hidelist: restrict list-mode viewing by rank; allow members to view lists by default (parity)

src/modules/hidelist.rs

@@ -0,0 +1,37 @@
+//! hidelist — hide a channel list mode's entries (e.g. the +b ban list) from users
+//! below a configured rank, so ordinary members can't enumerate who's banned.
+//! Config, repeatable: `hidelist = <modechar> <rank>` where rank is one of
+//! owner|admin|op|halfop|voice. Opers always see. Reference: InspIRCd's
+//! `m_hidelist`. Original native Rust.
+
+use crate::channels::{RANK_ADMIN, RANK_HALFOP, RANK_OP, RANK_OWNER, RANK_VOICE};
+use crate::server::Server;
+use crate::Uid;
+
+fn rank_value(name: &str) -> u8 {
+    match name.to_ascii_lowercase().as_str() {
+        "owner" | "founder" | "q" => RANK_OWNER,
+        "admin" | "protect" | "a" => RANK_ADMIN,
+        "op" | "o" => RANK_OP,
+        "halfop" | "h" => RANK_HALFOP,
+        "voice" | "v" => RANK_VOICE,
+        _ => RANK_OP, // unknown ⇒ require op, the safe default
+    }
+}
+
+/// True if `uid` may NOT view the `modechar` list in channel `key`: the config sets
+/// a per-mode minimum rank via `hidelist = <modechar> <rank>`. Opers always see.
+pub fn denied(s: &Server, uid: Uid, key: &str, modechar: char) -> bool {
+    if s.is_oper(uid) {
+        return false;
+    }
+    for line in s.conf_all("hidelist") {
+        let mut it = line.split_whitespace();
+        if let (Some(mc), Some(rank)) = (it.next(), it.next()) {
+            if mc.chars().next() == Some(modechar) {
+                return s.rank(uid, key) < rank_value(rank);
+            }
+        }
+    }
+    false
+}

src/modules/mod.rs

@@ -30,6 +30,7 @@ pub mod filter;
 pub mod flood;
 pub mod geoip;
 pub mod hashident;
+pub mod hidelist;
 pub mod hidewhois;
 pub mod irccloudtags;
 pub mod jsonlog;