shadow-plugin-bitcoin

Shadow plugin for bitcoind (the Satoshi reference client)

This repository holds a Shadow plug-in that runs bitcoind. It can be used to run a private bitcoin network on a single machine using the Shadow discrete-event network simulator. For more information about Shadow, see https://shadow.github.io and https://github.com/shadow.

dependencies

Fedora:

sudo yum install libstdc++ libstdc++-devel clang clang-devel llvm llvm-devel glib2 glib2-devel

Ubuntu:

sudo apt-get install libstdc++ libstdc++-dev clang llvm llvm-dev

setup plug-in and custom build requirements

There are several custom build requirements which we will build from the build directory:

git clone git@github.com:amiller/shadow-plugin-bitcoin.git
cd shadow-plugin-bitcoin
mkdir build; cd build

openssl

wget https://www.openssl.org/source/openssl-1.0.1h.tar.gz
tar xaf openssl-1.0.1h.tar.gz
cd openssl-1.0.1h
./config --prefix=/home/${USER}/.shadow shared threads enable-ec_nistp_64_gcc_128 -fPIC
make depend
make
make install_sw
cd ..

boost

Note - if using boost 1_50_0, you need to manually patch boost as shown in this issue before building

wget http://downloads.sourceforge.net/project/boost/boost/1.50.0/boost_1_50_0.tar.gz
tar xaf boost_1_50_0.tar.gz
cd boost_1_50_0
./bootstrap.sh --with-libraries=filesystem,system,thread,program_options
./b2
cd ..

bitcoin

We need to get the bitcoin source so we can compile it into our Shadow plug-in, and then configure it to obtain a proper bitcoin-config.h file.

git clone https://github.com/amiller/bitcoin.git -b 0.9.2-netmine
cd bitcoin
./autogen.sh
LD_LIBRARY_PATH=`pwd`/../boost_1_50_0/stage/lib PKG_CONFIG_PATH=/home/${USER}/.shadow/lib/pkgconfig LDFLAGS=-L/home/${USER}/.shadow/lib CFLAGS=-I/home/${USER}/.shadow/include CXXFLAGS=-I`pwd`/../boost_1_50_0 ./configure --prefix=/home/${USER}/.shadow --without-miniupnpc --without-gui --disable-wallet --disable-tests --with-boost-libdir=`pwd`/../boost_1_50_0/stage/lib
cd ..

Note that PKG_CONFIG_PATH, LDFLAGS, and CFLAGS need to be set to specify the install path of our custom-built OpenSSL.

The 0.9.2-netmine branch contains a small number of changes to the Bitcoin 0.9.2 release that facilitate experiments.

• The leveldb is modified not to use mmap, which reduces memory consumption
• Command line parameters -umd_createindexsnapshot and -umd_loadindexsnapshot can be used to skip some expensive startup processing
• Proof-of-work checking is disabled, to facilitate creating fake blocks
• The ECDSA signature check routine is to hacked to accept fake signatures from a particular pubkey (the pubkey that received the second ever block reward).

gnu pth

git clone git@github.com:amiller/gnu-pth.git -b shadow
cd gnu-pth
./configure --enable-epoll
cd ..

shadow-plugin-bitcoin

Now we are ready to build the actual Shadow plug-in using cmake.

mkdir shadow-plugin-bitcoin; cd shadow-plugin-bitcoin
CC=`which clang` CXX=`which clang++` cmake ../..
make -jN
make install
cd ..

Replace N with the number of cores you want to use for a parallel build.

Running an experiment

The script that drives the experiment is at src/bitcoind/shadow-bitcoind.

Command line options:

• -t prints the output to stdout as well as to data/shadow.log
• -r $N initializes $N data directories, named .bitcoin1, .bitcoin2, ..., .bitcoin$N
• -T $template if option -r $N is provided, this specifies the template directory that is copied over. If -T is not provided, then the initialized directories will be empty

basic example

To run the most basic experiment, first generate the bitcoind data directories, then run the example:

mkdir run
cd run
../src/bitcoind/shadow-bitcoind -y -i ../resource/shadow.config.xml -r 2 -t | grep -e "received: getaddr" -e "received: verack"

more realistic examples

In order to run a more realistic large scale example, we need to prepare some initialization blockchain datasets. It's useful to launch these experiments with Bitcoin nodes that have already processed the blockchain up to some point in history. To conserve memory, we can have multiple nodes share a single copy of most of the blockchain database files.

First create the dir structure:

mkdir initdata
cd initdata
mkdir pristine # will hold the single copy of the blockchain datasets
cp -R /storage/dotbitcoin_backing_120k pristine/.
mkdir dotbitcoin_template_120k
cd dotbitcoin_template_120k

The script tools/make_symlinks.sh is provided to build a dotbitcoin_template directory that contains symlinks to an underlying dotbitcoin_backing directory.

../../../tools/make_symlinks.sh ../pristine/dotbitcoin_backing_120k
cd ../..

Now we can run an experiment using the template we just created, where all nodes will share the backing datasets.

../src/bitcoind/shadow-bitcoind -y -i ../resource/shadow.config.xml -r 2 -t -T initdata/dotbitcoin_template_120k

other potentially useful information

cmake options

The cmake command above takes multiple options, specified as

cmake .. -DOPT=VAL

• SHADOW_ROOT = "path/to/shadow/install/root" (default is "~/.shadow")
  Specifies a custom path to the shadow installation root
• CMAKE_BUILD_TYPE = "Debug" or "Release" (default is "Debug")
• CMAKE_INSTALL_PREFIX = "path/to/install/root" (default is ${SHADOW_ROOT})
  Specifies a custom path to install this package
• CMAKE_PREFIX_PATH = "custom/search/path" (default is ${SHADOW_ROOT})
  Specifies a custom path to search for library dependencies

For example, the following will fully specify the default options:

CC=`which clang` CXX=`which clang++` cmake .. -DSHADOW_ROOT=/home/rob/.shadow -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=/home/rob/.shadow -DCMAKE_PREFIX_PATH=/home/rob/.shadow

troubleshooting

First try rebuilding to ensure that the cmake cache is up to date

rm -rf build
mkdir build
cd build

using VERBOSE=1 for more verbose output

CC=`which clang` CXX=`which clang++` cmake ..
VERBOSE=1 make

contributing

Please contribute by submitting pull requests via GitHub.