extensions: libipt_MASQUERADE: Add translation to nft

Add translation for masquerade to nftables.

Examples:

$ sudo iptables-translate -t nat -A POSTROUTING -j MASQUERADE
nft add rule ip nat POSTROUTING counter masquerade

$ sudo iptables-translate -t nat -A POSTROUTING -p tcp -j MASQUERADE --to-ports 10
nft add rule ip nat POSTROUTING ip protocol tcp counter masquerade to :10

$ sudo iptables-translate -t nat -A POSTROUTING -p tcp -j MASQUERADE --to-ports 10-20 --random
nft add rule ip nat POSTROUTING ip protocol tcp counter masquerade to :10-20 random

Signed-off-by: Shivani Bhardwaj <shivanib134@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/extensions/libipt_MASQUERADE.c b/extensions/libipt_MASQUERADE.c
index ea074454b18e916f4ad8dfad881e727912863ae5..d1393c11d7212ed5327d11b3841fa330aea72976 100644 (file)
--- a/extensions/libipt_MASQUERADE.c
+++ b/extensions/libipt_MASQUERADE.c
@@ -134,6 +134,29 @@ MASQUERADE_save(const void *ip, const struct xt_entry_target *target)
                printf(" --random");
 }
 
+static int
+MASQUERADE_xlate(const struct xt_entry_target *target,
+                struct xt_xlate *xl, int numeric)
+{
+       const struct nf_nat_ipv4_multi_range_compat *mr =
+                                       (const void *)target->data;
+       const struct nf_nat_ipv4_range *r = &mr->range[0];
+
+       xt_xlate_add(xl, "masquerade");
+
+       if (r->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+               xt_xlate_add(xl, " to :%hu", ntohs(r->min.tcp.port));
+               if (r->max.tcp.port != r->min.tcp.port)
+                       xt_xlate_add(xl, "-%hu", ntohs(r->max.tcp.port));
+        }
+
+       xt_xlate_add(xl, " ");
+       if (r->flags & NF_NAT_RANGE_PROTO_RANDOM)
+               xt_xlate_add(xl, "random ");
+
+       return 1;
+}
+
 static struct xtables_target masquerade_tg_reg = {
        .name           = "MASQUERADE",
        .version        = XTABLES_VERSION,
@@ -146,6 +169,7 @@ static struct xtables_target masquerade_tg_reg = {
        .print          = MASQUERADE_print,
        .save           = MASQUERADE_save,
        .x6_options     = MASQUERADE_opts,
+       .xlate          = MASQUERADE_xlate,
 };
 
 void _init(void)