Process.rtld now returns the base region of the RTLD.

1 files changed, 126 insertions, 0 deletions

diff --git a/hypodermic/process.py b/hypodermic/process.py
new file mode 100644
index 0000000..6fc1519
--- /dev/null
+++ b/hypodermic/process.py
@@ -0,0 +1,126 @@
+# Copyright (C) 2017 Jakob Kreuze, All Rights Reserved.
+#
+# This file is part of Hypodermic.
+#
+# Hypodermic is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# Hypodermic is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+# Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with Hypodermic. If not, see <http://www.gnu.org/licenses/>.
+
+"""ctypes wrapper for ptrace."""
+
+import ctypes
+import os.path
+import re
+
+from hypodermic.memory import Region, maps
+
+
+class Process(object):
+    """Process attached via ptrace.
+
+    Note:
+        The process is implicitly detached from upon destruction of this
+        object, if appropriate.
+
+    Args:
+        pid (:obj:`int`, optional): The pid of the process to attach to.
+            Defaults to 0, which means that the argument will not be
+            used.
+        path (:obj:`str`, optional): The path of the binary to run.
+            Defaults to "", which will as the target if a pid is not
+            specified, either.
+
+    Raises:
+        TypeError: If the pid argument is not an int, or if the path
+            argument is not a string.
+        OSError: If the pid cannot be attached to, if the process could
+            not be created for the given binary, or if any wrapper
+            libraries could not be loaded.
+    """
+
+    def __init__(self, pid=0, path=""):
+        if not isinstance(pid, int):
+            raise TypeError("pid argument must be an int")
+        elif not isinstance(path, str):
+            raise TypeError("path argument must be a string")
+        self._load_ffi_methods()
+
+        if pid != 0:
+            self._is_parent = False
+            if self._attach(ctypes.c_int(pid)):
+                raise OSError("Could not attach to pid {}".format(pid))
+        else:
+            self._is_parent = True
+            self.pid = self._new_proc(ctypes.c_char_p(path.encode()))
+            if self.pid < 0:
+                raise OSError("Could not create process {}".format(path))
+
+    def __del__(self):
+        if hasattr(self, "_is_parent") and not self._is_parent:
+            self.detach()
+
+    def _load_ffi_methods(self):
+        # setuptools/cython hack.
+        script_path = os.path.abspath(os.path.dirname(__file__))
+
+        for filename in os.listdir(os.path.join(script_path, "..")):
+            if filename.startswith("libhypodermicw"):
+                lib_path = os.path.join(script_path, "..", filename)
+                break
+        else:
+            raise OSError("Could not find wrapper library.")
+
+        self._so = ctypes.cdll.LoadLibrary(lib_path)
+        self._new_proc = self._so.new_proc
+        self._attach = self._so.attach
+        self._detach = self._so.detach
+        self._cont = self._so.cont
+
+    def detach(self):
+        """Explicitly detaches from the process.
+
+        Raises:
+            OSError: If the process cannot be detached from.
+        """
+        if not self._is_parent and self._detach(ctypes.c_int(self.pid)):
+            raise OSError("Could not detach from pid {}".format(self.pid))
+
+    def cont(self):
+        """Continues until the program is haulted.
+
+        Raises:
+            OSError: If the process cannot be continued.
+        """
+        if self._cont(ctypes.c_int(self.pid)):
+            raise OSError("Could not continue")
+
+    @property
+    def maps(self) -> list:
+        """Obtain the process' memory map.
+
+        Returns:
+            A list of Region objects.
+        """
+        return maps(self.pid)
+
+    @property
+    def rtld(self) -> Region:
+        """Obtain the base region of memory for the process' RTLD, if it
+           exists.
+
+        Returns:
+            The Region object belonging to the RTLD, or None if no
+            RTLD was found.
+        """
+        for region in self.maps:
+            if re.search(r"ld.+\.so", region.path) and region.off == 0:
+                return region