Ran into getting a different default value applied for `bucketsize` as
documented in the man page, i.e., 12 vs. 14, for example:
`create foo hash:net family inet hashsize 64 maxelem 64`
ipset save tells me:
`create foo hash:net family inet hashsize 64 maxelem 64 bucketsize 12 initval 0xd4f64074`
But the man page states:
> Possible values are any even number between 2-14 and the default is 14.
In the kernel code the `AHASH_MAX_SIZE`, which was used to bound
check any value coming from user space and acts also as default, was
defined to `2 * 6` = 12, it almost seems like it was inteded to
define the span of valid values (2 - 14 = 12 after all) but then used
as actual upper bound everywhere, so it was lost that the range
starts on 2, not zero.
Either one should be fixed and I went for the code, seems nicer to
have a bigger tuning range, the docs are quite explicit and the
commit ccf0a4b7fc68 ("netfilter: ipset: Add bucketsize parameter to
all hash types")' that introduced the change on the kernelside
doesn't mentions any range/default values at all.
So I just added the AHASH_INIT_SIZE and checked all use sites of
`AHASH_MAX_SIZE`, but those sites basically are only the range checks
anyway.
Signed-off-by: Thomas Lamprecht <t.lamprecht@xxxxxxxxxxx>
---
sending as RFC as one could still go for the docs fix instead and
because I'm not to versed with the whole netfilter code base, so may
overlook something.
net/netfilter/ipset/ip_set_hash_gen.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index 6e391308431d..8bc6c46403de 100644
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -39,7 +39,7 @@
/* Number of elements to store in an initial array block */
#define AHASH_INIT_SIZE 2
/* Max number of elements to store in an array block */
-#define AHASH_MAX_SIZE (6 * AHASH_INIT_SIZE)
+#define AHASH_MAX_SIZE (AHASH_INIT_SIZE + 6 * AHASH_INIT_SIZE)
/* Max muber of elements in the array block when tuned */
#define AHASH_MAX_TUNED 64
--
2.30.2
