From aea35ee7d293eddcf4dd27d3840cab274dc60516 Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Mon, 22 Sep 2014 00:05:09 +0200
Subject: [PATCH] lx_fs: improve root directory handling

- correctly catch and report non-existing root directories
- remove *all* leading slashes from root-directory attributes and
  sanitize empty declarations to current working directory
---
 repos/os/src/server/lx_fs/main.cc | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/repos/os/src/server/lx_fs/main.cc b/repos/os/src/server/lx_fs/main.cc
index 0ad7fd8d59..b3884e030f 100644
--- a/repos/os/src/server/lx_fs/main.cc
+++ b/repos/os/src/server/lx_fs/main.cc
@@ -351,18 +351,21 @@ class File_system::Root : public Root_component<Session_component>
 					/*
 					 * Make sure the root path is specified with a
 					 * leading path delimiter. For performing the
-					 * lookup, we skip the first character.
+					 * lookup, we remove all leading slashes.
 					 */
-					if (root[0] != '/')
-						throw Lookup_failed();
+					if (root[0] != '/') {
+						PERR("Root directory must start with / but is \"%s\"", root);
+						throw Root::Unavailable();
+					}
 
-					root_dir = root + 1;
+					for (root_dir = root; *root_dir == '/'; ++root_dir) ;
+
+					/* sanitize possibly empty root_dir to current directory */
+					if (*root_dir == 0)
+						root_dir = ".";
 				} catch (Xml_node::Nonexistent_attribute) {
 					PERR("Missing \"root\" attribute in policy definition");
 					throw Root::Unavailable();
-				} catch (Lookup_failed) {
-					PERR("Session root directory \"%s\" does not exist", root);
-					throw Root::Unavailable();
 				}
 
 				/*
@@ -392,8 +395,14 @@ class File_system::Root : public Root_component<Session_component>
 				     ram_quota, session_size);
 				throw Root::Quota_exceeded();
 			}
-			return new (md_alloc())
-				Session_component(tx_buf_size, _ep, root_dir, writeable, *md_alloc());
+
+			try {
+				return new (md_alloc())
+				       Session_component(tx_buf_size, _ep, root_dir, writeable, *md_alloc());
+			} catch (Lookup_failed) {
+				PERR("Session root directory \"%s\" does not exist", root);
+				throw Root::Unavailable();
+			}
 		}
 
 	public: