X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fchdir-safer.c;h=92451dc387bd732bdc2debc4b2ce01c0eae7de4c;hb=50901279d8e42ea4bccc2eef0a6b11e7c3dde4cf;hp=03f372050f9decc43e326e406d7f9aa3af0b5821;hpb=ff0b56d949424acc0ea32b546bf8b32f98153d63;p=gnulib.git diff --git a/lib/chdir-safer.c b/lib/chdir-safer.c index 03f372050..92451dc38 100644 --- a/lib/chdir-safer.c +++ b/lib/chdir-safer.c @@ -1,6 +1,6 @@ /* much like chdir(2), but safer - Copyright (C) 2005-2006, 2008 Free Software Foundation, Inc. + Copyright (C) 2005-2006, 2008-2011 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -29,21 +29,24 @@ #include #include "same-inode.h" -#ifndef ELOOP -# define ELOOP 0 +#ifndef HAVE_READLINK +# define HAVE_READLINK 0 #endif /* Like chdir, but fail if DIR is a symbolic link to a directory (or - similar funny business), or if DIR is not readable. This avoids a - minor race condition between when a directory is created or statted - and when the process chdirs into it. */ + similar funny business). This avoids a minor race condition + between when a directory is created or statted and when the process + chdirs into it. + + On older systems lacking full support for O_SEARCH, this function + can also fail if DIR is not readable. */ int chdir_no_follow (char const *dir) { int result = 0; int saved_errno; int fd = open (dir, - O_RDONLY | O_DIRECTORY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK); + O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NOFOLLOW | O_NONBLOCK); if (fd < 0) return -1; @@ -51,22 +54,22 @@ chdir_no_follow (char const *dir) they are the same file; if they are different files, set errno to ELOOP (the same value that open uses for symlinks with O_NOFOLLOW) so the caller can report a failure. - Skip this check if ELOOP == 0, which should be the case + Skip this check if HAVE_READLINK == 0, which should be the case on any system that lacks symlink support. */ - if (ELOOP && ! HAVE_WORKING_O_NOFOLLOW) + if (HAVE_READLINK && ! HAVE_WORKING_O_NOFOLLOW) { struct stat sb1; result = lstat (dir, &sb1); if (result == 0) - { - struct stat sb2; - result = fstat (fd, &sb2); - if (result == 0 && ! SAME_INODE (sb1, sb2)) - { - errno = ELOOP; - result = -1; - } - } + { + struct stat sb2; + result = fstat (fd, &sb2); + if (result == 0 && ! SAME_INODE (sb1, sb2)) + { + errno = ELOOP; + result = -1; + } + } } if (result == 0)