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, 4 insertions, 2 deletions

diff --git a/common/blspec.c b/common/blspec.c
index 2c682e1990..41f2a4c534 100644
--- a/common/blspec.c
+++ b/common/blspec.c
@@ -303,9 +303,11 @@ static char *parse_nfs_url(const char *url)
 		goto out;
 	}
 
-	ip = resolv(host);
-	if (ip == 0)
+	ret = resolv(host, &ip);
+	if (ret) {
+		pr_err("Cannot resolve \"%s\": %s\n", host, strerror(-ret));
 		goto out;
+	}
 
 	hostpath = basprintf("%pI4:%s", &ip, path);