X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Flookup_table.h;h=6fc5ae50c3f5f37439ca191f01d4fc3ef3ba0105;hp=9e082c77761b7b9bbd727201b80fd48672006518;hb=6f841e85af6215e88bce12a34a00548664fba6ea;hpb=f46894fd897b721ac3128743147bdbad70d19414 diff --git a/src/lookup_table.h b/src/lookup_table.h index 9e082c77..6fc5ae50 100644 --- a/src/lookup_table.h +++ b/src/lookup_table.h @@ -2,6 +2,7 @@ #define _WIMLIB_LOOKUP_TABLE_H #include "wimlib_internal.h" #include "dentry.h" +#include "sha1.h" #include /* Size of each lookup table entry in the WIM file. */ @@ -9,112 +10,245 @@ #define LOOKUP_FLAG_ADS_OK 0x00000001 #define LOOKUP_FLAG_DIRECTORY_OK 0x00000002 -#define LOOKUP_FLAG_FOLLOW_SYMLINKS 0x00000004 + +/* Not yet used */ +//#define LOOKUP_FLAG_FOLLOW_SYMLINKS 0x00000004 /* A lookup table that is used to translate the hash codes of dentries into the * offsets and sizes of uncompressed or compressed file resources. It is * implemented as a hash table. */ struct lookup_table { - struct lookup_table_entry **array; + struct hlist_head *array; u64 num_entries; u64 capacity; }; struct wimlib_fd; -/* An entry in the lookup table in the WIM file. */ +#ifdef WITH_NTFS_3G +struct ntfs_location { + char *path_utf8; + char *stream_name_utf16; + u16 stream_name_utf16_num_chars; + struct _ntfs_volume **ntfs_vol_p; + bool is_reparse_point; +}; +#endif + +/* + * An entry in the lookup table in the WIM file. + * + * It is used to find data streams for files in the WIM. + * + * Metadata resources and reparse point data buffers will also have lookup table + * entries associated with the data. + * + * The lookup_table_entry for a given dentry or alternate stream entry in the + * WIM is found using the SHA1 message digest field. + */ struct lookup_table_entry { - /* The next struct lookup_table_entry in the hash bucket. NULL if this is the - * last one. */ - struct lookup_table_entry *next; + /* List of lookup table entries in this hash bucket */ + struct hlist_node hash_list; - /* @resource_entry is read from the lookup table in the WIM - * file; it says where to find the file resource in the WIM - * file, and whether it is compressed or not. */ + /* Location and size of the stream in the WIM, whether it is compressed + * or not, and whether it's a metadata resource or not. This is an + * on-disk field. */ struct resource_entry resource_entry; - /* Currently ignored; set to 1 in new lookup table entries. */ + /* Specifies which part of the split WIM the resource is located in. + * This is on on-disk field. + * + * In stand-alone WIMs, this must be 1. + * + * In split WIMs, every split WIM part has its own lookup table, and in + * read_lookup_table() it's currently expected that the part number of + * each lookup table entry in a split WIM part's lookup table is the + * same as the part number of that split WIM part. So this makes this + * field redundant since we store a pointer to the corresponding + * WIMStruct in the lookup table entry anyway. + */ u16 part_number; - /* Number of times this lookup table entry is referenced by dentries. */ + /* An enumerated type that identifies where the stream corresponding to + * this lookup table entry is actually located. + * + * Obviously if we open a WIM and read its lookup table, the location is + * set to RESOURCE_IN_WIM since all the streams will initially be + * located in the WIM. However, to deal with problems such as image + * capture and image mount, we allow the actual location of the stream + * to be somewhere else, such as an external file. + */ + enum { + /* The lookup table entry does not correspond to a stream (this + * state should exist only temporarily) */ + RESOURCE_NONEXISTENT = 0, + + /* The stream resource is located in a WIM file. The WIMStruct + * for the WIM file will be pointed to by the @wim member. */ + RESOURCE_IN_WIM, + + /* The stream resource is located in an external file. The + * name of the file will be provided by @file_on_disk member. + * In addition, if @file_on_disk_fp is not NULL, it will be an + * open FILE * to the file. */ + RESOURCE_IN_FILE_ON_DISK, + + /* The stream resource is located in an external file in the + * staging directory for a read-write mount. */ + RESOURCE_IN_STAGING_FILE, + + /* The stream resource is directly attached in an in-memory + * buffer pointed to by @attached_buffer. */ + RESOURCE_IN_ATTACHED_BUFFER, + + /* The stream resource is located in an NTFS volume. It is + * identified by volume, filename, data stream name, and by + * whether it is a reparse point or not. @ntfs_loc points to a + * structure containing this information. */ + RESOURCE_IN_NTFS_VOLUME, + } resource_location; + + /* (On-disk field) + * Number of times this lookup table entry is referenced by dentries. + * Unfortunately, this field is not always set correctly in Microsoft's + * WIMs, so we have no choice but to fix it if more references to the + * lookup table entry are found than stated here. */ u32 refcnt; - /* If %true, this lookup table entry corresponds to a symbolic link - * reparse buffer. @symlink_reparse_data_buf will give the target of - * the symbolic link. */ - bool is_symlink; - union { - /* SHA1 hash of the file resource pointed to by this lookup - * table entry */ - u8 hash[WIM_HASH_SIZE]; - - /* First 4 or 8 bytes of the SHA1 hash, used for inserting the - * entry into the hash table. Since the SHA1 hashes can be - * considered random, we don't really need the full 20 byte hash - * just to insert the entry in a hash table. */ + /* (On-disk field) SHA1 message digest of the stream referenced + * by this lookup table entry */ + u8 hash[SHA1_HASH_SIZE]; + + /* First 4 or 8 bytes of the SHA1 message digest, used for + * inserting the entry into the hash table. Since the SHA1 + * message digest can be considered random, we don't really need + * the full 20 byte hash just to insert the entry in a hash + * table. */ size_t hash_short; }; - /* If @file_on_disk != NULL, the file resource indicated by this lookup - * table entry is not in the WIM file, but rather a file on disk; this - * occurs for files that are added to the WIM. In that case, - * file_on_disk is the name of the file in the outside filesystem. - * It will not be compressed, and its size will be given by - * resource_entry.size and resource_entry.original_size. */ + /* Pointers to somewhere where the stream is actually located. See the + * comments for the @resource_location field above. */ union { + WIMStruct *wim; char *file_on_disk; char *staging_file_name; - void *symlink_buf; - struct lookup_table_entry *next_lte_in_swm; + u8 *attached_buffer; + #ifdef WITH_NTFS_3G + struct ntfs_location *ntfs_loc; + #endif }; - union { - struct { /* Used for wimlib_export. */ - - /* If (other_wim_fp != NULL), the file resource indicated - * by this lookup table entry is in a different WIM - * file, and other_wim_fp is the FILE* for it. */ - FILE *other_wim_fp; - - /* Compression type used in other WIM. */ - int other_wim_ctype; - }; - struct wimlib_fd **fds; - u16 num_allocated_fds; - u16 num_opened_fds; + /* Temporary field for creating a singly linked list. Shouldn't + * really be here */ + struct lookup_table_entry *next_lte_in_swm; + + /* @file_on_disk_fp and @attr are both used to cache file/stream + * handles so we don't have re-open them on every read */ + FILE *file_on_disk_fp; + #ifdef WITH_NTFS_3G + struct _ntfs_attr *attr; + #endif }; +#ifdef WITH_FUSE + /* File descriptors table for this data stream. This is used if the WIM + * is mounted. Basically, each time a file is open()ed, a new file + * descriptor is added here, and each time a file is close()ed, the file + * descriptor is gotten rid of. If the stream is opened for writing, it + * will be extracted to the staging directory and there will be an + * actual native file descriptor associated with each "wimlib file + * descriptor". */ + u16 num_opened_fds; + u16 num_allocated_fds; + struct wimlib_fd **fds; +#endif /* When a WIM file is written, out_refcnt starts at 0 and is incremented * whenever the file resource pointed to by this lookup table entry - * needs to be written. Naturally, the file resource only need to be - * written when out_refcnt is 0. Incrementing it further is needed to - * find the correct reference count to write to the lookup table in the - * output file, which may be less than the regular refcnt if not all - * images in the WIM file are written. - * - * output_resource_entry is the struct resource_entry for the position of the - * file resource when written to the output file. */ + * needs to be written. The file resource only need to be written when + * out_refcnt is nonzero, since otherwise it is not referenced by any + * dentries. */ + u32 out_refcnt; + union { - u32 out_refcnt; - bool refcnt_is_incremented; + /* When a WIM file is written, @output_resource_entry is filled + * in with the resource entry for the output WIM. This will not + * necessarily be the same as the @resource_entry since: + * - The stream may have a different offset in the new WIM + * - The stream may have a different compressed size in the + * new WIM if the compression type changed + */ + struct resource_entry output_resource_entry; + + /* This field is used for the special hardlink or symlink image + * application mode. In these mode, all identical files are + * linked together, and @extracted_file will be set to the + * filename of the first extracted file containing this stream. + * */ + char *extracted_file; }; - struct resource_entry output_resource_entry; - struct dentry *hard_link_sets; + + /* Circular linked list of streams that share the same lookup table + * entry. + * + * This list of streams may include streams from different hard link + * sets that happen to be the same. */ + struct list_head lte_group_list; + + /* List of lookup table entries that correspond to streams that have + * been extracted to the staging directory when modifying a read-write + * mounted WIM. */ + struct list_head staging_list; }; +static inline u64 wim_resource_size(const struct lookup_table_entry *lte) +{ + return lte->resource_entry.original_size; +} + +static inline u64 +wim_resource_compressed_size(const struct lookup_table_entry *lte) +{ + return lte->resource_entry.size; +} + +/* + * XXX Probably should store the compression type directly in the lookup table + * entry + */ +static inline int +wim_resource_compression_type(const struct lookup_table_entry *lte) +{ + if (!(lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED) + || lte->resource_location != RESOURCE_IN_WIM) + return WIM_COMPRESSION_TYPE_NONE; + return wimlib_get_compression_type(lte->wim); +} + + extern struct lookup_table *new_lookup_table(size_t capacity); extern void lookup_table_insert(struct lookup_table *table, struct lookup_table_entry *lte); -extern void lookup_table_unlink(struct lookup_table *table, - struct lookup_table_entry *lte); +/* Unlinks a lookup table entry from the table; does not free it. */ +static inline void lookup_table_unlink(struct lookup_table *table, + struct lookup_table_entry *lte) +{ + hlist_del(<e->hash_list); + table->num_entries--; +} -extern bool lookup_table_decrement_refcnt(struct lookup_table* table, - const u8 hash[]); + +extern struct lookup_table_entry * +lookup_table_decrement_refcnt(struct lookup_table* table, const u8 hash[]); + +extern struct lookup_table_entry * +lte_decrement_refcnt(struct lookup_table_entry *lte, + struct lookup_table *table); extern struct lookup_table_entry *new_lookup_table_entry(); @@ -124,31 +258,26 @@ extern int for_lookup_table_entry(struct lookup_table *table, void *arg); extern struct lookup_table_entry * -__lookup_resource(const struct lookup_table *lookup_table, const u8 hash[]); +__lookup_resource(const struct lookup_table *table, const u8 hash[]); extern int lookup_resource(WIMStruct *w, const char *path, int lookup_flags, struct dentry **dentry_ret, struct lookup_table_entry **lte_ret, - u8 **hash_ret); + unsigned *stream_idx_ret); extern int zero_out_refcnts(struct lookup_table_entry *entry, void *ignore); -extern int print_lookup_table_entry(struct lookup_table_entry *entry, void *ignore); +extern void print_lookup_table_entry(const struct lookup_table_entry *entry); -extern int read_lookup_table(FILE *fp, u64 offset, u64 size, - struct lookup_table **table_ret); +extern int read_lookup_table(WIMStruct *w); extern void free_lookup_table(struct lookup_table *table); extern int write_lookup_table_entry(struct lookup_table_entry *lte, void *__out); -static inline void free_lookup_table_entry(struct lookup_table_entry *lte) -{ - if (lte) { - FREE(lte->file_on_disk); - FREE(lte); - } -} +extern void free_lookup_table_entry(struct lookup_table_entry *lte); + +extern int dentry_resolve_ltes(struct dentry *dentry, void *__table); /* Writes the lookup table to the output file. */ static inline int write_lookup_table(struct lookup_table *table, FILE *out) @@ -170,4 +299,123 @@ static inline struct resource_entry* wim_metadata_resource_entry(WIMStruct *w) w->current_image - 1].metadata_lte->resource_entry; } +static inline struct lookup_table_entry * +dentry_stream_lte_resolved(const struct dentry *dentry, unsigned stream_idx) +{ + wimlib_assert(dentry->resolved); + wimlib_assert(stream_idx <= dentry->num_ads); + if (stream_idx == 0) + return dentry->lte; + else + return dentry->ads_entries[stream_idx - 1].lte; +} + +static inline struct lookup_table_entry * +dentry_stream_lte_unresolved(const struct dentry *dentry, unsigned stream_idx, + const struct lookup_table *table) +{ + wimlib_assert(!dentry->resolved); + wimlib_assert(stream_idx <= dentry->num_ads); + if (!table) + return NULL; + if (stream_idx == 0) + return __lookup_resource(table, dentry->hash); + else + return __lookup_resource(table, + dentry->ads_entries[ + stream_idx - 1].hash); +} +/* + * Returns the lookup table entry for stream @stream_idx of the dentry, where + * stream_idx = 0 means the default un-named file stream, and stream_idx >= 1 + * corresponds to an alternate data stream. + * + * This works for both resolved and un-resolved dentries. + */ +static inline struct lookup_table_entry * +dentry_stream_lte(const struct dentry *dentry, unsigned stream_idx, + const struct lookup_table *table) +{ + if (dentry->resolved) + return dentry_stream_lte_resolved(dentry, stream_idx); + else + return dentry_stream_lte_unresolved(dentry, stream_idx, table); +} + + +static inline const u8 *dentry_stream_hash_unresolved(const struct dentry *dentry, + unsigned stream_idx) +{ + wimlib_assert(!dentry->resolved); + wimlib_assert(stream_idx <= dentry->num_ads); + if (stream_idx == 0) + return dentry->hash; + else + return dentry->ads_entries[stream_idx - 1].hash; +} + +static inline u16 dentry_stream_name_len(const struct dentry *dentry, + unsigned stream_idx) +{ + wimlib_assert(stream_idx <= dentry->num_ads); + if (stream_idx == 0) + return 0; + else + return dentry->ads_entries[stream_idx - 1].stream_name_len; +} + +static inline const u8 *dentry_stream_hash_resolved(const struct dentry *dentry, + unsigned stream_idx) +{ + struct lookup_table_entry *lte; + lte = dentry_stream_lte_resolved(dentry, stream_idx); + if (lte) + return lte->hash; + else + return zero_hash; +} + +/* + * Returns the hash for stream @stream_idx of the dentry, where stream_idx = 0 + * means the default un-named file stream, and stream_idx >= 1 corresponds to an + * alternate data stream. + * + * This works for both resolved and un-resolved dentries. + */ +static inline const u8 *dentry_stream_hash(const struct dentry *dentry, + unsigned stream_idx) +{ + if (dentry->resolved) + return dentry_stream_hash_resolved(dentry, stream_idx); + else + return dentry_stream_hash_unresolved(dentry, stream_idx); +} + +static inline struct lookup_table_entry * +dentry_unnamed_lte_resolved(const struct dentry *dentry) +{ + wimlib_assert(dentry->resolved); + for (unsigned i = 0; i <= dentry->num_ads; i++) + if (dentry_stream_name_len(dentry, i) == 0 && + !is_zero_hash(dentry_stream_hash_resolved(dentry, i))) + return dentry_stream_lte_resolved(dentry, i); + return NULL; +} + +static inline struct lookup_table_entry * +dentry_unnamed_lte_unresolved(const struct dentry *dentry, + const struct lookup_table *table) +{ + wimlib_assert(!dentry->resolved); + for (unsigned i = 0; i <= dentry->num_ads; i++) + if (dentry_stream_name_len(dentry, i) == 0 && + !is_zero_hash(dentry_stream_hash_unresolved(dentry, i))) + return dentry_stream_lte_unresolved(dentry, i, table); + return NULL; +} + +extern struct lookup_table_entry * +dentry_unnamed_lte(const struct dentry *dentry, + const struct lookup_table *table); + #endif