14887Schin /*********************************************************************** 24887Schin * * 34887Schin * This software is part of the ast package * 4*12068SRoger.Faulkner@Oracle.COM * Copyright (c) 1985-2010 AT&T Intellectual Property * 54887Schin * and is licensed under the * 64887Schin * Common Public License, Version 1.0 * 78462SApril.Chin@Sun.COM * by AT&T Intellectual Property * 84887Schin * * 94887Schin * A copy of the License is available at * 104887Schin * http://www.opensource.org/licenses/cpl1.0.txt * 114887Schin * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 124887Schin * * 134887Schin * Information and Software Systems Research * 144887Schin * AT&T Research * 154887Schin * Florham Park NJ * 164887Schin * * 174887Schin * Glenn Fowler <gsf@research.att.com> * 184887Schin * David Korn <dgk@research.att.com> * 194887Schin * Phong Vo <kpv@research.att.com> * 204887Schin * * 214887Schin ***********************************************************************/ 224887Schin #pragma prototyped 234887Schin /* 244887Schin * AT&T Bell Laboratories 254887Schin * return 1 if dir [any dir] is the preroot 264887Schin */ 274887Schin 284887Schin #include <ast.h> 294887Schin #include <preroot.h> 304887Schin 314887Schin #if FS_PREROOT 324887Schin 334887Schin #include <ls.h> 344887Schin 354887Schin /* 364887Schin * return 1 if files a and b are the same under preroot 374887Schin * 384887Schin * NOTE: the kernel disables preroot for set-uid processes 394887Schin */ 404887Schin 414887Schin static int same(const char * a,const char * b)424887Schinsame(const char* a, const char* b) 434887Schin { 444887Schin int i; 454887Schin int euid; 464887Schin int ruid; 474887Schin 484887Schin struct stat ast; 494887Schin struct stat bst; 504887Schin 514887Schin if ((ruid = getuid()) != (euid = geteuid())) setuid(ruid); 524887Schin i = !stat(a, &ast) && !stat(b, &bst) && ast.st_dev == bst.st_dev && ast.st_ino == bst.st_ino; 534887Schin if (ruid != euid) setuid(euid); 544887Schin return(i); 554887Schin } 564887Schin 574887Schin int ispreroot(const char * dir)584887Schinispreroot(const char* dir) 594887Schin { 604887Schin static int prerooted = -1; 614887Schin 624887Schin if (dir) return(same("/", dir)); 634887Schin if (prerooted < 0) prerooted = !same("/", PR_REAL); 644887Schin return(prerooted); 654887Schin } 664887Schin 674887Schin #else 684887Schin 694887Schin NoN(ispreroot) 704887Schin 714887Schin #endif 72