OperServ: MODE override and KICK

Two channel operator tools:

- MODE <#chan> <modes> [params] forces a channel mode change (TS 1, so it
  applies regardless of the current TS). A status-mode target may be given
  as a nick — it's resolved to the uid the ircd's FMODE expects.
- KICK <#chan> <nick> [reason] removes a user, sourced from OperServ and
  attributed to the operator.

Both admin-gated. To resolve status-mode params, channel-mode parameter
arity became one shared helper (chanmode_takes_param + STATUS_MODES in the
api): the ircd module now delegates to it instead of keeping its own copy,
so burst-parsing and MODE-building can never drift.

api/src/lib.rs

@@ -130,6 +130,23 @@ pub trait Protocol: Send {
     fn sid(&self) -> &str;
 }
 
+// Whether a channel mode consumes a parameter, given the direction (`adding`).
+// The canonical arity for the standard chanmodes, shared by the protocol module
+// (parsing bursts) and services (building a MODE change): list and prefix modes
+// and the key take a parameter both ways; the rest that take one do so only when
+// set. A single source of truth so the two never drift.
+pub fn chanmode_takes_param(m: char, adding: bool) -> bool {
+    match m {
+        'b' | 'e' | 'I' | 'q' | 'a' | 'o' | 'h' | 'v' | 'k' => true,
+        'l' | 'L' | 'f' | 'j' | 'J' | 'F' | 'H' => adding,
+        _ => false,
+    }
+}
+
+// The channel prefix (status) modes, whose parameter is a nick/uid rather than a
+// mask or value.
+pub const STATUS_MODES: &str = "qaohv";
+
 // ---------------------------------------------------------------------------
 // Service vocabulary
 // ---------------------------------------------------------------------------

inspircd/src/lib.rs

@@ -343,16 +343,9 @@ impl Protocol for InspIrcd {
     }
 }
 
-// Whether a channel mode consumes a parameter, for standard InspIRCd chanmodes.
+// Whether a channel mode consumes a parameter — the shared canonical arity, so
-// List and prefix modes take one on both set and unset; the key takes one on
+// parsing here and MODE-building in services never drift.
-// both; the rest that take one do so only on set.
+use fedserv_api::chanmode_takes_param as takes_param;
-fn takes_param(m: char, adding: bool) -> bool {
-    match m {
-        'b' | 'e' | 'I' | 'q' | 'a' | 'o' | 'h' | 'v' | 'k' => true,
-        'l' | 'L' | 'f' | 'j' | 'J' | 'F' | 'H' => adding,
-        _ => false,
-    }
-}
 
 // Walk a mode change and its params for a key (+k/-k). Returns Some(Some(key))
 // when a key is set, Some(None) when cleared, None when `k` isn't in the change.

operserv/src/kick.rs

@@ -0,0 +1,26 @@
+use fedserv_api::{NetView, Priv, Sender, ServiceCtx};
+
+// KICK <#channel> <nick> [reason]: remove a user from a channel, sourced from
+// OperServ so it's clearly a staff action. Admin-only.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &dyn NetView) {
+    if !from.privs.has(Priv::Admin) {
+        ctx.notice(me, from.uid, "Access denied — KICK needs the \x02admin\x02 privilege.");
+        return;
+    }
+    let Some(&chan) = args.get(1).filter(|c| c.starts_with('#') || c.starts_with('&')) else {
+        ctx.notice(me, from.uid, "Syntax: KICK <#channel> <nick> [reason]");
+        return;
+    };
+    let Some(&target) = args.get(2) else {
+        ctx.notice(me, from.uid, "Syntax: KICK <#channel> <nick> [reason]");
+        return;
+    };
+    let Some(uid) = net.uid_by_nick(target).map(str::to_string) else {
+        ctx.notice(me, from.uid, format!("There's no \x02{target}\x02 online."));
+        return;
+    };
+    let by = from.account.unwrap_or(from.nick);
+    let reason = if args.len() > 3 { args[3..].join(" ") } else { "Removed by services".to_string() };
+    ctx.kick(me, chan, &uid, &format!("({by}) {reason}"));
+    ctx.notice(me, from.uid, format!("\x02{target}\x02 kicked from \x02{chan}\x02."));
+}

operserv/src/lib.rs

@@ -11,6 +11,10 @@ mod xline;
 mod global;
 #[path = "kill.rs"]
 mod kill;
+#[path = "kick.rs"]
+mod kick;
+#[path = "mode.rs"]
+mod mode;
 
 pub struct OperServ {
     pub uid: String,
@@ -39,6 +43,8 @@ impl Service for OperServ {
             Some(cmd) if cmd.eq_ignore_ascii_case("SQLINE") => xline::SQLINE.handle(me, from, args, ctx, db),
             Some(cmd) if cmd.eq_ignore_ascii_case("GLOBAL") => global::handle(me, from, args, ctx),
             Some(cmd) if cmd.eq_ignore_ascii_case("KILL") => kill::handle(me, from, args, ctx, net),
+            Some(cmd) if cmd.eq_ignore_ascii_case("KICK") => kick::handle(me, from, args, ctx, net),
+            Some(cmd) if cmd.eq_ignore_ascii_case("MODE") => mode::handle(me, from, args, ctx, net),
             Some(cmd) if cmd.eq_ignore_ascii_case("HELP") => help(me, from, ctx),
             None => help(me, from, ctx),
             Some(other) => ctx.notice(me, from.uid, format!("I don't know \x02{other}\x02. Try \x02HELP\x02.")),
@@ -47,5 +53,5 @@ impl Service for OperServ {
 }
 
 fn help(me: &str, from: &Sender, ctx: &mut ServiceCtx) {
-    ctx.notice(me, from.uid, "OperServ holds network operator tools (Priv::Admin): \x02AKILL\x02 ADD|DEL|LIST (user@host bans), \x02SQLINE\x02 ADD|DEL|LIST (nick bans), \x02GLOBAL\x02 <message> (announce to everyone), \x02KILL\x02 <nick> [reason] (disconnect a user).");
+    ctx.notice(me, from.uid, "OperServ holds network operator tools (Priv::Admin): \x02AKILL\x02 ADD|DEL|LIST (user@host bans), \x02SQLINE\x02 ADD|DEL|LIST (nick bans), \x02GLOBAL\x02 <message> (announce to everyone), \x02KILL\x02 <nick> [reason] (disconnect a user), \x02KICK\x02 <#chan> <nick> [reason], \x02MODE\x02 <#chan> <modes> [params].");
 }

operserv/src/mode.rs

@@ -0,0 +1,45 @@
+use fedserv_api::{chanmode_takes_param, NetView, Priv, Sender, ServiceCtx, STATUS_MODES};
+
+// MODE <#channel> <modes> [params]: set channel modes as a services override
+// (forced, so it applies regardless of the current TS). Admin-only. Status-mode
+// targets may be given as nicks — they're resolved to uids for the ircd.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &dyn NetView) {
+    if !from.privs.has(Priv::Admin) {
+        ctx.notice(me, from.uid, "Access denied — MODE needs the \x02admin\x02 privilege.");
+        return;
+    }
+    let Some(&chan) = args.get(1).filter(|c| c.starts_with('#') || c.starts_with('&')) else {
+        ctx.notice(me, from.uid, "Syntax: MODE <#channel> <modes> [params]");
+        return;
+    };
+    let Some(&modes) = args.get(2) else {
+        ctx.notice(me, from.uid, "Syntax: MODE <#channel> <modes> [params]");
+        return;
+    };
+    let params = &args[3..];
+
+    // Walk the change alongside its params: each param-taking mode consumes one,
+    // and a status mode's param is a nick we translate to its uid.
+    let (mut adding, mut pi) = (true, 0);
+    let mut out_params: Vec<String> = Vec::new();
+    for m in modes.chars() {
+        match m {
+            '+' => adding = true,
+            '-' => adding = false,
+            _ if chanmode_takes_param(m, adding) => {
+                if let Some(&p) = params.get(pi) {
+                    pi += 1;
+                    if STATUS_MODES.contains(m) {
+                        out_params.push(net.uid_by_nick(p).map(str::to_string).unwrap_or_else(|| p.to_string()));
+                    } else {
+                        out_params.push(p.to_string());
+                    }
+                }
+            }
+            _ => {}
+        }
+    }
+    let full = if out_params.is_empty() { modes.to_string() } else { format!("{} {}", modes, out_params.join(" ")) };
+    ctx.channel_mode(me, chan, &full);
+    ctx.notice(me, from.uid, format!("Set \x02{modes}\x02 on \x02{chan}\x02."));
+}

src/engine/mod.rs

@@ -3957,6 +3957,55 @@ mod tests {
         }
     }
 
+    // OperServ MODE (forced channel mode override, resolving a status-mode nick
+    // to its uid) and KICK (remove a user from a channel), both admin-gated.
+    #[test]
+    fn operserv_mode_and_kick() {
+        use fedserv_operserv::OperServ;
+        let path = std::env::temp_dir().join("fedserv-osmodekick.jsonl");
+        let _ = std::fs::remove_file(&path);
+        let mut db = Db::open(&path, "42S");
+        db.scram_iterations = 4096;
+        db.register("staff", "password1", None).unwrap();
+        db.register("plain", "password1", None).unwrap();
+        let mut e = Engine::new(
+            vec![
+                Box::new(NickServ { uid: "42SAAAAAA".into(), guest_nick: "Guest".into(), guest_seq: 0 }),
+                Box::new(OperServ { uid: "42SAAAAAH".into() }),
+            ],
+            db,
+        );
+        e.set_sid("42S".into());
+        let mut opers = std::collections::HashMap::new();
+        opers.insert("staff".to_string(), Privs::default().with(fedserv_api::Priv::Admin));
+        e.set_opers(opers);
+        let os = |e: &mut Engine, uid: &str, t: &str| e.handle(NetEvent::Privmsg { from: uid.into(), to: "42SAAAAAH".into(), text: t.into() });
+
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAS".into(), nick: "staff".into(), host: "h".into() });
+        e.handle(NetEvent::Privmsg { from: "000AAAAAS".into(), to: "42SAAAAAA".into(), text: "IDENTIFY password1".into() });
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAP".into(), nick: "plain".into(), host: "h".into() });
+        e.handle(NetEvent::Privmsg { from: "000AAAAAP".into(), to: "42SAAAAAA".into(), text: "IDENTIFY password1".into() });
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAT".into(), nick: "target".into(), host: "h".into() });
+
+        // A status mode's nick target is resolved to its uid in the FMODE.
+        let out = os(&mut e, "000AAAAAS", "MODE #room +o target");
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { from, channel, modes } if from == "42SAAAAAH" && channel == "#room" && modes == "+o 000AAAAAT")), "status mode resolved: {out:?}");
+        // A paramless mode passes straight through.
+        let out = os(&mut e, "000AAAAAS", "MODE #room +mn");
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { modes, .. } if modes == "+mn")), "paramless mode: {out:?}");
+
+        // KICK removes the user, attributed to the operator.
+        let out = os(&mut e, "000AAAAAS", "KICK #room target trolling");
+        assert!(out.iter().any(|a| matches!(a, NetAction::Kick { from, channel, uid, reason } if from == "42SAAAAAH" && channel == "#room" && uid == "000AAAAAT" && reason.contains("trolling") && reason.contains("staff"))), "kick issued: {out:?}");
+
+        // A non-admin gets nothing but a refusal.
+        for cmd in ["MODE #room +o target", "KICK #room target go"] {
+            let out = os(&mut e, "000AAAAAP", cmd);
+            assert!(out.iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("Access denied"))), "non-admin refused {cmd}");
+            assert!(!out.iter().any(|a| matches!(a, NetAction::ChannelMode { .. } | NetAction::Kick { .. })), "no action from non-admin {cmd}");
+        }
+    }
+
     // NOEXPIRE is oper-only.
     #[test]
     fn noexpire_command_is_oper_gated() {