Implementation of chroot function

[scottmmorris]

Description

This PR will introduce the chroot function into EFS. This function will return a reference to the existing EFS object with the root iNode changed to a specified path.

Tasks

1. [x] Implement chroot function
2. [x] Handle any error cases
3. [x] Write tests for the new functionality
4. [x] Fix up any bugs encountered in testing

Final checklist

• [x] Domain specific tests
• [x] Full tests
• [x] Updated inline-comment documentation
• [x] Lint fixed
• [x] Squash and rebased
• [x] Sanity check the final build

[CMCDragonkai]

Tests need to be written for symlinks and also paths that use /../ anywhere to prevent the user escape the chroot.

[CMCDragonkai]

This should affect the root inode and current directory state. You might need to generalise the protected constructor of EncryptedFS.

What comes out should be a new EncryptedFS instance, but one that shares the same FileDescriptorManager, INodeManager and DB.

[scottmmorris]

After some testing, I will need to change more than just the properties of the encrypted file system. I needed to change these lines in the navigate function.

        if (parse.segment === '..' && curdir === this.rootIno) {
          target = curdir;
        } else {
          target = await this.iNodeMgr.dirGetEntry(tran, curdir, parse.segment);
        }

[scottmmorris]

Are hardlinks able to escape the chroot @CMCDragonkai ? The problem is that with hardlinks is that it doesn't use the navigate function

[CMCDragonkai]

Yes hardlinks are fine. I don't think it's a problem.

But if you're in the chroot it won't be possible to hardlink something outside the chroot.

Only if you are in the root context would you be able to hardlink between vaults. And there isn't a secret operation to do this.

On 9/27/21 1:36 PM, Scott wrote:

Are hardlinks able to escape the chroot @CMCDragonkai https://github.com/CMCDragonkai ? The problem is that with hardlinks is that it doesn't use the navigate function

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[scottmmorris]

Ready for merge

[CMCDragonkai]

Do you think chroot needs to be async? It seems like something that can be done synchronously.

[CMCDragonkai]

Oh I see you're using a transaction nvm.