From e20eac092725c982387181f3df557877b02eb345 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 15 Apr 2016 15:09:39 +0200 Subject: 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 Acked-by: Arturo Borrero Gonzalez Acked-by: Pablo Neira Ayuso --- src/rule.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'src/rule.c') diff --git a/src/rule.c b/src/rule.c index b7f4a07f..2fe67454 100644 --- a/src/rule.c +++ b/src/rule.c @@ -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; -- cgit v1.2.3