void
vsf_two_process_start(struct vsf_session* p_sess)
{
  /* Create the comms channel between privileged parent and no-priv child */
  priv_sock_init(p_sess);
  vsf_sysutil_install_async_sighandler(kVSFSysUtilSigCHLD, handle_sigchld);
  {
    int newpid = vsf_sysutil_fork();
    if (newpid != 0)
    {
      /* Parent - go into pre-login parent process mode */
      while (1)
      {
        process_login_req(p_sess);
      }
      /* NOTREACHED */
      bug("should not get here: vsf_two_process_start");
    }
  }
  /* Child process - time to lose as much privilege as possible and do the
   * login processing
   */
  if (tunable_local_enable && tunable_userlist_enable)
  {
    int retval = str_fileread(&p_sess->userlist_str, tunable_userlist_file,
                              VSFTP_CONF_FILE_MAX);
    if (vsf_sysutil_retval_is_error(retval))
    {
      die("cannot open user list file");
    }
  }
  drop_all_privs();
  init_connection(p_sess);
  /* NOTREACHED */
}
int
vsf_sysutil_fork_newnet()
{
#ifdef VSF_SYSDEP_HAVE_LINUX_CLONE
  static int cloneflags_work = -1;
  if (cloneflags_work < 0)
  {
    cloneflags_work = vsf_sysutil_netns_cleanup_is_fast();
  }
  if (cloneflags_work)
  {
    int ret = syscall(__NR_clone, CLONE_NEWNET | SIGCHLD, NULL);
    if (ret != -1 || (errno != EINVAL && errno != EPERM))
    {
      if (ret == 0)
      {
        vsf_sysutil_post_fork();
      }
      return ret;
    }
    cloneflags_work = 0;
  }
#endif
  return vsf_sysutil_fork();
}
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_default_sig(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();
  /* Handle loading per-user config options */
  handle_per_user_config(p_user_str);
  vsf_sysutil_install_async_sighandler(kVSFSysUtilSigCHLD, handle_sigchld);
  newpid = vsf_sysutil_fork(); 
  if (newpid == 0)
  {
    struct mystr guest_user_str = INIT_MYSTR;
    struct mystr chdir_str = INIT_MYSTR;
    unsigned int secutil_option = VSF_SECUTIL_OPTION_USE_GROUPS;
    calculate_chdir_dir(anon, &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;
      /* SECURITY: For now, apply the anonymous restrictions to
       * guest users
       */
      anon = 1;
    }
    if (!anon)
    {
      secutil_option |= VSF_SECUTIL_OPTION_CHANGE_EUID;
    }
    vsf_secutil_change_credentials(p_user_str, 0, &chdir_str,
                                   0, secutil_option);
    str_free(&guest_user_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");
}
void
vsf_two_process_start(struct vsf_session* p_sess)
{
  /* Create the comms channel between privileged parent and no-priv child */
  priv_sock_init(p_sess);
  if (tunable_ssl_enable)
  {
    /* Create the comms channel between the no-priv SSL child and the low-priv
     * protocol handling child.
     */
    ssl_comm_channel_init(p_sess);
  }
  vsf_sysutil_install_async_sighandler(kVSFSysUtilSigCHLD, twoproc_handle_sigchld);
  {
    int newpid = vsf_sysutil_fork();
    if (newpid != 0)
    {
      /* Parent - go into pre-login parent process mode */
      while (1)
      {
        process_login_req(p_sess);
      }
    }
  }
  /* Child process - time to lose as much privilege as possible and do the
   * login processing
   */
  vsf_sysutil_close(p_sess->parent_fd);
  if (tunable_ssl_enable)
  {
    vsf_sysutil_close(p_sess->ssl_consumer_fd);
  }
  if (tunable_local_enable && tunable_userlist_enable)
  {
    int retval = str_fileread(&p_sess->userlist_str, tunable_userlist_file,
                              VSFTP_CONF_FILE_MAX);
    if (vsf_sysutil_retval_is_error(retval))
    {
      die2("cannot open user list file:", tunable_userlist_file);
    }
  }
  drop_all_privs();
  init_connection(p_sess);
  /* NOTREACHED */
}
void
vsf_two_process_start(struct vsf_session* p_sess)
{
  vsf_sysutil_install_sighandler(kVSFSysUtilSigTERM, handle_sigterm, 0, 1);
  /* Overrides the SIGKILL setting set by the standalone listener. */
  vsf_set_term_if_parent_dies();
  /* Create the comms channel between privileged parent and no-priv child */
  priv_sock_init(p_sess);
  if (tunable_ssl_enable)
  {
    /* Create the comms channel between the no-priv SSL child and the low-priv
     * protocol handling child.
     */
    ssl_comm_channel_init(p_sess);
  }
  vsf_sysutil_install_sighandler(kVSFSysUtilSigCHLD, handle_sigchld, 0, 1);
  {
    int newpid;
    if (tunable_isolate_network)
    {
      newpid = vsf_sysutil_fork_newnet();
    }
    else
    {
      newpid = vsf_sysutil_fork();
    }
    if (newpid != 0)
    {
      priv_sock_set_parent_context(p_sess);
      if (tunable_ssl_enable)
      {
        ssl_comm_channel_set_consumer_context(p_sess);
      }
      /* Parent - go into pre-login parent process mode */
      while (1)
      {
        process_login_req(p_sess);
      }
    }
  }
  /* Child process - time to lose as much privilege as possible and do the
   * login processing
   */
  vsf_set_die_if_parent_dies();
  priv_sock_set_child_context(p_sess);
  if (tunable_ssl_enable)
  {
    ssl_comm_channel_set_producer_context(p_sess);
  }
  if (tunable_local_enable && tunable_userlist_enable)
  {
    int retval = str_fileread(&p_sess->userlist_str, tunable_userlist_file,
                              VSFTP_CONF_FILE_MAX);
    if (vsf_sysutil_retval_is_error(retval))
    {
      die2("cannot read user list file:", tunable_userlist_file);
    }
  }
  drop_all_privs();
  init_connection(p_sess);
  /* NOTREACHED */
}
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");
}
Beispiel #7
0
struct vsf_client_launch
vsf_standalone_main(void)
{
    struct vsf_sysutil_sockaddr* p_accept_addr = 0;
    int listen_sock = -1;
    int retval;
    s_ipaddr_size = vsf_sysutil_get_ipaddr_size();
    if (tunable_listen && tunable_listen_ipv6)
    {
        die("run two copies of vsftpd for IPv4 and IPv6");
    }
    if (tunable_background)
    {
        int forkret = vsf_sysutil_fork();
        if (forkret > 0)
        {
            /* Parent, just exit */
            vsf_sysutil_exit(0);
        }
        vsf_sysutil_make_session_leader();
    }
    if (tunable_listen)
    {
        listen_sock = vsf_sysutil_get_ipv4_sock();
    }
    else
    {
        listen_sock = vsf_sysutil_get_ipv6_sock();
    }
    vsf_sysutil_activate_reuseaddr(listen_sock);

    s_p_ip_count_hash = hash_alloc(256, s_ipaddr_size,
                                   sizeof(unsigned int), hash_ip);
    s_p_pid_ip_hash = hash_alloc(256, sizeof(int),
                                 s_ipaddr_size, hash_pid);
    if (tunable_setproctitle_enable)
    {
        vsf_sysutil_setproctitle("LISTENER");
    }
    vsf_sysutil_install_async_sighandler(kVSFSysUtilSigCHLD, handle_sigchld);
    vsf_sysutil_install_async_sighandler(kVSFSysUtilSigHUP, handle_sighup);
    if (tunable_listen)
    {
        struct vsf_sysutil_sockaddr* p_sockaddr = 0;
        vsf_sysutil_sockaddr_alloc_ipv4(&p_sockaddr);
        vsf_sysutil_sockaddr_set_port(p_sockaddr, tunable_listen_port);
        if (!tunable_listen_address)
        {
            vsf_sysutil_sockaddr_set_any(p_sockaddr);
        }
        else
        {
            if (!vsf_sysutil_inet_aton(tunable_listen_address, p_sockaddr))
            {
                die2("bad listen_address: ", tunable_listen_address);
            }
        }
        retval = vsf_sysutil_bind(listen_sock, p_sockaddr);
        vsf_sysutil_free(p_sockaddr);
        if (vsf_sysutil_retval_is_error(retval))
        {
            die("could not bind listening IPv4 socket");
        }
    }
    else
    {
        struct vsf_sysutil_sockaddr* p_sockaddr = 0;
        vsf_sysutil_sockaddr_alloc_ipv6(&p_sockaddr);
        vsf_sysutil_sockaddr_set_port(p_sockaddr, tunable_listen_port);
        if (!tunable_listen_address6)
        {
            vsf_sysutil_sockaddr_set_any(p_sockaddr);
        }
        else
        {
            struct mystr addr_str = INIT_MYSTR;
            const unsigned char* p_raw_addr;
            str_alloc_text(&addr_str, tunable_listen_address6);
            p_raw_addr = vsf_sysutil_parse_ipv6(&addr_str);
            str_free(&addr_str);
            if (!p_raw_addr)
            {
                die2("bad listen_address6: ", tunable_listen_address6);
            }
            vsf_sysutil_sockaddr_set_ipv6addr(p_sockaddr, p_raw_addr);
        }
        retval = vsf_sysutil_bind(listen_sock, p_sockaddr);
        vsf_sysutil_free(p_sockaddr);
        if (vsf_sysutil_retval_is_error(retval))
        {
            die("could not bind listening IPv6 socket");
        }
    }
    vsf_sysutil_listen(listen_sock, VSFTP_LISTEN_BACKLOG);
    vsf_sysutil_sockaddr_alloc(&p_accept_addr);
    while (1)
    {
        struct vsf_client_launch child_info;
        void* p_raw_addr;
        int new_child;
        int new_client_sock;
        vsf_sysutil_unblock_sig(kVSFSysUtilSigCHLD);
        vsf_sysutil_unblock_sig(kVSFSysUtilSigHUP);
        new_client_sock = vsf_sysutil_accept_timeout(
                              listen_sock, p_accept_addr, 0);
        vsf_sysutil_block_sig(kVSFSysUtilSigCHLD);
        vsf_sysutil_block_sig(kVSFSysUtilSigHUP);
        if (vsf_sysutil_retval_is_error(new_client_sock))
        {
            continue;
        }
        ++s_children;
        child_info.num_children = s_children;
        child_info.num_this_ip = 0;
        p_raw_addr = vsf_sysutil_sockaddr_get_raw_addr(p_accept_addr);
        child_info.num_this_ip = handle_ip_count(p_raw_addr);
        new_child = vsf_sysutil_fork_failok();
        if (new_child != 0)
        {
            /* Parent context */
            vsf_sysutil_close(new_client_sock);
            if (new_child > 0)
            {
                hash_add_entry(s_p_pid_ip_hash, (void*)&new_child, p_raw_addr);
            }
            else
            {
                /* fork() failed, clear up! */
                --s_children;
                drop_ip_count(p_raw_addr);
            }
            /* Fall through to while() loop and accept() again */
        }
        else
        {
            /* Child context */
            vsf_sysutil_close(listen_sock);
            prepare_child(new_client_sock);
            /* By returning here we "launch" the child process with the same
             * contract as xinetd would provide.
             */
            return child_info;
        }
    }
}
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;
  }
  /* 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, twoproc_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;
    struct mystr userdir_str = INIT_MYSTR;
    unsigned int secutil_option = VSF_SECUTIL_OPTION_USE_GROUPS;
    /* Child - drop privs and start proper FTP! */
    vsf_sysutil_close(p_sess->parent_fd);
    if (tunable_ssl_enable)
    {
      vsf_sysutil_close(p_sess->ssl_slave_fd);
    }
    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;
        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);
    /* 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 */
  if (tunable_ssl_enable)
  {
    vsf_sysutil_close(p_sess->ssl_consumer_fd);
    /* Keep the SSL slave fd around so we can shutdown() upon exit */
  }
  vsf_priv_parent_postlogin(p_sess);
  bug("should not get here in common_do_login");
}