3 // Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
4 // based on capchroot.cc by Jacques Gelinas
6 // This program is free software; you can redistribute it and/or modify
7 // it under the terms of the GNU General Public License as published by
8 // the Free Software Foundation; either version 2, or (at your option)
11 // This program is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License
17 // along with this program; if not, write to the Free Software
18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 This chroot command does very little. Once the chroot
22 system call is executed, it (option) remove the CAP_SYS_CHROOT
23 capability. Then it executes its argument
40 #include "linuxcaps.h"
43 int main (int argc, char *argv[])
46 fprintf (stderr,"capchroot version %s\n",VERSION);
48 ,"capchroot --nochroot directory [ --suid user ] command argument\n"
50 "--nochroot remove the CAP_SYS_CHROOT capability\n"
51 " after the chroot system call.\n"
52 "--suid switch to a different user (in the vserver context)\n"
53 " before executing the command.\n");
55 const char *uid = NULL;
56 bool nochroot = false;
58 for (dir=1; dir<argc; dir++){
59 const char *arg = argv[dir];
60 if (arg[0] != '-' && arg[1] != '-'){
62 }else if (strcmp(arg,"--nochroot")==0){
64 }else if (strcmp(arg,"--suid")==0){
70 // We resolve the UID before doing the chroot.
71 // If we do the getpwnam after the chroot, we will end
72 // up loading shared object from the vserver.
73 // This is causing two kind of problem: Incompatibilities
74 // and also a security flaw. The shared objects in the vserver
75 // may be tweaked to get control of the root server ...
77 if (vc_chrootsafe (argv[dir]) == -1){
78 fprintf (stderr,"Can't chroot to directory %s (%s)\n",argv[dir]
81 struct passwd *p = NULL;
85 vc_new_s_context (-2,1<<CAP_SYS_CHROOT,0);
88 if (uid != NULL && strcmp(uid,"root")!=0){
91 fprintf (stderr,"User not found: %s\n",uid);
101 fprintf (stderr,"capchroot: No command to execute, do nothing\n");
103 execvp (argv[cmd],argv+cmd);
104 fprintf (stderr,"Can't execute %s (%s)\n",argv[cmd]