freebsd-skq/lib/libarchive/archive_read.c
Tim Kientzle d911e48507 * Plug a buffer overrun in ACL parsing. (archive_entry.c)
* Re-use a single buffer for shar output formatting rather
   than hammering the heap. (archive_write_set_format_shar.c)
 * Fix a handful of minor memory leaks and clean up some of the
   memory-management code.
2004-04-13 23:45:37 +00:00

498 lines
13 KiB
C

/*-
* Copyright (c) 2003-2004 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
* in this position and unchanged.
* 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("$FreeBSD$");
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
static int choose_decompressor(struct archive *, const void*, size_t);
static int choose_format(struct archive *);
/*
* Allocate, initialize and return a struct archive object.
*/
struct archive *
archive_read_new(void)
{
struct archive *a;
char *nulls;
a = malloc(sizeof(*a));
memset(a, 0, sizeof(*a));
a->user_uid = geteuid();
a->magic = ARCHIVE_READ_MAGIC;
a->bytes_per_block = ARCHIVE_DEFAULT_BYTES_PER_BLOCK;
a->null_length = 1024;
nulls = malloc(a->null_length);
memset(nulls, 0, a->null_length);
a->nulls = nulls;
a->state = ARCHIVE_STATE_NEW;
a->entry = archive_entry_new();
/* We always support uncompressed archives. */
archive_read_support_compression_none((struct archive*)a);
return (a);
}
/*
* Set the block size.
*/
/*
int
archive_read_set_bytes_per_block(struct archive *a, int bytes_per_block)
{
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
if (bytes_per_block < 1)
bytes_per_block = 1;
a->bytes_per_block = bytes_per_block;
return (0);
}
*/
/*
* Open the archive
*/
int
archive_read_open(struct archive *a, void *client_data,
archive_open_callback *opener, archive_read_callback *reader,
archive_close_callback *closer)
{
const void *buffer;
size_t bytes_read;
int high_bidder;
int e;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
if (reader == NULL)
errx(1,
"Fatal: No reader function provided to archive_read_open");
a->client_reader = reader;
a->client_opener = opener;
a->client_closer = closer;
a->client_data = client_data;
a->state = ARCHIVE_STATE_HEADER;
/* Open data source. */
if (a->client_opener != NULL) {
e =(a->client_opener)(a, a->client_data);
if (e != 0)
return (e);
}
/* Read first block now for format detection. */
bytes_read = (a->client_reader)(a, a->client_data, &buffer);
/* Select a decompression routine. */
high_bidder = choose_decompressor(a, buffer, bytes_read);
if (high_bidder < 0)
return (ARCHIVE_FATAL);
/* Initialize decompression routine with the first block of data. */
e = (a->decompressors[high_bidder].init)(a, buffer, bytes_read);
return (e);
}
/*
* Allow each registered decompression routine to bid on whether it
* wants to handle this stream. Return index of winning bidder.
*/
static int
choose_decompressor(struct archive *a, const void *buffer, size_t bytes_read)
{
int decompression_slots, i, bid, best_bid, best_bid_slot;
decompression_slots = sizeof(a->decompressors) /
sizeof(a->decompressors[0]);
best_bid = -1;
best_bid_slot = -1;
for (i = 0; i < decompression_slots; i++) {
if (a->decompressors[i].bid) {
bid = (a->decompressors[i].bid)(buffer, bytes_read);
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)
errx(1, "Fatal: 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_ERRNO_FILE_FORMAT,
"Unrecognized archive format");
return (ARCHIVE_FATAL);
}
return (best_bid_slot);
}
/*
* Read header of next entry.
*/
int
archive_read_next_header(struct archive *a, struct archive_entry **entryp)
{
struct archive_entry *entry;
int slot, ret;
archive_check_magic(a, ARCHIVE_READ_MAGIC,
ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA);
*entryp = NULL;
entry = a->entry;
archive_entry_clear(entry);
/*
* If client didn't consume entire data, skip any remainder
* (This is especially important for GNU incremental directories.)
*/
if (a->state == ARCHIVE_STATE_DATA) {
ret = archive_read_data_skip(a);
if (ret == ARCHIVE_EOF) {
archive_set_error(a, EIO, "Premature end-of-file.");
a->state = ARCHIVE_STATE_FATAL;
return (ARCHIVE_FATAL);
}
}
/* Record start-of-header. */
a->header_position = a->file_position;
slot = choose_format(a);
if (slot < 0) {
a->state = ARCHIVE_STATE_FATAL;
return (ARCHIVE_FATAL);
}
a->format = &(a->formats[slot]);
a->pformat_data = &(a->format->format_data);
ret = (a->format->read_header)(a, entry);
/*
* EOF and FATAL are persistent at this layer. By
* modifying the state, we gaurantee that future calls to
* read a header or read data will fail.
*/
switch (ret) {
case ARCHIVE_EOF:
a->state = ARCHIVE_STATE_EOF;
break;
case ARCHIVE_OK:
a->state = ARCHIVE_STATE_DATA;
break;
case ARCHIVE_WARN:
a->state = ARCHIVE_STATE_DATA;
break;
case ARCHIVE_RETRY:
break;
case ARCHIVE_FATAL:
a->state = ARCHIVE_STATE_FATAL;
break;
}
*entryp = 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 *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) {
a->pformat_data = &(a->format->format_data);
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)
errx(1, "Fatal: 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_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)
{
return (a->header_position);
}
/*
* Read data from an archive entry.
*/
ssize_t
archive_read_data(struct archive *a, void *buff, size_t s)
{
const void *data;
ssize_t bytes_read;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA);
/*
* off_t is generally at least as wide as size_t, so widen for
* comparison and narrow for the assignment. Otherwise, on
* platforms with 32-bit size_t and 64-bit off_t, we won't be
* able to correctly read archives with entries larger than
* 4gig.
*/
if ((off_t)s > a->entry_bytes_remaining)
s = (size_t)a->entry_bytes_remaining;
if (s > 0) {
bytes_read = (a->compression_read_ahead)(a, &data, 1);
if (bytes_read < 0) {
a->state = ARCHIVE_STATE_FATAL;
return (bytes_read);
}
if ((size_t)bytes_read > s)
bytes_read = s;
} else
bytes_read = 0;
if (bytes_read > 0) {
memcpy(buff, data, bytes_read);
(a->compression_read_consume)(a, bytes_read);
}
a->entry_bytes_remaining -= bytes_read;
return (bytes_read);
}
/*
* Skip over all remaining data in this entry.
*/
int
archive_read_data_skip(struct archive *a)
{
const void *buff;
ssize_t bytes_read, to_skip;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA);
to_skip = a->entry_bytes_remaining + a->entry_padding;
a->entry_bytes_remaining = 0;
for (; to_skip > 0; to_skip -= bytes_read) {
/* TODO: Optimize skip in compression layer. */
bytes_read = (a->compression_read_ahead)(a, &buff, to_skip);
if (bytes_read < 0) {
a->entry_padding = to_skip;
return (ARCHIVE_FATAL);
}
if (bytes_read == 0) {
archive_set_error(a, EIO,
"Premature end of archive entry");
return (ARCHIVE_FATAL);
}
if (bytes_read > to_skip)
bytes_read = to_skip;
(a->compression_read_consume)(a, bytes_read);
}
a->entry_padding = 0;
a->state = ARCHIVE_STATE_HEADER;
return (ARCHIVE_OK);
}
/*
* Cleanup and free the archive object.
*
* 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.
*/
void
archive_read_finish(struct archive *a)
{
int i;
int slots;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY);
a->state = ARCHIVE_STATE_CLOSED;
/* Call cleanup functions registered by optional components. */
if (a->cleanup_archive_extract != NULL)
(a->cleanup_archive_extract)(a);
/* TODO: Finish the format processing. */
/* Close the input machinery. */
if (a->compression_finish != NULL)
(a->compression_finish)(a);
/* Cleanup format-specific data. */
slots = sizeof(a->formats) / sizeof(a->formats[0]);
for (i = 0; i < slots; i++) {
a->pformat_data = &(a->formats[i].format_data);
if (a->formats[i].cleanup)
(a->formats[i].cleanup)(a);
}
/* Casting a pointer to int allows us to remove 'const.' */
free((void *)(uintptr_t)(const void *)a->nulls);
archive_string_free(&a->extract_mkdirpath);
archive_string_free(&a->error_string);
if (a->entry)
archive_entry_free(a->entry);
a->magic = 0;
free(a);
}
/*
* Used internally by read format handlers to register their bid and
* initialization functions.
*/
int
__archive_read_register_format(struct archive *a,
void *format_data,
int (*bid)(struct archive *),
int (*read_header)(struct archive *, struct archive_entry *),
int (*cleanup)(struct archive *))
{
int i, number_slots;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
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].cleanup = cleanup;
a->formats[i].format_data = format_data;
return (ARCHIVE_OK);
}
}
errx(1, "Fatal: Not enough slots for format registration");
}
/*
* Used internally by decompression routines to register their bid and
* initialization functions.
*/
int
__archive_read_register_compression(struct archive *a,
int (*bid)(const void *, size_t),
int (*init)(struct archive *, const void *, size_t))
{
int i, number_slots;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW);
number_slots = sizeof(a->decompressors) / sizeof(a->decompressors[0]);
for (i = 0; i < number_slots; i++) {
if (a->decompressors[i].bid == bid)
return (ARCHIVE_OK); /* We've already installed */
if (a->decompressors[i].bid == NULL) {
a->decompressors[i].bid = bid;
a->decompressors[i].init = init;
return (ARCHIVE_OK);
}
}
errx(1, "Fatal: Not enough slots for compression registration");
}