From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samuel Attard <samuel.r.attard@gmail.com>
Date: Mon, 28 Mar 2022 02:36:39 -0700
Subject: refactor: use posix_spawn instead of NSTask so we can disclaim the
 spawned ShipIt executable

This ensures that if the ShipIt executable is hotswapped it doesn't inherit TCC permissions

diff --git a/Squirrel/ShipIt-main.m b/Squirrel/ShipIt-main.m
index db246534e176f9c3ea2dd8b1c8659378fdc2435d..032f0b3e9200b423f1cd25fa2f39bc4117443741 100644
--- a/Squirrel/ShipIt-main.m
+++ b/Squirrel/ShipIt-main.m
@@ -13,6 +13,9 @@
 #import <ReactiveObjC/RACSignal+Operations.h>
 #import <ReactiveObjC/RACScheduler.h>
 
+#include <spawn.h>
+#include <sys/wait.h>
+
 #import "NSError+SQRLVerbosityExtensions.h"
 #import "RACSignal+SQRLTransactionExtensions.h"
 #import "SQRLInstaller.h"
@@ -20,6 +23,20 @@
 #import "SQRLTerminationListener.h"
 #import "SQRLShipItRequest.h"
 
+extern char **environ;
+
+int responsibility_spawnattrs_setdisclaim(posix_spawnattr_t attrs, int disclaim)
+__attribute__((availability(macos,introduced=10.14),weak_import));
+
+#define CHECK_ERR(expr) \
+	{ \
+		int err = (expr); \
+    if (err) { \
+        fprintf(stderr, "%s: %s", #expr, strerror(err)); \
+        exit(err); \
+    } \
+	}
+
 // The maximum number of times ShipIt should run the same installation state, in
 // an attempt to update.
 //
@@ -136,11 +153,35 @@ static void installRequest(RACSignal *readRequestSignal, NSString *applicationId
 							NSString *exe = NSProcessInfo.processInfo.arguments[0];
 							NSLog(@"Launching new ShipIt at %@ with instructions to launch %@", exe, bundleURL);
 
-							NSTask *task = [[NSTask alloc] init];
-							[task setLaunchPath: exe];
-							[task setArguments: @[launchSignal, bundleURL.path]];
-							[task launch];
-							[task waitUntilExit];
+							posix_spawnattr_t attr;
+							CHECK_ERR(posix_spawnattr_init(&attr));
+
+							// Disclaim TCC responsibilities
+							if (responsibility_spawnattrs_setdisclaim)
+									CHECK_ERR(responsibility_spawnattrs_setdisclaim(&attr, 1));
+
+							pid_t pid = 0;
+
+							const char* launchPath = [exe fileSystemRepresentation];
+							const char* signal = [launchSignal fileSystemRepresentation];
+							const char* path = [bundleURL.path fileSystemRepresentation];
+							const char* args[] = { launchPath, signal, path, 0 };
+							int status = posix_spawn(&pid, [exe UTF8String], NULL, &attr, (char *const*)args, environ);
+							if (status == 0) {
+								NSLog(@"New ShipIt pid: %i", pid);
+								do {
+									if (waitpid(pid, &status, 0) != -1) {
+										NSLog(@"ShipIt status %d", WEXITSTATUS(status));
+									} else {
+										perror("waitpid");
+										exit(1);
+									}
+								} while (!WIFEXITED(status) && !WIFSIGNALED(status));
+							} else {
+								NSLog(@"posix_spawn: %s", strerror(status));
+							}
+
+							posix_spawnattr_destroy(&attr);
 
 							NSLog(@"New ShipIt exited");
 						} else {
@@ -172,7 +213,13 @@ int main(int argc, const char * argv[]) {
 		});
 
 		if (argc < 3) {
-			NSLog(@"Missing launchd job label or state path for ShipIt");
+			NSLog(@"Missing launchd job label or state path for ShipIt (%d)", argc);
+			if (argc >= 1) {
+				NSLog(@"Arg 1: {%s}", argv[0]);
+			}
+			if (argc >= 2) {
+				NSLog(@"Arg 2: {%s}", argv[1]);
+			}
 			return EXIT_FAILURE;
 		}
 
