discover: Implement device priorities
[petitboot] / discover / device-handler.c
1
2 #include <assert.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 #include <string.h>
6 #include <errno.h>
7 #include <sys/stat.h>
8 #include <sys/wait.h>
9
10 #include <pb-config/pb-config.h>
11 #include <talloc/talloc.h>
12 #include <list/list.h>
13 #include <log/log.h>
14 #include <types/types.h>
15 #include <system/system.h>
16 #include <process/process.h>
17 #include <url/url.h>
18
19 #include "device-handler.h"
20 #include "discover-server.h"
21 #include "event.h"
22 #include "parser.h"
23 #include "resource.h"
24 #include "paths.h"
25 #include "boot.h"
26
27 struct device_handler {
28         struct discover_server  *server;
29         int                     dry_run;
30
31         struct discover_device  **devices;
32         unsigned int            n_devices;
33
34         struct waitset          *waitset;
35         struct waiter           *timeout_waiter;
36         bool                    autoboot_enabled;
37         unsigned int            sec_to_boot;
38
39         struct discover_boot_option *default_boot_option;
40         struct list             unresolved_boot_options;
41 };
42
43 static int mount_device(struct discover_device *dev);
44 static int umount_device(struct discover_device *dev);
45
46 void discover_context_add_boot_option(struct discover_context *ctx,
47                 struct discover_boot_option *boot_option)
48 {
49         boot_option->source = ctx->parser;
50         list_add_tail(&ctx->boot_options, &boot_option->list);
51         talloc_steal(ctx, boot_option);
52 }
53
54 /**
55  * device_handler_get_device_count - Get the count of current handler devices.
56  */
57
58 int device_handler_get_device_count(const struct device_handler *handler)
59 {
60         return handler->n_devices;
61 }
62
63 /**
64  * device_handler_get_device - Get a handler device by index.
65  */
66
67 const struct discover_device *device_handler_get_device(
68         const struct device_handler *handler, unsigned int index)
69 {
70         if (index >= handler->n_devices) {
71                 assert(0 && "bad index");
72                 return NULL;
73         }
74
75         return handler->devices[index];
76 }
77
78 struct discover_boot_option *discover_boot_option_create(
79                 struct discover_context *ctx,
80                 struct discover_device *device)
81 {
82         struct discover_boot_option *opt;
83
84         opt = talloc_zero(ctx, struct discover_boot_option);
85         opt->option = talloc_zero(opt, struct boot_option);
86         opt->device = device;
87
88         return opt;
89 }
90
91 static int device_match_uuid(struct discover_device *dev, const char *uuid)
92 {
93         return dev->uuid && !strcmp(dev->uuid, uuid);
94 }
95
96 static int device_match_label(struct discover_device *dev, const char *label)
97 {
98         return dev->label && !strcmp(dev->label, label);
99 }
100
101 static int device_match_id(struct discover_device *dev, const char *id)
102 {
103         return !strcmp(dev->device->id, id);
104 }
105
106 static struct discover_device *device_lookup(
107                 struct device_handler *device_handler,
108                 int (match_fn)(struct discover_device *, const char *),
109                 const char *str)
110 {
111         struct discover_device *dev;
112         unsigned int i;
113
114         if (!str)
115                 return NULL;
116
117         for (i = 0; i < device_handler->n_devices; i++) {
118                 dev = device_handler->devices[i];
119
120                 if (match_fn(dev, str))
121                         return dev;
122         }
123
124         return NULL;
125 }
126
127 struct discover_device *device_lookup_by_name(struct device_handler *handler,
128                 const char *name)
129 {
130         if (!strncmp(name, "/dev/", strlen("/dev/")))
131                 name += strlen("/dev/");
132
133         return device_lookup_by_id(handler, name);
134 }
135
136 struct discover_device *device_lookup_by_uuid(
137                 struct device_handler *device_handler,
138                 const char *uuid)
139 {
140         return device_lookup(device_handler, device_match_uuid, uuid);
141 }
142
143 struct discover_device *device_lookup_by_label(
144                 struct device_handler *device_handler,
145                 const char *label)
146 {
147         return device_lookup(device_handler, device_match_label, label);
148 }
149
150 struct discover_device *device_lookup_by_id(
151                 struct device_handler *device_handler,
152                 const char *id)
153 {
154         return device_lookup(device_handler, device_match_id, id);
155 }
156
157 void device_handler_destroy(struct device_handler *handler)
158 {
159         talloc_free(handler);
160 }
161
162 static int destroy_device(void *arg)
163 {
164         struct discover_device *dev = arg;
165
166         umount_device(dev);
167
168         return 0;
169 }
170
171 struct discover_device *discover_device_create(struct device_handler *handler,
172                 const char *id)
173 {
174         struct discover_device *dev;
175
176         dev = device_lookup_by_id(handler, id);
177         if (dev)
178                 return dev;
179
180         dev = talloc_zero(handler, struct discover_device);
181         dev->device = talloc_zero(dev, struct device);
182         dev->device->id = talloc_strdup(dev->device, id);
183         list_init(&dev->params);
184         list_init(&dev->boot_options);
185
186         talloc_set_destructor(dev, destroy_device);
187
188         return dev;
189 }
190
191 struct discover_device_param {
192         char                    *name;
193         char                    *value;
194         struct list_item        list;
195 };
196
197 void discover_device_set_param(struct discover_device *device,
198                 const char *name, const char *value)
199 {
200         struct discover_device_param *param;
201         bool found = false;
202
203         list_for_each_entry(&device->params, param, list) {
204                 if (!strcmp(param->name, name)) {
205                         found = true;
206                         break;
207                 }
208         }
209
210         if (!found) {
211                 if (!value)
212                         return;
213                 param = talloc(device, struct discover_device_param);
214                 param->name = talloc_strdup(param, name);
215                 list_add(&device->params, &param->list);
216         } else {
217                 if (!value) {
218                         list_remove(&param->list);
219                         talloc_free(param);
220                         return;
221                 }
222                 talloc_free(param->value);
223         }
224
225         param->value = talloc_strdup(param, value);
226 }
227
228 const char *discover_device_get_param(struct discover_device *device,
229                 const char *name)
230 {
231         struct discover_device_param *param;
232
233         list_for_each_entry(&device->params, param, list) {
234                 if (!strcmp(param->name, name))
235                         return param->name;
236         }
237         return NULL;
238 }
239
240 struct device_handler *device_handler_init(struct discover_server *server,
241                 struct waitset *waitset, int dry_run)
242 {
243         struct device_handler *handler;
244
245         handler = talloc_zero(NULL, struct device_handler);
246         handler->server = server;
247         handler->waitset = waitset;
248         handler->dry_run = dry_run;
249         handler->autoboot_enabled = config_get()->autoboot_enabled;
250
251         list_init(&handler->unresolved_boot_options);
252
253         /* set up our mount point base */
254         pb_mkdir_recursive(mount_base());
255
256         parser_init();
257
258         return handler;
259 }
260
261 void device_handler_remove(struct device_handler *handler,
262                 struct discover_device *device)
263 {
264         unsigned int i;
265
266         for (i = 0; i < handler->n_devices; i++)
267                 if (handler->devices[i] == device)
268                         break;
269
270         if (i == handler->n_devices) {
271                 talloc_free(device);
272                 return;
273         }
274
275         handler->n_devices--;
276         memmove(&handler->devices[i], &handler->devices[i + 1],
277                 (handler->n_devices - i) * sizeof(handler->devices[0]));
278         handler->devices = talloc_realloc(handler, handler->devices,
279                 struct discover_device *, handler->n_devices);
280
281         if (device->notified)
282                 discover_server_notify_device_remove(handler->server,
283                                                         device->device);
284
285         talloc_free(device);
286 }
287
288 static void boot_status(void *arg, struct boot_status *status)
289 {
290         struct device_handler *handler = arg;
291
292         discover_server_notify_boot_status(handler->server, status);
293 }
294
295 static void countdown_status(struct device_handler *handler,
296                 struct discover_boot_option *opt, unsigned int sec)
297 {
298         struct boot_status status;
299
300         status.type = BOOT_STATUS_INFO;
301         status.progress = -1;
302         status.detail = NULL;
303         status.message = talloc_asprintf(handler,
304                         "Booting %s in %u sec", opt->option->name, sec);
305
306         discover_server_notify_boot_status(handler->server, &status);
307
308         talloc_free(status.message);
309 }
310
311 static int default_timeout(void *arg)
312 {
313         struct device_handler *handler = arg;
314         struct discover_boot_option *opt;
315
316         if (!handler->default_boot_option)
317                 return 0;
318
319         opt = handler->default_boot_option;
320
321         if (handler->sec_to_boot) {
322                 countdown_status(handler, opt, handler->sec_to_boot);
323                 handler->sec_to_boot--;
324                 handler->timeout_waiter = waiter_register_timeout(
325                                                 handler->waitset, 1000,
326                                                 default_timeout, handler);
327                 return 0;
328         }
329
330         pb_log("Timeout expired, booting default option %s\n", opt->option->id);
331
332         boot(handler, handler->default_boot_option, NULL,
333                         handler->dry_run, boot_status, handler);
334         return 0;
335 }
336
337 static bool priority_match(struct boot_priority *prio,
338                 struct discover_boot_option *opt)
339 {
340         return prio->type == opt->device->device->type;
341 }
342
343 static int default_option_priority(struct discover_boot_option *opt)
344 {
345         const struct config *config;
346         struct boot_priority *prio;
347         int i;
348
349         config = config_get();
350
351         for (i = 0; i < config->n_boot_priorities; i++) {
352                 prio = &config->boot_priorities[i];
353                 if (priority_match(prio, opt))
354                         break;
355         }
356
357         return i;
358 }
359
360 static void set_default(struct device_handler *handler,
361                 struct discover_boot_option *opt)
362 {
363         if (!handler->autoboot_enabled)
364                 return;
365
366         /* Resolve any conflicts: if we have a new default option, it only
367          * replaces the current if it has a higher priority. */
368         if (handler->default_boot_option) {
369                 int new_prio, cur_prio;
370
371                 new_prio = default_option_priority(opt);
372                 cur_prio = default_option_priority(
373                                         handler->default_boot_option);
374
375                 if (new_prio >= cur_prio)
376                         return;
377         }
378
379         handler->sec_to_boot = config_get()->autoboot_timeout_sec;
380         handler->default_boot_option = opt;
381
382         pb_log("Boot option %s set as default, timeout %u sec.\n",
383                opt->option->id, handler->sec_to_boot);
384
385         default_timeout(handler);
386 }
387
388 static bool resource_is_resolved(struct resource *res)
389 {
390         return !res || res->resolved;
391 }
392
393 /* We only use this in an assert, which will disappear if we're compiling
394  * with NDEBUG, so we need the 'used' attribute for these builds */
395 static bool __attribute__((used)) boot_option_is_resolved(
396                 struct discover_boot_option *opt)
397 {
398         return resource_is_resolved(opt->boot_image) &&
399                 resource_is_resolved(opt->initrd) &&
400                 resource_is_resolved(opt->dtb) &&
401                 resource_is_resolved(opt->icon);
402 }
403
404 static bool resource_resolve(struct resource *res, const char *name,
405                 struct discover_boot_option *opt,
406                 struct device_handler *handler)
407 {
408         struct parser *parser = opt->source;
409
410         if (resource_is_resolved(res))
411                 return true;
412
413         pb_log("Attempting to resolve resource %s->%s with parser %s\n",
414                         opt->option->id, name, parser->name);
415         parser->resolve_resource(handler, res);
416
417         return res->resolved;
418 }
419
420 static bool boot_option_resolve(struct discover_boot_option *opt,
421                 struct device_handler *handler)
422 {
423         return resource_resolve(opt->boot_image, "boot_image", opt, handler) &&
424                 resource_resolve(opt->initrd, "initrd", opt, handler) &&
425                 resource_resolve(opt->dtb, "dtb", opt, handler) &&
426                 resource_resolve(opt->icon, "icon", opt, handler);
427 }
428
429 static void boot_option_finalise(struct device_handler *handler,
430                 struct discover_boot_option *opt)
431 {
432         assert(boot_option_is_resolved(opt));
433
434         /* check that the parsers haven't set any of the final data */
435         assert(!opt->option->boot_image_file);
436         assert(!opt->option->initrd_file);
437         assert(!opt->option->dtb_file);
438         assert(!opt->option->icon_file);
439         assert(!opt->option->device_id);
440
441         if (opt->boot_image)
442                 opt->option->boot_image_file = opt->boot_image->url->full;
443         if (opt->initrd)
444                 opt->option->initrd_file = opt->initrd->url->full;
445         if (opt->dtb)
446                 opt->option->dtb_file = opt->dtb->url->full;
447         if (opt->icon)
448                 opt->option->icon_file = opt->icon->url->full;
449
450         opt->option->device_id = opt->device->device->id;
451
452         if (opt->option->is_default)
453                 set_default(handler, opt);
454 }
455
456 static void notify_boot_option(struct device_handler *handler,
457                 struct discover_boot_option *opt)
458 {
459         struct discover_device *dev = opt->device;
460
461         if (!dev->notified)
462                 discover_server_notify_device_add(handler->server,
463                                                   opt->device->device);
464         dev->notified = true;
465         discover_server_notify_boot_option_add(handler->server, opt->option);
466 }
467
468 static void process_boot_option_queue(struct device_handler *handler)
469 {
470         struct discover_boot_option *opt, *tmp;
471
472         list_for_each_entry_safe(&handler->unresolved_boot_options,
473                         opt, tmp, list) {
474
475                 pb_log("queue: attempting resolution for %s\n",
476                                 opt->option->id);
477
478                 if (!boot_option_resolve(opt, handler))
479                         continue;
480
481                 pb_log("\tresolved!\n");
482
483                 list_remove(&opt->list);
484                 list_add_tail(&opt->device->boot_options, &opt->list);
485                 talloc_steal(opt->device, opt);
486                 boot_option_finalise(handler, opt);
487                 notify_boot_option(handler, opt);
488         }
489 }
490
491 struct discover_context *device_handler_discover_context_create(
492                 struct device_handler *handler,
493                 struct discover_device *device)
494 {
495         struct discover_context *ctx;
496
497         ctx = talloc(handler, struct discover_context);
498         ctx->device = device;
499         ctx->conf_url = NULL;
500         list_init(&ctx->boot_options);
501
502         return ctx;
503 }
504
505 /**
506  * context_commit - Commit a temporary discovery context to the handler,
507  * and notify the clients about any new options / devices
508  */
509 void device_handler_discover_context_commit(struct device_handler *handler,
510                 struct discover_context *ctx)
511 {
512         struct discover_device *dev = ctx->device;
513         struct discover_boot_option *opt, *tmp;
514
515         if (!device_lookup_by_id(handler, dev->device->id))
516                 device_handler_add_device(handler, dev);
517
518         /* move boot options from the context to the device */
519         list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
520                 list_remove(&opt->list);
521
522                 if (boot_option_resolve(opt, handler)) {
523                         pb_log("boot option %s is resolved, "
524                                         "sending to clients\n",
525                                         opt->option->id);
526                         list_add_tail(&dev->boot_options, &opt->list);
527                         talloc_steal(dev, opt);
528                         boot_option_finalise(handler, opt);
529                         notify_boot_option(handler, opt);
530                 } else {
531                         if (!opt->source->resolve_resource) {
532                                 pb_log("parser %s gave us an unresolved "
533                                         "resource (%s), but no way to "
534                                         "resolve it\n",
535                                         opt->source->name, opt->option->id);
536                                 talloc_free(opt);
537                         } else {
538                                 pb_log("boot option %s is unresolved, "
539                                                 "adding to queue\n",
540                                                 opt->option->id);
541                                 list_add(&handler->unresolved_boot_options,
542                                                 &opt->list);
543                                 talloc_steal(handler, opt);
544                         }
545                 }
546         }
547 }
548
549 void device_handler_add_device(struct device_handler *handler,
550                 struct discover_device *device)
551 {
552         handler->n_devices++;
553         handler->devices = talloc_realloc(handler, handler->devices,
554                                 struct discover_device *, handler->n_devices);
555         handler->devices[handler->n_devices - 1] = device;
556
557 }
558
559 /* Start discovery on a hotplugged device. The device will be in our devices
560  * array, but has only just been initialised by the hotplug source.
561  */
562 int device_handler_discover(struct device_handler *handler,
563                 struct discover_device *dev, enum conf_method method)
564 {
565         struct discover_context *ctx;
566
567         process_boot_option_queue(handler);
568
569         /* create our context */
570         ctx = device_handler_discover_context_create(handler, dev);
571
572         mount_device(dev);
573
574         /* run the parsers. This will populate the ctx's boot_option list. */
575         iterate_parsers(ctx, method);
576
577         /* add discovered stuff to the handler */
578         device_handler_discover_context_commit(handler, ctx);
579
580         talloc_free(ctx);
581
582         return 0;
583 }
584
585 /* incoming conf event */
586 int device_handler_conf(struct device_handler *handler,
587                 struct discover_device *dev, struct pb_url *url,
588                 enum conf_method method)
589 {
590         struct discover_context *ctx;
591
592         /* create our context */
593         ctx = device_handler_discover_context_create(handler, dev);
594         ctx->conf_url = url;
595
596         iterate_parsers(ctx, method);
597
598         device_handler_discover_context_commit(handler, ctx);
599
600         talloc_free(ctx);
601
602         return 0;
603 }
604
605 static struct discover_boot_option *find_boot_option_by_id(
606                 struct device_handler *handler, const char *id)
607 {
608         unsigned int i;
609
610         for (i = 0; i < handler->n_devices; i++) {
611                 struct discover_device *dev = handler->devices[i];
612                 struct discover_boot_option *opt;
613
614                 list_for_each_entry(&dev->boot_options, opt, list)
615                         if (!strcmp(opt->option->id, id))
616                                 return opt;
617         }
618
619         return NULL;
620 }
621
622 void device_handler_boot(struct device_handler *handler,
623                 struct boot_command *cmd)
624 {
625         struct discover_boot_option *opt;
626
627         opt = find_boot_option_by_id(handler, cmd->option_id);
628
629         boot(handler, opt, cmd, handler->dry_run, boot_status, handler);
630 }
631
632 void device_handler_cancel_default(struct device_handler *handler)
633 {
634         struct boot_status status;
635
636         if (handler->timeout_waiter)
637                 waiter_remove(handler->timeout_waiter);
638
639         handler->timeout_waiter = NULL;
640         handler->autoboot_enabled = false;
641
642         /* we only send status if we had a default boot option queued */
643         if (!handler->default_boot_option)
644                 return;
645
646         pb_log("Cancelling default boot option\n");
647
648         handler->default_boot_option = NULL;
649
650         status.type = BOOT_STATUS_INFO;
651         status.progress = -1;
652         status.detail = NULL;
653         status.message = "Default boot cancelled";
654
655         discover_server_notify_boot_status(handler->server, &status);
656 }
657
658 #ifndef PETITBOOT_TEST
659 static int mount_device(struct discover_device *dev)
660 {
661         int rc;
662
663         if (!dev->device_path)
664                 return -1;
665
666         if (!dev->mount_path)
667                 dev->mount_path = join_paths(dev, mount_base(),
668                                                 dev->device_path);
669
670         if (pb_mkdir_recursive(dev->mount_path))
671                 pb_log("couldn't create mount directory %s: %s\n",
672                                 dev->mount_path, strerror(errno));
673
674         rc = process_run_simple(dev, pb_system_apps.mount,
675                         dev->device_path, dev->mount_path,
676                         "-o", "ro", NULL);
677
678         if (!rc)
679                 return 0;
680
681         /* Retry mount without ro option. */
682         rc = process_run_simple(dev, pb_system_apps.mount,
683                         dev->device_path, dev->mount_path, NULL);
684
685         if (!rc)
686                 return 0;
687
688         pb_rmdir_recursive(mount_base(), dev->mount_path);
689         return -1;
690 }
691
692 static int umount_device(struct discover_device *dev)
693 {
694         int status;
695
696         if (!dev->mount_path)
697                 return 0;
698
699         status = process_run_simple(dev, pb_system_apps.umount,
700                         dev->mount_path, NULL);
701
702         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
703                 return -1;
704
705         pb_rmdir_recursive(mount_base(), dev->mount_path);
706
707         return 0;
708 }
709 #else
710
711 static int umount_device(struct discover_device *dev __attribute__((unused)))
712 {
713         return 0;
714 }
715
716 static int __attribute__((unused)) mount_device(
717                 struct discover_device *dev __attribute__((unused)))
718 {
719         return 0;
720 }
721
722 #endif
723