fd.c revision cb8fa61c2b8b29d422d7310f064d60022f18f89b 
1/*
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <unistd.h>
9#include <errno.h>
10#include <termios.h>
11#include "chan_user.h"
12#include "kern_constants.h"
13#include "os.h"
14#include "um_malloc.h"
15#include "user.h"
16
17struct fd_chan {
18	int fd;
19	int raw;
20	struct termios tt;
21	char str[sizeof("1234567890\0")];
22};
23
24static void *fd_init(char *str, int device, const struct chan_opts *opts)
25{
26	struct fd_chan *data;
27	char *end;
28	int n;
29
30	if (*str != ':') {
31		printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
32		       "file descriptor\n");
33		return NULL;
34	}
35	str++;
36	n = strtoul(str, &end, 0);
37	if ((*end != '\0') || (end == str)) {
38		printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
39		       "'%s'\n", str);
40		return NULL;
41	}
42
43	data = kmalloc(sizeof(*data), UM_GFP_KERNEL);
44	if (data == NULL)
45		return NULL;
46
47	*data = ((struct fd_chan) { .fd  	= n,
48				    .raw  	= opts->raw });
49	return data;
50}
51
52static int fd_open(int input, int output, int primary, void *d, char **dev_out)
53{
54	struct fd_chan *data = d;
55	int err;
56
57	if (data->raw && isatty(data->fd)) {
58		CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
59		if (err)
60			return err;
61
62		err = raw(data->fd);
63		if (err)
64			return err;
65	}
66	sprintf(data->str, "%d", data->fd);
67	*dev_out = data->str;
68	return data->fd;
69}
70
71static void fd_close(int fd, void *d)
72{
73	struct fd_chan *data = d;
74	int err;
75
76	if (!data->raw || !isatty(fd))
77		return;
78
79	CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
80	if (err)
81		printk(UM_KERN_ERR "Failed to restore terminal state - "
82		       "errno = %d\n", -err);
83	data->raw = 0;
84}
85
86const struct chan_ops fd_ops = {
87	.type		= "fd",
88	.init		= fd_init,
89	.open		= fd_open,
90	.close		= fd_close,
91	.read		= generic_read,
92	.write		= generic_write,
93	.console_write	= generic_console_write,
94	.window_size	= generic_window_size,
95	.free		= generic_free,
96	.winch		= 1,
97};
98