NetBSD-5.0.2/dist/libarchive/libarchive/archive_read.c
/*-
* 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);
}