[CIFS] Allow setting mode via cifs acl
Requires cifsacl mount flag to be on and CIFS_EXPERIMENTAL enabled
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index c312adc..a7035bd 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -129,6 +129,54 @@
return (1); /* sids compare/match */
}
+
+/* copy ntsd, owner sid, and group sid from a security descriptor to another */
+static void copy_sec_desc(const struct cifs_ntsd *pntsd,
+ struct cifs_ntsd *pnntsd, __u32 sidsoffset)
+{
+ int i;
+
+ struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
+ struct cifs_sid *nowner_sid_ptr, *ngroup_sid_ptr;
+
+ /* copy security descriptor control portion */
+ pnntsd->revision = pntsd->revision;
+ pnntsd->type = pntsd->type;
+ pnntsd->dacloffset = cpu_to_le32(sizeof(struct cifs_ntsd));
+ pnntsd->sacloffset = 0;
+ pnntsd->osidoffset = cpu_to_le32(sidsoffset);
+ pnntsd->gsidoffset = cpu_to_le32(sidsoffset + sizeof(struct cifs_sid));
+
+ /* copy owner sid */
+ owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->osidoffset));
+ nowner_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset);
+
+ nowner_sid_ptr->revision = owner_sid_ptr->revision;
+ nowner_sid_ptr->num_subauth = owner_sid_ptr->num_subauth;
+ for (i = 0; i < 6; i++)
+ nowner_sid_ptr->authority[i] = owner_sid_ptr->authority[i];
+ for (i = 0; i < 5; i++)
+ nowner_sid_ptr->sub_auth[i] = owner_sid_ptr->sub_auth[i];
+
+ /* copy group sid */
+ group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->gsidoffset));
+ ngroup_sid_ptr = (struct cifs_sid *)((char *)pnntsd + sidsoffset +
+ sizeof(struct cifs_sid));
+
+ ngroup_sid_ptr->revision = group_sid_ptr->revision;
+ ngroup_sid_ptr->num_subauth = group_sid_ptr->num_subauth;
+ for (i = 0; i < 6; i++)
+ ngroup_sid_ptr->authority[i] = group_sid_ptr->authority[i];
+ for (i = 0; i < 5; i++)
+ ngroup_sid_ptr->sub_auth[i] =
+ cpu_to_le32(group_sid_ptr->sub_auth[i]);
+
+ return;
+}
+
+
/*
change posix mode to reflect permissions
pmode is the existing mode (we only want to overwrite part of this
@@ -220,6 +268,33 @@
return;
}
+static __le16 fill_ace_for_sid(struct cifs_ace *pntace,
+ const struct cifs_sid *psid, __u64 nmode, umode_t bits)
+{
+ int i;
+ __u16 size = 0;
+ __u32 access_req = 0;
+
+ pntace->type = ACCESS_ALLOWED;
+ pntace->flags = 0x0;
+ mode_to_access_flags(nmode, bits, &access_req);
+ if (!access_req)
+ access_req = SET_MINIMUM_RIGHTS;
+ pntace->access_req = cpu_to_le32(access_req);
+
+ pntace->sid.revision = psid->revision;
+ pntace->sid.num_subauth = psid->num_subauth;
+ for (i = 0; i < 6; i++)
+ pntace->sid.authority[i] = psid->authority[i];
+ for (i = 0; i < psid->num_subauth; i++)
+ pntace->sid.sub_auth[i] = psid->sub_auth[i];
+
+ size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4);
+ pntace->size = cpu_to_le16(size);
+
+ return (size);
+}
+
#ifdef CONFIG_CIFS_DEBUG2
static void dump_ace(struct cifs_ace *pace, char *end_of_acl)
@@ -243,7 +318,7 @@
int i;
cFYI(1, ("ACE revision %d num_auth %d type %d flags %d size %d",
pace->sid.revision, pace->sid.num_subauth, pace->type,
- pace->flags, pace->size));
+ pace->flags, le16_to_cpu(pace->size)));
for (i = 0; i < num_subauth; ++i) {
cFYI(1, ("ACE sub_auth[%d]: 0x%x", i,
le32_to_cpu(pace->sid.sub_auth[i])));
@@ -346,6 +421,28 @@
}
+static int set_chmod_dacl(struct cifs_acl *pndacl, struct cifs_sid *pownersid,
+ struct cifs_sid *pgrpsid, __u64 nmode)
+{
+ __le16 size = 0;
+ struct cifs_acl *pnndacl;
+
+ pnndacl = (struct cifs_acl *)((char *)pndacl + sizeof(struct cifs_acl));
+
+ size += fill_ace_for_sid((struct cifs_ace *) ((char *)pnndacl + size),
+ pownersid, nmode, S_IRWXU);
+ size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size),
+ pgrpsid, nmode, S_IRWXG);
+ size += fill_ace_for_sid((struct cifs_ace *)((char *)pnndacl + size),
+ &sid_everyone, nmode, S_IRWXO);
+
+ pndacl->size = cpu_to_le16(size + sizeof(struct cifs_acl));
+ pndacl->num_aces = 3;
+
+ return (0);
+}
+
+
static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
{
/* BB need to add parm so we can store the SID BB */
@@ -432,6 +529,46 @@
}
+/* Convert permission bits from mode to equivalent CIFS ACL */
+static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
+ int acl_len, struct inode *inode, __u64 nmode)
+{
+ int rc = 0;
+ __u32 dacloffset;
+ __u32 ndacloffset;
+ __u32 sidsoffset;
+ struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
+ struct cifs_acl *dacl_ptr = NULL; /* no need for SACL ptr */
+ struct cifs_acl *ndacl_ptr = NULL; /* no need for SACL ptr */
+
+ if ((inode == NULL) || (pntsd == NULL) || (pnntsd == NULL))
+ return (-EIO);
+
+ owner_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->osidoffset));
+ group_sid_ptr = (struct cifs_sid *)((char *)pntsd +
+ le32_to_cpu(pntsd->gsidoffset));
+
+ dacloffset = le32_to_cpu(pntsd->dacloffset);
+ dacl_ptr = (struct cifs_acl *)((char *)pntsd + dacloffset);
+
+ ndacloffset = sizeof(struct cifs_ntsd);
+ ndacl_ptr = (struct cifs_acl *)((char *)pnntsd + ndacloffset);
+ ndacl_ptr->revision = dacl_ptr->revision;
+ ndacl_ptr->size = 0;
+ ndacl_ptr->num_aces = 0;
+
+ rc = set_chmod_dacl(ndacl_ptr, owner_sid_ptr, group_sid_ptr, nmode);
+
+ sidsoffset = ndacloffset + le16_to_cpu(ndacl_ptr->size);
+
+ /* copy security descriptor control portion and owner and group sid */
+ copy_sec_desc(pntsd, pnntsd, sidsoffset);
+
+ return (rc);
+}
+
+
/* Retrieve an ACL from the server */
static struct cifs_ntsd *get_cifs_acl(u32 *pacllen, struct inode *inode,
const char *path)
@@ -487,6 +624,64 @@
return pntsd;
}
+/* Set an ACL on the server */
+static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
+ struct inode *inode, const char *path)
+{
+ struct cifsFileInfo *open_file;
+ int unlock_file = FALSE;
+ int xid;
+ int rc = -EIO;
+ __u16 fid;
+ struct super_block *sb;
+ struct cifs_sb_info *cifs_sb;
+
+#ifdef CONFIG_CIFS_DEBUG2
+ cFYI(1, ("set ACL for %s from mode 0x%x", path, inode->i_mode));
+#endif
+
+ if (!inode)
+ return (rc);
+
+ sb = inode->i_sb;
+ if (sb == NULL)
+ return (rc);
+
+ cifs_sb = CIFS_SB(sb);
+ xid = GetXid();
+
+ open_file = find_readable_file(CIFS_I(inode));
+ if (open_file) {
+ unlock_file = TRUE;
+ fid = open_file->netfid;
+ } else {
+ int oplock = FALSE;
+ /* open file */
+ rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
+ WRITE_DAC, 0, &fid, &oplock, NULL,
+ cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
+ CIFS_MOUNT_MAP_SPECIAL_CHR);
+ if (rc != 0) {
+ cERROR(1, ("Unable to open file to set ACL"));
+ FreeXid(xid);
+ return (rc);
+ }
+ }
+
+ rc = CIFSSMBSetCIFSACL(xid, cifs_sb->tcon, fid, pnntsd, acllen);
+#ifdef CONFIG_CIFS_DEBUG2
+ cFYI(1, ("SetCIFSACL rc = %d", rc));
+#endif
+ if (unlock_file == TRUE)
+ atomic_dec(&open_file->wrtPending);
+ else
+ CIFSSMBClose(xid, cifs_sb->tcon, fid);
+
+ FreeXid(xid);
+
+ return (rc);
+}
+
/* Translate the CIFS ACL (simlar to NTFS ACL) for a file into mode bits */
void acl_to_uid_mode(struct inode *inode, const char *path)
{
@@ -510,24 +705,53 @@
}
/* Convert mode bits to an ACL so we can update the ACL on the server */
-int mode_to_acl(struct inode *inode, const char *path)
+int mode_to_acl(struct inode *inode, const char *path, __u64 nmode)
{
int rc = 0;
__u32 acllen = 0;
- struct cifs_ntsd *pntsd = NULL;
+ struct cifs_ntsd *pntsd = NULL; /* acl obtained from server */
+ struct cifs_ntsd *pnntsd = NULL; /* modified acl to be sent to server */
+#ifdef CONFIG_CIFS_DEBUG2
cFYI(1, ("set ACL from mode for %s", path));
+#endif
/* Get the security descriptor */
pntsd = get_cifs_acl(&acllen, inode, path);
- /* Add/Modify the three ACEs for owner, group, everyone
- while retaining the other ACEs */
+ /* Add three ACEs for owner, group, everyone getting rid of
+ other ACEs as chmod disables ACEs and set the security descriptor */
- /* Set the security descriptor */
+ if (pntsd) {
+ /* allocate memory for the smb header,
+ set security descriptor request security descriptor
+ parameters, and secuirty descriptor itself */
+ pnntsd = kmalloc(acllen, GFP_KERNEL);
+ if (!pnntsd) {
+ cERROR(1, ("Unable to allocate security descriptor"));
+ kfree(pntsd);
+ return (-ENOMEM);
+ }
- kfree(pntsd);
- return rc;
+ rc = build_sec_desc(pntsd, pnntsd, acllen, inode, nmode);
+
+#ifdef CONFIG_CIFS_DEBUG2
+ cFYI(1, ("build_sec_desc rc: %d", rc));
+#endif
+
+ if (!rc) {
+ /* Set the security descriptor */
+ rc = set_cifs_acl(pnntsd, acllen, inode, path);
+#ifdef CONFIG_CIFS_DEBUG2
+ cFYI(1, ("set_cifs_acl rc: %d", rc));
+#endif
+ }
+
+ kfree(pnntsd);
+ kfree(pntsd);
+ }
+
+ return (rc);
}
#endif /* CONFIG_CIFS_EXPERIMENTAL */