diff --git a/volatility3/framework/plugins/mac/dmesg.py b/volatility3/framework/plugins/mac/dmesg.py new file mode 100644 index 0000000000..f9f06a6662 --- /dev/null +++ b/volatility3/framework/plugins/mac/dmesg.py @@ -0,0 +1,79 @@ +# This file is Copyright 2024 Volatility Foundation and licensed under the Volatility Software License 1.0 +# which is available at https://www.volatilityfoundation.org/license/vsl-v1.0 +# + +import logging +from volatility3.framework import interfaces, renderers, exceptions +from volatility3.framework.configuration import requirements +from volatility3.framework.objects import utility + +vollog = logging.getLogger(__name__) + + +class Dmesg(interfaces.plugins.PluginInterface): + """Prints the kernel log buffer.""" + + _required_framework_version = (2, 0, 0) + _version = (1, 0, 0) + + @classmethod + def get_requirements(cls): + return [ + requirements.ModuleRequirement( + name="kernel", + description="Kernel module for the OS", + architectures=["Intel32", "Intel64"], + ), + ] + + @classmethod + def get_kernel_log_buffer( + cls, context: interfaces.context.ContextInterface, kernel_module_name: str + ): + """ + Online documentation : + - https://github.com/apple-open-source/macos/blob/master/xnu/bsd/sys/msgbuf.h + - https://github.com/apple-open-source/macos/blob/ea4cd5a06831aca49e33df829d2976d6de5316ec/xnu/bsd/kern/subr_log.c#L751 + Volatility 2 plugin : + - https://github.com/volatilityfoundation/volatility/blob/master/volatility/plugins/mac/dmesg.py + """ + + kernel = context.modules[kernel_module_name] + if not kernel.has_symbol("msgbufp"): + raise exceptions.SymbolError( + "msgbufp", + kernel.symbol_table_name, + 'The provided symbol table does not include the "msgbufp" symbol. This means you are either analyzing an unsupported kernel version or that your symbol table is corrupt.', + ) + + msgbufp = kernel.object_from_symbol(symbol_name="msgbufp") + msg_size = msgbufp.msg_size # max buffer size + msg_bufx = msgbufp.msg_bufx # write index of the msg_bufc circular buffer + msg_bufc = msgbufp.msg_bufc + # msg_bufc is circular, meaning that if its size exceeds msg_size, + # msg_bufx will point to the beginning of the buffer and start overwriting. + msg_bufc_data: str = utility.pointer_to_string(msg_bufc, msg_size) + # Avoid OOB reads + msg_bufx = msg_bufx if msg_bufx <= msg_size else 0 + # We directly take into account the case where the write buffer did a loop, + # as older messages will start at msg_bufx offset (not overwritten yet). + dmesg = msg_bufc_data[msg_bufx:] + dmesg += msg_bufc_data[:msg_bufx] + + # Yield each line + for dmesg_line in dmesg.splitlines(): + yield (dmesg_line,) + + def _generator(self): + for value in self.get_kernel_log_buffer( + context=self.context, kernel_module_name=self.config["kernel"] + ): + yield (0, value) + + def run(self): + return renderers.TreeGrid( + [ + ("line", str), + ], + self._generator(), + )