1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
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 <os.h>
13 #include <um_malloc.h>
14
15 struct fd_chan {
16 int fd;
17 int raw;
18 struct termios tt;
19 char str[sizeof("1234567890\0")];
20 };
21
22 static void *fd_init(char *str, int device, const struct chan_opts *opts)
23 {
24 struct fd_chan *data;
25 char *end;
26 int n;
27
28 if (*str != ':') {
29 printk(UM_KERN_ERR "fd_init : channel type 'fd' must specify a "
30 "file descriptor\n");
31 return NULL;
32 }
33 str++;
34 n = strtoul(str, &end, 0);
35 if ((*end != '\0') || (end == str)) {
36 printk(UM_KERN_ERR "fd_init : couldn't parse file descriptor "
37 "'%s'\n", str);
38 return NULL;
39 }
40
41 data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
42 if (data == NULL)
43 return NULL;
44
45 *data = ((struct fd_chan) { .fd = n,
46 .raw = opts->raw });
47 return data;
48 }
49
50 static int fd_open(int input, int output, int primary, void *d, char **dev_out)
51 {
52 struct fd_chan *data = d;
53 int err;
54
55 if (data->raw && isatty(data->fd)) {
56 CATCH_EINTR(err = tcgetattr(data->fd, &data->tt));
57 if (err)
58 return err;
59
60 err = raw(data->fd);
61 if (err)
62 return err;
63 }
64 sprintf(data->str, "%d", data->fd);
65 *dev_out = data->str;
66 return data->fd;
67 }
68
69 static void fd_close(int fd, void *d)
70 {
71 struct fd_chan *data = d;
72 int err;
73
74 if (!data->raw || !isatty(fd))
75 return;
76
77 CATCH_EINTR(err = tcsetattr(fd, TCSAFLUSH, &data->tt));
78 if (err)
79 printk(UM_KERN_ERR "Failed to restore terminal state - "
80 "errno = %d\n", -err);
81 data->raw = 0;
82 }
83
84 const struct chan_ops fd_ops = {
85 .type = "fd",
86 .init = fd_init,
87 .open = fd_open,
88 .close = fd_close,
89 .read = generic_read,
90 .write = generic_write,
91 .console_write = generic_console_write,
92 .window_size = generic_window_size,
93 .free = generic_free,
94 .winch = 1,
95 };
96
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