November 2011 - launchd-dev - lists.macosforge.org

SMJobBless and plugins
by Jérome Laurens 25 Nov '11

25 Nov '11

Hi, I need to run an authorized tool from a preference pane. Actually, SMJobBless sample code explains how to install and run a tool from an application but it seems to me that it can't work for a plugin. A workaround I can see is to ship the preference pane with an installer app that contains the daemon. But I have no real idea of the security concerns of such a design. Any hint ? Thanks in advance JL

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The MachService key
by Jerry Krinock 23 Nov '11

23 Nov '11

In trying to understand how a process works, I found a launchd plist with a MachService key. From launchd.plist(5), I learn that that this is to "specify Mach services to be registered with the Mach bootstrap sub-system". I know a little about the Mach bootstrap sub-system, but I can't find much information about Mach services. Does anyone know a book or other resource where I could learn about Mach services? Thanks, Jerry Krinock

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Re: [launchd-dev] The MachService key
by Rainer Brockerhoff 22 Nov '11

22 Nov '11

On 22/11/2011, at 13:00, launchd-dev-request(a)lists.macosforge.org wrote: > Date: Tue, 22 Nov 2011 10:02:56 +0000 > From: "Quinn \"The Eskimo!\"" <eskimo1(a)apple.com> > Message-ID: <86B0B3BF-8627-40C7-9B29-24A38F3608E8(a)apple.com> > > XPC makes this much easier. Much of the focus of XPC is in providing XPC services, that is, small chunks of code that you include in an app that you can talk to from the app. This makes certain security tasks (sandboxing, privilege separation) much easier. However, it's also possible to use XPC to talk to a launchd daemon. > > With the above in mind, is taking a dependency on 10.7 feasible or not? If it is, I can explain how you can use XPC to talk to a launchd daemon via the MachServices key. I'll have a situation - 10.7 (and successors) only - where I'd like to talk to my launchd daemon, both from an app and perhaps from an XPC service launched by that app. Messages could be either NS/CFDictionaries or a blob of binary data. I'm not particularly set on using MachServices, or CFMessagePort, or whatever; but it would be helpful if you, in that explanation, could mention what the easiest (or more reliable?) API for doing so on Lion. Thanks, -- Rainer Brockerhoff <rainer(a)brockerhoff.net> Belo Horizonte, Brazil "In the affairs of others even fools are wise In their own business even sages err." Weblog: http://www.brockerhoff.net/blog

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launchd.plist & SMJobBless
by Jérome Laurens 04 Nov '11

04 Nov '11

Hi list, I have problems in removing calls to AuthorizationExecuteWithPrivileges. So far I played with both SMJobBless and ssd (simple socket daemon) sample codes and I am happy with them separately. I also played successfully with unix sockets but now time has come to put everything altogether. For ssd, we have to install in /Library/LaunchDaemons a custom plist containing definitions of a Socket that will be used to launch the daemon on demand. For SMJobBless, we seem to have no hand on the plist, except for the Label key. Every other key seems to be ignored by SMJobBless. The question is: what is the recipe to tell launchd to launch a daemon installed through SMJobBless ? Thanks in advance & regards J. Laurens

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Loading WatchPath job: Launches if path changed within prior 0.5 secs
by Jerry Krinock 03 Nov '11

03 Nov '11

STEPS TO REPRODUCE: • Install a launchd plist file, with a single WatchPaths parameter, but do not load it. • Touch the watched path • Load the job EXPECTED RESULT: Nothing should happen, because the file was touched *before* the job was loaded. ACTUAL RESULT: The job launches its program. * * * If I insert a slight wait between touching and loading, the job does not launch. In the script which follows, the threshold wait is about 0.5 seconds. In an application I've written, which invokes launchctl via NSTask, the threshold wait is 1-2 seconds. This seems to be a bug in launchd (Mac OS X 10.7.2)? You can demo it by running the following shell script. The script attempts to experiment with different wait (sleep) values, but unexpectedly, only the first run of the function doTest ever "launches". • If the first sleep value is about 0.4 or less, I get one "launch". • If it's 0.5, I may or may not get one "launch". • If it's 0.6 or more, I get zero "launches". • Playing with the other sleep values in the script does not affect the results. • Probably, the first time you run the script, there is no "launch". Retry. As you can see, there's a lot which does not make sense here. Any explanations of this behavior would be appreciated. Thanks, Jerry Krinock #!/bin/bash OUR_AGENT_LABEL=TestLoadUnload OUR_TOUCH_FILE=TestTouch.txt function isAgentLoaded { let IS_LOADED=`launchctl list | grep -c $OUR_AGENT_LABEL` echo "Our agent loaded = $IS_LOADED" } function doTest { isAgentLoaded # Touch watched file touch ~/Desktop/$OUR_TOUCH_FILE.txt echo "Did touch" sleep $SLEEPY_TIME echo "Slept for $SLEEPY_TIME" # Load Agent launchctl load $OUR_AGENT_LABEL.plist echo "Did load" sleep 1 isAgentLoaded sleep 1 # Unload Agent launchctl unload $OUR_AGENT_LABEL.plist echo "Did unload" # Wait sleep 1 } # Create a small text file which launchd will watch cd ~/Desktop echo "This is a test" > $OUR_TOUCH_FILE cd ~/Library/LaunchAgents # Install a launchd plist file which will define our Agent echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" > $OUR_AGENT_LABEL.plist echo "<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\"" >> $OUR_AGENT_LABEL.plist echo "\"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">" >> $OUR_AGENT_LABEL.plist echo "<plist version=\"1.0\">" >> $OUR_AGENT_LABEL.plist echo "<dict>" >> $OUR_AGENT_LABEL.plist echo " <key>Label</key>" >> $OUR_AGENT_LABEL.plist echo " <string>$OUR_AGENT_LABEL</string>" >> $OUR_AGENT_LABEL.plist echo " <key>ProgramArguments</key>" >> $OUR_AGENT_LABEL.plist echo " <array>" >> $OUR_AGENT_LABEL.plist echo " <string>osascript</string>" >> $OUR_AGENT_LABEL.plist echo " <string>-e</string>" >> $OUR_AGENT_LABEL.plist echo " <string>say \"Launched!\"</string>" >> $OUR_AGENT_LABEL.plist echo " </array>" >> $OUR_AGENT_LABEL.plist echo " <key>ThrottleInterval</key>" >> $OUR_AGENT_LABEL.plist echo " <integer>1</integer>" >> $OUR_AGENT_LABEL.plist echo " <key>WatchPaths</key>" >> $OUR_AGENT_LABEL.plist echo " <array>" >> $OUR_AGENT_LABEL.plist echo " <string>$HOME/Desktop/$OUR_TOUCH_FILE</string>" >> $OUR_AGENT_LABEL.plist echo " </array>" >> $OUR_AGENT_LABEL.plist echo "</dict>" >> $OUR_AGENT_LABEL.plist echo "</plist>" >> $OUR_AGENT_LABEL.plist # Begin actual testing SLEEPY_TIME=0.1 doTest SLEEPY_TIME=0.2 doTest SLEEPY_TIME=0.3 doTest SLEEPY_TIME=0.4 doTest SLEEPY_TIME=0.5 doTest SLEEPY_TIME=0.6 doTest

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