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