xref: /openbmc/qemu/chardev/char.c (revision 53ba2eee)
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 "qemu/qemu-print.h"
32 #include "chardev/char.h"
33 #include "qapi/error.h"
34 #include "qapi/qapi-commands-char.h"
35 #include "qapi/qmp/qerror.h"
36 #include "sysemu/replay.h"
37 #include "qemu/help_option.h"
38 #include "qemu/module.h"
39 #include "qemu/option.h"
40 #include "qemu/id.h"
41 #include "qemu/coroutine.h"
42 
43 #include "chardev-internal.h"
44 
45 /***********************************************************/
46 /* character device */
47 
48 Object *get_chardevs_root(void)
49 {
50     return container_get(object_get_root(), "/chardevs");
51 }
52 
53 static void chr_be_event(Chardev *s, QEMUChrEvent event)
54 {
55     CharBackend *be = s->be;
56 
57     if (!be || !be->chr_event) {
58         return;
59     }
60 
61     be->chr_event(be->opaque, event);
62 }
63 
64 void qemu_chr_be_event(Chardev *s, QEMUChrEvent event)
65 {
66     /* Keep track if the char device is open */
67     switch (event) {
68         case CHR_EVENT_OPENED:
69             s->be_open = 1;
70             break;
71         case CHR_EVENT_CLOSED:
72             s->be_open = 0;
73             break;
74     case CHR_EVENT_BREAK:
75     case CHR_EVENT_MUX_IN:
76     case CHR_EVENT_MUX_OUT:
77         /* Ignore */
78         break;
79     }
80 
81     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
82 }
83 
84 /* Not reporting errors from writing to logfile, as logs are
85  * defined to be "best effort" only */
86 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
87 {
88     size_t done = 0;
89     ssize_t ret;
90 
91     if (s->logfd < 0) {
92         return;
93     }
94 
95     while (done < len) {
96     retry:
97         ret = write(s->logfd, buf + done, len - done);
98         if (ret == -1 && errno == EAGAIN) {
99             g_usleep(100);
100             goto retry;
101         }
102 
103         if (ret <= 0) {
104             return;
105         }
106         done += ret;
107     }
108 }
109 
110 static int qemu_chr_write_buffer(Chardev *s,
111                                  const uint8_t *buf, int len,
112                                  int *offset, bool write_all)
113 {
114     ChardevClass *cc = CHARDEV_GET_CLASS(s);
115     int res = 0;
116     *offset = 0;
117 
118     qemu_mutex_lock(&s->chr_write_lock);
119     while (*offset < len) {
120     retry:
121         res = cc->chr_write(s, buf + *offset, len - *offset);
122         if (res < 0 && errno == EAGAIN && write_all) {
123             if (qemu_in_coroutine()) {
124                 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
125             } else {
126                 g_usleep(100);
127             }
128             goto retry;
129         }
130 
131         if (res <= 0) {
132             break;
133         }
134 
135         *offset += res;
136         if (!write_all) {
137             break;
138         }
139     }
140     if (*offset > 0) {
141         /*
142          * If some data was written by backend, we should
143          * only log what was actually written. This method
144          * may be invoked again to write the remaining
145          * method, thus we'll log the remainder at that time.
146          */
147         qemu_chr_write_log(s, buf, *offset);
148     } else if (res < 0) {
149         /*
150          * If a fatal error was reported by the backend,
151          * assume this method won't be invoked again with
152          * this buffer, so log it all right away.
153          */
154         qemu_chr_write_log(s, buf, len);
155     }
156     qemu_mutex_unlock(&s->chr_write_lock);
157 
158     return res;
159 }
160 
161 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
162 {
163     int offset = 0;
164     int res;
165 
166     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
167         replay_char_write_event_load(&res, &offset);
168         assert(offset <= len);
169         qemu_chr_write_buffer(s, buf, offset, &offset, true);
170         return res;
171     }
172 
173     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
174 
175     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
176         replay_char_write_event_save(res, offset);
177     }
178 
179     if (res < 0) {
180         return res;
181     }
182     return offset;
183 }
184 
185 int qemu_chr_be_can_write(Chardev *s)
186 {
187     CharBackend *be = s->be;
188 
189     if (!be || !be->chr_can_read) {
190         return 0;
191     }
192 
193     return be->chr_can_read(be->opaque);
194 }
195 
196 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
197 {
198     CharBackend *be = s->be;
199 
200     if (be && be->chr_read) {
201         be->chr_read(be->opaque, buf, len);
202     }
203 }
204 
205 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
206 {
207     if (qemu_chr_replay(s)) {
208         if (replay_mode == REPLAY_MODE_PLAY) {
209             return;
210         }
211         replay_chr_be_write(s, buf, len);
212     } else {
213         qemu_chr_be_write_impl(s, buf, len);
214     }
215 }
216 
217 void qemu_chr_be_update_read_handlers(Chardev *s,
218                                       GMainContext *context)
219 {
220     ChardevClass *cc = CHARDEV_GET_CLASS(s);
221 
222     assert(qemu_chr_has_feature(s, QEMU_CHAR_FEATURE_GCONTEXT)
223            || !context);
224     s->gcontext = context;
225     if (cc->chr_update_read_handler) {
226         cc->chr_update_read_handler(s);
227     }
228 }
229 
230 int qemu_chr_add_client(Chardev *s, int fd)
231 {
232     return CHARDEV_GET_CLASS(s)->chr_add_client ?
233         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
234 }
235 
236 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
237                            bool *be_opened, Error **errp)
238 {
239     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
240     /* Any ChardevCommon member would work */
241     ChardevCommon *common = backend ? backend->u.null.data : NULL;
242 
243     if (common && common->has_logfile) {
244         int flags = O_WRONLY | O_CREAT;
245         if (common->has_logappend &&
246             common->logappend) {
247             flags |= O_APPEND;
248         } else {
249             flags |= O_TRUNC;
250         }
251         chr->logfd = qemu_open_old(common->logfile, flags, 0666);
252         if (chr->logfd < 0) {
253             error_setg_errno(errp, errno,
254                              "Unable to open logfile %s",
255                              common->logfile);
256             return;
257         }
258     }
259 
260     if (cc->open) {
261         cc->open(chr, backend, be_opened, errp);
262     }
263 }
264 
265 static void char_init(Object *obj)
266 {
267     Chardev *chr = CHARDEV(obj);
268 
269     chr->logfd = -1;
270     qemu_mutex_init(&chr->chr_write_lock);
271 
272     /*
273      * Assume if chr_update_read_handler is implemented it will
274      * take the updated gcontext into account.
275      */
276     if (CHARDEV_GET_CLASS(chr)->chr_update_read_handler) {
277         qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT);
278     }
279 
280 }
281 
282 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
283 {
284     return len;
285 }
286 
287 static void char_class_init(ObjectClass *oc, void *data)
288 {
289     ChardevClass *cc = CHARDEV_CLASS(oc);
290 
291     cc->chr_write = null_chr_write;
292     cc->chr_be_event = chr_be_event;
293 }
294 
295 static void char_finalize(Object *obj)
296 {
297     Chardev *chr = CHARDEV(obj);
298 
299     if (chr->be) {
300         chr->be->chr = NULL;
301     }
302     g_free(chr->filename);
303     g_free(chr->label);
304     if (chr->logfd != -1) {
305         close(chr->logfd);
306     }
307     qemu_mutex_destroy(&chr->chr_write_lock);
308 }
309 
310 static const TypeInfo char_type_info = {
311     .name = TYPE_CHARDEV,
312     .parent = TYPE_OBJECT,
313     .instance_size = sizeof(Chardev),
314     .instance_init = char_init,
315     .instance_finalize = char_finalize,
316     .abstract = true,
317     .class_size = sizeof(ChardevClass),
318     .class_init = char_class_init,
319 };
320 
321 static bool qemu_chr_is_busy(Chardev *s)
322 {
323     if (CHARDEV_IS_MUX(s)) {
324         MuxChardev *d = MUX_CHARDEV(s);
325         return d->mux_cnt >= 0;
326     } else {
327         return s->be != NULL;
328     }
329 }
330 
331 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
332 {
333     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
334 
335     if (cc->chr_wait_connected) {
336         return cc->chr_wait_connected(chr, errp);
337     }
338 
339     return 0;
340 }
341 
342 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
343                                 bool permit_mux_mon)
344 {
345     char host[65], port[33], width[8], height[8];
346     int pos;
347     const char *p;
348     QemuOpts *opts;
349     Error *local_err = NULL;
350 
351     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
352     if (local_err) {
353         error_report_err(local_err);
354         return NULL;
355     }
356 
357     if (strstart(filename, "mon:", &p)) {
358         if (!permit_mux_mon) {
359             error_report("mon: isn't supported in this context");
360             return NULL;
361         }
362         filename = p;
363         qemu_opt_set(opts, "mux", "on", &error_abort);
364         if (strcmp(filename, "stdio") == 0) {
365             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
366              * but pass it to the guest.  Handle this only for compat syntax,
367              * for -chardev syntax we have special option for this.
368              * This is what -nographic did, redirecting+muxing serial+monitor
369              * to stdio causing Ctrl+C to be passed to guest. */
370             qemu_opt_set(opts, "signal", "off", &error_abort);
371         }
372     }
373 
374     if (strcmp(filename, "null")    == 0 ||
375         strcmp(filename, "pty")     == 0 ||
376         strcmp(filename, "msmouse") == 0 ||
377         strcmp(filename, "wctablet") == 0 ||
378         strcmp(filename, "braille") == 0 ||
379         strcmp(filename, "testdev") == 0 ||
380         strcmp(filename, "stdio")   == 0) {
381         qemu_opt_set(opts, "backend", filename, &error_abort);
382         return opts;
383     }
384     if (strstart(filename, "vc", &p)) {
385         qemu_opt_set(opts, "backend", "vc", &error_abort);
386         if (*p == ':') {
387             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
388                 /* pixels */
389                 qemu_opt_set(opts, "width", width, &error_abort);
390                 qemu_opt_set(opts, "height", height, &error_abort);
391             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
392                 /* chars */
393                 qemu_opt_set(opts, "cols", width, &error_abort);
394                 qemu_opt_set(opts, "rows", height, &error_abort);
395             } else {
396                 goto fail;
397             }
398         }
399         return opts;
400     }
401     if (strcmp(filename, "con:") == 0) {
402         qemu_opt_set(opts, "backend", "console", &error_abort);
403         return opts;
404     }
405     if (strstart(filename, "COM", NULL)) {
406         qemu_opt_set(opts, "backend", "serial", &error_abort);
407         qemu_opt_set(opts, "path", filename, &error_abort);
408         return opts;
409     }
410     if (strstart(filename, "file:", &p)) {
411         qemu_opt_set(opts, "backend", "file", &error_abort);
412         qemu_opt_set(opts, "path", p, &error_abort);
413         return opts;
414     }
415     if (strstart(filename, "pipe:", &p)) {
416         qemu_opt_set(opts, "backend", "pipe", &error_abort);
417         qemu_opt_set(opts, "path", p, &error_abort);
418         return opts;
419     }
420     if (strstart(filename, "tcp:", &p) ||
421         strstart(filename, "telnet:", &p) ||
422         strstart(filename, "tn3270:", &p) ||
423         strstart(filename, "websocket:", &p)) {
424         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
425             host[0] = 0;
426             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
427                 goto fail;
428         }
429         qemu_opt_set(opts, "backend", "socket", &error_abort);
430         qemu_opt_set(opts, "host", host, &error_abort);
431         qemu_opt_set(opts, "port", port, &error_abort);
432         if (p[pos] == ',') {
433             if (!qemu_opts_do_parse(opts, p + pos + 1, NULL, &local_err)) {
434                 error_report_err(local_err);
435                 goto fail;
436             }
437         }
438         if (strstart(filename, "telnet:", &p)) {
439             qemu_opt_set(opts, "telnet", "on", &error_abort);
440         } else if (strstart(filename, "tn3270:", &p)) {
441             qemu_opt_set(opts, "tn3270", "on", &error_abort);
442         } else if (strstart(filename, "websocket:", &p)) {
443             qemu_opt_set(opts, "websocket", "on", &error_abort);
444         }
445         return opts;
446     }
447     if (strstart(filename, "udp:", &p)) {
448         qemu_opt_set(opts, "backend", "udp", &error_abort);
449         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
450             host[0] = 0;
451             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
452                 goto fail;
453             }
454         }
455         qemu_opt_set(opts, "host", host, &error_abort);
456         qemu_opt_set(opts, "port", port, &error_abort);
457         if (p[pos] == '@') {
458             p += pos + 1;
459             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
460                 host[0] = 0;
461                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
462                     goto fail;
463                 }
464             }
465             qemu_opt_set(opts, "localaddr", host, &error_abort);
466             qemu_opt_set(opts, "localport", port, &error_abort);
467         }
468         return opts;
469     }
470     if (strstart(filename, "unix:", &p)) {
471         qemu_opt_set(opts, "backend", "socket", &error_abort);
472         if (!qemu_opts_do_parse(opts, p, "path", &local_err)) {
473             error_report_err(local_err);
474             goto fail;
475         }
476         return opts;
477     }
478     if (strstart(filename, "/dev/parport", NULL) ||
479         strstart(filename, "/dev/ppi", NULL)) {
480         qemu_opt_set(opts, "backend", "parallel", &error_abort);
481         qemu_opt_set(opts, "path", filename, &error_abort);
482         return opts;
483     }
484     if (strstart(filename, "/dev/", NULL)) {
485         qemu_opt_set(opts, "backend", "serial", &error_abort);
486         qemu_opt_set(opts, "path", filename, &error_abort);
487         return opts;
488     }
489 
490     error_report("'%s' is not a valid char driver", filename);
491 
492 fail:
493     qemu_opts_del(opts);
494     return NULL;
495 }
496 
497 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
498 {
499     const char *logfile = qemu_opt_get(opts, "logfile");
500 
501     backend->has_logfile = logfile != NULL;
502     backend->logfile = g_strdup(logfile);
503 
504     backend->has_logappend = true;
505     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
506 }
507 
508 static const ChardevClass *char_get_class(const char *driver, Error **errp)
509 {
510     ObjectClass *oc;
511     const ChardevClass *cc;
512     char *typename = g_strdup_printf("chardev-%s", driver);
513 
514     oc = module_object_class_by_name(typename);
515     g_free(typename);
516 
517     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
518         error_setg(errp, "'%s' is not a valid char driver name", driver);
519         return NULL;
520     }
521 
522     if (object_class_is_abstract(oc)) {
523         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
524                    "abstract device type");
525         return NULL;
526     }
527 
528     cc = CHARDEV_CLASS(oc);
529     if (cc->internal) {
530         error_setg(errp, "'%s' is not a valid char driver name", driver);
531         return NULL;
532     }
533 
534     return cc;
535 }
536 
537 static const struct ChardevAlias {
538     const char *typename;
539     const char *alias;
540 } chardev_alias_table[] = {
541 #ifdef HAVE_CHARDEV_PARPORT
542     { "parallel", "parport" },
543 #endif
544 #ifdef HAVE_CHARDEV_SERIAL
545     { "serial", "tty" },
546 #endif
547 };
548 
549 typedef struct ChadevClassFE {
550     void (*fn)(const char *name, void *opaque);
551     void *opaque;
552 } ChadevClassFE;
553 
554 static void
555 chardev_class_foreach(ObjectClass *klass, void *opaque)
556 {
557     ChadevClassFE *fe = opaque;
558 
559     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
560     if (CHARDEV_CLASS(klass)->internal) {
561         return;
562     }
563 
564     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
565 }
566 
567 static void
568 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
569 {
570     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
571     int i;
572 
573     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
574 
575     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
576         fn(chardev_alias_table[i].alias, opaque);
577     }
578 }
579 
580 static void
581 help_string_append(const char *name, void *opaque)
582 {
583     GString *str = opaque;
584 
585     g_string_append_printf(str, "\n  %s", name);
586 }
587 
588 static const char *chardev_alias_translate(const char *name)
589 {
590     int i;
591     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
592         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
593             return chardev_alias_table[i].typename;
594         }
595     }
596     return name;
597 }
598 
599 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
600 {
601     Error *local_err = NULL;
602     const ChardevClass *cc;
603     ChardevBackend *backend = NULL;
604     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
605 
606     if (name == NULL) {
607         error_setg(errp, "chardev: \"%s\" missing backend",
608                    qemu_opts_id(opts));
609         return NULL;
610     }
611 
612     cc = char_get_class(name, errp);
613     if (cc == NULL) {
614         return NULL;
615     }
616 
617     backend = g_new0(ChardevBackend, 1);
618     backend->type = CHARDEV_BACKEND_KIND_NULL;
619 
620     if (cc->parse) {
621         cc->parse(opts, backend, &local_err);
622         if (local_err) {
623             error_propagate(errp, local_err);
624             qapi_free_ChardevBackend(backend);
625             return NULL;
626         }
627     } else {
628         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
629         qemu_chr_parse_common(opts, ccom);
630         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
631     }
632 
633     return backend;
634 }
635 
636 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, GMainContext *context,
637                                 Error **errp)
638 {
639     const ChardevClass *cc;
640     Chardev *chr = NULL;
641     ChardevBackend *backend = NULL;
642     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
643     const char *id = qemu_opts_id(opts);
644     char *bid = NULL;
645 
646     if (name && is_help_option(name)) {
647         GString *str = g_string_new("");
648 
649         chardev_name_foreach(help_string_append, str);
650 
651         qemu_printf("Available chardev backend types: %s\n", str->str);
652         g_string_free(str, true);
653         return NULL;
654     }
655 
656     if (id == NULL) {
657         error_setg(errp, "chardev: no id specified");
658         return NULL;
659     }
660 
661     backend = qemu_chr_parse_opts(opts, errp);
662     if (backend == NULL) {
663         return NULL;
664     }
665 
666     cc = char_get_class(name, errp);
667     if (cc == NULL) {
668         goto out;
669     }
670 
671     if (qemu_opt_get_bool(opts, "mux", 0)) {
672         bid = g_strdup_printf("%s-base", id);
673     }
674 
675     chr = qemu_chardev_new(bid ? bid : id,
676                            object_class_get_name(OBJECT_CLASS(cc)),
677                            backend, context, errp);
678 
679     if (chr == NULL) {
680         goto out;
681     }
682 
683     if (bid) {
684         Chardev *mux;
685         qapi_free_ChardevBackend(backend);
686         backend = g_new0(ChardevBackend, 1);
687         backend->type = CHARDEV_BACKEND_KIND_MUX;
688         backend->u.mux.data = g_new0(ChardevMux, 1);
689         backend->u.mux.data->chardev = g_strdup(bid);
690         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, context, errp);
691         if (mux == NULL) {
692             object_unparent(OBJECT(chr));
693             chr = NULL;
694             goto out;
695         }
696         chr = mux;
697     }
698 
699 out:
700     qapi_free_ChardevBackend(backend);
701     g_free(bid);
702     return chr;
703 }
704 
705 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
706                                bool permit_mux_mon, GMainContext *context)
707 {
708     const char *p;
709     Chardev *chr;
710     QemuOpts *opts;
711     Error *err = NULL;
712 
713     if (strstart(filename, "chardev:", &p)) {
714         return qemu_chr_find(p);
715     }
716 
717     opts = qemu_chr_parse_compat(label, filename, permit_mux_mon);
718     if (!opts)
719         return NULL;
720 
721     chr = qemu_chr_new_from_opts(opts, context, &err);
722     if (!chr) {
723         error_report_err(err);
724         goto out;
725     }
726 
727     if (qemu_opt_get_bool(opts, "mux", 0)) {
728         assert(permit_mux_mon);
729         monitor_init_hmp(chr, true, &err);
730         if (err) {
731             error_report_err(err);
732             object_unparent(OBJECT(chr));
733             chr = NULL;
734             goto out;
735         }
736     }
737 
738 out:
739     qemu_opts_del(opts);
740     return chr;
741 }
742 
743 static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
744                                           const char *filename,
745                                           bool permit_mux_mon,
746                                           GMainContext *context)
747 {
748     Chardev *chr;
749     chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon, context);
750     if (chr) {
751         if (replay_mode != REPLAY_MODE_NONE) {
752             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
753         }
754         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
755             error_report("Replay: ioctl is not supported "
756                          "for serial devices yet");
757         }
758         replay_register_char_driver(chr);
759     }
760     return chr;
761 }
762 
763 Chardev *qemu_chr_new(const char *label, const char *filename,
764                       GMainContext *context)
765 {
766     return qemu_chr_new_permit_mux_mon(label, filename, false, context);
767 }
768 
769 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
770                               GMainContext *context)
771 {
772     return qemu_chr_new_permit_mux_mon(label, filename, true, context);
773 }
774 
775 static int qmp_query_chardev_foreach(Object *obj, void *data)
776 {
777     Chardev *chr = CHARDEV(obj);
778     ChardevInfoList **list = data;
779     ChardevInfoList *info = g_malloc0(sizeof(*info));
780 
781     info->value = g_malloc0(sizeof(*info->value));
782     info->value->label = g_strdup(chr->label);
783     info->value->filename = g_strdup(chr->filename);
784     info->value->frontend_open = chr->be && chr->be->fe_open;
785 
786     info->next = *list;
787     *list = info;
788 
789     return 0;
790 }
791 
792 ChardevInfoList *qmp_query_chardev(Error **errp)
793 {
794     ChardevInfoList *chr_list = NULL;
795 
796     object_child_foreach(get_chardevs_root(),
797                          qmp_query_chardev_foreach, &chr_list);
798 
799     return chr_list;
800 }
801 
802 static void
803 qmp_prepend_backend(const char *name, void *opaque)
804 {
805     ChardevBackendInfoList **list = opaque;
806     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
807 
808     info->value = g_malloc0(sizeof(*info->value));
809     info->value->name = g_strdup(name);
810     info->next = *list;
811     *list = info;
812 }
813 
814 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
815 {
816     ChardevBackendInfoList *backend_list = NULL;
817 
818     chardev_name_foreach(qmp_prepend_backend, &backend_list);
819 
820     return backend_list;
821 }
822 
823 Chardev *qemu_chr_find(const char *name)
824 {
825     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
826 
827     return obj ? CHARDEV(obj) : NULL;
828 }
829 
830 QemuOptsList qemu_chardev_opts = {
831     .name = "chardev",
832     .implied_opt_name = "backend",
833     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
834     .desc = {
835         {
836             .name = "backend",
837             .type = QEMU_OPT_STRING,
838         },{
839             .name = "path",
840             .type = QEMU_OPT_STRING,
841         },{
842             .name = "host",
843             .type = QEMU_OPT_STRING,
844         },{
845             .name = "port",
846             .type = QEMU_OPT_STRING,
847         },{
848             .name = "fd",
849             .type = QEMU_OPT_STRING,
850         },{
851             .name = "localaddr",
852             .type = QEMU_OPT_STRING,
853         },{
854             .name = "localport",
855             .type = QEMU_OPT_STRING,
856         },{
857             .name = "to",
858             .type = QEMU_OPT_NUMBER,
859         },{
860             .name = "ipv4",
861             .type = QEMU_OPT_BOOL,
862         },{
863             .name = "ipv6",
864             .type = QEMU_OPT_BOOL,
865         },{
866             .name = "wait",
867             .type = QEMU_OPT_BOOL,
868         },{
869             .name = "server",
870             .type = QEMU_OPT_BOOL,
871         },{
872             .name = "delay",
873             .type = QEMU_OPT_BOOL,
874         },{
875             .name = "reconnect",
876             .type = QEMU_OPT_NUMBER,
877         },{
878             .name = "telnet",
879             .type = QEMU_OPT_BOOL,
880         },{
881             .name = "tn3270",
882             .type = QEMU_OPT_BOOL,
883         },{
884             .name = "tls-creds",
885             .type = QEMU_OPT_STRING,
886         },{
887             .name = "tls-authz",
888             .type = QEMU_OPT_STRING,
889         },{
890             .name = "websocket",
891             .type = QEMU_OPT_BOOL,
892         },{
893             .name = "width",
894             .type = QEMU_OPT_NUMBER,
895         },{
896             .name = "height",
897             .type = QEMU_OPT_NUMBER,
898         },{
899             .name = "cols",
900             .type = QEMU_OPT_NUMBER,
901         },{
902             .name = "rows",
903             .type = QEMU_OPT_NUMBER,
904         },{
905             .name = "mux",
906             .type = QEMU_OPT_BOOL,
907         },{
908             .name = "signal",
909             .type = QEMU_OPT_BOOL,
910         },{
911             .name = "name",
912             .type = QEMU_OPT_STRING,
913         },{
914             .name = "debug",
915             .type = QEMU_OPT_NUMBER,
916         },{
917             .name = "size",
918             .type = QEMU_OPT_SIZE,
919         },{
920             .name = "chardev",
921             .type = QEMU_OPT_STRING,
922         },{
923             .name = "append",
924             .type = QEMU_OPT_BOOL,
925         },{
926             .name = "logfile",
927             .type = QEMU_OPT_STRING,
928         },{
929             .name = "logappend",
930             .type = QEMU_OPT_BOOL,
931         },{
932             .name = "tight",
933             .type = QEMU_OPT_BOOL,
934             .def_value_str = "on",
935         },{
936             .name = "abstract",
937             .type = QEMU_OPT_BOOL,
938         },
939         { /* end of list */ }
940     },
941 };
942 
943 bool qemu_chr_has_feature(Chardev *chr,
944                           ChardevFeature feature)
945 {
946     return test_bit(feature, chr->features);
947 }
948 
949 void qemu_chr_set_feature(Chardev *chr,
950                            ChardevFeature feature)
951 {
952     return set_bit(feature, chr->features);
953 }
954 
955 static Chardev *chardev_new(const char *id, const char *typename,
956                             ChardevBackend *backend,
957                             GMainContext *gcontext,
958                             Error **errp)
959 {
960     Object *obj;
961     Chardev *chr = NULL;
962     Error *local_err = NULL;
963     bool be_opened = true;
964 
965     assert(g_str_has_prefix(typename, "chardev-"));
966 
967     obj = object_new(typename);
968     chr = CHARDEV(obj);
969     chr->label = g_strdup(id);
970     chr->gcontext = gcontext;
971 
972     qemu_char_open(chr, backend, &be_opened, &local_err);
973     if (local_err) {
974         goto end;
975     }
976 
977     if (!chr->filename) {
978         chr->filename = g_strdup(typename + 8);
979     }
980     if (be_opened) {
981         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
982     }
983 
984     if (id) {
985         object_property_try_add_child(get_chardevs_root(), id, obj,
986                                       &local_err);
987         if (local_err) {
988             goto end;
989         }
990         object_unref(obj);
991     }
992 
993 end:
994     if (local_err) {
995         error_propagate(errp, local_err);
996         object_unref(obj);
997         return NULL;
998     }
999 
1000     return chr;
1001 }
1002 
1003 Chardev *qemu_chardev_new(const char *id, const char *typename,
1004                           ChardevBackend *backend,
1005                           GMainContext *gcontext,
1006                           Error **errp)
1007 {
1008     g_autofree char *genid = NULL;
1009 
1010     if (!id) {
1011         genid = id_generate(ID_CHR);
1012         id = genid;
1013     }
1014 
1015     return chardev_new(id, typename, backend, gcontext, errp);
1016 }
1017 
1018 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
1019                                Error **errp)
1020 {
1021     const ChardevClass *cc;
1022     ChardevReturn *ret;
1023     Chardev *chr;
1024 
1025     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1026     if (!cc) {
1027         return NULL;
1028     }
1029 
1030     chr = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
1031                       backend, NULL, errp);
1032     if (!chr) {
1033         return NULL;
1034     }
1035 
1036     ret = g_new0(ChardevReturn, 1);
1037     if (CHARDEV_IS_PTY(chr)) {
1038         ret->pty = g_strdup(chr->filename + 4);
1039         ret->has_pty = true;
1040     }
1041 
1042     return ret;
1043 }
1044 
1045 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
1046                                   Error **errp)
1047 {
1048     CharBackend *be;
1049     const ChardevClass *cc;
1050     Chardev *chr, *chr_new;
1051     bool closed_sent = false;
1052     ChardevReturn *ret;
1053 
1054     chr = qemu_chr_find(id);
1055     if (!chr) {
1056         error_setg(errp, "Chardev '%s' does not exist", id);
1057         return NULL;
1058     }
1059 
1060     if (CHARDEV_IS_MUX(chr)) {
1061         error_setg(errp, "Mux device hotswap not supported yet");
1062         return NULL;
1063     }
1064 
1065     if (qemu_chr_replay(chr)) {
1066         error_setg(errp,
1067             "Chardev '%s' cannot be changed in record/replay mode", id);
1068         return NULL;
1069     }
1070 
1071     be = chr->be;
1072     if (!be) {
1073         /* easy case */
1074         object_unparent(OBJECT(chr));
1075         return qmp_chardev_add(id, backend, errp);
1076     }
1077 
1078     if (!be->chr_be_change) {
1079         error_setg(errp, "Chardev user does not support chardev hotswap");
1080         return NULL;
1081     }
1082 
1083     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1084     if (!cc) {
1085         return NULL;
1086     }
1087 
1088     chr_new = chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1089                           backend, chr->gcontext, errp);
1090     if (!chr_new) {
1091         return NULL;
1092     }
1093     chr_new->label = g_strdup(id);
1094 
1095     if (chr->be_open && !chr_new->be_open) {
1096         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1097         closed_sent = true;
1098     }
1099 
1100     chr->be = NULL;
1101     qemu_chr_fe_init(be, chr_new, &error_abort);
1102 
1103     if (be->chr_be_change(be->opaque) < 0) {
1104         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1105         chr_new->be = NULL;
1106         qemu_chr_fe_init(be, chr, &error_abort);
1107         if (closed_sent) {
1108             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1109         }
1110         object_unref(OBJECT(chr_new));
1111         return NULL;
1112     }
1113 
1114     object_unparent(OBJECT(chr));
1115     object_property_add_child(get_chardevs_root(), chr_new->label,
1116                               OBJECT(chr_new));
1117     object_unref(OBJECT(chr_new));
1118 
1119     ret = g_new0(ChardevReturn, 1);
1120     if (CHARDEV_IS_PTY(chr_new)) {
1121         ret->pty = g_strdup(chr_new->filename + 4);
1122         ret->has_pty = true;
1123     }
1124 
1125     return ret;
1126 }
1127 
1128 void qmp_chardev_remove(const char *id, Error **errp)
1129 {
1130     Chardev *chr;
1131 
1132     chr = qemu_chr_find(id);
1133     if (chr == NULL) {
1134         error_setg(errp, "Chardev '%s' not found", id);
1135         return;
1136     }
1137     if (qemu_chr_is_busy(chr)) {
1138         error_setg(errp, "Chardev '%s' is busy", id);
1139         return;
1140     }
1141     if (qemu_chr_replay(chr)) {
1142         error_setg(errp,
1143             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1144         return;
1145     }
1146     object_unparent(OBJECT(chr));
1147 }
1148 
1149 void qmp_chardev_send_break(const char *id, Error **errp)
1150 {
1151     Chardev *chr;
1152 
1153     chr = qemu_chr_find(id);
1154     if (chr == NULL) {
1155         error_setg(errp, "Chardev '%s' not found", id);
1156         return;
1157     }
1158     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1159 }
1160 
1161 /*
1162  * Add a timeout callback for the chardev (in milliseconds), return
1163  * the GSource object created. Please use this to add timeout hook for
1164  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1165  * make sure the gcontext that the task bound to is correct.
1166  */
1167 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1168                                  GSourceFunc func, void *private)
1169 {
1170     GSource *source = g_timeout_source_new(ms);
1171 
1172     assert(func);
1173     g_source_set_callback(source, func, private, NULL);
1174     g_source_attach(source, chr->gcontext);
1175 
1176     return source;
1177 }
1178 
1179 void qemu_chr_cleanup(void)
1180 {
1181     object_unparent(get_chardevs_root());
1182 }
1183 
1184 static void register_types(void)
1185 {
1186     type_register_static(&char_type_info);
1187 }
1188 
1189 type_init(register_types);
1190