From dean-list-rdiff-backup@arctic.org Fri May 17 17:50:01 2002 From: dean gaudet To: rdiff-backup@keywest.Stanford.EDU Subject: --change-source-perms X-comment: visit http://arctic.org/~dean/legal for information regarding copyright and disclaimer. List-Subscribe: , List-Archive: Date: Fri, 17 May 2002 17:47:46 -0700 (PDT) before using rdiff-backup, i used tar ... and tar never complained about several dozen files on my system which have no read permission. but rdiff-backup started complaining, until i put in the --change-source-perms option. unfortunately i can't use this option when i'm doing the backup from a read-only snapshot. i looked at an strace of tar -- and when running as root, it has no problems opening a file for reading, even when the file has no read permissions for any user: lstat64("a1/unread", {st_mode=S_IFREG, st_size=0, ...}) = 0 open("a1/unread", O_RDONLY|O_LARGEFILE) = 4 fstat64(4, {st_mode=S_IFREG, st_size=0, ...}) = 0 close(4) = 0 studying an strace of rdiff-backup (without --change-source-perms) i notice that it doesn't even attempt to open the file: lstat64("a1/unread", {st_mode=S_IFREG, st_size=0, ...}) = 0 write(2, "Received error \'No read permissi"..., 83) = 83 it'd be preferable to behave more like tar -- attempt the open() regardless of what the permissions are. similarly, root is able to opendir() regardless of permissions. the patch below is a hack ... i think it's preferable to try the open()/opendir() and use the results of that to decide whether to try --change-source-perms. the hack in the patch just assumes root can open()/opendir(). in my quest for better security for the backup i'm going to be investigating non-root users which can do read-only opens of everything... which is why i think hard-coding root is a hack. but anyhow, here's the patch against 0.7.4 :) it's my first python, hee. -dean --- rdiff-backup.orig Tue May 14 21:39:56 2002 +++ rdiff-backup Fri May 17 17:43:31 2002 @@ -3706,7 +3706,8 @@ def set_init_perms(self, source): """If necessary, change permissions to ensure access""" - if self.isreg() and not self.readable(): + if self.conn.Globals.get('process_uid') == 0: return + elif self.isreg() and not self.readable(): if not source or Globals.change_source_perms and self.isowner(): self.chmod_bypass(0400) else: self.warn("No read permissions") _______________________________________________ Rdiff-backup mailing list Rdiff-backup@keywest.Stanford.EDU http://keywest.Stanford.EDU/mailman/listinfo/rdiff-backup