Skip to content

Instantly share code, notes, and snippets.

@astarasikov
Last active November 15, 2021 05:24
Show Gist options
  • Save astarasikov/1a67b948f3ca61f348b8e3eccf963a42 to your computer and use it in GitHub Desktop.
Save astarasikov/1a67b948f3ca61f348b8e3eccf963a42 to your computer and use it in GitHub Desktop.
Ghidra script to rename functions from debug prints
/* ###
* IP: GHIDRA
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Given a routine, show all the calls to that routine and their parameters.
// Place the cursor on a function (can be an external .dll function).
// Execute the script.
// The decompiler will be run on everything that calls the function at the cursor
// All calls to the function will display with their parameters to the function.
//
// This script assumes good flow, that switch stmts are good.
//
//@category Functions
import java.util.Iterator;
import java.util.LinkedList;
import ghidra.app.decompiler.*;
import ghidra.app.script.GhidraScript;
import ghidra.framework.options.ToolOptions;
import ghidra.framework.plugintool.util.OptionsService;
import ghidra.program.model.address.Address;
import ghidra.program.model.address.AddressFactory;
import ghidra.program.model.address.AddressSpace;
import ghidra.program.model.lang.Register;
import ghidra.program.model.listing.*;
import ghidra.program.model.mem.MemoryAccessException;
import ghidra.program.model.pcode.*;
import ghidra.program.model.symbol.Reference;
import ghidra.program.model.symbol.SourceType;
import ghidra.program.model.symbol.Symbol;
public class RenameFunctionsFromDebugPrints extends GhidraScript {
private Address lastAddr = null;
@Override
public void run() throws Exception {
if (currentLocation == null) {
println("No Location.");
return;
}
Listing listing = currentProgram.getListing();
Function func = listing.getFunctionContaining(currentAddress);
if (func == null) {
println("No Function at address " + currentAddress);
return;
}
DecompInterface decomplib = setUpDecompiler(currentProgram);
try {
if (!decomplib.openProgram(currentProgram)) {
println("Decompile Error: " + decomplib.getLastMessage());
return;
}
// call decompiler for all refs to current function
Symbol sym = this.getSymbolAt(func.getEntryPoint());
Reference refs[] = sym.getReferences(null);
int limit = 9999999;
for (int i = 0; i < refs.length && i < limit; i++) {
if (monitor.isCancelled()) {
break;
}
// get function containing.
Address refAddr = refs[i].getFromAddress();
Function refFunc = currentProgram.getFunctionManager()
.getFunctionContaining(refAddr);
if (refFunc == null) {
continue;
}
// decompile function
// look for call to this function
// display call
analyzeFunction(decomplib, currentProgram, refFunc, refAddr);
}
}
finally {
decomplib.dispose();
}
lastAddr = null;
}
private DecompInterface setUpDecompiler(Program program) {
DecompInterface decomplib = new DecompInterface();
DecompileOptions options;
options = new DecompileOptions();
OptionsService service = state.getTool().getService(OptionsService.class);
if (service != null) {
ToolOptions opt = service.getOptions("Decompiler");
options.grabFromToolAndProgram(null,opt,program);
}
decomplib.setOptions(options);
decomplib.toggleCCode(true);
decomplib.toggleSyntaxTree(true);
decomplib.setSimplificationStyle("decompile");
return decomplib;
}
/**
* Analyze a functions references
*/
public void analyzeFunction(DecompInterface decomplib, Program prog, Function f, Address refAddr) {
if (f == null) {
return;
}
// don't decompile the function again if it was the same as the last one
//
if (!f.getEntryPoint().equals(lastAddr))
decompileFunction(f, decomplib);
lastAddr = f.getEntryPoint();
Instruction instr = prog.getListing().getInstructionAt(refAddr);
if (instr == null) {
return;
}
println(printCall(prog, f, refAddr));
}
HighFunction hfunction = null;
ClangTokenGroup docroot = null;
public boolean decompileFunction(Function f, DecompInterface decomplib) {
// decomplib.setSimplificationStyle("normalize", null);
// HighFunction hfunction = decomplib.decompileFunction(f);
DecompileResults decompRes = decomplib.decompileFunction(f, decomplib.getOptions().getDefaultTimeout(), monitor);
//String statusMsg = decomplib.getDecompileMessage();
hfunction = decompRes.getHighFunction();
docroot = decompRes.getCCodeMarkup();
if (hfunction == null)
return false;
return true;
}
/**
* get the pcode ops that refer to an address
*/
public Iterator<PcodeOpAST> getPcodeOps(Address refAddr) {
if (hfunction == null) {
return null;
}
Iterator<PcodeOpAST> piter = hfunction.getPcodeOps(refAddr.getPhysicalAddress());
return piter;
}
public String printCall(Program prog, Function f, Address refAddr) {
StringBuffer buff = new StringBuffer();
printCall(prog, refAddr, docroot, buff, false, false);
return buff.toString();
}
private boolean printCall(Program prog, Address refAddr, ClangNode node, StringBuffer buff, boolean didStart, boolean isCall) {
if (node == null) {
return false;
}
Address min = node.getMinAddress();
Address max = node.getMaxAddress();
if (min == null)
return false;
if (refAddr.getPhysicalAddress().equals(max) && node instanceof ClangStatement) {
ClangStatement stmt = (ClangStatement) node;
// Don't check for an actual call. The call could be buried more deeply. As long as the original call reference site
// is the max address, then display the results.
// So this block assumes that the last address contained in the call will be the
// address you are looking for.
// - This could lead to strange behavior if the call reference is placed on some address
// that is not the final call point used by the decompiler.
// - Also if there is a delay slot, then the last address for the call reference point
// might not be the last address for the block of PCode.
//if (stmt.getPcodeOp().getOpcode() == PcodeOp.CALL) {
if (!didStart) {
Address nodeAddr = node.getMaxAddress();
// Decompiler only knows base space.
// If reference came from an overlay space, convert address back
if (refAddr.getAddressSpace().isOverlaySpace()) {
nodeAddr = refAddr.getAddressSpace().getOverlayAddress(nodeAddr);
}
buff.append(" " + nodeAddr + " : ");
}
buff.append(" [" + toString(stmt) + "]\n");
String fmt = null;
String name = null;
int idx_fmt = 1;
int idx_arg = 2;
boolean want_fmt = true;
//for TA
//idx_arg = 3;
//want_fmt = false;
for (int i = 0; i < stmt.getPcodeOp().getNumInputs(); i++) {
if (i == idx_fmt || i == idx_arg) {
Object sa = null;
Varnode vn = stmt.getPcodeOp().getInput(i);
PcodeOp po = vn.getDef();
if (po == null) {
continue;
}
if (!vn.isUnique()) {
continue;
}
if (po.getOpcode() == PcodeOp.COPY) {
if (po.getNumInputs() < 1) {
continue;
}
vn = po.getInput(0);
}
else if (po.getOpcode() == PcodeOp.PTRSUB) {
if (po.getNumInputs() < 2) {
continue;
}
vn = po.getInput(1);
}
else {
buff.append(String.format("ZZZ: Unknown opcode [%d] -> %s\n", i, po));
continue;
}
sa = vn.getAddress();
Address ma = prog.getMinAddress().getNewAddress(vn.getAddress().getOffset());
Data sdata = prog.getListing().getDefinedDataAt(ma);
if (sdata != null && sdata.getDataType().getName() == "string") {
sa = sdata.getValue();
}
if (i == idx_fmt) {
fmt = sa.toString();
}
else if (i == idx_arg) {
name = sa.toString();
}
Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
sa = fu;
buff.append(String.format("vn[%d] -> %s\n", i, sa));
}
}
//ta
if (!want_fmt) {
if (name != null) {
buff.append(String.format(">>>> printf with arg=[%s] <<<<\n", name));
//rename the caller
Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
try {
fu.setName(name, SourceType.ANALYSIS);
buff.append("Name set\n");
} catch (Exception e) {
buff.append(String.format("Failed to set function name: %s\n", e.toString()));
}
}
}
else {
if (fmt != null && name != null) {
fmt = fmt.trim();
buff.append(String.format(">>>> printf with fmt=[%s] and arg=[%s] <<<<\n", fmt, name));
if (fmt.startsWith("%s")) {
//rename the caller
Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
try {
fu.setName(name, SourceType.ANALYSIS);
buff.append("Name set\n");
} catch (Exception e) {
buff.append(String.format("Failed to set function name: %s\n", e.toString()));
}
}
}
}
return true;
//}
}
for (int j = 0; j < node.numChildren(); j++) {
isCall = node instanceof ClangStatement;
didStart |= printCall(prog, refAddr, node.Child(j), buff, didStart, isCall);
}
return didStart;
}
public String[] toStrings(ClangStatement node) {
LinkedList<String> strings = new LinkedList<>();
int open=-1;
for (int j = node.numChildren() - 1; j >= 0; j--) {
ClangNode subNode = node.Child(j);
if (subNode instanceof ClangSyntaxToken) {
ClangSyntaxToken syntaxNode = (ClangSyntaxToken) subNode;
if (syntaxNode.getOpen() != -1) {
if (node.Child(j+2) instanceof ClangTypeToken) {
open = syntaxNode.getOpen();
continue;
}
}
if (syntaxNode.getClose() == open && open != -1) {
open = -1;
continue;
}
}
if (open != -1) {
continue;
}
strings.push(subNode.toString());
}
return strings.toArray(new String[]{});
}
public String toString(ClangStatement node) {
StringBuffer buffer = new StringBuffer();
int open=-1;
for (int j = 0; j < node.numChildren(); j++) {
ClangNode subNode = node.Child(j);
if (subNode instanceof ClangSyntaxToken) {
ClangSyntaxToken syntaxNode = (ClangSyntaxToken) subNode;
if (syntaxNode.getOpen() != -1) {
if (node.Child(j+2) instanceof ClangTypeToken) {
open = syntaxNode.getOpen();
continue;
}
}
if (syntaxNode.getClose() == open && open != -1) {
open = -1;
continue;
}
}
if (open != -1) {
continue;
}
buffer.append(subNode.toString());
}
return buffer.toString();
}
}
@evandrix
Copy link

@evandrix
Copy link

cleaned up code formatting:

// Given a routine, show all the calls to that routine and their parameters.
//    Place the cursor on a function (can be an external .dll function).
//    Execute the script.
//    The decompiler will be run on everything that calls the function at the cursor
//    All calls to the function will display with their parameters to the function.
//   This script assumes good flow, that switch stmts are good.
//@category Functions

import java.util.Iterator;
import java.util.LinkedList;
import ghidra.app.decompiler.*;
import ghidra.app.script.GhidraScript;
import ghidra.framework.options.ToolOptions;
import ghidra.framework.plugintool.util.OptionsService;
import ghidra.program.model.address.Address;
import ghidra.program.model.address.AddressFactory;
import ghidra.program.model.address.AddressSpace;
import ghidra.program.model.lang.Register;
import ghidra.program.model.listing.*;
import ghidra.program.model.mem.MemoryAccessException;
import ghidra.program.model.pcode.*;
import ghidra.program.model.symbol.Reference;
import ghidra.program.model.symbol.SourceType;
import ghidra.program.model.symbol.Symbol;

public class RenameFunctionsFromDebugPrints extends GhidraScript {
	private Address lastAddr = null;

	@Override
	public void run() throws Exception {
		if (currentLocation == null) {
			println("No Location.");
			return;
		}
		Listing listing = currentProgram.getListing();
		Function func = listing.getFunctionContaining(currentAddress);
		if (func == null) {
			println("No Function at address " + currentAddress);
			return;
		}
		DecompInterface decomplib = setUpDecompiler(currentProgram);
		try {
			if (!decomplib.openProgram(currentProgram)) {
				println("Decompile Error: " + decomplib.getLastMessage());
				return;
			}
			// decompile for all refs to curr func
			Symbol sym = this.getSymbolAt(func.getEntryPoint());
			Reference refs[] = sym.getReferences(null);
			int limit = 9999999;
			for (int i = 0; i < refs.length && i < limit; i++) {
				if (monitor.isCancelled()) {
					break;
				}
				// get parent func
				Address refAddr = refs[i].getFromAddress();
				Function refFunc = currentProgram.getFunctionManager()
						.getFunctionContaining(refAddr);
				if (refFunc == null) {
					continue;
				}
				// decompile func
				// look for call to this func
				// display call
				analyzeFunction(decomplib, currentProgram, refFunc, refAddr);
			}
		}
		finally {
			decomplib.dispose();
		}
		lastAddr = null;
	}

	private DecompInterface setUpDecompiler(Program program) {
		DecompInterface decomplib = new DecompInterface();
		DecompileOptions options;
		options = new DecompileOptions();
		OptionsService service = state.getTool().getService(OptionsService.class);
		if (service != null) {
			ToolOptions opt = service.getOptions("Decompiler");
			options.grabFromToolAndProgram(null,opt,program);
		}
		decomplib.setOptions(options);
		decomplib.toggleCCode(true);
		decomplib.toggleSyntaxTree(true);
		decomplib.setSimplificationStyle("decompile");
		return decomplib;
	}

	// analyze func ref
	public void analyzeFunction(DecompInterface decomplib, Program prog, Function f, Address refAddr) {
		if (f == null) {
			return;
		}
		// don't decompile the function again if it was the same as the last one
		if (!f.getEntryPoint().equals(lastAddr))
			decompileFunction(f, decomplib);
		lastAddr = f.getEntryPoint();
		Instruction instr = prog.getListing().getInstructionAt(refAddr);
		if (instr == null) {
			return;
		}
		println(printCall(prog, f, refAddr));
	}

	HighFunction hfunction = null;
	ClangTokenGroup docroot = null;
	public boolean decompileFunction(Function f, DecompInterface decomplib) {
		// decomplib.setSimplificationStyle("normalize", null);
		// HighFunction hfunction = decomplib.decompileFunction(f);
		DecompileResults decompRes = decomplib.decompileFunction(f, decomplib.getOptions().getDefaultTimeout(), monitor);
		// String statusMsg = decomplib.getDecompileMessage();
		hfunction = decompRes.getHighFunction();
		docroot = decompRes.getCCodeMarkup();
		return hfunction != null;
	}

	// get pcode ops that refer to an addr
	public Iterator<PcodeOpAST> getPcodeOps(Address refAddr) {
		if (hfunction == null) {
			return null;
		}
		Iterator<PcodeOpAST> piter = hfunction.getPcodeOps(refAddr.getPhysicalAddress());
		return piter;
	}

	public String printCall(Program prog, Function f, Address refAddr) {
		StringBuffer buff = new StringBuffer();
		printCall(prog, refAddr, docroot, buff, false, false);
		return buff.toString();
	}

	private boolean printCall(Program prog, Address refAddr, ClangNode node, StringBuffer buff, boolean didStart, boolean isCall) {
		if (node == null) {
			return false;
		}
		Address min = node.getMinAddress();
		Address max = node.getMaxAddress();
		if (min == null) {
			return false;
		}
		if (refAddr.getPhysicalAddress().equals(max) && node instanceof ClangStatement) {
			ClangStatement stmt = (ClangStatement) node;
			// Don't check for an actual call. The call could be buried more deeply.  As long as the original call reference site
			// is the max address, then display the results.
			// So this block assumes that the last address contained in the call will be the
			// address you are looking for.
			//    - This could lead to strange behavior if the call reference is placed on some address
			//    that is not the final call point used by the decompiler.
			//    - Also if there is a delay slot, then the last address for the call reference point
			//    might not be the last address for the block of PCode.
			// if (stmt.getPcodeOp().getOpcode() == PcodeOp.CALL) {
			if (!didStart) {
				Address nodeAddr = node.getMaxAddress();
				// Decompiler only knows base space.
				//   If reference came from an overlay space, convert address back
				if (refAddr.getAddressSpace().isOverlaySpace()) {
					nodeAddr = refAddr.getAddressSpace().getOverlayAddress(nodeAddr);
				}
				buff.append(" " + nodeAddr + "   : ");
			}
			buff.append("   [" + toString(stmt) + "]\n");
			String fmt = null;
			String name = null;
			int idx_fmt = 1;
			int idx_arg = 2;
			boolean want_fmt = true;
			// for TA
			// idx_arg = 3;
			// want_fmt = false;
			for (int i = 0; i < stmt.getPcodeOp().getNumInputs(); i++) {
				if (i == idx_fmt || i == idx_arg) {
					Object sa = null;
					Varnode vn = stmt.getPcodeOp().getInput(i);
					PcodeOp po = vn.getDef();
					if (po == null) {
						continue;
					}
					if (!vn.isUnique()) {
						continue;
					}
					if (po.getOpcode() == PcodeOp.COPY) {
						if (po.getNumInputs() < 1) {
							continue;
						}
						vn = po.getInput(0);
					}
					else if (po.getOpcode() == PcodeOp.PTRSUB) {
						if (po.getNumInputs() < 2) {
							continue;
						}
						vn = po.getInput(1);
					}
					else {
						buff.append(String.format("ZZZ: Unknown opcode [%d] -> %s\n", i, po));
						continue;
					}
					sa = vn.getAddress();
					Address ma = prog.getMinAddress().getNewAddress(vn.getAddress().getOffset());
					Data sdata = prog.getListing().getDefinedDataAt(ma);
					if (sdata != null && sdata.getDataType().getName() == "string") {
						sa = sdata.getValue();
					}
					if (i == idx_fmt) {
						fmt = sa.toString();
					}
					else if (i == idx_arg) {
						name = sa.toString();
					}
					Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
					sa = fu;
					buff.append(String.format("vn[%d] -> %s\n", i, sa));
				}
			}
			// TA
			if (!want_fmt) {
				if (name != null) {
					buff.append(String.format(">>>> printf with arg=[%s] <<<<\n", name));
					// rename caller
					Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
					try {
						fu.setName(name, SourceType.ANALYSIS);
						buff.append("Name set\n");
					} catch (Exception e) {
						buff.append(String.format("Failed to set function name: %s\n", e.toString()));
					}
				}
			}
			else {
				if (fmt != null && name != null) {
					fmt = fmt.trim();
					buff.append(String.format(">>>> printf with fmt=[%s] and arg=[%s] <<<<\n", fmt, name));
					if (fmt.startsWith("%s")) {
						// rename caller
						Function fu = prog.getFunctionManager().getFunctionContaining(refAddr);
						try {
							fu.setName(name, SourceType.ANALYSIS);
							buff.append("Name set\n");
						} catch (Exception e) {
							buff.append(String.format("Failed to set function name: %s\n", e.toString()));
						}
					}
				}
			}
			return true;
			// }
		}
		for (int j = 0; j < node.numChildren(); j++) {
			isCall = node instanceof ClangStatement;
			didStart |= printCall(prog, refAddr, node.Child(j), buff, didStart, isCall);
		}
		return didStart;
	}

	public String[] toStrings(ClangStatement node) {
		LinkedList<String> strings = new LinkedList<>();
		int open=-1;
		for (int j = node.numChildren() - 1; j >= 0; j--) {
			ClangNode subNode = node.Child(j);
			if (subNode instanceof ClangSyntaxToken) {
				ClangSyntaxToken syntaxNode = (ClangSyntaxToken) subNode;
				if (syntaxNode.getOpen() != -1) {
					if (node.Child(j+2) instanceof ClangTypeToken) {
						open = syntaxNode.getOpen();
						continue;
					}
				}
				if (syntaxNode.getClose() == open && open != -1) {
					open = -1;
					continue;
				}
			}
			if (open != -1) {
				continue;
			}
			strings.push(subNode.toString());
		}
		return strings.toArray(new String[]{});
	}

	public String toString(ClangStatement node) {
		StringBuffer buffer = new StringBuffer();
		int open=-1;
		for (int j = 0; j < node.numChildren(); j++) {
			ClangNode subNode = node.Child(j);
			if (subNode instanceof ClangSyntaxToken) {
				ClangSyntaxToken syntaxNode = (ClangSyntaxToken) subNode;
				if (syntaxNode.getOpen() != -1) {
					if (node.Child(j+2) instanceof ClangTypeToken) {
						open = syntaxNode.getOpen();
						continue;
					}
				}
				if (syntaxNode.getClose() == open && open != -1) {
					open = -1;
					continue;
				}
			}
			if (open != -1) {
				continue;
			}
			buffer.append(subNode.toString());
		}
		return buffer.toString();
	}
}

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment