netfilter: remove NF_NAT_RANGE_PROTO_RANDOM support

Historically this was net_random() based, and was then converted to
a hash based algorithm (private boot seed + hash of endpoint addresses)
due to concerns of leaking net_random() bits.

RANDOM_FULLY mode was added later to avoid problems with hash
based mode (see commit 34ce324019,
"netfilter: nf_nat: add full port randomization support" for details).

Just make prandom_u32() the default search starting point and get rid of
->secure_port() altogether.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2018-12-13 16:01:27 +01:00 committed by Pablo Neira Ayuso
parent df7043bed4
commit 912da924a2
4 changed files with 2 additions and 23 deletions

View File

@ -9,8 +9,6 @@ struct nf_nat_l3proto {
bool (*in_range)(const struct nf_conntrack_tuple *t,
const struct nf_nat_range2 *range);
u32 (*secure_port)(const struct nf_conntrack_tuple *t, __be16);
bool (*manip_pkt)(struct sk_buff *skb,
unsigned int iphdroff,
const struct nf_nat_l4proto *l4proto,

View File

@ -69,12 +69,6 @@ static bool nf_nat_ipv4_in_range(const struct nf_conntrack_tuple *t,
ntohl(t->src.u3.ip) <= ntohl(range->max_addr.ip);
}
static u32 nf_nat_ipv4_secure_port(const struct nf_conntrack_tuple *t,
__be16 dport)
{
return secure_ipv4_port_ephemeral(t->src.u3.ip, t->dst.u3.ip, dport);
}
static bool nf_nat_ipv4_manip_pkt(struct sk_buff *skb,
unsigned int iphdroff,
const struct nf_nat_l4proto *l4proto,
@ -162,7 +156,6 @@ static int nf_nat_ipv4_nlattr_to_range(struct nlattr *tb[],
static const struct nf_nat_l3proto nf_nat_l3proto_ipv4 = {
.l3proto = NFPROTO_IPV4,
.in_range = nf_nat_ipv4_in_range,
.secure_port = nf_nat_ipv4_secure_port,
.manip_pkt = nf_nat_ipv4_manip_pkt,
.csum_update = nf_nat_ipv4_csum_update,
.csum_recalc = nf_nat_ipv4_csum_recalc,

View File

@ -68,12 +68,6 @@ static bool nf_nat_ipv6_in_range(const struct nf_conntrack_tuple *t,
ipv6_addr_cmp(&t->src.u3.in6, &range->max_addr.in6) <= 0;
}
static u32 nf_nat_ipv6_secure_port(const struct nf_conntrack_tuple *t,
__be16 dport)
{
return secure_ipv6_port_ephemeral(t->src.u3.ip6, t->dst.u3.ip6, dport);
}
static bool nf_nat_ipv6_manip_pkt(struct sk_buff *skb,
unsigned int iphdroff,
const struct nf_nat_l4proto *l4proto,
@ -171,7 +165,6 @@ static int nf_nat_ipv6_nlattr_to_range(struct nlattr *tb[],
static const struct nf_nat_l3proto nf_nat_l3proto_ipv6 = {
.l3proto = NFPROTO_IPV6,
.secure_port = nf_nat_ipv6_secure_port,
.in_range = nf_nat_ipv6_in_range,
.manip_pkt = nf_nat_ipv6_manip_pkt,
.csum_update = nf_nat_ipv6_csum_update,

View File

@ -77,15 +77,10 @@ void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
range_size = max - min + 1;
}
if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
off = l3proto->secure_port(tuple, maniptype == NF_NAT_MANIP_SRC
? tuple->dst.u.all
: tuple->src.u.all);
} else if (range->flags & NF_NAT_RANGE_PROTO_OFFSET) {
if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
off = (ntohs(*portptr) - ntohs(range->base_proto.all));
} else {
else
off = prandom_u32();
}
attempts = range_size;
if (attempts > max_attempts)