smb: client: provide dns_resolve_{unc,name} helpers

Some places pass hostnames rather than UNC paths to resolve them to ip
addresses, so provide helpers to handle both cases and then stop
converting hostnames to UNC paths by inserting path delimiters into
them.  Also kill @expiry parameter as it's not used anywhere.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 17 insertions, 27 deletions

diff --git a/fs/smb/client/dns_resolve.c b/fs/smb/client/dns_resolve.c
index 83db27f9c8f1..de7f4b384718 100644
--- a/fs/smb/client/dns_resolve.c
+++ b/fs/smb/client/dns_resolve.c
@@ -20,21 +20,19 @@
 #include "cifsproto.h"
 #include "cifs_debug.h"
 
-static int resolve_name(const char *name, size_t namelen,
-			struct sockaddr *addr, time64_t *expiry)
+static int resolve_name(const char *name, size_t namelen, struct sockaddr *addr)
 {
 	char *ip;
 	int rc;
 
 	rc = dns_query(current->nsproxy->net_ns, NULL, name,
-		       namelen, NULL, &ip, expiry, false);
+		       namelen, NULL, &ip, NULL, false);
 	if (rc < 0) {
 		cifs_dbg(FYI, "%s: unable to resolve: %*.*s\n",
 			 __func__, (int)namelen, (int)namelen, name);
 	} else {
-		cifs_dbg(FYI, "%s: resolved: %*.*s to %s expiry %llu\n",
-			 __func__, (int)namelen, (int)namelen, name, ip,
-			 expiry ? (*expiry) : 0);
+		cifs_dbg(FYI, "%s: resolved: %*.*s to %s\n",
+			 __func__, (int)namelen, (int)namelen, name, ip);
 
 		rc = cifs_convert_address(addr, ip, strlen(ip));
 		kfree(ip);
@@ -50,31 +48,23 @@ static int resolve_name(const char *name, size_t namelen,
 }
 
 /**
- * dns_resolve_server_name_to_ip - Resolve UNC server name to ip address.
- * @dom: optional DNS domain name
- * @unc: UNC path specifying the server (with '/' as delimiter)
- * @ip_addr: Where to return the IP address.
- * @expiry: Where to return the expiry time for the dns record.
+ * dns_resolve_name - Perform an upcall to resolve hostname to an ip address.
+ * @dom: DNS domain name (or NULL)
+ * @name: Name to look up
+ * @namelen: Length of name
+ * @ip_addr: Where to return the IP address
  *
- * Returns zero success, -ve on error.
+ * Returns zero on success, -ve code otherwise.
  */
-int dns_resolve_server_name_to_ip(const char *dom, const char *unc,
-				  struct sockaddr *ip_addr, time64_t *expiry)
+int dns_resolve_name(const char *dom, const char *name,
+		     size_t namelen, struct sockaddr *ip_addr)
 {
-	const char *name;
-	size_t namelen, len;
+	size_t len;
 	char *s;
 	int rc;
 
-	if (!ip_addr || !unc)
-		return -EINVAL;
-
-	cifs_dbg(FYI, "%s: dom=%s unc=%s\n", __func__, dom, unc);
-	if (strlen(unc) < 3)
-		return -EINVAL;
-
-	extract_unc_hostname(unc, &name, &namelen);
-	if (!namelen)
+	cifs_dbg(FYI, "%s: dom=%s name=%.*s\n", __func__, dom, (int)namelen, name);
+	if (!ip_addr || !name || !*name || !namelen)
 		return -EINVAL;
 
 	cifs_dbg(FYI, "%s: hostname=%.*s\n", __func__, (int)namelen, name);
@@ -97,10 +87,10 @@ int dns_resolve_server_name_to_ip(const char *dom, const char *unc,
 			return -ENOMEM;
 
 		scnprintf(s, len, "%.*s.%s", (int)namelen, name, dom);
-		rc = resolve_name(s, len - 1, ip_addr, expiry);
+		rc = resolve_name(s, len - 1, ip_addr);
 		kfree(s);
 		if (!rc)
 			return 0;
 	}
-	return resolve_name(name, namelen, ip_addr, expiry);
+	return resolve_name(name, namelen, ip_addr);
 }