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path: root/net/bridge/br_private.h
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9 daysnet: bridge: use option bits for CFM/MRP frame handlersZhiling Zou
CFM and MRP register a global br_frame_type whose hlist_node is linked into the per-bridge frame_type_list when the first MEP/MRP instance is created. Enabling the protocol on multiple bridges therefore inserts the same node into multiple lists. Unregistering it on one bridge then corrupts list state belonging to another. These handlers can only be installed once per bridge, and they are uncommon. Track their per-bridge enable state with net_bridge option bits, which already live on the Rx hot cache line, and dispatch the matching handler directly from the receive path. Check both bits together first as an unlikely case. Remove the generic frame_type_list and br_frame_type helpers, which have had no other users since CFM and MRP were added. That shrinks struct net_bridge by 8 bytes and drops the list walk from the fast path. When neither protocol is compiled in, BR_CFM_MRP_OPTS is 0 and the compiler prunes the branch. Fixes: 90c628dd47ff ("net: bridge: extend the process of special frames") Fixes: dc32cbb3dbd7 ("bridge: cfm: Kernel space implementation of CFM. CCM frame RX added.") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Suggested-by: Nikolay Aleksandrov <razor@blackwall.org> Co-developed-by: Yilin Zhu <zylzyl2333@gmail.com> Signed-off-by: Yilin Zhu <zylzyl2333@gmail.com> Signed-off-by: Zhiling Zou <zhilinz@nebusec.ai> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/0345b9d5aa60ba416f6738ff1b87140f0a749cb8.1788417901.git.zhilinz@nebusec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-07bridge: Validate NS/NA messages using ndisc_check_ns_na()Danielle Ratson
The bridge performs neighbor suppression by snooping NS/NA messages, but previously only checked the ICMPv6 type and code. This leaves it open to acting on malformed or spoofed packets that any RFC-compliant node should reject. Wire br_is_nd_neigh_msg() into the new ndisc_check_ns_na() helper, which enforces the full RFC 4861 section 7.1.1/7.1.2 receive validation: hop limit of 255, valid checksum, correct code, and type-specific rules (NS target not multicast; NA solicited flag clear for multicast destinations). MLD messages are already validated by ipv6_mc_check_mld() before the bridge acts on them; this brings NS/NA to the same standard. As a side effect, the skb parameter of br_is_nd_neigh_msg() changes from const to non-const, since ndisc_check_ns_na() may reallocate the skb head via pskb_may_pull() and sets the transport header. The returned pointer is now derived from skb_transport_header() rather than a direct cast. Reviewed-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Danielle Ratson <danieller@nvidia.com> Link: https://patch.msgid.link/20260803112505.613873-4-danieller@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-07bridge: Use direct pointer in br_is_nd_neigh_msg()Danielle Ratson
Both callers of br_is_nd_neigh_msg() already call pskb_may_pull() to ensure sizeof(struct ipv6hdr) + sizeof(struct nd_msg) bytes are in the linear area before invoking this function. The skb_header_pointer() call and its fallback buffer are therefore unnecessary. Replace skb_header_pointer() with a direct cast to ipv6_hdr(skb) + 1 and drop the now-unused 'msg' parameter and its corresponding stack buffer from all callers. Reviewed-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Danielle Ratson <danieller@nvidia.com> Link: https://patch.msgid.link/20260803112505.613873-2-danieller@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.2-rc5). Conflicts: drivers/net/amt.c 3656a79f94c47 ("amt: re-read skb header pointers after every pull") 586c4dcf28eb6 ("amt: no longer rely on RTNL in amt_fill_info()") https://lore.kernel.org/amIaJr3aOQNS_Fvl@sirena.org.uk Adjacent changes: drivers/net/geneve.c 8efb8f8bbb35 ("geneve: require CAP_NET_ADMIN in the device netns for changelink") 0ba269933f73 ("geneve: convert config to RCU-protected pointer") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-22net: bridge: vlan: fix vlan range dumps starting with pvidNikolay Aleksandrov
There is a bug in all range dumps that rely on br_vlan_can_enter_range() when the PVID is a range starting VLAN, all following VLANs that match its flags can enter the range, but when the range is filled in only the PVID VLAN is dumped and the rest of the range is discarded because br_vlan_fill_vids() checks for the PVID flag. Since the PVID VLAN can be only one, we need to break ranges around it, the best way to do that consistently for all is to alter br_vlan_can_enter_range() to take into account the PVID and return false to break the range when it's matched. Before the fix: $ ip l add br0 type bridge vlan_filtering 1 $ ip l add dumdum type dummy $ ip l set dumdum master br0 $ ip l set br0 up $ ip l set dumdum up $ bridge vlan add dev dumdum vid 1 pvid untagged master $ bridge vlan add dev dumdum vid 2 untagged master $ bridge vlan show dev dumdum # use legacy dump to show all vlans port vlan-id dumdum 1 PVID Egress Untagged 2 Egress Untagged $ bridge -d vlan show dev dumdum # use the new dump (RTM_GETVLAN) port vlan-id dumdum 1 PVID Egress Untagged state forwarding mcast_router 1 VLAN 2 is missing, and if there are more matching VLANs afterwards they'd be missing too. After the fix: [ same setup steps ] $ bridge vlan show dev dumdum port vlan-id dumdum 1 PVID Egress Untagged 2 Egress Untagged $ bridge -d vlan show dev dumdum # use the new dump (RTM_GETVLAN) port vlan-id dumdum 1 PVID Egress Untagged state forwarding mcast_router 1 2 Egress Untagged state forwarding mcast_router 1 Fixes: 0ab558795184 ("net: bridge: vlan: add rtm range support") Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260721140922.682265-2-razor@blackwall.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-21bridge: mcast: Fix a false positive lockdep splatIdo Schimmel
Connecting two bridges on the same system [1] can result in a lockdep splat [2]. The report is a false positive. Multicast queries are built and transmitted under the bridge multicast lock. When the outgoing port of one bridge is configured on top of another bridge, the transmit path re-enters bridge code and acquires the other bridge's multicast lock in order to snoop the query. Both lock instances share a single lockdep class, so lockdep flags the nested acquisition as an AA deadlock. Giving each bridge its own lock class will not solve the problem: the reverse topology would produce an ABBA splat with the same pair of classes. It also consumes a lockdep key per bridge. Instead, fix the problem by deferring the transmission of the queries to a workqueue. Build the skb and update querier state under the lock as before, then enqueue the skb on a per multicast context queue and schedule the work. Purge the queue when the multicast context is de-initialized. At this stage the work cannot be requeued. There is no need to take a reference on skb->dev since the work cannot outlive the bridge or the bridge port. Use the high priority workqueue to reduce the delay between the enqueue time and the transmission time. With default settings (i.e., querier interval - 255 seconds, query interval - 125 seconds) the extra delay should not be a problem. Avoid the unlikely case of the queue growing endlessly by limiting it to 1,000 skbs. Use this number for the simple reason that this is the default Tx queue length. Use local_bh_{disable,enable}() to disable/enable softIRQs and migration in order to avoid corrupting the multicast statistics (per-CPU u64_stats). [1] ip link add name br1 up type bridge mcast_snooping 1 mcast_querier 1 ip link add name br0 up type bridge mcast_snooping 1 mcast_querier 1 ip link add link br0 name br0.10 up master br1 type vlan id 10 [2] WARNING: possible recursive locking detected 7.0.0-virtme-gb50c64a58a90 #1 Not tainted [...] ip/339 is trying to acquire lock: ffff888104f0b480 (&br->multicast_lock){+.-.}-{3:3}, at: br_ip6_multicast_query (net/bridge/br_multicast.c:3584) but task is already holding lock: ffff888104f03480 (&br->multicast_lock){+.-.}-{3:3}, at: br_multicast_port_query_expired (net/bridge/br_multicast.c:1904) [...] Call Trace: [...] br_ip6_multicast_query (net/bridge/br_multicast.c:3584) br_multicast_ipv6_rcv (net/bridge/br_multicast.c:3988) br_dev_xmit (net/bridge/br_device.c:98 (discriminator 1)) dev_hard_start_xmit (net/core/dev.c:3904) __dev_queue_xmit (net/core/dev.c:4871) vlan_dev_hard_start_xmit (net/8021q/vlan_dev.c:131 (discriminator 1)) dev_hard_start_xmit (net/core/dev.c:3904) __dev_queue_xmit (net/core/dev.c:4871) br_dev_queue_push_xmit (net/bridge/br_forward.c:60) __br_multicast_send_query (net/bridge/br_multicast.c:1811 (discriminator 1)) br_multicast_send_query (net/bridge/br_multicast.c:1889) br_multicast_port_query_expired (net/bridge/br_multicast.c:1914) call_timer_fn (kernel/time/timer.c:1749) [...] Reported-by: syzbot+d7b7f1412c02134efa6d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/000000000000c4c9d405f2643e01@google.com/ Reviewed-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260708122820.1298718-2-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-05bridge: use BR_PROMISC_BITEric Dumazet
Use BR_PROMISC_BIT and set_bit(), clear_bit() and test_bit() lockless functions. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260604141343.2124500-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-14bridge: Add selective forwarding of gratuitous neighbor announcementsDanielle Ratson
The existing neighbor suppression unconditionally suppresses gratuitous ARPs and unsolicited Neighbor Advertisements, which prevents fast mobility of hosts between VTEPs. Add the neigh_forward_grat option to allow selective control of gratuitous neighbor announcements. When neigh_suppress is enabled but neigh_forward_grat is disabled (default), gratuitous announcements are suppressed. When neigh_forward_grat is enabled, gratuitous announcements are forwarded while regular neighbor discovery remains suppressed. The implementation provides per-output-port control by: 1. Adding a 'grat_arp' flag to BR_INPUT_SKB_CB to mark gratuitous ARPs and unsolicited NAs. 2. Setting both grat_arp and proxyarp_replied flags in br_do_proxy_suppress_arp() and br_do_suppress_nd() when gratuitous packets are detected. 3. Checking neigh_forward_grat per output port during flooding: - For gratuitous ARPs/NAs: suppress unless the output port has neigh_forward_grat enabled. - For regular ARPs/NDs: maintain existing behavior. This allows gratuitous announcements from any input port to be selectively forwarded based on each output port's individual neigh_forward_grat setting, enabling gratuitous neighbor announcements to be flooded to the VXLAN fabric. Regular neighbor discovery (ARP requests, NS queries, solicited replies) remains controlled by neigh_suppress and is unaffected. Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Danielle Ratson <danieller@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260511065936.4173106-4-danieller@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-14bridge: Add internal flags for neigh_forward_gratDanielle Ratson
Add internal flags for the neigh_forward_grat feature: - BR_NEIGH_FORWARD_GRAT: Port-level flag - BR_VLFLAG_NEIGH_FORWARD_GRAT_ENABLED: Per-VLAN flag These will be used to control whether gratuitous ARP and unsolicited NA packets are forwarded when neighbor suppression is enabled. Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Danielle Ratson <danieller@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260511065936.4173106-3-danieller@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-04-23net: remove unused ATM protocols and legacy ATM device driversJakub Kicinski
Remove the ATM protocol modules and PCI/SBUS ATM device drivers that are no longer in active use. The ATM core protocol stack, PPPoATM, BR2684, and USB DSL modem drivers (drivers/usb/atm/) are retained in-tree to maintain PPP over ATM (PPPoA) and PPPoE-over-BR2684 support for DSL connections. The Solos ADSL2+ PCI driver is also retained. Removed ATM protocol modules: - net/atm/clip.c - Classical IP over ATM (RFC 2225) - net/atm/lec.c - LAN Emulation Client (LANE) - net/atm/mpc.c, mpoa_caches.c, mpoa_proc.c - Multi-Protocol Over ATM Removed PCI/SBUS ATM device drivers (drivers/atm/): - adummy, atmtcp - software/testing ATM devices - eni - Efficient Networks ENI155P (OC-3, ~1995) - fore200e - FORE Systems 200E PCI/SBUS (OC-3, ~1999) - he - ForeRunner HE (OC-3/OC-12, ~2000) - idt77105 - IDT 77105 25 Mbps ATM PHY - idt77252 - IDT 77252 NICStAR II (OC-3, ~2000) - iphase - Interphase ATM PCI (OC-3/DS3/E3) - lanai - Efficient Networks Speedstream 3010 - nicstar - IDT 77201 NICStAR (155/25 Mbps, ~1999) - suni - PMC S/UNI SONET PHY library Also clean up references in: - net/bridge/ - remove ATM LANE hook (br_fdb_test_addr_hook, br_fdb_test_addr) - net/core/dev.c - remove br_fdb_test_addr_hook export - defconfig files - remove ATM driver config options The removed code is moved to an out-of-tree module package (mod-orphan). Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260422041846.2035118-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-10net: bridge: add stp_mode attribute for STP mode selectionAndy Roulin
The bridge-stp usermode helper is currently restricted to the initial network namespace, preventing userspace STP daemons (e.g. mstpd) from operating on bridges in other network namespaces. Since commit ff62198553e4 ("bridge: Only call /sbin/bridge-stp for the initial network namespace"), bridges in non-init namespaces silently fall back to kernel STP with no way to use userspace STP. Add a new bridge attribute IFLA_BR_STP_MODE that allows explicit per-bridge control over STP mode selection: BR_STP_MODE_AUTO (default) - Existing behavior: invoke the /sbin/bridge-stp helper in init_net only; fall back to kernel STP if it fails or in non-init namespaces. BR_STP_MODE_USER - Directly enable userspace STP (BR_USER_STP) without invoking the helper. Works in any network namespace. Userspace is responsible for ensuring an STP daemon manages the bridge. BR_STP_MODE_KERNEL - Directly enable kernel STP (BR_KERNEL_STP) without invoking the helper. The mode can only be changed while STP is disabled, or set to the same value (-EBUSY otherwise). IFLA_BR_STP_MODE is processed before IFLA_BR_STP_STATE in br_changelink(), so both can be set atomically in a single netlink message. The mode can also be changed in the same message that disables STP. The stp_mode struct field is u8 since all possible values fit, while NLA_U32 is used for the netlink attribute since it occupies the same space in the netlink message as NLA_U8. A new stp_helper_active boolean tracks whether the /sbin/bridge-stp helper was invoked during br_stp_start(), so that br_stp_stop() only calls the helper for stop when it was called for start. This avoids calling the helper asymmetrically when stp_mode changes between start and stop. Suggested-by: Ido Schimmel <idosch@nvidia.com> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Signed-off-by: Andy Roulin <aroulin@nvidia.com> Link: https://patch.msgid.link/20260405205224.3163000-2-aroulin@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-19bridge: No DEV_PATH_BR_VLAN_UNTAG_HW for dsa foreignEric Woudstra
In network setup as below: fastpath bypass .----------------------------------------. / \ | IP - forwarding | | / \ v | / wan ... | / | | | | | brlan.1 | | | +-------------------------------+ | | vlan 1 | | | | | | brlan (vlan-filtering) | | | +---------------+ | | | DSA-SWITCH | | | vlan 1 | | | | to | | | | untagged 1 vlan 1 | | +---------------+---------------+ . / \ ----->wlan1 lan0 . . . ^ ^ vlan 1 tagged packets untagged packets br_vlan_fill_forward_path_mode() sets DEV_PATH_BR_VLAN_UNTAG_HW when filling in from brlan.1 towards wlan1. But it should be set to DEV_PATH_BR_VLAN_UNTAG in this case. Using BR_VLFLAG_ADDED_BY_SWITCHDEV is not correct. The dsa switchdev adds it as a foreign port. The same problem for all foreignly added dsa vlans on the bridge. First add the vlan, trying only native devices. If this fails, we know this may be a vlan from a foreign device. Use BR_VLFLAG_TAGGING_BY_SWITCHDEV to make sure DEV_PATH_BR_VLAN_UNTAG_HW is set only when there if no foreign device involved. Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Eric Woudstra <ericwouds@gmail.com> Link: https://patch.msgid.link/20260317110347.363875-1-ericwouds@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-26bridge: Check relevant per-VLAN options in VLAN range groupingDanielle Ratson
The br_vlan_opts_eq_range() function determines if consecutive VLANs can be grouped together in a range for compact netlink notifications. It currently checks state, tunnel info, and multicast router configuration, but misses two categories of per-VLAN options that affect the output: 1. User-visible priv_flags (neigh_suppress, mcast_enabled) 2. Port multicast context (mcast_max_groups, mcast_n_groups) When VLANs have different settings for these options, they are incorrectly grouped into ranges, causing netlink notifications to report only one VLAN's settings for the entire range. Fix by checking priv_flags equality, but only for flags that affect netlink output (BR_VLFLAG_NEIGH_SUPPRESS_ENABLED and BR_VLFLAG_MCAST_ENABLED), and comparing multicast context (mcast_max_groups and mcast_n_groups). Example showing the bugs before the fix: $ bridge vlan set vid 10 dev dummy1 neigh_suppress on $ bridge vlan set vid 11 dev dummy1 neigh_suppress off $ bridge -d vlan show dev dummy1 port vlan-id dummy1 10-11 ... neigh_suppress on $ bridge vlan set vid 10 dev dummy1 mcast_max_groups 100 $ bridge vlan set vid 11 dev dummy1 mcast_max_groups 200 $ bridge -d vlan show dev dummy1 port vlan-id dummy1 10-11 ... mcast_max_groups 100 After the fix, VLANs 10 and 11 are shown as separate entries with their correct individual settings. Fixes: a1aee20d5db2 ("net: bridge: Add netlink knobs for number / maximum MDB entries") Fixes: 83f6d600796c ("bridge: vlan: Allow setting VLAN neighbor suppression state") Signed-off-by: Danielle Ratson <danieller@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260225143956.3995415-2-danieller@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-12-28net: bridge: Describe @tunnel_hash member in net_bridge_vlan_group structBagas Sanjaya
Sphinx reports kernel-doc warning: WARNING: ./net/bridge/br_private.h:267 struct member 'tunnel_hash' not described in 'net_bridge_vlan_group' Fix it by describing @tunnel_hash member. Fixes: efa5356b0d9753 ("bridge: per vlan dst_metadata netlink support") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20251218042936.24175-2-bagasdotme@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-06net: bridge: fix MST static key usageNikolay Aleksandrov
As Ido pointed out, the static key usage in MST is buggy and should use inc/dec instead of enable/disable because we can have multiple bridges with MST enabled which means a single bridge can disable MST for all. Use static_branch_inc/dec to avoid that. When destroying a bridge decrement the key if MST was enabled. Fixes: ec7328b59176 ("net: bridge: mst: Multiple Spanning Tree (MST) mode") Reported-by: Ido Schimmel <idosch@nvidia.com> Closes: https://lore.kernel.org/netdev/20251104120313.1306566-1-razor@blackwall.org/T/#m6888d87658f94ed1725433940f4f4ebb00b5a68b Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20251105111919.1499702-3-razor@blackwall.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-06net: bridge: fix use-after-free due to MST port state bypassNikolay Aleksandrov
syzbot reported[1] a use-after-free when deleting an expired fdb. It is due to a race condition between learning still happening and a port being deleted, after all its fdbs have been flushed. The port's state has been toggled to disabled so no learning should happen at that time, but if we have MST enabled, it will bypass the port's state, that together with VLAN filtering disabled can lead to fdb learning at a time when it shouldn't happen while the port is being deleted. VLAN filtering must be disabled because we flush the port VLANs when it's being deleted which will stop learning. This fix adds a check for the port's vlan group which is initialized to NULL when the port is getting deleted, that avoids the port state bypass. When MST is enabled there would be a minimal new overhead in the fast-path because the port's vlan group pointer is cache-hot. [1] https://syzkaller.appspot.com/bug?extid=dd280197f0f7ab3917be Fixes: ec7328b59176 ("net: bridge: mst: Multiple Spanning Tree (MST) mode") Reported-by: syzbot+dd280197f0f7ab3917be@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/69088ffa.050a0220.29fc44.003d.GAE@google.com/ Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20251105111919.1499702-2-razor@blackwall.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11net: bridge: Introduce UAPI for BR_BOOLOPT_FDB_LOCAL_VLAN_0Petr Machata
The previous patches introduced a new option, BR_BOOLOPT_FDB_LOCAL_VLAN_0. When enabled, it has local FDB entries installed only on VLAN 0, instead of duplicating them across all VLANs. In this patch, add the corresponding UAPI toggle, and the code for turning the feature on and off. Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/ea99bfb10f687fa58091e6e1c2f8acc33f47ca45.1757004393.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-11net: bridge: Introduce BROPT_FDB_LOCAL_VLAN_0Petr Machata
The following patches will gradually introduce the ability of the bridge to look up local FDB entries on VLAN 0 instead of using the VLAN indicated by a packet. In this patch, just introduce the option itself, with which the feature will be linked. Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/ab85e33ef41ed19a3deaef0ff7da26830da30642.1757004393.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-14net: bridge: fix soft lockup in br_multicast_query_expired()Wang Liang
When set multicast_query_interval to a large value, the local variable 'time' in br_multicast_send_query() may overflow. If the time is smaller than jiffies, the timer will expire immediately, and then call mod_timer() again, which creates a loop and may trigger the following soft lockup issue. watchdog: BUG: soft lockup - CPU#1 stuck for 221s! [rb_consumer:66] CPU: 1 UID: 0 PID: 66 Comm: rb_consumer Not tainted 6.16.0+ #259 PREEMPT(none) Call Trace: <IRQ> __netdev_alloc_skb+0x2e/0x3a0 br_ip6_multicast_alloc_query+0x212/0x1b70 __br_multicast_send_query+0x376/0xac0 br_multicast_send_query+0x299/0x510 br_multicast_query_expired.constprop.0+0x16d/0x1b0 call_timer_fn+0x3b/0x2a0 __run_timers+0x619/0x950 run_timer_softirq+0x11c/0x220 handle_softirqs+0x18e/0x560 __irq_exit_rcu+0x158/0x1a0 sysvec_apic_timer_interrupt+0x76/0x90 </IRQ> This issue can be reproduced with: ip link add br0 type bridge echo 1 > /sys/class/net/br0/bridge/multicast_querier echo 0xffffffffffffffff > /sys/class/net/br0/bridge/multicast_query_interval ip link set dev br0 up The multicast_startup_query_interval can also cause this issue. Similar to the commit 99b40610956a ("net: bridge: mcast: add and enforce query interval minimum"), add check for the query interval maximum to fix this issue. Link: https://lore.kernel.org/netdev/20250806094941.1285944-1-wangliang74@huawei.com/ Link: https://lore.kernel.org/netdev/20250812091818.542238-1-wangliang74@huawei.com/ Fixes: d902eee43f19 ("bridge: Add multicast count/interval sysfs entries") Suggested-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Wang Liang <wangliang74@huawei.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250813021054.1643649-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.15-rc8). Conflicts: 80f2ab46c2ee ("irdma: free iwdev->rf after removing MSI-X") 4bcc063939a5 ("ice, irdma: fix an off by one in error handling code") c24a65b6a27c ("iidc/ice/irdma: Update IDC to support multiple consumers") https://lore.kernel.org/20250513130630.280ee6c5@canb.auug.org.au No extra adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-05-16bridge: netfilter: Fix forwarding of fragmented packetsIdo Schimmel
When netfilter defrag hooks are loaded (due to the presence of conntrack rules, for example), fragmented packets entering the bridge will be defragged by the bridge's pre-routing hook (br_nf_pre_routing() -> ipv4_conntrack_defrag()). Later on, in the bridge's post-routing hook, the defragged packet will be fragmented again. If the size of the largest fragment is larger than what the kernel has determined as the destination MTU (using ip_skb_dst_mtu()), the defragged packet will be dropped. Before commit ac6627a28dbf ("net: ipv4: Consolidate ipv4_mtu and ip_dst_mtu_maybe_forward"), ip_skb_dst_mtu() would return dst_mtu() as the destination MTU. Assuming the dst entry attached to the packet is the bridge's fake rtable one, this would simply be the bridge's MTU (see fake_mtu()). However, after above mentioned commit, ip_skb_dst_mtu() ends up returning the route's MTU stored in the dst entry's metrics. Ideally, in case the dst entry is the bridge's fake rtable one, this should be the bridge's MTU as the bridge takes care of updating this metric when its MTU changes (see br_change_mtu()). Unfortunately, the last operation is a no-op given the metrics attached to the fake rtable entry are marked as read-only. Therefore, ip_skb_dst_mtu() ends up returning 1500 (the initial MTU value) and defragged packets are dropped during fragmentation when dealing with large fragments and high MTU (e.g., 9k). Fix by moving the fake rtable entry's metrics to be per-bridge (in a similar fashion to the fake rtable entry itself) and marking them as writable, thereby allowing MTU changes to be reflected. Fixes: 62fa8a846d7d ("net: Implement read-only protection and COW'ing of metrics.") Fixes: 33eb9873a283 ("bridge: initialize fake_rtable metrics") Reported-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com> Closes: https://lore.kernel.org/netdev/PH0PR10MB4504888284FF4CBA648197D0ACB82@PH0PR10MB4504.namprd10.prod.outlook.com/ Tested-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250515084848.727706-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-23net: bridge: mcast: update multicast contex when vlan state is changedYong Wang
When the vlan STP state is changed, which could be manipulated by "bridge vlan" commands, similar to port STP state, this also impacts multicast behaviors such as igmp query. In the scenario of per-VLAN snooping, there's a need to update the corresponding multicast context to re-arm the port query timer when vlan state becomes "forwarding" etc. Update br_vlan_set_state() function to enable vlan multicast context in such scenario. Before the patch, the IGMP query does not happen in the last step of the following test sequence, i.e. no growth for tx counter: # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0 # ip link add name swp1 up master br1 type dummy # sleep 1 # bridge vlan set vid 1 dev swp1 state 4 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 1 # sleep 1 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 1 # bridge vlan set vid 1 dev swp1 state 3 # sleep 2 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 1 After the patch, the IGMP query happens in the last step of the test: # ip link add name br1 up type bridge vlan_filtering 1 mcast_snooping 1 mcast_vlan_snooping 1 mcast_querier 1 mcast_stats_enabled 1 # bridge vlan global set vid 1 dev br1 mcast_snooping 1 mcast_querier 1 mcast_query_interval 100 mcast_startup_query_count 0 # ip link add name swp1 up master br1 type dummy # sleep 1 # bridge vlan set vid 1 dev swp1 state 4 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 1 # sleep 1 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 1 # bridge vlan set vid 1 dev swp1 state 3 # sleep 2 # ip -j -p stats show dev swp1 group xstats_slave subgroup bridge suite mcast | jq '.[]["multicast"]["igmp_queries"]["tx_v2"]' 3 Signed-off-by: Yong Wang <yongwang@nvidia.com> Reviewed-by: Andy Roulin <aroulin@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-04-14net: bridge: mcast: Notify on mdb offload failureJoseph Huang
Notify user space on mdb offload failure if mdb_offload_fail_notification is enabled. Signed-off-by: Joseph Huang <Joseph.Huang@garmin.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250411150323.1117797-4-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14net: bridge: Add offload_fail_notification boptJoseph Huang
Add BR_BOOLOPT_MDB_OFFLOAD_FAIL_NOTIFICATION bool option. Signed-off-by: Joseph Huang <Joseph.Huang@garmin.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250411150323.1117797-3-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-14net: bridge: mcast: Add offload failed mdb flagJoseph Huang
Add MDB_FLAGS_OFFLOAD_FAILED and MDB_PG_FLAGS_OFFLOAD_FAILED to indicate that an attempt to offload the MDB entry to switchdev has failed. Signed-off-by: Joseph Huang <Joseph.Huang@garmin.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250411150323.1117797-2-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-21net: Remove RTNL dance for SIOCBRADDIF and SIOCBRDELIF.Kuniyuki Iwashima
SIOCBRDELIF is passed to dev_ioctl() first and later forwarded to br_ioctl_call(), which causes unnecessary RTNL dance and the splat below [0] under RTNL pressure. Let's say Thread A is trying to detach a device from a bridge and Thread B is trying to remove the bridge. In dev_ioctl(), Thread A bumps the bridge device's refcnt by netdev_hold() and releases RTNL because the following br_ioctl_call() also re-acquires RTNL. In the race window, Thread B could acquire RTNL and try to remove the bridge device. Then, rtnl_unlock() by Thread B will release RTNL and wait for netdev_put() by Thread A. Thread A, however, must hold RTNL after the unlock in dev_ifsioc(), which may take long under RTNL pressure, resulting in the splat by Thread B. Thread A (SIOCBRDELIF) Thread B (SIOCBRDELBR) ---------------------- ---------------------- sock_ioctl sock_ioctl `- sock_do_ioctl `- br_ioctl_call `- dev_ioctl `- br_ioctl_stub |- rtnl_lock | |- dev_ifsioc ' ' |- dev = __dev_get_by_name(...) |- netdev_hold(dev, ...) . / |- rtnl_unlock ------. | | |- br_ioctl_call `---> |- rtnl_lock Race | | `- br_ioctl_stub |- br_del_bridge Window | | | |- dev = __dev_get_by_name(...) | | | May take long | `- br_dev_delete(dev, ...) | | | under RTNL pressure | `- unregister_netdevice_queue(dev, ...) | | | | `- rtnl_unlock \ | |- rtnl_lock <-' `- netdev_run_todo | |- ... `- netdev_run_todo | `- rtnl_unlock |- __rtnl_unlock | |- netdev_wait_allrefs_any |- netdev_put(dev, ...) <----------------' Wait refcnt decrement and log splat below To avoid blocking SIOCBRDELBR unnecessarily, let's not call dev_ioctl() for SIOCBRADDIF and SIOCBRDELIF. In the dev_ioctl() path, we do the following: 1. Copy struct ifreq by get_user_ifreq in sock_do_ioctl() 2. Check CAP_NET_ADMIN in dev_ioctl() 3. Call dev_load() in dev_ioctl() 4. Fetch the master dev from ifr.ifr_name in dev_ifsioc() 3. can be done by request_module() in br_ioctl_call(), so we move 1., 2., and 4. to br_ioctl_stub(). Note that 2. is also checked later in add_del_if(), but it's better performed before RTNL. SIOCBRADDIF and SIOCBRDELIF have been processed in dev_ioctl() since the pre-git era, and there seems to be no specific reason to process them there. [0]: unregister_netdevice: waiting for wpan3 to become free. Usage count = 2 ref_tracker: wpan3@ffff8880662d8608 has 1/1 users at __netdev_tracker_alloc include/linux/netdevice.h:4282 [inline] netdev_hold include/linux/netdevice.h:4311 [inline] dev_ifsioc+0xc6a/0x1160 net/core/dev_ioctl.c:624 dev_ioctl+0x255/0x10c0 net/core/dev_ioctl.c:826 sock_do_ioctl+0x1ca/0x260 net/socket.c:1213 sock_ioctl+0x23a/0x6c0 net/socket.c:1318 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x1a4/0x210 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcb/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: 893b19587534 ("net: bridge: fix ioctl locking") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: yan kang <kangyan91@outlook.com> Reported-by: yue sun <samsun1006219@gmail.com> Closes: https://lore.kernel.org/netdev/SY8P300MB0421225D54EB92762AE8F0F2A1D32@SY8P300MB0421.AUSP300.PROD.OUTLOOK.COM/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250316192851.19781-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-01-07bridge: Make br_is_nd_neigh_msg() accept pointer to "const struct sk_buff"Ted Chen
The skb_buff struct in br_is_nd_neigh_msg() is never modified. Mark it as const. Signed-off-by: Ted Chen <znscnchen@gmail.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250104083846.71612-1-znscnchen@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-20net: bridge: Handle changes in VLAN_FLAG_BRIDGE_BINDINGPetr Machata
When bridge binding is enabled on a VLAN netdevice, its link state should track bridge ports that are members of the corresponding VLAN. This works for newly-added netdevices. However toggling the option does not have the effect of enabling or disabling the behavior as appropriate. In this patch, react to bridge_binding toggles on VLAN uppers. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/90a8ca8aea4d81378b29d75d9e562433e0d5c7ff.1734540770.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15ndo_fdb_del: Add a parameter to report whether notification was sentPetr Machata
In a similar fashion to ndo_fdb_add, which was covered in the previous patch, add the bool *notified argument to ndo_fdb_del. Callees that send a notification on their own set the flag to true. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Amit Cohen <amcohen@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/06b1acf4953ef0a5ed153ef1f32d7292044f2be6.1731589511.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-15ndo_fdb_add: Add a parameter to report whether notification was sentPetr Machata
Currently when FDB entries are added to or deleted from a VXLAN netdevice, the VXLAN driver emits one notification, including the VXLAN-specific attributes. The core however always sends a notification as well, a generic one. Thus two notifications are unnecessarily sent for these operations. A similar situation comes up with bridge driver, which also emits notifications on its own: # ip link add name vx type vxlan id 1000 dstport 4789 # bridge monitor fdb & [1] 1981693 # bridge fdb add de:ad:be:ef:13:37 dev vx self dst 192.0.2.1 de:ad:be:ef:13:37 dev vx dst 192.0.2.1 self permanent de:ad:be:ef:13:37 dev vx self permanent In order to prevent this duplicity, add a paremeter to ndo_fdb_add, bool *notified. The flag is primed to false, and if the callee sends a notification on its own, it sets it to true, thus informing the core that it should not generate another notification. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Amit Cohen <amcohen@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/cbf6ae8195e85cbf922f8058ce4eba770f3b71ed.1731589511.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-10bridge: Handle error of rtnl_register_module().Kuniyuki Iwashima
Since introduced, br_vlan_rtnl_init() has been ignoring the returned value of rtnl_register_module(), which could fail silently. Handling the error allows users to view a module as an all-or-nothing thing in terms of the rtnetlink functionality. This prevents syzkaller from reporting spurious errors from its tests, where OOM often occurs and module is automatically loaded. Let's handle the errors by rtnl_register_many(). Fixes: 8dcea187088b ("net: bridge: vlan: add rtm definitions and dump support") Fixes: f26b296585dc ("net: bridge: vlan: add new rtm message support") Fixes: adb3ce9bcb0f ("net: bridge: vlan: add del rtm message support") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-11netfilter: br_netfilter: skip conntrack input hook for promisc packetsPablo Neira Ayuso
For historical reasons, when bridge device is in promisc mode, packets that are directed to the taps follow bridge input hook path. This patch adds a workaround to reset conntrack for these packets. Jianbo Liu reports warning splats in their test infrastructure where cloned packets reach the br_netfilter input hook to confirm the conntrack object. Scratch one bit from BR_INPUT_SKB_CB to annotate that this packet has reached the input hook because it is passed up to the bridge device to reach the taps. [ 57.571874] WARNING: CPU: 1 PID: 0 at net/bridge/br_netfilter_hooks.c:616 br_nf_local_in+0x157/0x180 [br_netfilter] [ 57.572749] Modules linked in: xt_MASQUERADE nf_conntrack_netlink nfnetlink iptable_nat xt_addrtype xt_conntrack nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay rpcrdma rdma_ucm ib_iser libiscsi scsi_transport_isc si ib_umad rdma_cm ib_ipoib iw_cm ib_cm mlx5_ib ib_uverbs ib_core mlx5ctl mlx5_core [ 57.575158] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0+ #19 [ 57.575700] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 57.576662] RIP: 0010:br_nf_local_in+0x157/0x180 [br_netfilter] [ 57.577195] Code: fe ff ff 41 bd 04 00 00 00 be 04 00 00 00 e9 4a ff ff ff be 04 00 00 00 48 89 ef e8 f3 a9 3c e1 66 83 ad b4 00 00 00 04 eb 91 <0f> 0b e9 f1 fe ff ff 0f 0b e9 df fe ff ff 48 89 df e8 b3 53 47 e1 [ 57.578722] RSP: 0018:ffff88885f845a08 EFLAGS: 00010202 [ 57.579207] RAX: 0000000000000002 RBX: ffff88812dfe8000 RCX: 0000000000000000 [ 57.579830] RDX: ffff88885f845a60 RSI: ffff8881022dc300 RDI: 0000000000000000 [ 57.580454] RBP: ffff88885f845a60 R08: 0000000000000001 R09: 0000000000000003 [ 57.581076] R10: 00000000ffff1300 R11: 0000000000000002 R12: 0000000000000000 [ 57.581695] R13: ffff8881047ffe00 R14: ffff888108dbee00 R15: ffff88814519b800 [ 57.582313] FS: 0000000000000000(0000) GS:ffff88885f840000(0000) knlGS:0000000000000000 [ 57.583040] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 57.583564] CR2: 000000c4206aa000 CR3: 0000000103847001 CR4: 0000000000370eb0 [ 57.584194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 57.584820] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 57.585440] Call Trace: [ 57.585721] <IRQ> [ 57.585976] ? __warn+0x7d/0x130 [ 57.586323] ? br_nf_local_in+0x157/0x180 [br_netfilter] [ 57.586811] ? report_bug+0xf1/0x1c0 [ 57.587177] ? handle_bug+0x3f/0x70 [ 57.587539] ? exc_invalid_op+0x13/0x60 [ 57.587929] ? asm_exc_invalid_op+0x16/0x20 [ 57.588336] ? br_nf_local_in+0x157/0x180 [br_netfilter] [ 57.588825] nf_hook_slow+0x3d/0xd0 [ 57.589188] ? br_handle_vlan+0x4b/0x110 [ 57.589579] br_pass_frame_up+0xfc/0x150 [ 57.589970] ? br_port_flags_change+0x40/0x40 [ 57.590396] br_handle_frame_finish+0x346/0x5e0 [ 57.590837] ? ipt_do_table+0x32e/0x430 [ 57.591221] ? br_handle_local_finish+0x20/0x20 [ 57.591656] br_nf_hook_thresh+0x4b/0xf0 [br_netfilter] [ 57.592286] ? br_handle_local_finish+0x20/0x20 [ 57.592802] br_nf_pre_routing_finish+0x178/0x480 [br_netfilter] [ 57.593348] ? br_handle_local_finish+0x20/0x20 [ 57.593782] ? nf_nat_ipv4_pre_routing+0x25/0x60 [nf_nat] [ 57.594279] br_nf_pre_routing+0x24c/0x550 [br_netfilter] [ 57.594780] ? br_nf_hook_thresh+0xf0/0xf0 [br_netfilter] [ 57.595280] br_handle_frame+0x1f3/0x3d0 [ 57.595676] ? br_handle_local_finish+0x20/0x20 [ 57.596118] ? br_handle_frame_finish+0x5e0/0x5e0 [ 57.596566] __netif_receive_skb_core+0x25b/0xfc0 [ 57.597017] ? __napi_build_skb+0x37/0x40 [ 57.597418] __netif_receive_skb_list_core+0xfb/0x220 Fixes: 62e7151ae3eb ("netfilter: bridge: confirm multicast packets before passing them up the stack") Reported-by: Jianbo Liu <jianbol@nvidia.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
2023-10-27bridge: 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>
2023-10-17net: 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>
2023-10-13net: 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>
2023-07-27bridge: 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>
2023-07-19bridge: 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>
2023-05-30skbuff: 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>
2023-04-21bridge: 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: 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>
2023-03-17rtnetlink: 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>
2023-03-17bridge: mcast: Implement MDB net device operationsIdo Schimmel
Implement the previously added MDB net device operations in the bridge driver so that they could be invoked by core rtnetlink code in the next patch. The operations are identical to the existing br_mdb_{dump,add,del} functions. The '_new' suffix will be removed in the next patch. The functions are re-implemented in this patch to make the conversion in the next patch easier to review. Add dummy implementations when 'CONFIG_BRIDGE_IGMP_SNOOPING' is disabled, so that an error will be returned to user space when it is trying to add or delete an MDB entry. This is consistent with existing behavior where the bridge driver does not even register rtnetlink handlers for RTM_{NEW,DEL,GET}MDB messages when this Kconfig option is disabled. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-06net: bridge: Add netlink knobs for number / maximum MDB entriesPetr Machata
The previous patch added accounting for number of MDB entries per port and per port-VLAN, and the logic to verify that these values stay within configured bounds. However it didn't provide means to actually configure those bounds or read the occupancy. This patch does that. Two new netlink attributes are added for the MDB occupancy: IFLA_BRPORT_MCAST_N_GROUPS for the per-port occupancy and BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS for the per-port-VLAN occupancy. And another two for the maximum number of MDB entries: IFLA_BRPORT_MCAST_MAX_GROUPS for the per-port maximum, and BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS for the per-port-VLAN one. Note that the two new IFLA_BRPORT_ attributes prompt bumping of RTNL_SLAVE_MAX_TYPE to size the slave attribute tables large enough. The new attributes are used like this: # ip link add name br up type bridge vlan_filtering 1 mcast_snooping 1 \ mcast_vlan_snooping 1 mcast_querier 1 # ip link set dev v1 master br # bridge vlan add dev v1 vid 2 # bridge vlan set dev v1 vid 1 mcast_max_groups 1 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1 # bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1 Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1. # bridge link set dev v1 mcast_max_groups 1 # bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 2 Error: bridge: Port is already in 1 groups, and mcast_max_groups=1. # bridge -d link show 5: v1@v2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br [...] [...] mcast_n_groups 1 mcast_max_groups 1 # bridge -d vlan show port vlan-id br 1 PVID Egress Untagged state forwarding mcast_router 1 v1 1 PVID Egress Untagged [...] mcast_n_groups 1 mcast_max_groups 1 2 [...] mcast_n_groups 0 mcast_max_groups 0 Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-02-06net: bridge: Maintain number of MDB entries in net_bridge_mcast_portPetr Machata
The MDB maintained by the bridge is limited. When the bridge is configured for IGMP / MLD snooping, a buggy or malicious client can easily exhaust its capacity. In SW datapath, the capacity is configurable through the IFLA_BR_MCAST_HASH_MAX parameter, but ultimately is finite. Obviously a similar limit exists in the HW datapath for purposes of offloading. In order to prevent the issue of unilateral exhaustion of MDB resources, introduce two parameters in each of two contexts: - Per-port and per-port-VLAN number of MDB entries that the port is member in. - Per-port and (when BROPT_MCAST_VLAN_SNOOPING_ENABLED is enabled) per-port-VLAN maximum permitted number of MDB entries, or 0 for no limit. The per-port multicast context is used for tracking of MDB entries for the port as a whole. This is available for all bridges. The per-port-VLAN multicast context is then only available on VLAN-filtering bridges on VLANs that have multicast snooping on. With these changes in place, it will be possible to configure MDB limit for bridge as a whole, or any one port as a whole, or any single port-VLAN. Note that unlike the global limit, exhaustion of the per-port and per-port-VLAN maximums does not cause disablement of multicast snooping. It is also permitted to configure the local limit larger than hash_max, even though that is not useful. In this patch, introduce only the accounting for number of entries, and the max field itself, but not the means to toggle the max. The next patch introduces the netlink APIs to toggle and read the values. Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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