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Diffstat (limited to 'Utilities/cmlibarchive/libarchive/archive_read.c')
| -rw-r--r-- | Utilities/cmlibarchive/libarchive/archive_read.c | 1342 |
1 files changed, 1342 insertions, 0 deletions
diff --git a/Utilities/cmlibarchive/libarchive/archive_read.c b/Utilities/cmlibarchive/libarchive/archive_read.c new file mode 100644 index 000000000..baf9dc467 --- /dev/null +++ b/Utilities/cmlibarchive/libarchive/archive_read.c @@ -0,0 +1,1342 @@ +/*- + * Copyright (c) 2003-2011 Tim Kientzle + * 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 AUTHOR(S) ``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 AUTHOR(S) 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. + */ + +/* + * This file contains the "essential" portions of the read API, that + * is, stuff that will probably always be used by any client that + * actually needs to read an archive. Optional pieces have been, as + * far as possible, separated out into separate files to avoid + * needlessly bloating statically-linked clients. + */ + +#include "archive_platform.h" +__FBSDID("$FreeBSD: head/lib/libarchive/archive_read.c 201157 2009-12-29 05:30:23Z kientzle $"); + +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif +#include <stdio.h> +#ifdef HAVE_STDLIB_H +#include <stdlib.h> +#endif +#ifdef HAVE_STRING_H +#include <string.h> +#endif +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include "archive.h" +#include "archive_entry.h" +#include "archive_private.h" +#include "archive_read_private.h" + +#define minimum(a, b) (a < b ? a : b) + +static int choose_filters(struct archive_read *); +static int choose_format(struct archive_read *); +static void free_filters(struct archive_read *); +static int close_filters(struct archive_read *); +static struct archive_vtable *archive_read_vtable(void); +static int64_t _archive_filter_bytes(struct archive *, int); +static int _archive_filter_code(struct archive *, int); +static const char *_archive_filter_name(struct archive *, int); +static int _archive_filter_count(struct archive *); +static int _archive_read_close(struct archive *); +static int _archive_read_data_block(struct archive *, + const void **, size_t *, int64_t *); +static int _archive_read_free(struct archive *); +static int _archive_read_next_header(struct archive *, + struct archive_entry **); +static int _archive_read_next_header2(struct archive *, + struct archive_entry *); +static int64_t advance_file_pointer(struct archive_read_filter *, int64_t); + +static struct archive_vtable * +archive_read_vtable(void) +{ + static struct archive_vtable av; + static int inited = 0; + + if (!inited) { + av.archive_filter_bytes = _archive_filter_bytes; + av.archive_filter_code = _archive_filter_code; + av.archive_filter_name = _archive_filter_name; + av.archive_filter_count = _archive_filter_count; + av.archive_read_data_block = _archive_read_data_block; + av.archive_read_next_header = _archive_read_next_header; + av.archive_read_next_header2 = _archive_read_next_header2; + av.archive_free = _archive_read_free; + av.archive_close = _archive_read_close; + inited = 1; + } + return (&av); +} + +/* + * Allocate, initialize and return a struct archive object. + */ +struct archive * +archive_read_new(void) +{ + struct archive_read *a; + + a = (struct archive_read *)malloc(sizeof(*a)); + if (a == NULL) + return (NULL); + memset(a, 0, sizeof(*a)); + a->archive.magic = ARCHIVE_READ_MAGIC; + + a->archive.state = ARCHIVE_STATE_NEW; + a->entry = archive_entry_new2(&a->archive); + a->archive.vtable = archive_read_vtable(); + + return (&a->archive); +} + +/* + * Record the do-not-extract-to file. This belongs in archive_read_extract.c. + */ +void +archive_read_extract_set_skip_file(struct archive *_a, int64_t d, int64_t i) +{ + struct archive_read *a = (struct archive_read *)_a; + + if (ARCHIVE_OK != __archive_check_magic(_a, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_ANY, "archive_read_extract_set_skip_file")) + return; + a->skip_file_set = 1; + a->skip_file_dev = d; + a->skip_file_ino = i; +} + +/* + * Open the archive + */ +int +archive_read_open(struct archive *a, void *client_data, + archive_open_callback *client_opener, archive_read_callback *client_reader, + archive_close_callback *client_closer) +{ + /* Old archive_read_open() is just a thin shell around + * archive_read_open1. */ + archive_read_set_open_callback(a, client_opener); + archive_read_set_read_callback(a, client_reader); + archive_read_set_close_callback(a, client_closer); + archive_read_set_callback_data(a, client_data); + return archive_read_open1(a); +} + + +int +archive_read_open2(struct archive *a, void *client_data, + archive_open_callback *client_opener, + archive_read_callback *client_reader, + archive_skip_callback *client_skipper, + archive_close_callback *client_closer) +{ + /* Old archive_read_open2() is just a thin shell around + * archive_read_open1. */ + archive_read_set_callback_data(a, client_data); + archive_read_set_open_callback(a, client_opener); + archive_read_set_read_callback(a, client_reader); + archive_read_set_skip_callback(a, client_skipper); + archive_read_set_close_callback(a, client_closer); + return archive_read_open1(a); +} + +static ssize_t +client_read_proxy(struct archive_read_filter *self, const void **buff) +{ + ssize_t r; + r = (self->archive->client.reader)(&self->archive->archive, + self->data, buff); + return (r); +} + +static int64_t +client_skip_proxy(struct archive_read_filter *self, int64_t request) +{ + if (request < 0) + __archive_errx(1, "Negative skip requested."); + if (request == 0) + return 0; + + if (self->archive->client.skipper != NULL) { + /* Seek requests over 1GiB are broken down into + * multiple seeks. This avoids overflows when the + * requests get passed through 32-bit arguments. */ + int64_t skip_limit = (int64_t)1 << 30; + int64_t total = 0; + for (;;) { + int64_t get, ask = request; + if (ask > skip_limit) + ask = skip_limit; + get = (self->archive->client.skipper)(&self->archive->archive, + self->data, ask); + if (get == 0) + return (total); + request -= get; + total += get; + } + return total; + } else if (self->archive->client.seeker != NULL + && request > 64 * 1024) { + /* If the client provided a seeker but not a skipper, + * we can use the seeker to skip forward. + * + * Note: This isn't always a good idea. The client + * skipper is allowed to skip by less than requested + * if it needs to maintain block alignment. The + * seeker is not allowed to play such games, so using + * the seeker here may be a performance loss compared + * to just reading and discarding. That's why we + * only do this for skips of over 64k. + */ + int64_t before = self->position; + int64_t after = (self->archive->client.seeker)(&self->archive->archive, + self->data, request, SEEK_CUR); + if (after != before + request) + return ARCHIVE_FATAL; + return after - before; + } + return 0; +} + +static int64_t +client_seek_proxy(struct archive_read_filter *self, int64_t offset, int whence) +{ + /* DO NOT use the skipper here! If we transparently handled + * forward seek here by using the skipper, that will break + * other libarchive code that assumes a successful forward + * seek means it can also seek backwards. + */ + if (self->archive->client.seeker == NULL) + return (ARCHIVE_FAILED); + return (self->archive->client.seeker)(&self->archive->archive, + self->data, offset, whence); +} + +static int +client_close_proxy(struct archive_read_filter *self) +{ + int r = ARCHIVE_OK; + + if (self->archive->client.closer != NULL) + r = (self->archive->client.closer)((struct archive *)self->archive, + self->data); + return (r); +} + +int +archive_read_set_open_callback(struct archive *_a, + archive_open_callback *client_opener) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_open_callback"); + a->client.opener = client_opener; + return ARCHIVE_OK; +} + +int +archive_read_set_read_callback(struct archive *_a, + archive_read_callback *client_reader) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_read_callback"); + a->client.reader = client_reader; + return ARCHIVE_OK; +} + +int +archive_read_set_skip_callback(struct archive *_a, + archive_skip_callback *client_skipper) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_skip_callback"); + a->client.skipper = client_skipper; + return ARCHIVE_OK; +} + +int +archive_read_set_seek_callback(struct archive *_a, + archive_seek_callback *client_seeker) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_seek_callback"); + a->client.seeker = client_seeker; + return ARCHIVE_OK; +} + +int +archive_read_set_close_callback(struct archive *_a, + archive_close_callback *client_closer) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_close_callback"); + a->client.closer = client_closer; + return ARCHIVE_OK; +} + +int +archive_read_set_callback_data(struct archive *_a, void *client_data) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_set_callback_data"); + a->client.data = client_data; + return ARCHIVE_OK; +} + +int +archive_read_open1(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + struct archive_read_filter *filter; + int slot, e; + + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "archive_read_open"); + archive_clear_error(&a->archive); + + if (a->client.reader == NULL) { + archive_set_error(&a->archive, EINVAL, + "No reader function provided to archive_read_open"); + a->archive.state = ARCHIVE_STATE_FATAL; + return (ARCHIVE_FATAL); + } + + /* Open data source. */ + if (a->client.opener != NULL) { + e =(a->client.opener)(&a->archive, a->client.data); + if (e != 0) { + /* If the open failed, call the closer to clean up. */ + if (a->client.closer) + (a->client.closer)(&a->archive, a->client.data); + return (e); + } + } + + filter = calloc(1, sizeof(*filter)); + if (filter == NULL) + return (ARCHIVE_FATAL); + filter->bidder = NULL; + filter->upstream = NULL; + filter->archive = a; + filter->data = a->client.data; + filter->read = client_read_proxy; + filter->skip = client_skip_proxy; + filter->seek = client_seek_proxy; + filter->close = client_close_proxy; + filter->name = "none"; + filter->code = ARCHIVE_COMPRESSION_NONE; + a->filter = filter; + + /* Build out the input pipeline. */ + e = choose_filters(a); + if (e < ARCHIVE_WARN) { + a->archive.state = ARCHIVE_STATE_FATAL; + return (ARCHIVE_FATAL); + } + + slot = choose_format(a); + if (slot < 0) { + close_filters(a); + a->archive.state = ARCHIVE_STATE_FATAL; + return (ARCHIVE_FATAL); + } + a->format = &(a->formats[slot]); + + a->archive.state = ARCHIVE_STATE_HEADER; + return (e); +} + +/* + * Allow each registered stream transform to bid on whether + * it wants to handle this stream. Repeat until we've finished + * building the pipeline. + */ +static int +choose_filters(struct archive_read *a) +{ + int number_bidders, i, bid, best_bid; + struct archive_read_filter_bidder *bidder, *best_bidder; + struct archive_read_filter *filter; + ssize_t avail; + int r; + + for (;;) { + number_bidders = sizeof(a->bidders) / sizeof(a->bidders[0]); + + best_bid = 0; + best_bidder = NULL; + + bidder = a->bidders; + for (i = 0; i < number_bidders; i++, bidder++) { + if (bidder->bid != NULL) { + bid = (bidder->bid)(bidder, a->filter); + if (bid > best_bid) { + best_bid = bid; + best_bidder = bidder; + } + } + } + + /* If no bidder, we're done. */ + if (best_bidder == NULL) { + /* Verify the filter by asking it for some data. */ + __archive_read_filter_ahead(a->filter, 1, &avail); + if (avail < 0) { + close_filters(a); + free_filters(a); + return (ARCHIVE_FATAL); + } + a->archive.compression_name = a->filter->name; + a->archive.compression_code = a->filter->code; + return (ARCHIVE_OK); + } + + filter + = (struct archive_read_filter *)calloc(1, sizeof(*filter)); + if (filter == NULL) + return (ARCHIVE_FATAL); + filter->bidder = best_bidder; + filter->archive = a; + filter->upstream = a->filter; + a->filter = filter; + r = (best_bidder->init)(a->filter); + if (r != ARCHIVE_OK) { + close_filters(a); + free_filters(a); + return (ARCHIVE_FATAL); + } + } +} + +/* + * Read header of next entry. + */ +static int +_archive_read_next_header2(struct archive *_a, struct archive_entry *entry) +{ + struct archive_read *a = (struct archive_read *)_a; + int r1 = ARCHIVE_OK, r2; + + archive_check_magic(_a, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA, + "archive_read_next_header"); + + archive_entry_clear(entry); + archive_clear_error(&a->archive); + + /* + * If client didn't consume entire data, skip any remainder + * (This is especially important for GNU incremental directories.) + */ + if (a->archive.state == ARCHIVE_STATE_DATA) { + r1 = archive_read_data_skip(&a->archive); + if (r1 == ARCHIVE_EOF) + archive_set_error(&a->archive, EIO, + "Premature end-of-file."); + if (r1 == ARCHIVE_EOF || r1 == ARCHIVE_FATAL) { + a->archive.state = ARCHIVE_STATE_FATAL; + return (ARCHIVE_FATAL); + } + } + + /* Record start-of-header offset in uncompressed stream. */ + a->header_position = a->filter->position; + + ++_a->file_count; + r2 = (a->format->read_header)(a, entry); + + /* + * EOF and FATAL are persistent at this layer. By + * modifying the state, we guarantee that future calls to + * read a header or read data will fail. + */ + switch (r2) { + case ARCHIVE_EOF: + a->archive.state = ARCHIVE_STATE_EOF; + --_a->file_count;/* Revert a file counter. */ + break; + case ARCHIVE_OK: + a->archive.state = ARCHIVE_STATE_DATA; + break; + case ARCHIVE_WARN: + a->archive.state = ARCHIVE_STATE_DATA; + break; + case ARCHIVE_RETRY: + break; + case ARCHIVE_FATAL: + a->archive.state = ARCHIVE_STATE_FATAL; + break; + } + + a->read_data_output_offset = 0; + a->read_data_remaining = 0; + /* EOF always wins; otherwise return the worst error. */ + return (r2 < r1 || r2 == ARCHIVE_EOF) ? r2 : r1; +} + +int +_archive_read_next_header(struct archive *_a, struct archive_entry **entryp) +{ + int ret; + struct archive_read *a = (struct archive_read *)_a; + *entryp = NULL; + ret = _archive_read_next_header2(_a, a->entry); + *entryp = a->entry; + return ret; +} + +/* + * Allow each registered format to bid on whether it wants to handle + * the next entry. Return index of winning bidder. + */ +static int +choose_format(struct archive_read *a) +{ + int slots; + int i; + int bid, best_bid; + int best_bid_slot; + + slots = sizeof(a->formats) / sizeof(a->formats[0]); + best_bid = -1; + best_bid_slot = -1; + + /* Set up a->format for convenience of bidders. */ + a->format = &(a->formats[0]); + for (i = 0; i < slots; i++, a->format++) { + if (a->format->bid) { + bid = (a->format->bid)(a, best_bid); + if (bid == ARCHIVE_FATAL) + return (ARCHIVE_FATAL); + if (a->filter->position != 0) + __archive_read_seek(a, 0, SEEK_SET); + if ((bid > best_bid) || (best_bid_slot < 0)) { + best_bid = bid; + best_bid_slot = i; + } + } + } + + /* + * There were no bidders; this is a serious programmer error + * and demands a quick and definitive abort. + */ + if (best_bid_slot < 0) { + archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT, + "No formats registered"); + return (ARCHIVE_FATAL); + } + + /* + * There were bidders, but no non-zero bids; this means we + * can't support this stream. + */ + if (best_bid < 1) { + archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT, + "Unrecognized archive format"); + return (ARCHIVE_FATAL); + } + + return (best_bid_slot); +} + +/* + * Return the file offset (within the uncompressed data stream) where + * the last header started. + */ +int64_t +archive_read_header_position(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_ANY, "archive_read_header_position"); + return (a->header_position); +} + +/* + * Read data from an archive entry, using a read(2)-style interface. + * This is a convenience routine that just calls + * archive_read_data_block and copies the results into the client + * buffer, filling any gaps with zero bytes. Clients using this + * API can be completely ignorant of sparse-file issues; sparse files + * will simply be padded with nulls. + * + * DO NOT intermingle calls to this function and archive_read_data_block + * to read a single entry body. + */ +ssize_t +archive_read_data(struct archive *_a, void *buff, size_t s) +{ + struct archive_read *a = (struct archive_read *)_a; + char *dest; + const void *read_buf; + size_t bytes_read; + size_t len; + int r; + + bytes_read = 0; + dest = (char *)buff; + + while (s > 0) { + if (a->read_data_remaining == 0) { + read_buf = a->read_data_block; + r = _archive_read_data_block(&a->archive, &read_buf, + &a->read_data_remaining, &a->read_data_offset); + a->read_data_block = read_buf; + if (r == ARCHIVE_EOF) + return (bytes_read); + /* + * Error codes are all negative, so the status + * return here cannot be confused with a valid + * byte count. (ARCHIVE_OK is zero.) + */ + if (r < ARCHIVE_OK) + return (r); + } + + if (a->read_data_offset < a->read_data_output_offset) { + archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT, + "Encountered out-of-order sparse blocks"); + return (ARCHIVE_RETRY); + } + + /* Compute the amount of zero padding needed. */ + if (a->read_data_output_offset + s < + a->read_data_offset) { + len = s; + } else if (a->read_data_output_offset < + a->read_data_offset) { + len = a->read_data_offset - + a->read_data_output_offset; + } else + len = 0; + + /* Add zeroes. */ + memset(dest, 0, len); + s -= len; + a->read_data_output_offset += len; + dest += len; + bytes_read += len; + + /* Copy data if there is any space left. */ + if (s > 0) { + len = a->read_data_remaining; + if (len > s) + len = s; + memcpy(dest, a->read_data_block, len); + s -= len; + a->read_data_block += len; + a->read_data_remaining -= len; + a->read_data_output_offset += len; + a->read_data_offset += len; + dest += len; + bytes_read += len; + } + } + return (bytes_read); +} + +/* + * Skip over all remaining data in this entry. + */ +int +archive_read_data_skip(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + int r; + const void *buff; + size_t size; + int64_t offset; + + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA, + "archive_read_data_skip"); + + if (a->format->read_data_skip != NULL) + r = (a->format->read_data_skip)(a); + else { + while ((r = archive_read_data_block(&a->archive, + &buff, &size, &offset)) + == ARCHIVE_OK) + ; + } + + if (r == ARCHIVE_EOF) + r = ARCHIVE_OK; + + a->archive.state = ARCHIVE_STATE_HEADER; + return (r); +} + +/* + * Read the next block of entry data from the archive. + * This is a zero-copy interface; the client receives a pointer, + * size, and file offset of the next available block of data. + * + * Returns ARCHIVE_OK if the operation is successful, ARCHIVE_EOF if + * the end of entry is encountered. + */ +static int +_archive_read_data_block(struct archive *_a, + const void **buff, size_t *size, int64_t *offset) +{ + struct archive_read *a = (struct archive_read *)_a; + archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA, + "archive_read_data_block"); + + if (a->format->read_data == NULL) { + archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER, + "Internal error: " + "No format_read_data_block function registered"); + return (ARCHIVE_FATAL); + } + + return (a->format->read_data)(a, buff, size, offset); +} + +static int +close_filters(struct archive_read *a) +{ + struct archive_read_filter *f = a->filter; + int r = ARCHIVE_OK; + /* Close each filter in the pipeline. */ + while (f != NULL) { + struct archive_read_filter *t = f->upstream; + if (!f->closed && f->close != NULL) { + int r1 = (f->close)(f); + f->closed = 1; + if (r1 < r) + r = r1; + } + free(f->buffer); + f->buffer = NULL; + f = t; + } + return r; +} + +static void +free_filters(struct archive_read *a) +{ + while (a->filter != NULL) { + struct archive_read_filter *t = a->filter->upstream; + free(a->filter); + a->filter = t; + } +} + +/* + * return the count of # of filters in use + */ +static int +_archive_filter_count(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + struct archive_read_filter *p = a->filter; + int count = 0; + while(p) { + count++; + p = p->upstream; + } + return count; +} + +/* + * Close the file and all I/O. + */ +static int +_archive_read_close(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + int r = ARCHIVE_OK, r1 = ARCHIVE_OK; + + archive_check_magic(&a->archive, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL, "archive_read_close"); + if (a->archive.state == ARCHIVE_STATE_CLOSED) + return (ARCHIVE_OK); + archive_clear_error(&a->archive); + a->archive.state = ARCHIVE_STATE_CLOSED; + + /* TODO: Clean up the formatters. */ + + /* Release the filter objects. */ + r1 = close_filters(a); + if (r1 < r) + r = r1; + + return (r); +} + +/* + * Release memory and other resources. + */ +static int +_archive_read_free(struct archive *_a) +{ + struct archive_read *a = (struct archive_read *)_a; + int i, n; + int slots; + int r = ARCHIVE_OK; + + if (_a == NULL) + return (ARCHIVE_OK); + archive_check_magic(_a, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_ANY | ARCHIVE_STATE_FATAL, "archive_read_free"); + if (a->archive.state != ARCHIVE_STATE_CLOSED + && a->archive.state != ARCHIVE_STATE_FATAL) + r = archive_read_close(&a->archive); + + /* Call cleanup functions registered by optional components. */ + if (a->cleanup_archive_extract != NULL) + r = (a->cleanup_archive_extract)(a); + + /* Cleanup format-specific data. */ + slots = sizeof(a->formats) / sizeof(a->formats[0]); + for (i = 0; i < slots; i++) { + a->format = &(a->formats[i]); + if (a->formats[i].cleanup) + (a->formats[i].cleanup)(a); + } + + /* Free the filters */ + free_filters(a); + + /* Release the bidder objects. */ + n = sizeof(a->bidders)/sizeof(a->bidders[0]); + for (i = 0; i < n; i++) { + if (a->bidders[i].free != NULL) { + int r1 = (a->bidders[i].free)(&a->bidders[i]); + if (r1 < r) + r = r1; + } + } + + archive_string_free(&a->archive.error_string); + if (a->entry) + archive_entry_free(a->entry); + a->archive.magic = 0; + __archive_clean(&a->archive); + free(a); + return (r); +} + +static struct archive_read_filter * +get_filter(struct archive *_a, int n) +{ + struct archive_read *a = (struct archive_read *)_a; + struct archive_read_filter *f = a->filter; + /* We use n == -1 for 'the last filter', which is always the client proxy. */ + if (n == -1 && f != NULL) { + struct archive_read_filter *last = f; + f = f->upstream; + while (f != NULL) { + last = f; + f = f->upstream; + } + return (last); + } + if (n < 0) + return NULL; + while (n > 0 && f != NULL) { + f = f->upstream; + --n; + } + return (f); +} + +static int +_archive_filter_code(struct archive *_a, int n) +{ + struct archive_read_filter *f = get_filter(_a, n); + return f == NULL ? -1 : f->code; +} + +static const char * +_archive_filter_name(struct archive *_a, int n) +{ + struct archive_read_filter *f = get_filter(_a, n); + return f != NULL ? f->name : NULL; +} + +static int64_t +_archive_filter_bytes(struct archive *_a, int n) +{ + struct archive_read_filter *f = get_filter(_a, n); + return f == NULL ? -1 : f->position; +} + +/* + * Used internally by read format handlers to register their bid and + * initialization functions. + */ +int +__archive_read_register_format(struct archive_read *a, + void *format_data, + const char *name, + int (*bid)(struct archive_read *, int), + int (*options)(struct archive_read *, const char *, const char *), + int (*read_header)(struct archive_read *, struct archive_entry *), + int (*read_data)(struct archive_read *, const void **, size_t *, int64_t *), + int (*read_data_skip)(struct archive_read *), + int (*cleanup)(struct archive_read *)) +{ + int i, number_slots; + + archive_check_magic(&a->archive, + ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "__archive_read_register_format"); + + number_slots = sizeof(a->formats) / sizeof(a->formats[0]); + + for (i = 0; i < number_slots; i++) { + if (a->formats[i].bid == bid) + return (ARCHIVE_WARN); /* We've already installed */ + if (a->formats[i].bid == NULL) { + a->formats[i].bid = bid; + a->formats[i].options = options; + a->formats[i].read_header = read_header; + a->formats[i].read_data = read_data; + a->formats[i].read_data_skip = read_data_skip; + a->formats[i].cleanup = cleanup; + a->formats[i].data = format_data; + a->formats[i].name = name; + return (ARCHIVE_OK); + } + } + + archive_set_error(&a->archive, ENOMEM, + "Not enough slots for format registration"); + return (ARCHIVE_FATAL); +} + +/* + * Used internally by decompression routines to register their bid and + * initialization functions. + */ +int +__archive_read_get_bidder(struct archive_read *a, + struct archive_read_filter_bidder **bidder) +{ + int i, number_slots; + + number_slots = sizeof(a->bidders) / sizeof(a->bidders[0]); + + for (i = 0; i < number_slots; i++) { + if (a->bidders[i].bid == NULL) { + memset(a->bidders + i, 0, sizeof(a->bidders[0])); + *bidder = (a->bidders + i); + return (ARCHIVE_OK); + } + } + + archive_set_error(&a->archive, ENOMEM, + "Not enough slots for filter registration"); + return (ARCHIVE_FATAL); +} + +/* + * The next section implements the peek/consume internal I/O + * system used by archive readers. This system allows simple + * read-ahead for consumers while preserving zero-copy operation + * most of the time. + * + * The two key operations: + * * The read-ahead function returns a pointer to a block of data + * that satisfies a minimum request. + * * The consume function advances the file pointer. + * + * In the ideal case, filters generate blocks of data + * and __archive_read_ahead() just returns pointers directly into + * those blocks. Then __archive_read_consume() just bumps those + * pointers. Only if your request would span blocks does the I/O + * layer use a copy buffer to provide you with a contiguous block of + * data. + * + * A couple of useful idioms: + * * "I just want some data." Ask for 1 byte and pay attention to + * the "number of bytes available" from __archive_read_ahead(). + * Consume whatever you actually use. + * * "I want to output a large block of data." As above, ask for 1 byte, + * emit all that's available (up to whatever limit you have), consume + * it all, then repeat until you're done. This effectively means that + * you're passing along the blocks that came from your provider. + * * "I want to peek ahead by a large amount." Ask for 4k or so, then + * double and repeat until you get an error or have enough. Note + * that the I/O layer will likely end up expanding its copy buffer + * to fit your request, so use this technique cautiously. This + * technique is used, for example, by some of the format tasting + * code that has uncertain look-ahead needs. + */ + +/* + * Looks ahead in the input stream: + * * If 'avail' pointer is provided, that returns number of bytes available + * in the current buffer, which may be much larger than requested. + * * If end-of-file, *avail gets set to zero. + * * If error, *avail gets error code. + * * If request can be met, returns pointer to data. + * * If minimum request cannot be met, returns NULL. + * + * Note: If you just want "some data", ask for 1 byte and pay attention + * to *avail, which will have the actual amount available. If you + * know exactly how many bytes you need, just ask for that and treat + * a NULL return as an error. + * + * Important: This does NOT move the file pointer. See + * __archive_read_consume() below. + */ +const void * +__archive_read_ahead(struct archive_read *a, size_t min, ssize_t *avail) +{ + return (__archive_read_filter_ahead(a->filter, min, avail)); +} + +const void * +__archive_read_filter_ahead(struct archive_read_filter *filter, + size_t min, ssize_t *avail) +{ + ssize_t bytes_read; + size_t tocopy; + + if (filter->fatal) { + if (avail) + *avail = ARCHIVE_FATAL; + return (NULL); + } + + /* + * Keep pulling more data until we can satisfy the request. + */ + for (;;) { + + /* + * If we can satisfy from the copy buffer (and the + * copy buffer isn't empty), we're done. In particular, + * note that min == 0 is a perfectly well-defined + * request. + */ + if (filter->avail >= min && filter->avail > 0) { + if (avail != NULL) + *avail = filter->avail; + return (filter->next); + } + + /* + * We can satisfy directly from client buffer if everything + * currently in the copy buffer is still in the client buffer. + */ + if (filter->client_total >= filter->client_avail + filter->avail + && filter->client_avail + filter->avail >= min) { + /* "Roll back" to client buffer. */ + filter->client_avail += filter->avail; + filter->client_next -= filter->avail; + /* Copy buffer is now empty. */ + filter->avail = 0; + filter->next = filter->buffer; + /* Return data from client buffer. */ + if (avail != NULL) + *avail = filter->client_avail; + return (filter->client_next); + } + + /* Move data forward in copy buffer if necessary. */ + if (filter->next > filter->buffer && + filter->next + min > filter->buffer + filter->buffer_size) { + if (filter->avail > 0) + memmove(filter->buffer, filter->next, filter->avail); + filter->next = filter->buffer; + } + + /* If we've used up the client data, get more. */ + if (filter->client_avail <= 0) { + if (filter->end_of_file) { + if (avail != NULL) + *avail = 0; + return (NULL); + } + bytes_read = (filter->read)(filter, + &filter->client_buff); + if (bytes_read < 0) { /* Read error. */ + filter->client_total = filter->client_avail = 0; + filter->client_next = filter->client_buff = NULL; + filter->fatal = 1; + if (avail != NULL) + *avail = ARCHIVE_FATAL; + return (NULL); + } + if (bytes_read == 0) { /* Premature end-of-file. */ + filter->client_total = filter->client_avail = 0; + filter->client_next = filter->client_buff = NULL; + filter->end_of_file = 1; + /* Return whatever we do have. */ + if (avail != NULL) + *avail = filter->avail; + return (NULL); + } + filter->client_total = bytes_read; + filter->client_avail = filter->client_total; + filter->client_next = filter->client_buff; + } + else + { + /* + * We can't satisfy the request from the copy + * buffer or the existing client data, so we + * need to copy more client data over to the + * copy buffer. + */ + + /* Ensure the buffer is big enough. */ + if (min > filter->buffer_size) { + size_t s, t; + char *p; + + /* Double the buffer; watch for overflow. */ + s = t = filter->buffer_size; + if (s == 0) + s = min; + while (s < min) { + t *= 2; + if (t <= s) { /* Integer overflow! */ + archive_set_error( + &filter->archive->archive, + ENOMEM, + "Unable to allocate copy buffer"); + filter->fatal = 1; + if (avail != NULL) + *avail = ARCHIVE_FATAL; + return (NULL); + } + s = t; + } + /* Now s >= min, so allocate a new buffer. */ + p = (char *)malloc(s); + if (p == NULL) { + archive_set_error( + &filter->archive->archive, + ENOMEM, + "Unable to allocate copy buffer"); + filter->fatal = 1; + if (avail != NULL) + *avail = ARCHIVE_FATAL; + return (NULL); + } + /* Move data into newly-enlarged buffer. */ + if (filter->avail > 0) + memmove(p, filter->next, filter->avail); + free(filter->buffer); + filter->next = filter->buffer = p; + filter->buffer_size = s; + } + + /* We can add client data to copy buffer. */ + /* First estimate: copy to fill rest of buffer. */ + tocopy = (filter->buffer + filter->buffer_size) + - (filter->next + filter->avail); + /* Don't waste time buffering more than we need to. */ + if (tocopy + filter->avail > min) + tocopy = min - filter->avail; + /* Don't copy more than is available. */ + if (tocopy > filter->client_avail) + tocopy = filter->client_avail; + + memcpy(filter->next + filter->avail, filter->client_next, + tocopy); + /* Remove this data from client buffer. */ + filter->client_next += tocopy; + filter->client_avail -= tocopy; + /* add it to copy buffer. */ + filter->avail += tocopy; + } + } +} + +/* + * Move the file pointer forward. + */ +int64_t +__archive_read_consume(struct archive_read *a, int64_t request) +{ + return (__archive_read_filter_consume(a->filter, request)); +} + +int64_t +__archive_read_filter_consume(struct archive_read_filter * filter, + int64_t request) +{ + int64_t skipped; + + if (request == 0) + return 0; + + skipped = advance_file_pointer(filter, request); + if (skipped == request) + return (skipped); + /* We hit EOF before we satisfied the skip request. */ + if (skipped < 0) /* Map error code to 0 for error message below. */ + skipped = 0; + archive_set_error(&filter->archive->archive, + ARCHIVE_ERRNO_MISC, + "Truncated input file (needed %jd bytes, only %jd available)", + (intmax_t)request, (intmax_t)skipped); + return (ARCHIVE_FATAL); +} + +/* + * Advance the file pointer by the amount requested. + * Returns the amount actually advanced, which may be less than the + * request if EOF is encountered first. + * Returns a negative value if there's an I/O error. + */ +static int64_t +advance_file_pointer(struct archive_read_filter *filter, int64_t request) +{ + int64_t bytes_skipped, total_bytes_skipped = 0; + ssize_t bytes_read; + size_t min; + + if (filter->fatal) + return (-1); + + /* Use up the copy buffer first. */ + if (filter->avail > 0) { + min = minimum(request, (int64_t)filter->avail); + filter->next += min; + filter->avail -= min; + request -= min; + filter->position += min; + total_bytes_skipped += min; + } + + /* Then use up the client buffer. */ + if (filter->client_avail > 0) { + min = minimum(request, (int64_t)filter->client_avail); + filter->client_next += min; + filter->client_avail -= min; + request -= min; + filter->position += min; + total_bytes_skipped += min; + } + if (request == 0) + return (total_bytes_skipped); + + /* If there's an optimized skip function, use it. */ + if (filter->skip != NULL) { + bytes_skipped = (filter->skip)(filter, request); + if (bytes_skipped < 0) { /* error */ + filter->fatal = 1; + return (bytes_skipped); + } + filter->position += bytes_skipped; + total_bytes_skipped += bytes_skipped; + request -= bytes_skipped; + if (request == 0) + return (total_bytes_skipped); + } + + /* Use ordinary reads as necessary to complete the request. */ + for (;;) { + bytes_read = (filter->read)(filter, &filter->client_buff); + if (bytes_read < 0) { + filter->client_buff = NULL; + filter->fatal = 1; + return (bytes_read); + } + + if (bytes_read == 0) { + filter->client_buff = NULL; + filter->end_of_file = 1; + return (total_bytes_skipped); + } + + if (bytes_read >= request) { + filter->client_next = + ((const char *)filter->client_buff) + request; + filter->client_avail = bytes_read - request; + filter->client_total = bytes_read; + total_bytes_skipped += request; + filter->position += request; + return (total_bytes_skipped); + } + + filter->position += bytes_read; + total_bytes_skipped += bytes_read; + request -= bytes_read; + } +} + +/** + * Returns ARCHIVE_FAILED if seeking isn't supported. + */ +int64_t +__archive_read_seek(struct archive_read *a, int64_t offset, int whence) +{ + return __archive_read_filter_seek(a->filter, offset, whence); +} + +int64_t +__archive_read_filter_seek(struct archive_read_filter *filter, int64_t offset, int whence) +{ + int64_t r; + + if (filter->closed || filter->fatal) + return (ARCHIVE_FATAL); + if (filter->seek == NULL) + return (ARCHIVE_FAILED); + r = filter->seek(filter, offset, whence); + if (r >= 0) { + /* + * Ouch. Clearing the buffer like this hurts, especially + * at bid time. A lot of our efficiency at bid time comes + * from having bidders reuse the data we've already read. + * + * TODO: If the seek request is in data we already + * have, then don't call the seek callback. + * + * TODO: Zip seeks to end-of-file at bid time. If + * other formats also start doing this, we may need to + * find a way for clients to fudge the seek offset to + * a block boundary. + * + * Hmmm... If whence was SEEK_END, we know the file + * size is (r - offset). Can we use that to simplify + * the TODO items above? + */ + filter->avail = filter->client_avail = 0; + filter->next = filter->buffer; + filter->position = r; + filter->end_of_file = 0; + } + return r; +} |