denyhosts/clamscan/libclamav/dmg.c
2022-10-22 18:41:00 +08:00

1137 lines
42 KiB
C

/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2013 Sourcefire, Inc.
*
* Authors: David Raynor <draynor@sourcefire.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <errno.h>
#if HAVE_STRING_H
#include <string.h>
#endif
#include <ctype.h>
#include <fcntl.h>
#if HAVE_SYS_PARAM_H
#include <sys/param.h> /* for NAME_MAX */
#endif
#if HAVE_LIBZ
#include <zlib.h>
#endif
#if HAVE_BZLIB_H
#include <bzlib.h>
#ifdef NOBZ2PREFIX
#define BZ2_bzDecompress bzDecompress
#define BZ2_bzDecompressEnd bzDecompressEnd
#define BZ2_bzDecompressInit bzDecompressInit
#endif
#endif
#if HAVE_LIBXML2
#include <libxml/xmlreader.h>
#endif
#include "clamav.h"
#include "others.h"
#include "dmg.h"
#include "scanners.h"
#include "sf_base64decode.h"
#include "adc.h"
/* #define DEBUG_DMG_PARSE */
/* #define DEBUG_DMG_BZIP */
#ifdef DEBUG_DMG_PARSE
#define dmg_parsemsg(...) cli_dbgmsg(__VA_ARGS__)
#else
#define dmg_parsemsg(...) ;
#endif
#ifdef DEBUG_DMG_BZIP
#define dmg_bzipmsg(...) cli_dbgmsg(__VA_ARGS__)
#else
#define dmg_bzipmsg(...) ;
#endif
enum dmgReadState {
DMG_FIND_BASE_PLIST = 0,
DMG_FIND_BASE_DICT = 1,
DMG_FIND_KEY_RESOURCE_FORK = 2,
DMG_FIND_DICT_RESOURCE_FORK = 3,
DMG_FIND_KEY_BLKX = 4,
DMG_FIND_BLKX_CONTAINER = 5,
DMG_FIND_KEY_DATA = 6,
DMG_FIND_DATA_MISH = 7,
DMG_MAX_STATE = 8
};
static int dmg_extract_xml(cli_ctx *, char *, struct dmg_koly_block *);
#if HAVE_LIBXML2
static int dmg_decode_mish(cli_ctx *, unsigned int *, xmlChar *, struct dmg_mish_with_stripes *);
#endif
static int cmp_mish_stripes(const void *stripe_a, const void *stripe_b);
static int dmg_track_sectors(uint64_t *, uint8_t *, uint32_t, uint32_t, uint64_t);
static int dmg_handle_mish(cli_ctx *, unsigned int, char *, uint64_t, struct dmg_mish_with_stripes *);
int cli_scandmg(cli_ctx *ctx)
{
struct dmg_koly_block hdr;
int ret;
size_t maplen, nread;
size_t pos = 0;
char *dirname;
const char *outdata;
unsigned int file = 0;
struct dmg_mish_with_stripes *mish_list = NULL, *mish_list_tail = NULL;
enum dmgReadState state = DMG_FIND_BASE_PLIST;
int stateDepth[DMG_MAX_STATE];
#if HAVE_LIBXML2
xmlTextReaderPtr reader;
#endif
if (!ctx || !ctx->fmap) {
cli_errmsg("cli_scandmg: Invalid context\n");
return CL_ENULLARG;
}
maplen = ctx->fmap->len;
if (maplen <= 512) {
cli_dbgmsg("cli_scandmg: DMG smaller than DMG koly block!\n");
return CL_CLEAN;
}
pos = maplen - 512;
/* Grab koly block */
if (fmap_readn(ctx->fmap, &hdr, pos, sizeof(hdr)) != sizeof(hdr)) {
cli_dbgmsg("cli_scandmg: Invalid DMG trailer block\n");
return CL_EFORMAT;
}
/* Check magic */
hdr.magic = be32_to_host(hdr.magic);
if (hdr.magic == 0x6b6f6c79) {
cli_dbgmsg("cli_scandmg: Found koly block @ %zu\n", pos);
} else {
cli_dbgmsg("cli_scandmg: No koly magic, %8x\n", hdr.magic);
return CL_EFORMAT;
}
hdr.dataForkOffset = be64_to_host(hdr.dataForkOffset);
hdr.dataForkLength = be64_to_host(hdr.dataForkLength);
cli_dbgmsg("cli_scandmg: data offset %lu len %d\n", (unsigned long)hdr.dataForkOffset, (int)hdr.dataForkLength);
hdr.xmlOffset = be64_to_host(hdr.xmlOffset);
hdr.xmlLength = be64_to_host(hdr.xmlLength);
if (hdr.xmlLength > (uint64_t)INT_MAX) {
cli_dbgmsg("cli_scandmg: The embedded XML is way larger than necessary, and probably corrupt or tampered with.\n");
return CL_EFORMAT;
}
if ((hdr.xmlOffset > (uint64_t)maplen) || (hdr.xmlLength > (uint64_t)maplen) || (hdr.xmlOffset + hdr.xmlLength) > (uint64_t)maplen) {
cli_dbgmsg("cli_scandmg: XML out of range for this file\n");
return CL_EFORMAT;
}
cli_dbgmsg("cli_scandmg: XML offset %lu len %d\n", (unsigned long)hdr.xmlOffset, (int)hdr.xmlLength);
if (hdr.xmlLength == 0) {
cli_dbgmsg("cli_scandmg: Embedded XML length is zero.\n");
return CL_EFORMAT;
}
/* Create temp folder for contents */
if (!(dirname = cli_gentemp_with_prefix(ctx->sub_tmpdir, "dmg-tmp"))) {
return CL_ETMPDIR;
}
if (mkdir(dirname, 0700)) {
cli_errmsg("cli_scandmg: Cannot create temporary directory %s\n", dirname);
free(dirname);
return CL_ETMPDIR;
}
cli_dbgmsg("cli_scandmg: Extracting into %s\n", dirname);
/* Dump XML to tempfile, if needed */
if (ctx->engine->keeptmp && !(ctx->engine->engine_options & ENGINE_OPTIONS_FORCE_TO_DISK)) {
int xret;
xret = dmg_extract_xml(ctx, dirname, &hdr);
if (xret != CL_SUCCESS) {
/* Printed err detail inside dmg_extract_xml */
free(dirname);
return xret;
}
}
/* scan XML with cli_magic_scan_nested_fmap_type */
ret = cli_magic_scan_nested_fmap_type(ctx->fmap, (size_t)hdr.xmlOffset, (size_t)hdr.xmlLength, ctx, CL_TYPE_ANY, NULL);
if (ret != CL_CLEAN) {
cli_dbgmsg("cli_scandmg: retcode from scanning TOC xml: %s\n", cl_strerror(ret));
if (!ctx->engine->keeptmp)
cli_rmdirs(dirname);
free(dirname);
return ret;
}
/* page data from map */
outdata = fmap_need_off_once_len(ctx->fmap, hdr.xmlOffset, hdr.xmlLength, &nread);
if (!outdata || (nread != hdr.xmlLength)) {
cli_errmsg("cli_scandmg: Failed getting XML from map, len %d\n", (int)hdr.xmlLength);
if (!ctx->engine->keeptmp)
cli_rmdirs(dirname);
free(dirname);
return CL_EMAP;
}
/* time to walk the tree */
/* plist -> dict -> (key:resource_fork) dict -> (key:blkx) array -> dict */
/* each of those bottom level dict should have 4 parts */
/* [ Attributes, Data, ID, Name ], where Data is Base64 mish block */
/* This is the block where we require libxml2 */
#if HAVE_LIBXML2
/* XML_PARSE_NOENT | XML_PARSE_NONET | XML_PARSE_COMPACT */
#define DMG_XML_PARSE_OPTS ((1 << 1 | 1 << 11 | 1 << 16) | CLAMAV_MIN_XMLREADER_FLAGS)
reader = xmlReaderForMemory(outdata, (int)hdr.xmlLength, "toc.xml", NULL, DMG_XML_PARSE_OPTS);
if (!reader) {
cli_dbgmsg("cli_scandmg: Failed parsing XML!\n");
if (!ctx->engine->keeptmp)
cli_rmdirs(dirname);
free(dirname);
return CL_EFORMAT;
}
stateDepth[DMG_FIND_BASE_PLIST] = -1;
// May need to check for (xmlTextReaderIsEmptyElement(reader) == 0)
/* Break loop if have return code or reader can't read any more */
while ((ret == CL_CLEAN) && (xmlTextReaderRead(reader) == 1)) {
xmlReaderTypes nodeType;
nodeType = xmlTextReaderNodeType(reader);
if (nodeType == XML_READER_TYPE_ELEMENT) {
// New element, do name check
xmlChar *nodeName;
int depth;
depth = xmlTextReaderDepth(reader);
if (depth < 0) {
break;
}
if ((depth > 50) && SCAN_HEURISTICS) {
// Possible heuristic, should limit runaway
cli_dbgmsg("cli_scandmg: Excessive nesting in DMG TOC.\n");
break;
}
nodeName = xmlTextReaderLocalName(reader);
if (!nodeName)
continue;
dmg_parsemsg("read: name %s depth %d\n", nodeName, depth);
if ((state == DMG_FIND_DATA_MISH) && (depth == stateDepth[state - 1])) {
xmlChar *textValue;
struct dmg_mish_with_stripes *mish_set;
/* Reset state early, for continue cases */
stateDepth[DMG_FIND_KEY_DATA] = -1;
state--;
if (xmlStrcmp(nodeName, (const xmlChar *)"data") != 0) {
cli_dbgmsg("cli_scandmg: Not blkx data element\n");
xmlFree(nodeName);
continue;
}
dmg_parsemsg("read: Found blkx data element\n");
/* Pull out data content from text */
if (xmlTextReaderIsEmptyElement(reader)) {
cli_dbgmsg("cli_scandmg: blkx data element is empty\n");
xmlFree(nodeName);
continue;
}
if (xmlTextReaderRead(reader) != 1) {
xmlFree(nodeName);
break;
}
if (xmlTextReaderNodeType(reader) != XML_READER_TYPE_TEXT) {
cli_dbgmsg("cli_scandmg: Next node not text\n");
xmlFree(nodeName);
continue;
}
textValue = xmlTextReaderValue(reader);
if (textValue == NULL) {
xmlFree(nodeName);
continue;
}
/* Have encoded mish block */
mish_set = cli_malloc(sizeof(struct dmg_mish_with_stripes));
if (mish_set == NULL) {
ret = CL_EMEM;
xmlFree(textValue);
xmlFree(nodeName);
break;
}
ret = dmg_decode_mish(ctx, &file, textValue, mish_set);
xmlFree(textValue);
if (ret == CL_EFORMAT) {
/* Didn't decode, or not a mish block */
ret = CL_CLEAN;
free(mish_set);
xmlFree(nodeName);
continue;
} else if (ret != CL_CLEAN) {
xmlFree(nodeName);
free(mish_set);
continue;
}
/* Add mish block to list */
if (mish_list_tail != NULL) {
mish_list_tail->next = mish_set;
mish_list_tail = mish_set;
} else {
mish_list = mish_set;
mish_list_tail = mish_set;
}
mish_list_tail->next = NULL;
}
if ((state == DMG_FIND_KEY_DATA) && (depth > stateDepth[state - 1]) && (xmlStrcmp(nodeName, (const xmlChar *)"key") == 0)) {
xmlChar *textValue;
dmg_parsemsg("read: Found key - checking for Data\n");
if (xmlTextReaderRead(reader) != 1) {
xmlFree(nodeName);
break;
}
if (xmlTextReaderNodeType(reader) != XML_READER_TYPE_TEXT) {
cli_dbgmsg("cli_scandmg: Key node no text\n");
xmlFree(nodeName);
continue;
}
textValue = xmlTextReaderValue(reader);
if (textValue == NULL) {
cli_dbgmsg("cli_scandmg: no value from xmlTextReaderValue\n");
xmlFree(nodeName);
continue;
}
if (xmlStrcmp(textValue, (const xmlChar *)"Data") == 0) {
dmg_parsemsg("read: Matched data\n");
stateDepth[DMG_FIND_KEY_DATA] = depth;
state++;
} else {
dmg_parsemsg("read: text value is %s\n", textValue);
}
xmlFree(textValue);
}
if ((state == DMG_FIND_BLKX_CONTAINER) && (depth == stateDepth[state - 1])) {
if (xmlStrcmp(nodeName, (const xmlChar *)"array") == 0) {
dmg_parsemsg("read: Found array blkx\n");
stateDepth[DMG_FIND_BLKX_CONTAINER] = depth;
state++;
} else if (xmlStrcmp(nodeName, (const xmlChar *)"dict") == 0) {
dmg_parsemsg("read: Found dict blkx\n");
stateDepth[DMG_FIND_BLKX_CONTAINER] = depth;
state++;
} else {
cli_dbgmsg("cli_scandmg: Bad blkx, not container\n");
stateDepth[DMG_FIND_KEY_BLKX] = -1;
state--;
}
}
if ((state == DMG_FIND_KEY_BLKX) && (depth == stateDepth[state - 1] + 1) && (xmlStrcmp(nodeName, (const xmlChar *)"key") == 0)) {
xmlChar *textValue;
dmg_parsemsg("read: Found key - checking for blkx\n");
if (xmlTextReaderRead(reader) != 1) {
xmlFree(nodeName);
break;
}
if (xmlTextReaderNodeType(reader) != XML_READER_TYPE_TEXT) {
cli_dbgmsg("cli_scandmg: Key node no text\n");
xmlFree(nodeName);
continue;
}
textValue = xmlTextReaderValue(reader);
if (textValue == NULL) {
cli_dbgmsg("cli_scandmg: no value from xmlTextReaderValue\n");
xmlFree(nodeName);
continue;
}
if (xmlStrcmp(textValue, (const xmlChar *)"blkx") == 0) {
cli_dbgmsg("cli_scandmg: Matched blkx\n");
stateDepth[DMG_FIND_KEY_BLKX] = depth;
state++;
} else {
cli_dbgmsg("cli_scandmg: wanted blkx, text value is %s\n", textValue);
}
xmlFree(textValue);
}
if ((state == DMG_FIND_DICT_RESOURCE_FORK) && (depth == stateDepth[state - 1])) {
if (xmlStrcmp(nodeName, (const xmlChar *)"dict") == 0) {
dmg_parsemsg("read: Found resource-fork dict\n");
stateDepth[DMG_FIND_DICT_RESOURCE_FORK] = depth;
state++;
} else {
dmg_parsemsg("read: Not resource-fork dict\n");
stateDepth[DMG_FIND_KEY_RESOURCE_FORK] = -1;
state--;
}
}
if ((state == DMG_FIND_KEY_RESOURCE_FORK) && (depth == stateDepth[state - 1] + 1) && (xmlStrcmp(nodeName, (const xmlChar *)"key") == 0)) {
dmg_parsemsg("read: Found resource-fork key\n");
stateDepth[DMG_FIND_KEY_RESOURCE_FORK] = depth;
state++;
}
if ((state == DMG_FIND_BASE_DICT) && (depth == stateDepth[state - 1] + 1) && (xmlStrcmp(nodeName, (const xmlChar *)"dict") == 0)) {
dmg_parsemsg("read: Found dict start\n");
stateDepth[DMG_FIND_BASE_DICT] = depth;
state++;
}
if ((state == DMG_FIND_BASE_PLIST) && (xmlStrcmp(nodeName, (const xmlChar *)"plist") == 0)) {
dmg_parsemsg("read: Found plist start\n");
stateDepth[DMG_FIND_BASE_PLIST] = depth;
state++;
}
xmlFree(nodeName);
} else if ((nodeType == XML_READER_TYPE_END_ELEMENT) && (state > DMG_FIND_BASE_PLIST)) {
int significantEnd = 0;
int depth = xmlTextReaderDepth(reader);
if (depth < 0) {
break;
} else if (depth < stateDepth[state - 1]) {
significantEnd = 1;
} else if ((depth == stateDepth[state - 1]) && (state - 1 == DMG_FIND_BLKX_CONTAINER)) {
/* Special case, ending blkx container */
significantEnd = 1;
}
if (significantEnd) {
dmg_parsemsg("read: significant end tag, state %d\n", state);
stateDepth[state - 1] = -1;
state--;
if ((state - 1 == DMG_FIND_KEY_RESOURCE_FORK) || (state - 1 == DMG_FIND_KEY_BLKX)) {
/* Keys end their own tag (validly) and the next state depends on the following tag */
// cli_dbgmsg("read: significant end tag ending prior key state\n");
stateDepth[state - 1] = -1;
state--;
}
} else {
dmg_parsemsg("read: not significant end tag, state %d depth %d prior depth %d\n", state, depth, stateDepth[state - 1]);
}
}
}
xmlFreeTextReader(reader);
#else
cli_dbgmsg("cli_scandmg: libxml2 support is compiled out. It is required for full DMG support.\n");
#endif
/* Loop over mish array */
file = 0;
while ((ret == CL_CLEAN) && (mish_list != NULL)) {
/* Handle & scan mish block */
ret = dmg_handle_mish(ctx, file++, dirname, hdr.xmlOffset, mish_list);
free(mish_list->mish);
mish_list_tail = mish_list;
mish_list = mish_list->next;
free(mish_list_tail);
}
/* Cleanup */
/* If error occurred, need to free mish items and mish blocks */
while (mish_list != NULL) {
free(mish_list->mish);
mish_list_tail = mish_list;
mish_list = mish_list->next;
free(mish_list_tail);
}
if (!ctx->engine->keeptmp)
cli_rmdirs(dirname);
free(dirname);
return ret;
}
#if HAVE_LIBXML2
/* Transform the base64-encoded string into the binary structure
* After this, the base64 string (from xml) can be released
* If mish_set->mish is set by this function, it must be freed by the caller */
static int dmg_decode_mish(cli_ctx *ctx, unsigned int *mishblocknum, xmlChar *mish_base64,
struct dmg_mish_with_stripes *mish_set)
{
size_t base64_len, buff_size, decoded_len;
uint8_t *decoded;
const uint8_t mish_magic[4] = {0x6d, 0x69, 0x73, 0x68};
UNUSEDPARAM(ctx);
(*mishblocknum)++;
base64_len = strlen((const char *)mish_base64);
dmg_parsemsg("dmg_decode_mish: len of encoded block %u is %lu\n", *mishblocknum, base64_len);
/* speed vs memory, could walk the encoded data and skip whitespace in calculation */
buff_size = 3 * base64_len / 4 + 4;
dmg_parsemsg("dmg_decode_mish: buffer for mish block %u is %lu\n", *mishblocknum, (unsigned long)buff_size);
decoded = cli_malloc(buff_size);
if (!decoded)
return CL_EMEM;
if (sf_base64decode((uint8_t *)mish_base64, base64_len, decoded, buff_size - 1, &decoded_len)) {
cli_dbgmsg("dmg_decode_mish: failed base64 decoding on mish block %u\n", *mishblocknum);
free(decoded);
return CL_EFORMAT;
}
dmg_parsemsg("dmg_decode_mish: len of decoded mish block %u is %lu\n", *mishblocknum, (unsigned long)decoded_len);
if (decoded_len < sizeof(struct dmg_mish_block)) {
cli_dbgmsg("dmg_decode_mish: block %u too short for valid mish block\n", *mishblocknum);
free(decoded);
return CL_EFORMAT;
}
/* mish check: magic is mish, have to check after conversion from base64
* mish base64 is bWlzaA [but last character can change last two bytes]
* won't see that in practice much (affects value of version field) */
if (memcmp(decoded, mish_magic, 4)) {
cli_dbgmsg("dmg_decode_mish: block %u does not have mish magic\n", *mishblocknum);
free(decoded);
return CL_EFORMAT;
}
mish_set->mish = (struct dmg_mish_block *)decoded;
mish_set->mish->startSector = be64_to_host(mish_set->mish->startSector);
mish_set->mish->sectorCount = be64_to_host(mish_set->mish->sectorCount);
mish_set->mish->dataOffset = be64_to_host(mish_set->mish->dataOffset);
// mish_set->mish->bufferCount = be32_to_host(mish_set->mish->bufferCount);
mish_set->mish->blockDataCount = be32_to_host(mish_set->mish->blockDataCount);
cli_dbgmsg("dmg_decode_mish: startSector = " STDu64 " sectorCount = " STDu64
" dataOffset = " STDu64 " stripeCount = " STDu32 "\n",
mish_set->mish->startSector, mish_set->mish->sectorCount,
mish_set->mish->dataOffset, mish_set->mish->blockDataCount);
/* decoded length should be mish block + blockDataCount * 40 */
if (decoded_len < (sizeof(struct dmg_mish_block) + mish_set->mish->blockDataCount * sizeof(struct dmg_block_data))) {
cli_dbgmsg("dmg_decode_mish: mish block %u too small\n", *mishblocknum);
free(decoded);
mish_set->mish = NULL;
return CL_EFORMAT;
} else if (decoded_len > (sizeof(struct dmg_mish_block) + mish_set->mish->blockDataCount * sizeof(struct dmg_block_data))) {
cli_dbgmsg("dmg_decode_mish: mish block %u bigger than needed, continuing\n", *mishblocknum);
}
mish_set->stripes = (struct dmg_block_data *)(decoded + sizeof(struct dmg_mish_block));
return CL_CLEAN;
}
#endif
/* Comparator for stripe sorting */
static int cmp_mish_stripes(const void *stripe_a, const void *stripe_b)
{
const struct dmg_block_data *a = stripe_a, *b = stripe_b;
return a->startSector - b->startSector;
}
/* Safely track sector sizes for output estimate */
static int dmg_track_sectors(uint64_t *total, uint8_t *data_to_write,
uint32_t stripeNum, uint32_t stripeType, uint64_t stripeCount)
{
int ret = CL_CLEAN, usable = 0;
switch (stripeType) {
case DMG_STRIPE_STORED:
*data_to_write = 1;
usable = 1;
break;
case DMG_STRIPE_ADC:
*data_to_write = 1;
usable = 1;
break;
case DMG_STRIPE_DEFLATE:
#if HAVE_LIBZ
*data_to_write = 1;
usable = 1;
#else
cli_warnmsg("dmg_track_sectors: Need zlib decompression to properly scan this file.\n");
return CL_EFORMAT;
#endif
break;
case DMG_STRIPE_BZ:
#if HAVE_BZLIB_H
*data_to_write = 1;
usable = 1;
#else
cli_warnmsg("dmg_track_sectors: Need bzip2 decompression to properly scan this file.\n");
return CL_EFORMAT;
#endif
break;
case DMG_STRIPE_EMPTY:
case DMG_STRIPE_ZEROES:
/* Usable, but only zeroes is not worth scanning on its own */
usable = 1;
break;
case DMG_STRIPE_SKIP:
case DMG_STRIPE_END:
/* These should be sectorCount 0 */
break;
default:
if (stripeCount) {
/* Continue for now */
cli_dbgmsg("dmg_track_sectors: unknown type on stripe " STDu32 ", will skip\n", stripeNum);
} else {
/* Continue, no sectors missed */
cli_dbgmsg("dmg_track_sectors: unknown type on empty stripe " STDu32 "\n", stripeNum);
}
break;
}
if (usable) {
/* Check for wrap */
if (*total < (*total + stripeCount)) {
*total = *total + stripeCount;
} else if (stripeCount) {
cli_dbgmsg("dmg_track_sectors: *total would wrap uint64, suspicious\n");
ret = CL_EFORMAT;
} else {
/* Can continue */
cli_dbgmsg("dmg_track_sectors: unexpected zero sectorCount on stripe " STDu32 "\n", stripeNum);
}
}
return ret;
}
/* Stripe handling: zero block (type 0x0 or 0x2) */
static int dmg_stripe_zeroes(cli_ctx *ctx, int fd, uint32_t index, struct dmg_mish_with_stripes *mish_set)
{
int ret = CL_CLEAN;
size_t len = mish_set->stripes[index].sectorCount * DMG_SECTOR_SIZE;
size_t written;
uint8_t obuf[BUFSIZ];
UNUSEDPARAM(ctx);
cli_dbgmsg("dmg_stripe_zeroes: stripe " STDu32 "\n", index);
if (len == 0)
return CL_CLEAN;
memset(obuf, 0, sizeof(obuf));
while (len > sizeof(obuf)) {
written = cli_writen(fd, obuf, sizeof(obuf));
if (written != sizeof(obuf)) {
ret = CL_EWRITE;
break;
}
len -= sizeof(obuf);
}
if ((ret == CL_CLEAN) && (len > 0)) {
written = cli_writen(fd, obuf, len);
if (written != len) {
ret = CL_EWRITE;
}
}
if (ret != CL_CLEAN) {
cli_errmsg("dmg_stripe_zeroes: error writing bytes to file (out of disk space?)\n");
return CL_EWRITE;
}
return CL_CLEAN;
}
/* Stripe handling: stored block (type 0x1) */
static int dmg_stripe_store(cli_ctx *ctx, int fd, uint32_t index, struct dmg_mish_with_stripes *mish_set)
{
const void *obuf;
size_t off = mish_set->stripes[index].dataOffset;
size_t len = mish_set->stripes[index].dataLength;
size_t written;
cli_dbgmsg("dmg_stripe_store: stripe " STDu32 "\n", index);
if (len == 0)
return CL_CLEAN;
obuf = (void *)fmap_need_off_once(ctx->fmap, off, len);
if (!obuf) {
cli_warnmsg("dmg_stripe_store: fmap need failed on stripe " STDu32 "\n", index);
return CL_EMAP;
}
written = cli_writen(fd, obuf, len);
if (written == (size_t)-1) {
cli_errmsg("dmg_stripe_store: error writing bytes to file (out of disk space?)\n");
return CL_EWRITE;
} else if (written != len) {
cli_errmsg("dmg_stripe_store: error writing bytes to file (out of disk space?)\n");
return CL_EWRITE;
}
return CL_CLEAN;
}
/* Stripe handling: ADC block (type 0x80000004) */
static int dmg_stripe_adc(cli_ctx *ctx, int fd, uint32_t index, struct dmg_mish_with_stripes *mish_set)
{
int adcret;
adc_stream strm;
size_t off = mish_set->stripes[index].dataOffset;
size_t len = mish_set->stripes[index].dataLength;
uint64_t size_so_far = 0;
uint64_t expected_len = mish_set->stripes[index].sectorCount * DMG_SECTOR_SIZE;
uint8_t obuf[BUFSIZ];
cli_dbgmsg("dmg_stripe_adc: stripe " STDu32 " initial len " STDu64 " expected len " STDu64 "\n",
index, (uint64_t)len, (uint64_t)expected_len);
if (len == 0)
return CL_CLEAN;
memset(&strm, 0, sizeof(strm));
strm.next_in = (uint8_t *)fmap_need_off_once(ctx->fmap, off, len);
if (!strm.next_in) {
cli_warnmsg("dmg_stripe_adc: fmap need failed on stripe " STDu32 "\n", index);
return CL_EMAP;
}
strm.avail_in = len;
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
adcret = adc_decompressInit(&strm);
if (adcret != ADC_OK) {
cli_warnmsg("dmg_stripe_adc: adc_decompressInit failed\n");
return CL_EMEM;
}
while (adcret == ADC_OK) {
size_t written;
if (size_so_far > expected_len) {
cli_warnmsg("dmg_stripe_adc: expected size exceeded!\n");
adc_decompressEnd(&strm);
return CL_EFORMAT;
}
adcret = adc_decompress(&strm);
switch (adcret) {
case ADC_OK:
if (strm.avail_out == 0) {
if ((written = cli_writen(fd, obuf, sizeof(obuf))) != sizeof(obuf)) {
cli_errmsg("dmg_stripe_adc: failed write to output file\n");
adc_decompressEnd(&strm);
return CL_EWRITE;
}
size_so_far += written;
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
}
continue;
case ADC_STREAM_END:
default:
written = sizeof(obuf) - strm.avail_out;
if (written) {
if ((cli_writen(fd, obuf, written)) != written) {
cli_errmsg("dmg_stripe_adc: failed write to output file\n");
adc_decompressEnd(&strm);
return CL_EWRITE;
}
size_so_far += written;
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
}
if (adcret == ADC_STREAM_END)
break;
cli_dbgmsg("dmg_stripe_adc: after writing " STDu64 " bytes, "
"got error %d decompressing stripe " STDu32 "\n",
size_so_far, adcret, index);
adc_decompressEnd(&strm);
return CL_EFORMAT;
}
break;
}
adc_decompressEnd(&strm);
cli_dbgmsg("dmg_stripe_adc: stripe " STDu32 " actual len " STDu64 " expected len " STDu64 "\n",
index, size_so_far, expected_len);
return CL_CLEAN;
}
/* Stripe handling: deflate block (type 0x80000005) */
static int dmg_stripe_inflate(cli_ctx *ctx, int fd, uint32_t index, struct dmg_mish_with_stripes *mish_set)
{
int zstat;
z_stream strm;
size_t off = mish_set->stripes[index].dataOffset;
size_t len = mish_set->stripes[index].dataLength;
uint64_t size_so_far = 0;
uint64_t expected_len = mish_set->stripes[index].sectorCount * DMG_SECTOR_SIZE;
uint8_t obuf[BUFSIZ];
cli_dbgmsg("dmg_stripe_inflate: stripe " STDu32 "\n", index);
if (len == 0)
return CL_CLEAN;
memset(&strm, 0, sizeof(strm));
strm.next_in = (void *)fmap_need_off_once(ctx->fmap, off, len);
if (!strm.next_in) {
cli_warnmsg("dmg_stripe_inflate: fmap need failed on stripe " STDu32 "\n", index);
return CL_EMAP;
}
strm.avail_in = len;
strm.next_out = obuf;
strm.avail_out = sizeof(obuf);
zstat = inflateInit(&strm);
if (zstat != Z_OK) {
cli_warnmsg("dmg_stripe_inflate: inflateInit failed\n");
return CL_EMEM;
}
while (strm.avail_in) {
size_t written;
if (size_so_far > expected_len) {
cli_warnmsg("dmg_stripe_inflate: expected size exceeded!\n");
inflateEnd(&strm);
return CL_EFORMAT;
}
zstat = inflate(&strm, Z_NO_FLUSH); /* zlib */
switch (zstat) {
case Z_OK:
if (strm.avail_out == 0) {
if ((written = cli_writen(fd, obuf, sizeof(obuf))) != sizeof(obuf)) {
cli_errmsg("dmg_stripe_inflate: failed write to output file\n");
inflateEnd(&strm);
return CL_EWRITE;
}
size_so_far += written;
strm.next_out = (Bytef *)obuf;
strm.avail_out = sizeof(obuf);
}
continue;
case Z_STREAM_END:
default:
written = sizeof(obuf) - strm.avail_out;
if (written) {
if ((cli_writen(fd, obuf, written)) != written) {
cli_errmsg("dmg_stripe_inflate: failed write to output file\n");
inflateEnd(&strm);
return CL_EWRITE;
}
size_so_far += written;
strm.next_out = (Bytef *)obuf;
strm.avail_out = sizeof(obuf);
if (zstat == Z_STREAM_END)
break;
}
if (strm.msg)
cli_dbgmsg("dmg_stripe_inflate: after writing " STDu64 " bytes, "
"got error \"%s\" inflating stripe " STDu32 "\n",
size_so_far, strm.msg, index);
else
cli_dbgmsg("dmg_stripe_inflate: after writing " STDu64 " bytes, "
"got error %d inflating stripe " STDu32 "\n",
size_so_far, zstat, index);
inflateEnd(&strm);
return CL_EFORMAT;
}
break;
}
if (strm.avail_out != sizeof(obuf)) {
if (cli_writen(fd, obuf, sizeof(obuf) - strm.avail_out) == (size_t)-1) {
cli_errmsg("dmg_stripe_inflate: failed write to output file\n");
inflateEnd(&strm);
return CL_EWRITE;
}
}
inflateEnd(&strm);
return CL_CLEAN;
}
/* Stripe handling: bzip block (type 0x80000006) */
static int dmg_stripe_bzip(cli_ctx *ctx, int fd, uint32_t index, struct dmg_mish_with_stripes *mish_set)
{
int ret = CL_CLEAN;
size_t off = mish_set->stripes[index].dataOffset;
size_t len = mish_set->stripes[index].dataLength;
uint64_t size_so_far = 0;
uint64_t expected_len = mish_set->stripes[index].sectorCount * DMG_SECTOR_SIZE;
#if HAVE_BZLIB_H
int rc;
bz_stream strm;
uint8_t obuf[BUFSIZ];
#endif
cli_dbgmsg("dmg_stripe_bzip: stripe " STDu32 " initial len " STDu64 " expected len " STDu64 "\n",
index, (uint64_t)len, (uint64_t)expected_len);
#if HAVE_BZLIB_H
memset(&strm, 0, sizeof(strm));
strm.next_out = (char *)obuf;
strm.avail_out = sizeof(obuf);
if (BZ2_bzDecompressInit(&strm, 0, 0) != BZ_OK) {
cli_dbgmsg("dmg_stripe_bzip: bzDecompressInit failed\n");
return CL_EOPEN;
}
do {
if (size_so_far > expected_len) {
cli_warnmsg("dmg_stripe_bzip: expected size exceeded!\n");
ret = CL_EFORMAT;
break;
}
if (strm.avail_in == 0) {
size_t next_len = (len > sizeof(obuf)) ? sizeof(obuf) : len;
dmg_bzipmsg("dmg_stripe_bzip: off %lu len %lu next_len %lu\n", off, len, next_len);
strm.next_in = (void *)fmap_need_off_once(ctx->fmap, off, next_len);
if (strm.next_in == NULL) {
cli_dbgmsg("dmg_stripe_bzip: expected more stream\n");
ret = CL_EMAP;
break;
}
strm.avail_in = next_len;
len -= next_len;
off += next_len;
}
dmg_bzipmsg("dmg_stripe_bzip: before = strm.avail_in %lu strm.avail_out: %lu\n", strm.avail_in, strm.avail_out);
rc = BZ2_bzDecompress(&strm);
if ((rc != BZ_OK) && (rc != BZ_STREAM_END)) {
cli_dbgmsg("dmg_stripe_bzip: decompress error: %d\n", rc);
ret = CL_EFORMAT;
break;
}
dmg_bzipmsg("dmg_stripe_bzip: after = strm.avail_in %lu strm.avail_out: %lu rc: %d %d\n",
strm.avail_in, strm.avail_out, rc, BZ_STREAM_END);
/* Drain output buffer */
if (!strm.avail_out) {
size_t next_write = sizeof(obuf);
do {
size_so_far += next_write;
dmg_bzipmsg("dmg_stripe_bzip: size_so_far: " STDu64 " next_write: %zu\n", size_so_far, next_write);
if (size_so_far > expected_len) {
cli_warnmsg("dmg_stripe_bzip: expected size exceeded!\n");
ret = CL_EFORMAT;
rc = BZ_DATA_ERROR; /* prevent stream end block */
break;
}
ret = cli_checklimits("dmg_stripe_bzip", ctx, (unsigned long)(size_so_far + sizeof(obuf)), 0, 0);
if (ret != CL_CLEAN) {
break;
}
if (cli_writen(fd, obuf, next_write) != next_write) {
cli_dbgmsg("dmg_stripe_bzip: error writing to tmpfile\n");
ret = CL_EWRITE;
break;
}
strm.next_out = (char *)obuf;
strm.avail_out = sizeof(obuf);
if (rc == BZ_OK)
rc = BZ2_bzDecompress(&strm);
if ((rc != BZ_OK) && (rc != BZ_STREAM_END)) {
cli_dbgmsg("dmg_stripe_bzip: decompress error: %d\n", rc);
ret = CL_EFORMAT;
break;
}
} while (!strm.avail_out);
}
/* Stream end, so write data if any remains in buffer */
if (rc == BZ_STREAM_END) {
size_t next_write = sizeof(obuf) - strm.avail_out;
size_so_far += next_write;
dmg_bzipmsg("dmg_stripe_bzip: size_so_far: " STDu64 " next_write: %zu\n", size_so_far, next_write);
ret = cli_checklimits("dmg_stripe_bzip", ctx, (unsigned long)(size_so_far + sizeof(obuf)), 0, 0);
if (ret != CL_CLEAN) {
break;
}
if (cli_writen(fd, obuf, next_write) != next_write) {
cli_dbgmsg("dmg_stripe_bzip: error writing to tmpfile\n");
ret = CL_EWRITE;
break;
}
strm.next_out = (char *)obuf;
strm.avail_out = sizeof(obuf);
}
} while ((rc == BZ_OK) && (len > 0));
BZ2_bzDecompressEnd(&strm);
#endif
if (ret == CL_CLEAN) {
if (size_so_far != expected_len) {
cli_dbgmsg("dmg_stripe_bzip: output does not match expected size!\n");
}
}
return ret;
}
/* Given mish data, reconstruct the partition details */
static int dmg_handle_mish(cli_ctx *ctx, unsigned int mishblocknum, char *dir,
uint64_t xmlOffset, struct dmg_mish_with_stripes *mish_set)
{
struct dmg_block_data *blocklist = mish_set->stripes;
uint64_t totalSectors = 0;
uint32_t i;
unsigned long projected_size;
int ret = CL_CLEAN, ofd;
uint8_t sorted = 1, writeable_data = 0;
char outfile[PATH_MAX + 1];
/* First loop, fix endian-ness and check if already sorted */
for (i = 0; i < mish_set->mish->blockDataCount; i++) {
blocklist[i].type = be32_to_host(blocklist[i].type);
// blocklist[i].reserved = be32_to_host(blocklist[i].reserved);
blocklist[i].startSector = be64_to_host(blocklist[i].startSector);
blocklist[i].sectorCount = be64_to_host(blocklist[i].sectorCount);
blocklist[i].dataOffset = be64_to_host(blocklist[i].dataOffset);
blocklist[i].dataLength = be64_to_host(blocklist[i].dataLength);
cli_dbgmsg("mish %u stripe " STDu32 " type " STDx32 " start " STDu64
" count " STDu64 " source " STDu64 " length " STDu64 "\n",
mishblocknum, i, blocklist[i].type, blocklist[i].startSector, blocklist[i].sectorCount,
blocklist[i].dataOffset, blocklist[i].dataLength);
if ((blocklist[i].dataOffset > xmlOffset) ||
(blocklist[i].dataOffset + blocklist[i].dataLength > xmlOffset)) {
cli_dbgmsg("dmg_handle_mish: invalid stripe offset and/or length\n");
return CL_EFORMAT;
}
if ((i > 0) && sorted && (blocklist[i].startSector < blocklist[i - 1].startSector)) {
cli_dbgmsg("dmg_handle_mish: stripes not in order, will have to sort\n");
sorted = 0;
}
if (dmg_track_sectors(&totalSectors, &writeable_data, i, blocklist[i].type, blocklist[i].sectorCount)) {
/* reason was logged from dmg_track_sector_count */
return CL_EFORMAT;
}
}
if (!sorted) {
cli_qsort(blocklist, mish_set->mish->blockDataCount, sizeof(struct dmg_block_data), cmp_mish_stripes);
}
cli_dbgmsg("dmg_handle_mish: stripes in order!\n");
/* Size checks */
if ((writeable_data == 0) || (totalSectors == 0)) {
cli_dbgmsg("dmg_handle_mish: no data to output\n");
return CL_CLEAN;
} else if (totalSectors > (ULONG_MAX / DMG_SECTOR_SIZE)) {
/* cli_checklimits only takes unsigned long for now */
cli_warnmsg("dmg_handle_mish: mish block %u too big to handle (for now)", mishblocknum);
return CL_CLEAN;
}
projected_size = (unsigned long)(totalSectors * DMG_SECTOR_SIZE);
ret = cli_checklimits("cli_scandmg", ctx, projected_size, 0, 0);
if (ret != CL_CLEAN) {
/* limits exceeded */
cli_dbgmsg("dmg_handle_mish: skipping block %u, limits exceeded\n", mishblocknum);
return ret;
}
/* Prepare for file */
snprintf(outfile, sizeof(outfile) - 1, "%s" PATHSEP "dmg%02u", dir, mishblocknum);
outfile[sizeof(outfile) - 1] = '\0';
ofd = open(outfile, O_RDWR | O_CREAT | O_EXCL | O_TRUNC | O_BINARY, 0600);
if (ofd < 0) {
char err[128];
cli_errmsg("cli_scandmg: Can't create temporary file %s: %s\n",
outfile, cli_strerror(errno, err, sizeof(err)));
return CL_ETMPFILE;
}
cli_dbgmsg("dmg_handle_mish: extracting block %u to %s\n", mishblocknum, outfile);
/* Push data, stripe by stripe */
for (i = 0; i < mish_set->mish->blockDataCount && ret == CL_CLEAN; i++) {
switch (blocklist[i].type) {
case DMG_STRIPE_EMPTY:
case DMG_STRIPE_ZEROES:
ret = dmg_stripe_zeroes(ctx, ofd, i, mish_set);
break;
case DMG_STRIPE_STORED:
ret = dmg_stripe_store(ctx, ofd, i, mish_set);
break;
case DMG_STRIPE_ADC:
ret = dmg_stripe_adc(ctx, ofd, i, mish_set);
break;
case DMG_STRIPE_DEFLATE:
ret = dmg_stripe_inflate(ctx, ofd, i, mish_set);
break;
case DMG_STRIPE_BZ:
ret = dmg_stripe_bzip(ctx, ofd, i, mish_set);
break;
case DMG_STRIPE_SKIP:
case DMG_STRIPE_END:
default:
cli_dbgmsg("dmg_handle_mish: stripe " STDu32 ", skipped\n", i);
break;
}
}
/* If okay so far, scan rebuilt partition */
if (ret == CL_CLEAN) {
/* Have to keep partition typing separate */
ret = cli_magic_scan_desc_type(ofd, outfile, ctx, CL_TYPE_PART_ANY, NULL);
}
close(ofd);
if (!ctx->engine->keeptmp)
if (cli_unlink(outfile)) return CL_EUNLINK;
return ret;
}
static int dmg_extract_xml(cli_ctx *ctx, char *dir, struct dmg_koly_block *hdr)
{
char *xmlfile;
const char *outdata;
size_t namelen, nread;
int ofd;
/* Prep TOC XML for output */
outdata = fmap_need_off_once_len(ctx->fmap, hdr->xmlOffset, hdr->xmlLength, &nread);
if (!outdata || (nread != hdr->xmlLength)) {
cli_errmsg("cli_scandmg: Failed getting XML from map, len " STDu64 "\n", hdr->xmlLength);
return CL_EMAP;
}
namelen = strlen(dir) + 1 + 7 + 1;
if (!(xmlfile = cli_malloc(namelen))) {
return CL_EMEM;
}
snprintf(xmlfile, namelen, "%s" PATHSEP "toc.xml", dir);
cli_dbgmsg("cli_scandmg: Extracting XML as %s\n", xmlfile);
/* Write out TOC XML */
if ((ofd = open(xmlfile, O_CREAT | O_RDWR | O_EXCL | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) < 0) {
char err[128];
cli_errmsg("cli_scandmg: Can't create temporary file %s: %s\n",
xmlfile, cli_strerror(errno, err, sizeof(err)));
free(xmlfile);
return CL_ETMPFILE;
}
if ((uint64_t)cli_writen(ofd, outdata, (size_t)hdr->xmlLength) != hdr->xmlLength) {
cli_errmsg("cli_scandmg: Not all bytes written!\n");
close(ofd);
free(xmlfile);
return CL_EWRITE;
}
close(ofd);
free(xmlfile);
return CL_SUCCESS;
}