[CIFS] Fix mount failure when domain not specified

    Fixes Samba bugzilla #4176

    When users do not specify their domain on mount, 2.6.18 started sending
    default domain instead of a null domain (which was the only way on some
    servers to use a default domain).  Users of 2.6.18 who did not specify
    their domain name on mounts to certain common Windows servers that were
    members of a domain, but not the domain controller, would get mount
    failures which they did not get in 2.6.18

    This fixes that issue and should remove complaints about mount
    behavior changing.

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 13 insertions, 10 deletions

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index a8a083543ba0..bbdda99dce61 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -90,7 +90,9 @@ static void unicode_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
         } */
         /* copy user */
         if(ses->userName == NULL) {
-                /* BB what about null user mounts - check that we do this BB */
+                /* null user mount */
+                *bcc_ptr = 0;
+                *(bcc_ptr+1) = 0;
         } else { /* 300 should be long enough for any conceivable user name */
                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->userName,
                                           300, nls_cp);
@@ -98,10 +100,13 @@ static void unicode_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
         bcc_ptr += 2 * bytes_ret;
         bcc_ptr += 2; /* account for null termination */
         /* copy domain */
-        if(ses->domainName == NULL)
-                bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr,
-                                          "CIFS_LINUX_DOM", 32, nls_cp);
-        else
+        if(ses->domainName == NULL) {
+                /* Sending null domain better than using a bogus domain name (as
+                we did briefly in 2.6.18) since server will use its default */
+                *bcc_ptr = 0;
+                *(bcc_ptr+1) = 0;
+                bytes_ret = 0;
+        } else
                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->domainName, 
                                           256, nls_cp);
         bcc_ptr += 2 * bytes_ret;
@@ -144,13 +149,11 @@ static void ascii_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
 
         /* copy domain */
         
-        if(ses->domainName == NULL) {
-                strcpy(bcc_ptr, "CIFS_LINUX_DOM");
-                bcc_ptr += 14;  /* strlen(CIFS_LINUX_DOM) */
-        } else {
+        if(ses->domainName != NULL) {
                 strncpy(bcc_ptr, ses->domainName, 256); 
                 bcc_ptr += strnlen(ses->domainName, 256);
-        }
+        } /* else we will send a null domain name 
+             so the server will default to its own domain */
         *bcc_ptr = 0;
         bcc_ptr++;