CIFS: Make cifs_convert_address() take a const src pointer and a length

Make cifs_convert_address() take a const src pointer and a length so that all
the strlen() calls in their can be cut out and to make it unnecessary to modify
the src string.

Also return the data length from dns_resolve_server_name_to_ip() so that a
strlen() can be cut out of cifs_compose_mount_options() too.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 9 insertions, 11 deletions

diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index 3ad7f4300c45..aa967e7917f8 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -40,11 +40,11 @@ static const struct cred *dns_resolver_cache;
  * 		0 - name is not IP
  */
 static int
-is_ip(char *name)
+is_ip(const char *name, int len)
 {
 	struct sockaddr_storage ss;
 
-	return cifs_convert_address((struct sockaddr *)&ss, name);
+	return cifs_convert_address((struct sockaddr *)&ss, name, len);
 }
 
 static int
@@ -54,6 +54,10 @@ dns_resolver_instantiate(struct key *key, const void *data,
 	int rc = 0;
 	char *ip;
 
+	/* make sure this looks like an address */
+	if (!is_ip(data, datalen))
+		return -EINVAL;
+
 	ip = kmalloc(datalen + 1, GFP_KERNEL);
 	if (!ip)
 		return -ENOMEM;
@@ -61,12 +65,6 @@ dns_resolver_instantiate(struct key *key, const void *data,
 	memcpy(ip, data, datalen);
 	ip[datalen] = '\0';
 
-	/* make sure this looks like an address */
-	if (!is_ip(ip)) {
-		kfree(ip);
-		return -EINVAL;
-	}
-
 	key->type_data.x[0] = datalen;
 	key->payload.data = ip;
 
@@ -93,7 +91,7 @@ struct key_type key_type_dns_resolver = {
  * 	unc - server UNC
  * output:
  * 	*ip_addr - pointer to server ip, caller responcible for freeing it.
- * return 0 on success
+ * return the length of the returned string on success
  */
 int
 dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
@@ -131,7 +129,7 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
 	memcpy(name, unc+2, len);
 	name[len] = 0;
 
-	if (is_ip(name)) {
+	if (is_ip(name, len)) {
 		cFYI(1, "%s: it is IP, skipping dns upcall: %s",
 					__func__, name);
 		data = name;
@@ -164,7 +162,7 @@ skip_upcall:
 							name,
 							*ip_addr
 					);
-			rc = 0;
+			rc = len;
 		} else {
 			rc = -ENOMEM;
 		}