xref: /openbmc/qemu/chardev/char.c (revision 4fe6d78b)
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 static void chr_be_event(Chardev *s, int event)
47 {
48     CharBackend *be = s->be;
49 
50     if (!be || !be->chr_event) {
51         return;
52     }
53 
54     be->chr_event(be->opaque, event);
55 }
56 
57 void qemu_chr_be_event(Chardev *s, int event)
58 {
59     /* Keep track if the char device is open */
60     switch (event) {
61         case CHR_EVENT_OPENED:
62             s->be_open = 1;
63             break;
64         case CHR_EVENT_CLOSED:
65             s->be_open = 0;
66             break;
67     }
68 
69     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
70 }
71 
72 /* Not reporting errors from writing to logfile, as logs are
73  * defined to be "best effort" only */
74 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
75 {
76     size_t done = 0;
77     ssize_t ret;
78 
79     if (s->logfd < 0) {
80         return;
81     }
82 
83     while (done < len) {
84     retry:
85         ret = write(s->logfd, buf + done, len - done);
86         if (ret == -1 && errno == EAGAIN) {
87             g_usleep(100);
88             goto retry;
89         }
90 
91         if (ret <= 0) {
92             return;
93         }
94         done += ret;
95     }
96 }
97 
98 static int qemu_chr_write_buffer(Chardev *s,
99                                  const uint8_t *buf, int len,
100                                  int *offset, bool write_all)
101 {
102     ChardevClass *cc = CHARDEV_GET_CLASS(s);
103     int res = 0;
104     *offset = 0;
105 
106     qemu_mutex_lock(&s->chr_write_lock);
107     while (*offset < len) {
108     retry:
109         res = cc->chr_write(s, buf + *offset, len - *offset);
110         if (res < 0 && errno == EAGAIN && write_all) {
111             g_usleep(100);
112             goto retry;
113         }
114 
115         if (res <= 0) {
116             break;
117         }
118 
119         *offset += res;
120         if (!write_all) {
121             break;
122         }
123     }
124     if (*offset > 0) {
125         qemu_chr_write_log(s, buf, *offset);
126     }
127     qemu_mutex_unlock(&s->chr_write_lock);
128 
129     return res;
130 }
131 
132 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
133 {
134     int offset = 0;
135     int res;
136 
137     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
138         replay_char_write_event_load(&res, &offset);
139         assert(offset <= len);
140         qemu_chr_write_buffer(s, buf, offset, &offset, true);
141         return res;
142     }
143 
144     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
145 
146     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
147         replay_char_write_event_save(res, offset);
148     }
149 
150     if (res < 0) {
151         return res;
152     }
153     return offset;
154 }
155 
156 int qemu_chr_be_can_write(Chardev *s)
157 {
158     CharBackend *be = s->be;
159 
160     if (!be || !be->chr_can_read) {
161         return 0;
162     }
163 
164     return be->chr_can_read(be->opaque);
165 }
166 
167 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
168 {
169     CharBackend *be = s->be;
170 
171     if (be && be->chr_read) {
172         be->chr_read(be->opaque, buf, len);
173     }
174 }
175 
176 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
177 {
178     if (qemu_chr_replay(s)) {
179         if (replay_mode == REPLAY_MODE_PLAY) {
180             return;
181         }
182         replay_chr_be_write(s, buf, len);
183     } else {
184         qemu_chr_be_write_impl(s, buf, len);
185     }
186 }
187 
188 void qemu_chr_be_update_read_handlers(Chardev *s,
189                                       GMainContext *context)
190 {
191     ChardevClass *cc = CHARDEV_GET_CLASS(s);
192 
193     s->gcontext = context;
194     if (cc->chr_update_read_handler) {
195         cc->chr_update_read_handler(s);
196     }
197 }
198 
199 int qemu_chr_add_client(Chardev *s, int fd)
200 {
201     return CHARDEV_GET_CLASS(s)->chr_add_client ?
202         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
203 }
204 
205 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
206                            bool *be_opened, Error **errp)
207 {
208     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
209     /* Any ChardevCommon member would work */
210     ChardevCommon *common = backend ? backend->u.null.data : NULL;
211 
212     if (common && common->has_logfile) {
213         int flags = O_WRONLY | O_CREAT;
214         if (common->has_logappend &&
215             common->logappend) {
216             flags |= O_APPEND;
217         } else {
218             flags |= O_TRUNC;
219         }
220         chr->logfd = qemu_open(common->logfile, flags, 0666);
221         if (chr->logfd < 0) {
222             error_setg_errno(errp, errno,
223                              "Unable to open logfile %s",
224                              common->logfile);
225             return;
226         }
227     }
228 
229     if (cc->open) {
230         cc->open(chr, backend, be_opened, errp);
231     }
232 }
233 
234 static void char_init(Object *obj)
235 {
236     Chardev *chr = CHARDEV(obj);
237 
238     chr->logfd = -1;
239     qemu_mutex_init(&chr->chr_write_lock);
240 }
241 
242 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
243 {
244     return len;
245 }
246 
247 static void char_class_init(ObjectClass *oc, void *data)
248 {
249     ChardevClass *cc = CHARDEV_CLASS(oc);
250 
251     cc->chr_write = null_chr_write;
252     cc->chr_be_event = chr_be_event;
253 }
254 
255 static void char_finalize(Object *obj)
256 {
257     Chardev *chr = CHARDEV(obj);
258 
259     if (chr->be) {
260         chr->be->chr = NULL;
261     }
262     g_free(chr->filename);
263     g_free(chr->label);
264     if (chr->logfd != -1) {
265         close(chr->logfd);
266     }
267     qemu_mutex_destroy(&chr->chr_write_lock);
268 }
269 
270 static const TypeInfo char_type_info = {
271     .name = TYPE_CHARDEV,
272     .parent = TYPE_OBJECT,
273     .instance_size = sizeof(Chardev),
274     .instance_init = char_init,
275     .instance_finalize = char_finalize,
276     .abstract = true,
277     .class_size = sizeof(ChardevClass),
278     .class_init = char_class_init,
279 };
280 
281 /**
282  * Called after processing of default and command-line-specified
283  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
284  * to a mux chardev. This is done here to ensure that
285  * output/prompts/banners are only displayed for the FE that has
286  * focus when initial command-line processing/machine init is
287  * completed.
288  *
289  * After this point, any new FE attached to any new or existing
290  * mux will receive CHR_EVENT_OPENED notifications for the BE
291  * immediately.
292  */
293 static int open_muxes(Object *child, void *opaque)
294 {
295     if (CHARDEV_IS_MUX(child)) {
296         /* send OPENED to all already-attached FEs */
297         mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
298         /* mark mux as OPENED so any new FEs will immediately receive
299          * OPENED event
300          */
301         qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
302     }
303 
304     return 0;
305 }
306 
307 static void muxes_realize_done(Notifier *notifier, void *unused)
308 {
309     muxes_realized = true;
310     object_child_foreach(get_chardevs_root(), open_muxes, NULL);
311 }
312 
313 static Notifier muxes_realize_notify = {
314     .notify = muxes_realize_done,
315 };
316 
317 static bool qemu_chr_is_busy(Chardev *s)
318 {
319     if (CHARDEV_IS_MUX(s)) {
320         MuxChardev *d = MUX_CHARDEV(s);
321         return d->mux_cnt >= 0;
322     } else {
323         return s->be != NULL;
324     }
325 }
326 
327 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
328 {
329     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
330 
331     if (cc->chr_wait_connected) {
332         return cc->chr_wait_connected(chr, errp);
333     }
334 
335     return 0;
336 }
337 
338 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
339 {
340     char host[65], port[33], width[8], height[8];
341     int pos;
342     const char *p;
343     QemuOpts *opts;
344     Error *local_err = NULL;
345 
346     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
347     if (local_err) {
348         error_report_err(local_err);
349         return NULL;
350     }
351 
352     if (strstart(filename, "mon:", &p)) {
353         filename = p;
354         qemu_opt_set(opts, "mux", "on", &error_abort);
355         if (strcmp(filename, "stdio") == 0) {
356             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
357              * but pass it to the guest.  Handle this only for compat syntax,
358              * for -chardev syntax we have special option for this.
359              * This is what -nographic did, redirecting+muxing serial+monitor
360              * to stdio causing Ctrl+C to be passed to guest. */
361             qemu_opt_set(opts, "signal", "off", &error_abort);
362         }
363     }
364 
365     if (strcmp(filename, "null")    == 0 ||
366         strcmp(filename, "pty")     == 0 ||
367         strcmp(filename, "msmouse") == 0 ||
368         strcmp(filename, "wctablet") == 0 ||
369         strcmp(filename, "braille") == 0 ||
370         strcmp(filename, "testdev") == 0 ||
371         strcmp(filename, "stdio")   == 0) {
372         qemu_opt_set(opts, "backend", filename, &error_abort);
373         return opts;
374     }
375     if (strstart(filename, "vc", &p)) {
376         qemu_opt_set(opts, "backend", "vc", &error_abort);
377         if (*p == ':') {
378             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
379                 /* pixels */
380                 qemu_opt_set(opts, "width", width, &error_abort);
381                 qemu_opt_set(opts, "height", height, &error_abort);
382             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
383                 /* chars */
384                 qemu_opt_set(opts, "cols", width, &error_abort);
385                 qemu_opt_set(opts, "rows", height, &error_abort);
386             } else {
387                 goto fail;
388             }
389         }
390         return opts;
391     }
392     if (strcmp(filename, "con:") == 0) {
393         qemu_opt_set(opts, "backend", "console", &error_abort);
394         return opts;
395     }
396     if (strstart(filename, "COM", NULL)) {
397         qemu_opt_set(opts, "backend", "serial", &error_abort);
398         qemu_opt_set(opts, "path", filename, &error_abort);
399         return opts;
400     }
401     if (strstart(filename, "file:", &p)) {
402         qemu_opt_set(opts, "backend", "file", &error_abort);
403         qemu_opt_set(opts, "path", p, &error_abort);
404         return opts;
405     }
406     if (strstart(filename, "pipe:", &p)) {
407         qemu_opt_set(opts, "backend", "pipe", &error_abort);
408         qemu_opt_set(opts, "path", p, &error_abort);
409         return opts;
410     }
411     if (strstart(filename, "tcp:", &p) ||
412         strstart(filename, "telnet:", &p) ||
413         strstart(filename, "tn3270:", &p)) {
414         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
415             host[0] = 0;
416             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
417                 goto fail;
418         }
419         qemu_opt_set(opts, "backend", "socket", &error_abort);
420         qemu_opt_set(opts, "host", host, &error_abort);
421         qemu_opt_set(opts, "port", port, &error_abort);
422         if (p[pos] == ',') {
423             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
424             if (local_err) {
425                 error_report_err(local_err);
426                 goto fail;
427             }
428         }
429         if (strstart(filename, "telnet:", &p)) {
430             qemu_opt_set(opts, "telnet", "on", &error_abort);
431         } else if (strstart(filename, "tn3270:", &p)) {
432             qemu_opt_set(opts, "tn3270", "on", &error_abort);
433         }
434         return opts;
435     }
436     if (strstart(filename, "udp:", &p)) {
437         qemu_opt_set(opts, "backend", "udp", &error_abort);
438         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
439             host[0] = 0;
440             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
441                 goto fail;
442             }
443         }
444         qemu_opt_set(opts, "host", host, &error_abort);
445         qemu_opt_set(opts, "port", port, &error_abort);
446         if (p[pos] == '@') {
447             p += pos + 1;
448             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
449                 host[0] = 0;
450                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
451                     goto fail;
452                 }
453             }
454             qemu_opt_set(opts, "localaddr", host, &error_abort);
455             qemu_opt_set(opts, "localport", port, &error_abort);
456         }
457         return opts;
458     }
459     if (strstart(filename, "unix:", &p)) {
460         qemu_opt_set(opts, "backend", "socket", &error_abort);
461         qemu_opts_do_parse(opts, p, "path", &local_err);
462         if (local_err) {
463             error_report_err(local_err);
464             goto fail;
465         }
466         return opts;
467     }
468     if (strstart(filename, "/dev/parport", NULL) ||
469         strstart(filename, "/dev/ppi", NULL)) {
470         qemu_opt_set(opts, "backend", "parallel", &error_abort);
471         qemu_opt_set(opts, "path", filename, &error_abort);
472         return opts;
473     }
474     if (strstart(filename, "/dev/", NULL)) {
475         qemu_opt_set(opts, "backend", "serial", &error_abort);
476         qemu_opt_set(opts, "path", filename, &error_abort);
477         return opts;
478     }
479 
480 fail:
481     qemu_opts_del(opts);
482     return NULL;
483 }
484 
485 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
486 {
487     const char *logfile = qemu_opt_get(opts, "logfile");
488 
489     backend->has_logfile = logfile != NULL;
490     backend->logfile = g_strdup(logfile);
491 
492     backend->has_logappend = true;
493     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
494 }
495 
496 static const ChardevClass *char_get_class(const char *driver, Error **errp)
497 {
498     ObjectClass *oc;
499     const ChardevClass *cc;
500     char *typename = g_strdup_printf("chardev-%s", driver);
501 
502     oc = object_class_by_name(typename);
503     g_free(typename);
504 
505     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
506         error_setg(errp, "'%s' is not a valid char driver name", driver);
507         return NULL;
508     }
509 
510     if (object_class_is_abstract(oc)) {
511         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
512                    "abstract device type");
513         return NULL;
514     }
515 
516     cc = CHARDEV_CLASS(oc);
517     if (cc->internal) {
518         error_setg(errp, "'%s' is not a valid char driver name", driver);
519         return NULL;
520     }
521 
522     return cc;
523 }
524 
525 static const struct ChardevAlias {
526     const char *typename;
527     const char *alias;
528 } chardev_alias_table[] = {
529 #ifdef HAVE_CHARDEV_PARPORT
530     { "parallel", "parport" },
531 #endif
532 #ifdef HAVE_CHARDEV_SERIAL
533     { "serial", "tty" },
534 #endif
535 };
536 
537 typedef struct ChadevClassFE {
538     void (*fn)(const char *name, void *opaque);
539     void *opaque;
540 } ChadevClassFE;
541 
542 static void
543 chardev_class_foreach(ObjectClass *klass, void *opaque)
544 {
545     ChadevClassFE *fe = opaque;
546 
547     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
548     if (CHARDEV_CLASS(klass)->internal) {
549         return;
550     }
551 
552     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
553 }
554 
555 static void
556 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
557 {
558     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
559     int i;
560 
561     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
562 
563     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
564         fn(chardev_alias_table[i].alias, opaque);
565     }
566 }
567 
568 static void
569 help_string_append(const char *name, void *opaque)
570 {
571     GString *str = opaque;
572 
573     g_string_append_printf(str, "\n%s", name);
574 }
575 
576 static const char *chardev_alias_translate(const char *name)
577 {
578     int i;
579     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
580         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
581             return chardev_alias_table[i].typename;
582         }
583     }
584     return name;
585 }
586 
587 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
588 {
589     Error *local_err = NULL;
590     const ChardevClass *cc;
591     ChardevBackend *backend = NULL;
592     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
593 
594     if (name == NULL) {
595         error_setg(errp, "chardev: \"%s\" missing backend",
596                    qemu_opts_id(opts));
597         return NULL;
598     }
599 
600     cc = char_get_class(name, errp);
601     if (cc == NULL) {
602         return NULL;
603     }
604 
605     backend = g_new0(ChardevBackend, 1);
606     backend->type = CHARDEV_BACKEND_KIND_NULL;
607 
608     if (cc->parse) {
609         cc->parse(opts, backend, &local_err);
610         if (local_err) {
611             error_propagate(errp, local_err);
612             qapi_free_ChardevBackend(backend);
613             return NULL;
614         }
615     } else {
616         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
617         qemu_chr_parse_common(opts, ccom);
618         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
619     }
620 
621     return backend;
622 }
623 
624 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
625 {
626     const ChardevClass *cc;
627     Chardev *chr = NULL;
628     ChardevBackend *backend = NULL;
629     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
630     const char *id = qemu_opts_id(opts);
631     char *bid = NULL;
632 
633     if (name && is_help_option(name)) {
634         GString *str = g_string_new("");
635 
636         chardev_name_foreach(help_string_append, str);
637 
638         error_report("Available chardev backend types: %s", str->str);
639         g_string_free(str, true);
640         return NULL;
641     }
642 
643     if (id == NULL) {
644         error_setg(errp, "chardev: no id specified");
645         return NULL;
646     }
647 
648     backend = qemu_chr_parse_opts(opts, errp);
649     if (backend == NULL) {
650         return NULL;
651     }
652 
653     cc = char_get_class(name, errp);
654     if (cc == NULL) {
655         goto out;
656     }
657 
658     if (qemu_opt_get_bool(opts, "mux", 0)) {
659         bid = g_strdup_printf("%s-base", id);
660     }
661 
662     chr = qemu_chardev_new(bid ? bid : id,
663                            object_class_get_name(OBJECT_CLASS(cc)),
664                            backend, errp);
665 
666     if (chr == NULL) {
667         goto out;
668     }
669 
670     if (bid) {
671         Chardev *mux;
672         qapi_free_ChardevBackend(backend);
673         backend = g_new0(ChardevBackend, 1);
674         backend->type = CHARDEV_BACKEND_KIND_MUX;
675         backend->u.mux.data = g_new0(ChardevMux, 1);
676         backend->u.mux.data->chardev = g_strdup(bid);
677         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
678         if (mux == NULL) {
679             object_unparent(OBJECT(chr));
680             chr = NULL;
681             goto out;
682         }
683         chr = mux;
684     }
685 
686 out:
687     qapi_free_ChardevBackend(backend);
688     g_free(bid);
689     return chr;
690 }
691 
692 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
693 {
694     const char *p;
695     Chardev *chr;
696     QemuOpts *opts;
697     Error *err = NULL;
698 
699     if (strstart(filename, "chardev:", &p)) {
700         return qemu_chr_find(p);
701     }
702 
703     opts = qemu_chr_parse_compat(label, filename);
704     if (!opts)
705         return NULL;
706 
707     chr = qemu_chr_new_from_opts(opts, &err);
708     if (err) {
709         error_report_err(err);
710     }
711     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
712         monitor_init(chr, MONITOR_USE_READLINE);
713     }
714     qemu_opts_del(opts);
715     return chr;
716 }
717 
718 Chardev *qemu_chr_new(const char *label, const char *filename)
719 {
720     Chardev *chr;
721     chr = qemu_chr_new_noreplay(label, filename);
722     if (chr) {
723         if (replay_mode != REPLAY_MODE_NONE) {
724             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
725         }
726         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
727             error_report("Replay: ioctl is not supported "
728                          "for serial devices yet");
729         }
730         replay_register_char_driver(chr);
731     }
732     return chr;
733 }
734 
735 static int qmp_query_chardev_foreach(Object *obj, void *data)
736 {
737     Chardev *chr = CHARDEV(obj);
738     ChardevInfoList **list = data;
739     ChardevInfoList *info = g_malloc0(sizeof(*info));
740 
741     info->value = g_malloc0(sizeof(*info->value));
742     info->value->label = g_strdup(chr->label);
743     info->value->filename = g_strdup(chr->filename);
744     info->value->frontend_open = chr->be && chr->be->fe_open;
745 
746     info->next = *list;
747     *list = info;
748 
749     return 0;
750 }
751 
752 ChardevInfoList *qmp_query_chardev(Error **errp)
753 {
754     ChardevInfoList *chr_list = NULL;
755 
756     object_child_foreach(get_chardevs_root(),
757                          qmp_query_chardev_foreach, &chr_list);
758 
759     return chr_list;
760 }
761 
762 static void
763 qmp_prepend_backend(const char *name, void *opaque)
764 {
765     ChardevBackendInfoList **list = opaque;
766     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
767 
768     info->value = g_malloc0(sizeof(*info->value));
769     info->value->name = g_strdup(name);
770     info->next = *list;
771     *list = info;
772 }
773 
774 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
775 {
776     ChardevBackendInfoList *backend_list = NULL;
777 
778     chardev_name_foreach(qmp_prepend_backend, &backend_list);
779 
780     return backend_list;
781 }
782 
783 Chardev *qemu_chr_find(const char *name)
784 {
785     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
786 
787     return obj ? CHARDEV(obj) : NULL;
788 }
789 
790 QemuOptsList qemu_chardev_opts = {
791     .name = "chardev",
792     .implied_opt_name = "backend",
793     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
794     .desc = {
795         {
796             .name = "backend",
797             .type = QEMU_OPT_STRING,
798         },{
799             .name = "path",
800             .type = QEMU_OPT_STRING,
801         },{
802             .name = "host",
803             .type = QEMU_OPT_STRING,
804         },{
805             .name = "port",
806             .type = QEMU_OPT_STRING,
807         },{
808             .name = "localaddr",
809             .type = QEMU_OPT_STRING,
810         },{
811             .name = "localport",
812             .type = QEMU_OPT_STRING,
813         },{
814             .name = "to",
815             .type = QEMU_OPT_NUMBER,
816         },{
817             .name = "ipv4",
818             .type = QEMU_OPT_BOOL,
819         },{
820             .name = "ipv6",
821             .type = QEMU_OPT_BOOL,
822         },{
823             .name = "wait",
824             .type = QEMU_OPT_BOOL,
825         },{
826             .name = "server",
827             .type = QEMU_OPT_BOOL,
828         },{
829             .name = "delay",
830             .type = QEMU_OPT_BOOL,
831         },{
832             .name = "reconnect",
833             .type = QEMU_OPT_NUMBER,
834         },{
835             .name = "telnet",
836             .type = QEMU_OPT_BOOL,
837         },{
838             .name = "tn3270",
839             .type = QEMU_OPT_BOOL,
840         },{
841             .name = "tls-creds",
842             .type = QEMU_OPT_STRING,
843         },{
844             .name = "width",
845             .type = QEMU_OPT_NUMBER,
846         },{
847             .name = "height",
848             .type = QEMU_OPT_NUMBER,
849         },{
850             .name = "cols",
851             .type = QEMU_OPT_NUMBER,
852         },{
853             .name = "rows",
854             .type = QEMU_OPT_NUMBER,
855         },{
856             .name = "mux",
857             .type = QEMU_OPT_BOOL,
858         },{
859             .name = "signal",
860             .type = QEMU_OPT_BOOL,
861         },{
862             .name = "name",
863             .type = QEMU_OPT_STRING,
864         },{
865             .name = "debug",
866             .type = QEMU_OPT_NUMBER,
867         },{
868             .name = "size",
869             .type = QEMU_OPT_SIZE,
870         },{
871             .name = "chardev",
872             .type = QEMU_OPT_STRING,
873         },{
874             .name = "append",
875             .type = QEMU_OPT_BOOL,
876         },{
877             .name = "logfile",
878             .type = QEMU_OPT_STRING,
879         },{
880             .name = "logappend",
881             .type = QEMU_OPT_BOOL,
882         },
883         { /* end of list */ }
884     },
885 };
886 
887 bool qemu_chr_has_feature(Chardev *chr,
888                           ChardevFeature feature)
889 {
890     return test_bit(feature, chr->features);
891 }
892 
893 void qemu_chr_set_feature(Chardev *chr,
894                            ChardevFeature feature)
895 {
896     return set_bit(feature, chr->features);
897 }
898 
899 Chardev *qemu_chardev_new(const char *id, const char *typename,
900                           ChardevBackend *backend,
901                           Error **errp)
902 {
903     Object *obj;
904     Chardev *chr = NULL;
905     Error *local_err = NULL;
906     bool be_opened = true;
907 
908     assert(g_str_has_prefix(typename, "chardev-"));
909 
910     obj = object_new(typename);
911     chr = CHARDEV(obj);
912     chr->label = g_strdup(id);
913 
914     qemu_char_open(chr, backend, &be_opened, &local_err);
915     if (local_err) {
916         goto end;
917     }
918 
919     if (!chr->filename) {
920         chr->filename = g_strdup(typename + 8);
921     }
922     if (be_opened) {
923         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
924     }
925 
926     if (id) {
927         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
928         if (local_err) {
929             goto end;
930         }
931         object_unref(obj);
932     }
933 
934 end:
935     if (local_err) {
936         error_propagate(errp, local_err);
937         object_unref(obj);
938         return NULL;
939     }
940 
941     return chr;
942 }
943 
944 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
945                                Error **errp)
946 {
947     const ChardevClass *cc;
948     ChardevReturn *ret;
949     Chardev *chr;
950 
951     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
952     if (!cc) {
953         return NULL;
954     }
955 
956     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
957                            backend, errp);
958     if (!chr) {
959         return NULL;
960     }
961 
962     ret = g_new0(ChardevReturn, 1);
963     if (CHARDEV_IS_PTY(chr)) {
964         ret->pty = g_strdup(chr->filename + 4);
965         ret->has_pty = true;
966     }
967 
968     return ret;
969 }
970 
971 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
972                                   Error **errp)
973 {
974     CharBackend *be;
975     const ChardevClass *cc;
976     Chardev *chr, *chr_new;
977     bool closed_sent = false;
978     ChardevReturn *ret;
979 
980     chr = qemu_chr_find(id);
981     if (!chr) {
982         error_setg(errp, "Chardev '%s' does not exist", id);
983         return NULL;
984     }
985 
986     if (CHARDEV_IS_MUX(chr)) {
987         error_setg(errp, "Mux device hotswap not supported yet");
988         return NULL;
989     }
990 
991     if (qemu_chr_replay(chr)) {
992         error_setg(errp,
993             "Chardev '%s' cannot be changed in record/replay mode", id);
994         return NULL;
995     }
996 
997     be = chr->be;
998     if (!be) {
999         /* easy case */
1000         object_unparent(OBJECT(chr));
1001         return qmp_chardev_add(id, backend, errp);
1002     }
1003 
1004     if (!be->chr_be_change) {
1005         error_setg(errp, "Chardev user does not support chardev hotswap");
1006         return NULL;
1007     }
1008 
1009     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1010     if (!cc) {
1011         return NULL;
1012     }
1013 
1014     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1015                                backend, errp);
1016     if (!chr_new) {
1017         return NULL;
1018     }
1019     chr_new->label = g_strdup(id);
1020 
1021     if (chr->be_open && !chr_new->be_open) {
1022         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1023         closed_sent = true;
1024     }
1025 
1026     chr->be = NULL;
1027     qemu_chr_fe_init(be, chr_new, &error_abort);
1028 
1029     if (be->chr_be_change(be->opaque) < 0) {
1030         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1031         chr_new->be = NULL;
1032         qemu_chr_fe_init(be, chr, &error_abort);
1033         if (closed_sent) {
1034             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1035         }
1036         object_unref(OBJECT(chr_new));
1037         return NULL;
1038     }
1039 
1040     object_unparent(OBJECT(chr));
1041     object_property_add_child(get_chardevs_root(), chr_new->label,
1042                               OBJECT(chr_new), &error_abort);
1043     object_unref(OBJECT(chr_new));
1044 
1045     ret = g_new0(ChardevReturn, 1);
1046     if (CHARDEV_IS_PTY(chr_new)) {
1047         ret->pty = g_strdup(chr_new->filename + 4);
1048         ret->has_pty = true;
1049     }
1050 
1051     return ret;
1052 }
1053 
1054 void qmp_chardev_remove(const char *id, Error **errp)
1055 {
1056     Chardev *chr;
1057 
1058     chr = qemu_chr_find(id);
1059     if (chr == NULL) {
1060         error_setg(errp, "Chardev '%s' not found", id);
1061         return;
1062     }
1063     if (qemu_chr_is_busy(chr)) {
1064         error_setg(errp, "Chardev '%s' is busy", id);
1065         return;
1066     }
1067     if (qemu_chr_replay(chr)) {
1068         error_setg(errp,
1069             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1070         return;
1071     }
1072     object_unparent(OBJECT(chr));
1073 }
1074 
1075 void qmp_chardev_send_break(const char *id, Error **errp)
1076 {
1077     Chardev *chr;
1078 
1079     chr = qemu_chr_find(id);
1080     if (chr == NULL) {
1081         error_setg(errp, "Chardev '%s' not found", id);
1082         return;
1083     }
1084     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1085 }
1086 
1087 /*
1088  * Add a timeout callback for the chardev (in milliseconds), return
1089  * the GSource object created. Please use this to add timeout hook for
1090  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1091  * make sure the gcontext that the task bound to is correct.
1092  */
1093 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1094                                  GSourceFunc func, void *private)
1095 {
1096     GSource *source = g_timeout_source_new(ms);
1097 
1098     assert(func);
1099     g_source_set_callback(source, func, private, NULL);
1100     g_source_attach(source, chr->gcontext);
1101 
1102     return source;
1103 }
1104 
1105 void qemu_chr_cleanup(void)
1106 {
1107     object_unparent(get_chardevs_root());
1108 }
1109 
1110 static void register_types(void)
1111 {
1112     type_register_static(&char_type_info);
1113 
1114     /* this must be done after machine init, since we register FEs with muxes
1115      * as part of realize functions like serial_isa_realizefn when -nographic
1116      * is specified
1117      */
1118     qemu_add_machine_init_done_notifier(&muxes_realize_notify);
1119 }
1120 
1121 type_init(register_types);
1122