# This file is Copyright 2019 Volatility Foundation and licensed under the Volatility Software License 1.0
# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0
#

from typing import List

from volatility3.framework import constants, interfaces
from volatility3.framework import renderers
from volatility3.framework.configuration import requirements
from volatility3.framework.objects import utility
from volatility3.framework.renderers import format_hints
from volatility3.plugins.linux import pslist


class Malfind(interfaces.plugins.PluginInterface):
    """Lists process memory ranges that potentially contain injected code."""

    _required_framework_version = (2, 0, 0)

    @classmethod
    def get_requirements(cls) -> List[interfaces.configuration.RequirementInterface]:
        return [
            requirements.ModuleRequirement(name = 'kernel', description = 'Linux kernel',
                                           architectures = ["Intel32", "Intel64"]),
            requirements.PluginRequirement(name = 'pslist', plugin = pslist.PsList, version = (2, 0, 0)),
            requirements.ListRequirement(name = 'pid',
                                         description = 'Filter on specific process IDs',
                                         element_type = int,
                                         optional = True)
        ]

    def _list_injections(self, task):
        """Generate memory regions for a process that may contain injected
        code."""

        proc_layer_name = task.add_process_layer()
        if not proc_layer_name:
            return

        proc_layer = self.context.layers[proc_layer_name]

        for vma in task.mm.get_mmap_iter():
            if vma.is_suspicious() and vma.get_name(self.context, task) != "[vdso]":
                data = proc_layer.read(vma.vm_start, 64, pad = True)
                yield vma, data

    def _generator(self, tasks):
        # determine if we're on a 32 or 64 bit kernel
        vmlinux = self.context.modules[self.config['kernel']]
        if self.context.symbol_space.get_type(vmlinux.symbol_table_name + constants.BANG + "pointer").size == 4:
            is_32bit_arch = True
        else:
            is_32bit_arch = False

        for task in tasks:
            process_name = utility.array_to_string(task.comm)

            for vma, data in self._list_injections(task):
                if is_32bit_arch:
                    architecture = "intel"
                else:
                    architecture = "intel64"

                disasm = interfaces.renderers.Disassembly(data, vma.vm_start, architecture)

                yield (0, (task.pid, process_name, format_hints.Hex(vma.vm_start), format_hints.Hex(vma.vm_end),
                           vma.get_protection(), format_hints.HexBytes(data), disasm))

    def run(self):
        filter_func = pslist.PsList.create_pid_filter(self.config.get('pid', None))

        return renderers.TreeGrid([("PID", int), ("Process", str), ("Start", format_hints.Hex),
                                   ("End", format_hints.Hex), ("Protection", str), ("Hexdump", format_hints.HexBytes),
                                   ("Disasm", interfaces.renderers.Disassembly)],
                                  self._generator(
                                      pslist.PsList.list_tasks(self.context,
                                                               self.config['kernel'],
                                                               filter_func = filter_func)))
