Commit Graph

188 Commits

Author SHA1 Message Date
Audrius Butkevicius
f619a7f4cc
lib/connections: Try TCP punchthrough (fixes #4259) (#5753) 2020-06-16 09:17:07 +02:00
Simon Frei
3065b127b5
lib/connections, lib/nat: Correctly dis-/enable nat (fixes #6552) (#6719) 2020-06-07 20:29:53 +02:00
Jakob Borg
d9cb7e2739
lib/connections: Skip and warn on malformed URLs (fixes #6697) (#6699) 2020-06-02 11:19:51 +02:00
Audrius Butkevicius
7dc290c3ed
lib/connections: React to listeners going up and down faster (#6590) 2020-05-11 15:02:22 +02:00
Audrius Butkevicius
ac7338f1f2
lib/connections: Update quic (#6591)
* lib/connections: Update quic

* Fix freebsd builds?

* Undo x/sys and gopsutil update

* Update quic_dial.go

* Update quic_listen.go
2020-05-01 08:14:28 +01:00
MikolajTwarog
4aa2199d5b
lib/connections: Accept new connections in place of old ones (fixes #5224) (#6548) 2020-04-20 08:23:38 +02:00
Jakob Borg
dd92b2b8f4
all: Tweak error creation (#6391)
- In the few places where we wrap errors, use the new Go 1.13 "%w"
  construction instead of %s or %v.

- Where we create errors with constant strings, consistently use
  errors.New and not fmt.Errorf.

- Remove capitalization from errors in the few places where we had that.
2020-03-03 22:40:00 +01:00
Simon Frei
680b0b14db
lib/connections: Refactor status for testing (ref #6361) (#6362) 2020-02-25 21:18:31 +01:00
Jakob Borg
55238e3b5b
lib/connections: Actually record connection errors (#6361) 2020-02-25 16:56:24 +01:00
Simon Frei
c3637f2191
lib: Faster termination on exit (ref #6319) (#6329) 2020-02-13 14:43:00 +01:00
Simon Frei
6fd5e78740 lib: Consistently unsubscribe from config-wrapper (fixes #6133) (#6205) 2019-12-04 07:15:00 +01:00
Simon Frei
b32821a586 lib/config, lib/connections: Remove ListenAddresses hack (#6188) 2019-11-26 17:07:25 +01:00
Simon Frei
1bae4b7f50 all: Use context in lib/dialer (#6177)
* all: Use context in lib/dialer

* a bit slimmer

* https://github.com/syncthing/syncthing/pull/5753

* bot

* missed adding debug.go

* errors.Cause

* simultaneous dialing

* anti-leak
2019-11-26 07:39:51 +00:00
Simon Frei
33258b06f4 lib/connections: Dialer code deduplication (#6187) 2019-11-26 07:36:58 +00:00
Simon Frei
cf312abc72 lib: Wrap errors with errors.Wrap instead of fmt.Errorf (#6181) 2019-11-23 15:20:54 +00:00
Simon Frei
90d85fd0a2
lib: Replace done channel with contexts in and add names to util services (#6166) 2019-11-21 08:41:15 +01:00
Jakob Borg
1d99e5277a all: Cleanups enabled by Go 1.12 2019-11-10 10:16:10 +01:00
Audrius Butkevicius
c4f161d8c5 lib/connections: Rate limit quic accept loop (fixes #6081) (#6082) 2019-10-18 09:55:37 +02:00
Lukas Lihotzki
96bb1c8e29 all, lib/logger: Refactor SetDebug calls (#6054) 2019-10-04 13:03:34 +02:00
Jakob Borg
0104e78589
lib/connections: Improve write rate limiting (fixes #5138) (#5996)
This splits large writes into smaller ones when using a rate limit,
making them into a legitimate trickle rather than large bursts with a
long time in between.
2019-09-04 11:12:17 +01:00
Jakob Borg
c2ea9d119d
lib/connections: Upgrade QUIC package, use contexts for timeout (#5972) 2019-08-23 10:15:52 +02:00
Simon Frei
b1c74860e8
all: Remove global events.Default (ref #4085) (#5886) 2019-08-15 16:29:37 +02:00
Simon Frei
cf40ed6cec lib/connections: Return exported intf from exported function (#5947) 2019-08-13 09:33:33 +02:00
Audrius Butkevicius
58ef5368f8
lib/connections: Validate device id before assuming success (fixes #5934) (#5935)
* lib/connections: Validate device id before assuming success (fixes #5934)

* Vet
2019-08-09 12:31:42 +01:00
Simon Frei
77cc87dfca lib/connections: Log errors in relay clients (#5917) 2019-08-01 17:37:58 +02:00
Simon Frei
ba056578ec
lib: Add util.Service as suture.Service template (fixes #5801) (#5806) 2019-07-09 11:40:30 +02:00
Audrius Butkevicius
ee746263fb
lib/connections: Do not leak FDs, fix address copy (fixes #5767) (#5768)
* lib/connections: Do not leak FDs, fix address copy (fixes #5767)

* build

* Update quic_listen.go

* Update quic_listen.go
2019-06-09 22:14:00 +01:00
Audrius Butkevicius
e714df013f lib/connections: Add QUIC protocol support (fixes #5377) (#5737) 2019-05-29 09:56:40 +02:00
Jakob Borg
2c866277a2 lib/api, lib/connections, gui: Show connection error for disconnected devices (fixes #3345) (#5727)
* lib/api, lib/connections, gui: Show connection error for disconnected devices (fixes #3345)

This adds functionality in the connetions service to track the last
error per address. That is in turn exposed in the /rest/system/status
API method, as that is also where we already show the listener status
from the connection service.

The GUI uses this info where it lists addresses, showing errors (if any)
in red underneath each address.

I also slightly refactored the existing status method on the connection
service to have a better name and return typed information.

* ok

* review

* formatting

* review
2019-05-16 22:11:45 +01:00
Jakob Borg
f24676ba5a
lib/tlsutil: Enable TLS 1.3 when available, on test builds (fixes #5065) (#5558)
* lib/tlsutil: Enable TLS 1.3 when available, on test builds (fixes #5065)

This enables TLS 1.3 negotiation on Go 1.12 by setting the GODEBUG
variable. For now, this just gets enabled on test versions (those with a
dash in the version number).

Users wishing to enable this on production builds can set GODEBUG
manually.

The string representation of connections now includes the TLS version
and cipher suite. This becomes part of the log output on connections.
That is, when talking to an old client:

    Established secure connection .../TLS1.2-TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256

and now potentially:

    Established secure connection .../TLS1.3-TLS_AES_128_GCM_SHA256

(The cipher suite was there previously in the log output, but not the
TLS version.)

I also added this info as a new Crypto() method on the connection, and
propagate this out to the API and GUI, where it can be seen in the
connection address hover (although with bad word wrapping sometimes).

* wip

* wip
2019-02-26 11:49:02 +01:00
Simon Frei
722b3fce6a all: Hide implementations behind interfaces for mocked testing (#5548)
* lib/model: Hide implementations behind interfaces for mocked testing

* review
2019-02-26 08:09:25 +00:00
Jakob Borg
c2ddc83509 all: Revert the underscore sillyness 2019-02-02 12:16:27 +01:00
Jakob Borg
9fd270d78e
all: A few more interesting linter fixes (#5502)
A couple of minor bugs and simplifications
2019-02-02 12:09:07 +01:00
Jakob Borg
df5c1eaf01
all: Bunch of more linter fixes (#5500) 2019-02-02 11:02:28 +01:00
Simon Frei
24ffd8be99 all: Send Close BEP msg on intentional disconnect (#5440)
This avoids waiting until next ping and timeout until the connection is actually
closed both by notifying the peer of the disconnect and by immediately closing
the local end of the connection after that. As a nice side effect, info level
logging about dropped connections now have the actual reason in it, not a generic
timeout error which looks like a real problem with the connection.
2019-01-09 17:31:09 +01:00
Simon Frei
01ade9c8ae lib/connections: Don't panic on removed device (fixes #5299) (#5300) 2018-10-30 10:34:19 +01:00
Simon Frei
c9d6366d75 lib/connections: Don't info log about LAN if there are no rate limits (#5242) 2018-10-05 08:22:47 +02:00
Jakob Borg
9e00b619ab all, vendor: Switch back to non-forked thejerf/suture (#5171) 2018-09-08 12:56:56 +03:00
Jakob Borg
48795dba07
all: Don't let Suture capture panics (fixes #4758) (#5119)
Fork with new option.
2018-08-13 20:39:08 +02:00
Jakob Borg
ff441d3b3e
lib/connections: Don't spin on accept failures (fixes #5025) (#5036) 2018-06-27 08:24:30 +02:00
Jakob Borg
bdbaa84989 lib/connections: Wrong context snuck in somehow 2018-03-27 07:18:26 -04:00
Jakob Borg
c49d864f14 lib/connections: Slightly refactor limiter juggling
Two small behavior changes: don't "charge" the data to the global rate
limit until it's been accepted by the device specific limiter, and fix
the send/recv direction in the log print on per device rate limits.
2018-03-26 11:45:02 -04:00
qepasa
2621c6fd2f lib/connections, lib/config: Bandwidth throttling per remote device (fixes #4516) (#4603) 2018-03-26 12:01:59 +02:00
Audrius Butkevicius
2751be57dc lib/connections: Fix relay connections when two devices use the same relay (fixes #4778) (#4779) 2018-02-25 16:12:46 +01:00
Jakob Borg
b97d5bcca8
Remove KCP (fixes #4737) (#4741) 2018-02-09 11:40:57 +01:00
Simon Frei
341b9691a7 lib/connections, lib/model: Additional connection info in logs (fixes #4499)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4665
2018-01-12 11:27:55 +00:00
Audrius Butkevicius
72172d853c vendor: Move back to upstream KCP (fixes #4407)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4614
2017-12-27 11:33:12 +00:00
Audrius Butkevicius
2547a29dd7 lib/connections: Don't close nil connections (fixes #4605) 2017-12-18 14:40:51 +00:00
Audrius Butkevicius
445c4edeca gui, lib/config, lib/model: Support auto-accepting folders (fixes #2299)
Also introduces a new Waiter interface for config changes and segments the
configuration GUI.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4551
2017-12-07 07:08:24 +00:00
Jakob Borg
6daa766fde lib/connections: Actually fix LAN detection, for real (ref #4534) 2017-11-22 09:01:21 +01:00
Audrius Butkevicius
4922b46fbd lib/connections: Fix local address priority
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4534
LGTM: imsodin, calmh
2017-11-22 07:05:49 +00:00
xjtdy888
a17d953334 lib/connections: Actually make connection attempts for lower priority addresses as well
Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4535
2017-11-21 14:58:18 +00:00
Audrius Butkevicius
44a542391e lib/connections: Trust the model to tell us if we are connected
This should address issue as described in https://forum.syncthing.net/t/stun-nig-party-with-paused-devices/10942/13
Essentially the model and the connection service goes out of sync in terms of thinking if we are connected or not.
Resort to model as being the ultimate source of truth.

I can't immediately pin down how this happens, yet some ideas.

ConfigSaved happens in separate routine, so it's possbile that we have some sort of device removed yet connection comes in parallel kind of thing.
However, in this case the connection exists in the model, and does not exist in the connection service and the only way for the connection to be removed
in the connection service is device removal from the config.

Given the subject, this might also be related to the device being paused.

Also, adds more info to the logs

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4533
2017-11-21 07:25:38 +00:00
Jakob Borg
72d645865e lib/connections: Fix race condition in parallel dial, minor cleanups (fixes #4526)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4527
2017-11-19 17:38:13 +00:00
Audrius Butkevicius
0518a92cdb lib/connections: Only announce punchable nats (fixes #4519)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4523
2017-11-17 14:46:45 +00:00
Jakob Borg
7ebf58f1bc Fix discovery in the absence of listen addresses (fixes #4418)
This makes it OK to not have any listeners working. Specifically,

- We don't complain about an empty listener address
- We don't complain about not having anything to announce to global
  discovery servers
- We don't send local discovery packets when there is nothing to
  announce.

The last point also fixes a thing where the list of addresses for local
discovery was set at startup time and never refreshed.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4517
2017-11-17 09:12:35 +00:00
AudriusButkevicius
aecd7c64ce lib/connections: Parallel dials in the same priority (fixes #4456)
Well Tested(TM)

Introduces a potential issue where we always pick some connectable but dodgy connection that breaks
soon after the TLS handshake.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4489
2017-11-15 09:36:33 +00:00
Simon Frei
4efff736b3 lib/connections: Consistent log levels & polish (fixes #4510)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4511
2017-11-14 21:49:36 +00:00
AudriusButkevicius
0ee1146e1c lib/connections: Indicate stack in transport (fixes #4463)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4486
2017-11-07 07:25:05 +00:00
AudriusButkevicius
62a4106a79 lib/connections: Fix lan detection (fixes #4421)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4487
2017-11-06 14:05:29 +00:00
HairyFotr
7cbd92e1b1 all: Fix comment typos
Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4481
2017-11-04 07:20:11 +00:00
Audrius Butkevicius
a9c221189b lib/connections: Stun resolves server adress beforehand (fixes #4453)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4454
2017-10-22 18:48:06 +00:00
Audrius Butkevicius
b2966957e0 lib/connections: Add KCP blacklist period 2017-10-22 13:56:52 +01:00
Audrius Butkevicius
0d30166357 lib/connections: Use own KCP fork, move listener setup earlier (ref #4446)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4452
2017-10-22 12:36:36 +00:00
Audrius Butkevicius
fb7264a663 cmd/syncthing: Enable KCP by default
Also, use upstream library, as my changes have been merged.
2017-10-17 23:17:10 +01:00
Audrius Butkevicius
2760d032ca cmd/syncthing: Add more stats to usage reports (ref #3628)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4347
2017-10-12 06:16:46 +00:00
Audrius Butkevicius
9e6a1fdcd4 vendor: Update kcp, removes closeConn (fixes #4343) 2017-09-02 16:11:48 +02:00
Audrius Butkevicius
cbcc3ea132 lib/connections: Use our own fork of kcp (fixes #4063)
This updates kcp and uses our own fork which:

1. Keys sessions not just by remote address, but by remote address +
conversation id 2. Allows not to close connections that were passed directly
to the library. 3. Resets cache key if the session gets terminated.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4339
LGTM: calmh
2017-09-02 06:04:35 +00:00
HairyFotr
0ad10b0fee all: Typos
Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4263
2017-07-20 13:10:46 +00:00
Audrius Butkevicius
9667a0a618 lib/connections: Fix race (fixes #4177) 2017-06-07 10:17:01 +02:00
Audrius Butkevicius
51518490c6 lib/connections: Fix KCP from locking up the service (fixes #4072) 2017-05-21 22:16:21 +02:00
Jakob Borg
dd1f7a5ab7 lib/connections: Allow negative ACL entries on devices (fixes #4096)
Prefix an entry with "!" to make it a negative entry. First match wins.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4097
2017-04-13 17:43:29 +00:00
Jakob Borg
c5e0c47989 lib/connections, lib/model, gui: Specify allowed networks per device (fixes #219)
This adds a new config AllowedNetworks per device, which when set should
contain a list of network prefixes (192.168.0.0/126 etc) that are
allowed for the given device. The connection service will not attempt
connections to addresses outside of the given networks and incoming
connections will be rejected as well.

I've added the config to the normal device editor and shown it (when
set) in the device summary on the main screen.

There's a unit test for the IsAllowedNetwork method, I've done some
manual sanity testing on top of that.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4073
2017-04-01 09:52:31 +00:00
Audrius Butkevicius
ceea5ebeb3 lib/connections, vendor: Change KCP mux to SMUX
Closes #4032
2017-03-09 14:03:09 +01:00
Jakob Borg
b3e2665a79 vendor: Update github.com/xtaci/kcp 2017-03-07 14:29:21 +01:00
Jakob Borg
81af29e3e2 lib/config, lib/connections: Configurables for KCP, disable by default
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4030
2017-03-07 12:55:50 +00:00
Audrius Butkevicius
0da0774ce4 lib/connections: Add KCP support (fixes #804)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3489
2017-03-07 12:44:16 +00:00
HairyFotr
c56c48a777 all: Correct various typos
Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4005
2017-02-25 08:12:13 +00:00
Jakob Borg
f7fc0c1d3e all: Update license url to https (ref #3976) 2017-02-09 08:04:16 +01:00
Audrius Butkevicius
2c4b92d410 lib/connections: Fix rate limiting on arm64 (fixes #3921)
Skip-check: metalint

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3922
2017-01-23 20:55:00 +00:00
Jakob Borg
ec62888539 lib/connections: Allow on the fly changes to rate limits (fixes #3846)
Also replaces github.com/juju/ratelimit with golang.org/x/time/rate as
the latter supports changing the rate on the fly.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3862
2017-01-02 11:29:20 +00:00
Audrius Butkevicius
bab7c8ebbf all: Add folder pause, make pauses permanent (fixes #3407, fixes #215, fixes #3001)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3520
2016-12-21 18:41:25 +00:00
AudriusButkevicius
9e0afb7d8a lib/connections: Support setting traffic class (fixes #3790) 2016-12-21 11:01:15 +01:00
Jakob Borg
b8c1c0e048 cmd/syncthing: Enable better crypto, print negotiated cipher suite
This adds support for AES_256_GCM_SHA384 (in there since Go 1.5, a bit
of a shame we missed it) and ChaCha20-Poly1305 (if built with Go 1.8;
ignored on older Gos).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3822
2016-12-18 21:07:44 +00:00
Jakob Borg
9c67bd2550 lib/connections: Fix port fixup in Go 1.8 (fixes #3817)
The test for the error string is fragile, and the error string changed
in Go 1.8 so the relevant part is no longer a prefix. This covers it
with a test though, so it should be fine in the future as well.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3818
2016-12-18 11:28:18 +00:00
Jakob Borg
2fd1dca905 lib/connections: Fix odd logging, forgot to call function 2016-12-02 12:56:14 +01:00
Jakob Borg
ed4f6fc4b3 lib/connections, lib/model: Connection service should expose a single interface
Makes testing easier, which we'll need

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3771
2016-11-30 07:54:20 +00:00
Jakob Borg
548a324256 lib/connections: Slow down failing listeners
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3745
2016-11-19 12:37:14 +00:00
Audrius Butkevicius
38d28c3f4a lib/relay: Close invitation channel in all error cases (fixes #3726) 2016-11-13 09:32:05 +01:00
Audrius Butkevicius
f60b424d70 lib/config: Raw() -> RawCopy() 2016-11-13 09:29:35 +01:00
Jakob Borg
e52be3d83e lib/connections, lib/model: Refactor connection close handling (fixes #3466)
So there were some issues here. The main problem was that
model.Close(deviceID) was overloaded to mean "the connection was closed
by the protocol layer" and "i want to close this connection". That meant
it could get called twice - once *to* close the connection and then once
more when the connection *was* closed.

After this refactor there is instead a Closed(conn) method that is the
callback. I didn't need to change the parameter in the end, but I think
it's clearer what it means when it takes the connection that was closed
instead of a device ID. To close a connection, the new close(deviceID)
method is used instead, which only closes the underlying connection and
leaves the cleanup to the Closed() callback.

I also changed how we do connection switching. Instead of the connection
service calling close and then adding the connection, it just adds the
new connection. The model knows that it already has a connection and
makes sure to close and clean out that one before adding the new
connection.

To make sure to sequence this properly I added a new map of channels
that get created on connection add and closed by Closed(), so that
AddConnection() can do the close and wait for the cleanup to happen
before proceeding.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3490
2016-08-10 09:37:32 +00:00
Jakob Borg
a4ed50ca85 build, lib: Correct total test coverage calculation
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3483
2016-08-08 16:29:32 +00:00
Audrius Butkevicius
af3b6f9c83 lib/model, lib/config: Support "live" device removal, folder unsharing and folder configuration changes
Furthermore:
1. Cleans configs received, migrates them as we receive them.
2. Clears indexes of devices we no longer share the folder with

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3478
2016-08-07 16:21:59 +00:00
Audrius Butkevicius
a4f052ad31 lib/connections: Fix connection switching
It seems that it would be impossible to drop down to relay after establishing a direct connection
Also, we should not drop the existing connection until after we've passed the validation steps,
and it seems it's being dropped in two places unnecesserily at the moment.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3480
2016-08-07 12:20:37 +00:00
Jakob Borg
f368d2278f lib/config, lib/connections: Refactor handling of ignored devices (fixes #3470)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3471
2016-08-05 09:29:49 +00:00
Jakob Borg
fa0101bd60 lib/protocol, lib/discover, lib/db: Use protocol buffer serialization (fixes #3080)
This changes the BEP protocol to use protocol buffer serialization
instead of XDR, and therefore also the database format. The local
discovery protocol is also updated to be protocol buffer format.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3276
LGTM: AudriusButkevicius
2016-07-04 10:40:29 +00:00
Jakob Borg
672824641b lib/connections: TLS handshake must complete in a timely fashion (fixes #3375)
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3376
2016-07-02 20:33:31 +00:00
Nicolas Braud-Santoni
8e39e2889d lib: Fix typos in connections/service.go and model/model.go
Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3366
LGTM: aviau
2016-06-30 13:42:53 +00:00
Jakob Borg
6f5ca53f99 lib/connections: Limit rate at which we print warnings about version mismatch
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3291
2016-06-09 12:30:35 +00:00
Jakob Borg
d507126101 lib/protocol: Understand older/newer Hello messages (fixes #3287)
This is in preparation for future changes, but also improves the
handling when talking to pre-v0.13 clients. It breaks out the Hello
message and magic from the rest of the protocol implementation, with the
intention that this small part of the protocol will survive future
changes.

To enable this, and future testing, the new ExchangeHello function takes
an interface that can be implemented by future Hello versions and
returns a version indendent result type. It correctly detects pre-v0.13
protocols and returns a "too old" error message which gets logged to the
user at warning level:

   [I6KAH] 09:21:36 WARNING: Connecting to [...]:
     the remote device speaks an older version of the protocol (v0.12) not
     compatible with this version

Conversely, something entirely unknown will generate:

   [I6KAH] 09:40:27 WARNING: Connecting to [...]:
     the remote device speaks an unknown (newer?) version of the protocol

The intention is that in future iterations the Hello exchange will
succeed on at least one side and ExchangeHello will return the actual
data from the Hello together with ErrTooOld and an even more precise
message can be generated.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3289
2016-06-09 10:50:14 +00:00