From: Ralph Boehme <slow@samba.org>
Date: Thu, 21 Jan 2021 16:05:17 +0000 (+0100)
Subject: smbd: add parent_pathref()
X-Git-Tag: tevent-0.11.0~1912
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6085f6c856e5da0bb703580d878e2302e360a902;p=thirdparty%2Fsamba.git

smbd: add parent_pathref()

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---

diff --git a/source3/smbd/files.c b/source3/smbd/files.c
index eceeaf2c6af..448a284780b 100644
--- a/source3/smbd/files.c
+++ b/source3/smbd/files.c
@@ -674,6 +674,70 @@ NTSTATUS synthetic_pathref(TALLOC_CTX *mem_ctx,
 	return NT_STATUS_OK;
 }
 
+static int atname_destructor(struct smb_filename *smb_fname)
+{
+	destroy_fsp_smb_fname_link(&smb_fname->fsp_link);
+	return 0;
+}
+
+/**
+ * Turn a path into a parent pathref and atname
+ *
+ * This returns the parent pathref in _parent and the name relative to it. If
+ * smb_fname was a pathref (ie smb_fname->fsp != NULL), then _atname will be a
+ * pathref as well, ie _atname->fsp will point at the same fsp as
+ * smb_fname->fsp.
+ **/
+NTSTATUS parent_pathref(TALLOC_CTX *mem_ctx,
+			struct files_struct *dirfsp,
+			const struct smb_filename *smb_fname,
+			struct smb_filename **_parent,
+			struct smb_filename **_atname)
+{
+	struct smb_filename *parent = NULL;
+	struct smb_filename *atname = NULL;
+	NTSTATUS status;
+	int ret;
+	bool ok;
+
+	ok = parent_smb_fname(mem_ctx,
+			      smb_fname,
+			      &parent,
+			      &atname);
+	if (!ok) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ret = vfs_stat(dirfsp->conn, parent);
+	if (ret != 0) {
+		TALLOC_FREE(parent);
+		return map_nt_error_from_unix(errno);
+	}
+
+	status = openat_pathref_fsp(dirfsp, parent);
+	if (NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK)) {
+		status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
+	}
+	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(parent);
+		return status;
+	}
+
+	if (smb_fname->fsp != NULL) {
+		status = fsp_smb_fname_link(smb_fname->fsp,
+					    &atname->fsp_link,
+					    &atname->fsp);
+		if (!NT_STATUS_IS_OK(status)) {
+			TALLOC_FREE(parent);
+			return status;
+		}
+		talloc_set_destructor(atname, atname_destructor);
+	}
+	*_parent = parent;
+	*_atname = atname;
+	return NT_STATUS_OK;
+}
+
 /****************************************************************************
  Close all open files for a connection.
 ****************************************************************************/
diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h
index a65c786c24d..f67daf2d2be 100644
--- a/source3/smbd/proto.h
+++ b/source3/smbd/proto.h
@@ -477,6 +477,12 @@ NTSTATUS synthetic_pathref(TALLOC_CTX *mem_ctx,
 			   uint32_t flags,
 			   struct smb_filename **_smb_fname);
 
+NTSTATUS parent_pathref(TALLOC_CTX *mem_ctx,
+			struct files_struct *dirfsp,
+			const struct smb_filename *smb_fname,
+			struct smb_filename **_parent,
+			struct smb_filename **_atname);
+
 /* The following definitions come from smbd/ipc.c  */
 
 NTSTATUS nt_status_np_pipe(NTSTATUS status);