xref: /qemu/chardev/char.c (revision b02cf99b)
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 #include "qemu/osdep.h"
25 #include "qemu/cutils.h"
26 #include "monitor/monitor.h"
27 #include "sysemu/sysemu.h"
28 #include "qemu/config-file.h"
29 #include "qemu/error-report.h"
30 #include "chardev/char.h"
31 #include "qmp-commands.h"
32 #include "qapi-visit.h"
33 #include "sysemu/replay.h"
34 #include "qemu/help_option.h"
35 
36 #include "chardev/char-mux.h"
37 
38 /***********************************************************/
39 /* character device */
40 
41 static Object *get_chardevs_root(void)
42 {
43     return container_get(object_get_root(), "/chardevs");
44 }
45 
46 void qemu_chr_be_event(Chardev *s, int event)
47 {
48     CharBackend *be = s->be;
49 
50     /* Keep track if the char device is open */
51     switch (event) {
52         case CHR_EVENT_OPENED:
53             s->be_open = 1;
54             break;
55         case CHR_EVENT_CLOSED:
56             s->be_open = 0;
57             break;
58     }
59 
60     if (!be || !be->chr_event) {
61         return;
62     }
63 
64     be->chr_event(be->opaque, event);
65 }
66 
67 /* Not reporting errors from writing to logfile, as logs are
68  * defined to be "best effort" only */
69 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
70 {
71     size_t done = 0;
72     ssize_t ret;
73 
74     if (s->logfd < 0) {
75         return;
76     }
77 
78     while (done < len) {
79     retry:
80         ret = write(s->logfd, buf + done, len - done);
81         if (ret == -1 && errno == EAGAIN) {
82             g_usleep(100);
83             goto retry;
84         }
85 
86         if (ret <= 0) {
87             return;
88         }
89         done += ret;
90     }
91 }
92 
93 static int qemu_chr_write_buffer(Chardev *s,
94                                  const uint8_t *buf, int len,
95                                  int *offset, bool write_all)
96 {
97     ChardevClass *cc = CHARDEV_GET_CLASS(s);
98     int res = 0;
99     *offset = 0;
100 
101     qemu_mutex_lock(&s->chr_write_lock);
102     while (*offset < len) {
103     retry:
104         res = cc->chr_write(s, buf + *offset, len - *offset);
105         if (res < 0 && errno == EAGAIN && write_all) {
106             g_usleep(100);
107             goto retry;
108         }
109 
110         if (res <= 0) {
111             break;
112         }
113 
114         *offset += res;
115         if (!write_all) {
116             break;
117         }
118     }
119     if (*offset > 0) {
120         qemu_chr_write_log(s, buf, *offset);
121     }
122     qemu_mutex_unlock(&s->chr_write_lock);
123 
124     return res;
125 }
126 
127 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
128 {
129     int offset = 0;
130     int res;
131 
132     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
133         replay_char_write_event_load(&res, &offset);
134         assert(offset <= len);
135         qemu_chr_write_buffer(s, buf, offset, &offset, true);
136         return res;
137     }
138 
139     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
140 
141     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
142         replay_char_write_event_save(res, offset);
143     }
144 
145     if (res < 0) {
146         return res;
147     }
148     return offset;
149 }
150 
151 int qemu_chr_be_can_write(Chardev *s)
152 {
153     CharBackend *be = s->be;
154 
155     if (!be || !be->chr_can_read) {
156         return 0;
157     }
158 
159     return be->chr_can_read(be->opaque);
160 }
161 
162 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
163 {
164     CharBackend *be = s->be;
165 
166     if (be && be->chr_read) {
167         be->chr_read(be->opaque, buf, len);
168     }
169 }
170 
171 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
172 {
173     if (qemu_chr_replay(s)) {
174         if (replay_mode == REPLAY_MODE_PLAY) {
175             return;
176         }
177         replay_chr_be_write(s, buf, len);
178     } else {
179         qemu_chr_be_write_impl(s, buf, len);
180     }
181 }
182 
183 int qemu_chr_add_client(Chardev *s, int fd)
184 {
185     return CHARDEV_GET_CLASS(s)->chr_add_client ?
186         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
187 }
188 
189 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
190                            bool *be_opened, Error **errp)
191 {
192     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
193     /* Any ChardevCommon member would work */
194     ChardevCommon *common = backend ? backend->u.null.data : NULL;
195 
196     if (common && common->has_logfile) {
197         int flags = O_WRONLY | O_CREAT;
198         if (common->has_logappend &&
199             common->logappend) {
200             flags |= O_APPEND;
201         } else {
202             flags |= O_TRUNC;
203         }
204         chr->logfd = qemu_open(common->logfile, flags, 0666);
205         if (chr->logfd < 0) {
206             error_setg_errno(errp, errno,
207                              "Unable to open logfile %s",
208                              common->logfile);
209             return;
210         }
211     }
212 
213     if (cc->open) {
214         cc->open(chr, backend, be_opened, errp);
215     }
216 }
217 
218 static void char_init(Object *obj)
219 {
220     Chardev *chr = CHARDEV(obj);
221 
222     chr->logfd = -1;
223     qemu_mutex_init(&chr->chr_write_lock);
224 }
225 
226 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
227 {
228     return len;
229 }
230 
231 static void char_class_init(ObjectClass *oc, void *data)
232 {
233     ChardevClass *cc = CHARDEV_CLASS(oc);
234 
235     cc->chr_write = null_chr_write;
236 }
237 
238 static void char_finalize(Object *obj)
239 {
240     Chardev *chr = CHARDEV(obj);
241 
242     if (chr->be) {
243         chr->be->chr = NULL;
244     }
245     g_free(chr->filename);
246     g_free(chr->label);
247     if (chr->logfd != -1) {
248         close(chr->logfd);
249     }
250     qemu_mutex_destroy(&chr->chr_write_lock);
251 }
252 
253 static const TypeInfo char_type_info = {
254     .name = TYPE_CHARDEV,
255     .parent = TYPE_OBJECT,
256     .instance_size = sizeof(Chardev),
257     .instance_init = char_init,
258     .instance_finalize = char_finalize,
259     .abstract = true,
260     .class_size = sizeof(ChardevClass),
261     .class_init = char_class_init,
262 };
263 
264 /**
265  * Called after processing of default and command-line-specified
266  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
267  * to a mux chardev. This is done here to ensure that
268  * output/prompts/banners are only displayed for the FE that has
269  * focus when initial command-line processing/machine init is
270  * completed.
271  *
272  * After this point, any new FE attached to any new or existing
273  * mux will receive CHR_EVENT_OPENED notifications for the BE
274  * immediately.
275  */
276 static int open_muxes(Object *child, void *opaque)
277 {
278     if (CHARDEV_IS_MUX(child)) {
279         /* send OPENED to all already-attached FEs */
280         mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
281         /* mark mux as OPENED so any new FEs will immediately receive
282          * OPENED event
283          */
284         qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
285     }
286 
287     return 0;
288 }
289 
290 static void muxes_realize_done(Notifier *notifier, void *unused)
291 {
292     muxes_realized = true;
293     object_child_foreach(get_chardevs_root(), open_muxes, NULL);
294 }
295 
296 static Notifier muxes_realize_notify = {
297     .notify = muxes_realize_done,
298 };
299 
300 static bool qemu_chr_is_busy(Chardev *s)
301 {
302     if (CHARDEV_IS_MUX(s)) {
303         MuxChardev *d = MUX_CHARDEV(s);
304         return d->mux_cnt >= 0;
305     } else {
306         return s->be != NULL;
307     }
308 }
309 
310 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
311 {
312     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
313 
314     if (cc->chr_wait_connected) {
315         return cc->chr_wait_connected(chr, errp);
316     }
317 
318     return 0;
319 }
320 
321 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
322 {
323     char host[65], port[33], width[8], height[8];
324     int pos;
325     const char *p;
326     QemuOpts *opts;
327     Error *local_err = NULL;
328 
329     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
330     if (local_err) {
331         error_report_err(local_err);
332         return NULL;
333     }
334 
335     if (strstart(filename, "mon:", &p)) {
336         filename = p;
337         qemu_opt_set(opts, "mux", "on", &error_abort);
338         if (strcmp(filename, "stdio") == 0) {
339             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
340              * but pass it to the guest.  Handle this only for compat syntax,
341              * for -chardev syntax we have special option for this.
342              * This is what -nographic did, redirecting+muxing serial+monitor
343              * to stdio causing Ctrl+C to be passed to guest. */
344             qemu_opt_set(opts, "signal", "off", &error_abort);
345         }
346     }
347 
348     if (strcmp(filename, "null")    == 0 ||
349         strcmp(filename, "pty")     == 0 ||
350         strcmp(filename, "msmouse") == 0 ||
351         strcmp(filename, "wctablet") == 0 ||
352         strcmp(filename, "braille") == 0 ||
353         strcmp(filename, "testdev") == 0 ||
354         strcmp(filename, "stdio")   == 0) {
355         qemu_opt_set(opts, "backend", filename, &error_abort);
356         return opts;
357     }
358     if (strstart(filename, "vc", &p)) {
359         qemu_opt_set(opts, "backend", "vc", &error_abort);
360         if (*p == ':') {
361             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
362                 /* pixels */
363                 qemu_opt_set(opts, "width", width, &error_abort);
364                 qemu_opt_set(opts, "height", height, &error_abort);
365             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
366                 /* chars */
367                 qemu_opt_set(opts, "cols", width, &error_abort);
368                 qemu_opt_set(opts, "rows", height, &error_abort);
369             } else {
370                 goto fail;
371             }
372         }
373         return opts;
374     }
375     if (strcmp(filename, "con:") == 0) {
376         qemu_opt_set(opts, "backend", "console", &error_abort);
377         return opts;
378     }
379     if (strstart(filename, "COM", NULL)) {
380         qemu_opt_set(opts, "backend", "serial", &error_abort);
381         qemu_opt_set(opts, "path", filename, &error_abort);
382         return opts;
383     }
384     if (strstart(filename, "file:", &p)) {
385         qemu_opt_set(opts, "backend", "file", &error_abort);
386         qemu_opt_set(opts, "path", p, &error_abort);
387         return opts;
388     }
389     if (strstart(filename, "pipe:", &p)) {
390         qemu_opt_set(opts, "backend", "pipe", &error_abort);
391         qemu_opt_set(opts, "path", p, &error_abort);
392         return opts;
393     }
394     if (strstart(filename, "tcp:", &p) ||
395         strstart(filename, "telnet:", &p) ||
396         strstart(filename, "tn3270:", &p)) {
397         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
398             host[0] = 0;
399             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
400                 goto fail;
401         }
402         qemu_opt_set(opts, "backend", "socket", &error_abort);
403         qemu_opt_set(opts, "host", host, &error_abort);
404         qemu_opt_set(opts, "port", port, &error_abort);
405         if (p[pos] == ',') {
406             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
407             if (local_err) {
408                 error_report_err(local_err);
409                 goto fail;
410             }
411         }
412         if (strstart(filename, "telnet:", &p)) {
413             qemu_opt_set(opts, "telnet", "on", &error_abort);
414         } else if (strstart(filename, "tn3270:", &p)) {
415             qemu_opt_set(opts, "tn3270", "on", &error_abort);
416         }
417         return opts;
418     }
419     if (strstart(filename, "udp:", &p)) {
420         qemu_opt_set(opts, "backend", "udp", &error_abort);
421         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
422             host[0] = 0;
423             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
424                 goto fail;
425             }
426         }
427         qemu_opt_set(opts, "host", host, &error_abort);
428         qemu_opt_set(opts, "port", port, &error_abort);
429         if (p[pos] == '@') {
430             p += pos + 1;
431             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
432                 host[0] = 0;
433                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
434                     goto fail;
435                 }
436             }
437             qemu_opt_set(opts, "localaddr", host, &error_abort);
438             qemu_opt_set(opts, "localport", port, &error_abort);
439         }
440         return opts;
441     }
442     if (strstart(filename, "unix:", &p)) {
443         qemu_opt_set(opts, "backend", "socket", &error_abort);
444         qemu_opts_do_parse(opts, p, "path", &local_err);
445         if (local_err) {
446             error_report_err(local_err);
447             goto fail;
448         }
449         return opts;
450     }
451     if (strstart(filename, "/dev/parport", NULL) ||
452         strstart(filename, "/dev/ppi", NULL)) {
453         qemu_opt_set(opts, "backend", "parallel", &error_abort);
454         qemu_opt_set(opts, "path", filename, &error_abort);
455         return opts;
456     }
457     if (strstart(filename, "/dev/", NULL)) {
458         qemu_opt_set(opts, "backend", "serial", &error_abort);
459         qemu_opt_set(opts, "path", filename, &error_abort);
460         return opts;
461     }
462 
463 fail:
464     qemu_opts_del(opts);
465     return NULL;
466 }
467 
468 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
469 {
470     const char *logfile = qemu_opt_get(opts, "logfile");
471 
472     backend->has_logfile = logfile != NULL;
473     backend->logfile = g_strdup(logfile);
474 
475     backend->has_logappend = true;
476     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
477 }
478 
479 static const ChardevClass *char_get_class(const char *driver, Error **errp)
480 {
481     ObjectClass *oc;
482     const ChardevClass *cc;
483     char *typename = g_strdup_printf("chardev-%s", driver);
484 
485     oc = object_class_by_name(typename);
486     g_free(typename);
487 
488     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
489         error_setg(errp, "'%s' is not a valid char driver name", driver);
490         return NULL;
491     }
492 
493     if (object_class_is_abstract(oc)) {
494         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
495                    "abstract device type");
496         return NULL;
497     }
498 
499     cc = CHARDEV_CLASS(oc);
500     if (cc->internal) {
501         error_setg(errp, "'%s' is not a valid char driver name", driver);
502         return NULL;
503     }
504 
505     return cc;
506 }
507 
508 static const struct ChardevAlias {
509     const char *typename;
510     const char *alias;
511 } chardev_alias_table[] = {
512 #ifdef HAVE_CHARDEV_PARPORT
513     { "parallel", "parport" },
514 #endif
515 #ifdef HAVE_CHARDEV_SERIAL
516     { "serial", "tty" },
517 #endif
518 };
519 
520 typedef struct ChadevClassFE {
521     void (*fn)(const char *name, void *opaque);
522     void *opaque;
523 } ChadevClassFE;
524 
525 static void
526 chardev_class_foreach(ObjectClass *klass, void *opaque)
527 {
528     ChadevClassFE *fe = opaque;
529 
530     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
531     if (CHARDEV_CLASS(klass)->internal) {
532         return;
533     }
534 
535     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
536 }
537 
538 static void
539 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
540 {
541     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
542     int i;
543 
544     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
545 
546     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
547         fn(chardev_alias_table[i].alias, opaque);
548     }
549 }
550 
551 static void
552 help_string_append(const char *name, void *opaque)
553 {
554     GString *str = opaque;
555 
556     g_string_append_printf(str, "\n%s", name);
557 }
558 
559 static const char *chardev_alias_translate(const char *name)
560 {
561     int i;
562     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
563         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
564             return chardev_alias_table[i].typename;
565         }
566     }
567     return name;
568 }
569 
570 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
571 {
572     Error *local_err = NULL;
573     const ChardevClass *cc;
574     ChardevBackend *backend = NULL;
575     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
576 
577     if (name == NULL) {
578         error_setg(errp, "chardev: \"%s\" missing backend",
579                    qemu_opts_id(opts));
580         return NULL;
581     }
582 
583     cc = char_get_class(name, errp);
584     if (cc == NULL) {
585         return NULL;
586     }
587 
588     backend = g_new0(ChardevBackend, 1);
589     backend->type = CHARDEV_BACKEND_KIND_NULL;
590 
591     if (cc->parse) {
592         cc->parse(opts, backend, &local_err);
593         if (local_err) {
594             error_propagate(errp, local_err);
595             qapi_free_ChardevBackend(backend);
596             return NULL;
597         }
598     } else {
599         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
600         qemu_chr_parse_common(opts, ccom);
601         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
602     }
603 
604     return backend;
605 }
606 
607 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
608 {
609     const ChardevClass *cc;
610     Chardev *chr = NULL;
611     ChardevBackend *backend = NULL;
612     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
613     const char *id = qemu_opts_id(opts);
614     char *bid = NULL;
615 
616     if (name && is_help_option(name)) {
617         GString *str = g_string_new("");
618 
619         chardev_name_foreach(help_string_append, str);
620 
621         error_report("Available chardev backend types: %s", str->str);
622         g_string_free(str, true);
623         exit(0);
624     }
625 
626     if (id == NULL) {
627         error_setg(errp, "chardev: no id specified");
628         return NULL;
629     }
630 
631     backend = qemu_chr_parse_opts(opts, errp);
632     if (backend == NULL) {
633         return NULL;
634     }
635 
636     cc = char_get_class(name, errp);
637     if (cc == NULL) {
638         goto out;
639     }
640 
641     if (qemu_opt_get_bool(opts, "mux", 0)) {
642         bid = g_strdup_printf("%s-base", id);
643     }
644 
645     chr = qemu_chardev_new(bid ? bid : id,
646                            object_class_get_name(OBJECT_CLASS(cc)),
647                            backend, errp);
648 
649     if (chr == NULL) {
650         goto out;
651     }
652 
653     if (bid) {
654         Chardev *mux;
655         qapi_free_ChardevBackend(backend);
656         backend = g_new0(ChardevBackend, 1);
657         backend->type = CHARDEV_BACKEND_KIND_MUX;
658         backend->u.mux.data = g_new0(ChardevMux, 1);
659         backend->u.mux.data->chardev = g_strdup(bid);
660         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
661         if (mux == NULL) {
662             object_unparent(OBJECT(chr));
663             chr = NULL;
664             goto out;
665         }
666         chr = mux;
667     }
668 
669 out:
670     qapi_free_ChardevBackend(backend);
671     g_free(bid);
672     return chr;
673 }
674 
675 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
676 {
677     const char *p;
678     Chardev *chr;
679     QemuOpts *opts;
680     Error *err = NULL;
681 
682     if (strstart(filename, "chardev:", &p)) {
683         return qemu_chr_find(p);
684     }
685 
686     opts = qemu_chr_parse_compat(label, filename);
687     if (!opts)
688         return NULL;
689 
690     chr = qemu_chr_new_from_opts(opts, &err);
691     if (err) {
692         error_report_err(err);
693     }
694     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
695         monitor_init(chr, MONITOR_USE_READLINE);
696     }
697     qemu_opts_del(opts);
698     return chr;
699 }
700 
701 Chardev *qemu_chr_new(const char *label, const char *filename)
702 {
703     Chardev *chr;
704     chr = qemu_chr_new_noreplay(label, filename);
705     if (chr) {
706         if (replay_mode != REPLAY_MODE_NONE) {
707             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
708         }
709         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
710             error_report("Replay: ioctl is not supported "
711                          "for serial devices yet");
712         }
713         replay_register_char_driver(chr);
714     }
715     return chr;
716 }
717 
718 static int qmp_query_chardev_foreach(Object *obj, void *data)
719 {
720     Chardev *chr = CHARDEV(obj);
721     ChardevInfoList **list = data;
722     ChardevInfoList *info = g_malloc0(sizeof(*info));
723 
724     info->value = g_malloc0(sizeof(*info->value));
725     info->value->label = g_strdup(chr->label);
726     info->value->filename = g_strdup(chr->filename);
727     info->value->frontend_open = chr->be && chr->be->fe_open;
728 
729     info->next = *list;
730     *list = info;
731 
732     return 0;
733 }
734 
735 ChardevInfoList *qmp_query_chardev(Error **errp)
736 {
737     ChardevInfoList *chr_list = NULL;
738 
739     object_child_foreach(get_chardevs_root(),
740                          qmp_query_chardev_foreach, &chr_list);
741 
742     return chr_list;
743 }
744 
745 static void
746 qmp_prepend_backend(const char *name, void *opaque)
747 {
748     ChardevBackendInfoList **list = opaque;
749     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
750 
751     info->value = g_malloc0(sizeof(*info->value));
752     info->value->name = g_strdup(name);
753     info->next = *list;
754     *list = info;
755 }
756 
757 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
758 {
759     ChardevBackendInfoList *backend_list = NULL;
760 
761     chardev_name_foreach(qmp_prepend_backend, &backend_list);
762 
763     return backend_list;
764 }
765 
766 Chardev *qemu_chr_find(const char *name)
767 {
768     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
769 
770     return obj ? CHARDEV(obj) : NULL;
771 }
772 
773 QemuOptsList qemu_chardev_opts = {
774     .name = "chardev",
775     .implied_opt_name = "backend",
776     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
777     .desc = {
778         {
779             .name = "backend",
780             .type = QEMU_OPT_STRING,
781         },{
782             .name = "path",
783             .type = QEMU_OPT_STRING,
784         },{
785             .name = "host",
786             .type = QEMU_OPT_STRING,
787         },{
788             .name = "port",
789             .type = QEMU_OPT_STRING,
790         },{
791             .name = "localaddr",
792             .type = QEMU_OPT_STRING,
793         },{
794             .name = "localport",
795             .type = QEMU_OPT_STRING,
796         },{
797             .name = "to",
798             .type = QEMU_OPT_NUMBER,
799         },{
800             .name = "ipv4",
801             .type = QEMU_OPT_BOOL,
802         },{
803             .name = "ipv6",
804             .type = QEMU_OPT_BOOL,
805         },{
806             .name = "wait",
807             .type = QEMU_OPT_BOOL,
808         },{
809             .name = "server",
810             .type = QEMU_OPT_BOOL,
811         },{
812             .name = "delay",
813             .type = QEMU_OPT_BOOL,
814         },{
815             .name = "reconnect",
816             .type = QEMU_OPT_NUMBER,
817         },{
818             .name = "telnet",
819             .type = QEMU_OPT_BOOL,
820         },{
821             .name = "tn3270",
822             .type = QEMU_OPT_BOOL,
823         },{
824             .name = "tls-creds",
825             .type = QEMU_OPT_STRING,
826         },{
827             .name = "width",
828             .type = QEMU_OPT_NUMBER,
829         },{
830             .name = "height",
831             .type = QEMU_OPT_NUMBER,
832         },{
833             .name = "cols",
834             .type = QEMU_OPT_NUMBER,
835         },{
836             .name = "rows",
837             .type = QEMU_OPT_NUMBER,
838         },{
839             .name = "mux",
840             .type = QEMU_OPT_BOOL,
841         },{
842             .name = "signal",
843             .type = QEMU_OPT_BOOL,
844         },{
845             .name = "name",
846             .type = QEMU_OPT_STRING,
847         },{
848             .name = "debug",
849             .type = QEMU_OPT_NUMBER,
850         },{
851             .name = "size",
852             .type = QEMU_OPT_SIZE,
853         },{
854             .name = "chardev",
855             .type = QEMU_OPT_STRING,
856         },{
857             .name = "append",
858             .type = QEMU_OPT_BOOL,
859         },{
860             .name = "logfile",
861             .type = QEMU_OPT_STRING,
862         },{
863             .name = "logappend",
864             .type = QEMU_OPT_BOOL,
865         },
866         { /* end of list */ }
867     },
868 };
869 
870 bool qemu_chr_has_feature(Chardev *chr,
871                           ChardevFeature feature)
872 {
873     return test_bit(feature, chr->features);
874 }
875 
876 void qemu_chr_set_feature(Chardev *chr,
877                            ChardevFeature feature)
878 {
879     return set_bit(feature, chr->features);
880 }
881 
882 Chardev *qemu_chardev_new(const char *id, const char *typename,
883                           ChardevBackend *backend,
884                           Error **errp)
885 {
886     Object *obj;
887     Chardev *chr = NULL;
888     Error *local_err = NULL;
889     bool be_opened = true;
890 
891     assert(g_str_has_prefix(typename, "chardev-"));
892 
893     obj = object_new(typename);
894     chr = CHARDEV(obj);
895     chr->label = g_strdup(id);
896 
897     qemu_char_open(chr, backend, &be_opened, &local_err);
898     if (local_err) {
899         goto end;
900     }
901 
902     if (!chr->filename) {
903         chr->filename = g_strdup(typename + 8);
904     }
905     if (be_opened) {
906         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
907     }
908 
909     if (id) {
910         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
911         if (local_err) {
912             goto end;
913         }
914         object_unref(obj);
915     }
916 
917 end:
918     if (local_err) {
919         error_propagate(errp, local_err);
920         object_unref(obj);
921         return NULL;
922     }
923 
924     return chr;
925 }
926 
927 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
928                                Error **errp)
929 {
930     const ChardevClass *cc;
931     ChardevReturn *ret;
932     Chardev *chr;
933 
934     cc = char_get_class(ChardevBackendKind_lookup[backend->type], errp);
935     if (!cc) {
936         return NULL;
937     }
938 
939     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
940                            backend, errp);
941     if (!chr) {
942         return NULL;
943     }
944 
945     ret = g_new0(ChardevReturn, 1);
946     if (CHARDEV_IS_PTY(chr)) {
947         ret->pty = g_strdup(chr->filename + 4);
948         ret->has_pty = true;
949     }
950 
951     return ret;
952 }
953 
954 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
955                                   Error **errp)
956 {
957     CharBackend *be;
958     const ChardevClass *cc;
959     Chardev *chr, *chr_new;
960     bool closed_sent = false;
961     ChardevReturn *ret;
962 
963     chr = qemu_chr_find(id);
964     if (!chr) {
965         error_setg(errp, "Chardev '%s' does not exist", id);
966         return NULL;
967     }
968 
969     if (CHARDEV_IS_MUX(chr)) {
970         error_setg(errp, "Mux device hotswap not supported yet");
971         return NULL;
972     }
973 
974     if (qemu_chr_replay(chr)) {
975         error_setg(errp,
976             "Chardev '%s' cannot be changed in record/replay mode", id);
977         return NULL;
978     }
979 
980     be = chr->be;
981     if (!be) {
982         /* easy case */
983         object_unparent(OBJECT(chr));
984         return qmp_chardev_add(id, backend, errp);
985     }
986 
987     if (!be->chr_be_change) {
988         error_setg(errp, "Chardev user does not support chardev hotswap");
989         return NULL;
990     }
991 
992     cc = char_get_class(ChardevBackendKind_lookup[backend->type], errp);
993     if (!cc) {
994         return NULL;
995     }
996 
997     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
998                                backend, errp);
999     if (!chr_new) {
1000         return NULL;
1001     }
1002     chr_new->label = g_strdup(id);
1003 
1004     if (chr->be_open && !chr_new->be_open) {
1005         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1006         closed_sent = true;
1007     }
1008 
1009     chr->be = NULL;
1010     qemu_chr_fe_init(be, chr_new, &error_abort);
1011 
1012     if (be->chr_be_change(be->opaque) < 0) {
1013         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1014         chr_new->be = NULL;
1015         qemu_chr_fe_init(be, chr, &error_abort);
1016         if (closed_sent) {
1017             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1018         }
1019         object_unref(OBJECT(chr_new));
1020         return NULL;
1021     }
1022 
1023     object_unparent(OBJECT(chr));
1024     object_property_add_child(get_chardevs_root(), chr_new->label,
1025                               OBJECT(chr_new), &error_abort);
1026     object_unref(OBJECT(chr_new));
1027 
1028     ret = g_new0(ChardevReturn, 1);
1029     if (CHARDEV_IS_PTY(chr_new)) {
1030         ret->pty = g_strdup(chr_new->filename + 4);
1031         ret->has_pty = true;
1032     }
1033 
1034     return ret;
1035 }
1036 
1037 void qmp_chardev_remove(const char *id, Error **errp)
1038 {
1039     Chardev *chr;
1040 
1041     chr = qemu_chr_find(id);
1042     if (chr == NULL) {
1043         error_setg(errp, "Chardev '%s' not found", id);
1044         return;
1045     }
1046     if (qemu_chr_is_busy(chr)) {
1047         error_setg(errp, "Chardev '%s' is busy", id);
1048         return;
1049     }
1050     if (qemu_chr_replay(chr)) {
1051         error_setg(errp,
1052             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1053         return;
1054     }
1055     object_unparent(OBJECT(chr));
1056 }
1057 
1058 void qmp_chardev_send_break(const char *id, Error **errp)
1059 {
1060     Chardev *chr;
1061 
1062     chr = qemu_chr_find(id);
1063     if (chr == NULL) {
1064         error_setg(errp, "Chardev '%s' not found", id);
1065         return;
1066     }
1067     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1068 }
1069 
1070 void qemu_chr_cleanup(void)
1071 {
1072     object_unparent(get_chardevs_root());
1073 }
1074 
1075 static void register_types(void)
1076 {
1077     type_register_static(&char_type_info);
1078 
1079     /* this must be done after machine init, since we register FEs with muxes
1080      * as part of realize functions like serial_isa_realizefn when -nographic
1081      * is specified
1082      */
1083     qemu_add_machine_init_done_notifier(&muxes_realize_notify);
1084 }
1085 
1086 type_init(register_types);
1087