gef/tests/api/gef_memory.py

"""
`gef.session` test module.
"""

import pathlib
import random
import pytest

from tests.base import RemoteGefUnitTestGeneric

from tests.utils import (
    ARCH,
    IN_GITHUB_ACTIONS,
    debug_target,
    gdbserver_session,
    qemuuser_session,
    GDBSERVER_DEFAULT_HOST,
)


class GefMemoryApi(RemoteGefUnitTestGeneric):
    """`gef.memory` test module."""

    def setUp(self) -> None:
        self._target = debug_target("default")
        return super().setUp()

    def test_api_gef_memory_only_running(self):
        gdb, gef = self._gdb, self._gef

        with pytest.raises(RuntimeError):
            assert gef.memory.maps is None

        gdb.execute("start")
        assert gef.memory.maps is not None

    def test_api_gef_memory_parse_info_proc_maps_expected_format(self):
        if self.gdb_version < (11, 0):
            pytest.skip(f"Skipping test for version {self.gdb_version} (min 10.0)")

        gdb, root = self._gdb, self._conn.root
        gdb.execute("start")

        # Check output format
        lines = (gdb.execute("info proc mappings", to_string=True) or "").splitlines()
        assert len(lines) >= 5
        assert all(map(lambda x: isinstance(x, str), lines))
        for line in lines[4:]:
            parts = [x.strip() for x in line.split()]
            start_addr = int(parts[0], 16)
            end_addr = int(parts[1], 16)
            size = int(parts[2], 16)
            int(parts[3], 16)
            assert end_addr == start_addr + size
            assert len(parts[4]) == 4, f"Expected permission string, got {parts[4]}"

            Permission = root.eval("Permission")
            Permission.from_process_maps(parts[4])

            # optional objfile
            if len(parts) == 5:
                continue

            objfile = " ".join(parts[5:]).strip()
            if objfile.startswith("/"):
                assert pathlib.Path(objfile).exists()

    def test_api_gef_memory_parse_info_proc_maps(self):
        gdb, gef, root = self._gdb, self._gef, self._conn.root
        gdb.execute("start")

        Section = root.eval("Section")

        if self.gdb_version < (11, 0):
            # expect an exception
            with pytest.raises(AttributeError):
                next(root.eval("gef.memory.parse_gdb_info_proc_maps()"))

        else:
            sections = list(root.eval("gef.memory.parse_gdb_info_proc_maps()"))
            with open(f"/proc/{gef.session.pid}/maps") as f:
                for section, line in zip(sections, f.read().splitlines()):
                    assert isinstance(section, Section)
                    assert section.offset == int(line.split()[2], 16)

    def test_func_parse_permissions(self):
        root = self._conn.root
        expected_values = [
            (
                "Permission.from_info_sections('ALLOC LOAD READONLY CODE HAS_CONTENTS')",
                "r-x",
            ),
            ("Permission.from_process_maps('r--')", "r--"),
            ("Permission.from_monitor_info_mem('-r-')", "r--"),
            ("Permission.from_info_mem('rw')", "rw-"),
        ]
        for cmd, expected in expected_values:
            assert str(root.eval(cmd)) == expected

    def test_func_parse_maps_local_procfs(self):
        root, gdb, gef = self._conn.root, self._gdb, self._gef

        with pytest.raises(FileNotFoundError):
            root.eval("list(gef.memory.parse_procfs_maps())")

        gdb.execute("start")

        sections = root.eval("list(gef.memory.parse_procfs_maps())")
        for section in sections:
            assert section.page_start & ~0xFFF
            assert section.page_end & ~0xFFF

            #
            # The parse maps function should automatically get called when we start
            # up, and we should be able to view the maps via the `gef.memory.maps`
            # property. So check the alias `gef.memory.maps`
            # However, since `gef.memory.maps` has more info, use it as source of
            # truth
            #
            assert section in gef.memory.maps

    @pytest.mark.slow
    def test_func_parse_maps_remote_gdbserver(self):
        gef, gdb = self._gef, self._gdb
        # When in a gef-remote session `parse_gdb_info_proc_maps` should work to
        # query the memory maps
        while True:
            port = random.randint(1025, 65535)
            if port != self._port:
                break

        with pytest.raises(Exception):
            gdb.execute(f"gef-remote {GDBSERVER_DEFAULT_HOST} {port}")

        with gdbserver_session(port=port) as _:
            gdb.execute(f"gef-remote {GDBSERVER_DEFAULT_HOST} {port}")
            sections = gef.memory.maps
            assert len(sections) > 0

    @pytest.mark.skipif(
        ARCH == "aarch64" and IN_GITHUB_ACTIONS, reason=f"Skipped for {ARCH} on CI"
    )
    def test_func_parse_maps_remote_qemu(self):
        gdb, gef = self._gdb, self._gef
        # When in a gef-remote qemu-user session `parse_gdb_info_proc_maps`
        # should work to query the memory maps
        while True:
            port = random.randint(1025, 65535)
            if port != self._port:
                break

        with qemuuser_session(port=port) as _:
            cmd = f"gef-remote --qemu-user --qemu-binary {self._target} {GDBSERVER_DEFAULT_HOST} {port}"
            gdb.execute(cmd)
            sections = gef.memory.maps
            assert len(sections) > 0

    @pytest.mark.skipif(
        ARCH == "aarch64" and IN_GITHUB_ACTIONS, reason=f"Skipped for {ARCH}"
    )
    def test_func_parse_maps_realpath(self):
        gef, gdb = self._gef, self._gdb
        # When in a gef-remote session `parse_gdb_info_proc_maps` should work to
        # query the memory maps
        while True:
            port = random.randint(1025, 65535)
            if port != self._port:
                break

        with gdbserver_session(port=port) as _:
            gdb.execute(f"gef-remote {GDBSERVER_DEFAULT_HOST} {port}")
            gdb.execute("b main")
            gdb.execute("continue")
            sections = gef.memory.maps
            assert len(sections) > 0
            #
            # Iterate over each of the maps, checking each path.  If the path from
            # the /proc/pid/maps file indicates a path that starts with /usr, but
            # realpath does not include "/usr", then _search_for_realpath has
            # probably corrected the path to account for gdb bug #23764
            #
            for section in sections:
                if (
                    section.is_executable()
                    and section.path.startswith("/usr")
                    and "/usr" not in section.realpath
                ):
                    assert pathlib.Path(section.realpath).is_file()
                    break

    def test_func_read_cstring_oob(self):
        gef, gdb = self._gef, self._gdb

        gdb.execute("b main")
        gdb.execute("start")

        section = gef.memory.maps[0]
        oob_val = gef.memory.read_cstring(
            section.page_start, section.page_end - section.page_start + 0x100
        )
        val = gef.memory.read_cstring(
            section.page_start, section.page_end - section.page_start
        )

        assert val == oob_val