and CONFIG_FORTIFY_SOURCE=y, the following warning appears: In function ‘fortify_memcpy_chk’, inlined from ‘size_entry_mwt’ at net/bridge/netfilter/ebtables.c:2118:2: ./include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning] 592 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The compiler is complaining: memcpy(&offsets[1], &entry->watchers_offset, sizeof(offsets) - sizeof(offsets[0])); where memcpy reads beyong &entry->watchers_offset to copy {watchers,target,next}_offset altogether into offsets[]. Silence the warning by wrapping these three up via struct_group(). Signed-off-by: GONG, Ruiqi <gongruiqi1@huawei.com> Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2023-08-15netfilter: Update to register_net_sysctl_szJoel Granados
Move from register_net_sysctl to register_net_sysctl_sz for all the netfilter related files. Do this while making sure to mirror the NULL assignments with a table_size of zero for the unprivileged users. We need to move to the new function in preparation for when we change SIZE_MAX to ARRAY_SIZE() in the register_net_sysctl macro. Failing to do so would erroneously allow ARRAY_SIZE() to be called on a pointer. We hold off the SIZE_MAX to ARRAY_SIZE change until we have migrated all the relevant net sysctl registering functions to register_net_sysctl_sz in subsequent commits. Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-07-27bridge: Remove unused declaration br_multicast_set_hash_max()YueHaibing
Since commit 19e3a9c90c53 ("net: bridge: convert multicast to generic rhashtable") this is not used, so can remove it. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20230726143141.11704-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-21net: switchdev: Add a helper to replay objects on a bridge portPetr Machata
When a front panel joins a bridge via another netdevice (typically a LAG), the driver needs to learn about the objects configured on the bridge port. When the bridge port is offloaded by the driver for the first time, this can be achieved by passing a notifier to switchdev_bridge_port_offload(). The notifier is then invoked for the individual objects (such as VLANs) configured on the bridge, and can look for the interesting ones. Calling switchdev_bridge_port_offload() when the second port joins the bridge lower is unnecessary, but the replay is still needed. To that end, add a new function, switchdev_bridge_port_replay(), which does only the replay part of the _offload() function in exactly the same way as that function. Cc: Jiri Pirko <jiri@resnulli.us> Cc: Ivan Vecera <ivecera@redhat.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Nikolay Aleksandrov <razor@blackwall.org> Cc: bridge@lists.linux-foundation.org Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Danielle Ratson <danieller@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-21net: bridge: br_switchdev: Tolerate -EOPNOTSUPP when replaying MDBPetr Machata
There are two kinds of MDB entries to be replayed: port MDB entries, and host MDB entries. They are both replayed by br_switchdev_mdb_replay(). If the driver supports one kind, but lacks the other, the first -EOPNOTSUPP returned terminates the whole replay, including any further still-supported objects in the list. For this to cause issues, there must be MDB entries for both the host and the port being replayed. In that case, if the driver bails out from handling the host entry, the port entries are never replayed. However, the replay is currently only done when a switchdev port joins a bridge. There would be no port memberships at that point. Thus despite being erroneous, the code does not cause observable bugs. This is not an issue with other object kinds either, because there, each function replays one object kind. If a driver does not support that kind, it makes sense to bail out early. -EOPNOTSUPP is then ignored in nbp_switchdev_sync_objs(). For MDB, suppress the -EOPNOTSUPP error code in br_switchdev_mdb_replay() already, so that the whole list gets replayed. The reason we need this patch is that a future patch will introduce a replay that should be used when a front-panel port netdevice is enslaved to a bridge lower, in particular a LAG. The LAG netdevice can already have both host and port MDB entries. The port entries need to be replayed so that they are offloaded on the port that joins the LAG. Cc: Jiri Pirko <jiri@resnulli.us> Cc: Ivan Vecera <ivecera@redhat.com> Cc: Roopa Prabhu <roopa@nvidia.com> Cc: Nikolay Aleksandrov <razor@blackwall.org> Cc: bridge@lists.linux-foundation.org Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Danielle Ratson <danieller@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-19bridge: Add backup nexthop ID supportIdo Schimmel
Add a new bridge port attribute that allows attaching a nexthop object ID to an skb that is redirected to a backup bridge port with VLAN tunneling enabled. Specifically, when redirecting a known unicast packet, read the backup nexthop ID from the bridge port that lost its carrier and set it in the bridge control block of the skb before forwarding it via the backup port. Note that reading the ID from the bridge port should not result in a cache miss as the ID is added next to the 'backup_port' field that was already accessed. After this change, the 'state' field still stays on the first cache line, together with other data path related fields such as 'flags and 'vlgrp': struct net_bridge_port { struct net_bridge * br; /* 0 8 */ struct net_device * dev; /* 8 8 */ netdevice_tracker dev_tracker; /* 16 0 */ struct list_head list; /* 16 16 */ long unsigned int flags; /* 32 8 */ struct net_bridge_vlan_group * vlgrp; /* 40 8 */ struct net_bridge_port * backup_port; /* 48 8 */ u32 backup_nhid; /* 56 4 */ u8 priority; /* 60 1 */ u8 state; /* 61 1 */ u16 port_no; /* 62 2 */ /* --- cacheline 1 boundary (64 bytes) --- */ [...] } __attribute__((__aligned__(8))); When forwarding an skb via a bridge port that has VLAN tunneling enabled, check if the backup nexthop ID stored in the bridge control block is valid (i.e., not zero). If so, instead of attaching the pre-allocated metadata (that only has the tunnel key set), allocate a new metadata, set both the tunnel key and the nexthop object ID and attach it to the skb. By default, do not dump the new attribute to user space as a value of zero is an invalid nexthop object ID. The above is useful for EVPN multihoming. When one of the links composing an Ethernet Segment (ES) fails, traffic needs to be redirected towards the host via one of the other ES peers. For example, if a host is multihomed to three different VTEPs, the backup port of each ES link needs to be set to the VXLAN device and the backup nexthop ID needs to point to an FDB nexthop group that includes the IP addresses of the other two VTEPs. The VXLAN driver will extract the ID from the metadata of the redirected skb, calculate its flow hash and forward it towards one of the other VTEPs. If the ID does not exist, or represents an invalid nexthop object, the VXLAN driver will drop the skb. This relieves the bridge driver from the need to validate the ID. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-03net: bridge: keep ports without IFF_UNICAST_FLT in BR_PROMISC modeVladimir Oltean
According to the synchronization rules for .ndo_get_stats() as seen in Documentation/networking/netdevices.rst, acquiring a plain spin_lock() should not be illegal, but the bridge driver implementation makes it so. After running these commands, I am being faced with the following lockdep splat: $ ip link add link swp0 name macsec0 type macsec encrypt on && ip link set swp0 up $ ip link add dev br0 type bridge vlan_filtering 1 && ip link set br0 up $ ip link set macsec0 master br0 && ip link set macsec0 up ======================================================== WARNING: possible irq lock inversion dependency detected 6.4.0-04295-g31b577b4bd4a #603 Not tainted -------------------------------------------------------- swapper/1/0 just changed the state of lock: ffff6bd348724cd8 (&br->lock){+.-.}-{3:3}, at: br_forward_delay_timer_expired+0x34/0x198 but this lock took another, SOFTIRQ-unsafe lock in the past: (&ocelot->stats_lock){+.+.}-{3:3} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Chain exists of: &br->lock --> &br->hash_lock --> &ocelot->stats_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ocelot->stats_lock); local_irq_disable(); lock(&br->lock); lock(&br->hash_lock); <Interrupt> lock(&br->lock); *** DEADLOCK *** (details about the 3 locks skipped) swp0 is instantiated by drivers/net/dsa/ocelot/felix.c, and this only matters to the extent that its .ndo_get_stats64() method calls spin_lock(&ocelot->stats_lock). Documentation/locking/lockdep-design.rst says: | A lock is irq-safe means it was ever used in an irq context, while a lock | is irq-unsafe means it was ever acquired with irq enabled. (...) | Furthermore, the following usage based lock dependencies are not allowed | between any two lock-classes:: | | <hardirq-safe> -> <hardirq-unsafe> | <softirq-safe> -> <softirq-unsafe> Lockdep marks br->hash_lock as softirq-safe, because it is sometimes taken in softirq context (for example br_fdb_update() which runs in NET_RX softirq), and when it's not in softirq context it blocks softirqs by using spin_lock_bh(). Lockdep marks ocelot->stats_lock as softirq-unsafe, because it never blocks softirqs from running, and it is never taken from softirq context. So it can always be interrupted by softirqs. There is a call path through which a function that holds br->hash_lock: fdb_add_hw_addr() will call a function that acquires ocelot->stats_lock: ocelot_port_get_stats64(). This can be seen below: ocelot_port_get_stats64+0x3c/0x1e0 felix_get_stats64+0x20/0x38 dsa_slave_get_stats64+0x3c/0x60 dev_get_stats+0x74/0x2c8 rtnl_fill_stats+0x4c/0x150 rtnl_fill_ifinfo+0x5cc/0x7b8 rtmsg_ifinfo_build_skb+0xe4/0x150 rtmsg_ifinfo+0x5c/0xb0 __dev_notify_flags+0x58/0x200 __dev_set_promiscuity+0xa0/0x1f8 dev_set_promiscuity+0x30/0x70 macsec_dev_change_rx_flags+0x68/0x88 __dev_set_promiscuity+0x1a8/0x1f8 __dev_set_rx_mode+0x74/0xa8 dev_uc_add+0x74/0xa0 fdb_add_hw_addr+0x68/0xd8 fdb_add_local+0xc4/0x110 br_fdb_add_local+0x54/0x88 br_add_if+0x338/0x4a0 br_add_slave+0x20/0x38 do_setlink+0x3a4/0xcb8 rtnl_newlink+0x758/0x9d0 rtnetlink_rcv_msg+0x2f0/0x550 netlink_rcv_skb+0x128/0x148 rtnetlink_rcv+0x24/0x38 the plain English explanation for it is: The macsec0 bridge port is created without p->flags & BR_PROMISC, because it is what br_manage_promisc() decides for a VLAN filtering bridge with a single auto port. As part of the br_add_if() procedure, br_fdb_add_local() is called for the MAC address of the device, and this results in a call to dev_uc_add() for macsec0 while the softirq-safe br->hash_lock is taken. Because macsec0 does not have IFF_UNICAST_FLT, dev_uc_add() ends up calling __dev_set_promiscuity() for macsec0, which is propagated by its implementation, macsec_dev_change_rx_flags(), to the lower device: swp0. This triggers the call path: dev_set_promiscuity(swp0) -> rtmsg_ifinfo() -> dev_get_stats() -> ocelot_port_get_stats64() with a calling context that lockdep doesn't like (br->hash_lock held). Normally we don't see this, because even though many drivers that can be bridge ports don't support IFF_UNICAST_FLT, we need a driver that (a) doesn't support IFF_UNICAST_FLT, *and* (b) it forwards the IFF_PROMISC flag to another driver, and (c) *that* driver implements ndo_get_stats64() using a softirq-unsafe spinlock. Condition (b) is necessary because the first __dev_set_rx_mode() calls __dev_set_promiscuity() with "bool notify=false", and thus, the rtmsg_ifinfo() code path won't be entered. The same criteria also hold true for DSA switches which don't report IFF_UNICAST_FLT. When the DSA master uses a spin_lock() in its ndo_get_stats64() method, the same lockdep splat can be seen. I think the deadlock possibility is real, even though I didn't reproduce it, and I'm thinking of the following situation to support that claim: fdb_add_hw_addr() runs on a CPU A, in a context with softirqs locally disabled and br->hash_lock held, and may end up attempting to acquire ocelot->stats_lock. In parallel, ocelot->stats_lock is currently held by a thread B (say, ocelot_check_stats_work()), which is interrupted while holding it by a softirq which attempts to lock br->hash_lock. Thread B cannot make progress because br->hash_lock is held by A. Whereas thread A cannot make progress because ocelot->stats_lock is held by B. When taking the issue at face value, the bridge can avoid that problem by simply making the ports promiscuous from a code path with a saner calling context (br->hash_lock not held). A bridge port without IFF_UNICAST_FLT is going to become promiscuous as soon as we call dev_uc_add() on it (which we do unconditionally), so why not be preemptive and make it promiscuous right from the beginning, so as to not be taken by surprise. With this, we've broken the links between code that holds br->hash_lock or br->lock and code that calls into the ndo_change_rx_flags() or ndo_get_stats64() ops of the bridge port. Fixes: 2796d0c648c9 ("bridge: Automatically manage port promiscuous mode.") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-30skbuff: bridge: Add layer 2 miss indicationIdo Schimmel
For EVPN non-DF (Designated Forwarder) filtering we need to be able to prevent decapsulated traffic from being flooded to a multi-homed host. Filtering of multicast and broadcast traffic can be achieved using the following flower filter: # tc filter add dev bond0 egress pref 1 proto all flower indev vxlan0 dst_mac 01:00:00:00:00:00/01:00:00:00:00:00 action drop Unlike broadcast and multicast traffic, it is not currently possible to filter unknown unicast traffic. The classification into unknown unicast is performed by the bridge driver, but is not visible to other layers such as tc. Solve this by adding a new 'l2_miss' bit to the tc skb extension. Clear the bit whenever a packet enters the bridge (received from a bridge port or transmitted via the bridge) and set it if the packet did not match an FDB or MDB entry. If there is no skb extension and the bit needs to be cleared, then do not allocate one as no extension is equivalent to the bit being cleared. The bit is not set for broadcast packets as they never perform a lookup and therefore never incur a miss. A bit that is set for every flooded packet would also work for the current use case, but it does not allow us to differentiate between registered and unregistered multicast traffic, which might be useful in the future. To keep the performance impact to a minimum, the marking of packets is guarded by the 'tc_skb_ext_tc' static key. When 'false', the skb is not touched and an skb extension is not allocated. Instead, only a 5 bytes nop is executed, as demonstrated below for the call site in br_handle_frame(). Before the patch: ``` memset(skb->cb, 0, sizeof(struct br_input_skb_cb)); c37b09: 49 c7 44 24 28 00 00 movq $0x0,0x28(%r12) c37b10: 00 00 p = br_port_get_rcu(skb->dev); c37b12: 49 8b 44 24 10 mov 0x10(%r12),%rax memset(skb->cb, 0, sizeof(struct br_input_skb_cb)); c37b17: 49 c7 44 24 30 00 00 movq $0x0,0x30(%r12) c37b1e: 00 00 c37b20: 49 c7 44 24 38 00 00 movq $0x0,0x38(%r12) c37b27: 00 00 ``` After the patch (when static key is disabled): ``` memset(skb->cb, 0, sizeof(struct br_input_skb_cb)); c37c29: 49 c7 44 24 28 00 00 movq $0x0,0x28(%r12) c37c30: 00 00 c37c32: 49 8d 44 24 28 lea 0x28(%r12),%rax c37c37: 48 c7 40 08 00 00 00 movq $0x0,0x8(%rax) c37c3e: 00 c37c3f: 48 c7 40 10 00 00 00 movq $0x0,0x10(%rax) c37c46: 00 #ifdef CONFIG_HAVE_JUMP_LABEL_HACK static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { asm_volatile_goto("1:" c37c47: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) br_tc_skb_miss_set(skb, false); p = br_port_get_rcu(skb->dev); c37c4c: 49 8b 44 24 10 mov 0x10(%r12),%rax ``` Subsequent patches will extend the flower classifier to be able to match on the new 'l2_miss' bit and enable / disable the static key when filters that match on it are added / deleted. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-17bridge: always declare tunnel functionsArnd Bergmann
When CONFIG_BRIDGE_VLAN_FILTERING is disabled, two functions are still defined but have no prototype or caller. This causes a W=1 warning for the missing prototypes: net/bridge/br_netlink_tunnel.c:29:6: error: no previous prototype for 'vlan_tunid_inrange' [-Werror=missing-prototypes] net/bridge/br_netlink_tunnel.c:199:5: error: no previous prototype for 'br_vlan_tunnel_info' [-Werror=missing-prototypes] The functions are already contitional on CONFIG_BRIDGE_VLAN_FILTERING, and I coulnd't easily figure out the right set of #ifdefs, so just move the declarations out of the #ifdef to avoid the warning, at a small cost in code size over a more elaborate fix. Fixes: 188c67dd1906 ("net: bridge: vlan options: add support for tunnel id dumping") Fixes: 569da0822808 ("net: bridge: vlan options: add support for tunnel mapping set/del") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://lore.kernel.org/r/20230516194625.549249-3-arnd@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10net: add vlan_get_protocol_and_depth() helperEric Dumazet
Before blamed commit, pskb_may_pull() was used instead of skb_header_pointer() in __vlan_get_protocol() and friends. Few callers depended on skb->head being populated with MAC header, syzbot caught one of them (skb_mac_gso_segment()) Add vlan_get_protocol_and_depth() to make the intent clearer and use it where sensible. This is a more generic fix than commit e9d3f80935b6 ("net/af_packet: make sure to pull mac header") which was dealing with a similar issue. kernel BUG at include/linux/skbuff.h:2655 ! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 1441 Comm: syz-executor199 Not tainted 6.1.24-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 RIP: 0010:__skb_pull include/linux/skbuff.h:2655 [inline] RIP: 0010:skb_mac_gso_segment+0x68f/0x6a0 net/core/gro.c:136 Code: fd 48 8b 5c 24 10 44 89 6b 70 48 c7 c7 c0 ae 0d 86 44 89 e6 e8 a1 91 d0 00 48 c7 c7 00 af 0d 86 48 89 de 31 d2 e8 d1 4a e9 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RSP: 0018:ffffc90001bd7520 EFLAGS: 00010286 RAX: ffffffff8469736a RBX: ffff88810f31dac0 RCX: ffff888115a18b00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90001bd75e8 R08: ffffffff84697183 R09: fffff5200037adf9 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000012 R13: 000000000000fee5 R14: 0000000000005865 R15: 000000000000fed7 FS: 000055555633f300(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 0000000116fea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> [<ffffffff847018dd>] __skb_gso_segment+0x32d/0x4c0 net/core/dev.c:3419 [<ffffffff8470398a>] skb_gso_segment include/linux/netdevice.h:4819 [inline] [<ffffffff8470398a>] validate_xmit_skb+0x3aa/0xee0 net/core/dev.c:3725 [<ffffffff84707042>] __dev_queue_xmit+0x1332/0x3300 net/core/dev.c:4313 [<ffffffff851a9ec7>] dev_queue_xmit+0x17/0x20 include/linux/netdevice.h:3029 [<ffffffff851b4a82>] packet_snd net/packet/af_packet.c:3111 [inline] [<ffffffff851b4a82>] packet_sendmsg+0x49d2/0x6470 net/packet/af_packet.c:3142 [<ffffffff84669a12>] sock_sendmsg_nosec net/socket.c:716 [inline] [<ffffffff84669a12>] sock_sendmsg net/socket.c:736 [inline] [<ffffffff84669a12>] __sys_sendto+0x472/0x5f0 net/socket.c:2139 [<ffffffff84669c75>] __do_sys_sendto net/socket.c:2151 [inline] [<ffffffff84669c75>] __se_sys_sendto net/socket.c:2147 [inline] [<ffffffff84669c75>] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147 [<ffffffff8551d40f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff8551d40f>] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80 [<ffffffff85600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 469aceddfa3e ("vlan: consolidate VLAN parsing code and limit max parsing depth") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Toke Høiland-Jørgensen <toke@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Allow setting per-{Port, VLAN} neighbor suppression stateIdo Schimmel
Add a new bridge port attribute that allows user space to enable per-{Port, VLAN} neighbor suppression. Example: # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]' false # bridge link set dev swp1 neigh_vlan_suppress on # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]' true # bridge link set dev swp1 neigh_vlan_suppress off # bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]' false Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: vlan: Allow setting VLAN neighbor suppression stateIdo Schimmel
Add a new VLAN attribute that allows user space to set the neighbor suppression state of the port VLAN. Example: # bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]' false # bridge vlan set vid 10 dev swp1 neigh_suppress on # bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]' true # bridge vlan set vid 10 dev swp1 neigh_suppress off # bridge -d -j -p vlan show dev swp1 vid 10 | jq '.[]["vlans"][]["neigh_suppress"]' false # bridge vlan set vid 10 dev br0 neigh_suppress on Error: bridge: Can't set neigh_suppress for non-port vlans. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Add per-{Port, VLAN} neighbor suppression data path supportIdo Schimmel
When the bridge is not VLAN-aware (i.e., VLAN ID is 0), determine if neighbor suppression is enabled on a given bridge port solely based on the existing 'BR_NEIGH_SUPPRESS' flag. Otherwise, if the bridge is VLAN-aware, first check if per-{Port, VLAN} neighbor suppression is enabled on the given bridge port using the 'BR_NEIGH_VLAN_SUPPRESS' flag. If so, look up the VLAN and check whether it has neighbor suppression enabled based on the per-VLAN 'BR_VLFLAG_NEIGH_SUPPRESS_ENABLED' flag. If the bridge is VLAN-aware, but the bridge port does not have per-{Port, VLAN} neighbor suppression enabled, then fallback to determine neighbor suppression based on the 'BR_NEIGH_SUPPRESS' flag. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Encapsulate data path neighbor suppression logicIdo Schimmel
Currently, there are various places in the bridge data path that check whether neighbor suppression is enabled on a given bridge port. As a preparation for per-{Port, VLAN} neighbor suppression, encapsulate this logic in a function and pass the VLAN ID of the packet as an argument. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Take per-{Port, VLAN} neighbor suppression into accountIdo Schimmel
The bridge driver gates the neighbor suppression code behind an internal per-bridge flag called 'BROPT_NEIGH_SUPPRESS_ENABLED'. The flag is set when at least one bridge port has neighbor suppression enabled. As a preparation for per-{Port, VLAN} neighbor suppression, make sure the global flag is also set if per-{Port, VLAN} neighbor suppression is enabled. That is, when the 'BR_NEIGH_VLAN_SUPPRESS' flag is set on at least one bridge port. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Add internal flags for per-{Port, VLAN} neighbor suppressionIdo Schimmel
Add two internal flags that will be used to enable / disable per-{Port, VLAN} neighbor suppression: 1. 'BR_NEIGH_VLAN_SUPPRESS': A per-port flag used to indicate that per-{Port, VLAN} neighbor suppression is enabled on the bridge port. When set, 'BR_NEIGH_SUPPRESS' has no effect. 2. 'BR_VLFLAG_NEIGH_SUPPRESS_ENABLED': A per-VLAN flag used to indicate that neighbor suppression is enabled on the given VLAN. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Pass VLAN ID to br_flood()Ido Schimmel
Subsequent patches are going to add per-{Port, VLAN} neighbor suppression, which will require br_flood() to potentially suppress ARP / NS packets on a per-{Port, VLAN} basis. As a preparation, pass the VLAN ID of the packet as another argument to br_flood(). Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-21bridge: Reorder neighbor suppression check when floodingIdo Schimmel
The bridge does not flood ARP / NS packets for which a reply was sent to bridge ports that have neighbor suppression enabled. Subsequent patches are going to add per-{Port, VLAN} neighbor suppression, which is going to make it more expensive to check whether neighbor suppression is enabled since a VLAN lookup will be required. Therefore, instead of unnecessarily performing this lookup for every packet, only perform it for ARP / NS packets for which a reply was sent. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-04-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Adjacent changes: net/mptcp/protocol.h 63740448a32e ("mptcp: fix accept vs worker race") 2a6a870e44dd ("mptcp: stops worker on unaccepted sockets at listener close") ddb1a072f858 ("mptcp: move first subflow allocation at mpc access time") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-04-20net: bridge: switchdev: don't notify FDB entries with "master dynamic"Vladimir Oltean
There is a structural problem in switchdev, where the flag bits in struct switchdev_notifier_fdb_info (added_by_user, is_local etc) only represent a simplified / denatured view of what's in struct net_bridge_fdb_entry :: flags (BR_FDB_ADDED_BY_USER, BR_FDB_LOCAL etc). Each time we want to pass more information about struct net_bridge_fdb_entry :: flags to struct switchdev_notifier_fdb_info (here, BR_FDB_STATIC), we find that FDB entries were already notified to switchdev with no regard to this flag, and thus, switchdev drivers had no indication whether the notified entries were static or not. For example, this command: ip link add br0 type bridge && ip link set swp0 master br0 bridge fdb add dev swp0 00:01:02:03:04:05 master dynamic has never worked as intended with switchdev. It causes a struct net_bridge_fdb_entry to be passed to br_switchdev_fdb_notify() which has a single flag set: BR_FDB_ADDED_BY_USER. This is further passed to the switchdev notifier chain, where interested drivers have no choice but to assume this is a static (does not age) and sticky (does not migrate) FDB entry. So currently, all drivers offload it to hardware as such, as can be seen below ("offload" is set). bridge fdb get 00:01:02:03:04:05 dev swp0 master 00:01:02:03:04:05 dev swp0 offload master br0 The software FDB entry expires $ageing_time centiseconds after the kernel last sees a packet with this MAC SA, and the bridge notifies its deletion as well, so it eventually disappears from hardware too. This is a problem, because it is actually desirable to start offloading "master dynamic" FDB entries correctly - they should expire $ageing_time centiseconds after the *hardware* port last sees a packet with this MAC SA - and this is how the current incorrect behavior was discovered. With an offloaded data plane, it can be expected that software only sees exception path packets, so an otherwise active dynamic FDB entry would be aged out by software sooner than it should. With the change in place, these FDB entries are no longer offloaded: bridge fdb get 00:01:02:03:04:05 dev swp0 master 00:01:02:03:04:05 dev swp0 master br0 and this also constitutes a better way (assuming a backport to stable kernels) for user space to determine whether the kernel has the capability of doing something sane with these or not. As opposed to "master dynamic" FDB entries, on the current behavior of which no one currently depends on (which can be deduced from the lack of kselftests), Ido Schimmel explains that entries with the "extern_learn" flag (BR_FDB_ADDED_BY_EXT_LEARN) should still be notified to switchdev, since the spectrum driver listens to them (and this is kind of okay, because although they are treated identically to "static", they are expected to not age, and to roam). Fixes: 6b26b51b1d13 ("net: bridge: Add support for notifying devices about FDB add/del") Link: https://lore.kernel.org/netdev/20230327115206.jk5q5l753aoelwus@skbuf/ Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/20230418155902.898627-1-vladimir.oltean@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-04-06netfilter: br_netfilter: fix recent physdev match breakageFlorian Westphal
Recent attempt to ensure PREROUTING hook is executed again when a decrypted ipsec packet received on a bridge passes through the network stack a second time broke the physdev match in INPUT hook. We can't discard the nf_bridge info strct from sabotage_in hook, as this is needed by the physdev match. Keep the struct around and handle this with another conditional instead. Fixes: 2b272bb558f1 ("netfilter: br_netfilter: disable sabotage_in hook after first suppression") Reported-and-tested-by: Farid BENAMROUCHE <fariouche@yahoo.fr> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-03-28net: dst: Switch to rcuref_t reference countingThomas Gleixner
Under high contention dst_entry::__refcnt becomes a significant bottleneck. atomic_inc_not_zero() is implemented with a cmpxchg() loop, which goes into high retry rates on contention. Switch the reference count to rcuref_t which results in a significant performance gain. Rename the reference count member to __rcuref to reflect the change. The gain depends on the micro-architecture and the number of concurrent operations and has been measured in the range of +25% to +130% with a localhost memtier/memcached benchmark which amplifies the problem massively. Running the memtier/memcached benchmark over a real (1Gb) network connection the conversion on top of the false sharing fix for struct dst_entry::__refcnt results in a total gain in the 2%-5% range over the upstream baseline. Reported-by: Wangyang Guo <wangyang.guo@intel.com> Reported-by: Arjan Van De Ven <arjan.van.de.ven@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230307125538.989175656@linutronix.de Link: https://lore.kernel.org/r/20230323102800.215027837@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-17rtnetlink: bridge: mcast: Relax group address validation in common codeIdo Schimmel
In the upcoming VXLAN MDB implementation, the 0.0.0.0 and :: MDB entries will act as catchall entries for unregistered IP multicast traffic in a similar fashion to the 00:00:00:00:00:00 VXLAN FDB entry that is used to transmit BUM traffic. In deployments where inter-subnet multicast forwarding is used, not all the VTEPs in a tenant domain are members in all the broadcast domains. It is therefore advantageous to transmit BULL (broadcast, unknown unicast and link-local multicast) and unregistered IP multicast traffic on different tunnels. If the same tunnel was used, a VTEP only interested in IP multicast traffic would also pull all the BULL traffic and drop it as it is not a member in the originating broadcast domain [1]. Prepare for this change by allowing the 0.0.0.0 group address in the common rtnetlink MDB code and forbid it in the bridge driver. A similar change is not needed for IPv6 because the common code only validates that the group address is not the all-nodes address. [1] https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-irb-mcast#section-2.6 Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-17rtnetlink: bridge: mcast: Move MDB handlers out of bridge driverIdo Schimmel
Currently, the bridge driver registers handlers for MDB netlink messages, making it impossible for other drivers to implement MDB support. As a preparation for VXLAN MDB support, move the MDB handlers out of the bridge driver to the core rtnetlink code. The rtnetlink code will call into individual drivers by invoking their previously added MDB net device operations. Note that while the diffstat is large, the change is mechanical. It moves code out of the bridge driver to rtnetlink code. Also note that a similar change was made in 2012 with commit 77162022ab26 ("net: add generic PF_BRIDGE:RTM_ FDB hooks") that moved FDB handlers out of the bridge driver to the core rtnetlink code. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>