xref: /openbmc/qemu/chardev/char.c (revision ced29396)
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 "qemu/config-file.h"
29 #include "qemu/error-report.h"
30 #include "qemu/qemu-print.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/module.h"
38 #include "qemu/option.h"
39 #include "qemu/id.h"
40 #include "qemu/coroutine.h"
41 #include "qemu/yank.h"
42 
43 #include "chardev-internal.h"
44 
45 /***********************************************************/
46 /* character device */
47 
48 Object *get_chardevs_root(void)
49 {
50     return container_get(object_get_root(), "/chardevs");
51 }
52 
53 static void chr_be_event(Chardev *s, QEMUChrEvent event)
54 {
55     CharBackend *be = s->be;
56 
57     if (!be || !be->chr_event) {
58         return;
59     }
60 
61     be->chr_event(be->opaque, event);
62 }
63 
64 void qemu_chr_be_event(Chardev *s, QEMUChrEvent event)
65 {
66     /* Keep track if the char device is open */
67     switch (event) {
68         case CHR_EVENT_OPENED:
69             s->be_open = 1;
70             break;
71         case CHR_EVENT_CLOSED:
72             s->be_open = 0;
73             break;
74     case CHR_EVENT_BREAK:
75     case CHR_EVENT_MUX_IN:
76     case CHR_EVENT_MUX_OUT:
77         /* Ignore */
78         break;
79     }
80 
81     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
82 }
83 
84 /* Not reporting errors from writing to logfile, as logs are
85  * defined to be "best effort" only */
86 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
87 {
88     size_t done = 0;
89     ssize_t ret;
90 
91     if (s->logfd < 0) {
92         return;
93     }
94 
95     while (done < len) {
96     retry:
97         ret = write(s->logfd, buf + done, len - done);
98         if (ret == -1 && errno == EAGAIN) {
99             g_usleep(100);
100             goto retry;
101         }
102 
103         if (ret <= 0) {
104             return;
105         }
106         done += ret;
107     }
108 }
109 
110 static int qemu_chr_write_buffer(Chardev *s,
111                                  const uint8_t *buf, int len,
112                                  int *offset, bool write_all)
113 {
114     ChardevClass *cc = CHARDEV_GET_CLASS(s);
115     int res = 0;
116     *offset = 0;
117 
118     qemu_mutex_lock(&s->chr_write_lock);
119     while (*offset < len) {
120     retry:
121         res = cc->chr_write(s, buf + *offset, len - *offset);
122         if (res < 0 && errno == EAGAIN && write_all) {
123             if (qemu_in_coroutine()) {
124                 qemu_co_sleep_ns(QEMU_CLOCK_REALTIME, 100000);
125             } else {
126                 g_usleep(100);
127             }
128             goto retry;
129         }
130 
131         if (res <= 0) {
132             break;
133         }
134 
135         *offset += res;
136         if (!write_all) {
137             break;
138         }
139     }
140     if (*offset > 0) {
141         /*
142          * If some data was written by backend, we should
143          * only log what was actually written. This method
144          * may be invoked again to write the remaining
145          * method, thus we'll log the remainder at that time.
146          */
147         qemu_chr_write_log(s, buf, *offset);
148     } else if (res < 0) {
149         /*
150          * If a fatal error was reported by the backend,
151          * assume this method won't be invoked again with
152          * this buffer, so log it all right away.
153          */
154         qemu_chr_write_log(s, buf, len);
155     }
156     qemu_mutex_unlock(&s->chr_write_lock);
157 
158     return res;
159 }
160 
161 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
162 {
163     int offset = 0;
164     int res;
165 
166     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
167         replay_char_write_event_load(&res, &offset);
168         assert(offset <= len);
169         qemu_chr_write_buffer(s, buf, offset, &offset, true);
170         return res;
171     }
172 
173     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
174 
175     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
176         replay_char_write_event_save(res, offset);
177     }
178 
179     if (res < 0) {
180         return res;
181     }
182     return offset;
183 }
184 
185 int qemu_chr_be_can_write(Chardev *s)
186 {
187     CharBackend *be = s->be;
188 
189     if (!be || !be->chr_can_read) {
190         return 0;
191     }
192 
193     return be->chr_can_read(be->opaque);
194 }
195 
196 void qemu_chr_be_write_impl(Chardev *s, const uint8_t *buf, int len)
197 {
198     CharBackend *be = s->be;
199 
200     if (be && be->chr_read) {
201         be->chr_read(be->opaque, buf, len);
202     }
203 }
204 
205 void qemu_chr_be_write(Chardev *s, const uint8_t *buf, int len)
206 {
207     if (qemu_chr_replay(s)) {
208         if (replay_mode == REPLAY_MODE_PLAY) {
209             return;
210         }
211         replay_chr_be_write(s, buf, len);
212     } else {
213         qemu_chr_be_write_impl(s, buf, len);
214     }
215 }
216 
217 void qemu_chr_be_update_read_handlers(Chardev *s,
218                                       GMainContext *context)
219 {
220     ChardevClass *cc = CHARDEV_GET_CLASS(s);
221 
222     assert(qemu_chr_has_feature(s, QEMU_CHAR_FEATURE_GCONTEXT)
223            || !context);
224     s->gcontext = context;
225     if (cc->chr_update_read_handler) {
226         cc->chr_update_read_handler(s);
227     }
228 }
229 
230 int qemu_chr_add_client(Chardev *s, int fd)
231 {
232     return CHARDEV_GET_CLASS(s)->chr_add_client ?
233         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
234 }
235 
236 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
237                            bool *be_opened, Error **errp)
238 {
239     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
240     /* Any ChardevCommon member would work */
241     ChardevCommon *common = backend ? backend->u.null.data : NULL;
242 
243     if (common && common->logfile) {
244         int flags = O_WRONLY;
245         if (common->has_logappend &&
246             common->logappend) {
247             flags |= O_APPEND;
248         } else {
249             flags |= O_TRUNC;
250         }
251         chr->logfd = qemu_create(common->logfile, flags, 0666, errp);
252         if (chr->logfd < 0) {
253             return;
254         }
255     }
256 
257     if (cc->open) {
258         cc->open(chr, backend, be_opened, errp);
259     }
260 }
261 
262 static void char_init(Object *obj)
263 {
264     Chardev *chr = CHARDEV(obj);
265 
266     chr->handover_yank_instance = false;
267     chr->logfd = -1;
268     qemu_mutex_init(&chr->chr_write_lock);
269 
270     /*
271      * Assume if chr_update_read_handler is implemented it will
272      * take the updated gcontext into account.
273      */
274     if (CHARDEV_GET_CLASS(chr)->chr_update_read_handler) {
275         qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_GCONTEXT);
276     }
277 
278 }
279 
280 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
281 {
282     return len;
283 }
284 
285 static void char_class_init(ObjectClass *oc, void *data)
286 {
287     ChardevClass *cc = CHARDEV_CLASS(oc);
288 
289     cc->chr_write = null_chr_write;
290     cc->chr_be_event = chr_be_event;
291 }
292 
293 static void char_finalize(Object *obj)
294 {
295     Chardev *chr = CHARDEV(obj);
296 
297     if (chr->be) {
298         chr->be->chr = NULL;
299     }
300     g_free(chr->filename);
301     g_free(chr->label);
302     if (chr->logfd != -1) {
303         close(chr->logfd);
304     }
305     qemu_mutex_destroy(&chr->chr_write_lock);
306 }
307 
308 static const TypeInfo char_type_info = {
309     .name = TYPE_CHARDEV,
310     .parent = TYPE_OBJECT,
311     .instance_size = sizeof(Chardev),
312     .instance_init = char_init,
313     .instance_finalize = char_finalize,
314     .abstract = true,
315     .class_size = sizeof(ChardevClass),
316     .class_init = char_class_init,
317 };
318 
319 static bool qemu_chr_is_busy(Chardev *s)
320 {
321     if (CHARDEV_IS_MUX(s)) {
322         MuxChardev *d = MUX_CHARDEV(s);
323         return d->mux_cnt >= 0;
324     } else {
325         return s->be != NULL;
326     }
327 }
328 
329 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
330 {
331     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
332 
333     if (cc->chr_wait_connected) {
334         return cc->chr_wait_connected(chr, errp);
335     }
336 
337     return 0;
338 }
339 
340 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename,
341                                 bool permit_mux_mon)
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         if (!permit_mux_mon) {
357             error_report("mon: isn't supported in this context");
358             return NULL;
359         }
360         filename = p;
361         qemu_opt_set(opts, "mux", "on", &error_abort);
362         if (strcmp(filename, "stdio") == 0) {
363             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
364              * but pass it to the guest.  Handle this only for compat syntax,
365              * for -chardev syntax we have special option for this.
366              * This is what -nographic did, redirecting+muxing serial+monitor
367              * to stdio causing Ctrl+C to be passed to guest. */
368             qemu_opt_set(opts, "signal", "off", &error_abort);
369         }
370     }
371 
372     if (strcmp(filename, "null")    == 0 ||
373         strcmp(filename, "pty")     == 0 ||
374         strcmp(filename, "msmouse") == 0 ||
375         strcmp(filename, "wctablet") == 0 ||
376         strcmp(filename, "braille") == 0 ||
377         strcmp(filename, "testdev") == 0 ||
378         strcmp(filename, "stdio")   == 0) {
379         qemu_opt_set(opts, "backend", filename, &error_abort);
380         return opts;
381     }
382     if (strstart(filename, "vc", &p)) {
383         qemu_opt_set(opts, "backend", "vc", &error_abort);
384         if (*p == ':') {
385             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
386                 /* pixels */
387                 qemu_opt_set(opts, "width", width, &error_abort);
388                 qemu_opt_set(opts, "height", height, &error_abort);
389             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
390                 /* chars */
391                 qemu_opt_set(opts, "cols", width, &error_abort);
392                 qemu_opt_set(opts, "rows", height, &error_abort);
393             } else {
394                 goto fail;
395             }
396         }
397         return opts;
398     }
399     if (strcmp(filename, "con:") == 0) {
400         qemu_opt_set(opts, "backend", "console", &error_abort);
401         return opts;
402     }
403     if (strstart(filename, "COM", NULL)) {
404         qemu_opt_set(opts, "backend", "serial", &error_abort);
405         qemu_opt_set(opts, "path", filename, &error_abort);
406         return opts;
407     }
408     if (strstart(filename, "file:", &p)) {
409         qemu_opt_set(opts, "backend", "file", &error_abort);
410         qemu_opt_set(opts, "path", p, &error_abort);
411         return opts;
412     }
413     if (strstart(filename, "pipe:", &p)) {
414         qemu_opt_set(opts, "backend", "pipe", &error_abort);
415         qemu_opt_set(opts, "path", p, &error_abort);
416         return opts;
417     }
418     if (strstart(filename, "tcp:", &p) ||
419         strstart(filename, "telnet:", &p) ||
420         strstart(filename, "tn3270:", &p) ||
421         strstart(filename, "websocket:", &p)) {
422         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
423             host[0] = 0;
424             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
425                 goto fail;
426         }
427         qemu_opt_set(opts, "backend", "socket", &error_abort);
428         qemu_opt_set(opts, "host", host, &error_abort);
429         qemu_opt_set(opts, "port", port, &error_abort);
430         if (p[pos] == ',') {
431             if (!qemu_opts_do_parse(opts, p + pos + 1, NULL, &local_err)) {
432                 error_report_err(local_err);
433                 goto fail;
434             }
435         }
436         if (strstart(filename, "telnet:", &p)) {
437             qemu_opt_set(opts, "telnet", "on", &error_abort);
438         } else if (strstart(filename, "tn3270:", &p)) {
439             qemu_opt_set(opts, "tn3270", "on", &error_abort);
440         } else if (strstart(filename, "websocket:", &p)) {
441             qemu_opt_set(opts, "websocket", "on", &error_abort);
442         }
443         return opts;
444     }
445     if (strstart(filename, "udp:", &p)) {
446         qemu_opt_set(opts, "backend", "udp", &error_abort);
447         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
448             host[0] = 0;
449             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
450                 goto fail;
451             }
452         }
453         qemu_opt_set(opts, "host", host, &error_abort);
454         qemu_opt_set(opts, "port", port, &error_abort);
455         if (p[pos] == '@') {
456             p += pos + 1;
457             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
458                 host[0] = 0;
459                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
460                     goto fail;
461                 }
462             }
463             qemu_opt_set(opts, "localaddr", host, &error_abort);
464             qemu_opt_set(opts, "localport", port, &error_abort);
465         }
466         return opts;
467     }
468     if (strstart(filename, "unix:", &p)) {
469         qemu_opt_set(opts, "backend", "socket", &error_abort);
470         if (!qemu_opts_do_parse(opts, p, "path", &local_err)) {
471             error_report_err(local_err);
472             goto fail;
473         }
474         return opts;
475     }
476     if (strstart(filename, "/dev/parport", NULL) ||
477         strstart(filename, "/dev/ppi", NULL)) {
478         qemu_opt_set(opts, "backend", "parallel", &error_abort);
479         qemu_opt_set(opts, "path", filename, &error_abort);
480         return opts;
481     }
482     if (strstart(filename, "/dev/", NULL)) {
483         qemu_opt_set(opts, "backend", "serial", &error_abort);
484         qemu_opt_set(opts, "path", filename, &error_abort);
485         return opts;
486     }
487 
488     error_report("'%s' is not a valid char driver", filename);
489 
490 fail:
491     qemu_opts_del(opts);
492     return NULL;
493 }
494 
495 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
496 {
497     const char *logfile = qemu_opt_get(opts, "logfile");
498 
499     backend->logfile = g_strdup(logfile);
500     backend->has_logappend = true;
501     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
502 }
503 
504 static const ChardevClass *char_get_class(const char *driver, Error **errp)
505 {
506     ObjectClass *oc;
507     const ChardevClass *cc;
508     char *typename = g_strdup_printf("chardev-%s", driver);
509 
510     oc = module_object_class_by_name(typename);
511     g_free(typename);
512 
513     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
514         error_setg(errp, "'%s' is not a valid char driver name", driver);
515         return NULL;
516     }
517 
518     if (object_class_is_abstract(oc)) {
519         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
520                    "an abstract device type");
521         return NULL;
522     }
523 
524     cc = CHARDEV_CLASS(oc);
525     if (cc->internal) {
526         error_setg(errp, "'%s' is not a valid char driver name", driver);
527         return NULL;
528     }
529 
530     return cc;
531 }
532 
533 static struct ChardevAlias {
534     const char *typename;
535     const char *alias;
536     bool deprecation_warning_printed;
537 } chardev_alias_table[] = {
538 #ifdef HAVE_CHARDEV_PARPORT
539     { "parallel", "parport" },
540 #endif
541 #ifdef HAVE_CHARDEV_SERIAL
542     { "serial", "tty" },
543 #endif
544 };
545 
546 typedef struct ChadevClassFE {
547     void (*fn)(const char *name, void *opaque);
548     void *opaque;
549 } ChadevClassFE;
550 
551 static void
552 chardev_class_foreach(ObjectClass *klass, void *opaque)
553 {
554     ChadevClassFE *fe = opaque;
555 
556     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
557     if (CHARDEV_CLASS(klass)->internal) {
558         return;
559     }
560 
561     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
562 }
563 
564 static void
565 chardev_name_foreach(void (*fn)(const char *name, void *opaque),
566                      void *opaque)
567 {
568     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
569 
570     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
571 }
572 
573 static void
574 help_string_append(const char *name, void *opaque)
575 {
576     GString *str = opaque;
577 
578     g_string_append_printf(str, "\n  %s", name);
579 }
580 
581 static const char *chardev_alias_translate(const char *name)
582 {
583     int i;
584     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
585         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
586             if (!chardev_alias_table[i].deprecation_warning_printed) {
587                 warn_report("The alias '%s' is deprecated, use '%s' instead",
588                             name, chardev_alias_table[i].typename);
589                 chardev_alias_table[i].deprecation_warning_printed = true;
590             }
591             return chardev_alias_table[i].typename;
592         }
593     }
594     return name;
595 }
596 
597 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
598 {
599     Error *local_err = NULL;
600     const ChardevClass *cc;
601     ChardevBackend *backend = NULL;
602     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
603 
604     if (name == NULL) {
605         error_setg(errp, "chardev: \"%s\" missing backend",
606                    qemu_opts_id(opts));
607         return NULL;
608     }
609 
610     cc = char_get_class(name, errp);
611     if (cc == NULL) {
612         return NULL;
613     }
614 
615     backend = g_new0(ChardevBackend, 1);
616     backend->type = CHARDEV_BACKEND_KIND_NULL;
617 
618     if (cc->parse) {
619         cc->parse(opts, backend, &local_err);
620         if (local_err) {
621             error_propagate(errp, local_err);
622             qapi_free_ChardevBackend(backend);
623             return NULL;
624         }
625     } else {
626         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
627         qemu_chr_parse_common(opts, ccom);
628         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
629     }
630 
631     return backend;
632 }
633 
634 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, GMainContext *context,
635                                 Error **errp)
636 {
637     const ChardevClass *cc;
638     Chardev *chr = NULL;
639     ChardevBackend *backend = NULL;
640     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
641     const char *id = qemu_opts_id(opts);
642     char *bid = NULL;
643 
644     if (name && is_help_option(name)) {
645         GString *str = g_string_new("");
646 
647         chardev_name_foreach(help_string_append, str);
648 
649         qemu_printf("Available chardev backend types: %s\n", str->str);
650         g_string_free(str, true);
651         return NULL;
652     }
653 
654     if (id == NULL) {
655         error_setg(errp, "chardev: no id specified");
656         return NULL;
657     }
658 
659     backend = qemu_chr_parse_opts(opts, errp);
660     if (backend == NULL) {
661         return NULL;
662     }
663 
664     cc = char_get_class(name, errp);
665     if (cc == NULL) {
666         goto out;
667     }
668 
669     if (qemu_opt_get_bool(opts, "mux", 0)) {
670         bid = g_strdup_printf("%s-base", id);
671     }
672 
673     chr = qemu_chardev_new(bid ? bid : id,
674                            object_class_get_name(OBJECT_CLASS(cc)),
675                            backend, context, errp);
676 
677     if (chr == NULL) {
678         goto out;
679     }
680 
681     if (bid) {
682         Chardev *mux;
683         qapi_free_ChardevBackend(backend);
684         backend = g_new0(ChardevBackend, 1);
685         backend->type = CHARDEV_BACKEND_KIND_MUX;
686         backend->u.mux.data = g_new0(ChardevMux, 1);
687         backend->u.mux.data->chardev = g_strdup(bid);
688         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, context, errp);
689         if (mux == NULL) {
690             object_unparent(OBJECT(chr));
691             chr = NULL;
692             goto out;
693         }
694         chr = mux;
695     }
696 
697 out:
698     qapi_free_ChardevBackend(backend);
699     g_free(bid);
700     return chr;
701 }
702 
703 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
704                                bool permit_mux_mon, GMainContext *context)
705 {
706     const char *p;
707     Chardev *chr;
708     QemuOpts *opts;
709     Error *err = NULL;
710 
711     if (strstart(filename, "chardev:", &p)) {
712         return qemu_chr_find(p);
713     }
714 
715     opts = qemu_chr_parse_compat(label, filename, permit_mux_mon);
716     if (!opts)
717         return NULL;
718 
719     chr = qemu_chr_new_from_opts(opts, context, &err);
720     if (!chr) {
721         error_report_err(err);
722         goto out;
723     }
724 
725     if (qemu_opt_get_bool(opts, "mux", 0)) {
726         assert(permit_mux_mon);
727         monitor_init_hmp(chr, true, &err);
728         if (err) {
729             error_report_err(err);
730             object_unparent(OBJECT(chr));
731             chr = NULL;
732             goto out;
733         }
734     }
735 
736 out:
737     qemu_opts_del(opts);
738     return chr;
739 }
740 
741 static Chardev *qemu_chr_new_permit_mux_mon(const char *label,
742                                           const char *filename,
743                                           bool permit_mux_mon,
744                                           GMainContext *context)
745 {
746     Chardev *chr;
747     chr = qemu_chr_new_noreplay(label, filename, permit_mux_mon, context);
748     if (chr) {
749         if (replay_mode != REPLAY_MODE_NONE) {
750             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
751         }
752         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
753             error_report("Replay: ioctl is not supported "
754                          "for serial devices yet");
755         }
756         replay_register_char_driver(chr);
757     }
758     return chr;
759 }
760 
761 Chardev *qemu_chr_new(const char *label, const char *filename,
762                       GMainContext *context)
763 {
764     return qemu_chr_new_permit_mux_mon(label, filename, false, context);
765 }
766 
767 Chardev *qemu_chr_new_mux_mon(const char *label, const char *filename,
768                               GMainContext *context)
769 {
770     return qemu_chr_new_permit_mux_mon(label, filename, true, context);
771 }
772 
773 static int qmp_query_chardev_foreach(Object *obj, void *data)
774 {
775     Chardev *chr = CHARDEV(obj);
776     ChardevInfoList **list = data;
777     ChardevInfo *value = g_malloc0(sizeof(*value));
778 
779     value->label = g_strdup(chr->label);
780     value->filename = g_strdup(chr->filename);
781     value->frontend_open = chr->be && chr->be->fe_open;
782 
783     QAPI_LIST_PREPEND(*list, value);
784 
785     return 0;
786 }
787 
788 ChardevInfoList *qmp_query_chardev(Error **errp)
789 {
790     ChardevInfoList *chr_list = NULL;
791 
792     object_child_foreach(get_chardevs_root(),
793                          qmp_query_chardev_foreach, &chr_list);
794 
795     return chr_list;
796 }
797 
798 static void
799 qmp_prepend_backend(const char *name, void *opaque)
800 {
801     ChardevBackendInfoList **list = opaque;
802     ChardevBackendInfo *value;
803 
804     value = g_new0(ChardevBackendInfo, 1);
805     value->name = g_strdup(name);
806     QAPI_LIST_PREPEND(*list, value);
807 }
808 
809 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
810 {
811     ChardevBackendInfoList *backend_list = NULL;
812 
813     chardev_name_foreach(qmp_prepend_backend, &backend_list);
814 
815     return backend_list;
816 }
817 
818 Chardev *qemu_chr_find(const char *name)
819 {
820     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
821 
822     return obj ? CHARDEV(obj) : NULL;
823 }
824 
825 QemuOptsList qemu_chardev_opts = {
826     .name = "chardev",
827     .implied_opt_name = "backend",
828     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
829     .desc = {
830         {
831             .name = "backend",
832             .type = QEMU_OPT_STRING,
833         },{
834             .name = "path",
835             .type = QEMU_OPT_STRING,
836         },{
837             .name = "host",
838             .type = QEMU_OPT_STRING,
839         },{
840             .name = "port",
841             .type = QEMU_OPT_STRING,
842         },{
843             .name = "fd",
844             .type = QEMU_OPT_STRING,
845         },{
846             .name = "localaddr",
847             .type = QEMU_OPT_STRING,
848         },{
849             .name = "localport",
850             .type = QEMU_OPT_STRING,
851         },{
852             .name = "to",
853             .type = QEMU_OPT_NUMBER,
854         },{
855             .name = "ipv4",
856             .type = QEMU_OPT_BOOL,
857         },{
858             .name = "ipv6",
859             .type = QEMU_OPT_BOOL,
860         },{
861             .name = "wait",
862             .type = QEMU_OPT_BOOL,
863         },{
864             .name = "server",
865             .type = QEMU_OPT_BOOL,
866         },{
867             .name = "delay",
868             .type = QEMU_OPT_BOOL,
869         },{
870             .name = "nodelay",
871             .type = QEMU_OPT_BOOL,
872         },{
873             .name = "reconnect",
874             .type = QEMU_OPT_NUMBER,
875         },{
876             .name = "telnet",
877             .type = QEMU_OPT_BOOL,
878         },{
879             .name = "tn3270",
880             .type = QEMU_OPT_BOOL,
881         },{
882             .name = "tls-creds",
883             .type = QEMU_OPT_STRING,
884         },{
885             .name = "tls-authz",
886             .type = QEMU_OPT_STRING,
887         },{
888             .name = "websocket",
889             .type = QEMU_OPT_BOOL,
890         },{
891             .name = "width",
892             .type = QEMU_OPT_NUMBER,
893         },{
894             .name = "height",
895             .type = QEMU_OPT_NUMBER,
896         },{
897             .name = "cols",
898             .type = QEMU_OPT_NUMBER,
899         },{
900             .name = "rows",
901             .type = QEMU_OPT_NUMBER,
902         },{
903             .name = "mux",
904             .type = QEMU_OPT_BOOL,
905         },{
906             .name = "signal",
907             .type = QEMU_OPT_BOOL,
908         },{
909             .name = "name",
910             .type = QEMU_OPT_STRING,
911         },{
912             .name = "debug",
913             .type = QEMU_OPT_NUMBER,
914         },{
915             .name = "size",
916             .type = QEMU_OPT_SIZE,
917         },{
918             .name = "chardev",
919             .type = QEMU_OPT_STRING,
920         },{
921             .name = "append",
922             .type = QEMU_OPT_BOOL,
923         },{
924             .name = "logfile",
925             .type = QEMU_OPT_STRING,
926         },{
927             .name = "logappend",
928             .type = QEMU_OPT_BOOL,
929         },{
930             .name = "mouse",
931             .type = QEMU_OPT_BOOL,
932         },{
933             .name = "clipboard",
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     ERRP_GUARD();
1030     const ChardevClass *cc;
1031     ChardevReturn *ret;
1032     g_autoptr(Chardev) chr = NULL;
1033 
1034     if (qemu_chr_find(id)) {
1035         error_setg(errp, "Chardev with id '%s' already exists", id);
1036         return NULL;
1037     }
1038 
1039     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1040     if (!cc) {
1041         goto err;
1042     }
1043 
1044     chr = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
1045                       backend, NULL, false, errp);
1046     if (!chr) {
1047         goto err;
1048     }
1049 
1050     if (!object_property_try_add_child(get_chardevs_root(), id, OBJECT(chr),
1051                                        errp)) {
1052         goto err;
1053     }
1054 
1055     ret = g_new0(ChardevReturn, 1);
1056     if (CHARDEV_IS_PTY(chr)) {
1057         ret->pty = g_strdup(chr->filename + 4);
1058     }
1059 
1060     return ret;
1061 
1062 err:
1063     error_prepend(errp, "Failed to add chardev '%s': ", id);
1064     return NULL;
1065 }
1066 
1067 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
1068                                   Error **errp)
1069 {
1070     CharBackend *be;
1071     const ChardevClass *cc, *cc_new;
1072     Chardev *chr, *chr_new;
1073     bool closed_sent = false;
1074     bool handover_yank_instance;
1075     ChardevReturn *ret;
1076 
1077     chr = qemu_chr_find(id);
1078     if (!chr) {
1079         error_setg(errp, "Chardev '%s' does not exist", id);
1080         return NULL;
1081     }
1082 
1083     if (CHARDEV_IS_MUX(chr)) {
1084         error_setg(errp, "Mux device hotswap not supported yet");
1085         return NULL;
1086     }
1087 
1088     if (qemu_chr_replay(chr)) {
1089         error_setg(errp,
1090             "Chardev '%s' cannot be changed in record/replay mode", id);
1091         return NULL;
1092     }
1093 
1094     be = chr->be;
1095     if (!be) {
1096         /* easy case */
1097         object_unparent(OBJECT(chr));
1098         return qmp_chardev_add(id, backend, errp);
1099     }
1100 
1101     if (!be->chr_be_change) {
1102         error_setg(errp, "Chardev user does not support chardev hotswap");
1103         return NULL;
1104     }
1105 
1106     cc = CHARDEV_GET_CLASS(chr);
1107     cc_new = char_get_class(ChardevBackendKind_str(backend->type), errp);
1108     if (!cc_new) {
1109         return NULL;
1110     }
1111 
1112     /*
1113      * The new chardev should not register a yank instance if the current
1114      * chardev has registered one already.
1115      */
1116     handover_yank_instance = cc->supports_yank && cc_new->supports_yank;
1117 
1118     chr_new = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc_new)),
1119                           backend, chr->gcontext, handover_yank_instance, errp);
1120     if (!chr_new) {
1121         return NULL;
1122     }
1123 
1124     if (chr->be_open && !chr_new->be_open) {
1125         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1126         closed_sent = true;
1127     }
1128 
1129     chr->be = NULL;
1130     qemu_chr_fe_init(be, chr_new, &error_abort);
1131 
1132     if (be->chr_be_change(be->opaque) < 0) {
1133         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1134         chr_new->be = NULL;
1135         qemu_chr_fe_init(be, chr, &error_abort);
1136         if (closed_sent) {
1137             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1138         }
1139         object_unref(OBJECT(chr_new));
1140         return NULL;
1141     }
1142 
1143     /* change successfull, clean up */
1144     chr_new->handover_yank_instance = false;
1145 
1146     /*
1147      * When the old chardev is freed, it should not unregister the yank
1148      * instance if the new chardev needs it.
1149      */
1150     chr->handover_yank_instance = handover_yank_instance;
1151 
1152     object_unparent(OBJECT(chr));
1153     object_property_add_child(get_chardevs_root(), chr_new->label,
1154                               OBJECT(chr_new));
1155     object_unref(OBJECT(chr_new));
1156 
1157     ret = g_new0(ChardevReturn, 1);
1158     if (CHARDEV_IS_PTY(chr_new)) {
1159         ret->pty = g_strdup(chr_new->filename + 4);
1160     }
1161 
1162     return ret;
1163 }
1164 
1165 void qmp_chardev_remove(const char *id, Error **errp)
1166 {
1167     Chardev *chr;
1168 
1169     chr = qemu_chr_find(id);
1170     if (chr == NULL) {
1171         error_setg(errp, "Chardev '%s' not found", id);
1172         return;
1173     }
1174     if (qemu_chr_is_busy(chr)) {
1175         error_setg(errp, "Chardev '%s' is busy", id);
1176         return;
1177     }
1178     if (qemu_chr_replay(chr)) {
1179         error_setg(errp,
1180             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1181         return;
1182     }
1183     object_unparent(OBJECT(chr));
1184 }
1185 
1186 void qmp_chardev_send_break(const char *id, Error **errp)
1187 {
1188     Chardev *chr;
1189 
1190     chr = qemu_chr_find(id);
1191     if (chr == NULL) {
1192         error_setg(errp, "Chardev '%s' not found", id);
1193         return;
1194     }
1195     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1196 }
1197 
1198 /*
1199  * Add a timeout callback for the chardev (in milliseconds), return
1200  * the GSource object created. Please use this to add timeout hook for
1201  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1202  * make sure the gcontext that the task bound to is correct.
1203  */
1204 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1205                                  GSourceFunc func, void *private)
1206 {
1207     GSource *source = g_timeout_source_new(ms);
1208 
1209     assert(func);
1210     g_source_set_callback(source, func, private, NULL);
1211     g_source_attach(source, chr->gcontext);
1212 
1213     return source;
1214 }
1215 
1216 void qemu_chr_cleanup(void)
1217 {
1218     object_unparent(get_chardevs_root());
1219 }
1220 
1221 static void register_types(void)
1222 {
1223     type_register_static(&char_type_info);
1224 }
1225 
1226 type_init(register_types);
1227