extensions: libxt_devgroup: Add translation to nft

Add translation for device group to nftables.

Examples:

$ sudo iptables-translate -A FORWARD -m devgroup --dst-group 0xc/0xc -j ACCEPT
nft add rule ip filter FORWARD oifgroup and 0xc == 0xc counter accept

$ sudo iptables-translate -t mangle -A PREROUTING -p tcp --dport 46000 -m devgroup --src-group 23 -j ACCEPT
nft add rule ip mangle PREROUTING tcp dport 46000 iifgroup 0x17 counter accept

$ sudo iptables-translate -A FORWARD -m devgroup ! --dst-group 0xc/0xc -j ACCEPT
nft add rule ip filter FORWARD oifgroup and 0xc != 0xc counter accept

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

---
 extensions/libxt_devgroup.c | 56 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 54 insertions(+), 2 deletions(-)

extensions/libxt_devgroup.c +54 -3

index 1a52627..207f106 100644
@@ -37,6 +37,7 @@ static struct xtables_lmap *devgroups;
 static void devgroup_init(struct xt_entry_match *match)
 {
        const char file[] = "/etc/iproute2/group";
+
        devgroups = xtables_lmap_init(file);
        if (devgroups == NULL && errno != ENOENT)
                fprintf(stderr, "Warning: %s: %s\n", file, strerror(errno));

@@ -52,7 +53,7 @@ static void devgroup_parse_groupspec(const char *arg, unsigned int *group,
        if (ok && (*end == '/' || *end == '\0')) {
                if (*end == '/')
                        ok = xtables_strtoui(end + 1, NULL, mask,
-                                            0, UINT32_MAX);
+                                            0, UINT32_MAX);
                else
                        *mask = ~0U;
                if (!ok)

@@ -129,7 +130,7 @@ static void devgroup_show(const char *pfx, const struct xt_devgroup_info *info,
 }
 
 static void devgroup_print(const void *ip, const struct xt_entry_match *match,
-                        int numeric)
+                          int numeric)
 {
        const struct xt_devgroup_info *info = (const void *)match->data;
 

@@ -151,6 +152,56 @@ static void devgroup_check(struct xt_fcheck_call *cb)
                              "'--src-group' or '--dst-group'");
 }
 
+static void
+print_devgroup_xlate(unsigned int id, const char *str,  unsigned int mask,
+                    struct xt_buf *buf, int numeric)
+{
+       const char *name = NULL;
+
+       if (mask != 0xffffffff)
+               xt_buf_add(buf, "and 0x%x %s 0x%x ", id, str, mask);
+       else {
+               if (numeric == 0)
+                       name = xtables_lmap_id2name(devgroups, id);
+               if (name)
+                       xt_buf_add(buf, "%s ", name);
+               else
+                       xt_buf_add(buf, "0x%x ", id);
+       }
+}
+
+static void devgroup_show_xlate(const struct xt_devgroup_info *info,
+                               struct xt_buf *buf, int numeric)
+{
+       const char *str = "==";
+
+       if (info->flags & XT_DEVGROUP_MATCH_SRC) {
+               if (info->flags & XT_DEVGROUP_INVERT_SRC)
+                       str = "!=";
+               xt_buf_add(buf, "iifgroup ");
+               print_devgroup_xlate(info->src_group, str,
+                                    info->src_mask, buf, numeric);
+       }
+
+       if (info->flags & XT_DEVGROUP_MATCH_DST) {
+               if (info->flags & XT_DEVGROUP_INVERT_DST)
+                       str = "!=";
+               xt_buf_add(buf, "oifgroup ");
+               print_devgroup_xlate(info->dst_group, str,
+                                    info->dst_mask, buf, numeric);
+       }
+}
+
+static int devgroup_xlate(const struct xt_entry_match *match,
+                         struct xt_buf *buf, int numeric)
+{
+       const struct xt_devgroup_info *info = (const void *)match->data;
+
+       devgroup_show_xlate(info, buf, 0);
+
+       return 1;
+}
+
 static struct xtables_match devgroup_mt_reg = {
        .name           = "devgroup",
        .version        = XTABLES_VERSION,

@@ -164,6 +215,7 @@ static struct xtables_match devgroup_mt_reg = {
        .x6_parse       = devgroup_parse,
        .x6_fcheck      = devgroup_check,
        .x6_options     = devgroup_opts,
+       .xlate          = devgroup_xlate,
 };
 
 void _init(void)
--

1.9.1