[iptables-nftables - RFC v2 PATCH 08/17] nft: Add support for xtables extensions callback to change cs

[Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>]

This add the support of xtables extension expressed in pure nft through
the nft translator. Thus feeding give command structure with the right
target or match. This has been implemented as a callback, in the core,
to let the extentions being able to feed the command structure. Which
command structure they cannot handle (its declaration is private to the core).

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
---
 iptables/nft-xt-ext.c | 20 ++++++++++++++++++++
 iptables/nft-xt-ext.h |  2 ++
 iptables/nft.c        |  3 ++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/iptables/nft-xt-ext.c b/iptables/nft-xt-ext.c
index f013493..660e417 100644
--- a/iptables/nft-xt-ext.c
+++ b/iptables/nft-xt-ext.c
@@ -143,3 +143,23 @@ int nft_xt_ext_into_translation_tree(struct nft_trans_instruction_tree *tree)
 
 	return 0;
 }
+
+int nft_xt_ext_parse_callback(const char *ident, void *data, void *user_data)
+{
+	struct nft_to_cs_data *i2cs = user_data;
+	struct xtables_target *target;
+	struct xtables_match *match;
+
+	target = xtables_find_target(ident, XTF_TRY_LOAD);
+	match = xtables_find_match(ident, XTF_TRY_LOAD, &i2cs->cs->matches);
+
+	if (target != NULL) {
+		target->t = data;
+		i2cs->cs->target = target;
+	} else if (match != NULL)
+		match->m = data;
+	else
+		return -1;
+
+	return 0;
+}
diff --git a/iptables/nft-xt-ext.h b/iptables/nft-xt-ext.h
index a367277..f3e6491 100644
--- a/iptables/nft-xt-ext.h
+++ b/iptables/nft-xt-ext.h
@@ -10,3 +10,5 @@
 #include <nft-translator.h>
 
 int nft_xt_ext_into_translation_tree(struct nft_trans_instruction_tree *tree);
+
+int nft_xt_ext_parse_callback(const char *ident, void *data, void *user_data);
diff --git a/iptables/nft.c b/iptables/nft.c
index 7b16bd3..7b619b5 100644
--- a/iptables/nft.c
+++ b/iptables/nft.c
@@ -1818,7 +1818,8 @@ nft_rule_to_iptables_command_state(struct nft_rule *r,
 	i2cs.family = nft_rule_attr_get_u8(r, NFT_RULE_ATTR_FAMILY);
 	i2cs.cs = cs;
 
-	nft_trans_rule_translate_to_instructions(xt_nft_tree, r, NULL, &i2cs);
+	nft_trans_rule_translate_to_instructions(xt_nft_tree, r,
+					nft_xt_ext_parse_callback, &i2cs);
 
 	if (i2cs.cs->target != NULL)
 		i2cs.cs->jumpto = i2cs.cs->target->name;
-- 
1.8.3.2