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| author | Harald Welte <laforge@netfilter.org> | 2005-10-10 20:52:19 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2005-10-10 20:52:19 -0700 |
| commit | ebe0bbf06c9e03613bdcb6b5a704595a9344b7ff (patch) | |
| tree | 33453cb2cd33095e3a226d0866bdfe1019473646 | |
| parent | f40863cec87464f3f4ec3a6c00e3fda3bbb0c91b (diff) | |
| download | linux-3.10-ebe0bbf06c9e03613bdcb6b5a704595a9344b7ff.tar.gz linux-3.10-ebe0bbf06c9e03613bdcb6b5a704595a9344b7ff.tar.bz2 linux-3.10-ebe0bbf06c9e03613bdcb6b5a704595a9344b7ff.zip | |
[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>
| -rw-r--r-- | include/linux/netfilter/nfnetlink.h | 12 | ||||
| -rw-r--r-- | net/netfilter/nfnetlink.c | 4 |
2 files changed, 10 insertions, 6 deletions
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 1d5b10ae239..f08e870100f 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -41,11 +41,15 @@ enum nfnetlink_groups { struct nfattr { u_int16_t nfa_len; - u_int16_t nfa_type; + u_int16_t nfa_type; /* we use 15 bits for the type, and the highest + * bit to indicate whether the payload is nested */ } __attribute__ ((packed)); -/* FIXME: Shamelessly copy and pasted from rtnetlink.h, it's time - * to put this in a generic file */ +/* FIXME: Apart from NFNL_NFA_NESTED shamelessly copy and pasted from + * rtnetlink.h, it's time to put this in a generic file */ + +#define NFNL_NFA_NEST 0x8000 +#define NFA_TYPE(attr) ((attr)->nfa_type & 0x7fff) #define NFA_ALIGNTO 4 #define NFA_ALIGN(len) (((len) + NFA_ALIGNTO - 1) & ~(NFA_ALIGNTO - 1)) @@ -59,7 +63,7 @@ struct nfattr #define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0)) #define NFA_NEST(skb, type) \ ({ struct nfattr *__start = (struct nfattr *) (skb)->tail; \ - NFA_PUT(skb, type, 0, NULL); \ + NFA_PUT(skb, (NFNL_NFA_NEST | type), 0, NULL); \ __start; }) #define NFA_NEST_END(skb, start) \ ({ (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \ diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 1caaca06f69..4bc27a6334c 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -133,7 +133,7 @@ int nfattr_parse(struct nfattr *tb[], int maxattr, struct nfattr *nfa, int len) 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 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys, 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; |