On 7/16/2018 5:56 PM, Yi-Hung Wei wrote:
This patch backports the following upstream commit from net-next, and
defines HAVE_NF_NAT_RANGE2 to determine whether to use
'struct nf_nat_range2'.
Upstream commit:
commit 2eb0f624b709e78ec8e2f4c3412947703db99301
Author: Thierry Du Tre <[email protected]>
Date: Wed Apr 4 15:38:22 2018 +0200
netfilter: add NAT support for shifted portmap ranges
This is a patch proposal to support shifted ranges in portmaps. (i.e.
tcp/udp
incoming port 5000-5100 on WAN redirected to LAN 192.168.1.5:2000-2100)
Currently DNAT only works for single port or identical port ranges. (i.e.
ports 5000-5100 on WAN interface redirected to a LAN host while original
destination port is not altered) When different port ranges are configured,
either 'random' mode should be used, or else all incoming connections are
mapped onto the first port in the redirect range. (in described example
WAN:5000-5100 will all be mapped to 192.168.1.5:2000)
This patch introduces a new mode indicated by flag
NF_NAT_RANGE_PROTO_OFFSET
which uses a base port value to calculate an offset with the destination
port
present in the incoming stream. That offset is then applied as index
within the
redirect port range (index modulo rangewidth to handle range overflow).
In described example the base port would be 5000. An incoming stream with
destination port 5004 would result in an offset value 4 which means that
the
NAT'ed stream will be using destination port 2004.
Other possibilities include deterministic mapping of larger or multiple
ranges
to a smaller range : WAN:5000-5999 -> LAN:5000-5099 (maps WAN port 5*xx to
port
51xx)
This patch does not change any current behavior. It just adds new NAT proto
range functionality which must be selected via the specific flag when
intended
to use.
A patch for iptables (libipt_DNAT.c + libip6t_DNAT.c) will also be proposed
which makes this functionality immediately available.
Signed-off-by: Thierry Du Tre <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Yi-Hung Wei <[email protected]>
LGTM but again, no chance to test.
Reviewed-by: Greg Rose <[email protected]>
---
acinclude.m4 | 1 +
datapath/conntrack.c | 8 ++++++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/acinclude.m4 b/acinclude.m4
index ae8e66fc4967..c6d18611f596 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -619,6 +619,7 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
[nf_conn_labels], [words])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_ct_nat_ext_add])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h],
[nf_nat_alloc_null_binding])
+ OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_nat.h], [nf_nat_range2])
OVS_GREP_IFELSE([$KSRC/include/net/netfilter/nf_conntrack_seqadj.h],
[nf_ct_seq_adjust])
OVS_GREP_IFELSE([$KSRC/include/linux/random.h], [prandom_u32])
diff --git a/datapath/conntrack.c b/datapath/conntrack.c
index e53b8e32b3f5..42c7929055f0 100644
--- a/datapath/conntrack.c
+++ b/datapath/conntrack.c
@@ -41,6 +41,10 @@
#include "flow_netlink.h"
#include "gso.h"
+#ifndef HAVE_NF_NAT_RANGE2
+#define nf_nat_range2 nf_nat_range
+#endif
+
struct ovs_ct_len_tbl {
int maxlen;
int minlen;
@@ -79,7 +83,7 @@ struct ovs_conntrack_info {
struct md_mark mark;
struct md_labels labels;
#ifdef CONFIG_NF_NAT_NEEDED
- struct nf_nat_range range; /* Only present for SRC NAT and DST NAT. */
+ struct nf_nat_range2 range; /* Only present for SRC NAT and DST NAT. */
#endif
};
@@ -744,7 +748,7 @@ static bool skb_nfct_cached(struct net *net,
*/
static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
- const struct nf_nat_range *range,
+ const struct nf_nat_range2 *range,
enum nf_nat_manip_type maniptype)
{
int hooknum, nh_off, err = NF_ACCEPT;
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