diff options
Diffstat (limited to 'Utilities/cmlibarchive/libarchive/archive_read.c')
| -rw-r--r-- | Utilities/cmlibarchive/libarchive/archive_read.c | 1241 |
1 files changed, 0 insertions, 1241 deletions
diff --git a/Utilities/cmlibarchive/libarchive/archive_read.c b/Utilities/cmlibarchive/libarchive/archive_read.c deleted file mode 100644 index 79dd1f8..0000000 --- a/Utilities/cmlibarchive/libarchive/archive_read.c +++ /dev/null @@ -1,1241 +0,0 @@ -/*- - * Copyright (c) 2003-2007 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: src/lib/libarchive/archive_read.c,v 1.39 2008/12/06 06:45:15 kientzle Exp $"); - -#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 build_stream(struct archive_read *); -static int choose_format(struct archive_read *); -static struct archive_vtable *archive_read_vtable(void); -static int _archive_read_close(struct archive *); -static int _archive_read_finish(struct archive *); - -static struct archive_vtable * -archive_read_vtable(void) -{ - static struct archive_vtable av; - static int inited = 0; - - if (!inited) { - av.archive_finish = _archive_read_finish; - av.archive_close = _archive_read_close; - } - 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_new(); - 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, dev_t d, ino_t i) -{ - struct archive_read *a = (struct archive_read *)_a; - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY, - "archive_read_extract_set_skip_file"); - a->skip_file_dev = d; - a->skip_file_ino = i; -} - -/* - * Set read options for the format. - */ -int -archive_read_set_format_options(struct archive *_a, const char *s) -{ - struct archive_read *a; - struct archive_format_descriptor *format; - char key[64], val[64]; - char *valp; - size_t i; - int len, r; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, - "archive_read_set_format_options"); - - if (s == NULL || *s == '\0') - return (ARCHIVE_OK); - a = (struct archive_read *)_a; - __archive_check_magic(&a->archive, ARCHIVE_READ_MAGIC, - ARCHIVE_STATE_NEW, "archive_read_set_format_options"); - len = 0; - for (i = 0; i < sizeof(a->formats)/sizeof(a->formats[0]); i++) { - format = &a->formats[i]; - if (format == NULL || format->options == NULL || - format->name == NULL) - /* This format does not support option. */ - continue; - - while ((len = __archive_parse_options(s, format->name, - sizeof(key), key, sizeof(val), val)) > 0) { - valp = val[0] == '\0' ? NULL : val; - a->format = format; - r = format->options(a, key, valp); - a->format = NULL; - if (r == ARCHIVE_FATAL) - return (r); - s += len; - } - } - if (len < 0) { - archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, - "Illegal format options."); - return (ARCHIVE_WARN); - } - return (ARCHIVE_OK); -} - -/* - * Set read options for the filter. - */ -int -archive_read_set_filter_options(struct archive *_a, const char *s) -{ - struct archive_read *a; - struct archive_read_filter *filter; - struct archive_read_filter_bidder *bidder; - char key[64], val[64]; - int len, r; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, - "archive_read_set_filter_options"); - - if (s == NULL || *s == '\0') - return (ARCHIVE_OK); - a = (struct archive_read *)_a; - __archive_check_magic(&a->archive, ARCHIVE_READ_MAGIC, - ARCHIVE_STATE_NEW, "archive_read_set_filter_options"); - filter = a->filter; - len = 0; - for (filter = a->filter; filter != NULL; filter = filter->upstream) { - bidder = filter->bidder; - if (bidder == NULL) - continue; - if (bidder->options == NULL) - /* This bidder does not support option */ - continue; - while ((len = __archive_parse_options(s, filter->name, - sizeof(key), key, sizeof(val), val)) > 0) { - if (val[0] == '\0') - r = bidder->options(bidder, key, NULL); - else - r = bidder->options(bidder, key, val); - if (r == ARCHIVE_FATAL) - return (r); - s += len; - } - } - if (len < 0) { - archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, - "Illegal format options."); - return (ARCHIVE_WARN); - } - return (ARCHIVE_OK); -} - -/* - * Set read options for the format and the filter. - */ -int -archive_read_set_options(struct archive *_a, const char *s) -{ - int r; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, - "archive_read_set_options"); - archive_clear_error(_a); - - r = archive_read_set_format_options(_a, s); - if (r != ARCHIVE_OK) - return (r); - r = archive_read_set_filter_options(_a, s); - if (r != ARCHIVE_OK) - return (r); - return (ARCHIVE_OK); -} - -/* - * 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_open2. */ - return archive_read_open2(a, client_data, client_opener, - client_reader, NULL, client_closer); -} - -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); - self->archive->archive.raw_position += r; - return (r); -} - -static int64_t -client_skip_proxy(struct archive_read_filter *self, int64_t request) -{ - int64_t ask, get, total; - /* Limit our maximum seek request to 1GB on platforms - * with 32-bit off_t (such as Windows). */ - int64_t skip_limit = ((int64_t)1) << (sizeof(off_t) * 8 - 2); - - if (self->archive->client.skipper == NULL) - return (0); - total = 0; - for (;;) { - 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; - self->archive->archive.raw_position += get; - total += get; - } -} - -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); - self->data = NULL; - return (r); -} - - -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) -{ - struct archive_read *a = (struct archive_read *)_a; - struct archive_read_filter *filter; - int e; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, - "archive_read_open"); - archive_clear_error(&a->archive); - - if (client_reader == NULL) - __archive_errx(1, - "No reader function provided to archive_read_open"); - - /* Open data source. */ - if (client_opener != NULL) { - e =(client_opener)(&a->archive, client_data); - if (e != 0) { - /* If the open failed, call the closer to clean up. */ - if (client_closer) - (client_closer)(&a->archive, client_data); - return (e); - } - } - - /* Save the client functions and mock up the initial source. */ - a->client.reader = client_reader; - a->client.skipper = client_skipper; - a->client.closer = client_closer; - - filter = calloc(1, sizeof(*filter)); - if (filter == NULL) - return (ARCHIVE_FATAL); - filter->bidder = NULL; - filter->upstream = NULL; - filter->archive = a; - filter->data = client_data; - filter->read = client_read_proxy; - filter->skip = client_skip_proxy; - filter->close = client_close_proxy; - filter->name = "none"; - filter->code = ARCHIVE_COMPRESSION_NONE; - a->filter = filter; - - /* Build out the input pipeline. */ - e = build_stream(a); - if (e == ARCHIVE_OK) - 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 -build_stream(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) { - 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; - r = (best_bidder->init)(filter); - if (r != ARCHIVE_OK) { - free(filter); - return (r); - } - /* Verify the filter by asking it for some data. */ - __archive_read_filter_ahead(filter, 1, &avail); - if (avail < 0) { - /* If the read failed, bail out now. */ - free(filter); - return (avail); - } - a->filter = filter; - } -} - -/* - * Read header of next entry. - */ -int -archive_read_next_header2(struct archive *_a, struct archive_entry *entry) -{ - struct archive_read *a = (struct archive_read *)_a; - int slot, ret; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, - ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA, - "archive_read_next_header"); - - ++_a->file_count; - archive_entry_clear(entry); - archive_clear_error(&a->archive); - - /* - * If no format has yet been chosen, choose one. - */ - if (a->format == NULL) { - slot = choose_format(a); - if (slot < 0) { - a->archive.state = ARCHIVE_STATE_FATAL; - return (ARCHIVE_FATAL); - } - a->format = &(a->formats[slot]); - } - - /* - * 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) { - ret = archive_read_data_skip(&a->archive); - if (ret == ARCHIVE_EOF) { - archive_set_error(&a->archive, EIO, "Premature end-of-file."); - a->archive.state = ARCHIVE_STATE_FATAL; - return (ARCHIVE_FATAL); - } - if (ret != ARCHIVE_OK) - return (ret); - } - - /* Record start-of-header. */ - a->header_position = a->archive.file_position; - - ret = (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 (ret) { - case ARCHIVE_EOF: - a->archive.state = ARCHIVE_STATE_EOF; - 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; - return (ret); -} - -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 and a->pformat_data 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); - if (bid == ARCHIVE_FATAL) - return (ARCHIVE_FATAL); - 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_errx(1, "No formats were registered; you must " - "invoke at least one archive_read_support_format_XXX " - "function in order to successfully read an archive."); - - /* - * 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 + (off_t)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); -} - -#if ARCHIVE_API_VERSION < 3 -/* - * Obsolete function provided for compatibility only. Note that the API - * of this function doesn't allow the caller to detect if the remaining - * data from the archive entry is shorter than the buffer provided, or - * even if an error occurred while reading data. - */ -int -archive_read_data_into_buffer(struct archive *a, void *d, ssize_t len) -{ - - archive_read_data(a, d, len); - return (ARCHIVE_OK); -} -#endif - -/* - * 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; - off_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. - */ -int -archive_read_data_block(struct archive *_a, - const void **buff, size_t *size, off_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); -} - -/* - * Close the file and release most resources. - * - * Be careful: client might just call read_new and then read_finish. - * Don't assume we actually read anything or performed any non-trivial - * initialization. - */ -static int -_archive_read_close(struct archive *_a) -{ - struct archive_read *a = (struct archive_read *)_a; - int r = ARCHIVE_OK, r1 = ARCHIVE_OK; - size_t i, n; - - __archive_check_magic(&a->archive, ARCHIVE_READ_MAGIC, - ARCHIVE_STATE_ANY, "archive_read_close"); - archive_clear_error(&a->archive); - a->archive.state = ARCHIVE_STATE_CLOSED; - - - /* Call cleanup functions registered by optional components. */ - if (a->cleanup_archive_extract != NULL) - r = (a->cleanup_archive_extract)(a); - - /* TODO: Clean up the formatters. */ - - /* Clean up the filter pipeline. */ - while (a->filter != NULL) { - struct archive_read_filter *t = a->filter->upstream; - if (a->filter->close != NULL) { - r1 = (a->filter->close)(a->filter); - if (r1 < r) - r = r1; - } - free(a->filter->buffer); - free(a->filter); - a->filter = t; - } - - /* Release the bidder objects. */ - n = sizeof(a->bidders)/sizeof(a->bidders[0]); - for (i = 0; i < n; i++) { - if (a->bidders[i].free != NULL) { - r1 = (a->bidders[i].free)(&a->bidders[i]); - if (r1 < r) - r = r1; - } - } - - return (r); -} - -/* - * Release memory and other resources. - */ -static int -_archive_read_finish(struct archive *_a) -{ - struct archive_read *a = (struct archive_read *)_a; - int i; - int slots; - int r = ARCHIVE_OK; - - __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY, - "archive_read_finish"); - if (a->archive.state != ARCHIVE_STATE_CLOSED) - r = archive_read_close(&a->archive); - - /* 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); - } - - archive_string_free(&a->archive.error_string); - if (a->entry) - archive_entry_free(a->entry); - a->archive.magic = 0; - free(a); -#if ARCHIVE_API_VERSION > 1 - return (r); -#endif -} - -/* - * 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 (*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 *, off_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_errx(1, "Not enough slots for format registration"); - return (ARCHIVE_FATAL); /* Never actually called. */ -} - -/* - * Used internally by decompression routines to register their bid and - * initialization functions. - */ -struct archive_read_filter_bidder * -__archive_read_get_bidder(struct archive_read *a) -{ - int i, number_slots; - - __archive_check_magic(&a->archive, - ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, - "__archive_read_get_bidder"); - - 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])); - return (a->bidders + i); - } - } - - __archive_errx(1, "Not enough slots for compression registration"); - return (NULL); /* Never actually executed. */ -} - -/* - * The next three functions comprise the peek/consume internal I/O - * system used by archive format readers. This system allows fairly - * flexible read-ahead and allows the I/O code to operate in a - * zero-copy manner most of the time. - * - * 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. The __archive_read_skip() is an optimization; it scans ahead - * very quickly (it usually translates into a seek() operation if - * you're reading uncompressed disk files). - * - * 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(). - * You can consume more than you asked for; you just can't consume - * more than is available. If you consume everything that's - * immediately available, the next read_ahead() call will pull - * the next block. - * * "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), then - * repeat until you're done. - * * "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. - * - * TODO: Someday, provide a more generic __archive_read_seek() for - * those cases where it's useful. This is tricky because there are lots - * of cases where seek() is not available (reading gzip data from a - * network socket, for instance), so there needs to be a good way to - * communicate whether seek() is available and users of that interface - * need to use non-seeking strategies whenever seek() is not available. - */ - -/* - * 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, returns NULL - * if request is not met. - * - * 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. - */ - -/* - * This is tricky. We need to provide our clients with pointers to - * contiguous blocks of memory but we want to avoid copying whenever - * possible. - * - * Mostly, this code returns pointers directly into the block of data - * provided by the client_read routine. It can do this unless the - * request would split across blocks. In that case, we have to copy - * into an internal buffer to combine reads. - */ -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->position += bytes_read; - 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. This should be called after - * __archive_read_ahead() returns data to you. Don't try to move - * ahead by more than the amount of data available according to - * __archive_read_ahead(). - */ -/* - * Mark the appropriate data as used. Note that the request here will - * often be much smaller than the size of the previous read_ahead - * request. - */ -ssize_t -__archive_read_consume(struct archive_read *a, size_t request) -{ - ssize_t r; - r = __archive_read_filter_consume(a->filter, request); - a->archive.file_position += r; - return (r); -} - -ssize_t -__archive_read_filter_consume(struct archive_read_filter * filter, - size_t request) -{ - if (filter->avail > 0) { - /* Read came from copy buffer. */ - filter->next += request; - filter->avail -= request; - } else { - /* Read came from client buffer. */ - filter->client_next += request; - filter->client_avail -= request; - } - return (request); -} - -/* - * Move the file pointer ahead by an arbitrary amount. If you're - * reading uncompressed data from a disk file, this will actually - * translate into a seek() operation. Even in cases where seek() - * isn't feasible, this at least pushes the read-and-discard loop - * down closer to the data source. - */ -int64_t -__archive_read_skip(struct archive_read *a, int64_t request) -{ - int64_t skipped = __archive_read_skip_lenient(a, 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(&a->archive, - ARCHIVE_ERRNO_MISC, - "Truncated input file (needed %jd bytes, only %jd available)", - (intmax_t)request, (intmax_t)skipped); - return (ARCHIVE_FATAL); -} - -int64_t -__archive_read_skip_lenient(struct archive_read *a, int64_t request) -{ - int64_t skipped = __archive_read_filter_skip(a->filter, request); - if (skipped > 0) - a->archive.file_position += skipped; - return (skipped); -} - -int64_t -__archive_read_filter_skip(struct archive_read_filter *filter, int64_t request) -{ - int64_t bytes_skipped, total_bytes_skipped = 0; - size_t min; - - if (filter->fatal) - return (-1); - /* - * If there is data in the buffers already, use that first. - */ - if (filter->avail > 0) { - min = minimum(request, (off_t)filter->avail); - bytes_skipped = __archive_read_filter_consume(filter, min); - request -= bytes_skipped; - total_bytes_skipped += bytes_skipped; - } - if (filter->client_avail > 0) { - min = minimum(request, (int64_t)filter->client_avail); - bytes_skipped = __archive_read_filter_consume(filter, min); - request -= bytes_skipped; - total_bytes_skipped += bytes_skipped; - } - if (request == 0) - return (total_bytes_skipped); - /* - * If a client_skipper was provided, try that first. - */ -#if ARCHIVE_API_VERSION < 2 - if ((filter->skip != NULL) && (request < SSIZE_MAX)) { -#else - if (filter->skip != NULL) { -#endif - bytes_skipped = (filter->skip)(filter, request); - if (bytes_skipped < 0) { /* error */ - filter->client_total = filter->client_avail = 0; - filter->client_next = filter->client_buff = NULL; - filter->fatal = 1; - return (bytes_skipped); - } - total_bytes_skipped += bytes_skipped; - request -= bytes_skipped; - filter->client_next = filter->client_buff; - filter->client_avail = filter->client_total = 0; - } - /* - * Note that client_skipper will usually not satisfy the - * full request (due to low-level blocking concerns), - * so even if client_skipper is provided, we may still - * have to use ordinary reads to finish out the request. - */ - while (request > 0) { - const void* dummy_buffer; - ssize_t bytes_read; - dummy_buffer = __archive_read_filter_ahead(filter, - 1, &bytes_read); - if (bytes_read < 0) - return (bytes_read); - if (bytes_read == 0) { - return (total_bytes_skipped); - } - min = (size_t)(minimum(bytes_read, request)); - bytes_read = __archive_read_filter_consume(filter, min); - total_bytes_skipped += bytes_read; - request -= bytes_read; - } - return (total_bytes_skipped); -} |