[PATCH v2] extensions: libip6t_hl: Add translation to nft

[PATCH v2] extensions: libip6t_hl: Add translation to nft

[Shivani Bhardwaj]

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>
---
Changes in v2:
	Alter the contents of array op

 extensions/libip6t_hl.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/extensions/libip6t_hl.c b/extensions/libip6t_hl.c
index 3559db4..226b69c 100644
--- 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,
 };
 
 
-- 
1.9.1

Re: [PATCH v2] extensions: libip6t_hl: Add translation to nft

[Pablo Neira Ayuso]

On Tue, Jan 12, 2016 at 07:58:29PM +0530, Shivani Bhardwaj wrote:
> 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

Applied, thanks.