extensions: libip6t_ah: Add translation to nft

Add translation for AH to nftables.

Examples:

$ sudo ip6tables-translate -A INPUT -m ah --ahspi 500 -j DROP
nft add rule ip6 filter INPUT ah spi 500 counter drop

$ sudo ip6tables-translate -A INPUT -m ah --ahspi 500:550 -j DROP
nft add rule ip6 filter INPUT ah spi 500-550 counter drop

$ sudo ip6tables-translate -A INPUT -m ah ! --ahlen 120
nft add rule ip6 filter INPUT ah hdrlength != 120 counter

$ sudo ip6tables-translate -A INPUT -m ah --ahres
nft add rule ip6 filter INPUT ah reserved 1 counter

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

diff --git a/extensions/libip6t_ah.c b/extensions/libip6t_ah.c
index 174d6d1d762014d514b70a5e049249ec37b13081..f7c30f466b5f37f3c20cdf4517ea73409361a877 100644 (file)
--- a/extensions/libip6t_ah.c
+++ b/extensions/libip6t_ah.c
@@ -128,6 +128,32 @@ static void ah_save(const void *ip, const struct xt_entry_match *match)
                printf(" --ahres");
 }
 
+static int ah_xlate(const struct xt_entry_match *match,
+                   struct xt_buf *buf, int numeric)
+{
+       const struct ip6t_ah *ahinfo = (struct ip6t_ah *)match->data;
+
+       if (!(ahinfo->spis[0] == 0 && ahinfo->spis[1] == 0xFFFFFFFF)) {
+               xt_buf_add(buf, "ah spi%s ",
+                          (ahinfo->invflags & IP6T_AH_INV_SPI) ? " !=" : "");
+       if (ahinfo->spis[0] != ahinfo->spis[1])
+               xt_buf_add(buf, "%u-%u ", ahinfo->spis[0], ahinfo->spis[1]);
+       else
+               xt_buf_add(buf, "%u ", ahinfo->spis[0]);
+       }
+
+       if (ahinfo->hdrlen != 0 || (ahinfo->invflags & IP6T_AH_INV_LEN)) {
+               xt_buf_add(buf, "ah hdrlength%s %u ",
+                          (ahinfo->invflags & IP6T_AH_INV_LEN) ? " !=" : "",
+                          ahinfo->hdrlen);
+       }
+
+       if (ahinfo->hdrres != 0)
+               xt_buf_add(buf, "ah reserved %u ", ahinfo->hdrres);
+
+       return 1;
+}
+
 static struct xtables_match ah_mt6_reg = {
        .name          = "ah",
        .version       = XTABLES_VERSION,
@@ -140,6 +166,7 @@ static struct xtables_match ah_mt6_reg = {
        .save          = ah_save,
        .x6_parse      = ah_parse,
        .x6_options    = ah_opts,
+       .xlate         = ah_xlate,
 };
 
 void