feat(cli): expose capture replay and watch commands with regression checks

(executable

 (name main)

 (public_name scope)

 (libraries scope unix))

open Scope

open Model

exception Usage of string

exception Interrupted of int

let usage = "scope 0.1.0\n\n\

  scope info CAPTURE\n\

  scope walk CAPTURE ADDRESS\n\

  scope explain CAPTURE ADDRESS --access read|write|execute --privilege supervisor|user\n\

  scope mappings CAPTURE\n\

  scope aliases CAPTURE\n\

  scope diff BEFORE AFTER [--include-ad]\n\

  scope capture DOMAIN OUTPUT --vcpu N --phys-bits N --nx on|off --gb-pages on|off [--pause]\n\

  scope watch DOMAIN DIRECTORY --vcpu N --phys-bits N --nx on|off --gb-pages on|off [--pause]\n\

  scope import TRANSCRIPT OUTPUT\n\

  scope demo DIRECTORY\n\n\

addresses are unsigned decimal or 0x-prefixed hexadecimal\n\

exit status: 0 success, 1 fault or findings, 2 incomplete or operational failure, 64 usage\n"

type options = {

  mutable json : bool;

  mutable root : int64 option;

  mutable max_entries : int;

  mutable max_pages : int;

  mutable max_pairs : int;

  mutable include_ad : bool;

  mutable access : access option;

  mutable privilege : privilege option;

  mutable ac : bool option;

  mutable vcpu : int option;

  mutable phys_bits : int option;

  mutable nx : bool option;

  mutable gb_pages : bool option;

  mutable pause : bool;

  mutable first : int64 option;

  mutable last : int64 option;

  mutable source : string;

  mutable interval : float;

  mutable count : int;

  mutable retain : int;

  mutable scan_aliases : bool;

}

let boolean = function "on" -> true | "off" -> false | _ -> raise (Usage "expected on or off")

let required name = function Some value -> value | None -> raise (Usage ("missing " ^ name))

let parse () =

  let options = { json = false; root = None; max_entries = 2_000_000; max_pages = 65536;

    max_pairs = 100_000; include_ad = false; access = None; privilege = None; ac = None;

    vcpu = None; phys_bits = None; nx = None; gb_pages = None; pause = false;

    first = None; last = None; source = "offline import";

    interval = 2.; count = 0; retain = 32; scan_aliases = false } in

  let positional = ref [] in

  let seen = Hashtbl.create 16 in

  let wrap flag action = fun value ->

    if Hashtbl.mem seen flag then raise (Usage ("duplicate option " ^ flag));

    Hashtbl.add seen flag ();

    action value

  in

  let specs = [

    "--interval", Arg.Float (wrap "--interval" (fun n -> options.interval <- n)), "SECONDS delay after each watch sample";

    "--count", Arg.Int (wrap "--count" (fun n -> options.count <- n)), "N watch samples, zero means until interrupted";

    "--retain", Arg.Int (wrap "--retain" (fun n -> options.retain <- n)), "N evidence pairs to retain";

    "--aliases", Arg.Unit (wrap "--aliases" (fun () -> options.scan_aliases <- true)), " scan writable/executable aliases while watching";

    "--json", Arg.Unit (wrap "--json" (fun () -> options.json <- true)), " emit scope.report.v1 json";

    "--root", Arg.String (wrap "--root" (fun s -> options.root <- Some (Address.parse s))), "ADDRESS select root while preserving captured cr3";

    "--max-entries", Arg.Int (wrap "--max-entries" (fun n -> options.max_entries <- n)), "N traversal budget";

    "--max-pages", Arg.Int (wrap "--max-pages" (fun n -> options.max_pages <- n)), "N capture page budget";

    "--max-pairs", Arg.Int (wrap "--max-pairs" (fun n -> options.max_pairs <- n)), "N alias output budget";

    "--include-ad", Arg.Unit (wrap "--include-ad" (fun () -> options.include_ad <- true)), " include accessed and dirty changes";

    "--access", Arg.Symbol (["read"; "write"; "execute"], wrap "--access" (fun s ->

      options.access <- Some (match s with "read" -> Read | "write" -> Write | _ -> Execute))), " requested access";

    "--privilege", Arg.Symbol (["supervisor"; "user"], wrap "--privilege" (fun s ->

      options.privilege <- Some (if s = "user" then User else Supervisor))), " access privilege";

    "--ac", Arg.String (wrap "--ac" (fun s -> options.ac <- Some (boolean s))), "on|off override captured ac for explicit data accesses";

    "--vcpu", Arg.Int (wrap "--vcpu" (fun n -> options.vcpu <- Some n)), "N vcpu to capture";

    "--phys-bits", Arg.Int (wrap "--phys-bits" (fun n -> options.phys_bits <- Some n)), "N guest maxphyaddr";

    "--nx", Arg.String (wrap "--nx" (fun s -> options.nx <- Some (boolean s))), "on|off guest nx capability";

    "--gb-pages", Arg.String (wrap "--gb-pages" (fun s -> options.gb_pages <- Some (boolean s))), "on|off guest 1 gib page capability";

    "--pause", Arg.Unit (wrap "--pause" (fun () -> options.pause <- true)), " hold a controller pause during capture";

    "--start", Arg.String (wrap "--start" (fun s -> options.first <- Some (Address.parse s))), "ADDRESS select overlapping regions";

    "--end", Arg.String (wrap "--end" (fun s -> options.last <- Some (Address.parse s))), "ADDRESS inclusive range end";

    "--source", Arg.String (wrap "--source" (fun s -> options.source <- s)), "TEXT import provenance";

  ] in

  Arg.parse_argv Sys.argv specs (fun value -> positional := value :: !positional) usage;

  if options.max_entries < 1 || options.max_pages < 1 || options.max_pairs < 1 then raise (Usage "budgets must be positive");

  if not (Float.is_finite options.interval) || options.interval <= 0. || options.count < 0 || options.retain < 1 then

    raise (Usage "watch interval and retention must be positive; count must be nonnegative");

  (match options.first, options.last with Some a, Some b when Address.compare a b > 0 ->

    raise (Usage "range start exceeds range end") | _ -> ());

  options, List.rev !positional, seen

let selected options (region : Paging.region) =

  (match options.first with None -> true | Some first -> Address.compare (Paging.last region) first >= 0) &&

  (match options.last with None -> true | Some last -> Address.compare region.start last <= 0)

let complete regions = List.for_all (fun (region : Paging.region) ->

  match region.state with Paging.Unknown _ -> false | _ -> true) regions

let invalid regions = List.exists (fun (region : Paging.region) ->

  match region.state with Paging.Broken _ -> true | _ -> false) regions

let run options positional seen =

  let command = match positional with command :: _ -> command | [] -> raise (Usage usage) in

  let allowed = ["--json"] @ (match command with

    | "info" -> []

    | "walk" -> ["--root"]

    | "explain" -> ["--root"; "--access"; "--privilege"; "--ac"]

    | "mappings" -> ["--root"; "--max-entries"; "--start"; "--end"]

    | "aliases" -> ["--root"; "--max-entries"; "--max-pairs"; "--start"; "--end"]

    | "diff" -> ["--root"; "--max-entries"; "--start"; "--end"; "--include-ad"]

    | "capture" -> ["--root"; "--max-pages"; "--vcpu"; "--phys-bits"; "--nx"; "--gb-pages"; "--pause"]

    | "watch" -> ["--root"; "--max-pages"; "--max-entries"; "--max-pairs"; "--vcpu"; "--phys-bits";

        "--nx"; "--gb-pages"; "--pause"; "--interval"; "--count"; "--retain"; "--aliases";

        "--include-ad"; "--start"; "--end"]

    | "import" -> ["--source"]

    | "demo" -> []

    | _ -> raise (Usage ("unknown command: " ^ command))) in

  Hashtbl.iter (fun flag () -> if not (List.mem flag allowed) then raise (Usage (flag ^ " does not apply to " ^ command))) seen;

  let load path =

    let capture = Capture.load path in

    match options.root with None -> capture | Some root -> Capture.with_root capture root

  in

  let enumerate capture = Paging.enumerate ~max_entries:options.max_entries (Capture.context capture) (Capture.read capture) in

  let output_context capture = if not options.json then Report.print_context (Capture.context capture) in

  let emit capture complete fields = Json.print (Report.envelope command (Capture.context capture) complete fields) in

  match positional with

  | ["watch"; domain; directory] ->

      let domid = try int_of_string domain with Failure _ -> raise (Usage "invalid domain id") in

      let vcpu = required "--vcpu" options.vcpu in

      let features = { phys_bits = required "--phys-bits" options.phys_bits;

        nx = required "--nx" options.nx; gb_pages = required "--gb-pages" options.gb_pages } in

      let capture () = Xen.capture ~domid ~vcpu ~pause:options.pause ~features ~root:options.root ~max_pages:options.max_pages in

      let emit (event : Watch.event) =

        let context = Capture.context event.after in

        if options.json then Json.print (Report.envelope "watch" context event.complete [

          "event", Json.String event.kind; "sample", Json.Int event.sample;

          "time", Json.String (Printf.sprintf "%.6f" event.time);

          "evidence", (if event.directory = "" then Json.Null else Json.String event.directory);

          "summary", Json.Object ["mappings", Json.Int event.mappings; "mapped_virtual_bytes", Json.hex event.bytes;

            "executable", Json.Int event.executable; "writable", Json.Int event.writable; "huge", Json.Int event.huge];

          "context_changes", Json.List (List.map Json.string event.context_changes);

          "changes", Json.List (List.map Report.change event.changes);

          "aliases", Json.List (List.map Report.alias event.aliases)])

        else begin

          Printf.printf "time=%.3f sample=%d event=%s root=%s mappings=%d bytes=%s executable=%d writable=%d huge=%d complete=%b\n"

            event.time event.sample event.kind (Address.hex (Address.Physical.to_int64 (Model.root context)))

            event.mappings (Address.hex event.bytes) event.executable event.writable event.huge event.complete;

          List.iter (fun (change : Analysis.change) ->

            Printf.printf "  %s length=%s changes=%s\n" (Address.hex change.start) (Address.hex change.length)

              (String.concat "," change.kinds);

            List.iter (fun (label, state) -> match state with

              | Some (Paging.Present m) -> Printf.printf "    %s physical=%s page_size=%s %s\n"

                  label (Address.hex (Address.Physical.to_int64 m.physical_address)) (Address.hex m.size) (Report.rights m.permissions)

              | _ -> ()) ["before", change.before; "after", change.after]) event.changes;

          if event.directory <> "" then Printf.printf "  evidence=%S aliases=%d context_changes=%s\n"

            event.directory (List.length event.aliases) (String.concat "," event.context_changes);

          if event.directory <> "" then List.iter (fun (alias : Analysis.alias) ->

            Printf.printf "  alias physical=%s length=%s writable=%s executable=%s\n"

              (Address.hex alias.physical) (Address.hex alias.length)

              (Address.hex (Address.Virtual.to_int64 alias.writable.virtual_address))

              (Address.hex (Address.Virtual.to_int64 alias.executable.virtual_address))) event.aliases

        end;

        flush stdout

      in

      (try Watch.run ~capture ~wait:Unix.sleepf ~emit ~directory ~interval:options.interval

        ~count:options.count ~retain:options.retain ~max_entries:options.max_entries ~max_pairs:options.max_pairs

        ~include_ad:options.include_ad ~scan_aliases:options.scan_aliases ~selected:(selected options) ()

      with Interrupted _ -> 0)

  | ["demo"; directory] ->

      Demo.write directory;

      if options.json then Json.print (Json.Object ["schema", Json.String "scope.report.v1";

        "command", Json.String "demo"; "directory", Json.String directory])

      else Printf.printf "captures=%s/before,%s/after source=synthetic\n" directory directory;

      0

  | ["import"; transcript; destination] ->

      let capture = Capture.import ~source:options.source transcript in

      let complete = Capture.complete capture in

      Capture.save destination capture;

      if options.json then emit capture complete ["path", Json.String destination; "pages", Json.Int (Capture.pages capture)]

      else Printf.printf "capture=%s pages=%d complete=%b\n" destination (Capture.pages capture) complete;

      if complete then 0 else 2

  | ["capture"; domain; destination] ->

      let domid = try int_of_string domain with Failure _ -> raise (Usage "invalid domain id") in

      let vcpu = required "--vcpu" options.vcpu in

      let features = { phys_bits = required "--phys-bits" options.phys_bits;

        nx = required "--nx" options.nx; gb_pages = required "--gb-pages" options.gb_pages } in

      let capture = Xen.capture ~domid ~vcpu ~pause:options.pause ~features ~root:options.root ~max_pages:options.max_pages in

      let complete = Capture.complete capture in

      Capture.save destination capture;

      output_context capture;

      if options.json then emit capture complete ["path", Json.String destination; "pages", Json.Int (Capture.pages capture)]

      else Printf.printf "capture=%s pages=%d complete=%b\n" destination (Capture.pages capture) complete;

      if complete then 0 else 2

  | ["info"; path] ->

      let capture = load path in

      let complete = Capture.complete capture in

      output_context capture;

      if options.json then emit capture complete ["pages", Json.Int (Capture.pages capture); "xen_available", Json.Bool (Xen.available ())]

      else Printf.printf "pages=%d complete=%b xen_available=%b\n" (Capture.pages capture) complete (Xen.available ());

      if complete then 0 else 2

  | [("walk" | "explain"); path; address] ->

      let capture = load path in

      let context = Capture.context capture in

      let address = Address.Virtual.of_int64 (Address.parse address) in

      let request = if command = "walk" then None else Some {

        access = required "--access" options.access;

        privilege = required "--privilege" options.privilege;

        ac = Option.value options.ac ~default:(Address.bit context.registers.rflags 18) } in

      let result = match request with

        | None -> Paging.walk context (Capture.read capture) address

        | Some request -> Paging.explain context (Capture.read capture) address request

      in

      let complete = match result.outcome with Incomplete _ -> false | _ -> true in

      output_context capture;

      if options.json then emit capture complete [

        "address", Json.hex (Address.Virtual.to_int64 address);

        "error_code_scope", Json.String (if request = None then "structural_bits_only" else "request");

        "request", Json.option (fun (request : request) -> Json.Object ["access", Json.String (access_name request.access);

          "privilege", Json.String (privilege_name request.privilege); "ac", Json.Bool request.ac]) request;

        "trace", Json.List (List.map Report.step result.trace); "result", Report.outcome result.outcome]

      else begin

        if request = None then print_endline "access=unspecified error_code=structural-bits-only";

        Option.iter (fun (request : request) -> Printf.printf "access=%s privilege=%s ac=%b\n"

          (access_name request.access) (privilege_name request.privilege) request.ac) request;

        Report.print_result result

      end;

      (match result.outcome with Mapped _ -> 0 | Fault _ -> 1 | Incomplete _ -> 2)

  | ["mappings"; path] ->

      let capture = load path in

      let regions = enumerate capture |> List.filter (selected options) in

      let complete = complete regions in

      output_context capture;

      if options.json then emit capture complete ["regions", Json.List (List.map Report.region regions)]

      else List.iter Report.print_region regions;

      if not complete then 2 else if invalid regions then 1 else 0

  | ["aliases"; path] ->

      let capture = load path in

      let regions = enumerate capture |> List.filter (selected options) in

      let complete = complete regions in

      let aliases = Analysis.aliases ~max_pairs:options.max_pairs regions in

      output_context capture;

      if options.json then emit capture complete ["aliases", Json.List (List.map Report.alias aliases);

        "regions", Json.List (List.filter_map (fun region ->

          match region.Paging.state with Paging.Present _ -> None | _ -> Some (Report.region region)) regions)]

      else begin

        List.iter (fun (alias : Analysis.alias) ->

          Printf.printf "physical=%s length=%s writable=%s executable=%s\n"

            (Address.hex alias.physical) (Address.hex alias.length)

            (Address.hex (Address.Virtual.to_int64 alias.writable.virtual_address))

            (Address.hex (Address.Virtual.to_int64 alias.executable.virtual_address));

          List.iter Report.print_step alias.writable.trace;

          List.iter Report.print_step alias.executable.trace) aliases;

        List.iter (fun region -> match region.Paging.state with Paging.Present _ -> () | _ -> Report.print_region region) regions

      end;

      if not complete then 2 else if aliases = [] && not (invalid regions) then 0 else 1

  | ["diff"; before; after] ->

      let a = load before and b = load after in

      let context_changes = Model.context_changes (Capture.context a) (Capture.context b) in

      let ra = enumerate a and rb = enumerate b in

      let changes = Analysis.diff ~include_ad:options.include_ad ra rb |> List.filter (fun (c : Analysis.change) ->

        selected options { Paging.start = c.start; length = c.length; state = Paging.Unknown "" }) in

      let complete = not (List.exists (fun (c : Analysis.change) -> List.mem "incomplete" c.kinds) changes) in

      if options.json then emit a complete ["after_context", Report.context (Capture.context b);

        "context_changes", Json.List (List.map Json.string context_changes);

        "include_ad", Json.Bool options.include_ad; "changes", Json.List (List.map Report.change changes)]

      else begin

        Report.print_context (Capture.context a);

        print_endline "after:";

        Report.print_context (Capture.context b);

        Printf.printf "context_changes=%s include_ad=%b\n" (String.concat "," context_changes) options.include_ad;

        List.iter (fun (c : Analysis.change) ->

          Printf.printf "%s length=%s changes=%s\n" (Address.hex c.start) (Address.hex c.length) (String.concat "," c.kinds);

          let print label = function

            | None -> Printf.printf "  %s absent\n" label

            | Some (Paging.Present m) -> Printf.printf "  %s physical=%s page_size=%s %s leaf=%s\n" label

                (Address.hex (Address.Physical.to_int64 m.physical_address)) (Address.hex m.size)

                (Report.rights m.permissions) (Address.hex m.leaf)

            | Some (Paging.Unknown reason) -> Printf.printf "  %s incomplete=%s\n" label reason

            | Some (Paging.Broken reason) -> Printf.printf "  %s invalid=%s\n" label reason

          in

          print "before" c.before;

          print "after" c.after) changes

      end;

      if not complete then 2 else if changes = [] && context_changes = [] then 0 else 1

  | _ -> raise (Usage ("wrong arguments for " ^ command ^ "\n" ^ usage))

let () =

  Sys.set_signal Sys.sigint (Sys.Signal_handle (fun signal -> raise (Interrupted signal)));

  Sys.set_signal Sys.sigterm (Sys.Signal_handle (fun signal -> raise (Interrupted signal)));

  let json = Array.exists ((=) "--json") Sys.argv in

  let fail code reason =

    if json then Json.output stderr (Json.Object ["schema", Json.String "scope.report.v1";

      "error", Json.String reason; "complete", Json.Bool false])

    else Printf.eprintf "scope: %s\n" reason;

    if json then output_char stderr '\n';

    exit code

  in

  try

    let options, positional, seen = parse () in

    exit (run options positional seen)

  with

  | Usage reason | Arg.Bad reason -> fail 64 reason

  | Arg.Help text -> print_string text; exit 0

  | Invalid_argument reason | Failure reason | Sys_error reason | Model.Limit reason -> fail 2 reason

  | Fun.Finally_raised exn -> fail 2 ("cleanup failed: " ^ Printexc.to_string exn)

  | Unix.Unix_error (error, operation, path) -> fail 2 (operation ^ " " ^ path ^ ": " ^ Unix.error_message error)

  | Interrupted signal -> fail 2 (Printf.sprintf "interrupted by signal %d" signal)

import json

from pathlib import Path

import subprocess

import sys

import tempfile

executable = str(Path(sys.argv[1]).resolve())

checks = 0

def run(*args, status=0, structured=True):

    global checks

    command = [executable, *map(str, args)]

    if structured:

        command.append("--json")

    result = subprocess.run(command, capture_output=True, text=True, timeout=10)

    assert result.returncode == status, (command, result.returncode, result.stdout, result.stderr)

    checks += 1

    if structured:

        value = json.loads(result.stdout if result.stdout else result.stderr)

        assert value["schema"] == "scope.report.v1"

        return value

    return result.stdout

with tempfile.TemporaryDirectory(prefix="scope") as directory:

    root = Path(directory)

    run("demo", root)

    before, after = root / "before", root / "after"

    assert run("info", before)["pages"] == 5

    result = run("walk", before, "0x400abc")

    assert result["result"]["mapping"]["physical"] == "0x0000000000009abc"

    result = run("explain", before, "0x400000", "--access", "write", "--privilege", "supervisor", status=1)

    assert result["result"]["fault"]["level"] == 2

    assert result["result"]["fault"]["error_code"] == 3

    assert len(run("aliases", before, status=1)["aliases"]) == 1

    assert run("aliases", after)["aliases"] == []

    assert len(run("diff", before, after, status=1)["changes"]) == 2

    assert run("diff", before, before)["changes"] == []

    assert len(run("mappings", before, "--start", "0x800000")["regions"]) == 1

    assert run("walk", before, "0x800000000000", status=1)["result"]["fault"]["vector"] == 13

    overridden = run("walk", before, "0x400000", "--root", "0x6000", status=2)

    assert overridden["complete"] is False

    assert overridden["context"]["registers"]["cr3"] == "0x0000000000001000"

    assert overridden["context"]["root"] == "0x0000000000006000"

    run("explain", before, "0x400000", status=64)

    run("walk", before, "0x400000", "--include-ad", status=64)

    run("walk", before, "0x400000", "--root", "0x1000", "--root", "0x2000", status=64)

    run("mappings", before, "--max-entries", "1", status=2)

    run("capture", "0", root / "capture", "--vcpu", "0", "--phys-bits", "48", "--nx", "on", "--gb-pages", "on", status=2)

    run("walk", before, "-1", status=64)

    run("unknown", status=64)