### Purpose
Fix https://github.com/syncthing/syncthing/issues/9336
The `emitLoginAttempt` function now checks for the presence of an
`X-Forwarded-For` header. The IP from this header is only used if the
connecting host is either on loopback or on the same LAN.
In the case of a host pretending to be a proxy, we'd still have both IPs
in the logs, which should make this much less critical from a security
standpoint.
### Testing
1. directly via localhost
2. via proxy an localhost
#### Logs
```
[3JPXJ] 2025/04/11 15:00:40 INFO: Wrong credentials supplied during API authorization from 127.0.0.1
[3JPXJ] 2025/04/11 15:03:04 INFO: Wrong credentials supplied during API authorization from 192.168.178.5 proxied by 127.0.0.1
```
#### Event API
```
{
"id": 23,
"globalID": 23,
"time": "2025-04-11T15:00:40.578577402+02:00",
"type": "LoginAttempt",
"data": {
"remoteAddress": "127.0.0.1",
"success": false,
"username": "sdfsd"
}
},
{
"id": 24,
"globalID": 24,
"time": "2025-04-11T15:03:04.423403976+02:00",
"type": "LoginAttempt",
"data": {
"proxy": "127.0.0.1",
"remoteAddress": "192.168.178.5",
"success": false,
"username": "sdfsd"
}
}
```
### Documentation
https://github.com/syncthing/docs/pull/907
---------
Co-authored-by: Jakob Borg <jakob@kastelo.net>
The workflow building Debian packages chokes on branches containing
underscores:
```
{:timestamp=>"2025-04-03T10:31:46.749835+0000", :message=>"Invalid package configuration: The version looks invalid for Debian packages. Debian version field must contain only alphanumerics and . (period), + (plus), - (hyphen) or ~ (tilde). I have '1.29.5~dev.13.ga38df11f~srv_stun' which which isn't valid.", :level=>:error}
```
This replaces the offending `_` with a `~` which should yield a valid
version.
The current limit is far too low for our workloads. Perhaps we should
aim even higher than the 64MiB this patch proposes?
Citing the sqlite docs:
> [...] after committing a transaction the rollback journal file may
remain in the file-system. **This increases performance for subsequent
transactions since overwriting an existing file is faster than append to
a file**, but it also consumes file-system space.
tl;dr: if the limit is too low, we're shooting ourselves in the foot in
terms of performance.
The allowed IPv4 ranges are the same as before. But we now also accept IPv6 addresses in the ULA range FC00::/7. These addresses don't require an interface identifier and are roughly equivalent to the IPv4 private ranges.
Typical usecases:
VPN interface IPs: Wireguard, OpenVPN, Tailscale, ...
fixed IPv6 LAN addressing while the provider assigns a dynamic prefix. e.g used by pihole
https://cs.opensource.google/go/go/+/refs/tags/go1.21.0:src/net/ip.go;l=146
* Provide a sysctl config to raise max UDP buffer size
* Add sysctl config to deb
* Check if `deb-systemd-invoke` is available
Co-authored-by: otbutz <tbutz@optitool.de>
bt90
