summaryrefslogtreecommitdiff
path: root/include/linux/netdevice.h
Commit message (Collapse)AuthorAgeFilesLines
* net: fix IFF_TX_SKB_NO_LINEAR definitionDan Carpenter2022-07-071-1/+1
| | | | | | | | | | | | | | commit 3b89b511ea0c705cc418440e2abf9d692a556d84 upstream. The "1<<31" shift has a sign extension bug so IFF_TX_SKB_NO_LINEAR is 0xffffffff80000000 instead of 0x0000000080000000. Fixes: c2ff53d8049f ("net: Add priv_flags for allow tx skb without linear") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Link: https://lore.kernel.org/r/YrRrcGttfEVnf85Q@kili Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: fix dev_fill_forward_path with pppoe + bridgeFelix Fietkau2022-05-161-1/+1
| | | | | | | | | | | When calling dev_fill_forward_path on a pppoe device, the provided destination address is invalid. In order for the bridge fdb lookup to succeed, the pppoe code needs to update ctx->daddr to the correct value. Fix this by storing the address inside struct net_device_path_ctx Fixes: f6efc675c9dd ("net: ppp: resolve forwarding path for bridge pppoe devices") Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* net: Use this_cpu_inc() to increment net->core_statsSebastian Andrzej Siewior2022-04-261-12/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The macro dev_core_stats_##FIELD##_inc() disables preemption and invokes netdev_core_stats_alloc() to return a per-CPU pointer. netdev_core_stats_alloc() will allocate memory on its first invocation which breaks on PREEMPT_RT because it requires non-atomic context for memory allocation. This can be avoided by enabling preemption in netdev_core_stats_alloc() assuming the caller always disables preemption. It might be better to replace local_inc() with this_cpu_inc() now that dev_core_stats_##FIELD##_inc() gained a preempt-disable section and does not rely on already disabled preemption. This results in less instructions on x86-64: local_inc: | incl %gs:__preempt_count(%rip) # __preempt_count | movq 488(%rdi), %rax # _1->core_stats, _22 | testq %rax, %rax # _22 | je .L585 #, | add %gs:this_cpu_off(%rip), %rax # this_cpu_off, tcp_ptr__ | .L586: | testq %rax, %rax # _27 | je .L587 #, | incq (%rax) # _6->a.counter | .L587: | decl %gs:__preempt_count(%rip) # __preempt_count this_cpu_inc(), this patch: | movq 488(%rdi), %rax # _1->core_stats, _5 | testq %rax, %rax # _5 | je .L591 #, | .L585: | incq %gs:(%rax) # _18->rx_dropped Use unsigned long as type for the counter. Use this_cpu_inc() to increment the counter. Use a plain read of the counter. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/YmbO0pxgtKpCw4SY@linutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: move net_unlink_todo() out of the headerJohannes Berg2022-03-281-10/+0
| | | | | | | | | | There's no reason for this to be in netdevice.h, it's all just used in dev.c. Also make it no longer inline and let the compiler decide to do that by itself. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Link: https://lore.kernel.org/r/20220325225023.f49b9056fe1c.I6b901a2df00000837a9bd251a8dd259bd23f5ded@changeid Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* netdevice: add missing dm_private kdocJakub Kicinski2022-03-221-0/+2
| | | | | | | | | | | Building htmldocs complains: include/linux/netdevice.h:2295: warning: Function parameter or member 'dm_private' not described in 'net_device' Fixes: b26ef81c46ed ("drop_monitor: remove quadratic behavior") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220322051053.1883186-1-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
* net: set default rss queues num to physical cores / 2Íñigo Huguet2022-03-181-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Network drivers can call to netif_get_num_default_rss_queues to get the default number of receive queues to use. Right now, this default number is min(8, num_online_cpus()). Instead, as suggested by Jakub, use the number of physical cores divided by 2 as a way to avoid wasting CPU resources and to avoid using both CPU threads, but still allowing to scale for high-end processors with many cores. As an exception, select 2 queues for processors with 2 cores, because otherwise it won't take any advantage of RSS despite being SMP capable. Tested: Processor Intel Xeon E5-2620 (2 sockets, 6 cores/socket, 2 threads/core). NIC Broadcom NetXtreme II BCM57810 (10GBps). Ran some tests with `perf stat iperf3 -R`, with parallelisms of 1, 8 and 24, getting the following results: - Number of queues: 6 (instead of 8) - Network throughput: not affected - CPU usage: utilized 0.05-0.12 CPUs more than before (having 24 CPUs this is only 0.2-0.5% higher) - Reduced the number of context switches by 7-50%, being more noticeable when using a higher number of parallel threads. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Íñigo Huguet <ihuguet@redhat.com> Link: https://lore.kernel.org/r/20220315091832.13873-1-ihuguet@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: disable preemption in dev_core_stats_XXX_inc() helpersEric Dumazet2022-03-141-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot was kind enough to remind us that dev->{tx_dropped|rx_dropped} could be increased in process context. BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor413/3593 caller is netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298 CPU: 1 PID: 3593 Comm: syz-executor413 Not tainted 5.17.0-rc7-syzkaller-02426-g97aeb877de7f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_preemption_disabled+0x16b/0x170 lib/smp_processor_id.c:49 netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298 dev_core_stats include/linux/netdevice.h:3855 [inline] dev_core_stats_rx_dropped_inc include/linux/netdevice.h:3866 [inline] tun_get_user+0x3455/0x3ab0 drivers/net/tun.c:1800 tun_chr_write_iter+0xe1/0x200 drivers/net/tun.c:2015 call_write_iter include/linux/fs.h:2074 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x12d/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f2cf4f887e3 Code: 5d 41 5c 41 5d 41 5e e9 9b fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18 RSP: 002b:00007ffd50dd5fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffd50dd6000 RCX: 00007f2cf4f887e3 RDX: 000000000000002a RSI: 0000000000000000 RDI: 00000000000000c8 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd50dd5ff0 R14: 00007ffd50dd5fe8 R15: 00007ffd50dd5fe4 </TASK> Fixes: 625788b58445 ("net: add per-cpu storage and net->core_stats") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: jeffreyji <jeffreyji@google.com> Cc: Brian Vazquez <brianvv@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220312214505.3294762-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* net: add per-cpu storage and net->core_statsEric Dumazet2022-03-111-9/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | Before adding yet another possibly contended atomic_long_t, it is time to add per-cpu storage for existing ones: dev->tx_dropped, dev->rx_dropped, and dev->rx_nohandler Because many devices do not have to increment such counters, allocate the per-cpu storage on demand, so that dev_get_stats() does not have to spend considerable time folding zero counters. Note that some drivers have abused these counters which were supposed to be only used by core networking stack. v4: should use per_cpu_ptr() in dev_get_stats() (Jakub) v3: added a READ_ONCE() in netdev_core_stats_alloc() (Paolo) v2: add a missing include (reported by kernel test robot <lkp@intel.com>) Change in netdev_core_stats_alloc() (Jakub) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: jeffreyji <jeffreyji@google.com> Reviewed-by: Brian Vazquez <brianvv@google.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220311051420.2608812-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-03-101-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | net/dsa/dsa2.c commit afb3cc1a397d ("net: dsa: unlock the rtnl_mutex when dsa_master_setup() fails") commit e83d56537859 ("net: dsa: replay master state events in dsa_tree_{setup,teardown}_master") https://lore.kernel.org/all/20220307101436.7ae87da0@canb.auug.org.au/ drivers/net/ethernet/intel/ice/ice.h commit 97b0129146b1 ("ice: Fix error with handling of bonding MTU") commit 43113ff73453 ("ice: add TTY for GNSS module for E810T device") https://lore.kernel.org/all/20220310112843.3233bcf1@canb.auug.org.au/ drivers/staging/gdm724x/gdm_lte.c commit fc7f750dc9d1 ("staging: gdm724x: fix use after free in gdm_lte_rx()") commit 4bcc4249b4cf ("staging: Use netif_rx().") https://lore.kernel.org/all/20220308111043.1018a59d@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net: Fix esp GSO on inter address family tunnels.Steffen Klassert2022-03-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The esp tunnel GSO handlers use skb_mac_gso_segment to push the inner packet to the segmentation handlers. However, skb_mac_gso_segment takes the Ethernet Protocol ID from 'skb->protocol' which is wrong for inter address family tunnels. We fix this by introducing a new skb_eth_gso_segment function. This function can be used if it is necessary to pass the Ethernet Protocol ID directly to the segmentation handler. First users of this function will be the esp4 and esp6 tunnel segmentation handlers. Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2") Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
* | net: Remove netif_rx_any_context() and netif_rx_ni().Sebastian Andrzej Siewior2022-03-071-10/+0
| | | | | | | | | | | | | | | | Remove netif_rx_any_context and netif_rx_ni() because there are no more users in tree. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: dev: Add hardware stats supportPetr Machata2022-03-031-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Offloading switch device drivers may be able to collect statistics of the traffic taking place in the HW datapath that pertains to a certain soft netdevice, such as VLAN. Add the necessary infrastructure to allow exposing these statistics to the offloaded netdevice in question. The API was shaped by the following considerations: - Collection of HW statistics is not free: there may be a finite number of counters, and the act of counting may have a performance impact. It is therefore necessary to allow toggling whether HW counting should be done for any particular SW netdevice. - As the drivers are loaded and removed, a particular device may get offloaded and unoffloaded again. At the same time, the statistics values need to stay monotonic (modulo the eventual 64-bit wraparound), increasing only to reflect traffic measured in the device. To that end, the netdevice keeps around a lazily-allocated copy of struct rtnl_link_stats64. Device drivers then contribute to the values kept therein at various points. Even as the driver goes away, the struct stays around to maintain the statistics values. - Different HW devices may be able to count different things. The motivation behind this patch in particular is exposure of HW counters on Nvidia Spectrum switches, where the only practical approach to counting traffic on offloaded soft netdevices currently is to use router interface counters, and count L3 traffic. Correspondingly that is the statistics suite added in this patch. Other devices may be able to measure different kinds of traffic, and for that reason, the APIs are built to allow uniform access to different statistics suites. - Because soft netdevices and offloading drivers are only loosely bound, a netdevice uses a notifier chain to communicate with the drivers. Several new notifiers, NETDEV_OFFLOAD_XSTATS_*, have been added to carry messages to the offloading drivers. - Devices can have various conditions for when a particular counter is available. As the device is configured and reconfigured, the device offload may become or cease being suitable for counter binding. A netdevice can use a notifier type NETDEV_OFFLOAD_XSTATS_REPORT_USED to ping offloading drivers and determine whether anyone currently implements a given statistics suite. This information can then be propagated to user space. When the driver decides to unoffload a netdevice, it can use a newly-added function, netdev_offload_xstats_report_delta(), to record outstanding collected statistics, before destroying the HW counter. This patch adds a helper, call_netdevice_notifiers_info_robust(), for dispatching a notifier with the possibility of unwind when one of the consumers bails. Given the wish to eventually get rid of the global notifier block altogether, this helper only invokes the per-netns notifier block. Signed-off-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | drop_monitor: remove quadratic behaviorEric Dumazet2022-02-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | drop_monitor is using an unique list on which all netdevices in the host have an element, regardless of their netns. This scales poorly, not only at device unregister time (what I caught during my netns dismantle stress tests), but also at packet processing time whenever trace_napi_poll_hit() is called. If the intent was to avoid adding one pointer in 'struct net_device' then surely we prefer O(1) behavior. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-02-171-1/+1
|\ \ | |/ | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net_sched: add __rcu annotation to netdev->qdiscEric Dumazet2022-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot found a data-race [1] which lead me to add __rcu annotations to netdev->qdisc, and proper accessors to get LOCKDEP support. [1] BUG: KCSAN: data-race in dev_activate / qdisc_lookup_rcu write to 0xffff888168ad6410 of 8 bytes by task 13559 on cpu 1: attach_default_qdiscs net/sched/sch_generic.c:1167 [inline] dev_activate+0x2ed/0x8f0 net/sched/sch_generic.c:1221 __dev_open+0x2e9/0x3a0 net/core/dev.c:1416 __dev_change_flags+0x167/0x3f0 net/core/dev.c:8139 rtnl_configure_link+0xc2/0x150 net/core/rtnetlink.c:3150 __rtnl_newlink net/core/rtnetlink.c:3489 [inline] rtnl_newlink+0xf4d/0x13e0 net/core/rtnetlink.c:3529 rtnetlink_rcv_msg+0x745/0x7e0 net/core/rtnetlink.c:5594 netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmsg+0x195/0x230 net/socket.c:2496 __do_sys_sendmsg net/socket.c:2505 [inline] __se_sys_sendmsg net/socket.c:2503 [inline] __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888168ad6410 of 8 bytes by task 13560 on cpu 0: qdisc_lookup_rcu+0x30/0x2e0 net/sched/sch_api.c:323 __tcf_qdisc_find+0x74/0x3a0 net/sched/cls_api.c:1050 tc_del_tfilter+0x1c7/0x1350 net/sched/cls_api.c:2211 rtnetlink_rcv_msg+0x5ba/0x7e0 net/core/rtnetlink.c:5585 netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494 rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] ____sys_sendmsg+0x39a/0x510 net/socket.c:2413 ___sys_sendmsg net/socket.c:2467 [inline] __sys_sendmsg+0x195/0x230 net/socket.c:2496 __do_sys_sendmsg net/socket.c:2505 [inline] __se_sys_sendmsg net/socket.c:2503 [inline] __x64_sys_sendmsg+0x42/0x50 net/socket.c:2503 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0xffffffff85dee080 -> 0xffff88815d96ec00 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 13560 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00116-gf1baf68e1383-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 470502de5bdb ("net: sched: unlock rules update API") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Buslov <vladbu@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: dev: Makes sure netif_rx() can be invoked in any context.Sebastian Andrzej Siewior2022-02-141-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dave suggested a while ago (eleven years by now) "Let's make netif_rx() work in all contexts and get rid of netif_rx_ni()". Eric agreed and pointed out that modern devices should use netif_receive_skb() to avoid the overhead. In the meantime someone added another variant, netif_rx_any_context(), which behaves as suggested. netif_rx() must be invoked with disabled bottom halves to ensure that pending softirqs, which were raised within the function, are handled. netif_rx_ni() can be invoked only from process context (bottom halves must be enabled) because the function handles pending softirqs without checking if bottom halves were disabled or not. netif_rx_any_context() invokes on the former functions by checking in_interrupts(). netif_rx() could be taught to handle both cases (disabled and enabled bottom halves) by simply disabling bottom halves while invoking netif_rx_internal(). The local_bh_enable() invocation will then invoke pending softirqs only if the BH-disable counter drops to zero. Eric is concerned about the overhead of BH-disable+enable especially in regard to the loopback driver. As critical as this driver is, it will receive a shortcut to avoid the additional overhead which is not needed. Add a local_bh_disable() section in netif_rx() to ensure softirqs are handled if needed. Provide __netif_rx() which does not disable BH and has a lockdep assert to ensure that interrupts are disabled. Use this shortcut in the loopback driver and in drivers/net/*.c. Make netif_rx_ni() and netif_rx_any_context() invoke netif_rx() so they can be removed once they are no more users left. Link: https://lkml.kernel.org/r/20100415.020246.218622820.davem@davemloft.net Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: add dev->dev_registered_trackerEric Dumazet2022-02-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | Convert one dev_hold()/dev_put() pair in register_netdevice() and unregister_netdevice_many() to dev_hold_track() and dev_put_track(). This would allow to detect a rogue dev_put() a bit earlier. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20220207184107.1401096-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: refine dev_put()/dev_hold() debuggingEric Dumazet2022-02-051-23/+46
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are still chasing some syzbot reports where we think a rogue dev_put() is called with no corresponding prior dev_hold(). Unfortunately it eats a reference on dev->dev_refcnt taken by innocent dev_hold_track(), meaning that the refcount saturation splat comes too late to be useful. Make sure that 'not tracked' dev_put() and dev_hold() better use CONFIG_NET_DEV_REFCNT_TRACKER=y debug infrastructure: Prior patch in the series allowed ref_tracker_alloc() and ref_tracker_free() to be called with a NULL @trackerp parameter, and to use a separate refcount only to detect too many put() even in the following case: dev_hold_track(dev, tracker_1, GFP_ATOMIC); dev_hold(dev); dev_put(dev); dev_put(dev); // Should complain loudly here. dev_put_track(dev, tracker_1); // instead of here Add clarification about netdev_tracker_alloc() role. v2: I replaced the dev_put() in linkwatch_do_dev() with __dev_put() because callers called netdev_tracker_free(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: fix information leakage in /proc/net/ptypeCongyu Liu2022-01-201-0/+1
| | | | | | | | | | | | | | | | In one net namespace, after creating a packet socket without binding it to a device, users in other net namespaces can observe the new `packet_type` added by this packet socket by reading `/proc/net/ptype` file. This is minor information leakage as packet socket is namespace aware. Add a net pointer in `packet_type` to keep the net namespace of of corresponding packet socket. In `ptype_seq_show`, this net pointer must be checked when it is not NULL. Fixes: 2feb27dbe00c ("[NETNS]: Minor information leak via /proc/net/ptype file.") Signed-off-by: Congyu Liu <liu3101@purdue.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* gro: add ability to control gro max packet sizeCoco Li2022-01-061-0/+11
| | | | | | | | | | | | | | | | | | | | | | Eric Dumazet suggested to allow users to modify max GRO packet size. We have seen GRO being disabled by users of appliances (such as wifi access points) because of claimed bufferbloat issues, or some work arounds in sch_cake, to split GRO/GSO packets. Instead of disabling GRO completely, one can chose to limit the maximum packet size of GRO packets, depending on their latency constraints. This patch adds a per device gro_max_size attribute that can be changed with ip link command. ip link set dev eth0 gro_max_size 16000 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: remove references to CONFIG_IRDA in network header filesLukas Bulwahn2021-12-301-1/+1
| | | | | | | | | | | | Commit d64c2a76123f ("staging: irda: remove the irda network stack and drivers") removes the config IRDA. Remove the remaining references to this non-existing config in the network header files. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20211229113620.19368-1-lukas.bulwahn@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-12-231-1/+1
|\ | | | | | | | | | | | | | | | | include/net/sock.h commit 8f905c0e7354 ("inet: fully convert sk->sk_rx_dst to RCU rules") commit 43f51df41729 ("net: move early demux fields close to sk_refcnt") https://lore.kernel.org/all/20211222141641.0caa0ab3@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net: fix typo in a commentXiang wangx2021-12-171-1/+1
| | | | | | | | | | | | | | The double 'as' in a comment is repeated, thus it should be removed. Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | flow_offload: allow user to offload tc action to net deviceBaowen Zheng2021-12-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Use flow_indr_dev_register/flow_indr_dev_setup_offload to offload tc action. We need to call tc_cleanup_flow_action to clean up tc action entry since in tc_setup_action, some actions may hold dev refcnt, especially the mirror action. Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com> Signed-off-by: Louis Peens <louis.peens@corigine.com> Signed-off-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: add net device refcount tracker to struct packet_typeEric Dumazet2021-12-151-0/+1
| | | | | | | | | | | | | | | | | | Most notable changes are in af_packet, tipc ones are trivial. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jon Maloy <jmaloy@redhat.com> Cc: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: dev_replace_track() cleanupEric Dumazet2021-12-141-6/+4
| | | | | | | | | | | | | | | | | | Use existing helpers (netdev_tracker_free() and netdev_tracker_alloc()) to remove ifdefery. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20211214151515.312535-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: add networking namespace refcount trackerEric Dumazet2021-12-101-8/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have 100+ syzbot reports about netns being dismantled too soon, still unresolved as of today. We think a missing get_net() or an extra put_net() is the root cause. In order to find the bug(s), and be able to spot future ones, this patch adds CONFIG_NET_NS_REFCNT_TRACKER and new helpers to precisely pair all put_net() with corresponding get_net(). To use these helpers, each data structure owning a refcount should also use a "netns_tracker" to pair the get and put. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: watchdog: add net device refcount trackerEric Dumazet2021-12-071-0/+2
| | | | | | | | | | | | | | | | Add a netdevice_tracker inside struct net_device, to track the self reference when a device has an active watchdog timer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: linkwatch: add net device refcount trackerEric Dumazet2021-12-061-0/+2
| | | | | | | | | | | | | | | | Add a netdevice_tracker inside struct net_device, to track the self reference when a device is in lweventlist. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: dst: add net device refcount tracking to dst_entryEric Dumazet2021-12-061-0/+17
| | | | | | | | | | | | | | We want to track all dev_hold()/dev_put() to ease leak hunting. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: add net device refcount tracker to struct netdev_queueEric Dumazet2021-12-061-0/+2
| | | | | | | | | | | | | | This will help debugging pesky netdev reference leaks. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: add net device refcount tracker to struct netdev_rx_queueEric Dumazet2021-12-061-0/+2
| | | | | | | | | | | | | | This helps debugging net device refcount leaks. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: add net device refcount tracker infrastructureEric Dumazet2021-12-061-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | net device are refcounted. Over the years we had numerous bugs caused by imbalanced dev_hold() and dev_put() calls. The general idea is to be able to precisely pair each decrement with a corresponding prior increment. Both share a cookie, basically a pointer to private data storing stack traces. This patch adds dev_hold_track() and dev_put_track(). To use these helpers, each data structure owning a refcount should also use a "netdevice_tracker" to pair the hold and put. netdevice_tracker dev_tracker; ... dev_hold_track(dev, &dev_tracker, GFP_ATOMIC); ... dev_put_track(dev, &dev_tracker); Whenever a leak happens, we will get precise stack traces of the point dev_hold_track() happened, at device dismantle phase. We will also get a stack trace if too many dev_put_track() for the same netdevice_tracker are attempted. This is guarded by CONFIG_NET_DEV_REFCNT_TRACKER option. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-12-021-6/+13
|\ \ | |/ | | | | Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * net: annotate data-races on txq->xmit_lock_ownerEric Dumazet2021-12-011-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot found that __dev_queue_xmit() is reading txq->xmit_lock_owner without annotations. No serious issue there, let's document what is happening there. BUG: KCSAN: data-race in __dev_queue_xmit / __dev_queue_xmit write to 0xffff888139d09484 of 4 bytes by interrupt on cpu 0: __netif_tx_unlock include/linux/netdevice.h:4437 [inline] __dev_queue_xmit+0x948/0xf70 net/core/dev.c:4229 dev_queue_xmit_accel+0x19/0x20 net/core/dev.c:4265 macvlan_queue_xmit drivers/net/macvlan.c:543 [inline] macvlan_start_xmit+0x2b3/0x3d0 drivers/net/macvlan.c:567 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3590 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606 sch_direct_xmit+0x1b2/0x7c0 net/sched/sch_generic.c:342 __dev_xmit_skb+0x83d/0x1370 net/core/dev.c:3817 __dev_queue_xmit+0x590/0xf70 net/core/dev.c:4194 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259 neigh_hh_output include/net/neighbour.h:511 [inline] neigh_output include/net/neighbour.h:525 [inline] ip6_finish_output2+0x995/0xbb0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] ip6_finish_output+0x444/0x4c0 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0x486/0x610 net/ipv6/ndisc.c:508 ndisc_send_rs+0x3b0/0x3e0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x370/0x540 net/ipv6/addrconf.c:3898 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1421 expire_timers+0x116/0x240 kernel/time/timer.c:1466 __run_timers+0x368/0x410 kernel/time/timer.c:1734 run_timer_softirq+0x2e/0x60 kernel/time/timer.c:1747 __do_softirq+0x158/0x2de kernel/softirq.c:558 __irq_exit_rcu kernel/softirq.c:636 [inline] irq_exit_rcu+0x37/0x70 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 read to 0xffff888139d09484 of 4 bytes by interrupt on cpu 1: __dev_queue_xmit+0x5e3/0xf70 net/core/dev.c:4213 dev_queue_xmit_accel+0x19/0x20 net/core/dev.c:4265 macvlan_queue_xmit drivers/net/macvlan.c:543 [inline] macvlan_start_xmit+0x2b3/0x3d0 drivers/net/macvlan.c:567 __netdev_start_xmit include/linux/netdevice.h:4987 [inline] netdev_start_xmit include/linux/netdevice.h:5001 [inline] xmit_one+0x105/0x2f0 net/core/dev.c:3590 dev_hard_start_xmit+0x72/0x120 net/core/dev.c:3606 sch_direct_xmit+0x1b2/0x7c0 net/sched/sch_generic.c:342 __dev_xmit_skb+0x83d/0x1370 net/core/dev.c:3817 __dev_queue_xmit+0x590/0xf70 net/core/dev.c:4194 dev_queue_xmit+0x13/0x20 net/core/dev.c:4259 neigh_resolve_output+0x3db/0x410 net/core/neighbour.c:1523 neigh_output include/net/neighbour.h:527 [inline] ip6_finish_output2+0x9be/0xbb0 net/ipv6/ip6_output.c:126 __ip6_finish_output net/ipv6/ip6_output.c:191 [inline] ip6_finish_output+0x444/0x4c0 net/ipv6/ip6_output.c:201 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip6_output+0x10e/0x210 net/ipv6/ip6_output.c:224 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ndisc_send_skb+0x486/0x610 net/ipv6/ndisc.c:508 ndisc_send_rs+0x3b0/0x3e0 net/ipv6/ndisc.c:702 addrconf_rs_timer+0x370/0x540 net/ipv6/addrconf.c:3898 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1421 expire_timers+0x116/0x240 kernel/time/timer.c:1466 __run_timers+0x368/0x410 kernel/time/timer.c:1734 run_timer_softirq+0x2e/0x60 kernel/time/timer.c:1747 __do_softirq+0x158/0x2de kernel/softirq.c:558 __irq_exit_rcu kernel/softirq.c:636 [inline] irq_exit_rcu+0x37/0x70 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x8d/0xb0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 kcsan_setup_watchpoint+0x94/0x420 kernel/kcsan/core.c:443 folio_test_anon include/linux/page-flags.h:581 [inline] PageAnon include/linux/page-flags.h:586 [inline] zap_pte_range+0x5ac/0x10e0 mm/memory.c:1347 zap_pmd_range mm/memory.c:1467 [inline] zap_pud_range mm/memory.c:1496 [inline] zap_p4d_range mm/memory.c:1517 [inline] unmap_page_range+0x2dc/0x3d0 mm/memory.c:1538 unmap_single_vma+0x157/0x210 mm/memory.c:1583 unmap_vmas+0xd0/0x180 mm/memory.c:1615 exit_mmap+0x23d/0x470 mm/mmap.c:3170 __mmput+0x27/0x1b0 kernel/fork.c:1113 mmput+0x3d/0x50 kernel/fork.c:1134 exit_mm+0xdb/0x170 kernel/exit.c:507 do_exit+0x608/0x17a0 kernel/exit.c:819 do_group_exit+0xce/0x180 kernel/exit.c:929 get_signal+0xfc3/0x1550 kernel/signal.c:2852 arch_do_signal_or_restart+0x8c/0x2e0 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x113/0x190 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:300 do_syscall_64+0x50/0xd0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00000000 -> 0xffffffff Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 28712 Comm: syz-executor.0 Tainted: G W 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20211130170155.2331929-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: remove .ndo_change_proto_downJakub Kicinski2021-11-231-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .ndo_change_proto_down was added seemingly to enable out-of-tree implementations. Over 2.5yrs later we still have no real users upstream. Hardwire the generic implementation for now, we can revert once real users materialize. (rocker is a test vehicle, not a user.) We need to drop the optimization on the sysfs side, because unlike ndos priv_flags will be changed at runtime, so we'd need READ_ONCE/WRITE_ONCE everywhere.. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: annotate accesses to dev->gso_max_segsEric Dumazet2021-11-221-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | dev->gso_max_segs is written under RTNL protection, or when the device is not yet visible, but is read locklessly. Add netif_set_gso_max_segs() helper. Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs() where we can to better document what is going on. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: annotate accesses to dev->gso_max_sizeEric Dumazet2021-11-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | dev->gso_max_size is written under RTNL protection, or when the device is not yet visible, but is read locklessly. Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_size() where we can to better document what is going on. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | dev_addr: add a modification checkJakub Kicinski2021-11-201-0/+5
| | | | | | | | | | | | | | | | | | netdev->dev_addr should only be modified via helpers, but someone may be casting off the const. Add a runtime check to catch abuses. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: constify netdev->dev_addrJakub Kicinski2021-11-201-9/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Commit 406f42fa0d3c ("net-next: When a bond have a massive amount of VLANs...") introduced a rbtree for faster Ethernet address look up. We converted all users to make modifications via appropriate helpers, make netdev->dev_addr const. The update helpers need to upcast from the buffer to struct netdev_hw_addr. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: do not inline netif_tx_lock()/netif_tx_unlock()Eric Dumazet2021-11-171-37/+2
| | | | | | | | | | | | | | | | | | | | These are not fast path, there is no point in inlining them. Also provide netif_freeze_queues()/netif_unfreeze_queues() so that we can use them from dev_watchdog() in the following patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: annotate accesses to queue->trans_startEric Dumazet2021-11-171-3/+13
| | | | | | | | | | | | | | | | In following patches, dev_watchdog() will no longer stop all queues. It will read queue->trans_start locklessly. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: use an atomic_long_t for queue->trans_timeoutEric Dumazet2021-11-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | tx_timeout_show() assumed dev_watchdog() would stop all the queues, to fetch queue->trans_timeout under protection of the queue->_xmit_lock. As we want to no longer disrupt transmits, we use an atomic_long_t instead. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: david decotigny <david.decotigny@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: use .data.once section in netdev_level_once()Eric Dumazet2021-11-161-1/+1
| | | | | | | | | | | | | | | | Same rationale than prior patch : using the dedicated section avoid holes and pack all these bool values. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
* | net: gro: populate net/core/gro.cEric Dumazet2021-11-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | Move gro code and data from net/core/dev.c to net/core/gro.c to ease maintenance. gro_normal_list() and gro_normal_one() are inlined because they are called from both files. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: gro: move skb_gro_receive into net/core/gro.cEric Dumazet2021-11-161-1/+0
| | | | | | | | | | | | | | | | net/core/gro.c will contain all core gro functions, to shrink net/core/skbuff.c and net/core/dev.c Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: gro: move skb_gro_receive_list to udp_offload.cEric Dumazet2021-11-161-1/+0
| | | | | | | | | | | | | | This helper is used once, no need to keep it in fat net/core/skbuff.c Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: move gro definitions to include/net/gro.hEric Dumazet2021-11-161-348/+0
|/ | | | | | | | include/linux/netdevice.h became too big, move gro stuff into include/net/gro.h Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller2021-10-181-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS for net-next: 1) Add new run_estimation toggle to IPVS to stop the estimation_timer logic, from Dust Li. 2) Relax superfluous dynset check on NFT_SET_TIMEOUT. 3) Add egress hook, from Lukas Wunner. 4) Nowadays, almost all hook functions in x_table land just call the hook evaluation loop. Remove remaining hook wrappers from iptables and IPVS. From Florian Westphal. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * netfilter: Introduce egress hookLukas Wunner2021-10-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Support classifying packets with netfilter on egress to satisfy user requirements such as: * outbound security policies for containers (Laura) * filtering and mangling intra-node Direct Server Return (DSR) traffic on a load balancer (Laura) * filtering locally generated traffic coming in through AF_PACKET, such as local ARP traffic generated for clustering purposes or DHCP (Laura; the AF_PACKET plumbing is contained in a follow-up commit) * L2 filtering from ingress and egress for AVB (Audio Video Bridging) and gPTP with nftables (Pablo) * in the future: in-kernel NAT64/NAT46 (Pablo) The egress hook introduced herein complements the ingress hook added by commit e687ad60af09 ("netfilter: add netfilter ingress hook after handle_ing() under unique static key"). A patch for nftables to hook up egress rules from user space has been submitted separately, so users may immediately take advantage of the feature. Alternatively or in addition to netfilter, packets can be classified with traffic control (tc). On ingress, packets are classified first by tc, then by netfilter. On egress, the order is reversed for symmetry. Conceptually, tc and netfilter can be thought of as layers, with netfilter layered above tc. Traffic control is capable of redirecting packets to another interface (man 8 tc-mirred). E.g., an ingress packet may be redirected from the host namespace to a container via a veth connection: tc ingress (host) -> tc egress (veth host) -> tc ingress (veth container) In this case, netfilter egress classifying is not performed when leaving the host namespace! That's because the packet is still on the tc layer. If tc redirects the packet to a physical interface in the host namespace such that it leaves the system, the packet is never subjected to netfilter egress classifying. That is only logical since it hasn't passed through netfilter ingress classifying either. Packets can alternatively be redirected at the netfilter layer using nft fwd. Such a packet *is* subjected to netfilter egress classifying since it has reached the netfilter layer. Internally, the skb->nf_skip_egress flag controls whether netfilter is invoked on egress by __dev_queue_xmit(). Because __dev_queue_xmit() may be called recursively by tunnel drivers such as vxlan, the flag is reverted to false after sch_handle_egress(). This ensures that netfilter is applied both on the overlay and underlying network. Interaction between tc and netfilter is possible by setting and querying skb->mark. If netfilter egress classifying is not enabled on any interface, it is patched out of the data path by way of a static_key and doesn't make a performance difference that is discernible from noise: Before: 1537 1538 1538 1537 1538 1537 Mb/sec After: 1536 1534 1539 1539 1539 1540 Mb/sec Before + tc accept: 1418 1418 1418 1419 1419 1418 Mb/sec After + tc accept: 1419 1424 1418 1419 1422 1420 Mb/sec Before + tc drop: 1620 1619 1619 1619 1620 1620 Mb/sec After + tc drop: 1616 1624 1625 1624 1622 1619 Mb/sec When netfilter egress classifying is enabled on at least one interface, a minimal performance penalty is incurred for every egress packet, even if the interface it's transmitted over doesn't have any netfilter egress rules configured. That is caused by checking dev->nf_hooks_egress against NULL. Measurements were performed on a Core i7-3615QM. Commands to reproduce: ip link add dev foo type dummy ip link set dev foo up modprobe pktgen echo "add_device foo" > /proc/net/pktgen/kpktgend_3 samples/pktgen/pktgen_bench_xmit_mode_queue_xmit.sh -i foo -n 400000000 -m "11:11:11:11:11:11" -d 1.1.1.1 Accept all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 0,' Drop all traffic with tc: tc qdisc add dev foo clsact tc filter add dev foo egress bpf da bytecode '1,6 0 0 2,' Apply this patch when measuring packet drops to avoid errors in dmesg: https://lore.kernel.org/netdev/a73dda33-57f4-95d8-ea51-ed483abd6a7a@iogearbox.net/ Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: Laura García Liébana <nevola@gmail.com> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
View Lorry Controller Status