extensions: libip6t_hl: Add translation to nft

Add translation for hop limit to nftables.

Examples:

$ sudo ip6tables-translate -t nat -A postrouting -m hl --hl-gt 3
nft add rule ip6 nat postrouting ip6 hoplimit gt 3 counter

$ sudo ip6tables-translate -t nat -A postrouting -m hl ! --hl-eq 3
nft add rule ip6 nat postrouting ip6 hoplimit != 3 counter

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

diff --git a/extensions/libip6t_hl.c b/extensions/libip6t_hl.c
index 3559db46e081b6aa7e51f216aae5759921f581e9..226b69c379cc70c77afacc098963ed66011df400 100644 (file)
--- a/extensions/libip6t_hl.c
+++ b/extensions/libip6t_hl.c
@@ -83,6 +83,23 @@ static void hl_save(const void *ip, const struct xt_entry_match *match)
        printf(" %s %u", op[info->mode], info->hop_limit);
 }
 
+static int hl_xlate(const struct xt_entry_match *match,
+                   struct xt_buf *buf, int numeric)
+{
+       static const char *const op[] = {
+               [IP6T_HL_EQ] = "",
+               [IP6T_HL_NE] = "!= ",
+               [IP6T_HL_LT] = "lt ",
+               [IP6T_HL_GT] = "gt " };
+
+       const struct ip6t_hl_info *info =
+               (struct ip6t_hl_info *) match->data;
+
+       xt_buf_add(buf, "ip6 hoplimit %s%u ", op[info->mode], info->hop_limit);
+
+       return 1;
+}
+
 #define s struct ip6t_hl_info
 static const struct xt_option_entry hl_opts[] = {
        {.name = "hl-lt", .id = O_HL_LT, .excl = F_ANY, .type = XTTYPE_UINT8,
@@ -109,6 +126,7 @@ static struct xtables_match hl_mt6_reg = {
        .x6_parse      = hl_parse,
        .x6_fcheck     = hl_check,
        .x6_options    = hl_opts,
+       .xlate         = hl_xlate,
 };