git.ozlabs.org Git - petitboot/blob - discover/boot.c

   1
   2 #define _GNU_SOURCE
   3
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <assert.h>
   7 #include <dirent.h>
   8 #include <string.h>
   9 #include <fcntl.h>
  10 #include <sys/types.h>
  11
  12 #include <log/log.h>
  13 #include <pb-protocol/pb-protocol.h>
  14 #include <process/process.h>
  15 #include <system/system.h>
  16 #include <talloc/talloc.h>
  17 #include <url/url.h>
  18 #include <util/util.h>
  19
  20 #include "device-handler.h"
  21 #include "boot.h"
  22 #include "paths.h"
  23 #include "resource.h"
  24
  25 static const char *boot_hook_dir = PKG_SYSCONF_DIR "/boot.d";
  26 enum {
  27         BOOT_HOOK_EXIT_OK       = 0,
  28         BOOT_HOOK_EXIT_UPDATE   = 2,
  29 };
  30
  31 struct boot_task {
  32         struct load_url_result *image;
  33         struct load_url_result *initrd;
  34         struct load_url_result *dtb;
  35         const char *local_image;
  36         const char *local_initrd;
  37         const char *local_dtb;
  38         const char *args;
  39         boot_status_fn status_fn;
  40         void *status_arg;
  41         bool dry_run;
  42         bool cancelled;
  43 };
  44
  45 /**
  46  * kexec_load - kexec load helper.
  47  */
  48 static int kexec_load(struct boot_task *boot_task)
  49 {
  50         int result;
  51         const char *argv[7];
  52         const char **p;
  53         char *s_initrd = NULL;
  54         char *s_dtb = NULL;
  55         char *s_args = NULL;
  56
  57         p = argv;
  58         *p++ = pb_system_apps.kexec;    /* 1 */
  59         *p++ = "-l";                    /* 2 */
  60
  61         if (boot_task->local_initrd) {
  62                 s_initrd = talloc_asprintf(boot_task, "--initrd=%s",
  63                                 boot_task->local_initrd);
  64                 assert(s_initrd);
  65                 *p++ = s_initrd;         /* 3 */
  66         }
  67
  68         if (boot_task->local_dtb) {
  69                 s_dtb = talloc_asprintf(boot_task, "--dtb=%s",
  70                                                 boot_task->local_dtb);
  71                 assert(s_dtb);
  72                 *p++ = s_dtb;            /* 4 */
  73         }
  74
  75         if (boot_task->args) {
  76                 s_args = talloc_asprintf(boot_task, "--append=%s",
  77                                                 boot_task->args);
  78                 assert(s_args);
  79                 *p++ = s_args;          /* 5 */
  80         }
  81
  82         *p++ = boot_task->local_image;  /* 6 */
  83         *p++ = NULL;                    /* 7 */
  84
  85         result = process_run_simple_argv(boot_task, argv);
  86
  87         if (result)
  88                 pb_log("%s: failed: (%d)\n", __func__, result);
  89
  90         return result;
  91 }
  92
  93 /**
  94  * kexec_reboot - Helper to boot the new kernel.
  95  *
  96  * Must only be called after a successful call to kexec_load().
  97  */
  98
  99 static int kexec_reboot(struct boot_task *task)
 100 {
 101         int result;
 102
 103         /* First try running shutdown.  Init scripts should run 'exec -e' */
 104         result = process_run_simple(task, pb_system_apps.shutdown, "-r",
 105                         "now", NULL);
 106
 107         /* On error, force a kexec with the -e option */
 108         if (result) {
 109                 result = process_run_simple(task, pb_system_apps.kexec,
 110                                                 "-e", NULL);
 111         }
 112
 113         if (result)
 114                 pb_log("%s: failed: (%d)\n", __func__, result);
 115
 116         /* okay, kexec -e -f */
 117         if (result) {
 118                 result = process_run_simple(task, pb_system_apps.kexec,
 119                                                 "-e", "-f", NULL);
 120         }
 121
 122         if (result)
 123                 pb_log("%s: failed: (%d)\n", __func__, result);
 124
 125
 126         return result;
 127 }
 128
 129 static void __attribute__((format(__printf__, 4, 5))) update_status(
 130                 boot_status_fn fn, void *arg, int type, char *fmt, ...)
 131 {
 132         struct boot_status status;
 133         va_list ap;
 134
 135         va_start(ap, fmt);
 136         status.message = talloc_vasprintf(NULL, fmt, ap);
 137         va_end(ap);
 138
 139         status.type = type;
 140         status.progress = -1;
 141         status.detail = NULL;
 142
 143         pb_debug("boot status: [%d] %s\n", type, status.message);
 144
 145         fn(arg, &status);
 146
 147         talloc_free(status.message);
 148 }
 149
 150 static void boot_hook_update_param(void *ctx, struct boot_task *task,
 151                 const char *name, const char *value)
 152 {
 153         struct p {
 154                 const char *name;
 155                 const char **p;
 156         } *param, params[] = {
 157                 { "boot_image",         &task->local_image },
 158                 { "boot_initrd",        &task->local_initrd },
 159                 { "boot_dtb",           &task->local_dtb },
 160                 { "boot_args",          &task->args },
 161                 { NULL, NULL },
 162         };
 163
 164         for (param = params; param->name; param++) {
 165                 if (strcmp(param->name, name))
 166                         continue;
 167
 168                 *param->p = talloc_strdup(ctx, value);
 169                 return;
 170         }
 171 }
 172
 173 static void boot_hook_update(struct boot_task *task, const char *hookname,
 174                 char *buf)
 175 {
 176         char *line, *name, *val, *sep;
 177         char *saveptr;
 178
 179         for (;; buf = NULL) {
 180
 181                 line = strtok_r(buf, "\n", &saveptr);
 182                 if (!line)
 183                         break;
 184
 185                 sep = strchr(line, '=');
 186                 if (!sep)
 187                         continue;
 188
 189                 *sep = '\0';
 190                 name = line;
 191                 val = sep + 1;
 192
 193                 boot_hook_update_param(task, task, name, val);
 194
 195                 pb_log("boot hook %s specified %s=%s\n",
 196                                 hookname, name, val);
 197         }
 198 }
 199
 200 static void boot_hook_setenv(struct boot_task *task)
 201 {
 202         unsetenv("boot_image");
 203         unsetenv("boot_initrd");
 204         unsetenv("boot_dtb");
 205         unsetenv("boot_args");
 206
 207         setenv("boot_image", task->local_image, 1);
 208         if (task->local_initrd)
 209                 setenv("boot_initrd", task->local_initrd, 1);
 210         if (task->local_dtb)
 211                 setenv("boot_dtb", task->local_dtb, 1);
 212         if (task->args)
 213                 setenv("boot_args", task->args, 1);
 214 }
 215
 216 static int hook_filter(const struct dirent *dirent)
 217 {
 218         return dirent->d_type == DT_REG || dirent->d_type == DT_LNK;
 219 }
 220
 221 static int hook_cmp(const struct dirent **a, const struct dirent **b)
 222 {
 223         return strcmp((*a)->d_name, (*b)->d_name);
 224 }
 225
 226 static void run_boot_hooks(struct boot_task *task)
 227 {
 228         struct dirent **hooks;
 229         int i, n;
 230
 231         n = scandir(boot_hook_dir, &hooks, hook_filter, hook_cmp);
 232         if (n < 1)
 233                 return;
 234
 235         update_status(task->status_fn, task->status_arg, BOOT_STATUS_INFO,
 236                         "running boot hooks");
 237
 238         boot_hook_setenv(task);
 239
 240         for (i = 0; i < n; i++) {
 241                 const char *argv[2] = { NULL, NULL };
 242                 struct process *process;
 243                 char *path;
 244                 int rc;
 245
 246                 path = join_paths(task, boot_hook_dir, hooks[i]->d_name);
 247
 248                 if (access(path, X_OK)) {
 249                         talloc_free(path);
 250                         continue;
 251                 }
 252
 253                 process = process_create(task);
 254
 255                 argv[0] = path;
 256                 process->path = path;
 257                 process->argv = argv;
 258                 process->keep_stdout = true;
 259
 260                 pb_log("running boot hook %s\n", hooks[i]->d_name);
 261
 262                 rc = process_run_sync(process);
 263                 if (rc) {
 264                         pb_log("boot hook exec failed!\n");
 265
 266                 } else if (WIFEXITED(process->exit_status) &&
 267                            WEXITSTATUS(process->exit_status)
 268                                 == BOOT_HOOK_EXIT_UPDATE) {
 269                         /* if the hook returned with BOOT_HOOK_EXIT_UPDATE,
 270                          * then we process stdout to look for updated params
 271                          */
 272                         boot_hook_update(task, hooks[i]->d_name,
 273                                         process->stdout_buf);
 274                         boot_hook_setenv(task);
 275                 }
 276
 277                 process_release(process);
 278                 talloc_free(path);
 279         }
 280
 281         free(hooks);
 282 }
 283
 284 static bool load_pending(struct load_url_result *result)
 285 {
 286         return result && result->status == LOAD_ASYNC;
 287 }
 288
 289 static int check_load(struct boot_task *task, const char *name,
 290                 struct load_url_result *result)
 291 {
 292         if (!result)
 293                 return 0;
 294         if (result->status != LOAD_ERROR)
 295                 return 0;
 296
 297         update_status(task->status_fn, task->status_arg,
 298                         BOOT_STATUS_ERROR,
 299                         "Couldn't load %s", name);
 300         return -1;
 301 }
 302
 303 static void cleanup_load(struct load_url_result *result)
 304 {
 305         if (!result)
 306                 return;
 307         if (result->status != LOAD_OK)
 308                 return;
 309         if (!result->cleanup_local)
 310                 return;
 311         unlink(result->local);
 312 }
 313
 314 static void cleanup_cancellations(struct boot_task *task,
 315                 struct load_url_result *cur_result)
 316 {
 317         struct load_url_result *result, **results[] = {
 318                 &task->image, &task->initrd, &task->dtb,
 319         };
 320         bool pending = false;
 321         unsigned int i;
 322
 323         for (i = 0; i < ARRAY_SIZE(results); i++) {
 324                 result = *results[i];
 325
 326                 if (!result)
 327                         continue;
 328
 329                 /* We need to cleanup and free any completed loads */
 330                 if (result == cur_result || result->status == LOAD_OK
 331                                 || result->status == LOAD_ERROR) {
 332                         cleanup_load(result);
 333                         talloc_free(result);
 334                         *results[i] = NULL;
 335
 336                 /* ... and cancel any pending loads, which we'll free in
 337                  * the completion callback */
 338                 } else if (result->status == LOAD_ASYNC) {
 339                         load_url_async_cancel(result);
 340                         pending = true;
 341                 }
 342         }
 343
 344         if (!pending)
 345                 talloc_free(task);
 346 }
 347
 348 static void boot_process(struct load_url_result *result, void *data)
 349 {
 350         struct boot_task *task = data;
 351         int rc = -1;
 352
 353         if (task->cancelled) {
 354                 cleanup_cancellations(task, result);
 355                 return;
 356         }
 357
 358         if (load_pending(task->image) ||
 359                         load_pending(task->initrd) ||
 360                         load_pending(task->dtb))
 361                 return;
 362
 363         if (check_load(task, "kernel image", task->image) ||
 364                         check_load(task, "initrd", task->initrd) ||
 365                         check_load(task, "dtb", task->dtb))
 366                 goto no_load;
 367
 368         /* we make a copy of the local paths, as the boot hooks might update
 369          * and/or create these */
 370         task->local_image = task->image ? task->image->local : NULL;
 371         task->local_initrd = task->initrd ? task->initrd->local : NULL;
 372         task->local_dtb = task->dtb ? task->dtb->local : NULL;
 373
 374         run_boot_hooks(task);
 375
 376         update_status(task->status_fn, task->status_arg, BOOT_STATUS_INFO,
 377                         "performing kexec_load");
 378
 379         rc = kexec_load(task);
 380         if (rc) {
 381                 update_status(task->status_fn, task->status_arg,
 382                                 BOOT_STATUS_ERROR, "kexec load failed");
 383         }
 384
 385 no_load:
 386         cleanup_load(task->image);
 387         cleanup_load(task->initrd);
 388         cleanup_load(task->dtb);
 389
 390         if (!rc) {
 391                 update_status(task->status_fn, task->status_arg,
 392                                 BOOT_STATUS_INFO,
 393                                 "performing kexec reboot");
 394
 395                 rc = kexec_reboot(task);
 396                 if (rc) {
 397                         update_status(task->status_fn, task->status_arg,
 398                                         BOOT_STATUS_ERROR,
 399                                         "kexec reboot failed");
 400                 }
 401         }
 402 }
 403
 404 static int start_url_load(struct boot_task *task, const char *name,
 405                 struct pb_url *url, struct load_url_result **result)
 406 {
 407         if (!url)
 408                 return 0;
 409
 410         *result = load_url_async(task, url, boot_process, task);
 411         if (!*result) {
 412                 update_status(task->status_fn, task->status_arg,
 413                                 BOOT_STATUS_ERROR,
 414                                 "Error loading %s", name);
 415                 return -1;
 416         }
 417         return 0;
 418 }
 419
 420 struct boot_task *boot(void *ctx, struct discover_boot_option *opt,
 421                 struct boot_command *cmd, int dry_run,
 422                 boot_status_fn status_fn, void *status_arg)
 423 {
 424         struct pb_url *image = NULL, *initrd = NULL, *dtb = NULL;
 425         struct boot_task *boot_task;
 426         const char *boot_desc;
 427         int rc;
 428
 429         if (opt && opt->option->name)
 430                 boot_desc = opt->option->name;
 431         else if (cmd && cmd->boot_image_file)
 432                 boot_desc = cmd->boot_image_file;
 433         else
 434                 boot_desc = "(unknown)";
 435
 436         update_status(status_fn, status_arg, BOOT_STATUS_INFO,
 437                         "Booting %s.", boot_desc);
 438
 439         if (cmd && cmd->boot_image_file) {
 440                 image = pb_url_parse(opt, cmd->boot_image_file);
 441         } else if (opt && opt->boot_image) {
 442                 image = opt->boot_image->url;
 443         } else {
 444                 pb_log("%s: no image specified\n", __func__);
 445                 update_status(status_fn, status_arg, BOOT_STATUS_INFO,
 446                                 "Boot failed: no image specified");
 447                 return NULL;
 448         }
 449
 450         if (cmd && cmd->initrd_file) {
 451                 initrd = pb_url_parse(opt, cmd->initrd_file);
 452         } else if (opt && opt->initrd) {
 453                 initrd = opt->initrd->url;
 454         }
 455
 456         if (cmd && cmd->dtb_file) {
 457                 dtb = pb_url_parse(opt, cmd->dtb_file);
 458         } else if (opt && opt->dtb) {
 459                 dtb = opt->dtb->url;
 460         }
 461
 462         boot_task = talloc_zero(ctx, struct boot_task);
 463         boot_task->dry_run = dry_run;
 464         boot_task->status_fn = status_fn;
 465         boot_task->status_arg = status_arg;
 466
 467         if (cmd && cmd->boot_args) {
 468                 boot_task->args = talloc_strdup(boot_task, cmd->boot_args);
 469         } else if (opt && opt->option->boot_args) {
 470                 boot_task->args = talloc_strdup(boot_task,
 471                                                 opt->option->boot_args);
 472         } else {
 473                 boot_task->args = NULL;
 474         }
 475
 476         /* start async loads for boot resources */
 477         rc = start_url_load(boot_task, "kernel image", image, &boot_task->image)
 478           || start_url_load(boot_task, "initrd", initrd, &boot_task->initrd)
 479           || start_url_load(boot_task, "dtb", dtb, &boot_task->dtb);
 480
 481         /* If all URLs are local, we may be done. */
 482         if (rc) {
 483                 talloc_free(boot_task);
 484                 return NULL;
 485         }
 486
 487         boot_process(NULL, boot_task);
 488
 489         return boot_task;
 490 }
 491
 492 void boot_cancel(struct boot_task *task)
 493 {
 494         task->cancelled = true;
 495
 496         update_status(task->status_fn, task->status_arg, BOOT_STATUS_INFO,
 497                         "Boot cancelled");
 498
 499         cleanup_cancellations(task, NULL);
 500 }