Fix for bug #14799 - autodetect whether destination handles highbit perms

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup/branches/r1-0@640 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

6 files changed, 29 insertions, 2 deletions

diff --git a/rdiff-backup/CHANGELOG b/rdiff-backup/CHANGELOG
index 5233609..f38efbb 100644
--- a/rdiff-backup/CHANGELOG
+++ b/rdiff-backup/CHANGELOG
@@ -13,6 +13,9 @@ If you know something about Mac OS X and want to look at the
 carbonfile code so it can be re-enabled by default, please do so :)
 (help available from list)
 
+Fix for bug #14799 reported by Bob McKay:  Crash when backing up files
+with high permissions (like suid) to some FAT systems.
+
 
 New in v1.0.1 (2005/09/10)
 --------------------------
diff --git a/rdiff-backup/rdiff_backup/Globals.py b/rdiff-backup/rdiff_backup/Globals.py
index 710d79d..9a34238 100644
--- a/rdiff-backup/rdiff_backup/Globals.py
+++ b/rdiff-backup/rdiff_backup/Globals.py
@@ -216,6 +216,10 @@ fsync_directories = None
 # If set, exit with error instead of dropping ACLs or ACL entries.
 never_drop_acls = None
 
+# Apply this mask to permissions before chmoding.  (Set to 0777 to
+# prevent highbit permissions on systems which don't support them.)
+permission_mask = 07777
+
 
 def get(name):
 	"""Return the value of something in this module"""
diff --git a/rdiff-backup/rdiff_backup/Main.py b/rdiff-backup/rdiff_backup/Main.py
index 62ce7fc..2bed0c2 100644
--- a/rdiff-backup/rdiff_backup/Main.py
+++ b/rdiff-backup/rdiff_backup/Main.py
@@ -441,6 +441,8 @@ def backup_set_fs_globals(rpin, rpout):
 	SetConnections.UpdateGlobal('fsync_directories', dest_fsa.fsync_dirs)
 	SetConnections.UpdateGlobal('change_ownership', dest_fsa.ownership)
 	SetConnections.UpdateGlobal('chars_to_quote', dest_fsa.chars_to_quote)
+	if not dest_fsa.high_perms:
+		SetConnections.UpdateGlobal('permission_mask', 0777)
 	if Globals.chars_to_quote: FilenameMapping.set_init_quote_vals()
 	
 def backup_touch_curmirror_local(rpin, rpout):
@@ -546,6 +548,8 @@ def restore_set_fs_globals(target):
 	if Globals.preserve_hardlinks != 0:
 		SetConnections.UpdateGlobal('preserve_hardlinks', target_fsa.hardlinks)
 	SetConnections.UpdateGlobal('change_ownership', target_fsa.ownership)
+	if not target_fsa.high_perms:
+		SetConnections.UpdateGlobal('permission_mask', 0777)
 
 	if Globals.chars_to_quote is None: # otherwise already overridden
 		if mirror_fsa.chars_to_quote:
@@ -726,6 +730,7 @@ def single_set_fs_globals(rbdir):
 		SetConnections.UpdateGlobal('preserve_hardlinks', fsa.hardlinks)
 	SetConnections.UpdateGlobal('fsync_directories', fsa.fsync_dirs)
 	SetConnections.UpdateGlobal('change_ownership', fsa.ownership)
+	if not fsa.high_perms: SetConnections.UpdateGlobal('permission_mask', 0777)
 	SetConnections.UpdateGlobal('chars_to_quote', fsa.chars_to_quote)
 	if Globals.chars_to_quote:
 		for conn in Globals.connections:
diff --git a/rdiff-backup/rdiff_backup/fs_abilities.py b/rdiff-backup/rdiff_backup/fs_abilities.py
index b3d69a0..e2285e7 100644
--- a/rdiff-backup/rdiff_backup/fs_abilities.py
+++ b/rdiff-backup/rdiff_backup/fs_abilities.py
@@ -43,6 +43,7 @@ class FSAbilities:
 	carbonfile = None # True if Mac Carbon file data is supported. 
 	name = None # Short string, not used for any technical purpose
 	read_only = None # True if capabilities were determined non-destructively
+	high_perms = None # True if suid etc perms are (read/write) supported
 
 	def __init__(self, name = None):
 		"""FSAbilities initializer.  name is only used in logging"""
@@ -89,7 +90,8 @@ class FSAbilities:
 							  ('Hard linking', self.hardlinks),
 							  ('fsync() directories', self.fsync_dirs),
 							  ('Directory inc permissions',
-							   self.dir_inc_perms)])
+							   self.dir_inc_perms),
+							  ('High-bit permissions', self.high_perms)])
 		add_boolean_list([('Access control lists', self.acls),
 						  ('Extended attributes', self.eas),
 						  ('Mac OS X style resource forks',
@@ -149,6 +151,7 @@ class FSAbilities:
 		self.set_dir_inc_perms(subdir)
 		self.set_resource_fork_readwrite(subdir)
 		self.set_carbonfile()
+		self.set_high_perms_readwrite(subdir)
 		if override_chars_to_quote is None: self.set_chars_to_quote(subdir)
 		else: self.chars_to_quote = override_chars_to_quote
 		if use_ctq_file: self.compare_chars_to_quote(rbdir)
@@ -378,6 +381,16 @@ rdiff-backup-data/chars_to_quote.
 				return
 		self.resource_forks = 0
 
+	def set_high_perms_readwrite(self, dir_rp):
+		"""Test for writing high-bit permissions like suid"""
+		tmp_rp = dir_rp.append("high_perms")
+		tmp_rp.touch()
+		try:
+			tmp_rp.chmod(07000)
+			tmp_rp.chmod(07777)
+		except (OSError, IOError), e: self.high_perms = 0
+		else: self.high_perms = 1
+		tmp_rp.delete()
 
 def get_fsabilities_readonly(desc_string, rp):
 	"""Return an FSAbilities object with given description_string
diff --git a/rdiff-backup/rdiff_backup/rpath.py b/rdiff-backup/rdiff_backup/rpath.py
index 95dd54f..15f4a59 100644
--- a/rdiff-backup/rdiff_backup/rpath.py
+++ b/rdiff-backup/rdiff_backup/rpath.py
@@ -756,7 +756,7 @@ class RPath(RORPath):
 
 	def chmod(self, permissions):
 		"""Wrapper around os.chmod"""
-		self.conn.os.chmod(self.path, permissions)
+		self.conn.os.chmod(self.path, permissions & Globals.permission_mask)
 		self.data['perms'] = permissions
 
 	def settime(self, accesstime, modtime):
diff --git a/rdiff-backup/testing/fs_abilitiestest.py b/rdiff-backup/testing/fs_abilitiestest.py
index da7198a..1aa3f68 100644
--- a/rdiff-backup/testing/fs_abilitiestest.py
+++ b/rdiff-backup/testing/fs_abilitiestest.py
@@ -20,6 +20,7 @@ class FSAbilitiesTest(unittest.TestCase):
 	dir_inc_perms = 1
 	resource_forks = 0
 	carbonfile = 0
+	high_perms = 1
 
 	# Describes MS-Windows style file system
 	#dir_to_test = "/mnt/fat"
@@ -63,6 +64,7 @@ class FSAbilitiesTest(unittest.TestCase):
 		assert fsa.dir_inc_perms == self.dir_inc_perms, fsa.dir_inc_perms
 		assert fsa.resource_forks == self.resource_forks, fsa.resource_forks
 		assert fsa.carbonfile == self.carbonfile, fsa.carbonfile
+		assert fsa.high_perms == self.high_perms, fsa.high_perms
 		
 		ctq_rp = new_dir.append("chars_to_quote")
 		assert ctq_rp.lstat()