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