diff options
author | Florian Westphal <fw@strlen.de> | 2016-04-15 15:09:39 +0200 |
---|---|---|
committer | Florian Westphal <fw@strlen.de> | 2016-04-19 15:23:20 +0200 |
commit | e20eac092725c982387181f3df557877b02eb345 (patch) | |
tree | bad4c5ba92918e470ea775692260fe772db5057e /src/rule.c | |
parent | c30fc3d731b711847fce7910e95d1c217886cb09 (diff) |
payload: only merge if adjacent and combined size fits into a register
add rule ip6 filter input ip6 saddr ::1/128 ip6 daddr ::1/128 fails,
we ask to compare a 32byte immediate which is not supported:
[ payload load 32b @ network header + 8 => reg 1 ]
[ cmp eq reg 1 0x00000000 0x00000000 0x00000000 0x01000000 0x00000000 0x00000000 0x00000000 0x02000000 ]
We would need to use two cmps in this case, i.e.:
[ payload load 32b @ network header + 8 => reg 1 ]
[ cmp eq reg 1 0x00000000 0x00000000 0x00000000 0x01000000 ]
[ cmp eq reg 2 0x00000000 0x00000000 0x00000000 0x02000000 ]
Seems however that this requires a bit more changes to how nft
handles register allocations, we'd also need to undo the constant merge.
Lets disable merging for now so that we generate
[ payload load 16b @ network header + 8 => reg 1 ]
[ cmp eq reg 1 0x00000000 0x00000000 0x00000000 0x01000000 ]
[ payload load 16b @ network header + 24 => reg 1 ]
[ cmp eq reg 1 0x00000000 0x00000000 0x00000000 0x02000000 ]
... if merge would bring us over the 128 bit register size.
Closes: http://bugzilla.netfilter.org/show_bug.cgi?id=1032
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/rule.c')
-rw-r--r-- | src/rule.c | 2 |
1 files changed, 1 insertions, 1 deletions
@@ -1292,7 +1292,7 @@ static void payload_do_merge(struct stmt *sa[], unsigned int n) stmt = sa[i]; this = stmt->expr; - if (!payload_is_adjacent(last->left, this->left) || + if (!payload_can_merge(last->left, this->left) || last->op != this->op) { last = this; j = i; |