IMAP preauth and stats-writer

[Stephan Bosch]

Op 06/01/2019 om 18:12 schreef John Fawcett:
> On 06/01/2019 11:37, Stephan Bosch wrote:
>> Op 06/01/2019 om 03:35 schreef John Fawcett:
>>> On 06/01/2019 02:26, John Fawcett wrote:
>>>
>>>> Can't see anything in the Dovecot 2.3.4 code that would give this
>>>> problem, setting
>>>>
>>>> stats_writer_socket_path =
>>>>
>>>> will overwrite the default value and dovecot does not attempt to
>>>> open a socket in that case.
>>>>
>>>> Using your configuration (though not FreeBSD) I don't get the
>>>> net_connect_unix error whether I use a blank setting or leave the
>>>> default. In the case of leaving the default I do get an additional
>>>> process (dovecot/stats). No errors on connecting to the imap service
>>>> or by running preauth (with the dovecot daemon already running).
>>>>
>>>> The net_connect_unix() error with a zero length socket name is
>>>> inexplicable to me, unless it's got a non printing character in it
>>>> or there is something different happening on FreeBSD.
>>>>
>>>> One suggestion is to run with the default setting, but look at
>>>> resolving the permission problem for the default socket creation at
>>>> /var/run/dovecot/stats-writer rather than working round it.
>>>>
>>>> John
>>>>
>>> Just following up, I don't get the error when I run preauth as root with
>>> -u parameter. I do get something similar when I run as the user (this
>>> wil the socket path set to blank)
>>>
>>> Centos 7:
>>>
>>> Error: net_connect_unix() failed: Connection refused
>>>
>>> FreeBSD 11.2:
>>>
>>> Error: net_connect_unix() failed: No such file or directory
>>>
>>> So it's close. If I get time I'll see if I can track it down.
>> Does this fix it?
>>
>> diff --git a/src/lib-master/master-service.c
>> b/src/lib-master/master-service.c
>> index 3de11fa1b..3c60a7a39 100644
>> --- a/src/lib-master/master-service.c
>> +++ b/src/lib-master/master-service.c
>> @@ -341,7 +341,7 @@ master_service_init(const char *name, enum
>> master_service_flags flags,
>>          if ((flags & MASTER_SERVICE_FLAG_DONT_SEND_STATS) == 0) {
>>                  /* Initialize stats-client early so it can see all
>> events. */
>>                  value = getenv(DOVECOT_STATS_WRITER_SOCKET_PATH);
>> -               if (value != NULL)
>> +               if (value != NULL && *value != '\0')
>>                          service->stats_client =
>> stats_client_init(value, FALSE);
>>          }
>>
>>
>> Regards,
>>
>> Stephan.
>>
> Hi Stephan
>
> that fixes the issue that I reproduced. For the OP he will probably need
> to wait for this to be picked up for FreeBSD ports.
>
> This code seems safer than the original but it is still a mystery as to
> why DOVECOT_STATS_WRITER_SOCKET_PATH is being put into the environment
> as an empty string (changed behaviour reported by OP compared to 2.3.2.1_1).

Behavior changed because the code I patched didn't exist in 2.3.2.1.

Regards,

Stephan.