vfs: Add inheritance emulation to vfs_nfs4acl_xattr.

Recursively inherit ACL from parent directory if no acl xattr is
found on the current file.
Use a default ACL if a non-inheriting ACL is encountered.
With this the nfs4acl_xattr.dynamic test passes.
But the nfs4acl_xattr.inheritance test results in an error because
of warnings that cause the test to pass a failed result.

Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

1 files changed, 263 insertions, 29 deletions

diff --git a/source3/modules/vfs_nfs4acl_xattr.c b/source3/modules/vfs_nfs4acl_xattr.c
index fedb768d0e..bdaca82b8c 100644
--- a/source3/modules/vfs_nfs4acl_xattr.c
+++ b/source3/modules/vfs_nfs4acl_xattr.c
@@ -176,30 +176,29 @@ static NTSTATUS nfs4_get_nfs4_acl(vfs_handle_struct *handle, TALLOC_CTX *mem_ctx
 	return status;
 }
 
-/* call-back function processing the NT acl -> NFS4 acl using NFSv4 conv. */
-static bool nfs4_process_smbacl(vfs_handle_struct *handle, files_struct *fsp, SMB4ACL_T *smbacl)
+static bool nfs4acl_smb4acl2nfs4acl(TALLOC_CTX *mem_ctx,
+				    SMB4ACL_T *smbacl,
+				    struct nfs4acl **pnfs4acl,
+				    bool denymissingspecial)
 {
-	TALLOC_CTX *frame = talloc_stackframe();
-	int i;
 	struct nfs4acl *nfs4acl;
 	SMB4ACE_T *smbace;
 	bool have_special_id = false;
-	int ret;
-	DATA_BLOB blob;
+	int i;
 
 	/* allocate the field of NFS4 aces */
-	nfs4acl = talloc_zero(frame, struct nfs4acl);
+	nfs4acl = talloc_zero(mem_ctx, struct nfs4acl);
 	if(nfs4acl == NULL) {
-		TALLOC_FREE(frame);
 		errno = ENOMEM;
 		return false;
 	}
 
 	nfs4acl->a_count = smb_get_naces(smbacl);
 
-	nfs4acl->ace = talloc_zero_array(nfs4acl, struct nfs4ace, nfs4acl->a_count);
+	nfs4acl->ace = talloc_zero_array(nfs4acl, struct nfs4ace,
+					 nfs4acl->a_count);
 	if(nfs4acl->ace == NULL) {
-		TALLOC_FREE(frame);
+		TALLOC_FREE(nfs4acl);
 		errno = ENOMEM;
 		return false;
 	}
@@ -239,26 +238,93 @@ static bool nfs4_process_smbacl(vfs_handle_struct *handle, files_struct *fsp, SM
 		}
 	}
 
-	if (!have_special_id
-	    && lp_parm_bool(fsp->conn->params->service, "nfs4acl_xattr",
-			    "denymissingspecial", false)) {
-		TALLOC_FREE(frame);
+	if (!have_special_id && denymissingspecial) {
+		TALLOC_FREE(nfs4acl);
 		errno = EACCES;
 		return false;
 	}
 
 	SMB_ASSERT(i == nfs4acl->a_count);
 
+	*pnfs4acl = nfs4acl;
+	return true;
+}
+
+static bool nfs4acl_xattr_set_smb4acl(vfs_handle_struct *handle,
+				      const char *path,
+				      SMB4ACL_T *smbacl)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct nfs4acl *nfs4acl;
+	int ret;
+	bool denymissingspecial;
+	DATA_BLOB blob;
+
+	denymissingspecial = lp_parm_bool(handle->conn->params->service,
+					  "nfs4acl_xattr",
+					  "denymissingspecial", false);
+
+	if (!nfs4acl_smb4acl2nfs4acl(frame, smbacl, &nfs4acl,
+				     denymissingspecial)) {
+		DEBUG(0, ("Failed to convert smb ACL to nfs4 ACL.\n"));
+		TALLOC_FREE(frame);
+		return false;
+	}
+
 	blob = nfs4acl_acl2blob(frame, nfs4acl);
 	if (!blob.data) {
-		DEBUG(0, ("Failed to convert ACL to linear blob for xattr storage\n"));
+		DEBUG(0, ("Failed to convert ACL to linear blob for xattr\n"));
 		TALLOC_FREE(frame);
 		errno = EINVAL;
 		return false;
 	}
-	ret = SMB_VFS_NEXT_FSETXATTR(handle, fsp, NFS4ACL_XATTR_NAME, blob.data, blob.length, 0);
+	ret = SMB_VFS_NEXT_SETXATTR(handle, path, NFS4ACL_XATTR_NAME,
+				    blob.data, blob.length, 0);
+	if (ret != 0) {
+		DEBUG(0, ("can't store acl in xattr: %s\n", strerror(errno)));
+	}
 	TALLOC_FREE(frame);
+	return ret == 0;
+}
 
+/* call-back function processing the NT acl -> NFS4 acl using NFSv4 conv. */
+static bool nfs4acl_xattr_fset_smb4acl(vfs_handle_struct *handle,
+				       files_struct *fsp,
+				       SMB4ACL_T *smbacl)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct nfs4acl *nfs4acl;
+	int ret;
+	bool denymissingspecial;
+	DATA_BLOB blob;
+
+	denymissingspecial = lp_parm_bool(fsp->conn->params->service,
+					  "nfs4acl_xattr",
+					  "denymissingspecial", false);
+
+	if (!nfs4acl_smb4acl2nfs4acl(frame, smbacl, &nfs4acl,
+				     denymissingspecial)) {
+		DEBUG(0, ("Failed to convert smb ACL to nfs4 ACL.\n"));
+		TALLOC_FREE(frame);
+		return false;
+	}
+
+	blob = nfs4acl_acl2blob(frame, nfs4acl);
+	if (!blob.data) {
+		DEBUG(0, ("Failed to convert ACL to linear blob for xattr\n"));
+		TALLOC_FREE(frame);
+		errno = EINVAL;
+		return false;
+	}
+	if (fsp->fh->fd == -1) {
+		DEBUG(0, ("Error: fsp->fh->fd == -1\n"));
+	}
+	ret = SMB_VFS_NEXT_FSETXATTR(handle, fsp, NFS4ACL_XATTR_NAME,
+				     blob.data, blob.length, 0);
+	if (ret != 0) {
+		DEBUG(0, ("can't store acl in xattr: %s\n", strerror(errno)));
+	}
+	TALLOC_FREE(frame);
 	return ret == 0;
 }
 
@@ -271,7 +337,180 @@ static NTSTATUS nfs4_set_nt_acl(vfs_handle_struct *handle, files_struct *fsp,
 			   const struct security_descriptor *psd)
 {
 	return smb_set_nt_acl_nfs4(handle, fsp, security_info_sent, psd,
-			nfs4_process_smbacl);
+			nfs4acl_xattr_fset_smb4acl);
+}
+
+static SMB4ACL_T *nfs4acls_defaultacl(TALLOC_CTX *mem_ctx)
+{
+	SMB4ACL_T *pacl = NULL;
+	SMB4ACE_T *pace;
+	SMB_ACE4PROP_T ace = { SMB_ACE4_ID_SPECIAL,
+		SMB_ACE4_WHO_EVERYONE,
+		SMB_ACE4_ACCESS_ALLOWED_ACE_TYPE,
+		0,
+		SMB_ACE4_ALL_MASKS };
+
+	DEBUG(10, ("Building default full access acl\n"));
+
+	pacl = smb_create_smb4acl(mem_ctx);
+	if (pacl == NULL) {
+		DEBUG(0, ("talloc failed\n"));
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	pace = smb_add_ace4(pacl, &ace);
+	if (pace == NULL) {
+		DEBUG(0, ("talloc failed\n"));
+		TALLOC_FREE(pacl);
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	return pacl;
+}
+
+/*
+ * Because there is no good way to guarantee that a new xattr will be
+ * created on file creation there might be no acl xattr on a file when
+ * trying to read the acl. In this case the acl xattr will get
+ * constructed at that time from the parent acl.
+ * If the parent ACL doesn't have an xattr either the call will
+ * recurse to the next parent directory until the share root is
+ * reached. If the share root doesn't contain an ACL xattr either a
+ * default ACL will be used.
+ * Also a default ACL will be set if a non inheriting ACL is encountered.
+ *
+ * Basic algorithm:
+ *   read acl xattr blob
+ *   if acl xattr blob doesn't exist
+ *     stat current directory to know if it's a file or directory
+ *     read acl xattr blob from parent dir
+ *     acl xattr blob to smb nfs4 acl
+ *     calculate inherited smb nfs4 acl
+ *     without inheritance use default smb nfs4 acl
+ *     smb nfs4 acl to acl xattr blob
+ *     set acl xattr blob
+ *     return smb nfs4 acl
+ *   else
+ *     acl xattr blob to smb nfs4 acl
+ *
+ * Todo: Really use mem_ctx after fixing interface of nfs4_acls
+ */
+static SMB4ACL_T *nfs4acls_inheritacl(vfs_handle_struct *handle,
+	const char *path,
+	TALLOC_CTX *mem_ctx)
+{
+	char *parent_dir = NULL;
+	SMB4ACL_T *pparentacl = NULL;
+	SMB4ACL_T *pchildacl = NULL;
+	SMB4ACE_T *pace;
+	SMB_ACE4PROP_T ace;
+	bool isdir;
+	struct smb_filename *smb_fname = NULL;
+	NTSTATUS status;
+	int ret;
+	TALLOC_CTX *frame = talloc_stackframe();
+
+	DEBUG(10, ("nfs4acls_inheritacl invoked for %s\n", path));
+	smb_fname = synthetic_smb_fname(frame, path, NULL, NULL);
+	if (smb_fname == NULL) {
+		TALLOC_FREE(frame);
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	ret = SMB_VFS_STAT(handle->conn, smb_fname);
+	if (ret == -1) {
+		DEBUG(0,("nfs4acls_inheritacl: failed to stat "
+			 "directory %s. Error was %s\n",
+			 smb_fname_str_dbg(smb_fname),
+			 strerror(errno)));
+		TALLOC_FREE(frame);
+		return NULL;
+	}
+	isdir = S_ISDIR(smb_fname->st.st_ex_mode);
+
+	if (!parent_dirname(talloc_tos(),
+			    path,
+			    &parent_dir,
+			    NULL)) {
+		TALLOC_FREE(frame);
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	status = nfs4_get_nfs4_acl(handle, frame, parent_dir, &pparentacl);
+	if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)
+	    && strncmp(parent_dir, ".", 2) != 0) {
+		pparentacl = nfs4acls_inheritacl(handle, parent_dir,
+						 frame);
+	}
+	else if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+		pparentacl = nfs4acls_defaultacl(frame);
+
+	}
+	else if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(frame);
+		return NULL;
+	}
+
+	pchildacl = smb_create_smb4acl(mem_ctx);
+	if (pchildacl == NULL) {
+		DEBUG(0, ("talloc failed\n"));
+		TALLOC_FREE(frame);
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	for (pace = smb_first_ace4(pparentacl); pace != NULL;
+	     pace = smb_next_ace4(pace)) {
+		SMB4ACE_T *pchildace;
+		ace = *smb_get_ace4(pace);
+		if (isdir && !(ace.aceFlags & SMB_ACE4_DIRECTORY_INHERIT_ACE)
+		    || !isdir && !(ace.aceFlags & SMB_ACE4_FILE_INHERIT_ACE)) {
+			DEBUG(10, ("non inheriting ace type: %d, iflags: %x, "
+				   "flags: %x, mask: %x, who: %d\n",
+				   ace.aceType, ace.flags, ace.aceFlags,
+				   ace.aceMask, ace.who.id));
+			continue;
+		}
+		DEBUG(10, ("inheriting ace type: %d, iflags: %x, "
+			   "flags: %x, mask: %x, who: %d\n",
+			   ace.aceType, ace.flags, ace.aceFlags,
+			   ace.aceMask, ace.who.id));
+		ace.aceFlags |= SMB_ACE4_INHERITED_ACE;
+		if ((isdir && (ace.aceFlags & SMB_ACE4_DIRECTORY_INHERIT_ACE)
+		     || !isdir && (ace.aceFlags & SMB_ACE4_FILE_INHERIT_ACE))
+		    && ace.aceFlags & SMB_ACE4_INHERIT_ONLY_ACE) {
+			ace.aceFlags &= ~SMB_ACE4_INHERIT_ONLY_ACE;
+		}
+		if (ace.aceFlags & SMB_ACE4_NO_PROPAGATE_INHERIT_ACE) {
+			ace.aceFlags &= ~SMB_ACE4_FILE_INHERIT_ACE;
+			ace.aceFlags &= ~SMB_ACE4_DIRECTORY_INHERIT_ACE;
+			ace.aceFlags &= ~SMB_ACE4_NO_PROPAGATE_INHERIT_ACE;
+		}
+		pchildace = smb_add_ace4(pchildacl, &ace);
+		if (pchildace == NULL) {
+			DEBUG(0, ("talloc failed\n"));
+			TALLOC_FREE(frame);
+			errno = ENOMEM;
+			return NULL;
+		}
+	}
+
+	/* Set a default ACL if we didn't inherit anything. */
+	if (smb_first_ace4(pchildacl) == NULL) {
+		TALLOC_FREE(pchildacl);
+		pchildacl = nfs4acls_defaultacl(mem_ctx);
+	}
+
+	/* store the returned ACL to get it directly in the
+	   future and avoid dynamic inheritance behavior. */
+	nfs4acl_xattr_set_smb4acl(handle, path, pchildacl);
+
+	TALLOC_FREE(frame);
+	return pchildacl;
 }
 
 static NTSTATUS nfs4acl_xattr_fget_nt_acl(struct vfs_handle_struct *handle,
@@ -285,11 +524,11 @@ static NTSTATUS nfs4acl_xattr_fget_nt_acl(struct vfs_handle_struct *handle,
 	TALLOC_CTX *frame = talloc_stackframe();
 
 	status = nfs4_fget_nfs4_acl(handle, frame, fsp, &pacl);
-	if (!NT_STATUS_IS_OK(status)) {
-		if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-			status = SMB_VFS_NEXT_FGET_NT_ACL(handle, fsp, security_info,
-							  mem_ctx, ppdesc);
-		}
+	if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+		pacl = nfs4acls_inheritacl(handle, fsp->fsp_name->base_name,
+					   frame);
+	}
+	else if (!NT_STATUS_IS_OK(status)) {
 		TALLOC_FREE(frame);
 		return status;
 	}
@@ -310,14 +549,9 @@ static NTSTATUS nfs4acl_xattr_get_nt_acl(struct vfs_handle_struct *handle,
 
 	status = nfs4_get_nfs4_acl(handle, frame, name, &pacl);
 	if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-		if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-			status = SMB_VFS_NEXT_GET_NT_ACL(handle, name, security_info,
-							 mem_ctx, ppdesc);
-		}
-		TALLOC_FREE(frame);
-		return status;
+		pacl = nfs4acls_inheritacl(handle, name, frame);
 	}
-	if (!NT_STATUS_IS_OK(status)) {
+	else if (!NT_STATUS_IS_OK(status)) {
 		TALLOC_FREE(frame);
 		return status;
 	}