/*      $NetBSD: partitions.h,v 1.30 2025/04/10 20:35:07 andvar Exp $   */

/*
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* Abstract interface to access arbitrary disk partitioning schemes and
* keep Sysinst proper independent of the implementation / on-disk
* details.
*
* NOTE:
*  - all sector numbers, alignment and sizes are in units of the
*    disks physical sector size (not necessarily 512 bytes)!
*  - some interfaces pass the disks sector size (when it is easily
*    available at typical callers), but the backends can always
*    assume it to be equal to the real physical sector size. If
*    no value is passed, the backend can query the disk data
*    via get_disk_geom().
*  - single exception: disk_partitioning_scheme::size_limit is in 512
*    byte sectors (as it is not associated with a concrete disk)
*/

#include <sys/types.h>
#include <stdbool.h>
#include "msg_defs.h"

/*
* Import all the file system types, as enum fs_type.
*/
#define FSTYPE_ENUMNAME fs_type
#define FSTYPENAMES
#include <sys/disklabel.h>
#undef FSTYPE_ENUMNAME

/*
* Use random values (outside uint8_t range) to mark special file system
* types that are not in the FSTYPE enumeration.
*/
#ifndef FS_TMPFS
#define FS_TMPFS        256     /* tmpfs (prefered for /tmp if available) */
#endif
#ifndef FS_MFS
#define FS_MFS          257     /* mfs, alternative to tmpfs if that is
                                  not available */
#endif
#ifndef FS_EFI_SP
#define FS_EFI_SP       258     /* EFI system partition, uses FS_MSDOS,
                                  but may have a different partition
                                  type */
#endif

#define MAX_LABEL_LEN           128     /* max. length of a partition label */
#define MAX_SHORTCUT_LEN        8       /* max. length of a shortcut ("a:") */

/*
* A partition index / handle, identifies a single partition within
* a struct disk_partitions. This is just an iterator/index - whenever
* changes to the set of partitions are done, partitions may get a new
* part_id.
* We assume that partitioning schemes keep partitions sorted (with
* key = start address, some schemes will have overlapping partitions,
* like MBR extended partitions).
*/
typedef size_t part_id;

/*
* An invalid value for a partition index / handle
*/
#define NO_PART         ((part_id)~0U)

/*
* Intended usage for a partition
*/
enum part_type {
       PT_undef,               /* invalid value */
       PT_unknown,             /* anything we can not map to one of these */
       PT_root,                /* the NetBSD / partition (bootable) */
       PT_swap,                /* the NetBSD swap partition */
       PT_FAT,                 /* boot partition (e.g. for u-boot) */
       PT_EXT2,                /* boot partition (for Linux appliances) */
       PT_SYSVBFS,             /* boot partition (for some SYSV machines) */
       PT_EFI_SYSTEM,          /* (U)EFI boot partition */
};

/*
* A generic structure describing partition types for menu/user interface
* purposes. The internal details may be richer and the *pointer* value
* is the unique token - that is: the partitioning scheme will hand out
* pointers to internal data and recognize the exact partition type details
* by pointer comparison.
*/
struct part_type_desc {
       enum part_type generic_ptype;   /* what this maps to in generic terms */
       const char *short_desc;         /* short type description */
       const char *description;        /* full description */
};

/* Bits for disk_part_info.flags: */
#define PTI_SEC_CONTAINER       1               /* this covers our secondary
                                                  partitions */
#define PTI_WHOLE_DISK          2               /* all of the NetBSD disk */
#define PTI_BOOT                4               /* required for booting */
#define PTI_PSCHEME_INTERNAL    8               /* no user partition, e.g.
                                                  MBRs extend partition */
#define PTI_RAW_PART            16              /* total disk */
#define PTI_INSTALL_TARGET      32              /* marks the target partition
                                                * assumed to become / after
                                                * reboot; may not be
                                                * persistent; may only be
                                                * set for a single partition!
                                                */
#define PTI_SPECIAL_PARTS       \
       (PTI_PSCHEME_INTERNAL|PTI_WHOLE_DISK|PTI_SEC_CONTAINER|PTI_RAW_PART)


/* A single partition */
struct disk_part_info {
       daddr_t start, size;                    /* start and size on disk */
       uint32_t flags;                         /* active PTI_ flags */
       const struct part_type_desc *nat_type;  /* native partition type */
       /*
        * The following will only be available
        *  a) for a small subset of file system types
        *  b) if the partition (in this state) has already been
        *     used before
        * It is OK to leave all these zeroed / NULL when setting
        * partition data - or leave them at the last values a get operation
        * returned. Backends can not rely on them to be valid.
        */
       const char *last_mounted;               /* last mount point or NULL */
       unsigned int fs_type, fs_sub_type,      /* FS_* type of filesystem
                                                * and for some FS a sub
                                                * type (e.g. FFSv1 vs. FFSv2)
                                                */
               fs_opt1, fs_opt2, fs_opt3;      /* FS specific option, used
                                                * for FFS block/fragsize
                                                * and inodes
                                                */
};

/* An unused area that may be used for new partitions */
struct disk_part_free_space {
       daddr_t start, size;
};

/*
* Some partition schemes define additional data that needs to be edited.
* These attributes are described in this structure and referenced by
* their index into the fixed list of available attributes.
*/
enum custom_attr_type { pet_bool, pet_cardinal, pet_str };
struct disk_part_custom_attribute {
       msg label;                      /* Name, like "active partition" */
       enum custom_attr_type type;     /* bool, long, char* */
       size_t strlen;                  /* maximum length if pet_str */
};

/*
* When displaying a partition editor, we have standard columns, but
* partitioning schemes add custom columns to the table as well.
* There is a fixed number of columns and they are described by this
* structure:
*/
struct disk_part_edit_column_desc {
       msg title;
       unsigned int width;
};

struct disk_partitions; /* in-memory representation of a set of partitions */

/*
* When querying partition "device" names, we may ask for:
*/
enum dev_name_usage {
       parent_device_only,     /* wd0 instead of wd0i, no path */
       logical_name,           /* NAME=my-root instead of dk7 */
       plain_name,             /* e.g. /dev/wd0i or /dev/dk7 */
       raw_dev_name,           /* e.g. /dev/rwd0i or /dev/rdk7 */
};

/*
* A scheme how to store partitions on-disk, and methods to read/write
* them to/from our abstract internal presentation.
*/
struct disk_partitioning_scheme {
       /* name of the on-disk scheme, retrieved via msg_string */
       msg name, short_name;

       /* prompt shown when creating custom partition types */
       msg new_type_prompt;

       /* description of scheme specific partition flags */
       msg part_flag_desc;

       /*
        * size restrictions for this partitioning scheme (number
        * of 512 byte sectors max)
        */
       daddr_t size_limit;     /* 0 if not limited */

       /*
        * If this scheme allows sub-partitions (i.e. MBR -> disklabel),
        * this is a pointer to the (potential/optional) secondary
        * scheme. Depending on partitioning details it may not be
        * used in the end.
        * This link is only here for better help messages.
        * See *secondary_partitions further below for actually accessing
        * secondary partitions.
        */
       const struct disk_partitioning_scheme *secondary_scheme;

       /*
        * Partition editor colum descriptions for whatever the scheme
        * needs to display (see format_partition_table_str below).
        */
       size_t edit_columns_count;
       const struct disk_part_edit_column_desc *edit_columns;

       /*
        * Custom attributes editable by the partitioning scheme (but of
        * no particular meaning for sysinst)
        */
       size_t custom_attribute_count;
       const struct disk_part_custom_attribute *custom_attributes;

       /*
        * Partition types supported by this scheme,
        * first function gets the number, second queries single elements
        */
       size_t (*get_part_types_count)(void);
       const struct part_type_desc * (*get_part_type)(size_t ndx);
       /*
        * Get the preferred native representation for a generic partition type
        */
       const struct part_type_desc * (*get_generic_part_type)(enum part_type);
       /*
        * Get the preferred native partition type for a specific file system
        * type (FS_*) and subtype (fs specific value)
        */
       const struct part_type_desc * (*get_fs_part_type)(
           enum part_type, unsigned, unsigned);
       /*
        * Optional: inverse to above: given a part_type_desc, set default
        * fstype and subtype.
        */
       bool (*get_default_fstype)(const struct part_type_desc *,
           unsigned *fstype, unsigned *fs_sub_type);
       /*
        * Create a custom partition type. If the type already exists
        * (or there is a collision), the old existing type will be
        * returned and no new type created. This is not considered
        * an error (to keep the user interface simple).
        * On failure NULL is returned and (if passed != NULL)
        * *err_msg is set to a message describing the error.
        */
       const struct part_type_desc * (*create_custom_part_type)
           (const char *custom, const char **err_msg);
       /*
        * Return a usable internal partition type representation
        * for types that are not otherwise mappable.
        * This could be FS_OTHER for disklabel, or a randomly
        * created type guid for GPT. This type may or may not be
        * in the regular type list. If not, it needs to behave like a
        * custom type.
        */
       const struct part_type_desc * (*create_unknown_part_type)(void);

       /*
        * Global attributes
        */
       /*
        * Get partition alignment suggestion. The schemen may enforce
        * additional/different alignment for some partitions.
        */
       daddr_t (*get_part_alignment)(const struct disk_partitions*);

       /*
        * Methods to manipulate the in-memory abstract representation
        */

       /* Retrieve data about a single partition, identified by the part_id.
        * Fill the disk_part_info structure
        */
       bool (*get_part_info)(const struct disk_partitions*, part_id,
           struct disk_part_info*);

       /* Optional: fill an attribute string describing the given partition */
       bool (*get_part_attr_str)(const struct disk_partitions*, part_id,
           char *str, size_t avail_space);
       /* Format a partition editor element for the "col" column in
        * edit_columns. Used e.g. with MBR to set "active" flags.
        */
       bool (*format_partition_table_str)(const struct disk_partitions*,
           part_id, size_t col, char *outstr, size_t outspace);

       /* is the type of this partition changeable? */
       bool (*part_type_can_change)(const struct disk_partitions*,
           part_id);

       /* can we add further partitions? */
       bool (*can_add_partition)(const struct disk_partitions*);

       /* is the custom attribute changeable? */
       bool (*custom_attribute_writable)(const struct disk_partitions*,
           part_id, size_t attr_no);
       /*
        * Output formatting for custom attributes.
        * If "info" is != NULL, use (where it makes sense)
        * values from that structure, as if a call to set_part_info
        * would have been done before this call.
        */
       bool (*format_custom_attribute)(const struct disk_partitions*,
           part_id, size_t attr_no, const struct disk_part_info *info,
           char *out, size_t out_space);
       /* value setter functions for custom attributes */
       /* pet_bool: */
       bool (*custom_attribute_toggle)(struct disk_partitions*,
           part_id, size_t attr_no);
       /* pet_cardinal: */
       bool (*custom_attribute_set_card)(struct disk_partitions*,
           part_id, size_t attr_no, long new_val);
       /* pet_str or pet_cardinal: */
       bool (*custom_attribute_set_str)(struct disk_partitions*,
           part_id, size_t attr_no, const char *new_val);

       /*
        * Optional: additional user information when showing the size
        * editor (especially for existing unknown partitions)
        */
       const char * (*other_partition_identifier)(const struct
           disk_partitions*, part_id);


       /* Retrieve device and partition names, e.g. for checking
        * against kern.root_device or invoking newfs.
        * For disklabel partitions, "part" will be set to the partition
        * index (a = 0, b = 1, ...), for others it will get set to -1.
        * If dev_name_usage is parent_device_only, the device name will
        * not include a partition letter - obviously this only makes a
        * difference with disklabel partitions.
        * If dev_name_usage is logical_name instead of a device name
        * a given name may be returned in NAME= syntax.
        * If with_path is true (and the returned value is a device
        * node), include the /dev/ prefix in the result string
        * (this is ignored when returning NAME= syntax for /etc/fstab).
        * If life is true, the device must be made available under
        * that name (only makes a difference for NAME=syntax if
        * no wedge has been created yet,) - implied for all variants
        * where dev_name_usage != logical_name.
        */
       bool (*get_part_device)(const struct disk_partitions*,
           part_id, char *devname, size_t max_devname_len, int *part,
           enum dev_name_usage, bool with_path, bool life);

       /*
        * How big could we resize the given position (start of existing
        * partition or free space)
        */
       daddr_t (*max_free_space_at)(const struct disk_partitions*, daddr_t);

       /*
        * Provide a list of free spaces usable for further partitioning,
        * assuming the given partition alignment.
        * If start is > 0 no space with lower sector numbers will
        * be found.
        * If ignore is > 0, any partition starting at that sector will
        * be considered "free", this is used e.g. when moving an existing
        * partition around.
        */
       size_t (*get_free_spaces)(const struct disk_partitions*,
           struct disk_part_free_space *result, size_t max_num_result,
           daddr_t min_space_size, daddr_t align, daddr_t start,
           daddr_t ignore /* -1 */);

       /*
        * Translate a partition description from a foreign partitioning
        * scheme as close as possible to what we can handle in add_partition.
        * This mostly adjusts flags and partition type pointers (using
        * more lose matching than add_partition would do).
        */
       bool (*adapt_foreign_part_info)(
           const struct disk_partitions *myself, struct disk_part_info *dest,
           const struct disk_partitioning_scheme *src_scheme,
           const struct disk_part_info *src);

       /*
        * Update data for an existing partition
        */
       bool (*set_part_info)(struct disk_partitions*, part_id,
           const struct disk_part_info*, const char **err_msg);

       /* Add a new partition and return its part_id. */
       part_id (*add_partition)(struct disk_partitions*,
           const struct disk_part_info*, const char **err_msg);

       /*
        * Optional: add a partition from an outer scheme, accept all
        * details w/o verification as best as possible.
        */
       part_id (*add_outer_partition)(struct disk_partitions*,
           const struct disk_part_info*, const char **err_msg);

       /* Delete all partitions */
       bool (*delete_all_partitions)(struct disk_partitions*);

       /* Optional: delete any partitions inside the given range */
       bool (*delete_partitions_in_range)(struct disk_partitions*,
           daddr_t start, daddr_t size);

       /* Delete the specified partition */
       bool (*delete_partition)(struct disk_partitions*, part_id,
           const char **err_msg);

       /*
        * Methods for the whole set of partitions
        */
       /*
        * If this scheme only creates a singly NetBSD partition, which
        * then is sub-partitioned (usually by disklabel), this returns a
        * pointer to the secondary partition set.
        * Otherwise NULL is returned, e.g. when there is no
        * NetBSD partition defined (so this might change over time).
        * Schemes that NEVER use a secondary scheme set this
        * function pointer to NULL.
        *
        * If force_empty = true, ignore all on-disk contents and just
        * create a new disk_partitions structure for the secondary scheme
        * (this is used after deleting all partitions and setting up
        * things for "use whole disk").
        *
        * The returned pointer is always owned by the primary partitions,
        * caller MUST never free it, but otherwise can manipulate it
        * arbitrarily.
        */
       struct disk_partitions *
           (*secondary_partitions)(struct disk_partitions *, daddr_t start,
               bool force_empty);

       /*
        * Write the whole set (in new_state) back to disk.
        */
       bool (*write_to_disk)(struct disk_partitions *new_state);

       /*
        * Try to read partitions from a disk, return NULL if this is not
        * the partitioning scheme in use on that device.
        * Usually start and len are 0 (and ignored).
        * If this is about a part of a disk (like only the NetBSD
        * MBR partition, start and len are the valid part of the
        * disk.
        */
       struct disk_partitions * (*read_from_disk)(const char *,
           daddr_t start, daddr_t len, size_t bytes_per_sec,
           const struct disk_partitioning_scheme *);

       /*
        * Set up all internal data for a new disk.
        */
       struct disk_partitions * (*create_new_for_disk)(const char *,
           daddr_t start, daddr_t len, bool is_boot_drive,
           struct disk_partitions *parent);

       /*
        * Optional: this scheme may be used to boot from the given disk
        */
       bool (*have_boot_support)(const char *disk);

       /*
        * Optional: try to guess disk geometry from the partition information
        */
       int (*guess_disk_geom)(struct disk_partitions *,
           int *cyl, int *head, int *sec);

       /*
        * Return a "cylinder size" (in number of blocks) - whatever that
        * means to a particular partitioning scheme.
        */
       size_t (*get_cylinder_size)(const struct disk_partitions *);

       /*
        * Optional: change used geometry info and update internal state
        */
       bool (*change_disk_geom)(struct disk_partitions *,
           int cyl, int head, int sec);

       /*
        * Optional:
        * Get or set a name for the whole disk (most partitioning
        * schemes do not provide this). Used for disklabel "pack names",
        * which then may be used for auto-discovery of wedges, so it
        * makes sense for the user to edit them.
        */
       bool (*get_disk_pack_name)(const struct disk_partitions *,
           char *, size_t);
       bool (*set_disk_pack_name)(struct disk_partitions *, const char *);

       /*
        * Optional:
        * Find a partition by name (as used in /etc/fstab NAME= entries)
        */
       part_id (*find_by_name)(struct disk_partitions *, const char *name);

       /*
        * Optional:
        * Try to guess install target partition from internal data,
        * returns true if a safe match was found and sets start/size
        * to the target partition.
        */
       bool (*guess_install_target)(const struct disk_partitions *,
               daddr_t *start, daddr_t *size);

       /*
        * Optional: verify that the whole set of partitions would be bootable,
        * fix up any issues (with user interaction) where needed.
        * If "quiet" is true, fix up everything silently if possible
        * and never return 1.
        * Returns:
        *  0: abort install
        *  1: re-edit partitions
        *  2: use anyway (continue)
        */
       int (*post_edit_verify)(struct disk_partitions *, bool quiet);

       /*
        * Optional: called during updates, before mounting the target disk(s),
        * before md_pre_update() is called. Can be used to fixup
        * partition info for historic errors (e.g. i386 changing MBR
        * partition type from 165 to 169), similar to post_edit_verify.
        * Returns:
        *   true if the partition info has changed (write back required)
        *   false if nothing further needs to be done.
        */
       bool (*pre_update_verify)(struct disk_partitions *);

       /* Free all the data */
       void (*free)(struct disk_partitions*);

       /* Wipe all on-disk state, leave blank disk - and free data */
       void (*destroy_part_scheme)(struct disk_partitions*);

       /* Scheme global cleanup */
       void (*cleanup)(void);
};

/*
* The in-memory representation of all partitions on a concrete disk,
* tied to the partitioning scheme in use.
*
* Concrete schemes will derive from the abstract disk_partitions
* structure (by aggregation), but consumers of the API will only
* ever see this public part.
*/
struct disk_partitions {
       /* which partitioning scheme is in use */
       const struct disk_partitioning_scheme *pscheme;

       /* the disk device this came from (or should go to) */
       const char *disk;

       /* global/public disk data */

       /*
        * The basic unit of size used for this disk (all "start",
        * "size" and "align" values are in this unit).
        */
       size_t bytes_per_sector;        /* must be 2^n and >= 512 */

       /*
        * Valid partitions may have IDs in the range 0 .. num_part (excl.)
        */
       part_id num_part;

       /*
        * If this is a sub-partitioning, the start of the "disk" is
        * some arbitrary partition in the parent. Sometimes we need
        * to be able to calculate absoluted offsets.
        */
       daddr_t disk_start;
       /*
        * Total size of the disk (usable for partitioning)
        */
       daddr_t disk_size;

       /*
        * Space not yet allocated
        */
       daddr_t free_space;

       /*
        * If this is the secondary partitioning scheme, pointer to
        * the outer one. Otherwise NULL.
        */
       struct disk_partitions *parent;
};

/*
* A list of partitioning schemes, so we can iterate over everything
* supported (e.g. when partitioning a new disk). NULL terminated.
*/
extern const struct disk_partitioning_scheme **available_part_schemes;
extern size_t num_available_part_schemes;

/*
* Generic reader - query a disk device and read all partitions from it
*/
struct disk_partitions *
partitions_read_disk(const char *, daddr_t disk_size,
   size_t bytes_per_sector, bool no_mbr);

/*
* Generic part info adaption, may be overridden by individual partitioning
* schemes
*/
bool generic_adapt_foreign_part_info(
   const struct disk_partitions *myself, struct disk_part_info *dest,
   const struct disk_partitioning_scheme *src_scheme,
   const struct disk_part_info *src);

/*
* One time initialization and cleanup
*/
void partitions_init(void);
void partitions_cleanup(void);