Get the parent directory before creating a file from a template

[juliusknorr]

Permissions when creating a new file or folder are always issued on the current node so when using the relative path directly on the user directory creating a new file will fail in scenarios where there is a read only mount on the user root.

Fixes nextcloud/android#8010
Fixes #25787

[szaimen]

@juliushaertl Thanks for taking this over!
I've applied the patch and it actually seems to fix both issues 🚀!
Thank your very much! :)

---

What I still can reproduce though is the following issue:

Click to expand

It happens when I try to create a new website (and folder) with the same configuration (root folder read only and mounted subfolder which is writeable) with the pico_cms app.

{
  "reqId": "ry1VnjQz6UVJFROuAiRq",
  "level": 2,
  "time": "2021-03-31T19:11:07+02:00",
  "remoteAddr": "192.168.178.155",
  "user": "admin",
  "app": "cms_pico",
  "method": "POST",
  "url": "/apps/cms_pico/personal/websites",
  "message": {
    "Exception": "OCP\\Files\\NotPermittedException",
    "Message": "No create permission for folder",
    "Code": 0,
    "Trace": [
      {
        "file": "/var/www/nextcloud/apps/cms_pico/lib/Files/StorageFolder.php",
        "line": 144,
        "function": "newFolder",
        "class": "OC\\Files\\Node\\Folder",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/cms_pico/lib/Service/TemplatesService.php",
        "line": 262,
        "function": "newFolder",
        "class": "OCA\\CMSPico\\Files\\StorageFolder",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/cms_pico/lib/Service/WebsitesService.php",
        "line": 146,
        "function": "installTemplate",
        "class": "OCA\\CMSPico\\Service\\TemplatesService",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/apps/cms_pico/lib/Controller/WebsitesController.php",
        "line": 118,
        "function": "createWebsite",
        "class": "OCA\\CMSPico\\Service\\WebsitesService",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 218,
        "function": "createPersonalWebsite",
        "class": "OCA\\CMSPico\\Controller\\WebsitesController",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/Http/Dispatcher.php",
        "line": 127,
        "function": "executeController",
        "class": "OC\\AppFramework\\Http\\Dispatcher",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/AppFramework/App.php",
        "line": 157,
        "function": "dispatch",
        "class": "OC\\AppFramework\\Http\\Dispatcher",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/lib/private/Route/Router.php",
        "line": 302,
        "function": "main",
        "class": "OC\\AppFramework\\App",
        "type": "::"
      },
      {
        "file": "/var/www/nextcloud/lib/base.php",
        "line": 993,
        "function": "match",
        "class": "OC\\Route\\Router",
        "type": "->"
      },
      {
        "file": "/var/www/nextcloud/index.php",
        "line": 37,
        "function": "handleRequest",
        "class": "OC",
        "type": "::"
      }
    ],
    "File": "/var/www/nextcloud/lib/private/Files/Node/Folder.php",
    "Line": 173,
    "CustomMessage": "--"
  },
  "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.105 Safari/537.36",
  "version": "21.0.0.18",
  "id": "6064ad32c8fd9"
}

But I am not sure if this is an issue of the Pico CMS app or server related?

[rullzer]

Looks good.
But needs CI and psalm love

[juliusknorr]

What I still can reproduce though is the following issue:
But I am not sure if this is an issue of the Pico CMS app or server related?

Seems to be a similar case where the pico_cms app would need a related fix to get the node of the parent directory first before creating the file, so I'd suggest to open an issue in the apps repo.

[juliusknorr]

Checks are happy except for acceptance-app-files-sharing which fails on master as well.

[szaimen]

Seems to be a similar case where the pico_cms app would need a related fix to get the node of the parent directory first before creating the file, so I'd suggest to open an issue in the apps repo.

I'll do, thanks for the advice! :)

[rullzer]

@juliushaertl backports?

[rullzer]

/backport to stable21

[PhrozenByte]

What I still can reproduce though is the following issue:
But I am not sure if this is an issue of the Pico CMS app or server related?

Seems to be a similar case where the pico_cms app would need a related fix to get the node of the parent directory first before creating the file, so I'd suggest to open an issue in the apps repo.

Thanks. Sure, adding such a check is no big deal 👍

However, I was thinking... What's the reason for Nextcloud to check the base path's permission instead of the parent folder's @juliushaertl? The only reason for this I could think of is, that newFile() was never supposed to accept relative $paths, but just a $fileName; if this is true, it should be enforced. However, Folder::newFile() explicitly states that it accepts a "relative path". This is true for most of the file operations API btw, I never was sure whether the methods accept just file names or relative paths. So, either the implantation is wrong, or a check is missing and the docs are misleading. Either way, it should be fixed.

[PhrozenByte]

@juliushaertl What do you think about this?

[juliusknorr]

However, I was thinking... What's the reason for Nextcloud to check the base path's permission instead of the parent folder's @juliushaertl? The only reason for this I could think of is, that newFile() was never supposed to accept relative $paths, but just a $fileName; if this is true, it should be enforced.

@rullzer @icewind1991 I'd say that is a valid point, was there any plan on if the nodes api should support relative paths or if the parameters should only be interpreted as a single level file/folder name?

Due to

server/lib/public/Files/Folder.php

Line 103 in 8a92229

* @param string $path relative path of the new folder

I'd say it would indeed make most sense to properly check if full path exists and has the proper create permissions.