diff options
Diffstat (limited to 'usr/src/lib/libast/common/preroot/ispreroot.c')
| -rw-r--r-- | usr/src/lib/libast/common/preroot/ispreroot.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/usr/src/lib/libast/common/preroot/ispreroot.c b/usr/src/lib/libast/common/preroot/ispreroot.c new file mode 100644 index 0000000000..540c42df50 --- /dev/null +++ b/usr/src/lib/libast/common/preroot/ispreroot.c @@ -0,0 +1,71 @@ +/*********************************************************************** +* * +* This software is part of the ast package * +* Copyright (c) 1985-2007 AT&T Knowledge Ventures * +* and is licensed under the * +* Common Public License, Version 1.0 * +* by AT&T Knowledge Ventures * +* * +* A copy of the License is available at * +* http://www.opensource.org/licenses/cpl1.0.txt * +* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * +* * +* Information and Software Systems Research * +* AT&T Research * +* Florham Park NJ * +* * +* Glenn Fowler <gsf@research.att.com> * +* David Korn <dgk@research.att.com> * +* Phong Vo <kpv@research.att.com> * +* * +***********************************************************************/ +#pragma prototyped +/* + * AT&T Bell Laboratories + * return 1 if dir [any dir] is the preroot + */ + +#include <ast.h> +#include <preroot.h> + +#if FS_PREROOT + +#include <ls.h> + +/* + * return 1 if files a and b are the same under preroot + * + * NOTE: the kernel disables preroot for set-uid processes + */ + +static int +same(const char* a, const char* b) +{ + int i; + int euid; + int ruid; + + struct stat ast; + struct stat bst; + + if ((ruid = getuid()) != (euid = geteuid())) setuid(ruid); + i = !stat(a, &ast) && !stat(b, &bst) && ast.st_dev == bst.st_dev && ast.st_ino == bst.st_ino; + if (ruid != euid) setuid(euid); + return(i); +} + +int +ispreroot(const char* dir) +{ + static int prerooted = -1; + + if (dir) return(same("/", dir)); + if (prerooted < 0) prerooted = !same("/", PR_REAL); + return(prerooted); +} + +#else + +NoN(ispreroot) + +#endif |