Exemple #1
0
static void
env_init(void)
{
  vsf_sysutil_make_session_leader();
  /* Set up a secure umask - we'll set the proper one after login */
  vsf_sysutil_set_umask(VSFTP_SECURE_UMASK);
  /* Fire up libc's timezone initialisation, before we chroot()! */
  vsf_sysutil_tzset();
  /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */
  vsf_sysutil_install_null_sighandler(kVSFSysUtilSigPIPE);
}
static void
common_do_login(struct vsf_session* p_sess, const struct mystr* p_user_str,
                int do_chroot, int anon)
{
  int was_anon = anon;
  const struct mystr* p_orig_user_str = p_user_str;
  int newpid;
  vsf_sysutil_install_null_sighandler(kVSFSysUtilSigCHLD);
  /* Tells the pre-login child all is OK (it may exit in response) */
  priv_sock_send_result(p_sess->parent_fd, PRIV_SOCK_RESULT_OK);
  if (!p_sess->control_use_ssl)
  {
    (void) vsf_sysutil_wait();
  }
  else
  {
    p_sess->ssl_slave_active = 1;
  }
  /* Handle loading per-user config options */
  handle_per_user_config(p_user_str);
  /* Set this before we fork */
  p_sess->is_anonymous = anon;
  priv_sock_close(p_sess);
  priv_sock_init(p_sess);
  vsf_sysutil_install_sighandler(kVSFSysUtilSigCHLD, handle_sigchld, 0, 1);
  if (tunable_isolate_network && !tunable_port_promiscuous)
  {
    newpid = vsf_sysutil_fork_newnet();
  }
  else
  {
    newpid = vsf_sysutil_fork();
  }
  if (newpid == 0)
  {
    struct mystr guest_user_str = INIT_MYSTR;
    struct mystr chroot_str = INIT_MYSTR;
    struct mystr chdir_str = INIT_MYSTR;
    struct mystr userdir_str = INIT_MYSTR;
    unsigned int secutil_option = VSF_SECUTIL_OPTION_USE_GROUPS |
                                  VSF_SECUTIL_OPTION_NO_PROCS;
    /* Child - drop privs and start proper FTP! */
    /* This PR_SET_PDEATHSIG doesn't work for all possible process tree setups.
     * The other cases are taken care of by a shutdown() of the command
     * connection in our SIGTERM handler.
     */
    vsf_set_die_if_parent_dies();
    priv_sock_set_child_context(p_sess);
    if (tunable_guest_enable && !anon)
    {
      p_sess->is_guest = 1;
      /* Remap to the guest user */
      str_alloc_text(&guest_user_str, tunable_guest_username);
      p_user_str = &guest_user_str;
      if (!tunable_virtual_use_local_privs)
      {
        anon = 1;
        do_chroot = 1;
      }
    }
    if (do_chroot)
    {
      secutil_option |= VSF_SECUTIL_OPTION_CHROOT;
    }
    if (!anon)
    {
      secutil_option |= VSF_SECUTIL_OPTION_CHANGE_EUID;
    }
    calculate_chdir_dir(was_anon, &userdir_str, &chroot_str, &chdir_str,
                        p_user_str, p_orig_user_str);
    vsf_secutil_change_credentials(p_user_str, &userdir_str, &chroot_str,
                                   0, secutil_option);
    if (!str_isempty(&chdir_str))
    {
      (void) str_chdir(&chdir_str);
    }
    str_free(&guest_user_str);
    str_free(&chroot_str);
    str_free(&chdir_str);
    str_free(&userdir_str);
    p_sess->is_anonymous = anon;
    process_post_login(p_sess);
    bug("should not get here: common_do_login");
  }
  /* Parent */
  priv_sock_set_parent_context(p_sess);
  if (tunable_ssl_enable)
  {
    ssl_comm_channel_set_producer_context(p_sess);
  }
  vsf_priv_parent_postlogin(p_sess);
  bug("should not get here in common_do_login");
}
static void
common_do_login(struct vsf_session* p_sess, const struct mystr* p_user_str,
                int do_chroot, int anon)
{
  int was_anon = anon;
  int newpid;
  vsf_sysutil_install_null_sighandler(kVSFSysUtilSigCHLD);
  /* Asks the pre-login child to go away (by exiting) */
  priv_sock_send_result(p_sess, PRIV_SOCK_RESULT_OK);
  (void) vsf_sysutil_wait();
  /* Absorb the SIGCHLD */
  vsf_sysutil_unblock_sig(kVSFSysUtilSigCHLD);
  /* Handle loading per-user config options */
  handle_per_user_config(p_user_str);
  /* Set this before we fork */
  p_sess->is_anonymous = anon;
  vsf_sysutil_install_async_sighandler(kVSFSysUtilSigCHLD, handle_sigchld);
  newpid = vsf_sysutil_fork(); 
  if (newpid == 0)
  {
    struct mystr guest_user_str = INIT_MYSTR;
    struct mystr chroot_str = INIT_MYSTR;
    struct mystr chdir_str = INIT_MYSTR;
    unsigned int secutil_option = VSF_SECUTIL_OPTION_USE_GROUPS;
    calculate_chdir_dir(anon, &chroot_str, &chdir_str, p_user_str);
    if (do_chroot)
    {
      secutil_option |= VSF_SECUTIL_OPTION_CHROOT;
    }
    /* Child - drop privs and start proper FTP! */
    if (tunable_guest_enable && !anon)
    {
      /* Remap to the guest user */
      str_alloc_text(&guest_user_str, tunable_guest_username);
      p_user_str = &guest_user_str;
      if (!tunable_virtual_use_local_privs)
      {
        anon = 1;
      }
    }
    if (!anon)
    {
      secutil_option |= VSF_SECUTIL_OPTION_CHANGE_EUID;
    }
    vsf_secutil_change_credentials(p_user_str, 0, &chroot_str,
                                   0, secutil_option);
    if (!str_isempty(&chdir_str))
    {
      (void) str_chdir(&chdir_str);
    }
    str_free(&guest_user_str);
    str_free(&chroot_str);
    str_free(&chdir_str);
    /* Guard against the config error of having the anonymous ftp tree owned
     * by the user we are running as
     */
    if (was_anon && vsf_sysutil_write_access("/"))
    {
      die("vsftpd: refusing to run with writable anonymous root");
    }
    p_sess->is_anonymous = anon;
    process_post_login(p_sess);
    bug("should not get here: common_do_login");
  }
  /* Parent */
  vsf_priv_parent_postlogin(p_sess);
  bug("should not get here in common_do_login");
}