[Pdns-users] Possible bug regarding the storage of records including a "._"

[James Watson]

Hi,

Using 4.0.1 Authoritive server on 16.04 Ubuntu with MySQL backend.

I have a couple of zones that the server is slave to and I am getting some null records in the AXFR transfer, null records that don't exist in the transfer data but are somehow being saved to the database by powerdns. The master to slave replication works fine but I can't help but feel these extra null records shoudn't exist.

If I disallow storage of null records I get the following error on the "content", "type" and "ttl" columns in the "records" table.


Unable to AXFR zone 'changed.com.au' from remote '203.[removed]' (PDNSException): GSQLBackend unable to feed empty non-terminal: Could not execute mysql statement: insert into records (type,domain_id,disabled,name,ordername,auth,change_date,content,ttl,prio) values (null,?,0,?,?,?,NULL,NULL,NULL,NULL): Column 'type' cannot be null


Upon doing more investigation all the null records that it is storing end up being version's of records that were stored correctly but are missing data preceding the first "._", for example here are the null records:

Null records stored as a result of transfer (id,domain_id,name,type,content,ttl,prio,change_date,disabled,ordername,auth):

| 30588967 | 255 | _tcp.changed.com.au                 | NULL  | NULL |  NULL | NULL |        NULL |        0 | NULL      |    1 |
| 30588968 | 255 | _tls.changed.com.au                   | NULL  | NULL  |  NULL | NULL |        NULL |        0 | NULL      |    1 |
| 30588969 | 255 | _domainkey.changed.com.au      | NULL  | NULL  |  NULL | NULL |        NULL |        0 | NULL      |    1 |

Correct records also stored as a result of the same zone transfer

| 30588964 | 255 | _sipfederationtls._tcp.changed.com.au | SRV   | 1 5061 sipfed.somthing.else.com  |  3600 |  100 |        NULL |        0 | NULL      |    1 |
| 30588963 | 255 | _sip._tls.changed.com.au              | SRV   | 1 443 sipdir.somthing.else.com |  3600 |  100 |        NULL |        0 | NULL      |    1 |
| 30588947 | 255 | k1._domainkey.changed.com.au   | CNAME | dkim.somthing.net |  7200 |    0 |        NULL |        0 | NULL      |    1 |

I am assuming this is a bug for records that contain "._" or is this somthing that should be happening?

As a side note, when I check the domain via pdnsutil it returns 57 records, when there are actually 60 records in the database including the null records, so it doesn't seem to break powerdns by having them there.

Kind Regards,
James Watson


James Watson



Technical Engineer

Business Technology Group LTD





p: +64 9 580 1374 x9833

m: +64274596684

James.Watson at btg.co.nz



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