The not-per-CPU variant of qdisc tc (traffic control) statistics,
Qdisc::gnet_stats_basic_packed bstats, is protected with Qdisc::running
sequence counter.

This sequence counter is used for reliably protecting bstats reads from
parallel writes. Meanwhile, the seqcount's write section covers a much
wider area than bstats update: qdisc_run_begin() => qdisc_run_end().

That read/write section asymmetry can lead to needless retries of the
read section. To prepare for removing the Qdisc::running sequence
counter altogether, introduce a u64_stats sync point inside bstats
instead.

Modify _bstats_update() to start/end the bstats u64_stats write
section.

For bisectability, and finer commits granularity, the bstats read
section is still protected with a Qdisc::running read/retry loop and
qdisc_run_begin/end() still starts/ends that seqcount write section.
Once all call sites are modified to use _bstats_update(), the
Qdisc::running seqcount will be removed and bstats read/retry loop will
be modified to utilize the internal u64_stats sync point.

Note, using u64_stats implies no sequence counter protection for 64-bit
architectures. This can lead to the statistics "packets" vs. "bytes"
values getting out of sync on rare occasions. The individual values will
still be valid.

[bigeasy: Minor commit message edits, init all gnet_stats_basic_packed.]
Signed-off-by: NAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TC action ->init() API has 10 parameters, it becomes harder
to read. Some of them are just boolean and can be replaced
by flags. Similarly for the internal API tcf_action_init()
and tcf_exts_validate().

This patch converts them to flags and fold them into
the upper 16 bits of "flags", whose lower 16 bits are still
reserved for user-space. More specifically, the following
kernel flags are introduced:

TCA_ACT_FLAGS_POLICE replace 'name' in a few contexts, to
distinguish whether it is compatible with policer.

TCA_ACT_FLAGS_BIND replaces 'bind', to indicate whether
this action is bound to a filter.

TCA_ACT_FLAGS_REPLACE  replaces 'ovr' in most contexts,
means we are replacing an existing action.

TCA_ACT_FLAGS_NO_RTNL replaces 'rtnl_held' but has the
opposite meaning, because we still hold RTNL in most
cases.

The only user-space flag TCA_ACT_FLAGS_NO_PERCPU_STATS is
untouched and still stored as before.

I have tested this patch with tdc and I do not see any
failure related to this patch.
Tested-by: NVlad Buslov <vladbu@nvidia.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <cong.wang@bytedance.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It has been deal with the 'if (err' statement in rtnetlink_send()
and rtnl_unicast(). so remove unnecessary if statement.

v2: use the raw name rtnetlink_send().
Signed-off-by: NYajun Deng <yajun.deng@linux.dev>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When nla_put_u32() fails, 'ret' could be 0, it should
return error code in tcf_del_walker().
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With recent changes that separated action module load from action
initialization tcf_action_init() function error handling code was modified
to manually release the loaded modules if loading/initialization of any
further action in same batch failed. For the case when all modules
successfully loaded and some of the actions were initialized before one of
them failed in init handler. In this case for all previous actions the
module will be released twice by the error handler: First time by the loop
that manually calls module_put() for all ops, and second time by the action
destroy code that puts the module after destroying the action.

Reproduction:

$ sudo tc actions add action simple sdata \"2\" index 2
$ sudo tc actions add action simple sdata \"1\" index 1 \
                      action simple sdata \"2\" index 2
RTNETLINK answers: File exists
We have an error talking to the kernel
$ sudo tc actions ls action simple
total acts 1

        action order 0: Simple <"2">
         index 2 ref 1 bind 0
$ sudo tc actions flush action simple
$ sudo tc actions ls action simple
$ sudo tc actions add action simple sdata \"2\" index 2
Error: Failed to load TC action module.
We have an error talking to the kernel
$ lsmod | grep simple
act_simple             20480  -1

Fix the issue by modifying module reference counting handling in action
initialization code:

- Get module reference in tcf_idr_create() and put it in tcf_idr_release()
instead of taking over the reference held by the caller.

- Modify users of tcf_action_init_1() to always release the module
reference which they obtain before calling init function instead of
assuming that created action takes over the reference.

- Finally, modify tcf_action_init_1() to not release the module reference
when overwriting existing action as this is no longer necessary since both
upper and lower layers obtain and manage their own module references
independently.

Fixes: d349f997 ("net_sched: fix RTNL deadlock again caused by request_module()")
Suggested-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Action init code increments reference counter when it changes an action.
This is the desired behavior for cls API which needs to obtain action
reference for every classifier that points to action. However, act API just
needs to change the action and releases the reference before returning.
This sequence breaks when the requested action doesn't exist, which causes
act API init code to create new action with specified index, but action is
still released before returning and is deleted (unless it was referenced
concurrently by cls API).

Reproduction:

$ sudo tc actions ls action gact
$ sudo tc actions change action gact drop index 1
$ sudo tc actions ls action gact

Extend tcf_action_init() to accept 'init_res' array and initialize it with
action->ops->init() result. In tcf_action_add() remove pointers to created
actions from actions array before passing it to tcf_action_put_many().

Fixes: cae422f3 ("net: sched: use reference counting action init")
Reported-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 6855e821.

Following commit in series fixes the issue without introducing regression
in error rollback of tcf_action_destroy().
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, action creation using ACT API in replace mode is buggy.
When invoking for non-existent action index 42,

	tc action replace action bpf obj foo.o sec <xyz> index 42

kernel creates the action, fills up the netlink response, and then just
deletes the action after notifying userspace.

	tc action show action bpf

doesn't list the action.

This happens due to the following sequence when ovr = 1 (replace mode)
is enabled:

tcf_idr_check_alloc is used to atomically check and either obtain
reference for existing action at index, or reserve the index slot using
a dummy entry (ERR_PTR(-EBUSY)).

This is necessary as pointers to these actions will be held after
dropping the idrinfo lock, so bumping the reference count is necessary
as we need to insert the actions, and notify userspace by dumping their
attributes. Finally, we drop the reference we took using the
tcf_action_put_many call in tcf_action_add. However, for the case where
a new action is created due to free index, its refcount remains one.
This when paired with the put_many call leads to the kernel setting up
the action, notifying userspace of its creation, and then tearing it
down. For existing actions, the refcount is still held so they remain
unaffected.

Fortunately due to rtnl_lock serialization requirement, such an action
with refcount == 1 will not be concurrently deleted by anything else, at
best CLS API can move its refcount up and down by binding to it after it
has been published from tcf_idr_insert_many. Since refcount is atleast
one until put_many call, CLS API cannot delete it. Also __tcf_action_put
release path already ensures deterministic outcome (either new action
will be created or existing action will be reused in case CLS API tries
to bind to action concurrently) due to idr lock serialization.

We fix this by making refcount of newly created actions as 2 in ACT API
replace mode. A relaxed store will suffice as visibility is ensured only
after the tcf_idr_insert_many call.

Note that in case of creation or overwriting using CLS API only (i.e.
bind = 1), overwriting existing action object is not allowed, and any
such request is silently ignored (without error).

The refcount bump that occurs in tcf_idr_check_alloc call there for
existing action will pair with tcf_exts_destroy call made from the
owner module for the same action. In case of action creation, there
is no existing action, so no tcf_exts_destroy callback happens.

This means no code changes for CLS API.

Fixes: cae422f3 ("net: sched: use reference counting action init")
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When police action is created by cls API tcf_exts_validate() first
conditional that calls tcf_action_init_1() directly, the action idr is not
updated according to latest changes in action API that require caller to
commit newly created action to idr with tcf_idr_insert_many(). This results
such action not being accessible through act API and causes crash reported
by syzbot:

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in __tcf_idr_release net/sched/act_api.c:178 [inline]
BUG: KASAN: null-ptr-deref in tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
Read of size 4 at addr 0000000000000010 by task kworker/u4:5/204

CPU: 0 PID: 204 Comm: kworker/u4:5 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 __kasan_report mm/kasan/report.c:400 [inline]
 kasan_report.cold+0x5f/0xd5 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/generic.c:179 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:185
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:178 [inline]
 tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
 tc_action_net_exit include/net/act_api.h:151 [inline]
 police_exit_net+0x168/0x360 net/sched/act_police.c:390
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 204 Comm: kworker/u4:5 Tainted: G    B             5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 panic+0x306/0x73d kernel/panic.c:231
 end_report+0x58/0x5e mm/kasan/report.c:100
 __kasan_report mm/kasan/report.c:403 [inline]
 kasan_report.cold+0x67/0xd5 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/generic.c:179 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:185
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:178 [inline]
 tcf_idrinfo_destroy+0x129/0x1d0 net/sched/act_api.c:598
 tc_action_net_exit include/net/act_api.h:151 [inline]
 police_exit_net+0x168/0x360 net/sched/act_police.c:390
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:190
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled

Fix the issue by calling tcf_idr_insert_many() after successful action
initialization.

Fixes: 0fedc63f ("net_sched: commit action insertions together")
Reported-by: syzbot+151e3e714d34ae4ce7e8@syzkaller.appspotmail.com
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Reviewed-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcf_action_init_1() loads tc action modules automatically with
request_module() after parsing the tc action names, and it drops RTNL
lock and re-holds it before and after request_module(). This causes a
lot of troubles, as discovered by syzbot, because we can be in the
middle of batch initializations when we create an array of tc actions.

One of the problem is deadlock:

CPU 0					CPU 1
rtnl_lock();
for (...) {
  tcf_action_init_1();
    -> rtnl_unlock();
    -> request_module();
				rtnl_lock();
				for (...) {
				  tcf_action_init_1();
				    -> tcf_idr_check_alloc();
				   // Insert one action into idr,
				   // but it is not committed until
				   // tcf_idr_insert_many(), then drop
				   // the RTNL lock in the _next_
				   // iteration
				   -> rtnl_unlock();
    -> rtnl_lock();
    -> a_o->init();
      -> tcf_idr_check_alloc();
      // Now waiting for the same index
      // to be committed
				    -> request_module();
				    -> rtnl_lock()
				    // Now waiting for RTNL lock
				}
				rtnl_unlock();
}
rtnl_unlock();

This is not easy to solve, we can move the request_module() before
this loop and pre-load all the modules we need for this netlink
message and then do the rest initializations. So the loop breaks down
to two now:

        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
                struct tc_action_ops *a_o;

                a_o = tc_action_load_ops(name, tb[i]...);
                ops[i - 1] = a_o;
        }

        for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
                act = tcf_action_init_1(ops[i - 1]...);
        }

Although this looks serious, it only has been reported by syzbot, so it
seems hard to trigger this by humans. And given the size of this patch,
I'd suggest to make it to net-next and not to backport to stable.

This patch has been tested by syzbot and tested with tdc.py by me.

Fixes: 0fedc63f ("net_sched: commit action insertions together")
Reported-and-tested-by: syzbot+82752bc5331601cf4899@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+b3b63b6bff456bd95294@syzkaller.appspotmail.com
Reported-by: syzbot+ba67b12b1ca729912834@syzkaller.appspotmail.com
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <cong.wang@bytedance.com>
Tested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20210117005657.14810-1-xiyou.wangcong@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Currently kernel tc subsystem can do conntrack in cat_ct. But when several
fragment packets go through the act_ct, function tcf_ct_handle_fragments
will defrag the packets to a big one. But the last action will redirect
mirred to a device which maybe lead the reassembly big packet over the mtu
of target device.

This patch add support for a xmit hook to mirred, that gets executed before
xmiting the packet. Then, when act_ct gets loaded, it configs that hook.
The frag xmit hook maybe reused by other modules.
Signed-off-by: Nwenxu <wenxu@ucloud.cn>
Acked-by: NCong Wang <cong.wang@bytedance.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Currently both filter and action flags use same "TCA_" prefix which makes
them hard to distinguish to code and confusing for users. Create aliases
for existing action flags constants with "TCA_ACT_" prefix.
Signed-off-by: NVlad Buslov <vlad@buslov.dev>
Link: https://lore.kernel.org/r/20201124164054.893168-1-vlad@buslov.devSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.
Signed-off-by: NFrancis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

nla_strlcpy now returns -E2BIG if src was truncated when written to dst.
It also returns this error value if dstsize is 0 or higher than INT_MAX.

For example, if src is "foo\0" and dst is 3 bytes long, the result will be:
1. "foG" after memcpy (G means garbage).
2. "fo\0" after memset.
3. -E2BIG is returned because src was not completely written into dst.

The callers of nla_strlcpy were modified to take into account this modification.
Signed-off-by: NFrancis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Some typos are found out by misspell-fixer tool:

$ misspell-fixer -rnv ./net/sched/
./net/sched/act_api.c:686
./net/sched/act_bpf.c:68
./net/sched/cls_rsvp.h:241
./net/sched/em_cmp.c:44
./net/sched/sch_pie.c:408

Fix typos found by misspell-fixer.
Signed-off-by: NMenglong Dong <dong.menglong@zte.com.cn>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/5fa8e9d4.1c69fb81.5d889.5c64@mx.google.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Allow user to request action terse dump with new flag value
TCA_FLAG_TERSE_DUMP. Only output essential action info in terse dump (kind,
stats, index and cookie, if set by the user when creating the action). This
is different from filter terse dump where index is excluded (filter can be
identified by its own handle).

Move tcf_action_dump_terse() function to the beginning of source file in
order to call it from tcf_dump_walker().
Signed-off-by: NVlad Buslov <vlad@buslov.dev>
Suggested-by: NJamal Hadi Salim <jhs@mojatatu.com>
Acked-by: NCong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/20201102201243.287486-1-vlad@buslov.devSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Although we take RTNL on dump path, it is possible to
skip RTNL on insertion path. So the following race condition
is possible:

rtnl_lock()		// no rtnl lock
			mutex_lock(&idrinfo->lock);
			// insert ERR_PTR(-EBUSY)
			mutex_unlock(&idrinfo->lock);
tc_dump_action()
rtnl_unlock()

So we have to skip those temporary -EBUSY entries on dump path
too.

Reported-and-tested-by: syzbot+b47bc4f247856fb4d9e1@syzkaller.appspotmail.com
Fixes: 0fedc63f ("net_sched: commit action insertions together")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All TC actions call tcf_action_check_ctrlact() to validate
goto chain, so this check in tcf_action_init_1() is actually
redundant. Remove it to save troubles of leaking memory.

Fixes: e49d8c22 ("net_sched: defer tcf_idr_insert() in tcf_action_init_1()")
Reported-by: NVlad Buslov <vladbu@mellanox.com>
Suggested-by: NDavide Caratti <dcaratti@redhat.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NDavide Caratti <dcaratti@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot is able to trigger a failure case inside the loop in
tcf_action_init(), and when this happens we clean up with
tcf_action_destroy(). But, as these actions are already inserted
into the global IDR, other parallel process could free them
before tcf_action_destroy(), then we will trigger a use-after-free.

Fix this by deferring the insertions even later, after the loop,
and committing all the insertions in a separate loop, so we will
never fail in the middle of the insertions any more.

One side effect is that the window between alloction and final
insertion becomes larger, now it is more likely that the loop in
tcf_del_walker() sees the placeholder -EBUSY pointer. So we have
to check for error pointer in tcf_del_walker().

Reported-and-tested-by: syzbot+2287853d392e4b42374a@syzkaller.appspotmail.com
Fixes: 0190c1d4 ("net: sched: atomically check-allocate action")
Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All TC actions call tcf_idr_insert() for new action at the end
of their ->init(), so we can actually move it to a central place
in tcf_action_init_1().

And once the action is inserted into the global IDR, other parallel
process could free it immediately as its refcnt is still 1, so we can
not fail after this, we need to move it after the goto action
validation to avoid handling the failure case after insertion.

This is found during code review, is not directly triggered by syzbot.
And this prepares for the next patch.

Cc: Vlad Buslov <vladbu@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reviewing the error handling in tcf_action_init_1()
most of the early handling uses

err_out:
	if (cookie) {
		kfree(cookie->data);
		kfree(cookie);
	}

before cookie could ever be set.

So skip the unnecessay check.
Signed-off-by: NTom Rix <trix@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the redundant null check for skb.
Signed-off-by: NGaurav Singh <gaurav1086@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a drop frames counter to tc flower offloading.
Reporting h/w dropped frames is necessary for some actions.
Some actions like police action and the coming introduced stream gate
action would produce dropped frames which is necessary for user. Status
update shows how many filtered packets increasing and how many dropped
in those packets.

v2: Changes
 - Update commit comments suggest by Jiri Pirko.
Signed-off-by: NPo Liu <Po.Liu@nxp.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend tcf_action_dump() with boolean argument 'terse' that is used to
request terse-mode action dump. In terse mode only essential data needed to
identify particular action (action kind, cookie, etc.) and its stats is put
to resulting skb and everything else is omitted. Implement
tcf_exts_terse_dump() helper in cls API that is intended to be used to
request terse dump of all exts (actions) attached to the filter.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the netlink policy, we currently have a void *validation_data
that's pointing to different things:
 * a u32 value for bitfield32,
 * the netlink policy for nested/nested array
 * the string for NLA_REJECT

Remove the pointer and place appropriate type-safe items in the
union instead.

While at it, completely dissolve the pointer for the bitfield32
case and just put the value there directly.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It may be up to the driver (in case ANY HW stats is passed) to select
which type of HW stats he is going to use. Add an infrastructure to
expose this information to user.

$ tc filter add dev enp3s0np1 ingress proto ip handle 1 pref 1 flower dst_ip 192.168.1.1 action drop
$ tc -s filter show dev enp3s0np1 ingress
filter protocol ip pref 1 flower chain 0
filter protocol ip pref 1 flower chain 0 handle 0x1
  eth_type ipv4
  dst_ip 192.168.1.1
  in_hw in_hw_count 2
        action order 1: gact action drop
         random type none pass val 0
         index 1 ref 1 bind 1 installed 10 sec used 10 sec
        Action statistics:
        Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
        backlog 0b 0p requeues 0
        used_hw_stats immediate     <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a helper to pass value and selector to. The helper packs them
into struct and puts them into netlink message.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 53eca1f3 ("net: rename flow_action_hw_stats_types* ->
flow_action_hw_stats*") renamed just the flow action types and
helpers. For consistency rename variables, enums, struct members
and UAPI too (note that this UAPI was not in any official release,
yet).
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Reviewed-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, user who is adding an action expects HW to report stats,
however it does not have exact expectations about the stats types.
That is aligned with TCA_ACT_HW_STATS_TYPE_ANY.

Allow user to specify the type of HW stats for an action and require it.

Pass the information down to flow_offload layer.
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The put of the flags was added by the commit referenced in fixes tag,
however the size of the message was not extended accordingly.

Fix this by adding size of the flags bitfield to the message size.

Fixes: e3822678 ("net: sched: update action implementations to support flags")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

after commit 4097e9d2 ("net: sched: don't use tc_action->order during
action dump"), 'act->order' is initialized but then it's no more read, so
we can just remove this member of struct tc_action.

CC: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Reviewed-by: NIvan Vecera <ivecera@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now the kernel uses 64bit packet counters in scheduler layer,
we want to export these counters to user space.

Instead risking breaking user space by adding fields
to struct gnet_stats_basic, add a new TCA_STATS_PKT64.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend struct tc_action with new "tcfa_flags" field. Set the field in
tcf_idr_create() function and provide new helper
tcf_idr_create_from_flags() that derives 'cpustats' boolean from flags
value. Update individual hardware-offloaded actions init() to pass their
"flags" argument to new helper in order to skip percpu stats allocation
when user requested it through flags.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend TCA_ACT space with nla_bitfield32 flags. Add
TCA_ACT_FLAGS_NO_PERCPU_STATS as the only allowed flag. Parse the flags in
tcf_action_init_1() and pass resulting value as additional argument to
a_o->init().
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Modify stats update helper functions introduced in previous patches in this
series to fallback to regular tc_action->tcfa_{b|q}stats if cpu stats are
not allocated for the action argument. If regular non-percpu allocated
counters are in use, then obtain action tcfa_lock while modifying them.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, all implementations of tc_action_ops->stats_update() callback
have almost exactly the same implementation of counters update
code (besides gact which also updates drop counter). In order to simplify
support for using both percpu-allocated and regular action counters
depending on run-time flag in following patches, extract action counters
update code into standalone function in act API.

This commit doesn't change functionality.
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit replaces the use of rcu_swap_protected() with the more
intuitively appealing rcu_replace_pointer() as a step towards removing
rcu_swap_protected().

Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@mail.gmail.com/Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
[ paulmck: From rcu_replace() to rcu_replace_pointer() per Ingo Molnar. ]
Signed-off-by: NPaul E. McKenney <paulmck@kernel.org>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>

tc_ctl_action() has the ability to loop forever if tcf_action_add()
returns -EAGAIN.

This special case has been done in case a module needed to be loaded,
but it turns out that tcf_add_notify() could also return -EAGAIN
if the socket sk_rcvbuf limit is hit.

We need to separate the two cases, and only loop for the module
loading case.

While we are at it, add a limit of 10 attempts since unbounded
loops are always scary.

syzbot repro was something like :

socket(PF_NETLINK, SOCK_RAW|SOCK_NONBLOCK, NETLINK_ROUTE) = 3
write(3, ..., 38) = 38
setsockopt(3, SOL_SOCKET, SO_RCVBUF, [0], 4) = 0
sendmsg(3, {msg_name(0)=NULL, msg_iov(1)=[{..., 388}], msg_controllen=0, msg_flags=0x10}, ...)

NMI backtrace for cpu 0
CPU: 0 PID: 1054 Comm: khungtaskd Not tainted 5.4.0-rc1+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0x9d0/0xef0 kernel/hung_task.c:289
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8859 Comm: syz-executor910 Not tainted 5.4.0-rc1+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:751 [inline]
RIP: 0010:lockdep_hardirqs_off+0x1df/0x2e0 kernel/locking/lockdep.c:3453
Code: 5c 08 00 00 5b 41 5c 41 5d 5d c3 48 c7 c0 58 1d f3 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d3 00 00 00 <48> 83 3d 21 9e 99 07 00 0f 84 b9 00 00 00 9c 58 0f 1f 44 00 00 f6
RSP: 0018:ffff8880a6f3f1b8 EFLAGS: 00000046
RAX: 1ffffffff11e63ab RBX: ffff88808c9c6080 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88808c9c6914
RBP: ffff8880a6f3f1d0 R08: ffff88808c9c6080 R09: fffffbfff16be5d1
R10: fffffbfff16be5d0 R11: 0000000000000003 R12: ffffffff8746591f
R13: ffff88808c9c6080 R14: ffffffff8746591f R15: 0000000000000003
FS:  00000000011e4880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000a8920000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_hardirqs_off+0x62/0x240 kernel/trace/trace_preemptirq.c:45
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
 _raw_spin_lock_irqsave+0x6f/0xcd kernel/locking/spinlock.c:159
 __wake_up_common_lock+0xc8/0x150 kernel/sched/wait.c:122
 __wake_up+0xe/0x10 kernel/sched/wait.c:142
 netlink_unlock_table net/netlink/af_netlink.c:466 [inline]
 netlink_unlock_table net/netlink/af_netlink.c:463 [inline]
 netlink_broadcast_filtered+0x705/0xb80 net/netlink/af_netlink.c:1514
 netlink_broadcast+0x3a/0x50 net/netlink/af_netlink.c:1534
 rtnetlink_send+0xdd/0x110 net/core/rtnetlink.c:714
 tcf_add_notify net/sched/act_api.c:1343 [inline]
 tcf_action_add+0x243/0x370 net/sched/act_api.c:1362
 tc_ctl_action+0x3b5/0x4bc net/sched/act_api.c:1410
 rtnetlink_rcv_msg+0x463/0xb00 net/core/rtnetlink.c:5386
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5404
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x531/0x710 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x8a5/0xd60 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x803/0x920 net/socket.c:2311
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2356
 __do_sys_sendmsg net/socket.c:2365 [inline]
 __se_sys_sendmsg net/socket.c:2363 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2363
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440939

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: syzbot+cf0adbb9c28c8866c788@syzkaller.appspotmail.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For TCA_ACT_KIND, we have to keep the backward compatibility too,
and rely on nla_strlcpy() to check and terminate the string with
a NUL.

Note for TC actions, nla_strcmp() is already used to compare kind
strings, so we don't need to fix other places.

Fixes: 199ce850 ("net_sched: add policy validation for action attributes")
Reported-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Similar to commit 8b4c3cdd
("net: sched: Add policy validation for tc attributes"), we need
to add proper policy validation for TC action attributes too.

Cc: David Ahern <dsahern@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>