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
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
|
/* fhandler_fifo.cc - See fhandler.h for a description of the fhandler classes.
Copyright 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Red Hat, Inc.
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
#include "winsup.h"
#include "miscfuncs.h"
#include "cygerrno.h"
#include "security.h"
#include "path.h"
#include "fhandler.h"
#include "dtable.h"
#include "cygheap.h"
#include "sigproc.h"
#include "cygtls.h"
#include "shared_info.h"
#include "ntdll.h"
fhandler_fifo::fhandler_fifo ():
fhandler_base_overlapped (),
read_ready (NULL), write_ready (NULL)
{
max_atomic_write = DEFAULT_PIPEBUFSIZE;
need_fork_fixup (true);
}
#define fnevent(w) fifo_name (npbuf, w "-event")
#define fnpipe() fifo_name (npbuf, "fifo")
#define create_pipe(r, w) \
fhandler_pipe::create (sa_buf, (r), (w), 0, fnpipe (), open_mode)
char *
fhandler_fifo::fifo_name (char *buf, const char *what)
{
/* Generate a semi-unique name to associate with this fifo. */
__small_sprintf (buf, "%s.%08x.%016X", what, get_dev (),
get_ino ());
return buf;
}
inline PSECURITY_ATTRIBUTES
sec_user_cloexec (bool cloexec, PSECURITY_ATTRIBUTES sa, PSID sid)
{
return cloexec ? sec_user_nih (sa, sid) : sec_user (sa, sid);
}
int
fhandler_fifo::open (int flags, mode_t)
{
enum
{
success,
error_errno_set,
error_set_errno
} res;
bool reader, writer;
DWORD open_mode = FILE_FLAG_OVERLAPPED;
/* Determine what we're doing with this fhandler: reading, writing, both */
switch (flags & O_ACCMODE)
{
case O_RDONLY:
reader = true;
writer = false;
break;
case O_WRONLY:
writer = true;
reader = false;
break;
case O_RDWR:
reader = true;
writer = true;
open_mode |= PIPE_ACCESS_DUPLEX;
break;
default:
set_errno (EINVAL);
res = error_errno_set;
goto out;
}
set_flags (flags);
char char_sa_buf[1024];
LPSECURITY_ATTRIBUTES sa_buf;
sa_buf = sec_user_cloexec (flags & O_CLOEXEC, (PSECURITY_ATTRIBUTES) char_sa_buf,
cygheap->user.sid());
char npbuf[MAX_PATH];
/* Create control events for this named pipe */
if (!(read_ready = CreateEvent (sa_buf, true, false, fnevent ("r"))))
{
debug_printf ("CreatEvent for %s failed, %E", npbuf);
res = error_set_errno;
goto out;
}
if (!(write_ready = CreateEvent (sa_buf, true, false, fnevent ("w"))))
{
debug_printf ("CreatEvent for %s failed, %E", npbuf);
res = error_set_errno;
goto out;
}
/* If we're reading, create the pipe, signal that we're ready and wait for
a writer.
FIXME: Probably need to special case O_RDWR case. */
if (!reader)
/* We are not a reader */;
else if (create_pipe (&get_io_handle (), NULL))
{
debug_printf ("create of reader failed");
res = error_set_errno;
goto out;
}
else if (!SetEvent (read_ready))
{
debug_printf ("SetEvent for read_ready failed, %E");
res = error_set_errno;
goto out;
}
else if (!writer && !wait (write_ready))
{
debug_printf ("wait for write_ready failed, %E");
res = error_errno_set;
goto out;
}
/* If we're writing, it's a little tricky since it is possible that
we're attempting to open the other end of a pipe which is already
connected. In that case, we detect ERROR_PIPE_BUSY, reset the
read_ready event and wait for the reader to allow us to connect
by signalling read_ready.
Once the pipe has been set up, we signal write_ready. */
if (writer)
{
int err;
while (1)
if (!wait (read_ready))
{
res = error_errno_set;
goto out;
}
else if ((err = create_pipe (NULL, &get_io_handle ())) == 0)
break;
else if (err == ERROR_PIPE_BUSY)
{
debug_only_printf ("pipe busy");
ResetEvent (read_ready);
}
else
{
debug_printf ("create of writer failed");
res = error_set_errno;
goto out;
}
if (!SetEvent (write_ready))
{
debug_printf ("SetEvent for write_ready failed, %E");
res = error_set_errno;
goto out;
}
}
/* If setup_overlapped() succeeds (and why wouldn't it?) we are all set. */
if (setup_overlapped () == 0)
res = success;
else
{
debug_printf ("setup_overlapped failed, %E");
res = error_set_errno;
}
out:
if (res == error_set_errno)
__seterrno ();
if (res != success)
{
if (read_ready)
{
CloseHandle (read_ready);
read_ready = NULL;
}
if (write_ready)
{
CloseHandle (write_ready);
write_ready = NULL;
}
if (get_io_handle ())
CloseHandle (get_io_handle ());
}
debug_printf ("res %d", res);
return res == success;
}
bool
fhandler_fifo::wait (HANDLE h)
{
#ifdef DEBUGGING
const char *what;
if (h == read_ready)
what = "reader";
else if (h == write_ready)
what = "writer";
else
what = "overlapped event";
#endif
/* Set the wait to zero for non-blocking I/O-related events. */
DWORD wait = ((h == read_ready || h == write_ready)
&& get_flags () & O_NONBLOCK) ? 0 : INFINITE;
debug_only_printf ("waiting for %s", what);
/* Wait for the event. Set errno, as appropriate if something goes wrong. */
switch (cygwait (h, wait))
{
case WAIT_OBJECT_0:
debug_only_printf ("successfully waited for %s", what);
return true;
case WAIT_TIMEOUT:
if (h == write_ready)
{
debug_only_printf ("wait timed out waiting for write but will still open reader since non-blocking mode");
return true;
}
else
{
set_errno (ENXIO);
return false;
}
break;
case WAIT_OBJECT_0 + 1:
debug_only_printf ("interrupted by signal while waiting for %s", what);
set_errno (EINTR);
return false;
case WAIT_OBJECT_0 + 2:
debug_only_printf ("cancellable interruption while waiting for %s", what);
pthread::static_cancel_self (); /* never returns */
break;
default:
debug_only_printf ("unknown error while waiting for %s", what);
__seterrno ();
return false;
}
}
void __stdcall
fhandler_fifo::raw_read (void *in_ptr, size_t& len)
{
size_t orig_len = len;
for (int i = 0; i < 2; i++)
{
fhandler_base_overlapped::raw_read (in_ptr, len);
if (len || i || WaitForSingleObject (read_ready, 0) == WAIT_OBJECT_0)
break;
/* If we got here, then fhandler_base_overlapped::raw_read returned 0,
indicating "EOF" and something has set read_ready to zero. That means
we should have a client waiting to connect.
FIXME: If the client CTRL-C's the open during this time then this
could hang indefinitely. Maybe implement a timeout? */
if (!DisconnectNamedPipe (get_io_handle ()))
{
debug_printf ("DisconnecttNamedPipe failed, %E");
goto errno_out;
}
else if (!ConnectNamedPipe (get_io_handle (), get_overlapped ())
&& GetLastError () != ERROR_IO_PENDING)
{
debug_printf ("ConnectNamedPipe failed, %E");
goto errno_out;
}
else if (!SetEvent (read_ready))
{
debug_printf ("SetEvent (read_ready) failed, %E");
goto errno_out;
}
else if (!wait (get_overlapped_buffer ()->hEvent))
goto errout; /* If wait() fails, errno is set so no need to set it */
len = orig_len; /* Reset since raw_read above set it to zero. */
}
return;
errno_out:
__seterrno ();
errout:
len = -1;
}
int __stdcall
fhandler_fifo::fstatvfs (struct statvfs *sfs)
{
fhandler_disk_file fh (pc);
fh.get_device () = FH_FS;
return fh.fstatvfs (sfs);
}
int
fhandler_fifo::close ()
{
CloseHandle (read_ready);
CloseHandle (write_ready);
return fhandler_base::close ();
}
int
fhandler_fifo::dup (fhandler_base *child, int flags)
{
if (fhandler_base_overlapped::dup (child, flags))
{
__seterrno ();
return -1;
}
fhandler_fifo *fhf = (fhandler_fifo *) child;
if (!DuplicateHandle (GetCurrentProcess (), read_ready,
GetCurrentProcess (), &fhf->read_ready,
0, true, DUPLICATE_SAME_ACCESS))
{
fhf->close ();
__seterrno ();
return -1;
}
if (!DuplicateHandle (GetCurrentProcess (), write_ready,
GetCurrentProcess (), &fhf->write_ready,
0, true, DUPLICATE_SAME_ACCESS))
{
CloseHandle (fhf->read_ready);
fhf->close ();
__seterrno ();
return -1;
}
return 0;
}
void
fhandler_fifo::fixup_after_fork (HANDLE parent)
{
fhandler_base_overlapped::fixup_after_fork (parent);
fork_fixup (parent, read_ready, "read_ready");
fork_fixup (parent, write_ready, "write_ready");
}
void
fhandler_fifo::set_close_on_exec (bool val)
{
fhandler_base::set_close_on_exec (val);
set_no_inheritance (read_ready, val);
set_no_inheritance (write_ready, val);
}
|