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2018-08-31Revert "net: sched: act: add extack for lookup callback"Cong Wang
This reverts commit 331a9295de23 ("net: sched: act: add extack for lookup callback"). This extack is never used after 6 months... In fact, it can be just set in the caller, right after ->lookup(). Cc: Alexander Aring <aring@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-21net_sched: remove unnecessary ops->delete()Cong Wang
All ops->delete() wants is getting the tn->idrinfo, but we already have tc_action before calling ops->delete(), and tc_action has a pointer ->idrinfo. More importantly, each type of action does the same thing, that is, just calling tcf_idr_delete_index(). So it can be just removed. Fixes: b409074e6693 ("net: sched: add 'delete' function to action ops") Cc: Jiri Pirko <jiri@mellanox.com> Cc: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13net: sched: act_skbmod method rename for grep-ability and consistencyJamal Hadi Salim
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11net: sched: act_skbmod: remove dependency on rtnl lockVlad Buslov
Move read of skbmod_p rcu pointer to be protected by tcf spinlock. Use tcf spinlock to protect private skbmod data from concurrent modification during dump. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-30tc/act: remove unneeded RCU lock in action callbackPaolo Abeni
Each lockless action currently does its own RCU locking in ->act(). This allows using plain RCU accessor, even if the context is really RCU BH. This change drops the per action RCU lock, replace the accessors with the _bh variant, cleans up a bit the surrounding code and documents the RCU status in the relevant header. No functional nor performance change is intended. The goal of this patch is clarifying that the RCU critical section used by the tc actions extends up to the classifier's caller. v1 -> v2: - preserve rcu lock in act_bpf: it's needed by eBPF helpers, as pointed out by Daniel v3 -> v4: - fixed some typos in the commit message (JiriP) Signed-off-by: Paolo Abeni <pabeni@redhat.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08net: sched: atomically check-allocate actionVlad Buslov
Implement function that atomically checks if action exists and either takes reference to it, or allocates idr slot for action index to prevent concurrent allocations of actions with same index. Use EBUSY error pointer to indicate that idr slot is reserved. Implement cleanup helper function that removes temporary error pointer from idr. (in case of error between idr allocation and insertion of newly created action to specified index) Refactor all action init functions to insert new action to idr using this API. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08net: sched: don't release reference on action overwriteVlad Buslov
Return from action init function with reference to action taken, even when overwriting existing action. Action init API initializes its fourth argument (pointer to pointer to tc action) to either existing action with same index or newly created action. In case of existing index(and bind argument is zero), init function returns without incrementing action reference counter. Caller of action init then proceeds working with action, without actually holding reference to it. This means that action could be deleted concurrently. Change action init behavior to always take reference to action before returning successfully, in order to protect from concurrent deletion. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08net: sched: add 'delete' function to action opsVlad Buslov
Extend action ops with 'delete' function. Each action type to implements its own delete function that doesn't depend on rtnl lock. Implement delete function that is required to delete actions without holding rtnl lock. Use action API function that atomically deletes action only if it is still in action idr. This implementation prevents concurrent threads from deleting same action twice. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08net: sched: implement unlocked action init APIVlad Buslov
Add additional 'rtnl_held' argument to act API init functions. It is required to implement actions that need to release rtnl lock before loading kernel module and reacquire if afterwards. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-08net: sched: change type of reference and bind countersVlad Buslov
Change type of action reference counter to refcount_t. Change type of action bind counter to atomic_t. This type is used to allow decrementing bind counter without testing for 0 result. Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-11net sched actions: fix refcnt leak in skbmodRoman Mashak
When application fails to pass flags in netlink TLV when replacing existing skbmod action, the kernel will leak refcnt: $ tc actions get action skbmod index 1 total acts 0 action order 0: skbmod pipe set smac 00:11:22:33:44:55 index 1 ref 1 bind 0 For example, at this point a buggy application replaces the action with index 1 with new smac 00:aa:22:33:44:55, it fails because of zero flags, however refcnt gets bumped: $ tc actions get actions skbmod index 1 total acts 0 action order 0: skbmod pipe set smac 00:11:22:33:44:55 index 1 ref 2 bind 0 $ Tha patch fixes this by calling tcf_idr_release() on existing actions. Fixes: 86da71b57383d ("net_sched: Introduce skbmod action") Signed-off-by: Roman Mashak <mrv@mojatatu.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-27net: Drop pernet_operations::asyncKirill Tkhai
Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Fun set of conflict resolutions here... For the mac80211 stuff, these were fortunately just parallel adds. Trivially resolved. In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the function phy_disable_interrupts() earlier in the file, whilst in 'net-next' the phy_error() call from this function was removed. In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the 'rt_table_id' member of rtable collided with a bug fix in 'net' that added a new struct member "rt_mtu_locked" which needs to be copied over here. The mlxsw driver conflict consisted of net-next separating the span code and definitions into separate files, whilst a 'net' bug fix made some changes to that moved code. The mlx5 infiniband conflict resolution was quite non-trivial, the RDMA tree's merge commit was used as a guide here, and here are their notes: ==================== Due to bug fixes found by the syzkaller bot and taken into the for-rc branch after development for the 4.17 merge window had already started being taken into the for-next branch, there were fairly non-trivial merge issues that would need to be resolved between the for-rc branch and the for-next branch. This merge resolves those conflicts and provides a unified base upon which ongoing development for 4.17 can be based. Conflicts: drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f9524 (IB/mlx5: Fix cleanup order on unload) added to for-rc and commit b5ca15ad7e61 (IB/mlx5: Add proper representors support) add as part of the devel cycle both needed to modify the init/de-init functions used by mlx5. To support the new representors, the new functions added by the cleanup patch needed to be made non-static, and the init/de-init list added by the representors patch needed to be modified to match the init/de-init list changes made by the cleanup patch. Updates: drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function prototypes added by representors patch to reflect new function names as changed by cleanup patch drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init stage list to match new order from cleanup patch ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-21net/sched: fix idr leak in the error path of tcf_skbmod_init()Davide Caratti
tcf_skbmod_init() can fail after the idr has been successfully reserved. When this happens, every subsequent attempt to configure skbmod rules using the same idr value will systematically fail with -ENOSPC, unless the first attempt was done using the 'replace' keyword: # tc action add action skbmod swap mac index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel ... Fix this in tcf_skbmod_init(), ensuring that tcf_idr_release() is called on the error path when the idr has been reserved, but not yet inserted. Also, don't test 'ovr' in the error path, to avoid a 'replace' failure implicitly become a 'delete' that leaks refcount in act_skbmod module: # rmmod act_skbmod; modprobe act_skbmod # tc action add action skbmod swap mac index 100 # tc action add action skbmod swap mac continue index 100 RTNETLINK answers: File exists We have an error talking to the kernel # tc action replace action skbmod swap mac continue index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action list action skbmod # # rmmod act_skbmod rmmod: ERROR: Module act_skbmod is in use Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-17net/sched: fix NULL dereference on the error path of tcf_skbmod_init()Davide Caratti
when the following command # tc action replace action skbmod swap mac index 100 is run for the first time, and tcf_skbmod_init() fails to allocate struct tcf_skbmod_params, tcf_skbmod_cleanup() calls kfree_rcu(NULL), thus causing the following error: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: __call_rcu+0x23/0x2b0 PGD 8000000034057067 P4D 8000000034057067 PUD 74937067 PMD 0 Oops: 0002 [#1] SMP PTI Modules linked in: act_skbmod(E) psample ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic snd_hda_intel snd_hda_codec crct10dif_pclmul mbcache jbd2 crc32_pclmul snd_hda_core ghash_clmulni_intel snd_hwdep pcbc snd_seq snd_seq_device snd_pcm aesni_intel snd_timer crypto_simd glue_helper snd cryptd virtio_balloon joydev soundcore pcspkr i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_console virtio_net virtio_blk ata_piix libata crc32c_intel virtio_pci serio_raw virtio_ring virtio i2c_core floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_skbmod] CPU: 3 PID: 3144 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__call_rcu+0x23/0x2b0 RSP: 0018:ffffbd2e403e7798 EFLAGS: 00010246 RAX: ffffffffc0872080 RBX: ffff981d34bff780 RCX: 00000000ffffffff RDX: ffffffff922a5f00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000021f R10: 000000003d003000 R11: 0000000000aaaaaa R12: 0000000000000000 R13: ffffffff922a5f00 R14: 0000000000000001 R15: ffff981d3b698c2c FS: 00007f3678292740(0000) GS:ffff981d3fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 000000007c57a006 CR4: 00000000001606e0 Call Trace: __tcf_idr_release+0x79/0xf0 tcf_skbmod_init+0x1d1/0x210 [act_skbmod] tcf_action_init_1+0x2cc/0x430 tcf_action_init+0xd3/0x1b0 tc_ctl_action+0x18b/0x240 rtnetlink_rcv_msg+0x29c/0x310 ? _cond_resched+0x15/0x30 ? __kmalloc_node_track_caller+0x1b9/0x270 ? rtnl_calcit.isra.28+0x100/0x100 netlink_rcv_skb+0xd2/0x110 netlink_unicast+0x17c/0x230 netlink_sendmsg+0x2cd/0x3c0 sock_sendmsg+0x30/0x40 ___sys_sendmsg+0x27a/0x290 ? filemap_map_pages+0x34a/0x3a0 ? __handle_mm_fault+0xbfd/0xe20 __sys_sendmsg+0x51/0x90 do_syscall_64+0x6e/0x1a0 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7f36776a3ba0 RSP: 002b:00007fff4703b618 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fff4703b740 RCX: 00007f36776a3ba0 RDX: 0000000000000000 RSI: 00007fff4703b690 RDI: 0000000000000003 RBP: 000000005aaaba36 R08: 0000000000000002 R09: 0000000000000000 R10: 00007fff4703b0a0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff4703b754 R14: 0000000000000001 R15: 0000000000669f60 Code: 5d e9 42 da ff ff 66 90 0f 1f 44 00 00 41 57 41 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 08 40 f6 c7 07 0f 85 19 02 00 00 <48> 89 75 08 48 c7 45 00 00 00 00 00 9c 58 0f 1f 44 00 00 49 89 RIP: __call_rcu+0x23/0x2b0 RSP: ffffbd2e403e7798 CR2: 0000000000000008 Fix it in tcf_skbmod_cleanup(), ensuring that kfree_rcu(p, ...) is called only when p is not NULL. Fixes: 86da71b57383 ("net_sched: Introduce skbmod action") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-27net: Convert tc_action_net_init() and tc_action_net_exit() based ↵Kirill Tkhai
pernet_operations These pernet_operations are from net/sched directory, and they call only tc_action_net_init() and tc_action_net_exit(): bpf_net_ops connmark_net_ops csum_net_ops gact_net_ops ife_net_ops ipt_net_ops xt_net_ops mirred_net_ops nat_net_ops pedit_net_ops police_net_ops sample_net_ops simp_net_ops skbedit_net_ops skbmod_net_ops tunnel_key_net_ops vlan_net_ops 1)tc_action_net_init() just allocates and initializes per-net memory. 2)There should not be in-flight packets at the time of tc_action_net_exit() call, or another pernet_operations send packets to dying net (except netlink). So, it seems they can be marked as async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16net: sched: act: handle extack in tcf_generic_walkerAlexander Aring
This patch adds extack handling for a common used TC act function "tcf_generic_walker()" to add an extack message on failures. The tcf_generic_walker() function can fail if get a invalid command different than DEL and GET. The naming "action" here is wrong, the correct naming would be command. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16net: sched: act: add extack for walk callbackAlexander Aring
This patch adds extack support for act walker callback api. This prepares to handle extack support inside each specific act implementation. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16net: sched: act: add extack for lookup callbackAlexander Aring
This patch adds extack support for act lookup callback api. This prepares to handle extack support inside each specific act implementation. Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16net: sched: act: add extack to init callbackAlexander Aring
This patch adds extack support for act init callback api. This prepares to handle extack support inside each specific act implementation. Based on work by David Ahern <dsahern@gmail.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-13net_sched: switch to exit_batch for action pernet opsCong Wang
Since we now hold RTNL lock in tc_action_net_exit(), it is good to batch them to speedup tc action dismantle. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-05net_sched: remove unused parameter from act cleanup opsCong Wang
No one actually uses it. Cc: Jiri Pirko <jiri@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-09Revert "net_sched: hold netns refcnt for each action"Cong Wang
This reverts commit ceffcc5e254b450e6159f173e4538215cebf1b59. If we hold that refcnt, the netns can never be destroyed until all actions are destroyed by user, this breaks our netns design which we expect all actions are destroyed when we destroy the whole netns. Cc: Lucas Bates <lucasb@mojatatu.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-03net_sched: hold netns refcnt for each actionCong Wang
TC actions have been destroyed asynchronously for a long time, previously in a RCU callback and now in a workqueue. If we don't hold a refcnt for its netns, we could use the per netns data structure, struct tcf_idrinfo, after it has been freed by netns workqueue. Hold refcnt to ensure netns destroy happens after all actions are gone. Fixes: ddf97ccdd7cb ("net_sched: add network namespace support for tc actions") Reported-by: Lucas Bates <lucasb@mojatatu.com> Tested-by: Lucas Bates <lucasb@mojatatu.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-30net/sched: Change act_api and act_xxx modules to use IDRChris Mi
Typically, each TC filter has its own action. All the actions of the same type are saved in its hash table. But the hash buckets are too small that it degrades to a list. And the performance is greatly affected. For example, it takes about 0m11.914s to insert 64K rules. If we convert the hash table to IDR, it only takes about 0m1.500s. The improvement is huge. But please note that the test result is based on previous patch that cls_flower uses IDR. Signed-off-by: Chris Mi <chrism@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-07net/sched: act_skbmod: remove unneeded rcu_read_unlock in tcf_skbmod_dumpAlexey Khoroshilov
Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18netns: make struct pernet_operations::id unsigned intAlexey Dobriyan
Make struct pernet_operations::id unsigned. There are 2 reasons to do so: 1) This field is really an index into an zero based array and thus is unsigned entity. Using negative value is out-of-bound access by definition. 2) On x86_64 unsigned 32-bit data which are mixed with pointers via array indexing or offsets added or subtracted to pointers are preffered to signed 32-bit data. "int" being used as an array index needs to be sign-extended to 64-bit before being used. void f(long *p, int i) { g(p[i]); } roughly translates to movsx rsi, esi mov rdi, [rsi+...] call g MOVSX is 3 byte instruction which isn't necessary if the variable is unsigned because x86_64 is zero extending by default. Now, there is net_generic() function which, you guessed it right, uses "int" as an array index: static inline void *net_generic(const struct net *net, int id) { ... ptr = ng->ptr[id - 1]; ... } And this function is used a lot, so those sign extensions add up. Patch snipes ~1730 bytes on allyesconfig kernel (without all junk messing with code generation): add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) Unfortunately some functions actually grow bigger. This is a semmingly random artefact of code generation with register allocator being used differently. gcc decides that some variable needs to live in new r8+ registers and every access now requires REX prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be used which is longer than [r8] However, overall balance is in negative direction: add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730) function old new delta nfsd4_lock 3886 3959 +73 tipc_link_build_proto_msg 1096 1140 +44 mac80211_hwsim_new_radio 2776 2808 +32 tipc_mon_rcv 1032 1058 +26 svcauth_gss_legacy_init 1413 1429 +16 tipc_bcbase_select_primary 379 392 +13 nfsd4_exchange_id 1247 1260 +13 nfsd4_setclientid_confirm 782 793 +11 ... put_client_renew_locked 494 480 -14 ip_set_sockfn_get 730 716 -14 geneve_sock_add 829 813 -16 nfsd4_sequence_done 721 703 -18 nlmclnt_lookup_host 708 686 -22 nfsd4_lockt 1085 1063 -22 nfs_get_client 1077 1050 -27 tcf_bpf_init 1106 1076 -30 nfsd4_encode_fattr 5997 5930 -67 Total: Before=154856051, After=154854321, chg -0.00% Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-15net_sched: Introduce skbmod actionJamal Hadi Salim
This action is intended to be an upgrade from a usability perspective from pedit (as well as operational debugability). Compare this: sudo tc filter add dev $ETH parent 1: protocol ip prio 10 \ u32 match ip protocol 1 0xff flowid 1:2 \ action pedit munge offset -14 u8 set 0x02 \ munge offset -13 u8 set 0x15 \ munge offset -12 u8 set 0x15 \ munge offset -11 u8 set 0x15 \ munge offset -10 u16 set 0x1515 \ pipe to: sudo tc filter add dev $ETH parent 1: protocol ip prio 10 \ u32 match ip protocol 1 0xff flowid 1:2 \ action skbmod dmac 02:15:15:15:15:15 Also try to do a MAC address swap with pedit or worse try to debug a policy with destination mac, source mac and etherype. Then make few rules out of those and you'll get my point. In the future common use cases on pedit can be migrated to this action (as an example different fields in ip v4/6, transports like tcp/udp/sctp etc). For this first cut, this allows modifying basic ethernet header. The most important ethernet use case at the moment is when redirecting or mirroring packets to a remote machine. The dst mac address needs a re-write so that it doesnt get dropped or confuse an interconnecting (learning) switch or dropped by a target machine (which looks at the dst mac). And at times when flipping back the packet a swap of the MAC addresses is needed. Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>