rsys

rsys is a remote syscall forwarding client/server for Linux. It runs a program locally under ptrace and forwards effect-creating syscalls (file and network I/O, readiness, and a few identity/environment helpers) to a remote rsysd over TCP, so the program behaves as if it were running on the remote host.

Build

Requirements: a Linux x86_64 machine with a C toolchain.

make

This produces two binaries in the repository root:

• rsys: client (traces a local program and forwards syscalls)
• rsysd: server (executes forwarded syscalls)

Run

Start the server on the remote host:

./rsysd 5555

Run a program via the client (connects to rsysd and execs the program locally):

./rsys 192.0.2.10 5555 ls -la

Enable verbose logging:

./rsys -v 192.0.2.10 5555 curl https://example.com/

Expose a local path at a different path for the traced program (repeatable):

./rsys -m /home/me/project:/mnt/project 192.0.2.10 5555 ls /mnt/project

Client options (see rsys -h for the authoritative list):

• -v, --verbose: verbose logging
• -m, --mount SRC:DST: expose local SRC at path DST
• -p PORT|LOCAL:REMOTE: forward remote listen port to local port
• -R, --read-only: block remote filesystem mutations
• -e: use local environment for the traced program
• -E: use remote environment for the traced program (default)

Server options:

• -v: verbose logging

Project structure

• rsys.c, rsysd.c: tiny main() wrappers.
• rsys_protocol.h: wire protocol framing + integer encoding helpers.
• rsys_tracee_mem.h: helpers to read/write tracee memory (process_vm_* with ptrace fallback).
• src/rsys/: client implementation modules (ptrace loop, fd mapping, rpc, env/path helpers, etc).
  • src/rsys/intercept/: per-domain syscall interception/forwarding code + dispatcher.
• src/rsysd/: server implementation modules (dispatch + grouped syscall handlers + server loop).