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
|
/* Copyright (C) 1992-1997,1999,2000,2002 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <fcntl.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <stdarg.h>
#include <sys/file.h> /* XXX for LOCK_* */
/* Perform file control operations on FD. */
int
__libc_fcntl (int fd, int cmd, ...)
{
va_list ap;
struct hurd_fd *d;
int result;
d = _hurd_fd_get (fd);
if (d == NULL)
return __hurd_fail (EBADF);
va_start (ap, cmd);
switch (cmd)
{
error_t err;
default: /* Bad command. */
errno = EINVAL;
result = -1;
break;
/* First the descriptor-based commands, which do no RPCs. */
case F_DUPFD: /* Duplicate the file descriptor. */
{
struct hurd_fd *new;
io_t port, ctty;
struct hurd_userlink ulink, ctty_ulink;
int flags;
HURD_CRITICAL_BEGIN;
/* Extract the ports and flags from the file descriptor. */
__spin_lock (&d->port.lock);
flags = d->flags;
ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */
/* Get a new file descriptor. The third argument to __fcntl is the
minimum file descriptor number for it. */
new = _hurd_alloc_fd (&result, va_arg (ap, int));
if (new == NULL)
/* _hurd_alloc_fd has set errno. */
result = -1;
else
{
/* Give the ports each a user ref for the new descriptor. */
__mach_port_mod_refs (__mach_task_self (), port,
MACH_PORT_RIGHT_SEND, 1);
if (ctty != MACH_PORT_NULL)
__mach_port_mod_refs (__mach_task_self (), ctty,
MACH_PORT_RIGHT_SEND, 1);
/* Install the ports and flags in the new descriptor. */
if (ctty != MACH_PORT_NULL)
_hurd_port_set (&new->ctty, ctty);
/* Duplication clears the FD_CLOEXEC flag. */
new->flags = flags & ~FD_CLOEXEC;
_hurd_port_locked_set (&new->port, port); /* Unlocks NEW. */
}
HURD_CRITICAL_END;
_hurd_port_free (&d->port, &ulink, port);
if (ctty != MACH_PORT_NULL)
_hurd_port_free (&d->ctty, &ctty_ulink, port);
break;
}
/* Set RESULT by evaluating EXPR with the descriptor locked.
Check for an empty descriptor and return EBADF. */
#define LOCKED(expr) \
HURD_CRITICAL_BEGIN; \
__spin_lock (&d->port.lock); \
if (d->port.port == MACH_PORT_NULL) \
result = __hurd_fail (EBADF); \
else \
result = (expr); \
__spin_unlock (&d->port.lock); \
HURD_CRITICAL_END;
case F_GETFD: /* Get descriptor flags. */
LOCKED (d->flags);
break;
case F_SETFD: /* Set descriptor flags. */
LOCKED ((d->flags = va_arg (ap, int), 0));
break;
/* Now the real io operations, done by RPCs to io servers. */
case F_GETLK:
case F_SETLK:
case F_SETLKW:
{
/* XXX
We need new RPCs to support POSIX.1 fcntl file locking!!
For the time being we support the whole-file case only,
with all kinds of WRONG WRONG WRONG semantics,
by using flock. This is definitely the Wrong Thing,
but it might be better than nothing (?). */
struct flock *fl = va_arg (ap, struct flock *);
va_end (ap);
switch (cmd)
{
case F_GETLK:
errno = ENOSYS;
return -1;
case F_SETLK:
cmd = LOCK_NB;
break;
default:
cmd = 0;
break;
}
switch (fl->l_type)
{
case F_RDLCK: cmd |= LOCK_SH; break;
case F_WRLCK: cmd |= LOCK_EX; break;
case F_UNLCK: cmd |= LOCK_UN; break;
default:
errno = EINVAL;
return -1;
}
switch (fl->l_whence)
{
case SEEK_SET:
if (fl->l_start == 0 && fl->l_len == 0) /* Whole file request. */
break;
/* It seems to be common for applications to lock the first
byte of the file when they are really doing whole-file locking.
So, since it's so wrong already, might as well do that too. */
if (fl->l_start == 0 && fl->l_len == 1)
break;
/* FALLTHROUGH */
case SEEK_CUR:
case SEEK_END:
errno = ENOTSUP;
return -1;
default:
errno = EINVAL;
return -1;
}
return __flock (fd, cmd);
}
case F_GETFL: /* Get per-open flags. */
if (err = HURD_FD_PORT_USE (d, __io_get_openmodes (port, &result)))
result = __hurd_dfail (fd, err);
break;
case F_SETFL: /* Set per-open flags. */
err = HURD_FD_PORT_USE (d, __io_set_all_openmodes (port,
va_arg (ap, int)));
result = err ? __hurd_dfail (fd, err) : 0;
break;
case F_GETOWN: /* Get owner. */
if (err = HURD_FD_PORT_USE (d, __io_get_owner (port, &result)))
result = __hurd_dfail (fd, err);
break;
case F_SETOWN: /* Set owner. */
err = HURD_FD_PORT_USE (d, __io_mod_owner (port, va_arg (ap, pid_t)));
result = err ? __hurd_dfail (fd, err) : 0;
break;
}
va_end (ap);
return result;
}
libc_hidden_def (__libc_fcntl)
weak_alias (__libc_fcntl, __fcntl)
libc_hidden_weak (__fcntl)
weak_alias (__libc_fcntl, fcntl)
|
