Implement support for IRCv3.1 CAP negotiation

docs/signals.txt

@@ -131,6 +131,11 @@ irc-nicklist.c:
 irc-servers.c:
  "event connected", SERVER_REC
 
+irc-cap.c
+ "server cap ack "<cmd>, SERVER_REC
+ "server cap nak "<cmd>, SERVER_REC
+ "server cap end", SERVER_REC
+
 irc.c:
 
  "server event", SERVER_REC, char *data, char *sender_nick, char *sender_address

src/core/misc.c

@@ -211,6 +211,30 @@ void *gslist_foreach_find(GSList *list, FOREACH_FIND_FUNC func, const void *data
 	return NULL;
 }
 
+void gslist_free_full (GSList *list, GDestroyNotify free_func)
+{
+	GSList *tmp;
+
+	if (!list)
+		return;
+
+	for (tmp = list; tmp != NULL; tmp = tmp->next)
+		free_func(tmp->data);
+
+	g_slist_free(list);
+}
+
+GSList *gslist_remove_string (GSList *list, const char *str)
+{
+	GSList *l;
+
+	l = g_slist_find_custom(list, str, (GCompareFunc) g_strcmp0);
+	if (l != NULL)
+		return g_slist_remove_link(list, l);
+
+	return list;
+}
+
 /* `list' contains pointer to structure with a char* to string. */
 char *gslistptr_to_string(GSList *list, int offset, const char *delimiter)
 {

src/core/misc.h

@@ -21,6 +21,9 @@ GSList *gslist_find_string(GSList *list, const char *key);
 GSList *gslist_find_icase_string(GSList *list, const char *key);
 GList *glist_find_string(GList *list, const char *key);
 GList *glist_find_icase_string(GList *list, const char *key);
+GSList *gslist_remove_string (GSList *list, const char *str);
+
+void gslist_free_full (GSList *list, GDestroyNotify free_func);
 
 void *gslist_foreach_find(GSList *list, FOREACH_FIND_FUNC func, const void *data);
 

src/irc/core/Makefile.am

@@ -26,6 +26,7 @@ libirc_core_a_SOURCES = \
         irc-servers-reconnect.c \
         irc-servers-setup.c \
         irc-session.c \
+        irc-cap.c \
         lag.c \
         massjoin.c \
         modes.c \
@@ -48,6 +49,7 @@ pkginc_irc_core_HEADERS = \
         irc-queries.h \
         irc-servers.h \
         irc-servers-setup.h \
+        irc-cap.h \
         modes.h \
         mode-lists.h \
 	module.h \

src/irc/core/irc-cap.c

@@ -0,0 +1,172 @@
+#include "module.h"
+#include "signals.h"
+#include "misc.h"
+
+#include "irc-cap.h"
+#include "irc-servers.h"
+
+int cap_toggle (IRC_SERVER_REC *server, char *cap, int enable)
+{
+	if (cap == NULL || *cap == '\0')
+		return FALSE;
+
+	/* If the negotiation hasn't been completed yet just queue the requests */
+	if (!server->cap_complete) {
+		if (enable && !gslist_find_string(server->cap_queue, cap)) {
+			server->cap_queue = g_slist_prepend(server->cap_queue, g_strdup(cap));
+			return TRUE;
+		}
+		else if (!enable && gslist_find_string(server->cap_queue, cap)) {
+			server->cap_queue = gslist_remove_string(server->cap_queue, cap);
+			return TRUE;
+		}
+
+		return FALSE;
+	}
+
+	if (enable && !gslist_find_string(server->cap_active, cap)) {
+		/* Make sure the required cap is supported by the server */
+		if (!gslist_find_string(server->cap_supported, cap))
+			return FALSE;
+
+		irc_send_cmdv(server, "CAP REQ %s", cap);
+		return TRUE;
+	}
+	else if (!enable && gslist_find_string(server->cap_active, cap)) {
+		irc_send_cmdv(server, "CAP REQ -%s", cap);
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+void cap_finish_negotiation (IRC_SERVER_REC *server)
+{
+	if (server->cap_complete)
+		return;
+
+	server->cap_complete = TRUE;
+	irc_send_cmd_now(server, "CAP END");
+
+	signal_emit("server cap end", 1, server);
+}
+
+static void cap_emit_signal (IRC_SERVER_REC *server, char *cmd, char *args)
+{
+	char *signal_name;
+
+	signal_name = g_strdup_printf("server cap %s %s", cmd, args? args: "");
+	signal_emit(signal_name, 1, server);
+	g_free(signal_name);
+}
+
+static void event_cap (IRC_SERVER_REC *server, char *args, char *nick, char *address)
+{
+	GSList *tmp;
+	GString *cmd;
+	char *params, *evt, *list, **caps;
+	int i, caps_length, disable, avail_caps;
+
+	params = event_get_params(args, 3, NULL, &evt, &list);
+	if (params == NULL)
+		return;
+
+	/* Strip the trailing whitespaces before splitting the string, some servers send responses with
+	 * superfluous whitespaces that g_strsplit the interprets as tokens */
+	caps = g_strsplit(g_strchomp(list), " ", -1);
+	caps_length = g_strv_length(caps);
+
+	if (!g_strcmp0(evt, "LS")) {
+		/* Create a list of the supported caps */
+		for (i = 0; i < caps_length; i++)
+			server->cap_supported = g_slist_prepend(server->cap_supported, g_strdup(caps[i]));
+
+		/* Request the required caps, if any */
+		if (server->cap_queue == NULL) {
+			cap_finish_negotiation(server);
+		}
+		else {
+			cmd = g_string_new("CAP REQ :");
+
+			avail_caps = 0;
+
+			/* Check whether the cap is supported by the server */
+			for (tmp = server->cap_queue; tmp != NULL; tmp = tmp->next) {
+				if (gslist_find_string(server->cap_supported, tmp->data)) {
+					g_string_append_c(cmd, ' ');
+					g_string_append(cmd, tmp->data);
+
+					avail_caps++;
+				}
+			}
+
+			/* Clear the queue here */
+			gslist_free_full(server->cap_queue, (GDestroyNotify) g_free);
+			server->cap_queue = NULL;
+
+			/* If the server doesn't support any cap we requested close the negotiation here */
+			if (avail_caps > 0)
+				irc_send_cmd_now(server, cmd->str);
+			else
+				cap_finish_negotiation(server);
+
+			g_string_free(cmd, TRUE);
+		}
+	}
+	else if (!g_strcmp0(evt, "ACK")) {
+		int got_sasl = FALSE;
+
+		/* Emit a signal for every ack'd cap */
+		for (i = 0; i < caps_length; i++) {
+			disable = (*caps[i] == '-');
+
+			if (disable)
+				server->cap_active = gslist_remove_string(server->cap_active, caps[i] + 1);
+			else
+				server->cap_active = g_slist_prepend(server->cap_active, g_strdup(caps[i]));
+
+			if (!g_strcmp0(caps[i], "sasl"))
+				got_sasl = TRUE;
+
+			cap_emit_signal(server, "ack", caps[i]);
+		}
+
+		/* Hopefully the server has ack'd all the caps requested and we're ready to terminate the
+		 * negotiation, unless sasl was requested. In this case we must not terminate the negotiation
+		 * until the sasl handshake is over. */
+		if (got_sasl == FALSE)
+			cap_finish_negotiation(server);
+	}
+	else if (!g_strcmp0(evt, "NAK")) {
+		g_warning("The server answered with a NAK to our CAP request, this should not happen");
+
+		/* A NAK'd request means that a required cap can't be enabled or disabled, don't update the
+		 * list of active caps and notify the listeners. */
+		for (i = 0; i < caps_length; i++)
+			cap_emit_signal(server, "nak", caps[i]);
+	}
+
+	g_strfreev(caps);
+	g_free(params);
+}
+
+static void event_invalid_cap (IRC_SERVER_REC *server, const char *data, const char *from)
+{
+	/* The server didn't understand one (or more) requested caps, terminate the negotiation.
+	 * This could be handled in a graceful way but since it shouldn't really ever happen this seems a
+	 * good way to deal with 410 errors. */
+	server->cap_complete = FALSE;
+	irc_send_cmd_now(server, "CAP END");
+}
+
+void cap_init (void)
+{
+	signal_add_first("event cap", (SIGNAL_FUNC) event_cap);
+	signal_add_first("event 410", (SIGNAL_FUNC) event_invalid_cap);
+}
+
+void cap_deinit (void)
+{
+	signal_remove("event cap", (SIGNAL_FUNC) event_cap);
+	signal_remove("event 410", (SIGNAL_FUNC) event_invalid_cap);
+}

src/irc/core/irc-cap.h

@@ -0,0 +1,9 @@
+#ifndef __IRC_CAP_H
+#define __IRC_CAP_H
+
+void cap_init(void);
+void cap_deinit(void);
+int cap_toggle (IRC_SERVER_REC *server, char *cap, int enable);
+void cap_finish_negotiation (IRC_SERVER_REC *server);
+
+#endif

src/irc/core/irc-core.c

@@ -26,6 +26,7 @@
 #include "irc-chatnets.h"
 #include "irc-channels.h"
 #include "irc-queries.h"
+#include "irc-cap.h"
 
 #include "irc-servers-setup.h"
 #include "channels-setup.h"
@@ -117,6 +118,7 @@ void irc_core_init(void)
 	lag_init();
 	netsplit_init();
 	irc_expandos_init();
+	cap_init();
 
 	settings_check();
 	module_register("core", "irc");
@@ -126,6 +128,7 @@ void irc_core_deinit(void)
 {
 	signal_emit("chat protocol deinit", 1, chat_protocol_find("IRC"));
 
+	cap_deinit();
 	irc_expandos_deinit();
 	netsplit_deinit();
 	lag_deinit();

src/irc/core/irc-servers.c

@@ -32,6 +32,7 @@
 #include "irc-queries.h"
 #include "irc-servers-setup.h"
 #include "irc-servers.h"
+#include "irc-cap.h"
 #include "channel-rejoin.h"
 #include "servers-idle.h"
 #include "servers-reconnect.h"
@@ -201,6 +202,8 @@ static void server_init(IRC_SERVER_REC *server)
 
 	conn = server->connrec;
 
+	irc_send_cmd_now(server, "CAP LS");
+
 	if (conn->proxy != NULL && conn->proxy_password != NULL &&
 	    *conn->proxy_password != '\0') {
 		cmd = g_strdup_printf("PASS %s", conn->proxy_password);
@@ -409,7 +412,16 @@ static void sig_disconnected(IRC_SERVER_REC *server)
                         server_redirect_destroy(tmp->next->data);
 	}
 	g_slist_free(server->cmdqueue);
-        server->cmdqueue = NULL;
+	server->cmdqueue = NULL;
+
+	gslist_free_full(server->cap_active, (GDestroyNotify) g_free);
+	server->cap_active = NULL;
+
+	gslist_free_full(server->cap_supported, (GDestroyNotify) g_free);
+	server->cap_supported = NULL;
+
+	gslist_free_full(server->cap_queue, (GDestroyNotify) g_free);
+	server->cap_queue = NULL;
 
 	/* these are dynamically allocated only if isupport was sent */
 	g_hash_table_foreach(server->isupport,

src/irc/core/irc-servers.h

@@ -69,6 +69,13 @@ struct _IRC_SERVER_REC {
 	int max_whois_in_cmd; /* max. number of nicks in one /WHOIS command */
 	int max_msgs_in_cmd; /* max. number of targets in one /MSG */
 
+	GSList *cap_supported; /* A list of caps supported by the server */
+	GSList *cap_active;    /* A list of caps active for this session */
+	GSList *cap_queue;     /* A list of caps to request on connection */ 
+	int cap_complete:1;    /* We've done the initial CAP negotiation */
+
+	guint sasl_timeout; /* Holds the source id of the running timeout */
+
 	/* Command sending queue */
 	int cmdcount; /* number of commands in `cmdqueue'. Can be more than
 	                 there actually is, to make flood control remember