libhostile

Release:1.0.0-161a575
Date:May 12, 2017

About libhostile

“What if I tossed small pox into a room filled with sprinters after filling their water cups with red bull.”

—Brian Aker

Libhostile is a lightweight library to be used with LD_PRELOAD which will intentially break certain libc calls at various intervals. Specifically designed to cause random failures in network functions and memory allocation.

The tool was originally designed by Data Differential as part of Gearman but is now being continued as an independent project maintained by Andrew Hutchings.

Contents

Compiling libhostile

Simply download the source and run:

$ autoreconf -fi
$ ./configure
$ make
$ sudo make install

Using libhostile

libhostile adds a very thin layer over every call that it breaks. By default it will not break any calls, it needs to be told what calls you wish to be hostile to. There are two ways of doing this:

  1. Using the hostile.sh tool
  2. Manually as below

Manual hostility

You can manually invoke libhostile using LD_PRELOAD as follows:

$ LD_PRELOAD=/usr/local/lib/libhostile.so application

Where application is the application/service you wish to be hostile to.

To become hostile to libc functions you will need to set environment variables. Multiple environment variables can be used in the same run.

Each environment variable should be set to an integer representation of the frequency of failures. For example:

$ export HOSTILE_MALLOC=500

The above will tell libhostile to return an error for roughly 1/500 malloc() calls (there is a random element and a small grace period).

HOSTILE_ACCEPT

Become hostile to accept() calls

HOSTILE_ACCEPT4

Become hostile to accept4() calls

HOSTILE_CLOSE

Become hostile to close() calls

HOSTILE_CONNECT

Become hostile to connect() calls

HOSTILE_GETADDRINFO

Become hostile to getaddrinfo() calls

HOSTILE_MALLOC

Become hostile to malloc() calls

HOSTILE_PIPE

Become hostile to pipe() calls

HOSTILE_PIPE2

Become hostile to pipe2() calls

HOSTILE_POLL

Become hostile to poll() calls

HOSTILE_REALLOC

Become hostile to realloc() calls

HOSTILE_RECV

Become hostile to recv() calls

HOSTILE_SEND

Become hostile to send() calls

HOSTILE_SETSOCKOPT

Become hostile to setsockopt() calls

HOSTILE_SOCKET

Become hostile to socket() calls

HOSTILE_WRITE

Become hostile to write() calls

FAQ

  1. Why do I not get the familar “Hostile Engaged” when trying to be hostile to certain binaries?

    This is because LD_PRELOAD will not work on binaries that do not have the same set-user-ID/set-group-ID as the libarary. This is from the documentation of LD_PRELOAD:

    A whitespace-separated list of additional, user-specified, ELF shared libraries to be loaded before all others. This can be used to selectively override functions in other shared libraries. For set- user-ID/set-group-ID ELF binaries, only libraries in the standard search directories that are also set-user-ID will be loaded.

hostile.sh

The hostile.sh script is a wrapper for libhostile. It will do the LD_PRELOAD for you as well as setup the required calls you want to be hostile with. It should be used as follows:

$ hostile.sh [options] <program> [program_options]

Where <program> is the application/service you wish to be hostile to and [program_options] are the options for it. For example, this would be hostile to malloc() calls with curl:

$ hostile.sh -m 500 curl -L http://www.google.com/

With all the below options the frequency is roughly how often the call should fail. So a frequency of 500 will fail roughly every 1/500 calls (there is a random element to it and a small grace period).

-a frequency

Become hostile on accept() and accept4() calls.

-c frequency

Become hostile on connect() calls

-e frequency

Become hostile on recv() calls

-g frequency

Become hostile on getaddrinfo() calls

-l frequency

Become hostile on poll() calls

-m frequency

Become hostile on malloc() calls

-o frequency

Become hostile on socket() calls

-p frequency

Become hostile on pipe() and pipe2() calls

-r frequency

Become hostile on realloc() calls

-s frequency

Become hostile on send() calls

-t frequency

Become hostile on setsockopt() calls

-w frequency

Become hostile on write() calls

-x frequency

Become hostile on close() calls