[PATCH nft 3/5] libnftables: consolidate evaluation and netlink run

[Pablo Neira Ayuso <pablo@netfilter.org>]

Add a helper function to wrap the code that evaluates the list of
commands and serialize them into the netlink batch.

Add a first user: nft_run_cmd_from_buffer(), there is a follow up patch
which will do the same for nft_run_cmd_from_filename().

No functional changes are intended, this comes in preparation to
support several list/reset commands in a batch.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/libnftables.c | 61 ++++++++++++++++++++++++++++-------------------
 1 file changed, 37 insertions(+), 24 deletions(-)

diff --git a/src/libnftables.c b/src/libnftables.c
index 46d9c0df590b..5471ccf6f789 100644
--- a/src/libnftables.c
+++ b/src/libnftables.c
@@ -618,22 +618,13 @@ static void nft_run_cmd_release(struct nft_ctx *nft,
 	}
 }
 
-EXPORT_SYMBOL(nft_run_cmd_from_buffer);
-int nft_run_cmd_from_buffer(struct nft_ctx *nft, const char *buf)
+static int nft_eval_run_cmds(struct nft_ctx *nft, struct list_head *msgs,
+			     struct list_head *cmds, int rc)
 {
-	int rc = -EINVAL, parser_rc;
-	LIST_HEAD(msgs);
-	LIST_HEAD(cmds);
-	char *nlbuf;
+	int parser_rc;
 
-	nlbuf = xzalloc(strlen(buf) + 2);
-	sprintf(nlbuf, "%s\n", buf);
-
-	if (nft_output_json(&nft->output) || nft_input_json(&nft->input))
-		rc = nft_parse_json_buffer(nft, nlbuf, &msgs, &cmds);
-	if (rc == -EINVAL)
-		rc = nft_parse_bison_buffer(nft, nlbuf, &msgs, &cmds,
-					    &indesc_cmdline);
+	if (rc < 0)
+		goto err;
 
 #if HAVE_FUZZER_BUILD
 	if (nft->afl_ctx_stage == NFT_AFL_FUZZER_PARSER)
@@ -641,7 +632,7 @@ int nft_run_cmd_from_buffer(struct nft_ctx *nft, const char *buf)
 #endif
 	parser_rc = rc;
 
-	rc = nft_evaluate(nft, &msgs, &cmds);
+	rc = nft_evaluate(nft, msgs, cmds);
 	if (rc < 0) {
 		if (errno == EPERM) {
 			fprintf(stderr, "%s (you must be root)\n",
@@ -655,17 +646,10 @@ int nft_run_cmd_from_buffer(struct nft_ctx *nft, const char *buf)
 		goto err;
 	}
 
-	if (nft_netlink(nft, &cmds, &msgs) != 0)
+	if (nft_netlink(nft, cmds, msgs) != 0)
 		rc = -1;
 err:
-	nft_run_cmd_release(nft, &msgs, &cmds);
-
-	iface_cache_release();
-	if (nft->scanner) {
-		scanner_destroy(nft);
-		nft->scanner = NULL;
-	}
-	free(nlbuf);
+	nft_run_cmd_release(nft, msgs, cmds);
 
 	if (!rc &&
 	    nft_output_json(&nft->output) &&
@@ -678,6 +662,35 @@ err:
 	return rc;
 }
 
+EXPORT_SYMBOL(nft_run_cmd_from_buffer);
+int nft_run_cmd_from_buffer(struct nft_ctx *nft, const char *buf)
+{
+	int rc = -EINVAL;
+	LIST_HEAD(msgs);
+	LIST_HEAD(cmds);
+	char *nlbuf;
+
+	nlbuf = xzalloc(strlen(buf) + 2);
+	sprintf(nlbuf, "%s\n", buf);
+
+	if (nft_output_json(&nft->output) || nft_input_json(&nft->input))
+		rc = nft_parse_json_buffer(nft, nlbuf, &msgs, &cmds);
+	if (rc == -EINVAL)
+		rc = nft_parse_bison_buffer(nft, nlbuf, &msgs, &cmds,
+					    &indesc_cmdline);
+
+	rc = nft_eval_run_cmds(nft, &msgs, &cmds, rc);
+
+	free(nlbuf);
+	iface_cache_release();
+	if (nft->scanner) {
+		scanner_destroy(nft);
+		nft->scanner = NULL;
+	}
+
+	return rc;
+}
+
 static int load_cmdline_vars(struct nft_ctx *ctx, struct list_head *msgs)
 {
 	unsigned int bufsize, ret, i, offset = 0;
-- 
2.47.3