On 2022-01-25 09:06, John Fastabend wrote:
Maxim Mikityanskiy wrote:
When CONFIG_SYN_COOKIES is off, bpf_tcp_check_syncookie returns
ENOTSUPP. It's a non-standard and deprecated code. The related function
bpf_tcp_gen_syncookie and most of the other functions use EOPNOTSUPP if
some feature is not available. This patch changes ENOTSUPP to EOPNOTSUPP
in bpf_tcp_check_syncookie.
Fixes: 399040847084 ("bpf: add helper to check for a valid SYN cookie")
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
This came up in another thread? Or was it the same and we lost the context
in the commit msg. Either way I don't think we should start one-off
changing these user facing error codes. Its not the only spot we do this
and its been this way for sometime.
Is it causing a real problem?
I'm not aware of anyone complaining about it. It's just a cleanup to use
the proper error code, since ENOTSUPP is a non-standard one (used in
NFS?), for example, strerror() returns "Unknown error 524" instead of
"Operation not supported".
Source: Documentation/dev-tools/checkpatch.rst:
> ENOTSUPP is not a standard error code and should be avoided in new
> patches. EOPNOTSUPP should be used instead.
>
> See: https://lore.kernel.org/netdev/20200510182252.GA411829@xxxxxxx/
---
net/core/filter.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 780e635fb52a..2c9106704821 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -6814,7 +6814,7 @@ BPF_CALL_5(bpf_tcp_check_syncookie, struct sock *, sk, void *, iph, u32, iph_len
return -ENOENT;
#else
- return -ENOTSUPP;
+ return -EOPNOTSUPP;
#endif
}
--
2.30.2
