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| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-01-17 22:36:49 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-01-17 17:14:06 -0500 |
| commit | ad9294dbc227cbc8e173b3b963e7dd9af5314f77 (patch) | |
| tree | 3f398c96a1d2930d88fe26da921d3aac697da99f /net/sched/cls_bpf.c | |
| parent | 5a717843177c96ca3fe4565187de395afdb28092 (diff) | |
| download | linux-ad9294dbc227cbc8e173b3b963e7dd9af5314f77.tar.bz2 | |
bpf: fix cls_bpf on filter replace
Running the following sequence is currently broken:
# tc qdisc add dev foo clsact
# tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o
# tc filter replace dev foo ingress prio 1 handle 1 bpf da obj bar.o
RTNETLINK answers: Invalid argument
The normal expectation on kernel side is that the second command
succeeds replacing the existing program. However, what happens is
in cls_bpf_change(), we bail out with err in the second run in
cls_bpf_offload(). The EINVAL comes directly in cls_bpf_offload()
when comparing prog vs oldprog's gen_flags. In case of above
replace the new prog's gen_flags are 0, but the old ones are 8,
which means TCA_CLS_FLAGS_NOT_IN_HW is set (e.g. drivers not having
cls_bpf offload).
Fix 102740bd9436 ("cls_bpf: fix offload assumptions after callback
conversion") in the following way: gen_flags from user space passed
down via netlink cannot include status flags like TCA_CLS_FLAGS_IN_HW
or TCA_CLS_FLAGS_NOT_IN_HW as opposed to oldprog that we previously
loaded. Therefore, it doesn't make any sense to include them in the
gen_flags comparison with the new prog before we even attempt to
offload. Thus, lets fix this before 4.15 goes out.
Fixes: 102740bd9436 ("cls_bpf: fix offload assumptions after callback conversion")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/cls_bpf.c')
| -rw-r--r-- | net/sched/cls_bpf.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c index 8d78e7f4ecc3..a62586e2dbdb 100644 --- a/net/sched/cls_bpf.c +++ b/net/sched/cls_bpf.c @@ -183,10 +183,17 @@ static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog, return 0; } +static u32 cls_bpf_flags(u32 flags) +{ + return flags & CLS_BPF_SUPPORTED_GEN_FLAGS; +} + static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog, struct cls_bpf_prog *oldprog) { - if (prog && oldprog && prog->gen_flags != oldprog->gen_flags) + if (prog && oldprog && + cls_bpf_flags(prog->gen_flags) != + cls_bpf_flags(oldprog->gen_flags)) return -EINVAL; if (prog && tc_skip_hw(prog->gen_flags)) |