Cole Dishington Cole.Dishington@alliedtelesis.co.nz wrote:
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 7de595ead06a..4a9448684504 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -195,13 +195,36 @@ static bool nf_nat_inet_in_range(const struct nf_conntrack_tuple *t, static bool l4proto_in_range(const struct nf_conntrack_tuple *tuple, enum nf_nat_manip_type maniptype, const union nf_conntrack_man_proto *min,
const union nf_conntrack_man_proto *max)
const union nf_conntrack_man_proto *max,const union nf_conntrack_man_proto *base,bool is_psid){ __be16 port;
- u16 psid, psid_mask, offset_mask;
- /* In this case we are in PSID mode, avoid checking all ranges by computing bitmasks */
- if (is_psid) {
u16 power_j = ntohs(max->all) - ntohs(min->all) + 1;u32 offset = ntohs(base->all);u16 power_a;if (offset == 0)offset = 1 << 16;power_a = (1 << 16) / offset;
Since the dividie is only needed nat setup and not for each packet I think its ok.
- if (range->flags & NF_NAT_RANGE_PSID) {
u16 base = ntohs(range->base_proto.all);u16 min = ntohs(range->min_proto.all);u16 off = 0;/* If offset=0, port range is in one contiguous block */if (base)off = prandom_u32() % (((1 << 16) / base) - 1);
Bases 32769 > gives 0 for the modulo value, so perhaps compute that independently.
You could reject > 32769 in the iptables checkentry target.
Also, base of 21846 and above always give 0 result (% 1).
I don't know psid well enough to give a recommendation here.
If such inputs are nonsensical, just reject it when userspace asks for this and add a
if (WARN_ON_ONCE(base > bogus)) return NF_DROP;
with s small coment explaining that xtables is supposed to not provide such value.
Other than this I think its ok.
I still dislike the 'bool is_psid' in the nat core, but I can't find a better solution.