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