openkylin
/
platform_kernel-5.15
mirror of https://gitee.com/openkylin/platform_kernel-5.15.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

cifs: get mode bits from special sid on stat 

When mounting with "modefromsid" retrieve mode bits from
special SID (S-1-5-88-3) on stat.  Subsequent patch will fix
setattr (chmod) to save mode bits in S-1-5-88-3-<mode>

Note that when an ACE matching S-1-5-88-3 is not found, we
default the mode to an approximation based on the owner, group
and everyone permissions (as with the "cifsacl" mount option).

See See e.g.
    https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/hh509017(v=ws.10)

Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Steve French 2019-07-19 06:30:07 +00:00
parent 1afdea4f19
commit e2f8fbfb8d
3 changed files with 38 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
fs/cifs/cifsacl.c
View File

@ -701,10 +701,9 @@ static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
}
#endif
static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
struct cifs_sid *pownersid, struct cifs_sid *pgrpsid,
struct cifs_fattr *fattr)
struct cifs_fattr *fattr, bool mode_from_special_sid)
{
int i;
int num_aces = 0;
@ -757,22 +756,34 @@ static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
#ifdef CONFIG_CIFS_DEBUG2
dump_ace(ppace[i], end_of_acl);
#endif
if (compare_sids(&(ppace[i]->sid), pownersid) == 0)
if (mode_from_special_sid &&
(compare_sids(&(ppace[i]->sid),
&sid_unix_NFS_mode) == 0)) {
/*
* Full permissions are:
* 07777 = S_ISUID | S_ISGID | S_ISVTX |
* S_IRWXU | S_IRWXG | S_IRWXO
*/
fattr->cf_mode &= ~07777;
fattr->cf_mode |=
le32_to_cpu(ppace[i]->sid.sub_auth[2]);
break;
} else if (compare_sids(&(ppace[i]->sid), pownersid) == 0)
access_flags_to_mode(ppace[i]->access_req,
ppace[i]->type,
&fattr->cf_mode,
&user_mask);
if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0)
else if (compare_sids(&(ppace[i]->sid), pgrpsid) == 0)
access_flags_to_mode(ppace[i]->access_req,
ppace[i]->type,
&fattr->cf_mode,
&group_mask);
if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0)
else if (compare_sids(&(ppace[i]->sid), &sid_everyone) == 0)
access_flags_to_mode(ppace[i]->access_req,
ppace[i]->type,
&fattr->cf_mode,
&other_mask);
if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)
else if (compare_sids(&(ppace[i]->sid), &sid_authusers) == 0)
access_flags_to_mode(ppace[i]->access_req,
ppace[i]->type,
&fattr->cf_mode,
@ -851,7 +862,8 @@ static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
/* Convert CIFS ACL to POSIX form */
static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr)
struct cifs_ntsd *pntsd, int acl_len, struct cifs_fattr *fattr,
bool get_mode_from_special_sid)
{
int rc = 0;
struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
@ -900,7 +912,7 @@ static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
if (dacloffset)
parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr,
group_sid_ptr, fattr);
group_sid_ptr, fattr, get_mode_from_special_sid);
else
cifs_dbg(FYI, "no ACL\n"); /* BB grant all or default perms? */
@ -1128,8 +1140,8 @@ int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
/* Translate the CIFS ACL (similar to NTFS ACL) for a file into mode bits */
int
cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
struct inode *inode, const char *path,
const struct cifs_fid *pfid)
struct inode *inode, bool mode_from_special_sid,
const char *path, const struct cifs_fid *pfid)
{
struct cifs_ntsd *pntsd = NULL;
u32 acllen = 0;
@ -1156,8 +1168,11 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
if (IS_ERR(pntsd)) {
rc = PTR_ERR(pntsd);
cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
} else if (mode_from_special_sid) {
rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr, true);
} else {
rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr);
/* get approximated mode from ACL */
rc = parse_sec_desc(cifs_sb, pntsd, acllen, fattr, false);
kfree(pntsd);
if (rc)
cifs_dbg(VFS, "parse sec desc failed rc = %d\n", rc);

1
fs/cifs/cifsproto.h
View File

@ -197,6 +197,7 @@ extern int cifs_rename_pending_delete(const char *full_path,
const unsigned int xid);
extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
struct cifs_fattr *fattr, struct inode *inode,
bool get_mode_from_special_sid,
const char *path, const struct cifs_fid *pfid);
extern int id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64,
kuid_t, kgid_t);

13
fs/cifs/inode.c
View File

@ -893,8 +893,17 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
}
/* fill in 0777 bits from ACL */
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
rc = cifs_acl_to_fattr(cifs_sb, &fattr, *inode, full_path, fid);
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID) {
rc = cifs_acl_to_fattr(cifs_sb, &fattr, *inode, true,
full_path, fid);
if (rc) {
cifs_dbg(FYI, "%s: Get mode from SID failed. rc=%d\n",
__func__, rc);
goto cgii_exit;
}
} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
rc = cifs_acl_to_fattr(cifs_sb, &fattr, *inode, false,
full_path, fid);
if (rc) {
cifs_dbg(FYI, "%s: Getting ACL failed with error: %d\n",
__func__, rc);