[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>

5 files changed, 37 insertions, 8 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index bb468de4f474..f55be8efa26d 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -291,6 +291,7 @@ struct cifsTconInfo {
         FILE_SYSTEM_DEVICE_INFO fsDevInfo;
         FILE_SYSTEM_ATTRIBUTE_INFO fsAttrInfo; /* ok if fs name truncated */
         FILE_SYSTEM_UNIX_INFO fsUnixInfo;
+        unsigned ipc:1;         /* set if connection to IPC$ eg for RPC/PIPES */
         unsigned retry:1;
         unsigned nocase:1;
         unsigned unix_ext:1; /* if off disable Linux extensions to CIFS protocol
@@ -341,6 +342,7 @@ struct cifsFileInfo {
         struct list_head llist; /* list of byte range locks we have. */
         unsigned closePend:1;   /* file is marked to close */
         unsigned invalidHandle:1;  /* file closed via session abend */
+        unsigned messageMode:1    /* for pipes: is message or byte mode */
         atomic_t wrtPending;   /* handle in use - defer close */
         struct semaphore fh_sem; /* prevents reopen race after dead ses*/
         char *search_resume_name; /* BB removeme BB */
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) {
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index db5287abc30f..99321ab439d2 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -3,7 +3,7 @@
  *
  *   vfs operations that deal with dentries
  *
- *   Copyright (C) International Business Machines  Corp., 2002,2005
+ *   Copyright (C) International Business Machines  Corp., 2002,2007
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *
  *   This library is free software; you can redistribute it and/or modify
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 552d68b9d6f4..ece17ca00d08 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -115,7 +115,7 @@ int cifs_get_inode_info_unix(struct inode **pinode,
                 inode->i_mode = le64_to_cpu(findData.Permissions);
                 /* since we set the inode type below we need to mask off
                    to avoid strange results if bits set above */
-                        inode->i_mode &= ~S_IFMT;
+                inode->i_mode &= ~S_IFMT;
                 if (type == UNIX_FILE) {
                         inode->i_mode |= S_IFREG;
                 } else if (type == UNIX_SYMLINK) {
@@ -575,19 +575,33 @@ int cifs_get_inode_info(struct inode **pinode,
         return rc;
 }
 
+static const struct inode_operations cifs_ipc_inode_ops = {
+        .lookup = cifs_lookup,
+};
+
 /* gets root inode */
 void cifs_read_inode(struct inode *inode)
 {
-        int xid;
+        int xid, rc;
         struct cifs_sb_info *cifs_sb;
 
         cifs_sb = CIFS_SB(inode->i_sb);
         xid = GetXid();
 
         if (cifs_sb->tcon->unix_ext)
-                cifs_get_inode_info_unix(&inode, "", inode->i_sb, xid);
+                rc = cifs_get_inode_info_unix(&inode, "", inode->i_sb, xid);
         else
-                cifs_get_inode_info(&inode, "", NULL, inode->i_sb, xid);
+                rc = cifs_get_inode_info(&inode, "", NULL, inode->i_sb, xid);
+        if (rc && cifs_sb->tcon->ipc) {
+                cFYI(1, ("ipc connection - fake read inode"));
+                inode->i_mode |= S_IFDIR;
+                inode->i_nlink = 2;
+                inode->i_op = &cifs_ipc_inode_ops;
+                inode->i_fop = &simple_dir_operations;
+                inode->i_uid = cifs_sb->mnt_uid;
+                inode->i_gid = cifs_sb->mnt_gid;
+        }
+
         /* can not call macro FreeXid here since in a void func */
         _FreeXid(xid);
 }
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 0bcec0844bee..51ec681fe74a 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -169,7 +169,6 @@ cifs_buf_get(void)
 void
 cifs_buf_release(void *buf_to_free)
 {
-
         if (buf_to_free == NULL) {
                 /* cFYI(1, ("Null buffer passed to cifs_buf_release"));*/
                 return;