Commit 716b23c1 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso

netfilter: nat: un-export nf_nat_l4proto_unique_tuple

almost all l4proto->unique_tuple implementations just call this helper,
so make ->unique_tuple() optional and call its helper directly if the
l4proto doesn't override it.

This is an intermediate step to get rid of ->unique_tuple completely.
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 912da924
......@@ -70,12 +70,6 @@ bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
const union nf_conntrack_man_proto *min,
const union nf_conntrack_man_proto *max);
void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct);
int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
struct nf_nat_range2 *range);
......
......@@ -310,6 +310,77 @@ find_best_ips_proto(const struct nf_conntrack_zone *zone,
}
}
static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
unsigned int range_size, min, max, i, attempts;
__be16 *portptr;
u16 off;
static const unsigned int max_attempts = 128;
if (maniptype == NF_NAT_MANIP_SRC)
portptr = &tuple->src.u.all;
else
portptr = &tuple->dst.u.all;
/* If no range specified... */
if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
/* If it's dst rewrite, can't change port */
if (maniptype == NF_NAT_MANIP_DST)
return;
if (ntohs(*portptr) < 1024) {
/* Loose convention: >> 512 is credential passing */
if (ntohs(*portptr) < 512) {
min = 1;
range_size = 511 - min + 1;
} else {
min = 600;
range_size = 1023 - min + 1;
}
} else {
min = 1024;
range_size = 65535 - 1024 + 1;
}
} else {
min = ntohs(range->min_proto.all);
max = ntohs(range->max_proto.all);
if (unlikely(max < min))
swap(max, min);
range_size = max - min + 1;
}
if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
off = (ntohs(*portptr) - ntohs(range->base_proto.all));
else
off = prandom_u32();
attempts = range_size;
if (attempts > max_attempts)
attempts = max_attempts;
/* We are in softirq; doing a search of the entire range risks
* soft lockup when all tuples are already used.
*
* If we can't find any free port from first offset, pick a new
* one and try again, with ever smaller search window.
*/
another_round:
for (i = 0; i < attempts; i++, off++) {
*portptr = htons(min + off % range_size);
if (!nf_nat_used_tuple(tuple, ct))
return;
}
if (attempts >= range_size || attempts < 16)
return;
attempts /= 2;
off = prandom_u32();
goto another_round;
}
/* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
* we change the source to map into the range. For NF_INET_PRE_ROUTING
* and NF_INET_LOCAL_OUT, we change the destination to map into the
......@@ -383,7 +454,10 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple,
}
/* Last chance: get protocol to try to obtain unique tuple. */
if (l4proto->unique_tuple)
l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
else
nf_nat_l4proto_unique_tuple(tuple, range, maniptype, ct);
out:
rcu_read_unlock();
}
......
......@@ -34,79 +34,6 @@ bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
}
EXPORT_SYMBOL_GPL(nf_nat_l4proto_in_range);
void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
unsigned int range_size, min, max, i, attempts;
__be16 *portptr;
u16 off;
static const unsigned int max_attempts = 128;
if (maniptype == NF_NAT_MANIP_SRC)
portptr = &tuple->src.u.all;
else
portptr = &tuple->dst.u.all;
/* If no range specified... */
if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
/* If it's dst rewrite, can't change port */
if (maniptype == NF_NAT_MANIP_DST)
return;
if (ntohs(*portptr) < 1024) {
/* Loose convention: >> 512 is credential passing */
if (ntohs(*portptr) < 512) {
min = 1;
range_size = 511 - min + 1;
} else {
min = 600;
range_size = 1023 - min + 1;
}
} else {
min = 1024;
range_size = 65535 - 1024 + 1;
}
} else {
min = ntohs(range->min_proto.all);
max = ntohs(range->max_proto.all);
if (unlikely(max < min))
swap(max, min);
range_size = max - min + 1;
}
if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
off = (ntohs(*portptr) - ntohs(range->base_proto.all));
else
off = prandom_u32();
attempts = range_size;
if (attempts > max_attempts)
attempts = max_attempts;
/* We are in softirq; doing a search of the entire range risks
* soft lockup when all tuples are already used.
*
* If we can't find any free port from first offset, pick a new
* one and try again, with ever smaller search window.
*/
another_round:
for (i = 0; i < attempts; i++, off++) {
*portptr = htons(min + off % range_size);
if (!nf_nat_used_tuple(tuple, ct))
return;
}
if (attempts >= range_size || attempts < 16)
return;
attempts /= 2;
off = prandom_u32();
goto another_round;
}
EXPORT_SYMBOL_GPL(nf_nat_l4proto_unique_tuple);
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
struct nf_nat_range2 *range)
......
......@@ -18,16 +18,6 @@
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.h>
static void
dccp_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
}
static bool
dccp_manip_pkt(struct sk_buff *skb,
const struct nf_nat_l3proto *l3proto,
......@@ -72,7 +62,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_dccp = {
.l4proto = IPPROTO_DCCP,
.manip_pkt = dccp_manip_pkt,
.in_range = nf_nat_l4proto_in_range,
.unique_tuple = dccp_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
#endif
......
......@@ -12,16 +12,6 @@
#include <net/netfilter/nf_nat_l4proto.h>
static void
sctp_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
}
static bool
sctp_manip_pkt(struct sk_buff *skb,
const struct nf_nat_l3proto *l3proto,
......@@ -67,7 +57,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_sctp = {
.l4proto = IPPROTO_SCTP,
.manip_pkt = sctp_manip_pkt,
.in_range = nf_nat_l4proto_in_range,
.unique_tuple = sctp_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
#endif
......
......@@ -18,16 +18,6 @@
#include <net/netfilter/nf_nat_l4proto.h>
#include <net/netfilter/nf_nat_core.h>
static void
tcp_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
}
static bool
tcp_manip_pkt(struct sk_buff *skb,
const struct nf_nat_l3proto *l3proto,
......@@ -75,7 +65,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_tcp = {
.l4proto = IPPROTO_TCP,
.manip_pkt = tcp_manip_pkt,
.in_range = nf_nat_l4proto_in_range,
.unique_tuple = tcp_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
#endif
......
......@@ -17,16 +17,6 @@
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.h>
static void
udp_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
}
static void
__udp_manip_pkt(struct sk_buff *skb,
const struct nf_nat_l3proto *l3proto,
......@@ -92,21 +82,10 @@ static bool udplite_manip_pkt(struct sk_buff *skb,
return true;
}
static void
udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
struct nf_conntrack_tuple *tuple,
const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct)
{
nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct);
}
const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
.l4proto = IPPROTO_UDPLITE,
.manip_pkt = udplite_manip_pkt,
.in_range = nf_nat_l4proto_in_range,
.unique_tuple = udplite_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
#endif
......@@ -117,7 +96,6 @@ const struct nf_nat_l4proto nf_nat_l4proto_udp = {
.l4proto = IPPROTO_UDP,
.manip_pkt = udp_manip_pkt,
.in_range = nf_nat_l4proto_in_range,
.unique_tuple = udp_unique_tuple,
#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
#endif
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment