xref: /openbmc/qemu/chardev/char.c (revision e688df6b)
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 "sysemu/replay.h"
36 #include "qemu/help_option.h"
37 
38 #include "chardev/char-mux.h"
39 
40 /***********************************************************/
41 /* character device */
42 
43 static Object *get_chardevs_root(void)
44 {
45     return container_get(object_get_root(), "/chardevs");
46 }
47 
48 static void chr_be_event(Chardev *s, int event)
49 {
50     CharBackend *be = s->be;
51 
52     if (!be || !be->chr_event) {
53         return;
54     }
55 
56     be->chr_event(be->opaque, event);
57 }
58 
59 void qemu_chr_be_event(Chardev *s, int event)
60 {
61     /* Keep track if the char device is open */
62     switch (event) {
63         case CHR_EVENT_OPENED:
64             s->be_open = 1;
65             break;
66         case CHR_EVENT_CLOSED:
67             s->be_open = 0;
68             break;
69     }
70 
71     CHARDEV_GET_CLASS(s)->chr_be_event(s, event);
72 }
73 
74 /* Not reporting errors from writing to logfile, as logs are
75  * defined to be "best effort" only */
76 static void qemu_chr_write_log(Chardev *s, const uint8_t *buf, size_t len)
77 {
78     size_t done = 0;
79     ssize_t ret;
80 
81     if (s->logfd < 0) {
82         return;
83     }
84 
85     while (done < len) {
86     retry:
87         ret = write(s->logfd, buf + done, len - done);
88         if (ret == -1 && errno == EAGAIN) {
89             g_usleep(100);
90             goto retry;
91         }
92 
93         if (ret <= 0) {
94             return;
95         }
96         done += ret;
97     }
98 }
99 
100 static int qemu_chr_write_buffer(Chardev *s,
101                                  const uint8_t *buf, int len,
102                                  int *offset, bool write_all)
103 {
104     ChardevClass *cc = CHARDEV_GET_CLASS(s);
105     int res = 0;
106     *offset = 0;
107 
108     qemu_mutex_lock(&s->chr_write_lock);
109     while (*offset < len) {
110     retry:
111         res = cc->chr_write(s, buf + *offset, len - *offset);
112         if (res < 0 && errno == EAGAIN && write_all) {
113             g_usleep(100);
114             goto retry;
115         }
116 
117         if (res <= 0) {
118             break;
119         }
120 
121         *offset += res;
122         if (!write_all) {
123             break;
124         }
125     }
126     if (*offset > 0) {
127         qemu_chr_write_log(s, buf, *offset);
128     }
129     qemu_mutex_unlock(&s->chr_write_lock);
130 
131     return res;
132 }
133 
134 int qemu_chr_write(Chardev *s, const uint8_t *buf, int len, bool write_all)
135 {
136     int offset = 0;
137     int res;
138 
139     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_PLAY) {
140         replay_char_write_event_load(&res, &offset);
141         assert(offset <= len);
142         qemu_chr_write_buffer(s, buf, offset, &offset, true);
143         return res;
144     }
145 
146     res = qemu_chr_write_buffer(s, buf, len, &offset, write_all);
147 
148     if (qemu_chr_replay(s) && replay_mode == REPLAY_MODE_RECORD) {
149         replay_char_write_event_save(res, offset);
150     }
151 
152     if (res < 0) {
153         return res;
154     }
155     return offset;
156 }
157 
158 int qemu_chr_be_can_write(Chardev *s)
159 {
160     CharBackend *be = s->be;
161 
162     if (!be || !be->chr_can_read) {
163         return 0;
164     }
165 
166     return be->chr_can_read(be->opaque);
167 }
168 
169 void qemu_chr_be_write_impl(Chardev *s, uint8_t *buf, int len)
170 {
171     CharBackend *be = s->be;
172 
173     if (be && be->chr_read) {
174         be->chr_read(be->opaque, buf, len);
175     }
176 }
177 
178 void qemu_chr_be_write(Chardev *s, uint8_t *buf, int len)
179 {
180     if (qemu_chr_replay(s)) {
181         if (replay_mode == REPLAY_MODE_PLAY) {
182             return;
183         }
184         replay_chr_be_write(s, buf, len);
185     } else {
186         qemu_chr_be_write_impl(s, buf, len);
187     }
188 }
189 
190 void qemu_chr_be_update_read_handlers(Chardev *s,
191                                       GMainContext *context)
192 {
193     ChardevClass *cc = CHARDEV_GET_CLASS(s);
194 
195     s->gcontext = context;
196     if (cc->chr_update_read_handler) {
197         cc->chr_update_read_handler(s);
198     }
199 }
200 
201 int qemu_chr_add_client(Chardev *s, int fd)
202 {
203     return CHARDEV_GET_CLASS(s)->chr_add_client ?
204         CHARDEV_GET_CLASS(s)->chr_add_client(s, fd) : -1;
205 }
206 
207 static void qemu_char_open(Chardev *chr, ChardevBackend *backend,
208                            bool *be_opened, Error **errp)
209 {
210     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
211     /* Any ChardevCommon member would work */
212     ChardevCommon *common = backend ? backend->u.null.data : NULL;
213 
214     if (common && common->has_logfile) {
215         int flags = O_WRONLY | O_CREAT;
216         if (common->has_logappend &&
217             common->logappend) {
218             flags |= O_APPEND;
219         } else {
220             flags |= O_TRUNC;
221         }
222         chr->logfd = qemu_open(common->logfile, flags, 0666);
223         if (chr->logfd < 0) {
224             error_setg_errno(errp, errno,
225                              "Unable to open logfile %s",
226                              common->logfile);
227             return;
228         }
229     }
230 
231     if (cc->open) {
232         cc->open(chr, backend, be_opened, errp);
233     }
234 }
235 
236 static void char_init(Object *obj)
237 {
238     Chardev *chr = CHARDEV(obj);
239 
240     chr->logfd = -1;
241     qemu_mutex_init(&chr->chr_write_lock);
242 }
243 
244 static int null_chr_write(Chardev *chr, const uint8_t *buf, int len)
245 {
246     return len;
247 }
248 
249 static void char_class_init(ObjectClass *oc, void *data)
250 {
251     ChardevClass *cc = CHARDEV_CLASS(oc);
252 
253     cc->chr_write = null_chr_write;
254     cc->chr_be_event = chr_be_event;
255 }
256 
257 static void char_finalize(Object *obj)
258 {
259     Chardev *chr = CHARDEV(obj);
260 
261     if (chr->be) {
262         chr->be->chr = NULL;
263     }
264     g_free(chr->filename);
265     g_free(chr->label);
266     if (chr->logfd != -1) {
267         close(chr->logfd);
268     }
269     qemu_mutex_destroy(&chr->chr_write_lock);
270 }
271 
272 static const TypeInfo char_type_info = {
273     .name = TYPE_CHARDEV,
274     .parent = TYPE_OBJECT,
275     .instance_size = sizeof(Chardev),
276     .instance_init = char_init,
277     .instance_finalize = char_finalize,
278     .abstract = true,
279     .class_size = sizeof(ChardevClass),
280     .class_init = char_class_init,
281 };
282 
283 /**
284  * Called after processing of default and command-line-specified
285  * chardevs to deliver CHR_EVENT_OPENED events to any FEs attached
286  * to a mux chardev. This is done here to ensure that
287  * output/prompts/banners are only displayed for the FE that has
288  * focus when initial command-line processing/machine init is
289  * completed.
290  *
291  * After this point, any new FE attached to any new or existing
292  * mux will receive CHR_EVENT_OPENED notifications for the BE
293  * immediately.
294  */
295 static int open_muxes(Object *child, void *opaque)
296 {
297     if (CHARDEV_IS_MUX(child)) {
298         /* send OPENED to all already-attached FEs */
299         mux_chr_send_all_event(CHARDEV(child), CHR_EVENT_OPENED);
300         /* mark mux as OPENED so any new FEs will immediately receive
301          * OPENED event
302          */
303         qemu_chr_be_event(CHARDEV(child), CHR_EVENT_OPENED);
304     }
305 
306     return 0;
307 }
308 
309 static void muxes_realize_done(Notifier *notifier, void *unused)
310 {
311     muxes_realized = true;
312     object_child_foreach(get_chardevs_root(), open_muxes, NULL);
313 }
314 
315 static Notifier muxes_realize_notify = {
316     .notify = muxes_realize_done,
317 };
318 
319 static bool qemu_chr_is_busy(Chardev *s)
320 {
321     if (CHARDEV_IS_MUX(s)) {
322         MuxChardev *d = MUX_CHARDEV(s);
323         return d->mux_cnt >= 0;
324     } else {
325         return s->be != NULL;
326     }
327 }
328 
329 int qemu_chr_wait_connected(Chardev *chr, Error **errp)
330 {
331     ChardevClass *cc = CHARDEV_GET_CLASS(chr);
332 
333     if (cc->chr_wait_connected) {
334         return cc->chr_wait_connected(chr, errp);
335     }
336 
337     return 0;
338 }
339 
340 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
341 {
342     char host[65], port[33], width[8], height[8];
343     int pos;
344     const char *p;
345     QemuOpts *opts;
346     Error *local_err = NULL;
347 
348     opts = qemu_opts_create(qemu_find_opts("chardev"), label, 1, &local_err);
349     if (local_err) {
350         error_report_err(local_err);
351         return NULL;
352     }
353 
354     if (strstart(filename, "mon:", &p)) {
355         filename = p;
356         qemu_opt_set(opts, "mux", "on", &error_abort);
357         if (strcmp(filename, "stdio") == 0) {
358             /* Monitor is muxed to stdio: do not exit on Ctrl+C by default
359              * but pass it to the guest.  Handle this only for compat syntax,
360              * for -chardev syntax we have special option for this.
361              * This is what -nographic did, redirecting+muxing serial+monitor
362              * to stdio causing Ctrl+C to be passed to guest. */
363             qemu_opt_set(opts, "signal", "off", &error_abort);
364         }
365     }
366 
367     if (strcmp(filename, "null")    == 0 ||
368         strcmp(filename, "pty")     == 0 ||
369         strcmp(filename, "msmouse") == 0 ||
370         strcmp(filename, "wctablet") == 0 ||
371         strcmp(filename, "braille") == 0 ||
372         strcmp(filename, "testdev") == 0 ||
373         strcmp(filename, "stdio")   == 0) {
374         qemu_opt_set(opts, "backend", filename, &error_abort);
375         return opts;
376     }
377     if (strstart(filename, "vc", &p)) {
378         qemu_opt_set(opts, "backend", "vc", &error_abort);
379         if (*p == ':') {
380             if (sscanf(p+1, "%7[0-9]x%7[0-9]", width, height) == 2) {
381                 /* pixels */
382                 qemu_opt_set(opts, "width", width, &error_abort);
383                 qemu_opt_set(opts, "height", height, &error_abort);
384             } else if (sscanf(p+1, "%7[0-9]Cx%7[0-9]C", width, height) == 2) {
385                 /* chars */
386                 qemu_opt_set(opts, "cols", width, &error_abort);
387                 qemu_opt_set(opts, "rows", height, &error_abort);
388             } else {
389                 goto fail;
390             }
391         }
392         return opts;
393     }
394     if (strcmp(filename, "con:") == 0) {
395         qemu_opt_set(opts, "backend", "console", &error_abort);
396         return opts;
397     }
398     if (strstart(filename, "COM", NULL)) {
399         qemu_opt_set(opts, "backend", "serial", &error_abort);
400         qemu_opt_set(opts, "path", filename, &error_abort);
401         return opts;
402     }
403     if (strstart(filename, "file:", &p)) {
404         qemu_opt_set(opts, "backend", "file", &error_abort);
405         qemu_opt_set(opts, "path", p, &error_abort);
406         return opts;
407     }
408     if (strstart(filename, "pipe:", &p)) {
409         qemu_opt_set(opts, "backend", "pipe", &error_abort);
410         qemu_opt_set(opts, "path", p, &error_abort);
411         return opts;
412     }
413     if (strstart(filename, "tcp:", &p) ||
414         strstart(filename, "telnet:", &p) ||
415         strstart(filename, "tn3270:", &p)) {
416         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
417             host[0] = 0;
418             if (sscanf(p, ":%32[^,]%n", port, &pos) < 1)
419                 goto fail;
420         }
421         qemu_opt_set(opts, "backend", "socket", &error_abort);
422         qemu_opt_set(opts, "host", host, &error_abort);
423         qemu_opt_set(opts, "port", port, &error_abort);
424         if (p[pos] == ',') {
425             qemu_opts_do_parse(opts, p+pos+1, NULL, &local_err);
426             if (local_err) {
427                 error_report_err(local_err);
428                 goto fail;
429             }
430         }
431         if (strstart(filename, "telnet:", &p)) {
432             qemu_opt_set(opts, "telnet", "on", &error_abort);
433         } else if (strstart(filename, "tn3270:", &p)) {
434             qemu_opt_set(opts, "tn3270", "on", &error_abort);
435         }
436         return opts;
437     }
438     if (strstart(filename, "udp:", &p)) {
439         qemu_opt_set(opts, "backend", "udp", &error_abort);
440         if (sscanf(p, "%64[^:]:%32[^@,]%n", host, port, &pos) < 2) {
441             host[0] = 0;
442             if (sscanf(p, ":%32[^@,]%n", port, &pos) < 1) {
443                 goto fail;
444             }
445         }
446         qemu_opt_set(opts, "host", host, &error_abort);
447         qemu_opt_set(opts, "port", port, &error_abort);
448         if (p[pos] == '@') {
449             p += pos + 1;
450             if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
451                 host[0] = 0;
452                 if (sscanf(p, ":%32[^,]%n", port, &pos) < 1) {
453                     goto fail;
454                 }
455             }
456             qemu_opt_set(opts, "localaddr", host, &error_abort);
457             qemu_opt_set(opts, "localport", port, &error_abort);
458         }
459         return opts;
460     }
461     if (strstart(filename, "unix:", &p)) {
462         qemu_opt_set(opts, "backend", "socket", &error_abort);
463         qemu_opts_do_parse(opts, p, "path", &local_err);
464         if (local_err) {
465             error_report_err(local_err);
466             goto fail;
467         }
468         return opts;
469     }
470     if (strstart(filename, "/dev/parport", NULL) ||
471         strstart(filename, "/dev/ppi", NULL)) {
472         qemu_opt_set(opts, "backend", "parallel", &error_abort);
473         qemu_opt_set(opts, "path", filename, &error_abort);
474         return opts;
475     }
476     if (strstart(filename, "/dev/", NULL)) {
477         qemu_opt_set(opts, "backend", "serial", &error_abort);
478         qemu_opt_set(opts, "path", filename, &error_abort);
479         return opts;
480     }
481 
482 fail:
483     qemu_opts_del(opts);
484     return NULL;
485 }
486 
487 void qemu_chr_parse_common(QemuOpts *opts, ChardevCommon *backend)
488 {
489     const char *logfile = qemu_opt_get(opts, "logfile");
490 
491     backend->has_logfile = logfile != NULL;
492     backend->logfile = g_strdup(logfile);
493 
494     backend->has_logappend = true;
495     backend->logappend = qemu_opt_get_bool(opts, "logappend", false);
496 }
497 
498 static const ChardevClass *char_get_class(const char *driver, Error **errp)
499 {
500     ObjectClass *oc;
501     const ChardevClass *cc;
502     char *typename = g_strdup_printf("chardev-%s", driver);
503 
504     oc = object_class_by_name(typename);
505     g_free(typename);
506 
507     if (!object_class_dynamic_cast(oc, TYPE_CHARDEV)) {
508         error_setg(errp, "'%s' is not a valid char driver name", driver);
509         return NULL;
510     }
511 
512     if (object_class_is_abstract(oc)) {
513         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
514                    "abstract device type");
515         return NULL;
516     }
517 
518     cc = CHARDEV_CLASS(oc);
519     if (cc->internal) {
520         error_setg(errp, "'%s' is not a valid char driver name", driver);
521         return NULL;
522     }
523 
524     return cc;
525 }
526 
527 static const struct ChardevAlias {
528     const char *typename;
529     const char *alias;
530 } chardev_alias_table[] = {
531 #ifdef HAVE_CHARDEV_PARPORT
532     { "parallel", "parport" },
533 #endif
534 #ifdef HAVE_CHARDEV_SERIAL
535     { "serial", "tty" },
536 #endif
537 };
538 
539 typedef struct ChadevClassFE {
540     void (*fn)(const char *name, void *opaque);
541     void *opaque;
542 } ChadevClassFE;
543 
544 static void
545 chardev_class_foreach(ObjectClass *klass, void *opaque)
546 {
547     ChadevClassFE *fe = opaque;
548 
549     assert(g_str_has_prefix(object_class_get_name(klass), "chardev-"));
550     if (CHARDEV_CLASS(klass)->internal) {
551         return;
552     }
553 
554     fe->fn(object_class_get_name(klass) + 8, fe->opaque);
555 }
556 
557 static void
558 chardev_name_foreach(void (*fn)(const char *name, void *opaque), void *opaque)
559 {
560     ChadevClassFE fe = { .fn = fn, .opaque = opaque };
561     int i;
562 
563     object_class_foreach(chardev_class_foreach, TYPE_CHARDEV, false, &fe);
564 
565     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
566         fn(chardev_alias_table[i].alias, opaque);
567     }
568 }
569 
570 static void
571 help_string_append(const char *name, void *opaque)
572 {
573     GString *str = opaque;
574 
575     g_string_append_printf(str, "\n%s", name);
576 }
577 
578 static const char *chardev_alias_translate(const char *name)
579 {
580     int i;
581     for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
582         if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
583             return chardev_alias_table[i].typename;
584         }
585     }
586     return name;
587 }
588 
589 ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
590 {
591     Error *local_err = NULL;
592     const ChardevClass *cc;
593     ChardevBackend *backend = NULL;
594     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
595 
596     if (name == NULL) {
597         error_setg(errp, "chardev: \"%s\" missing backend",
598                    qemu_opts_id(opts));
599         return NULL;
600     }
601 
602     cc = char_get_class(name, errp);
603     if (cc == NULL) {
604         return NULL;
605     }
606 
607     backend = g_new0(ChardevBackend, 1);
608     backend->type = CHARDEV_BACKEND_KIND_NULL;
609 
610     if (cc->parse) {
611         cc->parse(opts, backend, &local_err);
612         if (local_err) {
613             error_propagate(errp, local_err);
614             qapi_free_ChardevBackend(backend);
615             return NULL;
616         }
617     } else {
618         ChardevCommon *ccom = g_new0(ChardevCommon, 1);
619         qemu_chr_parse_common(opts, ccom);
620         backend->u.null.data = ccom; /* Any ChardevCommon member would work */
621     }
622 
623     return backend;
624 }
625 
626 Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
627 {
628     const ChardevClass *cc;
629     Chardev *chr = NULL;
630     ChardevBackend *backend = NULL;
631     const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
632     const char *id = qemu_opts_id(opts);
633     char *bid = NULL;
634 
635     if (name && is_help_option(name)) {
636         GString *str = g_string_new("");
637 
638         chardev_name_foreach(help_string_append, str);
639 
640         error_report("Available chardev backend types: %s", str->str);
641         g_string_free(str, true);
642         return NULL;
643     }
644 
645     if (id == NULL) {
646         error_setg(errp, "chardev: no id specified");
647         return NULL;
648     }
649 
650     backend = qemu_chr_parse_opts(opts, errp);
651     if (backend == NULL) {
652         return NULL;
653     }
654 
655     cc = char_get_class(name, errp);
656     if (cc == NULL) {
657         goto out;
658     }
659 
660     if (qemu_opt_get_bool(opts, "mux", 0)) {
661         bid = g_strdup_printf("%s-base", id);
662     }
663 
664     chr = qemu_chardev_new(bid ? bid : id,
665                            object_class_get_name(OBJECT_CLASS(cc)),
666                            backend, errp);
667 
668     if (chr == NULL) {
669         goto out;
670     }
671 
672     if (bid) {
673         Chardev *mux;
674         qapi_free_ChardevBackend(backend);
675         backend = g_new0(ChardevBackend, 1);
676         backend->type = CHARDEV_BACKEND_KIND_MUX;
677         backend->u.mux.data = g_new0(ChardevMux, 1);
678         backend->u.mux.data->chardev = g_strdup(bid);
679         mux = qemu_chardev_new(id, TYPE_CHARDEV_MUX, backend, errp);
680         if (mux == NULL) {
681             object_unparent(OBJECT(chr));
682             chr = NULL;
683             goto out;
684         }
685         chr = mux;
686     }
687 
688 out:
689     qapi_free_ChardevBackend(backend);
690     g_free(bid);
691     return chr;
692 }
693 
694 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename)
695 {
696     const char *p;
697     Chardev *chr;
698     QemuOpts *opts;
699     Error *err = NULL;
700 
701     if (strstart(filename, "chardev:", &p)) {
702         return qemu_chr_find(p);
703     }
704 
705     opts = qemu_chr_parse_compat(label, filename);
706     if (!opts)
707         return NULL;
708 
709     chr = qemu_chr_new_from_opts(opts, &err);
710     if (err) {
711         error_report_err(err);
712     }
713     if (chr && qemu_opt_get_bool(opts, "mux", 0)) {
714         monitor_init(chr, MONITOR_USE_READLINE);
715     }
716     qemu_opts_del(opts);
717     return chr;
718 }
719 
720 Chardev *qemu_chr_new(const char *label, const char *filename)
721 {
722     Chardev *chr;
723     chr = qemu_chr_new_noreplay(label, filename);
724     if (chr) {
725         if (replay_mode != REPLAY_MODE_NONE) {
726             qemu_chr_set_feature(chr, QEMU_CHAR_FEATURE_REPLAY);
727         }
728         if (qemu_chr_replay(chr) && CHARDEV_GET_CLASS(chr)->chr_ioctl) {
729             error_report("Replay: ioctl is not supported "
730                          "for serial devices yet");
731         }
732         replay_register_char_driver(chr);
733     }
734     return chr;
735 }
736 
737 static int qmp_query_chardev_foreach(Object *obj, void *data)
738 {
739     Chardev *chr = CHARDEV(obj);
740     ChardevInfoList **list = data;
741     ChardevInfoList *info = g_malloc0(sizeof(*info));
742 
743     info->value = g_malloc0(sizeof(*info->value));
744     info->value->label = g_strdup(chr->label);
745     info->value->filename = g_strdup(chr->filename);
746     info->value->frontend_open = chr->be && chr->be->fe_open;
747 
748     info->next = *list;
749     *list = info;
750 
751     return 0;
752 }
753 
754 ChardevInfoList *qmp_query_chardev(Error **errp)
755 {
756     ChardevInfoList *chr_list = NULL;
757 
758     object_child_foreach(get_chardevs_root(),
759                          qmp_query_chardev_foreach, &chr_list);
760 
761     return chr_list;
762 }
763 
764 static void
765 qmp_prepend_backend(const char *name, void *opaque)
766 {
767     ChardevBackendInfoList **list = opaque;
768     ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
769 
770     info->value = g_malloc0(sizeof(*info->value));
771     info->value->name = g_strdup(name);
772     info->next = *list;
773     *list = info;
774 }
775 
776 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)
777 {
778     ChardevBackendInfoList *backend_list = NULL;
779 
780     chardev_name_foreach(qmp_prepend_backend, &backend_list);
781 
782     return backend_list;
783 }
784 
785 Chardev *qemu_chr_find(const char *name)
786 {
787     Object *obj = object_resolve_path_component(get_chardevs_root(), name);
788 
789     return obj ? CHARDEV(obj) : NULL;
790 }
791 
792 QemuOptsList qemu_chardev_opts = {
793     .name = "chardev",
794     .implied_opt_name = "backend",
795     .head = QTAILQ_HEAD_INITIALIZER(qemu_chardev_opts.head),
796     .desc = {
797         {
798             .name = "backend",
799             .type = QEMU_OPT_STRING,
800         },{
801             .name = "path",
802             .type = QEMU_OPT_STRING,
803         },{
804             .name = "host",
805             .type = QEMU_OPT_STRING,
806         },{
807             .name = "port",
808             .type = QEMU_OPT_STRING,
809         },{
810             .name = "localaddr",
811             .type = QEMU_OPT_STRING,
812         },{
813             .name = "localport",
814             .type = QEMU_OPT_STRING,
815         },{
816             .name = "to",
817             .type = QEMU_OPT_NUMBER,
818         },{
819             .name = "ipv4",
820             .type = QEMU_OPT_BOOL,
821         },{
822             .name = "ipv6",
823             .type = QEMU_OPT_BOOL,
824         },{
825             .name = "wait",
826             .type = QEMU_OPT_BOOL,
827         },{
828             .name = "server",
829             .type = QEMU_OPT_BOOL,
830         },{
831             .name = "delay",
832             .type = QEMU_OPT_BOOL,
833         },{
834             .name = "reconnect",
835             .type = QEMU_OPT_NUMBER,
836         },{
837             .name = "telnet",
838             .type = QEMU_OPT_BOOL,
839         },{
840             .name = "tn3270",
841             .type = QEMU_OPT_BOOL,
842         },{
843             .name = "tls-creds",
844             .type = QEMU_OPT_STRING,
845         },{
846             .name = "width",
847             .type = QEMU_OPT_NUMBER,
848         },{
849             .name = "height",
850             .type = QEMU_OPT_NUMBER,
851         },{
852             .name = "cols",
853             .type = QEMU_OPT_NUMBER,
854         },{
855             .name = "rows",
856             .type = QEMU_OPT_NUMBER,
857         },{
858             .name = "mux",
859             .type = QEMU_OPT_BOOL,
860         },{
861             .name = "signal",
862             .type = QEMU_OPT_BOOL,
863         },{
864             .name = "name",
865             .type = QEMU_OPT_STRING,
866         },{
867             .name = "debug",
868             .type = QEMU_OPT_NUMBER,
869         },{
870             .name = "size",
871             .type = QEMU_OPT_SIZE,
872         },{
873             .name = "chardev",
874             .type = QEMU_OPT_STRING,
875         },{
876             .name = "append",
877             .type = QEMU_OPT_BOOL,
878         },{
879             .name = "logfile",
880             .type = QEMU_OPT_STRING,
881         },{
882             .name = "logappend",
883             .type = QEMU_OPT_BOOL,
884         },
885         { /* end of list */ }
886     },
887 };
888 
889 bool qemu_chr_has_feature(Chardev *chr,
890                           ChardevFeature feature)
891 {
892     return test_bit(feature, chr->features);
893 }
894 
895 void qemu_chr_set_feature(Chardev *chr,
896                            ChardevFeature feature)
897 {
898     return set_bit(feature, chr->features);
899 }
900 
901 Chardev *qemu_chardev_new(const char *id, const char *typename,
902                           ChardevBackend *backend,
903                           Error **errp)
904 {
905     Object *obj;
906     Chardev *chr = NULL;
907     Error *local_err = NULL;
908     bool be_opened = true;
909 
910     assert(g_str_has_prefix(typename, "chardev-"));
911 
912     obj = object_new(typename);
913     chr = CHARDEV(obj);
914     chr->label = g_strdup(id);
915 
916     qemu_char_open(chr, backend, &be_opened, &local_err);
917     if (local_err) {
918         goto end;
919     }
920 
921     if (!chr->filename) {
922         chr->filename = g_strdup(typename + 8);
923     }
924     if (be_opened) {
925         qemu_chr_be_event(chr, CHR_EVENT_OPENED);
926     }
927 
928     if (id) {
929         object_property_add_child(get_chardevs_root(), id, obj, &local_err);
930         if (local_err) {
931             goto end;
932         }
933         object_unref(obj);
934     }
935 
936 end:
937     if (local_err) {
938         error_propagate(errp, local_err);
939         object_unref(obj);
940         return NULL;
941     }
942 
943     return chr;
944 }
945 
946 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
947                                Error **errp)
948 {
949     const ChardevClass *cc;
950     ChardevReturn *ret;
951     Chardev *chr;
952 
953     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
954     if (!cc) {
955         return NULL;
956     }
957 
958     chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
959                            backend, errp);
960     if (!chr) {
961         return NULL;
962     }
963 
964     ret = g_new0(ChardevReturn, 1);
965     if (CHARDEV_IS_PTY(chr)) {
966         ret->pty = g_strdup(chr->filename + 4);
967         ret->has_pty = true;
968     }
969 
970     return ret;
971 }
972 
973 ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
974                                   Error **errp)
975 {
976     CharBackend *be;
977     const ChardevClass *cc;
978     Chardev *chr, *chr_new;
979     bool closed_sent = false;
980     ChardevReturn *ret;
981 
982     chr = qemu_chr_find(id);
983     if (!chr) {
984         error_setg(errp, "Chardev '%s' does not exist", id);
985         return NULL;
986     }
987 
988     if (CHARDEV_IS_MUX(chr)) {
989         error_setg(errp, "Mux device hotswap not supported yet");
990         return NULL;
991     }
992 
993     if (qemu_chr_replay(chr)) {
994         error_setg(errp,
995             "Chardev '%s' cannot be changed in record/replay mode", id);
996         return NULL;
997     }
998 
999     be = chr->be;
1000     if (!be) {
1001         /* easy case */
1002         object_unparent(OBJECT(chr));
1003         return qmp_chardev_add(id, backend, errp);
1004     }
1005 
1006     if (!be->chr_be_change) {
1007         error_setg(errp, "Chardev user does not support chardev hotswap");
1008         return NULL;
1009     }
1010 
1011     cc = char_get_class(ChardevBackendKind_str(backend->type), errp);
1012     if (!cc) {
1013         return NULL;
1014     }
1015 
1016     chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
1017                                backend, errp);
1018     if (!chr_new) {
1019         return NULL;
1020     }
1021     chr_new->label = g_strdup(id);
1022 
1023     if (chr->be_open && !chr_new->be_open) {
1024         qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
1025         closed_sent = true;
1026     }
1027 
1028     chr->be = NULL;
1029     qemu_chr_fe_init(be, chr_new, &error_abort);
1030 
1031     if (be->chr_be_change(be->opaque) < 0) {
1032         error_setg(errp, "Chardev '%s' change failed", chr_new->label);
1033         chr_new->be = NULL;
1034         qemu_chr_fe_init(be, chr, &error_abort);
1035         if (closed_sent) {
1036             qemu_chr_be_event(chr, CHR_EVENT_OPENED);
1037         }
1038         object_unref(OBJECT(chr_new));
1039         return NULL;
1040     }
1041 
1042     object_unparent(OBJECT(chr));
1043     object_property_add_child(get_chardevs_root(), chr_new->label,
1044                               OBJECT(chr_new), &error_abort);
1045     object_unref(OBJECT(chr_new));
1046 
1047     ret = g_new0(ChardevReturn, 1);
1048     if (CHARDEV_IS_PTY(chr_new)) {
1049         ret->pty = g_strdup(chr_new->filename + 4);
1050         ret->has_pty = true;
1051     }
1052 
1053     return ret;
1054 }
1055 
1056 void qmp_chardev_remove(const char *id, Error **errp)
1057 {
1058     Chardev *chr;
1059 
1060     chr = qemu_chr_find(id);
1061     if (chr == NULL) {
1062         error_setg(errp, "Chardev '%s' not found", id);
1063         return;
1064     }
1065     if (qemu_chr_is_busy(chr)) {
1066         error_setg(errp, "Chardev '%s' is busy", id);
1067         return;
1068     }
1069     if (qemu_chr_replay(chr)) {
1070         error_setg(errp,
1071             "Chardev '%s' cannot be unplugged in record/replay mode", id);
1072         return;
1073     }
1074     object_unparent(OBJECT(chr));
1075 }
1076 
1077 void qmp_chardev_send_break(const char *id, Error **errp)
1078 {
1079     Chardev *chr;
1080 
1081     chr = qemu_chr_find(id);
1082     if (chr == NULL) {
1083         error_setg(errp, "Chardev '%s' not found", id);
1084         return;
1085     }
1086     qemu_chr_be_event(chr, CHR_EVENT_BREAK);
1087 }
1088 
1089 /*
1090  * Add a timeout callback for the chardev (in milliseconds), return
1091  * the GSource object created. Please use this to add timeout hook for
1092  * chardev instead of g_timeout_add() and g_timeout_add_seconds(), to
1093  * make sure the gcontext that the task bound to is correct.
1094  */
1095 GSource *qemu_chr_timeout_add_ms(Chardev *chr, guint ms,
1096                                  GSourceFunc func, void *private)
1097 {
1098     GSource *source = g_timeout_source_new(ms);
1099 
1100     assert(func);
1101     g_source_set_callback(source, func, private, NULL);
1102     g_source_attach(source, chr->gcontext);
1103 
1104     return source;
1105 }
1106 
1107 void qemu_chr_cleanup(void)
1108 {
1109     object_unparent(get_chardevs_root());
1110 }
1111 
1112 static void register_types(void)
1113 {
1114     type_register_static(&char_type_info);
1115 
1116     /* this must be done after machine init, since we register FEs with muxes
1117      * as part of realize functions like serial_isa_realizefn when -nographic
1118      * is specified
1119      */
1120     qemu_add_machine_init_done_notifier(&muxes_realize_notify);
1121 }
1122 
1123 type_init(register_types);
1124