extensions: libip6t_REDIRECT: Add translation to nft

Add translation for REDIRECT target to nftables.

Examples:

$ sudo ip6tables-translate -t nat -A prerouting -p tcp --dport 80 -j REDIRECT --to-ports 8080
nft add rule ip6 nat prerouting tcp dport 80 counter redirect to 8080

$ sudo ip6tables-translate -t nat -A prerouting -p tcp --dport 80 -j REDIRECT --to-ports 8080 --random
nft add rule ip6 nat prerouting tcp dport 80 counter redirect to 8080 random

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

diff --git a/extensions/libip6t_REDIRECT.c b/extensions/libip6t_REDIRECT.c
index 1724aa6732a2f7b0ea6a786f845fd61798c8ccaa..d907d94c29af1214c641a0d63fc4a515ed0be42c 100644 (file)
--- a/extensions/libip6t_REDIRECT.c
+++ b/extensions/libip6t_REDIRECT.c
@@ -132,6 +132,24 @@ static void REDIRECT_save(const void *ip, const struct xt_entry_target *target)
        }
 }
 
+static int REDIRECT_xlate(const struct xt_entry_target *target,
+                         struct xt_buf *buf, int numeric)
+{
+       const struct nf_nat_range *range = (const void *)target->data;
+
+       if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+               xt_buf_add(buf, "redirect to %hu",
+                          ntohs(range->min_proto.tcp.port));
+               if (range->max_proto.tcp.port != range->min_proto.tcp.port)
+                       xt_buf_add(buf, "-%hu ",
+                                  ntohs(range->max_proto.tcp.port));
+               if (range->flags & NF_NAT_RANGE_PROTO_RANDOM)
+                       xt_buf_add(buf, " random ");
+       }
+
+       return 1;
+}
+
 static struct xtables_target redirect_tg_reg = {
        .name           = "REDIRECT",
        .version        = XTABLES_VERSION,
@@ -143,6 +161,7 @@ static struct xtables_target redirect_tg_reg = {
        .print          = REDIRECT_print,
        .save           = REDIRECT_save,
        .x6_options     = REDIRECT_opts,
+       .xlate          = REDIRECT_xlate,
 };
 
 void _init(void)