linux/include/net/tc_act, branch v5.7

net: tc_skbedit: Make the skbedit priority offloadable

2020-03-20T04:09:19Z

The skbedit action "priority" is used for adjusting SKB priority. Allow drivers to offload the action by introducing two new skbedit getters and a new flow action, and initializing appropriately in tc_setup_flow_action(). Signed-off-by: Petr Machata Reviewed-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

net: tc_skbedit: Factor a helper out of is_tcf_skbedit_{mark, ptype}()

2020-03-20T04:09:19Z

The two functions is_tcf_skbedit_mark() and is_tcf_skbedit_ptype() have a very similar structure. A follow-up patch will add one more such function. Instead of more cut'n'pasting, extract a helper function that checks whether a TC action is an skbedit with the required flag. Convert the two existing functions into thin wrappers around the helper. Signed-off-by: Petr Machata Reviewed-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

net: sched: Do not assume RTNL is held in tunnel key action helpers

2020-03-20T03:25:52Z

The cited commit removed RTNL from tc_setup_flow_action(), but the function calls two tunnel key action helpers that use rtnl_dereference() to fetch the action's parameters. This leads to "suspicious RCU usage" warnings [1][2]. Change the helpers to use rcu_dereference_protected() while requiring the action's lock to be held. This is safe because the two helpers are only called from tc_setup_flow_action() which acquires the lock. [1] [ 156.950855] ============================= [ 156.955463] WARNING: suspicious RCU usage [ 156.960085] 5.6.0-rc5-custom-47426-gdfe43878d573 #2409 Not tainted [ 156.967116] ----------------------------- [ 156.971728] include/net/tc_act/tc_tunnel_key.h:31 suspicious rcu_dereference_protected() usage! [ 156.981583] [ 156.981583] other info that might help us debug this: [ 156.981583] [ 156.990675] [ 156.990675] rcu_scheduler_active = 2, debug_locks = 1 [ 156.998205] 1 lock held by tc/877: [ 157.002187] #0: ffff8881cbf7bea0 (&(&p->tcfa_lock)->rlock){+...}, at: tc_setup_flow_action+0xbe/0x4f78 [ 157.012866] [ 157.012866] stack backtrace: [ 157.017886] CPU: 2 PID: 877 Comm: tc Not tainted 5.6.0-rc5-custom-47426-gdfe43878d573 #2409 [ 157.027253] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ 157.037389] Call Trace: [ 157.040170] dump_stack+0xfd/0x178 [ 157.044034] lockdep_rcu_suspicious+0x14a/0x153 [ 157.049157] tc_setup_flow_action+0x89f/0x4f78 [ 157.054227] fl_hw_replace_filter+0x375/0x640 [ 157.064348] fl_change+0x28ec/0x4f6b [ 157.088843] tc_new_tfilter+0x15e2/0x2260 [ 157.176801] rtnetlink_rcv_msg+0x8d6/0xb60 [ 157.190915] netlink_rcv_skb+0x177/0x460 [ 157.208884] rtnetlink_rcv+0x21/0x30 [ 157.212925] netlink_unicast+0x5d0/0x7f0 [ 157.227728] netlink_sendmsg+0x981/0xe90 [ 157.245416] ____sys_sendmsg+0x76d/0x8f0 [ 157.255348] ___sys_sendmsg+0x10f/0x190 [ 157.320308] __sys_sendmsg+0x115/0x1f0 [ 157.342553] __x64_sys_sendmsg+0x7d/0xc0 [ 157.346987] do_syscall_64+0xc1/0x600 [ 157.351142] entry_SYSCALL_64_after_hwframe+0x49/0xbe [2] [ 157.432346] ============================= [ 157.436937] WARNING: suspicious RCU usage [ 157.441537] 5.6.0-rc5-custom-47426-gdfe43878d573 #2409 Not tainted [ 157.448559] ----------------------------- [ 157.453204] include/net/tc_act/tc_tunnel_key.h:43 suspicious rcu_dereference_protected() usage! [ 157.463042] [ 157.463042] other info that might help us debug this: [ 157.463042] [ 157.472112] [ 157.472112] rcu_scheduler_active = 2, debug_locks = 1 [ 157.479529] 1 lock held by tc/877: [ 157.483442] #0: ffff8881cbf7bea0 (&(&p->tcfa_lock)->rlock){+...}, at: tc_setup_flow_action+0xbe/0x4f78 [ 157.494119] [ 157.494119] stack backtrace: [ 157.499114] CPU: 2 PID: 877 Comm: tc Not tainted 5.6.0-rc5-custom-47426-gdfe43878d573 #2409 [ 157.508485] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ 157.518628] Call Trace: [ 157.521416] dump_stack+0xfd/0x178 [ 157.525293] lockdep_rcu_suspicious+0x14a/0x153 [ 157.530425] tc_setup_flow_action+0x993/0x4f78 [ 157.535505] fl_hw_replace_filter+0x375/0x640 [ 157.545650] fl_change+0x28ec/0x4f6b [ 157.570204] tc_new_tfilter+0x15e2/0x2260 [ 157.658199] rtnetlink_rcv_msg+0x8d6/0xb60 [ 157.672315] netlink_rcv_skb+0x177/0x460 [ 157.690278] rtnetlink_rcv+0x21/0x30 [ 157.694320] netlink_unicast+0x5d0/0x7f0 [ 157.709129] netlink_sendmsg+0x981/0xe90 [ 157.726813] ____sys_sendmsg+0x76d/0x8f0 [ 157.736725] ___sys_sendmsg+0x10f/0x190 [ 157.801721] __sys_sendmsg+0x115/0x1f0 [ 157.823967] __x64_sys_sendmsg+0x7d/0xc0 [ 157.828403] do_syscall_64+0xc1/0x600 [ 157.832558] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: b15e7a6e8d31 ("net: sched: don't take rtnl lock during flow_action setup") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Vlad Buslov Signed-off-by: David S. Miller

net/sched: act_ct: Enable hardware offload of flow table entires

2020-03-12T22:00:39Z

Pass the zone's flow table instance on the flow action to the drivers. Thus, allowing drivers to register FT add/del/stats callbacks. Finally, enable hardware offload on the flow table instance. Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

net/sched: act_ct: Support restoring conntrack info on skbs

2020-03-12T22:00:38Z

Provide an API to restore the ct state pointer. This may be used by drivers to restore the ct state if they miss in tc chain after they already did the hardware connection tracking action (ct_metadata action). For example, consider the following rule on chain 0 that is in_hw, however chain 1 is not_in_hw: $ tc filter add dev ... chain 0 ... \ flower ... action ct pipe action goto chain 1 Packets of a flow offloaded (via nf flow table offload) by the driver hit this rule in hardware, will be marked with the ct metadata action (mark, label, zone) that does the equivalent of the software ct action, and when the packet jumps to hardware chain 1, there would be a miss. CT was already processed in hardware. Therefore, the driver's miss handling should restore the ct state on the skb, using the provided API, and continue the packet processing in chain 1. Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

net/sched: act_ct: Create nf flow table per zone

2020-03-03T23:09:12Z

Use the NF flow tables infrastructure for CT offload. Create a nf flow table per zone. Next patches will add FT entries to this table, and do the software offload. Signed-off-by: Paul Blakey Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

net: sched: refactor ct action helpers to require tcf_lock

2020-02-17T22:17:02Z

In order to remove rtnl lock dependency from flow_action representation translator, change rtnl_dereference() to rcu_dereference_protected() in ct action helpers that provide external access to zone and action values. This is safe to do because the functions are not called from anywhere else outside flow_action infrastructure which was modified to obtain tcf_lock when accessing action data in one of previous patches in the series. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net: sched: refactor police action helpers to require tcf_lock

2020-02-17T22:17:02Z

In order to remove rtnl lock dependency from flow_action representation translator, change rcu_dereference_bh_rtnl() to rcu_dereference_protected() in police action helpers that provide external access to rate and burst values. This is safe to do because the functions are not called from anywhere else outside flow_action infrastructure which was modified to obtain tcf_lock when accessing action data in one of previous patches in the series. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net: sched: lock action when translating it to flow_action infra

2020-02-17T22:17:02Z

In order to remove dependency on rtnl lock, take action's tcfa_lock when constructing its representation as flow_action_entry structure. Refactor tcf_sample_get_group() to assume that caller holds tcf_lock and don't take it manually. This callback is only called from flow_action infra representation translator which now calls it with tcf_lock held, so this refactoring is necessary to prevent deadlock. Allocate memory with GFP_ATOMIC flag for ip_tunnel_info copy because tcf_tunnel_info_copy() is only called from flow_action representation infra code with tcf_lock spinlock taken. Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller

net: sched: take reference to psample group in flow_action infra

2019-09-16T07:18:03Z

With recent patch set that removed rtnl lock dependency from cls hardware offload API rtnl lock is only taken when reading action data and can be released after action-specific data is parsed into intermediate representation. However, sample action psample group is passed by pointer without obtaining reference to it first, which makes it possible to concurrently overwrite the action and deallocate object pointed by psample_group pointer after rtnl lock is released but before driver finished using the pointer. To prevent such race condition, obtain reference to psample group while it is used by flow_action infra. Extend psample API with function psample_group_take() that increments psample group reference counter. Extend struct tc_action_ops with new get_psample_group() API. Implement the API for action sample using psample_group_take() and already existing psample_group_put() as a destructor. Use it in tc_setup_flow_action() to take reference to psample group pointed to by entry->sample.psample_group and release it in tc_cleanup_flow_action(). Disable bh when taking psample_groups_lock. The lock is now taken while holding action tcf_lock that is used by data path and requires bh to be disabled, so doing the same for psample_groups_lock is necessary to preserve SOFTIRQ-irq-safety. Fixes: 918190f50eb6 ("net: sched: flower: don't take rtnl lock for cls hw offloads API") Signed-off-by: Vlad Buslov Acked-by: Jiri Pirko Signed-off-by: David S. Miller