cmd/nvedit_efi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  Integrate UEFI variables to u-boot env interface
   4  *
   5  *  Copyright (c) 2018 AKASHI Takahiro, Linaro Limited
   6  */
   7
   8 #include <charset.h>
   9 #include <common.h>
  10 #include <command.h>
  11 #include <efi_loader.h>
  12 #include <env.h>
  13 #include <exports.h>
  14 #include <hexdump.h>
  15 #include <malloc.h>
  16 #include <linux/kernel.h>
  17
  18 /*
  19  * From efi_variable.c,
  20  *
  21  * Mapping between UEFI variables and u-boot variables:
  22  *
  23  *   efi_$guid_$varname = {attributes}(type)value
  24  */
  25
  26 static const struct {
  27         u32 mask;
  28         char *text;
  29 } efi_var_attrs[] = {
  30         {EFI_VARIABLE_NON_VOLATILE, "NV"},
  31         {EFI_VARIABLE_BOOTSERVICE_ACCESS, "BS"},
  32         {EFI_VARIABLE_RUNTIME_ACCESS, "RT"},
  33         {EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS, "AW"},
  34         {EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS, "AT"},
  35 };
  36
  37 /**
  38  * efi_dump_single_var() - show information about a UEFI variable
  39  *
  40  * @name:       Name of the variable
  41  * @guid:       Vendor GUID
  42  *
  43  * Show information encoded in one UEFI variable
  44  */
  45 static void efi_dump_single_var(u16 *name, efi_guid_t *guid)
  46 {
  47         u32 attributes;
  48         u8 *data;
  49         efi_uintn_t size;
  50         int count, i;
  51         efi_status_t ret;
  52
  53         data = NULL;
  54         size = 0;
  55         ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size, data));
  56         if (ret == EFI_BUFFER_TOO_SMALL) {
  57                 data = malloc(size);
  58                 if (!data)
  59                         goto out;
  60
  61                 ret = EFI_CALL(efi_get_variable(name, guid, &attributes, &size,
  62                                                 data));
  63         }
  64         if (ret == EFI_NOT_FOUND) {
  65                 printf("Error: \"%ls\" not defined\n", name);
  66                 goto out;
  67         }
  68         if (ret != EFI_SUCCESS)
  69                 goto out;
  70
  71         printf("%ls:", name);
  72         for (count = 0, i = 0; i < ARRAY_SIZE(efi_var_attrs); i++)
  73                 if (attributes & efi_var_attrs[i].mask) {
  74                         if (count)
  75                                 putc('|');
  76                         else
  77                                 putc(' ');
  78                         count++;
  79                         puts(efi_var_attrs[i].text);
  80                 }
  81         printf(", DataSize = 0x%zx\n", size);
  82         print_hex_dump("    ", DUMP_PREFIX_OFFSET, 16, 1, data, size, true);
  83
  84 out:
  85         free(data);
  86 }
  87
  88 /**
  89  * efi_dump_vars() - show information about named UEFI variables
  90  *
  91  * @argc:       Number of arguments (variables)
  92  * @argv:       Argument (variable name) array
  93  * Return:      CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
  94  *
  95  * Show information encoded in named UEFI variables
  96  */
  97 static int efi_dump_vars(int argc,  char * const argv[])
  98 {
  99         u16 *var_name16, *p;
 100         efi_uintn_t buf_size, size;
 101
 102         buf_size = 128;
 103         var_name16 = malloc(buf_size);
 104         if (!var_name16)
 105                 return CMD_RET_FAILURE;
 106
 107         for (; argc > 0; argc--, argv++) {
 108                 size = (utf8_utf16_strlen(argv[0]) + 1) * sizeof(u16);
 109                 if (buf_size < size) {
 110                         buf_size = size;
 111                         p = realloc(var_name16, buf_size);
 112                         if (!p) {
 113                                 free(var_name16);
 114                                 return CMD_RET_FAILURE;
 115                         }
 116                         var_name16 = p;
 117                 }
 118
 119                 p = var_name16;
 120                 utf8_utf16_strcpy(&p, argv[0]);
 121
 122                 efi_dump_single_var(var_name16,
 123                                     (efi_guid_t *)&efi_global_variable_guid);
 124         }
 125
 126         free(var_name16);
 127
 128         return CMD_RET_SUCCESS;
 129 }
 130
 131 /**
 132  * efi_dump_vars() - show information about all the UEFI variables
 133  *
 134  * Return:      CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
 135  *
 136  * Show information encoded in all the UEFI variables
 137  */
 138 static int efi_dump_var_all(void)
 139 {
 140         u16 *var_name16, *p;
 141         efi_uintn_t buf_size, size;
 142         efi_guid_t guid;
 143         efi_status_t ret;
 144
 145         buf_size = 128;
 146         var_name16 = malloc(buf_size);
 147         if (!var_name16)
 148                 return CMD_RET_FAILURE;
 149
 150         var_name16[0] = 0;
 151         for (;;) {
 152                 size = buf_size;
 153                 ret = EFI_CALL(efi_get_next_variable_name(&size, var_name16,
 154                                                           &guid));
 155                 if (ret == EFI_NOT_FOUND)
 156                         break;
 157                 if (ret == EFI_BUFFER_TOO_SMALL) {
 158                         buf_size = size;
 159                         p = realloc(var_name16, buf_size);
 160                         if (!p) {
 161                                 free(var_name16);
 162                                 return CMD_RET_FAILURE;
 163                         }
 164                         var_name16 = p;
 165                         ret = EFI_CALL(efi_get_next_variable_name(&size,
 166                                                                   var_name16,
 167                                                                   &guid));
 168                 }
 169                 if (ret != EFI_SUCCESS) {
 170                         free(var_name16);
 171                         return CMD_RET_FAILURE;
 172                 }
 173
 174                 efi_dump_single_var(var_name16, &guid);
 175         }
 176
 177         free(var_name16);
 178
 179         return CMD_RET_SUCCESS;
 180 }
 181
 182 /**
 183  * do_env_print_efi() - show information about UEFI variables
 184  *
 185  * @cmdtp:      Command table
 186  * @flag:       Command flag
 187  * @argc:       Number of arguments
 188  * @argv:       Argument array
 189  * Return:      CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
 190  *
 191  * This function is for "env print -e" or "printenv -e" command:
 192  *   => env print -e [var [...]]
 193  * If one or more variable names are specified, show information
 194  * named UEFI variables, otherwise show all the UEFI variables.
 195  */
 196 int do_env_print_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 197 {
 198         efi_status_t ret;
 199
 200         /* Initialize EFI drivers */
 201         ret = efi_init_obj_list();
 202         if (ret != EFI_SUCCESS) {
 203                 printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
 204                        ret & ~EFI_ERROR_MASK);
 205                 return CMD_RET_FAILURE;
 206         }
 207
 208         if (argc > 1)
 209                 /* show specified UEFI variables */
 210                 return efi_dump_vars(--argc, ++argv);
 211
 212         /* enumerate and show all UEFI variables */
 213         return efi_dump_var_all();
 214 }
 215
 216 /**
 217  * append_value() - encode UEFI variable's value
 218  * @bufp:       Buffer of encoded UEFI variable's value
 219  * @sizep:      Size of buffer
 220  * @data:       data to be encoded into the value
 221  * Return:      0 on success, -1 otherwise
 222  *
 223  * Interpret a given data string and append it to buffer.
 224  * Buffer will be realloc'ed if necessary.
 225  *
 226  * Currently supported formats are:
 227  *   =0x0123...:                Hexadecimal number
 228  *   =H0123...:                 Hexadecimal-byte array
 229  *   ="...", =S"..." or <string>:
 230  *                              String
 231  */
 232 static int append_value(char **bufp, size_t *sizep, char *data)
 233 {
 234         char *tmp_buf = NULL, *new_buf = NULL, *value;
 235         unsigned long len = 0;
 236
 237         if (!strncmp(data, "=0x", 2)) { /* hexadecimal number */
 238                 union {
 239                         u8 u8;
 240                         u16 u16;
 241                         u32 u32;
 242                         u64 u64;
 243                 } tmp_data;
 244                 unsigned long hex_value;
 245                 void *hex_ptr;
 246
 247                 data += 3;
 248                 len = strlen(data);
 249                 if ((len & 0x1)) /* not multiple of two */
 250                         return -1;
 251
 252                 len /= 2;
 253                 if (len > 8)
 254                         return -1;
 255                 else if (len > 4)
 256                         len = 8;
 257                 else if (len > 2)
 258                         len = 4;
 259
 260                 /* convert hex hexadecimal number */
 261                 if (strict_strtoul(data, 16, &hex_value) < 0)
 262                         return -1;
 263
 264                 tmp_buf = malloc(len);
 265                 if (!tmp_buf)
 266                         return -1;
 267
 268                 if (len == 1) {
 269                         tmp_data.u8 = hex_value;
 270                         hex_ptr = &tmp_data.u8;
 271                 } else if (len == 2) {
 272                         tmp_data.u16 = hex_value;
 273                         hex_ptr = &tmp_data.u16;
 274                 } else if (len == 4) {
 275                         tmp_data.u32 = hex_value;
 276                         hex_ptr = &tmp_data.u32;
 277                 } else {
 278                         tmp_data.u64 = hex_value;
 279                         hex_ptr = &tmp_data.u64;
 280                 }
 281                 memcpy(tmp_buf, hex_ptr, len);
 282                 value = tmp_buf;
 283
 284         } else if (!strncmp(data, "=H", 2)) { /* hexadecimal-byte array */
 285                 data += 2;
 286                 len = strlen(data);
 287                 if (len & 0x1) /* not multiple of two */
 288                         return -1;
 289
 290                 len /= 2;
 291                 tmp_buf = malloc(len);
 292                 if (!tmp_buf)
 293                         return -1;
 294
 295                 if (hex2bin((u8 *)tmp_buf, data, len) < 0) {
 296                         printf("Error: illegal hexadecimal string\n");
 297                         free(tmp_buf);
 298                         return -1;
 299                 }
 300
 301                 value = tmp_buf;
 302         } else { /* string */
 303                 if (!strncmp(data, "=\"", 2) || !strncmp(data, "=S\"", 3)) {
 304                         if (data[1] == '"')
 305                                 data += 2;
 306                         else
 307                                 data += 3;
 308                         value = data;
 309                         len = strlen(data) - 1;
 310                         if (data[len] != '"')
 311                                 return -1;
 312                 } else {
 313                         value = data;
 314                         len = strlen(data);
 315                 }
 316         }
 317
 318         new_buf = realloc(*bufp, *sizep + len);
 319         if (!new_buf)
 320                 goto out;
 321
 322         memcpy(new_buf + *sizep, value, len);
 323         *bufp = new_buf;
 324         *sizep += len;
 325
 326 out:
 327         free(tmp_buf);
 328
 329         return 0;
 330 }
 331
 332 /**
 333  * do_env_print_efi() - set UEFI variable
 334  *
 335  * @cmdtp:      Command table
 336  * @flag:       Command flag
 337  * @argc:       Number of arguments
 338  * @argv:       Argument array
 339  * Return:      CMD_RET_SUCCESS on success, or CMD_RET_RET_FAILURE
 340  *
 341  * This function is for "env set -e" or "setenv -e" command:
 342  *   => env set -e var [value ...]]
 343  * Encode values specified and set given UEFI variable.
 344  * If no value is specified, delete the variable.
 345  */
 346 int do_env_set_efi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 347 {
 348         char *var_name, *value = NULL;
 349         efi_uintn_t size = 0;
 350         u16 *var_name16 = NULL, *p;
 351         size_t len;
 352         efi_guid_t guid;
 353         u32 attributes;
 354         efi_status_t ret;
 355
 356         if (argc == 1)
 357                 return CMD_RET_USAGE;
 358
 359         /* Initialize EFI drivers */
 360         ret = efi_init_obj_list();
 361         if (ret != EFI_SUCCESS) {
 362                 printf("Error: Cannot initialize UEFI sub-system, r = %lu\n",
 363                        ret & ~EFI_ERROR_MASK);
 364                 return CMD_RET_FAILURE;
 365         }
 366
 367         attributes = EFI_VARIABLE_BOOTSERVICE_ACCESS |
 368                      EFI_VARIABLE_RUNTIME_ACCESS;
 369         if (!strcmp(argv[1], "-nv")) {
 370                 attributes |= EFI_VARIABLE_NON_VOLATILE;
 371                 argc--;
 372                 argv++;
 373                 if (argc == 1)
 374                         return CMD_RET_SUCCESS;
 375         }
 376
 377         var_name = argv[1];
 378         if (argc == 2) {
 379                 /* delete */
 380                 value = NULL;
 381                 size = 0;
 382         } else { /* set */
 383                 argc -= 2;
 384                 argv += 2;
 385
 386                 for ( ; argc > 0; argc--, argv++)
 387                         if (append_value(&value, &size, argv[0]) < 0) {
 388                                 printf("## Failed to process an argument, %s\n",
 389                                        argv[0]);
 390                                 ret = CMD_RET_FAILURE;
 391                                 goto out;
 392                         }
 393         }
 394
 395         len = utf8_utf16_strnlen(var_name, strlen(var_name));
 396         var_name16 = malloc((len + 1) * 2);
 397         if (!var_name16) {
 398                 printf("## Out of memory\n");
 399                 ret = CMD_RET_FAILURE;
 400                 goto out;
 401         }
 402         p = var_name16;
 403         utf8_utf16_strncpy(&p, var_name, len + 1);
 404
 405         guid = efi_global_variable_guid;
 406         ret = EFI_CALL(efi_set_variable(var_name16, &guid, attributes,
 407                                         size, value));
 408         if (ret == EFI_SUCCESS) {
 409                 ret = CMD_RET_SUCCESS;
 410         } else {
 411                 printf("## Failed to set EFI variable\n");
 412                 ret = CMD_RET_FAILURE;
 413         }
 414 out:
 415         free(value);
 416         free(var_name16);
 417
 418         return ret;
 419 }