[PATCH 04/12] payload: disable payload merge if offsets are not on byte boundary

[Florian Westphal <fw@strlen.de>]

... because it doesn't work, we attempt to merge it into wrong
place, we would have to merge the second value at a specific location.

F.e. vlan hdr 4094 gives us

0xfe0f

Merging in the CFI should yield 0xfe1f, but the constant merging
doesn't know how to achive that; at the moment 'vlan id 4094'
and 'vlan id 4094 vlan cfi 1' give same result -- 0xfe0f.

For now just turn off the optimization step unless everything is
byte divisible (the common case).

Signed-off-by: Florian Westphal <fw@strlen.de>
---
 src/payload.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/payload.c b/src/payload.c
index bd574ee..372dcec 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -357,6 +357,10 @@ raw:
  */
 bool payload_is_adjacent(const struct expr *e1, const struct expr *e2)
 {
+	if (e1->payload.offset % BITS_PER_BYTE || e1->len % BITS_PER_BYTE ||
+	    e2->payload.offset % BITS_PER_BYTE || e2->len % BITS_PER_BYTE)
+		return false;
+
 	if (e1->payload.base		 == e2->payload.base &&
 	    e1->payload.offset + e1->len == e2->payload.offset)
 		return true;
-- 
2.0.5