net: dns: return error codes

The resolv() function used to return the IP address. When net_udp_new()
fails we return an error code though which the callers of resolv() take
as an IP address. This is wrong of course and we could return 0 in this
case. Instead we return an error code and pass the resolved IP as a
pointer which allows us to return proper error codes.

This patch also adds error messages and error returns to the various
callers of resolv() which used to just continue with a zero IP and
let the user figure out what went wrong.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 10 insertions, 1 deletions

diff --git a/fs/tftp.c b/fs/tftp.c
index 0d9ee6effd..907adc7434 100644
--- a/fs/tftp.c
+++ b/fs/tftp.c
@@ -696,10 +696,15 @@ static int tftp_probe(struct device_d *dev)
 	struct tftp_priv *priv = xzalloc(sizeof(struct tftp_priv));
 	struct super_block *sb = &fsdev->sb;
 	struct inode *inode;
+	int ret;
 
 	dev->priv = priv;
 
-	priv->server = resolv(fsdev->backingstore);
+	ret = resolv(fsdev->backingstore, &priv->server);
+	if (ret) {
+		pr_err("Cannot resolve \"%s\": %s\n", fsdev->backingstore, strerror(-ret));
+		goto err;
+	}
 
 	sb->s_op = &tftp_ops;
 
@@ -707,6 +712,10 @@ static int tftp_probe(struct device_d *dev)
 	sb->s_root = d_make_root(inode);
 
 	return 0;
+err:
+	free(priv);
+
+	return ret;
 }
 
 static void tftp_remove(struct device_d *dev)