xt: Rewrite unsupported compat expression dumping

Choose a format which provides more information and is easily parseable.
Then teach parsers about it and make it explicitly reject the ruleset
giving a meaningful explanation. Also update the man pages with some
more details.

Signed-off-by: Phil Sutter <phil@nwl.cc>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/xt.c b/src/xt.c
index 300416a1..12b52aa3 100644
--- a/src/xt.c
+++ b/src/xt.c
@@ -115,7 +115,13 @@ void xt_stmt_xlate(const struct stmt *stmt, struct output_ctx *octx)
 	xt_xlate_free(xl);
 	xfree(entry);
 #else
-	nft_print(octx, "# xt_%s", stmt->xt.name);
+	static const char *typename[NFT_XT_MAX] = {
+		[NFT_XT_MATCH]		= "match",
+		[NFT_XT_TARGET]		= "target",
+		[NFT_XT_WATCHER]	= "watcher",
+	};
+
+	nft_print(octx, "xt %s %s", typename[stmt->xt.type], stmt->xt.name);
 #endif
 }