1 files changed, 75 insertions, 0 deletions
diff --git a/hypodermic/ptrace.py b/hypodermic/ptrace.py
new file mode 100644
index 0000000..fdfe5b8
--- /dev/null
+++ b/hypodermic/ptrace.py
@@ -0,0 +1,75 @@
+# 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/>.
+
+"""Wrapper for the ptrace system call, since python-ptrace sucks."""
+
+import ctypes
+
+
+# TODO: Instantiate from binary path, as well.
+class Process(object):
+    """Process attached via ptrace.
+
+    Note:
+        The process is implicitly detached from upon destruction of this
+        object.
+
+    Args:
+        pid (int): The pid of the process to attach to.
+
+    Raises:
+        TypeError: If the pid argument is not an int.
+        OSError: If the pid cannot be attached to.
+    """
+
+    def __init__(self, pid: int):
+        if not isinstance(pid, int):
+            raise TypeError("pid argument must be an int")
+        self._load_ffi_methods()
+
+        if self._attach(ctypes.c_int(pid)):
+            raise OSError("Could not attach to pid {}".format(pid))
+        self.pid = pid
+
+    def __del__(self):
+        if hasattr(self, "pid"):
+            self.detach()
+
+    def _load_ffi_methods(self):
+        # FIXME: How are we going to deal with the path?
+        self._so = ctypes.cdll.LoadLibrary("/tmp/libptracew.so")
+        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 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")