summary refs log tree commit diff
path: root/hurd/dtable.c
blob: 3e785a9710e13f36c18869c10ca000cec0c8b675 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <hurd.h>
#include <hurd/term.h>
#include <hurd/fd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <limits.h>
#include <cthreads.h>		/* For `struct mutex'.  */
#include "set-hooks.h"
#include "hurdmalloc.h"		/* XXX */


struct mutex _hurd_dtable_lock = MUTEX_INITIALIZER; /* XXX ld bug; must init */
struct hurd_fd **_hurd_dtable;
int _hurd_dtablesize;


DEFINE_HOOK (_hurd_fd_subinit, (void));

/* Initialize the file descriptor table at startup.  */

static void
init_dtable (void)
{
  register size_t i;

  __mutex_init (&_hurd_dtable_lock);

  /* The initial size of the descriptor table is that of the passed-in
     table.  It will be expanded as necessary up to _hurd_dtable_rlimit.  */
  _hurd_dtablesize = _hurd_init_dtablesize;

  /* Allocate the vector of pointers.  */
  _hurd_dtable = malloc (_hurd_dtablesize * sizeof (*_hurd_dtable));
  if (_hurd_dtablesize != 0 && _hurd_dtable == NULL)
    __libc_fatal ("hurd: Can't allocate file descriptor table\n");

  /* Initialize the descriptor table.  */
  for (i = 0; i < _hurd_init_dtablesize; ++i)
    {
      if (_hurd_init_dtable[i] == MACH_PORT_NULL)
	/* An unused descriptor is marked by a null pointer.  */
	_hurd_dtable[i] = NULL;
      else
	{
	  /* Allocate a new file descriptor structure.  */
	  struct hurd_fd *new = malloc (sizeof (struct hurd_fd));
	  if (new == NULL)
	    __libc_fatal ("hurd: Can't allocate initial file descriptors\n");

	  /* Initialize the port cells.  */
	  _hurd_port_init (&new->port, MACH_PORT_NULL);
	  _hurd_port_init (&new->ctty, MACH_PORT_NULL);

	  /* Install the port in the descriptor.
	     This sets up all the ctty magic.  */
	  _hurd_port2fd (new, _hurd_init_dtable[i], 0);

	  _hurd_dtable[i] = new;
	}
    }

  /* Clear out the initial descriptor table.
     Everything must use _hurd_dtable now.  */
  __vm_deallocate (__mach_task_self (),
		   (vm_address_t) _hurd_init_dtable,
		   _hurd_init_dtablesize * sizeof (_hurd_init_dtable[0]));
  _hurd_init_dtable = NULL;
  _hurd_init_dtablesize = 0;

  /* Initialize the remaining empty slots in the table.  */
  for (; i < _hurd_dtablesize; ++i)
    _hurd_dtable[i] = NULL;

  /* Run things that want to run after the file descriptor table
     is initialized.  */
  RUN_HOOK (_hurd_fd_subinit, ());

  (void) &init_dtable;		/* Avoid "defined but not used" warning.  */
}

text_set_element (_hurd_subinit, init_dtable);

/* XXX when the linker supports it, the following functions should all be
   elsewhere and just have text_set_elements here.  */

/* Called by `getdport' to do its work.  */

static file_t
get_dtable_port (int fd)
{
  file_t dport;
  int err = HURD_DPORT_USE (fd, __mach_port_mod_refs (__mach_task_self (),
						      (dport = port),
						      MACH_PORT_RIGHT_SEND,
						      1));
  if (err)
    {
      errno = err;
      return MACH_PORT_NULL;
    }
  else
    return dport;
}

file_t (*_hurd_getdport_fn) (int fd) = get_dtable_port;

#include <hurd/signal.h>

/* We are in the child fork; the dtable lock is still held.
   The parent has inserted send rights for all the normal io ports,
   but we must recover ctty-special ports for ourselves.  */
static error_t
fork_child_dtable (void)
{
  error_t err;
  int i;

  err = 0;

  for (i = 0; !err && i < _hurd_dtablesize; ++i)
    {
      struct hurd_fd *d = _hurd_dtable[i];
      if (d == NULL)
	continue;

      /* No other thread is using the send rights in the child task.  */
      d->port.users = d->ctty.users = NULL;

      if (d->ctty.port != MACH_PORT_NULL)
	{
	  /* There was a ctty-special port in the parent.
	     We need to get one for ourselves too.  */
	  __mach_port_deallocate (__mach_task_self (), d->ctty.port);
	  err = __term_open_ctty (d->port.port, _hurd_pid, _hurd_pgrp,
				  &d->ctty.port);
	  if (err)
	    d->ctty.port = MACH_PORT_NULL;
	}

      /* XXX for each fd with a cntlmap, reauth and re-map_cntl.  */
    }
  return err;

  (void) &fork_child_dtable;	/* Avoid "defined but not used" warning.  */
}

data_set_element (_hurd_fork_locks, _hurd_dtable_lock);	/* XXX ld bug: bss */
text_set_element (_hurd_fork_child_hook, fork_child_dtable);

/* Called when our process group has changed.  */

static void
ctty_new_pgrp (void)
{
  int i;
  
  HURD_CRITICAL_BEGIN;
  __mutex_lock (&_hurd_dtable_lock);

  for (i = 0; i < _hurd_dtablesize; ++i)
    {
      struct hurd_fd *const d = _hurd_dtable[i];
      struct hurd_userlink ulink, ctty_ulink;
      io_t port, ctty;

      if (d == NULL)
	/* Nothing to do for an unused descriptor cell.  */
	continue;

      port = _hurd_port_get (&d->port, &ulink);
      ctty = _hurd_port_get (&d->ctty, &ctty_ulink);

      if (ctty != MACH_PORT_NULL)
	{
	  /* This fd has a ctty-special port.  We need a new one, to tell
             the io server of our different process group.  */
	  io_t new;
	  if (__term_open_ctty (port, _hurd_pid, _hurd_pgrp, &new))
	    new = MACH_PORT_NULL;
	  _hurd_port_set (&d->ctty, new);
	}

      _hurd_port_free (&d->port, &ulink, port);
      _hurd_port_free (&d->ctty, &ctty_ulink, ctty);
    }

  __mutex_unlock (&_hurd_dtable_lock);
  HURD_CRITICAL_END;

  (void) &ctty_new_pgrp;	/* Avoid "defined but not used" warning.  */
}

text_set_element (_hurd_pgrp_changed_hook, ctty_new_pgrp);

/* Called to reauthenticate the dtable when the auth port changes.  */

static void
reauth_dtable (void)
{
  int i;

  HURD_CRITICAL_BEGIN;
  __mutex_lock (&_hurd_dtable_lock);

  for (i = 0; i < _hurd_dtablesize; ++i)
    {
      struct hurd_fd *const d = _hurd_dtable[i];
      mach_port_t new, newctty, ref;
      
      if (d == NULL)
	/* Nothing to do for an unused descriptor cell.  */
	continue;

      ref = __mach_reply_port ();

      /* Take the descriptor cell's lock.  */
      __spin_lock (&d->port.lock);
      
      /* Reauthenticate the descriptor's port.  */
      if (d->port.port != MACH_PORT_NULL &&
	  ! __io_reauthenticate (d->port.port,
				 ref, MACH_MSG_TYPE_MAKE_SEND) &&
	  ! __USEPORT (AUTH, __auth_user_authenticate
		       (port,
			d->port.port,
			ref, MACH_MSG_TYPE_MAKE_SEND,
			&new)))
	{
	  /* Replace the port in the descriptor cell
	     with the newly reauthenticated port.  */

	  if (d->ctty.port != MACH_PORT_NULL &&
	      ! __io_reauthenticate (d->ctty.port,
				     ref, MACH_MSG_TYPE_MAKE_SEND) &&
	      ! __USEPORT (AUTH, __auth_user_authenticate
			   (port,
			    d->ctty.port,
			    ref, MACH_MSG_TYPE_MAKE_SEND,
			    &newctty)))
	    _hurd_port_set (&d->ctty, newctty);

	  _hurd_port_locked_set (&d->port, new);
	}
      else
	/* Lost.  Leave this descriptor cell alone.  */
	__spin_unlock (&d->port.lock);

      __mach_port_destroy (__mach_task_self (), ref);
    }

  __mutex_unlock (&_hurd_dtable_lock);
  HURD_CRITICAL_END;

  (void) &reauth_dtable;	/* Avoid "defined but not used" warning.  */
}

text_set_element (_hurd_reauth_hook, reauth_dtable);