xref: /openbmc/qemu/chardev/char.c (revision db1015e9)
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         qemu_chr_write_log(s, buf, *offset);
142     }
143     qemu_mutex_unlock(&s->chr_write_lock);
144 
145     return res;
146 }
147 
148 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
149 {
150     int offset = 0;
151     int res;
152 
153     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
154         replay_char_write_event_load(&res, &offset);
155         assert(offset <= len);
156         qemu_chr_write_buffer(s, buf, offset, &offset, true);
157         return res;
158     }
159 
160     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
161 
162     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
163         replay_char_write_event_save(res, offset);
164     }
165 
166     if (res < 0) {
167         return res;
168     }
169     return offset;
170 }
171 
172 int qemu_chr_be_can_write(Chardev *s)
173 {
174     CharBackend *be = s->be;
175 
176     if (!be || !be->chr_can_read) {
177         return 0;
178     }
179 
180     return be->chr_can_read(be->opaque);
181 }
182 
183 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
184 {
185     CharBackend *be = s->be;
186 
187     if (be && be->chr_read) {
188         be->chr_read(be->opaque, buf, len);
189     }
190 }
191 
192 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
193 {
194     if (qemu_chr_replay(s)) {
195         if (replay_mode == REPLAY_MODE_PLAY) {
196             return;
197         }
198         replay_chr_be_write(s, buf, len);
199     } else {
200         qemu_chr_be_write_impl(s, buf, len);
201     }
202 }
203 
204 void qemu_chr_be_update_read_handlers(Chardev *s,
205                                       GMainContext *context)
206 {
207     ChardevClass *cc = CHARDEV_GET_CLASS(s);
208 
209     assert(qemu_chr_has_feature(s, QEMU_CHAR_FEATURE_GCONTEXT)
210            || !context);
211     s->gcontext = context;
212     if (cc->chr_update_read_handler) {
213         cc->chr_update_read_handler(s);
214     }
215 }
216 
217 int qemu_chr_add_client(Chardev *s, int fd)
218 {
219     return CHARDEV_GET_CLASS(s)->chr_add_client ?
220         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
221 }
222 
223 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
224                            bool *be_opened, Error **errp)
225 {
226     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
227     /* Any ChardevCommon member would work */
228     ChardevCommon *common = backend ? backend->u.null.data : NULL;
229 
230     if (common && common->has_logfile) {
231         int flags = O_WRONLY | O_CREAT;
232         if (common->has_logappend &&
233             common->logappend) {
234             flags |= O_APPEND;
235         } else {
236             flags |= O_TRUNC;
237         }
238         chr->logfd = qemu_open(common->logfile, flags, 0666);
239         if (chr->logfd < 0) {
240             error_setg_errno(errp, errno,
241                              "Unable to open logfile %s",
242                              common->logfile);
243             return;
244         }
245     }
246 
247     if (cc->open) {
248         cc->open(chr, backend, be_opened, errp);
249     }
250 }
251 
252 static void char_init(Object *obj)
253 {
254     Chardev *chr = CHARDEV(obj);
255 
256     chr->logfd = -1;
257     qemu_mutex_init(&chr->chr_write_lock);
258 
259     /*
260      * Assume if chr_update_read_handler is implemented it will
261      * take the updated gcontext into account.
262      */
263     if (CHARDEV_GET_CLASS(chr)->chr_update_read_handler) {
264         qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT);
265     }
266 
267 }
268 
269 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
270 {
271     return len;
272 }
273 
274 static void char_class_init(ObjectClass *oc, void *data)
275 {
276     ChardevClass *cc = CHARDEV_CLASS(oc);
277 
278     cc->chr_write = null_chr_write;
279     cc->chr_be_event = chr_be_event;
280 }
281 
282 static void char_finalize(Object *obj)
283 {
284     Chardev *chr = CHARDEV(obj);
285 
286     if (chr->be) {
287         chr->be->chr = NULL;
288     }
289     g_free(chr->filename);
290     g_free(chr->label);
291     if (chr->logfd != -1) {
292         close(chr->logfd);
293     }
294     qemu_mutex_destroy(&chr->chr_write_lock);
295 }
296 
297 static const TypeInfo char_type_info = {
298     .name = TYPE_CHARDEV,
299     .parent = TYPE_OBJECT,
300     .instance_size = sizeof(Chardev),
301     .instance_init = char_init,
302     .instance_finalize = char_finalize,
303     .abstract = true,
304     .class_size = sizeof(ChardevClass),
305     .class_init = char_class_init,
306 };
307 
308 static bool qemu_chr_is_busy(Chardev *s)
309 {
310     if (CHARDEV_IS_MUX(s)) {
311         MuxChardev *d = MUX_CHARDEV(s);
312         return d->mux_cnt >= 0;
313     } else {
314         return s->be != NULL;
315     }
316 }
317 
318 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
319 {
320     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
321 
322     if (cc->chr_wait_connected) {
323         return cc->chr_wait_connected(chr, errp);
324     }
325 
326     return 0;
327 }
328 
329 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
330                                 bool permit_mux_mon)
331 {
332     char host[65], port[33], width[8], height[8];
333     int pos;
334     const char *p;
335     QemuOpts *opts;
336     Error *local_err = NULL;
337 
338     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
339     if (local_err) {
340         error_report_err(local_err);
341         return NULL;
342     }
343 
344     if (strstart(filename, "mon:", &p)) {
345         if (!permit_mux_mon) {
346             error_report("mon: isn't supported in this context");
347             return NULL;
348         }
349         filename = p;
350         qemu_opt_set(opts, "mux", "on", &error_abort);
351         if (strcmp(filename, "stdio") == 0) {
352             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
353              * but pass it to the guest.  Handle this only for compat syntax,
354              * for -chardev syntax we have special option for this.
355              * This is what -nographic did, redirecting+muxing serial+monitor
356              * to stdio causing Ctrl+C to be passed to guest. */
357             qemu_opt_set(opts, "signal", "off", &error_abort);
358         }
359     }
360 
361     if (strcmp(filename, "null")    == 0 ||
362         strcmp(filename, "pty")     == 0 ||
363         strcmp(filename, "msmouse") == 0 ||
364         strcmp(filename, "wctablet") == 0 ||
365         strcmp(filename, "braille") == 0 ||
366         strcmp(filename, "testdev") == 0 ||
367         strcmp(filename, "stdio")   == 0) {
368         qemu_opt_set(opts, "backend", filename, &error_abort);
369         return opts;
370     }
371     if (strstart(filename, "vc", &p)) {
372         qemu_opt_set(opts, "backend", "vc", &error_abort);
373         if (*p == ':') {
374             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
375                 /* pixels */
376                 qemu_opt_set(opts, "width", width, &error_abort);
377                 qemu_opt_set(opts, "height", height, &error_abort);
378             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
379                 /* chars */
380                 qemu_opt_set(opts, "cols", width, &error_abort);
381                 qemu_opt_set(opts, "rows", height, &error_abort);
382             } else {
383                 goto fail;
384             }
385         }
386         return opts;
387     }
388     if (strcmp(filename, "con:") == 0) {
389         qemu_opt_set(opts, "backend", "console", &error_abort);
390         return opts;
391     }
392     if (strstart(filename, "COM", NULL)) {
393         qemu_opt_set(opts, "backend", "serial", &error_abort);
394         qemu_opt_set(opts, "path", filename, &error_abort);
395         return opts;
396     }
397     if (strstart(filename, "file:", &p)) {
398         qemu_opt_set(opts, "backend", "file", &error_abort);
399         qemu_opt_set(opts, "path", p, &error_abort);
400         return opts;
401     }
402     if (strstart(filename, "pipe:", &p)) {
403         qemu_opt_set(opts, "backend", "pipe", &error_abort);
404         qemu_opt_set(opts, "path", p, &error_abort);
405         return opts;
406     }
407     if (strstart(filename, "tcp:", &p) ||
408         strstart(filename, "telnet:", &p) ||
409         strstart(filename, "tn3270:", &p) ||
410         strstart(filename, "websocket:", &p)) {
411         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
412             host[0] = 0;
413             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
414                 goto fail;
415         }
416         qemu_opt_set(opts, "backend", "socket", &error_abort);
417         qemu_opt_set(opts, "host", host, &error_abort);
418         qemu_opt_set(opts, "port", port, &error_abort);
419         if (p[pos] == ',') {
420             if (!qemu_opts_do_parse(opts, p + pos + 1, NULL, &local_err)) {
421                 error_report_err(local_err);
422                 goto fail;
423             }
424         }
425         if (strstart(filename, "telnet:", &p)) {
426             qemu_opt_set(opts, "telnet", "on", &error_abort);
427         } else if (strstart(filename, "tn3270:", &p)) {
428             qemu_opt_set(opts, "tn3270", "on", &error_abort);
429         } else if (strstart(filename, "websocket:", &p)) {
430             qemu_opt_set(opts, "websocket", "on", &error_abort);
431         }
432         return opts;
433     }
434     if (strstart(filename, "udp:", &p)) {
435         qemu_opt_set(opts, "backend", "udp", &error_abort);
436         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
437             host[0] = 0;
438             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
439                 goto fail;
440             }
441         }
442         qemu_opt_set(opts, "host", host, &error_abort);
443         qemu_opt_set(opts, "port", port, &error_abort);
444         if (p[pos] == '@') {
445             p += pos + 1;
446             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
447                 host[0] = 0;
448                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
449                     goto fail;
450                 }
451             }
452             qemu_opt_set(opts, "localaddr", host, &error_abort);
453             qemu_opt_set(opts, "localport", port, &error_abort);
454         }
455         return opts;
456     }
457     if (strstart(filename, "unix:", &p)) {
458         qemu_opt_set(opts, "backend", "socket", &error_abort);
459         if (!qemu_opts_do_parse(opts, p, "path", &local_err)) {
460             error_report_err(local_err);
461             goto fail;
462         }
463         return opts;
464     }
465     if (strstart(filename, "/dev/parport", NULL) ||
466         strstart(filename, "/dev/ppi", NULL)) {
467         qemu_opt_set(opts, "backend", "parallel", &error_abort);
468         qemu_opt_set(opts, "path", filename, &error_abort);
469         return opts;
470     }
471     if (strstart(filename, "/dev/", NULL)) {
472         qemu_opt_set(opts, "backend", "serial", &error_abort);
473         qemu_opt_set(opts, "path", filename, &error_abort);
474         return opts;
475     }
476 
477     error_report("'%s' is not a valid char driver", filename);
478 
479 fail:
480     qemu_opts_del(opts);
481     return NULL;
482 }
483 
484 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
485 {
486     const char *logfile = qemu_opt_get(opts, "logfile");
487 
488     backend->has_logfile = logfile != NULL;
489     backend->logfile = g_strdup(logfile);
490 
491     backend->has_logappend = true;
492     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
493 }
494 
495 static const ChardevClass *char_get_class(const char *driver, Error **errp)
496 {
497     ObjectClass *oc;
498     const ChardevClass *cc;
499     char *typename = g_strdup_printf("chardev-%s", driver);
500 
501     oc = module_object_class_by_name(typename);
502     g_free(typename);
503 
504     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
505         error_setg(errp, "'%s' is not a valid char driver name", driver);
506         return NULL;
507     }
508 
509     if (object_class_is_abstract(oc)) {
510         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
511                    "abstract device type");
512         return NULL;
513     }
514 
515     cc = CHARDEV_CLASS(oc);
516     if (cc->internal) {
517         error_setg(errp, "'%s' is not a valid char driver name", driver);
518         return NULL;
519     }
520 
521     return cc;
522 }
523 
524 static const struct ChardevAlias {
525     const char *typename;
526     const char *alias;
527 } chardev_alias_table[] = {
528 #ifdef HAVE_CHARDEV_PARPORT
529     { "parallel", "parport" },
530 #endif
531 #ifdef HAVE_CHARDEV_SERIAL
532     { "serial", "tty" },
533 #endif
534 };
535 
536 typedef struct ChadevClassFE {
537     void (*fn)(const char *name, void *opaque);
538     void *opaque;
539 } ChadevClassFE;
540 
541 static void
542 chardev_class_foreach(ObjectClass *klass, void *opaque)
543 {
544     ChadevClassFE *fe = opaque;
545 
546     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
547     if (CHARDEV_CLASS(klass)->internal) {
548         return;
549     }
550 
551     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
552 }
553 
554 static void
555 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
556 {
557     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
558     int i;
559 
560     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
561 
562     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
563         fn(chardev_alias_table[i].alias, opaque);
564     }
565 }
566 
567 static void
568 help_string_append(const char *name, void *opaque)
569 {
570     GString *str = opaque;
571 
572     g_string_append_printf(str, "\n  %s", name);
573 }
574 
575 static const char *chardev_alias_translate(const char *name)
576 {
577     int i;
578     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
579         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
580             return chardev_alias_table[i].typename;
581         }
582     }
583     return name;
584 }
585 
586 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
587 {
588     Error *local_err = NULL;
589     const ChardevClass *cc;
590     ChardevBackend *backend = NULL;
591     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
592 
593     if (name == NULL) {
594         error_setg(errp, "chardev: \"%s\" missing backend",
595                    qemu_opts_id(opts));
596         return NULL;
597     }
598 
599     cc = char_get_class(name, errp);
600     if (cc == NULL) {
601         return NULL;
602     }
603 
604     backend = g_new0(ChardevBackend, 1);
605     backend->type = CHARDEV_BACKEND_KIND_NULL;
606 
607     if (cc->parse) {
608         cc->parse(opts, backend, &local_err);
609         if (local_err) {
610             error_propagate(errp, local_err);
611             qapi_free_ChardevBackend(backend);
612             return NULL;
613         }
614     } else {
615         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
616         qemu_chr_parse_common(opts, ccom);
617         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
618     }
619 
620     return backend;
621 }
622 
623 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, GMainContext *context,
624                                 Error **errp)
625 {
626     const ChardevClass *cc;
627     Chardev *chr = NULL;
628     ChardevBackend *backend = NULL;
629     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
630     const char *id = qemu_opts_id(opts);
631     char *bid = NULL;
632 
633     if (name && is_help_option(name)) {
634         GString *str = g_string_new("");
635 
636         chardev_name_foreach(help_string_append, str);
637 
638         qemu_printf("Available chardev backend types: %s\n", str->str);
639         g_string_free(str, true);
640         return NULL;
641     }
642 
643     if (id == NULL) {
644         error_setg(errp, "chardev: no id specified");
645         return NULL;
646     }
647 
648     backend = qemu_chr_parse_opts(opts, errp);
649     if (backend == NULL) {
650         return NULL;
651     }
652 
653     cc = char_get_class(name, errp);
654     if (cc == NULL) {
655         goto out;
656     }
657 
658     if (qemu_opt_get_bool(opts, "mux", 0)) {
659         bid = g_strdup_printf("%s-base", id);
660     }
661 
662     chr = qemu_chardev_new(bid ? bid : id,
663                            object_class_get_name(OBJECT_CLASS(cc)),
664                            backend, context, errp);
665 
666     if (chr == NULL) {
667         goto out;
668     }
669 
670     if (bid) {
671         Chardev *mux;
672         qapi_free_ChardevBackend(backend);
673         backend = g_new0(ChardevBackend, 1);
674         backend->type = CHARDEV_BACKEND_KIND_MUX;
675         backend->u.mux.data = g_new0(ChardevMux, 1);
676         backend->u.mux.data->chardev = g_strdup(bid);
677         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, context, errp);
678         if (mux == NULL) {
679             object_unparent(OBJECT(chr));
680             chr = NULL;
681             goto out;
682         }
683         chr = mux;
684     }
685 
686 out:
687     qapi_free_ChardevBackend(backend);
688     g_free(bid);
689     return chr;
690 }
691 
692 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
693                                bool permit_mux_mon, GMainContext *context)
694 {
695     const char *p;
696     Chardev *chr;
697     QemuOpts *opts;
698     Error *err = NULL;
699 
700     if (strstart(filename, "chardev:", &p)) {
701         return qemu_chr_find(p);
702     }
703 
704     opts = qemu_chr_parse_compat(label, filename, permit_mux_mon);
705     if (!opts)
706         return NULL;
707 
708     chr = qemu_chr_new_from_opts(opts, context, &err);
709     if (!chr) {
710         error_report_err(err);
711         goto out;
712     }
713 
714     if (qemu_opt_get_bool(opts, "mux", 0)) {
715         assert(permit_mux_mon);
716         monitor_init_hmp(chr, true, &err);
717         if (err) {
718             error_report_err(err);
719             object_unparent(OBJECT(chr));
720             chr = NULL;
721             goto out;
722         }
723     }
724 
725 out:
726     qemu_opts_del(opts);
727     return chr;
728 }
729 
730 static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
731                                           const char *filename,
732                                           bool permit_mux_mon,
733                                           GMainContext *context)
734 {
735     Chardev *chr;
736     chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon, context);
737     if (chr) {
738         if (replay_mode != REPLAY_MODE_NONE) {
739             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
740         }
741         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
742             error_report("Replay: ioctl is not supported "
743                          "for serial devices yet");
744         }
745         replay_register_char_driver(chr);
746     }
747     return chr;
748 }
749 
750 Chardev *qemu_chr_new(const char *label, const char *filename,
751                       GMainContext *context)
752 {
753     return qemu_chr_new_permit_mux_mon(label, filename, false, context);
754 }
755 
756 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
757                               GMainContext *context)
758 {
759     return qemu_chr_new_permit_mux_mon(label, filename, true, context);
760 }
761 
762 static int qmp_query_chardev_foreach(Object *obj, void *data)
763 {
764     Chardev *chr = CHARDEV(obj);
765     ChardevInfoList **list = data;
766     ChardevInfoList *info = g_malloc0(sizeof(*info));
767 
768     info->value = g_malloc0(sizeof(*info->value));
769     info->value->label = g_strdup(chr->label);
770     info->value->filename = g_strdup(chr->filename);
771     info->value->frontend_open = chr->be && chr->be->fe_open;
772 
773     info->next = *list;
774     *list = info;
775 
776     return 0;
777 }
778 
779 ChardevInfoList *qmp_query_chardev(Error **errp)
780 {
781     ChardevInfoList *chr_list = NULL;
782 
783     object_child_foreach(get_chardevs_root(),
784                          qmp_query_chardev_foreach, &chr_list);
785 
786     return chr_list;
787 }
788 
789 static void
790 qmp_prepend_backend(const char *name, void *opaque)
791 {
792     ChardevBackendInfoList **list = opaque;
793     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
794 
795     info->value = g_malloc0(sizeof(*info->value));
796     info->value->name = g_strdup(name);
797     info->next = *list;
798     *list = info;
799 }
800 
801 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
802 {
803     ChardevBackendInfoList *backend_list = NULL;
804 
805     chardev_name_foreach(qmp_prepend_backend, &backend_list);
806 
807     return backend_list;
808 }
809 
810 Chardev *qemu_chr_find(const char *name)
811 {
812     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
813 
814     return obj ? CHARDEV(obj) : NULL;
815 }
816 
817 QemuOptsList qemu_chardev_opts = {
818     .name = "chardev",
819     .implied_opt_name = "backend",
820     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
821     .desc = {
822         {
823             .name = "backend",
824             .type = QEMU_OPT_STRING,
825         },{
826             .name = "path",
827             .type = QEMU_OPT_STRING,
828         },{
829             .name = "host",
830             .type = QEMU_OPT_STRING,
831         },{
832             .name = "port",
833             .type = QEMU_OPT_STRING,
834         },{
835             .name = "fd",
836             .type = QEMU_OPT_STRING,
837         },{
838             .name = "localaddr",
839             .type = QEMU_OPT_STRING,
840         },{
841             .name = "localport",
842             .type = QEMU_OPT_STRING,
843         },{
844             .name = "to",
845             .type = QEMU_OPT_NUMBER,
846         },{
847             .name = "ipv4",
848             .type = QEMU_OPT_BOOL,
849         },{
850             .name = "ipv6",
851             .type = QEMU_OPT_BOOL,
852         },{
853             .name = "wait",
854             .type = QEMU_OPT_BOOL,
855         },{
856             .name = "server",
857             .type = QEMU_OPT_BOOL,
858         },{
859             .name = "delay",
860             .type = QEMU_OPT_BOOL,
861         },{
862             .name = "reconnect",
863             .type = QEMU_OPT_NUMBER,
864         },{
865             .name = "telnet",
866             .type = QEMU_OPT_BOOL,
867         },{
868             .name = "tn3270",
869             .type = QEMU_OPT_BOOL,
870         },{
871             .name = "tls-creds",
872             .type = QEMU_OPT_STRING,
873         },{
874             .name = "tls-authz",
875             .type = QEMU_OPT_STRING,
876         },{
877             .name = "websocket",
878             .type = QEMU_OPT_BOOL,
879         },{
880             .name = "width",
881             .type = QEMU_OPT_NUMBER,
882         },{
883             .name = "height",
884             .type = QEMU_OPT_NUMBER,
885         },{
886             .name = "cols",
887             .type = QEMU_OPT_NUMBER,
888         },{
889             .name = "rows",
890             .type = QEMU_OPT_NUMBER,
891         },{
892             .name = "mux",
893             .type = QEMU_OPT_BOOL,
894         },{
895             .name = "signal",
896             .type = QEMU_OPT_BOOL,
897         },{
898             .name = "name",
899             .type = QEMU_OPT_STRING,
900         },{
901             .name = "debug",
902             .type = QEMU_OPT_NUMBER,
903         },{
904             .name = "size",
905             .type = QEMU_OPT_SIZE,
906         },{
907             .name = "chardev",
908             .type = QEMU_OPT_STRING,
909         },{
910             .name = "append",
911             .type = QEMU_OPT_BOOL,
912         },{
913             .name = "logfile",
914             .type = QEMU_OPT_STRING,
915         },{
916             .name = "logappend",
917             .type = QEMU_OPT_BOOL,
918         },{
919             .name = "tight",
920             .type = QEMU_OPT_BOOL,
921             .def_value_str = "on",
922         },{
923             .name = "abstract",
924             .type = QEMU_OPT_BOOL,
925         },
926         { /* end of list */ }
927     },
928 };
929 
930 bool qemu_chr_has_feature(Chardev *chr,
931                           ChardevFeature feature)
932 {
933     return test_bit(feature, chr->features);
934 }
935 
936 void qemu_chr_set_feature(Chardev *chr,
937                            ChardevFeature feature)
938 {
939     return set_bit(feature, chr->features);
940 }
941 
942 static Chardev *chardev_new(const char *id, const char *typename,
943                             ChardevBackend *backend,
944                             GMainContext *gcontext,
945                             Error **errp)
946 {
947     Object *obj;
948     Chardev *chr = NULL;
949     Error *local_err = NULL;
950     bool be_opened = true;
951 
952     assert(g_str_has_prefix(typename, "chardev-"));
953 
954     obj = object_new(typename);
955     chr = CHARDEV(obj);
956     chr->label = g_strdup(id);
957     chr->gcontext = gcontext;
958 
959     qemu_char_open(chr, backend, &be_opened, &local_err);
960     if (local_err) {
961         goto end;
962     }
963 
964     if (!chr->filename) {
965         chr->filename = g_strdup(typename + 8);
966     }
967     if (be_opened) {
968         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
969     }
970 
971     if (id) {
972         object_property_try_add_child(get_chardevs_root(), id, obj,
973                                       &local_err);
974         if (local_err) {
975             goto end;
976         }
977         object_unref(obj);
978     }
979 
980 end:
981     if (local_err) {
982         error_propagate(errp, local_err);
983         object_unref(obj);
984         return NULL;
985     }
986 
987     return chr;
988 }
989 
990 Chardev *qemu_chardev_new(const char *id, const char *typename,
991                           ChardevBackend *backend,
992                           GMainContext *gcontext,
993                           Error **errp)
994 {
995     g_autofree char *genid = NULL;
996 
997     if (!id) {
998         genid = id_generate(ID_CHR);
999         id = genid;
1000     }
1001 
1002     return chardev_new(id, typename, backend, gcontext, errp);
1003 }
1004 
1005 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
1006                                Error **errp)
1007 {
1008     const ChardevClass *cc;
1009     ChardevReturn *ret;
1010     Chardev *chr;
1011 
1012     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1013     if (!cc) {
1014         return NULL;
1015     }
1016 
1017     chr = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
1018                       backend, NULL, errp);
1019     if (!chr) {
1020         return NULL;
1021     }
1022 
1023     ret = g_new0(ChardevReturn, 1);
1024     if (CHARDEV_IS_PTY(chr)) {
1025         ret->pty = g_strdup(chr->filename + 4);
1026         ret->has_pty = true;
1027     }
1028 
1029     return ret;
1030 }
1031 
1032 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
1033                                   Error **errp)
1034 {
1035     CharBackend *be;
1036     const ChardevClass *cc;
1037     Chardev *chr, *chr_new;
1038     bool closed_sent = false;
1039     ChardevReturn *ret;
1040 
1041     chr = qemu_chr_find(id);
1042     if (!chr) {
1043         error_setg(errp, "Chardev '%s' does not exist", id);
1044         return NULL;
1045     }
1046 
1047     if (CHARDEV_IS_MUX(chr)) {
1048         error_setg(errp, "Mux device hotswap not supported yet");
1049         return NULL;
1050     }
1051 
1052     if (qemu_chr_replay(chr)) {
1053         error_setg(errp,
1054             "Chardev '%s' cannot be changed in record/replay mode", id);
1055         return NULL;
1056     }
1057 
1058     be = chr->be;
1059     if (!be) {
1060         /* easy case */
1061         object_unparent(OBJECT(chr));
1062         return qmp_chardev_add(id, backend, errp);
1063     }
1064 
1065     if (!be->chr_be_change) {
1066         error_setg(errp, "Chardev user does not support chardev hotswap");
1067         return NULL;
1068     }
1069 
1070     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1071     if (!cc) {
1072         return NULL;
1073     }
1074 
1075     chr_new = chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1076                           backend, chr->gcontext, errp);
1077     if (!chr_new) {
1078         return NULL;
1079     }
1080     chr_new->label = g_strdup(id);
1081 
1082     if (chr->be_open && !chr_new->be_open) {
1083         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1084         closed_sent = true;
1085     }
1086 
1087     chr->be = NULL;
1088     qemu_chr_fe_init(be, chr_new, &error_abort);
1089 
1090     if (be->chr_be_change(be->opaque) < 0) {
1091         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1092         chr_new->be = NULL;
1093         qemu_chr_fe_init(be, chr, &error_abort);
1094         if (closed_sent) {
1095             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1096         }
1097         object_unref(OBJECT(chr_new));
1098         return NULL;
1099     }
1100 
1101     object_unparent(OBJECT(chr));
1102     object_property_add_child(get_chardevs_root(), chr_new->label,
1103                               OBJECT(chr_new));
1104     object_unref(OBJECT(chr_new));
1105 
1106     ret = g_new0(ChardevReturn, 1);
1107     if (CHARDEV_IS_PTY(chr_new)) {
1108         ret->pty = g_strdup(chr_new->filename + 4);
1109         ret->has_pty = true;
1110     }
1111 
1112     return ret;
1113 }
1114 
1115 void qmp_chardev_remove(const char *id, Error **errp)
1116 {
1117     Chardev *chr;
1118 
1119     chr = qemu_chr_find(id);
1120     if (chr == NULL) {
1121         error_setg(errp, "Chardev '%s' not found", id);
1122         return;
1123     }
1124     if (qemu_chr_is_busy(chr)) {
1125         error_setg(errp, "Chardev '%s' is busy", id);
1126         return;
1127     }
1128     if (qemu_chr_replay(chr)) {
1129         error_setg(errp,
1130             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1131         return;
1132     }
1133     object_unparent(OBJECT(chr));
1134 }
1135 
1136 void qmp_chardev_send_break(const char *id, Error **errp)
1137 {
1138     Chardev *chr;
1139 
1140     chr = qemu_chr_find(id);
1141     if (chr == NULL) {
1142         error_setg(errp, "Chardev '%s' not found", id);
1143         return;
1144     }
1145     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1146 }
1147 
1148 /*
1149  * Add a timeout callback for the chardev (in milliseconds), return
1150  * the GSource object created. Please use this to add timeout hook for
1151  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1152  * make sure the gcontext that the task bound to is correct.
1153  */
1154 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1155                                  GSourceFunc func, void *private)
1156 {
1157     GSource *source = g_timeout_source_new(ms);
1158 
1159     assert(func);
1160     g_source_set_callback(source, func, private, NULL);
1161     g_source_attach(source, chr->gcontext);
1162 
1163     return source;
1164 }
1165 
1166 void qemu_chr_cleanup(void)
1167 {
1168     object_unparent(get_chardevs_root());
1169 }
1170 
1171 static void register_types(void)
1172 {
1173     type_register_static(&char_type_info);
1174 }
1175 
1176 type_init(register_types);
1177