box/bin/box-sys-op.py

#!/usr/bin/env python3
"""
box-sys-op.py — Sandboxed execution helper for core system operations:
  files.read, files.write, web.fetch, service.status, service.restart
Called via fixed argv from exec-constrained.py.
"""
import sys
import os
import json
import urllib.request
import urllib.error
import urllib.parse
import ipaddress
import subprocess
from pathlib import Path

REPO_ROOT = Path("/home/super/Projects/NetVM").resolve()
MAX_OUTPUT = 4096
ALLOWED_SERVICES = {
    "board.service", "caddy.service", "response-harvester.timer",
    "self-main-loop.timer", "job-heartbeat.timer", "job-scheduler.timer"
}

def safe_repo_path(raw):
    clean = os.path.normpath(raw.strip())
    if not os.path.isabs(clean):
        clean = os.path.normpath(str(REPO_ROOT / clean))
    real = Path(clean).resolve()
    if not str(real).startswith(str(REPO_ROOT) + "/") and real != REPO_ROOT:
        raise ValueError("path must reside inside repository root (/home/super/Projects/NetVM)")
    return real

def op_files_read(path_str, max_lines=100):
    p = safe_repo_path(path_str)
    if not p.exists() or not p.is_file():
        return {"ok": False, "error": f"File not found: {path_str}"}
    with open(p, "r", encoding="utf-8", errors="replace") as f:
        lines = f.readlines()
    total_lines = len(lines)
    snippet = "".join(lines[:max_lines])
    truncated = total_lines > max_lines or len(snippet) > MAX_OUTPUT
    if len(snippet) > MAX_OUTPUT:
        snippet = snippet[:MAX_OUTPUT] + "\n... [truncated]"
    return {
        "ok": True,
        "path": str(p.relative_to(REPO_ROOT)),
        "lines": total_lines,
        "displayed_lines": min(total_lines, max_lines),
        "content": snippet,
        "truncated": truncated
    }

def op_files_write(path_str, content):
    p = safe_repo_path(path_str)
    p.parent.mkdir(parents=True, exist_ok=True)
    with open(p, "w", encoding="utf-8") as f:
        f.write(content)
    return {
        "ok": True,
        "path": str(p.relative_to(REPO_ROOT)),
        "bytes_written": len(content.encode("utf-8")),
        "lines": content.count("\n") + 1
    }

def op_web_fetch(url_str):
    parsed = urllib.parse.urlparse(url_str)
    if parsed.scheme not in ("http", "https"):
        return {"ok": False, "error": "URL scheme must be http or https"}
    host = parsed.hostname or ""
    if not host or host in ("localhost", "127.0.0.1", "::1"):
        return {"ok": False, "error": "Loopback destinations blocked"}
    try:
        ip = ipaddress.ip_address(host)
        if ip.is_private or ip.is_loopback or ip.is_link_local:
            return {"ok": False, "error": "Private and local IP addresses blocked"}
    except ValueError:
        pass

    req = urllib.request.Request(
        url_str,
        headers={"User-Agent": "Mozilla/5.0 Box-Agent-Client/1.0"}
    )
    try:
        with urllib.request.urlopen(req, timeout=10) as resp:
            data = resp.read(MAX_OUTPUT + 1024).decode("utf-8", errors="replace")
            status = resp.status
            truncated = len(data) > MAX_OUTPUT
            if truncated:
                data = data[:MAX_OUTPUT] + "\n... [truncated]"
            return {
                "ok": True,
                "url": url_str,
                "status": status,
                "length": len(data),
                "body": data,
                "truncated": truncated
            }
    except urllib.error.HTTPError as he:
        return {"ok": False, "status": he.code, "error": f"HTTP {he.code}: {he.reason}"}
    except Exception as e:
        return {"ok": False, "error": str(e)}

def op_service_status(unit):
    if unit not in ALLOWED_SERVICES:
        return {"ok": False, "error": f"Service not allowed: {unit}"}
    flag = "--user" if unit.endswith(".timer") else "--system"
    cmd = ["systemctl", flag, "status", unit] if flag == "--user" else ["systemctl", "is-active", unit]
    r = subprocess.run(cmd, capture_output=True, text=True, timeout=10)
    active = "active" in r.stdout.lower() or "active" in r.stderr.lower()
    return {
        "ok": True,
        "service": unit,
        "active": active,
        "status_line": r.stdout.splitlines()[0] if r.stdout.splitlines() else "unknown",
        "output": r.stdout[:500].strip()
    }

def op_service_restart(unit):
    if unit not in ALLOWED_SERVICES:
        return {"ok": False, "error": f"Service not allowed: {unit}"}
    if unit.endswith(".timer"):
        cmd = ["systemctl", "--user", "restart", unit]
    else:
        cmd = ["sudo", "-n", "systemctl", "restart", unit]
    r = subprocess.run(cmd, capture_output=True, text=True, timeout=15)
    return {
        "ok": r.returncode == 0,
        "service": unit,
        "restarted": r.returncode == 0,
        "error": r.stderr.strip() if r.returncode != 0 else None
    }

def main():
    if len(sys.argv) < 2:
        print(json.dumps({"ok": False, "error": "missing operation"}))
        sys.exit(1)
    op = sys.argv[1]
    raw_args = sys.stdin.read()
    try:
        args = json.loads(raw_args) if raw_args.strip() else {}
    except Exception as e:
        print(json.dumps({"ok": False, "error": f"bad json args: {e}"}))
        sys.exit(1)

    try:
        if op == "files.read":
            res = op_files_read(args.get("path", ""), int(args.get("lines", 100)))
        elif op == "files.write":
            res = op_files_write(args.get("path", ""), args.get("content", ""))
        elif op == "web.fetch":
            res = op_web_fetch(args.get("url", ""))
        elif op == "service.status":
            res = op_service_status(args.get("unit", args.get("name", "")))
        elif op == "service.restart":
            res = op_service_restart(args.get("unit", args.get("name", "")))
        else:
            res = {"ok": False, "error": f"unknown operation: {op}"}
    except Exception as e:
        res = {"ok": False, "error": str(e)}

    print(json.dumps(res))

if __name__ == "__main__":
    main()