chanserv: topic, invite, akick, list, status

Adds the remaining moderation and listing commands. Auto-kick masks are
stored in the event log and enforced on join: a matching user is banned
and kicked. Topic and invite are sourced from the ChanServ pseudoclient.

modules/chanserv/akick.rs

@@ -0,0 +1,52 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// AKICK <#channel> ADD <mask> [reason] | DEL <mask> | LIST
+// Masks are nick!user@host globs; matching users are banned and kicked on join.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, db: &mut Db) {
+    let Some(&chan) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: AKICK <#channel> ADD <mask> [reason] | DEL <mask> | LIST");
+        return;
+    };
+    match args.get(2).map(|s| s.to_ascii_uppercase()).as_deref() {
+        None | Some("LIST") => match db.channel(chan) {
+            None => ctx.notice(me, from.uid, format!("\x02{chan}\x02 isn't registered.")),
+            Some(info) if info.akick.is_empty() => ctx.notice(me, from.uid, format!("\x02{chan}\x02 has an empty auto-kick list.")),
+            Some(info) => {
+                ctx.notice(me, from.uid, format!("Auto-kick list for \x02{}\x02:", info.name));
+                for k in &info.akick {
+                    ctx.notice(me, from.uid, format!("  \x02{}\x02 ({})", k.mask, k.reason));
+                }
+            }
+        },
+        Some("ADD") => {
+            let Some(&mask) = args.get(3) else {
+                ctx.notice(me, from.uid, "Syntax: AKICK <#channel> ADD <mask> [reason]");
+                return;
+            };
+            if !super::require_op(me, from, chan, ctx, db) {
+                return;
+            }
+            let reason = if args.len() > 4 { args[4..].join(" ") } else { "Auto-kicked".to_string() };
+            match db.akick_add(chan, mask, &reason) {
+                Ok(()) => ctx.notice(me, from.uid, format!("Added \x02{mask}\x02 to \x02{chan}\x02's auto-kick list.")),
+                Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+            }
+        }
+        Some("DEL") => {
+            let Some(&mask) = args.get(3) else {
+                ctx.notice(me, from.uid, "Syntax: AKICK <#channel> DEL <mask>");
+                return;
+            };
+            if !super::require_op(me, from, chan, ctx, db) {
+                return;
+            }
+            match db.akick_del(chan, mask) {
+                Ok(true) => ctx.notice(me, from.uid, format!("Removed \x02{mask}\x02 from \x02{chan}\x02's auto-kick list.")),
+                Ok(false) => ctx.notice(me, from.uid, format!("\x02{mask}\x02 isn't on \x02{chan}\x02's auto-kick list.")),
+                Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+            }
+        }
+        _ => ctx.notice(me, from.uid, "Syntax: AKICK <#channel> ADD <mask> [reason] | DEL <mask> | LIST"),
+    }
+}

modules/chanserv/chanserv.rs

@@ -14,6 +14,16 @@ mod kick;
 mod ban;
 #[path = "unban.rs"]
 mod unban;
+#[path = "topic.rs"]
+mod topic;
+#[path = "invite.rs"]
+mod invite;
+#[path = "akick.rs"]
+mod akick;
+#[path = "list.rs"]
+mod list;
+#[path = "status.rs"]
+mod status;
 
 pub struct ChanServ {
     pub uid: String,
@@ -146,7 +156,12 @@ impl Service for ChanServ {
             Some("KICK") => kick::handle(me, from, args, ctx, net, db),
             Some("BAN") => ban::handle(me, from, args, ctx, net, db),
             Some("UNBAN") => unban::handle(me, from, args, ctx, net, db),
-            Some("HELP") => ctx.notice(me, from.uid, "ChanServ registers and looks after channels. Commands: \x02REGISTER\x02, \x02INFO\x02, \x02ACCESS\x02, \x02OP\x02/\x02DEOP\x02, \x02VOICE\x02/\x02DEVOICE\x02, \x02KICK\x02, \x02BAN\x02/\x02UNBAN\x02, \x02MODE\x02, \x02MLOCK\x02, \x02DROP\x02 — each takes a <#channel>."),
+            Some("TOPIC") => topic::handle(me, from, args, ctx, db),
+            Some("INVITE") => invite::handle(me, from, args, ctx, net, db),
+            Some("AKICK") => akick::handle(me, from, args, ctx, db),
+            Some("STATUS") => status::handle(me, from, args, ctx, net, db),
+            Some("LIST") => list::handle(me, from, args, ctx, db),
+            Some("HELP") => ctx.notice(me, from.uid, "ChanServ registers and looks after channels. Commands: \x02REGISTER\x02, \x02INFO\x02, \x02LIST\x02, \x02ACCESS\x02, \x02STATUS\x02, \x02OP\x02/\x02DEOP\x02, \x02VOICE\x02/\x02DEVOICE\x02, \x02KICK\x02, \x02BAN\x02/\x02UNBAN\x02, \x02AKICK\x02, \x02TOPIC\x02, \x02INVITE\x02, \x02MODE\x02, \x02MLOCK\x02, \x02DROP\x02."),
             Some(other) => ctx.notice(me, from.uid, format!("I don't know the command \x02{other}\x02. Try \x02HELP\x02.")),
             None => {}
         }

modules/chanserv/invite.rs

@@ -0,0 +1,26 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+use crate::engine::state::Network;
+
+// INVITE <#channel> [nick]: invite a user (self if no nick) into the channel.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &Network, db: &Db) {
+    let Some(&chan) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: INVITE <#channel> [nick]");
+        return;
+    };
+    if !super::require_op(me, from, chan, ctx, db) {
+        return;
+    }
+    let target = match args.get(2) {
+        Some(&nick) => match net.uid_by_nick(nick) {
+            Some(u) => u.to_string(),
+            None => {
+                ctx.notice(me, from.uid, format!("\x02{nick}\x02 isn't here."));
+                return;
+            }
+        },
+        None => from.uid.to_string(),
+    };
+    ctx.invite(me, &target, chan);
+    ctx.notice(me, from.uid, format!("Invited to \x02{chan}\x02."));
+}

modules/chanserv/list.rs

@@ -0,0 +1,16 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// LIST: show all registered channels.
+pub fn handle(me: &str, from: &Sender, _args: &[&str], ctx: &mut ServiceCtx, db: &Db) {
+    let mut names: Vec<&str> = db.channels().map(|c| c.name.as_str()).collect();
+    if names.is_empty() {
+        ctx.notice(me, from.uid, "No channels are registered.");
+        return;
+    }
+    names.sort_unstable();
+    ctx.notice(me, from.uid, format!("Registered channels ({}):", names.len()));
+    for n in names {
+        ctx.notice(me, from.uid, format!("  \x02{n}\x02"));
+    }
+}

modules/chanserv/status.rs

@@ -0,0 +1,29 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+use crate::engine::state::Network;
+
+// STATUS <#channel> [nick]: show a user's access level (self if no nick).
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &Network, db: &Db) {
+    let Some(&chan) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: STATUS <#channel> [nick]");
+        return;
+    };
+    let Some(info) = db.channel(chan) else {
+        ctx.notice(me, from.uid, format!("\x02{chan}\x02 isn't registered."));
+        return;
+    };
+    let (label, account) = match args.get(2) {
+        Some(&nick) => (nick.to_string(), net.uid_by_nick(nick).and_then(|u| net.account_of(u)).map(str::to_string)),
+        None => (from.nick.to_string(), from.account.map(str::to_string)),
+    };
+    let level = match account.as_deref() {
+        None => "none (not logged in)",
+        Some(a) if info.founder.eq_ignore_ascii_case(a) => "founder",
+        Some(a) => match info.join_mode(a) {
+            Some("+o") => "op",
+            Some("+v") => "voice",
+            _ => "none",
+        },
+    };
+    ctx.notice(me, from.uid, format!("\x02{label}\x02 access on \x02{chan}\x02: \x02{level}\x02"));
+}

modules/chanserv/topic.rs

@@ -0,0 +1,16 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// TOPIC <#channel> <text>: set the channel topic (empty clears it).
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, db: &Db) {
+    let Some(&chan) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: TOPIC <#channel> <text>");
+        return;
+    };
+    if !super::require_op(me, from, chan, ctx, db) {
+        return;
+    }
+    let text = if args.len() > 2 { args[2..].join(" ") } else { String::new() };
+    ctx.topic(me, chan, &text);
+    ctx.notice(me, from.uid, format!("Topic for \x02{chan}\x02 updated."));
+}

modules/protocol/inspircd.rs

@@ -236,6 +236,16 @@ impl Protocol for InspIrcd {
             NetAction::Kick { from, channel, uid, reason } => {
                 vec![format!(":{} KICK {} {} :{}", from, channel, uid, reason)]
             }
+            // FTOPIC <chan> <chanTS> <topicTS> <setter> :<topic>. TS 1 so the ircd
+            // always accepts it; sourced from the given pseudoclient.
+            NetAction::Topic { from, channel, topic } => {
+                let now = SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(self.ts);
+                vec![format!(":{} FTOPIC {} 1 {} {} :{}", from, channel, now, from, topic)]
+            }
+            // INVITE <uid> <chan> <chanTS> <expiry>. Expiry 0 = no expiry.
+            NetAction::Invite { from, uid, channel } => {
+                vec![format!(":{} INVITE {} {} 1 0", from, uid, channel)]
+            }
             NetAction::Raw(s) => vec![s.clone()],
             // Internal: the link layer handles this before serialization.
             NetAction::DeferRegister { .. } => vec![],

modules/protocol/mod.rs

@@ -52,6 +52,10 @@ pub enum NetAction {
     ChannelMode { from: String, channel: String, modes: String },
     // Kick a user from a channel, sourced from pseudoclient `from`.
     Kick { from: String, channel: String, uid: String, reason: String },
+    // Set a channel's topic, sourced from pseudoclient `from`.
+    Topic { from: String, channel: String, topic: String },
+    // Invite a user to a channel, sourced from pseudoclient `from`.
+    Invite { from: String, uid: String, channel: String },
     Raw(String),
     // Internal only, never serialized to the wire: a registration whose password
     // still needs its (expensive) key derivation. The link layer runs the

src/engine/db.rs

@@ -43,6 +43,8 @@ pub enum Event {
     ChannelMlock { name: String, on: String, off: String },
     ChannelAccessAdd { channel: String, account: String, level: String },
     ChannelAccessDel { channel: String, account: String },
+    ChannelAkickAdd { channel: String, mask: String, reason: String },
+    ChannelAkickDel { channel: String, mask: String },
 }
 
 // An access-list entry: an account and its level ("op" or "voice").
@@ -52,6 +54,13 @@ pub struct ChanAccess {
     pub level: String,
 }
 
+// An auto-kick entry: a nick!user@host mask and why it was added.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ChanAkick {
+    pub mask: String,
+    pub reason: String,
+}
+
 // A registered channel and who owns it.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct ChannelInfo {
@@ -65,6 +74,8 @@ pub struct ChannelInfo {
     pub lock_off: String,
     #[serde(default)]
     pub access: Vec<ChanAccess>,
+    #[serde(default)]
+    pub akick: Vec<ChanAkick>,
 }
 
 impl ChannelInfo {
@@ -85,6 +96,11 @@ impl ChannelInfo {
         self.join_mode(account) == Some("+o")
     }
 
+    /// The matching auto-kick entry for `hostmask` (nick!user@host), if any.
+    pub fn akick_match(&self, hostmask: &str) -> Option<&ChanAkick> {
+        self.akick.iter().find(|k| glob_match(&k.mask, hostmask))
+    }
+
     /// The mode string services keep applied: +r plus the lock.
     pub fn lock_modes(&self) -> String {
         let mut s = format!("+r{}", self.lock_on);
@@ -376,6 +392,9 @@ impl Db {
             for a in &c.access {
                 snapshot.push(Event::ChannelAccessAdd { channel: c.name.clone(), account: a.account.clone(), level: a.level.clone() });
             }
+            for k in &c.akick {
+                snapshot.push(Event::ChannelAkickAdd { channel: c.name.clone(), mask: k.mask.clone(), reason: k.reason.clone() });
+            }
         }
         self.log.compact(snapshot)?;
         tracing::info!(before, after = self.log.len(), "compacted event log");
@@ -516,7 +535,7 @@ impl Db {
         self.log
             .append(Event::ChannelRegistered { name: name.to_string(), founder: founder.to_string(), ts })
             .map_err(|_| ChanError::Internal)?;
-        self.channels.insert(k, ChannelInfo { name: name.to_string(), founder: founder.to_string(), ts, lock_on: String::new(), lock_off: String::new(), access: Vec::new() });
+        self.channels.insert(k, ChannelInfo { name: name.to_string(), founder: founder.to_string(), ts, lock_on: String::new(), lock_off: String::new(), access: Vec::new(), akick: Vec::new() });
         Ok(())
     }
 
@@ -525,6 +544,11 @@ impl Db {
         self.channels.get(&key(name))
     }
 
+    /// All registered channels, for listing.
+    pub fn channels(&self) -> impl Iterator<Item = &ChannelInfo> {
+        self.channels.values()
+    }
+
     /// Set the mode-lock (chars to keep set / unset) for a registered channel.
     pub fn set_mlock(&mut self, name: &str, on: &str, off: &str) -> Result<(), ChanError> {
         let k = key(name);
@@ -571,6 +595,37 @@ impl Db {
         Ok(true)
     }
 
+    /// Add an auto-kick `mask` (with `reason`) to `channel`.
+    pub fn akick_add(&mut self, channel: &str, mask: &str, reason: &str) -> Result<(), ChanError> {
+        let k = key(channel);
+        if !self.channels.contains_key(&k) {
+            return Err(ChanError::NoChannel);
+        }
+        self.log
+            .append(Event::ChannelAkickAdd { channel: channel.to_string(), mask: mask.to_string(), reason: reason.to_string() })
+            .map_err(|_| ChanError::Internal)?;
+        let c = self.channels.get_mut(&k).unwrap();
+        c.akick.retain(|a| !a.mask.eq_ignore_ascii_case(mask));
+        c.akick.push(ChanAkick { mask: mask.to_string(), reason: reason.to_string() });
+        Ok(())
+    }
+
+    /// Remove auto-kick `mask` from `channel`. Ok(false) if not present.
+    pub fn akick_del(&mut self, channel: &str, mask: &str) -> Result<bool, ChanError> {
+        let k = key(channel);
+        let Some(c) = self.channels.get(&k) else {
+            return Err(ChanError::NoChannel);
+        };
+        if !c.akick.iter().any(|a| a.mask.eq_ignore_ascii_case(mask)) {
+            return Ok(false);
+        }
+        self.log
+            .append(Event::ChannelAkickDel { channel: channel.to_string(), mask: mask.to_string() })
+            .map_err(|_| ChanError::Internal)?;
+        self.channels.get_mut(&k).unwrap().akick.retain(|a| !a.mask.eq_ignore_ascii_case(mask));
+        Ok(true)
+    }
+
     /// Unregister `name`.
     pub fn drop_channel(&mut self, name: &str) -> Result<(), ChanError> {
         let k = key(name);
@@ -603,7 +658,7 @@ fn apply(accounts: &mut HashMap<String, Account>, channels: &mut HashMap<String,
             }
         }
         Event::ChannelRegistered { name, founder, ts } => {
-            channels.insert(key(&name), ChannelInfo { name, founder, ts, lock_on: String::new(), lock_off: String::new(), access: Vec::new() });
+            channels.insert(key(&name), ChannelInfo { name, founder, ts, lock_on: String::new(), lock_off: String::new(), access: Vec::new(), akick: Vec::new() });
         }
         Event::ChannelDropped { name } => {
             channels.remove(&key(&name));
@@ -625,8 +680,50 @@ fn apply(accounts: &mut HashMap<String, Account>, channels: &mut HashMap<String,
                 c.access.retain(|a| !a.account.eq_ignore_ascii_case(&account));
             }
         }
+        Event::ChannelAkickAdd { channel, mask, reason } => {
+            if let Some(c) = channels.get_mut(&key(&channel)) {
+                c.akick.retain(|k| !k.mask.eq_ignore_ascii_case(&mask));
+                c.akick.push(ChanAkick { mask, reason });
             }
         }
+        Event::ChannelAkickDel { channel, mask } => {
+            if let Some(c) = channels.get_mut(&key(&channel)) {
+                c.akick.retain(|k| !k.mask.eq_ignore_ascii_case(&mask));
+            }
+        }
+    }
+}
+
+// Case-insensitive glob match supporting `*` (any run) and `?` (one char),
+// used for auto-kick hostmasks. Iterative with backtracking, no allocation.
+fn glob_match(pattern: &str, text: &str) -> bool {
+    let (p, t): (Vec<char>, Vec<char>) = (
+        pattern.chars().flat_map(char::to_lowercase).collect(),
+        text.chars().flat_map(char::to_lowercase).collect(),
+    );
+    let (mut pi, mut ti) = (0, 0);
+    let (mut star, mut mark) = (None, 0);
+    while ti < t.len() {
+        if pi < p.len() && (p[pi] == '?' || p[pi] == t[ti]) {
+            pi += 1;
+            ti += 1;
+        } else if pi < p.len() && p[pi] == '*' {
+            star = Some(pi);
+            mark = ti;
+            pi += 1;
+        } else if let Some(s) = star {
+            pi = s + 1;
+            mark += 1;
+            ti = mark;
+        } else {
+            return false;
+        }
+    }
+    while pi < p.len() && p[pi] == '*' {
+        pi += 1;
+    }
+    pi == p.len()
+}
 
 fn hash_password(password: &str) -> Option<String> {
     let salt = SaltString::generate(&mut OsRng);
@@ -653,6 +750,29 @@ mod tests {
         Event::CertAdded { account: account.into(), fp: fp.into() }
     }
 
+    #[test]
+    fn glob_matches_hostmasks() {
+        assert!(glob_match("*!*@host.example", "bob!~b@host.example"));
+        assert!(glob_match("bob!*@*", "BOB!~b@1.2.3.4"));
+        assert!(glob_match("*", "anything"));
+        assert!(glob_match("nick?!*@*", "nickX!~x@h"));
+        assert!(!glob_match("*!*@host.example", "bob!~b@other"));
+        assert!(!glob_match("alice!*@*", "bob!~b@h"));
+    }
+
+    #[test]
+    fn akick_add_del_and_match() {
+        let mut db = Db::open(&tmp("akick"), "N1");
+        db.register_channel("#c", "founder").unwrap();
+        db.akick_add("#c", "*!*@bad.host", "spam").unwrap();
+        let info = db.channel("#c").unwrap();
+        assert!(info.akick_match("evil!~e@bad.host").is_some());
+        assert!(info.akick_match("good!~g@ok.host").is_none());
+        assert!(db.akick_del("#c", "*!*@bad.host").unwrap());
+        assert!(!db.akick_del("#c", "*!*@bad.host").unwrap());
+        assert!(db.channel("#c").unwrap().akick.is_empty());
+    }
+
     // Locally-authored events get an incrementing per-origin seq and a ticking
     // Lamport clock.
     #[test]

src/engine/mod.rs

@@ -194,15 +194,30 @@ impl Engine {
             // Give the founder and access-list members their status on join.
             NetEvent::Join { uid, channel } => {
                 let account = self.network.account_of(&uid).map(str::to_string);
+                let from = self.chan_service.clone().unwrap_or_default();
                 let mode = account.as_deref().and_then(|a| self.db.channel(&channel).and_then(|c| c.join_mode(a)));
                 match mode {
-                    Some(m) => {
-                        let from = self.chan_service.clone().unwrap_or_default();
-                        vec![NetAction::ChannelMode { from, channel, modes: format!("{m} {uid}") }]
+                    // A user with access gets their status mode.
+                    Some(m) => vec![NetAction::ChannelMode { from, channel, modes: format!("{m} {uid}") }],
+                    // Otherwise, enforce the auto-kick list.
+                    None => {
+                        let nick = self.network.nick_of(&uid).unwrap_or("*");
+                        let host = self.network.host_of(&uid).unwrap_or("*");
+                        let hostmask = format!("{nick}!*@{host}");
+                        match self.db.channel(&channel).and_then(|c| c.akick_match(&hostmask)) {
+                            Some(k) => {
+                                let mask = k.mask.clone();
+                                let reason = if k.reason.is_empty() { "You are banned from this channel.".to_string() } else { k.reason.clone() };
+                                vec![
+                                    NetAction::ChannelMode { from: from.clone(), channel: channel.clone(), modes: format!("+b {mask}") },
+                                    NetAction::Kick { from, channel, uid, reason },
+                                ]
                             }
                             None => Vec::new(),
                         }
                     }
+                }
+            }
             NetEvent::Quit { uid } => {
                 self.network.user_quit(&uid);
                 self.sasl_sessions.remove(&uid); // drop any half-finished exchange
@@ -1033,6 +1048,47 @@ mod tests {
         assert!(to_cs(&mut e, "000AAAAAD", "KICK #m alice").iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("operator access"))));
     }
 
+    // ChanServ topic, invite, auto-kick (with enforcement on join), list and status.
+    #[test]
+    fn chanserv_topic_invite_akick() {
+        use crate::chanserv::ChanServ;
+        let path = std::env::temp_dir().join("fedserv-cs-tia.jsonl");
+        let _ = std::fs::remove_file(&path);
+        let mut db = Db::open(&path, "42S");
+        db.scram_iterations = 4096;
+        db.register("alice", "sesame", None).unwrap();
+        db.register_channel("#c", "alice").unwrap();
+        let ns = NickServ { uid: "42SAAAAAA".into(), guest_nick: "Guest".into(), guest_seq: 0 };
+        let cs = ChanServ { uid: "42SAAAAAB".into() };
+        let mut e = Engine::new(vec![Box::new(ns), Box::new(cs)], db);
+        let to_cs = |e: &mut Engine, from: &str, text: &str| {
+            e.handle(NetEvent::Privmsg { from: from.into(), to: "42SAAAAAB".into(), text: text.into() })
+        };
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAB".into(), nick: "alice".into(), host: "h1".into() });
+        e.handle(NetEvent::Privmsg { from: "000AAAAAB".into(), to: "42SAAAAAA".into(), text: "IDENTIFY sesame".into() });
+        e.handle(NetEvent::UserConnect { uid: "000AAAAAC".into(), nick: "bob".into(), host: "bad.host".into() });
+
+        // TOPIC and INVITE are sourced from ChanServ.
+        let out = to_cs(&mut e, "000AAAAAB", "TOPIC #c hello there");
+        assert!(out.iter().any(|a| matches!(a, NetAction::Topic { channel, topic, .. } if channel == "#c" && topic == "hello there")), "{out:?}");
+        let out = to_cs(&mut e, "000AAAAAB", "INVITE #c bob");
+        assert!(out.iter().any(|a| matches!(a, NetAction::Invite { uid, channel, .. } if uid == "000AAAAAC" && channel == "#c")), "{out:?}");
+
+        // LIST and STATUS.
+        assert!(to_cs(&mut e, "000AAAAAB", "LIST").iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("#c"))));
+        assert!(to_cs(&mut e, "000AAAAAB", "STATUS #c").iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("founder"))));
+
+        // AKICK a mask, then a matching join is banned and kicked.
+        assert!(to_cs(&mut e, "000AAAAAB", "AKICK #c ADD *!*@bad.host begone").iter().any(|a| matches!(a, NetAction::Notice { text, .. } if text.contains("Added"))));
+        let out = e.handle(NetEvent::Join { uid: "000AAAAAC".into(), channel: "#c".into() });
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { channel, modes, .. } if channel == "#c" && modes == "+b *!*@bad.host")), "{out:?}");
+        assert!(out.iter().any(|a| matches!(a, NetAction::Kick { channel, uid, reason, .. } if channel == "#c" && uid == "000AAAAAC" && reason == "begone")), "{out:?}");
+
+        // The founder joining is never auto-kicked (they get +o instead).
+        let out = e.handle(NetEvent::Join { uid: "000AAAAAB".into(), channel: "#c".into() });
+        assert!(out.iter().any(|a| matches!(a, NetAction::ChannelMode { modes, .. } if modes.starts_with("+o"))), "{out:?}");
+    }
+
     // A registered channel (re)appearing re-asserts +r; an unregistered one does not.
     #[test]
     fn channel_create_reasserts_registered_mode() {

src/engine/service.rs

@@ -99,4 +99,22 @@ impl ServiceCtx {
             reason: reason.to_string(),
         });
     }
+
+    // Set a channel's topic, sourced from pseudoclient `from`.
+    pub fn topic(&mut self, from: &str, channel: &str, topic: &str) {
+        self.actions.push(NetAction::Topic {
+            from: from.to_string(),
+            channel: channel.to_string(),
+            topic: topic.to_string(),
+        });
+    }
+
+    // Invite a user to a channel, sourced from pseudoclient `from`.
+    pub fn invite(&mut self, from: &str, uid: &str, channel: &str) {
+        self.actions.push(NetAction::Invite {
+            from: from.to_string(),
+            uid: uid.to_string(),
+            channel: channel.to_string(),
+        });
+    }
 }