Mailman 3 December 2007 - pypy-dev

Re: [pypy-dev] [pypy-svn] r49617 - pypy/branch/clr-module-improvements/pypy/module/clr
by Antonio Cuni Dec. 11, 2007

Dec. 11, 2007

Hi Amit, regmee(a)codespeak.net wrote: > + assembliesToScan = [ "/usr/lib/mono/1.0/mscorlib.dll", > + "/usr/lib/mono/1.0/System.dll", > + "/usr/lib/mono/1.0/System.Web.dll", > + "/usr/lib/mono/1.0/System.Data.dll", > + "/usr/lib/mono/1.0/System.Xml.dll", > + "/usr/lib/mono/1.0/System.Drawing.dll" > + ] > + assems = [] > + for assemblyName in assembliesToScan: > + assems.append(System.Reflection.Assembly.LoadFile(assemblyName)) sorry for bugging you again :-), but this is not what we want. We don't need to preload assemblies that the user might not want. For example, in IronPython to access the System.Xml namespace you need to explicitly load System.Xml.dll by using one of the clr.LoadAssembly* methods. Moreover, what happens if I wanto to load an assembly that it's not on this list? And what if I load an assembly after the list of namespaces has already been computed? I think what you need to do is to maintain a cache of valid namespaces, and check whether a new assembly has been loaded every time you import something. You can easily get the list of currently loaded assemblies by calling AppDomain.CurrentDomain.GetAssemblies(). ciao Anto

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Re: [pypy-dev] Sandboxing in Pypy and Crunchy
by Laura Creighton Dec. 10, 2007

Dec. 10, 2007

In a message of Sun, 09 Dec 2007 13:22:10 -0400, "Andre Roberge" writes: >Hello everyone, > >Please forget the intrusion but I did not know where else to ask this que >stion. Welcome. This is not an intrusion. You have come to the right place. You may want to start by reading this. http://codespeak.net/pypy/dist/pypy/doc/sandbox.html Cpython is the python you know and use, the one that is written in C. pypy-c is a pypy interpreter, which could be interpreting python, but could also be interpreting prolog, or javascript, or squeak -- and which produces as its output c code that you can run. Just so you don't confuse them as you are reading. > >Through my involvement with Google's Highly Open Participation >contest, I have learned about the sandboxing capabilities of pypy and, >I believe although I can't find it anymore, the ability to limit the >time allowed to a given process. Even if this last one is wrong, the >sandboxing capability is something I would be extremely interested in >using. > >The application I have in mind is Crunchy. In a nutshell: Crunchy >takes an arbitrary html page (with embedded Python code inside <pre> >tags) and transforms it so that the user can execute, in a variety of >ways, the Python code displayed in a browser (Firefox) window. It is >a different way to interact with code than the ones given as examples >on http://play1.codespeak.net/. > >Crunchy's user code (executed from the browser window) is not >sandboxed. I was wondering how difficult it would be to have it >sandboxed. > >Here are a few more specific questions: > >1 a. Is it possible to create a "sandboxed python interpreter" that >can be included as a module distributed with a cPython based program >(Crunchy) without having pypy included in the distribution? >1 b. If so, does that module has to be (pre-)compiled for a given >target machine? > >2. Is it possible to limit the time for a given process (as mentioned abo >ve)? > >Thank you in advance for anyone that can give me some information >regarding the above. If you feel this discussion is not appropriate >for this list, please do not hesitate to tell me so and perhaps answer >the questions "off-list". And, if the answers are simply: read this >URL, and try this example, it would be appreciated as well. > >Cheers, > >André This list is the appropriate place for this discussion. But so is #pypy on irc.freenode.net. There you can hold real conversations, so its often faster to figure things out by talking to us there. Can you post the details of the architecture of crunchy? Where does the student's code run? On the student's machine? or on the teacher's server machine? The ability to sandbox is a property of the architecture of pypy. It's not a module that you could port to Cpython. The person you want to sandbox has to be running pypy. Laura > >P.S. Crunchy's code is ... the work of two Python hobbyists ... and is >probably not worth looking at - I can probably clarify any specific >point needed to find out how it works, if needed to answer the >questions I raised, better by email than having anyone read its code. >_______________________________________________ >pypy-dev(a)codespeak.net >http://codespeak.net/mailman/listinfo/pypy-dev

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thunk object space : become() quirks
by Boris Borcic Dec. 10, 2007

Dec. 10, 2007

Hello, Looking for a way to use pypy in any manner, I came up with an idea for a deterministic sudoku solver that would use the 'become()' feature of the thunk object space. However, this doesn't work as I expected. The following shell trace illustrates my problem. Is this a bug or otherwise ? Can anybody explain ? BTW, I am using the pypy 1.0.0 build 41438 windows binary distribution. [subquestion : is pypy-dev appropriate for such a question ?] TIA, Boris Borcic >>>> s = lambda *x : set(x) >>>> s1 = s(1) >>>> s2 = s(2) >>>> s3 = s(3) >>>> s4 = s(4) >>>> s1,s2,s3,s4 (set([1]), set([2]), set([3]), set([4])) >>>> s1.update(s2) >>>> become(s2,s1) >>>> s3.update(s4) >>>> become(s4,s3) >>>> s1,s2,s3,s4 (set([1, 2]), set([1, 2]), set([3, 4]), set([3, 4])) >>>> s4.update(s2) >>>> s4 set([3, 4]) ------------------> expected set([1,2,3,4]) >>>> s2 set([1, 2]) >>>> s4 is s3 True >>>> s3.update(s2) >>>> s4 set([3, 4, 2]) ------------------> expected set([1,2,3,4]) >>>> s3 set([3, 4, 2]) >>>> s1 set([1, 2]) >>>> s1 is s2 True >>>> s3.update(s1) >>>> s4 set([3, 4, 2, 1]) >>>>

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Re: [pypy-dev] Sandboxing in Pypy and Crunchy
by Laura Creighton Dec. 10, 2007

Dec. 10, 2007

In a message of Sun, 09 Dec 2007 18:56:17 -0400, "Andre Roberge" writes: >Hi Laura, >Hmm, I'm not sure I can do that very well... the best I can do I >think is to describe what it does. > >1. Crunchy retrieves an html page. >2. It process it, removing pre-existing javascript and various >undesired html tags >3. It identifies where it needs to add custom elements (new html tags >& javascript code) >4. It feeds the page to the browser, leaving a line of communication >open, waiting for user instruction. > >At step 3. above, a new thread is started for each place in the page >where an interaction with a Python interpreter is required. >Following user interaction (click of a button or entering some code in >an html input box), the user code is fed back to the appropriate >interpreter (thread) and the result is sent back to the browser. If I >recall correctly, the interpreter used is a small variation from >code.py included in Python standard library. It is this part (I >believe) that needs to be sandboxed - a single module. I'm still confused. Once you have figured out "each place in the page where an interaction with a python interpreter is wanted" -- where do you want the python interpreter which runs that code to itself run? locally, on the same machine that has the browser? inside the browser? or do you open up a connection to some other machine -- yours, perhaps -- send the code there, and run it, and then send some sort of result back to the machine where the student is running the browser? Wherever this is, this is where you need to run pypy. And all of these are possible. You can run a sandboxed version of javascript -- a pypy with a javascript front end -- in your browser. You can even embed a sandboxed version of a python console in a browser. too. >> Where does >> the student's code run? On the student's machine? or on the teacher's >> server machine? > >Right now Crunchy is primarily used in a single user environment. It >would be possible to host it on a server, but it would be very >insecure to do so. Ideally it should be hosted in a secure way on a >server in most situations. Let me check one more thing -- are you running crunchy with the idea that every student has one host machine, and every host machine has one student? And crunchy runs standalone on each and every machine? So your sandbox is to protect the student from him or her self? Because that is what this sounds like to me. If so, then each student needs a pypy intepreter. But, usually, you want to sandbox somebody because the code they are running is on a machine they share with other users, especially a time sharing system where the other users could be using the machine simultaneously. Is this what you plan to do? Because, in that case, it is only the timesharing system that needs to be running pypy. And the students could connect to it using a crunchy-client that ran under Cpython. What is the part you want to sandbox? The code that parses the html page, looking for python code to run? (I don't think so, but I could be confused.) Or the actual python code it finds? >> The ability to sandbox is a property of the architecture of pypy. >> It's not a module that you could port to Cpython. The person you >> want to sandbox has to be running pypy. >> > >Darn :( I was hoping I could somehow just call a sandboxed >interpreter module .... Aha. Sandboxing is not something that you construct around the outside of arbitrary code. It is a function of the transation process itself. You need to construct a sandboxed version of pypy, and use that to run any code that you want sandboxed. When you run the special "pypy-c-sandbox" executable, instead of running any library or system calls, it instead marshals the operation name and the arguments to its stdout and it waits for the marshalled result on its stdin. Which means there has to be an 'other side' -- a separate process that reads the stdout and does something with it and then marshals it up and sends it back. This has 2 implications. First of all, if the other side hasn't been written with the ability to do something appropriate with a particular library or system call that is of interest to you, then we will have to write that part before the program will be of use. Not every python system call is supported now. We'd have to investigate to see if you need one that hasn't been written yet. And secondly, it is not the case that this second program, the other side, is written in such a way that it, in effect, says 'using my Godlike powers of understanding, I know that you, nasty person, just tried to break out of the sandbox using a buffer overflow! I won't allow that!! ' Instead, the reason that things are secure is that no matter what horrible things the other side is asked to deal with, the user is still waiting for something to come back to his stdin. If all you can do is read from stdin and write to stdout, then there is no ability to exploit whatever bug you are interested in. You discover that when some other process attempted to run the nasty code you typed in, it generated a fatal RPython error. That doesn't help you use the error. Thus, no cleverness and Godlike understanding is required. >Then again, it means that I'll have to try >pypy myself, and play with it - something I meant to do ... but did >not for lack of time. It also makes it more of a burden on potential >users if they have to install pypy in addition to Crunchy. Maybe over Christmas -- if there is no pyContest for the shortest python program to do something -- we could work together on getting a sandboxed-server version of crunchy working. You wouldn't have any more trips to Switzerland planned, either, would you? Because we could probably get together over a weekend around a trip like that, too. And there is always PyCon. > >Thanks for your clarifications, Any time. > >> Laura >> > >PS. Yes, Laura, it is cold and there is snow (unusual at this time of >the year) in your beloved Nova Scotia ;-) You _really_ know how to make a person want to go home. :-( Enjoy it for those of us who cannot. Nothing but rain around here in Göteborg. Bah! Where's the real winter? PS. It's a _very polite and friendly_ irc channel. I promise.

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Re: [pypy-dev] pypy and crunchy
by Maciej Fijalkowski Dec. 10, 2007

Dec. 10, 2007

(I've tried sending this mail from genesilico, but failed) Hi Andre. I think there is a bit of confusion. The ideal way would be to run crunchy on top of cpython and fork a new process with sandboxed pypy. Sandboxing works slightly different than import sandbox; sandbox.interact(), hence even on top of pypy it would be hard to run one sadboxed thread and other not sandboxed (I cannot really think about feasible solution). So this looks like you would need to distribute pypy as a compiled interpreter. This is the way play1 is done, it forks and runs different process for each interpreter (without sandboxing, it's older than those features). Although as I said before play1 is just a hack to make demos work, nothing more :) Cheers, fijal

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Sandboxing in Pypy and Crunchy
by Andre Roberge Dec. 9, 2007

Dec. 9, 2007

Hello everyone, Please forget the intrusion but I did not know where else to ask this question. Through my involvement with Google's Highly Open Participation contest, I have learned about the sandboxing capabilities of pypy and, I believe although I can't find it anymore, the ability to limit the time allowed to a given process. Even if this last one is wrong, the sandboxing capability is something I would be extremely interested in using. The application I have in mind is Crunchy. In a nutshell: Crunchy takes an arbitrary html page (with embedded Python code inside <pre> tags) and transforms it so that the user can execute, in a variety of ways, the Python code displayed in a browser (Firefox) window. It is a different way to interact with code than the ones given as examples on http://play1.codespeak.net/. Crunchy's user code (executed from the browser window) is not sandboxed. I was wondering how difficult it would be to have it sandboxed. Here are a few more specific questions: 1 a. Is it possible to create a "sandboxed python interpreter" that can be included as a module distributed with a cPython based program (Crunchy) without having pypy included in the distribution? 1 b. If so, does that module has to be (pre-)compiled for a given target machine? 2. Is it possible to limit the time for a given process (as mentioned above)? Thank you in advance for anyone that can give me some information regarding the above. If you feel this discussion is not appropriate for this list, please do not hesitate to tell me so and perhaps answer the questions "off-list". And, if the answers are simply: read this URL, and try this example, it would be appreciated as well. Cheers, André P.S. Crunchy's code is ... the work of two Python hobbyists ... and is probably not worth looking at - I can probably clarify any specific point needed to find out how it works, if needed to answer the questions I raised, better by email than having anyone read its code.

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/module/clr - Unable to load assembly.
by amit Dec. 8, 2007

Dec. 8, 2007

Hi, Just uncommenting the line below in interp_clr.py raises System.IO FileNotFound. # currentDomain.Load("System.Windows.Forms",asEvidence) right now GetAssemblies() get "System.Xml" and "mscorlib" internally and the code makes use of these two to scan the namespaces. I tried loading the dll with full path as well but without joy. am I missing something ? -AmitReg

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System calls in Java
by Niko Matsakis Dec. 6, 2007

Dec. 6, 2007

So, there are a few system calls that I don't think Java supports, but Python does. So far I have found getpid() and setenv(), but probably I will run into a few more. Rather than implement the native wrappers required myself, I was considering linking against a pre-written library. I found two, jnios, used by Jython, and jtux, which seems a bit more general. The Jython wrapper is a bit problematic because it relies on a lot of Jython classes for building tuples and things. I haven't experimented with jtux yet, but it seems to be a straightforward wrapper. The biggest problem is that it does not have lots of easy-to-download-and-install jar files available for various platforms. http://basepath.com/aup/jtux/ The idea would be that if the library were not present on the CLASSPATH, everything would continue to work except those methods that require extra support. Does this make sense? Anybody have a better idea? Niko

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mapping C# Delegates to Python
by amit Dec. 5, 2007

Dec. 5, 2007

/* C# delegate */ using System; delegate void Deleg(int x); class testclass { public static void Method1(int i) { Console.WriteLine("testClass.Method1 : "+ i); } public static void Method2(int i) { Console.WriteLine(".Method2 : "+ i*2); } } class Test { static void Main(string[] args) { Deleg DL1 = new Deleg(testclass.Method1); DL1(-55); Deleg DL2 = new Deleg(testclass.Method2); DL2(-22); Deleg DL3 = DL2 + DL1; DL3(-3333); } } /* * Now in Python what I might want to do is * * import System.Delegate * * class Deleg(Delegate): * __init__(self, ...): * pass * * t1 = testclass() * DL1 = Deleg(t1.Method1) * DL1(-55) # calls Method1 * * DL2 = Deleg(t1.Method2) * DL3 = DL2 + DL1 * * DL2(54) # calls Method2 * DL3(32) # calls Method2 then Method1 */ I tried : import clr deleg = clr.load_cli_class('System','Delegate') dd = deleg() and landed up with AttributeError: 'NoneType' object has no attribute 'Invoke' This looks like a rocket science to me but I really have to come up with this implementation to prevent myself from the pain of getting a "C" :( which now appears almost certain :(( Need guidance. -AmitReg

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getting the IBM talk to run with firefox.
by Laura Creighton Dec. 5, 2007

Dec. 5, 2007

I've got some advice from IBM on how to get our talk there to display properly. It's still not working for me. But perhaps some of you, especially those of you with macs can try it. Laura ------- Forwarded Message Return-Path: c1nose(a)us.ibm.com To: Laura Creighton <lac(a)openend.se> Cc: Martin J Hirzel <hirzel(a)us.ibm.com> MIME-Version: 1.0 Subject: Re: Copy of your PyPy Talk X-Mailer: Lotus Notes Release 7.0 HF277 June 21, 2006 Message-ID: <OF04D8160E.8933B7DE-ON852573A1.006065FE-852573A1.0060B1E0(a)us.ibm.com> From: John Noschese <c1nose(a)us.ibm.com> Laura, Did you try installing the windows media ActiveX control for Firefox? If not try this: http://support.mozilla.com/kb/ActiveX Thanks, John ================================ John Noschese Watson Audio Visual Group (914) 784-7223 T/L 863 Internet: c1nose(a)us.ibm.com https://reswat4.research.ibm.com/projects/tcs/labops.nsf/pages/sss.av.html ================================ Laura Creighton <lac(a)openend.se> 11/28/2007 11:26 AM To: John Noschese/Watson/Contr/IBM@IBMUS cc: Laura Creighton <lac(a)openend.se>, Martin J Hirzel/Watson/IBM@IBMUS, lac(a)openend.se Subject: Re: Copy of your PyPy Talk In a message of Wed, 28 Nov 2007 09:45:11 EST, John Noschese writes: >This is a multipart message in MIME format. >--=_alternative 00510AE3852573A1_= >Content-Type: text/plain; charset="US-ASCII" > >Laura, > >If you're using Firefox here are some instructions: > > >Using Firefox to view Webcasts: >Please follow the Mozilla recommendations in order to view the Research >webcast presentations. >The navigation will take users that do note have the plug-in to download >Activex Control and hit continue I don't know how to do this. Is this a url, or what I should try to point at? Or what? >Please ensure your firewall will allow you to navigate to the external >site trusted site >You will be prompted to a green screen to "Download the precompiled >Plug-in >For users using Mozilla Firefox Version 2.0.0.3 will need to select the >Firefox 1.5 Plug in and hit the Click Here link. Please adhere to the >warning before downloading. >You will only need to download the plug-in once >You must restart your Mozilla browser and click on the Research webcast >presentation link Ok, now I need to know how to get to the 'download the presentation plugin page'. This is not happening automatically when I try to look at the zip file. >Hope this helps. > >Thanks, >John We're getting somewhere, but aren't quite there yet. Laura - --=_alternative 0060B1DD852573A1_=

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