That is the correct way to do it from a security perspective. I suppose you could get around it by making the app's data directory world writable - but that's not a good idea for obvious reasons.
On Dec 30, 1:21 pm, cturner <[email protected]> wrote: > Hi Dave, > I've been following along here. I think you're saying that the only > way for the native code to create/read/write to files in the private > directory is by having the Java app pass an open file descriptor to > the native code. Is that correct? > > Progressive download is one use case, but we have others as well, so I > want to understand all the possibilities. Writing files to sdcard is > not always an acceptable method, since the card can be removed or > swapped out. > > On Dec 30, 10:43 am, Dave Sparks <[email protected]> wrote: > > > I think my earlier post was just confusing - sorry about that .I > > assume we're talking about the text file OpenCore uses for resuming a > > progressive download. > > > If your application wants to allow the media server to write a file in > > its private directory, it needs to pass in an open file descriptor > > with write access rights. The media server should then close the fd > > when it is done, the same way that it works when we pass in an open fd > > for media playback. > > > On Dec 24, 11:05 pm, rktb <[email protected]> wrote: > > > > Ok thanks. > > > > <waiting for Dave> :-) > > > > On Dec 25, 12:01 pm, freepine <[email protected]> wrote: > > > > > Hi Ravi, > > > > I don't have more useful information except the links your are referring > > > > from android website:( I think Dave might can help to share some > > > > resource > > > > for us. > > > > > There was some discussions in the list about granting access permission > > > > to > > > > other applications, which might require delicate solutions and also > > > > depends > > > > on the concrete requirements. > > > > > -freepine > > > > > On Thu, Dec 25, 2008 at 2:41 PM, rktb <[email protected]> wrote: > > > > > > Hi freepine, > > > > > > I would like to read more about the permissions and access before > > > > > posting any educated question. Can you point me to any code or doc? If > > > > > not, read further for my questions :-) > > > > > > Though progressive download is a good example, the files that I am > > > > > referring to is not media content. The media content, I am almost > > > > > certain, should be accessed by content providers. What I am talking > > > > > about is a normal text file that, in this case, stores the state of > > > > > the download. And, a different app. needs access to this text file. > > > > > This is the required behavior. > > > > > > Thanks, > > > > > Ravi > > > > > > On Dec 25, 10:05 am, freepine <[email protected]> wrote: > > > > > > I think it depends:). > > > > > > Are you trying to implement something like progressive download in > > > > > opencore > > > > > > player? > > > > > > If so, I think you might not want to grant the access permission of > > > > > > downloaded files only to the default music player? > > > > > > > Will it be played as ringtone or inserted to MMS? :) > > > > > > > -freepine > > > > > > > On Thu, Dec 25, 2008 at 12:49 PM, rktb <[email protected]> wrote: > > > > > > > > Oh ok. Thanks freepine ! > > > > > > > > So, can we summarize that the mediaserver cannot really create a > > > > > > > file > > > > > > > in internal memory. And, the best way to provide a file access is > > > > > > > to > > > > > > > pass it through a file descriptor from the application to the > > > > > > > mediaserver process. > > > > > > > > -Ravi > > > > > > > > On Dec 25, 9:11 am, freepine <[email protected]> wrote: > > > > > > > > I guess it's the java app you are using, i.e. com.android.music > > > > > > > > > On Thu, Dec 25, 2008 at 9:57 AM, rktb <[email protected]> wrote: > > > > > > > > > > Hi Dave, > > > > > > > > > > Sorry...I did not understand completely. > > > > > > > > > > What is the native app? > > > > > > > > > > -Ravi > > > > > > > > > > On Dec 25, 12:34 am, Dave Sparks <[email protected]> > > > > > > > > > wrote: > > > > > > > > > > Hi Ravi, > > > > > > > > > > > I think you need to have the native app create the file and > > > > > > > > > > pass > > > > > the > > > > > > > > > > open file descriptor to the media server. This is how > > > > > > > > > > rights are > > > > > > > > > > conferred from one process to another in the Android > > > > > > > > > > security > > > > > model. > > > > > > > > > > > Dave > > > > > > > > > > > On Dec 24, 12:58 am, rktb <[email protected]> wrote: > > > > > > > > > > > > Hi, > > > > > > > > > > > > Need some pointers about file access permissions: > > > > > > > > > > > > Here is what I have tried: > > > > > > > > > > > > From the Java app., I can create a file in /data/data/ > > > > > > > > > > > <my_package_name>/files/ using the API openFileOutput(). > > > > > > > > > > > The > > > > > > > > > > > permissions of the file is as follows: > > > > > > > > > > > -rw-rw---- app_10 app_10 0 2008-12-23 09:17 > > > > > > > testFile1.txt > > > > > > > > > > > > The files folder itself has the permissions: > > > > > > > > > > > drwxrwx--x app_10 app_10 2008-12-23 09:17 > > > > > > > > > > > files > > > > > > > > > > > > When I create a file using native code on /sdcard, the > > > > > permissions > > > > > > > are > > > > > > > > > > > as follows: > > > > > > > > > > > ----rw-rw- system system 0 2008-12-23 09:17 > > > > > > > > > > > fromNativeCode.txt > > > > > > > > > > > Is it right to say that native code process has "system" > > > > > rights? > > > > > > > > > > > > Now, when I create a file using the Java layer, I can > > > > > > > > > > > open the > > > > > same > > > > > > > > > > > file for "reading" through native code. But, I cannot > > > > > > > > > > > open a > > > > > file > > > > > > > in > > > > > > > > > > > the same place using the native code with "writing" > > > > > > > > > > > capability. > > > > > > > The > > > > > > > > > > > permissions of the "files" folder is "app_10", which is > > > > > > > > > > > the > > > > > userID > > > > > > > of > > > > > > > > > > > the app. Right? Doesn't "system" trump "app_10" in terms > > > > > > > > > > > of > > > > > > > > > > > permissions? > > > > > > > > > > > > In other words, the objective that I am trying to achieve > > > > > > > > > > > is to > > > > > > > create > > > > > > > > > > > a file inside native code at a place other than sdcard. > > > > > Preferably, > > > > > > > > > > > application specific location. > > > > > > > > > > > > Any document that anybody could point that would detail > > > > > > > > > > > more > > > > > about > > > > > > > > > > > security and permissions? I have already readhttp:// > > > > > > > > > code.google.com/android/devel/security.html. But, it does not > > > > > > > > > > > deal with native code details. > > > > > > > > > > > > Thanks, > > > > > > > > > > > Ravi- Hide quoted text - > > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-framework?hl=en -~----------~----~----~----~------~----~------~--~---
