[CIFS] CIFS support for named pipes (part 1)

This allows cifs to mount to ipc shares (IPC$)
which will allow user space applications to
layer over authenticated cifs connections
(useful for Wine and others that would want
to put DCE/RPC over CIFS or run CIFS named
pipes)

Acked-by: Rob Shearman <rob@codeweavers.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e43cb880f54a..21cac15ed9a7 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2186,8 +2186,10 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                 tcon->ses = pSesInfo;
 
                 /* do not care if following two calls succeed - informational */
-                CIFSSMBQFSDeviceInfo(xid, tcon);
-                CIFSSMBQFSAttributeInfo(xid, tcon);
+                if (!tcon->ipc) {
+                        CIFSSMBQFSDeviceInfo(xid, tcon);
+                        CIFSSMBQFSAttributeInfo(xid, tcon);
+                }
 
                 /* tell server which Unix caps we support */
                 if (tcon->ses->capabilities & CAP_UNIX)
@@ -3385,6 +3387,18 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
                 bcc_ptr = pByteArea(smb_buffer_response);
                 length = strnlen(bcc_ptr, BCC(smb_buffer_response) - 2);
                 /* skip service field (NB: this field is always ASCII) */
+                if (length == 3) {
+                        if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
+                            (bcc_ptr[2] == 'C')) {
+                                cFYI(1, ("IPC connection"));
+                                tcon->ipc = 1;
+                        }
+                } else if (length == 2) {
+                        if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
+                                /* the most common case */
+                                cFYI(1, ("disk share connection"));
+                        }
+                }
                 bcc_ptr += length + 1;
                 strncpy(tcon->treeName, tree, MAX_TREE_SIZE);
                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE) {