From 2034d8c60ed91c36b74e86e0c195eb6f2c27f9fa Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 18 Aug 2023 11:40:38 +0200
Subject: src: add input flag NFT_CTX_INPUT_JSON to enable JSON parsing

By default, the input is parsed using the nftables grammar. When setting
NFT_CTX_OUTPUT_JSON flag, nftables will first try to parse the input as
JSON before falling back to the nftables grammar.

But NFT_CTX_OUTPUT_JSON flag also turns on JSON for the output. Add a
flag NFT_CTX_INPUT_JSON which allows to treat only the input as JSON,
but keep the output mode unchanged.

Signed-off-by: Thomas Haller <thaller@redhat.com>
Reviewed-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 doc/libnftables.adoc | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'doc/libnftables.adoc')

diff --git a/doc/libnftables.adoc b/doc/libnftables.adoc
index 62de75f3..2cf78d7a 100644
--- a/doc/libnftables.adoc
+++ b/doc/libnftables.adoc
@@ -87,6 +87,7 @@ The flags setting controls the input format.
 ----
 enum {
         NFT_CTX_INPUT_NO_DNS = (1 << 0),
+        NFT_CTX_INPUT_JSON   = (1 << 1),
 };
 ----
 
@@ -94,6 +95,11 @@ NFT_CTX_INPUT_NO_DNS::
 	Avoid resolving IP addresses with blocking getaddrinfo(). In that case,
 	only plain IP addresses are accepted.
 
+NFT_CTX_INPUT_JSON:
+	When parsing the input, first try to interpret the input as JSON before
+	falling back to the nftables format. This behavior is implied when setting
+	the NFT_CTX_OUTPUT_JSON flag.
+
 The *nft_ctx_input_get_flags*() function returns the input flags setting's value in 'ctx'.
 
 The *nft_ctx_input_set_flags*() function sets the input flags setting in 'ctx' to the value of 'val'
@@ -139,7 +145,8 @@ NFT_CTX_OUTPUT_HANDLE::
 NFT_CTX_OUTPUT_JSON::
 	If enabled at compile-time, libnftables accepts input in JSON format and is able to print output in JSON format as well.
 	See *libnftables-json*(5) for a description of the supported schema.
-	This flag controls JSON output format, input is auto-detected.
+	This flag enables JSON output format. If the flag is set, the input will first be tried as JSON format,
+	before falling back to nftables format. This flag implies NFT_CTX_INPUT_JSON.
 NFT_CTX_OUTPUT_ECHO::
 	The echo setting makes libnftables print the changes once they are committed to the kernel, just like a running instance of *nft monitor* would.
 	Amongst other things, this allows one to retrieve an added rule's handle atomically.
-- 
cgit v1.2.3

