Some notes on how to build DMS Core in Unix.
(for OpenBSD specific instructions, see build-openbsd.md)
Building the dependencies and DMS Core requires some essential build tools and libraries to be installed before.
Run the following commands to install required packages:
$ sudo apt-get install curl build-essential libtool autotools-dev automake pkg-config python3 bsdmainutils
$ sudo dnf install gcc-c++ libtool make autoconf automake python3 libstdc++-static patch
$ pacman -S base-devel python3
$ sudo apk --update --no-cache add autoconf automake curl g++ gcc libexecinfo-dev libexecinfo-static libtool make perl pkgconfig python3 patch linux-headers
pkg_add gmake libtool
pkg_add autoconf # (select highest version, e.g. 2.69)
pkg_add automake # (select highest version, e.g. 1.15)
pkg_add python # (select highest version, e.g. 3.5)
Follow the instructions in build-generic
To help make your DMS Core installation more secure by making certain attacks impossible to exploit even if a vulnerability is found, binaries are hardened by default. This can be disabled with:
Hardening Flags:
./configure --prefix=<prefix> --enable-hardening
./configure --prefix=<prefix> --disable-hardening
Hardening enables the following features:
-
Position Independent Executable Build position independent code to take advantage of Address Space Layout Randomization offered by some kernels. Attackers who can cause execution of code at an arbitrary memory location are thwarted if they don't know where anything useful is located. The stack and heap are randomly located by default but this allows the code section to be randomly located as well.
On an AMD64 processor where a library was not compiled with -fPIC, this will cause an error such as: "relocation R_X86_64_32 against `......' can not be used when making a shared object;"
To test that you have built PIE executable, install scanelf, part of paxutils, and use:
scanelf -e ./dmsd
The output should contain:
TYPE ET_DYN
-
Non-executable Stack If the stack is executable then trivial stack based buffer overflow exploits are possible if vulnerable buffers are found. By default, DMS Core should be built with a non-executable stack but if one of the libraries it uses asks for an executable stack or someone makes a mistake and uses a compiler extension which requires an executable stack, it will silently build an executable without the non-executable stack protection.
To verify that the stack is non-executable after compiling use:
scanelf -e ./dmsd
the output should contain: STK/REL/PTL RW- R-- RW-
The STK RW- means that the stack is readable and writeable but not executable.
When the intention is to run only a P2P node without a wallet, DMS Core may be compiled in disable-wallet mode with:
./configure --prefix=<prefix> --disable-wallet
In this case there is no dependency on Berkeley DB 4.8.
Mining is also possible in disable-wallet mode, but only using the getblocktemplate
RPC
call not getwork
.
A list of additional configure flags can be displayed with:
./configure --help
(TODO, this is untested, please report if it works and if changes to this documentation are needed)
Building on FreeBSD is basically the same as on Linux based systems, with the difference that you have to use gmake
instead of make
.
Note on debugging: The version of gdb
installed by default is ancient and considered harmful.
It is not suitable for debugging a multi-threaded C++ program, not even for getting backtraces. Please install the package gdb
and
use the versioned gdb command e.g. gdb7111
.
(TODO, this is untested, please report if it works and if changes to this documentation are needed)
Important: From OpenBSD 6.2 onwards a C++11-supporting clang compiler is
part of the base image, and while building it is necessary to make sure that this
compiler is used and not ancient g++ 4.2.1. This is done by appending
CC=cc CXX=c++
to configuration commands. Mixing different compilers
within the same executable will result in linker errors.
$ cd depends
$ make CC=cc CXX=c++
$ cd ..
$ export AUTOCONF_VERSION=2.69 # replace this with the autoconf version that you installed
$ export AUTOMAKE_VERSION=1.15 # replace this with the automake version that you installed
$ ./autogen.sh
$ ./configure --prefix=<prefix> CC=cc CXX=c++
$ gmake # use -jX here for parallelism
If the build runs into out-of-memory errors, the instructions in this section might help.
The standard ulimit restrictions in OpenBSD are very strict:
data(kbytes) 1572864
This, unfortunately, in some cases not enough to compile some .cpp
files in the project,
(see issue #6658).
If your user is in the staff
group the limit can be raised with:
ulimit -d 3000000
The change will only affect the current shell and processes spawned by it. To
make the change system-wide, change datasize-cur
and datasize-max
in
/etc/login.conf
, and reboot.