travis.yml: Update Travis to use Bionic and Focal instead of Xenial
[qemu.git] / chardev / char-pty.c
1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "qapi/error.h"
28 #include "chardev/char.h"
29 #include "io/channel-file.h"
30 #include "qemu/sockets.h"
31 #include "qemu/error-report.h"
32 #include "qemu/module.h"
33 #include "qemu/qemu-print.h"
34
35 #include "chardev/char-io.h"
36 #include "qom/object.h"
37
38 struct PtyChardev {
39 Chardev parent;
40 QIOChannel *ioc;
41 int read_bytes;
42
43 int connected;
44 GSource *timer_src;
45 };
46 typedef struct PtyChardev PtyChardev;
47
48 DECLARE_INSTANCE_CHECKER(PtyChardev, PTY_CHARDEV,
49 TYPE_CHARDEV_PTY)
50
51 static void pty_chr_state(Chardev *chr, int connected);
52
53 static void pty_chr_timer_cancel(PtyChardev *s)
54 {
55 if (s->timer_src) {
56 g_source_destroy(s->timer_src);
57 g_source_unref(s->timer_src);
58 s->timer_src = NULL;
59 }
60 }
61
62 static gboolean pty_chr_timer(gpointer opaque)
63 {
64 struct Chardev *chr = CHARDEV(opaque);
65 PtyChardev *s = PTY_CHARDEV(opaque);
66
67 pty_chr_timer_cancel(s);
68 if (!s->connected) {
69 /* Next poll ... */
70 qemu_chr_be_update_read_handlers(chr, chr->gcontext);
71 }
72 return FALSE;
73 }
74
75 static void pty_chr_rearm_timer(Chardev *chr, int ms)
76 {
77 PtyChardev *s = PTY_CHARDEV(chr);
78 char *name;
79
80 pty_chr_timer_cancel(s);
81 name = g_strdup_printf("pty-timer-%s", chr->label);
82 s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
83 g_source_set_name(s->timer_src, name);
84 g_free(name);
85 }
86
87 static void pty_chr_update_read_handler(Chardev *chr)
88 {
89 PtyChardev *s = PTY_CHARDEV(chr);
90 GPollFD pfd;
91 int rc;
92 QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);
93
94 pfd.fd = fioc->fd;
95 pfd.events = G_IO_OUT;
96 pfd.revents = 0;
97 do {
98 rc = g_poll(&pfd, 1, 0);
99 } while (rc == -1 && errno == EINTR);
100 assert(rc >= 0);
101
102 if (pfd.revents & G_IO_HUP) {
103 pty_chr_state(chr, 0);
104 } else {
105 pty_chr_state(chr, 1);
106 }
107 }
108
109 static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
110 {
111 PtyChardev *s = PTY_CHARDEV(chr);
112
113 if (!s->connected) {
114 return len;
115 }
116 return io_channel_send(s->ioc, buf, len);
117 }
118
119 static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond)
120 {
121 PtyChardev *s = PTY_CHARDEV(chr);
122 if (!s->connected) {
123 return NULL;
124 }
125 return qio_channel_create_watch(s->ioc, cond);
126 }
127
128 static int pty_chr_read_poll(void *opaque)
129 {
130 Chardev *chr = CHARDEV(opaque);
131 PtyChardev *s = PTY_CHARDEV(opaque);
132
133 s->read_bytes = qemu_chr_be_can_write(chr);
134 return s->read_bytes;
135 }
136
137 static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
138 {
139 Chardev *chr = CHARDEV(opaque);
140 PtyChardev *s = PTY_CHARDEV(opaque);
141 gsize len;
142 uint8_t buf[CHR_READ_BUF_LEN];
143 ssize_t ret;
144
145 len = sizeof(buf);
146 if (len > s->read_bytes) {
147 len = s->read_bytes;
148 }
149 if (len == 0) {
150 return TRUE;
151 }
152 ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
153 if (ret <= 0) {
154 pty_chr_state(chr, 0);
155 return FALSE;
156 } else {
157 pty_chr_state(chr, 1);
158 qemu_chr_be_write(chr, buf, ret);
159 }
160 return TRUE;
161 }
162
163 static void pty_chr_state(Chardev *chr, int connected)
164 {
165 PtyChardev *s = PTY_CHARDEV(chr);
166
167 if (!connected) {
168 remove_fd_in_watch(chr);
169 s->connected = 0;
170 /* (re-)connect poll interval for idle guests: once per second.
171 * We check more frequently in case the guests sends data to
172 * the virtual device linked to our pty. */
173 pty_chr_rearm_timer(chr, 1000);
174 } else {
175 pty_chr_timer_cancel(s);
176 if (!s->connected) {
177 s->connected = 1;
178 qemu_chr_be_event(chr, CHR_EVENT_OPENED);
179 }
180 if (!chr->gsource) {
181 chr->gsource = io_add_watch_poll(chr, s->ioc,
182 pty_chr_read_poll,
183 pty_chr_read,
184 chr, chr->gcontext);
185 }
186 }
187 }
188
189 static void char_pty_finalize(Object *obj)
190 {
191 Chardev *chr = CHARDEV(obj);
192 PtyChardev *s = PTY_CHARDEV(obj);
193
194 pty_chr_state(chr, 0);
195 object_unref(OBJECT(s->ioc));
196 pty_chr_timer_cancel(s);
197 qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
198 }
199
200 static void char_pty_open(Chardev *chr,
201 ChardevBackend *backend,
202 bool *be_opened,
203 Error **errp)
204 {
205 PtyChardev *s;
206 int master_fd, slave_fd;
207 char pty_name[PATH_MAX];
208 char *name;
209
210 master_fd = qemu_openpty_raw(&slave_fd, pty_name);
211 if (master_fd < 0) {
212 error_setg_errno(errp, errno, "Failed to create PTY");
213 return;
214 }
215
216 close(slave_fd);
217 qemu_set_nonblock(master_fd);
218
219 chr->filename = g_strdup_printf("pty:%s", pty_name);
220 qemu_printf("char device redirected to %s (label %s)\n",
221 pty_name, chr->label);
222
223 s = PTY_CHARDEV(chr);
224 s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
225 name = g_strdup_printf("chardev-pty-%s", chr->label);
226 qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
227 g_free(name);
228 s->timer_src = NULL;
229 *be_opened = false;
230 }
231
232 static void char_pty_class_init(ObjectClass *oc, void *data)
233 {
234 ChardevClass *cc = CHARDEV_CLASS(oc);
235
236 cc->open = char_pty_open;
237 cc->chr_write = char_pty_chr_write;
238 cc->chr_update_read_handler = pty_chr_update_read_handler;
239 cc->chr_add_watch = pty_chr_add_watch;
240 }
241
242 static const TypeInfo char_pty_type_info = {
243 .name = TYPE_CHARDEV_PTY,
244 .parent = TYPE_CHARDEV,
245 .instance_size = sizeof(PtyChardev),
246 .instance_finalize = char_pty_finalize,
247 .class_init = char_pty_class_init,
248 };
249
250 static void register_types(void)
251 {
252 type_register_static(&char_pty_type_info);
253 }
254
255 type_init(register_types);