extensions: libxt_connmark: Add translation to nft

Add translation for connmark to nftables.

Examples:

$ sudo iptables-translate -A INPUT -m connmark --mark 10/10 -j ACCEPT
nft add rule ip filter INPUT ct mark and 0xa == 0xa counter accept

$ sudo iptables-translate -A INPUT -m connmark ! --mark 10/10 -j ACCEPT
nft add rule ip filter INPUT ct mark and 0xa != 0xa counter accept

$ sudo iptables-translate -t mangle -A PREROUTING -p tcp --dport 40 -m connmark --mark 0x40
nft add rule ip mangle PREROUTING tcp dport 40 ct mark 0x40 counter

Signed-off-by Shivani Bhardwaj <[email protected]>

---
Changes in v2:
Fix coding errors for invert test case

 extensions/libxt_connmark.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

extensions/libxt_connmark.c +44 -2

index 95477de..385ed6e 100644
@@ -89,7 +89,8 @@ connmark_print(const void *ip, const struct xt_entry_match *match, int numeric)
 }
 
 static void
-connmark_mt_print(const void *ip, const struct xt_entry_match *match, int numeric)
+connmark_mt_print(const void *ip, const struct xt_entry_match *match,
+                 int numeric)
 {
        const struct xt_connmark_mtinfo1 *info = (const void *)match->data;
 

@@ -122,6 +123,46 @@ connmark_mt_save(const void *ip, const struct xt_entry_match *match)
        print_mark(info->mark, info->mask);
 }
 
+static void print_mark_xlate(unsigned int mark, unsigned int mask,
+                            struct xt_buf *buf, const char *str)
+{
+       if (mask != 0xffffffffU)
+               xt_buf_add(buf, " and 0x%x %s 0x%x ", mark, str, mask);
+       else
+               xt_buf_add(buf, " 0x%x ", mark);
+}
+
+static int connmark_xlate(const struct xt_entry_match *match,
+                         struct xt_buf *buf, int numeric)
+{
+       const struct xt_connmark_info *info = (const void *)match->data;
+       const char *str = "==";
+
+       if (info->invert)
+               str = "!=";
+
+       xt_buf_add(buf, "ct mark");
+       print_mark_xlate(info->mark, info->mask, buf, str);
+
+       return 1;
+}
+
+static int
+connmark_mt_xlate(const struct xt_entry_match *match,
+                struct xt_buf *buf, int numeric)
+{
+       const struct xt_connmark_mtinfo1 *info = (const void *)match->data;
+       const char *str = "==";
+
+       if (info->invert)
+               str = "!=";
+
+       xt_buf_add(buf, "ct mark");
+       print_mark_xlate(info->mark, info->mask, buf, str);
+
+       return 1;
+}
+
 static struct xtables_match connmark_mt_reg[] = {
        {
                .family        = NFPROTO_UNSPEC,

@@ -135,6 +176,7 @@ static struct xtables_match connmark_mt_reg[] = {
                .save          = connmark_save,
                .x6_parse      = connmark_parse,
                .x6_options    = connmark_mt_opts,
+               .xlate         = connmark_xlate,
        },
        {
                .version       = XTABLES_VERSION,

@@ -148,6 +190,7 @@ static struct xtables_match connmark_mt_reg[] = {
                .save          = connmark_mt_save,
                .x6_parse      = connmark_mt_parse,
                .x6_options    = connmark_mt_opts,
+               .xlate         = connmark_mt_xlate,
        },
 };
 
--

1.9.1