bunpen: plumb pasta CLI options up through main

pkgs/additional/bunpen/config/cli.ha

@@ -25,9 +25,9 @@ export type cli_opts = struct {
   run_paths: []str,
   try_keep_users: bool,
 
-  net_dev: (void | str),
-  net_gateway: (void | str),
-  dns: (void | str),
+  net_dev: str,
+  net_gateway: str,
+  dns: str,
 };
 
 export fn usage() void = {
@@ -99,7 +99,7 @@ export fn usage() void = {
 };
 
 export fn parse_args(args: []str) (cli_opts | errors::invalid) = {
-  let parsed = cli_opts { autodetect = void, net_dev = void, net_gateway = void, dns = void, ... };
+  let parsed = cli_opts { autodetect = void, ... };
 
   match (os::getenv("BUNPEN_DISABLE")) {
     case let d: str => parsed.disable = d;

pkgs/additional/bunpen/config/translate_opts.ha

@@ -61,7 +61,10 @@ fn cli_opts_get_exec_params(opts: cli_opts) exec_params = {
 };
 
 export fn ingest_cli_opts(opts: cli_opts) (cli_request | exec_params | help) = {
-  let req = cli_request { ... };
+  let req = cli_request {
+    resources = restrict::resources { net = restrict::net_none, ... },
+    ...
+  };
 
   //---- ingest `help` ----//
   if (opts.help) {
@@ -90,7 +93,6 @@ export fn ingest_cli_opts(opts: cli_opts) (cli_request | exec_params | help) = {
   //---- ingest `caps` ----//
   req.resources.caps = restrict::cap_array_to_caps(opts.keep_caps);
 
-
   //---- ingest `home_paths` ----//
   ingest_paths(&req.resources.paths, opts.home_paths, os::getenv("HOME"));
   //---- ingest `keep_all_caps` ----//
@@ -100,8 +102,19 @@ export fn ingest_cli_opts(opts: cli_opts) (cli_request | exec_params | help) = {
   //---- ingest `keep_ipc` ----//
   req.resources.ipc = opts.keep_ipc;
 
+  //---- ingest `net_dev`, `net_gateway`, `dns` ----//
+  let net_subset = restrict::net_subset {
+    dev = opts.net_dev,
+    dns = opts.dns,
+    gateway = opts.net_gateway,
+  };
+
+  if (net_subset.dev != "" && net_subset.dns != "" && net_subset.gateway != "")
+    req.resources.net = net_subset;
+
   //---- ingest `keep_net` ----//
-  req.resources.net = opts.keep_net;
+  if (opts.keep_net)
+    req.resources.net = restrict::net_all;
 
   //---- ingest `keep_pid` ----//
   req.resources.pid = opts.keep_pid;

pkgs/additional/bunpen/restrict/landlock.ha

@@ -82,11 +82,15 @@ export fn landlock_restrict(what: *resources) void = {
     ruleset_attr.handled_access_fs &= ~rt::ext::landlock_access_fs::IOCTL_DEV;
   };
 
-  if (what.net) {
-    // un-restrict net access
-    log::println("[landlock] permit net");
-    ruleset_attr.handled_access_net = 0;
-  }; // XXX: `what.net` only affects TCP. UDP, and ICMP remain possible always
+  // XXX: `what.net` only affects TCP. UDP, and ICMP remain possible always
+  match (what.net) {
+    case net_none => void;
+    case let subset: net_subset =>
+      log::println("[landlock] unable to retain just a subset of net resources");
+    case net_all =>
+      log::println("[landlock] permit net");
+      ruleset_attr.handled_access_net = 0;
+  };
 
   let ruleset_fd = errors::ext::check_u64(
     "landlock_create_ruleset",

pkgs/additional/bunpen/restrict/namespace.ha

@@ -34,9 +34,13 @@ export fn namespace_restrict(what: *resources) void = {
     log::println("[namespace] keeping ipc namespace");
     what_to_unshare &= ~rt::ext::clone_flag::NEWIPC;
   };
-  if (what.net) {
-    log::println("[namespace] keeping net namespace");
-    what_to_unshare &= ~rt::ext::clone_flag::NEWNET;
+  match (what.net) {
+    case net_none => void;
+    case let subset: net_subset =>
+      log::println("[namespace] TODO: not keeping subset of net namespace");
+    case net_all =>
+      log::println("[namespace] keeping net namespace");
+      what_to_unshare &= ~rt::ext::clone_flag::NEWNET;
   };
   if (what.pid) {
     log::println("[namespace] keeping pid namespace");

pkgs/additional/bunpen/restrict/resources.ha

@@ -9,9 +9,7 @@ export type resources = struct {
   caps: rt::ext::caps,
   // true to allow speaking to other processes in the same IPC namespace
   ipc: bool,
-  // true to allow unrestricted net access.
-  // false to maximally disable net access.
-  net: bool,
+  net: net_resources,
   // true to allow operations on other processes (e.g. viewing their cmdline,
   // killing them, etc).
   pid: bool,
@@ -19,3 +17,15 @@ export type resources = struct {
   // onto it would prevent us from sandboxing further
   try_users: bool,
 };
+
+export type net_subset = struct {
+  // name of the network device through which traffic should be routed
+  dev: str,
+  // IP address of a DNS server reachable through these other settings
+  dns: str,
+  // IP address of the gateway, by which traffic will be routed
+  gateway: str,
+};
+export type net_none = void;
+export type net_all = void;
+export type net_resources = (net_none | net_subset | net_all);