com.sun.jna.ELFAnalyser Maven / Gradle / Ivy
/* Copyright (c) 2017 Matthias Bläsing, All Rights Reserved
*
* The contents of this file is dual-licensed under 2
* alternative Open Source/Free licenses: LGPL 2.1 or later and
* Apache License 2.0. (starting with JNA version 4.0.0).
*
* You can freely decide which license you want to apply to
* the project.
*
* You may obtain a copy of the LGPL License at:
*
* http://www.gnu.org/licenses/licenses.html
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "LGPL2.1".
*
* You may obtain a copy of the Apache License at:
*
* http://www.apache.org/licenses/
*
* A copy is also included in the downloadable source code package
* containing JNA, in file "AL2.0".
*/
package com.sun.jna;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
/**
* Analyse an ELF file for platform specific attributes.
*
* Primary use-case: Detect whether the java binary is arm hardfloat or softfloat.
*/
class ELFAnalyser {
/**
* Generic ELF header
*/
private static final byte[] ELF_MAGIC = new byte[]{(byte) 0x7F, (byte) 'E', (byte) 'L', (byte) 'F'};
/**
* e_flags mask if executable file conforms to hardware floating-point
* procedure-call standard (arm ABI version 5)
*/
private static final int EF_ARM_ABI_FLOAT_HARD = 0x00000400;
/**
* e_flags mask if executable file conforms to software floating-point
* procedure-call standard (arm ABI version 5)
*/
private static final int EF_ARM_ABI_FLOAT_SOFT = 0x00000200;
private static final int EI_DATA_BIG_ENDIAN = 2;
private static final int E_MACHINE_ARM = 0x28;
private static final int EI_CLASS_64BIT = 2;
public static ELFAnalyser analyse(String filename) throws IOException {
ELFAnalyser res = new ELFAnalyser(filename);
res.runDetection();
return res;
}
private final String filename;
private boolean ELF = false;
private boolean _64Bit = false;
private boolean bigEndian = false;
private boolean armHardFloatFlag = false;
private boolean armSoftFloatFlag = false;
private boolean armEabiAapcsVfp = false;
private boolean arm = false;
/**
* @return true if the parsed file was detected to be an ELF file
*/
public boolean isELF() {
return ELF;
}
/**
* @return true if the parsed file was detected to be for a 64bit architecture
* and pointers are expected to be 8byte wide
*/
public boolean is64Bit() {
return _64Bit;
}
/**
* @return true if the parsed file is detected to be big endian, false if
* the file is little endian
*/
public boolean isBigEndian() {
return bigEndian;
}
/**
* @return filename of the parsed file
*/
public String getFilename() {
return filename;
}
public boolean isArmHardFloat() {
return isArmEabiAapcsVfp() || isArmHardFloatFlag();
}
/**
* @return true if file was detected to specify, that FP parameters/result
* passing conforms to AAPCS, VFP variant (hardfloat)
*/
public boolean isArmEabiAapcsVfp() {
return armEabiAapcsVfp;
}
/**
* @return true if file was detected to conform to the hardware floating-point
* procedure-call standard via ELF flags
*/
public boolean isArmHardFloatFlag() {
return armHardFloatFlag;
}
/**
* @return true if file was detected to conform to the software floating-point
* procedure-call standard via ELF flags
*/
public boolean isArmSoftFloatFlag() {
return armSoftFloatFlag;
}
/**
* @return true if the parsed file was detected to be build for the arm
* architecture
*/
public boolean isArm() {
return arm;
}
private ELFAnalyser(String filename) {
this.filename = filename;
}
private void runDetection() throws IOException {
RandomAccessFile raf = new RandomAccessFile(filename, "r");
try {
// run precheck - only of if the file at least hold an ELF header parsing
// runs further.
if (raf.length() > 4) {
byte[] magic = new byte[4];
raf.seek(0);
raf.read(magic);
if (Arrays.equals(magic, ELF_MAGIC)) {
ELF = true;
}
}
if (!ELF) {
return;
}
raf.seek(4);
// The total header size depends on the pointer size of the platform
// so before the header is loaded the pointer size has to be determined
byte sizeIndicator = raf.readByte();
byte endianessIndicator = raf.readByte();
_64Bit = sizeIndicator == EI_CLASS_64BIT;
bigEndian = endianessIndicator == EI_DATA_BIG_ENDIAN;
raf.seek(0);
// header length
ByteBuffer headerData = ByteBuffer.allocate(_64Bit ? 64 : 52);
raf.getChannel().read(headerData, 0);
headerData.order(bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
// e_machine
arm = headerData.get(0x12) == E_MACHINE_ARM;
if(arm) {
// e_flags
int flags = headerData.getInt(_64Bit ? 0x30 : 0x24);
armHardFloatFlag = (flags & EF_ARM_ABI_FLOAT_HARD) == EF_ARM_ABI_FLOAT_HARD;
armSoftFloatFlag = (flags & EF_ARM_ABI_FLOAT_SOFT) == EF_ARM_ABI_FLOAT_SOFT;
parseEabiAapcsVfp(headerData, raf);
}
} finally {
try {
raf.close();
} catch (IOException ex) {
// Swallow - closing
}
}
}
private void parseEabiAapcsVfp(ByteBuffer headerData, RandomAccessFile raf) throws IOException {
ELFSectionHeaders sectionHeaders = new ELFSectionHeaders(_64Bit, bigEndian, headerData, raf);
for (ELFSectionHeaderEntry eshe : sectionHeaders.getEntries()) {
if(".ARM.attributes".equals(eshe.getName())) {
ByteBuffer armAttributesBuffer = ByteBuffer.allocate(eshe.getSize());
armAttributesBuffer.order(bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
raf.getChannel().read(armAttributesBuffer, eshe.getOffset());
armAttributesBuffer.rewind();
Map> armAttributes = parseArmAttributes(armAttributesBuffer);
Map fileAttributes = armAttributes.get(1);
if(fileAttributes == null) {
continue;
}
/**
* Tag_ABI_VFP_args, (=28), uleb128
* 0 The user intended FP parameter/result passing to conform to AAPCS, base variant
* 1 The user intended FP parameter/result passing to conform to AAPCS, VFP variant
* 2 The user intended FP parameter/result passing to conform to tool chain-specific conventions
* 3 Code is compatible with both the base and VFP variants; the non-variadic functions to pass FP parameters/results
*/
Object abiVFPargValue = fileAttributes.get(ArmAeabiAttributesTag.ABI_VFP_args);
if(abiVFPargValue instanceof Integer && ((Integer) abiVFPargValue).equals(1)) {
armEabiAapcsVfp = true;
} else if (abiVFPargValue instanceof BigInteger && ((BigInteger) abiVFPargValue).intValue() == 1) {
armEabiAapcsVfp = true;
}
}
}
}
static class ELFSectionHeaders {
private final List entries = new ArrayList();
public ELFSectionHeaders(boolean _64bit, boolean bigEndian, ByteBuffer headerData, RandomAccessFile raf) throws IOException {
long shoff;
int shentsize;
int shnum;
short shstrndx;
if (_64bit) {
shoff = headerData.getLong(0x28);
shentsize = headerData.getShort(0x3A);
shnum = headerData.getShort(0x3C);
shstrndx = headerData.getShort(0x3E);
} else {
shoff = headerData.getInt(0x20);
shentsize = headerData.getShort(0x2E);
shnum = headerData.getShort(0x30);
shstrndx = headerData.getShort(0x32);
}
int tableLength = shnum * shentsize;
ByteBuffer data = ByteBuffer.allocate(tableLength);
data.order(bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
raf.getChannel().read(data, shoff);
for(int i = 0; i < shnum; i++) {
data.position(i * shentsize);
ByteBuffer header = data.slice();
header.order(data.order());
header.limit(shentsize);
entries.add(new ELFSectionHeaderEntry(_64bit, header));
}
ELFSectionHeaderEntry stringTable = entries.get(shstrndx);
ByteBuffer stringBuffer = ByteBuffer.allocate(stringTable.getSize());
stringBuffer.order(bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN);
raf.getChannel().read(stringBuffer, stringTable.getOffset());
stringBuffer.rewind();
ByteArrayOutputStream baos = new ByteArrayOutputStream(20);
for (ELFSectionHeaderEntry eshe : entries) {
baos.reset();
((Buffer) stringBuffer).position(eshe.getNameOffset());
while(stringBuffer.position() < stringBuffer.limit()) {
byte b = stringBuffer.get();
if(b == 0) {
break;
} else {
baos.write(b);
}
}
eshe.setName(baos.toString("ASCII"));
}
}
public List getEntries() {
return entries;
}
}
static class ELFSectionHeaderEntry {
private final int nameOffset;
private String name;
private final int type;
private final int flags;
private final int offset;
private final int size;
public ELFSectionHeaderEntry(boolean _64bit, ByteBuffer sectionHeaderData) {
this.nameOffset = sectionHeaderData.getInt(0x0);
this.type = sectionHeaderData.getInt(0x4);
this.flags = (int) (_64bit ? sectionHeaderData.getLong(0x8) : sectionHeaderData.getInt(0x8));
this.offset = (int) (_64bit ? sectionHeaderData.getLong(0x18) : sectionHeaderData.getInt(0x10));
this.size = (int) (_64bit ? sectionHeaderData.getLong(0x20) : sectionHeaderData.getInt(0x14));
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getNameOffset() {
return nameOffset;
}
public int getType() {
return type;
}
public int getFlags() {
return flags;
}
public int getOffset() {
return offset;
}
public int getSize() {
return size;
}
@Override
public String toString() {
return "ELFSectionHeaderEntry{" + "nameIdx=" + nameOffset + ", name=" + name + ", type=" + type + ", flags=" + flags + ", offset=" + offset + ", size=" + size + '}';
}
}
static class ArmAeabiAttributesTag {
public enum ParameterType {
UINT32, NTBS, ULEB128
}
private final int value;
private final String name;
private final ParameterType parameterType;
public ArmAeabiAttributesTag(int value, String name, ParameterType parameterType) {
this.value = value;
this.name = name;
this.parameterType = parameterType;
}
public int getValue() {
return value;
}
public String getName() {
return name;
}
public ParameterType getParameterType() {
return parameterType;
}
@Override
public String toString() {
return name + " (" + value + ")";
}
@Override
public int hashCode() {
int hash = 7;
hash = 67 * hash + this.value;
return hash;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final ArmAeabiAttributesTag other = (ArmAeabiAttributesTag) obj;
if (this.value != other.value) {
return false;
}
return true;
}
private static final List tags = new LinkedList();
private static final Map valueMap = new HashMap();
private static final Map nameMap = new HashMap();
// Enumerated from ARM IHI 0045E, 2.5 Attributes summary and history
public static final ArmAeabiAttributesTag File = addTag(1, "File", ParameterType.UINT32);
public static final ArmAeabiAttributesTag Section = addTag(2, "Section", ParameterType.UINT32);
public static final ArmAeabiAttributesTag Symbol = addTag(3, "Symbol", ParameterType.UINT32);
public static final ArmAeabiAttributesTag CPU_raw_name = addTag(4, "CPU_raw_name", ParameterType.NTBS);
public static final ArmAeabiAttributesTag CPU_name = addTag(5, "CPU_name", ParameterType.NTBS);
public static final ArmAeabiAttributesTag CPU_arch = addTag(6, "CPU_arch", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag CPU_arch_profile = addTag(7, "CPU_arch_profile", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ARM_ISA_use = addTag(8, "ARM_ISA_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag THUMB_ISA_use = addTag(9, "THUMB_ISA_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag FP_arch = addTag(10, "FP_arch", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag WMMX_arch = addTag(11, "WMMX_arch", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag Advanced_SIMD_arch = addTag(12, "Advanced_SIMD_arch", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag PCS_config = addTag(13, "PCS_config", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_PCS_R9_use = addTag(14, "ABI_PCS_R9_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_PCS_RW_data = addTag(15, "ABI_PCS_RW_data", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_PCS_RO_data = addTag(16, "ABI_PCS_RO_data", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_PCS_GOT_use = addTag(17, "ABI_PCS_GOT_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_PCS_wchar_t = addTag(18, "ABI_PCS_wchar_t", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_rounding = addTag(19, "ABI_FP_rounding", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_denormal = addTag(20, "ABI_FP_denormal", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_exceptions = addTag(21, "ABI_FP_exceptions", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_user_exceptions = addTag(22, "ABI_FP_user_exceptions", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_number_model = addTag(23, "ABI_FP_number_model", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_align_needed = addTag(24, "ABI_align_needed", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_align8_preserved = addTag(25, "ABI_align8_preserved", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_enum_size = addTag(26, "ABI_enum_size", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_HardFP_use = addTag(27, "ABI_HardFP_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_VFP_args = addTag(28, "ABI_VFP_args", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_WMMX_args = addTag(29, "ABI_WMMX_args", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_optimization_goals = addTag(30, "ABI_optimization_goals", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_optimization_goals = addTag(31, "ABI_FP_optimization_goals", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag compatibility = addTag(32, "compatibility", ParameterType.NTBS);
public static final ArmAeabiAttributesTag CPU_unaligned_access = addTag(34, "CPU_unaligned_access", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag FP_HP_extension = addTag(36, "FP_HP_extension", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag ABI_FP_16bit_format = addTag(38, "ABI_FP_16bit_format", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag MPextension_use = addTag(42, "MPextension_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag DIV_use = addTag(44, "DIV_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag nodefaults = addTag(64, "nodefaults", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag also_compatible_with = addTag(65, "also_compatible_with", ParameterType.NTBS);
public static final ArmAeabiAttributesTag conformance = addTag(67, "conformance", ParameterType.NTBS);
public static final ArmAeabiAttributesTag T2EE_use = addTag(66, "T2EE_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag Virtualization_use = addTag(68, "Virtualization_use", ParameterType.ULEB128);
public static final ArmAeabiAttributesTag MPextension_use2 = addTag(70, "MPextension_use", ParameterType.ULEB128);
private static ArmAeabiAttributesTag addTag(int value, String name, ArmAeabiAttributesTag.ParameterType type) {
ArmAeabiAttributesTag tag = new ArmAeabiAttributesTag(value, name, type);
if (!valueMap.containsKey(tag.getValue())) {
valueMap.put(tag.getValue(), tag);
}
if (!nameMap.containsKey(tag.getName())) {
nameMap.put(tag.getName(), tag);
}
tags.add(tag);
return tag;
}
public static List getTags() {
return Collections.unmodifiableList(tags);
}
public static ArmAeabiAttributesTag getByName(String name) {
return nameMap.get(name);
}
public static ArmAeabiAttributesTag getByValue(int value) {
if (valueMap.containsKey(value)) {
return valueMap.get(value);
} else {
ArmAeabiAttributesTag pseudoTag = new ArmAeabiAttributesTag(value, "Unknown " + value, getParameterType(value));
return pseudoTag;
}
}
private static ArmAeabiAttributesTag.ParameterType getParameterType(int value) {
// ARM IHI 0045E, 2.2.6 Coding extensibility and compatibility
ArmAeabiAttributesTag tag = getByValue(value);
if (tag == null) {
if ((value % 2) == 0) {
return ArmAeabiAttributesTag.ParameterType.ULEB128;
} else {
return ArmAeabiAttributesTag.ParameterType.NTBS;
}
} else {
return tag.getParameterType();
}
}
}
private static Map> parseArmAttributes(ByteBuffer bb) {
byte format = bb.get();
if (format != 0x41) {
// Version A
// Not supported
return Collections.EMPTY_MAP;
}
while (bb.position() < bb.limit()) {
int posSectionStart = bb.position();
int sectionLength = bb.getInt();
if (sectionLength <= 0) {
// Fail!
break;
}
String vendorName = readNTBS(bb, null);
if ("aeabi".equals(vendorName)) {
return parseAEABI(bb);
}
((Buffer) bb).position(posSectionStart + sectionLength);
}
return Collections.EMPTY_MAP;
}
private static Map> parseAEABI(ByteBuffer buffer) {
Map> data = new HashMap>();
while (buffer.position() < buffer.limit()) {
int pos = buffer.position();
int subsectionTag = readULEB128(buffer).intValue();
int length = buffer.getInt();
if (subsectionTag == (byte) 1) {
data.put(subsectionTag, parseFileAttribute(buffer));
}
((Buffer) buffer).position(pos + length);
}
return data;
}
private static Map parseFileAttribute(ByteBuffer bb) {
Map result = new HashMap();
while (bb.position() < bb.limit()) {
int tagValue = readULEB128(bb).intValue();
ArmAeabiAttributesTag tag = ArmAeabiAttributesTag.getByValue(tagValue);
switch (tag.getParameterType()) {
case UINT32:
result.put(tag, bb.getInt());
break;
case NTBS:
result.put(tag, readNTBS(bb, null));
break;
case ULEB128:
result.put(tag, readULEB128(bb));
break;
}
}
return result;
}
private static String readNTBS(ByteBuffer buffer, Integer position) {
if (position != null) {
((Buffer) buffer).position(position);
}
int startingPos = buffer.position();
byte currentByte;
do {
currentByte = buffer.get();
} while (currentByte != '\0' && buffer.position() <= buffer.limit());
int terminatingPosition = buffer.position();
byte[] data = new byte[terminatingPosition - startingPos - 1];
((Buffer) buffer).position(startingPos);
buffer.get(data);
((Buffer) buffer).position(buffer.position() + 1);
try {
return new String(data, "ASCII");
} catch (UnsupportedEncodingException ex) {
throw new RuntimeException(ex);
}
}
private static BigInteger readULEB128(ByteBuffer buffer) {
BigInteger result = BigInteger.ZERO;
int shift = 0;
while (true) {
byte b = buffer.get();
result = result.or(BigInteger.valueOf(b & 127).shiftLeft(shift));
if ((b & 128) == 0) {
break;
}
shift += 7;
}
return result;
}
}
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