diff options
Diffstat (limited to 'src/udev/udev-builtin-blkid.c')
-rw-r--r-- | src/udev/udev-builtin-blkid.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/src/udev/udev-builtin-blkid.c b/src/udev/udev-builtin-blkid.c new file mode 100644 index 0000000..11419a3 --- /dev/null +++ b/src/udev/udev-builtin-blkid.c @@ -0,0 +1,474 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * probe disks for filesystems and partitions + * + * Copyright © 2011 Karel Zak <kzak@redhat.com> + */ + +#if HAVE_VALGRIND_MEMCHECK_H +#include <valgrind/memcheck.h> +#endif + +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <linux/loop.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/ioctl.h> +#include <sys/stat.h> + +#include "sd-id128.h" + +#include "alloc-util.h" +#include "blkid-util.h" +#include "device-util.h" +#include "devnum-util.h" +#include "efi-loader.h" +#include "errno-util.h" +#include "fd-util.h" +#include "gpt.h" +#include "parse-util.h" +#include "string-util.h" +#include "strv.h" +#include "strxcpyx.h" +#include "udev-builtin.h" + +static void print_property(sd_device *dev, bool test, const char *name, const char *value) { + char s[256]; + + s[0] = '\0'; + + if (streq(name, "TYPE")) { + udev_builtin_add_property(dev, test, "ID_FS_TYPE", value); + + } else if (streq(name, "USAGE")) { + udev_builtin_add_property(dev, test, "ID_FS_USAGE", value); + + } else if (streq(name, "VERSION")) { + udev_builtin_add_property(dev, test, "ID_FS_VERSION", value); + + } else if (streq(name, "UUID")) { + blkid_safe_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_UUID", s); + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_UUID_ENC", s); + + } else if (streq(name, "UUID_SUB")) { + blkid_safe_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_UUID_SUB", s); + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_UUID_SUB_ENC", s); + + } else if (streq(name, "LABEL")) { + blkid_safe_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_LABEL", s); + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_LABEL_ENC", s); + + } else if (STR_IN_SET(name, "FSSIZE", "FSLASTBLOCK", "FSBLOCKSIZE")) { + strscpyl(s, sizeof(s), "ID_FS_", name + 2, NULL); + udev_builtin_add_property(dev, test, s, value); + + } else if (streq(name, "PTTYPE")) { + udev_builtin_add_property(dev, test, "ID_PART_TABLE_TYPE", value); + + } else if (streq(name, "PTUUID")) { + udev_builtin_add_property(dev, test, "ID_PART_TABLE_UUID", value); + + } else if (streq(name, "PART_ENTRY_NAME")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_PART_ENTRY_NAME", s); + + } else if (streq(name, "PART_ENTRY_TYPE")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_PART_ENTRY_TYPE", s); + + } else if (startswith(name, "PART_ENTRY_")) { + strscpyl(s, sizeof(s), "ID_", name, NULL); + udev_builtin_add_property(dev, test, s, value); + + } else if (streq(name, "SYSTEM_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_SYSTEM_ID", s); + + } else if (streq(name, "PUBLISHER_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_PUBLISHER_ID", s); + + } else if (streq(name, "APPLICATION_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_APPLICATION_ID", s); + + } else if (streq(name, "BOOT_SYSTEM_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_BOOT_SYSTEM_ID", s); + + } else if (streq(name, "VOLUME_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_VOLUME_ID", s); + + } else if (streq(name, "LOGICAL_VOLUME_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_LOGICAL_VOLUME_ID", s); + + } else if (streq(name, "VOLUME_SET_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_VOLUME_SET_ID", s); + + } else if (streq(name, "DATA_PREPARER_ID")) { + blkid_encode_string(value, s, sizeof(s)); + udev_builtin_add_property(dev, test, "ID_FS_DATA_PREPARER_ID", s); + } +} + +static int find_gpt_root(sd_device *dev, blkid_probe pr, bool test) { + +#if defined(SD_GPT_ROOT_NATIVE) && ENABLE_EFI + + _cleanup_free_ char *root_label = NULL; + bool found_esp_or_xbootldr = false; + sd_id128_t root_id = SD_ID128_NULL; + int r; + + assert(pr); + + /* Iterate through the partitions on this disk, and see if the UEFI ESP or XBOOTLDR partition we + * booted from is on it. If so, find the first root disk, and add a property indicating its partition + * UUID. */ + + errno = 0; + blkid_partlist pl = blkid_probe_get_partitions(pr); + if (!pl) + return errno_or_else(ENOMEM); + + int nvals = blkid_partlist_numof_partitions(pl); + for (int i = 0; i < nvals; i++) { + blkid_partition pp; + const char *label; + sd_id128_t type, id; + + pp = blkid_partlist_get_partition(pl, i); + if (!pp) + continue; + + r = blkid_partition_get_uuid_id128(pp, &id); + if (r < 0) { + log_debug_errno(r, "Failed to get partition UUID, ignoring: %m"); + continue; + } + + r = blkid_partition_get_type_id128(pp, &type); + if (r < 0) { + log_debug_errno(r, "Failed to get partition type UUID, ignoring: %m"); + continue; + } + + label = blkid_partition_get_name(pp); /* returns NULL if empty */ + + if (sd_id128_in_set(type, SD_GPT_ESP, SD_GPT_XBOOTLDR)) { + sd_id128_t esp_or_xbootldr; + + /* We found an ESP or XBOOTLDR, let's see if it matches the ESP/XBOOTLDR we booted from. */ + + r = efi_loader_get_device_part_uuid(&esp_or_xbootldr); + if (r < 0) + return r; + + if (sd_id128_equal(id, esp_or_xbootldr)) + found_esp_or_xbootldr = true; + + } else if (sd_id128_equal(type, SD_GPT_ROOT_NATIVE)) { + unsigned long long flags; + + flags = blkid_partition_get_flags(pp); + if (flags & SD_GPT_FLAG_NO_AUTO) + continue; + + /* We found a suitable root partition, let's remember the first one, or the one with + * the newest version, as determined by comparing the partition labels. */ + + if (sd_id128_is_null(root_id) || strverscmp_improved(label, root_label) > 0) { + root_id = id; + + r = free_and_strdup(&root_label, label); + if (r < 0) + return r; + } + } + } + + /* We found the ESP/XBOOTLDR on this disk, and also found a root partition, nice! Let's export its + * UUID */ + if (found_esp_or_xbootldr && !sd_id128_is_null(root_id)) + udev_builtin_add_property(dev, test, "ID_PART_GPT_AUTO_ROOT_UUID", SD_ID128_TO_UUID_STRING(root_id)); +#endif + + return 0; +} + +static int probe_superblocks(blkid_probe pr) { + struct stat st; + int rc; + + /* TODO: Return negative errno. */ + + if (fstat(blkid_probe_get_fd(pr), &st)) + return -errno; + + blkid_probe_enable_partitions(pr, 1); + + if (!S_ISCHR(st.st_mode) && + blkid_probe_get_size(pr) <= 1024 * 1440 && + blkid_probe_is_wholedisk(pr)) { + /* + * check if the small disk is partitioned, if yes then + * don't probe for filesystems. + */ + blkid_probe_enable_superblocks(pr, 0); + + rc = blkid_do_fullprobe(pr); + if (rc < 0) + return rc; /* -1 = error, 1 = nothing, 0 = success */ + + if (blkid_probe_lookup_value(pr, "PTTYPE", NULL, NULL) == 0) + return 0; /* partition table detected */ + } + + blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS); + blkid_probe_enable_superblocks(pr, 1); + + return blkid_do_safeprobe(pr); +} + +static int read_loopback_backing_inode( + sd_device *dev, + int fd, + dev_t *ret_devno, + ino_t *ret_inode, + char **ret_fname) { + + _cleanup_free_ char *fn = NULL; + struct loop_info64 info; + const char *name; + int r; + + assert(dev); + assert(fd >= 0); + assert(ret_devno); + assert(ret_inode); + assert(ret_fname); + + /* Retrieves various fields of the current loopback device backing file, so that we can ultimately + * use it to create stable symlinks to loopback block devices, based on what they are backed by. We + * pick up inode/device as well as file name field. Note that we pick up the "lo_file_name" field + * here, which is an arbitrary free-form string provided by userspace. We do not return the sysfs + * attribute loop/backing_file here, because that is directly accessible from udev rules anyway. And + * sometimes, depending on context, it's a good thing to return the string userspace can freely pick + * over the string automatically generated by the kernel. */ + + r = sd_device_get_sysname(dev, &name); + if (r < 0) + return r; + + if (!startswith(name, "loop")) + goto notloop; + + if (ioctl(fd, LOOP_GET_STATUS64, &info) < 0) { + if (ERRNO_IS_NOT_SUPPORTED(errno)) + goto notloop; + + return -errno; + } + +#if HAVE_VALGRIND_MEMCHECK_H + VALGRIND_MAKE_MEM_DEFINED(&info, sizeof(info)); +#endif + + if (isempty((char*) info.lo_file_name) || + strnlen((char*) info.lo_file_name, sizeof(info.lo_file_name)-1) == sizeof(info.lo_file_name)-1) + /* Don't pick up file name if it is unset or possibly truncated. (Note: the kernel silently + * truncates the string passed from userspace by LOOP_SET_STATUS64 ioctl. See + * loop_set_status_from_info() in drivers/block/loop.c. Hence, we can't really know the file + * name is truncated if it uses sizeof(info.lo_file_name)-1 as length; it could also mean the + * string is just that long and wasn't truncated — but the fact is simply that we cannot know + * in that case if it was truncated or not. Thus, we assume the worst and suppress — at least + * for now. For shorter strings we know for sure it wasn't truncated, hence that's always + * safe.) */ + fn = NULL; + else { + fn = memdup_suffix0(info.lo_file_name, sizeof(info.lo_file_name)); + if (!fn) + return -ENOMEM; + } + + *ret_inode = info.lo_inode; + *ret_devno = info.lo_device; + *ret_fname = TAKE_PTR(fn); + return 1; + + +notloop: + *ret_devno = 0; + *ret_inode = 0; + *ret_fname = NULL; + return 0; +} + +static int builtin_blkid(UdevEvent *event, int argc, char *argv[], bool test) { + sd_device *dev = ASSERT_PTR(ASSERT_PTR(event)->dev); + const char *devnode, *root_partition = NULL, *data, *name; + _cleanup_(blkid_free_probep) blkid_probe pr = NULL; + _cleanup_free_ char *backing_fname = NULL; + bool noraid = false, is_gpt = false; + _cleanup_close_ int fd = -EBADF; + ino_t backing_inode = 0; + dev_t backing_devno = 0; + int64_t offset = 0; + int r; + + static const struct option options[] = { + { "offset", required_argument, NULL, 'o' }, + { "hint", required_argument, NULL, 'H' }, + { "noraid", no_argument, NULL, 'R' }, + {} + }; + + errno = 0; + pr = blkid_new_probe(); + if (!pr) + return log_device_debug_errno(dev, errno_or_else(ENOMEM), "Failed to create blkid prober: %m"); + + for (;;) { + int option; + + option = getopt_long(argc, argv, "o:H:R", options, NULL); + if (option == -1) + break; + + switch (option) { + case 'H': +#if HAVE_BLKID_PROBE_SET_HINT + errno = 0; + r = blkid_probe_set_hint(pr, optarg, 0); + if (r < 0) + return log_device_error_errno(dev, errno_or_else(ENOMEM), "Failed to use '%s' probing hint: %m", optarg); + break; +#else + /* Use the hint <name>=<offset> as probing offset for old versions */ + optarg = strchr(optarg, '='); + if (!optarg) + /* no value means 0, do nothing for old versions */ + break; + ++optarg; + _fallthrough_; +#endif + case 'o': + r = safe_atoi64(optarg, &offset); + if (r < 0) + return log_device_error_errno(dev, r, "Failed to parse '%s' as an integer: %m", optarg); + if (offset < 0) + return log_device_error_errno(dev, SYNTHETIC_ERRNO(EINVAL), "Invalid offset %"PRIi64": %m", offset); + break; + case 'R': + noraid = true; + break; + } + } + + blkid_probe_set_superblocks_flags(pr, + BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID | + BLKID_SUBLKS_TYPE | BLKID_SUBLKS_SECTYPE | +#ifdef BLKID_SUBLKS_FSINFO + BLKID_SUBLKS_FSINFO | +#endif + BLKID_SUBLKS_USAGE | BLKID_SUBLKS_VERSION); + + if (noraid) + blkid_probe_filter_superblocks_usage(pr, BLKID_FLTR_NOTIN, BLKID_USAGE_RAID); + + r = sd_device_get_devname(dev, &devnode); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get device name: %m"); + + fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); + if (fd < 0) { + bool ignore = ERRNO_IS_DEVICE_ABSENT(fd); + log_device_debug_errno(dev, fd, "Failed to open block device %s%s: %m", + devnode, ignore ? ", ignoring" : ""); + return ignore ? 0 : fd; + } + + errno = 0; + r = blkid_probe_set_device(pr, fd, offset, 0); + if (r < 0) + return log_device_debug_errno(dev, errno_or_else(ENOMEM), "Failed to set device to blkid prober: %m"); + + log_device_debug(dev, "Probe %s with %sraid and offset=%"PRIi64, devnode, noraid ? "no" : "", offset); + + r = probe_superblocks(pr); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to probe superblocks: %m"); + + /* If the device is a partition then its parent passed the root partition UUID to the device */ + (void) sd_device_get_property_value(dev, "ID_PART_GPT_AUTO_ROOT_UUID", &root_partition); + + errno = 0; + int nvals = blkid_probe_numof_values(pr); + if (nvals < 0) + return log_device_debug_errno(dev, errno_or_else(ENOMEM), "Failed to get number of probed values: %m"); + + for (int i = 0; i < nvals; i++) { + if (blkid_probe_get_value(pr, i, &name, &data, NULL) < 0) + continue; + + print_property(dev, test, name, data); + + /* Is this a disk with GPT partition table? */ + if (streq(name, "PTTYPE") && streq(data, "gpt")) + is_gpt = true; + + /* Is this a partition that matches the root partition + * property inherited from the parent? */ + if (root_partition && streq(name, "PART_ENTRY_UUID") && streq(data, root_partition)) + udev_builtin_add_property(dev, test, "ID_PART_GPT_AUTO_ROOT", "1"); + } + + if (is_gpt) + find_gpt_root(dev, pr, test); + + r = read_loopback_backing_inode( + dev, + fd, + &backing_devno, + &backing_inode, + &backing_fname); + if (r < 0) + log_device_debug_errno(dev, r, "Failed to read loopback backing inode, ignoring: %m"); + else if (r > 0) { + udev_builtin_add_propertyf(dev, test, "ID_LOOP_BACKING_DEVICE", DEVNUM_FORMAT_STR, DEVNUM_FORMAT_VAL(backing_devno)); + udev_builtin_add_propertyf(dev, test, "ID_LOOP_BACKING_INODE", "%" PRIu64, (uint64_t) backing_inode); + + if (backing_fname) { + /* In the worst case blkid_encode_string() will blow up to 4x the string + * length. Hence size the buffer to 4x of the longest string + * read_loopback_backing_inode() might return */ + char encoded[sizeof_field(struct loop_info64, lo_file_name) * 4 + 1]; + + assert(strlen(backing_fname) < ELEMENTSOF(encoded) / 4); + blkid_encode_string(backing_fname, encoded, ELEMENTSOF(encoded)); + + udev_builtin_add_property(dev, test, "ID_LOOP_BACKING_FILENAME", backing_fname); + udev_builtin_add_property(dev, test, "ID_LOOP_BACKING_FILENAME_ENC", encoded); + } + } + + return 0; +} + +const UdevBuiltin udev_builtin_blkid = { + .name = "blkid", + .cmd = builtin_blkid, + .help = "Filesystem and partition probing", + .run_once = true, +}; |