Upgrade channel membership lists.

extensions/m_findforwards.cc

@@ -52,7 +52,7 @@ m_findforwards(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *
 	/* Allow ircops to search for forwards to nonexistent channels */
 	if(!IsOper(source_p))
 	{
-		if((chptr = find_channel(parv[1])) == NULL || (msptr = find_channel_membership(chptr, source_p)) == NULL)
+		if((chptr = find_channel(parv[1])) == NULL || (msptr = get(chptr->members, *source_p, std::nothrow)) == NULL)
 		{
 			sendto_one_numeric(source_p, ERR_NOTONCHANNEL,
 					form_str(ERR_NOTONCHANNEL), parv[1]);

extensions/m_ojoin.cc

@@ -84,7 +84,7 @@ mo_ojoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 
 	if(*parv[1] == '@')
 	{
-		add_user_to_channel(chptr, source_p, chan::CHANOP);
+		add(*chptr, *source_p, chan::CHANOP);
 		sendto_server(client_p, chptr, CAP_TS6, NOCAPS,
 			      ":%s SJOIN %ld %s + :@%s",
 			      me.id, (long) chptr->channelts, chptr->name.c_str(), source_p->id);
@@ -95,7 +95,7 @@ mo_ojoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 	}
 	else if(*parv[1] == '+')
 	{
-		add_user_to_channel(chptr, source_p, chan::VOICE);
+		add(*chptr, *source_p, chan::VOICE);
 		sendto_server(client_p, chptr, CAP_TS6, NOCAPS,
 			      ":%s SJOIN %ld %s + :+%s",
 			      me.id, (long) chptr->channelts, chptr->name.c_str(), source_p->id);
@@ -105,7 +105,7 @@ mo_ojoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 	}
 	else
 	{
-		add_user_to_channel(chptr, source_p, chan::PEON);
+		add(*chptr, *source_p, chan::PEON);
 		sendto_server(client_p, chptr, CAP_TS6, NOCAPS,
 			      ":%s JOIN %ld %s +",
 			      source_p->id, (long) chptr->channelts, chptr->name.c_str());

extensions/m_okick.cc

@@ -97,7 +97,7 @@ mo_okick(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 		return;
 	}
 
-	if((msptr = find_channel_membership(chptr, target_p)) == NULL)
+	if((msptr = get(chptr->members, *target_p, std::nothrow)) == NULL)
 	{
 		sendto_one(source_p, form_str(ERR_USERNOTINCHANNEL), parv[1], parv[2]);
 		return;
@@ -120,5 +120,6 @@ mo_okick(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 			     me.name, chptr->name.c_str(), who->name, comment);
 	sendto_server(&me, chptr, CAP_TS6, NOCAPS,
 		      ":%s KICK %s %s :%s", me.id, chptr->name.c_str(), who->id, comment);
-	remove_user_from_channel(msptr);
+
+	del(*chptr, *target_p);
 }

extensions/m_omode.cc

@@ -76,7 +76,7 @@ mo_omode(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 	}
 
 	/* Now know the channel exists */
-	msptr = find_channel_membership(chptr, source_p);
+	msptr = get(chptr->members, *source_p, std::nothrow);
 	wasonchannel = msptr != NULL;
 
 	if (is_chanop(msptr))
@@ -133,8 +133,8 @@ mo_omode(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 			msptr->flags |= chan::CHANOP;
 		else
 		{
-			add_user_to_channel(chptr, source_p, chan::CHANOP);
+			add(*chptr, *source_p, chan::CHANOP);
-			msptr = find_channel_membership(chptr, source_p);
+			msptr = get(chptr->members, *source_p, std::nothrow);
 		}
 		set_channel_mode(client_p, source_p, chptr, msptr,
 				parc - 2, parv + 2);
@@ -144,7 +144,7 @@ mo_omode(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 		if (wasonchannel)
 			msptr->flags &= ~chan::CHANOP;
 		else
-			remove_user_from_channel(msptr);
+			del(*chptr, get_client(*msptr));
 	}
 #endif
 }

extensions/m_opme.cc

@@ -57,9 +57,9 @@ mo_opme(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_
 		return;
 	}
 
-	RB_DLINK_FOREACH(ptr, chptr->members.head)
+	for(auto &pit : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		msptr = &pit.second;
 
 		if(is_chanop(msptr))
 		{
@@ -68,7 +68,7 @@ mo_opme(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_
 		}
 	}
 
-	msptr = find_channel_membership(chptr, source_p);
+	msptr = get(chptr->members, *source_p, std::nothrow);
 
 	if(msptr == NULL)
 		return;

extensions/m_remove.cc

@@ -80,7 +80,7 @@ m_remove(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 
 	if(!IsServer(source_p))
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		if((msptr == NULL) && MyConnect(source_p))
 		{
@@ -139,7 +139,7 @@ m_remove(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 		return;
 	}
 
-	msptr = find_channel_membership(chptr, who);
+	msptr = get(chptr->members, *who, std::nothrow);
 
 	if(msptr != NULL)
 	{
@@ -190,7 +190,7 @@ m_remove(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 			      ":%s KICK %s %s :%s",
 			      use_id(source_p), chptr->name.c_str(), use_id(who), comment);
 
-		remove_user_from_channel(msptr);
+		del(*chptr, get_client(*msptr));
 	}
 	else if (MyClient(source_p))
 		sendto_one_numeric(source_p, ERR_USERNOTINCHANNEL,

extensions/m_roleplay.cc

@@ -140,7 +140,7 @@ m_displaymsg(struct MsgBuf *msgbuf_p, struct Client *source_p, const char *chann
 		return;
 	}
 
-	if(!(msptr = find_channel_membership(chptr, source_p)))
+	if(!(msptr = get(chptr->members, *source_p, std::nothrow)))
 	{
 		sendto_one_numeric(source_p, ERR_NOTONCHANNEL,
 				   form_str(ERR_NOTONCHANNEL), chptr->name.c_str());

extensions/sno_channelcreate.cc

@@ -43,7 +43,7 @@ h_scc_channel_join(void *vdata)
 	struct Client *source_p = data->client;
 
 	/* If they just joined a channel, and it only has one member, then they just created it. */
-	if(rb_dlink_list_length(&chptr->members) == 1 && is_chanop(find_channel_membership(chptr, source_p)))
+	if(size(chptr->members) == 1 && is_chanop(get(chptr->members, *source_p, std::nothrow)))
 	{
 		sendto_realops_snomask(snomask_modes['l'], L_NETWIDE, "%s is creating new channel %s",
 					source_p->name, chptr->name.c_str());

extensions/spamfilter_nicks.cc

@@ -165,11 +165,10 @@ int chans_add(struct chan *const chan)
 	if(!rb_radixtree_add(chans, chan->name.c_str(), chan))
 		return 0;
 
-	rb_dlink_node *ptr;
+	for(const auto &pit : chan->members.global)
-	RB_DLINK_FOREACH(ptr, chan->members.head)
 	{
-		const auto msptr(reinterpret_cast<membership *>(ptr->data));
+		const auto &client(pit.first);
-		bloom_add_str(msptr->client->name);
+		bloom_add_str(client->name);
 	}
 
 	return 1;

include/ircd/channel.h

@@ -34,6 +34,7 @@ namespace chan {
 IRCD_EXCEPTION(ircd::error,  error)
 IRCD_EXCEPTION(error,        not_found)
 IRCD_EXCEPTION(error,        invalid_list)
+IRCD_EXCEPTION(error,        invalid_argument)
 
 enum status
 {
@@ -96,17 +97,15 @@ uint operator~(const modes &);
 
 struct membership
 {
-	rb_dlink_node channode;
+	using global = std::map<client *, membership>;
-	rb_dlink_node locchannode;
+	using local = std::list<membership *>;
-	rb_dlink_node usernode;
-
-	struct chan *chan;
-	Client *client;
-	unsigned int flags;
 
+	uint flags;
 	time_t bants;
+	global::iterator git;
+	local::iterator lit;
 
-	membership();
+	membership(const uint &flags = 0);
 	~membership() noexcept;
 };
 
@@ -119,6 +118,27 @@ bool is_chanop_voiced(const membership *const &);
 bool can_send_banned(const membership &);
 bool can_send_banned(const membership *const &);
 const char *find_status(const membership *const &msptr, const int &combine);
+const client &get_client(const membership &);
+client &get_client(membership &);
+
+struct members
+{
+	membership::global global;
+	membership::local local;
+
+	members();
+	~members() noexcept;
+};
+
+bool empty(const members &);
+size_t size(const members &);
+bool local_empty(const members &);
+size_t local_size(const members &);
+bool exists(const members &, const client &);
+const membership *get(const members &, const client &, std::nothrow_t);
+const membership &get(const members &, const client &);
+membership *get(members &, const client &, std::nothrow_t);
+membership &get(members &, const client &);
 
 bool has_prefix(const char *const &name);
 bool has_prefix(const std::string &name);
@@ -131,11 +151,8 @@ struct chan
 	struct modes mode;
 	std::string mode_lock;
 	struct topic topic;
-
+	struct members members;
-	rb_dlink_list members;
-	rb_dlink_list locmembers;
 	std::set<client *> invites;
-
 	list bans;
 	list excepts;
 	list invexs;
@@ -160,6 +177,7 @@ struct chan
 	~chan() noexcept;
 };
 
+const auto &name(const chan &);
 bool is_secret(const chan &);
 bool is_secret(const chan *const &);
 bool is_hidden(const chan &);
@@ -206,9 +224,6 @@ void del_invite(chan &, client &);
 void clear_invites(chan &);
 
 bool flood_attack_channel(int p_or_n, client *source, chan *);
-void add_user_to_channel(chan *, client *, int flags);
-void remove_user_from_channel(membership *);
-void remove_user_from_channels(client *);
 void invalidate_bancache_user(client *);
 void channel_member_names(chan *, client *, int show_eon);
 const char *channel_modes(chan *, client *who);
@@ -227,13 +242,17 @@ int match_extban(const char *banstr, client *, chan *, long mode_type);
 int valid_extban(const char *banstr, client *, chan *, long mode_type);
 const char * get_extban_string(void);
 int get_channel_access(client *source, chan *, membership *, int dir, const char *modestr);
-membership *find_channel_membership(chan *chptr, client *client_p);
 void send_join(chan &, client &);
 
 //extern std::map<std::string, std::unique_ptr<chan>> chans;
 extern rb_dlink_list global_channel_list;
 
+// Add and remove clients from channels
+void add(chan &, client &, const int &flags = PEON);
+void del(chan &, client &);
+void del(client &);             // remove from all channels
 
+// Initialize subsystem
 void init();
 
 
@@ -276,8 +295,7 @@ is_public(const chan *const &c)
 inline bool
 is_member(const chan &c, const client &client)
 {
-	//return client.user && get(c, client, std::nothrow) != nullptr;
+	return exists(c.members, client);
-	return find_channel_membership(const_cast<struct chan *>(&c), const_cast<Client *>(&client)) != nullptr;
 }
 
 inline bool
@@ -322,6 +340,42 @@ valid_name(const std::string &name)
 	return !name.empty() && std::all_of(begin(name), end(name), rfc1459::is_chan);
 }
 
+inline const auto &
+name(const chan &chan)
+{
+	return chan.name;
+}
+
+inline size_t
+local_size(const members &m)
+{
+	return std::distance(begin(m.local), end(m.local));
+}
+
+inline bool
+local_empty(const members &m)
+{
+	return m.local.empty();
+}
+
+inline size_t
+size(const members &m)
+{
+	return m.global.size();
+}
+
+inline bool
+empty(const members &m)
+{
+	return m.global.empty();
+}
+
+inline bool
+exists(const members &m, const client &c)
+{
+	return m.global.count(const_cast<client *>(&c));
+}
+
 inline bool
 is_chanop(const membership &m)
 {
@@ -358,6 +412,18 @@ is_chanop_voiced(const membership *const &m)
 	return m && is_chanop_voiced(*m);
 }
 
+inline client &
+get_client(membership &m)
+{
+	return *m.git->first;
+}
+
+inline const client &
+get_client(const membership &m)
+{
+	return *m.git->first;
+}
+
 inline bool
 can_send_banned(const membership &m)
 {

include/ircd/client.h

@@ -68,7 +68,7 @@ typedef int SSL_OPEN_CB(struct Client *, int status);
  */
 struct User
 {
-	rb_dlink_list channel;	/* chain of channel pointer blocks */
+	std::map<chan::chan *, chan::membership *> channel;
 	std::set<chan::chan *> invited;
 	char *away;		/* pointer to away message */
 	int refcnt;		/* Number of times this block is referenced */

ircd/channel.cc

@@ -49,8 +49,7 @@ chan::chan::chan(const std::string &name)
 ,mode{}
 ,mode_lock{}
 ,topic{}
-,members{0}
+,members{}
-,locmembers{0}
 ,join_count{0}
 ,join_delta{0}
 ,flood_noticed{0}
@@ -74,13 +73,108 @@ noexcept
 	del_from_channel_hash(name.c_str(), this);
 }
 
-chan::membership::membership()
+/* remove_user_from_channels()
-:channode{0}
+ *
-,locchannode{0}
+ * input        - user to remove from all channels
-,usernode{0}
+ * output       -
-,chan{nullptr}
+ * side effects - user is removed from all channels
-,client{nullptr}
+ */
-,flags{0}
+void
+chan::del(client &client)
+{
+	auto &client_chans(client.user->channel);
+	for(const auto &pit : client_chans)
+	{
+		auto &chan(*pit.first);
+		auto &member(*pit.second);
+
+		if (my(client))
+			chan.members.local.erase(member.lit);
+
+		chan.members.global.erase(member.git);
+		chan.invites.erase(&client);
+
+		if (empty(chan.members) && ~chan.mode & mode::PERMANENT)
+			delete &chan;
+	}
+
+	client_chans.clear();
+	client.user->invited.clear();
+}
+
+void
+chan::del(chan &chan,
+          client &client)
+{
+	// These are the relevant containers.
+	auto &global(chan.members.global);
+	auto &local(chan.members.local);
+	auto &client_chans(client.user->channel);
+
+	const auto it(client_chans.find(&chan));
+	if (it == end(client_chans))
+		return;
+
+	auto &member(*it->second);
+
+	if (my(client))
+		chan.members.local.erase(member.lit);
+
+	chan.members.global.erase(member.git);      // The member is destroyed at this point.
+	client_chans.erase(it);
+
+	if (empty(chan.members) && ~chan.mode & mode::PERMANENT)
+		delete &chan;
+}
+
+void
+chan::add(chan &chan,
+          client &client,
+          const int &flags)
+{
+	if (!client.user)
+	{
+		s_assert(0);
+		return;
+	}
+
+	// These are the relevant containers.
+	auto &global(chan.members.global);
+	auto &local(chan.members.local);
+	auto &client_chans(client.user->channel);
+
+	// Add client to channel's global map
+	const auto iit(global.emplace(&client, flags));
+	if (!iit.second)
+		return;
+
+	// The global map hosts the membership structure.
+	auto &member(iit.first->second);
+
+	// Add iterator (pointer to the element) for constant time lookup/removal
+	member.git = iit.first;
+
+	// Add channel to client's channel map, pointing to the membership;
+	client_chans.emplace(&chan, &member);
+
+	// Add membership to a local list which can be iterated for local IO;
+	// iterator to this element is saved more crucially here to prevent linear removal
+	if (my(client))
+		member.lit = local.emplace(end(local), &member);
+}
+
+
+chan::members::members()
+{
+}
+
+chan::members::~members()
+noexcept
+{
+}
+
+chan::membership::membership(const uint &flags)
+:flags{flags}
 ,bants{0}
 {
 }
@@ -144,46 +238,66 @@ chan::send_join(chan &chan,
 		                                            client.user->away);
 }
 
-/* find_channel_membership()
+chan::membership &
- *
+chan::get(members &members,
- * input	- channel to find them in, client to find
+          const client &client)
- * output	- membership of client in channel, else NULL
- * side effects	-
- */
-chan::membership *
-chan::find_channel_membership(chan *chptr, client *client_p)
 {
-	struct membership *msptr;
+	if (!is_client(client))
-	rb_dlink_node *ptr;
+		throw invalid_argument();
 
-	if(!IsClient(client_p))
+	const auto key(const_cast<ircd::chan::client *>(&client)); //TODO: temp elaborated
-		return NULL;
+	const auto it(members.global.find(key));
+	if (it == end(members.global))
+		throw not_found();
 
-	/* Pick the most efficient list to use to be nice to things like
+	return it->second;
-	 * CHANSERV which could be in a large number of channels
+}
-	 */
-	if(rb_dlink_list_length(&chptr->members) < rb_dlink_list_length(&client_p->user->channel))
-	{
-		RB_DLINK_FOREACH(ptr, chptr->members.head)
-		{
-			msptr = (membership *)ptr->data;
 
-			if(msptr->client == client_p)
+const chan::membership &
-				return msptr;
+chan::get(const members &members,
-		}
+          const client &client)
-	}
+{
-	else
+	if (!is_client(client))
-	{
+		throw invalid_argument();
-		RB_DLINK_FOREACH(ptr, client_p->user->channel.head)
-		{
-			msptr = (membership *)ptr->data;
 
-			if(msptr->chan == chptr)
+	const auto key(const_cast<ircd::chan::client *>(&client)); //TODO: temp elaborated
-				return msptr;
+	const auto it(members.global.find(key));
-		}
+	if (it == end(members.global))
-	}
+		throw not_found();
 
-	return NULL;
+	return it->second;
+}
+
+chan::membership *
+chan::get(members &members,
+          const client &client,
+          std::nothrow_t)
+{
+	if (!is_client(client))
+		return nullptr;
+
+	const auto key(const_cast<ircd::chan::client *>(&client)); //TODO: temp elaborated
+	const auto it(members.global.find(key));
+	if (it == end(members.global))
+		return nullptr;
+
+	return &it->second;
+}
+
+const chan::membership *
+chan::get(const members &members,
+          const client &client,
+          std::nothrow_t)
+{
+	if (!is_client(client))
+		return nullptr;
+
+	const auto key(const_cast<ircd::chan::client *>(&client)); //TODO: temp elaborated
+	const auto it(members.global.find(key));
+	if (it == end(members.global))
+		return nullptr;
+
+	return &it->second;
 }
 
 /* find_channel_status()
@@ -215,102 +329,6 @@ chan::find_status(const membership *const &msptr,
 	return buffer;
 }
 
-/* add_user_to_channel()
- *
- * input	- channel to add client to, client to add, channel flags
- * output	-
- * side effects - user is added to channel
- */
-void
-chan::add_user_to_channel(chan *chptr, client *client_p, int flags)
-{
-	membership *msptr;
-
-	s_assert(client_p->user != NULL);
-	if(client_p->user == NULL)
-		return;
-
-	msptr = new membership;
-
-	msptr->chan = chptr;
-	msptr->client = client_p;
-	msptr->flags = flags;
-
-	rb_dlinkAdd(msptr, &msptr->usernode, &client_p->user->channel);
-	rb_dlinkAdd(msptr, &msptr->channode, &chptr->members);
-
-	if(MyClient(client_p))
-		rb_dlinkAdd(msptr, &msptr->locchannode, &chptr->locmembers);
-}
-
-/* remove_user_from_channel()
- *
- * input	- membership pointer to remove from channel
- * output	-
- * side effects - membership (thus user) is removed from channel
- */
-void
-chan::remove_user_from_channel(membership *msptr)
-{
-	client *client_p;
-	chan *chptr;
-	s_assert(msptr != NULL);
-	if(msptr == NULL)
-		return;
-
-	client_p = msptr->client;
-	chptr = msptr->chan;
-
-	rb_dlinkDelete(&msptr->usernode, &client_p->user->channel);
-	rb_dlinkDelete(&msptr->channode, &chptr->members);
-
-	if(client_p->servptr == &me)
-		rb_dlinkDelete(&msptr->locchannode, &chptr->locmembers);
-
-	if(!(chptr->mode.mode & mode::PERMANENT) && rb_dlink_list_length(&chptr->members) <= 0)
-		delete chptr;
-
-	delete msptr;
-	return;
-}
-
-/* remove_user_from_channels()
- *
- * input        - user to remove from all channels
- * output       -
- * side effects - user is removed from all channels
- */
-void
-chan::remove_user_from_channels(client *client_p)
-{
-	chan *chptr;
-	membership *msptr;
-	rb_dlink_node *ptr;
-	rb_dlink_node *next_ptr;
-
-	if(client_p == NULL)
-		return;
-
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->user->channel.head)
-	{
-		msptr = (membership *)ptr->data;
-		chptr = msptr->chan;
-
-		rb_dlinkDelete(&msptr->channode, &chptr->members);
-
-		if(client_p->servptr == &me)
-			rb_dlinkDelete(&msptr->locchannode, &chptr->locmembers);
-
-		if(!(chptr->mode.mode & mode::PERMANENT) && rb_dlink_list_length(&chptr->members) <= 0)
-			delete chptr;
-
-		delete msptr;
-	}
-
-	client_p->user->channel.head = client_p->user->channel.tail = NULL;
-	client_p->user->channel.length = 0;
-}
-
 /* invalidate_bancache_user()
  *
  * input	- user to invalidate ban cache for
@@ -319,19 +337,17 @@ chan::remove_user_from_channels(client *client_p)
  *                to be used after a nick change
  */
 void
-chan::invalidate_bancache_user(client *client_p)
+chan::invalidate_bancache_user(client *client)
 {
-	membership *msptr;
+	if(!client)
-	rb_dlink_node *ptr;
-
-	if(client_p == NULL)
 		return;
 
-	RB_DLINK_FOREACH(ptr, client_p->user->channel.head)
+	for(const auto &pair : client->user->channel)
 	{
-		msptr = (membership *)ptr->data;
+		auto &chan(*pair.first);
-		msptr->bants = 0;
+		auto &member(*pair.second);
-		msptr->flags &= ~BANNED;
+		member.bants = 0;
+		member.flags &= ~BANNED;
 	}
 }
 
@@ -358,7 +374,6 @@ channel_pub_or_secret(chan::chan *const &chptr)
 void
 chan::channel_member_names(chan *chptr, client *client_p, int show_eon)
 {
-	membership *msptr;
 	client *target_p;
 	rb_dlink_node *ptr;
 	char lbuf[BUFSIZE];
@@ -376,10 +391,10 @@ chan::channel_member_names(chan *chptr, client *client_p, int show_eon)
 
 		t = lbuf + cur_len;
 
-		RB_DLINK_FOREACH(ptr, chptr->members.head)
+		for(const auto &pair : chptr->members.global)
 		{
-			msptr = (membership *)ptr->data;
+			auto *const target_p(pair.first);
-			target_p = msptr->client;
+			const auto &member(pair.second);
 
 			if(IsInvisible(target_p) && !is_member(chptr, client_p))
 				continue;
@@ -395,7 +410,7 @@ chan::channel_member_names(chan *chptr, client *client_p, int show_eon)
 					t = lbuf + mlen;
 				}
 
-				tlen = sprintf(t, "%s%s!%s@%s ", find_status(msptr, stack),
+				tlen = sprintf(t, "%s%s!%s@%s ", find_status(&member, stack),
 						  target_p->name, target_p->username, target_p->host);
 			}
 			else
@@ -409,7 +424,7 @@ chan::channel_member_names(chan *chptr, client *client_p, int show_eon)
 					t = lbuf + mlen;
 				}
 
-				tlen = sprintf(t, "%s%s ", find_status(msptr, stack),
+				tlen = sprintf(t, "%s%s ", find_status(&member, stack),
 						  target_p->name);
 			}
 
@@ -733,8 +748,7 @@ chan::can_join(client *source_p, chan *chptr, const char *key, const char **forw
 		}
 	}
 
-	if(chptr->mode.limit &&
+	if(chptr->mode.limit && size(chptr->members) >= ulong(chptr->mode.limit))
-	   rb_dlink_list_length(&chptr->members) >= (unsigned long) chptr->mode.limit)
 		i = ERR_CHANNELISFULL;
 	if(chptr->mode.mode & mode::REGONLY && EmptyString(source_p->user->suser))
 		i = ERR_NEEDREGGEDNICK;
@@ -783,7 +797,7 @@ chan::can_send(chan *chptr, client *source_p, membership *msptr)
 
 	if(msptr == NULL)
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		if(msptr == NULL)
 		{
@@ -828,7 +842,7 @@ chan::can_send(chan *chptr, client *source_p, membership *msptr)
 		moduledata.approved = CAN_SEND_OPV;
 
 	moduledata.client = source_p;
-	moduledata.chptr = msptr->chan;
+	moduledata.chptr = chptr;
 	moduledata.msptr = msptr;
 	moduledata.target = NULL;
 	moduledata.dir = moduledata.approved == CAN_SEND_NO? MODE_ADD : MODE_QUERY;
@@ -913,10 +927,11 @@ chan::find_bannickchange_channel(client *client_p)
 	sprintf(src_host, "%s!%s@%s", client_p->name, client_p->username, client_p->host);
 	sprintf(src_iphost, "%s!%s@%s", client_p->name, client_p->username, client_p->sockhost);
 
-	RB_DLINK_FOREACH(ptr, client_p->user->channel.head)
+	for(const auto &pit : client_p->user->channel)
 	{
-		msptr = (membership *)ptr->data;
+		auto &chptr(pit.first);
-		chptr = msptr->chan;
+		auto &msptr(pit.second);
+
 		if (is_chanop_voiced(msptr))
 			continue;
 		/* cached can_send */
@@ -1270,10 +1285,11 @@ chan::resv_chan_forcepart(const char *name, const char *reason, int temp_time)
 	chptr = find_channel(name);
 	if(chptr != NULL)
 	{
-		RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->locmembers.head)
+		// Iterate a copy of the local list while all of this is going on
+		auto local(chptr->members.local);
+		for(auto &msptr : local)
 		{
-			msptr = (membership *)ptr->data;
+			const auto target_p(msptr->git->first);
-			target_p = msptr->client;
 
 			if(IsExemptResv(target_p))
 				continue;
@@ -1285,7 +1301,7 @@ chan::resv_chan_forcepart(const char *name, const char *reason, int temp_time)
 			                     target_p->name, target_p->username,
 			                     target_p->host, chptr->name.c_str(), target_p->name);
 
-			remove_user_from_channel(msptr);
+			del(*chptr, *target_p);
 
 			/* notify opers & user they were removed from the channel */
 			sendto_realops_snomask(SNO_GENERAL, L_ALL,

ircd/chmode.cc

@@ -409,8 +409,7 @@ pretty_mask(const char *idmask)
  * side effects - numeric sent if not allowed
  */
 static bool
-check_forward(struct Client *source_p, chan::chan *chptr,
+check_forward(Client *source_p, chan::chan *chptr, const char *forward)
-		const char *forward)
 {
 	chan::chan *targptr = NULL;
 	chan::membership *msptr;
@@ -436,11 +435,13 @@ check_forward(struct Client *source_p, chan::chan *chptr,
 	}
 	if(MyClient(source_p) && !(targptr->mode.mode & mode::FREETARGET))
 	{
-		if((msptr = find_channel_membership(targptr, source_p)) == NULL ||
+		auto *const msptr(get(targptr->members, *source_p, std::nothrow));
-			chan::get_channel_access(source_p, targptr, msptr, MODE_QUERY, NULL) < chan::CHANOP)
+		if(!msptr || get_channel_access(source_p, targptr, msptr, MODE_QUERY, NULL) < chan::CHANOP)
 		{
 			sendto_one(source_p, form_str(ERR_CHANOPRIVSNEEDED),
-				   me.name, source_p->name, targptr->name.c_str());
+			           me.name,
+			           source_p->name,
+			           targptr->name.c_str());
 			return false;
 		}
 	}
@@ -954,7 +955,7 @@ mode::functor::op(client *source_p, chan *chptr,
 		return;
 	}
 
-	mstptr = find_channel_membership(chptr, targ_p);
+	mstptr = get(chptr->members, *targ_p, std::nothrow);
 
 	if(mstptr == NULL)
 	{
@@ -1030,7 +1031,7 @@ mode::functor::voice(client *source_p, chan *chptr,
 		return;
 	}
 
-	mstptr = find_channel_membership(chptr, targ_p);
+	mstptr = get(chptr->members, *targ_p, std::nothrow);
 
 	if(mstptr == NULL)
 	{

ircd/client.cc

@@ -1265,10 +1265,10 @@ exit_generic_client(struct Client *client_p, struct Client *source_p, struct Cli
 				     source_p->name,
 				     source_p->username, source_p->host, comment);
 
-	chan::remove_user_from_channels(source_p);
+	chan::del(*source_p);
 
 	/* Should not be in any channels now */
-	s_assert(source_p->user->channel.head == NULL);
+	s_assert(source_p->user->channel.empty());
 
 	// Clean up invitefield
 	for (auto &chan : source_p->user->invited)
@@ -1839,10 +1839,10 @@ free_user(struct User *user, struct Client *client_p)
 		/*
 		 * sanity check
 		 */
-		if(user->refcnt < 0 || !user->invited.empty() || user->channel.head)
+		if(user->refcnt < 0 || !user->invited.empty() || !user->channel.empty())
 		{
 			sendto_realops_snomask(SNO_GENERAL, L_ALL,
-					     "* %p user (%s!%s@%s) %p %lu %p %lu %d *",
+					     "* %p user (%s!%s@%s) %p %lu %lu %d *",
 					     client_p,
 					     client_p ? client_p->
 					     name : "<noname>",
@@ -1850,12 +1850,11 @@ free_user(struct User *user, struct Client *client_p)
 					     client_p->host,
 					     user,
 					     user->invited.size(),
-					     user->channel.head,
+					     user->channel.size(),
-					     rb_dlink_list_length(&user->channel),
 					     user->refcnt);
 			s_assert(!user->refcnt);
 			s_assert(user->invited.empty());
-			s_assert(!user->channel.head);
+			s_assert(user->channel.empty());
 		}
 
 		rb_bh_free(user_heap, user);

ircd/s_serv.cc

@@ -646,11 +646,12 @@ burst_TS6(struct Client *client_p)
 
 		t = buf + mlen;
 
-		RB_DLINK_FOREACH(uptr, chptr->members.head)
+		for (auto &pair : chptr->members.global)
 		{
-			msptr = (chan::membership *)uptr->data;
+			msptr = &pair.second;
+			auto *const client(pair.first);
 
-			tlen = strlen(use_id(msptr->client)) + 1;
+			tlen = strlen(use_id(client)) + 1;
 			if(is_chanop(msptr))
 				tlen++;
 			if(is_voiced(msptr))
@@ -664,13 +665,13 @@ burst_TS6(struct Client *client_p)
 				t = buf + mlen;
 			}
 
-			sprintf(t, "%s%s ", chan::find_status(msptr, 1), use_id(msptr->client));
+			sprintf(t, "%s%s ", chan::find_status(msptr, 1), use_id(client));
 
 			cur_len += tlen;
 			t += tlen;
 		}
 
-		if (rb_dlink_list_length(&chptr->members) > 0)
+		if (!empty(chptr->members))
 		{
 			/* remove trailing space */
 			*(t-1) = '\0';

ircd/s_user.cc

@@ -1473,11 +1473,10 @@ change_nick_user_host(struct Client *target_p,	const char *nick, const char *use
 {
 	rb_dlink_node *ptr;
 	chan::chan *chptr;
-	chan::membership *mscptr;
 	int changed = irccmp(target_p->name, nick);
 	int changed_case = strcmp(target_p->name, nick);
 	int do_qjm = irccmp(target_p->username, user) || irccmp(target_p->host, host);
-	char mode[10], modeval[NICKLEN * 2 + 2], reason[256], *mptr;
+	char mode[10], modeval[NICKLEN * 2 + 2], reason[256];
 	va_list ap;
 
 	modeval[0] = '\0';
@@ -1499,20 +1498,20 @@ change_nick_user_host(struct Client *target_p,	const char *nick, const char *use
 				target_p->name, target_p->username, target_p->host,
 				reason);
 
-		RB_DLINK_FOREACH(ptr, target_p->user->channel.head)
+		for(const auto &pit : target_p->user->channel)
 		{
-			mscptr = (chan::membership *)ptr->data;
+			auto &chan(*pit.first);
-			chptr = mscptr->chan;
+			auto &member(*pit.second);
-			mptr = mode;
+			char *mptr(mode);
 
-			if(is_chanop(mscptr))
+			if(is_chanop(member))
 			{
 				*mptr++ = 'o';
 				strcat(modeval, nick);
 				strcat(modeval, " ");
 			}
 
-			if(is_voiced(mscptr))
+			if(is_voiced(member))
 			{
 				*mptr++ = 'v';
 				strcat(modeval, nick);
@@ -1520,16 +1519,16 @@ change_nick_user_host(struct Client *target_p,	const char *nick, const char *use
 
 			*mptr = '\0';
 
-			sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, NOCAPS, CLICAP_EXTENDED_JOIN | CLICAP_CHGHOST, chptr,
+			sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, NOCAPS, CLICAP_EXTENDED_JOIN | CLICAP_CHGHOST, &chan,
-								    ":%s!%s@%s JOIN %s", nick, user, host, chptr->name.c_str());
+								    ":%s!%s@%s JOIN %s", nick, user, host, chan.name.c_str());
-			sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, CLICAP_EXTENDED_JOIN, CLICAP_CHGHOST, chptr,
+			sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, CLICAP_EXTENDED_JOIN, CLICAP_CHGHOST, &chan,
-								    ":%s!%s@%s JOIN %s %s :%s", nick, user, host, chptr->name.c_str(),
+								    ":%s!%s@%s JOIN %s %s :%s", nick, user, host, chan.name.c_str(),
 								    EmptyString(target_p->user->suser) ? "*" : target_p->user->suser,
 								    target_p->info);
 
 			if(*mode)
-				sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, NOCAPS, CLICAP_CHGHOST, chptr,
+				sendto_channel_local_with_capability_butone(target_p, chan::ALL_MEMBERS, NOCAPS, CLICAP_CHGHOST, &chan,
-						":%s MODE %s +%s %s", target_p->servptr->name, chptr->name.c_str(), mode, modeval);
+						":%s MODE %s +%s %s", target_p->servptr->name, chan.name.c_str(), mode, modeval);
 
 			*modeval = '\0';
 		}

ircd/send.cc

@@ -485,8 +485,6 @@ sendto_channel_flags(struct Client *one, int type, struct Client *source_p,
 	va_list args;
 	buf_head_t rb_linebuf_local;
 	buf_head_t rb_linebuf_id;
-	struct Client *target_p;
-	chan::membership *msptr;
 	rb_dlink_node *ptr;
 	rb_dlink_node *next_ptr;
 	int current_capmask = 0;
@@ -506,10 +504,10 @@ sendto_channel_flags(struct Client *one, int type, struct Client *source_p,
 	linebuf_put_msgbuf(&msgbuf, &rb_linebuf_local, NOCAPS, "%s", buf);
 	rb_linebuf_putmsg(&rb_linebuf_id, NULL, NULL, ":%s %s", use_id(source_p), buf);
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->members.head)
+	for(const auto &pair : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto *const target_p(pair.first);
-		target_p = msptr->client;
+		const auto &member(pair.second);
 
 		if(!MyClient(source_p) && (IsIOError(target_p->from) || target_p->from == one))
 			continue;
@@ -517,7 +515,7 @@ sendto_channel_flags(struct Client *one, int type, struct Client *source_p,
 		if(MyClient(source_p) && !IsCapable(source_p, CLICAP_ECHO_MESSAGE) && target_p == one)
 			continue;
 
-		if(type && ((msptr->flags & type) == 0))
+		if(type && ((member.flags & type) == 0))
 			continue;
 
 		if(IsDeaf(target_p))
@@ -572,8 +570,6 @@ sendto_channel_opmod(struct Client *one, struct Client *source_p,
 	buf_head_t rb_linebuf_local;
 	buf_head_t rb_linebuf_old;
 	buf_head_t rb_linebuf_new;
-	struct Client *target_p;
-	chan::membership *msptr;
 	rb_dlink_node *ptr;
 	rb_dlink_node *next_ptr;
 
@@ -606,10 +602,10 @@ sendto_channel_opmod(struct Client *one, struct Client *source_p,
 		       ":%s %s =%s :%s",
 		       use_id(source_p), command, chptr->name.c_str(), text);
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->members.head)
+	for(const auto &pair : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto *const target_p(pair.first);
-		target_p = msptr->client;
+		const auto &member(pair.second);
 
 		if(!MyClient(source_p) && (IsIOError(target_p->from) || target_p->from == one))
 			continue;
@@ -617,7 +613,7 @@ sendto_channel_opmod(struct Client *one, struct Client *source_p,
 		if(MyClient(source_p) && !IsCapable(source_p, CLICAP_ECHO_MESSAGE) && target_p == one)
 			continue;
 
-		if((msptr->flags & chan::CHANOP) == 0)
+		if((member.flags & chan::CHANOP) == 0)
 			continue;
 
 		if(IsDeaf(target_p))
@@ -660,10 +656,6 @@ sendto_channel_local(int type, chan::chan *chptr, const char *pattern, ...)
 {
 	va_list args;
 	buf_head_t linebuf;
-	chan::membership *msptr;
-	struct Client *target_p;
-	rb_dlink_node *ptr;
-	rb_dlink_node *next_ptr;
 
 	rb_linebuf_newbuf(&linebuf);
 
@@ -671,10 +663,10 @@ sendto_channel_local(int type, chan::chan *chptr, const char *pattern, ...)
 	rb_linebuf_putmsg(&linebuf, pattern, &args, NULL);
 	va_end(args);
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->locmembers.head)
+	for (const auto &pair : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto *const target_p(pair.first);
-		target_p = msptr->client;
+		const auto &member(pair.second);
 
 		if(IsIOError(target_p))
 			continue;
@@ -684,7 +676,7 @@ sendto_channel_local(int type, chan::chan *chptr, const char *pattern, ...)
 			if (!IsOper(target_p))
 				continue;
 		}
-		else if(type && ((msptr->flags & type) == 0))
+		else if(type && ((member.flags & type) == 0))
 			continue;
 
 		_send_linebuf(target_p, &linebuf);
@@ -703,18 +695,13 @@ _sendto_channel_local_with_capability_butone(struct Client *one, int type, int c
 	const char *pattern, va_list * args)
 {
 	buf_head_t linebuf;
-	chan::membership *msptr;
-	struct Client *target_p;
-	rb_dlink_node *ptr;
-	rb_dlink_node *next_ptr;
 
 	rb_linebuf_newbuf(&linebuf);
 	rb_linebuf_putmsg(&linebuf, pattern, args, NULL);
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->locmembers.head)
+	for(const auto &member : chptr->members.local)
 	{
-		msptr = (chan::membership *)ptr->data;
+		const auto target_p(member->git->first);
-		target_p = msptr->client;
 
 		if (target_p == one)
 			continue;
@@ -724,7 +711,7 @@ _sendto_channel_local_with_capability_butone(struct Client *one, int type, int c
  		   !NotCapable(target_p, negcaps))
 			continue;
 
-		if(type && ((msptr->flags & type) == 0))
+		if(type && ((member->flags & type) == 0))
 			continue;
 
 		_send_linebuf(target_p, &linebuf);
@@ -780,8 +767,6 @@ sendto_channel_local_butone(struct Client *one, int type, chan::chan *chptr, con
 {
 	va_list args;
 	buf_head_t linebuf;
-	chan::membership *msptr;
-	struct Client *target_p;
 	struct MsgBuf msgbuf;
 	rb_dlink_node *ptr;
 	rb_dlink_node *next_ptr;
@@ -794,10 +779,9 @@ sendto_channel_local_butone(struct Client *one, int type, chan::chan *chptr, con
 	rb_linebuf_putmsg(&linebuf, pattern, &args, NULL);
 	va_end(args);
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->locmembers.head)
+	for(const auto &member : chptr->members.local)
 	{
-		msptr = (chan::membership *)ptr->data;
+		const auto target_p(member->git->first);
-		target_p = msptr->client;
 
 		if(target_p == one)
 			continue;
@@ -805,7 +789,7 @@ sendto_channel_local_butone(struct Client *one, int type, chan::chan *chptr, con
 		if(IsIOError(target_p))
 			continue;
 
-		if(type && ((msptr->flags & type) == 0))
+		if(type && ((member->flags & type) == 0))
 			continue;
 
 		/* attach the present linebuf to the target */
@@ -848,15 +832,14 @@ sendto_common_channels_local(struct Client *user, int cap, int negcap, const cha
 
 	++current_serial;
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, user->user->channel.head)
+	for(const auto &pit : user->user->channel)
 	{
-		mscptr = (chan::membership *)ptr->data;
+		auto &chptr(pit.first);
-		chptr = mscptr->chan;
+		auto &mscptr(pit.second);
 
-		RB_DLINK_FOREACH_SAFE(uptr, next_uptr, chptr->locmembers.head)
+		for(const auto &msptr : chptr->members.local)
 		{
-			msptr = (chan::membership *)uptr->data;
+			const auto target_p(msptr->git->first);
-			target_p = msptr->client;
 
 			if(IsIOError(target_p) ||
 			   target_p->serial == current_serial ||
@@ -915,15 +898,14 @@ sendto_common_channels_local_butone(struct Client *user, int cap, int negcap, co
 	/* Skip them -- jilles */
 	user->serial = current_serial;
 
-	RB_DLINK_FOREACH_SAFE(ptr, next_ptr, user->user->channel.head)
+	for(const auto &pit : user->user->channel)
 	{
-		mscptr = (membership *)ptr->data;
+		auto &chptr(pit.first);
-		chptr = mscptr->chan;
+		auto &mscptr(pit.second);
 
-		RB_DLINK_FOREACH_SAFE(uptr, next_uptr, chptr->locmembers.head)
+		for(const auto &msptr : chptr->members.local)
 		{
-			msptr = (membership *)uptr->data;
+			const auto target_p(msptr->git->first);
-			target_p = msptr->client;
 
 			if(IsIOError(target_p) ||
 			   target_p->serial == current_serial ||

ircd/tgchange.cc

@@ -27,18 +27,18 @@ namespace ircd {
 static int add_hashed_target(struct Client *source_p, uint32_t hashv);
 
 chan::chan *
-find_allowing_channel(struct Client *source_p, struct Client *target_p)
+find_allowing_channel(struct Client *source, struct Client *target)
 {
-	rb_dlink_node *ptr;
+	for(const auto &pit : source->user->channel)
-	chan::membership *msptr;
-
-	RB_DLINK_FOREACH(ptr, source_p->user->channel.head)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto &chan(*pit.first);
-		if (is_chanop_voiced(msptr) && is_member(msptr->chan, target_p))
+		auto &member(*pit.second);
-			return msptr->chan;
+
+		if (is_chanop_voiced(member) && is_member(chan, *target))
+			return &chan;
 	}
-	return NULL;
+
+	return nullptr;
 }
 
 int

modules/chm_noctcp.cc

@@ -48,7 +48,7 @@ chm_noctcp_process(hook_data_privmsg_channel *data)
 		data->approved = ERR_CANNOTSENDTOCHAN;
 		return;
 	}
-	else if (rb_dlink_list_length(&data->chptr->locmembers) > (unsigned)(GlobalSetOptions.floodcount / 2))
+	else if (local_size(data->chptr->members) > (unsigned)(GlobalSetOptions.floodcount / 2))
 		data->source_p->large_ctcp_sent = rb_current_time();
 }
 

modules/core/m_join.cc

@@ -221,7 +221,7 @@ m_join(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 		/* JOIN 0 simply parts all channels the user is in */
 		if(*name == '0' && !atoi(name))
 		{
-			if(source_p->user->channel.head == NULL)
+			if(source_p->user->channel.empty())
 				continue;
 
 			do_join_0(&me, source_p);
@@ -265,10 +265,10 @@ m_join(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 			flags = chan::CHANOP;
 		}
 
-		if((rb_dlink_list_length(&source_p->user->channel) >=
+		if(((source_p->user->channel.size()) >=
 		    (unsigned long) ConfigChannel.max_chans_per_user) &&
 		   (!IsExtendChans(source_p) ||
-		    (rb_dlink_list_length(&source_p->user->channel) >=
+		    (source_p->user->channel.size() >=
 		     (unsigned long) ConfigChannel.max_chans_per_user_large)))
 		{
 			sendto_one(source_p, form_str(ERR_TOOMANYCHANNELS),
@@ -309,7 +309,7 @@ m_join(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 			chan::check_spambot_warning(source_p, name);
 
 		/* add the user to the channel */
-		add_user_to_channel(chptr, source_p, flags);
+		add(*chptr, *source_p, flags);
 		if (chptr->mode.join_num &&
 			rb_current_time() - chptr->join_delta >= chptr->mode.join_time)
 		{
@@ -482,7 +482,7 @@ ms_join(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_
 
 	if(!is_member(chptr, source_p))
 	{
-		add_user_to_channel(chptr, source_p, chan::PEON);
+		add(*chptr, *source_p, chan::PEON);
 		if (chptr->mode.join_num &&
 			rb_current_time() - chptr->join_delta >= chptr->mode.join_time)
 		{
@@ -637,12 +637,11 @@ ms_sjoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 		{
 			chan::membership *msptr;
 			struct Client *who;
-			int l = rb_dlink_list_length(&chptr->members);
+			int l = size(chptr->members);
 
-			RB_DLINK_FOREACH_SAFE(ptr, next_ptr, chptr->locmembers.head)
+			for(const auto &msptr : chptr->members.local)
 			{
-				msptr = (chan::membership *)ptr->data;
+				who = &get_client(*msptr);
-				who = msptr->client;
 				sendto_one(who, ":%s KICK %s %s :Net Rider",
 						     me.name, chptr->name.c_str(), who->name);
 
@@ -650,7 +649,7 @@ ms_sjoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 					      ":%s KICK %s %s :Net Rider",
 					      me.id, chptr->name.c_str(),
 					      who->id);
-				remove_user_from_channel(msptr);
+				del(*chptr, *who);
 				if (--l == 0)
 					break;
 			}
@@ -822,7 +821,7 @@ ms_sjoin(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 
 		if(!is_member(chptr, target_p))
 		{
-			add_user_to_channel(chptr, target_p, fl);
+			add(*chptr, *target_p, fl);
 			send_join(*chptr, *target_p);
 			joins++;
 		}
@@ -953,18 +952,19 @@ do_join_0(struct Client *client_p, struct Client *source_p)
 
 	sendto_server(client_p, NULL, CAP_TS6, NOCAPS, ":%s JOIN 0", use_id(source_p));
 
-	while((ptr = source_p->user->channel.head))
+	for(const auto &pit : source_p->user->channel)
 	{
 		if(MyConnect(source_p) &&
 		   !IsOper(source_p) && !IsExemptSpambot(source_p))
 			chan::check_spambot_warning(source_p, NULL);
 
-		msptr = (chan::membership *)ptr->data;
+		auto &msptr(pit.second);
-		chptr = msptr->chan;
+		auto &chptr(pit.first);
 		sendto_channel_local(chan::ALL_MEMBERS, chptr, ":%s!%s@%s PART %s",
 				     source_p->name,
 				     source_p->username, source_p->host, chptr->name.c_str());
-		remove_user_from_channel(msptr);
+
+		del(*chptr, get_client(*msptr));
 	}
 }
 
@@ -1162,7 +1162,6 @@ set_final_mode(chan::modes *mode, chan::modes *oldmode)
 static void
 remove_our_modes(chan::chan *chptr, struct Client *source_p)
 {
-	chan::membership *msptr;
 	rb_dlink_node *ptr;
 	char lmodebuf[chan::mode::BUFLEN];
 	char *lpara[chan::mode::MAXPARAMS];
@@ -1175,14 +1174,15 @@ remove_our_modes(chan::chan *chptr, struct Client *source_p)
 	for(i = 0; i < chan::mode::MAXPARAMS; i++)
 		lpara[i] = NULL;
 
-	RB_DLINK_FOREACH(ptr, chptr->members.head)
+	for(auto &pit : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto &client(pit.first);
+		auto &msptr(pit.second);
 
 		if(is_chanop(msptr))
 		{
-			msptr->flags &= ~chan::CHANOP;
+			msptr.flags &= ~chan::CHANOP;
-			lpara[count++] = msptr->client->name;
+			lpara[count++] = client->name;
 			*mbuf++ = 'o';
 
 			/* +ov, might not fit so check. */
@@ -1206,15 +1206,15 @@ remove_our_modes(chan::chan *chptr, struct Client *source_p)
 						lpara[i] = NULL;
 				}
 
-				msptr->flags &= ~chan::VOICE;
+				msptr.flags &= ~chan::VOICE;
-				lpara[count++] = msptr->client->name;
+				lpara[count++] = client->name;
 				*mbuf++ = 'v';
 			}
 		}
 		else if(is_voiced(msptr))
 		{
-			msptr->flags &= ~chan::VOICE;
+			msptr.flags &= ~chan::VOICE;
-			lpara[count++] = msptr->client->name;
+			lpara[count++] = client->name;
 			*mbuf++ = 'v';
 		}
 		else

modules/core/m_kick.cc

@@ -75,7 +75,7 @@ m_kick(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 
 	if(!IsServer(source_p))
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		if((msptr == NULL) && MyConnect(source_p))
 		{
@@ -114,7 +114,7 @@ m_kick(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 		return;
 	}
 
-	msptr = find_channel_membership(chptr, who);
+	msptr = get(chptr->members, *who, std::nothrow);
 
 	if(msptr != NULL)
 	{
@@ -168,7 +168,8 @@ m_kick(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 		sendto_server(client_p, chptr, CAP_TS6, NOCAPS,
 			      ":%s KICK %s %s :%s",
 			      use_id(source_p), chptr->name.c_str(), use_id(who), comment);
-		remove_user_from_channel(msptr);
+
+		del(*chptr, *who);
 	}
 	else if (MyClient(source_p))
 		sendto_one_numeric(source_p, ERR_USERNOTINCHANNEL,

modules/core/m_message.cc

@@ -336,7 +336,7 @@ build_target_list(enum message_type msgtype, struct Client *client_p,
 			{
 				chan::membership *msptr;
 
-				msptr = find_channel_membership(chptr, source_p);
+				msptr = get(chptr->members, *source_p, std::nothrow);
 
 				if(!IsServer(source_p) && !IsService(source_p) && !is_chanop_voiced(msptr))
 				{

modules/core/m_mode.cc

@@ -120,7 +120,7 @@ m_mode(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p
 	}
 	else
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		/* Finish the flood grace period... */
 		if(MyClient(source_p) && !IsFloodDone(source_p))
@@ -182,7 +182,7 @@ ms_tmode(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 	}
 	else
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		set_channel_mode(client_p, source_p, chptr, msptr, parc - 3, parv + 3);
 	}

modules/core/m_part.cc

@@ -95,7 +95,7 @@ part_one_client(struct Client *client_p, struct Client *source_p, char *name, co
 		return;
 	}
 
-	msptr = find_channel_membership(chptr, source_p);
+	msptr = get(chptr->members, *source_p, std::nothrow);
 	if(msptr == NULL)
 	{
 		sendto_one_numeric(source_p, ERR_NOTONCHANNEL, form_str(ERR_NOTONCHANNEL), name);
@@ -145,7 +145,7 @@ part_one_client(struct Client *client_p, struct Client *source_p, char *name, co
 		                     chptr->name.c_str());
 	}
 
-	remove_user_from_channel(msptr);
+	del(*chptr, *source_p);
 }
 
 /*

modules/m_etrace.cc

@@ -212,7 +212,6 @@ m_chantrace(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *sou
 {
 	struct Client *target_p;
 	chan::chan *chptr;
-	chan::membership *msptr;
 	const char *sockhost;
 	const char *name;
 	rb_dlink_node *ptr;
@@ -251,10 +250,10 @@ m_chantrace(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *sou
 		return;
 	}
 
-	RB_DLINK_FOREACH(ptr, chptr->members.head)
+	for(const auto &pit : chptr->members.global)
 	{
-		msptr = (chan::membership *)ptr->data;
+		auto &target_p(pit.first);
-		target_p = msptr->client;
+		auto &member(pit.second);
 
 		if(EmptyString(target_p->sockhost))
 			sockhost = empty_sockhost;

modules/m_invite.cc

@@ -112,7 +112,7 @@ m_invite(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source
 		return;
 	}
 
-	msptr = find_channel_membership(chptr, source_p);
+	msptr = get(chptr->members, *source_p, std::nothrow);
 	if(MyClient(source_p) && (msptr == NULL))
 	{
 		sendto_one_numeric(source_p, ERR_NOTONCHANNEL,

modules/m_knock.cc

@@ -98,7 +98,7 @@ m_knock(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_
 
 	if(!((chptr->mode.mode & chan::mode::INVITEONLY) || (*chptr->mode.key) ||
 	     (chptr->mode.limit &&
-	      rb_dlink_list_length(&chptr->members) >= (unsigned long)chptr->mode.limit)))
+	      size(chptr->members) >= (unsigned long)chptr->mode.limit)))
 	{
 		sendto_one_numeric(source_p, ERR_CHANOPEN,
 				   form_str(ERR_CHANOPEN), name);

modules/m_list.cc

@@ -291,7 +291,7 @@ static void list_one_channel(struct Client *source_p, chan::chan *chptr,
 	strip_colour(topic);
 	sendto_one(source_p, form_str(RPL_LIST), me.name, source_p->name,
 		   visible ? "" : "!",
-		   chptr->name.c_str(), rb_dlink_list_length(&chptr->members),
+		   chptr->name.c_str(), size(chptr->members),
 		   topic);
 }
 
@@ -422,8 +422,7 @@ static void safelist_one_channel(struct Client *source_p, chan::chan *chptr, str
 	if (!visible && !params->operspy)
 		return;
 
-	if ((unsigned int)chptr->members.length < params->users_min
+	if (size(chptr->members) < params->users_min || size(chptr->members) > params->users_max)
-	    || (unsigned int)chptr->members.length > params->users_max)
 		return;
 
 	if (params->topic_min && chptr->topic.time < params->topic_min)

modules/m_names.cc

@@ -113,7 +113,6 @@ names_global(struct Client *source_p)
 	rb_dlink_node *lp, *ptr;
 	struct Client *target_p;
 	chan::chan *chptr = NULL;
-	chan::membership *msptr;
 	char buf[BUFSIZE];
 	char *t;
 
@@ -143,10 +142,9 @@ names_global(struct Client *source_p)
 		 * both were missed out above.  if the target is on a
 		 * common channel with source, its already been shown.
 		 */
-		RB_DLINK_FOREACH(lp, target_p->user->channel.head)
+		for(const auto &pit : target_p->user->channel)
 		{
-			msptr = (chan::membership *)lp->data;
+			auto &chptr(pit.first);
-			chptr = msptr->chan;
 
 			if(is_public(chptr) || is_member(chptr, source_p) || is_secret(chptr))
 			{

modules/m_stats.cc

@@ -1336,7 +1336,7 @@ stats_memory (struct Client *source_p)
 		{
 			users_counted++;
 			users_invited_count += target_p->user->invited.size();
-			user_channels += rb_dlink_list_length(&target_p->user->channel);
+			user_channels += target_p->user->channel.size();
 			if(target_p->user->away)
 			{
 				aways_counted++;
@@ -1352,7 +1352,7 @@ stats_memory (struct Client *source_p)
 		channel_count++;
 		channel_memory += (strlen(chptr->name.c_str()) + sizeof(chan::chan));
 
-		channel_users += rb_dlink_list_length(&chptr->members);
+		channel_users += size(chptr->members);
 		channel_invites += chptr->invites.size();
 
 		channel_bans += size(*chptr, chan::mode::BAN);

modules/m_topic.cc

@@ -85,7 +85,7 @@ m_topic(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_
 	/* setting topic */
 	if(parc > 2)
 	{
-		msptr = find_channel_membership(chptr, source_p);
+		msptr = get(chptr->members, *source_p, std::nothrow);
 
 		if(msptr == NULL)
 		{

modules/m_who.cc

@@ -54,7 +54,7 @@ static void do_who_on_channel(struct Client *source_p, chan::chan *chptr,
 			      struct who_format *fmt);
 static void who_global(struct Client *source_p, const char *mask, int server_oper, int operspy, struct who_format *fmt);
 static void do_who(struct Client *source_p,
-		   struct Client *target_p, chan::membership *msptr,
+		   struct Client *target_p, chan::chan *, chan::membership *msptr,
 		   struct who_format *fmt);
 
 struct Message who_msgtab = {
@@ -144,10 +144,10 @@ m_who(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 		if(source_p->user == NULL)
 			return;
 
-		if((lp = source_p->user->channel.head) != NULL)
+		if (!source_p->user->channel.empty())
 		{
-			msptr = (chan::membership *)lp->data;
+			auto *const chan(begin(source_p->user->channel)->first);
-			do_who_on_channel(source_p, msptr->chan, server_oper, true, &fmt);
+			do_who_on_channel(source_p, chan, server_oper, true, &fmt);
 		}
 
 		sendto_one(source_p, form_str(RPL_ENDOFWHO),
@@ -176,7 +176,7 @@ m_who(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 
 		if(chptr != NULL)
 		{
-			if (!IsOper(source_p) && !ratelimit_client_who(source_p, rb_dlink_list_length(&chptr->members)/50))
+			if (!IsOper(source_p) && !ratelimit_client_who(source_p, size(chptr->members)/50))
 			{
 				sendto_one(source_p, form_str(RPL_LOAD2HI),
 						me.name, source_p->name, "WHO");
@@ -207,27 +207,27 @@ m_who(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *source_p,
 		int isinvis = 0;
 
 		isinvis = IsInvisible(target_p);
-		RB_DLINK_FOREACH(lp, target_p->user->channel.head)
+		for(const auto &pit : target_p->user->channel)
 		{
-			msptr = (chan::membership *)lp->data;
+			chptr = pit.first;
-			chptr = msptr->chan;
+			msptr = get(chptr->members, *source_p, std::nothrow);
-
-			member = is_member(chptr, source_p);
 
 			if(isinvis && !member)
+			{
+				msptr = nullptr;
 				continue;
+			}
 
 			if(member || (!isinvis && is_public(chptr)))
 				break;
+
+			msptr = nullptr;
 		}
 
-		/* if we stopped midlist, lp->data is the membership for
+		/* if we stopped midlist, msptr is the membership for
 		 * target_p of chptr
 		 */
-		if(lp != NULL)
+		do_who(source_p, target_p, chptr, msptr, &fmt);
-			do_who(source_p, target_p, (chan::membership *)lp->data, &fmt);
-		else
-			do_who(source_p, target_p, NULL, &fmt);
 
 		sendto_one(source_p, form_str(RPL_ENDOFWHO),
 			   me.name, source_p->name, mask);
@@ -286,32 +286,28 @@ who_common_channel(struct Client *source_p, chan::chan *chptr,
 		   const char *mask, int server_oper, int *maxmatches,
 		   struct who_format *fmt)
 {
-	chan::membership *msptr;
+	for(const auto &pit : chptr->members.global)
-	struct Client *target_p;
-	rb_dlink_node *ptr;
-
-	RB_DLINK_FOREACH(ptr, chptr->members.head)
 	{
-		msptr = (chan::membership *)ptr->data;
+		const auto &target(pit.first);
-		target_p = msptr->client;
+		const auto &member(pit.second);
 
-		if(!IsInvisible(target_p) || IsMarked(target_p))
+		if(!IsInvisible(target) || IsMarked(target))
 			continue;
 
-		if(server_oper && !IsOper(target_p))
+		if(server_oper && !IsOper(target))
 			continue;
 
-		SetMark(target_p);
+		SetMark(target);
 
 		if(*maxmatches > 0)
 		{
 			if((mask == NULL) ||
-					match(mask, target_p->name) || match(mask, target_p->username) ||
+					match(mask, target->name) || match(mask, target->username) ||
-					match(mask, target_p->host) || match(mask, target_p->servptr->name) ||
+					match(mask, target->host) || match(mask, target->servptr->name) ||
-					(IsOper(source_p) && match(mask, target_p->orighost)) ||
+					(IsOper(source_p) && match(mask, target->orighost)) ||
-					match(mask, target_p->info))
+					match(mask, target->info))
 			{
-				do_who(source_p, target_p, NULL, fmt);
+				do_who(source_p, target, chptr, nullptr, fmt);
 				--(*maxmatches);
 			}
 		}
@@ -345,10 +341,10 @@ who_global(struct Client *source_p, const char *mask, int server_oper, int opers
 	 */
 	if(!operspy)
 	{
-		RB_DLINK_FOREACH(lp, source_p->user->channel.head)
+		for(const auto &pit : source_p->user->channel)
 		{
-			msptr = (chan::membership *)lp->data;
+			auto &chan(pit.first);
-			who_common_channel(source_p, msptr->chan, mask, server_oper, &maxmatches, fmt);
+			who_common_channel(source_p, chan, mask, server_oper, &maxmatches, fmt);
 		}
 	}
 	else if (!ConfigFileEntry.operspy_dont_care_user_info)
@@ -382,7 +378,7 @@ who_global(struct Client *source_p, const char *mask, int server_oper, int opers
 					(IsOper(source_p) && match(mask, target_p->orighost)) ||
 					match(mask, target_p->info))
 			{
-				do_who(source_p, target_p, NULL, fmt);
+				do_who(source_p, target_p, nullptr, nullptr, fmt);
 				--maxmatches;
 			}
 		}
@@ -408,22 +404,18 @@ who_global(struct Client *source_p, const char *mask, int server_oper, int opers
  */
 static void
 do_who_on_channel(struct Client *source_p, chan::chan *chptr,
-		  int server_oper, int member, struct who_format *fmt)
+		  int server_oper, int source_member, struct who_format *fmt)
 {
-	struct Client *target_p;
+	for(auto &pit : chptr->members.global)
-	chan::membership *msptr;
-	rb_dlink_node *ptr;
-
-	RB_DLINK_FOREACH(ptr, chptr->members.head)
 	{
-		msptr = (chan::membership *)ptr->data;
+		const auto &target(pit.first);
-		target_p = msptr->client;
+		auto &member(pit.second);
 
-		if(server_oper && !IsOper(target_p))
+		if(server_oper && !IsOper(target))
 			continue;
 
-		if(member || !IsInvisible(target_p))
+		if(source_member || !IsInvisible(target))
-			do_who(source_p, target_p, msptr, fmt);
+			do_who(source_p, target, chptr, &member, fmt);
 	}
 }
 
@@ -464,7 +456,7 @@ append_format(char *buf, size_t bufsize, size_t *pos, const char *fmt, ...)
  */
 
 static void
-do_who(struct Client *source_p, struct Client *target_p, chan::membership *msptr, struct who_format *fmt)
+do_who(struct Client *source_p, struct Client *target_p, chan::chan *chan, chan::membership *msptr, struct who_format *fmt)
 {
 	char status[16];
 	char str[510 + 1]; /* linebuf.c will add \r\n */
@@ -476,7 +468,7 @@ do_who(struct Client *source_p, struct Client *target_p, chan::membership *msptr
 
 	if (fmt->fields == 0)
 		sendto_one(source_p, form_str(RPL_WHOREPLY), me.name,
-			   source_p->name, msptr ? msptr->chan->name.c_str() : "*",
+			   source_p->name, msptr ? chan->name.c_str() : "*",
 			   target_p->username, target_p->host,
 			   target_p->servptr->name, target_p->name, status,
 			   ConfigServerHide.flatten_links && !IsOper(source_p) && !IsExemptShide(source_p) ? 0 : target_p->hopcount,
@@ -490,7 +482,7 @@ do_who(struct Client *source_p, struct Client *target_p, chan::membership *msptr
 		if (fmt->fields & FIELD_QUERYTYPE)
 			append_format(str, sizeof str, &pos, " %s", fmt->querytype);
 		if (fmt->fields & FIELD_CHANNEL)
-			append_format(str, sizeof str, &pos, " %s", msptr? msptr->chan->name.c_str() : "*");
+			append_format(str, sizeof str, &pos, " %s", msptr? name(*chan).c_str() : "*");
 		if (fmt->fields & FIELD_USER)
 			append_format(str, sizeof str, &pos, " %s", target_p->username);
 		if (fmt->fields & FIELD_IP)

modules/m_whois.cc

@@ -252,10 +252,10 @@ single_whois(struct Client *source_p, struct Client *target_p, int operspy)
 
 	if (!IsService(target_p))
 	{
-		RB_DLINK_FOREACH(ptr, target_p->user->channel.head)
+		for(const auto &pit : target_p->user->channel)
 		{
-			msptr = (chan::membership *)ptr->data;
+			auto &chptr(pit.first);
-			chptr = msptr->chan;
+			auto &msptr(pit.second);
 
 			hdata.chptr = chptr;