:py:mod:`dissect.ffs.c_ffs` =========================== .. py:module:: dissect.ffs.c_ffs Module Contents --------------- .. py:data:: ffs_def :value: Multiline-String .. raw:: html
Show Value .. code-block:: python """ typedef uint8 u_int8_t; typedef uint16 u_int16_t; typedef uint32 u_int32_t; typedef uint64 u_int64_t; typedef uchar u_char; typedef uint32 u_int; /* * The size of physical and logical block numbers and time fields in UFS. */ typedef int32_t ufs1_daddr_t; typedef int64_t ufs2_daddr_t; typedef int64_t ufs_lbn_t; typedef int64_t ufs_time_t; /* * The root inode is the root of the filesystem. Inode 0 can't be used for * normal purposes and historically bad blocks were linked to inode 1, thus * the root inode is 2. (Inode 1 is no longer used for this purpose, however * numerous dump tapes make this assumption, so we are stuck with it). */ #define UFS_ROOTINO 2 /* * Each disk drive contains some number of filesystems. * A filesystem consists of a number of cylinder groups. * Each cylinder group has inodes and data. * * A filesystem is described by its super-block, which in turn * describes the cylinder groups. The super-block is critical * data and is replicated in each cylinder group to protect against * catastrophic loss. This is done at `newfs' time and the critical * super-block data does not change, so the copies need not be * referenced further unless disaster strikes. * * For filesystem fs, the offsets of the various blocks of interest * are given in the super block as: * [fs->fs_sblkno] Super-block * [fs->fs_cblkno] Cylinder group block * [fs->fs_iblkno] Inode blocks * [fs->fs_dblkno] Data blocks * The beginning of cylinder group cg in fs, is given by * the ``cgbase(fs, cg)'' macro. * * Depending on the architecture and the media, the superblock may * reside in any one of four places. For tiny media where every block * counts, it is placed at the very front of the partition. Historically, * UFS1 placed it 8K from the front to leave room for the disk label and * a small bootstrap. For UFS2 it got moved to 64K from the front to leave * room for the disk label and a bigger bootstrap, and for really piggy * systems we check at 256K from the front if the first three fail. In * all cases the size of the superblock will be SBLOCKSIZE. All values are * given in byte-offset form, so they do not imply a sector size. The * SBLOCKSEARCH specifies the order in which the locations should be searched. */ #define SBLOCK_FLOPPY 0 #define SBLOCK_UFS1 8192 #define SBLOCK_UFS2 65536 #define SBLOCK_PIGGY 262144 #define SBLOCKSIZE 8192 /* * Max number of fragments per block. This value is NOT tweakable. */ #define MAXFRAG 8 /* * Addresses stored in inodes are capable of addressing fragments * of `blocks'. File system blocks of at most size MAXBSIZE can * be optionally broken into 2, 4, or 8 pieces, each of which is * addressable; these pieces may be DEV_BSIZE, or some multiple of * a DEV_BSIZE unit. * * Large files consist of exclusively large data blocks. To avoid * undue wasted disk space, the last data block of a small file may be * allocated as only as many fragments of a large block as are * necessary. The filesystem format retains only a single pointer * to such a fragment, which is a piece of a single large block that * has been divided. The size of such a fragment is determinable from * information in the inode, using the ``blksize(fs, ip, lbn)'' macro. * * The filesystem records space availability at the fragment level; * to determine block availability, aligned fragments are examined. */ /* * MINBSIZE is the smallest allowable block size. * In order to insure that it is possible to create files of size * 2^32 with only two levels of indirection, MINBSIZE is set to 4096. * MINBSIZE must be big enough to hold a cylinder group block, * thus changes to (struct cg) must keep its size within MINBSIZE. * Note that super blocks are always of size SBLOCKSIZE, * and that both SBLOCKSIZE and MAXBSIZE must be >= MINBSIZE. */ #define MINBSIZE 4096 #define MAXBSIZE 65536 /* * The path name on which the filesystem is mounted is maintained * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in * the super block for this name. */ #define MAXMNTLEN 468 /* * The volume name for this filesystem is maintained in fs_volname. * MAXVOLLEN defines the length of the buffer allocated. */ #define MAXVOLLEN 32 /* * A summary of contiguous blocks of various sizes is maintained * in each cylinder group. Normally this is set by the initial * value of fs_maxcontig. To conserve space, a maximum summary size * is set by FS_MAXCONTIG. */ #define FS_MAXCONTIG 16 /* * The maximum number of snapshot nodes that can be associated * with each filesystem. This limit affects only the number of * snapshot files that can be recorded within the superblock so * that they can be found when the filesystem is mounted. However, * maintaining too many will slow the filesystem performance, so * having this limit is a good idea. */ #define FSMAXSNAP 20 /* * Per cylinder group information; summarized in blocks allocated * from first cylinder group data blocks. These blocks have to be * read in from fs_csaddr (size fs_cssize) in addition to the * super block. */ struct csum { int32_t cs_ndir; /* number of directories */ int32_t cs_nbfree; /* number of free blocks */ int32_t cs_nifree; /* number of free inodes */ int32_t cs_nffree; /* number of free frags */ }; struct csum_total { int64_t cs_ndir; /* number of directories */ int64_t cs_nbfree; /* number of free blocks */ int64_t cs_nifree; /* number of free inodes */ int64_t cs_nffree; /* number of free frags */ int64_t cs_numclusters; /* number of free clusters */ int64_t cs_spare[3]; /* future expansion */ }; /* * Pointers to super block summary information. Placed in a separate * structure so there is just one pointer in the superblock. * * The pointers in this structure are used as follows: * fs_contigdirs references an array that tracks the creation of new * directories * fs_csp references a contiguous array of struct csum for * all cylinder groups * fs_maxcluster references an array of cluster sizes that is computed * as cylinder groups are inspected * fs_active is used when creating snapshots; it points to a bitmap * of cylinder groups for which the free-block bitmap has changed * since the snapshot operation began. */ struct fs_summary_info { uint8_t *si_contigdirs; /* (u) # of contig. allocated dirs */ struct csum *si_csp; /* (u) cg summary info buffer */ int32_t *si_maxcluster; /* (u) max cluster in each cyl group */ u_int *si_active; /* (u) used by snapshots to track fs */ }; /* * Super block for an FFS filesystem. */ struct fs { int32_t fs_firstfield; /* historic filesystem linked list, */ int32_t fs_unused_1; /* used for incore super blocks */ int32_t fs_sblkno; /* offset of super-block in filesys */ int32_t fs_cblkno; /* offset of cyl-block in filesys */ int32_t fs_iblkno; /* offset of inode-blocks in filesys */ int32_t fs_dblkno; /* offset of first data after cg */ int32_t fs_old_cgoffset; /* cylinder group offset in cylinder */ int32_t fs_old_cgmask; /* used to calc mod fs_ntrak */ int32_t fs_old_time; /* last time written */ int32_t fs_old_size; /* number of blocks in fs */ int32_t fs_old_dsize; /* number of data blocks in fs */ u_int32_t fs_ncg; /* number of cylinder groups */ int32_t fs_bsize; /* size of basic blocks in fs */ int32_t fs_fsize; /* size of frag blocks in fs */ int32_t fs_frag; /* number of frags in a block in fs */ /* these are configuration parameters */ int32_t fs_minfree; /* minimum percentage of free blocks */ int32_t fs_old_rotdelay; /* num of ms for optimal next block */ int32_t fs_old_rps; /* disk revolutions per second */ /* these fields can be computed from the others */ int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */ int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */ int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */ int32_t fs_fshift; /* ``numfrags'' calc number of frags */ /* these are configuration parameters */ int32_t fs_maxcontig; /* max number of contiguous blks */ int32_t fs_maxbpg; /* max number of blks per cyl group */ /* these fields can be computed from the others */ int32_t fs_fragshift; /* block to frag shift */ int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */ int32_t fs_sbsize; /* actual size of super block */ int32_t fs_spare1[2]; /* old fs_csmask */ /* old fs_csshift */ int32_t fs_nindir; /* value of NINDIR */ u_int32_t fs_inopb; /* value of INOPB */ int32_t fs_old_nspf; /* value of NSPF */ /* yet another configuration parameter */ int32_t fs_optim; /* optimization preference, see below */ int32_t fs_old_npsect; /* # sectors/track including spares */ int32_t fs_old_interleave; /* hardware sector interleave */ int32_t fs_old_trackskew; /* sector 0 skew, per track */ int32_t fs_id[2]; /* unique filesystem id */ /* sizes determined by number of cylinder groups and their sizes */ int32_t fs_old_csaddr; /* blk addr of cyl grp summary area */ int32_t fs_cssize; /* size of cyl grp summary area */ int32_t fs_cgsize; /* cylinder group size */ int32_t fs_spare2; /* old fs_ntrak */ int32_t fs_old_nsect; /* sectors per track */ int32_t fs_old_spc; /* sectors per cylinder */ int32_t fs_old_ncyl; /* cylinders in filesystem */ int32_t fs_old_cpg; /* cylinders per group */ u_int32_t fs_ipg; /* inodes per group */ int32_t fs_fpg; /* blocks per group * fs_frag */ /* this data must be re-computed after crashes */ struct csum fs_old_cstotal; /* cylinder summary information */ /* these fields are cleared at mount time */ int8_t fs_fmod; /* super block modified flag */ int8_t fs_clean; /* filesystem is clean flag */ int8_t fs_ronly; /* mounted read-only flag */ int8_t fs_old_flags; /* old FS_ flags */ u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */ u_char fs_volname[MAXVOLLEN]; /* volume name */ u_int64_t fs_swuid; /* system-wide uid */ int32_t fs_pad; /* due to alignment of fs_swuid */ /* these fields retain the current block allocation info */ int32_t fs_cgrotor; /* last cg searched */ uint8 fs_ocsp[120]; /* padding; was list of fs_cs buffers */ struct fs_summary_info *fs_si; /* In-core pointer to summary info */ int32_t fs_old_cpc; /* cyl per cycle in postbl */ int32_t fs_maxbsize; /* maximum blocking factor permitted */ int64_t fs_unrefs; /* number of unreferenced inodes */ int64_t fs_providersize; /* size of underlying GEOM provider */ int64_t fs_metaspace; /* size of area reserved for metadata */ int64_t fs_sparecon64[13]; /* old rotation block list head */ int64_t fs_sblockactualloc; /* byte offset of this superblock */ int64_t fs_sblockloc; /* byte offset of standard superblock */ struct csum_total fs_cstotal; /* (u) cylinder summary information */ ufs_time_t fs_time; /* last time written */ int64_t fs_size; /* number of blocks in fs */ int64_t fs_dsize; /* number of data blocks in fs */ ufs2_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */ int64_t fs_pendingblocks; /* (u) blocks being freed */ u_int32_t fs_pendinginodes; /* (u) inodes being freed */ uint32_t fs_snapinum[FSMAXSNAP]; /* list of snapshot inode numbers */ u_int32_t fs_avgfilesize; /* expected average file size */ u_int32_t fs_avgfpdir; /* expected # of files per directory */ int32_t fs_save_cgsize; /* save real cg size to use fs_bsize */ ufs_time_t fs_mtime; /* Last mount or fsck time. */ int32_t fs_sujfree; /* SUJ free list */ int32_t fs_sparecon32[21]; /* reserved for future constants */ u_int32_t fs_ckhash; /* if CK_SUPERBLOCK, its check-hash */ u_int32_t fs_metackhash; /* metadata check-hash, see CK_ below */ int32_t fs_flags; /* see FS_ flags below */ int32_t fs_contigsumsize; /* size of cluster summary array */ int32_t fs_maxsymlinklen; /* max length of an internal symlink */ int32_t fs_old_inodefmt; /* format of on-disk inodes */ u_int64_t fs_maxfilesize; /* maximum representable file size */ int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */ int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */ int32_t fs_state; /* validate fs_clean field */ int32_t fs_old_postblformat; /* format of positional layout tables */ int32_t fs_old_nrpos; /* number of rotational positions */ int32_t fs_spare5[2]; /* old fs_postbloff */ /* old fs_rotbloff */ int32_t fs_magic; /* magic number */ }; /* * Filesystem identification */ #define FS_UFS1_MAGIC 0x011954 /* UFS1 fast filesystem magic number */ #define FS_UFS2_MAGIC 0x19540119 /* UFS2 fast filesystem magic number */ #define FS_BAD_MAGIC 0x19960408 /* UFS incomplete newfs magic number */ #define FS_42INODEFMT -1 /* 4.2BSD inode format */ #define FS_44INODEFMT 2 /* 4.4BSD inode format */ /* * Filesystem flags. * * The FS_UNCLEAN flag is set by the kernel when the filesystem was * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates * that the filesystem should be managed by the soft updates code. * Note that the FS_NEEDSFSCK flag is set and cleared by the fsck * utility. It is set when background fsck finds an unexpected * inconsistency which requires a traditional foreground fsck to be * run. Such inconsistencies should only be found after an uncorrectable * disk error. The FS_NEEDSFSCK can also be set when a mounted filesystem * discovers an internal inconsistency such as freeing a freed inode. * A foreground fsck will clear the FS_NEEDSFSCK flag when it has * successfully cleaned up the filesystem. The kernel uses this * flag to enforce that inconsistent filesystems be mounted read-only. * * The FS_METACKHASH flag when set indicates that the kernel maintains * one or more check hashes. The actual set of supported check hashes * is stored in the fs_metackhash field. Kernels that do not support * check hashes clear the FS_METACKHASH flag to indicate that the * check hashes need to be rebuilt (by fsck) before they can be used. * * When a filesystem is mounted, any flags not included in FS_SUPPORTED * are cleared. This lets newer features know that the filesystem has * been run on an older version of the filesystem and thus that data * structures associated with those features are out-of-date and need * to be rebuilt. * * FS_ACLS indicates that POSIX.1e ACLs are administratively enabled * for the file system, so they should be loaded from extended attributes, * observed for access control purposes, and be administered by object * owners. FS_NFS4ACLS indicates that NFSv4 ACLs are administratively * enabled. This flag is mutually exclusive with FS_ACLS. FS_MULTILABEL * indicates that the TrustedBSD MAC Framework should attempt to back MAC * labels into extended attributes on the file system rather than maintain * a single mount label for all objects. */ #define FS_UNCLEAN 0x00000001 /* filesystem not clean at mount */ #define FS_DOSOFTDEP 0x00000002 /* filesystem using soft dependencies */ #define FS_NEEDSFSCK 0x00000004 /* filesystem needs sync fsck before mount */ #define FS_SUJ 0x00000008 /* Filesystem using softupdate journal */ #define FS_ACLS 0x00000010 /* file system has POSIX.1e ACLs enabled */ #define FS_MULTILABEL 0x00000020 /* file system is MAC multi-label */ #define FS_GJOURNAL 0x00000040 /* gjournaled file system */ #define FS_FLAGS_UPDATED 0x0000080 /* flags have been moved to new location */ #define FS_NFS4ACLS 0x00000100 /* file system has NFSv4 ACLs enabled */ #define FS_METACKHASH 0x00000200 /* kernel supports metadata check hashes */ #define FS_TRIM 0x00000400 /* issue BIO_DELETE for deleted blocks */ #define FS_SUPPORTED 0x00FFFFFF /* supported flags, others cleared at mount*/ /* * Cylinder group block for a filesystem. */ #define CG_MAGIC 0x090255 struct cg { int32_t cg_firstfield; /* historic cyl groups linked list */ int32_t cg_magic; /* magic number */ int32_t cg_old_time; /* time last written */ u_int32_t cg_cgx; /* we are the cgx'th cylinder group */ int16_t cg_old_ncyl; /* number of cyl's this cg */ int16_t cg_old_niblk; /* number of inode blocks this cg */ u_int32_t cg_ndblk; /* number of data blocks this cg */ struct csum cg_cs; /* cylinder summary information */ u_int32_t cg_rotor; /* position of last used block */ u_int32_t cg_frotor; /* position of last used frag */ u_int32_t cg_irotor; /* position of last used inode */ u_int32_t cg_frsum[MAXFRAG]; /* counts of available frags */ int32_t cg_old_btotoff; /* (int32) block totals per cylinder */ int32_t cg_old_boff; /* (u_int16) free block positions */ u_int32_t cg_iusedoff; /* (u_int8) used inode map */ u_int32_t cg_freeoff; /* (u_int8) free block map */ u_int32_t cg_nextfreeoff; /* (u_int8) next available space */ u_int32_t cg_clustersumoff; /* (u_int32) counts of avail clusters */ u_int32_t cg_clusteroff; /* (u_int8) free cluster map */ u_int32_t cg_nclusterblks; /* number of clusters this cg */ u_int32_t cg_niblk; /* number of inode blocks this cg */ u_int32_t cg_initediblk; /* last initialized inode */ u_int32_t cg_unrefs; /* number of unreferenced inodes */ int32_t cg_sparecon32[1]; /* reserved for future use */ u_int32_t cg_ckhash; /* check-hash of this cg */ ufs_time_t cg_time; /* time last written */ int64_t cg_sparecon64[3]; /* reserved for future use */ u_int8_t cg_space[1]; /* space for cylinder group maps */ /* actually longer */ }; /* * A dinode contains all the meta-data associated with a UFS2 file. * This structure defines the on-disk format of a dinode. Since * this structure describes an on-disk structure, all its fields * are defined by types with precise widths. */ #define UFS_NXADDR 2 /* External addresses in inode. */ #define UFS_NDADDR 12 /* Direct addresses in inode. */ #define UFS_NIADDR 3 /* Indirect addresses in inode. */ struct ufs2_dinode { u_int16_t di_mode; /* 0: IFMT, permissions; see below. */ int16_t di_nlink; /* 2: File link count. */ u_int32_t di_uid; /* 4: File owner. */ u_int32_t di_gid; /* 8: File group. */ u_int32_t di_blksize; /* 12: Inode blocksize. */ u_int64_t di_size; /* 16: File byte count. */ u_int64_t di_blocks; /* 24: Blocks actually held. */ ufs_time_t di_atime; /* 32: Last access time. */ ufs_time_t di_mtime; /* 40: Last modified time. */ ufs_time_t di_ctime; /* 48: Last inode change time. */ ufs_time_t di_birthtime; /* 56: Inode creation time. */ int32_t di_mtimensec; /* 64: Last modified time. */ int32_t di_atimensec; /* 68: Last access time. */ int32_t di_ctimensec; /* 72: Last inode change time. */ int32_t di_birthnsec; /* 76: Inode creation time. */ u_int32_t di_gen; /* 80: Generation number. */ u_int32_t di_kernflags; /* 84: Kernel flags. */ u_int32_t di_flags; /* 88: Status flags (chflags). */ u_int32_t di_extsize; /* 92: External attributes size. */ ufs2_daddr_t di_extb[UFS_NXADDR]; /* 96: External attributes block. */ ufs2_daddr_t di_db[UFS_NDADDR]; /* 112: Direct disk blocks. */ ufs2_daddr_t di_ib[UFS_NIADDR]; /* 208: Indirect disk blocks. */ u_int64_t di_modrev; /* 232: i_modrev for NFSv4 */ uint32_t di_freelink; /* 240: SUJ: Next unlinked inode. */ uint32_t di_ckhash; /* 244: if CK_INODE, its check-hash */ uint32_t di_spare[2]; /* 248: Reserved; currently unused */ }; /* * A UFS1 dinode contains all the meta-data associated with a UFS1 file. * This structure defines the on-disk format of a UFS1 dinode. Since * this structure describes an on-disk structure, all its fields * are defined by types with precise widths. */ struct ufs1_dinode { u_int16_t di_mode; /* 0: IFMT, permissions; see below. */ int16_t di_nlink; /* 2: File link count. */ uint32_t di_freelink; /* 4: SUJ: Next unlinked inode. */ u_int64_t di_size; /* 8: File byte count. */ int32_t di_atime; /* 16: Last access time. */ int32_t di_atimensec; /* 20: Last access time. */ int32_t di_mtime; /* 24: Last modified time. */ int32_t di_mtimensec; /* 28: Last modified time. */ int32_t di_ctime; /* 32: Last inode change time. */ int32_t di_ctimensec; /* 36: Last inode change time. */ ufs1_daddr_t di_db[UFS_NDADDR]; /* 40: Direct disk blocks. */ ufs1_daddr_t di_ib[UFS_NIADDR]; /* 88: Indirect disk blocks. */ u_int32_t di_flags; /* 100: Status flags (chflags). */ u_int32_t di_blocks; /* 104: Blocks actually held. */ u_int32_t di_gen; /* 108: Generation number. */ u_int32_t di_uid; /* 112: File owner. */ u_int32_t di_gid; /* 116: File group. */ u_int64_t di_modrev; /* 120: i_modrev for NFSv4 */ }; #define UFS_LINK_MAX 32767 #define UFS_MAXNAMLEN 255 struct direct { u_int32_t d_ino; /* inode number of entry */ u_int16_t d_reclen; /* length of this record */ u_int8_t d_type; /* file type, see below */ u_int8_t d_namlen; /* length of string in d_name */ char d_name[0]; /* name with length <= UFS_MAXNAMLEN */ }; """ .. raw:: html
.. py:data:: c_ffs