bash-loadables

An extension to bash's builtin, providing more functionalities and potentially better performance.

How to build this project

Requirements

• Clang: sudo apt install clang
• LLD: sudo apt install lld
• cap-ng.h: sudo apt install libcap-ng-dev
• seccomp.h: sudo apt install libseccomp-dev

# Clone this repo
git clone --recurse-submodules https://github.com/NobodyXu/bash-loadables
cd bash-loadables

# Build the bash submodule
cd bash
./configure
make

# Build this project
cd ..
make all -j $(nproc)

How to load builtin from a loadable

#!/bin/bash

# To load builtins
enable -f /path/to/loadable builtin_name ...

# Load all builtins from a loadable
enable -f /path/to/loadable loadable_name
loadable_name

Get usage/help of builtin

After a builtin is enabled, type help builtin to get detailed help.

builtins provided by loadables

os_basic

• create_memfd [-C] VAR
• create_tmpfile [-CE] VAR /path/to/dir rw/w [mode]
• lseek <int> fd <off64_t> offset SEEK_SET/SEEK_CUR/SEEK_END
• fexecve <int> fd program_name [args...]
• flink <int> fd path
• flink <int> fd mode
• fchown <int> fd uid/username:gid/groupname
• getresuid var1 var2 var3
• getresgid var1 var2 var3
• setresuid var1 var2 var3
• getresgid var1 var2 var3
• has_supplementary_group_member group/gid
• get_supplementary_groups varname
• set_supplementary_groups [gid/group ...]
• create_unixsocketpair stream/dgram var1 var2
• fdputs <int> fd msg
• fdecho <int> fd msgs ...
• sendfds [-N] <int> fd_of_unix_socket fd1 [fds...]
• recvfds [-C] <int> fd_of_unix_socket nfd var
• pause
• sleep [-R] seconds nanoseconds
• create_socket [-NC] domain type <int> protocol var
• bind <int> socketfd domain socketaddr
• listen <int> socketfd <int> backlog
• accept [-NC] <int> socketfd var
• bind <int> socketfd domain socketaddr
• clone [-FPVS] [var]
• unshare [-FS]
• os_basic

sandboxing

• enable_no_new_privs_strict
• clone_ns [-VCINMPuU] [var]
• unshare_ns [-CINMPuU]
• chroot path
• setns [-CINMPuU] <int> fd
• sandboxing

common_commands

• realpath path [var]
• mkdir path [mode]
• common_commands