DARWIN: Convert prefpane write ops to privhelper

Convert the prefpane logic for writing to config files to use
privhelper, so it can work with macOS 10.8+. With this commit, the
"CellServDB Editor" and "Parameter" tabs in the prefpane should now
work.

Specifically, define the privhelper task "write". Define a new variant
to TaskUtil's executePrivTask() called executePrivTaskWrite() to use the
new task type, and convert the prefpane code to use it.

Most files are straightforward, but converting writeAfsdOption() is a
little awkward due to the repeated checking of useAfsdConfVersion. Just
remove the writeAfsdOption() method and make the caller choose between
writeNewAfsdOption() and writeOldAfsdOption().

The new "write" task takes a new argument (data) to indicate what data
to write to the config file in question. Like the "backup" task, it also
takes a "filename" argument that is checked against our list of config
files.

Change-Id: Ib93da5a75a92e3507c15f9ee03eb8f7fbad7d088
Reviewed-on: https://gerrit.openafs.org/15960
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/AFSPropertyManager.h

@@ -258,10 +258,9 @@
 /*!
  @function	 writeCacheInfo
  @abstract   Write the cache info down the file
- @param      filePath where to write the CacheInfo
  @result     return the execution error
  */
--(int) writeCacheInfo:(NSString*)filePath;
+-(int) writeCacheInfo;
 
 /*!
  @function	 readAfsdOption
@@ -292,14 +291,6 @@
  @param      filePath path of the new file with afs.conf file format
  */
 -(int) readNewAfsdOption:(NSString*)filePath;
-/*!
- @function	 writeAfsdOption
- @abstract   <#(description)#>
- @discussion <#(description)#>
- @param      <#(name) (description)#>
- @result     <#(description)#>
- */
--(int) writeAfsdOption:(NSString*)filePath;
 /*!
  @function	 writeOldAfsdOption
  @abstract   Write the cache manager parameter to file
@@ -307,13 +298,12 @@
  @param      filePath file path for file to write into
  @result     <#(description)#>
  */
--(int) writeOldAfsdOption:(NSString*)filePath;
+-(int) writeOldAfsdOption;
 /*!
  @function	 writeNewAfsdOption
  @abstract   Write the cache parameter to a file with the new format
- @param      filePath file path where write into
  */
--(int) writeNewAfsdOption:(NSString*)filePath;
+-(int) writeNewAfsdOption;
 /*!
  @function	 getAfsVersion
  @abstract   Return the string representing the afs version

src/platform/DARWIN/AFSPreference/AFSPropertyManager.m

@@ -402,7 +402,7 @@
 // -------------------------------------------------------------------------------
 //  writeCacheInfo:
 // -------------------------------------------------------------------------------
--(int) writeCacheInfo:(NSString*)filePath
+-(int) writeCacheInfo
 {
 	NSNumber *tmpNum = nil;
 	NSMutableString *cacheInfoContent = [[NSMutableString alloc] init];
@@ -427,10 +427,7 @@
 									 userInfo:nil];
 	[cacheInfoContent appendString:[tmpNum stringValue]];
 	
-	[cacheInfoContent writeToFile: [filePath stringByExpandingTildeInPath]
+	[TaskUtil executePrivTaskWrite:@"/etc/cacheinfo" data:cacheInfoContent];
-					   atomically: YES 
-						 encoding: NSASCIIStringEncoding 
-							error: nil];
 	
 	[cacheInfoContent release];
 	return noErr;
@@ -580,31 +577,10 @@
 }
 
 
-// -------------------------------------------------------------------------------
-//  writeCacheInfo:
-// -------------------------------------------------------------------------------
--(int) writeAfsdOption:(NSString*)filePath
-{
-	int result = 0;
-	@try{
-		if(useAfsdConfVersion) {
-			result = [self writeNewAfsdOption:filePath];			
-		} else {
-			result = [self writeOldAfsdOption:filePath];
-		}
-		
-	}@catch(NSException *e){
-		@throw e;
-	}@finally{
-		
-	}
-	return result;
-}
-
 // -------------------------------------------------------------------------------
 //  writeOldAfsdOption:
 // -------------------------------------------------------------------------------
--(int) writeOldAfsdOption:(NSString*)filePath;
+-(int) writeOldAfsdOption
 {
 	NSMutableString *oldConfFileContent = [[[NSMutableString alloc] init] autorelease];
 	//add afsd param
@@ -614,12 +590,9 @@
 	[oldConfFileContent appendString:@"\n"];
 	
 	//write content on file
-	[oldConfFileContent writeToFile: [filePath stringByExpandingTildeInPath]
+	[TaskUtil executePrivTaskWrite:AFSD_OLD_PREFERENCE_FILE data:oldConfFileContent];
-						 atomically: YES 
+
-						   encoding: NSASCIIStringEncoding 
-							  error: nil];
 	return noErr;
-	
 }
 
 // -------------------------------------------------------------------------------
@@ -629,7 +602,7 @@
 //  AFS_POST_INIT=afs_server_prefs
 //  AFS_PRE_SHUTDOWN=
 // -------------------------------------------------------------------------------
--(int) writeNewAfsdOption:(NSString*)filePath
+-(int) writeNewAfsdOption
 {
 	NSMutableString *newConfFileContent = [[[NSMutableString alloc] init] autorelease];
 	
@@ -652,10 +625,8 @@
 	[newConfFileContent appendString:@"\n"];
 	
 	//Write to file
-	[newConfFileContent writeToFile: [filePath stringByExpandingTildeInPath]
+	[TaskUtil executePrivTaskWrite:AFSD_NEW_PREFERENCE_FILE data:newConfFileContent];
-						 atomically: YES 
+
-						   encoding: NSASCIIStringEncoding 
-							  error: nil];
 	return noErr;
 }
 
@@ -1108,8 +1079,6 @@
 // -------------------------------------------------------------------------------
 -(void) saveConfigurationFiles:(BOOL) makeBackup
 {
-	NSError *err;
-	NSMutableString *filePath = [[NSMutableString alloc] initWithCapacity:256];
 	NSMutableString *cellServDBString = [[NSMutableString alloc] initWithCapacity:256];
 	NSMutableString *theseCellString = [[NSMutableString alloc] initWithCapacity:256];
 	DBCellElement *cellElement = nil;
@@ -1118,14 +1087,6 @@
 	@try{
 		[self exceptionOnInvalidPath];
 
-		// ThisCell
-		[filePath setString: @"/tmp/ThisCell"];
-		[cellName writeToFile: [filePath stringByExpandingTildeInPath]
-				   atomically:YES 
-					 encoding: NSASCIIStringEncoding 
-						error:nil];
-		// CellServDB
-		
 		for(int idx = 0; idx < [cellList count]; idx++){
 			cellElement = [cellList objectAtIndex:idx];
 			[cellServDBString appendString:[cellElement description]];
@@ -1135,45 +1096,18 @@
 			}
 		}
 		
-		
-		[filePath setString: @"/tmp/CellServDB"];
-		[cellServDBString writeToFile: [filePath stringByExpandingTildeInPath]
-						   atomically:YES 
-							 encoding:  NSUTF8StringEncoding 
-								error:&err];
-		
-		[filePath setString: @"/tmp/TheseCells"];
-		[theseCellString writeToFile: [filePath stringByExpandingTildeInPath]
-						   atomically:YES 
-							 encoding:  NSUTF8StringEncoding 
-								error:&err];
-		
 		if(makeBackup) [self backupConfigurationFiles];
 
-		// install ThisCell
+		[TaskUtil executePrivTaskWrite:@"/etc/ThisCell" data:cellName];
-		[filePath setString: installationPath];
+		[TaskUtil executePrivTaskWrite:@"/etc/CellServDB" data:cellServDBString];
-		[filePath appendString: @"/etc/ThisCell"];
+		[TaskUtil executePrivTaskWrite:@"/etc/TheseCells" data:theseCellString];
-		[self installConfigurationFile:@"/tmp/ThisCell" 
-							  destPath:filePath];		
-		
-		// install CellServDB
-		[filePath setString: installationPath];
-		[filePath appendString: @"/etc/CellServDB"];
-		[self installConfigurationFile:@"/tmp/CellServDB" 
-							  destPath:filePath];
-		
-		// install CellServDB
-		[filePath setString: installationPath];
-		[filePath appendString: @"/etc/TheseCells"];
-		[self installConfigurationFile:@"/tmp/TheseCells" 
-							  destPath:filePath];
 		
 	} @catch (NSException *e) {
 		@throw e;
 	}@finally {
 		// dispose all variable used
-		if(filePath) [filePath release];
 		if(cellServDBString) [cellServDBString release];
+		if(theseCellString) [theseCellString release];
 	}
 	
 }
@@ -1188,12 +1122,6 @@
 	@try{
 		[self exceptionOnInvalidPath];
 		
-		// cacheinfo file creation
-		[self writeCacheInfo:@"/tmp/cacheinfo"];
-		
-		//afsd.option or afs.conf file creation
-		[self writeAfsdOption:useAfsdConfVersion?AFSD_TMP_NEW_PREFERENCE_FILE:AFSD_TMP_OLD_PREFERENCE_FILE];
-		
 		// backup original file
 		if(makeBackup) {
 			//cacheinfo
@@ -1206,18 +1134,17 @@
 			    [TaskUtil executePrivTaskBackup:AFSD_OLD_PREFERENCE_FILE];
 			}
 		}
+
+		// cacheinfo
+		[self writeCacheInfo];
 		
-		// install cacheinfo
+		if (useAfsdConfVersion) {
-		[filePath setString:installationPath];
+		    // afs.conf
-		[filePath appendString: @"/etc/cacheinfo"];
+		    [self writeNewAfsdOption];
-		[self installConfigurationFile:@"/tmp/cacheinfo" 
+		} else {
-							  destPath:filePath];		
+		    // afsd.options
-		
+		    [self writeOldAfsdOption];
-		// install afsd.conf or afs.conf configuration file 
+		}
-		[filePath setString: installationPath];
-		[filePath appendString: useAfsdConfVersion?AFSD_NEW_PREFERENCE_FILE:AFSD_OLD_PREFERENCE_FILE];
-		[self installConfigurationFile:useAfsdConfVersion?AFSD_TMP_NEW_PREFERENCE_FILE:AFSD_TMP_OLD_PREFERENCE_FILE
-							  destPath:filePath];
 		
 	} @catch (NSException *e) {
 		@throw e;

src/platform/DARWIN/AFSPreference/TaskUtil.h

@@ -17,7 +17,8 @@
 +(NSString*) searchExecutablePath:(NSString*)unixCommand;
 +(NSString*) executeTaskSearchingPath:(NSString*)unixCommand args:(NSArray*)args;
 +(NSString*) executeTask:(NSString*) taskName arguments:(NSArray *)args;
-+(int) executePrivTask:(const char *)task filename:(char *)filename;
++(int) executePrivTask:(const char *)task filename:(char *)filename data:(char *)data;
 +(int) executePrivTask:(const char *)task;
 +(int) executePrivTaskBackup:(NSString *)filename;
++(int) executePrivTaskWrite:(NSString *)filename data:(NSString *)data;
 @end

src/platform/DARWIN/AFSPreference/TaskUtil.m

@@ -85,8 +85,11 @@
  *
  * @param[in] task  The name of the task to perform (e.g. "startup_enable").
  *		    See privhelper.c:ProcessRequest for what tasks we define.
- * @param[in] filename	Used for the "backup" task. Don't specify this with
+ * @param[in] filename	Used for the "backup"/"write" tasks. Don't specify this with
- *			executePrivTask; use executePrivTaskBackup instead.
+ *			executePrivTask; use executePrivTaskBackup or
+ *			executePrivTaskWrite instead.
+ * @param[in] data	Used for the "write" task. Don't specify this with
+ *			executePrivTask; use executePrivTaskWrite instead.
  *
  * @returns Return status of the task
  * @retval 0 success
@@ -94,7 +97,7 @@
  * @retval nonzero The return value of system() of a failed command for the
  *                 task.
  */
-+(int) executePrivTask:(const char *)task filename:(char *)filename {
++(int) executePrivTask:(const char *)task filename:(char *)filename data:(char *)data {
     int status = -1;
 
     OSErr autherr = [[AuthUtil shared] autorize];
@@ -140,6 +143,9 @@
     if (filename != NULL) {
 	xpc_dictionary_set_string(msg, "filename", filename);
     }
+    if (data != NULL) {
+	xpc_dictionary_set_string(msg, "data", data);
+    }
 
     xpc_object_t reply = xpc_connection_send_message_with_reply_sync(conn, msg);
     if (reply == NULL) {
@@ -166,10 +172,14 @@
 }
 
 +(int) executePrivTask:(const char *)task {
-    return [self executePrivTask:task filename:NULL];
+    return [self executePrivTask:task filename:NULL data:NULL];
 }
 
 +(int) executePrivTaskBackup:(NSString *)filename {
-    return [self executePrivTask:"backup" filename:[filename UTF8String]];
+    return [self executePrivTask:"backup" filename:[filename UTF8String] data:NULL];
+}
+
++(int) executePrivTaskWrite:(NSString *)filename data:(NSString *)data {
+    return [self executePrivTask:"write" filename:[filename UTF8String] data:[data UTF8String]];
 }
 @end

src/platform/DARWIN/PrivilegedHelper/privhelper.c

@@ -293,6 +293,68 @@ BackupFile(const char *filename)
     return code;
 }
 
+/*
+ * Writes the given "data" into "filename".
+ */
+static int
+WriteFile(const char *filename, const char *data)
+{
+    int code;
+    char *path = NULL;
+    char *tmp_path = NULL;
+    FILE *fh = NULL;
+
+    path = GetFullPath("write", filename);
+    if (path == NULL) {
+	goto error;
+    }
+
+    code = asprintf(&tmp_path, "%s.tmp", path);
+    if (code < 0) {
+	tmp_path = NULL;
+	mem_error();
+	goto error;
+    }
+
+    fh = fopen(tmp_path, "w");
+    if (fh == NULL) {
+	code = errno;
+	syslog(LOG_WARNING, "%s: Cannot open %s for writing, errno %d",
+	       PRIVHELPER_ID, tmp_path, code);
+	goto error;
+    }
+
+    if (fputs(data, fh) == EOF) {
+	syslog(LOG_ERR, "%s: Error writing to %s", PRIVHELPER_ID, tmp_path);
+	goto error;
+    }
+
+    if (fclose(fh) == EOF) {
+	syslog(LOG_ERR, "%s: Error closing %s", PRIVHELPER_ID, tmp_path);
+	goto error;
+    }
+    fh = NULL;
+
+    code = RunCommand(1, "/usr/sbin/chown", "root:wheel", tmp_path, NULL);
+    if (code != 0) {
+	goto done;
+    }
+
+    code = RunCommand(1, "/bin/mv", "-f", tmp_path, path);
+
+ done:
+    free(path);
+    free(tmp_path);
+    if (fh != NULL) {
+	fclose(fh);
+    }
+    return code;
+
+ error:
+    code = -1;
+    goto done;
+}
+
 /**
  * Run the requested privileged task.
  *
@@ -314,6 +376,9 @@ BackupFile(const char *filename)
  * - backup: Make a backup copy of the configuration file named in the argument
  *   "filename". This copies file "X" to "X.afscommander_bk".
  *
+ * - write: Write data to a given file. The filename is given in the argument
+ *   "filename"; the data to write is in the argument "data".
+ *
  * @param[in] task	The name of the requested task.
  * @param[in] event	The XPC dictionary containing other task-specific
  *			arguments.
@@ -349,6 +414,24 @@ ProcessRequest(const char *task, xpc_object_t event)
 	    return -1;
 	}
 	return BackupFile(filename);
+
+    } else if (strcmp(task, "write") == 0) {
+	const char *filename;
+	const char *data;
+
+	filename = xpc_dictionary_get_string(event, "filename");
+	if (filename == NULL) {
+	    syslog(LOG_WARNING, "%s: Task 'write' missing filename", PRIVHELPER_ID);
+	    return -1;
+	}
+
+	data = xpc_dictionary_get_string(event, "data");
+	if (data == NULL) {
+	    syslog(LOG_WARNING, "%s: Task 'write' missing data", PRIVHELPER_ID);
+	    return -1;
+	}
+
+	return WriteFile(filename, data);
     }
 
     syslog(LOG_WARNING, "%s: Received unknown task '%s'", PRIVHELPER_ID, task);