path: root/exec/main.c

/* GNU Hurd standard exec server, main program and server mechanics.

   Copyright (C) 1992,93,94,95,96,97,98,99,2000,01,02
   	Free Software Foundation, Inc.
   Written by Roland McGrath.
   This file is part of the GNU Hurd.

   The GNU Hurd 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.

   The GNU Hurd 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 the GNU Hurd; see the file COPYING.  If not, write to
   the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "priv.h"
#include <error.h>
#include <hurd/paths.h>
#include <hurd/startup.h>
#include <argp.h>
#include <version.h>
#include <pids.h>

const char *argp_program_version = STANDARD_HURD_VERSION (exec);

#ifdef BFD
bfd_arch_info_type host_bfd_arch_info;
bfd host_bfd = { arch_info: &host_bfd_arch_info };
extern error_t bfd_mach_host_arch_mach (host_t host,
					enum bfd_architecture *bfd_arch,
					long int *bfd_machine,
					ElfW(Half) *elf_machine);
#endif

/* Trivfs hooks.  */
int trivfs_fstype = FSTYPE_MISC;
int trivfs_fsid = 0;
int trivfs_support_read = 0;
int trivfs_support_write = 0;
int trivfs_allow_open = 0;

struct port_class *trivfs_protid_portclasses[1];
struct port_class *trivfs_cntl_portclasses[1];
int trivfs_protid_nportclasses = 1;
int trivfs_cntl_nportclasses = 1;

struct trivfs_control *fsys;

char **save_argv;


static int
exec_demuxer (mach_msg_header_t *inp, mach_msg_header_t *outp)
{
  extern int exec_server (mach_msg_header_t *inp, mach_msg_header_t *outp);
  extern int exec_startup_server (mach_msg_header_t *, mach_msg_header_t *);
  return (exec_startup_server (inp, outp) ||
	  exec_server (inp, outp) ||
	  trivfs_demuxer (inp, outp));
}


/* Clean up the storage in BOOT, which was never used.  */

void
deadboot (void *p)
{
  struct bootinfo *boot = p;
  size_t i;

  munmap (boot->argv, boot->argvlen);
  munmap (boot->envp, boot->envplen);

  for (i = 0; i < boot->dtablesize; ++i)
    mach_port_deallocate (mach_task_self (), boot->dtable[i]);
  for (i = 0; i < boot->nports; ++i)
    mach_port_deallocate (mach_task_self (), boot->portarray[i]);
  munmap (boot->portarray, boot->nports * sizeof (mach_port_t));
  munmap (boot->intarray, boot->nints * sizeof (int));

  /* See if we are going away and this was the last thing keeping us up.  */
  if (ports_count_class (trivfs_cntl_portclasses[0]) == 0)
    {
      /* We have no fsys control port, so we are detached from the
	 parent filesystem.  Maybe we have no users left either.  */
      if (ports_count_class (trivfs_protid_portclasses[0]) == 0)
	{
	  /* We have no user ports left.  Are we still listening for
	     exec_startup RPCs from any tasks we already started?  */
	  if (ports_count_class (execboot_portclass) == 0)
	    /* Nobody talking.  Time to die.  */
	    exit (0);
	  ports_enable_class (execboot_portclass);
	}
      ports_enable_class (trivfs_protid_portclasses[0]);
    }
  ports_enable_class (trivfs_cntl_portclasses[0]);
}


int
main (int argc, char **argv)
{
  error_t err;
  mach_port_t bootstrap;
  struct argp argp = { 0, 0, 0, "Hurd standard exec server." };

  argp_parse (&argp, argc, argv, 0, 0, 0);

  save_argv = argv;

#ifdef BFD
  /* Put the Mach kernel's idea of what flavor of machine this is into the
     fake BFD against which architecture compatibility checks are made.  */
  err = bfd_mach_host_arch_mach (mach_host_self (),
				 &host_bfd.arch_info->arch,
				 &host_bfd.arch_info->mach);
  if (err)
    error (1, err, "Getting host architecture from Mach");
#endif

  task_get_bootstrap_port (mach_task_self (), &bootstrap);
  if (bootstrap == MACH_PORT_NULL)
    error (2, 0, "Must be started as a translator");

  /* Fetch our proc server port for easy use.  If we are booting, it is not
     set yet and `getproc' returns MACH_PORT_NULL; we reset PROCSERVER in
     S_exec_init (below).  */
  procserver = getproc ();

  port_bucket = ports_create_bucket ();
  trivfs_cntl_portclasses[0] = ports_create_class (trivfs_clean_cntl, 0);
  trivfs_protid_portclasses[0] = ports_create_class (trivfs_clean_protid, 0);
  execboot_portclass = ports_create_class (deadboot, NULL);

  /* Reply to our parent.  */
  err = trivfs_startup (bootstrap, 0,
			trivfs_cntl_portclasses[0], port_bucket,
			trivfs_protid_portclasses[0], port_bucket,
			&fsys);
  mach_port_deallocate (mach_task_self (), bootstrap);
  if (err)
    error (3, err, "Contacting parent");

  /* Launch.  */
  ports_manage_port_operations_multithread (port_bucket, exec_demuxer,
					    2 * 60 * 1000, 0, 0);

  return 0;
}


void
trivfs_modify_stat (struct trivfs_protid *cred, struct stat *st)
{
  st->st_fstype = FSTYPE_MISC;
}

error_t
trivfs_goaway (struct trivfs_control *fsys, int flags)
{
  int count;

  /* Stop new requests.  */
  ports_inhibit_class_rpcs (trivfs_cntl_portclasses[0]);
  ports_inhibit_class_rpcs (trivfs_protid_portclasses[0]);

  /* Are there any extant user ports for the /servers/exec file?  */
  count = ports_count_class (trivfs_protid_portclasses[0]);
  if (count == 0 || (flags & FSYS_GOAWAY_FORCE))
    {
      /* No users.  Disconnect from the filesystem.  */
      mach_port_deallocate (mach_task_self (), fsys->underlying);

      /* Are there remaining exec_startup RPCs to answer?  */
      count = ports_count_class (execboot_portclass);
      if (count == 0)
	/* Nope.  We got no reason to live.  */
	exit (0);

      /* Continue servicing tasks starting up.  */
      ports_enable_class (execboot_portclass);

      /* No more communication with the parent filesystem.  */
      ports_destroy_right (fsys);

      return 0;
    }
  else
    {
      /* We won't go away, so start things going again...  */
      ports_enable_class (trivfs_protid_portclasses[0]);
      ports_resume_class_rpcs (trivfs_cntl_portclasses[0]);
      ports_resume_class_rpcs (trivfs_protid_portclasses[0]);

      return EBUSY;
    }
}

/* Sent by the bootstrap filesystem after the other essential
   servers have been started up.  */

kern_return_t
S_exec_init (struct trivfs_protid *protid,
	     auth_t auth, process_t proc)
{
  mach_port_t host_priv, startup;
  error_t err;

  if (! protid || ! protid->isroot)
    return EPERM;

  _hurd_port_set (&_hurd_ports[INIT_PORT_PROC], proc); /* Consume.  */
  _hurd_port_set (&_hurd_ports[INIT_PORT_AUTH], auth); /* Consume.  */

  /* Do initial setup with the proc server.  */
  _hurd_proc_init (save_argv, NULL, 0);

  procserver = getproc ();

  /* Have the proc server notify us when the canonical ints and ports
     change.  This will generate an immediate callback giving us the
     initial boot-time canonical sets.  */
  {
    struct iouser *user;
    struct trivfs_protid *cred;
    mach_port_t right;

    err = iohelp_create_empty_iouser (&user);
    assert_perror (err);
    err = trivfs_open (fsys, user, 0, MACH_PORT_NULL, &cred);
    assert_perror (err);

    right = ports_get_send_right (cred);
    proc_execdata_notify (procserver, right, MACH_MSG_TYPE_COPY_SEND);
    mach_port_deallocate (mach_task_self (), right);
  }

  err = get_privileged_ports (&host_priv, NULL);
  assert_perror (err);

  proc_register_version (procserver, host_priv, "exec", "", HURD_VERSION);

  err = proc_getmsgport (procserver, HURD_PID_STARTUP, &startup);
  assert_perror (err);
  mach_port_deallocate (mach_task_self (), procserver);

  /* Call startup_essential task last; init assumes we are ready to
     run once we call it. */
  err = startup_essential_task (startup, mach_task_self (), MACH_PORT_NULL,
				"exec", host_priv);
  assert_perror (err);
  mach_port_deallocate (mach_task_self (), startup);

  mach_port_deallocate (mach_task_self (), host_priv);

  return 0;
}