Improve 'search' grub-shell command with functionality to search for a partition by PARTUUID string. This is useful on systems where FSUUID is not guaranteed to be constant, e.g. it is not preserved between system updates, and modifying grub.cfg is undesired.
V2: This patch is based on Michael Grzeschik version from 27 May 2019 [1] with the following changes: 1. Addressed review feedback from Daniel Kiper [2] and Nick Vinson [3]. 2. Added support for GPT PARTUUID. 3. Moved MBR disk signature reading from partmap/msdos.c to commands/search.c to read it only when it is needed. [1] https://lists.gnu.org/archive/html/grub-devel/2019-05/msg00124.html [2] https://lists.gnu.org/archive/html/grub-devel/2019-05/msg00131.html [3] https://lists.gnu.org/archive/html/grub-devel/2019-05/msg00134.html Signed-off-by: Vitaly Kuzmichev <vkuzmic...@dev.rtsoft.ru> --- grub-core/Makefile.core.def | 5 ++ grub-core/commands/search.c | 80 +++++++++++++++++++++++++++- grub-core/commands/search_partuuid.c | 5 ++ grub-core/commands/search_wrap.c | 8 ++- include/grub/search.h | 2 + 5 files changed, 97 insertions(+), 3 deletions(-) create mode 100644 grub-core/commands/search_partuuid.c diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def index 8022e1c0a..4568943e3 100644 --- a/grub-core/Makefile.core.def +++ b/grub-core/Makefile.core.def @@ -1063,6 +1063,11 @@ module = { common = commands/search_file.c; }; +module = { + name = search_partuuid; + common = commands/search_partuuid.c; +}; + module = { name = search_fs_uuid; common = commands/search_uuid.c; diff --git a/grub-core/commands/search.c b/grub-core/commands/search.c index ed090b3af..5014982fd 100644 --- a/grub-core/commands/search.c +++ b/grub-core/commands/search.c @@ -54,6 +54,28 @@ struct search_ctx int is_cache; }; +#ifdef DO_SEARCH_PARTUUID +#include <grub/gpt_partition.h> +#include <grub/i386/pc/boot.h> + +/* Helper for iterate_device. */ +static char * +gpt_guid_to_str (grub_gpt_part_guid_t *gpt_guid) +{ + /* Convert mixed-endian UUID from bytes to string */ + return + grub_xasprintf ( + "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", + grub_le_to_cpu32(gpt_guid->data1), + grub_le_to_cpu16(gpt_guid->data2), + grub_le_to_cpu16(gpt_guid->data3), + gpt_guid->data4[0], gpt_guid->data4[1], + gpt_guid->data4[2], gpt_guid->data4[3], + gpt_guid->data4[4], gpt_guid->data4[5], + gpt_guid->data4[6], gpt_guid->data4[7]); +} +#endif + /* Helper for FUNC_NAME. */ static int iterate_device (const char *name, void *data) @@ -66,13 +88,63 @@ iterate_device (const char *name, void *data) name[0] == 'f' && name[1] == 'd' && name[2] >= '0' && name[2] <= '9') return 1; -#ifdef DO_SEARCH_FS_UUID +#if defined (DO_SEARCH_FS_UUID) || defined (DO_SEARCH_PARTUUID) #define compare_fn grub_strcasecmp #else #define compare_fn grub_strcmp #endif -#ifdef DO_SEARCH_FILE +#ifdef DO_SEARCH_PARTUUID + { + struct grub_gpt_partentry gptdata; + grub_uint32_t disk_sig; + grub_disk_t ptdisk; + grub_disk_t disk; + char *part_uuid; + + ptdisk = grub_disk_open (name); + if (ptdisk && ptdisk->partition && ptdisk->partition->partmap) + { + if (grub_strcmp (ptdisk->partition->partmap->name, "gpt") == 0) + { + disk = grub_disk_open (ptdisk->name); + if (disk && grub_disk_read (disk, ptdisk->partition->offset, + ptdisk->partition->index, + sizeof (gptdata), &gptdata) == 0) + { + part_uuid = gpt_guid_to_str (&gptdata.guid); + + if (part_uuid && compare_fn (part_uuid, ctx->key) == 0) + found = 1; + if (part_uuid) + grub_free (part_uuid); + } + if (disk) + grub_disk_close (disk); + } + else if (grub_strcmp (ptdisk->partition->partmap->name, "msdos") == 0) + { + disk = grub_disk_open (ptdisk->name); + if (disk && grub_disk_read (disk, 0, + GRUB_BOOT_MACHINE_WINDOWS_NT_MAGIC, + sizeof(disk_sig), &disk_sig) == 0) + { + part_uuid = grub_xasprintf ("%08x-%02x", + grub_le_to_cpu32(disk_sig), + ptdisk->partition->index + 1); + if (part_uuid && compare_fn (part_uuid, ctx->key) == 0) + found = 1; + if (part_uuid) + grub_free (part_uuid); + } + if (disk) + grub_disk_close (disk); + } + } + if (ptdisk) + grub_disk_close (ptdisk); + } +#elif defined (DO_SEARCH_FILE) { char *buf; grub_file_t file; @@ -313,6 +385,8 @@ static grub_command_t cmd; #ifdef DO_SEARCH_FILE GRUB_MOD_INIT(search_fs_file) +#elif defined (DO_SEARCH_PARTUUID) +GRUB_MOD_INIT(search_partuuid) #elif defined (DO_SEARCH_FS_UUID) GRUB_MOD_INIT(search_fs_uuid) #else @@ -327,6 +401,8 @@ GRUB_MOD_INIT(search_label) #ifdef DO_SEARCH_FILE GRUB_MOD_FINI(search_fs_file) +#elif defined (DO_SEARCH_PARTUUID) +GRUB_MOD_FINI(search_partuuid) #elif defined (DO_SEARCH_FS_UUID) GRUB_MOD_FINI(search_fs_uuid) #else diff --git a/grub-core/commands/search_partuuid.c b/grub-core/commands/search_partuuid.c new file mode 100644 index 000000000..e4aa20b5f --- /dev/null +++ b/grub-core/commands/search_partuuid.c @@ -0,0 +1,5 @@ +#define DO_SEARCH_PARTUUID 1 +#define FUNC_NAME grub_search_partuuid +#define COMMAND_NAME "search.partuuid" +#define HELP_MESSAGE N_("Search devices by PARTUUID. If VARIABLE is specified, the first device found is set to a variable.") +#include "search.c" diff --git a/grub-core/commands/search_wrap.c b/grub-core/commands/search_wrap.c index 47fc8eb99..90e7cc9a0 100644 --- a/grub-core/commands/search_wrap.c +++ b/grub-core/commands/search_wrap.c @@ -36,6 +36,8 @@ static const struct grub_arg_option options[] = 0, 0}, {"fs-uuid", 'u', 0, N_("Search devices by a filesystem UUID."), 0, 0}, + {"partuuid", 'p', 0, N_("Search devices by a PARTUUID."), + 0, 0}, {"set", 's', GRUB_ARG_OPTION_OPTIONAL, N_("Set a variable to the first device found."), N_("VARNAME"), ARG_TYPE_STRING}, @@ -71,6 +73,7 @@ enum options SEARCH_FILE, SEARCH_LABEL, SEARCH_FS_UUID, + SEARCH_PARTUUID, SEARCH_SET, SEARCH_NO_FLOPPY, SEARCH_HINT, @@ -186,6 +189,9 @@ grub_cmd_search (grub_extcmd_context_t ctxt, int argc, char **args) else if (state[SEARCH_FS_UUID].set) grub_search_fs_uuid (id, var, state[SEARCH_NO_FLOPPY].set, hints, nhints); + else if (state[SEARCH_PARTUUID].set) + grub_search_partuuid (id, var, state[SEARCH_NO_FLOPPY].set, + hints, nhints); else if (state[SEARCH_FILE].set) grub_search_fs_file (id, var, state[SEARCH_NO_FLOPPY].set, hints, nhints); @@ -207,7 +213,7 @@ GRUB_MOD_INIT(search) N_("[-f|-l|-u|-s|-n] [--hint HINT [--hint HINT] ...]" " NAME"), N_("Search devices by file, filesystem label" - " or filesystem UUID." + " PARTUUID or filesystem UUID." " If --set is specified, the first device found is" " set to a variable. If no variable name is" " specified, `root' is used."), diff --git a/include/grub/search.h b/include/grub/search.h index d80347df3..7ca0b6b03 100644 --- a/include/grub/search.h +++ b/include/grub/search.h @@ -25,5 +25,7 @@ void grub_search_fs_uuid (const char *key, const char *var, int no_floppy, char **hints, unsigned nhints); void grub_search_label (const char *key, const char *var, int no_floppy, char **hints, unsigned nhints); +void grub_search_partuuid (const char *key, const char *var, int no_floppy, + char **hints, unsigned nhints); #endif -- 2.17.1 _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel
