Merge tag 'pull-riscv-to-apply-20220703-1' of github.com:alistair23/qemu into staging
[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 "qapi/error.h"
27 #include "chardev/char.h"
28 #include "io/channel-file.h"
29 #include "qemu/sockets.h"
30 #include "qemu/error-report.h"
31 #include "qemu/module.h"
32 #include "qemu/qemu-print.h"
33
34 #include "chardev/char-io.h"
35 #include "qom/object.h"
36
37 struct PtyChardev {
38 Chardev parent;
39 QIOChannel *ioc;
40 int read_bytes;
41
42 int connected;
43 GSource *timer_src;
44 };
45 typedef struct PtyChardev PtyChardev;
46
47 DECLARE_INSTANCE_CHECKER(PtyChardev, PTY_CHARDEV,
48 TYPE_CHARDEV_PTY)
49
50 static void pty_chr_state(Chardev *chr, int connected);
51
52 static void pty_chr_timer_cancel(PtyChardev *s)
53 {
54 if (s->timer_src) {
55 g_source_destroy(s->timer_src);
56 g_source_unref(s->timer_src);
57 s->timer_src = NULL;
58 }
59 }
60
61 static gboolean pty_chr_timer(gpointer opaque)
62 {
63 struct Chardev *chr = CHARDEV(opaque);
64 PtyChardev *s = PTY_CHARDEV(opaque);
65
66 pty_chr_timer_cancel(s);
67 if (!s->connected) {
68 /* Next poll ... */
69 qemu_chr_be_update_read_handlers(chr, chr->gcontext);
70 }
71 return FALSE;
72 }
73
74 static void pty_chr_rearm_timer(Chardev *chr, int ms)
75 {
76 PtyChardev *s = PTY_CHARDEV(chr);
77 char *name;
78
79 pty_chr_timer_cancel(s);
80 name = g_strdup_printf("pty-timer-%s", chr->label);
81 s->timer_src = qemu_chr_timeout_add_ms(chr, ms, pty_chr_timer, chr);
82 g_source_set_name(s->timer_src, name);
83 g_free(name);
84 }
85
86 static void pty_chr_update_read_handler(Chardev *chr)
87 {
88 PtyChardev *s = PTY_CHARDEV(chr);
89 GPollFD pfd;
90 int rc;
91 QIOChannelFile *fioc = QIO_CHANNEL_FILE(s->ioc);
92
93 pfd.fd = fioc->fd;
94 pfd.events = G_IO_OUT;
95 pfd.revents = 0;
96 do {
97 rc = g_poll(&pfd, 1, 0);
98 } while (rc == -1 && errno == EINTR);
99 assert(rc >= 0);
100
101 if (pfd.revents & G_IO_HUP) {
102 pty_chr_state(chr, 0);
103 } else {
104 pty_chr_state(chr, 1);
105 }
106 }
107
108 static int char_pty_chr_write(Chardev *chr, const uint8_t *buf, int len)
109 {
110 PtyChardev *s = PTY_CHARDEV(chr);
111
112 if (!s->connected) {
113 return len;
114 }
115 return io_channel_send(s->ioc, buf, len);
116 }
117
118 static GSource *pty_chr_add_watch(Chardev *chr, GIOCondition cond)
119 {
120 PtyChardev *s = PTY_CHARDEV(chr);
121 if (!s->connected) {
122 return NULL;
123 }
124 return qio_channel_create_watch(s->ioc, cond);
125 }
126
127 static int pty_chr_read_poll(void *opaque)
128 {
129 Chardev *chr = CHARDEV(opaque);
130 PtyChardev *s = PTY_CHARDEV(opaque);
131
132 s->read_bytes = qemu_chr_be_can_write(chr);
133 return s->read_bytes;
134 }
135
136 static gboolean pty_chr_read(QIOChannel *chan, GIOCondition cond, void *opaque)
137 {
138 Chardev *chr = CHARDEV(opaque);
139 PtyChardev *s = PTY_CHARDEV(opaque);
140 gsize len;
141 uint8_t buf[CHR_READ_BUF_LEN];
142 ssize_t ret;
143
144 len = sizeof(buf);
145 if (len > s->read_bytes) {
146 len = s->read_bytes;
147 }
148 if (len == 0) {
149 return TRUE;
150 }
151 ret = qio_channel_read(s->ioc, (char *)buf, len, NULL);
152 if (ret <= 0) {
153 pty_chr_state(chr, 0);
154 return FALSE;
155 } else {
156 pty_chr_state(chr, 1);
157 qemu_chr_be_write(chr, buf, ret);
158 }
159 return TRUE;
160 }
161
162 static void pty_chr_state(Chardev *chr, int connected)
163 {
164 PtyChardev *s = PTY_CHARDEV(chr);
165
166 if (!connected) {
167 remove_fd_in_watch(chr);
168 s->connected = 0;
169 /* (re-)connect poll interval for idle guests: once per second.
170 * We check more frequently in case the guests sends data to
171 * the virtual device linked to our pty. */
172 pty_chr_rearm_timer(chr, 1000);
173 } else {
174 pty_chr_timer_cancel(s);
175 if (!s->connected) {
176 s->connected = 1;
177 qemu_chr_be_event(chr, CHR_EVENT_OPENED);
178 }
179 if (!chr->gsource) {
180 chr->gsource = io_add_watch_poll(chr, s->ioc,
181 pty_chr_read_poll,
182 pty_chr_read,
183 chr, chr->gcontext);
184 }
185 }
186 }
187
188 static void char_pty_finalize(Object *obj)
189 {
190 Chardev *chr = CHARDEV(obj);
191 PtyChardev *s = PTY_CHARDEV(obj);
192
193 pty_chr_state(chr, 0);
194 object_unref(OBJECT(s->ioc));
195 pty_chr_timer_cancel(s);
196 qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
197 }
198
199 #if defined HAVE_PTY_H
200 # include <pty.h>
201 #elif defined CONFIG_BSD
202 # include <termios.h>
203 # if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
204 # include <libutil.h>
205 # else
206 # include <util.h>
207 # endif
208 #elif defined CONFIG_SOLARIS
209 # include <termios.h>
210 # include <stropts.h>
211 #else
212 # include <termios.h>
213 #endif
214
215 #ifdef __sun__
216
217 #if !defined(HAVE_OPENPTY)
218 /* Once illumos has openpty(), this is going to be removed. */
219 static int openpty(int *amaster, int *aslave, char *name,
220 struct termios *termp, struct winsize *winp)
221 {
222 const char *slave;
223 int mfd = -1, sfd = -1;
224
225 *amaster = *aslave = -1;
226
227 mfd = open("/dev/ptmx", O_RDWR | O_NOCTTY);
228 if (mfd < 0) {
229 goto err;
230 }
231
232 if (grantpt(mfd) == -1 || unlockpt(mfd) == -1) {
233 goto err;
234 }
235
236 if ((slave = ptsname(mfd)) == NULL) {
237 goto err;
238 }
239
240 if ((sfd = open(slave, O_RDONLY | O_NOCTTY)) == -1) {
241 goto err;
242 }
243
244 if (ioctl(sfd, I_PUSH, "ptem") == -1 ||
245 (termp != NULL && tcgetattr(sfd, termp) < 0)) {
246 goto err;
247 }
248
249 *amaster = mfd;
250 *aslave = sfd;
251
252 if (winp) {
253 ioctl(sfd, TIOCSWINSZ, winp);
254 }
255
256 return 0;
257
258 err:
259 if (sfd != -1) {
260 close(sfd);
261 }
262 close(mfd);
263 return -1;
264 }
265 #endif
266
267 static void cfmakeraw (struct termios *termios_p)
268 {
269 termios_p->c_iflag &=
270 ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
271 termios_p->c_oflag &= ~OPOST;
272 termios_p->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
273 termios_p->c_cflag &= ~(CSIZE | PARENB);
274 termios_p->c_cflag |= CS8;
275
276 termios_p->c_cc[VMIN] = 0;
277 termios_p->c_cc[VTIME] = 0;
278 }
279 #endif
280
281 /* like openpty() but also makes it raw; return master fd */
282 static int qemu_openpty_raw(int *aslave, char *pty_name)
283 {
284 int amaster;
285 struct termios tty;
286 #if defined(__OpenBSD__) || defined(__DragonFly__)
287 char pty_buf[PATH_MAX];
288 #define q_ptsname(x) pty_buf
289 #else
290 char *pty_buf = NULL;
291 #define q_ptsname(x) ptsname(x)
292 #endif
293
294 if (openpty(&amaster, aslave, pty_buf, NULL, NULL) < 0) {
295 return -1;
296 }
297
298 /* Set raw attributes on the pty. */
299 tcgetattr(*aslave, &tty);
300 cfmakeraw(&tty);
301 tcsetattr(*aslave, TCSAFLUSH, &tty);
302
303 if (pty_name) {
304 strcpy(pty_name, q_ptsname(amaster));
305 }
306
307 return amaster;
308 }
309
310 static void char_pty_open(Chardev *chr,
311 ChardevBackend *backend,
312 bool *be_opened,
313 Error **errp)
314 {
315 PtyChardev *s;
316 int master_fd, slave_fd;
317 char pty_name[PATH_MAX];
318 char *name;
319
320 master_fd = qemu_openpty_raw(&slave_fd, pty_name);
321 if (master_fd < 0) {
322 error_setg_errno(errp, errno, "Failed to create PTY");
323 return;
324 }
325
326 close(slave_fd);
327 if (!g_unix_set_fd_nonblocking(master_fd, true, NULL)) {
328 error_setg_errno(errp, errno, "Failed to set FD nonblocking");
329 return;
330 }
331
332 chr->filename = g_strdup_printf("pty:%s", pty_name);
333 qemu_printf("char device redirected to %s (label %s)\n",
334 pty_name, chr->label);
335
336 s = PTY_CHARDEV(chr);
337 s->ioc = QIO_CHANNEL(qio_channel_file_new_fd(master_fd));
338 name = g_strdup_printf("chardev-pty-%s", chr->label);
339 qio_channel_set_name(QIO_CHANNEL(s->ioc), name);
340 g_free(name);
341 s->timer_src = NULL;
342 *be_opened = false;
343 }
344
345 static void char_pty_class_init(ObjectClass *oc, void *data)
346 {
347 ChardevClass *cc = CHARDEV_CLASS(oc);
348
349 cc->open = char_pty_open;
350 cc->chr_write = char_pty_chr_write;
351 cc->chr_update_read_handler = pty_chr_update_read_handler;
352 cc->chr_add_watch = pty_chr_add_watch;
353 }
354
355 static const TypeInfo char_pty_type_info = {
356 .name = TYPE_CHARDEV_PTY,
357 .parent = TYPE_CHARDEV,
358 .instance_size = sizeof(PtyChardev),
359 .instance_finalize = char_pty_finalize,
360 .class_init = char_pty_class_init,
361 };
362
363 static void register_types(void)
364 {
365 type_register_static(&char_pty_type_info);
366 }
367
368 type_init(register_types);