I originally wrote the code to handle public calendars in the "shared" namespace, but I focused on user calendars first, and public calendar support got tossed on the back burner. It appears that the code for public calendars partly works.

My first thought to get auto-discovery of public calendars is to add /dav/calendars as a second calendar-home-set for users and see what the Apple clients do with that. I don't know if they can handle multiple home-sets. If that doesn't work, then we could map public calendars into the user's home-set via the same subscription mechanism that we use for CalDAV sharing.

To answer the original question, calendars are enumerated by meth_propfind() and propfind_by_collection() in http_dav.c

On 4/7/18 8:25 PM, Bron Gondwana wrote:
Ken knows this code best. I bet there's something which is requiring that there's a user on the mboxname because we implement the same behaviour at FastMail by having a separate user on which shared resources are kept. The DAV resources are stored per-user, and without a place to keep them for "shared calendars" that code might just not be accessible. I'm sure it would be possible to create a shared DAV database as well for this case, but it just needs some programming effort.


On Sun, 8 Apr 2018, at 07:30, Anatoli wrote:
Hi All,

I'm trying to understand the code responsible for enumerating user calendars (and xDAV resources in general) to try to make the discovery work for shared resources too (currently there's no way to access shared resources with Apple xDAV client implementation, yes with Thunderbird as it doesn't use the discovery mechanism, but instead should be pointed to the exact URL for each calendar). If I understand it correctly, the functionality is in imap/http_caldav.c.

Could you please point me to the place where the enumeration occurs and briefly mention how the general workflow looks like?

The client asks for:

PROPFIND /dav/calendars/user/<user@domain>/

<A:propfind xmlns:A="DAV:">

The server responds with:

HTTP/1.1 207 Multi-Status

<A:multistatus xmlns:A="DAV:" ...>

The idea is to include in the returned lists the shared calendars too with the discovery logic based on the IMAP shared folders.

Below goes the initial exchange between the calendar app on iOS 10.2.6 and Cyrus 3.0.5 when the exact URL (/dav/calendars/shared/) for the shared calendar is provided in the advanced settings of the app (the URL finally resets to the user principals folder (/dav/principals/user/t...@domain.com/) as iOS is pointed to it by Cyrus). In the attached file goes the telemetry for the rest of the communication.


---------- t...@domain.com <mailto:t...@domain.com> Sun Mar 25 06:05:36 2018

<1521968736<*PROPFIND* */dav/calendars/shared/* HTTP/1.1
Accept: */*
Content-type: text/xml
Connection: keep-alive
Content-length: 181
Host: mail.domain.com
User-agent: iOS/11.2.6 (15D100) accountsd/1.0
Prefer: return=minimal
Depth: 0
Brief: t
Accept-language: en-us
Authorization: Basic ...
Accept-encoding: br, gzip, deflate

<1521968736<<?xml version="1.0" encoding="UTF-8"?>
<A:propfind xmlns:A="DAV:">

>1521968736>HTTP/1.1 207 Multi-Status
Date: Sun, 25 Mar 2018 09:05:36 GMT
Strict-Transport-Security: max-age=600
Vary: Accept-Encoding, Brief, Prefer
Preference-Applied: return=minimal
Content-Type: application/xml; charset=utf-8
Content-Length: 546

<?xml version="1.0" encoding="utf-8"?>
<A:multistatus xmlns:A="DAV:" xmlns:C="urn:ietf:params:xml:ns:caldav">
      <A:status>HTTP/1.1 200 OK</A:status>

<1521968736<OPTIONS /dav/principals/user/t3%40domain.com/ HTTP/1.1
Host: mail.domain.com
Connection: keep-alive
Accept: */*
User-Agent: iOS/11.2.6 (15D100) accountsd/1.0
Accept-Language: en-us
Content-Length: 0
Accept-Encoding: br, gzip, deflate

>1521968736>HTTP/1.1 200 OK
Date: Sun, 25 Mar 2018 09:05:36 GMT
Strict-Transport-Security: max-age=600
Cache-Control: no-cache
Link: </dav/principals/.server-info>; rel="server-info"; token="80769c2c66d340ecd178710db26d56b9c4699e3e"
DAV: 1, 2, 3, access-control, extended-mkcol, resource-sharing
DAV: calendar-access, calendar-auto-schedule
DAV: calendar-query-extended, calendar-availability, calendar-managed-attachments
DAV: calendarserver-sharing, inbox-availability
DAV: addressbook
Content-Length: 0

Email had 1 attachment:

      36k (text/x-log)

  Bron Gondwana, CEO, FastMail Pty Ltd

Kenneth Murchison
Cyrus Development Team
FastMail Pty Ltd

Reply via email to