go-sandbox/README.md
2019-08-05 15:55:36 -07:00

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## go-judger
Under developing.
Goal is to reimplement [uoj-judger/run_program](https://github.com/vfleaking/uoj) in GO language using [libseccomp](https://github.com/seccomp/libseccomp-golang).
Install:
- install go compiler: `apt install golang-go`
- install libseccomp-dev: `apt install libseccomp-dev`
- install: `go install github.com/criyle/go-judger/...`
Features (same as uoj-judger/run_program):
1. Restricted computing resource: Time & Memory (Stack) & Output
2. Restricted syscall access (by libseccomp & ptrace)
3. Restricted file access (read & write & access & exec)
New Features:
1. Percise resource limits (s -> ms, mb -> kb)
2. More architectures (arm32, arm64, x86)
3. Allow multiple traced programs in different threads
4. Allow pipes as input / output files
5. Use Linux Namespace to isolate file access (elimilate ptrace)
6. Use Linux Control Groups to limit & acct CPU & memory (elimilate wait4.rusage)
7. Container tech with execveat memfd, sethostname, setdomainname
Default file access action:
- check file read / write: `open`, `openat`
- check file read: `readlink`, `readlinkat`
- check file write: `unlink`, `unlinkat`, `chmod`, `rename`
- check file access: `stat`, `lstat`, `access`, `faccessat`
- check file exec: `execve`
Packages:
- seccomp: provides utility function that wrappers libseccomp
- forkexec: fork-exec provides mount, unshare, ptrace, seccomp, capset before exec
- memfd: read regular file and creates a seaed memfd for its contents
- unixsocket: send / recv oob msg from a unix socket
- cgroup: creates cgroup directories and collects resource usage / limits
- tracer: ptrace tracer and provides syscall trap filter context
- runprogram: wrapper to call forkexec and trecer
- rununshared: wrapper to call forkexec and unshared namespaces
- runconfig: defines arch & language specified trace condition for seccomp and ptrace
- types: general runtime specs
- mount: provides utility function that wrappers mount syscall
- rlimit: provides utility function that defines rlimit syscall
- specs: provides general res / result data structures
Executable:
- run_program: under construction
Configuations:
- run_program/config.go: all configs toward running specs
Benchmarks for unshare:
- 1ms: fork, unshare pid / user / cgroup
- 50ms: unshare ipc / mount
- 100ms: unshare pid & user & cgroup & mount & pivot root
- 400ms: unshare net
- 800ms: unshare all
- 880ms: unshare all & pivot root
It seems unshare net or ipc takes time, maybe limits action by seccomp instead.
TODO:
1. Add ability to pre-fork container deamons