Implemented parsing for procfs maps

6 files changed, 202 insertions, 15 deletions

diff --git a/.gitignore b/.gitignore
index e7ffb10..e2fad71 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,4 +10,4 @@ dist/
 *.egg-info
 *.pyc
 *.egg
-libptracew.so
+libhypodermicw.so
diff --git a/hypodermic/main.py b/hypodermic/main.py
index 05d467a..b0d709b 100644
--- a/hypodermic/main.py
+++ b/hypodermic/main.py
@@ -15,6 +15,79 @@
 # You should have received a copy of the GNU General Public License along
 # with Hypodermic. If not, see <http://www.gnu.org/licenses/>.
 
+"""Command-line interface to Hypodermic."""
+
+import argparse
+import sys
+import textwrap
+import pprint #
+
+from hypodermic.memory import maps
+from hypodermic.ptrace import Process
+
+
+class CustomHelp(argparse.HelpFormatter):
+    """Modifications to argparse's default HelpFormatter."""
+    def _fill_text(self, text, width, indent):
+        filled = []
+        for line in text.splitlines(keepends=True):
+            filled.append(indent + line)
+        return "".join(filled)
+
+    def _split_lines(self, text, width):
+        return text.splitlines()
+
+    def add_usage(self, usage, actions, groups, prefix=None):
+        prefix = prefix or "Usage: "
+        both = super(CustomHelp, self)
+        return both.add_usage(usage, actions, groups, prefix)
+
 
 def main():
-    print("Don't share needles, brah!")
+    parser = argparse.ArgumentParser(
+        add_help=False,
+        formatter_class=CustomHelp,
+        usage="%(prog)s [-a pid] [-c path] [options]",
+        description="Don't share needles, brah!"
+    )
+
+    doc = parser.add_argument_group("Documentation")
+    doc.add_argument(
+        "-h",
+        "--help",
+        action="help",
+        help="Display this help page and exit."
+    )
+    doc.add_argument(
+        "-V",
+        "--version",
+        action="version",
+        version="What version?",
+        help="Display the currently installed version and exit."
+    )
+
+    proc = parser.add_argument_group("Process Manipulation")
+    meth = proc.add_mutually_exclusive_group()
+    proc.add_argument(
+        "-a",
+        "--attach",
+        metavar="PID",
+        help="The pid of a process to attach to."
+    )
+    proc.add_argument(
+        "-c",
+        "--create",
+        metavar="BIN",
+        help="The path of a binary to execute and attach to."
+    )
+
+    args = parser.parse_args()
+
+    if args.attach is None and args.create is None:
+        print("No action specified. Quitting!")
+        sys.exit(1)
+
+    if args.create:
+        p = Process(path=args.create)
+    else:
+        p = Process(pid=args.attach)
diff --git a/hypodermic/memory.py b/hypodermic/memory.py
new file mode 100644
index 0000000..6ffa5d1
--- /dev/null
+++ b/hypodermic/memory.py
@@ -0,0 +1,111 @@
+# 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/>.
+
+"""Parsing of a program's memory mapping info from procfs."""
+
+import collections
+import re
+
+
+Device = collections.namedtuple(
+    "Device",
+    ["major", "minor"]
+)
+
+Perms = collections.namedtuple(
+    "Perms",
+    ["r", "w", "x", "s"]
+)
+
+Region = collections.namedtuple(
+    "Region",
+    ["start", "end", "perms", "off", "dev", "inode", "path"]
+)
+
+
+def parse_device(line: str) -> Device:
+    """Converts a device line of the form "maj:min" into a Device
+       object.
+
+    Args:
+        line(str): The line to parse.
+
+    Returns:
+        The parsed Device object.
+    """
+    major, minor = line.split(':')
+    return Device(major, minor)
+
+
+def parse_perms(line: str) -> Perms:
+    """Converts a permissions line of the form "rwxp" into a Perms
+       object.
+
+    Args:
+        line(str): The line to parse.
+
+    Returns:
+        The parsed Perms object.
+    """
+    return Perms(line[0] == 'r', line[1] == 'w', line[2] == 'x', line[3] == 's')
+
+
+def parse_region(line: str) -> Region:
+    """Converts a line of text from the "maps" file into a Region
+       object.
+
+    Args:
+        line(str): The line to parse.
+
+    Returns:
+        The parsed Region object.
+    """
+    ret = re.split(r"\s+", line.strip())
+    if len(ret) == 6:
+        address, perms, off, dev, inode, path = ret
+    else:
+        address, perms, off, dev, inode = ret
+        path = ""
+    start, end = address.split('-')
+    return Region(int(start, 16), int(end, 16), parse_perms(perms),
+                  int(off, 16), parse_device(dev), int(inode), path)
+
+
+def maps(pid: int) -> list:
+    """Gets memory mapping information for a given pid.
+
+    Args:
+        pid (int): The pid of the process to get memory mapping
+        information for.
+
+    Raises:
+        TypeError: If the pid argument is not an int.
+        PermissionError: If the mapping information cannot be read.
+
+    Returns:
+        A list of Region objects.
+    """
+    if not isinstance(pid, int):
+        raise TypeError("pid argument must be an int")
+
+    regions = []
+
+    with open("/proc/{}/maps".format(pid)) as maps:
+        for line in maps:
+            regions.append(parse_region(line))
+
+    return regions
diff --git a/hypodermic/ptrace.py b/hypodermic/ptrace.py
index d073930..7a14dea 100644
--- a/hypodermic/ptrace.py
+++ b/hypodermic/ptrace.py
@@ -15,28 +15,31 @@
 # 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."""
+"""ctypes wrapper for ptrace."""
 
 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.
+        object, if appropriate.
 
     Args:
         pid (:obj:`int`, optional): The pid of the process to attach to.
-            Defaults to 0, which means that it will not be used.
+            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 be used if no pid is specified.
+            Defaults to "", which will as the target if a pid is not
+            specified, either.
 
     Raises:
-        TypeError: If the pid argument is not an int.
-        OSError: If the pid cannot be attached to.
+        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, or if the process
+            could not be created for the given binary.
     """
 
     def __init__(self, pid=0, path=""):
@@ -56,14 +59,12 @@ class Process(object):
             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):
-        # FIXME: How are we going to deal with the path?
-        self._so = ctypes.cdll.LoadLibrary("/tmp/libptracew.so")
+        self._so = ctypes.cdll.LoadLibrary("/tmp/libhypodermicw.so")
         self._new_proc = self._so.new_proc
         self._attach = self._so.attach
         self._detach = self._so.detach
diff --git a/wrapper/Makefile b/wrapper/Makefile
index 026f4ba..19fa189 100644
--- a/wrapper/Makefile
+++ b/wrapper/Makefile
@@ -6,7 +6,7 @@ CFLAGS += $(USER_CFLAGS)
 LDFLAGS = -shared
 LDFLAGS += $(USER_LDFLAGS)
 
-all: libptracew.so
+all: libhypodermicw.so
 
-libptracew.so: ptrace.c
+libhypodermicw.so: ptrace.c
 	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
diff --git a/wrapper/ptrace.c b/wrapper/ptrace.c
index caf510f..706b13e 100644
--- a/wrapper/ptrace.c
+++ b/wrapper/ptrace.c
@@ -1,4 +1,6 @@
-/* Copyright (C) 2017 Jakob Kreuze, All Rights Reserved.
+/* ptrace.c - Wrappers for the ptrace system call.
+
+   Copyright (C) 2017 Jakob Kreuze, All Rights Reserved.
 
    This file is part of Hypodermic.