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.
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