wip: add namespace implementation
Don't send TAGMSG to upstreams that don't support it

TAGMSG are (in current specs and drafts from IRCv3) only used for
client tags. These are optional information by design (since they are
not distributed to all users), therefore it is preferable to discard
them accordingly to upstream, instead of waiting for all upstreams to
support the capability to advertise it.
Don't accept any IP as a proxy by default

It's too easy to setup a reverse proxy which doesn't support the PROXY
protocol, or lets the X-Forwarded-For header fields pass through.
Disable this by default.

To restore the previous behaviour, add `accept-proxy-ip localhost` to
the config file.
Upgrade dependencies
Switch to go-scfg

We don't use child directives yet, but likely will in the future.
Add message store abstraction

Introduce a messageStore type, which will allow for multiple
implementations (e.g. in the DB or in-memory instead of on-disk).

The message store is per-user so that we don't need to deal with locking
and it's easier to implement per-user limits.
Switch to sql.NullString

Not really better than what we had before, however new contributors will
maybe be familiar with it.
Switch DB API to user IDs

This commit changes the Network schema to use user IDs instead of
usernames. While at it, a new UNIQUE(user, name) constraint ensures
there is no conflict with custom network names.

Closes: https://todo.sr.ht/~emersion/soju/86
References: https://todo.sr.ht/~emersion/soju/29
Add id column to User table

We used rowid before, but an explicit ID column is cleaner.
Add support for the extended-join capability

This simple implementation only advertises extended-join to downstreams
when all upstreams support it.

In the future, it could be modified so that soju buffers incoming
upstream JOINs, sends a WHO, waits for the reply, and sends an extended
join to the downstream; so that soju could advertise that capability
even when some or all upstreams do not support it. This is not the case
in this commit.
Add support for the PROXY protocol

IPs whitelisted in accept-proxy-ip can now use the PROXY protocol to
indicate the original source/destination addresses.

Closes: https://todo.sr.ht/~emersion/soju/81
Set Server.AcceptProxyIPs
7310f67f — Hubert Hirtz 5 months ago
Make DB.DeleteChannel take the channel ID

... to allow the caller to correctly do any necessary casemapping.
42828d68 — Hubert Hirtz 5 months ago
Make sure that WebSocket messages are valid UTF-8

... by replacing invalid bytes with the REPLACEMENT CHARACTER U+FFFD

This is better than:
- discarding the whole message, since the user would not see it...
- removing invalid bytes, since the user would not see their presence,
- converting the encoding (this is actually not possible).

Contrary to its documentation, strings.ToValidUTF8 doesn't copy the
string if it's valid UTF-8:
Don't update history when msgID is empty in appendLog

Log files don't record all message types. If the message isn't inserted
in the log file, don't update the history cursors for downstream
Fix panic in downstreamConn.sendNetworkHistory

This panic happens when sending history to a multi-upstream client.
sendNetworkHistory is called on each network, but dc.network is nil.

Closes: https://todo.sr.ht/~emersion/soju/93
Fix downstream PING argument handling

The PONG message should have these arguments:

- Our server name
- The PING message's source name

Closes: https://todo.sr.ht/~emersion/soju/92
Allow '/' in nickname

This allows to specify a network name in the nickname.

Closes: https://todo.sr.ht/~emersion/soju/91
Update dependencies
Nuke in-memory ring buffer

Instead, always read chat history from logs. Unify the implicit chat
history (pushing history to clients) and explicit chat history
(via the CHATHISTORY command).

Instead of keeping track of ring buffer cursors for each client, use
message IDs.

If necessary, the ring buffer could be re-introduced behind a
common MessageStore interface (could be useful when on-disk logs are

References: https://todo.sr.ht/~emersion/soju/80
Introduce loadHistoryLatestID

This loads latest messages from logs up to a given message ID. This is
similar to the IRCv3 CHATHISTORY LATEST command [1].

[1]: https://github.com/ircv3/ircv3-specifications/blob/0c271a5f1df4f93b5ae4c7597422821c40a8cfeb/extensions/chathistory.md#latest