bpf: Fix DEVMAP_HASH overflow check on 32-bit arches

[ Upstream commit 281d464a34f540de166cee74b723e97ac2515ec3 ]

The devmap code allocates a number hash buckets equal to the next power
of two of t

bpf: Fix DEVMAP_HASH overflow check on 32-bit arches

[ Upstream commit 281d464a34f540de166cee74b723e97ac2515ec3 ]

The devmap code allocates a number hash buckets equal to the next power
of two of the max_entries value provided when creating the map. When
rounding up to the next power of two, the 32-bit variable storing the
number of buckets can overflow, and the code checks for overflow by
checking if the truncated 32-bit value is equal to 0. However, on 32-bit
arches the rounding up itself can overflow mid-way through, because it
ends up doing a left-shift of 32 bits on an unsigned long value. If the
size of an unsigned long is four bytes, this is undefined behaviour, so
there is no guarantee that we'll end up with a nice and tidy 0-value at
the end.

Syzbot managed to turn this into a crash on arm32 by creating a
DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it.
Fix this by moving the overflow check to before the rounding up
operation.

Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Link: https://lore.kernel.org/r/000000000000ed666a0611af6818@google.com
Reported-and-tested-by: syzbot+8cd36f6b65f3cafd400a@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Message-ID: <20240307120340.99577-2-toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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bpf, devmap: Remove unused dtab field from bpf_dtab_netdev

Commit 96360004b862 ("xdp: Make devmap flush_list common for all map
instances") removes the use of bpf_dtab_netdev::dtab in bq_enqueue(),

bpf, devmap: Remove unused dtab field from bpf_dtab_netdev

Commit 96360004b862 ("xdp: Make devmap flush_list common for all map
instances") removes the use of bpf_dtab_netdev::dtab in bq_enqueue(),
so just remove dtab from bpf_dtab_netdev.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230728014942.892272-3-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

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bpf: Centralize permissions checks for all BPF map types

This allows to do more centralized decisions later on, and generally
makes it very explicit which maps are privileged and which are not
(e.g.

bpf: Centralize permissions checks for all BPF map types

This allows to do more centralized decisions later on, and generally
makes it very explicit which maps are privileged and which are not
(e.g., LRU_HASH and LRU_PERCPU_HASH, which are privileged HASH variants,
as opposed to unprivileged HASH and HASH_PERCPU; now this is explicit
and easy to verify).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230613223533.3689589-4-andrii@kernel.org

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bpf: return long from bpf_map_ops funcs

This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the si

bpf: return long from bpf_map_ops funcs

This patch changes the return types of bpf_map_ops functions to long, where
previously int was returned. Using long allows for bpf programs to maintain
the sign bit in the absence of sign extension during situations where
inlined bpf helper funcs make calls to the bpf_map_ops funcs and a negative
error is returned.

The definitions of the helper funcs are generated from comments in the bpf
uapi header at `include/uapi/linux/bpf.h`. The return type of these
helpers was previously changed from int to long in commit bdb7b79b4ce8. For
any case where one of the map helpers call the bpf_map_ops funcs that are
still returning 32-bit int, a compiler might not include sign extension
instructions to properly convert the 32-bit negative value a 64-bit
negative value.

For example:
bpf assembly excerpt of an inlined helper calling a kernel function and
checking for a specific error:

; err = bpf_map_update_elem(&mymap, &key, &val, BPF_NOEXIST);
...
46: call 0xffffffffe103291c ; htab_map_update_elem
; if (err && err != -EEXIST) {
4b: cmp $0xffffffffffffffef,%rax ; cmp -EEXIST,%rax

kernel function assembly excerpt of return value from
`htab_map_update_elem` returning 32-bit int:

movl $0xffffffef, %r9d
...
movl %r9d, %eax

...results in the comparison:
cmp $0xffffffffffffffef, $0x00000000ffffffef

Fixes: bdb7b79b4ce8 ("bpf: Switch most helper return values from 32-bit int to 64-bit long")
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20230322194754.185781-3-inwardvessel@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: devmap memory usage

A new helper is introduced to calculate the memory usage of devmap and
devmap_hash. The number of dynamically allocated elements are recored
for devmap_hash already, but not

bpf: devmap memory usage

A new helper is introduced to calculate the memory usage of devmap and
devmap_hash. The number of dynamically allocated elements are recored
for devmap_hash already, but not for devmap. To track the memory size of
dynamically allocated elements, this patch also count the numbers for
devmap.

The result as follows,
- before
40: devmap name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock 524288B
41: devmap_hash name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock 524288B

- after
40: devmap name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock 524608B
41: devmap_hash name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock 524608B

Note that the number of buckets is same with max_entries for devmap_hash
in this case.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-11-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: devmap: check XDP features in __xdp_enqueue routine

Check if the destination device implements ndo_xdp_xmit callback relying
on NETDEV_XDP_ACT_NDO_XMIT flags. Moreover, check if the destination

bpf: devmap: check XDP features in __xdp_enqueue routine

Check if the destination device implements ndo_xdp_xmit callback relying
on NETDEV_XDP_ACT_NDO_XMIT flags. Moreover, check if the destination device
supports XDP non-linear frame in __xdp_enqueue and is_valid_dst routines.
This patch allows to perform XDP_REDIRECT on non-linear XDP buffers.

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/26a94c33520c0bfba021b3fbb2cb8c1e69bf53b8.1675245258.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: Expand map key argument of bpf_redirect_map to u64

For queueing packets in XDP we want to add a new redirect map type with
support for 64-bit indexes. To prepare fore this, expand the width of

bpf: Expand map key argument of bpf_redirect_map to u64

For queueing packets in XDP we want to add a new redirect map type with
support for 64-bit indexes. To prepare fore this, expand the width of the
'key' argument to the bpf_redirect_map() helper. Since BPF registers are
always 64-bit, this should be safe to do after the fact.

Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20221108140601.149971-3-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: Use bpf_map_area_alloc consistently on bpf map creation

Let's use the generic helper bpf_map_area_alloc() instead of the
open-coded kzalloc helpers in bpf maps creation path.

Signed-off-by: Ya

bpf: Use bpf_map_area_alloc consistently on bpf map creation

Let's use the generic helper bpf_map_area_alloc() instead of the
open-coded kzalloc helpers in bpf maps creation path.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20220810151840.16394-5-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: Make __GFP_NOWARN consistent in bpf map creation

Some of the bpf maps are created with __GFP_NOWARN, i.e. arraymap,
bloom_filter, bpf_local_storage, bpf_struct_ops, lpm_trie,
queue_stack_maps,

bpf: Make __GFP_NOWARN consistent in bpf map creation

Some of the bpf maps are created with __GFP_NOWARN, i.e. arraymap,
bloom_filter, bpf_local_storage, bpf_struct_ops, lpm_trie,
queue_stack_maps, reuseport_array, stackmap and xskmap, while others are
created without __GFP_NOWARN, i.e. cpumap, devmap, hashtab,
local_storage, offload, ringbuf and sock_map. But there are not key
differences between the creation of these maps. So let make this
allocation flag consistent in all bpf maps creation. Then we can use a
generic helper to alloc all bpf maps.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20220810151840.16394-4-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf, devmap: Compute proper xdp_frame len redirecting frames

Even if it is currently forbidden to XDP_REDIRECT a multi-frag xdp_frame into
a devmap, compute proper xdp_frame length in __xdp_enqueue

bpf, devmap: Compute proper xdp_frame len redirecting frames

Even if it is currently forbidden to XDP_REDIRECT a multi-frag xdp_frame into
a devmap, compute proper xdp_frame length in __xdp_enqueue and is_valid_dst
routines running xdp_get_frame_len().

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/894d99c01139e921bdb6868158ff8e67f661c072.1658596075.git.lorenzo@kernel.org

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bpf: Make non-preallocated allocation low priority

GFP_ATOMIC doesn't cooperate well with memcg pressure so far, especially
if we allocate too much GFP_ATOMIC memory. For example, when we set the
me

bpf: Make non-preallocated allocation low priority

GFP_ATOMIC doesn't cooperate well with memcg pressure so far, especially
if we allocate too much GFP_ATOMIC memory. For example, when we set the
memcg limit to limit a non-preallocated bpf memory, the GFP_ATOMIC can
easily break the memcg limit by force charge. So it is very dangerous to
use GFP_ATOMIC in non-preallocated case. One way to make it safe is to
remove __GFP_HIGH from GFP_ATOMIC, IOW, use (__GFP_ATOMIC |
__GFP_KSWAPD_RECLAIM) instead, then it will be limited if we allocate
too much memory. There's a plan to completely remove __GFP_ATOMIC in the
mm side[1], so let's use GFP_NOWAIT instead.

We introduced BPF_F_NO_PREALLOC is because full map pre-allocation is
too memory expensive for some cases. That means removing __GFP_HIGH
doesn't break the rule of BPF_F_NO_PREALLOC, but has the same goal with
it-avoiding issues caused by too much memory. So let's remove it.

This fix can also apply to other run-time allocations, for example, the
allocation in lpm trie, local storage and devmap. So let fix it
consistently over the bpf code

It also fixes a typo in the comment.

[1]. https://lore.kernel.org/linux-mm/163712397076.13692.4727608274002939094@noble.neil.brown.name/

Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: NeilBrown <neilb@suse.de>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Link: https://lore.kernel.org/r/20220709154457.57379-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: Compute map_btf_id during build time

For now, the field 'map_btf_id' in 'struct bpf_map_ops' for all map
types are computed during vmlinux-btf init:

btf_parse_vmlinux() -> btf_vmlinux_map_id

bpf: Compute map_btf_id during build time

For now, the field 'map_btf_id' in 'struct bpf_map_ops' for all map
types are computed during vmlinux-btf init:

btf_parse_vmlinux() -> btf_vmlinux_map_ids_init()

It will lookup the btf_type according to the 'map_btf_name' field in
'struct bpf_map_ops'. This process can be done during build time,
thanks to Jiri's resolve_btfids.

selftest of map_ptr has passed:

$96 map_ptr:OK
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: generalise tail call map compatibility check

The check for tail call map compatibility ensures that tail calls only
happen between maps of the same type. To ensure backwards compatibility for
X

bpf: generalise tail call map compatibility check

The check for tail call map compatibility ensures that tail calls only
happen between maps of the same type. To ensure backwards compatibility for
XDP frags we need a similar type of check for cpumap and devmap
programs, so move the state from bpf_array_aux into bpf_map, add
xdp_has_frags to the check, and apply the same check to cpumap and devmap.

Acked-by: John Fastabend <john.fastabend@gmail.com>
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/f19fd97c0328a39927f3ad03e1ca6b43fd53cdfd.1642758637.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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xdp: Move conversion to xdp_frame out of map functions

All map redirect functions except XSK maps convert xdp_buff to xdp_frame
before enqueueing it. So move this conversion of out the map functions

xdp: Move conversion to xdp_frame out of map functions

All map redirect functions except XSK maps convert xdp_buff to xdp_frame
before enqueueing it. So move this conversion of out the map functions
and into xdp_do_redirect(). This removes a bit of duplicated code, but more
importantly it makes it possible to support caller-allocated xdp_frame
structures, which will be added in a subsequent commit.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220103150812.87914-5-toke@redhat.com

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bpf: Let bpf_warn_invalid_xdp_action() report more info

In non trivial scenarios, the action id alone is not sufficient to
identify the program causing the warning. Before the previous patch,
the ge

bpf: Let bpf_warn_invalid_xdp_action() report more info

In non trivial scenarios, the action id alone is not sufficient to
identify the program causing the warning. Before the previous patch,
the generated stack-trace pointed out at least the involved device
driver.

Let's additionally include the program name and id, and the relevant
device name.

If the user needs additional infos, he can fetch them via a kernel
probe, leveraging the arguments added here.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/ddb96bb975cbfddb1546cf5da60e77d5100b533c.1638189075.git.pabeni@redhat.com

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bpf, devmap: Exclude XDP broadcast to master device

If the ingress device is bond slave, do not broadcast back through it or
the bond master.

Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-of

bpf, devmap: Exclude XDP broadcast to master device

If the ingress device is bond slave, do not broadcast back through it or
the bond master.

Signed-off-by: Jussi Maki <joamaki@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210731055738.16820-5-joamaki@gmail.com

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bpf: devmap: Implement devmap prog execution for generic XDP

This lifts the restriction on running devmap BPF progs in generic
redirect mode. To match native XDP behavior, it is invoked right before

bpf: devmap: Implement devmap prog execution for generic XDP

This lifts the restriction on running devmap BPF progs in generic
redirect mode. To match native XDP behavior, it is invoked right before
generic_xdp_tx is called, and only supports XDP_PASS/XDP_ABORTED/
XDP_DROP actions.

We also return 0 even if devmap program drops the packet, as
semantically redirect has already succeeded and the devmap prog is the
last point before TX of the packet to device where it can deliver a
verdict on the packet.

This also means it must take care of freeing the skb, as
xdp_do_generic_redirect callers only do that in case an error is
returned.

Since devmap entry prog is supported, remove the check in
generic_xdp_install entirely.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210702111825.491065-5-memxor@gmail.com

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bpf, devmap: Convert remaining READ_ONCE() to rcu_dereference_check()

There were a couple of READ_ONCE()-invocations left-over by the devmap
RCU conversion. Convert these to rcu_dereference_check()

bpf, devmap: Convert remaining READ_ONCE() to rcu_dereference_check()

There were a couple of READ_ONCE()-invocations left-over by the devmap
RCU conversion. Convert these to rcu_dereference_check() as well to avoid
complaints from sparse.

Fixes: 782347b6bcad ("xdp: Add proper __rcu annotations to redirect map entries")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210629093907.573598-1-toke@redhat.com

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xdp: Add proper __rcu annotations to redirect map entries

XDP_REDIRECT works by a three-step process: the bpf_redirect() and
bpf_redirect_map() helpers will lookup the target of the redirect and sto

xdp: Add proper __rcu annotations to redirect map entries

XDP_REDIRECT works by a three-step process: the bpf_redirect() and
bpf_redirect_map() helpers will lookup the target of the redirect and store
it (along with some other metadata) in a per-CPU struct bpf_redirect_info.
Next, when the program returns the XDP_REDIRECT return code, the driver
will call xdp_do_redirect() which will use the information thus stored to
actually enqueue the frame into a bulk queue structure (that differs
slightly by map type, but shares the same principle). Finally, before
exiting its NAPI poll loop, the driver will call xdp_do_flush(), which will
flush all the different bulk queues, thus completing the redirect.

Pointers to the map entries will be kept around for this whole sequence of
steps, protected by RCU. However, there is no top-level rcu_read_lock() in
the core code; instead drivers add their own rcu_read_lock() around the XDP
portions of the code, but somewhat inconsistently as Martin discovered[0].
However, things still work because everything happens inside a single NAPI
poll sequence, which means it's between a pair of calls to
local_bh_disable()/local_bh_enable(). So Paul suggested[1] that we could
document this intention by using rcu_dereference_check() with
rcu_read_lock_bh_held() as a second parameter, thus allowing sparse and
lockdep to verify that everything is done correctly.

This patch does just that: we add an __rcu annotation to the map entry
pointers and remove the various comments explaining the NAPI poll assurance
strewn through devmap.c in favour of a longer explanation in filter.c. The
goal is to have one coherent documentation of the entire flow, and rely on
the RCU annotations as a "standard" way of communicating the flow in the
map code (which can additionally be understood by sparse and lockdep).

The RCU annotation replacements result in a fairly straight-forward
replacement where READ_ONCE() becomes rcu_dereference_check(), WRITE_ONCE()
becomes rcu_assign_pointer() and xchg() and cmpxchg() gets wrapped in the
proper constructs to cast the pointer back and forth between __rcu and
__kernel address space (for the benefit of sparse). The one complication is
that xskmap has a few constructions where double-pointers are passed back
and forth; these simply all gain __rcu annotations, and only the final
reference/dereference to the inner-most pointer gets changed.

With this, everything can be run through sparse without eliciting
complaints, and lockdep can verify correctness even without the use of
rcu_read_lock() in the drivers. Subsequent patches will clean these up from
the drivers.

[0] https://lore.kernel.org/bpf/20210415173551.7ma4slcbqeyiba2r@kafai-mbp.dhcp.thefacebook.com/
[1] https://lore.kernel.org/bpf/20210419165837.GA975577@paulmck-ThinkPad-P17-Gen-1/

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-6-toke@redhat.com

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bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc

In 32-bit architecture, the result of sizeof() is a 32-bit integer so
the expression becomes the multiplication between 2 32-

bpf: Fix integer overflow in argument calculation for bpf_map_area_alloc

In 32-bit architecture, the result of sizeof() is a 32-bit integer so
the expression becomes the multiplication between 2 32-bit integer which
can potentially leads to integer overflow. As a result,
bpf_map_area_alloc() allocates less memory than needed.

Fix this by casting 1 operand to u64.

Fixes: 0d2c4f964050 ("bpf: Eliminate rlimit-based memory accounting for sockmap and sockhash maps")
Fixes: 99c51064fb06 ("devmap: Use bpf_map_area_alloc() for allocating hash buckets")
Fixes: 546ac1ffb70d ("bpf: add devmap, a map for storing net device references")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210613143440.71975-1-minhquangbui99@gmail.com

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bpf, devmap: Remove drops variable from bq_xmit_all()

As Colin pointed out, the first drops assignment after declaration will
be overwritten by the second drops assignment before using, which makes

bpf, devmap: Remove drops variable from bq_xmit_all()

As Colin pointed out, the first drops assignment after declaration will
be overwritten by the second drops assignment before using, which makes
it useless.

Since the drops variable will be used only once. Just remove it and
use "cnt - sent" in trace_xdp_devmap_xmit().

Fixes: cb261b594b41 ("bpf: Run devmap xdp_prog on flush instead of bulk enqueue")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210528024356.24333-1-liuhangbin@gmail.com

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xdp: Extend xdp_redirect_map with broadcast support

This patch adds two flags BPF_F_BROADCAST and BPF_F_EXCLUDE_INGRESS to
extend xdp_redirect_map for broadcast support.

With BPF_F_BROADCAST the pa

xdp: Extend xdp_redirect_map with broadcast support

This patch adds two flags BPF_F_BROADCAST and BPF_F_EXCLUDE_INGRESS to
extend xdp_redirect_map for broadcast support.

With BPF_F_BROADCAST the packet will be broadcasted to all the interfaces
in the map. with BPF_F_EXCLUDE_INGRESS the ingress interface will be
excluded when do broadcasting.

When getting the devices in dev hash map via dev_map_hash_get_next_key(),
there is a possibility that we fall back to the first key when a device
was removed. This will duplicate packets on some interfaces. So just walk
the whole buckets to avoid this issue. For dev array map, we also walk the
whole map to find valid interfaces.

Function bpf_clear_redirect_map() was removed in
commit ee75aef23afe ("bpf, xdp: Restructure redirect actions").
Add it back as we need to use ri->map again.

With test topology:
+-------------------+ +-------------------+
| Host A (i40e 10G) | ---------- | eno1(i40e 10G) |
+-------------------+ | |
| Host B |
+-------------------+ | |
| Host C (i40e 10G) | ---------- | eno2(i40e 10G) |
+-------------------+ | |
| +------+ |
| veth0 -- | Peer | |
| veth1 -- | | |
| veth2 -- | NS | |
| +------+ |
+-------------------+

On Host A:
# pktgen/pktgen_sample03_burst_single_flow.sh -i eno1 -d $dst_ip -m $dst_mac -s 64

On Host B(Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz, 128G Memory):
Use xdp_redirect_map and xdp_redirect_map_multi in samples/bpf for testing.
All the veth peers in the NS have a XDP_DROP program loaded. The
forward_map max_entries in xdp_redirect_map_multi is modify to 4.

Testing the performance impact on the regular xdp_redirect path with and
without patch (to check impact of additional check for broadcast mode):

5.12 rc4 | redirect_map i40e->i40e | 2.0M | 9.7M
5.12 rc4 | redirect_map i40e->veth | 1.7M | 11.8M
5.12 rc4 + patch | redirect_map i40e->i40e | 2.0M | 9.6M
5.12 rc4 + patch | redirect_map i40e->veth | 1.7M | 11.7M

Testing the performance when cloning packets with the redirect_map_multi
test, using a redirect map size of 4, filled with 1-3 devices:

5.12 rc4 + patch | redirect_map multi i40e->veth (x1) | 1.7M | 11.4M
5.12 rc4 + patch | redirect_map multi i40e->veth (x2) | 1.1M | 4.3M
5.12 rc4 + patch | redirect_map multi i40e->veth (x3) | 0.8M | 2.6M

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20210519090747.1655268-3-liuhangbin@gmail.com

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bpf: Run devmap xdp_prog on flush instead of bulk enqueue

This changes the devmap XDP program support to run the program when the
bulk queue is flushed instead of before the frame is enqueued. This

bpf: Run devmap xdp_prog on flush instead of bulk enqueue

This changes the devmap XDP program support to run the program when the
bulk queue is flushed instead of before the frame is enqueued. This has
a couple of benefits:

- It "sorts" the packets by destination devmap entry, and then runs the
same BPF program on all the packets in sequence. This ensures that we
keep the XDP program and destination device properties hot in I-cache.

- It makes the multicast implementation simpler because it can just
enqueue packets using bq_enqueue() without having to deal with the
devmap program at all.

The drawback is that if the devmap program drops the packet, the enqueue
step is redundant. However, arguably this is mostly visible in a
micro-benchmark, and with more mixed traffic the I-cache benefit should
win out. The performance impact of just this patch is as follows:

Using 2 10Gb i40e NIC, redirecting one to another, or into a veth interface,
which do XDP_DROP on veth peer. With xdp_redirect_map in sample/bpf, send
pkts via pktgen cmd:
./pktgen_sample03_burst_single_flow.sh -i eno1 -d $dst_ip -m $dst_mac -t 10 -s 64

There are about +/- 0.1M deviation for native testing, the performance
improved for the base-case, but some drop back with xdp devmap prog attached.

Version | Test | Generic | Native | Native + 2nd xdp_prog
5.12 rc4 | xdp_redirect_map i40e->i40e | 1.9M | 9.6M | 8.4M
5.12 rc4 | xdp_redirect_map i40e->veth | 1.7M | 11.7M | 9.8M
5.12 rc4 + patch | xdp_redirect_map i40e->i40e | 1.9M | 9.8M | 8.0M
5.12 rc4 + patch | xdp_redirect_map i40e->veth | 1.7M | 12.0M | 9.4M

When bq_xmit_all() is called from bq_enqueue(), another packet will
always be enqueued immediately after, so clearing dev_rx, xdp_prog and
flush_node in bq_xmit_all() is redundant. Move the clear to __dev_flush(),
and only check them once in bq_enqueue() since they are all modified
together.

This change also has the side effect of extending the lifetime of the
RCU-protected xdp_prog that lives inside the devmap entries: Instead of
just living for the duration of the XDP program invocation, the
reference now lives all the way until the bq is flushed. This is safe
because the bq flush happens at the end of the NAPI poll loop, so
everything happens between a local_bh_disable()/local_bh_enable() pair.
However, this is by no means obvious from looking at the call sites; in
particular, some drivers have an additional rcu_read_lock() around only
the XDP program invocation, which only confuses matters further.
Cleaning this up will be done in a separate patch series.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210519090747.1655268-2-liuhangbin@gmail.com

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bpf: Fix spelling mistakes

Fix some spelling mistakes in comments:
aother ==> another
Netiher ==> Neither
desribe ==> describe
intializing ==> initializing
funciton ==> function
wont ==> won't and m

bpf: Fix spelling mistakes

Fix some spelling mistakes in comments:
aother ==> another
Netiher ==> Neither
desribe ==> describe
intializing ==> initializing
funciton ==> function
wont ==> won't and move the word 'the' at the end to the next line
accross ==> across
pathes ==> paths
triggerred ==> triggered
excute ==> execute
ether ==> either
conervative ==> conservative
convetion ==> convention
markes ==> marks
interpeter ==> interpreter

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210525025659.8898-2-thunder.leizhen@huawei.com

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bpf, devmap: Move drop error path to devmap for XDP_REDIRECT

We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is w

bpf, devmap: Move drop error path to devmap for XDP_REDIRECT

We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is working
towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error
path handling from each XDP ethernet driver to devmap code. According to
the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx
loop whenever the hw reports a tx error and it will just return to devmap
caller the number of successfully transmitted frames. It will be devmap
responsibility to free dropped frames.

Move each XDP ndo_xdp_xmit capable driver to the new APIs:

- veth
- virtio-net
- mvneta
- mvpp2
- socionext
- amazon ena
- bnxt
- freescale (dpaa2, dpaa)
- xen-frontend
- qede
- ice
- igb
- ixgbe
- i40e
- mlx5
- ti (cpsw, cpsw-new)
- tun
- sfc

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org

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