Add translation for target SNAT to nftables.
Examples:
$ sudo iptables-translate -t nat -A postrouting -o eth0 -j SNAT --to 1.2.3.4
nft add rule ip nat postrouting oifname eth0 counter snat 1.2.3.4
$ sudo iptables-translate -t nat -A postrouting -o eth0 -j SNAT --to 1.2.3.4-1.2.3.6
nft add rule ip nat postrouting oifname eth0 counter snat 1.2.3.4-1.2.3.6
$ sudo iptables-translate -t nat -A postrouting -p tcp -o eth0 -j SNAT --to 1.2.3.4:1-1023
nft add rule ip nat postrouting oifname eth0 ip protocol tcp counter snat 1.2.3.4:1-1023
$ sudo iptables-translate -t nat -A postrouting -o eth0 -j SNAT --to 1.2.3.4 --random
nft add rule ip nat postrouting oifname eth0 counter snat 1.2.3.4 random
$ sudo iptables-translate -t nat -A postrouting -o eth0 -j SNAT --to 1.2.3.4 --random-fully
nft add rule ip nat postrouting oifname eth0 counter snat 1.2.3.4 fully-random
$ sudo iptables-translate -t nat -A postrouting -p tcp -o eth0 -j SNAT --to 1.2.3.4 --persistent
nft add rule ip nat postrouting oifname eth0 ip protocol tcp counter snat 1.2.3.4 persistent
Signed-off-by: Shivani Bhardwaj <shivanib134@xxxxxxxxx>
---
extensions/libipt_SNAT.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
diff --git a/extensions/libipt_SNAT.c b/extensions/libipt_SNAT.c
index 78d2c2b..f1b8d9a 100644
--- a/extensions/libipt_SNAT.c
+++ b/extensions/libipt_SNAT.c
@@ -252,6 +252,47 @@ static void SNAT_save(const void *ip, const struct xt_entry_target *target)
}
}
+static void print_range_xlate(const struct nf_nat_ipv4_range *r,
+ struct xt_buf *buf)
+{
+ if (r->flags & NF_NAT_RANGE_MAP_IPS) {
+ struct in_addr a;
+
+ a.s_addr = r->min_ip;
+ xt_buf_add(buf, "%s", xtables_ipaddr_to_numeric(&a));
+ if (r->max_ip != r->min_ip) {
+ a.s_addr = r->max_ip;
+ xt_buf_add(buf, "-%s", xtables_ipaddr_to_numeric(&a));
+ }
+ }
+ if (r->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+ xt_buf_add(buf, ":");
+ xt_buf_add(buf, "%hu", ntohs(r->min.tcp.port));
+ if (r->max.tcp.port != r->min.tcp.port)
+ xt_buf_add(buf, "-%hu", ntohs(r->max.tcp.port));
+ }
+}
+
+static int SNAT_xlate(const struct xt_entry_target *target,
+ struct xt_buf *buf, int numeric)
+{
+ const struct ipt_natinfo *info = (const void *)target;
+ unsigned int i = 0;
+
+ for (i = 0; i < info->mr.rangesize; i++) {
+ xt_buf_add(buf, "snat ");
+ print_range_xlate(&info->mr.range[i], buf);
+ if (info->mr.range[i].flags & NF_NAT_RANGE_PROTO_RANDOM)
+ xt_buf_add(buf, " random");
+ if (info->mr.range[i].flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY)
+ xt_buf_add(buf, " fully-random");
+ if (info->mr.range[i].flags & NF_NAT_RANGE_PERSISTENT)
+ xt_buf_add(buf, " persistent");
+ }
+
+ return 1;
+}
+
static struct xtables_target snat_tg_reg = {
.name = "SNAT",
.version = XTABLES_VERSION,
@@ -264,6 +305,7 @@ static struct xtables_target snat_tg_reg = {
.print = SNAT_print,
.save = SNAT_save,
.x6_options = SNAT_opts,
+ .xlate = SNAT_xlate,
};
void _init(void)
--
1.9.1
--
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