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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:51 +0000 |
commit | 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e (patch) | |
tree | 32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/commands/loadenv.c | |
parent | Initial commit. (diff) | |
download | grub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.tar.xz grub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.zip |
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | grub-core/commands/loadenv.c | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/grub-core/commands/loadenv.c b/grub-core/commands/loadenv.c new file mode 100644 index 0000000..3fd664a --- /dev/null +++ b/grub-core/commands/loadenv.c @@ -0,0 +1,470 @@ +/* loadenv.c - command to load/save environment variable. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2008,2009,2010 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/dl.h> +#include <grub/mm.h> +#include <grub/file.h> +#include <grub/disk.h> +#include <grub/misc.h> +#include <grub/env.h> +#include <grub/partition.h> +#include <grub/lib/envblk.h> +#include <grub/extcmd.h> +#include <grub/i18n.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +static const struct grub_arg_option options[] = + { + /* TRANSLATORS: This option is used to override default filename + for loading and storing environment. */ + {"file", 'f', 0, N_("Specify filename."), 0, ARG_TYPE_PATHNAME}, + {"skip-sig", 's', 0, + N_("Skip signature-checking of the environment file."), 0, ARG_TYPE_NONE}, + {0, 0, 0, 0, 0, 0} + }; + +/* Opens 'filename' with compression filters disabled. Optionally disables the + PUBKEY filter (that insists upon properly signed files) as well. PUBKEY + filter is restored before the function returns. */ +static grub_file_t +open_envblk_file (char *filename, + enum grub_file_type type) +{ + grub_file_t file; + char *buf = 0; + + if (! filename) + { + const char *prefix; + int len; + + prefix = grub_env_get ("prefix"); + if (! prefix) + { + grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("variable `%s' isn't set"), "prefix"); + return 0; + } + + len = grub_strlen (prefix); + buf = grub_malloc (len + 1 + sizeof (GRUB_ENVBLK_DEFCFG)); + if (! buf) + return 0; + filename = buf; + + grub_strcpy (filename, prefix); + filename[len] = '/'; + grub_strcpy (filename + len + 1, GRUB_ENVBLK_DEFCFG); + } + + file = grub_file_open (filename, type); + + grub_free (buf); + return file; +} + +static grub_envblk_t +read_envblk_file (grub_file_t file) +{ + grub_off_t offset = 0; + char *buf; + grub_size_t size = grub_file_size (file); + grub_envblk_t envblk; + + buf = grub_malloc (size); + if (! buf) + return 0; + + while (size > 0) + { + grub_ssize_t ret; + + ret = grub_file_read (file, buf + offset, size); + if (ret <= 0) + { + grub_free (buf); + return 0; + } + + size -= ret; + offset += ret; + } + + envblk = grub_envblk_open (buf, offset); + if (! envblk) + { + grub_free (buf); + grub_error (GRUB_ERR_BAD_FILE_TYPE, "invalid environment block"); + return 0; + } + + return envblk; +} + +struct grub_env_whitelist +{ + grub_size_t len; + char **list; +}; +typedef struct grub_env_whitelist grub_env_whitelist_t; + +static int +test_whitelist_membership (const char* name, + const grub_env_whitelist_t* whitelist) +{ + grub_size_t i; + + for (i = 0; i < whitelist->len; i++) + if (grub_strcmp (name, whitelist->list[i]) == 0) + return 1; /* found it */ + + return 0; /* not found */ +} + +/* Helper for grub_cmd_load_env. */ +static int +set_var (const char *name, const char *value, void *whitelist) +{ + if (! whitelist) + { + grub_env_set (name, value); + return 0; + } + + if (test_whitelist_membership (name, + (const grub_env_whitelist_t *) whitelist)) + grub_env_set (name, value); + + return 0; +} + +static grub_err_t +grub_cmd_load_env (grub_extcmd_context_t ctxt, int argc, char **args) +{ + struct grub_arg_list *state = ctxt->state; + grub_file_t file; + grub_envblk_t envblk; + grub_env_whitelist_t whitelist; + + whitelist.len = argc; + whitelist.list = args; + + /* state[0] is the -f flag; state[1] is the --skip-sig flag */ + file = open_envblk_file ((state[0].set) ? state[0].arg : 0, + GRUB_FILE_TYPE_LOADENV + | (state[1].set + ? GRUB_FILE_TYPE_SKIP_SIGNATURE : GRUB_FILE_TYPE_NONE)); + if (! file) + return grub_errno; + + envblk = read_envblk_file (file); + if (! envblk) + goto fail; + + /* argc > 0 indicates caller provided a whitelist of variables to read. */ + grub_envblk_iterate (envblk, argc > 0 ? &whitelist : 0, set_var); + grub_envblk_close (envblk); + + fail: + grub_file_close (file); + return grub_errno; +} + +/* Print all variables in current context. */ +static int +print_var (const char *name, const char *value, + void *hook_data __attribute__ ((unused))) +{ + grub_printf ("%s=%s\n", name, value); + return 0; +} + +static grub_err_t +grub_cmd_list_env (grub_extcmd_context_t ctxt, + int argc __attribute__ ((unused)), + char **args __attribute__ ((unused))) +{ + struct grub_arg_list *state = ctxt->state; + grub_file_t file; + grub_envblk_t envblk; + + file = open_envblk_file ((state[0].set) ? state[0].arg : 0, + GRUB_FILE_TYPE_LOADENV + | (state[1].set + ? GRUB_FILE_TYPE_SKIP_SIGNATURE : GRUB_FILE_TYPE_NONE)); + if (! file) + return grub_errno; + + envblk = read_envblk_file (file); + if (! envblk) + goto fail; + + grub_envblk_iterate (envblk, NULL, print_var); + grub_envblk_close (envblk); + + fail: + grub_file_close (file); + return grub_errno; +} + +/* Used to maintain a variable length of blocklists internally. */ +struct blocklist +{ + grub_disk_addr_t sector; + unsigned offset; + unsigned length; + struct blocklist *next; +}; + +static void +free_blocklists (struct blocklist *p) +{ + struct blocklist *q; + + for (; p; p = q) + { + q = p->next; + grub_free (p); + } +} + +static grub_err_t +check_blocklists (grub_envblk_t envblk, struct blocklist *blocklists, + grub_file_t file) +{ + grub_size_t total_length; + grub_size_t index; + grub_disk_t disk; + grub_disk_addr_t part_start; + struct blocklist *p; + char *buf; + + /* Sanity checks. */ + total_length = 0; + for (p = blocklists; p; p = p->next) + { + struct blocklist *q; + /* Check if any pair of blocks overlap. */ + for (q = p->next; q; q = q->next) + { + grub_disk_addr_t s1, s2; + grub_disk_addr_t e1, e2; + + s1 = p->sector; + e1 = s1 + ((p->length + GRUB_DISK_SECTOR_SIZE - 1) >> GRUB_DISK_SECTOR_BITS); + + s2 = q->sector; + e2 = s2 + ((q->length + GRUB_DISK_SECTOR_SIZE - 1) >> GRUB_DISK_SECTOR_BITS); + + if (s1 < e2 && s2 < e1) + { + /* This might be actually valid, but it is unbelievable that + any filesystem makes such a silly allocation. */ + return grub_error (GRUB_ERR_BAD_FS, "malformed file"); + } + } + + total_length += p->length; + } + + if (total_length != grub_file_size (file)) + { + /* Maybe sparse, unallocated sectors. No way in GRUB. */ + return grub_error (GRUB_ERR_BAD_FILE_TYPE, "sparse file not allowed"); + } + + /* One more sanity check. Re-read all sectors by blocklists, and compare + those with the data read via a file. */ + disk = file->device->disk; + + part_start = grub_partition_get_start (disk->partition); + + buf = grub_envblk_buffer (envblk); + char *blockbuf = NULL; + grub_size_t blockbuf_len = 0; + for (p = blocklists, index = 0; p; index += p->length, p = p->next) + { + if (p->length > blockbuf_len) + { + grub_free (blockbuf); + blockbuf_len = 2 * p->length; + blockbuf = grub_malloc (blockbuf_len); + if (!blockbuf) + return grub_errno; + } + + if (grub_disk_read (disk, p->sector - part_start, + p->offset, p->length, blockbuf)) + return grub_errno; + + if (grub_memcmp (buf + index, blockbuf, p->length) != 0) + return grub_error (GRUB_ERR_FILE_READ_ERROR, "invalid blocklist"); + } + + return GRUB_ERR_NONE; +} + +static int +write_blocklists (grub_envblk_t envblk, struct blocklist *blocklists, + grub_file_t file) +{ + char *buf; + grub_disk_t disk; + grub_disk_addr_t part_start; + struct blocklist *p; + grub_size_t index; + + buf = grub_envblk_buffer (envblk); + disk = file->device->disk; + part_start = grub_partition_get_start (disk->partition); + + index = 0; + for (p = blocklists; p; index += p->length, p = p->next) + { + if (grub_disk_write (disk, p->sector - part_start, + p->offset, p->length, buf + index)) + return 0; + } + + return 1; +} + +/* Context for grub_cmd_save_env. */ +struct grub_cmd_save_env_ctx +{ + struct blocklist *head, *tail; +}; + +/* Store blocklists in a linked list. */ +static void +save_env_read_hook (grub_disk_addr_t sector, unsigned offset, unsigned length, + void *data) +{ + struct grub_cmd_save_env_ctx *ctx = data; + struct blocklist *block; + + block = grub_malloc (sizeof (*block)); + if (! block) + return; + + block->sector = sector; + block->offset = offset; + block->length = length; + + /* Slightly complicated, because the list should be FIFO. */ + block->next = 0; + if (ctx->tail) + ctx->tail->next = block; + ctx->tail = block; + if (! ctx->head) + ctx->head = block; +} + +static grub_err_t +grub_cmd_save_env (grub_extcmd_context_t ctxt, int argc, char **args) +{ + struct grub_arg_list *state = ctxt->state; + grub_file_t file; + grub_envblk_t envblk; + struct grub_cmd_save_env_ctx ctx = { + .head = 0, + .tail = 0 + }; + + if (! argc) + return grub_error (GRUB_ERR_BAD_ARGUMENT, "no variable is specified"); + + file = open_envblk_file ((state[0].set) ? state[0].arg : 0, + GRUB_FILE_TYPE_SAVEENV + | GRUB_FILE_TYPE_SKIP_SIGNATURE); + if (! file) + return grub_errno; + + if (! file->device->disk) + { + grub_file_close (file); + return grub_error (GRUB_ERR_BAD_DEVICE, "disk device required"); + } + + file->read_hook = save_env_read_hook; + file->read_hook_data = &ctx; + envblk = read_envblk_file (file); + file->read_hook = 0; + if (! envblk) + goto fail; + + if (check_blocklists (envblk, ctx.head, file)) + goto fail; + + while (argc) + { + const char *value; + + value = grub_env_get (args[0]); + if (value) + { + if (! grub_envblk_set (envblk, args[0], value)) + { + grub_error (GRUB_ERR_BAD_ARGUMENT, "environment block too small"); + goto fail; + } + } + else + grub_envblk_delete (envblk, args[0]); + + argc--; + args++; + } + + write_blocklists (envblk, ctx.head, file); + + fail: + if (envblk) + grub_envblk_close (envblk); + free_blocklists (ctx.head); + grub_file_close (file); + return grub_errno; +} + +static grub_extcmd_t cmd_load, cmd_list, cmd_save; + +GRUB_MOD_INIT(loadenv) +{ + cmd_load = + grub_register_extcmd ("load_env", grub_cmd_load_env, 0, + N_("[-f FILE] [-s|--skip-sig] [variable_name_to_whitelist] [...]"), + N_("Load variables from environment block file."), + options); + cmd_list = + grub_register_extcmd ("list_env", grub_cmd_list_env, 0, N_("[-f FILE]"), + N_("List variables from environment block file."), + options); + cmd_save = + grub_register_extcmd ("save_env", grub_cmd_save_env, 0, + N_("[-f FILE] variable_name [...]"), + N_("Save variables to environment block file."), + options); +} + +GRUB_MOD_FINI(loadenv) +{ + grub_unregister_extcmd (cmd_load); + grub_unregister_extcmd (cmd_list); + grub_unregister_extcmd (cmd_save); +} |