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5aa3a74a | 1 | /* Duplicate a file descriptor to a given number, with flags. Hurd version. |
d4697bc9 | 2 | Copyright (C) 1991-2014 Free Software Foundation, Inc. |
5aa3a74a TS |
3 | |
4 | This file is part of the GNU C Library. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
febb44a4 TS |
17 | License along with the GNU C Library; see the file COPYING.LIB. If |
18 | not, see <http://www.gnu.org/licenses/>. */ | |
5aa3a74a TS |
19 | |
20 | #include <errno.h> | |
21 | #include <fcntl.h> | |
22 | #include <unistd.h> | |
23 | #include <hurd.h> | |
24 | #include <hurd/fd.h> | |
25 | ||
26 | /* Duplicate FD to FD2, closing the old FD2 and making FD2 be | |
27 | open on the same file as FD is, and setting FD2's flags according to FLAGS. | |
28 | Return FD2 or -1. */ | |
29 | int | |
30 | __dup3 (int fd, int fd2, int flags) | |
31 | { | |
32 | struct hurd_fd *d; | |
33 | ||
34 | /* Both passing flags different from O_CLOEXEC and FD2 being the same as FD | |
35 | are invalid. */ | |
36 | if ((flags & ~O_CLOEXEC | |
37 | || fd2 == fd) | |
38 | /* ... with the exception in case that dup2 behavior is requested: if FD | |
39 | is valid and FD2 is already the same then just return it. */ | |
40 | && ! (flags == -1 | |
41 | && fd2 == fd)) | |
42 | return __hurd_fail (EINVAL); | |
43 | ||
44 | /* Extract the ports and flags from FD. */ | |
45 | d = _hurd_fd_get (fd); | |
46 | if (d == NULL) | |
47 | return __hurd_fail (EBADF); | |
48 | ||
49 | HURD_CRITICAL_BEGIN; | |
50 | ||
51 | __spin_lock (&d->port.lock); | |
52 | if (d->port.port == MACH_PORT_NULL) | |
53 | { | |
54 | __spin_unlock (&d->port.lock); | |
55 | fd2 = __hurd_fail (EBADF); | |
56 | } | |
57 | else if (fd2 == fd) | |
58 | __spin_unlock (&d->port.lock); | |
59 | else | |
60 | { | |
61 | struct hurd_userlink ulink, ctty_ulink; | |
62 | int d_flags = d->flags; | |
63 | io_t ctty = _hurd_port_get (&d->ctty, &ctty_ulink); | |
64 | io_t port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */ | |
65 | ||
66 | if (fd2 < 0) | |
67 | fd2 = __hurd_fail (EBADF); | |
68 | else | |
69 | { | |
70 | /* Get a hold of the destination descriptor. */ | |
71 | struct hurd_fd *d2; | |
72 | ||
f34d6f84 ST |
73 | __mutex_lock (&_hurd_dtable_lock); |
74 | ||
5aa3a74a TS |
75 | if (fd2 >= _hurd_dtablesize) |
76 | { | |
77 | /* The table is not large enough to hold the destination | |
78 | descriptor. Enlarge it as necessary to allocate this | |
79 | descriptor. */ | |
80 | __mutex_unlock (&_hurd_dtable_lock); | |
5aa3a74a TS |
81 | d2 = _hurd_alloc_fd (NULL, fd2); |
82 | if (d2) | |
83 | __spin_unlock (&d2->port.lock); | |
84 | __mutex_lock (&_hurd_dtable_lock); | |
85 | } | |
86 | else | |
87 | { | |
88 | d2 = _hurd_dtable[fd2]; | |
89 | if (d2 == NULL) | |
90 | { | |
91 | /* Must allocate a new one. We don't initialize the port | |
92 | cells with this call so that if it fails (out of | |
93 | memory), we will not have already added user | |
94 | references for the ports, which we would then have to | |
95 | deallocate. */ | |
96 | d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL, | |
97 | MACH_PORT_NULL); | |
98 | } | |
99 | } | |
f34d6f84 | 100 | __mutex_unlock (&_hurd_dtable_lock); |
5aa3a74a TS |
101 | |
102 | if (d2 == NULL) | |
103 | { | |
104 | fd2 = -1; | |
105 | if (errno == EINVAL) | |
106 | errno = EBADF; /* POSIX.1-1990 6.2.1.2 ll 54-55. */ | |
107 | } | |
108 | else | |
109 | { | |
110 | /* Give the ports each a user ref for the new descriptor. */ | |
111 | __mach_port_mod_refs (__mach_task_self (), port, | |
112 | MACH_PORT_RIGHT_SEND, 1); | |
113 | if (ctty != MACH_PORT_NULL) | |
114 | __mach_port_mod_refs (__mach_task_self (), ctty, | |
115 | MACH_PORT_RIGHT_SEND, 1); | |
116 | ||
117 | /* Install the ports and flags in the new descriptor slot. */ | |
118 | __spin_lock (&d2->port.lock); | |
119 | if (flags & O_CLOEXEC) | |
120 | d2->flags = d_flags | FD_CLOEXEC; | |
121 | else | |
122 | /* dup clears FD_CLOEXEC. */ | |
123 | d2->flags = d_flags & ~FD_CLOEXEC; | |
124 | _hurd_port_set (&d2->ctty, ctty); | |
125 | _hurd_port_locked_set (&d2->port, port); /* Unlocks D2. */ | |
126 | } | |
127 | } | |
5aa3a74a TS |
128 | |
129 | _hurd_port_free (&d->port, &ulink, port); | |
130 | if (ctty != MACH_PORT_NULL) | |
131 | _hurd_port_free (&d->ctty, &ctty_ulink, port); | |
132 | } | |
133 | ||
134 | HURD_CRITICAL_END; | |
135 | ||
136 | return fd2; | |
137 | } | |
138 | libc_hidden_def (__dup3) | |
139 | weak_alias (__dup3, dup3) |