[PATCH nft,v2 6/7] mnl: mnl_batch_talk() returns -1 on internal netlink errors

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

Display an error in case internal netlink plumbing hits problems.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/libnftables.c | 8 ++++++++
 src/mnl.c         | 7 ++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/libnftables.c b/src/libnftables.c
index a58b8ca9dcf6..d8de89ca509c 100644
--- a/src/libnftables.c
+++ b/src/libnftables.c
@@ -58,6 +58,14 @@ static int nft_netlink(struct nft_ctx *nft,
 		goto out;
 
 	ret = mnl_batch_talk(&ctx, &err_list, num_cmds);
+	if (ret < 0) {
+		netlink_io_error(&ctx, NULL,
+				 "Could not process rule: %s", strerror(errno));
+		goto out;
+	}
+
+	if (!list_empty(&err_list))
+		ret = -1;
 
 	list_for_each_entry_safe(err, tmp, &err_list, head) {
 		list_for_each_entry(cmd, cmds, list) {
diff --git a/src/mnl.c b/src/mnl.c
index 96984f03e1be..4c15387000e9 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -313,7 +313,6 @@ int mnl_batch_talk(struct netlink_ctx *ctx, struct list_head *err_list,
 	struct iovec iov[iov_len];
 	struct msghdr msg = {};
 	fd_set readfds;
-	int err = 0;
 
 	mnl_set_sndbuffer(ctx->nft->nf_sock, ctx->batch);
 
@@ -343,10 +342,8 @@ int mnl_batch_talk(struct netlink_ctx *ctx, struct list_head *err_list,
 
 		ret = mnl_cb_run(rcv_buf, ret, 0, portid, &netlink_echo_callback, ctx);
 		/* Continue on error, make sure we get all acknowledgments */
-		if (ret == -1) {
+		if (ret == -1)
 			mnl_err_list_node_add(err_list, errno, nlh->nlmsg_seq);
-			err = -1;
-		}
 
 		ret = select(fd+1, &readfds, NULL, NULL, &tv);
 		if (ret == -1)
@@ -355,7 +352,7 @@ int mnl_batch_talk(struct netlink_ctx *ctx, struct list_head *err_list,
 		FD_ZERO(&readfds);
 		FD_SET(fd, &readfds);
 	}
-	return err;
+	return 0;
 }
 
 int mnl_nft_rule_add(struct netlink_ctx *ctx, const struct cmd *cmd,
-- 
2.11.0