chore(ghidra): modularize ghidra functions into utils and commands

Splitting the logic into ghidra related functionality, context
processing and plain command invocation makes the code better structured
and the individual files smaller.

pwndbg/__init__.py

@@ -23,6 +23,7 @@ import pwndbg.commands.dt
 import pwndbg.commands.dumpargs
 import pwndbg.commands.elf
 import pwndbg.commands.gdbinit
+import pwndbg.commands.ghidra
 import pwndbg.commands.got
 import pwndbg.commands.heap
 import pwndbg.commands.hexdump

pwndbg/commands/context.py

@@ -26,6 +26,7 @@ import pwndbg.commands.telescope
 import pwndbg.config
 import pwndbg.disasm
 import pwndbg.events
+import pwndbg.ghidra
 import pwndbg.ida
 import pwndbg.regs
 import pwndbg.symbol
@@ -206,96 +207,31 @@ def context_expressions(target=sys.stdout, with_banner=True, width=None):
         output.extend(lines)
     return banner + output if with_banner else output
 
-# Ghidra integration through radare2
-# This is not (sorry couldn't help it) "the yellow of the egg"
-# Using radare2 is suboptimal and will only be an intermediate step to have
-# ghidra decompiler within pwndbg.
-# But having ghidra in pwndgb is a lot more work as it requires quite some code and c/c++
-radare2 = {}
 
 config_context_ghidra = pwndbg.config.Parameter('context-ghidra',
-                                                  'never',
-                                                  'if or/when to try to decompile with '
-                                                  'ghidra (slow and requires radare2/r2pipe) '
-                                                  '(valid values: always, never, if-no-source)')
-def init_radare2(filename):
-    r2 = radare2.get(filename)
-    if r2:
-        return r2
-    import r2pipe
-    r2 = r2pipe.open(filename)
-    radare2[filename] = r2
-    r2.cmd("aaaa")
-    return r2
+                                                'never',
+                                                'when to try to decompile the current function with ghidra (slow and requires radare2/r2pipe) (valid values: always, never, if-no-source)')
 
-parser = argparse.ArgumentParser()
-parser.description = """Show current function decompiled by ghidra"""
-parser.add_argument("func", type=str, default=None, nargs="?",
-                    help="Function to be shown. Defaults to current")
-@pwndbg.commands.ArgparsedCommand(parser, aliases=['ctx-ghidra'])
-def contextghidra(func):
-    print("\n".join(context_ghidra(func, with_banner=False, force_show=True)))
 
-def context_ghidra(func=None, target=sys.stdout, with_banner=True, width=None, force_show=False):
-    banner = [pwndbg.ui.banner("ghidra decompile", target=target, width=width)]
+def context_ghidra(target=sys.stdout, with_banner=True, width=None):
+    """
+    Print out the source of the current function decompiled by ghidra.
+
+    The context-ghidra config parameter is used to configure whether to always,
+    never or only show the context if no source is available.
+    """
+    banner = [pwndbg.ui.banner("ghidra decompile", target=target, width=width)] if with_banner else []
 
-    if config_context_ghidra == "never" and not force_show:
+    if config_context_ghidra == "never":
         return []
-    elif config_context_ghidra == "if-no-source" and not force_show:
+    elif config_context_ghidra == "if-no-source":
         try:
             with open(gdb.selected_frame().find_sal().symtab.fullname()) as _:
                 pass
         except:         # a lot can go wrong in search of source code.
             return []   # we don't care what, just that it did not work out well...
 
-    filename = gdb.current_progspace().filename
-    try:
-        r2 = init_radare2(filename)
-        # LD         list supported decompilers (e cmd.pdc=?)
-        # Outputs for example:: pdc\npdg
-        if not "pdg" in r2.cmd("LD").split("\n"):
-            return banner + ["radare2 plugin r2ghidra-dec must be installed and available from r2"]
-    except ImportError: # no r2pipe present
-        return banner + ["r2pipe not available, but required for r2->ghidra-bridge"]
-    if func is None:
-        try:
-            func = hex(pwndbg.regs[pwndbg.regs.current.pc])
-        except:
-            func = "main"
-    src = r2.cmdj("pdgj @" + func)
-    source = src.get("code", "")
-    curline = None
-    try:
-        cur = pwndbg.regs[pwndbg.regs.current.pc]
-    except AttributeError:
-        cur = None # If not running there is no current.pc
-    if cur is not None:
-        closest = 0
-        for off in (a.get("offset", 0) for a in src.get("annotations", [])):
-            if abs(cur - closest) > abs(cur - off):
-                closest = off
-        pos_annotations = sorted([a for a in src.get("annotations", []) if a.get("offset") == closest],
-                         key=lambda a: a["start"])
-        if pos_annotations:
-            curline = source.count("\n", 0, pos_annotations[0]["start"])
-    source = source.split("\n")
-    # Append --> for the current line if possible
-    if curline is not None:
-        line = source[curline]
-        if line.startswith('    '):
-            line = line[4:]
-        source[curline] = '--> ' + line
-    # Join the source for highlighting
-    source = "\n".join(source)
-    if pwndbg.config.syntax_highlight:
-        # highlighting depends on the file extension to guess the language, so try to get one...
-        try: # try to read the source filename from debug information
-            src_filename = gdb.selected_frame().find_sal().symtab.fullname()
-        except: # if non, take the original filename and maybe append .c (just assuming is was c)
-            src_filename = filename+".c" if os.path.basename(filename).find(".") < 0 else filename
-        source = H.syntax_highlight(source, src_filename)
-    source = source.split("\n")
-    return banner + source if with_banner else source
+    return banner + pwndbg.ghidra.decompile()
 
 
 
@@ -303,14 +239,14 @@ def context_ghidra(func=None, target=sys.stdout, with_banner=True, width=None, f
 
 parser = argparse.ArgumentParser()
 parser.description = "Print out the current register, instruction, and stack context."
-parser.add_argument("subcontext", nargs="*", type=str, default=None, help="Submenu to display: 'reg', 'disasm', 'code', 'stack', 'backtrace', and/or 'args'")
+parser.add_argument("subcontext", nargs="*", type=str, default=None, help="Submenu to display: 'reg', 'disasm', 'code', 'stack', 'backtrace', 'ghidra', and/or 'args'")
 @pwndbg.commands.ArgparsedCommand(parser, aliases=['ctx'])
 @pwndbg.commands.OnlyWhenRunning
 def context(subcontext=None):
     """
     Print out the current register, instruction, and stack context.
 
-    Accepts subcommands 'reg', 'disasm', 'code', 'stack', 'backtrace', and 'args'.
+    Accepts subcommands 'reg', 'disasm', 'code', 'stack', 'backtrace', 'ghidra' and 'args'.
     """
     if subcontext is None:
         subcontext = []

pwndbg/commands/ghidra.py

@@ -0,0 +1,15 @@
+import argparse
+
+import pwndbg.color.message as message
+import pwndbg.commands
+import pwndbg.ghidra
+
+parser = argparse.ArgumentParser()
+parser.description = """Decompile a given function using ghidra"""
+parser.add_argument("func", type=str, default=None, nargs="?", help="Function to be decompiled. Defaults to the current function.")
+
+
+@pwndbg.commands.OnlyWithFile
+@pwndbg.commands.ArgparsedCommand(parser)
+def ghidra(func):
+    print("\n".join(pwndbg.ghidra.decompile(func)))

pwndbg/ghidra.py

@@ -0,0 +1,66 @@
+import os
+
+import gdb
+
+import pwndbg.color.syntax_highlight as H
+import pwndbg.radare2
+import pwndbg.regs
+
+
+def decompile(func=None):
+    """
+    Return the source of the given function decompiled by ghidra.
+
+    If no function is given, decompile the function within the current pc.
+    This function requires radare2, r2pipe and r2ghidra.
+
+    Raises Exception if any fatal error occures.
+    """
+    filename = gdb.current_progspace().filename
+    try:
+        r2 = pwndbg.radare2.r2pipe(filename)
+        # LD         list supported decompilers (e cmd.pdc=?)
+        # Outputs for example:: pdc\npdg
+        if not "pdg" in r2.cmd("LD").split("\n"):
+            return ["radare2 plugin r2ghidra-dec must be installed and available from r2"]
+    except ImportError: # no r2pipe present
+        return ["r2pipe not available, but required for r2->ghidra-bridge"]
+    if func is None:
+        try:
+            func = hex(pwndbg.regs[pwndbg.regs.current.pc])
+        except:
+            func = "main"
+    src = r2.cmdj("pdgj @" + func)
+    source = src.get("code", "")
+    curline = None
+    try:
+        cur = pwndbg.regs[pwndbg.regs.current.pc]
+    except AttributeError:
+        cur = None # If not running there is no current.pc
+    if cur is not None:
+        closest = 0
+        for off in (a.get("offset", 0) for a in src.get("annotations", [])):
+            if abs(cur - closest) > abs(cur - off):
+                closest = off
+        pos_annotations = sorted([a for a in src.get("annotations", []) if a.get("offset") == closest],
+                         key=lambda a: a["start"])
+        if pos_annotations:
+            curline = source.count("\n", 0, pos_annotations[0]["start"])
+    source = source.split("\n")
+    # Append --> for the current line if possible
+    if curline is not None:
+        line = source[curline]
+        if line.startswith('    '):
+            line = line[4:]
+        source[curline] = '--> ' + line
+    # Join the source for highlighting
+    source = "\n".join(source)
+    if pwndbg.config.syntax_highlight:
+        # highlighting depends on the file extension to guess the language, so try to get one...
+        try: # try to read the source filename from debug information
+            src_filename = gdb.selected_frame().find_sal().symtab.fullname()
+        except: # if non, take the original filename and maybe append .c (just assuming is was c)
+            src_filename = filename+".c" if os.path.basename(filename).find(".") < 0 else filename
+        source = H.syntax_highlight(source, src_filename)
+    source = source.split("\n")
+    return source

pwndbg/radare2.py

@@ -0,0 +1,12 @@
+radare2 = {}
+
+
+def r2pipe(filename):
+    r2 = radare2.get(filename)
+    if r2:
+        return r2
+    import r2pipe
+    r2 = r2pipe.open(filename)
+    radare2[filename] = r2
+    r2.cmd("aaaa")
+    return r2