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;
                 }