1/* 2 Unix SMB/Netbios implementation. 3 Version 1.9. 4 external program running routine 5 Copyright (C) Andrew Tridgell 1992-1998 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 20*/ 21 22#include "includes.h" 23 24 25/******************************************************************* 26close the low 3 fd's and open dev/null in their place 27********************************************************************/ 28static void close_fds(void) 29{ 30 int fd; 31 int i; 32 close(0); close(1); close(2); 33 /* try and use up these file descriptors, so silly 34 library routines writing to stdout etc won't cause havoc */ 35 for (i=0;i<3;i++) { 36 fd = open("/dev/null",O_RDWR,0); 37 if (fd < 0) fd = open("/dev/null",O_WRONLY,0); 38 if (fd != i) return; 39 } 40} 41 42 43/* 44This is a wrapper around the system() call to allow commands to run correctly 45as non root from a program which is switching between root and non-root 46 47It takes 3 arguments as uid,gid,command and runs command after 48becoming a non-root user */ 49 int main(int argc,char *argv[]) 50{ 51 uid_t uid; 52 gid_t gid; 53 54 close_fds(); 55 56 if (argc != 4) exit(2); 57 58 uid = (uid_t)atoi(argv[1]); 59 gid = (gid_t)atoi(argv[2]); 60 61 become_user_permanently( uid, gid); 62 63 /* paranoia :-) */ 64 if (getuid() != uid) 65 return(3); 66 67 if (geteuid() != getuid()) 68 return(4); 69 70 /* this is to make sure that the system() call doesn't run forever */ 71 alarm(30); 72 73 return(system(argv[3])); 74} 75