xref: /openbmc/qemu/chardev/char.c (revision 9f2d175d)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/cutils.h"
27 #include "monitor/monitor.h"
28 #include "sysemu/sysemu.h"
29 #include "qemu/config-file.h"
30 #include "qemu/error-report.h"
31 #include "chardev/char.h"
32 #include "qapi/error.h"
33 #include "qapi/qapi-commands-char.h"
34 #include "qapi/qmp/qerror.h"
35 #include "sysemu/replay.h"
36 #include "qemu/help_option.h"
37 #include "qemu/option.h"
38 
39 #include "chardev/char-mux.h"
40 
41 /***********************************************************/
42 /* character device */
43 
44 static Object *get_chardevs_root(void)
45 {
46     return container_get(object_get_root(), "/chardevs");
47 }
48 
49 static void chr_be_event(Chardev *s, int event)
50 {
51     CharBackend *be = s->be;
52 
53     if (!be || !be->chr_event) {
54         return;
55     }
56 
57     be->chr_event(be->opaque, event);
58 }
59 
60 void qemu_chr_be_event(Chardev *s, int event)
61 {
62     /* Keep track if the char device is open */
63     switch (event) {
64         case CHR_EVENT_OPENED:
65             s->be_open = 1;
66             break;
67         case CHR_EVENT_CLOSED:
68             s->be_open = 0;
69             break;
70     }
71 
72     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
73 }
74 
75 /* Not reporting errors from writing to logfile, as logs are
76  * defined to be "best effort" only */
77 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
78 {
79     size_t done = 0;
80     ssize_t ret;
81 
82     if (s->logfd < 0) {
83         return;
84     }
85 
86     while (done < len) {
87     retry:
88         ret = write(s->logfd, buf + done, len - done);
89         if (ret == -1 && errno == EAGAIN) {
90             g_usleep(100);
91             goto retry;
92         }
93 
94         if (ret <= 0) {
95             return;
96         }
97         done += ret;
98     }
99 }
100 
101 static int qemu_chr_write_buffer(Chardev *s,
102                                  const uint8_t *buf, int len,
103                                  int *offset, bool write_all)
104 {
105     ChardevClass *cc = CHARDEV_GET_CLASS(s);
106     int res = 0;
107     *offset = 0;
108 
109     qemu_mutex_lock(&s->chr_write_lock);
110     while (*offset < len) {
111     retry:
112         res = cc->chr_write(s, buf + *offset, len - *offset);
113         if (res < 0 && errno == EAGAIN && write_all) {
114             g_usleep(100);
115             goto retry;
116         }
117 
118         if (res <= 0) {
119             break;
120         }
121 
122         *offset += res;
123         if (!write_all) {
124             break;
125         }
126     }
127     if (*offset > 0) {
128         qemu_chr_write_log(s, buf, *offset);
129     }
130     qemu_mutex_unlock(&s->chr_write_lock);
131 
132     return res;
133 }
134 
135 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
136 {
137     int offset = 0;
138     int res;
139 
140     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
141         replay_char_write_event_load(&res, &offset);
142         assert(offset <= len);
143         qemu_chr_write_buffer(s, buf, offset, &offset, true);
144         return res;
145     }
146 
147     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
148 
149     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
150         replay_char_write_event_save(res, offset);
151     }
152 
153     if (res < 0) {
154         return res;
155     }
156     return offset;
157 }
158 
159 int qemu_chr_be_can_write(Chardev *s)
160 {
161     CharBackend *be = s->be;
162 
163     if (!be || !be->chr_can_read) {
164         return 0;
165     }
166 
167     return be->chr_can_read(be->opaque);
168 }
169 
170 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
171 {
172     CharBackend *be = s->be;
173 
174     if (be && be->chr_read) {
175         be->chr_read(be->opaque, buf, len);
176     }
177 }
178 
179 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
180 {
181     if (qemu_chr_replay(s)) {
182         if (replay_mode == REPLAY_MODE_PLAY) {
183             return;
184         }
185         replay_chr_be_write(s, buf, len);
186     } else {
187         qemu_chr_be_write_impl(s, buf, len);
188     }
189 }
190 
191 void qemu_chr_be_update_read_handlers(Chardev *s,
192                                       GMainContext *context)
193 {
194     ChardevClass *cc = CHARDEV_GET_CLASS(s);
195 
196     s->gcontext = context;
197     if (cc->chr_update_read_handler) {
198         cc->chr_update_read_handler(s);
199     }
200 }
201 
202 int qemu_chr_add_client(Chardev *s, int fd)
203 {
204     return CHARDEV_GET_CLASS(s)->chr_add_client ?
205         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
206 }
207 
208 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
209                            bool *be_opened, Error **errp)
210 {
211     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
212     /* Any ChardevCommon member would work */
213     ChardevCommon *common = backend ? backend->u.null.data : NULL;
214 
215     if (common && common->has_logfile) {
216         int flags = O_WRONLY | O_CREAT;
217         if (common->has_logappend &&
218             common->logappend) {
219             flags |= O_APPEND;
220         } else {
221             flags |= O_TRUNC;
222         }
223         chr->logfd = qemu_open(common->logfile, flags, 0666);
224         if (chr->logfd < 0) {
225             error_setg_errno(errp, errno,
226                              "Unable to open logfile %s",
227                              common->logfile);
228             return;
229         }
230     }
231 
232     if (cc->open) {
233         cc->open(chr, backend, be_opened, errp);
234     }
235 }
236 
237 static void char_init(Object *obj)
238 {
239     Chardev *chr = CHARDEV(obj);
240 
241     chr->logfd = -1;
242     qemu_mutex_init(&chr->chr_write_lock);
243 }
244 
245 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
246 {
247     return len;
248 }
249 
250 static void char_class_init(ObjectClass *oc, void *data)
251 {
252     ChardevClass *cc = CHARDEV_CLASS(oc);
253 
254     cc->chr_write = null_chr_write;
255     cc->chr_be_event = chr_be_event;
256 }
257 
258 static void char_finalize(Object *obj)
259 {
260     Chardev *chr = CHARDEV(obj);
261 
262     if (chr->be) {
263         chr->be->chr = NULL;
264     }
265     g_free(chr->filename);
266     g_free(chr->label);
267     if (chr->logfd != -1) {
268         close(chr->logfd);
269     }
270     qemu_mutex_destroy(&chr->chr_write_lock);
271 }
272 
273 static const TypeInfo char_type_info = {
274     .name = TYPE_CHARDEV,
275     .parent = TYPE_OBJECT,
276     .instance_size = sizeof(Chardev),
277     .instance_init = char_init,
278     .instance_finalize = char_finalize,
279     .abstract = true,
280     .class_size = sizeof(ChardevClass),
281     .class_init = char_class_init,
282 };
283 
284 /**
285  * Called after processing of default and command-line-specified
286  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
287  * to a mux chardev. This is done here to ensure that
288  * output/prompts/banners are only displayed for the FE that has
289  * focus when initial command-line processing/machine init is
290  * completed.
291  *
292  * After this point, any new FE attached to any new or existing
293  * mux will receive CHR_EVENT_OPENED notifications for the BE
294  * immediately.
295  */
296 static int open_muxes(Object *child, void *opaque)
297 {
298     if (CHARDEV_IS_MUX(child)) {
299         /* send OPENED to all already-attached FEs */
300         mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
301         /* mark mux as OPENED so any new FEs will immediately receive
302          * OPENED event
303          */
304         qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
305     }
306 
307     return 0;
308 }
309 
310 static void muxes_realize_done(Notifier *notifier, void *unused)
311 {
312     muxes_realized = true;
313     object_child_foreach(get_chardevs_root(), open_muxes, NULL);
314 }
315 
316 static Notifier muxes_realize_notify = {
317     .notify = muxes_realize_done,
318 };
319 
320 static bool qemu_chr_is_busy(Chardev *s)
321 {
322     if (CHARDEV_IS_MUX(s)) {
323         MuxChardev *d = MUX_CHARDEV(s);
324         return d->mux_cnt >= 0;
325     } else {
326         return s->be != NULL;
327     }
328 }
329 
330 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
331 {
332     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
333 
334     if (cc->chr_wait_connected) {
335         return cc->chr_wait_connected(chr, errp);
336     }
337 
338     return 0;
339 }
340 
341 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
342 {
343     char host[65], port[33], width[8], height[8];
344     int pos;
345     const char *p;
346     QemuOpts *opts;
347     Error *local_err = NULL;
348 
349     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
350     if (local_err) {
351         error_report_err(local_err);
352         return NULL;
353     }
354 
355     if (strstart(filename, "mon:", &p)) {
356         filename = p;
357         qemu_opt_set(opts, "mux", "on", &error_abort);
358         if (strcmp(filename, "stdio") == 0) {
359             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
360              * but pass it to the guest.  Handle this only for compat syntax,
361              * for -chardev syntax we have special option for this.
362              * This is what -nographic did, redirecting+muxing serial+monitor
363              * to stdio causing Ctrl+C to be passed to guest. */
364             qemu_opt_set(opts, "signal", "off", &error_abort);
365         }
366     }
367 
368     if (strcmp(filename, "null")    == 0 ||
369         strcmp(filename, "pty")     == 0 ||
370         strcmp(filename, "msmouse") == 0 ||
371         strcmp(filename, "wctablet") == 0 ||
372         strcmp(filename, "braille") == 0 ||
373         strcmp(filename, "testdev") == 0 ||
374         strcmp(filename, "stdio")   == 0) {
375         qemu_opt_set(opts, "backend", filename, &error_abort);
376         return opts;
377     }
378     if (strstart(filename, "vc", &p)) {
379         qemu_opt_set(opts, "backend", "vc", &error_abort);
380         if (*p == ':') {
381             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
382                 /* pixels */
383                 qemu_opt_set(opts, "width", width, &error_abort);
384                 qemu_opt_set(opts, "height", height, &error_abort);
385             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
386                 /* chars */
387                 qemu_opt_set(opts, "cols", width, &error_abort);
388                 qemu_opt_set(opts, "rows", height, &error_abort);
389             } else {
390                 goto fail;
391             }
392         }
393         return opts;
394     }
395     if (strcmp(filename, "con:") == 0) {
396         qemu_opt_set(opts, "backend", "console", &error_abort);
397         return opts;
398     }
399     if (strstart(filename, "COM", NULL)) {
400         qemu_opt_set(opts, "backend", "serial", &error_abort);
401         qemu_opt_set(opts, "path", filename, &error_abort);
402         return opts;
403     }
404     if (strstart(filename, "file:", &p)) {
405         qemu_opt_set(opts, "backend", "file", &error_abort);
406         qemu_opt_set(opts, "path", p, &error_abort);
407         return opts;
408     }
409     if (strstart(filename, "pipe:", &p)) {
410         qemu_opt_set(opts, "backend", "pipe", &error_abort);
411         qemu_opt_set(opts, "path", p, &error_abort);
412         return opts;
413     }
414     if (strstart(filename, "tcp:", &p) ||
415         strstart(filename, "telnet:", &p) ||
416         strstart(filename, "tn3270:", &p)) {
417         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
418             host[0] = 0;
419             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
420                 goto fail;
421         }
422         qemu_opt_set(opts, "backend", "socket", &error_abort);
423         qemu_opt_set(opts, "host", host, &error_abort);
424         qemu_opt_set(opts, "port", port, &error_abort);
425         if (p[pos] == ',') {
426             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
427             if (local_err) {
428                 error_report_err(local_err);
429                 goto fail;
430             }
431         }
432         if (strstart(filename, "telnet:", &p)) {
433             qemu_opt_set(opts, "telnet", "on", &error_abort);
434         } else if (strstart(filename, "tn3270:", &p)) {
435             qemu_opt_set(opts, "tn3270", "on", &error_abort);
436         }
437         return opts;
438     }
439     if (strstart(filename, "udp:", &p)) {
440         qemu_opt_set(opts, "backend", "udp", &error_abort);
441         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
442             host[0] = 0;
443             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
444                 goto fail;
445             }
446         }
447         qemu_opt_set(opts, "host", host, &error_abort);
448         qemu_opt_set(opts, "port", port, &error_abort);
449         if (p[pos] == '@') {
450             p += pos + 1;
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, "localaddr", host, &error_abort);
458             qemu_opt_set(opts, "localport", port, &error_abort);
459         }
460         return opts;
461     }
462     if (strstart(filename, "unix:", &p)) {
463         qemu_opt_set(opts, "backend", "socket", &error_abort);
464         qemu_opts_do_parse(opts, p, "path", &local_err);
465         if (local_err) {
466             error_report_err(local_err);
467             goto fail;
468         }
469         return opts;
470     }
471     if (strstart(filename, "/dev/parport", NULL) ||
472         strstart(filename, "/dev/ppi", NULL)) {
473         qemu_opt_set(opts, "backend", "parallel", &error_abort);
474         qemu_opt_set(opts, "path", filename, &error_abort);
475         return opts;
476     }
477     if (strstart(filename, "/dev/", NULL)) {
478         qemu_opt_set(opts, "backend", "serial", &error_abort);
479         qemu_opt_set(opts, "path", filename, &error_abort);
480         return opts;
481     }
482 
483 fail:
484     qemu_opts_del(opts);
485     return NULL;
486 }
487 
488 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
489 {
490     const char *logfile = qemu_opt_get(opts, "logfile");
491 
492     backend->has_logfile = logfile != NULL;
493     backend->logfile = g_strdup(logfile);
494 
495     backend->has_logappend = true;
496     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
497 }
498 
499 static const ChardevClass *char_get_class(const char *driver, Error **errp)
500 {
501     ObjectClass *oc;
502     const ChardevClass *cc;
503     char *typename = g_strdup_printf("chardev-%s", driver);
504 
505     oc = object_class_by_name(typename);
506     g_free(typename);
507 
508     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
509         error_setg(errp, "'%s' is not a valid char driver name", driver);
510         return NULL;
511     }
512 
513     if (object_class_is_abstract(oc)) {
514         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
515                    "abstract device type");
516         return NULL;
517     }
518 
519     cc = CHARDEV_CLASS(oc);
520     if (cc->internal) {
521         error_setg(errp, "'%s' is not a valid char driver name", driver);
522         return NULL;
523     }
524 
525     return cc;
526 }
527 
528 static const struct ChardevAlias {
529     const char *typename;
530     const char *alias;
531 } chardev_alias_table[] = {
532 #ifdef HAVE_CHARDEV_PARPORT
533     { "parallel", "parport" },
534 #endif
535 #ifdef HAVE_CHARDEV_SERIAL
536     { "serial", "tty" },
537 #endif
538 };
539 
540 typedef struct ChadevClassFE {
541     void (*fn)(const char *name, void *opaque);
542     void *opaque;
543 } ChadevClassFE;
544 
545 static void
546 chardev_class_foreach(ObjectClass *klass, void *opaque)
547 {
548     ChadevClassFE *fe = opaque;
549 
550     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
551     if (CHARDEV_CLASS(klass)->internal) {
552         return;
553     }
554 
555     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
556 }
557 
558 static void
559 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
560 {
561     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
562     int i;
563 
564     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
565 
566     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
567         fn(chardev_alias_table[i].alias, opaque);
568     }
569 }
570 
571 static void
572 help_string_append(const char *name, void *opaque)
573 {
574     GString *str = opaque;
575 
576     g_string_append_printf(str, "\n%s", name);
577 }
578 
579 static const char *chardev_alias_translate(const char *name)
580 {
581     int i;
582     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
583         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
584             return chardev_alias_table[i].typename;
585         }
586     }
587     return name;
588 }
589 
590 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
591 {
592     Error *local_err = NULL;
593     const ChardevClass *cc;
594     ChardevBackend *backend = NULL;
595     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
596 
597     if (name == NULL) {
598         error_setg(errp, "chardev: \"%s\" missing backend",
599                    qemu_opts_id(opts));
600         return NULL;
601     }
602 
603     cc = char_get_class(name, errp);
604     if (cc == NULL) {
605         return NULL;
606     }
607 
608     backend = g_new0(ChardevBackend, 1);
609     backend->type = CHARDEV_BACKEND_KIND_NULL;
610 
611     if (cc->parse) {
612         cc->parse(opts, backend, &local_err);
613         if (local_err) {
614             error_propagate(errp, local_err);
615             qapi_free_ChardevBackend(backend);
616             return NULL;
617         }
618     } else {
619         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
620         qemu_chr_parse_common(opts, ccom);
621         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
622     }
623 
624     return backend;
625 }
626 
627 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
628 {
629     const ChardevClass *cc;
630     Chardev *chr = NULL;
631     ChardevBackend *backend = NULL;
632     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
633     const char *id = qemu_opts_id(opts);
634     char *bid = NULL;
635 
636     if (name && is_help_option(name)) {
637         GString *str = g_string_new("");
638 
639         chardev_name_foreach(help_string_append, str);
640 
641         error_report("Available chardev backend types: %s", str->str);
642         g_string_free(str, true);
643         return NULL;
644     }
645 
646     if (id == NULL) {
647         error_setg(errp, "chardev: no id specified");
648         return NULL;
649     }
650 
651     backend = qemu_chr_parse_opts(opts, errp);
652     if (backend == NULL) {
653         return NULL;
654     }
655 
656     cc = char_get_class(name, errp);
657     if (cc == NULL) {
658         goto out;
659     }
660 
661     if (qemu_opt_get_bool(opts, "mux", 0)) {
662         bid = g_strdup_printf("%s-base", id);
663     }
664 
665     chr = qemu_chardev_new(bid ? bid : id,
666                            object_class_get_name(OBJECT_CLASS(cc)),
667                            backend, errp);
668 
669     if (chr == NULL) {
670         goto out;
671     }
672 
673     if (bid) {
674         Chardev *mux;
675         qapi_free_ChardevBackend(backend);
676         backend = g_new0(ChardevBackend, 1);
677         backend->type = CHARDEV_BACKEND_KIND_MUX;
678         backend->u.mux.data = g_new0(ChardevMux, 1);
679         backend->u.mux.data->chardev = g_strdup(bid);
680         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
681         if (mux == NULL) {
682             object_unparent(OBJECT(chr));
683             chr = NULL;
684             goto out;
685         }
686         chr = mux;
687     }
688 
689 out:
690     qapi_free_ChardevBackend(backend);
691     g_free(bid);
692     return chr;
693 }
694 
695 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
696 {
697     const char *p;
698     Chardev *chr;
699     QemuOpts *opts;
700     Error *err = NULL;
701 
702     if (strstart(filename, "chardev:", &p)) {
703         return qemu_chr_find(p);
704     }
705 
706     opts = qemu_chr_parse_compat(label, filename);
707     if (!opts)
708         return NULL;
709 
710     chr = qemu_chr_new_from_opts(opts, &err);
711     if (err) {
712         error_report_err(err);
713     }
714     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
715         monitor_init(chr, MONITOR_USE_READLINE);
716     }
717     qemu_opts_del(opts);
718     return chr;
719 }
720 
721 Chardev *qemu_chr_new(const char *label, const char *filename)
722 {
723     Chardev *chr;
724     chr = qemu_chr_new_noreplay(label, filename);
725     if (chr) {
726         if (replay_mode != REPLAY_MODE_NONE) {
727             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
728         }
729         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
730             error_report("Replay: ioctl is not supported "
731                          "for serial devices yet");
732         }
733         replay_register_char_driver(chr);
734     }
735     return chr;
736 }
737 
738 static int qmp_query_chardev_foreach(Object *obj, void *data)
739 {
740     Chardev *chr = CHARDEV(obj);
741     ChardevInfoList **list = data;
742     ChardevInfoList *info = g_malloc0(sizeof(*info));
743 
744     info->value = g_malloc0(sizeof(*info->value));
745     info->value->label = g_strdup(chr->label);
746     info->value->filename = g_strdup(chr->filename);
747     info->value->frontend_open = chr->be && chr->be->fe_open;
748 
749     info->next = *list;
750     *list = info;
751 
752     return 0;
753 }
754 
755 ChardevInfoList *qmp_query_chardev(Error **errp)
756 {
757     ChardevInfoList *chr_list = NULL;
758 
759     object_child_foreach(get_chardevs_root(),
760                          qmp_query_chardev_foreach, &chr_list);
761 
762     return chr_list;
763 }
764 
765 static void
766 qmp_prepend_backend(const char *name, void *opaque)
767 {
768     ChardevBackendInfoList **list = opaque;
769     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
770 
771     info->value = g_malloc0(sizeof(*info->value));
772     info->value->name = g_strdup(name);
773     info->next = *list;
774     *list = info;
775 }
776 
777 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
778 {
779     ChardevBackendInfoList *backend_list = NULL;
780 
781     chardev_name_foreach(qmp_prepend_backend, &backend_list);
782 
783     return backend_list;
784 }
785 
786 Chardev *qemu_chr_find(const char *name)
787 {
788     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
789 
790     return obj ? CHARDEV(obj) : NULL;
791 }
792 
793 QemuOptsList qemu_chardev_opts = {
794     .name = "chardev",
795     .implied_opt_name = "backend",
796     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
797     .desc = {
798         {
799             .name = "backend",
800             .type = QEMU_OPT_STRING,
801         },{
802             .name = "path",
803             .type = QEMU_OPT_STRING,
804         },{
805             .name = "host",
806             .type = QEMU_OPT_STRING,
807         },{
808             .name = "port",
809             .type = QEMU_OPT_STRING,
810         },{
811             .name = "localaddr",
812             .type = QEMU_OPT_STRING,
813         },{
814             .name = "localport",
815             .type = QEMU_OPT_STRING,
816         },{
817             .name = "to",
818             .type = QEMU_OPT_NUMBER,
819         },{
820             .name = "ipv4",
821             .type = QEMU_OPT_BOOL,
822         },{
823             .name = "ipv6",
824             .type = QEMU_OPT_BOOL,
825         },{
826             .name = "wait",
827             .type = QEMU_OPT_BOOL,
828         },{
829             .name = "server",
830             .type = QEMU_OPT_BOOL,
831         },{
832             .name = "delay",
833             .type = QEMU_OPT_BOOL,
834         },{
835             .name = "reconnect",
836             .type = QEMU_OPT_NUMBER,
837         },{
838             .name = "telnet",
839             .type = QEMU_OPT_BOOL,
840         },{
841             .name = "tn3270",
842             .type = QEMU_OPT_BOOL,
843         },{
844             .name = "tls-creds",
845             .type = QEMU_OPT_STRING,
846         },{
847             .name = "width",
848             .type = QEMU_OPT_NUMBER,
849         },{
850             .name = "height",
851             .type = QEMU_OPT_NUMBER,
852         },{
853             .name = "cols",
854             .type = QEMU_OPT_NUMBER,
855         },{
856             .name = "rows",
857             .type = QEMU_OPT_NUMBER,
858         },{
859             .name = "mux",
860             .type = QEMU_OPT_BOOL,
861         },{
862             .name = "signal",
863             .type = QEMU_OPT_BOOL,
864         },{
865             .name = "name",
866             .type = QEMU_OPT_STRING,
867         },{
868             .name = "debug",
869             .type = QEMU_OPT_NUMBER,
870         },{
871             .name = "size",
872             .type = QEMU_OPT_SIZE,
873         },{
874             .name = "chardev",
875             .type = QEMU_OPT_STRING,
876         },{
877             .name = "append",
878             .type = QEMU_OPT_BOOL,
879         },{
880             .name = "logfile",
881             .type = QEMU_OPT_STRING,
882         },{
883             .name = "logappend",
884             .type = QEMU_OPT_BOOL,
885         },
886         { /* end of list */ }
887     },
888 };
889 
890 bool qemu_chr_has_feature(Chardev *chr,
891                           ChardevFeature feature)
892 {
893     return test_bit(feature, chr->features);
894 }
895 
896 void qemu_chr_set_feature(Chardev *chr,
897                            ChardevFeature feature)
898 {
899     return set_bit(feature, chr->features);
900 }
901 
902 Chardev *qemu_chardev_new(const char *id, const char *typename,
903                           ChardevBackend *backend,
904                           Error **errp)
905 {
906     Object *obj;
907     Chardev *chr = NULL;
908     Error *local_err = NULL;
909     bool be_opened = true;
910 
911     assert(g_str_has_prefix(typename, "chardev-"));
912 
913     obj = object_new(typename);
914     chr = CHARDEV(obj);
915     chr->label = g_strdup(id);
916 
917     qemu_char_open(chr, backend, &be_opened, &local_err);
918     if (local_err) {
919         goto end;
920     }
921 
922     if (!chr->filename) {
923         chr->filename = g_strdup(typename + 8);
924     }
925     if (be_opened) {
926         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
927     }
928 
929     if (id) {
930         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
931         if (local_err) {
932             goto end;
933         }
934         object_unref(obj);
935     }
936 
937 end:
938     if (local_err) {
939         error_propagate(errp, local_err);
940         object_unref(obj);
941         return NULL;
942     }
943 
944     return chr;
945 }
946 
947 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
948                                Error **errp)
949 {
950     const ChardevClass *cc;
951     ChardevReturn *ret;
952     Chardev *chr;
953 
954     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
955     if (!cc) {
956         return NULL;
957     }
958 
959     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
960                            backend, errp);
961     if (!chr) {
962         return NULL;
963     }
964 
965     ret = g_new0(ChardevReturn, 1);
966     if (CHARDEV_IS_PTY(chr)) {
967         ret->pty = g_strdup(chr->filename + 4);
968         ret->has_pty = true;
969     }
970 
971     return ret;
972 }
973 
974 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
975                                   Error **errp)
976 {
977     CharBackend *be;
978     const ChardevClass *cc;
979     Chardev *chr, *chr_new;
980     bool closed_sent = false;
981     ChardevReturn *ret;
982 
983     chr = qemu_chr_find(id);
984     if (!chr) {
985         error_setg(errp, "Chardev '%s' does not exist", id);
986         return NULL;
987     }
988 
989     if (CHARDEV_IS_MUX(chr)) {
990         error_setg(errp, "Mux device hotswap not supported yet");
991         return NULL;
992     }
993 
994     if (qemu_chr_replay(chr)) {
995         error_setg(errp,
996             "Chardev '%s' cannot be changed in record/replay mode", id);
997         return NULL;
998     }
999 
1000     be = chr->be;
1001     if (!be) {
1002         /* easy case */
1003         object_unparent(OBJECT(chr));
1004         return qmp_chardev_add(id, backend, errp);
1005     }
1006 
1007     if (!be->chr_be_change) {
1008         error_setg(errp, "Chardev user does not support chardev hotswap");
1009         return NULL;
1010     }
1011 
1012     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1013     if (!cc) {
1014         return NULL;
1015     }
1016 
1017     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1018                                backend, errp);
1019     if (!chr_new) {
1020         return NULL;
1021     }
1022     chr_new->label = g_strdup(id);
1023 
1024     if (chr->be_open && !chr_new->be_open) {
1025         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1026         closed_sent = true;
1027     }
1028 
1029     chr->be = NULL;
1030     qemu_chr_fe_init(be, chr_new, &error_abort);
1031 
1032     if (be->chr_be_change(be->opaque) < 0) {
1033         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1034         chr_new->be = NULL;
1035         qemu_chr_fe_init(be, chr, &error_abort);
1036         if (closed_sent) {
1037             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1038         }
1039         object_unref(OBJECT(chr_new));
1040         return NULL;
1041     }
1042 
1043     object_unparent(OBJECT(chr));
1044     object_property_add_child(get_chardevs_root(), chr_new->label,
1045                               OBJECT(chr_new), &error_abort);
1046     object_unref(OBJECT(chr_new));
1047 
1048     ret = g_new0(ChardevReturn, 1);
1049     if (CHARDEV_IS_PTY(chr_new)) {
1050         ret->pty = g_strdup(chr_new->filename + 4);
1051         ret->has_pty = true;
1052     }
1053 
1054     return ret;
1055 }
1056 
1057 void qmp_chardev_remove(const char *id, Error **errp)
1058 {
1059     Chardev *chr;
1060 
1061     chr = qemu_chr_find(id);
1062     if (chr == NULL) {
1063         error_setg(errp, "Chardev '%s' not found", id);
1064         return;
1065     }
1066     if (qemu_chr_is_busy(chr)) {
1067         error_setg(errp, "Chardev '%s' is busy", id);
1068         return;
1069     }
1070     if (qemu_chr_replay(chr)) {
1071         error_setg(errp,
1072             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1073         return;
1074     }
1075     object_unparent(OBJECT(chr));
1076 }
1077 
1078 void qmp_chardev_send_break(const char *id, Error **errp)
1079 {
1080     Chardev *chr;
1081 
1082     chr = qemu_chr_find(id);
1083     if (chr == NULL) {
1084         error_setg(errp, "Chardev '%s' not found", id);
1085         return;
1086     }
1087     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1088 }
1089 
1090 /*
1091  * Add a timeout callback for the chardev (in milliseconds), return
1092  * the GSource object created. Please use this to add timeout hook for
1093  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1094  * make sure the gcontext that the task bound to is correct.
1095  */
1096 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1097                                  GSourceFunc func, void *private)
1098 {
1099     GSource *source = g_timeout_source_new(ms);
1100 
1101     assert(func);
1102     g_source_set_callback(source, func, private, NULL);
1103     g_source_attach(source, chr->gcontext);
1104 
1105     return source;
1106 }
1107 
1108 void qemu_chr_cleanup(void)
1109 {
1110     object_unparent(get_chardevs_root());
1111 }
1112 
1113 static void register_types(void)
1114 {
1115     type_register_static(&char_type_info);
1116 
1117     /* this must be done after machine init, since we register FEs with muxes
1118      * as part of realize functions like serial_isa_realizefn when -nographic
1119      * is specified
1120      */
1121     qemu_add_machine_init_done_notifier(&muxes_realize_notify);
1122 }
1123 
1124 type_init(register_types);
1125