src: add nft_ctx_output_{get,set}_stateless() to nft_ctx_output_{get,flags}_flags

Add NFT_CTX_OUTPUT_STATELESS flag and enable stateless printing from new
output flags interface.

This patch adds nft_output_save_flags() and nft_output_restore_flags()
to temporarily disable stateful printing

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

9 files changed, 34 insertions, 44 deletions

diff --git a/doc/libnftables.adoc b/doc/libnftables.adoc
index 9655834f..c0ce5be2 100644
--- a/doc/libnftables.adoc
+++ b/doc/libnftables.adoc
@@ -25,9 +25,6 @@ enum nft_numeric_level nft_ctx_output_get_numeric(struct nft_ctx* '\*ctx'*);
 void nft_ctx_output_set_numeric(struct nft_ctx* '\*ctx'*,
 				enum nft_numeric_level* 'level'*);
 
-bool nft_ctx_output_get_stateless(struct nft_ctx* '\*ctx'*);
-void nft_ctx_output_set_stateless(struct nft_ctx* '\*ctx'*, bool* 'val'*);
-
 unsigned int nft_ctx_output_get_debug(struct nft_ctx* '\*ctx'*);
 void nft_ctx_output_set_debug(struct nft_ctx* '\*ctx'*, unsigned int* 'mask'*);
 
@@ -98,6 +95,7 @@ The flags setting controls the output format.
 enum {
         NFT_CTX_OUTPUT_REVERSEDNS  = (1 << 0),
         NFT_CTX_OUTPUT_SERVICE     = (1 << 1),
+        NFT_CTX_OUTPUT_STATELESS   = (1 << 2),
 };
 ----
 
@@ -105,6 +103,9 @@ NFT_CTX_OUTPUT_REVERSEDNS::
 	Reverse DNS lookups are performed for IP addresses when printing. Note that this may add significant delay to *list* commands depending on DNS resolver speed.
 NFT_CTX_OUTPUT_SERVICE::
 	Print port numbers as services as described in the /etc/services file.
+NFT_CTX_OUTPUT_STATELESS::
+	If stateless output has been requested then stateful data is not printed.
+Stateful data refers to those objects that carry run-time data, eg. the *counter* statement holds packet and byte counter values, making it stateful.
 
 The *nft_ctx_output_get_flags*() function returns the output flags setting's value in 'ctx'.
 
@@ -141,17 +142,6 @@ The *nft_ctx_output_get_numeric*() function returns the numeric output setting's
 
 The *nft_ctx_output_set_numeric*() function sets the numeric output setting in 'ctx' to the value of 'level'.
 
-=== nft_ctx_output_get_stateless() and nft_ctx_output_set_stateless()
-In nftables, there are stateful objects, i.e. ruleset elements which carry run-time data.
-For example the *counter* statement holds packet and byte counter values, making it stateful.
-If stateless output has been requested, this data is omitted when printing ruleset elements.
-The default setting is *false*.
-
-
-The *nft_ctx_output_get_stateless*() function returns the stateless output setting's value in 'ctx'.
-
-The *nft_ctx_output_set_stateless*() function sets the stateless output setting in 'ctx' to the value of 'val'.
-
 === nft_ctx_output_get_debug() and nft_ctx_output_set_debug()
 Libnftables supports separate debugging of different parts of its internals.
 To facilitate this, debugging output is controlled via a bit mask.
diff --git a/include/nftables.h b/include/nftables.h
index 86b44f17..cb36e066 100644
--- a/include/nftables.h
+++ b/include/nftables.h
@@ -18,7 +18,6 @@ struct cookie {
 struct output_ctx {
 	unsigned int flags;
 	unsigned int numeric;
-	unsigned int stateless;
 	unsigned int handle;
 	unsigned int echo;
 	unsigned int json;
@@ -42,6 +41,11 @@ static inline bool nft_output_service(const struct output_ctx *octx)
 	return octx->flags & NFT_CTX_OUTPUT_SERVICE;
 }
 
+static inline bool nft_output_stateless(const struct output_ctx *octx)
+{
+	return octx->flags & NFT_CTX_OUTPUT_STATELESS;
+}
+
 struct nft_cache {
 	uint16_t		genid;
 	struct list_head	list;
diff --git a/include/nftables/libnftables.h b/include/nftables/libnftables.h
index 321441b0..4f1c1090 100644
--- a/include/nftables/libnftables.h
+++ b/include/nftables/libnftables.h
@@ -47,6 +47,7 @@ void nft_ctx_set_dry_run(struct nft_ctx *ctx, bool dry);
 enum {
 	NFT_CTX_OUTPUT_REVERSEDNS	= (1 << 0),
 	NFT_CTX_OUTPUT_SERVICE		= (1 << 1),
+	NFT_CTX_OUTPUT_STATELESS	= (1 << 2),
 };
 
 unsigned int nft_ctx_output_get_flags(struct nft_ctx *ctx);
@@ -54,8 +55,6 @@ void nft_ctx_output_set_flags(struct nft_ctx *ctx, unsigned int flags);
 
 enum nft_numeric_level nft_ctx_output_get_numeric(struct nft_ctx *ctx);
 void nft_ctx_output_set_numeric(struct nft_ctx *ctx, enum nft_numeric_level level);
-bool nft_ctx_output_get_stateless(struct nft_ctx *ctx);
-void nft_ctx_output_set_stateless(struct nft_ctx *ctx, bool val);
 unsigned int nft_ctx_output_get_debug(struct nft_ctx *ctx);
 void nft_ctx_output_set_debug(struct nft_ctx *ctx, unsigned int mask);
 bool nft_ctx_output_get_handle(struct nft_ctx *ctx);
diff --git a/src/expression.c b/src/expression.c
index d1d6bee4..25883ea7 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -1043,7 +1043,7 @@ static void set_elem_expr_print(const struct expr *expr,
 		nft_print(octx, " timeout ");
 		time_print(expr->timeout, octx);
 	}
-	if (!octx->stateless && expr->expiration) {
+	if (!nft_output_stateless(octx) && expr->expiration) {
 		nft_print(octx, " expires ");
 		time_print(expr->expiration, octx);
 	}
diff --git a/src/json.c b/src/json.c
index 5c426ce7..5c96bcd0 100644
--- a/src/json.c
+++ b/src/json.c
@@ -1075,7 +1075,7 @@ json_t *quota_stmt_json(const struct stmt *stmt, struct output_ctx *octx)
 
 	if (stmt->quota.flags & NFT_QUOTA_F_INV)
 		json_object_set_new(root, "inv", json_true());
-	if (!octx->stateless && stmt->quota.used) {
+	if (!nft_output_stateless(octx) && stmt->quota.used) {
 		data_unit = get_rate(stmt->quota.used, &bytes);
 		json_object_set_new(root, "used", json_integer(bytes));
 		json_object_set_new(root, "used_unit", json_string(data_unit));
@@ -1324,7 +1324,7 @@ json_t *reject_stmt_json(const struct stmt *stmt, struct output_ctx *octx)
 
 json_t *counter_stmt_json(const struct stmt *stmt, struct output_ctx *octx)
 {
-	if (octx->stateless)
+	if (nft_output_stateless(octx))
 		return json_pack("{s:n}", "counter");
 
 	return json_pack("{s:{s:I, s:I}}", "counter",
@@ -1354,11 +1354,12 @@ json_t *objref_stmt_json(const struct stmt *stmt, struct output_ctx *octx)
 
 json_t *meter_stmt_json(const struct stmt *stmt, struct output_ctx *octx)
 {
+	unsigned int flags = octx->flags;
 	json_t *root, *tmp;
 
-	octx->stateless++;
+	octx->flags |= NFT_CTX_OUTPUT_STATELESS;
 	tmp = stmt_print_json(stmt->meter.stmt, octx);
-	octx->stateless--;
+	octx->flags = flags;
 
 	root = json_pack("{s:o, s:o, s:i}",
 			 "key", expr_print_json(stmt->meter.key, octx),
diff --git a/src/libnftables.c b/src/libnftables.c
index 06d7c177..35e755e9 100644
--- a/src/libnftables.c
+++ b/src/libnftables.c
@@ -323,16 +323,6 @@ void nft_ctx_output_set_numeric(struct nft_ctx *ctx,
 	ctx->output.numeric = level;
 }
 
-bool nft_ctx_output_get_stateless(struct nft_ctx *ctx)
-{
-	return ctx->output.stateless;
-}
-
-void nft_ctx_output_set_stateless(struct nft_ctx *ctx, bool val)
-{
-	ctx->output.stateless = val;
-}
-
 unsigned int nft_ctx_output_get_flags(struct nft_ctx *ctx)
 {
 	return ctx->output.flags;
diff --git a/src/main.c b/src/main.c
index 86c8fe88..384bde5c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -228,7 +228,7 @@ int main(int argc, char * const *argv)
 			nft_ctx_output_set_numeric(nft, numeric + 1);
 			break;
 		case OPT_STATELESS:
-			nft_ctx_output_set_stateless(nft, true);
+			output_flags |= NFT_CTX_OUTPUT_STATELESS;
 			break;
 		case OPT_IP2NAME:
 			output_flags |= NFT_CTX_OUTPUT_REVERSEDNS;
diff --git a/src/rule.c b/src/rule.c
index 63da3306..35c60de4 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -486,7 +486,7 @@ static void do_set_print(const struct set *set, struct print_fmt_options *opts,
 {
 	set_print_declaration(set, opts, octx);
 
-	if (set->flags & NFT_SET_EVAL && octx->stateless) {
+	if (set->flags & NFT_SET_EVAL && nft_output_stateless(octx)) {
 		nft_print(octx, "%s}%s", opts->tab, opts->nl);
 		return;
 	}
@@ -1683,7 +1683,7 @@ static void obj_print_data(const struct obj *obj,
 		if (octx->handle > 0)
 			nft_print(octx, " # handle %" PRIu64, obj->handle.handle.id);
 		nft_print(octx, "%s%s%s", opts->nl, opts->tab, opts->tab);
-		if (octx->stateless) {
+		if (nft_output_stateless(octx)) {
 			nft_print(octx, "packets 0 bytes 0");
 			break;
 		}
@@ -1702,7 +1702,7 @@ static void obj_print_data(const struct obj *obj,
 		nft_print(octx, "%s%" PRIu64 " %s",
 			  obj->quota.flags & NFT_QUOTA_F_INV ? "over " : "",
 			  bytes, data_unit);
-		if (!octx->stateless && obj->quota.used) {
+		if (!nft_output_stateless(octx) && obj->quota.used) {
 			data_unit = get_rate(obj->quota.used, &bytes);
 			nft_print(octx, " used %" PRIu64 " %s",
 				  bytes, data_unit);
diff --git a/src/statement.c b/src/statement.c
index e50ac706..1eaaf585 100644
--- a/src/statement.c
+++ b/src/statement.c
@@ -112,6 +112,8 @@ struct stmt *verdict_stmt_alloc(const struct location *loc, struct expr *expr)
 
 static void meter_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 {
+	unsigned int flags = octx->flags;
+
 	nft_print(octx, "meter ");
 	if (stmt->meter.set) {
 		expr_print(stmt->meter.set, octx);
@@ -121,9 +123,9 @@ static void meter_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 	expr_print(stmt->meter.key, octx);
 	nft_print(octx, " ");
 
-	octx->stateless++;
+	octx->flags |= NFT_CTX_OUTPUT_STATELESS;
 	stmt_print(stmt->meter.stmt, octx);
-	octx->stateless--;
+	octx->flags = flags;
 
 	nft_print(octx, "} ");
 
@@ -175,7 +177,7 @@ static void counter_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 {
 	nft_print(octx, "counter");
 
-	if (octx->stateless)
+	if (nft_output_stateless(octx))
 		return;
 
 	nft_print(octx, " packets %" PRIu64 " bytes %" PRIu64,
@@ -463,7 +465,7 @@ static void quota_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 	nft_print(octx, "quota %s%" PRIu64 " %s",
 		  inv ? "over " : "", bytes, data_unit);
 
-	if (!octx->stateless && stmt->quota.used) {
+	if (!nft_output_stateless(octx) && stmt->quota.used) {
 		data_unit = get_rate(stmt->quota.used, &used);
 		nft_print(octx, " used %" PRIu64 " %s", used, data_unit);
 	}
@@ -631,15 +633,17 @@ const char * const set_stmt_op_names[] = {
 
 static void set_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 {
+	unsigned int flags = octx->flags;
+
 	nft_print(octx, "%s ", set_stmt_op_names[stmt->set.op]);
 	expr_print(stmt->set.set, octx);
 	nft_print(octx, " { ");
 	expr_print(stmt->set.key, octx);
 	if (stmt->set.stmt) {
 		nft_print(octx, " ");
-		octx->stateless++;
+		octx->flags |= NFT_CTX_OUTPUT_STATELESS;
 		stmt_print(stmt->set.stmt, octx);
-		octx->stateless--;
+		octx->flags = flags;
 	}
 	nft_print(octx, " }");
 }
@@ -665,15 +669,17 @@ struct stmt *set_stmt_alloc(const struct location *loc)
 
 static void map_stmt_print(const struct stmt *stmt, struct output_ctx *octx)
 {
+	unsigned int flags = octx->flags;
+
 	nft_print(octx, "%s ", set_stmt_op_names[stmt->map.op]);
 	expr_print(stmt->map.set, octx);
 	nft_print(octx, " { ");
 	expr_print(stmt->map.key, octx);
 	if (stmt->map.stmt) {
 		nft_print(octx, " ");
-		octx->stateless++;
+		octx->flags |= NFT_CTX_OUTPUT_STATELESS;
 		stmt_print(stmt->map.stmt, octx);
-		octx->stateless--;
+		octx->flags = flags;
 	}
 	nft_print(octx, " : ");
 	expr_print(stmt->map.data, octx);