linux-stable/net/core
Johan Almbladh 1fd6e56753 xdp: Fix spurious packet loss in generic XDP TX path
The byte queue limits (BQL) mechanism is intended to move queuing from
the driver to the network stack in order to reduce latency caused by
excessive queuing in hardware. However, when transmitting or redirecting
a packet using generic XDP, the qdisc layer is bypassed and there are no
additional queues. Since netif_xmit_stopped() also takes BQL limits into
account, but without having any alternative queuing, packets are
silently dropped.

This patch modifies the drop condition to only consider cases when the
driver itself cannot accept any more packets. This is analogous to the
condition in __dev_direct_xmit(). Dropped packets are also counted on
the device.

Bypassing the qdisc layer in the generic XDP TX path means that XDP
packets are able to starve other packets going through a qdisc, and
DDOS attacks will be more effective. In-driver-XDP use dedicated TX
queues, so they do not have this starvation issue.

Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220705082345.2494312-1-johan.almbladh@anyfinetworks.com
2022-07-06 16:43:53 +02:00
..
bpf_sk_storage.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
datagram.c net: inline skb_zerocopy_iter_dgram 2022-04-30 12:58:44 +01:00
dev.c xdp: Fix spurious packet loss in generic XDP TX path 2022-07-06 16:43:53 +02:00
dev.h net: add skb_defer_max sysctl 2022-05-16 11:33:59 +01:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_addr_lists_test.c net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
dev_ioctl.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
devlink.c Revert "Merge branch 'mlxsw-line-card-model'" 2022-05-05 15:47:23 -07:00
drop_monitor.c net: dm: check the boundary of skb drop reasons 2022-05-16 10:47:43 +01:00
dst.c net: dst: add net device refcount tracking to dst_entry 2021-12-06 16:05:10 -08:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
failover.c net: failover: add net device refcount tracker 2021-12-06 16:06:02 -08:00
fib_notifier.c
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c bpf: Fix request_sock leak in sk lookup helpers 2022-06-15 16:10:07 +02:00
flow_dissector.c flow_dissector: Add number of vlan tags dissector 2022-04-20 11:09:13 +01:00
flow_offload.c netfilter: nf_tables: bail out early if hardware offload is not supported 2022-06-06 19:19:15 +02:00
gen_estimator.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
gen_stats.c net: stats: Read the statistics in ___gnet_stats_copy_basic() instead of adding. 2021-10-21 12:47:56 +01:00
gro.c net: allow gro_max_size to exceed 65536 2022-05-16 10:18:56 +01:00
gro_cells.c net: add per-cpu storage and net->core_stats 2022-03-11 23:17:24 -08:00
hwbm.c
link_watch.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
lwt_bpf.c bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook 2022-04-22 17:45:25 +02:00
lwtunnel.c lwtunnel: Validate RTA_ENCAP_TYPE attribute length 2021-12-31 14:31:59 +00:00
Makefile net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
neighbour.c net, neigh: Set lower cap for neigh_managed_work rearming 2022-05-25 22:00:48 -07:00
net-procfs.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
net-sysfs.c net: fix data-race in dev_isalive() 2022-06-17 10:59:31 +01:00
net-sysfs.h
net-traces.c
net_namespace.c net: initialize init_net earlier 2022-02-06 11:04:29 +00:00
netclassid_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
netevent.c
netpoll.c netpoll: add net device refcount tracker to struct netpoll 2021-12-06 16:06:02 -08:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c Revert "of: net: support NVMEM cells with MAC in text format" 2022-01-12 14:14:36 +00:00
page_pool.c net: page_pool: add page allocation stats for two fast page allocate path 2022-05-13 11:28:55 +01:00
pktgen.c proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c
rtnetlink.c net: allow gro_max_size to exceed 65536 2022-05-16 10:18:56 +01:00
scm.c
secure_seq.c tcp: resalt the secret every 10 seconds 2022-05-04 19:22:21 -07:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: avoid strange behavior with skb_defer_max == 1 2022-05-20 17:05:36 -07:00
skmsg.c sock: redo the psock vs ULP protection check 2022-06-23 10:08:30 +02:00
sock.c net: core: add READ_ONCE/WRITE_ONCE annotations for sk->sk_bound_dev_if 2022-05-16 10:31:06 +01:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
sock_map.c bpf: Compute map_btf_id during build time 2022-04-26 11:35:21 -07:00
sock_reuseport.c
stream.c net: stream: don't purge sk_error_queue in sk_stream_kill_queues() 2021-10-16 09:06:09 +01:00
sysctl_net_core.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-05-23 16:07:14 -07:00
timestamping.c
tso.c
utils.c net: core: Use csum_replace_by_diff() and csum_sub() instead of opencoding 2022-02-21 11:40:44 +00:00
xdp.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-03-22 11:18:49 -07:00