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Diffstat (limited to 'src/shared/dissect-image.h')
| -rw-r--r-- | src/shared/dissect-image.h | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/shared/dissect-image.h b/src/shared/dissect-image.h new file mode 100644 index 0000000..15c0bf7 --- /dev/null +++ b/src/shared/dissect-image.h @@ -0,0 +1,230 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <stdbool.h> + +#include "sd-id128.h" + +#include "architecture.h" +#include "env-util.h" +#include "gpt.h" +#include "list.h" +#include "loop-util.h" +#include "macro.h" +#include "os-util.h" +#include "strv.h" + +typedef struct DissectedImage DissectedImage; +typedef struct DissectedPartition DissectedPartition; +typedef struct DecryptedImage DecryptedImage; +typedef struct MountOptions MountOptions; +typedef struct VeritySettings VeritySettings; + +struct DissectedPartition { + bool found:1; + bool ignored:1; + bool rw:1; + bool growfs:1; + int partno; /* -1 if there was no partition and the images contains a file system directly */ + Architecture architecture; /* Intended architecture: either native, secondary or unset ARCHITECTURE_INVALID. */ + sd_id128_t uuid; /* Partition entry UUID as reported by the GPT */ + char *fstype; + char *node; + char *label; + char *decrypted_node; + char *decrypted_fstype; + char *mount_options; + int mount_node_fd; + uint64_t size; + uint64_t offset; + uint64_t gpt_flags; + int fsmount_fd; +}; + +#define DISSECTED_PARTITION_NULL \ + ((DissectedPartition) { \ + .partno = -1, \ + .architecture = _ARCHITECTURE_INVALID, \ + .mount_node_fd = -EBADF, \ + .fsmount_fd = -EBADF, \ + }) +#define TAKE_PARTITION(p) \ + ({ \ + DissectedPartition *_pp = &(p), _p = *_pp; \ + *_pp = DISSECTED_PARTITION_NULL; \ + _p; \ + }) + +typedef enum DissectImageFlags { + DISSECT_IMAGE_DEVICE_READ_ONLY = 1 << 0, /* Make device read-only */ + DISSECT_IMAGE_DISCARD_ON_LOOP = 1 << 1, /* Turn on "discard" if on a loop device and file system supports it */ + DISSECT_IMAGE_DISCARD = 1 << 2, /* Turn on "discard" if file system supports it, on all block devices */ + DISSECT_IMAGE_DISCARD_ON_CRYPTO = 1 << 3, /* Turn on "discard" also on crypto devices */ + DISSECT_IMAGE_DISCARD_ANY = DISSECT_IMAGE_DISCARD_ON_LOOP | + DISSECT_IMAGE_DISCARD | + DISSECT_IMAGE_DISCARD_ON_CRYPTO, + DISSECT_IMAGE_GPT_ONLY = 1 << 4, /* Only recognize images with GPT partition tables */ + DISSECT_IMAGE_GENERIC_ROOT = 1 << 5, /* If no partition table or only single generic partition, assume it's the root fs */ + DISSECT_IMAGE_MOUNT_ROOT_ONLY = 1 << 6, /* Mount only the root and /usr partitions */ + DISSECT_IMAGE_MOUNT_NON_ROOT_ONLY = 1 << 7, /* Mount only the non-root and non-/usr partitions */ + DISSECT_IMAGE_VALIDATE_OS = 1 << 8, /* Refuse mounting images that aren't identifiable as OS images */ + DISSECT_IMAGE_VALIDATE_OS_EXT = 1 << 9, /* Refuse mounting images that aren't identifiable as OS extension images */ + DISSECT_IMAGE_RELAX_VAR_CHECK = 1 << 10, /* Don't insist that the UUID of /var is hashed from /etc/machine-id */ + DISSECT_IMAGE_FSCK = 1 << 11, /* File system check the partition before mounting (no effect when combined with DISSECT_IMAGE_READ_ONLY) */ + DISSECT_IMAGE_NO_PARTITION_TABLE = 1 << 12, /* Only recognize single file system images */ + DISSECT_IMAGE_VERITY_SHARE = 1 << 13, /* When activating a verity device, reuse existing one if already open */ + DISSECT_IMAGE_MKDIR = 1 << 14, /* Make top-level directory to mount right before mounting, if missing */ + DISSECT_IMAGE_USR_NO_ROOT = 1 << 15, /* If no root fs is in the image, but /usr is, then allow this (so that we can mount the rootfs as tmpfs or so */ + DISSECT_IMAGE_REQUIRE_ROOT = 1 << 16, /* Don't accept disks without root partition (or at least /usr partition if DISSECT_IMAGE_USR_NO_ROOT is set) */ + DISSECT_IMAGE_MOUNT_READ_ONLY = 1 << 17, /* Make mounts read-only */ + DISSECT_IMAGE_READ_ONLY = DISSECT_IMAGE_DEVICE_READ_ONLY | + DISSECT_IMAGE_MOUNT_READ_ONLY, + DISSECT_IMAGE_GROWFS = 1 << 18, /* Grow file systems in partitions marked for that to the size of the partitions after mount */ + DISSECT_IMAGE_MOUNT_IDMAPPED = 1 << 19, /* Mount mounts with kernel 5.12-style userns ID mapping, if file system type doesn't support uid=/gid= */ + DISSECT_IMAGE_ADD_PARTITION_DEVICES = 1 << 20, /* Create partition devices via BLKPG_ADD_PARTITION */ + DISSECT_IMAGE_PIN_PARTITION_DEVICES = 1 << 21, /* Open dissected partitions and decrypted partitions and pin them by fd */ + DISSECT_IMAGE_RELAX_EXTENSION_CHECK = 1 << 22, /* Don't insist that the extension-release file name matches the image name */ + DISSECT_IMAGE_DISKSEQ_DEVNODE = 1 << 23, /* Prefer /dev/disk/by-diskseq/… device nodes */ + DISSECT_IMAGE_ALLOW_EMPTY = 1 << 24, /* Allow that no usable partitions is present */ + DISSECT_IMAGE_TRY_ATOMIC_MOUNT_EXCHANGE = 1 << 25, /* Try to mount the image beneath the specified mountpoint, rather than on top of it, and then umount the top */ +} DissectImageFlags; + +struct DissectedImage { + bool encrypted:1; + bool has_verity:1; /* verity available in image, but not necessarily used */ + bool has_verity_sig:1; /* pkcs#7 signature embedded in image */ + bool verity_ready:1; /* verity available, fully specified and usable */ + bool verity_sig_ready:1; /* verity signature logic, fully specified and usable */ + bool single_file_system:1; /* MBR/GPT or single file system */ + + LoopDevice *loop; + DissectedPartition partitions[_PARTITION_DESIGNATOR_MAX]; + DecryptedImage *decrypted_image; + + uint32_t sector_size; + + char *image_name; + sd_id128_t image_uuid; + + /* Meta information extracted from /etc/os-release and similar */ + char *hostname; + sd_id128_t machine_id; + char **machine_info; + char **os_release; + char **initrd_release; + char **confext_release; + char **sysext_release; + int has_init_system; +}; + +struct MountOptions { + PartitionDesignator partition_designator; + char *options; + LIST_FIELDS(MountOptions, mount_options); +}; + +struct VeritySettings { + /* Binary root hash for the Verity Merkle tree */ + void *root_hash; + size_t root_hash_size; + + /* PKCS#7 signature of the above */ + void *root_hash_sig; + size_t root_hash_sig_size; + + /* Path to the verity data file, if stored externally */ + char *data_path; + + /* PARTITION_ROOT or PARTITION_USR, depending on what these Verity settings are for */ + PartitionDesignator designator; +}; + +#define VERITY_SETTINGS_DEFAULT { \ + .designator = _PARTITION_DESIGNATOR_INVALID \ + } + +/* We include image-policy.h down here, since ImagePolicy wants a complete definition of PartitionDesignator first. */ +#include "image-policy.h" + +MountOptions* mount_options_free_all(MountOptions *options); +DEFINE_TRIVIAL_CLEANUP_FUNC(MountOptions*, mount_options_free_all); +const char* mount_options_from_designator(const MountOptions *options, PartitionDesignator designator); + +int probe_filesystem_full(int fd, const char *path, uint64_t offset, uint64_t size, char **ret_fstype); +static inline int probe_filesystem(const char *path, char **ret_fstype) { + return probe_filesystem_full(-1, path, 0, UINT64_MAX, ret_fstype); +} + +int dissect_log_error(int log_level, int r, const char *name, const VeritySettings *verity); +int dissect_image_file(const char *path, const VeritySettings *verity, const MountOptions *mount_options, const ImagePolicy *image_policy, DissectImageFlags flags, DissectedImage **ret); +int dissect_image_file_and_warn(const char *path, const VeritySettings *verity, const MountOptions *mount_options, const ImagePolicy *image_policy, DissectImageFlags flags, DissectedImage **ret); +int dissect_loop_device(LoopDevice *loop, const VeritySettings *verity, const MountOptions *mount_options, const ImagePolicy *image_policy, DissectImageFlags flags, DissectedImage **ret); +int dissect_loop_device_and_warn(LoopDevice *loop, const VeritySettings *verity, const MountOptions *mount_options, const ImagePolicy *image_policy, DissectImageFlags flags, DissectedImage **ret); + +DissectedImage* dissected_image_unref(DissectedImage *m); +DEFINE_TRIVIAL_CLEANUP_FUNC(DissectedImage*, dissected_image_unref); + +int dissected_image_decrypt(DissectedImage *m, const char *passphrase, const VeritySettings *verity, DissectImageFlags flags); +int dissected_image_decrypt_interactively(DissectedImage *m, const char *passphrase, const VeritySettings *verity, DissectImageFlags flags); +int dissected_image_mount(DissectedImage *m, const char *dest, uid_t uid_shift, uid_t uid_range, int userns_fd, DissectImageFlags flags); +int dissected_image_mount_and_warn(DissectedImage *m, const char *where, uid_t uid_shift, uid_t uid_range, int userns_fd, DissectImageFlags flags); + +int dissected_image_acquire_metadata(DissectedImage *m, DissectImageFlags extra_flags); + +Architecture dissected_image_architecture(DissectedImage *m); + +static inline bool dissected_image_is_bootable_os(DissectedImage *m) { + return m && m->has_init_system > 0; +} + +static inline bool dissected_image_is_bootable_uefi(DissectedImage *m) { + return m && m->partitions[PARTITION_ESP].found && dissected_image_is_bootable_os(m); +} + +static inline bool dissected_image_is_portable(DissectedImage *m) { + return m && strv_env_pairs_get(m->os_release, "PORTABLE_PREFIXES"); +} + +static inline bool dissected_image_is_initrd(DissectedImage *m) { + return m && !strv_isempty(m->initrd_release); +} + +DecryptedImage* decrypted_image_ref(DecryptedImage *p); +DecryptedImage* decrypted_image_unref(DecryptedImage *p); +DEFINE_TRIVIAL_CLEANUP_FUNC(DecryptedImage*, decrypted_image_unref); + +int dissected_image_relinquish(DissectedImage *m); + +int verity_settings_load(VeritySettings *verity, const char *image, const char *root_hash_path, const char *root_hash_sig_path); +void verity_settings_done(VeritySettings *verity); + +static inline bool verity_settings_data_covers(const VeritySettings *verity, PartitionDesignator d) { + /* Returns true if the verity settings contain sufficient information to cover the specified partition */ + return verity && + ((d >= 0 && verity->designator == d) || (d == PARTITION_ROOT && verity->designator < 0)) && + verity->root_hash && + verity->data_path; +} + +int dissected_image_load_verity_sig_partition(DissectedImage *m, int fd, VeritySettings *verity); + +bool dissected_image_verity_candidate(const DissectedImage *image, PartitionDesignator d); +bool dissected_image_verity_ready(const DissectedImage *image, PartitionDesignator d); +bool dissected_image_verity_sig_ready(const DissectedImage *image, PartitionDesignator d); + +int mount_image_privately_interactively(const char *path, const ImagePolicy *image_policy, DissectImageFlags flags, char **ret_directory, int *ret_dir_fd, LoopDevice **ret_loop_device); + +int verity_dissect_and_mount(int src_fd, const char *src, const char *dest, const MountOptions *options, const ImagePolicy *image_policy, const char *required_host_os_release_id, const char *required_host_os_release_version_id, const char *required_host_os_release_sysext_level, const char *required_host_os_release_confext_level, const char *required_sysext_scope, DissectedImage **ret_image); + +int dissect_fstype_ok(const char *fstype); + +int probe_sector_size(int fd, uint32_t *ret); +int probe_sector_size_prefer_ioctl(int fd, uint32_t *ret); + +int partition_pick_mount_options(PartitionDesignator d, const char *fstype, bool rw, bool discard, char **ret_options, unsigned long *ret_ms_flags); + +static inline const char *dissected_partition_fstype(const DissectedPartition *m) { + assert(m); + + return m->decrypted_node ? m->decrypted_fstype : m->fstype; +} |