1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <unistd.h>
9 #include <errno.h>
10 #include <fcntl.h>
11 #include <string.h>
12 #include <termios.h>
13 #include <sys/stat.h>
14 #include "chan_user.h"
15 #include <os.h>
16 #include <um_malloc.h>
17
18 struct pty_chan {
19 void (*announce)(char *dev_name, int dev);
20 int dev;
21 int raw;
22 struct termios tt;
23 char dev_name[sizeof("/dev/pts/0123456\0")];
24 };
25
26 static void *pty_chan_init(char *str, int device, const struct chan_opts *opts)
27 {
28 struct pty_chan *data;
29
30 data = uml_kmalloc(sizeof(*data), UM_GFP_KERNEL);
31 if (data == NULL)
32 return NULL;
33
34 *data = ((struct pty_chan) { .announce = opts->announce,
35 .dev = device,
36 .raw = opts->raw });
37 return data;
38 }
39
40 static int pts_open(int input, int output, int primary, void *d,
41 char **dev_out)
42 {
43 struct pty_chan *data = d;
44 char *dev;
45 int fd, err;
46
47 fd = get_pty();
48 if (fd < 0) {
49 err = -errno;
50 printk(UM_KERN_ERR "open_pts : Failed to open pts\n");
51 return err;
52 }
53
54 if (data->raw) {
55 CATCH_EINTR(err = tcgetattr(fd, &data->tt));
56 if (err)
57 goto out_close;
58
59 err = raw(fd);
60 if (err)
61 goto out_close;
62 }
63
64 dev = ptsname(fd);
65 sprintf(data->dev_name, "%s", dev);
66 *dev_out = data->dev_name;
67
68 if (data->announce)
69 (*data->announce)(dev, data->dev);
70
71 return fd;
72
73 out_close:
74 close(fd);
75 return err;
76 }
77
78 static int getmaster(char *line)
79 {
80 struct stat buf;
81 char *pty, *bank, *cp;
82 int master, err;
83
84 pty = &line[strlen("/dev/ptyp")];
85 for (bank = "pqrs"; *bank; bank++) {
86 line[strlen("/dev/pty")] = *bank;
87 *pty = '';
88 /* Did we hit the end ? */
89 if ((stat(line, &buf) < 0) && (errno == ENOENT))
90 break;
91
92 for (cp = "0123456789abcdef"; *cp; cp++) {
93 *pty = *cp;
94 master = open(line, O_RDWR);
95 if (master >= 0) {
96 char *tp = &line[strlen("/dev/")];
97
98 /* verify slave side is usable */
99 *tp = 't';
100 err = access(line, R_OK | W_OK);
101 *tp = 'p';
102 if (!err)
103 return master;
104 close(master);
105 }
106 }
107 }
108
109 printk(UM_KERN_ERR "getmaster - no usable host pty devices\n");
110 return -ENOENT;
111 }
112
113 static int pty_open(int input, int output, int primary, void *d,
114 char **dev_out)
115 {
116 struct pty_chan *data = d;
117 int fd, err;
118 char dev[sizeof("/dev/ptyxx\0")] = "/dev/ptyxx";
119
120 fd = getmaster(dev);
121 if (fd < 0)
122 return fd;
123
124 if (data->raw) {
125 err = raw(fd);
126 if (err) {
127 close(fd);
128 return err;
129 }
130 }
131
132 if (data->announce)
133 (*data->announce)(dev, data->dev);
134
135 sprintf(data->dev_name, "%s", dev);
136 *dev_out = data->dev_name;
137
138 return fd;
139 }
140
141 const struct chan_ops pty_ops = {
142 .type = "pty",
143 .init = pty_chan_init,
144 .open = pty_open,
145 .close = generic_close,
146 .read = generic_read,
147 .write = generic_write,
148 .console_write = generic_console_write,
149 .window_size = generic_window_size,
150 .free = generic_free,
151 .winch = 0,
152 };
153
154 const struct chan_ops pts_ops = {
155 .type = "pts",
156 .init = pty_chan_init,
157 .open = pts_open,
158 .close = generic_close,
159 .read = generic_read,
160 .write = generic_write,
161 .console_write = generic_console_write,
162 .window_size = generic_window_size,
163 .free = generic_free,
164 .winch = 0,
165 };
166
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