git.ozlabs.org Git - petitboot/blob - discover/grub2/builtins.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 #include <log/log.h>
   6 #include <types/types.h>
   7 #include <talloc/talloc.h>
   8 #include <util/util.h>
   9
  10 #include "discover/parser.h"
  11 #include "grub2.h"
  12
  13
  14 static int builtin_set(struct grub2_script *script,
  15                 void *data __attribute__((unused)),
  16                 int argc, char *argv[])
  17 {
  18         char *name, *value, *p;
  19         int i;
  20
  21         if (argc < 2)
  22                 return -1;
  23
  24         p = strchr(argv[1], '=');
  25         if (!p)
  26                 return -1;
  27
  28         name = talloc_strndup(script, argv[1], p - argv[1]);
  29         value = talloc_strdup(script, p+1);
  30
  31         for (i = 2; i < argc; i++)
  32                 value = talloc_asprintf_append(value, " %s", argv[i]);
  33
  34         script_env_set(script, name, value);
  35
  36         return 0;
  37 }
  38
  39 static int builtin_linux(struct grub2_script *script,
  40                 void *data __attribute__((unused)),
  41                 int argc, char *argv[])
  42 {
  43         struct discover_boot_option *opt = script->opt;
  44         const char *root;
  45         int i;
  46
  47         if (!opt) {
  48                 pb_log("grub2 syntax error: 'linux' statement outside "
  49                                 "a menuentry.\n");
  50                 return -1;
  51         }
  52
  53         if (argc < 2) {
  54                 pb_log("grub2 syntax error: no filename provided to "
  55                                 "linux statement\n");
  56                 return -1;
  57         }
  58
  59         root = script_env_get(script, "root");
  60
  61         opt->boot_image = create_grub2_resource(opt, script->ctx->device,
  62                                                 root, argv[1]);
  63         opt->option->boot_args = NULL;
  64
  65         if (argc > 2)
  66                 opt->option->boot_args = talloc_strdup(opt, argv[2]);
  67
  68         for (i = 3; i < argc; i++)
  69                 opt->option->boot_args = talloc_asprintf_append(
  70                                                 opt->option->boot_args,
  71                                                 " %s", argv[i]);
  72         return 0;
  73 }
  74
  75 static int builtin_initrd(struct grub2_script *script,
  76                 void *data __attribute__((unused)),
  77                 int argc, char *argv[])
  78 {
  79         struct discover_boot_option *opt = script->opt;
  80         const char *root;
  81
  82         if (!opt) {
  83                 pb_log("grub2 syntax error: 'initrd' statement outside "
  84                                 "a menuentry.\n");
  85                 return -1;
  86         }
  87
  88         if (argc < 2) {
  89                 pb_log("grub2 syntax error: no filename provided to "
  90                                 "initrd statement\n");
  91                 return -1;
  92         }
  93
  94         root = script_env_get(script, "root");
  95         opt->initrd = create_grub2_resource(opt, script->ctx->device,
  96                                                 root, argv[1]);
  97
  98         return 0;
  99 }
 100
 101 static int builtin_search(struct grub2_script *script,
 102                 void *data __attribute__((unused)),
 103                 int argc, char *argv[])
 104 {
 105         const char *env_var, *spec;
 106         int i;
 107
 108         env_var = NULL;
 109
 110         for (i = 1; i < argc - 1; i++) {
 111                 if (!strncmp(argv[i], "--set=", strlen("--set="))) {
 112                         env_var = argv[i] + strlen("--set=");
 113                         break;
 114                 }
 115         }
 116
 117         if (!env_var)
 118                 return 0;
 119
 120         spec = argv[argc - 1];
 121
 122         script_env_set(script, env_var, spec);
 123
 124         return 0;
 125 }
 126
 127 static bool builtin_test_op_file(struct grub2_script *script, char op,
 128                 const char *file)
 129 {
 130         bool result;
 131         int len, rc;
 132         char *buf;
 133
 134         rc = parser_request_file(script->ctx, script->ctx->device,
 135                         file, &buf, &len);
 136         if (rc)
 137                 return false;
 138
 139         switch (op) {
 140         case 's':
 141                 /* -s: return true if file exists and has non-zero size */
 142                 result = len > 0;
 143                 break;
 144         case 'f':
 145                 /* -f: return true if file exists */
 146                 result = true;
 147                 break;
 148         default:
 149                 result = false;
 150
 151         }
 152
 153         talloc_free(buf);
 154         return result;
 155 }
 156
 157 static bool builtin_test_op_dir(struct grub2_script *script, char op,
 158                 const char *dir)
 159 {
 160         if (op != 'd')
 161                 return false;
 162
 163         return parser_check_dir(script->ctx, script->ctx->device, dir) == 0;
 164 }
 165
 166 static bool builtin_test_op(struct grub2_script *script,
 167                 int argc, char **argv, int *consumed)
 168 {
 169         char *op;
 170
 171         if (argc >= 3) {
 172                 const char *a1, *a2;
 173
 174                 a1 = argv[0];
 175                 op = argv[1];
 176                 a2 = argv[2];
 177
 178                 if (!strcmp(op, "=") || !strcmp(op, "==")) {
 179                         *consumed = 3;
 180                         return !strcmp(a1, a2);
 181                 }
 182
 183                 if (!strcmp(op, "!=")) {
 184                         *consumed = 3;
 185                         return strcmp(a1, a2);
 186                 }
 187
 188                 if (!strcmp(op, "<")) {
 189                         *consumed = 3;
 190                         return strcmp(a1, a2) < 0;
 191                 }
 192
 193                 if (!strcmp(op, ">")) {
 194                         *consumed = 3;
 195                         return strcmp(a1, a2) > 0;
 196                 }
 197         }
 198
 199         if (argc >= 2) {
 200                 const char *a1;
 201
 202                 op = argv[0];
 203                 a1 = argv[1];
 204
 205                 if (!strcmp(op, "-z")) {
 206                         *consumed = 2;
 207                         return strlen(a1) == 0;
 208                 }
 209
 210                 if (!strcmp(op, "-n")) {
 211                         *consumed = 2;
 212                         return strlen(a1) != 0;
 213                 }
 214
 215                 if (!strcmp(op, "-s") || !strcmp(op, "-f")) {
 216                         *consumed = 2;
 217                         return builtin_test_op_file(script, op[1], a1);
 218                 }
 219
 220                 if (!strcmp(op, "-d")) {
 221                         *consumed = 2;
 222                         return builtin_test_op_dir(script, op[1], a1);
 223                 }
 224         }
 225
 226         op = argv[0];
 227         *consumed = 1;
 228         return strlen(op) > 0;
 229 }
 230
 231 static int builtin_test(struct grub2_script *script,
 232                 void *data __attribute__((unused)),
 233                 int argc, char *argv[])
 234 {
 235         int consumed;
 236         bool not, rc;
 237
 238         if (!strcmp(argv[0], "[") && !strcmp(argv[argc - 1], "]"))
 239                 argc--;
 240
 241         /* skip command name */
 242         argc--;
 243         argv++;
 244
 245         not = false;
 246         rc = false;
 247
 248         for (consumed = 0; argc > 0; argv += consumed, argc -= consumed) {
 249
 250                 if (!strcmp(argv[0], "!")) {
 251                         not = true;
 252                         consumed = 1;
 253                         continue;
 254                 }
 255
 256                 if (!strcmp(argv[0], "-a")) {
 257                         if (!rc)
 258                                 return 1;
 259                         consumed = 1;
 260                         continue;
 261                 }
 262
 263                 if (!strcmp(argv[0], "-o")) {
 264                         if (rc)
 265                                 return 0;
 266                         consumed = 1;
 267                         continue;
 268                 }
 269
 270                 rc = builtin_test_op(script, argc, argv, &consumed);
 271                 if (not) {
 272                         rc = !rc;
 273                         not = false;
 274                 }
 275         }
 276
 277         return rc ? 0 : 1;
 278 }
 279
 280 static int builtin_true(struct grub2_script *script __attribute__((unused)),
 281                 void *data __attribute__((unused)),
 282                 int argc __attribute__((unused)),
 283                 char *argv[] __attribute__((unused)))
 284 {
 285         return 0;
 286 }
 287
 288 static int builtin_false(struct grub2_script *script __attribute__((unused)),
 289                 void *data __attribute__((unused)),
 290                 int argc __attribute__((unused)),
 291                 char *argv[] __attribute__((unused)))
 292 {
 293         return 1;
 294 }
 295
 296 static int builtin_nop(struct grub2_script *script __attribute__((unused)),
 297                 void *data __attribute__((unused)),
 298                 int argc __attribute__((unused)),
 299                 char *argv[] __attribute__((unused)))
 300 {
 301         return 0;
 302 }
 303
 304 extern int builtin_load_env(struct grub2_script *script,
 305                 void *data __attribute__((unused)),
 306                 int argc, char *argv[]);
 307 int builtin_save_env(struct grub2_script *script,
 308                 void *data __attribute__((unused)),
 309                 int argc, char *argv[]);
 310
 311
 312 static struct {
 313         const char *name;
 314         grub2_function fn;
 315 } builtins[] = {
 316         {
 317                 .name = "set",
 318                 .fn = builtin_set,
 319         },
 320         {
 321                 .name = "linux",
 322                 .fn = builtin_linux,
 323         },
 324         {
 325                 .name = "linux16",
 326                 .fn = builtin_linux,
 327         },
 328         {
 329                 .name = "initrd",
 330                 .fn = builtin_initrd,
 331         },
 332         {
 333                 .name = "search",
 334                 .fn = builtin_search,
 335         },
 336         {
 337                 .name = "[",
 338                 .fn = builtin_test,
 339         },
 340         {
 341                 .name = "test",
 342                 .fn = builtin_test,
 343         },
 344         {
 345                 .name = "true",
 346                 .fn = builtin_true,
 347         },
 348         {
 349                 .name = "false",
 350                 .fn = builtin_false,
 351         },
 352         {
 353                 .name = "load_env",
 354                 .fn = builtin_load_env,
 355         },
 356         {
 357                 .name = "save_env",
 358                 .fn = builtin_save_env,
 359         },
 360 };
 361
 362 static const char *nops[] = {
 363         "echo", "export", "insmod", "loadfont", "terminfo",
 364 };
 365
 366 void register_builtins(struct grub2_script *script)
 367 {
 368         unsigned int i;
 369
 370         for (i = 0; i < ARRAY_SIZE(builtins); i++)
 371                 script_register_function(script, builtins[i].name,
 372                                 builtins[i].fn, NULL);
 373
 374         for (i = 0; i < ARRAY_SIZE(nops); i++)
 375                 script_register_function(script, nops[i], builtin_nop, NULL);
 376 }