From 422ea52ad66f7c7004e26ca625feec98d4763160 Mon Sep 17 00:00:00 2001
From: Egor <egor@patchysicp.xyz>
Date: Fri, 3 Feb 2023 18:14:31 +0200
Subject: [PATCH] add multi-prefix cap

---
 common.h |  7 +++++--
 irc.c    | 52 ++++++++++++++++++++++++++++++++++++++++++----------
 ircfmt.c | 43 ++++++++++++++++++-------------------------
 3 files changed, 65 insertions(+), 37 deletions(-)

diff --git a/common.h b/common.h
index 2d4acd6..387f3f9 100644
--- a/common.h
+++ b/common.h
@@ -19,6 +19,8 @@ struct tls;
 #define REG_INIT 0
 #define REG_CAPLS 1
 #define REG_REGISTERED 2
+#define CAP_302 1
+#define CAP_MULTIPREFIX 2
 struct client_data {
 	SOCKET FD;
 	struct tls *cctx;
@@ -44,6 +46,7 @@ struct client_data {
 	int    cookie;
 	time_t signon;
 	time_t lastactivity;
+	unsigned int caps;
 };
 struct channel {
 	char *key;
@@ -73,8 +76,8 @@ struct channel {
 #define DMODE_NOEXTERNAL 8
 #define DMODE_SECRET 16
 #define DMODE_TOPICPROT 32
-#define is_chanop(chan, client) (trie_get(&(chan)->o, (client)->key))
-#define is_chanvoice(chan, client) (trie_get(&(chan)->v, (client)->key))
+#define is_chanop(chan, client) (!!trie_get(&(chan)->o, (client)->key))
+#define is_chanvoice(chan, client) (!!trie_get(&(chan)->v, (client)->key))
 extern struct trie_node *client_map;
 extern struct trie_node *channel_map;
 extern struct trie_node *autojoin;
diff --git a/irc.c b/irc.c
index 55d5aa9..b1e0a96 100644
--- a/irc.c
+++ b/irc.c
@@ -178,28 +178,61 @@ int processPacket(struct client_data *client, char *source, char *command, int a
 		msg_pong(args[0]);
 		sendbuf(client);
 	} else if(strcmp(command, "CAP") == 0) {
+		static const struct cap {
+			const char *name;
+			unsigned caps;
+		} caps[] = {
+			{ "multi-prefix", CAP_MULTIPREFIX },
+			{ "cap-notify", 0 },
+			{ 0, 0 }
+		};
+
 		if (!args[0])
 			return err_needmoreparams(client, command), sendbuf(client), 0;
 		stringupper(args[0]);
-		// don't enable CAP command until we actually have CAPs
-		// because clients can't handle NAKs
-		goto unknown;
-#if 0
 		if (strcmp(args[0], "LS") == 0) {
-			// at least one client hangs if it doesn't see a known extension
-			copy_strf(&databuf, ":%s CAP * LS :multi-prefix\n", hostname);
+			if (args[1] && atoi(args[1]) >= 302)
+				client->caps |= CAP_302;
+			copy_strf(&databuf, ":%s CAP * LS :multi-prefix\r\n", hostname);
 			sendbuf(client);
 			if (!is_registered(client)) {
 				client->regstate = REG_CAPLS;
 			}
 		} else if (strcmp(args[0], "LIST") == 0) {
-			copy_strf(&databuf, ":%s CAP * LIST :\n", hostname);
+			copy_strf(&databuf, ":%s CAP * LIST :\r\n", hostname);
+			for (const struct cap *c = caps; c->name; c++) {
+				if (client->caps & c->caps)
+				append_strf(&databuf, "%s ", c->name);
+			}
+			if (databuf.buf[databuf.len-1] == ' ')
+				databuf.len--;
+			append_strf(&databuf, "\r\n");
 			sendbuf(client);
 		} else if (strcmp(args[0], "REQ") == 0) {
 			if (!args[1]) // FIXME: error message
 				return 0;
-			copy_strf(&databuf, ":%s CAP * NAK :%s\n", hostname, args[1]);
-			sendbuf(client);
+			char *p;
+			if ((p = strtok(args[1], " "))) {
+				do {
+					int invert = *p == '-';
+					p += invert;
+					const struct cap *c;
+					for (c = caps; c->name; c++) {
+						if (strcmp(p, c->name) == 0) {
+							copy_strf(&databuf, ":%s CAP * ACK :%s%s\r\n", hostname, invert?"-":"", c->name);
+							if (!invert)
+								client->caps |= c->caps;
+							else
+								client->caps &= ~c->caps;
+							break;
+						}
+					}
+					if (!c->name)
+						copy_strf(&databuf, ":%s CAP * NAK :%s\r\n", hostname, p);
+					sendbuf(client);
+				} while ((p = strtok(NULL, " ")));
+			}
+			// FIXME: else error?
 		} else if (strcmp(args[0], "END") == 0) {
 			if (!is_registered(client)) {
 				client->regstate = REG_INIT;
@@ -208,7 +241,6 @@ int processPacket(struct client_data *client, char *source, char *command, int a
 		} else {
 			goto unknown;
 		}
-#endif
 	} else if(strcmp(command, "NICK") == 0) {
 		// User now registered
 		if (!args[0])
diff --git a/ircfmt.c b/ircfmt.c
index 61a6790..ad70f48 100644
--- a/ircfmt.c
+++ b/ircfmt.c
@@ -2,6 +2,19 @@
 extern struct dynarr databuf;
 extern const char *hostname;
 extern const char *format_umodes(struct client_data *cl);
+const char *format_prefixes(struct client_data *client, struct client_data *cl, struct channel *chan) {
+	if (!chan) return "";
+	int o = is_chanop(chan, cl);
+	int v = is_chanvoice(chan, cl);
+	if (client->caps & CAP_MULTIPREFIX && o && v)
+		return "@+";
+	else if (o)
+		return "@";
+	else if (v)
+		return "+";
+	else
+		return "";
+}
 
 void msg_nick(struct client_data *src, const char *newnick)
 {
@@ -223,16 +236,9 @@ void rpl_nowaway(struct client_data *client) // 306
 }
 void rpl_whoreply(struct client_data *client, struct client_data *cl, struct channel *chan) // 352
 {
-	char prefix[2] = {0,0};
-	if (chan) {
-		if (trie_get(&chan->o, cl->key))
-			prefix[0] = '@';
-		else if (trie_get(&chan->v, cl->key))
-			prefix[0] = '+';
-	}
 	copy_strf(&databuf, ":%s 352 %s %s %s %s %s %s %s%s%s :1 %s\r\n",
 			hostname, client->nick, chan ? chan->name : "*", cl->username, cl->hostname, hostname, cl->nick,
-			cl->away ? "G" : "H", cl->umode&UMODE_OPER ? "*" : "", prefix, cl->realname);
+			cl->away ? "G" : "H", cl->umode&UMODE_OPER ? "*" : "", format_prefixes(client, cl, chan), cl->realname);
 }
 void rpl_endofwho(struct client_data *client, const char *query) // 315
 {
@@ -267,14 +273,7 @@ void rpl_endofwhois(struct client_data *client, struct client_data *cl) // 318
 }
 void rpl_whoischannels(struct client_data *client, struct client_data *cl, struct channel *chan) // 319
 {
-	char prefix[2] = {0,0};
-	if (chan) {
-		if (trie_get(&chan->o, cl->key))
-			prefix[0] = '@';
-		else if (trie_get(&chan->v, cl->key))
-			prefix[0] = '+';
-	}
-	copy_strf(&databuf, ":%s 319 %s %s :%s%s\r\n", hostname, client->nick, cl->nick, prefix, chan->name);
+	copy_strf(&databuf, ":%s 319 %s %s :%s%s\r\n", hostname, client->nick, cl->nick, format_prefixes(client, cl, chan), chan->name);
 }
 #if 0
 void rpl_whoisspecial(struct client_data *client, struct client_data *cl, const char *info) // 320
@@ -382,16 +381,10 @@ int rpl_namreply(struct client_data *client, struct channel *chan, struct client
 			return 0;
 		}
 	}
-	const char *prefix = NULL;
-	if (is_chanop(chan, cl))
-		prefix = "@";
-	else if (is_chanvoice(chan, cl))
-		prefix = "+";
-	else
-		prefix = "";
+	const char *prefix = format_prefixes(client, cl, chan);
 	if (databuf.len == 0) {
-		// TODO: secret channel "@"
-		copy_strf(&databuf, ":%s 353 %s = %s :", hostname, client->nick, chan->name);
+		const char *chanchar = chan->dmode & DMODE_SECRET ? "@" : "=";
+		copy_strf(&databuf, ":%s 353 %s %s %s :", hostname, client->nick, chanchar, chan->name);
 	} else {
 		if (databuf.len + 1 + strlen(prefix) + strlen(cl->nick) > 510) {
 			append_str(&databuf, "\r\n");
-- 
2.56.0