rea/src/native/elf/ElfNotesProvider.ts

import { ArtifactReaderFailure } from "../../artifacts/ArtifactReader.js";
import { readStableArtifact } from "../../artifacts/readStableArtifact.js";
import {
  ArtifactFileCleanupFailure,
  bindArtifactFileCleanup,
  artifactFileCancellationCause,
} from "../../artifacts/ArtifactFileOperation.js";
import { ArtifactResourceScope } from "../../artifacts/ArtifactResourceScope.js";
import { analysisErrorWithCleanupFailure } from "../../domain/analysisErrorCleanup.js";
import type { ElfNotesPort } from "../../application/binaryDiagnostics/ElfNotesPort.js";
import type { ExecutionOptions } from "../../application/AnalysisProvider.js";
import { ArtifactOperationError } from "../../domain/artifactOperationError.js";
import {
  AnalysisAccessDeniedError,
  AnalysisArtifactChangedError,
  AnalysisCancelledError,
  AnalysisInputError,
  AnalysisResourceConstraintError,
} from "../../domain/analysisErrorCore.js";
import { fixedAllowanceOptions } from "../../domain/fixedAllowanceRemediation.js";
import {
  MAX_INSPECT_ELF_NOTE_ENTRIES,
  MAX_INSPECT_ELF_NOTE_FILE_BYTES,
  type InspectElfNotesInput,
} from "../../domain/native/elfNotes.js";
import { err, ok } from "../../domain/result.js";
import { ProviderCleanupError } from "../../domain/providerCleanupError.js";
import { ELF_NOTES_PROVIDER } from "../../application/InvestigationProviders.js";
import { parseElfNotes } from "./ElfNoteParser.js";

const OPERATION = "inspect_elf_notes";

/** Portable parser over one bounded, identity-checked regular file. */
export class ElfNotesProvider implements ElfNotesPort {
  readonly identity = ELF_NOTES_PROVIDER;
  readonly #resources = new ArtifactResourceScope();

  async close(): Promise<void> {
    try {
      await this.#resources.close();
    } catch (cause: unknown) {
      if (
        !(cause instanceof ArtifactReaderFailure) ||
        cause.cleanup === undefined
      )
        throw cause;
      const error = new ProviderCleanupError(
        ELF_NOTES_PROVIDER.id,
        cause.cleanup.resources,
        { reason: cause.cleanup.reason },
        { cause, operation: OPERATION },
      );
      bindArtifactFileCleanup(cause, error);
      throw error;
    }
  }

  async inspect(input: InspectElfNotesInput, options?: ExecutionOptions) {
    try {
      return await this.#resources.run(async () => {
        const snapshot = await readStableArtifact(
          input.path,
          input.max_file_bytes,
          options?.signal,
          undefined,
          this.#resources,
        );
        return ok(
          parseElfNotes(
            snapshot.bytes,
            {
              path: input.path,
              sha256: snapshot.sha256,
              bytes: snapshot.bytes.length,
            },
            input,
          ),
        );
      });
    } catch (cause) {
      return err(elfNotesFailure(cause, input, options?.signal));
    }
  }
}

const NOTE_TEXT_BUDGET =
  "The ELF note text, hash, and scan budget tied to the admitted image length";

const inputBudgetRemediation = (
  boundary: "file-size" | "capacity",
  input: InspectElfNotesInput,
): string =>
  boundary === "file-size"
    ? input.max_file_bytes >= MAX_INSPECT_ELF_NOTE_FILE_BYTES
      ? `The image exceeds the ${String(MAX_INSPECT_ELF_NOTE_FILE_BYTES)}-byte input ceiling this operation accepts; select a smaller artifact.`
      : `Raise max_file_bytes above ${String(input.max_file_bytes)} bytes or select a smaller artifact; the limit is the caller-selected input read budget.`
    : input.max_entries >= MAX_INSPECT_ELF_NOTE_ENTRIES
      ? `The image exceeds the ${String(MAX_INSPECT_ELF_NOTE_ENTRIES)}-entry note-table ceiling this operation accepts; select a smaller artifact.`
      : `Raise max_entries above ${String(input.max_entries)} or select a smaller artifact; the limit is the caller-selected note entry budget.`;

const elfNotesFailurePrimary = (
  cause: unknown,
  input: InspectElfNotesInput,
) => {
  if (cause instanceof ArtifactReaderFailure && cause.reason === "integrity")
    return new AnalysisArtifactChangedError(
      OPERATION,
      input.path,
      cause.message,
      {
        cause,
      },
    );
  if (cause instanceof ArtifactReaderFailure && cause.reason === "cancelled")
    return new AnalysisCancelledError(OPERATION, {
      cause: artifactFileCancellationCause(cause),
    });
  if (cause instanceof ArtifactReaderFailure) {
    if (cause.reason === "limit") {
      // Caller-selected read and entry budgets name the bound to raise.
      // The note text, hash, and scan ceiling equals the admitted image
      // length, so host memory cannot raise it.
      const noteTextBudget = cause.boundary === "memory";
      return new AnalysisResourceConstraintError(
        OPERATION,
        cause.boundary ?? "memory",
        cause.message,
        {
          max_file_bytes: input.max_file_bytes,
          max_entries: input.max_entries,
        },
        {
          cause,
          ...(cause.boundary === undefined
            ? {}
            : noteTextBudget
              ? fixedAllowanceOptions(NOTE_TEXT_BUDGET, "parser")
              : {
                  retryable: false as const,
                  remediationAction: inputBudgetRemediation(
                    cause.boundary,
                    input,
                  ),
                }),
        },
      );
    }
    if (cause.reason === "path" || cause.reason === "format")
      return new AnalysisInputError(OPERATION, { cause }, [
        {
          path: ["path"],
          reason: "invalid_format",
          message: cause.message,
        },
      ]);
  }
  if (cause instanceof Error && "code" in cause) {
    if (cause.code === "EACCES" || cause.code === "EPERM")
      return new AnalysisAccessDeniedError(OPERATION, input.path, cause.code, {
        cause,
      });
    if (
      ["ENOENT", "ENOTDIR", "ELOOP", "ENAMETOOLONG"].includes(
        String(cause.code),
      )
    )
      return new AnalysisInputError(OPERATION, { cause }, [
        {
          path: ["path"],
          reason: "invalid_value",
          message: `Selected ELF image could not be read (${String(cause.code)}): ${input.path}.`,
        },
      ]);
  }
  return new ArtifactOperationError(
    OPERATION,
    cause instanceof ArtifactReaderFailure ? cause.reason : "io",
    undefined,
    cause instanceof Error ? cause.message : "ELF note inspection failed.",
    { cause },
  );
};

const elfNotesFailure = (
  cause: unknown,
  input: InspectElfNotesInput,
  signal: AbortSignal | undefined,
) => {
  const primary =
    cause instanceof ArtifactFileCleanupFailure &&
    cause.fileCleanupFailure.outcome.kind === "failed"
      ? elfNotesFailurePrimary(cause.fileCleanupFailure.outcome.cause, input)
      : cause instanceof ArtifactFileCleanupFailure && signal?.aborted
        ? new AnalysisCancelledError(OPERATION, { cause: signal.reason })
        : elfNotesFailurePrimary(cause, input);
  if (!(cause instanceof ArtifactReaderFailure) || cause.cleanup === undefined)
    return primary;
  const cleanup = new ProviderCleanupError(
    ELF_NOTES_PROVIDER.id,
    cause.cleanup.resources,
    { reason: cause.cleanup.reason },
    { operation: OPERATION, cause },
  );
  const error = analysisErrorWithCleanupFailure(primary, cleanup, OPERATION);
  bindArtifactFileCleanup(cause, error);
  return error;
};