This commit was generated by cvs2svn to compensate for changes in r120,

[util-vserver.git] / src / capchroot.c

diff --git a/src/capchroot.c b/src/capchroot.c
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+++ b/src/capchroot.c
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+// $Id: capchroot.c,v 1.1.4.2 2003/11/28 23:08:43 ensc Exp $
+
+// Copyright (C) 2003 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
+// based on capchroot.cc by Jacques Gelinas
+//  
+// 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
+// the Free Software Foundation; either version 2, or (at your option)
+// any later version.
+//  
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//  
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+/*
+       This chroot command does very little. Once the chroot
+       system call is executed, it (option) remove the CAP_SYS_CHROOT
+       capability. Then it executes its argument
+*/
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+#include "compat.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <pwd.h>
+#include <grp.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "linuxcaps.h"
+#include "vserver.h"
+
+int main (int argc, char *argv[])
+{
+       if (argc < 3){
+               fprintf (stderr,"capchroot version %s\n",VERSION);
+               fprintf (stderr
+                       ,"capchroot --nochroot directory [ --suid user ] command argument\n"
+                        "\n"
+                        "--nochroot remove the CAP_SYS_CHROOT capability\n"
+                        "           after the chroot system call.\n"
+                        "--suid switch to a different user (in the vserver context)\n"
+                        "       before executing the command.\n");
+       }else{
+               const char *uid = NULL;
+               bool nochroot = false;
+               int dir;
+               for (dir=1; dir<argc; dir++){
+                       const char *arg = argv[dir];
+                       if (arg[0] != '-' && arg[1] != '-'){
+                               break;
+                       }else if (strcmp(arg,"--nochroot")==0){
+                               nochroot = true;
+                       }else if (strcmp(arg,"--suid")==0){
+                               dir++;
+                               uid = argv[dir];
+                       }
+                       
+               }
+               // We resolve the UID before doing the chroot.
+               // If we do the getpwnam after the chroot, we will end
+               // up loading shared object from the vserver.
+               // This is causing two kind of problem: Incompatibilities
+               // and also a security flaw. The shared objects in the vserver
+               // may be tweaked to get control of the root server ...
+               getpwnam ("root");
+               if (chroot(argv[dir]) == -1){
+                       fprintf (stderr,"Can't chroot to directory %s (%s)\n",argv[dir]
+                               ,strerror(errno));
+               }else{
+                       struct passwd *p = NULL;
+                       int cmd          = dir + 1;
+
+                       if (nochroot){
+                               vc_new_s_context (-2,1<<CAP_SYS_CHROOT,0);
+                       }
+
+                       if (uid != NULL && strcmp(uid,"root")!=0){
+                               p = getpwnam(uid);
+                               if (p == NULL){
+                                       fprintf (stderr,"User not found: %s\n",uid);
+                                       exit (-1);
+                               }
+                       }
+                       if (p != NULL) {
+                               setgroups (0,NULL);
+                               setgid(p->pw_gid);
+                               setuid(p->pw_uid);
+                       }
+                       if (cmd >= argc){
+                               fprintf (stderr,"capchroot: No command to execute, do nothing\n");
+                       }else{
+                               execvp (argv[cmd],argv+cmd);
+                               fprintf (stderr,"Can't execute %s (%s)\n",argv[cmd]
+                                       ,strerror(errno));
+                       }
+               }
+       }
+       return -1;
+}
+
+