DARWIN: Convert prefpane startup ops to privhelper

Convert the logic for the "start at login" option in the prefpane to use
privhelper, so it can work with macOS 10.8+.

Specifically, define these new privhelper tasks:

- startup_enable
- startup_disable
- startup_check

And convert our startup-related logic in the prefpane to use them.

Get rid of our now-unused method executeTaskWithAuth() and related
methods.

Change-Id: I2cb4c31f964529ab1af43ab7828c14eba7354af0
Reviewed-on: https://gerrit.openafs.org/15957
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>

src/platform/DARWIN/AFSPreference/AFSCommanderPref.m

@@ -750,14 +750,13 @@
 //  afsStartupSwitchEvent:
 // -------------------------------------------------------------------------------
 - (IBAction) afsStartupSwitchEvent:(id) sender {
-    NSString *rootHelperApp = [[self bundle] pathForResource:@"afshlp" ofType:@""];
     //get the new state
     startAFSAtLogin = [checkButtonAfsAtBootTime state];
-    [PListManager launchctlStringCommandAuth:startAFSAtLogin?@"load":@"unload"
-		  option:[NSArray arrayWithObjects:@"-w", nil]
-		  plistName:@AFS_DAEMON_PATH
-		  helper:rootHelperApp
-		  withAuthRef:[[authView authorization] authorizationRef]];
+    if (startAFSAtLogin) {
+	[TaskUtil executePrivTask:"startup_enable"];
+    } else {
+	[TaskUtil executePrivTask:"startup_disable"];
+    }
 }
 
 
@@ -878,16 +877,13 @@
 {
     BOOL afsIsUp = [afsProperty checkAfsStatus];
     BOOL afsEnabledAtStartup = NO;
-    NSString *rootHelperApp = [[self bundle] pathForResource:@"afshlp" ofType:@""];
 
     if ([self isUnlocked]) {
-	afsEnabledAtStartup = (
-	    [TaskUtil executeTaskWithAuth:@"/bin/launchctl"
-		      arguments:[NSArray arrayWithObjects:@"list",
-					 @"org.openafs.filesystems.afs", nil]
-		      helper:rootHelperApp
-		      withAuthRef:[[authView authorization] authorizationRef]
-	     ] == noErr)?YES:NO;
+	if ([TaskUtil executePrivTask:"startup_check"] == 0) {
+	    afsEnabledAtStartup = YES;
+	} else {
+	    afsEnabledAtStartup = NO;
+	}
 	[checkButtonAfsAtBootTime setState:afsEnabledAtStartup];
     }
 

src/platform/DARWIN/AFSPreference/PListManager.h

@@ -75,12 +75,6 @@
  @discussion <#(comprehensive description)#>
 */ 
 +(void) launchctlCommand:(BOOL)enable userDomain:(BOOL)userDomain option:(NSArray*)option plistName:(NSString*)plistName;
-/*!
- @method     launchctlCommand
- @abstract   exec the launchctl command on a particular plist job
- @discussion <#(comprehensive description)#>
- */
-+(void) launchctlStringCommandAuth:(NSString*)operation option:(NSArray*)option plistName:(NSString*)plistName helper:(NSString *)helper withAuthRef:(AuthorizationRef)authRef;
 /*!
  @method     launchdJobState
  @abstract   check is a job has been submitted to launchd

src/platform/DARWIN/AFSPreference/PListManager.m

@@ -314,31 +314,6 @@
 		  arguments:argument];
 }
 
-// -------------------------------------------------------------------------------
-//  launchctlCommand:
-// -------------------------------------------------------------------------------
-+(void) launchctlStringCommandAuth:(NSString *)operation
-			    option:(NSArray *)option
-			 plistName:(NSString *)plistName
-			    helper:(NSString *)helper
-		       withAuthRef:(AuthorizationRef)authRef
-{
-	NSMutableArray *argument = [NSMutableArray array];
-
-	//set the load unload
-	[argument addObject:operation];
-
-	//if there are load the user custom option
-	if(option) [argument addObjectsFromArray:option];
-
-	//construct the path
-	[argument addObject: plistName];
-
-	//exec the command
-	[TaskUtil executeTaskWithAuth:@"/bin/launchctl"
-		  arguments:argument helper:helper withAuthRef:authRef];
-}
-
 // -------------------------------------------------------------------------------
 //  launchdJobState:
 // -------------------------------------------------------------------------------

src/platform/DARWIN/AFSPreference/TaskUtil.h

@@ -17,7 +17,5 @@
 +(NSString*) searchExecutablePath:(NSString*)unixCommand;
 +(NSString*) executeTaskSearchingPath:(NSString*)unixCommand args:(NSArray*)args;
 +(NSString*) executeTask:(NSString*) taskName arguments:(NSArray *)args;
-+(int) executeTaskWithAuth:(NSString*) taskName arguments:(NSArray *)args authExtForm:(NSData*)auth;
-+(int) executeTaskWithAuth:(NSString*) taskName arguments:(NSArray *)args helper:(NSString *)helper withAuthRef:(AuthorizationRef)authRef;
 +(int) executePrivTask:(const char *)task;
 @end

src/platform/DARWIN/AFSPreference/TaskUtil.m

@@ -75,81 +75,6 @@
 	return [result autorelease];
 }
 
-
-// -------------------------------------------------------------------------------
-//  executeTask:
-// -------------------------------------------------------------------------------
-+(int) executeTaskWithAuth:(NSString*) taskName arguments:(NSArray *)args helper:(NSString *)helper withAuthRef:(AuthorizationRef)authRef {
-    const char *rootHelperApp = [helper fileSystemRepresentation];
-    OSStatus status;
-    AuthorizationFlags flags = kAuthorizationFlagDefaults;
-    int count = [args count];
-    char **myArguments = calloc(count + 2, sizeof(char *));
-    int i=0;
-
-    myArguments[0] = strdup([taskName UTF8String]);
-    for(i=0;i < count;i++) {
-	const char *string = [[args objectAtIndex:i] UTF8String];
-	if(!string)
-	    break;
-	myArguments[1+i] = strdup(string);
-    }
-    myArguments[1+i] = NULL;
-
-    // should use SMJobBless but we need to sign things...
-    status = AuthorizationExecuteWithPrivileges(authRef, rootHelperApp, flags, myArguments, NULL);
-
-    i = 0;
-    while (myArguments[i] != NULL) {
-        free(myArguments[i]);
-        i++;
-    }
-
-    free(myArguments);
-    return status;
-}
-
-+(int) executeTaskWithAuth:(NSString*) taskName arguments:(NSArray *)args authExtForm:(NSData*)auth {
-	NSString *result = nil;
-	int status = 0;
-	NSFileHandle *file = nil;
-	NSDictionary *environment =  [NSDictionary dictionaryWithObjectsAndKeys: @"$PATH:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin",@"PATH",nil];
-	
-	NSPipe *pipe = [NSPipe pipe];
-	NSPipe *pipeIn = [NSPipe pipe];
-	NSTask *taskToRun  = [[NSTask alloc] init];
-	
-	[taskToRun setLaunchPath: taskName];
-	[taskToRun setArguments: args];
-	[taskToRun setEnvironment:environment];
-	[taskToRun setStandardOutput: pipe];
-	[taskToRun setStandardInput: pipeIn];
-	file = [pipe fileHandleForReading];
-	//Write to standard in
-	[taskToRun launch];
-	
-	NSFileHandle* taskInput = [[ taskToRun standardInput ] fileHandleForWriting ];
-	[taskInput writeData:auth];
-	[taskToRun waitUntilExit];
-	status = [taskToRun terminationStatus];
-	if (status == 0){
-		NSData *data = [file readDataToEndOfFile];
-		// remove the \n character from unix command
-		if([data length] > 0){
-			NSData *realData = [NSData dataWithBytes:[data bytes] 
-											  length:[data length]-1];
-			
-			[taskToRun release];
-			result = [[NSString alloc] initWithData: realData 
-										   encoding: NSUTF8StringEncoding];
-			[result release];
-		}
-	} else {
-	}
-	
-	return status;
-}
-
 /**
  * Perform a task that requires root access via privhelper.
  *

src/platform/DARWIN/PrivilegedHelper/privhelper.c

@@ -29,6 +29,9 @@
 #include <syslog.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <spawn.h>
 
 #include <xpc/xpc.h>
 #include <Security/Security.h>
@@ -39,7 +42,11 @@
 
 #include <xpc/xpc.h>
 
+#define LAUNCHCTL   "/bin/launchctl"
+
 #define PRIVHELPER_ID	"org.openafs.privhelper"
+#define AFS_ID		"org.openafs.filesystems.afs"
+#define AFS_PLIST	"/Library/LaunchDaemons/org.openafs.filesystems.afs.plist"
 
 /*
  * This is the code signing requirement imposed on anyone that connects to our
@@ -157,10 +164,81 @@ SecCodeCreateWithXPCMessage(xpc_object_t event, SecCSFlags secflags, SecCodeRef
 }
 #endif /* !HAVE_SECCODECREATEWITHXPCMESSAGE */
 
+static int
+RunCommand(int log_failure, const char *arg1, const char *arg2,
+	   const char *arg3, const char *arg4)
+{
+    extern char **environ;
+    pid_t pid;
+    int code;
+    int status;
+    const char *argv[] = {
+	arg1, arg2, arg3, arg4, NULL
+    };
+
+    code = posix_spawn(&pid, argv[0], NULL, NULL, argv, environ);
+    if (code != 0) {
+	syslog(LOG_ERR, "%s: Failed to execute %s, error %d", PRIVHELPER_ID,
+	       argv[0], code);
+	return -1;
+    }
+
+    code = waitpid(pid, &status, 0);
+    if (code <= 0) {
+	syslog(LOG_ERR, "%s: waitpid for %s failed, error %d/%d",
+	       PRIVHELPER_ID, argv[0], code, errno);
+	return -1;
+    }
+
+    if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+	/* Command exited successfully. */
+	return 0;
+    }
+
+    if (log_failure) {
+	syslog(LOG_WARNING, "%s: Command %s failed, status %d",
+	       PRIVHELPER_ID, argv[0], status);
+    }
+
+    return status;
+}
+
+/**
+ * Run the requested privileged task.
+ *
+ * We implement the following tasks:
+ *
+ * - startup_enable: Run "launchctl load" to configure the OpenAFS client to
+ *   run at startup.
+ *
+ * - startup_disable: Run "launchctl unload" to configure the OpenAFS client to
+ *   not run at startup.
+ *
+ * - startup_check: Run "launchctl list" to check whether OpenAFS is configured
+ *   to run at startup. If it is, return 0; otherwise, return nonzero.
+ *
+ * @param[in] task	The name of the requested task.
+ * @param[in] event	The XPC dictionary containing other task-specific
+ *			arguments.
+ *
+ * @returns Return status of the task
+ * @retval 0 success
+ * @retval -1 internal error
+ * @retval nonzero The return value of system() of a failed command for the
+ *                 task.
+ */
 static int
 ProcessRequest(const char *task, xpc_object_t event)
 {
-    /* Tasks we understand will be added here as they are implemented. */
+    if (strcmp(task, "startup_enable") == 0) {
+	return RunCommand(1, LAUNCHCTL, "load", "-w", AFS_PLIST);
+
+    } else if (strcmp(task, "startup_disable") == 0) {
+	return RunCommand(1, LAUNCHCTL, "unload", "-w", AFS_PLIST);
+
+    } else if (strcmp(task, "startup_check") == 0) {
+	return RunCommand(0, LAUNCHCTL, "list", AFS_ID, NULL);
+    }
 
     syslog(LOG_WARNING, "%s: Received unknown task '%s'", PRIVHELPER_ID, task);