xref: /openbmc/qemu/chardev/char.c (revision 4011a686)
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 #include "qemu/yank.h"
43 
44 #include "chardev-internal.h"
45 
46 /***********************************************************/
47 /* character device */
48 
49 Object *get_chardevs_root(void)
50 {
51     return container_get(object_get_root(), "/chardevs");
52 }
53 
54 static void chr_be_event(Chardev *s, QEMUChrEvent event)
55 {
56     CharBackend *be = s->be;
57 
58     if (!be || !be->chr_event) {
59         return;
60     }
61 
62     be->chr_event(be->opaque, event);
63 }
64 
65 void qemu_chr_be_event(Chardev *s, QEMUChrEvent event)
66 {
67     /* Keep track if the char device is open */
68     switch (event) {
69         case CHR_EVENT_OPENED:
70             s->be_open = 1;
71             break;
72         case CHR_EVENT_CLOSED:
73             s->be_open = 0;
74             break;
75     case CHR_EVENT_BREAK:
76     case CHR_EVENT_MUX_IN:
77     case CHR_EVENT_MUX_OUT:
78         /* Ignore */
79         break;
80     }
81 
82     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
83 }
84 
85 /* Not reporting errors from writing to logfile, as logs are
86  * defined to be "best effort" only */
87 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
88 {
89     size_t done = 0;
90     ssize_t ret;
91 
92     if (s->logfd < 0) {
93         return;
94     }
95 
96     while (done < len) {
97     retry:
98         ret = write(s->logfd, buf + done, len - done);
99         if (ret == -1 && errno == EAGAIN) {
100             g_usleep(100);
101             goto retry;
102         }
103 
104         if (ret <= 0) {
105             return;
106         }
107         done += ret;
108     }
109 }
110 
111 static int qemu_chr_write_buffer(Chardev *s,
112                                  const uint8_t *buf, int len,
113                                  int *offset, bool write_all)
114 {
115     ChardevClass *cc = CHARDEV_GET_CLASS(s);
116     int res = 0;
117     *offset = 0;
118 
119     qemu_mutex_lock(&s->chr_write_lock);
120     while (*offset < len) {
121     retry:
122         res = cc->chr_write(s, buf + *offset, len - *offset);
123         if (res < 0 && errno == EAGAIN && write_all) {
124             if (qemu_in_coroutine()) {
125                 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
126             } else {
127                 g_usleep(100);
128             }
129             goto retry;
130         }
131 
132         if (res <= 0) {
133             break;
134         }
135 
136         *offset += res;
137         if (!write_all) {
138             break;
139         }
140     }
141     if (*offset > 0) {
142         /*
143          * If some data was written by backend, we should
144          * only log what was actually written. This method
145          * may be invoked again to write the remaining
146          * method, thus we'll log the remainder at that time.
147          */
148         qemu_chr_write_log(s, buf, *offset);
149     } else if (res < 0) {
150         /*
151          * If a fatal error was reported by the backend,
152          * assume this method won't be invoked again with
153          * this buffer, so log it all right away.
154          */
155         qemu_chr_write_log(s, buf, len);
156     }
157     qemu_mutex_unlock(&s->chr_write_lock);
158 
159     return res;
160 }
161 
162 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
163 {
164     int offset = 0;
165     int res;
166 
167     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
168         replay_char_write_event_load(&res, &offset);
169         assert(offset <= len);
170         qemu_chr_write_buffer(s, buf, offset, &offset, true);
171         return res;
172     }
173 
174     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
175 
176     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
177         replay_char_write_event_save(res, offset);
178     }
179 
180     if (res < 0) {
181         return res;
182     }
183     return offset;
184 }
185 
186 int qemu_chr_be_can_write(Chardev *s)
187 {
188     CharBackend *be = s->be;
189 
190     if (!be || !be->chr_can_read) {
191         return 0;
192     }
193 
194     return be->chr_can_read(be->opaque);
195 }
196 
197 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
198 {
199     CharBackend *be = s->be;
200 
201     if (be && be->chr_read) {
202         be->chr_read(be->opaque, buf, len);
203     }
204 }
205 
206 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
207 {
208     if (qemu_chr_replay(s)) {
209         if (replay_mode == REPLAY_MODE_PLAY) {
210             return;
211         }
212         replay_chr_be_write(s, buf, len);
213     } else {
214         qemu_chr_be_write_impl(s, buf, len);
215     }
216 }
217 
218 void qemu_chr_be_update_read_handlers(Chardev *s,
219                                       GMainContext *context)
220 {
221     ChardevClass *cc = CHARDEV_GET_CLASS(s);
222 
223     assert(qemu_chr_has_feature(s, QEMU_CHAR_FEATURE_GCONTEXT)
224            || !context);
225     s->gcontext = context;
226     if (cc->chr_update_read_handler) {
227         cc->chr_update_read_handler(s);
228     }
229 }
230 
231 int qemu_chr_add_client(Chardev *s, int fd)
232 {
233     return CHARDEV_GET_CLASS(s)->chr_add_client ?
234         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
235 }
236 
237 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
238                            bool *be_opened, Error **errp)
239 {
240     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
241     /* Any ChardevCommon member would work */
242     ChardevCommon *common = backend ? backend->u.null.data : NULL;
243 
244     if (common && common->has_logfile) {
245         int flags = O_WRONLY | O_CREAT;
246         if (common->has_logappend &&
247             common->logappend) {
248             flags |= O_APPEND;
249         } else {
250             flags |= O_TRUNC;
251         }
252         chr->logfd = qemu_open_old(common->logfile, flags, 0666);
253         if (chr->logfd < 0) {
254             error_setg_errno(errp, errno,
255                              "Unable to open logfile %s",
256                              common->logfile);
257             return;
258         }
259     }
260 
261     if (cc->open) {
262         cc->open(chr, backend, be_opened, errp);
263     }
264 }
265 
266 static void char_init(Object *obj)
267 {
268     Chardev *chr = CHARDEV(obj);
269 
270     chr->handover_yank_instance = false;
271     chr->logfd = -1;
272     qemu_mutex_init(&chr->chr_write_lock);
273 
274     /*
275      * Assume if chr_update_read_handler is implemented it will
276      * take the updated gcontext into account.
277      */
278     if (CHARDEV_GET_CLASS(chr)->chr_update_read_handler) {
279         qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT);
280     }
281 
282 }
283 
284 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
285 {
286     return len;
287 }
288 
289 static void char_class_init(ObjectClass *oc, void *data)
290 {
291     ChardevClass *cc = CHARDEV_CLASS(oc);
292 
293     cc->chr_write = null_chr_write;
294     cc->chr_be_event = chr_be_event;
295 }
296 
297 static void char_finalize(Object *obj)
298 {
299     Chardev *chr = CHARDEV(obj);
300 
301     if (chr->be) {
302         chr->be->chr = NULL;
303     }
304     g_free(chr->filename);
305     g_free(chr->label);
306     if (chr->logfd != -1) {
307         close(chr->logfd);
308     }
309     qemu_mutex_destroy(&chr->chr_write_lock);
310 }
311 
312 static const TypeInfo char_type_info = {
313     .name = TYPE_CHARDEV,
314     .parent = TYPE_OBJECT,
315     .instance_size = sizeof(Chardev),
316     .instance_init = char_init,
317     .instance_finalize = char_finalize,
318     .abstract = true,
319     .class_size = sizeof(ChardevClass),
320     .class_init = char_class_init,
321 };
322 
323 static bool qemu_chr_is_busy(Chardev *s)
324 {
325     if (CHARDEV_IS_MUX(s)) {
326         MuxChardev *d = MUX_CHARDEV(s);
327         return d->mux_cnt >= 0;
328     } else {
329         return s->be != NULL;
330     }
331 }
332 
333 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
334 {
335     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
336 
337     if (cc->chr_wait_connected) {
338         return cc->chr_wait_connected(chr, errp);
339     }
340 
341     return 0;
342 }
343 
344 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
345                                 bool permit_mux_mon)
346 {
347     char host[65], port[33], width[8], height[8];
348     int pos;
349     const char *p;
350     QemuOpts *opts;
351     Error *local_err = NULL;
352 
353     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
354     if (local_err) {
355         error_report_err(local_err);
356         return NULL;
357     }
358 
359     if (strstart(filename, "mon:", &p)) {
360         if (!permit_mux_mon) {
361             error_report("mon: isn't supported in this context");
362             return NULL;
363         }
364         filename = p;
365         qemu_opt_set(opts, "mux", "on", &error_abort);
366         if (strcmp(filename, "stdio") == 0) {
367             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
368              * but pass it to the guest.  Handle this only for compat syntax,
369              * for -chardev syntax we have special option for this.
370              * This is what -nographic did, redirecting+muxing serial+monitor
371              * to stdio causing Ctrl+C to be passed to guest. */
372             qemu_opt_set(opts, "signal", "off", &error_abort);
373         }
374     }
375 
376     if (strcmp(filename, "null")    == 0 ||
377         strcmp(filename, "pty")     == 0 ||
378         strcmp(filename, "msmouse") == 0 ||
379         strcmp(filename, "wctablet") == 0 ||
380         strcmp(filename, "braille") == 0 ||
381         strcmp(filename, "testdev") == 0 ||
382         strcmp(filename, "stdio")   == 0) {
383         qemu_opt_set(opts, "backend", filename, &error_abort);
384         return opts;
385     }
386     if (strstart(filename, "vc", &p)) {
387         qemu_opt_set(opts, "backend", "vc", &error_abort);
388         if (*p == ':') {
389             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
390                 /* pixels */
391                 qemu_opt_set(opts, "width", width, &error_abort);
392                 qemu_opt_set(opts, "height", height, &error_abort);
393             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
394                 /* chars */
395                 qemu_opt_set(opts, "cols", width, &error_abort);
396                 qemu_opt_set(opts, "rows", height, &error_abort);
397             } else {
398                 goto fail;
399             }
400         }
401         return opts;
402     }
403     if (strcmp(filename, "con:") == 0) {
404         qemu_opt_set(opts, "backend", "console", &error_abort);
405         return opts;
406     }
407     if (strstart(filename, "COM", NULL)) {
408         qemu_opt_set(opts, "backend", "serial", &error_abort);
409         qemu_opt_set(opts, "path", filename, &error_abort);
410         return opts;
411     }
412     if (strstart(filename, "file:", &p)) {
413         qemu_opt_set(opts, "backend", "file", &error_abort);
414         qemu_opt_set(opts, "path", p, &error_abort);
415         return opts;
416     }
417     if (strstart(filename, "pipe:", &p)) {
418         qemu_opt_set(opts, "backend", "pipe", &error_abort);
419         qemu_opt_set(opts, "path", p, &error_abort);
420         return opts;
421     }
422     if (strstart(filename, "tcp:", &p) ||
423         strstart(filename, "telnet:", &p) ||
424         strstart(filename, "tn3270:", &p) ||
425         strstart(filename, "websocket:", &p)) {
426         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
427             host[0] = 0;
428             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
429                 goto fail;
430         }
431         qemu_opt_set(opts, "backend", "socket", &error_abort);
432         qemu_opt_set(opts, "host", host, &error_abort);
433         qemu_opt_set(opts, "port", port, &error_abort);
434         if (p[pos] == ',') {
435             if (!qemu_opts_do_parse(opts, p + pos + 1, NULL, &local_err)) {
436                 error_report_err(local_err);
437                 goto fail;
438             }
439         }
440         if (strstart(filename, "telnet:", &p)) {
441             qemu_opt_set(opts, "telnet", "on", &error_abort);
442         } else if (strstart(filename, "tn3270:", &p)) {
443             qemu_opt_set(opts, "tn3270", "on", &error_abort);
444         } else if (strstart(filename, "websocket:", &p)) {
445             qemu_opt_set(opts, "websocket", "on", &error_abort);
446         }
447         return opts;
448     }
449     if (strstart(filename, "udp:", &p)) {
450         qemu_opt_set(opts, "backend", "udp", &error_abort);
451         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
452             host[0] = 0;
453             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
454                 goto fail;
455             }
456         }
457         qemu_opt_set(opts, "host", host, &error_abort);
458         qemu_opt_set(opts, "port", port, &error_abort);
459         if (p[pos] == '@') {
460             p += pos + 1;
461             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
462                 host[0] = 0;
463                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
464                     goto fail;
465                 }
466             }
467             qemu_opt_set(opts, "localaddr", host, &error_abort);
468             qemu_opt_set(opts, "localport", port, &error_abort);
469         }
470         return opts;
471     }
472     if (strstart(filename, "unix:", &p)) {
473         qemu_opt_set(opts, "backend", "socket", &error_abort);
474         if (!qemu_opts_do_parse(opts, p, "path", &local_err)) {
475             error_report_err(local_err);
476             goto fail;
477         }
478         return opts;
479     }
480     if (strstart(filename, "/dev/parport", NULL) ||
481         strstart(filename, "/dev/ppi", NULL)) {
482         qemu_opt_set(opts, "backend", "parallel", &error_abort);
483         qemu_opt_set(opts, "path", filename, &error_abort);
484         return opts;
485     }
486     if (strstart(filename, "/dev/", NULL)) {
487         qemu_opt_set(opts, "backend", "serial", &error_abort);
488         qemu_opt_set(opts, "path", filename, &error_abort);
489         return opts;
490     }
491 
492     error_report("'%s' is not a valid char driver", filename);
493 
494 fail:
495     qemu_opts_del(opts);
496     return NULL;
497 }
498 
499 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
500 {
501     const char *logfile = qemu_opt_get(opts, "logfile");
502 
503     backend->has_logfile = logfile != NULL;
504     backend->logfile = g_strdup(logfile);
505 
506     backend->has_logappend = true;
507     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
508 }
509 
510 static const ChardevClass *char_get_class(const char *driver, Error **errp)
511 {
512     ObjectClass *oc;
513     const ChardevClass *cc;
514     char *typename = g_strdup_printf("chardev-%s", driver);
515 
516     oc = module_object_class_by_name(typename);
517     g_free(typename);
518 
519     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
520         error_setg(errp, "'%s' is not a valid char driver name", driver);
521         return NULL;
522     }
523 
524     if (object_class_is_abstract(oc)) {
525         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
526                    "an abstract device type");
527         return NULL;
528     }
529 
530     cc = CHARDEV_CLASS(oc);
531     if (cc->internal) {
532         error_setg(errp, "'%s' is not a valid char driver name", driver);
533         return NULL;
534     }
535 
536     return cc;
537 }
538 
539 static struct ChardevAlias {
540     const char *typename;
541     const char *alias;
542     bool deprecation_warning_printed;
543 } chardev_alias_table[] = {
544 #ifdef HAVE_CHARDEV_PARPORT
545     { "parallel", "parport" },
546 #endif
547 #ifdef HAVE_CHARDEV_SERIAL
548     { "serial", "tty" },
549 #endif
550 };
551 
552 typedef struct ChadevClassFE {
553     void (*fn)(const char *name, void *opaque);
554     void *opaque;
555 } ChadevClassFE;
556 
557 static void
558 chardev_class_foreach(ObjectClass *klass, void *opaque)
559 {
560     ChadevClassFE *fe = opaque;
561 
562     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
563     if (CHARDEV_CLASS(klass)->internal) {
564         return;
565     }
566 
567     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
568 }
569 
570 static void
571 chardev_name_foreach(void (*fn)(const char *name, void *opaque),
572                      void *opaque)
573 {
574     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
575 
576     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
577 }
578 
579 static void
580 help_string_append(const char *name, void *opaque)
581 {
582     GString *str = opaque;
583 
584     g_string_append_printf(str, "\n  %s", name);
585 }
586 
587 static const char *chardev_alias_translate(const char *name)
588 {
589     int i;
590     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
591         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
592             if (!chardev_alias_table[i].deprecation_warning_printed) {
593                 warn_report("The alias '%s' is deprecated, use '%s' instead",
594                             name, chardev_alias_table[i].typename);
595                 chardev_alias_table[i].deprecation_warning_printed = true;
596             }
597             return chardev_alias_table[i].typename;
598         }
599     }
600     return name;
601 }
602 
603 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
604 {
605     Error *local_err = NULL;
606     const ChardevClass *cc;
607     ChardevBackend *backend = NULL;
608     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
609 
610     if (name == NULL) {
611         error_setg(errp, "chardev: \"%s\" missing backend",
612                    qemu_opts_id(opts));
613         return NULL;
614     }
615 
616     cc = char_get_class(name, errp);
617     if (cc == NULL) {
618         return NULL;
619     }
620 
621     backend = g_new0(ChardevBackend, 1);
622     backend->type = CHARDEV_BACKEND_KIND_NULL;
623 
624     if (cc->parse) {
625         cc->parse(opts, backend, &local_err);
626         if (local_err) {
627             error_propagate(errp, local_err);
628             qapi_free_ChardevBackend(backend);
629             return NULL;
630         }
631     } else {
632         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
633         qemu_chr_parse_common(opts, ccom);
634         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
635     }
636 
637     return backend;
638 }
639 
640 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, GMainContext *context,
641                                 Error **errp)
642 {
643     const ChardevClass *cc;
644     Chardev *chr = NULL;
645     ChardevBackend *backend = NULL;
646     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
647     const char *id = qemu_opts_id(opts);
648     char *bid = NULL;
649 
650     if (name && is_help_option(name)) {
651         GString *str = g_string_new("");
652 
653         chardev_name_foreach(help_string_append, str);
654 
655         qemu_printf("Available chardev backend types: %s\n", str->str);
656         g_string_free(str, true);
657         return NULL;
658     }
659 
660     if (id == NULL) {
661         error_setg(errp, "chardev: no id specified");
662         return NULL;
663     }
664 
665     backend = qemu_chr_parse_opts(opts, errp);
666     if (backend == NULL) {
667         return NULL;
668     }
669 
670     cc = char_get_class(name, errp);
671     if (cc == NULL) {
672         goto out;
673     }
674 
675     if (qemu_opt_get_bool(opts, "mux", 0)) {
676         bid = g_strdup_printf("%s-base", id);
677     }
678 
679     chr = qemu_chardev_new(bid ? bid : id,
680                            object_class_get_name(OBJECT_CLASS(cc)),
681                            backend, context, errp);
682 
683     if (chr == NULL) {
684         goto out;
685     }
686 
687     if (bid) {
688         Chardev *mux;
689         qapi_free_ChardevBackend(backend);
690         backend = g_new0(ChardevBackend, 1);
691         backend->type = CHARDEV_BACKEND_KIND_MUX;
692         backend->u.mux.data = g_new0(ChardevMux, 1);
693         backend->u.mux.data->chardev = g_strdup(bid);
694         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, context, errp);
695         if (mux == NULL) {
696             object_unparent(OBJECT(chr));
697             chr = NULL;
698             goto out;
699         }
700         chr = mux;
701     }
702 
703 out:
704     qapi_free_ChardevBackend(backend);
705     g_free(bid);
706     return chr;
707 }
708 
709 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
710                                bool permit_mux_mon, GMainContext *context)
711 {
712     const char *p;
713     Chardev *chr;
714     QemuOpts *opts;
715     Error *err = NULL;
716 
717     if (strstart(filename, "chardev:", &p)) {
718         return qemu_chr_find(p);
719     }
720 
721     opts = qemu_chr_parse_compat(label, filename, permit_mux_mon);
722     if (!opts)
723         return NULL;
724 
725     chr = qemu_chr_new_from_opts(opts, context, &err);
726     if (!chr) {
727         error_report_err(err);
728         goto out;
729     }
730 
731     if (qemu_opt_get_bool(opts, "mux", 0)) {
732         assert(permit_mux_mon);
733         monitor_init_hmp(chr, true, &err);
734         if (err) {
735             error_report_err(err);
736             object_unparent(OBJECT(chr));
737             chr = NULL;
738             goto out;
739         }
740     }
741 
742 out:
743     qemu_opts_del(opts);
744     return chr;
745 }
746 
747 static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
748                                           const char *filename,
749                                           bool permit_mux_mon,
750                                           GMainContext *context)
751 {
752     Chardev *chr;
753     chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon, context);
754     if (chr) {
755         if (replay_mode != REPLAY_MODE_NONE) {
756             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
757         }
758         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
759             error_report("Replay: ioctl is not supported "
760                          "for serial devices yet");
761         }
762         replay_register_char_driver(chr);
763     }
764     return chr;
765 }
766 
767 Chardev *qemu_chr_new(const char *label, const char *filename,
768                       GMainContext *context)
769 {
770     return qemu_chr_new_permit_mux_mon(label, filename, false, context);
771 }
772 
773 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
774                               GMainContext *context)
775 {
776     return qemu_chr_new_permit_mux_mon(label, filename, true, context);
777 }
778 
779 static int qmp_query_chardev_foreach(Object *obj, void *data)
780 {
781     Chardev *chr = CHARDEV(obj);
782     ChardevInfoList **list = data;
783     ChardevInfo *value = g_malloc0(sizeof(*value));
784 
785     value->label = g_strdup(chr->label);
786     value->filename = g_strdup(chr->filename);
787     value->frontend_open = chr->be && chr->be->fe_open;
788 
789     QAPI_LIST_PREPEND(*list, value);
790 
791     return 0;
792 }
793 
794 ChardevInfoList *qmp_query_chardev(Error **errp)
795 {
796     ChardevInfoList *chr_list = NULL;
797 
798     object_child_foreach(get_chardevs_root(),
799                          qmp_query_chardev_foreach, &chr_list);
800 
801     return chr_list;
802 }
803 
804 static void
805 qmp_prepend_backend(const char *name, void *opaque)
806 {
807     ChardevBackendInfoList **list = opaque;
808     ChardevBackendInfo *value;
809 
810     value = g_new0(ChardevBackendInfo, 1);
811     value->name = g_strdup(name);
812     QAPI_LIST_PREPEND(*list, value);
813 }
814 
815 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
816 {
817     ChardevBackendInfoList *backend_list = NULL;
818 
819     chardev_name_foreach(qmp_prepend_backend, &backend_list);
820 
821     return backend_list;
822 }
823 
824 Chardev *qemu_chr_find(const char *name)
825 {
826     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
827 
828     return obj ? CHARDEV(obj) : NULL;
829 }
830 
831 QemuOptsList qemu_chardev_opts = {
832     .name = "chardev",
833     .implied_opt_name = "backend",
834     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
835     .desc = {
836         {
837             .name = "backend",
838             .type = QEMU_OPT_STRING,
839         },{
840             .name = "path",
841             .type = QEMU_OPT_STRING,
842         },{
843             .name = "host",
844             .type = QEMU_OPT_STRING,
845         },{
846             .name = "port",
847             .type = QEMU_OPT_STRING,
848         },{
849             .name = "fd",
850             .type = QEMU_OPT_STRING,
851         },{
852             .name = "localaddr",
853             .type = QEMU_OPT_STRING,
854         },{
855             .name = "localport",
856             .type = QEMU_OPT_STRING,
857         },{
858             .name = "to",
859             .type = QEMU_OPT_NUMBER,
860         },{
861             .name = "ipv4",
862             .type = QEMU_OPT_BOOL,
863         },{
864             .name = "ipv6",
865             .type = QEMU_OPT_BOOL,
866         },{
867             .name = "wait",
868             .type = QEMU_OPT_BOOL,
869         },{
870             .name = "server",
871             .type = QEMU_OPT_BOOL,
872         },{
873             .name = "delay",
874             .type = QEMU_OPT_BOOL,
875         },{
876             .name = "nodelay",
877             .type = QEMU_OPT_BOOL,
878         },{
879             .name = "reconnect",
880             .type = QEMU_OPT_NUMBER,
881         },{
882             .name = "telnet",
883             .type = QEMU_OPT_BOOL,
884         },{
885             .name = "tn3270",
886             .type = QEMU_OPT_BOOL,
887         },{
888             .name = "tls-creds",
889             .type = QEMU_OPT_STRING,
890         },{
891             .name = "tls-authz",
892             .type = QEMU_OPT_STRING,
893         },{
894             .name = "websocket",
895             .type = QEMU_OPT_BOOL,
896         },{
897             .name = "width",
898             .type = QEMU_OPT_NUMBER,
899         },{
900             .name = "height",
901             .type = QEMU_OPT_NUMBER,
902         },{
903             .name = "cols",
904             .type = QEMU_OPT_NUMBER,
905         },{
906             .name = "rows",
907             .type = QEMU_OPT_NUMBER,
908         },{
909             .name = "mux",
910             .type = QEMU_OPT_BOOL,
911         },{
912             .name = "signal",
913             .type = QEMU_OPT_BOOL,
914         },{
915             .name = "name",
916             .type = QEMU_OPT_STRING,
917         },{
918             .name = "debug",
919             .type = QEMU_OPT_NUMBER,
920         },{
921             .name = "size",
922             .type = QEMU_OPT_SIZE,
923         },{
924             .name = "chardev",
925             .type = QEMU_OPT_STRING,
926         },{
927             .name = "append",
928             .type = QEMU_OPT_BOOL,
929         },{
930             .name = "logfile",
931             .type = QEMU_OPT_STRING,
932         },{
933             .name = "logappend",
934             .type = QEMU_OPT_BOOL,
935 #ifdef CONFIG_LINUX
936         },{
937             .name = "tight",
938             .type = QEMU_OPT_BOOL,
939             .def_value_str = "on",
940         },{
941             .name = "abstract",
942             .type = QEMU_OPT_BOOL,
943 #endif
944         },
945         { /* end of list */ }
946     },
947 };
948 
949 bool qemu_chr_has_feature(Chardev *chr,
950                           ChardevFeature feature)
951 {
952     return test_bit(feature, chr->features);
953 }
954 
955 void qemu_chr_set_feature(Chardev *chr,
956                            ChardevFeature feature)
957 {
958     return set_bit(feature, chr->features);
959 }
960 
961 static Chardev *chardev_new(const char *id, const char *typename,
962                             ChardevBackend *backend,
963                             GMainContext *gcontext,
964                             bool handover_yank_instance,
965                             Error **errp)
966 {
967     Object *obj;
968     Chardev *chr = NULL;
969     Error *local_err = NULL;
970     bool be_opened = true;
971 
972     assert(g_str_has_prefix(typename, "chardev-"));
973     assert(id);
974 
975     obj = object_new(typename);
976     chr = CHARDEV(obj);
977     chr->handover_yank_instance = handover_yank_instance;
978     chr->label = g_strdup(id);
979     chr->gcontext = gcontext;
980 
981     qemu_char_open(chr, backend, &be_opened, &local_err);
982     if (local_err) {
983         error_propagate(errp, local_err);
984         object_unref(obj);
985         return NULL;
986     }
987 
988     if (!chr->filename) {
989         chr->filename = g_strdup(typename + 8);
990     }
991     if (be_opened) {
992         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
993     }
994 
995     return chr;
996 }
997 
998 Chardev *qemu_chardev_new(const char *id, const char *typename,
999                           ChardevBackend *backend,
1000                           GMainContext *gcontext,
1001                           Error **errp)
1002 {
1003     Chardev *chr;
1004     g_autofree char *genid = NULL;
1005 
1006     if (!id) {
1007         genid = id_generate(ID_CHR);
1008         id = genid;
1009     }
1010 
1011     chr = chardev_new(id, typename, backend, gcontext, false, errp);
1012     if (!chr) {
1013         return NULL;
1014     }
1015 
1016     if (!object_property_try_add_child(get_chardevs_root(), id, OBJECT(chr),
1017                                        errp)) {
1018         object_unref(OBJECT(chr));
1019         return NULL;
1020     }
1021     object_unref(OBJECT(chr));
1022 
1023     return chr;
1024 }
1025 
1026 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
1027                                Error **errp)
1028 {
1029     const ChardevClass *cc;
1030     ChardevReturn *ret;
1031     Chardev *chr;
1032 
1033     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1034     if (!cc) {
1035         return NULL;
1036     }
1037 
1038     chr = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
1039                       backend, NULL, false, errp);
1040     if (!chr) {
1041         return NULL;
1042     }
1043 
1044     if (!object_property_try_add_child(get_chardevs_root(), id, OBJECT(chr),
1045                                        errp)) {
1046         object_unref(OBJECT(chr));
1047         return NULL;
1048     }
1049     object_unref(OBJECT(chr));
1050 
1051     ret = g_new0(ChardevReturn, 1);
1052     if (CHARDEV_IS_PTY(chr)) {
1053         ret->pty = g_strdup(chr->filename + 4);
1054         ret->has_pty = true;
1055     }
1056 
1057     return ret;
1058 }
1059 
1060 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
1061                                   Error **errp)
1062 {
1063     CharBackend *be;
1064     const ChardevClass *cc, *cc_new;
1065     Chardev *chr, *chr_new;
1066     bool closed_sent = false;
1067     bool handover_yank_instance;
1068     ChardevReturn *ret;
1069 
1070     chr = qemu_chr_find(id);
1071     if (!chr) {
1072         error_setg(errp, "Chardev '%s' does not exist", id);
1073         return NULL;
1074     }
1075 
1076     if (CHARDEV_IS_MUX(chr)) {
1077         error_setg(errp, "Mux device hotswap not supported yet");
1078         return NULL;
1079     }
1080 
1081     if (qemu_chr_replay(chr)) {
1082         error_setg(errp,
1083             "Chardev '%s' cannot be changed in record/replay mode", id);
1084         return NULL;
1085     }
1086 
1087     be = chr->be;
1088     if (!be) {
1089         /* easy case */
1090         object_unparent(OBJECT(chr));
1091         return qmp_chardev_add(id, backend, errp);
1092     }
1093 
1094     if (!be->chr_be_change) {
1095         error_setg(errp, "Chardev user does not support chardev hotswap");
1096         return NULL;
1097     }
1098 
1099     cc = CHARDEV_GET_CLASS(chr);
1100     cc_new = char_get_class(ChardevBackendKind_str(backend->type), errp);
1101     if (!cc_new) {
1102         return NULL;
1103     }
1104 
1105     /*
1106      * The new chardev should not register a yank instance if the current
1107      * chardev has registered one already.
1108      */
1109     handover_yank_instance = cc->supports_yank && cc_new->supports_yank;
1110 
1111     chr_new = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc_new)),
1112                           backend, chr->gcontext, handover_yank_instance, errp);
1113     if (!chr_new) {
1114         return NULL;
1115     }
1116 
1117     if (chr->be_open && !chr_new->be_open) {
1118         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1119         closed_sent = true;
1120     }
1121 
1122     chr->be = NULL;
1123     qemu_chr_fe_init(be, chr_new, &error_abort);
1124 
1125     if (be->chr_be_change(be->opaque) < 0) {
1126         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1127         chr_new->be = NULL;
1128         qemu_chr_fe_init(be, chr, &error_abort);
1129         if (closed_sent) {
1130             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1131         }
1132         object_unref(OBJECT(chr_new));
1133         return NULL;
1134     }
1135 
1136     /* change successfull, clean up */
1137     chr_new->handover_yank_instance = false;
1138 
1139     /*
1140      * When the old chardev is freed, it should not unregister the yank
1141      * instance if the new chardev needs it.
1142      */
1143     chr->handover_yank_instance = handover_yank_instance;
1144 
1145     object_unparent(OBJECT(chr));
1146     object_property_add_child(get_chardevs_root(), chr_new->label,
1147                               OBJECT(chr_new));
1148     object_unref(OBJECT(chr_new));
1149 
1150     ret = g_new0(ChardevReturn, 1);
1151     if (CHARDEV_IS_PTY(chr_new)) {
1152         ret->pty = g_strdup(chr_new->filename + 4);
1153         ret->has_pty = true;
1154     }
1155 
1156     return ret;
1157 }
1158 
1159 void qmp_chardev_remove(const char *id, Error **errp)
1160 {
1161     Chardev *chr;
1162 
1163     chr = qemu_chr_find(id);
1164     if (chr == NULL) {
1165         error_setg(errp, "Chardev '%s' not found", id);
1166         return;
1167     }
1168     if (qemu_chr_is_busy(chr)) {
1169         error_setg(errp, "Chardev '%s' is busy", id);
1170         return;
1171     }
1172     if (qemu_chr_replay(chr)) {
1173         error_setg(errp,
1174             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1175         return;
1176     }
1177     object_unparent(OBJECT(chr));
1178 }
1179 
1180 void qmp_chardev_send_break(const char *id, Error **errp)
1181 {
1182     Chardev *chr;
1183 
1184     chr = qemu_chr_find(id);
1185     if (chr == NULL) {
1186         error_setg(errp, "Chardev '%s' not found", id);
1187         return;
1188     }
1189     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1190 }
1191 
1192 /*
1193  * Add a timeout callback for the chardev (in milliseconds), return
1194  * the GSource object created. Please use this to add timeout hook for
1195  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1196  * make sure the gcontext that the task bound to is correct.
1197  */
1198 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1199                                  GSourceFunc func, void *private)
1200 {
1201     GSource *source = g_timeout_source_new(ms);
1202 
1203     assert(func);
1204     g_source_set_callback(source, func, private, NULL);
1205     g_source_attach(source, chr->gcontext);
1206 
1207     return source;
1208 }
1209 
1210 void qemu_chr_cleanup(void)
1211 {
1212     object_unparent(get_chardevs_root());
1213 }
1214 
1215 static void register_types(void)
1216 {
1217     type_register_static(&char_type_info);
1218 }
1219 
1220 type_init(register_types);
1221