Overview

Repository is a suite of tools for manipulating debian packages. At a high level, dep-find generates a dependency list for use with dep-symbol and dep-src. I have also created a script, dep-all.sh, that chains the use of all three scripts together.

dep-find

This tool builds a dependency graph of the debian packages cached by apt. I have incluced the files direct.txt and transitive.txt which show the direct and transitive dependencies for debian packages respectively.

You can grab a dependency list for a package with:

./dep-find.py -p PACKAGE

which will create a file PACKAGE.dep in the current working directory. This can then be feed into dep-symbols. For example, ./dep-find.py -p wget will get the dependencies for wget and create wget.dep.

You might also find it useful to search for dependecies and packages with apt: apt-cache depends PACKAGE and apt-cache search PACKAGE.

dep-symbol

Tool uses a dependency list for a package (built from dep-find.py) to download all dependencies and build a small repository of those dependency that contain symbol information.

Install

All that is required for dep-symbol itself is a working python installation. Once you've pulled the repository, you can kickoff the test.sh script to make sure dep-symbol works. I've done my work on fir02, and have hardcoded the test script to use a copy of jq in my local installation directory (/home/acanino/local). If you do not run on fir02, you'll have to setup jq yourself and modify the test script.

Usage

1. Generate symbol repository for dependency list

mkdir symbol-out
./dep-symbol.py -d symbol-out wget.dep

lzload

lzload is a C library that does the actual shim / dummy library loading at runtime. Build and install with cmake:

cd lzload
mkdir build && cd build
cmake .. -DCMAKE_C_COMPILER=/path/to/clang 
make
sudo make install

dep-src

Install

Run setup.sh to install dependencies and place the necessary make/dpkg-buildflags files on the system (this will require root). This will also setup a local symbol repository for lzload to use at runtime at $HOME/var/symbol-out.

Usage

1. Building a dependency list

dep-src downloads and builds debian source packages from a dependency list.

./dep-find.py -p wget
mkdir src-out
./dep-src.py -d src-out wget.dep

2. Generating symbol database

Generate a symbol repository for lzload to use to help find the correct symbol / library mapping at runtime.

./dep-symbol.py -d $HOME/var/symbol-out wget.dep

3. Build dummy libraries

Generate dummy libraries for use with lzload. The following will attempt to build the dummy libraries and then store them in src-out/lib

mkdir src-out
./dep-src.py -d src-out wget.dep

4. Running with the dummy libraries.

There is a script at the top level, wget.sh, that demonstrates what environmnet variables need to be set to hook into the dummy libs. We need to set three environment variables: LZLOAD_LIB, LZ_LIBRARY_PATH, and LD_LIBRARY_PATH.

LZLOAD_LIB contains a colon seperate list of libraries that lzload should intercept. LZ_LIBRARY_PATH points to the actual path of the real libraries that lzload should load on a fault. LD_LIBRARY_PATH must point to the dummy libraries and liblzload.so. ~