January 2008 - launchd-dev - lists.macosforge.org

~/LaunchAgent + KeepAlive=true = Login Jail
by James Bucanek 31 Jan '08

31 Jan '08

Greetings, I have a user launch agent (~/Library/LaunchAgents) that has KeepAlive set to true. The launch agent is a Cocoa application, UIElement=YES. It provides a small status window to the user. I want this application to run all of the time, which is why the KeepAlive property was set. Whenever my application quits, launchd restarts it (as one would expect). The problem is that when the user tries to log out, the agent quits, launchd immediately restarts it, and the user gets a nasty message that the logout/restart/shutdown was canceled by my application. [There's clearly an amusing race condition: Once it's down to the Finder, launchd, my application and maybe one or two other small applications, the system manages to log out by killing my app and launchd before launchd has a chance to restart my application again.] Anyway, is there a workaround for this or do I just have to abandon KeepAlive? -- James Bucanek

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User agent modified file check for all users?
by Galen Sprague 30 Jan '08

30 Jan '08

Hey All, I had a question about creating a User Agent for multiple users in Lingon. Is there a way to set the When:Run it if this file is modified as: ~/Library/Preferences/com.systempreferences.plist instead of /Users/loggedInUser/LibraryPreferences/com.apple.systempreferences.plist? It doesn¹t seem to recognize ~/Library This way my terminal command will run if any User¹s com.apple.systempreferences.plist is modified. Thank you very much! Galen Sprague Senior Analyst Technical ..: Apple Systems :.. Marketing IS Staples, Inc. 500 Staples Dr. Framingham, Ma 01702 galen.sprague(a)staples.com :.. 508-253-1374

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LaunchAgents, SecureSocketWithKey, and permissions
by Benjamin Reed 28 Jan '08

28 Jan '08

I've added launchd support to dbus (https://bugs.freedesktop.org/show_bug.cgi?id=14259) -- however, I have a problem with permissions if I try to use it on 10.4. On 10.5, it creates the SecureSocketWithKey socket propertly, but on 10.4, it appears I have 2 sockets: 89990228 0 srwx------ 1 ranger wheel 0 Jan 26 14:44 /tmp/launch-Gi7nee/session 89990177 0 srwx------ 1 root wheel 0 Jan 26 14:42 /tmp/launch-xURB7Y/session ...but the one that gets set in the env var while logged in as ranger is the xURB7Y one. On a whim, I thought "hm, maybe I just need to reboot for launchd to grok it properly." On reboot, I've started a shell, and now the environment variable is not set at all. However, an lsof shows that the socket is being held by launchd: $ sudo lsof | grep /session launchd 158 ranger 9u unix 0x39cb220 0t0 /tmp/launch-7woJl9/session ...and ls shows it's owned properly: srwx------ 1 ranger wheel 0 Jan 26 15:09 /tmp/launch-7woJl9/session Any idea what I need to do to make things set up properly? Do I need to set it to KeepAlive or OnDemand=false to make it initialize right, maybe? -- Benjamin Reed a.k.a. Ranger Rick Fink, KDE, and Mac OS X development http://www.racoonfink.com/

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Agent started two different was, two different bootstraps?
by James Bucanek 28 Jan '08

28 Jan '08

Hello again, I've got a persistent oddity. I have a drag-install application that automatically installs a couple of launch agents with configuration plists (in ~/Library/LaunchAgents/). The processes and my GUI Cocoa application all communicate using distributed objects via Mach ports. When the agents get installed the first time, I kick-start them using 'launchctl load ...'. The problem is this: The two launch agents are installed and started using launchctl load (running launchctl as the regular user). The Cocoa application then starts a helper process (using NSTask) which registers a named Mach port. Now at this point, I would think that all four processes should be running in the Auqa bootstrap (the Cocoa application, the agent, and the helper process). But the agent can't see/connect with the Mach port registered by the helper process. The application can see it, connect to it, and does its thing. But when one of the agents attempts to connect with the same helper process, they get an error. Here's the oddity: If I restart the computer things appear to work correctly. When they agents are started automatically as part of the user's login procedure, they all communicate with each other just fine. Am I loading the agents incorrectly? Is this a known problem, or do I have to try to develop a reproducible case and file a bug report?

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Re: [launchd-dev] Binding an individual user's agent to a privileged port
by Hamish Allan 28 Jan '08

28 Jan '08

On Jan 28, 2008 11:30 AM, Quinn <eskimo1(a)apple.com> wrote: > launchd agents are managed by the per-user launchds. Those launchds > have irrevocably dropped all privileges. Thus, there's no way for > them to be able to bind to a privileged port on your behalf. Good news for security. Bad news for my purposes! On Jan 28, 2008 11:30 AM, Quinn <eskimo1(a)apple.com> wrote: > At 22:23 +0000 23/1/08, Hamish Allan wrote: >>As far as I can tell, there are two ways of demonstrating to launchd >>that you have the authority to perform privileged operations such as >>binding to a port < 1024: putting a plist file in /Library/Launch*, or >>running launchctl sudo. > > I believe you mean "/Library/LaunchDaemons" and not > "/Library/Launch*". The latter would include agents (in > "/Library/LaunchAgents"), which are restricted as I've described > above. FWIW, I *did* mean /Library/Launch*: putting a file in /Library/LaunchAgents does demonstrate that you have the *authority* to perform privileged operations (because its permissions are the same as those of /Library/LaunchDaemons), but the architecture of launchd prevents this from being translated into actual privileges. On Jan 28, 2008 11:30 AM, Quinn <eskimo1(a)apple.com> wrote: > btw These two mechanism are fundamentally the same. > > o When you put a file in "/Library/LaunchDaemons", it is consulted by > the root launchd at system startup. > > o When you run launchctl using sudo, it always talks to the root launchd. > > Thus, in both cases the launchd job gets loaded into the root > launchd, which is the only one capable of binding to privileged ports. Aha. Makes sense. Good to know. Thanks, Hamish

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Binding an individual user's agent to a privileged port
by Hamish Allan 28 Jan '08

28 Jan '08

>From "Getting started with launchd" (http://developer.apple.com/macosx/launchd.html) "Of particular interest is that launchd can run a job as a non-root user, but still bind it to a privileged port. This removes one common reason to run daemons as root." Is it possible for a user agent to be bound to a privileged port? This might sound like an odd thing to do, but I wish to automatically mount a remote SMB share on my local machine using SSH port forwarding. Unfortunately, since Finder is too stupid to let me mount shares at alternative ports on localhost (it tells me that I should just access the files locally!) and mount_smbfs doesn't take a port argument, I need to bind the remote ports 139 and 445 to the same ports on my local machine. I want this as an agent rather than a daemon for the purposes of SSH key management. It needs to run as an agent in the GUI context when I log in, as this is where the automatic SSH_AUTH_SOCK facility in Leopard lives. As far as I can tell, there are two ways of demonstrating to launchd that you have the authority to perform privileged operations such as binding to a port < 1024: putting a plist file in /Library/Launch*, or running launchctl sudo. The former means that the operation would be executed for all users, and the latter is sort of missing the point of the original exercise (not to mention bringing file permissions problems of its own). Is what I am trying to do possible with launchd? Hamish

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launchd not loading for me in Leopard
by Eddy Martinez 19 Jan '08

19 Jan '08

Hello, I've been searching around and have not been able to find any hints. I have a plist, pref pane based app that fires off at a preset time. With Tiger its all good. However Leopard is failing to run the app at the scheduled time. Pasted are some errors that I hope will help to identify the problem. I'm not the developer, who is a contractor dealing with another deadline. I'm hoping to gather information on his behalf in order to expedite the resolution. I have access to the dev boxes and can run commands and capture any needed output. Any help appreciated, and thanks in advance, Eddy vmini01:~ $ cat /tmp/agentLauncher.stderr 2008-01-17 12:38:00.136 AgentLauncher[218:20b] Cannot checkin with launchd, exiting. 2008-01-17 14:14:00.032 AgentLauncher[323:20b] Cannot checkin with launchd, exiting. 2008-01-17 14:36:00.057 AgentLauncher[389:20b] Cannot checkin with launchd, exiting. vmini01:~ $ vmini01:~$ tail -f /var/log/system.log | grep devapp Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for array: excluded Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for boolean: Enabled Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for array: included Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key: ServiceDescription Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key: server Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for string: cistern Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key: bucket Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for integer: finish Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key for string: CustomerID Jan 18 10:54:44 vmini01 com.apple.launchd[1] (com.devapp.AgentLauncher): Unknown key: CustomerID vmini01:~ eddy$ sudo launchctl list | grep devapp - 1 com.devapp.AgentLauncher vmini01:~ $ ls -la /Library/LaunchDaemons/ total 8 drwxr-xr-x 3 root wheel 102 Jan 18 10:54 . drwxrwxr-t+ 46 root admin 1564 Sep 14 10:14 .. -rw-r--r-- 1 root wheel 1248 Jan 18 10:54 com.devapp.AgentLauncher.plist vmini01:~ $ -- Eddy Martinez fasteddy760(a)gmail.com

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Loading LaunchDaemons
by Jeremy Reichman 18 Jan '08

18 Jan '08

Do new jobs that are copied to a directory like /Library/LaunchDaemons get loaded automatically by the system at startup, so that they run when they would normally be scheduled? Or must we specifically load them with launchctl? I've looked back through the launchd and launchctl man pages and I don't see there whether a new job must be explicitly loaded, or if simply having it in the right directory at startup is enough to load/activate it. I have a custom LaunchDaemon which works fine when loaded -- I'm very enthusiastic about how well it works on Leopard vs. Tiger, because the job is scheduled to run when systems are typically asleep. The new behavior of running the job at wakeup is great. Anyway, on some systems (all of which are Intel-based Macs running 10.5.1 with all current updates except for iTunes 7.6 and QuickTime 7.4), the job I've installed does not and has not been running, even though the computers in question have been rebooted multiple times. It appears the job itself is not loading; when I grep for it in the long results of `launchctl list`, I don't see it. (Loading it manually does show that it is loaded, of course.) The LaunchDaemon file was installed by a simple copy -- actually, via the Radmind system management tool. Ergo, `launchctl load` was never explicitly run on it on any of the systems, but I seem to get different behavior -- some load it, some don't. (I'm still in the process of collecting information on where it works and where it doesn't.) Thanks! -- Jeremy

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launchd support ranges for StartCalendarInterval?
by Richard Glaser 17 Jan '08

17 Jan '08

FYI: Sorry, for this slightly off-topic.. Does launchd does support ranges say for "Days" in the StartCalendarInterval? For example, with cron if I wanted to run a script on the first & third Sunday of each month at 4 AM. I could use this code with a range... # minute hour mday month wday who command 0 4 1-7,15-21 * 0 root /path/to/script1 Then I could run another script the second & fourth Sunday of each month at 4 AM... # minute hour mday month wday who command 0 4 8-14,22-31 * 0 root /path/to/script2 Is this possible with launchd? Thanks: Richard Glaser University of Utah - Student Computing Labs richard(a)scl.utah.edu 801-585-8016

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A launchd blog post
by Dave Zarzycki 16 Jan '08

16 Jan '08

And while we are on the topic of the last email, I just created a blog post: http://launchd.macosforge.org/?p=5 Cheers, davez

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