[NETFILTER] nfnetlink: use highest bit of nfa_type to indicate nested TLV
As Henrik Nordstrom pointed out, all our efforts with "split endian" (i.e.
host byte order tags, net byte order values) are useless, unless a parser
can determine whether an attribute is nested or not.
This patch steals the highest bit of nfattr.nfa_type to indicate whether
the data payload contains a nested nfattr (1) or not (0).
This will break userspace compatibility, but luckily no kernel with
nfnetlink was released so far.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 1caaca0..4bc27a6 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -133,7 +133,7 @@
memset(tb, 0, sizeof(struct nfattr *) * maxattr);
while (NFA_OK(nfa, len)) {
- unsigned flavor = nfa->nfa_type;
+ unsigned flavor = NFA_TYPE(nfa);
if (flavor && flavor <= maxattr)
tb[flavor-1] = nfa;
nfa = NFA_NEXT(nfa, len);
@@ -177,7 +177,7 @@
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
while (NFA_OK(attr, attrlen)) {
- unsigned flavor = attr->nfa_type;
+ unsigned flavor = NFA_TYPE(attr);
if (flavor) {
if (flavor > attr_count)
return -EINVAL;