Fix invite-notify and move it to an extension

The existing approach to invite-notify is deeply flawed--it currently
notifies only the target user's server, and that can't be fixed without
sending notifies for invites that end up not happening.

I'm resolving this by broadcasting a second message, INVITED, from the
target user's server. I'm also pulling it out into an extension while
I'm at it--invite notifies reveal new information, so I don't think
they should be mandatory.

extensions/Makefile.am

@@ -35,6 +35,7 @@ extension_LTLIBRARIES =		\
   force_user_invis.la		\
   helpops.la			\
   hurt.la			\
+  invite_notify.la		\
   ip_cloaking.la		\
   ip_cloaking_old.la		\
   ip_cloaking_3.0.la		\

extensions/invite_notify.c

@@ -0,0 +1,74 @@
+#include <stdinc.h>
+#include <modules.h>
+#include <msgbuf.h>
+#include <client.h>
+#include <hash.h>
+#include <send.h>
+#include <s_serv.h>
+
+static const char inv_notify_desc[] = "Notifies channel on /invite and provides the invite-notify client capability";
+
+static void hook_invite(void *);
+static void m_invited(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
+static unsigned int CAP_INVITE_NOTIFY;
+
+mapi_hfn_list_av1 inv_notify_hfnlist[] = {
+	{ "invite", hook_invite },
+	{ NULL, NULL }
+};
+
+struct Message invited_msgtab = {
+	"INVITED", 0, 0, 0, 0,
+	{mg_ignore, mg_ignore, mg_ignore, mg_ignore, {m_invited, 4}, mg_ignore}
+};
+
+mapi_cap_list_av2 inv_notify_caplist[] = {
+	{ MAPI_CAP_CLIENT, "invite-notify", NULL, &CAP_INVITE_NOTIFY },
+	{ 0, NULL, NULL, NULL }
+};
+
+mapi_clist_av1 inv_notify_clist[] = { &invited_msgtab, NULL };
+
+static void
+invite_notify(struct Client *source, struct Client *target, struct Channel *channel)
+{
+	sendto_channel_local_with_capability(source, CHFL_CHANOP, 0, CAP_INVITE_NOTIFY, channel,
+		":%s NOTICE %s :%s is inviting %s to %s.",
+		me.name, channel->chname, source->name, target->name, channel->chname);
+	sendto_channel_local_with_capability(source, CHFL_CHANOP, CAP_INVITE_NOTIFY, 0, channel,
+		":%s!%s@%s INVITE %s %s", source->name, source->username,
+		source->host, target->name, channel->chname);
+}
+
+static void
+hook_invite(void *data_)
+{
+	hook_data_channel_approval *data = data_;
+
+	if (data->approved)
+		/* Don't notify if another hook is rejecting the invite.
+		 * This won't work if the other hook is after us... but really, it's
+		 * the thought that counts.
+		 */
+		return;
+
+	sendto_server(NULL, NULL, CAP_TS6 | CAP_ENCAP, 0, "ENCAP * INVITED %s %s %s",
+	              use_id(data->client), use_id(data->target),
+	              data->chptr->chname);
+	invite_notify(data->client, data->target, data->chptr);
+}
+
+static void
+m_invited(struct MsgBuf *msgbuf, struct Client *client_p, struct Client *source_p, int parc, const char **parv)
+{
+	struct Client *inviter = find_person(parv[1]);
+	struct Client *target = find_person(parv[2]);
+	struct Channel *chptr = find_channel(parv[3]);
+
+	if (inviter == NULL || target == NULL || chptr == NULL)
+		return;
+
+	invite_notify(inviter, target, chptr);
+}
+
+DECLARE_MODULE_AV2("invite_notify", NULL, NULL, inv_notify_clist, NULL, inv_notify_hfnlist, inv_notify_caplist, NULL, inv_notify_desc);

modules/m_invite.c

@@ -38,10 +38,9 @@
 #include "packet.h"
 #include "tgchange.h"
 
-static const char invite_desc[] = "Provides facilities for invite and related notifications";
+static const char invite_desc[] = "Provides /invite";
 
 static void m_invite(struct MsgBuf *, struct Client *, struct Client *, int, const char **);
-static unsigned int CAP_INVITE_NOTIFY = 0;
 
 struct Message invite_msgtab = {
 	"INVITE", 0, 0, 0, 0,
@@ -58,12 +57,7 @@ mapi_hlist_av1 invite_hlist[] = {
 	{ NULL, NULL }
 };
 
-mapi_cap_list_av2 invite_cap_list[] = {
+DECLARE_MODULE_AV2(invite, NULL, NULL, invite_clist, invite_hlist, NULL, NULL, NULL, invite_desc);
-	{ MAPI_CAP_CLIENT, "invite-notify", NULL, &CAP_INVITE_NOTIFY },
-	{ 0, NULL, NULL, NULL }
-};
-
-DECLARE_MODULE_AV2(invite, NULL, NULL, invite_clist, invite_hlist, NULL, invite_cap_list, NULL, invite_desc);
 
 static bool add_invite(struct Channel *, struct Client *);
 
@@ -255,23 +249,14 @@ m_invite(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 			   target_p->name, chptr->chname);
 
 		if(store_invite)
+			add_invite(chptr, target_p);
+	}
+	else if (target_p->from != client_p)
 	{
-			if (!add_invite(chptr, target_p))
+		sendto_one_prefix(target_p, source_p, "INVITE", "%s %lu",
-				return;
-
-			sendto_channel_local_with_capability(source_p, CHFL_CHANOP, 0, CAP_INVITE_NOTIFY, chptr,
-				":%s NOTICE %s :%s is inviting %s to %s.",
-				me.name, chptr->chname, source_p->name, target_p->name, chptr->chname);
-			sendto_channel_local_with_capability(source_p, CHFL_CHANOP, CAP_INVITE_NOTIFY, 0, chptr,
-				":%s!%s@%s INVITE %s %s", source_p->name, source_p->username,
-				source_p->host, target_p->name, chptr->chname);
-		}
-	}
-
-	sendto_server(source_p, chptr, CAP_TS6, 0, ":%s INVITE %s %s %lu",
-		      use_id(source_p), use_id(target_p),
 				  chptr->chname, (unsigned long) chptr->channelts);
 	}
+}
 
 /* add_invite()
  *