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(struct grub2_script *script,
 158                 int argc, char **argv, int *consumed)
 159 {
 160         char *op;
 161
 162         if (argc >= 3) {
 163                 const char *a1, *a2;
 164
 165                 a1 = argv[0];
 166                 op = argv[1];
 167                 a2 = argv[2];
 168
 169                 if (!strcmp(op, "=") || !strcmp(op, "==")) {
 170                         *consumed = 3;
 171                         return !strcmp(a1, a2);
 172                 }
 173
 174                 if (!strcmp(op, "!=")) {
 175                         *consumed = 3;
 176                         return strcmp(a1, a2);
 177                 }
 178
 179                 if (!strcmp(op, "<")) {
 180                         *consumed = 3;
 181                         return strcmp(a1, a2) < 0;
 182                 }
 183
 184                 if (!strcmp(op, ">")) {
 185                         *consumed = 3;
 186                         return strcmp(a1, a2) > 0;
 187                 }
 188         }
 189
 190         if (argc >= 2) {
 191                 const char *a1;
 192
 193                 op = argv[0];
 194                 a1 = argv[1];
 195
 196                 if (!strcmp(op, "-z")) {
 197                         *consumed = 2;
 198                         return strlen(a1) == 0;
 199                 }
 200
 201                 if (!strcmp(op, "-n")) {
 202                         *consumed = 2;
 203                         return strlen(a1) != 0;
 204                 }
 205
 206                 if (!strcmp(op, "-s") || !strcmp(op, "-f")) {
 207                         *consumed = 2;
 208                         return builtin_test_op_file(script, op[1], a1);
 209                 }
 210         }
 211
 212         op = argv[0];
 213         *consumed = 1;
 214         return strlen(op) > 0;
 215 }
 216
 217 static int builtin_test(struct grub2_script *script,
 218                 void *data __attribute__((unused)),
 219                 int argc, char *argv[])
 220 {
 221         int consumed;
 222         bool not, rc;
 223
 224         if (!strcmp(argv[0], "[") && !strcmp(argv[argc - 1], "]"))
 225                 argc--;
 226
 227         /* skip command name */
 228         argc--;
 229         argv++;
 230
 231         not = false;
 232         rc = false;
 233
 234         for (consumed = 0; argc > 0; argv += consumed, argc -= consumed) {
 235
 236                 if (!strcmp(argv[0], "!")) {
 237                         not = true;
 238                         consumed = 1;
 239                         continue;
 240                 }
 241
 242                 if (!strcmp(argv[0], "-a")) {
 243                         if (!rc)
 244                                 return 1;
 245                         consumed = 1;
 246                         continue;
 247                 }
 248
 249                 if (!strcmp(argv[0], "-o")) {
 250                         if (rc)
 251                                 return 0;
 252                         consumed = 1;
 253                         continue;
 254                 }
 255
 256                 rc = builtin_test_op(script, argc, argv, &consumed);
 257                 if (not) {
 258                         rc = !rc;
 259                         not = false;
 260                 }
 261         }
 262
 263         return rc ? 0 : 1;
 264 }
 265
 266 static int builtin_true(struct grub2_script *script __attribute__((unused)),
 267                 void *data __attribute__((unused)),
 268                 int argc __attribute__((unused)),
 269                 char *argv[] __attribute__((unused)))
 270 {
 271         return 0;
 272 }
 273
 274 static int builtin_false(struct grub2_script *script __attribute__((unused)),
 275                 void *data __attribute__((unused)),
 276                 int argc __attribute__((unused)),
 277                 char *argv[] __attribute__((unused)))
 278 {
 279         return 1;
 280 }
 281
 282 static int builtin_nop(struct grub2_script *script __attribute__((unused)),
 283                 void *data __attribute__((unused)),
 284                 int argc __attribute__((unused)),
 285                 char *argv[] __attribute__((unused)))
 286 {
 287         return 0;
 288 }
 289
 290 extern int builtin_load_env(struct grub2_script *script,
 291                 void *data __attribute__((unused)),
 292                 int argc, char *argv[]);
 293 int builtin_save_env(struct grub2_script *script,
 294                 void *data __attribute__((unused)),
 295                 int argc, char *argv[]);
 296
 297
 298 static struct {
 299         const char *name;
 300         grub2_function fn;
 301 } builtins[] = {
 302         {
 303                 .name = "set",
 304                 .fn = builtin_set,
 305         },
 306         {
 307                 .name = "linux",
 308                 .fn = builtin_linux,
 309         },
 310         {
 311                 .name = "linux16",
 312                 .fn = builtin_linux,
 313         },
 314         {
 315                 .name = "initrd",
 316                 .fn = builtin_initrd,
 317         },
 318         {
 319                 .name = "search",
 320                 .fn = builtin_search,
 321         },
 322         {
 323                 .name = "[",
 324                 .fn = builtin_test,
 325         },
 326         {
 327                 .name = "test",
 328                 .fn = builtin_test,
 329         },
 330         {
 331                 .name = "true",
 332                 .fn = builtin_true,
 333         },
 334         {
 335                 .name = "false",
 336                 .fn = builtin_false,
 337         },
 338         {
 339                 .name = "load_env",
 340                 .fn = builtin_load_env,
 341         },
 342         {
 343                 .name = "save_env",
 344                 .fn = builtin_save_env,
 345         },
 346 };
 347
 348 static const char *nops[] = {
 349         "echo", "export", "insmod", "loadfont", "terminfo",
 350 };
 351
 352 void register_builtins(struct grub2_script *script)
 353 {
 354         unsigned int i;
 355
 356         for (i = 0; i < ARRAY_SIZE(builtins); i++)
 357                 script_register_function(script, builtins[i].name,
 358                                 builtins[i].fn, NULL);
 359
 360         for (i = 0; i < ARRAY_SIZE(nops); i++)
 361                 script_register_function(script, nops[i], builtin_nop, NULL);
 362 }