Commit | Line | Data |
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067428c1 PE |
1 | /* Create a pipe, with specific opening flags. |
2 | Copyright (C) 2009-2013 Free Software Foundation, Inc. | |
3 | ||
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 3, or (at your option) | |
7 | any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License along | |
15 | with this program; if not, see <http://www.gnu.org/licenses/>. */ | |
16 | ||
17 | #include <config.h> | |
18 | ||
19 | /* Specification. */ | |
20 | #include <unistd.h> | |
21 | ||
22 | #include <errno.h> | |
23 | #include <fcntl.h> | |
24 | ||
25 | #if GNULIB_BINARY_IO | |
26 | # include "binary-io.h" | |
27 | #endif | |
28 | ||
29 | #include "verify.h" | |
30 | ||
31 | #if GNULIB_defined_O_NONBLOCK | |
32 | # include "nonblocking.h" | |
33 | #endif | |
34 | ||
35 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
36 | /* Native Windows API. */ | |
37 | ||
38 | # include <io.h> | |
39 | ||
40 | #endif | |
41 | ||
42 | int | |
43 | pipe2 (int fd[2], int flags) | |
44 | { | |
45 | /* Mingw _pipe() corrupts fd on failure; also, if we succeed at | |
46 | creating the pipe but later fail at changing fcntl, we want | |
47 | to leave fd unchanged: http://austingroupbugs.net/view.php?id=467 */ | |
48 | int tmp[2]; | |
49 | tmp[0] = fd[0]; | |
50 | tmp[1] = fd[1]; | |
51 | ||
52 | #if HAVE_PIPE2 | |
53 | # undef pipe2 | |
54 | /* Try the system call first, if it exists. (We may be running with a glibc | |
55 | that has the function but with an older kernel that lacks it.) */ | |
56 | { | |
57 | /* Cache the information whether the system call really exists. */ | |
58 | static int have_pipe2_really; /* 0 = unknown, 1 = yes, -1 = no */ | |
59 | if (have_pipe2_really >= 0) | |
60 | { | |
61 | int result = pipe2 (fd, flags); | |
62 | if (!(result < 0 && errno == ENOSYS)) | |
63 | { | |
64 | have_pipe2_really = 1; | |
65 | return result; | |
66 | } | |
67 | have_pipe2_really = -1; | |
68 | } | |
69 | } | |
70 | #endif | |
71 | ||
72 | /* Check the supported flags. */ | |
73 | if ((flags & ~(O_CLOEXEC | O_NONBLOCK | O_BINARY | O_TEXT)) != 0) | |
74 | { | |
75 | errno = EINVAL; | |
76 | return -1; | |
77 | } | |
78 | ||
79 | #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__ | |
80 | /* Native Windows API. */ | |
81 | ||
82 | if (_pipe (fd, 4096, flags & ~O_NONBLOCK) < 0) | |
83 | { | |
84 | fd[0] = tmp[0]; | |
85 | fd[1] = tmp[1]; | |
86 | return -1; | |
87 | } | |
88 | ||
89 | /* O_NONBLOCK handling. | |
90 | On native Windows platforms, O_NONBLOCK is defined by gnulib. Use the | |
91 | functions defined by the gnulib module 'nonblocking'. */ | |
92 | # if GNULIB_defined_O_NONBLOCK | |
93 | if (flags & O_NONBLOCK) | |
94 | { | |
95 | if (set_nonblocking_flag (fd[0], true) != 0 | |
96 | || set_nonblocking_flag (fd[1], true) != 0) | |
97 | goto fail; | |
98 | } | |
99 | # else | |
100 | { | |
101 | verify (O_NONBLOCK == 0); | |
102 | } | |
103 | # endif | |
104 | ||
105 | return 0; | |
106 | ||
107 | #else | |
108 | /* Unix API. */ | |
109 | ||
110 | if (pipe (fd) < 0) | |
111 | return -1; | |
112 | ||
113 | /* POSIX <http://www.opengroup.org/onlinepubs/9699919799/functions/pipe.html> | |
114 | says that initially, the O_NONBLOCK and FD_CLOEXEC flags are cleared on | |
115 | both fd[0] and fd[1]. */ | |
116 | ||
117 | /* O_NONBLOCK handling. | |
118 | On Unix platforms, O_NONBLOCK is defined by the system. Use fcntl(). */ | |
119 | if (flags & O_NONBLOCK) | |
120 | { | |
121 | int fcntl_flags; | |
122 | ||
123 | if ((fcntl_flags = fcntl (fd[1], F_GETFL, 0)) < 0 | |
124 | || fcntl (fd[1], F_SETFL, fcntl_flags | O_NONBLOCK) == -1 | |
125 | || (fcntl_flags = fcntl (fd[0], F_GETFL, 0)) < 0 | |
126 | || fcntl (fd[0], F_SETFL, fcntl_flags | O_NONBLOCK) == -1) | |
127 | goto fail; | |
128 | } | |
129 | ||
130 | if (flags & O_CLOEXEC) | |
131 | { | |
132 | int fcntl_flags; | |
133 | ||
134 | if ((fcntl_flags = fcntl (fd[1], F_GETFD, 0)) < 0 | |
135 | || fcntl (fd[1], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1 | |
136 | || (fcntl_flags = fcntl (fd[0], F_GETFD, 0)) < 0 | |
137 | || fcntl (fd[0], F_SETFD, fcntl_flags | FD_CLOEXEC) == -1) | |
138 | goto fail; | |
139 | } | |
140 | ||
141 | # if O_BINARY | |
142 | if (flags & O_BINARY) | |
143 | { | |
144 | setmode (fd[1], O_BINARY); | |
145 | setmode (fd[0], O_BINARY); | |
146 | } | |
147 | else if (flags & O_TEXT) | |
148 | { | |
149 | setmode (fd[1], O_TEXT); | |
150 | setmode (fd[0], O_TEXT); | |
151 | } | |
152 | # endif | |
153 | ||
154 | return 0; | |
155 | ||
156 | #endif | |
157 | ||
158 | #if GNULIB_defined_O_NONBLOCK || \ | |
159 | !((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) | |
160 | fail: | |
161 | { | |
162 | int saved_errno = errno; | |
163 | close (fd[0]); | |
164 | close (fd[1]); | |
165 | fd[0] = tmp[0]; | |
166 | fd[1] = tmp[1]; | |
167 | errno = saved_errno; | |
168 | return -1; | |
169 | } | |
170 | #endif | |
171 | } |