xref: /openbmc/qemu/chardev/char.c (revision dda2441b)
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/cutils.h"
27 #include "monitor/monitor.h"
28 #include "sysemu/sysemu.h"
29 #include "qemu/config-file.h"
30 #include "qemu/error-report.h"
31 #include "chardev/char.h"
32 #include "qapi/error.h"
33 #include "qapi/qapi-commands-char.h"
34 #include "qapi/qmp/qerror.h"
35 #include "sysemu/replay.h"
36 #include "qemu/help_option.h"
37 #include "qemu/option.h"
38 
39 #include "chardev/char-mux.h"
40 
41 /***********************************************************/
42 /* character device */
43 
44 static Object *get_chardevs_root(void)
45 {
46     return container_get(object_get_root(), "/chardevs");
47 }
48 
49 static void chr_be_event(Chardev *s, int event)
50 {
51     CharBackend *be = s->be;
52 
53     if (!be || !be->chr_event) {
54         return;
55     }
56 
57     be->chr_event(be->opaque, event);
58 }
59 
60 void qemu_chr_be_event(Chardev *s, int event)
61 {
62     /* Keep track if the char device is open */
63     switch (event) {
64         case CHR_EVENT_OPENED:
65             s->be_open = 1;
66             break;
67         case CHR_EVENT_CLOSED:
68             s->be_open = 0;
69             break;
70     }
71 
72     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
73 }
74 
75 /* Not reporting errors from writing to logfile, as logs are
76  * defined to be "best effort" only */
77 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
78 {
79     size_t done = 0;
80     ssize_t ret;
81 
82     if (s->logfd < 0) {
83         return;
84     }
85 
86     while (done < len) {
87     retry:
88         ret = write(s->logfd, buf + done, len - done);
89         if (ret == -1 && errno == EAGAIN) {
90             g_usleep(100);
91             goto retry;
92         }
93 
94         if (ret <= 0) {
95             return;
96         }
97         done += ret;
98     }
99 }
100 
101 static int qemu_chr_write_buffer(Chardev *s,
102                                  const uint8_t *buf, int len,
103                                  int *offset, bool write_all)
104 {
105     ChardevClass *cc = CHARDEV_GET_CLASS(s);
106     int res = 0;
107     *offset = 0;
108 
109     qemu_mutex_lock(&s->chr_write_lock);
110     while (*offset < len) {
111     retry:
112         res = cc->chr_write(s, buf + *offset, len - *offset);
113         if (res < 0 && errno == EAGAIN && write_all) {
114             g_usleep(100);
115             goto retry;
116         }
117 
118         if (res <= 0) {
119             break;
120         }
121 
122         *offset += res;
123         if (!write_all) {
124             break;
125         }
126     }
127     if (*offset > 0) {
128         qemu_chr_write_log(s, buf, *offset);
129     }
130     qemu_mutex_unlock(&s->chr_write_lock);
131 
132     return res;
133 }
134 
135 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
136 {
137     int offset = 0;
138     int res;
139 
140     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
141         replay_char_write_event_load(&res, &offset);
142         assert(offset <= len);
143         qemu_chr_write_buffer(s, buf, offset, &offset, true);
144         return res;
145     }
146 
147     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
148 
149     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
150         replay_char_write_event_save(res, offset);
151     }
152 
153     if (res < 0) {
154         return res;
155     }
156     return offset;
157 }
158 
159 int qemu_chr_be_can_write(Chardev *s)
160 {
161     CharBackend *be = s->be;
162 
163     if (!be || !be->chr_can_read) {
164         return 0;
165     }
166 
167     return be->chr_can_read(be->opaque);
168 }
169 
170 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
171 {
172     CharBackend *be = s->be;
173 
174     if (be && be->chr_read) {
175         be->chr_read(be->opaque, buf, len);
176     }
177 }
178 
179 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
180 {
181     if (qemu_chr_replay(s)) {
182         if (replay_mode == REPLAY_MODE_PLAY) {
183             return;
184         }
185         replay_chr_be_write(s, buf, len);
186     } else {
187         qemu_chr_be_write_impl(s, buf, len);
188     }
189 }
190 
191 void qemu_chr_be_update_read_handlers(Chardev *s,
192                                       GMainContext *context)
193 {
194     ChardevClass *cc = CHARDEV_GET_CLASS(s);
195 
196     s->gcontext = context;
197     if (cc->chr_update_read_handler) {
198         cc->chr_update_read_handler(s);
199     }
200 }
201 
202 int qemu_chr_add_client(Chardev *s, int fd)
203 {
204     return CHARDEV_GET_CLASS(s)->chr_add_client ?
205         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
206 }
207 
208 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
209                            bool *be_opened, Error **errp)
210 {
211     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
212     /* Any ChardevCommon member would work */
213     ChardevCommon *common = backend ? backend->u.null.data : NULL;
214 
215     if (common && common->has_logfile) {
216         int flags = O_WRONLY | O_CREAT;
217         if (common->has_logappend &&
218             common->logappend) {
219             flags |= O_APPEND;
220         } else {
221             flags |= O_TRUNC;
222         }
223         chr->logfd = qemu_open(common->logfile, flags, 0666);
224         if (chr->logfd < 0) {
225             error_setg_errno(errp, errno,
226                              "Unable to open logfile %s",
227                              common->logfile);
228             return;
229         }
230     }
231 
232     if (cc->open) {
233         cc->open(chr, backend, be_opened, errp);
234     }
235 }
236 
237 static void char_init(Object *obj)
238 {
239     Chardev *chr = CHARDEV(obj);
240 
241     chr->logfd = -1;
242     qemu_mutex_init(&chr->chr_write_lock);
243 }
244 
245 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
246 {
247     return len;
248 }
249 
250 static void char_class_init(ObjectClass *oc, void *data)
251 {
252     ChardevClass *cc = CHARDEV_CLASS(oc);
253 
254     cc->chr_write = null_chr_write;
255     cc->chr_be_event = chr_be_event;
256 }
257 
258 static void char_finalize(Object *obj)
259 {
260     Chardev *chr = CHARDEV(obj);
261 
262     if (chr->be) {
263         chr->be->chr = NULL;
264     }
265     g_free(chr->filename);
266     g_free(chr->label);
267     if (chr->logfd != -1) {
268         close(chr->logfd);
269     }
270     qemu_mutex_destroy(&chr->chr_write_lock);
271 }
272 
273 static const TypeInfo char_type_info = {
274     .name = TYPE_CHARDEV,
275     .parent = TYPE_OBJECT,
276     .instance_size = sizeof(Chardev),
277     .instance_init = char_init,
278     .instance_finalize = char_finalize,
279     .abstract = true,
280     .class_size = sizeof(ChardevClass),
281     .class_init = char_class_init,
282 };
283 
284 static int chardev_machine_done_notify_one(Object *child, void *opaque)
285 {
286     Chardev *chr = (Chardev *)child;
287     ChardevClass *class = CHARDEV_GET_CLASS(chr);
288 
289     if (class->chr_machine_done) {
290         return class->chr_machine_done(chr);
291     }
292 
293     return 0;
294 }
295 
296 static void chardev_machine_done_hook(Notifier *notifier, void *unused)
297 {
298     int ret = object_child_foreach(get_chardevs_root(),
299                                    chardev_machine_done_notify_one, NULL);
300 
301     if (ret) {
302         error_report("Failed to call chardev machine_done hooks");
303         exit(1);
304     }
305 }
306 
307 static Notifier chardev_machine_done_notify = {
308     .notify = chardev_machine_done_hook,
309 };
310 
311 static bool qemu_chr_is_busy(Chardev *s)
312 {
313     if (CHARDEV_IS_MUX(s)) {
314         MuxChardev *d = MUX_CHARDEV(s);
315         return d->mux_cnt >= 0;
316     } else {
317         return s->be != NULL;
318     }
319 }
320 
321 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
322 {
323     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
324 
325     if (cc->chr_wait_connected) {
326         return cc->chr_wait_connected(chr, errp);
327     }
328 
329     return 0;
330 }
331 
332 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
333 {
334     char host[65], port[33], width[8], height[8];
335     int pos;
336     const char *p;
337     QemuOpts *opts;
338     Error *local_err = NULL;
339 
340     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
341     if (local_err) {
342         error_report_err(local_err);
343         return NULL;
344     }
345 
346     if (strstart(filename, "mon:", &p)) {
347         filename = p;
348         qemu_opt_set(opts, "mux", "on", &error_abort);
349         if (strcmp(filename, "stdio") == 0) {
350             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
351              * but pass it to the guest.  Handle this only for compat syntax,
352              * for -chardev syntax we have special option for this.
353              * This is what -nographic did, redirecting+muxing serial+monitor
354              * to stdio causing Ctrl+C to be passed to guest. */
355             qemu_opt_set(opts, "signal", "off", &error_abort);
356         }
357     }
358 
359     if (strcmp(filename, "null")    == 0 ||
360         strcmp(filename, "pty")     == 0 ||
361         strcmp(filename, "msmouse") == 0 ||
362         strcmp(filename, "wctablet") == 0 ||
363         strcmp(filename, "braille") == 0 ||
364         strcmp(filename, "testdev") == 0 ||
365         strcmp(filename, "stdio")   == 0) {
366         qemu_opt_set(opts, "backend", filename, &error_abort);
367         return opts;
368     }
369     if (strstart(filename, "vc", &p)) {
370         qemu_opt_set(opts, "backend", "vc", &error_abort);
371         if (*p == ':') {
372             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
373                 /* pixels */
374                 qemu_opt_set(opts, "width", width, &error_abort);
375                 qemu_opt_set(opts, "height", height, &error_abort);
376             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
377                 /* chars */
378                 qemu_opt_set(opts, "cols", width, &error_abort);
379                 qemu_opt_set(opts, "rows", height, &error_abort);
380             } else {
381                 goto fail;
382             }
383         }
384         return opts;
385     }
386     if (strcmp(filename, "con:") == 0) {
387         qemu_opt_set(opts, "backend", "console", &error_abort);
388         return opts;
389     }
390     if (strstart(filename, "COM", NULL)) {
391         qemu_opt_set(opts, "backend", "serial", &error_abort);
392         qemu_opt_set(opts, "path", filename, &error_abort);
393         return opts;
394     }
395     if (strstart(filename, "file:", &p)) {
396         qemu_opt_set(opts, "backend", "file", &error_abort);
397         qemu_opt_set(opts, "path", p, &error_abort);
398         return opts;
399     }
400     if (strstart(filename, "pipe:", &p)) {
401         qemu_opt_set(opts, "backend", "pipe", &error_abort);
402         qemu_opt_set(opts, "path", p, &error_abort);
403         return opts;
404     }
405     if (strstart(filename, "tcp:", &p) ||
406         strstart(filename, "telnet:", &p) ||
407         strstart(filename, "tn3270:", &p)) {
408         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
409             host[0] = 0;
410             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
411                 goto fail;
412         }
413         qemu_opt_set(opts, "backend", "socket", &error_abort);
414         qemu_opt_set(opts, "host", host, &error_abort);
415         qemu_opt_set(opts, "port", port, &error_abort);
416         if (p[pos] == ',') {
417             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
418             if (local_err) {
419                 error_report_err(local_err);
420                 goto fail;
421             }
422         }
423         if (strstart(filename, "telnet:", &p)) {
424             qemu_opt_set(opts, "telnet", "on", &error_abort);
425         } else if (strstart(filename, "tn3270:", &p)) {
426             qemu_opt_set(opts, "tn3270", "on", &error_abort);
427         }
428         return opts;
429     }
430     if (strstart(filename, "udp:", &p)) {
431         qemu_opt_set(opts, "backend", "udp", &error_abort);
432         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
433             host[0] = 0;
434             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
435                 goto fail;
436             }
437         }
438         qemu_opt_set(opts, "host", host, &error_abort);
439         qemu_opt_set(opts, "port", port, &error_abort);
440         if (p[pos] == '@') {
441             p += pos + 1;
442             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
443                 host[0] = 0;
444                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
445                     goto fail;
446                 }
447             }
448             qemu_opt_set(opts, "localaddr", host, &error_abort);
449             qemu_opt_set(opts, "localport", port, &error_abort);
450         }
451         return opts;
452     }
453     if (strstart(filename, "unix:", &p)) {
454         qemu_opt_set(opts, "backend", "socket", &error_abort);
455         qemu_opts_do_parse(opts, p, "path", &local_err);
456         if (local_err) {
457             error_report_err(local_err);
458             goto fail;
459         }
460         return opts;
461     }
462     if (strstart(filename, "/dev/parport", NULL) ||
463         strstart(filename, "/dev/ppi", NULL)) {
464         qemu_opt_set(opts, "backend", "parallel", &error_abort);
465         qemu_opt_set(opts, "path", filename, &error_abort);
466         return opts;
467     }
468     if (strstart(filename, "/dev/", NULL)) {
469         qemu_opt_set(opts, "backend", "serial", &error_abort);
470         qemu_opt_set(opts, "path", filename, &error_abort);
471         return opts;
472     }
473 
474 fail:
475     qemu_opts_del(opts);
476     return NULL;
477 }
478 
479 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
480 {
481     const char *logfile = qemu_opt_get(opts, "logfile");
482 
483     backend->has_logfile = logfile != NULL;
484     backend->logfile = g_strdup(logfile);
485 
486     backend->has_logappend = true;
487     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
488 }
489 
490 static const ChardevClass *char_get_class(const char *driver, Error **errp)
491 {
492     ObjectClass *oc;
493     const ChardevClass *cc;
494     char *typename = g_strdup_printf("chardev-%s", driver);
495 
496     oc = object_class_by_name(typename);
497     g_free(typename);
498 
499     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
500         error_setg(errp, "'%s' is not a valid char driver name", driver);
501         return NULL;
502     }
503 
504     if (object_class_is_abstract(oc)) {
505         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
506                    "abstract device type");
507         return NULL;
508     }
509 
510     cc = CHARDEV_CLASS(oc);
511     if (cc->internal) {
512         error_setg(errp, "'%s' is not a valid char driver name", driver);
513         return NULL;
514     }
515 
516     return cc;
517 }
518 
519 static const struct ChardevAlias {
520     const char *typename;
521     const char *alias;
522 } chardev_alias_table[] = {
523 #ifdef HAVE_CHARDEV_PARPORT
524     { "parallel", "parport" },
525 #endif
526 #ifdef HAVE_CHARDEV_SERIAL
527     { "serial", "tty" },
528 #endif
529 };
530 
531 typedef struct ChadevClassFE {
532     void (*fn)(const char *name, void *opaque);
533     void *opaque;
534 } ChadevClassFE;
535 
536 static void
537 chardev_class_foreach(ObjectClass *klass, void *opaque)
538 {
539     ChadevClassFE *fe = opaque;
540 
541     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
542     if (CHARDEV_CLASS(klass)->internal) {
543         return;
544     }
545 
546     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
547 }
548 
549 static void
550 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
551 {
552     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
553     int i;
554 
555     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
556 
557     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
558         fn(chardev_alias_table[i].alias, opaque);
559     }
560 }
561 
562 static void
563 help_string_append(const char *name, void *opaque)
564 {
565     GString *str = opaque;
566 
567     g_string_append_printf(str, "\n%s", name);
568 }
569 
570 static const char *chardev_alias_translate(const char *name)
571 {
572     int i;
573     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
574         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
575             return chardev_alias_table[i].typename;
576         }
577     }
578     return name;
579 }
580 
581 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
582 {
583     Error *local_err = NULL;
584     const ChardevClass *cc;
585     ChardevBackend *backend = NULL;
586     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
587 
588     if (name == NULL) {
589         error_setg(errp, "chardev: \"%s\" missing backend",
590                    qemu_opts_id(opts));
591         return NULL;
592     }
593 
594     cc = char_get_class(name, errp);
595     if (cc == NULL) {
596         return NULL;
597     }
598 
599     backend = g_new0(ChardevBackend, 1);
600     backend->type = CHARDEV_BACKEND_KIND_NULL;
601 
602     if (cc->parse) {
603         cc->parse(opts, backend, &local_err);
604         if (local_err) {
605             error_propagate(errp, local_err);
606             qapi_free_ChardevBackend(backend);
607             return NULL;
608         }
609     } else {
610         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
611         qemu_chr_parse_common(opts, ccom);
612         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
613     }
614 
615     return backend;
616 }
617 
618 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
619 {
620     const ChardevClass *cc;
621     Chardev *chr = NULL;
622     ChardevBackend *backend = NULL;
623     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
624     const char *id = qemu_opts_id(opts);
625     char *bid = NULL;
626 
627     if (name && is_help_option(name)) {
628         GString *str = g_string_new("");
629 
630         chardev_name_foreach(help_string_append, str);
631 
632         error_report("Available chardev backend types: %s", str->str);
633         g_string_free(str, true);
634         return NULL;
635     }
636 
637     if (id == NULL) {
638         error_setg(errp, "chardev: no id specified");
639         return NULL;
640     }
641 
642     backend = qemu_chr_parse_opts(opts, errp);
643     if (backend == NULL) {
644         return NULL;
645     }
646 
647     cc = char_get_class(name, errp);
648     if (cc == NULL) {
649         goto out;
650     }
651 
652     if (qemu_opt_get_bool(opts, "mux", 0)) {
653         bid = g_strdup_printf("%s-base", id);
654     }
655 
656     chr = qemu_chardev_new(bid ? bid : id,
657                            object_class_get_name(OBJECT_CLASS(cc)),
658                            backend, errp);
659 
660     if (chr == NULL) {
661         goto out;
662     }
663 
664     if (bid) {
665         Chardev *mux;
666         qapi_free_ChardevBackend(backend);
667         backend = g_new0(ChardevBackend, 1);
668         backend->type = CHARDEV_BACKEND_KIND_MUX;
669         backend->u.mux.data = g_new0(ChardevMux, 1);
670         backend->u.mux.data->chardev = g_strdup(bid);
671         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
672         if (mux == NULL) {
673             object_unparent(OBJECT(chr));
674             chr = NULL;
675             goto out;
676         }
677         chr = mux;
678     }
679 
680 out:
681     qapi_free_ChardevBackend(backend);
682     g_free(bid);
683     return chr;
684 }
685 
686 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
687 {
688     const char *p;
689     Chardev *chr;
690     QemuOpts *opts;
691     Error *err = NULL;
692 
693     if (strstart(filename, "chardev:", &p)) {
694         return qemu_chr_find(p);
695     }
696 
697     opts = qemu_chr_parse_compat(label, filename);
698     if (!opts)
699         return NULL;
700 
701     chr = qemu_chr_new_from_opts(opts, &err);
702     if (err) {
703         error_report_err(err);
704     }
705     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
706         monitor_init(chr, MONITOR_USE_READLINE);
707     }
708     qemu_opts_del(opts);
709     return chr;
710 }
711 
712 Chardev *qemu_chr_new(const char *label, const char *filename)
713 {
714     Chardev *chr;
715     chr = qemu_chr_new_noreplay(label, filename);
716     if (chr) {
717         if (replay_mode != REPLAY_MODE_NONE) {
718             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
719         }
720         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
721             error_report("Replay: ioctl is not supported "
722                          "for serial devices yet");
723         }
724         replay_register_char_driver(chr);
725     }
726     return chr;
727 }
728 
729 static int qmp_query_chardev_foreach(Object *obj, void *data)
730 {
731     Chardev *chr = CHARDEV(obj);
732     ChardevInfoList **list = data;
733     ChardevInfoList *info = g_malloc0(sizeof(*info));
734 
735     info->value = g_malloc0(sizeof(*info->value));
736     info->value->label = g_strdup(chr->label);
737     info->value->filename = g_strdup(chr->filename);
738     info->value->frontend_open = chr->be && chr->be->fe_open;
739 
740     info->next = *list;
741     *list = info;
742 
743     return 0;
744 }
745 
746 ChardevInfoList *qmp_query_chardev(Error **errp)
747 {
748     ChardevInfoList *chr_list = NULL;
749 
750     object_child_foreach(get_chardevs_root(),
751                          qmp_query_chardev_foreach, &chr_list);
752 
753     return chr_list;
754 }
755 
756 static void
757 qmp_prepend_backend(const char *name, void *opaque)
758 {
759     ChardevBackendInfoList **list = opaque;
760     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
761 
762     info->value = g_malloc0(sizeof(*info->value));
763     info->value->name = g_strdup(name);
764     info->next = *list;
765     *list = info;
766 }
767 
768 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
769 {
770     ChardevBackendInfoList *backend_list = NULL;
771 
772     chardev_name_foreach(qmp_prepend_backend, &backend_list);
773 
774     return backend_list;
775 }
776 
777 Chardev *qemu_chr_find(const char *name)
778 {
779     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
780 
781     return obj ? CHARDEV(obj) : NULL;
782 }
783 
784 QemuOptsList qemu_chardev_opts = {
785     .name = "chardev",
786     .implied_opt_name = "backend",
787     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
788     .desc = {
789         {
790             .name = "backend",
791             .type = QEMU_OPT_STRING,
792         },{
793             .name = "path",
794             .type = QEMU_OPT_STRING,
795         },{
796             .name = "host",
797             .type = QEMU_OPT_STRING,
798         },{
799             .name = "port",
800             .type = QEMU_OPT_STRING,
801         },{
802             .name = "fd",
803             .type = QEMU_OPT_STRING,
804         },{
805             .name = "localaddr",
806             .type = QEMU_OPT_STRING,
807         },{
808             .name = "localport",
809             .type = QEMU_OPT_STRING,
810         },{
811             .name = "to",
812             .type = QEMU_OPT_NUMBER,
813         },{
814             .name = "ipv4",
815             .type = QEMU_OPT_BOOL,
816         },{
817             .name = "ipv6",
818             .type = QEMU_OPT_BOOL,
819         },{
820             .name = "wait",
821             .type = QEMU_OPT_BOOL,
822         },{
823             .name = "server",
824             .type = QEMU_OPT_BOOL,
825         },{
826             .name = "delay",
827             .type = QEMU_OPT_BOOL,
828         },{
829             .name = "reconnect",
830             .type = QEMU_OPT_NUMBER,
831         },{
832             .name = "telnet",
833             .type = QEMU_OPT_BOOL,
834         },{
835             .name = "tn3270",
836             .type = QEMU_OPT_BOOL,
837         },{
838             .name = "tls-creds",
839             .type = QEMU_OPT_STRING,
840         },{
841             .name = "width",
842             .type = QEMU_OPT_NUMBER,
843         },{
844             .name = "height",
845             .type = QEMU_OPT_NUMBER,
846         },{
847             .name = "cols",
848             .type = QEMU_OPT_NUMBER,
849         },{
850             .name = "rows",
851             .type = QEMU_OPT_NUMBER,
852         },{
853             .name = "mux",
854             .type = QEMU_OPT_BOOL,
855         },{
856             .name = "signal",
857             .type = QEMU_OPT_BOOL,
858         },{
859             .name = "name",
860             .type = QEMU_OPT_STRING,
861         },{
862             .name = "debug",
863             .type = QEMU_OPT_NUMBER,
864         },{
865             .name = "size",
866             .type = QEMU_OPT_SIZE,
867         },{
868             .name = "chardev",
869             .type = QEMU_OPT_STRING,
870         },{
871             .name = "append",
872             .type = QEMU_OPT_BOOL,
873         },{
874             .name = "logfile",
875             .type = QEMU_OPT_STRING,
876         },{
877             .name = "logappend",
878             .type = QEMU_OPT_BOOL,
879         },
880         { /* end of list */ }
881     },
882 };
883 
884 bool qemu_chr_has_feature(Chardev *chr,
885                           ChardevFeature feature)
886 {
887     return test_bit(feature, chr->features);
888 }
889 
890 void qemu_chr_set_feature(Chardev *chr,
891                            ChardevFeature feature)
892 {
893     return set_bit(feature, chr->features);
894 }
895 
896 Chardev *qemu_chardev_new(const char *id, const char *typename,
897                           ChardevBackend *backend,
898                           Error **errp)
899 {
900     Object *obj;
901     Chardev *chr = NULL;
902     Error *local_err = NULL;
903     bool be_opened = true;
904 
905     assert(g_str_has_prefix(typename, "chardev-"));
906 
907     obj = object_new(typename);
908     chr = CHARDEV(obj);
909     chr->label = g_strdup(id);
910 
911     qemu_char_open(chr, backend, &be_opened, &local_err);
912     if (local_err) {
913         goto end;
914     }
915 
916     if (!chr->filename) {
917         chr->filename = g_strdup(typename + 8);
918     }
919     if (be_opened) {
920         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
921     }
922 
923     if (id) {
924         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
925         if (local_err) {
926             goto end;
927         }
928         object_unref(obj);
929     }
930 
931 end:
932     if (local_err) {
933         error_propagate(errp, local_err);
934         object_unref(obj);
935         return NULL;
936     }
937 
938     return chr;
939 }
940 
941 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
942                                Error **errp)
943 {
944     const ChardevClass *cc;
945     ChardevReturn *ret;
946     Chardev *chr;
947 
948     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
949     if (!cc) {
950         return NULL;
951     }
952 
953     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
954                            backend, errp);
955     if (!chr) {
956         return NULL;
957     }
958 
959     ret = g_new0(ChardevReturn, 1);
960     if (CHARDEV_IS_PTY(chr)) {
961         ret->pty = g_strdup(chr->filename + 4);
962         ret->has_pty = true;
963     }
964 
965     return ret;
966 }
967 
968 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
969                                   Error **errp)
970 {
971     CharBackend *be;
972     const ChardevClass *cc;
973     Chardev *chr, *chr_new;
974     bool closed_sent = false;
975     ChardevReturn *ret;
976 
977     chr = qemu_chr_find(id);
978     if (!chr) {
979         error_setg(errp, "Chardev '%s' does not exist", id);
980         return NULL;
981     }
982 
983     if (CHARDEV_IS_MUX(chr)) {
984         error_setg(errp, "Mux device hotswap not supported yet");
985         return NULL;
986     }
987 
988     if (qemu_chr_replay(chr)) {
989         error_setg(errp,
990             "Chardev '%s' cannot be changed in record/replay mode", id);
991         return NULL;
992     }
993 
994     be = chr->be;
995     if (!be) {
996         /* easy case */
997         object_unparent(OBJECT(chr));
998         return qmp_chardev_add(id, backend, errp);
999     }
1000 
1001     if (!be->chr_be_change) {
1002         error_setg(errp, "Chardev user does not support chardev hotswap");
1003         return NULL;
1004     }
1005 
1006     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1007     if (!cc) {
1008         return NULL;
1009     }
1010 
1011     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1012                                backend, errp);
1013     if (!chr_new) {
1014         return NULL;
1015     }
1016     chr_new->label = g_strdup(id);
1017 
1018     if (chr->be_open && !chr_new->be_open) {
1019         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1020         closed_sent = true;
1021     }
1022 
1023     chr->be = NULL;
1024     qemu_chr_fe_init(be, chr_new, &error_abort);
1025 
1026     if (be->chr_be_change(be->opaque) < 0) {
1027         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1028         chr_new->be = NULL;
1029         qemu_chr_fe_init(be, chr, &error_abort);
1030         if (closed_sent) {
1031             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1032         }
1033         object_unref(OBJECT(chr_new));
1034         return NULL;
1035     }
1036 
1037     object_unparent(OBJECT(chr));
1038     object_property_add_child(get_chardevs_root(), chr_new->label,
1039                               OBJECT(chr_new), &error_abort);
1040     object_unref(OBJECT(chr_new));
1041 
1042     ret = g_new0(ChardevReturn, 1);
1043     if (CHARDEV_IS_PTY(chr_new)) {
1044         ret->pty = g_strdup(chr_new->filename + 4);
1045         ret->has_pty = true;
1046     }
1047 
1048     return ret;
1049 }
1050 
1051 void qmp_chardev_remove(const char *id, Error **errp)
1052 {
1053     Chardev *chr;
1054 
1055     chr = qemu_chr_find(id);
1056     if (chr == NULL) {
1057         error_setg(errp, "Chardev '%s' not found", id);
1058         return;
1059     }
1060     if (qemu_chr_is_busy(chr)) {
1061         error_setg(errp, "Chardev '%s' is busy", id);
1062         return;
1063     }
1064     if (qemu_chr_replay(chr)) {
1065         error_setg(errp,
1066             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1067         return;
1068     }
1069     object_unparent(OBJECT(chr));
1070 }
1071 
1072 void qmp_chardev_send_break(const char *id, Error **errp)
1073 {
1074     Chardev *chr;
1075 
1076     chr = qemu_chr_find(id);
1077     if (chr == NULL) {
1078         error_setg(errp, "Chardev '%s' not found", id);
1079         return;
1080     }
1081     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1082 }
1083 
1084 /*
1085  * Add a timeout callback for the chardev (in milliseconds), return
1086  * the GSource object created. Please use this to add timeout hook for
1087  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1088  * make sure the gcontext that the task bound to is correct.
1089  */
1090 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1091                                  GSourceFunc func, void *private)
1092 {
1093     GSource *source = g_timeout_source_new(ms);
1094 
1095     assert(func);
1096     g_source_set_callback(source, func, private, NULL);
1097     g_source_attach(source, chr->gcontext);
1098 
1099     return source;
1100 }
1101 
1102 void qemu_chr_cleanup(void)
1103 {
1104     object_unparent(get_chardevs_root());
1105 }
1106 
1107 static void register_types(void)
1108 {
1109     type_register_static(&char_type_info);
1110 
1111     /* this must be done after machine init, since we register FEs with muxes
1112      * as part of realize functions like serial_isa_realizefn when -nographic
1113      * is specified
1114      */
1115     qemu_add_machine_init_done_notifier(&chardev_machine_done_notify);
1116 }
1117 
1118 type_init(register_types);
1119