/*
* Copyright (C) 2014-2019 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*
* Authors: Kevin Lin <klin@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>
#include <zlib.h>
#include "clamav.h"
#include "others.h"
#include "gpt.h"
#include "mbr.h"
#include "str.h"
#include "prtn_intxn.h"
#include "scanners.h"
#include "dconf.h"
//#define DEBUG_GPT_PARSE
//#define DEBUG_GPT_PRINT
#ifdef DEBUG_GPT_PARSE
#define gpt_parsemsg(...) cli_dbgmsg(__VA_ARGS__)
#else
#define gpt_parsemsg(...) ;
#endif
#ifdef DEBUG_GPT_PRINT
#define gpt_printmsg(...) cli_dbgmsg(__VA_ARGS__)
#else
#define gpt_printmsg(...) ;
#endif
enum GPT_SCANSTATE {
INVALID,
PRIMARY_ONLY,
SECONDARY_ONLY,
BOTH
};
static int gpt_scan_partitions(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
static int gpt_validate_header(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
static int gpt_check_mbr(cli_ctx *ctx, size_t sectorsize);
static void gpt_printSectors(cli_ctx *ctx, size_t sectorsize);
static void gpt_printName(uint16_t name[], const char *msg);
static void gpt_printGUID(uint8_t GUID[], const char *msg);
static int gpt_prtn_intxn(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize);
/* returns 0 on failing to detect sectorsize */
size_t gpt_detect_size(fmap_t *map)
{
unsigned char *buff;
buff = (unsigned char *)fmap_need_off_once(map, 512, 8);
if (!buff) return 0;
if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
return 512;
buff = (unsigned char *)fmap_need_off_once(map, 1024, 8);
if (!buff) return 0;
if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
return 1024;
buff = (unsigned char *)fmap_need_off_once(map, 2048, 8);
if (!buff) return 0;
if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
return 2048;
buff = (unsigned char *)fmap_need_off_once(map, 4096, 8);
if (!buff) return 0;
if (0 == strncmp((const char *)buff, GPT_SIGNATURE_STR, 8))
return 4096;
return 0;
}
/* attempts to detect sector size is input as 0 */
int cli_scangpt(cli_ctx *ctx, size_t sectorsize)
{
struct gpt_header phdr, shdr;
enum GPT_SCANSTATE state = INVALID;
int ret = CL_CLEAN, detection = CL_CLEAN;
size_t maplen;
off_t pos = 0;
gpt_parsemsg("The beginning of something big: GPT parsing\n");
if (!ctx || !ctx->fmap) {
cli_errmsg("cli_scangpt: Invalid context\n");
return CL_ENULLARG;
}
/* sector size calculation */
if (sectorsize == 0) {
sectorsize = gpt_detect_size((*ctx->fmap));
cli_dbgmsg("cli_scangpt: detected %lu sector size\n", (unsigned long)sectorsize);
}
if (sectorsize == 0) {
cli_errmsg("cli_scangpt: could not determine sector size\n");
return CL_EFORMAT;
}
/* size of total file must be a multiple of the sector size */
maplen = (*ctx->fmap)->real_len;
if ((maplen % sectorsize) != 0) {
cli_dbgmsg("cli_scangpt: File sized %lu is not a multiple of sector size %lu\n",
(unsigned long)maplen, (unsigned long)sectorsize);
return CL_EFORMAT;
}
/* check the protective mbr */
ret = gpt_check_mbr(ctx, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
pos = GPT_PRIMARY_HDR_LBA * sectorsize; /* sector 1 (second sector) is the primary gpt header */
/* read primary gpt header */
cli_dbgmsg("cli_scangpt: Using primary GPT header\n");
if (fmap_readn(*ctx->fmap, &phdr, pos, sizeof(phdr)) != sizeof(phdr)) {
cli_dbgmsg("cli_scangpt: Invalid primary GPT header\n");
return CL_EFORMAT;
}
pos = maplen - sectorsize; /* last sector is the secondary gpt header */
if (gpt_validate_header(ctx, phdr, sectorsize)) {
cli_dbgmsg("cli_scangpt: Primary GPT header is invalid\n");
cli_dbgmsg("cli_scangpt: Using secondary GPT header\n");
state = SECONDARY_ONLY;
/* read secondary gpt header */
if (fmap_readn(*ctx->fmap, &shdr, pos, sizeof(shdr)) != sizeof(shdr)) {
cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
return CL_EFORMAT;
}
if (gpt_validate_header(ctx, shdr, sectorsize)) {
cli_dbgmsg("cli_scangpt: Secondary GPT header is invalid\n");
cli_dbgmsg("cli_scangpt: Disk is unusable\n");
return CL_EFORMAT;
}
} else {
cli_dbgmsg("cli_scangpt: Checking secondary GPT header\n");
state = PRIMARY_ONLY;
/* check validity of secondary header; still using the primary */
if (fmap_readn(*ctx->fmap, &shdr, pos, sizeof(shdr)) != sizeof(shdr)) {
cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
} else if (gpt_validate_header(ctx, shdr, sectorsize)) {
cli_dbgmsg("cli_scangpt: Secondary GPT header is invalid\n");
}
/* check that the two partition table crc32 checksum match,
* may want a different hashing function */
else if (phdr.tableCRC32 != shdr.tableCRC32) {
cli_dbgmsg("cli_scangpt: Primary and secondary GPT header table CRC32 differ\n");
cli_dbgmsg("cli_scangpt: Set to scan primary and secondary partition tables\n");
state = BOTH;
} else {
cli_dbgmsg("cli_scangpt: Secondary GPT header check OK\n");
}
}
/* check that the partition table has no intersections - HEURISTICS */
if (SCAN_HEURISTIC_PARTITION_INTXN && (ctx->dconf->other & OTHER_CONF_PRTNINTXN)) {
ret = gpt_prtn_intxn(ctx, phdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
ret = gpt_prtn_intxn(ctx, shdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
}
/* scanning partitions */
switch (state) {
case PRIMARY_ONLY:
cli_dbgmsg("cli_scangpt: Scanning primary GPT partitions only\n");
ret = gpt_scan_partitions(ctx, phdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
break;
case SECONDARY_ONLY:
cli_dbgmsg("cli_scangpt: Scanning secondary GPT partitions only\n");
ret = gpt_scan_partitions(ctx, shdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
break;
case BOTH:
cli_dbgmsg("cli_scangpt: Scanning primary GPT partitions\n");
ret = gpt_scan_partitions(ctx, phdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
cli_dbgmsg("cli_scangpt: Scanning secondary GPT partitions\n");
ret = gpt_scan_partitions(ctx, shdr, sectorsize);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
break;
default:
cli_dbgmsg("cli_scangpt: State is invalid\n");
}
return detection;
}
static int gpt_scan_partitions(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
{
struct gpt_partition_entry gpe;
int ret = CL_CLEAN, detection = CL_CLEAN;
size_t maplen, part_size = 0;
off_t pos = 0, part_off = 0;
unsigned i = 0, j = 0;
uint32_t max_prtns = 0;
/* convert endian to host */
hdr.signature = be64_to_host(hdr.signature);
hdr.revision = be32_to_host(hdr.revision);
hdr.headerSize = le32_to_host(hdr.headerSize);
hdr.headerCRC32 = le32_to_host(hdr.headerCRC32);
hdr.reserved = le32_to_host(hdr.reserved);
hdr.currentLBA = le64_to_host(hdr.currentLBA);
hdr.backupLBA = le64_to_host(hdr.backupLBA);
hdr.firstUsableLBA = le64_to_host(hdr.firstUsableLBA);
hdr.lastUsableLBA = le64_to_host(hdr.lastUsableLBA);
hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
hdr.tableEntrySize = le32_to_host(hdr.tableEntrySize);
hdr.tableCRC32 = le32_to_host(hdr.tableCRC32);
/* print header info for the debug */
cli_dbgmsg("GPT Header:\n");
cli_dbgmsg("Signature: 0x%llx\n", (long long unsigned)hdr.signature);
cli_dbgmsg("Revision: %x\n", hdr.revision);
gpt_printGUID(hdr.DiskGUID, "DISK GUID");
cli_dbgmsg("Partition Entry Count: %u\n", hdr.tableNumEntries);
cli_dbgmsg("Partition Entry Size: %u\n", hdr.tableEntrySize);
maplen = (*ctx->fmap)->real_len;
/* check engine maxpartitions limit */
if (hdr.tableNumEntries < ctx->engine->maxpartitions) {
max_prtns = hdr.tableNumEntries;
} else {
max_prtns = ctx->engine->maxpartitions;
}
/* use the partition tables to pass partitions to cli_map_scan */
pos = hdr.tableStartLBA * sectorsize;
for (i = 0; i < max_prtns; ++i) {
/* read in partition entry */
if (fmap_readn(*ctx->fmap, &gpe, pos, sizeof(gpe)) != sizeof(gpe)) {
cli_dbgmsg("cli_scangpt: Invalid GPT partition entry\n");
return CL_EFORMAT;
}
/* convert the endian to host */
gpe.firstLBA = le64_to_host(gpe.firstLBA);
gpe.lastLBA = le64_to_host(gpe.lastLBA);
gpe.attributes = le64_to_host(gpe.attributes);
for (j = 0; j < 36; ++j) {
gpe.name[i] = le16_to_host(gpe.name[i]);
}
/* check that partition is not empty and within a valid location */
if (gpe.firstLBA == 0) {
/* empty partition, invalid */
} else if ((gpe.firstLBA > gpe.lastLBA) ||
(gpe.firstLBA < hdr.firstUsableLBA) || (gpe.lastLBA > hdr.lastUsableLBA)) {
cli_dbgmsg("cli_scangpt: GPT partition exists outside specified bounds\n");
gpt_parsemsg("%llu < %llu, %llu > %llu\n", gpe.firstLBA, hdr.firstUsableLBA,
gpe.lastLBA, hdr.lastUsableLBA);
/* partition exists outside bounds specified by header or invalid */
} else if (((gpe.lastLBA + 1) * sectorsize) > maplen) {
/* partition exists outside bounds of the file map */
} else {
/* print partition entry data for debug */
cli_dbgmsg("GPT Partition Entry %u:\n", i);
gpt_printName(gpe.name, "Name");
gpt_printGUID(gpe.typeGUID, "Type GUID");
gpt_printGUID(gpe.uniqueGUID, "Unique GUID");
cli_dbgmsg("Attributes: %llx\n", (long long unsigned)gpe.attributes);
cli_dbgmsg("Blocks: [%llu(%llu) -> %llu(%llu)]\n",
(long long unsigned)gpe.firstLBA, (long long unsigned)(gpe.firstLBA * sectorsize),
(long long unsigned)gpe.lastLBA, (long long unsigned)((gpe.lastLBA + 1) * sectorsize));
/* send the partition to cli_map_scan */
part_off = gpe.firstLBA * sectorsize;
part_size = (gpe.lastLBA - gpe.firstLBA + 1) * sectorsize;
ret = cli_map_scan(*ctx->fmap, part_off, part_size, ctx, CL_TYPE_PART_ANY);
if (ret != CL_CLEAN) {
if (SCAN_ALLMATCHES && (ret == CL_VIRUS))
detection = CL_VIRUS;
else
return ret;
}
}
/* increment the offsets to next partition entry */
pos += hdr.tableEntrySize;
}
if (i >= ctx->engine->maxpartitions) {
cli_dbgmsg("cli_scangpt: max partitions reached\n");
}
return detection;
}
static int gpt_validate_header(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
{
uint32_t crc32_calc, crc32_ref;
uint64_t tableLastLBA, lastLBA;
size_t maplen, ptable_start, ptable_len;
unsigned char *ptable;
maplen = (*ctx->fmap)->real_len;
/* checking header crc32 checksum */
crc32_ref = le32_to_host(hdr.headerCRC32);
hdr.headerCRC32 = 0; /* checksum is calculated with field = 0 */
crc32_calc = crc32(0, (unsigned char *)&hdr, sizeof(hdr));
if (crc32_calc != crc32_ref) {
cli_dbgmsg("cli_scangpt: GPT header checksum mismatch\n");
gpt_parsemsg("%x != %x\n", crc32_calc, crc32_ref);
return CL_EFORMAT;
}
/* convert endian to host to check partition table */
hdr.signature = be64_to_host(hdr.signature);
hdr.revision = be32_to_host(hdr.revision);
hdr.headerSize = le32_to_host(hdr.headerSize);
hdr.headerCRC32 = crc32_ref;
hdr.reserved = le32_to_host(hdr.reserved);
hdr.currentLBA = le64_to_host(hdr.currentLBA);
hdr.backupLBA = le64_to_host(hdr.backupLBA);
hdr.firstUsableLBA = le64_to_host(hdr.firstUsableLBA);
hdr.lastUsableLBA = le64_to_host(hdr.lastUsableLBA);
hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
hdr.tableEntrySize = le32_to_host(hdr.tableEntrySize);
hdr.tableCRC32 = le32_to_host(hdr.tableCRC32);
ptable_start = hdr.tableStartLBA * sectorsize;
ptable_len = hdr.tableNumEntries * hdr.tableEntrySize;
tableLastLBA = (hdr.tableStartLBA + (ptable_len / sectorsize)) - 1;
lastLBA = (maplen / sectorsize) - 1;
/** HEADER CHECKS **/
gpt_printSectors(ctx, sectorsize);
/* check signature */
if (hdr.signature != GPT_SIGNATURE) {
cli_dbgmsg("cli_scangpt: Invalid GPT header signature %llx\n",
(long long unsigned)hdr.signature);
return CL_EFORMAT;
}
/* check header size */
if (hdr.headerSize != sizeof(hdr)) {
cli_dbgmsg("cli_scangpt: GPT header size does not match stated size\n");
return CL_EFORMAT;
}
/* check reserved value == 0 */
if (hdr.reserved != GPT_HDR_RESERVED) {
cli_dbgmsg("cli_scangpt: GPT header reserved is not expected value\n");
return CL_EFORMAT;
}
/* check that sectors are in a valid configuration */
if (!((hdr.currentLBA == GPT_PRIMARY_HDR_LBA && hdr.backupLBA == lastLBA) ||
(hdr.currentLBA == lastLBA && hdr.backupLBA == GPT_PRIMARY_HDR_LBA))) {
cli_dbgmsg("cli_scangpt: GPT secondary header is not last LBA\n");
return CL_EFORMAT;
}
if (hdr.firstUsableLBA > hdr.lastUsableLBA) {
cli_dbgmsg("cli_scangpt: GPT first usable sectors is after last usable sector\n");
return CL_EFORMAT;
}
if (hdr.firstUsableLBA <= GPT_PRIMARY_HDR_LBA || hdr.lastUsableLBA >= lastLBA) {
cli_dbgmsg("cli_scangpt: GPT usable sectors intersects header sector\n");
return CL_EFORMAT;
}
if ((hdr.tableStartLBA <= hdr.firstUsableLBA && tableLastLBA >= hdr.firstUsableLBA) ||
(hdr.tableStartLBA >= hdr.firstUsableLBA && hdr.tableStartLBA <= hdr.lastUsableLBA)) {
cli_dbgmsg("cli_scangpt: GPT usable sectors intersects partition table\n");
return CL_EFORMAT;
}
if (hdr.tableStartLBA <= GPT_PRIMARY_HDR_LBA || tableLastLBA >= lastLBA) {
cli_dbgmsg("cli_scangpt: GPT partition table intersects header sector\n");
return CL_EFORMAT;
}
/* check that valid table entry size */
if (hdr.tableEntrySize != sizeof(struct gpt_partition_entry)) {
cli_dbgmsg("cli_scangpt: cannot parse gpt with partition entry sized %u\n",
hdr.tableEntrySize);
return CL_EFORMAT;
}
/* check valid table */
if ((ptable_start + ptable_len) > maplen) {
cli_dbgmsg("cli_scangpt: GPT partition table extends over fmap limit\n");
return CL_EFORMAT;
}
/** END HEADER CHECKS **/
/* checking partition table crc32 checksum */
ptable = (unsigned char *)fmap_need_off_once((*ctx->fmap), ptable_start, ptable_len);
crc32_calc = crc32(0, ptable, ptable_len);
if (crc32_calc != hdr.tableCRC32) {
cli_dbgmsg("cli_scangpt: GPT partition table checksum mismatch\n");
gpt_parsemsg("%x != %x\n", crc32_calc, hdr.tableCRC32);
return CL_EFORMAT;
}
return CL_SUCCESS;
}
static int gpt_check_mbr(cli_ctx *ctx, size_t sectorsize)
{
struct mbr_boot_record pmbr;
off_t pos = 0, mbr_base = 0;
int ret = CL_CLEAN;
unsigned i = 0;
/* read the mbr */
mbr_base = sectorsize - sizeof(struct mbr_boot_record);
pos = (MBR_SECTOR * sectorsize) + mbr_base;
if (fmap_readn(*ctx->fmap, &pmbr, pos, sizeof(pmbr)) != sizeof(pmbr)) {
cli_dbgmsg("cli_scangpt: Invalid primary MBR header\n");
return CL_EFORMAT;
}
/* convert mbr */
mbr_convert_to_host(&pmbr);
/* check the protective mbr - warning */
if (pmbr.entries[0].type == MBR_PROTECTIVE) {
/* check the efi partition matches the gpt spec */
if (pmbr.entries[0].firstLBA != GPT_PRIMARY_HDR_LBA) {
cli_warnmsg("cli_scangpt: protective MBR first LBA is incorrect %u\n",
pmbr.entries[0].firstLBA);
}
/* other entries are empty */
for (i = 1; i < MBR_MAX_PARTITION_ENTRIES; ++i) {
if (pmbr.entries[i].type != MBR_EMPTY) {
cli_warnmsg("cli_scangpt: protective MBR has non-empty partition\n");
break;
}
}
} else if (pmbr.entries[0].type == MBR_HYBRID) {
/* hybrid mbr detected */
cli_warnmsg("cli_scangpt: detected a hybrid MBR\n");
} else {
/* non-protective mbr detected */
cli_warnmsg("cli_scangpt: detected a non-protective MBR\n");
}
/* scan the bootloader segment - pushed to scanning mbr */
/* check if MBR size matches GPT size */
/* check if the MBR and GPT partitions align - heuristic */
/* scan the MBR partitions - additional scans */
return ret;
}
static void gpt_printSectors(cli_ctx *ctx, size_t sectorsize)
{
#ifdef DEBUG_GPT_PARSE
struct gpt_header phdr, shdr;
off_t ppos = 0, spos = 0;
size_t pptable_len, sptable_len, maplen;
uint64_t ptableLastLBA, stableLastLBA;
/* sector size calculation */
sectorsize = GPT_DEFAULT_SECTOR_SIZE;
maplen = (*ctx->fmap)->real_len;
ppos = 1 * sectorsize; /* sector 1 (second sector) is the primary gpt header */
spos = maplen - sectorsize; /* last sector is the secondary gpt header */
/* read in the primary and secondary gpt headers */
if (fmap_readn(*ctx->fmap, &phdr, ppos, sizeof(phdr)) != sizeof(phdr)) {
cli_dbgmsg("cli_scangpt: Invalid primary GPT header\n");
return;
}
if (fmap_readn(*ctx->fmap, &shdr, spos, sizeof(shdr)) != sizeof(shdr)) {
cli_dbgmsg("cli_scangpt: Invalid secondary GPT header\n");
return;
}
pptable_len = phdr.tableNumEntries * phdr.tableEntrySize;
sptable_len = shdr.tableNumEntries * shdr.tableEntrySize;
ptableLastLBA = (phdr.tableStartLBA + (pptable_len / sectorsize)) - 1;
stableLastLBA = (shdr.tableStartLBA + (sptable_len / sectorsize)) - 1;
gpt_parsemsg("0: MBR\n");
gpt_parsemsg("%llu: Primary GPT Header\n", phdr.currentLBA);
gpt_parsemsg("%llu-%llu: Primary GPT Partition Table\n", phdr.tableStartLBA, ptableLastLBA);
gpt_parsemsg("%llu-%llu: Usable LBAs\n", phdr.firstUsableLBA, phdr.lastUsableLBA);
gpt_parsemsg("%llu-%llu: Secondary GPT Partition Table\n", shdr.tableStartLBA, stableLastLBA);
gpt_parsemsg("%llu: Secondary GPT Header\n", phdr.backupLBA);
#else
UNUSEDPARAM(ctx);
UNUSEDPARAM(sectorsize);
return;
#endif
}
static void gpt_printName(uint16_t name[], const char *msg)
{
char *namestr;
namestr = (char *)cli_utf16toascii((char *)name, 72);
cli_dbgmsg("%s: %s\n", msg, namestr);
free(namestr);
}
static void gpt_printGUID(uint8_t GUID[], const char *msg)
{
cli_dbgmsg("%s: %02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
msg, GUID[0], GUID[1], GUID[2], GUID[3], GUID[4], GUID[5], GUID[6], GUID[7],
GUID[8], GUID[9], GUID[10], GUID[11], GUID[12], GUID[13], GUID[14], GUID[15]);
}
static int gpt_prtn_intxn(cli_ctx *ctx, struct gpt_header hdr, size_t sectorsize)
{
prtn_intxn_list_t prtncheck;
struct gpt_partition_entry gpe;
unsigned i, pitxn;
int ret = CL_CLEAN, tmp = CL_CLEAN;
off_t pos;
size_t maplen;
uint32_t max_prtns = 0;
int virus_found = 0;
maplen = (*ctx->fmap)->real_len;
/* convert endian to host to check partition table */
hdr.tableStartLBA = le64_to_host(hdr.tableStartLBA);
hdr.tableNumEntries = le32_to_host(hdr.tableNumEntries);
prtn_intxn_list_init(&prtncheck);
/* check engine maxpartitions limit */
if (hdr.tableNumEntries < ctx->engine->maxpartitions) {
max_prtns = hdr.tableNumEntries;
} else {
max_prtns = ctx->engine->maxpartitions;
}
pos = hdr.tableStartLBA * sectorsize;
for (i = 0; i < max_prtns; ++i) {
/* read in partition entry */
if (fmap_readn(*ctx->fmap, &gpe, pos, sizeof(gpe)) != sizeof(gpe)) {
cli_dbgmsg("cli_scangpt: Invalid GPT partition entry\n");
prtn_intxn_list_free(&prtncheck);
return CL_EFORMAT;
}
/* convert the endian to host */
gpe.firstLBA = le64_to_host(gpe.firstLBA);
gpe.lastLBA = le64_to_host(gpe.lastLBA);
if (gpe.firstLBA == 0) {
/* empty partition, invalid */
} else if ((gpe.firstLBA > gpe.lastLBA) ||
(gpe.firstLBA < hdr.firstUsableLBA) || (gpe.lastLBA > hdr.lastUsableLBA)) {
/* partition exists outside bounds specified by header or invalid */
} else if (((gpe.lastLBA + 1) * sectorsize) > maplen) {
/* partition exists outside bounds of the file map */
} else {
tmp = prtn_intxn_list_check(&prtncheck, &pitxn, gpe.firstLBA, gpe.lastLBA - gpe.firstLBA + 1);
if (tmp != CL_CLEAN) {
if (tmp == CL_VIRUS) {
cli_dbgmsg("cli_scangpt: detected intersection with partitions "
"[%u, %u]\n",
pitxn, i);
ret = cli_append_virus(ctx, PRTN_INTXN_DETECTION);
if (ret == CL_VIRUS)
virus_found = 1;
if (SCAN_ALLMATCHES || ret == CL_CLEAN)
tmp = 0;
else
goto leave;
} else {
ret = tmp;
goto leave;
}
}
}
/* increment the offsets to next partition entry */
pos += hdr.tableEntrySize;
}
leave:
prtn_intxn_list_free(&prtncheck);
if (virus_found)
return CL_VIRUS;
return ret;
}