nickserv: grouped nicks (GROUP/GLIST/UNGROUP) and GHOST

A nick can be grouped to an account and then identifies to it; the store
resolves an alias to its account everywhere it authenticates. GHOST (and
RECOVER) rename off a session using a nick you own. Grouped nicks
federate and are dropped with their account.

modules/nickserv/ghost.rs

@@ -0,0 +1,33 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+use crate::engine::state::Network;
+
+// GHOST/RECOVER <nick> [password]: rename off a session using a nick you own,
+// either by being identified to its account or giving that account's password.
+pub fn handle(me: &str, guest_nick: &str, guest_seq: &mut u32, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &Network, db: &Db) {
+    let Some(&target) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: GHOST <nick> [password]");
+        return;
+    };
+    let Some(account) = db.resolve_account(target).map(str::to_string) else {
+        ctx.notice(me, from.uid, format!("\x02{target}\x02 isn't registered."));
+        return;
+    };
+    let owns = from.account == Some(account.as_str()) || args.get(2).is_some_and(|pw| db.authenticate(target, pw).is_some());
+    if !owns {
+        ctx.notice(me, from.uid, format!("Access denied. Identify to \x02{account}\x02 or give its password."));
+        return;
+    }
+    let Some(ghost) = net.uid_by_nick(target).map(str::to_string) else {
+        ctx.notice(me, from.uid, format!("Nobody is using \x02{target}\x02."));
+        return;
+    };
+    if ghost == from.uid {
+        ctx.notice(me, from.uid, "That's you.");
+        return;
+    }
+    let guest = format!("{guest_nick}{guest_seq}");
+    *guest_seq = guest_seq.wrapping_add(1);
+    ctx.force_nick(&ghost, &guest);
+    ctx.notice(me, from.uid, format!("\x02{target}\x02 has been freed."));
+}

modules/nickserv/glist.rs

@@ -0,0 +1,17 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// GLIST: list the nicks grouped to your account.
+pub fn handle(me: &str, from: &Sender, ctx: &mut ServiceCtx, db: &Db) {
+    let Some(account) = from.account else {
+        ctx.notice(me, from.uid, "You need to be logged in. Identify to NickServ first.");
+        return;
+    };
+    let mut nicks = db.grouped_nicks(account);
+    nicks.sort();
+    ctx.notice(me, from.uid, format!("Nicks grouped to \x02{account}\x02:"));
+    ctx.notice(me, from.uid, format!("  \x02{account}\x02 (main)"));
+    for n in nicks {
+        ctx.notice(me, from.uid, format!("  \x02{n}\x02"));
+    }
+}

modules/nickserv/group.rs

@@ -0,0 +1,23 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// GROUP <account> <password>: link your current nick to an existing account, so
+// you can identify to it under this nick too.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, db: &mut Db) {
+    let (Some(&account), Some(&password)) = (args.get(1), args.get(2)) else {
+        ctx.notice(me, from.uid, "Syntax: GROUP <account> <password>");
+        return;
+    };
+    let Some(canonical) = db.authenticate(account, password).map(str::to_string) else {
+        ctx.notice(me, from.uid, "Invalid account or password.");
+        return;
+    };
+    if db.account(from.nick).is_some() {
+        ctx.notice(me, from.uid, format!("\x02{}\x02 is itself a registered account.", from.nick));
+        return;
+    }
+    match db.group_nick(from.nick, &canonical) {
+        Ok(()) => ctx.notice(me, from.uid, format!("Your nick \x02{}\x02 is now grouped to \x02{canonical}\x02.", from.nick)),
+        Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+    }
+}

modules/nickserv/nickserv.rs

@@ -18,6 +18,14 @@ mod alist;
 mod set;
 #[path = "drop.rs"]
 mod drop;
+#[path = "group.rs"]
+mod group;
+#[path = "glist.rs"]
+mod glist;
+#[path = "ungroup.rs"]
+mod ungroup;
+#[path = "ghost.rs"]
+mod ghost;
 
 pub struct NickServ {
     pub uid: String,
@@ -52,7 +60,11 @@ impl Service for NickServ {
             Some("ALIST") => alist::handle(me, from, ctx, db),
             Some("SET") => set::handle(me, from, args, ctx, db),
             Some("DROP") => drop::handle(me, from, args, ctx, net, db),
-            Some("HELP") => ctx.notice(me, from.uid, "NickServ looks after your nickname. Commands: \x02REGISTER\x02 <password> [email], \x02IDENTIFY\x02 [account] <password>, \x02INFO\x02 [account], \x02ALIST\x02, \x02SET\x02 PASSWORD|EMAIL, \x02DROP\x02 <password>, \x02LOGOUT\x02, \x02CERT\x02 ADD|DEL|LIST <password> [fingerprint]."),
+            Some("GROUP") => group::handle(me, from, args, ctx, db),
+            Some("GLIST") => glist::handle(me, from, ctx, db),
+            Some("UNGROUP") => ungroup::handle(me, from, args, ctx, db),
+            Some("GHOST") | Some("RECOVER") => ghost::handle(me, &self.guest_nick, &mut self.guest_seq, from, args, ctx, net, db),
+            Some("HELP") => ctx.notice(me, from.uid, "NickServ looks after your nickname. Commands: \x02REGISTER\x02 <password> [email], \x02IDENTIFY\x02 [account] <password>, \x02INFO\x02 [account], \x02ALIST\x02, \x02GROUP\x02/\x02GLIST\x02/\x02UNGROUP\x02, \x02GHOST\x02 <nick> [password], \x02SET\x02 PASSWORD|EMAIL, \x02DROP\x02 <password>, \x02LOGOUT\x02, \x02CERT\x02 ADD|DEL|LIST <password> [fingerprint]."),
             Some(other) => ctx.notice(me, from.uid, format!("I don't know the command \x02{other}\x02. Try \x02HELP\x02.")),
             None => {}
         }

modules/nickserv/ungroup.rs

@@ -0,0 +1,24 @@
+use crate::engine::db::Db;
+use crate::engine::service::{Sender, ServiceCtx};
+
+// UNGROUP [nick]: remove a nick grouped to your account (defaults to your current nick).
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, db: &mut Db) {
+    let Some(account) = from.account else {
+        ctx.notice(me, from.uid, "You need to be logged in. Identify to NickServ first.");
+        return;
+    };
+    let nick = args.get(1).copied().unwrap_or(from.nick);
+    if nick.eq_ignore_ascii_case(account) {
+        ctx.notice(me, from.uid, "You can't ungroup your main account name.");
+        return;
+    }
+    if db.resolve_account(nick).map_or(true, |a| !a.eq_ignore_ascii_case(account)) {
+        ctx.notice(me, from.uid, format!("\x02{nick}\x02 isn't grouped to your account."));
+        return;
+    }
+    match db.ungroup_nick(nick) {
+        Ok(true) => ctx.notice(me, from.uid, format!("\x02{nick}\x02 is no longer grouped to \x02{account}\x02.")),
+        Ok(false) => ctx.notice(me, from.uid, format!("\x02{nick}\x02 isn't a grouped nick.")),
+        Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+    }
+}