kernel-ark/fs/cifs/dir.c
Steve French 6473a559c3 [CIFS] Fix missing permission check on setattr when noperm mount option is
disabled.  Also set mode, uid, gid better on mkdir and create for the
case when Unix Extensions is not enabled and setuids is enabled. This is
necessary to fix the hole in which chown could be allowed for non-root
users in some cases if root mounted, and also to display the mode and uid
properly in some cases.

Signed-off-by: Steve French <sfrench@us.ibm.com>
2005-11-29 20:20:10 -08:00

577 lines
16 KiB
C

/*
* fs/cifs/dir.c
*
* vfs operations that deal with dentries
*
* Copyright (C) International Business Machines Corp., 2002,2003
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
void
renew_parental_timestamps(struct dentry *direntry)
{
/* BB check if there is a way to get the kernel to do this or if we really need this */
do {
direntry->d_time = jiffies;
direntry = direntry->d_parent;
} while (!IS_ROOT(direntry));
}
/* Note: caller must free return buffer */
char *
build_path_from_dentry(struct dentry *direntry)
{
struct dentry *temp;
int namelen = 0;
char *full_path;
char dirsep = CIFS_DIR_SEP(CIFS_SB(direntry->d_sb));
if(direntry == NULL)
return NULL; /* not much we can do if dentry is freed and
we need to reopen the file after it was closed implicitly
when the server crashed */
cifs_bp_rename_retry:
for (temp = direntry; !IS_ROOT(temp);) {
namelen += (1 + temp->d_name.len);
temp = temp->d_parent;
if(temp == NULL) {
cERROR(1,("corrupt dentry"));
return NULL;
}
}
full_path = kmalloc(namelen+1, GFP_KERNEL);
if(full_path == NULL)
return full_path;
full_path[namelen] = 0; /* trailing null */
for (temp = direntry; !IS_ROOT(temp);) {
namelen -= 1 + temp->d_name.len;
if (namelen < 0) {
break;
} else {
full_path[namelen] = dirsep;
strncpy(full_path + namelen + 1, temp->d_name.name,
temp->d_name.len);
cFYI(0, (" name: %s ", full_path + namelen));
}
temp = temp->d_parent;
if(temp == NULL) {
cERROR(1,("corrupt dentry"));
kfree(full_path);
return NULL;
}
}
if (namelen != 0) {
cERROR(1,
("We did not end path lookup where we expected namelen is %d",
namelen));
/* presumably this is only possible if we were racing with a rename
of one of the parent directories (we can not lock the dentries
above us to prevent this, but retrying should be harmless) */
kfree(full_path);
namelen = 0;
goto cifs_bp_rename_retry;
}
return full_path;
}
/* char * build_wildcard_path_from_dentry(struct dentry *direntry)
{
if(full_path == NULL)
return full_path;
full_path[namelen] = '\\';
full_path[namelen+1] = '*';
full_path[namelen+2] = 0;
BB remove above eight lines BB */
/* Inode operations in similar order to how they appear in the Linux file fs.h */
int
cifs_create(struct inode *inode, struct dentry *direntry, int mode,
struct nameidata *nd)
{
int rc = -ENOENT;
int xid;
int oplock = 0;
int desiredAccess = GENERIC_READ | GENERIC_WRITE;
__u16 fileHandle;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
FILE_ALL_INFO * buf = NULL;
struct inode *newinode = NULL;
struct cifsFileInfo * pCifsFile = NULL;
struct cifsInodeInfo * pCifsInode;
int disposition = FILE_OVERWRITE_IF;
int write_only = FALSE;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
down(&direntry->d_sb->s_vfs_rename_sem);
full_path = build_path_from_dentry(direntry);
up(&direntry->d_sb->s_vfs_rename_sem);
if(full_path == NULL) {
FreeXid(xid);
return -ENOMEM;
}
if(nd && (nd->flags & LOOKUP_OPEN)) {
int oflags = nd->intent.open.flags;
desiredAccess = 0;
if (oflags & FMODE_READ)
desiredAccess |= GENERIC_READ;
if (oflags & FMODE_WRITE) {
desiredAccess |= GENERIC_WRITE;
if (!(oflags & FMODE_READ))
write_only = TRUE;
}
if((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
disposition = FILE_CREATE;
else if((oflags & (O_CREAT | O_TRUNC)) == (O_CREAT | O_TRUNC))
disposition = FILE_OVERWRITE_IF;
else if((oflags & O_CREAT) == O_CREAT)
disposition = FILE_OPEN_IF;
else {
cFYI(1,("Create flag not set in create function"));
}
}
/* BB add processing to set equivalent of mode - e.g. via CreateX with ACLs */
if (oplockEnabled)
oplock = REQ_OPLOCK;
buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
if(buf == NULL) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
desiredAccess, CREATE_NOT_DIR,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if(rc == -EIO) {
/* old server, retry the open legacy style */
rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
desiredAccess, CREATE_NOT_DIR,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
}
if (rc) {
cFYI(1, ("cifs_create returned 0x%x ", rc));
} else {
/* If Open reported that we actually created a file
then we now have to set the mode if possible */
if ((cifs_sb->tcon->ses->capabilities & CAP_UNIX) &&
(oplock & CIFS_CREATE_ACTION))
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
(__u64)current->euid,
(__u64)current->egid,
0 /* dev */,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
} else {
CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
(__u64)-1,
(__u64)-1,
0 /* dev */,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
}
else {
/* BB implement mode setting via Windows security descriptors */
/* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
/* could set r/o dos attribute if mode & 0222 == 0 */
}
/* BB server might mask mode so we have to query for Unix case*/
if (pTcon->ses->capabilities & CAP_UNIX)
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb,xid);
else {
rc = cifs_get_inode_info(&newinode, full_path,
buf, inode->i_sb,xid);
if(newinode) {
newinode->i_mode = mode;
if((oplock & CIFS_CREATE_ACTION) &&
(cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_SET_UID)) {
newinode->i_uid = current->fsuid;
newinode->i_gid = current->fsgid;
}
}
}
if (rc != 0) {
cFYI(1,
("Create worked but get_inode_info failed rc = %d",
rc));
} else {
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_instantiate(direntry, newinode);
}
if((nd->flags & LOOKUP_OPEN) == FALSE) {
/* mknod case - do not leave file open */
CIFSSMBClose(xid, pTcon, fileHandle);
} else if(newinode) {
pCifsFile =
kmalloc(sizeof (struct cifsFileInfo), GFP_KERNEL);
if(pCifsFile == NULL)
goto cifs_create_out;
memset((char *)pCifsFile, 0,
sizeof (struct cifsFileInfo));
pCifsFile->netfid = fileHandle;
pCifsFile->pid = current->tgid;
pCifsFile->pInode = newinode;
pCifsFile->invalidHandle = FALSE;
pCifsFile->closePend = FALSE;
init_MUTEX(&pCifsFile->fh_sem);
/* set the following in open now
pCifsFile->pfile = file; */
write_lock(&GlobalSMBSeslock);
list_add(&pCifsFile->tlist,&pTcon->openFileList);
pCifsInode = CIFS_I(newinode);
if(pCifsInode) {
/* if readable file instance put first in list*/
if (write_only == TRUE) {
list_add_tail(&pCifsFile->flist,
&pCifsInode->openFileList);
} else {
list_add(&pCifsFile->flist,
&pCifsInode->openFileList);
}
if((oplock & 0xF) == OPLOCK_EXCLUSIVE) {
pCifsInode->clientCanCacheAll = TRUE;
pCifsInode->clientCanCacheRead = TRUE;
cFYI(1,("Exclusive Oplock for inode %p",
newinode));
} else if((oplock & 0xF) == OPLOCK_READ)
pCifsInode->clientCanCacheRead = TRUE;
}
write_unlock(&GlobalSMBSeslock);
}
}
cifs_create_out:
kfree(buf);
kfree(full_path);
FreeXid(xid);
return rc;
}
int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
dev_t device_number)
{
int rc = -EPERM;
int xid;
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
char *full_path = NULL;
struct inode * newinode = NULL;
if (!old_valid_dev(device_number))
return -EINVAL;
xid = GetXid();
cifs_sb = CIFS_SB(inode->i_sb);
pTcon = cifs_sb->tcon;
down(&direntry->d_sb->s_vfs_rename_sem);
full_path = build_path_from_dentry(direntry);
up(&direntry->d_sb->s_vfs_rename_sem);
if(full_path == NULL)
rc = -ENOMEM;
else if (pTcon->ses->capabilities & CAP_UNIX) {
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
rc = CIFSSMBUnixSetPerms(xid, pTcon, full_path,
mode,(__u64)current->euid,(__u64)current->egid,
device_number, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
} else {
rc = CIFSSMBUnixSetPerms(xid, pTcon,
full_path, mode, (__u64)-1, (__u64)-1,
device_number, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
}
if(!rc) {
rc = cifs_get_inode_info_unix(&newinode, full_path,
inode->i_sb,xid);
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
if(rc == 0)
d_instantiate(direntry, newinode);
}
} else {
if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
int oplock = 0;
u16 fileHandle;
FILE_ALL_INFO * buf;
cFYI(1,("sfu compat create special file"));
buf = kmalloc(sizeof(FILE_ALL_INFO),GFP_KERNEL);
if(buf == NULL) {
kfree(full_path);
FreeXid(xid);
return -ENOMEM;
}
rc = CIFSSMBOpen(xid, pTcon, full_path,
FILE_CREATE, /* fail if exists */
GENERIC_WRITE /* BB would
WRITE_OWNER | WRITE_DAC be better? */,
/* Create a file and set the
file attribute to SYSTEM */
CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
&fileHandle, &oplock, buf,
cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if(!rc) {
/* BB Do not bother to decode buf since no
local inode yet to put timestamps in,
but we can reuse it safely */
int bytes_written;
struct win_dev *pdev;
pdev = (struct win_dev *)buf;
if(S_ISCHR(mode)) {
memcpy(pdev->type, "IntxCHR", 8);
pdev->major =
cpu_to_le64(MAJOR(device_number));
pdev->minor =
cpu_to_le64(MINOR(device_number));
rc = CIFSSMBWrite(xid, pTcon,
fileHandle,
sizeof(struct win_dev),
0, &bytes_written, (char *)pdev,
NULL, 0);
} else if(S_ISBLK(mode)) {
memcpy(pdev->type, "IntxBLK", 8);
pdev->major =
cpu_to_le64(MAJOR(device_number));
pdev->minor =
cpu_to_le64(MINOR(device_number));
rc = CIFSSMBWrite(xid, pTcon,
fileHandle,
sizeof(struct win_dev),
0, &bytes_written, (char *)pdev,
NULL, 0);
} /* else if(S_ISFIFO */
CIFSSMBClose(xid, pTcon, fileHandle);
d_drop(direntry);
}
kfree(buf);
/* add code here to set EAs */
}
}
kfree(full_path);
FreeXid(xid);
return rc;
}
struct dentry *
cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry, struct nameidata *nd)
{
int xid;
int rc = 0; /* to get around spurious gcc warning, set to zero here */
struct cifs_sb_info *cifs_sb;
struct cifsTconInfo *pTcon;
struct inode *newInode = NULL;
char *full_path = NULL;
xid = GetXid();
cFYI(1,
(" parent inode = 0x%p name is: %s and dentry = 0x%p",
parent_dir_inode, direntry->d_name.name, direntry));
/* BB Add check of incoming data - e.g. frame not longer than maximum SMB - let server check the namelen BB */
/* check whether path exists */
cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
pTcon = cifs_sb->tcon;
/* can not grab the rename sem here since it would
deadlock in the cases (beginning of sys_rename itself)
in which we already have the sb rename sem */
full_path = build_path_from_dentry(direntry);
if(full_path == NULL) {
FreeXid(xid);
return ERR_PTR(-ENOMEM);
}
if (direntry->d_inode != NULL) {
cFYI(1, (" non-NULL inode in lookup"));
} else {
cFYI(1, (" NULL inode in lookup"));
}
cFYI(1,
(" Full path: %s inode = 0x%p", full_path, direntry->d_inode));
if (pTcon->ses->capabilities & CAP_UNIX)
rc = cifs_get_inode_info_unix(&newInode, full_path,
parent_dir_inode->i_sb,xid);
else
rc = cifs_get_inode_info(&newInode, full_path, NULL,
parent_dir_inode->i_sb,xid);
if ((rc == 0) && (newInode != NULL)) {
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_add(direntry, newInode);
/* since paths are not looked up by component - the parent
directories are presumed to be good here */
renew_parental_timestamps(direntry);
} else if (rc == -ENOENT) {
rc = 0;
direntry->d_time = jiffies;
if (pTcon->nocase)
direntry->d_op = &cifs_ci_dentry_ops;
else
direntry->d_op = &cifs_dentry_ops;
d_add(direntry, NULL);
/* if it was once a directory (but how can we tell?) we could do
shrink_dcache_parent(direntry); */
} else {
cERROR(1,("Error 0x%x on cifs_get_inode_info in lookup of %s",
rc,full_path));
/* BB special case check for Access Denied - watch security
exposure of returning dir info implicitly via different rc
if file exists or not but no access BB */
}
kfree(full_path);
FreeXid(xid);
return ERR_PTR(rc);
}
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
int isValid = 1;
if (direntry->d_inode) {
if (cifs_revalidate(direntry)) {
return 0;
}
} else {
cFYI(1, ("neg dentry 0x%p name = %s",
direntry, direntry->d_name.name));
if(time_after(jiffies, direntry->d_time + HZ) ||
!lookupCacheEnabled) {
d_drop(direntry);
isValid = 0;
}
}
return isValid;
}
/* static int cifs_d_delete(struct dentry *direntry)
{
int rc = 0;
cFYI(1, ("In cifs d_delete, name = %s", direntry->d_name.name));
return rc;
} */
struct dentry_operations cifs_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
/* d_delete: cifs_d_delete, *//* not needed except for debugging */
/* no need for d_hash, d_compare, d_release, d_iput ... yet. BB confirm this BB */
};
static int cifs_ci_hash(struct dentry *dentry, struct qstr *q)
{
struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
unsigned long hash;
int i;
hash = init_name_hash();
for (i = 0; i < q->len; i++)
hash = partial_name_hash(nls_tolower(codepage, q->name[i]),
hash);
q->hash = end_name_hash(hash);
return 0;
}
static int cifs_ci_compare(struct dentry *dentry, struct qstr *a,
struct qstr *b)
{
struct nls_table *codepage = CIFS_SB(dentry->d_inode->i_sb)->local_nls;
if ((a->len == b->len) &&
(nls_strnicmp(codepage, a->name, b->name, a->len) == 0)) {
/*
* To preserve case, don't let an existing negative dentry's
* case take precedence. If a is not a negative dentry, this
* should have no side effects
*/
memcpy((unsigned char *)a->name, b->name, a->len);
return 0;
}
return 1;
}
struct dentry_operations cifs_ci_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
.d_hash = cifs_ci_hash,
.d_compare = cifs_ci_compare,
};