From 20fc6c17d1bd776087d274b319977d265a8c0656 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Janouch?= <p.janouch@gmail.com>
Date: Thu, 11 Jun 2015 22:41:01 +0200
Subject: [PATCH] kike: stubplement CAP

---
 kike-replies |  1 +
 kike.c       | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/kike-replies b/kike-replies
index c5deec5..c585740 100644
--- a/kike-replies
+++ b/kike-replies
@@ -48,6 +48,7 @@
 403 IRC_ERR_NOSUCHCHANNEL "%s :No such channel"
 404 IRC_ERR_CANNOTSENDTOCHAN "%s :Cannot send to channel"
 409 IRC_ERR_NOORIGIN ":No origin specified"
+410 IRC_ERR_INVALIDCAPCMD "%s :%s"
 411 IRC_ERR_NORECIPIENT ":No recipient given (%s)"
 412 IRC_ERR_NOTEXTTOSEND ":No text to send"
 421 IRC_ERR_UNKNOWNCOMMAND "%s: Unknown command"
diff --git a/kike.c b/kike.c
index df30ec0..4f9e3cd 100644
--- a/kike.c
+++ b/kike.c
@@ -308,10 +308,13 @@ struct client
 	struct poller_timer kill_timer;     ///< Hard kill timeout
 
 	bool initialized;                   ///< Has any data been received yet?
+	bool cap_negotiating;               ///< Negotiating capabilities
 	bool registered;                    ///< The user has registered
 	bool closing_link;                  ///< Closing link
 	bool half_closed;                   ///< Closing link: conn. is half-closed
 
+	unsigned long cap_version;          ///< CAP protocol version
+
 	bool ssl_rx_want_tx;                ///< SSL_read() wants to write
 	bool ssl_tx_want_rx;                ///< SSL_write() wants to read
 	SSL *ssl;                           ///< SSL connection
@@ -339,6 +342,7 @@ client_init (struct client *self)
 	self->socket_fd = -1;
 	str_init (&self->read_buffer);
 	str_init (&self->write_buffer);
+	self->cap_version = 301;
 	// TODO: make this configurable and more fine-grained
 	flood_detector_init (&self->antiflood, 10, 20);
 	str_map_init (&self->invites);
@@ -1078,6 +1082,8 @@ irc_try_finish_registration (struct client *c)
 	struct server_context *ctx = c->ctx;
 	if (!c->nickname || !c->username || !c->realname)
 		return;
+	if (c->registered || c->cap_negotiating)
+		return;
 
 	c->registered = true;
 	irc_send_reply (c, IRC_RPL_WELCOME, c->nickname, c->username, c->hostname);
@@ -1109,6 +1115,66 @@ irc_try_finish_registration (struct client *c)
 			ctx->server_name, c->nickname, c->ssl_cert_fingerprint);
 }
 
+static void
+irc_handle_cap (const struct irc_message *msg, struct client *c)
+{
+	if (msg->params.len < 1)
+		RETURN_WITH_REPLY (c, IRC_ERR_NEEDMOREPARAMS, msg->command);
+
+	struct str_vector v;
+	str_vector_init (&v);
+
+	const char *subcommand = msg->params.vector[0];
+	const char *params = "";
+	if (msg->params.len > 1)
+	{
+		params = msg->params.vector[1];
+		split_str_ignore_empty (params, ' ', &v);
+	}
+
+	const char *target = c->nickname ? c->nickname : "*";
+	if (!irc_strcmp (subcommand, "LS"))
+	{
+		if (v.len == 1 && !xstrtoul (&c->cap_version, v.vector[0], 10))
+			irc_send_reply (c, IRC_ERR_INVALIDCAPCMD,
+				subcommand, "Ignoring invalid protocol version number");
+
+		c->cap_negotiating = true;
+		// TODO: actually implement a few capabilities
+		client_send (c, "CAP %s LS :", target);
+	}
+	else if (!irc_strcmp (subcommand, "LIST"))
+	{
+		// TODO: list currently enabled capabilities
+		client_send (c, "CAP %s LIST :", target);
+	}
+	else if (!irc_strcmp (subcommand, "REQ"))
+	{
+		c->cap_negotiating = true;
+		// TODO: process the capability change request, "-" disables
+		if (v.len)
+			client_send (c, "CAP %s NAK :%s", target, params);
+		else
+			client_send (c, "CAP %s ACK :%s", target, params);
+	}
+	else if (!irc_strcmp (subcommand, "ACK"))
+	{
+		if (v.len)
+			irc_send_reply (c, IRC_ERR_INVALIDCAPCMD,
+				subcommand, "No acknowledgable capabilities supported");
+	}
+	else if (!irc_strcmp (subcommand, "END"))
+	{
+		c->cap_negotiating = false;
+		irc_try_finish_registration (c);
+	}
+	else
+		irc_send_reply (c, IRC_ERR_INVALIDCAPCMD,
+			subcommand, "Invalid CAP subcommand");
+
+	str_vector_free (&v);
+}
+
 static void
 irc_handle_pass (const struct irc_message *msg, struct client *c)
 {
@@ -2516,6 +2582,7 @@ irc_register_handlers (struct server_context *ctx)
 	// TODO: add a field for oper-only commands?
 	static const struct irc_command message_handlers[] =
 	{
+		{ "CAP",      false, irc_handle_cap      },
 		{ "PASS",     false, irc_handle_pass     },
 		{ "NICK",     false, irc_handle_nick     },
 		{ "USER",     false, irc_handle_user     },