filter (m_filter) as a self-contained module: Server.ext typemap for module state + module_commands() wiring; FILTER command + on_pre_message hook all in modules/filter.rs

src/modules/filter.rs

@@ -0,0 +1,182 @@
+//! filter — InspIRCd's `m_filter`: oper-configured spam/word filters. A glob is
+//! matched against PRIVMSG/NOTICE text and, on a hit, an action is taken. Fully
+//! self-contained: the rule set lives in `Server.ext` (the module-owned typemap),
+//! the `FILTER` command manages it, and the `on_pre_message` hook enforces it —
+//! nothing leaks into server.rs or config.rs.
+
+use crate::channels::glob_match;
+use crate::command::{CmdResult, Command};
+use crate::module::{ModResult, Module};
+use crate::numeric::ERR_NOPRIVILEGES;
+use crate::server::Server;
+use crate::xline::{parse_duration, XKind};
+use crate::Uid;
+
+/// One filter rule.
+#[derive(Clone)]
+pub struct SpamFilter {
+    pub pattern: String, // glob matched against message text
+    pub action: String,  // block | silent | kill | kline | gline | zline
+    pub duration: u64,   // ban length for the *line actions (seconds; 0 = permanent)
+    pub reason: String,
+}
+
+/// The rule set — stored in `Server.ext`, so it never touches the core struct.
+#[derive(Default)]
+pub struct Filters(pub Vec<SpamFilter>);
+
+impl Filters {
+    /// The (action, reason, duration) of the first rule whose glob matches `text`.
+    fn hit(&self, text: &str) -> Option<(String, String, u64)> {
+        self.0
+            .iter()
+            .find(|f| glob_match(&f.pattern, text))
+            .map(|f| (f.action.clone(), f.reason.clone(), f.duration))
+    }
+}
+
+/// The enforcement hook.
+pub struct Filter;
+impl Module for Filter {
+    fn name(&self) -> &'static str {
+        "filter"
+    }
+    fn on_pre_message(&mut self, s: &mut Server, uid: Uid, _target: &str, text: &str) -> ModResult {
+        let Some((action, reason, duration)) = s.ext.get::<Filters>().and_then(|f| f.hit(text))
+        else {
+            return ModResult::Passthru;
+        };
+        let (mask, ip) = match s.users.get(&uid) {
+            Some(u) => (u.prefix(), u.addr.ip().to_string()),
+            None => return ModResult::Deny,
+        };
+        s.snotice(&format!(
+            "FILTER: {mask} matched a filter (action={action}): {reason}"
+        ));
+        match action.as_str() {
+            "block" => s.notice_star(uid, &format!("Your message was blocked: {reason}")),
+            "silent" => {}
+            "kill" => {
+                s.send(uid, format!("ERROR :Closing link: ({reason})"));
+                s.remove_user(uid, &reason);
+            }
+            "kline" => {
+                s.add_xline(
+                    XKind::Kline,
+                    &format!("*@{ip}"),
+                    duration,
+                    "filter",
+                    &reason,
+                );
+                s.remove_user(uid, &reason);
+            }
+            "gline" => {
+                s.add_xline(
+                    XKind::Gline,
+                    &format!("*@{ip}"),
+                    duration,
+                    "filter",
+                    &reason,
+                );
+                s.remove_user(uid, &reason);
+            }
+            "zline" => {
+                s.add_xline(XKind::Zline, &ip, duration, "filter", &reason);
+                s.remove_user(uid, &reason);
+            }
+            _ => {}
+        }
+        ModResult::Deny // the message never reaches the channel/user
+    }
+}
+
+pub fn commands() -> Vec<Box<dyn Command>> {
+    vec![Box::new(FilterCmd)]
+}
+
+/// FILTER — manage spam filters (oper). No args = list; `<pattern>` = remove;
+/// `<pattern> <action> [duration] :<reason>` = add/replace.
+struct FilterCmd;
+impl Command for FilterCmd {
+    fn name(&self) -> &'static str {
+        "FILTER"
+    }
+    fn handle(&self, s: &mut Server, uid: Uid, params: &[String]) -> CmdResult {
+        if !s.is_oper(uid) {
+            s.numeric(
+                uid,
+                ERR_NOPRIVILEGES,
+                ":Permission Denied- You're not an IRC operator",
+            );
+            return CmdResult::Fail;
+        }
+        let nick = s
+            .users
+            .get(&uid)
+            .map(|u| u.nick.clone())
+            .unwrap_or_default();
+        match params.first() {
+            None => {
+                let list: Vec<String> = s
+                    .ext
+                    .get::<Filters>()
+                    .map(|f| {
+                        f.0.iter()
+                            .map(|r| {
+                                format!("{} {} {} :{}", r.pattern, r.action, r.duration, r.reason)
+                            })
+                            .collect()
+                    })
+                    .unwrap_or_default();
+                for r in list {
+                    s.send(uid, format!(":{} NOTICE {nick} :FILTER {r}", s.name));
+                }
+                s.send(
+                    uid,
+                    format!(":{} NOTICE {nick} :End of FILTER list", s.name),
+                );
+            }
+            Some(pattern) => {
+                let pattern = pattern.clone();
+                if params.len() < 2 {
+                    let removed = s
+                        .ext
+                        .get_mut::<Filters>()
+                        .map(|f| {
+                            let before = f.0.len();
+                            f.0.retain(|r| r.pattern != pattern);
+                            before != f.0.len()
+                        })
+                        .unwrap_or(false);
+                    let word = if removed { "removed" } else { "not found" };
+                    s.send(
+                        uid,
+                        format!(":{} NOTICE {nick} :FILTER {word}: {pattern}", s.name),
+                    );
+                } else {
+                    let action = params[1].clone();
+                    let (duration, reason) = match params.get(2).and_then(|p| parse_duration(p)) {
+                        Some(d) if params.len() > 3 => (d, params[3].clone()),
+                        _ => (
+                            0,
+                            params
+                                .get(2)
+                                .cloned()
+                                .unwrap_or_else(|| "Filtered".to_string()),
+                        ),
+                    };
+                    let f = s.ext.get_or_insert_with::<Filters>(Filters::default);
+                    f.0.retain(|r| r.pattern != pattern);
+                    f.0.push(SpamFilter {
+                        pattern: pattern.clone(),
+                        action: action.clone(),
+                        duration,
+                        reason,
+                    });
+                    s.snotice(&format!("{nick} added FILTER {pattern} (action={action})"));
+                }
+            }
+        }
+        CmdResult::Ok
+    }
+}

src/modules/mod.rs

@@ -6,9 +6,11 @@
 pub mod antimixedutf8;
 pub mod cloak;
 pub mod dnsbl;
+pub mod filter;
 pub mod flood;
 pub mod snoop;
 
+use crate::command::Command;
 use crate::module::Module;
 
 /// The modules loaded at boot. (Later: load by name from the config.)
@@ -18,5 +20,12 @@ pub fn default_modules() -> Vec<Box<dyn Module>> {
         Box::new(flood::Flood),
         Box::new(cloak::Cloak),
         Box::new(antimixedutf8::AntiMixedUtf8),
+        Box::new(filter::Filter),
     ]
 }
+
+/// Commands contributed by modules (chained into the core command table), so a
+/// module that adds a command keeps it in its own file, InspIRCd-style.
+pub fn module_commands() -> Vec<Box<dyn Command>> {
+    filter::commands().into_iter().collect()
+}