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
|
/* ----------------------------------------------------------------------- *
*
* Copyright 2003-2008 H. Peter Anvin - All Rights Reserved
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom
* the Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall
* be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* ----------------------------------------------------------------------- */
#include <errno.h>
#include <com32.h>
#include <string.h>
#include <unistd.h>
#include "file.h"
/*
* opendev.c
*
* Open a special device
*/
int opendev(const struct input_dev *idev,
const struct output_dev *odev, int flags)
{
int fd;
struct file_info *fp;
int okflags;
int e;
okflags = (idev ? idev->fileflags : 0) | (odev ? odev->fileflags : 0);
if ( !(flags & 3) || (flags & ~okflags) ) {
errno = EINVAL;
return -1;
}
for ( fd = 0, fp = __file_info ; fd < NFILES ; fd++, fp++ )
if ( !fp->iop && !fp->oop )
break;
if ( fd >= NFILES ) {
errno = EMFILE;
return -1;
}
/* The file structure is already zeroed */
fp->iop = &dev_error_r;
fp->oop = &dev_error_w;
fp->i.datap = fp->i.buf;
if (idev) {
if (idev->open && (e = idev->open(fp))) {
errno = e;
goto puke;
}
fp->iop = idev;
}
while (odev) {
if (odev->open && (e = odev->open(fp))) {
if (e == EAGAIN) {
if (odev->fallback) {
odev = odev->fallback;
continue;
} else {
e = EIO;
}
}
errno = e;
goto puke;
}
fp->oop = odev;
break;
}
return fd;
puke:
close(fd);
return -1;
}
|
