Fix segmentation fault in early shutdown from `quit()` in config

kresd was segfaulting if configuration file contained `quit()`

See merge request !42

DNS over TLS and TCP out-of-order processing

Refresh !18

I merged few bits from @dkg branch, but there are two notable things missing:
- watch for on-disk chang of credentials - not sure if this is really needed, I would suggest a separate MR, where we can discuss benefits of doing so.
- ephemeral key generation from `net.tls_servicename` - this is fine, but instead of setting `tls_servicename`, let's make it an explicit generator e.g. net.generate_certificate("name") instead of setting `tls_servicename` in the `struct network`. Again I would suggest a separate MR.

To test the TLS listen, you can use a dns-over-tls branch from Knot DNS:
```
./daemon/kresd --tls=127.0.0.1\#5353
net.tls("cert", "key")
```

```
$ ./src/kdig +tls -p 5353 www.cmu.edu @127.0.0.1
;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 9741
;; Flags: qr rd ra; QUERY: 1; ANSWER: 2; AUTHORITY: 0; ADDITIONAL: 0

;; QUESTION SECTION:
;; www.cmu.edu.        		IN	A

;; ANSWER SECTION:
www.cmu.edu.        	86400	IN	CNAME	www-cmu-prod-vip.andrew.cmu.edu.
www-cmu-prod-vip.andrew.cmu.edu. 21600	IN	A	128.2.42.52

;; Received 107 B
;; Time 2016-08-05 11:52:25 CEST
;; From 127.0.0.1@5353(TCP) in 2146.1 ms
;; TLS session info: (TLS1.2)-(ECDHE-RSA-SECP256R1)-(AES-256-GCM)
```


See merge request !41

Ensure that kr_log_info() gets sent promptly to stdout

If stdout is buffered, kr_log_info() might take ages to show up in the
output stream.  Since this stream could be interleaved with stderr
(e.g. kr_log_error()), it would be good to be able to see the messages
in the order in which they are generated.

See merge request !40

If stdout is buffered, kr_log_info() might take ages to show up in the
output stream.  Since this stream could be interleaved with stderr
(e.g. kr_log_error()), it would be good to be able to see the messages
in the order in which they are generated.

Daniel Kahn Gillmor authored 8 years ago and Ondřej Surý committed 8 years ago

RFC 7858 explicitly defines an out-of-band key pinning profile as one
authentication mechanism.  It uses the same format for representing
the pin as HPKP does (RFC 7469).

By logging this pin directly upon first use of the X.509 credentials,
we make it a little bit easier for an admin to publish part of a
pinset.

For ideal operation (including preparation for key rollover), a backup
public key should also be provided, but this is not defined
functionally here.

Daniel Kahn Gillmor authored 8 years ago and Ondřej Surý committed 8 years ago

We also propagate kresd's verbosity into the TLS logging level

Marek Vavrusa authored 8 years ago and Ondřej Surý committed 8 years ago

there are cases where switches or middle-boxes
block DNS/UDP answers >512 octets completely,
this gives user an option to mitigate that.
however, there are authoritatives serving
large answers that don't support TCP, so it's
a compromise as always

Daniel Kahn Gillmor authored 8 years ago and Ondřej Surý committed 8 years ago

kresd has --tls/-t by analogy with --addr/-a where the daemon opens
the socket itself.

This changeset adds equivalent functionality for inherited sockets:
--tlsfd/-T by analogy with --fd/-Sa

Marek Vavrusa authored 8 years ago and Ondřej Surý committed 8 years ago

the TLS sessions now bypass the usuall event loop asynchronous iops
this is because the whole operation is synchronous right now, and
implementing asynchronous send operations would require TLS session to
restart write events on the event loop and making sure the "on complete"
callback is called eventually

Marek Vavrusa authored 8 years ago and Ondřej Surý committed 8 years ago

this is a workaround probably, but we need to
process all records in received buffer otherwise
it loses the rest of the data

add Documentation= reference to knot-resolver.service

This makes "systemctl help knot-resolver" bring up the appropriate man
page.

See merge request !39

This makes "systemctl help knot-resolver" bring up the appropriate man
page.

Control socket activation

This branch provides reasonable configs for full systemd socket activation for kresd.

See merge request !36

This is a fully-socket-activated knot-resolver service that can run as
a non-priivleged user named knot-resolver.