xref: /openbmc/qemu/chardev/char.c (revision fb0bc835e56b894cbc7236294921e5393c786ad8)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu/cutils.h"
27 #include "monitor/monitor.h"
28 #include "sysemu/sysemu.h"
29 #include "qemu/config-file.h"
30 #include "qemu/error-report.h"
31 #include "chardev/char.h"
32 #include "qmp-commands.h"
33 #include "qapi-visit.h"
34 #include "qapi/error.h"
35 #include "qapi/qmp/qerror.h"
36 #include "sysemu/replay.h"
37 #include "qemu/help_option.h"
38 #include "qemu/option.h"
39 
40 #include "chardev/char-mux.h"
41 
42 /***********************************************************/
43 /* character device */
44 
45 static Object *get_chardevs_root(void)
46 {
47     return container_get(object_get_root(), "/chardevs");
48 }
49 
50 static void chr_be_event(Chardev *s, int event)
51 {
52     CharBackend *be = s->be;
53 
54     if (!be || !be->chr_event) {
55         return;
56     }
57 
58     be->chr_event(be->opaque, event);
59 }
60 
61 void qemu_chr_be_event(Chardev *s, int event)
62 {
63     /* Keep track if the char device is open */
64     switch (event) {
65         case CHR_EVENT_OPENED:
66             s->be_open = 1;
67             break;
68         case CHR_EVENT_CLOSED:
69             s->be_open = 0;
70             break;
71     }
72 
73     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
74 }
75 
76 /* Not reporting errors from writing to logfile, as logs are
77  * defined to be "best effort" only */
78 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
79 {
80     size_t done = 0;
81     ssize_t ret;
82 
83     if (s->logfd < 0) {
84         return;
85     }
86 
87     while (done < len) {
88     retry:
89         ret = write(s->logfd, buf + done, len - done);
90         if (ret == -1 && errno == EAGAIN) {
91             g_usleep(100);
92             goto retry;
93         }
94 
95         if (ret <= 0) {
96             return;
97         }
98         done += ret;
99     }
100 }
101 
102 static int qemu_chr_write_buffer(Chardev *s,
103                                  const uint8_t *buf, int len,
104                                  int *offset, bool write_all)
105 {
106     ChardevClass *cc = CHARDEV_GET_CLASS(s);
107     int res = 0;
108     *offset = 0;
109 
110     qemu_mutex_lock(&s->chr_write_lock);
111     while (*offset < len) {
112     retry:
113         res = cc->chr_write(s, buf + *offset, len - *offset);
114         if (res < 0 && errno == EAGAIN && write_all) {
115             g_usleep(100);
116             goto retry;
117         }
118 
119         if (res <= 0) {
120             break;
121         }
122 
123         *offset += res;
124         if (!write_all) {
125             break;
126         }
127     }
128     if (*offset > 0) {
129         qemu_chr_write_log(s, buf, *offset);
130     }
131     qemu_mutex_unlock(&s->chr_write_lock);
132 
133     return res;
134 }
135 
136 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
137 {
138     int offset = 0;
139     int res;
140 
141     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
142         replay_char_write_event_load(&res, &offset);
143         assert(offset <= len);
144         qemu_chr_write_buffer(s, buf, offset, &offset, true);
145         return res;
146     }
147 
148     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
149 
150     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
151         replay_char_write_event_save(res, offset);
152     }
153 
154     if (res < 0) {
155         return res;
156     }
157     return offset;
158 }
159 
160 int qemu_chr_be_can_write(Chardev *s)
161 {
162     CharBackend *be = s->be;
163 
164     if (!be || !be->chr_can_read) {
165         return 0;
166     }
167 
168     return be->chr_can_read(be->opaque);
169 }
170 
171 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
172 {
173     CharBackend *be = s->be;
174 
175     if (be && be->chr_read) {
176         be->chr_read(be->opaque, buf, len);
177     }
178 }
179 
180 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
181 {
182     if (qemu_chr_replay(s)) {
183         if (replay_mode == REPLAY_MODE_PLAY) {
184             return;
185         }
186         replay_chr_be_write(s, buf, len);
187     } else {
188         qemu_chr_be_write_impl(s, buf, len);
189     }
190 }
191 
192 void qemu_chr_be_update_read_handlers(Chardev *s,
193                                       GMainContext *context)
194 {
195     ChardevClass *cc = CHARDEV_GET_CLASS(s);
196 
197     s->gcontext = context;
198     if (cc->chr_update_read_handler) {
199         cc->chr_update_read_handler(s);
200     }
201 }
202 
203 int qemu_chr_add_client(Chardev *s, int fd)
204 {
205     return CHARDEV_GET_CLASS(s)->chr_add_client ?
206         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
207 }
208 
209 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
210                            bool *be_opened, Error **errp)
211 {
212     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
213     /* Any ChardevCommon member would work */
214     ChardevCommon *common = backend ? backend->u.null.data : NULL;
215 
216     if (common && common->has_logfile) {
217         int flags = O_WRONLY | O_CREAT;
218         if (common->has_logappend &&
219             common->logappend) {
220             flags |= O_APPEND;
221         } else {
222             flags |= O_TRUNC;
223         }
224         chr->logfd = qemu_open(common->logfile, flags, 0666);
225         if (chr->logfd < 0) {
226             error_setg_errno(errp, errno,
227                              "Unable to open logfile %s",
228                              common->logfile);
229             return;
230         }
231     }
232 
233     if (cc->open) {
234         cc->open(chr, backend, be_opened, errp);
235     }
236 }
237 
238 static void char_init(Object *obj)
239 {
240     Chardev *chr = CHARDEV(obj);
241 
242     chr->logfd = -1;
243     qemu_mutex_init(&chr->chr_write_lock);
244 }
245 
246 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
247 {
248     return len;
249 }
250 
251 static void char_class_init(ObjectClass *oc, void *data)
252 {
253     ChardevClass *cc = CHARDEV_CLASS(oc);
254 
255     cc->chr_write = null_chr_write;
256     cc->chr_be_event = chr_be_event;
257 }
258 
259 static void char_finalize(Object *obj)
260 {
261     Chardev *chr = CHARDEV(obj);
262 
263     if (chr->be) {
264         chr->be->chr = NULL;
265     }
266     g_free(chr->filename);
267     g_free(chr->label);
268     if (chr->logfd != -1) {
269         close(chr->logfd);
270     }
271     qemu_mutex_destroy(&chr->chr_write_lock);
272 }
273 
274 static const TypeInfo char_type_info = {
275     .name = TYPE_CHARDEV,
276     .parent = TYPE_OBJECT,
277     .instance_size = sizeof(Chardev),
278     .instance_init = char_init,
279     .instance_finalize = char_finalize,
280     .abstract = true,
281     .class_size = sizeof(ChardevClass),
282     .class_init = char_class_init,
283 };
284 
285 /**
286  * Called after processing of default and command-line-specified
287  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
288  * to a mux chardev. This is done here to ensure that
289  * output/prompts/banners are only displayed for the FE that has
290  * focus when initial command-line processing/machine init is
291  * completed.
292  *
293  * After this point, any new FE attached to any new or existing
294  * mux will receive CHR_EVENT_OPENED notifications for the BE
295  * immediately.
296  */
297 static int open_muxes(Object *child, void *opaque)
298 {
299     if (CHARDEV_IS_MUX(child)) {
300         /* send OPENED to all already-attached FEs */
301         mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
302         /* mark mux as OPENED so any new FEs will immediately receive
303          * OPENED event
304          */
305         qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
306     }
307 
308     return 0;
309 }
310 
311 static void muxes_realize_done(Notifier *notifier, void *unused)
312 {
313     muxes_realized = true;
314     object_child_foreach(get_chardevs_root(), open_muxes, NULL);
315 }
316 
317 static Notifier muxes_realize_notify = {
318     .notify = muxes_realize_done,
319 };
320 
321 static bool qemu_chr_is_busy(Chardev *s)
322 {
323     if (CHARDEV_IS_MUX(s)) {
324         MuxChardev *d = MUX_CHARDEV(s);
325         return d->mux_cnt >= 0;
326     } else {
327         return s->be != NULL;
328     }
329 }
330 
331 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
332 {
333     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
334 
335     if (cc->chr_wait_connected) {
336         return cc->chr_wait_connected(chr, errp);
337     }
338 
339     return 0;
340 }
341 
342 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
343 {
344     char host[65], port[33], width[8], height[8];
345     int pos;
346     const char *p;
347     QemuOpts *opts;
348     Error *local_err = NULL;
349 
350     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
351     if (local_err) {
352         error_report_err(local_err);
353         return NULL;
354     }
355 
356     if (strstart(filename, "mon:", &p)) {
357         filename = p;
358         qemu_opt_set(opts, "mux", "on", &error_abort);
359         if (strcmp(filename, "stdio") == 0) {
360             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
361              * but pass it to the guest.  Handle this only for compat syntax,
362              * for -chardev syntax we have special option for this.
363              * This is what -nographic did, redirecting+muxing serial+monitor
364              * to stdio causing Ctrl+C to be passed to guest. */
365             qemu_opt_set(opts, "signal", "off", &error_abort);
366         }
367     }
368 
369     if (strcmp(filename, "null")    == 0 ||
370         strcmp(filename, "pty")     == 0 ||
371         strcmp(filename, "msmouse") == 0 ||
372         strcmp(filename, "wctablet") == 0 ||
373         strcmp(filename, "braille") == 0 ||
374         strcmp(filename, "testdev") == 0 ||
375         strcmp(filename, "stdio")   == 0) {
376         qemu_opt_set(opts, "backend", filename, &error_abort);
377         return opts;
378     }
379     if (strstart(filename, "vc", &p)) {
380         qemu_opt_set(opts, "backend", "vc", &error_abort);
381         if (*p == ':') {
382             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
383                 /* pixels */
384                 qemu_opt_set(opts, "width", width, &error_abort);
385                 qemu_opt_set(opts, "height", height, &error_abort);
386             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
387                 /* chars */
388                 qemu_opt_set(opts, "cols", width, &error_abort);
389                 qemu_opt_set(opts, "rows", height, &error_abort);
390             } else {
391                 goto fail;
392             }
393         }
394         return opts;
395     }
396     if (strcmp(filename, "con:") == 0) {
397         qemu_opt_set(opts, "backend", "console", &error_abort);
398         return opts;
399     }
400     if (strstart(filename, "COM", NULL)) {
401         qemu_opt_set(opts, "backend", "serial", &error_abort);
402         qemu_opt_set(opts, "path", filename, &error_abort);
403         return opts;
404     }
405     if (strstart(filename, "file:", &p)) {
406         qemu_opt_set(opts, "backend", "file", &error_abort);
407         qemu_opt_set(opts, "path", p, &error_abort);
408         return opts;
409     }
410     if (strstart(filename, "pipe:", &p)) {
411         qemu_opt_set(opts, "backend", "pipe", &error_abort);
412         qemu_opt_set(opts, "path", p, &error_abort);
413         return opts;
414     }
415     if (strstart(filename, "tcp:", &p) ||
416         strstart(filename, "telnet:", &p) ||
417         strstart(filename, "tn3270:", &p)) {
418         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
419             host[0] = 0;
420             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
421                 goto fail;
422         }
423         qemu_opt_set(opts, "backend", "socket", &error_abort);
424         qemu_opt_set(opts, "host", host, &error_abort);
425         qemu_opt_set(opts, "port", port, &error_abort);
426         if (p[pos] == ',') {
427             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
428             if (local_err) {
429                 error_report_err(local_err);
430                 goto fail;
431             }
432         }
433         if (strstart(filename, "telnet:", &p)) {
434             qemu_opt_set(opts, "telnet", "on", &error_abort);
435         } else if (strstart(filename, "tn3270:", &p)) {
436             qemu_opt_set(opts, "tn3270", "on", &error_abort);
437         }
438         return opts;
439     }
440     if (strstart(filename, "udp:", &p)) {
441         qemu_opt_set(opts, "backend", "udp", &error_abort);
442         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
443             host[0] = 0;
444             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
445                 goto fail;
446             }
447         }
448         qemu_opt_set(opts, "host", host, &error_abort);
449         qemu_opt_set(opts, "port", port, &error_abort);
450         if (p[pos] == '@') {
451             p += pos + 1;
452             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
453                 host[0] = 0;
454                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
455                     goto fail;
456                 }
457             }
458             qemu_opt_set(opts, "localaddr", host, &error_abort);
459             qemu_opt_set(opts, "localport", port, &error_abort);
460         }
461         return opts;
462     }
463     if (strstart(filename, "unix:", &p)) {
464         qemu_opt_set(opts, "backend", "socket", &error_abort);
465         qemu_opts_do_parse(opts, p, "path", &local_err);
466         if (local_err) {
467             error_report_err(local_err);
468             goto fail;
469         }
470         return opts;
471     }
472     if (strstart(filename, "/dev/parport", NULL) ||
473         strstart(filename, "/dev/ppi", NULL)) {
474         qemu_opt_set(opts, "backend", "parallel", &error_abort);
475         qemu_opt_set(opts, "path", filename, &error_abort);
476         return opts;
477     }
478     if (strstart(filename, "/dev/", NULL)) {
479         qemu_opt_set(opts, "backend", "serial", &error_abort);
480         qemu_opt_set(opts, "path", filename, &error_abort);
481         return opts;
482     }
483 
484 fail:
485     qemu_opts_del(opts);
486     return NULL;
487 }
488 
489 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
490 {
491     const char *logfile = qemu_opt_get(opts, "logfile");
492 
493     backend->has_logfile = logfile != NULL;
494     backend->logfile = g_strdup(logfile);
495 
496     backend->has_logappend = true;
497     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
498 }
499 
500 static const ChardevClass *char_get_class(const char *driver, Error **errp)
501 {
502     ObjectClass *oc;
503     const ChardevClass *cc;
504     char *typename = g_strdup_printf("chardev-%s", driver);
505 
506     oc = object_class_by_name(typename);
507     g_free(typename);
508 
509     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
510         error_setg(errp, "'%s' is not a valid char driver name", driver);
511         return NULL;
512     }
513 
514     if (object_class_is_abstract(oc)) {
515         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
516                    "abstract device type");
517         return NULL;
518     }
519 
520     cc = CHARDEV_CLASS(oc);
521     if (cc->internal) {
522         error_setg(errp, "'%s' is not a valid char driver name", driver);
523         return NULL;
524     }
525 
526     return cc;
527 }
528 
529 static const struct ChardevAlias {
530     const char *typename;
531     const char *alias;
532 } chardev_alias_table[] = {
533 #ifdef HAVE_CHARDEV_PARPORT
534     { "parallel", "parport" },
535 #endif
536 #ifdef HAVE_CHARDEV_SERIAL
537     { "serial", "tty" },
538 #endif
539 };
540 
541 typedef struct ChadevClassFE {
542     void (*fn)(const char *name, void *opaque);
543     void *opaque;
544 } ChadevClassFE;
545 
546 static void
547 chardev_class_foreach(ObjectClass *klass, void *opaque)
548 {
549     ChadevClassFE *fe = opaque;
550 
551     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
552     if (CHARDEV_CLASS(klass)->internal) {
553         return;
554     }
555 
556     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
557 }
558 
559 static void
560 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
561 {
562     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
563     int i;
564 
565     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
566 
567     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
568         fn(chardev_alias_table[i].alias, opaque);
569     }
570 }
571 
572 static void
573 help_string_append(const char *name, void *opaque)
574 {
575     GString *str = opaque;
576 
577     g_string_append_printf(str, "\n%s", name);
578 }
579 
580 static const char *chardev_alias_translate(const char *name)
581 {
582     int i;
583     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
584         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
585             return chardev_alias_table[i].typename;
586         }
587     }
588     return name;
589 }
590 
591 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
592 {
593     Error *local_err = NULL;
594     const ChardevClass *cc;
595     ChardevBackend *backend = NULL;
596     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
597 
598     if (name == NULL) {
599         error_setg(errp, "chardev: \"%s\" missing backend",
600                    qemu_opts_id(opts));
601         return NULL;
602     }
603 
604     cc = char_get_class(name, errp);
605     if (cc == NULL) {
606         return NULL;
607     }
608 
609     backend = g_new0(ChardevBackend, 1);
610     backend->type = CHARDEV_BACKEND_KIND_NULL;
611 
612     if (cc->parse) {
613         cc->parse(opts, backend, &local_err);
614         if (local_err) {
615             error_propagate(errp, local_err);
616             qapi_free_ChardevBackend(backend);
617             return NULL;
618         }
619     } else {
620         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
621         qemu_chr_parse_common(opts, ccom);
622         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
623     }
624 
625     return backend;
626 }
627 
628 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
629 {
630     const ChardevClass *cc;
631     Chardev *chr = NULL;
632     ChardevBackend *backend = NULL;
633     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
634     const char *id = qemu_opts_id(opts);
635     char *bid = NULL;
636 
637     if (name && is_help_option(name)) {
638         GString *str = g_string_new("");
639 
640         chardev_name_foreach(help_string_append, str);
641 
642         error_report("Available chardev backend types: %s", str->str);
643         g_string_free(str, true);
644         return NULL;
645     }
646 
647     if (id == NULL) {
648         error_setg(errp, "chardev: no id specified");
649         return NULL;
650     }
651 
652     backend = qemu_chr_parse_opts(opts, errp);
653     if (backend == NULL) {
654         return NULL;
655     }
656 
657     cc = char_get_class(name, errp);
658     if (cc == NULL) {
659         goto out;
660     }
661 
662     if (qemu_opt_get_bool(opts, "mux", 0)) {
663         bid = g_strdup_printf("%s-base", id);
664     }
665 
666     chr = qemu_chardev_new(bid ? bid : id,
667                            object_class_get_name(OBJECT_CLASS(cc)),
668                            backend, errp);
669 
670     if (chr == NULL) {
671         goto out;
672     }
673 
674     if (bid) {
675         Chardev *mux;
676         qapi_free_ChardevBackend(backend);
677         backend = g_new0(ChardevBackend, 1);
678         backend->type = CHARDEV_BACKEND_KIND_MUX;
679         backend->u.mux.data = g_new0(ChardevMux, 1);
680         backend->u.mux.data->chardev = g_strdup(bid);
681         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
682         if (mux == NULL) {
683             object_unparent(OBJECT(chr));
684             chr = NULL;
685             goto out;
686         }
687         chr = mux;
688     }
689 
690 out:
691     qapi_free_ChardevBackend(backend);
692     g_free(bid);
693     return chr;
694 }
695 
696 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
697 {
698     const char *p;
699     Chardev *chr;
700     QemuOpts *opts;
701     Error *err = NULL;
702 
703     if (strstart(filename, "chardev:", &p)) {
704         return qemu_chr_find(p);
705     }
706 
707     opts = qemu_chr_parse_compat(label, filename);
708     if (!opts)
709         return NULL;
710 
711     chr = qemu_chr_new_from_opts(opts, &err);
712     if (err) {
713         error_report_err(err);
714     }
715     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
716         monitor_init(chr, MONITOR_USE_READLINE);
717     }
718     qemu_opts_del(opts);
719     return chr;
720 }
721 
722 Chardev *qemu_chr_new(const char *label, const char *filename)
723 {
724     Chardev *chr;
725     chr = qemu_chr_new_noreplay(label, filename);
726     if (chr) {
727         if (replay_mode != REPLAY_MODE_NONE) {
728             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
729         }
730         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
731             error_report("Replay: ioctl is not supported "
732                          "for serial devices yet");
733         }
734         replay_register_char_driver(chr);
735     }
736     return chr;
737 }
738 
739 static int qmp_query_chardev_foreach(Object *obj, void *data)
740 {
741     Chardev *chr = CHARDEV(obj);
742     ChardevInfoList **list = data;
743     ChardevInfoList *info = g_malloc0(sizeof(*info));
744 
745     info->value = g_malloc0(sizeof(*info->value));
746     info->value->label = g_strdup(chr->label);
747     info->value->filename = g_strdup(chr->filename);
748     info->value->frontend_open = chr->be && chr->be->fe_open;
749 
750     info->next = *list;
751     *list = info;
752 
753     return 0;
754 }
755 
756 ChardevInfoList *qmp_query_chardev(Error **errp)
757 {
758     ChardevInfoList *chr_list = NULL;
759 
760     object_child_foreach(get_chardevs_root(),
761                          qmp_query_chardev_foreach, &chr_list);
762 
763     return chr_list;
764 }
765 
766 static void
767 qmp_prepend_backend(const char *name, void *opaque)
768 {
769     ChardevBackendInfoList **list = opaque;
770     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
771 
772     info->value = g_malloc0(sizeof(*info->value));
773     info->value->name = g_strdup(name);
774     info->next = *list;
775     *list = info;
776 }
777 
778 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
779 {
780     ChardevBackendInfoList *backend_list = NULL;
781 
782     chardev_name_foreach(qmp_prepend_backend, &backend_list);
783 
784     return backend_list;
785 }
786 
787 Chardev *qemu_chr_find(const char *name)
788 {
789     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
790 
791     return obj ? CHARDEV(obj) : NULL;
792 }
793 
794 QemuOptsList qemu_chardev_opts = {
795     .name = "chardev",
796     .implied_opt_name = "backend",
797     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
798     .desc = {
799         {
800             .name = "backend",
801             .type = QEMU_OPT_STRING,
802         },{
803             .name = "path",
804             .type = QEMU_OPT_STRING,
805         },{
806             .name = "host",
807             .type = QEMU_OPT_STRING,
808         },{
809             .name = "port",
810             .type = QEMU_OPT_STRING,
811         },{
812             .name = "localaddr",
813             .type = QEMU_OPT_STRING,
814         },{
815             .name = "localport",
816             .type = QEMU_OPT_STRING,
817         },{
818             .name = "to",
819             .type = QEMU_OPT_NUMBER,
820         },{
821             .name = "ipv4",
822             .type = QEMU_OPT_BOOL,
823         },{
824             .name = "ipv6",
825             .type = QEMU_OPT_BOOL,
826         },{
827             .name = "wait",
828             .type = QEMU_OPT_BOOL,
829         },{
830             .name = "server",
831             .type = QEMU_OPT_BOOL,
832         },{
833             .name = "delay",
834             .type = QEMU_OPT_BOOL,
835         },{
836             .name = "reconnect",
837             .type = QEMU_OPT_NUMBER,
838         },{
839             .name = "telnet",
840             .type = QEMU_OPT_BOOL,
841         },{
842             .name = "tn3270",
843             .type = QEMU_OPT_BOOL,
844         },{
845             .name = "tls-creds",
846             .type = QEMU_OPT_STRING,
847         },{
848             .name = "width",
849             .type = QEMU_OPT_NUMBER,
850         },{
851             .name = "height",
852             .type = QEMU_OPT_NUMBER,
853         },{
854             .name = "cols",
855             .type = QEMU_OPT_NUMBER,
856         },{
857             .name = "rows",
858             .type = QEMU_OPT_NUMBER,
859         },{
860             .name = "mux",
861             .type = QEMU_OPT_BOOL,
862         },{
863             .name = "signal",
864             .type = QEMU_OPT_BOOL,
865         },{
866             .name = "name",
867             .type = QEMU_OPT_STRING,
868         },{
869             .name = "debug",
870             .type = QEMU_OPT_NUMBER,
871         },{
872             .name = "size",
873             .type = QEMU_OPT_SIZE,
874         },{
875             .name = "chardev",
876             .type = QEMU_OPT_STRING,
877         },{
878             .name = "append",
879             .type = QEMU_OPT_BOOL,
880         },{
881             .name = "logfile",
882             .type = QEMU_OPT_STRING,
883         },{
884             .name = "logappend",
885             .type = QEMU_OPT_BOOL,
886         },
887         { /* end of list */ }
888     },
889 };
890 
891 bool qemu_chr_has_feature(Chardev *chr,
892                           ChardevFeature feature)
893 {
894     return test_bit(feature, chr->features);
895 }
896 
897 void qemu_chr_set_feature(Chardev *chr,
898                            ChardevFeature feature)
899 {
900     return set_bit(feature, chr->features);
901 }
902 
903 Chardev *qemu_chardev_new(const char *id, const char *typename,
904                           ChardevBackend *backend,
905                           Error **errp)
906 {
907     Object *obj;
908     Chardev *chr = NULL;
909     Error *local_err = NULL;
910     bool be_opened = true;
911 
912     assert(g_str_has_prefix(typename, "chardev-"));
913 
914     obj = object_new(typename);
915     chr = CHARDEV(obj);
916     chr->label = g_strdup(id);
917 
918     qemu_char_open(chr, backend, &be_opened, &local_err);
919     if (local_err) {
920         goto end;
921     }
922 
923     if (!chr->filename) {
924         chr->filename = g_strdup(typename + 8);
925     }
926     if (be_opened) {
927         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
928     }
929 
930     if (id) {
931         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
932         if (local_err) {
933             goto end;
934         }
935         object_unref(obj);
936     }
937 
938 end:
939     if (local_err) {
940         error_propagate(errp, local_err);
941         object_unref(obj);
942         return NULL;
943     }
944 
945     return chr;
946 }
947 
948 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
949                                Error **errp)
950 {
951     const ChardevClass *cc;
952     ChardevReturn *ret;
953     Chardev *chr;
954 
955     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
956     if (!cc) {
957         return NULL;
958     }
959 
960     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
961                            backend, errp);
962     if (!chr) {
963         return NULL;
964     }
965 
966     ret = g_new0(ChardevReturn, 1);
967     if (CHARDEV_IS_PTY(chr)) {
968         ret->pty = g_strdup(chr->filename + 4);
969         ret->has_pty = true;
970     }
971 
972     return ret;
973 }
974 
975 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
976                                   Error **errp)
977 {
978     CharBackend *be;
979     const ChardevClass *cc;
980     Chardev *chr, *chr_new;
981     bool closed_sent = false;
982     ChardevReturn *ret;
983 
984     chr = qemu_chr_find(id);
985     if (!chr) {
986         error_setg(errp, "Chardev '%s' does not exist", id);
987         return NULL;
988     }
989 
990     if (CHARDEV_IS_MUX(chr)) {
991         error_setg(errp, "Mux device hotswap not supported yet");
992         return NULL;
993     }
994 
995     if (qemu_chr_replay(chr)) {
996         error_setg(errp,
997             "Chardev '%s' cannot be changed in record/replay mode", id);
998         return NULL;
999     }
1000 
1001     be = chr->be;
1002     if (!be) {
1003         /* easy case */
1004         object_unparent(OBJECT(chr));
1005         return qmp_chardev_add(id, backend, errp);
1006     }
1007 
1008     if (!be->chr_be_change) {
1009         error_setg(errp, "Chardev user does not support chardev hotswap");
1010         return NULL;
1011     }
1012 
1013     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1014     if (!cc) {
1015         return NULL;
1016     }
1017 
1018     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1019                                backend, errp);
1020     if (!chr_new) {
1021         return NULL;
1022     }
1023     chr_new->label = g_strdup(id);
1024 
1025     if (chr->be_open && !chr_new->be_open) {
1026         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1027         closed_sent = true;
1028     }
1029 
1030     chr->be = NULL;
1031     qemu_chr_fe_init(be, chr_new, &error_abort);
1032 
1033     if (be->chr_be_change(be->opaque) < 0) {
1034         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1035         chr_new->be = NULL;
1036         qemu_chr_fe_init(be, chr, &error_abort);
1037         if (closed_sent) {
1038             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1039         }
1040         object_unref(OBJECT(chr_new));
1041         return NULL;
1042     }
1043 
1044     object_unparent(OBJECT(chr));
1045     object_property_add_child(get_chardevs_root(), chr_new->label,
1046                               OBJECT(chr_new), &error_abort);
1047     object_unref(OBJECT(chr_new));
1048 
1049     ret = g_new0(ChardevReturn, 1);
1050     if (CHARDEV_IS_PTY(chr_new)) {
1051         ret->pty = g_strdup(chr_new->filename + 4);
1052         ret->has_pty = true;
1053     }
1054 
1055     return ret;
1056 }
1057 
1058 void qmp_chardev_remove(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     if (qemu_chr_is_busy(chr)) {
1068         error_setg(errp, "Chardev '%s' is busy", id);
1069         return;
1070     }
1071     if (qemu_chr_replay(chr)) {
1072         error_setg(errp,
1073             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1074         return;
1075     }
1076     object_unparent(OBJECT(chr));
1077 }
1078 
1079 void qmp_chardev_send_break(const char *id, Error **errp)
1080 {
1081     Chardev *chr;
1082 
1083     chr = qemu_chr_find(id);
1084     if (chr == NULL) {
1085         error_setg(errp, "Chardev '%s' not found", id);
1086         return;
1087     }
1088     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1089 }
1090 
1091 /*
1092  * Add a timeout callback for the chardev (in milliseconds), return
1093  * the GSource object created. Please use this to add timeout hook for
1094  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1095  * make sure the gcontext that the task bound to is correct.
1096  */
1097 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1098                                  GSourceFunc func, void *private)
1099 {
1100     GSource *source = g_timeout_source_new(ms);
1101 
1102     assert(func);
1103     g_source_set_callback(source, func, private, NULL);
1104     g_source_attach(source, chr->gcontext);
1105 
1106     return source;
1107 }
1108 
1109 void qemu_chr_cleanup(void)
1110 {
1111     object_unparent(get_chardevs_root());
1112 }
1113 
1114 static void register_types(void)
1115 {
1116     type_register_static(&char_type_info);
1117 
1118     /* this must be done after machine init, since we register FEs with muxes
1119      * as part of realize functions like serial_isa_realizefn when -nographic
1120      * is specified
1121      */
1122     qemu_add_machine_init_done_notifier(&muxes_realize_notify);
1123 }
1124 
1125 type_init(register_types);
1126