/* Proc server host management calls

   Copyright (C) 1992, 1993, 1994, 1996, 1997, 2001, 2002, 2013 Free Software
   Foundation, Inc.

   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.  */

/* Written by Michael I. Bushnell.  */

#include <mach.h>
#include <hurd.h>
#include <sys/types.h>
#include <hurd/hurd_types.h>
#include <stdlib.h>
#include <errno.h>
#include <mach/notify.h>
#include <string.h>
#include <stdio.h>
#include <hurd/exec.h>
#include <unistd.h>
#include <assert-backtrace.h>
#include <version.h>
#include <sys/mman.h>

#include "proc.h"
#include "process_S.h"

static mach_port_t *std_port_array;
static int *std_int_array;
static int n_std_ports, n_std_ints;
static struct utsname uname_info;

struct server_version
{
  char *name;
  char *version;
} *server_versions;
int nserver_versions, server_versions_nalloc;

struct execdata_notify
{
  mach_port_t notify_port;
  struct execdata_notify *next;
} *execdata_notifys;


/* Implement proc_getprivports as described in <hurd/process.defs>. */
kern_return_t
S_proc_getprivports (struct proc *p,
		     mach_port_t *hostpriv,
		     mach_port_t *devpriv)
{
  if (!p)
    return EOPNOTSUPP;

  if (! check_uid (p, 0))
    return EPERM;

  *hostpriv = _hurd_host_priv;
  *devpriv = _hurd_device_master;
  return 0;
}


/* Implement proc_setexecdata as described in <hurd/process.defs>. */
kern_return_t
S_proc_setexecdata (struct proc *p,
		    const mach_port_t *ports,
		    size_t nports,
		    const int *ints,
		    size_t nints)
{
  int i;
  struct execdata_notify *n;
  mach_port_t *std_port_array_new;
  int *std_int_array_new;

  if (!p)
    return EOPNOTSUPP;

  if (!check_uid (p, 0))
    return EPERM;

  /* Allocate memory up front.  */
  std_port_array_new = malloc (sizeof (mach_port_t) * nports);
  if (! std_port_array_new)
    return ENOMEM;

  std_int_array_new = malloc (sizeof (int) * nints);
  if (! std_int_array_new)
    {
      free (std_port_array_new);
      return ENOMEM;
    }

  if (std_port_array)
    {
      for (i = 0; i < n_std_ports; i++)
	mach_port_deallocate (mach_task_self (), std_port_array[i]);
      free (std_port_array);
    }
  free (std_int_array);

  std_port_array = std_port_array_new;
  n_std_ports = nports;
  memcpy (std_port_array, ports, sizeof (mach_port_t) * nports);

  std_int_array = std_int_array_new;
  n_std_ints = nints;
  memcpy (std_int_array, ints, sizeof (int) * nints);

  for (n = execdata_notifys; n; n = n->next)
    exec_setexecdata (n->notify_port, std_port_array, MACH_MSG_TYPE_COPY_SEND,
		      n_std_ports, std_int_array, n_std_ints);

  return 0;
}

/* Implement proc_getexecdata as described in <hurd/process.defs>. */
kern_return_t
S_proc_getexecdata (struct proc *p,
		    mach_port_t **ports,
		    mach_msg_type_name_t *portspoly,
		    size_t *nports,
		    int **ints,
		    size_t *nints)
{
  int i;
  int ports_allocated = 0;
  /* No need to check P here; we don't use it. */

  if (!std_port_array)
    return ENOENT;

  if (*nports < n_std_ports)
    {
      *ports = mmap (0, round_page (n_std_ports * sizeof (mach_port_t)),
		     PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
      if (*ports == MAP_FAILED)
        return ENOMEM;
      ports_allocated = 1;
    }
  memcpy (*ports, std_port_array, n_std_ports * sizeof (mach_port_t));
  *nports = n_std_ports;

  if (*nints < n_std_ints)
    {
      *ints = mmap (0, round_page (n_std_ints * sizeof (int)),
		    PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
      if (*ints == MAP_FAILED)
	{
	  if (ports_allocated)
	    munmap (*ports, round_page (n_std_ports * sizeof (mach_port_t)));
	  return ENOMEM;
	}
    }
  memcpy (*ints, std_int_array, n_std_ints * sizeof (int));
  *nints = n_std_ints;

  for (i = 0; i < n_std_ports; i++)
    mach_port_mod_refs (mach_task_self (), std_port_array[i], MACH_PORT_RIGHT_SEND, 1);
  *portspoly = MACH_MSG_TYPE_MOVE_SEND;

  return 0;
}

/* Implement proc_execdata_notify as described in <hurd/process.defs>. */
kern_return_t
S_proc_execdata_notify (struct proc *p,
			mach_port_t notify)
{
  struct execdata_notify *n;
  mach_port_t foo;

  /* No need to check P here; we don't use it. */

  n = malloc (sizeof (struct execdata_notify));
  if (! n)
    return ENOMEM;

  n->notify_port = notify;
  n->next = execdata_notifys;
  execdata_notifys = n;

  mach_port_request_notification (mach_task_self (), notify,
				  MACH_NOTIFY_DEAD_NAME, 1,
				  generic_port, MACH_MSG_TYPE_MAKE_SEND_ONCE,
				  &foo);

  if (foo)
    mach_port_deallocate (mach_task_self (), foo);

  if (std_port_array)
    exec_setexecdata (n->notify_port, std_port_array, MACH_MSG_TYPE_COPY_SEND,
		      n_std_ports, std_int_array, n_std_ints);
  return 0;
}

/* Check all the execdata notify ports and see if one of them is
   PORT; if it is, then free it. */
void
check_dead_execdata_notify (mach_port_t port)
{
  struct execdata_notify *en, **prevp;

  for (en = execdata_notifys, prevp = &execdata_notifys; en; en = *prevp)
    {
      if (en->notify_port == port)
	{
	  mach_port_deallocate (mach_task_self (), port);
	  *prevp = en->next;
	  free (en);
	}
      else
	prevp = &en->next;
    }
}

/* Version information handling.

   A server registers its name and version with proc_register_version.

   The uname release is the most popular version number.

   The uname version string is composed of all the server names and
   versions, omitting special mention of those which match the uname
   release, plus the kernel version string. */

char *kernel_name, *kernel_version;


/* Rebuild the uname version string.  */
static void
rebuild_uname (void)
{
  unsigned int i, j;
  char *p, *end;

  /* Set up for addstr to write into STRING.  */
  inline void initstr (char *string)
    {
      p = string;
      end = p + _UTSNAME_LENGTH;
    }
  /* If NAME is not null, write "name-version/", else "version/".  */
  inline void addstr (const char *name, const char *version)
    {
      size_t len;
      if (name)
	{
	  len = strlen (name);
	  if (p + len + 1 < end)
	    memcpy (p, name, len);
	  p += len;
	  if (p < end)
	    *p++ = '-';
	}
      len = strlen (version);
      if (p + len + 1 < end)
	memcpy (p, version, len);
      p += len;
      if (p < end)
	*p++ = '/';
    }

  /* Collect all the differing version strings and count how many
     servers use each.  */
  struct version
    {
      const char *version;
      unsigned int count;
    } versions[nserver_versions];
  int compare_versions (const void *a, const void *b)
    {
      return (((const struct version *) b)->count -
	      ((const struct version *) a)->count);
    }
  unsigned int nversions = 0;

  for (i = 0; i < nserver_versions; ++i)
    {
      for (j = 0; j < nversions; ++j)
	if (! strcmp (versions[j].version, server_versions[i].version))
	  {
	    ++versions[j].count;
	    break;
	  }
      if (j == nversions)
	{
	  versions[nversions].version = server_versions[i].version;
	  versions[nversions].count = 1;
	  ++nversions;
	}
    }

  /* Sort the versions in order of decreasing popularity.  */
  qsort (versions, nversions, sizeof (struct version), compare_versions);

  /* Now build the uname strings.  */

  /* release is the most popular version */
  strcpy (uname_info.release, versions[0].version);

  initstr (uname_info.version);

  addstr (kernel_name, kernel_version);

  if (versions[0].count > 1)
    addstr ("Hurd", versions[0].version);

  /* Now, for any which differ (if there might be any), write it out
     separately. */
  if (versions[0].count != nserver_versions)
    for (i = 0; i < nserver_versions; i++)
      if (versions[0].count == 1
	  || strcmp (server_versions[i].version, versions[0].version))
	addstr (server_versions[i].name, server_versions[i].version);

  if (p > end)
#ifdef notyet
    syslog (LOG_EMERG,
	    "_UTSNAME_LENGTH %u too short; inform bug-glibc@prep.ai.mit.edu\n",
	    p - end)
#endif
      ;
  else
    p[-1] = '\0';
  end[-1] = '\0';
}

void
initialize_version_info (void)
{
  extern const char *const mach_cpu_types[];
  extern const char *const mach_cpu_subtypes[][32];
  kernel_version_t kv;
  char *p;
  struct host_basic_info info;
  size_t n = sizeof info;
  error_t err;

  /* Fill in fixed slots sysname and machine.  */
  strcpy (uname_info.sysname, "GNU");

  err = host_info (mach_host_self (), HOST_BASIC_INFO,
		   (host_info_t) &info, &n);
  assert_backtrace (! err);
  snprintf (uname_info.machine, sizeof uname_info.machine, "%s-%s",
	    mach_cpu_types[info.cpu_type],
	    mach_cpu_subtypes[info.cpu_type][info.cpu_subtype]);

  /* Notice Mach's and our own version and initialize server version
     variables. */
  server_versions = malloc (sizeof (struct server_version) * 10);
  assert_backtrace (server_versions);
  server_versions_nalloc = 10;

  err = host_kernel_version (mach_host_self (), kv);
  assert_backtrace (! err);
  /* Make sure the result is null-terminated, as the kernel doesn't
     guarantee it.  */
  kv[sizeof (kv) - 1] = '\0';
  p = index (kv, ':');
  if (p)
    *p = '\0';
  p = index (kv, ' ');
  if (p)
    *p = '\0';
  kernel_name = strdup (p ? kv : "mach");
  assert_backtrace (kernel_name);
  kernel_version = strdup (p ? p + 1 : kv);
  assert_backtrace (kernel_version);

  server_versions[0].name = strdup ("proc");
  assert_backtrace (server_versions[0].name);
  server_versions[0].version = strdup (HURD_VERSION);
  assert_backtrace (server_versions[0].version);

  nserver_versions = 1;

  rebuild_uname ();

  uname_info.nodename[0] = '\0';
}

kern_return_t
S_proc_uname (pstruct_t process,
	      struct utsname *uname)
{
  /* No need to check PROCESS here, we don't use it. */
  *uname = uname_info;
  return 0;
}

kern_return_t
S_proc_register_version (pstruct_t server,
			 mach_port_t credential,
			 const_string_t name,
			 const_string_t release,
			 const_string_t version)
{
  error_t err = 0;
  int i;

  /* No need to check SERVER here; we don't use it. */

  if (credential != _hurd_host_priv)
    /* Must be privileged to register for uname. */
    return EPERM;

  for (i = 0; i < nserver_versions; i++)
    if (!strcmp (name, server_versions[i].name))
      {
	/* Change this entry.  */
	free (server_versions[i].version);
	server_versions[i].version = malloc (strlen (version) + 1);
	if (! server_versions[i].version)
	  {
	    err = ENOMEM;
	    goto out;
	  }
	strcpy (server_versions[i].version, version);
	break;
      }
  if (i == nserver_versions)
    {
      /* Didn't find it; extend.  */
      if (nserver_versions == server_versions_nalloc)
	{
	  void *new = realloc (server_versions,
			       sizeof (struct server_version) *
			       server_versions_nalloc * 2);
	  if (! new)
	    {
	      err = ENOMEM;
	      goto out;
	    }

	  server_versions_nalloc *= 2;
	  server_versions = new;
	}
      server_versions[nserver_versions].name = malloc (strlen (name) + 1);
      if (! server_versions[nserver_versions].name)
	{
	  err = ENOMEM;
	  goto out;
	}
      server_versions[nserver_versions].version = malloc (strlen (version)
							  + 1);
      if (! server_versions[nserver_versions].version)
        {
	  free (server_versions[nserver_versions].name);
	  err = ENOMEM;
	  goto out;
	}
      strcpy (server_versions[nserver_versions].name, name);
      strcpy (server_versions[nserver_versions].version, version);
      nserver_versions++;
    }

  rebuild_uname ();
out:
  if (!err)
    mach_port_deallocate (mach_task_self (), credential);
  return err;
}
