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6ec2e0f5 SDJ |
1 | /* Duplicate an open file descriptor to a specified file descriptor. |
2 | ||
5e8754f9 | 3 | Copyright (C) 1999, 2004-2007, 2009-2016 Free Software Foundation, Inc. |
6ec2e0f5 SDJ |
4 | |
5 | This program is free software: you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 3 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
5e8754f9 | 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
6ec2e0f5 SDJ |
17 | |
18 | /* written by Paul Eggert */ | |
19 | ||
20 | #include <config.h> | |
21 | ||
22 | /* Specification. */ | |
23 | #include <unistd.h> | |
24 | ||
25 | #include <errno.h> | |
26 | #include <fcntl.h> | |
27 | ||
28 | #if HAVE_DUP2 | |
29 | ||
30 | # undef dup2 | |
31 | ||
5e8754f9 | 32 | # if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ |
6ec2e0f5 SDJ |
33 | |
34 | /* Get declarations of the native Windows API functions. */ | |
35 | # define WIN32_LEAN_AND_MEAN | |
36 | # include <windows.h> | |
37 | ||
5e8754f9 | 38 | # include "msvc-inval.h" |
6ec2e0f5 SDJ |
39 | |
40 | /* Get _get_osfhandle. */ | |
5e8754f9 | 41 | # include "msvc-nothrow.h" |
6ec2e0f5 SDJ |
42 | |
43 | static int | |
44 | ms_windows_dup2 (int fd, int desired_fd) | |
45 | { | |
46 | int result; | |
47 | ||
48 | /* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open, | |
49 | dup2 (fd, fd) returns 0, but all further attempts to use fd in | |
50 | future dup2 calls will hang. */ | |
51 | if (fd == desired_fd) | |
52 | { | |
53 | if ((HANDLE) _get_osfhandle (fd) == INVALID_HANDLE_VALUE) | |
54 | { | |
55 | errno = EBADF; | |
56 | return -1; | |
57 | } | |
58 | return fd; | |
59 | } | |
60 | ||
61 | /* Wine 1.0.1 return 0 when desired_fd is negative but not -1: | |
5e8754f9 | 62 | http://bugs.winehq.org/show_bug.cgi?id=21289 */ |
6ec2e0f5 SDJ |
63 | if (desired_fd < 0) |
64 | { | |
65 | errno = EBADF; | |
66 | return -1; | |
67 | } | |
68 | ||
5e8754f9 SDJ |
69 | TRY_MSVC_INVAL |
70 | { | |
71 | result = dup2 (fd, desired_fd); | |
72 | } | |
73 | CATCH_MSVC_INVAL | |
74 | { | |
75 | errno = EBADF; | |
76 | result = -1; | |
77 | } | |
78 | DONE_MSVC_INVAL; | |
6ec2e0f5 SDJ |
79 | |
80 | if (result == 0) | |
81 | result = desired_fd; | |
82 | ||
83 | return result; | |
84 | } | |
85 | ||
86 | # define dup2 ms_windows_dup2 | |
87 | ||
88 | # elif defined __KLIBC__ | |
89 | ||
90 | # include <InnoTekLIBC/backend.h> | |
91 | ||
92 | static int | |
93 | klibc_dup2dirfd (int fd, int desired_fd) | |
94 | { | |
95 | int tempfd; | |
96 | int dupfd; | |
97 | ||
98 | tempfd = open ("NUL", O_RDONLY); | |
99 | if (tempfd == -1) | |
100 | return -1; | |
101 | ||
102 | if (tempfd == desired_fd) | |
103 | { | |
104 | close (tempfd); | |
105 | ||
106 | char path[_MAX_PATH]; | |
107 | if (__libc_Back_ioFHToPath (fd, path, sizeof (path))) | |
108 | return -1; | |
109 | ||
110 | return open(path, O_RDONLY); | |
111 | } | |
112 | ||
113 | dupfd = klibc_dup2dirfd (fd, desired_fd); | |
114 | ||
115 | close (tempfd); | |
116 | ||
117 | return dupfd; | |
118 | } | |
119 | ||
120 | static int | |
121 | klibc_dup2 (int fd, int desired_fd) | |
122 | { | |
123 | int dupfd; | |
124 | struct stat sbuf; | |
125 | ||
126 | dupfd = dup2 (fd, desired_fd); | |
127 | if (dupfd == -1 && errno == ENOTSUP \ | |
128 | && !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode)) | |
129 | { | |
130 | close (desired_fd); | |
131 | ||
132 | return klibc_dup2dirfd (fd, desired_fd); | |
133 | } | |
134 | ||
135 | return dupfd; | |
136 | } | |
137 | ||
138 | # define dup2 klibc_dup2 | |
139 | # endif | |
140 | ||
141 | int | |
142 | rpl_dup2 (int fd, int desired_fd) | |
143 | { | |
144 | int result; | |
145 | ||
146 | # ifdef F_GETFL | |
147 | /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. | |
148 | On Cygwin 1.5.x, dup2 (1, 1) returns 0. | |
149 | On Cygwin 1.7.17, dup2 (1, -1) dumps core. | |
150 | On Cygwin 1.7.25, dup2 (1, 256) can dump core. | |
151 | On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ | |
152 | # if HAVE_SETDTABLESIZE | |
153 | setdtablesize (desired_fd + 1); | |
154 | # endif | |
155 | if (desired_fd < 0) | |
156 | fd = desired_fd; | |
157 | if (fd == desired_fd) | |
158 | return fcntl (fd, F_GETFL) == -1 ? -1 : fd; | |
159 | # endif | |
160 | ||
161 | result = dup2 (fd, desired_fd); | |
162 | ||
163 | /* Correct an errno value on FreeBSD 6.1 and Cygwin 1.5.x. */ | |
164 | if (result == -1 && errno == EMFILE) | |
165 | errno = EBADF; | |
166 | # if REPLACE_FCHDIR | |
167 | if (fd != desired_fd && result != -1) | |
168 | result = _gl_register_dup (fd, result); | |
169 | # endif | |
170 | return result; | |
171 | } | |
172 | ||
173 | #else /* !HAVE_DUP2 */ | |
174 | ||
175 | /* On older platforms, dup2 did not exist. */ | |
176 | ||
177 | # ifndef F_DUPFD | |
178 | static int | |
179 | dupfd (int fd, int desired_fd) | |
180 | { | |
181 | int duplicated_fd = dup (fd); | |
182 | if (duplicated_fd < 0 || duplicated_fd == desired_fd) | |
183 | return duplicated_fd; | |
184 | else | |
185 | { | |
186 | int r = dupfd (fd, desired_fd); | |
187 | int e = errno; | |
188 | close (duplicated_fd); | |
189 | errno = e; | |
190 | return r; | |
191 | } | |
192 | } | |
193 | # endif | |
194 | ||
195 | int | |
196 | dup2 (int fd, int desired_fd) | |
197 | { | |
198 | int result = fcntl (fd, F_GETFL) < 0 ? -1 : fd; | |
199 | if (result == -1 || fd == desired_fd) | |
200 | return result; | |
201 | close (desired_fd); | |
202 | # ifdef F_DUPFD | |
203 | result = fcntl (fd, F_DUPFD, desired_fd); | |
204 | # if REPLACE_FCHDIR | |
205 | if (0 <= result) | |
206 | result = _gl_register_dup (fd, result); | |
207 | # endif | |
208 | # else | |
209 | result = dupfd (fd, desired_fd); | |
210 | # endif | |
211 | if (result == -1 && (errno == EMFILE || errno == EINVAL)) | |
212 | errno = EBADF; | |
213 | return result; | |
214 | } | |
215 | #endif /* !HAVE_DUP2 */ |