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Diffstat (limited to 'libarchive/archive_read.c')
| -rw-r--r-- | libarchive/archive_read.c | 739 |
1 files changed, 739 insertions, 0 deletions
diff --git a/libarchive/archive_read.c b/libarchive/archive_read.c new file mode 100644 index 00000000..327969f4 --- /dev/null +++ b/libarchive/archive_read.c @@ -0,0 +1,739 @@ +/*- + * 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 1.38 2008/03/12 04:58:32 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" + +static void choose_decompressor(struct archive_read *, const void*, size_t); +static int choose_format(struct archive_read *); +static off_t dummy_skip(struct archive_read *, off_t); + +/* + * 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(); + + /* We always support uncompressed archives. */ + archive_read_support_compression_none(&a->archive); + + 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; +} + + +/* + * 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); +} + +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; + const void *buffer; + ssize_t bytes_read; + int e; + + __archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, "archive_read_open"); + + if (client_reader == NULL) + __archive_errx(1, + "No reader function provided to archive_read_open"); + + /* + * Set these NULL initially. If the open or initial read fails, + * we'll leave them NULL to indicate that the file is invalid. + * (In particular, this helps ensure that the closer doesn't + * get called more than once.) + */ + a->client_opener = NULL; + a->client_reader = NULL; + a->client_skipper = NULL; + a->client_closer = NULL; + a->client_data = NULL; + + /* 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); + } + } + + /* Read first block now for compress format detection. */ + bytes_read = (client_reader)(&a->archive, client_data, &buffer); + + if (bytes_read < 0) { + /* If the first read fails, close before returning error. */ + if (client_closer) + (client_closer)(&a->archive, client_data); + /* client_reader should have already set error information. */ + return (ARCHIVE_FATAL); + } + + /* Now that the client callbacks have worked, remember them. */ + a->client_opener = client_opener; /* Do we need to remember this? */ + a->client_reader = client_reader; + a->client_skipper = client_skipper; + a->client_closer = client_closer; + a->client_data = client_data; + + /* Select a decompression routine. */ + choose_decompressor(a, buffer, (size_t)bytes_read); + if (a->decompressor == NULL) + return (ARCHIVE_FATAL); + + /* Initialize decompression routine with the first block of data. */ + e = (a->decompressor->init)(a, buffer, (size_t)bytes_read); + + if (e == ARCHIVE_OK) + a->archive.state = ARCHIVE_STATE_HEADER; + + /* + * If the decompressor didn't register a skip function, provide a + * dummy compression-layer skip function. + */ + if (a->decompressor->skip == NULL) + a->decompressor->skip = dummy_skip; + + return (e); +} + +/* + * Allow each registered decompression routine to bid on whether it + * wants to handle this stream. Return index of winning bidder. + */ +static void +choose_decompressor(struct archive_read *a, + const void *buffer, size_t bytes_read) +{ + int decompression_slots, i, bid, best_bid; + struct decompressor_t *decompressor, *best_decompressor; + + decompression_slots = sizeof(a->decompressors) / + sizeof(a->decompressors[0]); + + best_bid = 0; + a->decompressor = NULL; + best_decompressor = NULL; + + decompressor = a->decompressors; + for (i = 0; i < decompression_slots; i++) { + if (decompressor->bid) { + bid = (decompressor->bid)(buffer, bytes_read); + if (bid > best_bid || best_decompressor == NULL) { + best_bid = bid; + best_decompressor = decompressor; + } + } + decompressor ++; + } + + /* + * There were no bidders; this is a serious programmer error + * and demands a quick and definitive abort. + */ + if (best_decompressor == NULL) + __archive_errx(1, "No decompressors were registered; you " + "must call at least one " + "archive_read_support_compression_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; + } + + /* Record the best decompressor for this stream. */ + a->decompressor = best_decompressor; +} + +/* + * Dummy skip function, for use if the compression layer doesn't provide + * one: This code just reads data and discards it. + */ +static off_t +dummy_skip(struct archive_read * a, off_t request) +{ + const void * dummy_buffer; + ssize_t bytes_read; + off_t bytes_skipped; + + for (bytes_skipped = 0; request > 0;) { + bytes_read = (a->decompressor->read_ahead)(a, &dummy_buffer, 1); + if (bytes_read < 0) + return (bytes_read); + if (bytes_read == 0) { + /* Premature EOF. */ + archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, + "Truncated input file (need to skip %jd bytes)", + (intmax_t)request); + return (ARCHIVE_FATAL); + } + if (bytes_read > request) + bytes_read = (ssize_t)request; + (a->decompressor->consume)(a, (size_t)bytes_read); + request -= bytes_read; + bytes_skipped += bytes_read; + } + + return (bytes_skipped); +} + +/* + * Read header of next entry. + */ +int +archive_read_next_header(struct archive *_a, struct archive_entry **entryp) +{ + struct archive_read *a = (struct archive_read *)_a; + struct archive_entry *entry; + int slot, ret; + + __archive_check_magic(_a, ARCHIVE_READ_MAGIC, + ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA, + "archive_read_next_header"); + + *entryp = NULL; + entry = a->entry; + 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; + } + + *entryp = entry; + a->read_data_output_offset = 0; + a->read_data_remaining = 0; + 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. + */ +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"); + 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 decompressors. */ + n = sizeof(a->decompressors)/sizeof(a->decompressors[0]); + for (i = 0; i < n; i++) { + if (a->decompressors[i].finish != NULL) { + r1 = (a->decompressors[i].finish)(a); + if (r1 < r) + r = r1; + } + } + + /* Close the client stream. */ + if (a->client_closer != NULL) { + r1 = ((a->client_closer)(&a->archive, a->client_data)); + if (r1 < r) + r = r1; + } + + return (r); +} + +/* + * Release memory and other resources. + */ +#if ARCHIVE_API_VERSION > 1 +int +#else +/* Temporarily allow library to compile with either 1.x or 2.0 API. */ +void +#endif +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, + int (*bid)(struct archive_read *), + 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].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; + 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 decompressor_t * +__archive_read_register_compression(struct archive_read *a, + int (*bid)(const void *, size_t), + int (*init)(struct archive_read *, const void *, size_t)) +{ + int i, number_slots; + + __archive_check_magic(&a->archive, + ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW, + "__archive_read_register_compression"); + + number_slots = sizeof(a->decompressors) / sizeof(a->decompressors[0]); + + for (i = 0; i < number_slots; i++) { + if (a->decompressors[i].bid == bid) + return (a->decompressors + i); + if (a->decompressors[i].bid == NULL) { + a->decompressors[i].bid = bid; + a->decompressors[i].init = init; + return (a->decompressors + i); + } + } + + __archive_errx(1, "Not enough slots for compression registration"); + return (NULL); /* Never actually executed. */ +} + +/* used internally to simplify read-ahead */ +const void * +__archive_read_ahead(struct archive_read *a, size_t len) +{ + const void *h; + + if ((a->decompressor->read_ahead)(a, &h, len) < (ssize_t)len) + return (NULL); + return (h); +} |