LXR toybox/toys/lsb/su.c

   1/* su.c - switch user
   2 *
   3 * Copyright 2013 CE Strake <strake888@gmail.com>
   4 *
   5 * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/su.html
   6 * TODO: log su attempts
   7
   8USE_SU(NEWTOY(su, "lmpc:s:", TOYFLAG_BIN|TOYFLAG_ROOTONLY))
   9
  10config SU
  11  bool "su"
  12  default y
  13  depends on TOYBOX_SHADOW
  14  help
  15    usage: su [-lmp] [-c CMD] [-s SHELL] [USER [ARGS...]]
  16
  17    Switch to user (or root) and run shell (with optional command line).
  18
  19    -s  shell to use
  20    -c  command to pass to shell with -c
  21    -l  login shell
  22    -(m|p)      preserve environment
  23*/
  24
  25#define FOR_su
  26#include "toys.h"
  27
  28GLOBALS(
  29  char *s;
  30  char *c;
  31)
  32
  33static char *snapshot_env(char *name)
  34{
  35  char *s = getenv(name);
  36
  37  if (s) return xmprintf("%s=%s", name, s);
  38
  39  return 0;
  40}
  41
  42void su_main()
  43{
  44  char *name, *passhash = 0, **argu, **argv;
  45  struct passwd *up;
  46  struct spwd *shp;
  47
  48  if (*toys.optargs && !strcmp("-", *toys.optargs)) {
  49    toys.optflags |= FLAG_l;
  50    toys.optargs++;
  51  }
  52
  53  if (*toys.optargs) name = *(toys.optargs++);
  54  else name = "root";
  55
  56  if (!(shp = getspnam(name))) perror_exit("no '%s'", name);
  57  if (getuid()) {
  58    if (*shp->sp_pwdp != '$') goto deny;
  59    if (read_password(toybuf, sizeof(toybuf), "Password: ")) goto deny;
  60    passhash = crypt(toybuf, shp->sp_pwdp);
  61    memset(toybuf, 0, sizeof(toybuf));
  62    if (!passhash || strcmp(passhash, shp->sp_pwdp)) goto deny;
  63  }
  64
  65  up = xgetpwnam(name);
  66  xsetuser(up);
  67
  68  argv = argu = xmalloc(sizeof(char *)*(toys.optc + 4));
  69  *(argv++) = TT.s ? TT.s : up->pw_shell;
  70
  71  if (toys.optflags & FLAG_l) {
  72    int i;
  73    char *stuff[] = {snapshot_env("TERM"), snapshot_env("DISPLAY"),
  74      snapshot_env("COLORTERM"), snapshot_env("XAUTHORITY")};
  75
  76    clearenv();
  77    for (i=0; i < ARRAY_LEN(stuff); i++) if (stuff[i]) putenv(stuff[i]);
  78    *(argv++) = "-l";
  79    xchdir(up->pw_dir);
  80  } else unsetenv("IFS");
  81  setenv("PATH", "/sbin:/bin:/usr/sbin:/usr/bin", 1);
  82  if (!(toys.optflags & (FLAG_m|FLAG_p))) {
  83    setenv("HOME", up->pw_dir, 1);
  84    setenv("SHELL", up->pw_shell, 1);
  85    setenv("USER", up->pw_name, 1);
  86    setenv("LOGNAME", up->pw_name, 1);
  87  } else unsetenv("IFS");
  88
  89  if (toys.optflags & FLAG_c) {
  90    *(argv++) = "-c";
  91    *(argv++) = TT.c;
  92  }
  93  while ((*(argv++) = *(toys.optargs++)));
  94  xexec(argu);
  95
  96deny:
  97  puts("No.");
  98  toys.exitval = 1;
  99}
 100