COMPEL(1) | CRIU Manual | COMPEL(1) |
NAME
compel - Execute parasitic code within another process.
SYNOPSIS
compel hgen [option ...]
compel plugins [PLUGIN_NAME ...]
compel [--compat] includes | cflags | ldflags
compel [--compat] [--static] libs
DESCRIPTION
compel is a utility to execute arbitrary code, also called parasite code, in the context of a foreign process. The parasitic code, once compiled with compel flags and packed, can be executed in the context of other tasks. Currently there is only one way to load the parasitic blob into victim task using libcompel.a, called c-header.
ARGUMENTS
Positional Arguments
hgen
plugins
ldflags
cflags
includes
libs
OPTIONS
-f, --file FILE
-o, --output FILE
-p, --prefix NAME
-l, --log-level NUM
-h, --help
-V, --version
SOURCE EXAMPLES
Parasitic Code
#include <compel/plugins/std.h>
int parasite_trap_cmd(int cmd, void *args); //gets called by compel_run_in_thread()
int parasite_daemon_cmd(int cmd, void *arg); // gets called by compel_rpc_call() and compel_rpc_call_sync()
void parasite_cleanup(void); //gets called on parasite unload by compel_cure()
Infecting code
The parasitic code is compiled and converted to a header using compel, and included here.
#include <compel/infect.h>
#include "parasite.h"
Following steps are performed to infect the victim process:
ctl must be configured with blob information by calling PREFIX_setup_c_header(), with ctl as its argument. PREFIX is the argument given to -p when calling hgen, else it is deduced from file name.
EXAMPLES
To generate a header file(.h) from a parasite binary file(.po) use:
compel hgen -f parasite.po -o parasite.h
parasite.po file is obtained by compiling the parasite source with compel flags and linking it with the compel plugins.
AUTHOR
The CRIU team.
12/20/2022 | criu 3.17.1 |