From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
Add mount options backupuid and backugid.
It allows an authenticated user to access files with the intent to back them
up including their ACLs, who may not have access permission but has
"Backup files and directories user right" on them (by virtue of being part
of the built-in group Backup Operators.
When mount options backupuid is specified, cifs client restricts the
use of backup intents to the user whose effective user id is specified
along with the mount option.
When mount options backupgid is specified, cifs client restricts the
use of backup intents to the users whose effective user id belongs to the
group id specified along with the mount option.
These mount options are mutually excluisve to mount option mulituser.
If an authenticated user is not part of the built-in group Backup Operators
at the server, access to such files is denied, even if allowed by the client.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
---
fs/cifs/cifs_fs_sb.h | 3 +++
fs/cifs/cifsacl.c | 23 ++++++++++++++++++-----
fs/cifs/cifsglob.h | 6 +++++-
fs/cifs/connect.c | 14 ++++++++++++++
fs/cifs/dir.c | 22 +++++++++++++++++++---
fs/cifs/file.c | 24 ++++++++++++++++++++++--
fs/cifs/link.c | 23 ++++++++++++++++++-----
7 files changed, 99 insertions(+), 16 deletions(-)
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 7260e11..f5483c8 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -43,6 +43,7 @@
#define CIFS_MOUNT_STRICT_IO 0x40000 /* strict cache mode */
#define CIFS_MOUNT_RWPIDFORWARD 0x80000 /* use pid forwarding for rw */
#define CIFS_MOUNT_POSIXACL 0x100000 /* mirror of MS_POSIXACL in mnt_cifs_flags */
+#define CIFS_MOUNT_CIFS_BACKUP 0x200000 /* open file with backup intent bit */
struct cifs_sb_info {
struct rb_root tlink_tree;
@@ -55,6 +56,8 @@ struct cifs_sb_info {
atomic_t active;
uid_t mnt_uid;
gid_t mnt_gid;
+ uid_t mnt_backupuid;
+ gid_t mnt_backupgid;
mode_t mnt_file_mode;
mode_t mnt_dir_mode;
unsigned int mnt_cifs_flags;
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index d0f59fa..a0af87a 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -945,7 +945,7 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
{
struct cifs_ntsd *pntsd = NULL;
int oplock = 0;
- int xid, rc;
+ int xid, rc, create_options = 0;
__u16 fid;
struct cifs_tcon *tcon;
struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
@@ -956,9 +956,18 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
tcon = tlink_tcon(tlink);
xid = GetXid();
- rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, 0,
- &fid, &oplock, NULL, cifs_sb->local_nls,
- cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
+
+ rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL,
+ create_options, &fid, &oplock, NULL, cifs_sb->local_nls,
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if (!rc) {
rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen);
CIFSSMBClose(xid, tcon, fid);
@@ -995,7 +1004,7 @@ static int set_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, const char *path,
struct cifs_ntsd *pnntsd, u32 acllen)
{
int oplock = 0;
- int xid, rc;
+ int xid, rc, create_options = 0;
__u16 fid;
struct cifs_tcon *tcon;
struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
@@ -1006,6 +1015,10 @@ static int set_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, const char *path,
tcon = tlink_tcon(tlink);
xid = GetXid();
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP)
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+
rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, WRITE_DAC, 0,
&fid, &oplock, NULL, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 95dad9d..cd0d7fa 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -167,6 +167,8 @@ struct smb_vol {
uid_t cred_uid;
uid_t linux_uid;
gid_t linux_gid;
+ uid_t backupuid;
+ gid_t backupgid;
mode_t file_mode;
mode_t dir_mode;
unsigned secFlg;
@@ -179,6 +181,7 @@ struct smb_vol {
bool noperm:1;
bool no_psx_acl:1; /* set if posix acl support should be disabled */
bool cifs_acl:1;
+ bool cifs_backup:1; /* to indicates backup intent during file open */
bool no_xattr:1; /* set if xattr (EA) support should be disabled*/
bool server_ino:1; /* use inode numbers from server ie UniqueId */
bool direct_io:1;
@@ -219,7 +222,8 @@ struct smb_vol {
CIFS_MOUNT_OVERR_GID | CIFS_MOUNT_DYNPERM | \
CIFS_MOUNT_NOPOSIXBRL | CIFS_MOUNT_NOSSYNC | \
CIFS_MOUNT_FSCACHE | CIFS_MOUNT_MF_SYMLINKS | \
- CIFS_MOUNT_MULTIUSER | CIFS_MOUNT_STRICT_IO)
+ CIFS_MOUNT_MULTIUSER | CIFS_MOUNT_STRICT_IO | \
+ CIFS_MOUNT_CIFS_BACKUP)
#define CIFS_MS_MASK (MS_RDONLY | MS_MANDLOCK | MS_NOEXEC | MS_NOSUID | \
MS_NODEV | MS_SYNCHRONOUS)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index f4af4cc..a56624a 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -854,6 +854,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
vol->cred_uid = current_uid();
vol->linux_uid = current_uid();
vol->linux_gid = current_gid();
+ vol->backupuid = NO_CHANGE_32;
+ vol->backupgid = NO_CHANGE_32;
/* default to only allowing write access to owner of the mount */
vol->dir_mode = vol->file_mode = S_IRUGO | S_IXUGO | S_IWUSR;
@@ -883,6 +885,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
cFYI(1, "Null separator not allowed");
}
}
+ vol->cifs_backup = 0; /* no backup intent */
while ((data = strsep(&options, separator)) != NULL) {
if (!*data)
@@ -1405,6 +1408,8 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
vol->rwpidforward = 1;
} else if (strnicmp(data, "cifsacl", 7) == 0) {
vol->cifs_acl = 1;
+ } else if (strnicmp(data, "backup", 7) == 0) {
+ vol->cifs_backup = 1;
} else if (strnicmp(data, "nocifsacl", 9) == 0) {
vol->cifs_acl = 0;
} else if (strnicmp(data, "acl", 3) == 0) {
@@ -1442,6 +1447,10 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
vol->mfsymlinks = true;
} else if (strnicmp(data, "multiuser", 8) == 0) {
vol->multiuser = true;
+ } else if (!strnicmp(data, "backupuid", 9) && value && *value) {
+ kstrtouint(value, 0, &vol->backupuid);
+ } else if (!strnicmp(data, "backupgid", 9) && value && *value) {
+ kstrtouint(value, 0, &vol->backupgid);
} else
printk(KERN_WARNING "CIFS: Unknown mount option %s\n",
data);
@@ -2733,6 +2742,8 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
cifs_sb->mnt_uid = pvolume_info->linux_uid;
cifs_sb->mnt_gid = pvolume_info->linux_gid;
+ cifs_sb->mnt_backupuid = pvolume_info->backupuid;
+ cifs_sb->mnt_backupgid = pvolume_info->backupgid;
cifs_sb->mnt_file_mode = pvolume_info->file_mode;
cifs_sb->mnt_dir_mode = pvolume_info->dir_mode;
cFYI(1, "file mode: 0x%x dir mode: 0x%x",
@@ -2763,6 +2774,9 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RWPIDFORWARD;
if (pvolume_info->cifs_acl)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_ACL;
+ if (pvolume_info->backupuid != NO_CHANGE_32 ||
+ pvolume_info->backupgid != NO_CHANGE_32)
+ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_BACKUP;
if (pvolume_info->override_uid)
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_OVERR_UID;
if (pvolume_info->override_gid)
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 72d448b..8a2bff6 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -243,7 +243,14 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
*/
if (!tcon->unix_ext && (mode & S_IWUGO) == 0)
create_options |= CREATE_OPTION_READONLY;
-
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
if (tcon->ses->capabilities & CAP_NT_SMBS)
rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
desiredAccess, create_options,
@@ -357,6 +364,7 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
{
int rc = -EPERM;
int xid;
+ int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
struct cifs_sb_info *cifs_sb;
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
@@ -431,9 +439,17 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode,
return rc;
}
- /* FIXME: would WRITE_OWNER | WRITE_DAC be better? */
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
+
rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE,
- GENERIC_WRITE, CREATE_NOT_DIR | CREATE_OPTION_SPECIAL,
+ GENERIC_WRITE, create_options,
&fileHandle, &oplock, buf, cifs_sb->local_nls,
cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 9f41a10..12eed36 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -174,6 +174,7 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
int rc;
int desiredAccess;
int disposition;
+ int create_options = CREATE_NOT_DIR;
FILE_ALL_INFO *buf;
desiredAccess = cifs_convert_flags(f_flags);
@@ -210,9 +211,18 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,
if (!buf)
return -ENOMEM;
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
+
if (tcon->ses->capabilities & CAP_NT_SMBS)
rc = CIFSSMBOpen(xid, tcon, full_path, disposition,
- desiredAccess, CREATE_NOT_DIR, pnetfid, poplock, buf,
+ desiredAccess, create_options, pnetfid, poplock, buf,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags
& CIFS_MOUNT_MAP_SPECIAL_CHR);
else
@@ -465,6 +475,7 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
char *full_path = NULL;
int desiredAccess;
int disposition = FILE_OPEN;
+ int create_options = CREATE_NOT_DIR;
__u16 netfid;
xid = GetXid();
@@ -524,6 +535,15 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
desiredAccess = cifs_convert_flags(pCifsFile->f_flags);
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
+
/* Can not refresh inode by passing in file_info buf to be returned
by SMBOpen and then calling get_inode_info with returned buf
since file might have write behind data that needs to be flushed
@@ -531,7 +551,7 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
that inode was not dirty locally we could do this */
rc = CIFSSMBOpen(xid, tcon, full_path, disposition, desiredAccess,
- CREATE_NOT_DIR, &netfid, &oplock, NULL,
+ create_options, &netfid, &oplock, NULL,
cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
if (rc) {
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index db3f18c..81b6bf9 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -183,14 +183,20 @@ CIFSFormatMFSymlink(u8 *buf, unsigned int buf_len, const char *link_str)
static int
CIFSCreateMFSymLink(const int xid, struct cifs_tcon *tcon,
const char *fromName, const char *toName,
- const struct nls_table *nls_codepage, int remap)
+ struct cifs_sb_info *cifs_sb)
{
int rc;
int oplock = 0;
+ int remap;
+ int create_options = CREATE_NOT_DIR;
__u16 netfid = 0;
u8 *buf;
unsigned int bytes_written = 0;
struct cifs_io_parms io_parms;
+ struct nls_table *nls_codepage;
+
+ nls_codepage = cifs_sb->local_nls;
+ remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR;
buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
if (!buf)
@@ -202,8 +208,17 @@ CIFSCreateMFSymLink(const int xid, struct cifs_tcon *tcon,
return rc;
}
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL &&
+ cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUP) {
+ if ((cifs_sb->mnt_backupuid != NO_CHANGE_32 &&
+ cifs_sb->mnt_backupuid == current_euid()) ||
+ (cifs_sb->mnt_backupgid != NO_CHANGE_32 &&
+ in_group_p(cifs_sb->mnt_backupgid)))
+ create_options |= CREATE_OPEN_BACKUP_INTENT;
+ }
+
rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE,
- CREATE_NOT_DIR, &netfid, &oplock, NULL,
+ create_options, &netfid, &oplock, NULL,
nls_codepage, remap);
if (rc != 0) {
kfree(buf);
@@ -559,9 +574,7 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
/* BB what if DFS and this volume is on different share? BB */
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
rc = CIFSCreateMFSymLink(xid, pTcon, full_path, symname,
- cifs_sb->local_nls,
- cifs_sb->mnt_cifs_flags &
- CIFS_MOUNT_MAP_SPECIAL_CHR);
+ cifs_sb);
else if (pTcon->unix_ext)
rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
cifs_sb->local_nls);
--
1.6.0.2
--
To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
