[CIFS] acl support part 6

Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
CC: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsacl.c

@@ -97,7 +97,7 @@ int match_sid(struct cifs_sid *ctsid)
 
 /* if the two SIDs (roughly equivalent to a UUID for a user or group) are
    the same returns 1, if they do not match returns 0 */
-int compare_sids(struct cifs_sid *ctsid, struct cifs_sid *cwsid)
+int compare_sids(const struct cifs_sid *ctsid, const struct cifs_sid *cwsid)
 {
 	int i;
 	int num_subauth, num_sat, num_saw;
@@ -129,28 +129,77 @@ int compare_sids(struct cifs_sid *ctsid, struct cifs_sid *cwsid)
 	return (1); /* sids compare/match */
 }
 
-void get_mode_from_acl(struct inode * inode, const char * path)
+/*
+   change posix mode to reflect permissions
+   pmode is the existing mode (we only want to overwrite part of this
+   bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
+*/
+static void access_flags_to_mode(__u32 access_flags, umode_t * pmode,
+				 umode_t bits_to_set)
 {
 
+#ifdef CONFIG_CIFS_DEBUG2
+	cFYI(1, ("access flags 0x%x mode now 0x%x", access_flags, *pmode);
+#endif
+
+	return;
+}
+
+/* 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)
+{
+	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;
+
 	cFYI(1, ("get mode from ACL for %s", path));
 	
 	if (inode == NULL)
 		return;
 
-	/* find an open readable handle
+	xid = GetXid();
-	   if handle found
+	open_file = find_readable_file(CIFS_I(inode));
-		 lock handle 
+	if (open_file) {
-	   else open file
+		unlock_file = TRUE;
-	      if no open file can not hurt to check if path is null
+		fid = open_file->netfid;
-	   GetCIFSACL
+	} else {
-	   for all ACEs in ACL {
+		int oplock = FALSE;
-		   if U or G or O
+		/* open file */
-			   inode->i_mode = parse_ace(file_type, UG or O, ace->perms, inode->i_mode)
+		sb = inode->i_sb;
-		   else continue
+		if (sb == NULL) {
+			FreeXid(xid);
+			return;
+		}
+		cifs_sb = CIFS_SB(sb);
+		rc = CIFSSMBOpen(xid, cifs_sb->tcon, path, FILE_OPEN,
+				GENERIC_READ, 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 get ACL"));
+			FreeXid(xid);
+			return;
+		}
 	}
-	   if handle open close it
-	   else unlock handle */
 
+	/*   rc = CIFSSMBGetCIFSACL(xid, cifs_sb->tcon, fid, pntsd, acllen,
+				    ACL_TYPE_ACCESS); */
+
+	if (unlock_file == TRUE)
+		atomic_dec(&open_file->wrtPending);
+	else
+		CIFSSMBClose(xid, cifs_sb->tcon, fid);
+
+/* parse ACEs e.g.
+	rc = parse_sec_desc(pntsd, acllen, inode);
+*/
+
+	FreeXid(xid);
 	return;
 }
 
@@ -193,7 +242,8 @@ static void parse_ace(struct cifs_ace *pace, char *end_of_acl)
 
 
 static void parse_dacl(struct cifs_acl *pdacl, char *end_of_acl,
-		       struct cifs_sid *pownersid, struct cifs_sid *pgrpsid)
+		       struct cifs_sid *pownersid, struct cifs_sid *pgrpsid
+		       struct inode *inode)
 {
 	int i;
 	int num_aces = 0;
@@ -281,7 +331,8 @@ static int parse_sid(struct cifs_sid *psid, char *end_of_acl)
 
 
 /* Convert CIFS ACL to POSIX form */
-int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len)
+static int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len,
+			  struct inode *inode)
 {
 	int rc;
 	struct cifs_sid *owner_sid_ptr, *group_sid_ptr;
@@ -310,7 +361,7 @@ int parse_sec_desc(struct cifs_ntsd *pntsd, int acl_len)
 	if (rc)
 		return rc;
 
-	parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr);
+	parse_dacl(dacl_ptr, end_of_acl, owner_sid_ptr, group_sid_ptr, inode);
 
 /*	cifscred->uid = owner_sid_ptr->rid;
 	cifscred->gid = group_sid_ptr->rid;

fs/cifs/cifsproto.h

@@ -61,6 +61,9 @@ extern int checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length);
 extern int is_valid_oplock_break(struct smb_hdr *smb, struct TCP_Server_Info *);
 extern int is_size_safe_to_change(struct cifsInodeInfo *, __u64 eof);
 extern struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *);
+#ifdef CONFIG_CIFS_EXPERIMENTAL
+extern struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *);
+#endif
 extern unsigned int smbCalcSize(struct smb_hdr *ptr);
 extern unsigned int smbCalcSize_LE(struct smb_hdr *ptr);
 extern int decode_negTokenInit(unsigned char *security_blob, int length,
@@ -92,7 +95,7 @@ extern int cifs_get_inode_info(struct inode **pinode,
 extern int cifs_get_inode_info_unix(struct inode **pinode,
 			const unsigned char *search_path,
 			struct super_block *sb, int xid);
-extern void get_mode_from_acl(struct inode * inode, const char * search_path);
+extern void acl_to_uid_mode(struct inode *inode, const char *search_path);
 extern int cifs_mount(struct super_block *, struct cifs_sb_info *, char *,
 			const char *);
 extern int cifs_umount(struct super_block *, struct cifs_sb_info *);
@@ -311,7 +314,6 @@ extern void setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern void calc_lanman_hash(struct cifsSesInfo *ses, char *lnm_session_key);
 #endif /* CIFS_WEAK_PW_HASH */
-extern int parse_sec_desc(struct cifs_ntsd *, int);
 extern int CIFSSMBCopy(int xid,
 			struct cifsTconInfo *source_tcon,
 			const char *fromName,
@@ -336,8 +338,7 @@ extern int CIFSSMBSetEA(const int xid, struct cifsTconInfo *tcon,
 		const void *ea_value, const __u16 ea_value_len,
 		const struct nls_table *nls_codepage, int remap_special_chars);
 extern int CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon,
-			__u16 fid, char *acl_inf, const int buflen,
+			__u16 fid, struct cifs_ntsd **acl_inf, __u32 *buflen);
-			const int acl_type /* ACCESS vs. DEFAULT */);
 extern int CIFSSMBGetPosixACL(const int xid, struct cifsTconInfo *tcon,
 		const unsigned char *searchName,
 		char *acl_inf, const int buflen, const int acl_type,

fs/cifs/cifssmb.c

@@ -2526,12 +2526,15 @@ smb_init_ntransact(const __u16 sub_command, const int setup_count,
 
 static int
 validate_ntransact(char *buf, char **ppparm, char **ppdata,
-		   int *pdatalen, int *pparmlen)
+		   __u32 *pdatalen, __u32 *pparmlen)
 {
 	char *end_of_smb;
 	__u32 data_count, data_offset, parm_count, parm_offset;
 	struct smb_com_ntransact_rsp *pSMBr;
 
+	*pdatalen = 0;
+	*pparmlen = 0;
+
 	if (buf == NULL)
 		return -EINVAL;
 
@@ -2568,6 +2571,8 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
 		cFYI(1, ("parm count and data count larger than SMB"));
 		return -EINVAL;
 	}
+	*pdatalen = data_count;
+	*pparmlen = parm_count;
 	return 0;
 }
 #endif /* CIFS_EXPERIMENTAL */
@@ -3069,8 +3074,7 @@ CIFSGetExtAttr(const int xid, struct cifsTconInfo *tcon,
 /* Get Security Descriptor (by handle) from remote server for a file or dir */
 int
 CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
-		/* BB fix up return info */ char *acl_inf, const int buflen,
+		  struct cifs_ntsd **acl_inf, __u32 *pbuflen)
-		  const int acl_type)
 {
 	int rc = 0;
 	int buf_type = 0;
@@ -3079,6 +3083,9 @@ CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
 
 	cFYI(1, ("GetCifsACL"));
 
+	*pbuflen = 0;
+	*acl_inf = NULL;
+
 	rc = smb_init_ntransact(NT_TRANSACT_QUERY_SECURITY_DESC, 0,
 			8 /* parm len */, tcon, (void **) &pSMB);
 	if (rc)
@@ -3101,34 +3108,52 @@ CIFSSMBGetCIFSACL(const int xid, struct cifsTconInfo *tcon, __u16 fid,
 	if (rc) {
 		cFYI(1, ("Send error in QuerySecDesc = %d", rc));
 	} else {                /* decode response */
-		struct cifs_ntsd *psec_desc;
 		__le32 * parm;
-		int parm_len;
+		__u32 parm_len;
-		int data_len;
+		__u32 acl_len;
-		int acl_len;
 		struct smb_com_ntransact_rsp *pSMBr;
+		char *pdata;
 
 /* validate_nttransact */
 		rc = validate_ntransact(iov[0].iov_base, (char **)&parm,
-					(char **)&psec_desc,
+					&pdata, &parm_len, pbuflen);
-					&parm_len, &data_len);
 		if (rc)
 			goto qsec_out;
 		pSMBr = (struct smb_com_ntransact_rsp *)iov[0].iov_base;
 
-		cFYI(1, ("smb %p parm %p data %p", pSMBr, parm, psec_desc));
+		cFYI(1, ("smb %p parm %p data %p", pSMBr, parm, *acl_inf));
 
 		if (le32_to_cpu(pSMBr->ParameterCount) != 4) {
 			rc = -EIO;      /* bad smb */
+			*pbuflen = 0;
 			goto qsec_out;
 		}
 
 /* BB check that data area is minimum length and as big as acl_len */
 
 		acl_len = le32_to_cpu(*parm);
-		/* BB check if (acl_len > bufsize) */
+		if (acl_len != *pbuflen) {
+			cERROR(1, ("acl length %d does not match %d",
+				   acl_len, *pbuflen));
+			if (*pbuflen > acl_len)
+				*pbuflen = acl_len;
+		}
 
-		parse_sec_desc(psec_desc, acl_len);
+		/* check if buffer is big enough for the acl
+		   header followed by the smallest SID */
+		if ((*pbuflen < sizeof(struct cifs_ntsd) + 8) ||
+		    (*pbuflen >= 64 * 1024)) {
+			cERROR(1, ("bad acl length %d", *pbuflen));
+			rc = -EINVAL;
+			*pbuflen = 0;
+		} else {
+			*acl_inf = kmalloc(*pbuflen, GFP_KERNEL);
+			if (*acl_inf == NULL) {
+				*pbuflen = 0;
+				rc = -ENOMEM;
+			}
+			memcpy(*acl_inf, pdata, *pbuflen);
+		}
 	}
 qsec_out:
 	if (buf_type == CIFS_SMALL_BUFFER)

fs/cifs/file.c

@@ -1026,6 +1026,37 @@ static ssize_t cifs_write(struct file *file, const char *write_data,
 	return total_written;
 }
 
+#ifdef CONFIG_CIFS_EXPERIMENTAL
+struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode)
+{
+	struct cifsFileInfo *open_file = NULL;
+
+	read_lock(&GlobalSMBSeslock);
+	/* we could simply get the first_list_entry since write-only entries
+	   are always at the end of the list but since the first entry might
+	   have a close pending, we go through the whole list */
+	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
+		if (open_file->closePend)
+			continue;
+		if (open_file->pfile && ((open_file->pfile->f_flags & O_RDWR) ||
+		    (open_file->pfile->f_flags & O_RDONLY))) {
+			if (!open_file->invalidHandle) {
+				/* found a good file */
+				/* lock it so it will not be closed on us */
+				atomic_inc(&open_file->wrtPending);
+				read_unlock(&GlobalSMBSeslock);
+				return open_file;
+			} /* else might as well continue, and look for
+			     another, or simply have the caller reopen it
+			     again rather than trying to fix this handle */
+		} else /* write only file */
+			break; /* write only files are last so must be done */
+	}
+	read_unlock(&GlobalSMBSeslock);
+	return NULL;
+}
+#endif
+
 struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *cifs_inode)
 {
 	struct cifsFileInfo *open_file;

fs/cifs/inode.c

@@ -530,7 +530,7 @@ int cifs_get_inode_info(struct inode **pinode,
 #ifdef CONFIG_CIFS_EXPERIMENTAL
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
 			cFYI(1, ("Getting mode bits from ACL"));
-			get_mode_from_acl(inode, search_path);
+			acl_to_uid_mode(inode, search_path);
 		}
 #endif
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {

fs/cifs/xattr.c

@@ -265,6 +265,8 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 		else if(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
 			__u16 fid;
 			int oplock = FALSE;
+			struct cifs_ntsd *pacl = NULL;
+			__u32 buflen = 0;
 			if (experimEnabled) 
 				rc = CIFSSMBOpen(xid, pTcon, full_path,
 					FILE_OPEN, GENERIC_READ, 0, &fid,
@@ -274,9 +276,8 @@ ssize_t cifs_getxattr(struct dentry *direntry, const char *ea_name,
 			/* else rc is EOPNOTSUPP from above */
 
 			if(rc == 0) {
-				rc = CIFSSMBGetCIFSACL(xid, pTcon, fid,
+				rc = CIFSSMBGetCIFSACL(xid, pTcon, fid, &pacl,
-					ea_value, buf_size,
+						      &buflen);
-					ACL_TYPE_ACCESS);
 				CIFSSMBClose(xid, pTcon, fid);
 			}
 		}