[user/henk/code/inspircd.git] / src / modules / m_spanningtree.cpp

/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  Inspire is copyright (C) 2002-2005 ChatSpike-Dev.
 *                       E-mail:
 *                <brain@chatspike.net>
 *                <Craig@chatspike.net>
 *     
 * Written by Craig Edwards, Craig McLure, and others.
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

/* $ModDesc: Povides a spanning tree server link protocol */

using namespace std;

#include <stdio.h>
#include <vector>
#include <deque>
#include "globals.h"
#include "inspircd_config.h"
#ifdef GCC3
#include <ext/hash_map>
#else
#include <hash_map>
#endif
#include "users.h"
#include "channels.h"
#include "modules.h"
#include "commands.h"
#include "socket.h"
#include "helperfuncs.h"
#include "inspircd.h"
#include "inspstring.h"
#include "hashcomp.h"
#include "message.h"
#include "xline.h"
#include "typedefs.h"
#include "cull_list.h"
#include "aes.h"

#ifdef GCC3
#define nspace __gnu_cxx
#else
#define nspace std
#endif

/*
 * The server list in InspIRCd is maintained as two structures
 * which hold the data in different ways. Most of the time, we
 * want to very quicky obtain three pieces of information:
 *
 * (1) The information on a server
 * (2) The information on the server we must send data through
 *     to actually REACH the server we're after
 * (3) Potentially, the child/parent objects of this server
 *
 * The InspIRCd spanning protocol provides easy access to these
 * by storing the data firstly in a recursive structure, where
 * each item references its parent item, and a dynamic list
 * of child items, and another structure which stores the items
 * hashed, linearly. This means that if we want to find a server
 * by name quickly, we can look it up in the hash, avoiding
 * any O(n) lookups. If however, during a split or sync, we want
 * to apply an operation to a server, and any of its child objects
 * we can resort to recursion to walk the tree structure.
 */

class ModuleSpanningTree;
static ModuleSpanningTree* TreeProtocolModule;

extern std::vector<Module*> modules;
extern std::vector<ircd_module*> factory;
extern int MODCOUNT;

/* Any socket can have one of five states at any one time.
 * The LISTENER state indicates a socket which is listening
 * for connections. It cannot receive data itself, only incoming
 * sockets.
 * The CONNECTING state indicates an outbound socket which is
 * waiting to be writeable.
 * The WAIT_AUTH_1 state indicates the socket is outbound and
 * has successfully connected, but has not yet sent and received
 * SERVER strings.
 * The WAIT_AUTH_2 state indicates that the socket is inbound
 * (allocated by a LISTENER) but has not yet sent and received
 * SERVER strings.
 * The CONNECTED state represents a fully authorized, fully
 * connected server.
 */
enum ServerState { LISTENER, CONNECTING, WAIT_AUTH_1, WAIT_AUTH_2, CONNECTED };

/* We need to import these from the core for use in netbursts */
/*typedef nspace::hash_map<std::string, userrec*, nspace::hash<string>, irc::StrHashComp> user_hash;
typedef nspace::hash_map<std::string, chanrec*, nspace::hash<string>, irc::StrHashComp> chan_hash;*/
extern user_hash clientlist;
extern chan_hash chanlist;

/* Foward declarations */
class TreeServer;
class TreeSocket;

/* This variable represents the root of the server tree
 * (for all intents and purposes, it's us)
 */
TreeServer *TreeRoot;

Server* Srv;

/* This hash_map holds the hash equivalent of the server
 * tree, used for rapid linear lookups.
 */
typedef nspace::hash_map<std::string, TreeServer*> server_hash;
server_hash serverlist;

/* More forward declarations */
bool DoOneToOne(std::string prefix, std::string command, std::deque<std::string> &params, std::string target);
bool DoOneToAllButSender(std::string prefix, std::string command, std::deque<std::string> &params, std::string omit);
bool DoOneToMany(std::string prefix, std::string command, std::deque<std::string> &params);
bool DoOneToAllButSenderRaw(std::string data, std::string omit, std::string prefix, std::string command, std::deque<std::string> &params);
void ReadConfiguration(bool rebind);

/* Imported from xline.cpp for use during netburst */
extern std::vector<KLine> klines;
extern std::vector<GLine> glines;
extern std::vector<ZLine> zlines;
extern std::vector<QLine> qlines;
extern std::vector<ELine> elines;
extern std::vector<KLine> pklines;
extern std::vector<GLine> pglines;
extern std::vector<ZLine> pzlines;
extern std::vector<QLine> pqlines;
extern std::vector<ELine> pelines;

/* Each server in the tree is represented by one class of
 * type TreeServer. A locally connected TreeServer can
 * have a class of type TreeSocket associated with it, for
 * remote servers, the TreeSocket entry will be NULL.
 * Each server also maintains a pointer to its parent
 * (NULL if this server is ours, at the top of the tree)
 * and a pointer to its "Route" (see the comments in the
 * constructors below), and also a dynamic list of pointers
 * to its children which can be iterated recursively
 * if required. Creating or deleting objects of type
 * TreeServer automatically maintains the hash_map of
 * TreeServer items, deleting and inserting them as they
 * are created and destroyed.
 */

class TreeServer
{
        TreeServer* Parent;                     /* Parent entry */
        TreeServer* Route;                      /* Route entry */
        std::vector<TreeServer*> Children;      /* List of child objects */
        std::string ServerName;                 /* Server's name */
        std::string ServerDesc;                 /* Server's description */
        std::string VersionString;              /* Version string or empty string */
        int UserCount;                          /* Not used in this version */
        int OperCount;                          /* Not used in this version */
        TreeSocket* Socket;                     /* For directly connected servers this points at the socket object */
        time_t NextPing;                        /* After this time, the server should be PINGed*/
        bool LastPingWasGood;                   /* True if the server responded to the last PING with a PONG */
        
 public:

        /* We don't use this constructor. Its a dummy, and won't cause any insertion
         * of the TreeServer into the hash_map. See below for the two we DO use.
         */
        TreeServer()
        {
                Parent = NULL;
                ServerName = "";
                ServerDesc = "";
                VersionString = "";
                UserCount = OperCount = 0;
                VersionString = Srv->GetVersion();
        }

        /* We use this constructor only to create the 'root' item, TreeRoot, which
         * represents our own server. Therefore, it has no route, no parent, and
         * no socket associated with it. Its version string is our own local version.
         */
        TreeServer(std::string Name, std::string Desc) : ServerName(Name), ServerDesc(Desc)
        {
                Parent = NULL;
                VersionString = "";
                UserCount = OperCount = 0;
                VersionString = Srv->GetVersion();
                Route = NULL;
                AddHashEntry();
        }

        /* When we create a new server, we call this constructor to initialize it.
         * This constructor initializes the server's Route and Parent, and sets up
         * its ping counters so that it will be pinged one minute from now.
         */
        TreeServer(std::string Name, std::string Desc, TreeServer* Above, TreeSocket* Sock) : Parent(Above), ServerName(Name), ServerDesc(Desc), Socket(Sock)
        {
                VersionString = "";
                UserCount = OperCount = 0;
                this->SetNextPingTime(time(NULL) + 60);
                this->SetPingFlag();

                /* find the 'route' for this server (e.g. the one directly connected
                 * to the local server, which we can use to reach it)
                 *
                 * In the following example, consider we have just added a TreeServer
                 * class for server G on our network, of which we are server A.
                 * To route traffic to G (marked with a *) we must send the data to
                 * B (marked with a +) so this algorithm initializes the 'Route'
                 * value to point at whichever server traffic must be routed through
                 * to get here. If we were to try this algorithm with server B,
                 * the Route pointer would point at its own object ('this').
                 *
                 *              A
                 *             / \
                 *          + B   C
                 *           / \   \
                 *          D   E   F
                 *         /         \
                 *      * G           H
                 *
                 * We only run this algorithm when a server is created, as
                 * the routes remain constant while ever the server exists, and
                 * do not need to be re-calculated.
                 */

                Route = Above;
                if (Route == TreeRoot)
                {
                        Route = this;
                }
                else
                {
                        while (this->Route->GetParent() != TreeRoot)
                        {
                                this->Route = Route->GetParent();
                        }
                }

                /* Because recursive code is slow and takes a lot of resources,
                 * we store two representations of the server tree. The first
                 * is a recursive structure where each server references its
                 * children and its parent, which is used for netbursts and
                 * netsplits to dump the whole dataset to the other server,
                 * and the second is used for very fast lookups when routing
                 * messages and is instead a hash_map, where each item can
                 * be referenced by its server name. The AddHashEntry()
                 * call below automatically inserts each TreeServer class
                 * into the hash_map as it is created. There is a similar
                 * maintainance call in the destructor to tidy up deleted
                 * servers.
                 */

                this->AddHashEntry();
        }

        /* This method is used to add the structure to the
         * hash_map for linear searches. It is only called
         * by the constructors.
         */
        void AddHashEntry()
        {
                server_hash::iterator iter;
                iter = serverlist.find(this->ServerName);
                if (iter == serverlist.end())
                        serverlist[this->ServerName] = this;
        }

        /* This method removes the reference to this object
         * from the hash_map which is used for linear searches.
         * It is only called by the default destructor.
         */
        void DelHashEntry()
        {
                server_hash::iterator iter;
                iter = serverlist.find(this->ServerName);
                if (iter != serverlist.end())
                        serverlist.erase(iter);
        }

        /* These accessors etc should be pretty self-
         * explanitory.
         */

        TreeServer* GetRoute()
        {
                return Route;
        }

        std::string GetName()
        {
                return this->ServerName;
        }

        std::string GetDesc()
        {
                return this->ServerDesc;
        }

        std::string GetVersion()
        {
                return this->VersionString;
        }

        void SetNextPingTime(time_t t)
        {
                this->NextPing = t;
                LastPingWasGood = false;
        }

        time_t NextPingTime()
        {
                return this->NextPing;
        }

        bool AnsweredLastPing()
        {
                return LastPingWasGood;
        }

        void SetPingFlag()
        {
                LastPingWasGood = true;
        }

        int GetUserCount()
        {
                return this->UserCount;
        }

        int GetOperCount()
        {
                return this->OperCount;
        }

        TreeSocket* GetSocket()
        {
                return this->Socket;
        }

        TreeServer* GetParent()
        {
                return this->Parent;
        }

        void SetVersion(std::string Version)
        {
                VersionString = Version;
        }

        unsigned int ChildCount()
        {
                return Children.size();
        }

        TreeServer* GetChild(unsigned int n)
        {
                if (n < Children.size())
                {
                        /* Make sure they  cant request
                         * an out-of-range object. After
                         * all we know what these programmer
                         * types are like *grin*.
                         */
                        return Children[n];
                }
                else
                {
                        return NULL;
                }
        }

        void AddChild(TreeServer* Child)
        {
                Children.push_back(Child);
        }

        bool DelChild(TreeServer* Child)
        {
                for (std::vector<TreeServer*>::iterator a = Children.begin(); a < Children.end(); a++)
                {
                        if (*a == Child)
                        {
                                Children.erase(a);
                                return true;
                        }
                }
                return false;
        }

        /* Removes child nodes of this node, and of that node, etc etc.
         * This is used during netsplits to automatically tidy up the
         * server tree. It is slow, we don't use it for much else.
         */
        bool Tidy()
        {
                bool stillchildren = true;
                while (stillchildren)
                {
                        stillchildren = false;
                        for (std::vector<TreeServer*>::iterator a = Children.begin(); a < Children.end(); a++)
                        {
                                TreeServer* s = (TreeServer*)*a;
                                s->Tidy();
                                Children.erase(a);
                                delete s;
                                stillchildren = true;
                                break;
                        }
                }
                return true;
        }

        ~TreeServer()
        {
                /* We'd better tidy up after ourselves, eh? */
                this->DelHashEntry();
        }
};

/* The Link class might as well be a struct,
 * but this is C++ and we don't believe in structs (!).
 * It holds the entire information of one <link>
 * tag from the main config file. We maintain a list
 * of them, and populate the list on rehash/load.
 */

class Link
{
 public:
         std::string Name;
         std::string IPAddr;
         int Port;
         std::string SendPass;
         std::string RecvPass;
         unsigned long AutoConnect;
         time_t NextConnectTime;
         std::string EncryptionKey;
};

/* The usual stuff for inspircd modules,
 * plus the vector of Link classes which we
 * use to store the <link> tags from the config
 * file.
 */
ConfigReader *Conf;
std::vector<Link> LinkBlocks;

/* Yay for fast searches!
 * This is hundreds of times faster than recursion
 * or even scanning a linked list, especially when
 * there are more than a few servers to deal with.
 * (read as: lots).
 */
TreeServer* FindServer(std::string ServerName)
{
        server_hash::iterator iter;
        iter = serverlist.find(ServerName);
        if (iter != serverlist.end())
        {
                return iter->second;
        }
        else
        {
                return NULL;
        }
}

/* Returns the locally connected server we must route a
 * message through to reach server 'ServerName'. This
 * only applies to one-to-one and not one-to-many routing.
 * See the comments for the constructor of TreeServer
 * for more details.
 */
TreeServer* BestRouteTo(std::string ServerName)
{
        if (ServerName.c_str() == TreeRoot->GetName())
                return NULL;
        TreeServer* Found = FindServer(ServerName);
        if (Found)
        {
                return Found->GetRoute();
        }
        else
        {
                return NULL;
        }
}

/* Find the first server matching a given glob mask.
 * Theres no find-using-glob method of hash_map [awwww :-(]
 * so instead, we iterate over the list using an iterator
 * and match each one until we get a hit. Yes its slow,
 * deal with it.
 */
TreeServer* FindServerMask(std::string ServerName)
{
        for (server_hash::iterator i = serverlist.begin(); i != serverlist.end(); i++)
        {
                if (Srv->MatchText(i->first,ServerName))
                        return i->second;
        }
        return NULL;
}

/* A convenient wrapper that returns true if a server exists */
bool IsServer(std::string ServerName)
{
        return (FindServer(ServerName) != NULL);
}

/* Every SERVER connection inbound or outbound is represented by
 * an object of type TreeSocket.
 * TreeSockets, being inherited from InspSocket, can be tied into
 * the core socket engine, and we cn therefore receive activity events
 * for them, just like activex objects on speed. (yes really, that
 * is a technical term!) Each of these which relates to a locally
 * connected server is assocated with it, by hooking it onto a
 * TreeSocket class using its constructor. In this way, we can
 * maintain a list of servers, some of which are directly connected,
 * some of which are not.
 */

class TreeSocket : public InspSocket
{
        std::string myhost;
        std::string in_buffer;
        ServerState LinkState;
        std::string InboundServerName;
        std::string InboundDescription;
        int num_lost_users;
        int num_lost_servers;
        time_t NextPing;
        bool LastPingWasGood;
        bool bursting;
        AES* ctx;
        unsigned int keylength;
        
 public:

        /* Because most of the I/O gubbins are encapsulated within
         * InspSocket, we just call the superclass constructor for
         * most of the action, and append a few of our own values
         * to it.
         */
        TreeSocket(std::string host, int port, bool listening, unsigned long maxtime)
                : InspSocket(host, port, listening, maxtime)
        {
                myhost = host;
                this->LinkState = LISTENER;
        }

        TreeSocket(std::string host, int port, bool listening, unsigned long maxtime, std::string ServerName)
                : InspSocket(host, port, listening, maxtime)
        {
                myhost = ServerName;
                this->LinkState = CONNECTING;
        }

        /* When a listening socket gives us a new file descriptor,
         * we must associate it with a socket without creating a new
         * connection. This constructor is used for this purpose.
         */
        TreeSocket(int newfd, char* ip)
                : InspSocket(newfd, ip)
        {
                this->LinkState = WAIT_AUTH_1;
        }

        void InitAES(std::string key)
        {
                if (key == "")
                        return;

                ctx = new AES();
                log(DEBUG,"Initialized AES key %s",key.c_str());
                // key must be 16, 24, 32 etc bytes (multiple of 8)
                keylength = key.length();
                if (!(keylength == 16 || keylength == 24 || keylength == 32))
                {
                        log(DEBUG,"Key length not 16, 24 or 32 characters!");
                }
                else
                {
                        ctx->MakeKey(key.c_str(), "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\
                                \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", keylength, keylength);
                }
        }
        
        /* When an outbound connection finishes connecting, we receive
         * this event, and must send our SERVER string to the other
         * side. If the other side is happy, as outlined in the server
         * to server docs on the inspircd.org site, the other side
         * will then send back its own server string.
         */
        virtual bool OnConnected()
        {
                if (this->LinkState == CONNECTING)
                {
                        Srv->SendOpers("*** Connection to "+myhost+"["+this->GetIP()+"] established.");
                        /* we do not need to change state here. */
                        for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                        {
                                if (x->Name == this->myhost)
                                {
                                        /* found who we're supposed to be connecting to, send the neccessary gubbins. */
                                        this->WriteLine("SERVER "+Srv->GetServerName()+" "+x->SendPass+" 0 :"+Srv->GetServerDescription());
                                        return true;
                                }
                        }
                }
                /* There is a (remote) chance that between the /CONNECT and the connection
                 * being accepted, some muppet has removed the <link> block and rehashed.
                 * If that happens the connection hangs here until it's closed. Unlikely
                 * and rather harmless.
                 */
                return true;
        }
        
        virtual void OnError(InspSocketError e)
        {
                /* We don't handle this method, because all our
                 * dirty work is done in OnClose() (see below)
                 * which is still called on error conditions too.
                 */
        }

        virtual int OnDisconnect()
        {
                /* For the same reason as above, we don't
                 * handle OnDisconnect()
                 */
                return true;
        }

        /* Recursively send the server tree with distances as hops.
         * This is used during network burst to inform the other server
         * (and any of ITS servers too) of what servers we know about.
         * If at any point any of these servers already exist on the other
         * end, our connection may be terminated. The hopcounts given
         * by this function are relative, this doesn't matter so long as
         * they are all >1, as all the remote servers re-calculate them
         * to be relative too, with themselves as hop 0.
         */
        void SendServers(TreeServer* Current, TreeServer* s, int hops)
        {
                char command[1024];
                for (unsigned int q = 0; q < Current->ChildCount(); q++)
                {
                        TreeServer* recursive_server = Current->GetChild(q);
                        if (recursive_server != s)
                        {
                                snprintf(command,1024,":%s SERVER %s * %d :%s",Current->GetName().c_str(),recursive_server->GetName().c_str(),hops,recursive_server->GetDesc().c_str());
                                this->WriteLine(command);
                                this->WriteLine(":"+recursive_server->GetName()+" VERSION :"+recursive_server->GetVersion());
                                /* down to next level */
                                this->SendServers(recursive_server, s, hops+1);
                        }
                }
        }

        /* This function forces this server to quit, removing this server
         * and any users on it (and servers and users below that, etc etc).
         * It's very slow and pretty clunky, but luckily unless your network
         * is having a REAL bad hair day, this function shouldnt be called
         * too many times a month ;-)
         */
        void SquitServer(TreeServer* Current, CullList* Goners)
        {
                /* recursively squit the servers attached to 'Current'.
                 * We're going backwards so we don't remove users
                 * while we still need them ;)
                 */
                for (unsigned int q = 0; q < Current->ChildCount(); q++)
                {
                        TreeServer* recursive_server = Current->GetChild(q);
                        this->SquitServer(recursive_server,Goners);
                }
                /* Now we've whacked the kids, whack self */
                num_lost_servers++;
                for (user_hash::iterator u = clientlist.begin(); u != clientlist.end(); u++)
                {
                        if (!strcasecmp(u->second->server,Current->GetName().c_str()))
                        {
                                std::string qreason = Current->GetName()+" "+std::string(Srv->GetServerName());
                                Goners->AddItem(u->second,qreason);
                                num_lost_users++;
                        }
                }
        }

        /* This is a wrapper function for SquitServer above, which
         * does some validation first and passes on the SQUIT to all
         * other remaining servers.
         */
        void Squit(TreeServer* Current,std::string reason)
        {
                if (Current)
                {
                        std::deque<std::string> params;
                        params.push_back(Current->GetName());
                        params.push_back(":"+reason);
                        DoOneToAllButSender(Current->GetParent()->GetName(),"SQUIT",params,Current->GetName());
                        if (Current->GetParent() == TreeRoot)
                        {
                                Srv->SendOpers("Server \002"+Current->GetName()+"\002 split: "+reason);
                        }
                        else
                        {
                                Srv->SendOpers("Server \002"+Current->GetName()+"\002 split from server \002"+Current->GetParent()->GetName()+"\002 with reason: "+reason);
                        }
                        num_lost_servers = 0;
                        num_lost_users = 0;
                        CullList* Goners = new CullList();
                        SquitServer(Current, Goners);
                        Goners->Apply();
                        Current->Tidy();
                        Current->GetParent()->DelChild(Current);
                        delete Current;
                        delete Goners;
                        WriteOpers("Netsplit complete, lost \002%d\002 users on \002%d\002 servers.", num_lost_users, num_lost_servers);
                }
                else
                {
                        log(DEFAULT,"Squit from unknown server");
                }
        }

        /* FMODE command */
        bool ForceMode(std::string source, std::deque<std::string> params)
        {
                userrec* who = new userrec;
                who->fd = FD_MAGIC_NUMBER;
                if (params.size() < 2)
                        return true;
                char* modelist[255];
                for (unsigned int q = 0; q < params.size(); q++)
                {
                        modelist[q] = (char*)params[q].c_str();
                }
                Srv->SendMode(modelist,params.size(),who);
                DoOneToAllButSender(source,"FMODE",params,source);
                delete who;
                return true;
        }

        /* FTOPIC command */
        bool ForceTopic(std::string source, std::deque<std::string> params)
        {
                if (params.size() != 4)
                        return true;
                std::string channel = params[0];
                time_t ts = atoi(params[1].c_str());
                std::string setby = params[2];
                std::string topic = params[3];

                chanrec* c = Srv->FindChannel(channel);
                if (c)
                {
                        if ((ts >= c->topicset) || (!*c->topic))
                        {
                                std::string oldtopic = c->topic;
                                strlcpy(c->topic,topic.c_str(),MAXTOPIC);
                                strlcpy(c->setby,setby.c_str(),NICKMAX);
                                c->topicset = ts;
                                /* if the topic text is the same as the current topic,
                                 * dont bother to send the TOPIC command out, just silently
                                 * update the set time and set nick.
                                 */
                                if (oldtopic != topic)
                                        WriteChannelWithServ((char*)source.c_str(), c, "TOPIC %s :%s", c->name, c->topic);
                        }
                        
                }
                
                /* all done, send it on its way */
                params[3] = ":" + params[3];
                DoOneToAllButSender(source,"FTOPIC",params,source);

                return true;
        }

        /* FJOIN, similar to unreal SJOIN */
        bool ForceJoin(std::string source, std::deque<std::string> params)
        {
                if (params.size() < 3)
                        return true;

                char first[MAXBUF];
                char modestring[MAXBUF];
                char* mode_users[127];
                mode_users[0] = first;
                mode_users[1] = modestring;
                strcpy(mode_users[1],"+");
                unsigned int modectr = 2;
                
                userrec* who = NULL;
                std::string channel = params[0];
                time_t TS = atoi(params[1].c_str());
                char* key = "";
                
                chanrec* chan = Srv->FindChannel(channel);
                if (chan)
                {
                        key = chan->key;
                }
                strlcpy(mode_users[0],channel.c_str(),MAXBUF);

                /* default is a high value, which if we dont have this
                 * channel will let the other side apply their modes.
                 */
                time_t ourTS = time(NULL)+600;
                chanrec* us = Srv->FindChannel(channel);
                if (us)
                {
                        ourTS = us->age;
                }

                log(DEBUG,"FJOIN detected, our TS=%lu, their TS=%lu",ourTS,TS);

                /* do this first, so our mode reversals are correctly received by other servers
                 * if there is a TS collision.
                 */
                DoOneToAllButSender(source,"FJOIN",params,source);
                
                for (unsigned int usernum = 2; usernum < params.size(); usernum++)
                {
                        /* process one channel at a time, applying modes. */
                        char* usr = (char*)params[usernum].c_str();
                        char permissions = *usr;
                        switch (permissions)
                        {
                                case '@':
                                        usr++;
                                        mode_users[modectr++] = usr;
                                        strlcat(modestring,"o",MAXBUF);
                                break;
                                case '%':
                                        usr++;
                                        mode_users[modectr++] = usr;
                                        strlcat(modestring,"h",MAXBUF);
                                break;
                                case '+':
                                        usr++;
                                        mode_users[modectr++] = usr;
                                        strlcat(modestring,"v",MAXBUF);
                                break;
                        }
                        who = Srv->FindNick(usr);
                        if (who)
                        {
                                Srv->JoinUserToChannel(who,channel,key);
                                if (modectr >= (MAXMODES-1))
                                {
                                        /* theres a mode for this user. push them onto the mode queue, and flush it
                                         * if there are more than MAXMODES to go.
                                         */
                                        if ((ourTS >= TS) || (Srv->IsUlined(who->server)))
                                        {
                                                /* We also always let u-lined clients win, no matter what the TS value */
                                                log(DEBUG,"Our our channel newer than theirs, accepting their modes");
                                                Srv->SendMode(mode_users,modectr,who);
                                        }
                                        else
                                        {
                                                log(DEBUG,"Their channel newer than ours, bouncing their modes");
                                                /* bouncy bouncy! */
                                                std::deque<std::string> params;
                                                /* modes are now being UNSET... */
                                                *mode_users[1] = '-';
                                                for (unsigned int x = 0; x < modectr; x++)
                                                {
                                                        params.push_back(mode_users[x]);
                                                }
                                                // tell everyone to bounce the modes. bad modes, bad!
                                                DoOneToMany(Srv->GetServerName(),"FMODE",params);
                                        }
                                        strcpy(mode_users[1],"+");
                                        modectr = 2;
                                }
                        }
                }
                /* there werent enough modes built up to flush it during FJOIN,
                 * or, there are a number left over. flush them out.
                 */
                if ((modectr > 2) && (who))
                {
                        if (ourTS >= TS)
                        {
                                log(DEBUG,"Our our channel newer than theirs, accepting their modes");
                                Srv->SendMode(mode_users,modectr,who);
                        }
                        else
                        {
                                log(DEBUG,"Their channel newer than ours, bouncing their modes");
                                std::deque<std::string> params;
                                *mode_users[1] = '-';
                                for (unsigned int x = 0; x < modectr; x++)
                                {
                                        params.push_back(mode_users[x]);
                                }
                                DoOneToMany(Srv->GetServerName(),"FMODE",params);
                        }
                }
                return true;
        }

        /* NICK command */
        bool IntroduceClient(std::string source, std::deque<std::string> params)
        {
                if (params.size() < 8)
                        return true;
                // NICK age nick host dhost ident +modes ip :gecos
                //       0   1    2    3      4     5    6   7
                std::string nick = params[1];
                std::string host = params[2];
                std::string dhost = params[3];
                std::string ident = params[4];
                time_t age = atoi(params[0].c_str());
                std::string modes = params[5];
                while (*(modes.c_str()) == '+')
                {
                        char* m = (char*)modes.c_str();
                        m++;
                        modes = m;
                }
                std::string ip = params[6];
                std::string gecos = params[7];
                char* tempnick = (char*)nick.c_str();
                log(DEBUG,"Introduce client %s!%s@%s",tempnick,ident.c_str(),host.c_str());
                
                user_hash::iterator iter;
                iter = clientlist.find(tempnick);
                if (iter != clientlist.end())
                {
                        // nick collision
                        log(DEBUG,"Nick collision on %s!%s@%s: %lu %lu",tempnick,ident.c_str(),host.c_str(),(unsigned long)age,(unsigned long)iter->second->age);
                        this->WriteLine(":"+Srv->GetServerName()+" KILL "+tempnick+" :Nickname collision");
                        return true;
                }

                clientlist[tempnick] = new userrec();
                clientlist[tempnick]->fd = FD_MAGIC_NUMBER;
                strlcpy(clientlist[tempnick]->nick, tempnick,NICKMAX);
                strlcpy(clientlist[tempnick]->host, host.c_str(),160);
                strlcpy(clientlist[tempnick]->dhost, dhost.c_str(),160);
                clientlist[tempnick]->server = (char*)FindServerNamePtr(source.c_str());
                strlcpy(clientlist[tempnick]->ident, ident.c_str(),IDENTMAX);
                strlcpy(clientlist[tempnick]->fullname, gecos.c_str(),MAXGECOS);
                clientlist[tempnick]->registered = 7;
                clientlist[tempnick]->signon = age;
                strlcpy(clientlist[tempnick]->modes, modes.c_str(),53);
                strlcpy(clientlist[tempnick]->ip,ip.c_str(),16);

                ucrec a;
                a.channel = NULL;
                a.uc_modes = 0;
                for (int i = 0; i < MAXCHANS; i++)
                        clientlist[tempnick]->chans.push_back(a);

                if (!this->bursting)
                {
                        WriteOpers("*** Client connecting at %s: %s!%s@%s [%s]",clientlist[tempnick]->server,clientlist[tempnick]->nick,clientlist[tempnick]->ident,clientlist[tempnick]->host,clientlist[tempnick]->ip);
                }
                params[7] = ":" + params[7];
                DoOneToAllButSender(source,"NICK",params,source);
                return true;
        }

        /* Send one or more FJOINs for a channel of users.
         * If the length of a single line is more than 480-NICKMAX
         * in length, it is split over multiple lines.
         */
        void SendFJoins(TreeServer* Current, chanrec* c)
        {
                log(DEBUG,"Sending FJOINs to other server for %s",c->name);
                char list[MAXBUF];
                snprintf(list,MAXBUF,":%s FJOIN %s %lu",Srv->GetServerName().c_str(),c->name,(unsigned long)c->age);
                std::vector<char*> *ulist = c->GetUsers();
                for (unsigned int i = 0; i < ulist->size(); i++)
                {
                        char* o = (*ulist)[i];
                        userrec* otheruser = (userrec*)o;
                        strlcat(list," ",MAXBUF);
                        strlcat(list,cmode(otheruser,c),MAXBUF);
                        strlcat(list,otheruser->nick,MAXBUF);
                        if (strlen(list)>(480-NICKMAX))
                        {
                                log(DEBUG,"FJOIN line wrapped");
                                this->WriteLine(list);
                                snprintf(list,MAXBUF,":%s FJOIN %s %lu",Srv->GetServerName().c_str(),c->name,(unsigned long)c->age);
                        }
                }
                if (list[strlen(list)-1] != ':')
                {
                        log(DEBUG,"Final FJOIN line");
                        this->WriteLine(list);
                }
        }

        /* Send G, Q, Z and E lines */
        void SendXLines(TreeServer* Current)
        {
                char data[MAXBUF];
                /* Yes, these arent too nice looking, but they get the job done */
                for (std::vector<ZLine>::iterator i = zlines.begin(); i != zlines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE Z %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->ipaddr,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<QLine>::iterator i = qlines.begin(); i != qlines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE Q %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->nick,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<GLine>::iterator i = glines.begin(); i != glines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE G %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->hostmask,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<ELine>::iterator i = elines.begin(); i != elines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE E %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->hostmask,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<ZLine>::iterator i = pzlines.begin(); i != pzlines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE Z %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->ipaddr,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<QLine>::iterator i = pqlines.begin(); i != pqlines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE Q %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->nick,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<GLine>::iterator i = pglines.begin(); i != pglines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE G %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->hostmask,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
                for (std::vector<ELine>::iterator i = pelines.begin(); i != pelines.end(); i++)
                {
                        snprintf(data,MAXBUF,":%s ADDLINE E %s %s %lu %lu :%s",Srv->GetServerName().c_str(),i->hostmask,i->source,(unsigned long)i->set_time,(unsigned long)i->duration,i->reason);
                        this->WriteLine(data);
                }
        }

        /* Send channel modes and topics */
        void SendChannelModes(TreeServer* Current)
        {
                char data[MAXBUF];
                std::deque<std::string> list;
                for (chan_hash::iterator c = chanlist.begin(); c != chanlist.end(); c++)
                {
                        SendFJoins(Current, c->second);
                        snprintf(data,MAXBUF,":%s FMODE %s +%s",Srv->GetServerName().c_str(),c->second->name,chanmodes(c->second));
                        this->WriteLine(data);
                        if (*c->second->topic)
                        {
                                snprintf(data,MAXBUF,":%s FTOPIC %s %lu %s :%s",Srv->GetServerName().c_str(),c->second->name,(unsigned long)c->second->topicset,c->second->setby,c->second->topic);
                                this->WriteLine(data);
                        }
                        for (BanList::iterator b = c->second->bans.begin(); b != c->second->bans.end(); b++)
                        {
                                snprintf(data,MAXBUF,":%s FMODE %s +b %s",Srv->GetServerName().c_str(),c->second->name,b->data);
                                this->WriteLine(data);
                        }
                        FOREACH_MOD OnSyncChannel(c->second,(Module*)TreeProtocolModule,(void*)this);
                        list.clear();
                        c->second->GetExtList(list);
                        for (unsigned int j = 0; j < list.size(); j++)
                        {
                                FOREACH_MOD OnSyncChannelMetaData(c->second,(Module*)TreeProtocolModule,(void*)this,list[j]);
                        }
                }
        }

        /* send all users and their oper state/modes */
        void SendUsers(TreeServer* Current)
        {
                char data[MAXBUF];
                std::deque<std::string> list;
                for (user_hash::iterator u = clientlist.begin(); u != clientlist.end(); u++)
                {
                        if (u->second->registered == 7)
                        {
                                snprintf(data,MAXBUF,":%s NICK %lu %s %s %s %s +%s %s :%s",u->second->server,(unsigned long)u->second->age,u->second->nick,u->second->host,u->second->dhost,u->second->ident,u->second->modes,u->second->ip,u->second->fullname);
                                this->WriteLine(data);
                                if (strchr(u->second->modes,'o'))
                                {
                                        this->WriteLine(":"+std::string(u->second->nick)+" OPERTYPE "+std::string(u->second->oper));
                                }
                                FOREACH_MOD OnSyncUser(u->second,(Module*)TreeProtocolModule,(void*)this);
                                list.clear();
                                u->second->GetExtList(list);
                                for (unsigned int j = 0; j < list.size(); j++)
                                {
                                        FOREACH_MOD OnSyncUserMetaData(u->second,(Module*)TreeProtocolModule,(void*)this,list[j]);
                                }
                        }
                }
        }

        /* This function is called when we want to send a netburst to a local
         * server. There is a set order we must do this, because for example
         * users require their servers to exist, and channels require their
         * users to exist. You get the idea.
         */
        void DoBurst(TreeServer* s)
        {
                Srv->SendOpers("*** Bursting to \2"+s->GetName()+"\2.");
                this->WriteLine("BURST");
                /* send our version string */
                this->WriteLine(":"+Srv->GetServerName()+" VERSION :"+Srv->GetVersion());
                /* Send server tree */
                this->SendServers(TreeRoot,s,1);
                /* Send users and their oper status */
                this->SendUsers(s);
                /* Send everything else (channel modes, xlines etc) */
                this->SendChannelModes(s);
                this->SendXLines(s);
                this->WriteLine("ENDBURST");
                Srv->SendOpers("*** Finished bursting to \2"+s->GetName()+"\2.");
        }

        /* This function is called when we receive data from a remote
         * server. We buffer the data in a std::string (it doesnt stay
         * there for long), reading using InspSocket::Read() which can
         * read up to 16 kilobytes in one operation.
         *
         * IF THIS FUNCTION RETURNS FALSE, THE CORE CLOSES AND DELETES
         * THE SOCKET OBJECT FOR US.
         */
        virtual bool OnDataReady()
        {
                char* data = this->Read();
                if (data)
                {
                        Srv->Log(DEBUG,"m_spanningtree: READ");
                        this->in_buffer += data;
                        /* While there is at least one new line in the buffer,
                         * do something useful (we hope!) with it.
                         */
                        while (in_buffer.find("\n") != std::string::npos)
                        {
                                char* line = (char*)in_buffer.c_str();
                                std::string ret = "";
                                while ((*line != '\n') && (strlen(line)))
                                {
                                        ret = ret + *line;
                                        line++;
                                }
                                if ((*line == '\n') || (*line == '\r'))
                                        line++;
                                in_buffer = line;
                                /* Process this one, abort if it
                                 * didnt return true.
                                 */
                                if (this->ctx)
                                {
                                        char out[1024];
                                        char result[1024];
                                        log(DEBUG,"Original string '%s'",ret.c_str());
                                        int nbytes = from64tobits(out, ret.c_str(), 1024);
                                        log(DEBUG,"m_spanningtree: decrypt %d bytes",nbytes);
                                        ctx->Decrypt(out, result, nbytes, 0);
                                        for (int t = 0; t < nbytes; t++)
                                                if (result[t] == '\7') result[t] = 0;
                                        ret = result;
                                }
                                if (!this->ProcessLine(ret))
                                {
                                        return false;
                                }
                        }
                }
                return (data != NULL);
        }

        int WriteLine(std::string line)
        {
                log(DEBUG,"OUT: %s",line.c_str());
                if (this->ctx)
                {
                        log(DEBUG,"AES context");
                        char result[1024];
                        char result64[1024];
                        if (this->keylength)
                        {
                                while (line.length() % this->keylength != 0)
                                {
                                        // pad it to be a multiple of the key length
                                        line = line + "\7";
                                }
                        }
                        ctx->Encrypt(line.c_str(), result, line.length(),0);
                        to64frombits((unsigned char*)result64,
                                        (unsigned char*)result,
                                        line.length());
                        line = result64;
                        log(DEBUG,"Encrypted: %s",line.c_str());
                        //int from64tobits(char *out, const char *in, int maxlen);
                }
                return this->Write(line + "\r\n");
        }

        /* Handle ERROR command */
        bool Error(std::deque<std::string> params)
        {
                if (params.size() < 1)
                        return false;
                std::string Errmsg = params[0];
                std::string SName = myhost;
                if (InboundServerName != "")
                {
                        SName = InboundServerName;
                }
                Srv->SendOpers("*** ERROR from "+SName+": "+Errmsg);
                /* we will return false to cause the socket to close.
                 */
                return false;
        }

        /* Because the core won't let users or even SERVERS set +o,
         * we use the OPERTYPE command to do this.
         */
        bool OperType(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() != 1)
                        return true;
                std::string opertype = params[0];
                userrec* u = Srv->FindNick(prefix);
                if (u)
                {
                        strlcpy(u->oper,opertype.c_str(),NICKMAX);
                        if (!strchr(u->modes,'o'))
                        {
                                strcat(u->modes,"o");
                        }
                        DoOneToAllButSender(u->nick,"OPERTYPE",params,u->server);
                }
                return true;
        }

        /* Because Andy insists that services-compatible servers must
         * implement SVSNICK and SVSJOIN, that's exactly what we do :p
         */
        bool ForceNick(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 3)
                        return true;
                userrec* u = Srv->FindNick(params[0]);
                if (u)
                {
                        Srv->ChangeUserNick(u,params[1]);
                        u->age = atoi(params[2].c_str());
                        DoOneToAllButSender(prefix,"SVSNICK",params,prefix);
                }
                return true;
        }

        bool ServiceJoin(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 2)
                        return true;
                userrec* u = Srv->FindNick(params[0]);
                if (u)
                {
                        Srv->JoinUserToChannel(u,params[1],"");
                        DoOneToAllButSender(prefix,"SVSJOIN",params,prefix);
                }
                return true;
        }

        bool RemoteRehash(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return false;
                std::string servermask = params[0];
                if (Srv->MatchText(Srv->GetServerName(),servermask))
                {
                        Srv->SendOpers("*** Remote rehash initiated from server \002"+prefix+"\002.");
                        Srv->RehashServer();
                        ReadConfiguration(false);
                }
                DoOneToAllButSender(prefix,"REHASH",params,prefix);
                return true;
        }

        bool RemoteKill(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() != 2)
                        return true;
                std::string nick = params[0];
                userrec* u = Srv->FindNick(prefix);
                userrec* who = Srv->FindNick(nick);
                if (who)
                {
                        /* Prepend kill source, if we don't have one */
                        std::string sourceserv = prefix;
                        if (u)
                        {
                                sourceserv = u->server;
                        }
                        if (*(params[1].c_str()) != '[')
                        {
                                params[1] = "[" + sourceserv + "] Killed (" + params[1] +")";
                        }
                        std::string reason = params[1];
                        params[1] = ":" + params[1];
                        DoOneToAllButSender(prefix,"KILL",params,sourceserv);
                        Srv->QuitUser(who,reason);
                }
                return true;
        }

        bool LocalPong(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                TreeServer* ServerSource = FindServer(prefix);
                if (ServerSource)
                {
                        ServerSource->SetPingFlag();
                }
                return true;
        }
        
        bool MetaData(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 3)
                        return true;
                TreeServer* ServerSource = FindServer(prefix);
                if (ServerSource)
                {
                        if (*(params[0].c_str()) == '#')
                        {
                                chanrec* c = Srv->FindChannel(params[0]);
                                if (c)
                                {
                                        FOREACH_MOD OnDecodeMetaData(TYPE_CHANNEL,c,params[1],params[2]);
                                }
                        }
                        else
                        {
                                userrec* u = Srv->FindNick(params[0]);
                                if (u)
                                {
                                        FOREACH_MOD OnDecodeMetaData(TYPE_USER,u,params[1],params[2]);
                                }
                        }
                }
                params[2] = ":" + params[2];
                DoOneToAllButSender(prefix,"METADATA",params,prefix);
                return true;
        }

        bool ServerVersion(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                TreeServer* ServerSource = FindServer(prefix);
                if (ServerSource)
                {
                        ServerSource->SetVersion(params[0]);
                }
                params[0] = ":" + params[0];
                DoOneToAllButSender(prefix,"VERSION",params,prefix);
                return true;
        }

        bool ChangeHost(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                userrec* u = Srv->FindNick(prefix);
                if (u)
                {
                        Srv->ChangeHost(u,params[0]);
                        DoOneToAllButSender(prefix,"FHOST",params,u->server);
                }
                return true;
        }

        bool AddLine(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 6)
                        return true;
                std::string linetype = params[0]; /* Z, Q, E, G, K */
                std::string mask = params[1]; /* Line type dependent */
                std::string source = params[2]; /* may not be online or may be a server */
                std::string settime = params[3]; /* EPOCH time set */
                std::string duration = params[4]; /* Duration secs */
                std::string reason = params[5];

                switch (*(linetype.c_str()))
                {
                        case 'Z':
                                add_zline(atoi(duration.c_str()), source.c_str(), reason.c_str(), mask.c_str());
                                zline_set_creation_time((char*)mask.c_str(), atoi(settime.c_str()));
                        break;
                        case 'Q':
                                add_qline(atoi(duration.c_str()), source.c_str(), reason.c_str(), mask.c_str());
                                qline_set_creation_time((char*)mask.c_str(), atoi(settime.c_str()));
                        break;
                        case 'E':
                                add_eline(atoi(duration.c_str()), source.c_str(), reason.c_str(), mask.c_str());
                                eline_set_creation_time((char*)mask.c_str(), atoi(settime.c_str()));
                        break;
                        case 'G':
                                add_gline(atoi(duration.c_str()), source.c_str(), reason.c_str(), mask.c_str());
                                gline_set_creation_time((char*)mask.c_str(), atoi(settime.c_str()));
                        break;
                        case 'K':
                                add_kline(atoi(duration.c_str()), source.c_str(), reason.c_str(), mask.c_str());
                        break;
                        default:
                                /* Just in case... */
                                Srv->SendOpers("*** \2WARNING\2: Invalid xline type '"+linetype+"' sent by server "+prefix+", ignored!");
                        break;
                }
                /* Send it on its way */
                params[5] = ":" + params[5];
                DoOneToAllButSender(prefix,"ADDLINE",params,prefix);
                return true;
        }

        bool ChangeName(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                userrec* u = Srv->FindNick(prefix);
                if (u)
                {
                        Srv->ChangeGECOS(u,params[0]);
                        params[0] = ":" + params[0];
                        DoOneToAllButSender(prefix,"FNAME",params,u->server);
                }
                return true;
        }

        bool Whois(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                log(DEBUG,"In IDLE command");
                userrec* u = Srv->FindNick(prefix);
                if (u)
                {
                        log(DEBUG,"USER EXISTS: %s",u->nick);
                        // an incoming request
                        if (params.size() == 1)
                        {
                                userrec* x = Srv->FindNick(params[0]);
                                if (x->fd > -1)
                                {
                                        userrec* x = Srv->FindNick(params[0]);
                                        log(DEBUG,"Got IDLE");
                                        char signon[MAXBUF];
                                        char idle[MAXBUF];
                                        log(DEBUG,"Sending back IDLE 3");
                                        snprintf(signon,MAXBUF,"%lu",(unsigned long)x->signon);
                                        snprintf(idle,MAXBUF,"%lu",(unsigned long)abs((x->idle_lastmsg)-time(NULL)));
                                        std::deque<std::string> par;
                                        par.push_back(prefix);
                                        par.push_back(signon);
                                        par.push_back(idle);
                                        // ours, we're done, pass it BACK
                                        DoOneToOne(params[0],"IDLE",par,u->server);
                                }
                                else
                                {
                                        // not ours pass it on
                                        DoOneToOne(prefix,"IDLE",params,x->server);
                                }
                        }
                        else if (params.size() == 3)
                        {
                                std::string who_did_the_whois = params[0];
                                userrec* who_to_send_to = Srv->FindNick(who_did_the_whois);
                                if (who_to_send_to->fd > -1)
                                {
                                        log(DEBUG,"Got final IDLE");
                                        // an incoming reply to a whois we sent out
                                        std::string nick_whoised = prefix;
                                        unsigned long signon = atoi(params[1].c_str());
                                        unsigned long idle = atoi(params[2].c_str());
                                        if ((who_to_send_to) && (who_to_send_to->fd > -1))
                                                do_whois(who_to_send_to,u,signon,idle,(char*)nick_whoised.c_str());
                                }
                                else
                                {
                                        // not ours, pass it on
                                        DoOneToOne(prefix,"IDLE",params,who_to_send_to->server);
                                }
                        }
                }
                return true;
        }
        
        bool LocalPing(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 1)
                        return true;
                std::string stufftobounce = params[0];
                this->WriteLine(":"+Srv->GetServerName()+" PONG "+stufftobounce);
                return true;
        }

        bool RemoteServer(std::string prefix, std::deque<std::string> &params)
        {
                if (params.size() < 4)
                        return false;
                std::string servername = params[0];
                std::string password = params[1];
                // hopcount is not used for a remote server, we calculate this ourselves
                std::string description = params[3];
                TreeServer* ParentOfThis = FindServer(prefix);
                if (!ParentOfThis)
                {
                        this->WriteLine("ERROR :Protocol error - Introduced remote server from unknown server "+prefix);
                        return false;
                }
                TreeServer* CheckDupe = FindServer(servername);
                if (CheckDupe)
                {
                        this->WriteLine("ERROR :Server "+servername+" already exists on server "+CheckDupe->GetParent()->GetName()+"!");
                        return false;
                }
                TreeServer* Node = new TreeServer(servername,description,ParentOfThis,NULL);
                ParentOfThis->AddChild(Node);
                params[3] = ":" + params[3];
                DoOneToAllButSender(prefix,"SERVER",params,prefix);
                Srv->SendOpers("*** Server \002"+prefix+"\002 introduced server \002"+servername+"\002 ("+description+")");
                return true;
        }

        bool Outbound_Reply_Server(std::deque<std::string> &params)
        {
                if (params.size() < 4)
                        return false;
                std::string servername = params[0];
                std::string password = params[1];
                int hops = atoi(params[2].c_str());
                if (hops)
                {
                        this->WriteLine("ERROR :Server too far away for authentication");
                        return false;
                }
                std::string description = params[3];
                for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                {
                        if ((x->Name == servername) && (x->RecvPass == password))
                        {
                                TreeServer* CheckDupe = FindServer(servername);
                                if (CheckDupe)
                                {
                                        this->WriteLine("ERROR :Server "+servername+" already exists on server "+CheckDupe->GetParent()->GetName()+"!");
                                        return false;
                                }
                                // Begin the sync here. this kickstarts the
                                // other side, waiting in WAIT_AUTH_2 state,
                                // into starting their burst, as it shows
                                // that we're happy.
                                this->LinkState = CONNECTED;
                                // we should add the details of this server now
                                // to the servers tree, as a child of the root
                                // node.
                                TreeServer* Node = new TreeServer(servername,description,TreeRoot,this);
                                TreeRoot->AddChild(Node);
                                params[3] = ":" + params[3];
                                DoOneToAllButSender(TreeRoot->GetName(),"SERVER",params,servername);
                                this->bursting = true;
                                this->DoBurst(Node);
                                return true;
                        }
                }
                this->WriteLine("ERROR :Invalid credentials");
                return false;
        }

        bool Inbound_Server(std::deque<std::string> &params)
        {
                if (params.size() < 4)
                        return false;
                std::string servername = params[0];
                std::string password = params[1];
                int hops = atoi(params[2].c_str());
                if (hops)
                {
                        this->WriteLine("ERROR :Server too far away for authentication");
                        return false;
                }
                std::string description = params[3];
                for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                {
                        if ((x->Name == servername) && (x->RecvPass == password))
                        {
                                TreeServer* CheckDupe = FindServer(servername);
                                if (CheckDupe)
                                {
                                        this->WriteLine("ERROR :Server "+servername+" already exists on server "+CheckDupe->GetParent()->GetName()+"!");
                                        return false;
                                }
                                Srv->SendOpers("*** Verified incoming server connection from \002"+servername+"\002["+this->GetIP()+"] ("+description+")");
                                this->InboundServerName = servername;
                                this->InboundDescription = description;
                                // this is good. Send our details: Our server name and description and hopcount of 0,
                                // along with the sendpass from this block.
                                this->WriteLine("SERVER "+Srv->GetServerName()+" "+x->SendPass+" 0 :"+Srv->GetServerDescription());
                                // move to the next state, we are now waiting for THEM.
                                this->LinkState = WAIT_AUTH_2;
                                return true;
                        }
                }
                this->WriteLine("ERROR :Invalid credentials");
                return false;
        }

        void Split(std::string line, bool stripcolon, std::deque<std::string> &n)
        {
                if (!strchr(line.c_str(),' '))
                {
                        n.push_back(line);
                        return;
                }
                std::stringstream s(line);
                std::string param = "";
                n.clear();
                int item = 0;
                while (!s.eof())
                {
                        char c;
                        s.get(c);
                        if (c == ' ')
                        {
                                n.push_back(param);
                                param = "";
                                item++;
                        }
                        else
                        {
                                if (!s.eof())
                                {
                                        param = param + c;
                                }
                                if ((param == ":") && (item > 0))
                                {
                                        param = "";
                                        while (!s.eof())
                                        {
                                                s.get(c);
                                                if (!s.eof())
                                                {
                                                        param = param + c;
                                                }
                                        }
                                        n.push_back(param);
                                        param = "";
                                }
                        }
                }
                if (param != "")
                {
                        n.push_back(param);
                }
                return;
        }

        bool ProcessLine(std::string line)
        {
                char* l = (char*)line.c_str();
                while ((strlen(l)) && (l[strlen(l)-1] == '\r') || (l[strlen(l)-1] == '\n'))
                        l[strlen(l)-1] = '\0';
                line = l;
                if (line == "")
                        return true;
                Srv->Log(DEBUG,"IN: "+line);
                std::deque<std::string> params;
                this->Split(line,true,params);
                std::string command = "";
                std::string prefix = "";
                if (((params[0].c_str())[0] == ':') && (params.size() > 1))
                {
                        prefix = params[0];
                        command = params[1];
                        char* pref = (char*)prefix.c_str();
                        prefix = ++pref;
                        params.pop_front();
                        params.pop_front();
                }
                else
                {
                        prefix = "";
                        command = params[0];
                        params.pop_front();
                }
                
                switch (this->LinkState)
                {
                        TreeServer* Node;
                        
                        case WAIT_AUTH_1:
                                // Waiting for SERVER command from remote server. Server initiating
                                // the connection sends the first SERVER command, listening server
                                // replies with theirs if its happy, then if the initiator is happy,
                                // it starts to send its net sync, which starts the merge, otherwise
                                // it sends an ERROR.
                                if (command == "SERVER")
                                {
                                        return this->Inbound_Server(params);
                                }
                                else if (command == "ERROR")
                                {
                                        return this->Error(params);
                                }
                        break;
                        case WAIT_AUTH_2:
                                // Waiting for start of other side's netmerge to say they liked our
                                // password.
                                if (command == "SERVER")
                                {
                                        // cant do this, they sent it to us in the WAIT_AUTH_1 state!
                                        // silently ignore.
                                        return true;
                                }
                                else if (command == "BURST")
                                {
                                        this->LinkState = CONNECTED;
                                        Node = new TreeServer(InboundServerName,InboundDescription,TreeRoot,this);
                                        TreeRoot->AddChild(Node);
                                        params.clear();
                                        params.push_back(InboundServerName);
                                        params.push_back("*");
                                        params.push_back("1");
                                        params.push_back(":"+InboundDescription);
                                        DoOneToAllButSender(TreeRoot->GetName(),"SERVER",params,InboundServerName);
                                        this->bursting = true;
                                        this->DoBurst(Node);
                                }
                                else if (command == "ERROR")
                                {
                                        return this->Error(params);
                                }
                                
                        break;
                        case LISTENER:
                                this->WriteLine("ERROR :Internal error -- listening socket accepted its own descriptor!!!");
                                return false;
                        break;
                        case CONNECTING:
                                if (command == "SERVER")
                                {
                                        // another server we connected to, which was in WAIT_AUTH_1 state,
                                        // has just sent us their credentials. If we get this far, theyre
                                        // happy with OUR credentials, and they are now in WAIT_AUTH_2 state.
                                        // if we're happy with this, we should send our netburst which
                                        // kickstarts the merge.
                                        return this->Outbound_Reply_Server(params);
                                }
                                else if (command == "ERROR")
                                {
                                        return this->Error(params);
                                }
                        break;
                        case CONNECTED:
                                // This is the 'authenticated' state, when all passwords
                                // have been exchanged and anything past this point is taken
                                // as gospel.
                                
                                if (prefix != "")
                                {
                                        std::string direction = prefix;
                                        userrec* t = Srv->FindNick(prefix);
                                        if (t)
                                        {
                                                direction = t->server;
                                        }
                                        TreeServer* route_back_again = BestRouteTo(direction);
                                        if ((!route_back_again) || (route_back_again->GetSocket() != this))
                                        {
                                                if (route_back_again)
                                                {
                                                        WriteOpers("Protocol violation: Fake direction in command '%s' from connection '%s'",line.c_str(),this->GetName().c_str());
                                                }
                                                else
                                                {
                                                        WriteOpers("Protocol violation: Invalid source '%s' in command '%s' from connection '%s'",direction.c_str(),line.c_str(),this->GetName().c_str());
                                                }
                                                
                                                return true;
                                        }
                                }
                                
                                if (command == "SVSMODE")
                                {
                                        /* Services expects us to implement
                                         * SVSMODE. In inspircd its the same as
                                         * MODE anyway.
                                         */
                                        command = "MODE";
                                }
                                std::string target = "";
                                /* Yes, know, this is a mess. Its reasonably fast though as we're
                                 * working with std::string here.
                                 */
                                if ((command == "NICK") && (params.size() > 1))
                                {
                                        return this->IntroduceClient(prefix,params);
                                }
                                else if (command == "FJOIN")
                                {
                                        return this->ForceJoin(prefix,params);
                                }
                                else if (command == "SERVER")
                                {
                                        return this->RemoteServer(prefix,params);
                                }
                                else if (command == "ERROR")
                                {
                                        return this->Error(params);
                                }
                                else if (command == "OPERTYPE")
                                {
                                        return this->OperType(prefix,params);
                                }
                                else if (command == "FMODE")
                                {
                                        return this->ForceMode(prefix,params);
                                }
                                else if (command == "KILL")
                                {
                                        return this->RemoteKill(prefix,params);
                                }
                                else if (command == "FTOPIC")
                                {
                                        return this->ForceTopic(prefix,params);
                                }
                                else if (command == "REHASH")
                                {
                                        return this->RemoteRehash(prefix,params);
                                }
                                else if (command == "METADATA")
                                {
                                        return this->MetaData(prefix,params);
                                }
                                else if (command == "PING")
                                {
                                        return this->LocalPing(prefix,params);
                                }
                                else if (command == "PONG")
                                {
                                        return this->LocalPong(prefix,params);
                                }
                                else if (command == "VERSION")
                                {
                                        return this->ServerVersion(prefix,params);
                                }
                                else if (command == "FHOST")
                                {
                                        return this->ChangeHost(prefix,params);
                                }
                                else if (command == "FNAME")
                                {
                                        return this->ChangeName(prefix,params);
                                }
                                else if (command == "ADDLINE")
                                {
                                        return this->AddLine(prefix,params);
                                }
                                else if (command == "SVSNICK")
                                {
                                        if (prefix == "")
                                        {
                                                prefix = this->GetName();
                                        }
                                        return this->ForceNick(prefix,params);
                                }
                                else if (command == "IDLE")
                                {
                                        return this->Whois(prefix,params);
                                }
                                else if (command == "SVSJOIN")
                                {
                                        if (prefix == "")
                                        {
                                                prefix = this->GetName();
                                        }
                                        return this->ServiceJoin(prefix,params);
                                }
                                else if (command == "SQUIT")
                                {
                                        if (params.size() == 2)
                                        {
                                                this->Squit(FindServer(params[0]),params[1]);
                                        }
                                        return true;
                                }
                                else if (command == "ENDBURST")
                                {
                                        this->bursting = false;
                                        std::string sserv = this->myhost;
                                        if (this->InboundServerName != "")
                                                sserv = this->InboundServerName;
                                        for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                                        {
                                                if ((x->EncryptionKey != "") && (x->Name == sserv))
                                                {
                                                        this->InitAES(x->EncryptionKey);
                                                }
                                        }
                                        return true;
                                }
                                else
                                {
                                        // not a special inter-server command.
                                        // Emulate the actual user doing the command,
                                        // this saves us having a huge ugly parser.
                                        userrec* who = Srv->FindNick(prefix);
                                        std::string sourceserv = this->myhost;
                                        if (this->InboundServerName != "")
                                        {
                                                sourceserv = this->InboundServerName;
                                        }
                                        if (who)
                                        {
                                                // its a user
                                                target = who->server;
                                                char* strparams[127];
                                                for (unsigned int q = 0; q < params.size(); q++)
                                                {
                                                        strparams[q] = (char*)params[q].c_str();
                                                }
                                                Srv->CallCommandHandler(command, strparams, params.size(), who);
                                        }
                                        else
                                        {
                                                // its not a user. Its either a server, or somethings screwed up.
                                                if (IsServer(prefix))
                                                {
                                                        target = Srv->GetServerName();
                                                }
                                                else
                                                {
                                                        log(DEBUG,"Command with unknown origin '%s'",prefix.c_str());
                                                        return true;
                                                }
                                        }
                                        return DoOneToAllButSenderRaw(line,sourceserv,prefix,command,params);

                                }
                                return true;
                        break;
                }
                return true;
        }

        virtual std::string GetName()
        {
                std::string sourceserv = this->myhost;
                if (this->InboundServerName != "")
                {
                        sourceserv = this->InboundServerName;
                }
                return sourceserv;
        }

        virtual void OnTimeout()
        {
                if (this->LinkState == CONNECTING)
                {
                        Srv->SendOpers("*** CONNECT: Connection to \002"+myhost+"\002 timed out.");
                }
        }

        virtual void OnClose()
        {
                // Connection closed.
                // If the connection is fully up (state CONNECTED)
                // then propogate a netsplit to all peers.
                std::string quitserver = this->myhost;
                if (this->InboundServerName != "")
                {
                        quitserver = this->InboundServerName;
                }
                TreeServer* s = FindServer(quitserver);
                if (s)
                {
                        Squit(s,"Remote host closed the connection");
                }
        }

        virtual int OnIncomingConnection(int newsock, char* ip)
        {
                TreeSocket* s = new TreeSocket(newsock, ip);
                Srv->AddSocket(s);
                return true;
        }
};

void AddThisServer(TreeServer* server, std::deque<TreeServer*> &list)
{
        for (unsigned int c = 0; c < list.size(); c++)
        {
                if (list[c] == server)
                {
                        return;
                }
        }
        list.push_back(server);
}

// returns a list of DIRECT servernames for a specific channel
void GetListOfServersForChannel(chanrec* c, std::deque<TreeServer*> &list)
{
        std::vector<char*> *ulist = c->GetUsers();
        unsigned int ucount = ulist->size();
        for (unsigned int i = 0; i < ucount; i++)
        {
                char* o = (*ulist)[i];
                userrec* otheruser = (userrec*)o;
                if (otheruser->fd < 0)
                {
                        TreeServer* best = BestRouteTo(otheruser->server);
                        if (best)
                                AddThisServer(best,list);
                }
        }
        return;
}

bool DoOneToAllButSenderRaw(std::string data, std::string omit, std::string prefix, std::string command, std::deque<std::string> &params)
{
        TreeServer* omitroute = BestRouteTo(omit);
        if ((command == "NOTICE") || (command == "PRIVMSG"))
        {
                if ((params.size() >= 2) && (*(params[0].c_str()) != '$'))
                {
                        if (*(params[0].c_str()) != '#')
                        {
                                // special routing for private messages/notices
                                userrec* d = Srv->FindNick(params[0]);
                                if (d)
                                {
                                        std::deque<std::string> par;
                                        par.push_back(params[0]);
                                        par.push_back(":"+params[1]);
                                        DoOneToOne(prefix,command,par,d->server);
                                        return true;
                                }
                        }
                        else
                        {
                                log(DEBUG,"Channel privmsg going to chan %s",params[0].c_str());
                                chanrec* c = Srv->FindChannel(params[0]);
                                if (c)
                                {
                                        std::deque<TreeServer*> list;
                                        GetListOfServersForChannel(c,list);
                                        log(DEBUG,"Got a list of %d servers",list.size());
                                        unsigned int lsize = list.size();
                                        for (unsigned int i = 0; i < lsize; i++)
                                        {
                                                TreeSocket* Sock = list[i]->GetSocket();
                                                if ((Sock) && (list[i]->GetName() != omit) && (omitroute != list[i]))
                                                {
                                                        log(DEBUG,"Writing privmsg to server %s",list[i]->GetName().c_str());
                                                        Sock->WriteLine(data);
                                                }
                                        }
                                        return true;
                                }
                        }
                }
        }
        unsigned int items = TreeRoot->ChildCount();
        for (unsigned int x = 0; x < items; x++)
        {
                TreeServer* Route = TreeRoot->GetChild(x);
                if ((Route->GetSocket()) && (Route->GetName() != omit) && (omitroute != Route))
                {
                        TreeSocket* Sock = Route->GetSocket();
                        Sock->WriteLine(data);
                }
        }
        return true;
}

bool DoOneToAllButSender(std::string prefix, std::string command, std::deque<std::string> &params, std::string omit)
{
        TreeServer* omitroute = BestRouteTo(omit);
        std::string FullLine = ":" + prefix + " " + command;
        unsigned int words = params.size();
        for (unsigned int x = 0; x < words; x++)
        {
                FullLine = FullLine + " " + params[x];
        }
        unsigned int items = TreeRoot->ChildCount();
        for (unsigned int x = 0; x < items; x++)
        {
                TreeServer* Route = TreeRoot->GetChild(x);
                // Send the line IF:
                // The route has a socket (its a direct connection)
                // The route isnt the one to be omitted
                // The route isnt the path to the one to be omitted
                if ((Route->GetSocket()) && (Route->GetName() != omit) && (omitroute != Route))
                {
                        TreeSocket* Sock = Route->GetSocket();
                        Sock->WriteLine(FullLine);
                }
        }
        return true;
}

bool DoOneToMany(std::string prefix, std::string command, std::deque<std::string> &params)
{
        std::string FullLine = ":" + prefix + " " + command;
        unsigned int words = params.size();
        for (unsigned int x = 0; x < words; x++)
        {
                FullLine = FullLine + " " + params[x];
        }
        unsigned int items = TreeRoot->ChildCount();
        for (unsigned int x = 0; x < items; x++)
        {
                TreeServer* Route = TreeRoot->GetChild(x);
                if (Route->GetSocket())
                {
                        TreeSocket* Sock = Route->GetSocket();
                        Sock->WriteLine(FullLine);
                }
        }
        return true;
}

bool DoOneToOne(std::string prefix, std::string command, std::deque<std::string> &params, std::string target)
{
        TreeServer* Route = BestRouteTo(target);
        if (Route)
        {
                std::string FullLine = ":" + prefix + " " + command;
                unsigned int words = params.size();
                for (unsigned int x = 0; x < words; x++)
                {
                        FullLine = FullLine + " " + params[x];
                }
                if (Route->GetSocket())
                {
                        TreeSocket* Sock = Route->GetSocket();
                        Sock->WriteLine(FullLine);
                }
                return true;
        }
        else
        {
                return true;
        }
}

std::vector<TreeSocket*> Bindings;

void ReadConfiguration(bool rebind)
{
        Conf = new ConfigReader;
        if (rebind)
        {
                for (int j =0; j < Conf->Enumerate("bind"); j++)
                {
                        std::string Type = Conf->ReadValue("bind","type",j);
                        std::string IP = Conf->ReadValue("bind","address",j);
                        long Port = Conf->ReadInteger("bind","port",j,true);
                        if (Type == "servers")
                        {
                                if (IP == "*")
                                {
                                        IP = "";
                                }
                                TreeSocket* listener = new TreeSocket(IP.c_str(),Port,true,10);
                                if (listener->GetState() == I_LISTENING)
                                {
                                        Srv->AddSocket(listener);
                                        Bindings.push_back(listener);
                                }
                                else
                                {
                                        log(DEFAULT,"m_spanningtree: Warning: Failed to bind server port %d",Port);
                                        listener->Close();
                                        delete listener;
                                }
                        }
                }
        }
        LinkBlocks.clear();
        for (int j =0; j < Conf->Enumerate("link"); j++)
        {
                Link L;
                L.Name = Conf->ReadValue("link","name",j);
                L.IPAddr = Conf->ReadValue("link","ipaddr",j);
                L.Port = Conf->ReadInteger("link","port",j,true);
                L.SendPass = Conf->ReadValue("link","sendpass",j);
                L.RecvPass = Conf->ReadValue("link","recvpass",j);
                L.AutoConnect = Conf->ReadInteger("link","autoconnect",j,true);
                L.EncryptionKey =  Conf->ReadValue("link","encryptionkey",j);
                L.NextConnectTime = time(NULL) + L.AutoConnect;
                /* Bugfix by brain, do not allow people to enter bad configurations */
                if ((L.RecvPass != "") && (L.SendPass != "") && (L.Name != "") && (L.Port))
                {
                        LinkBlocks.push_back(L);
                        log(DEBUG,"m_spanningtree: Read server %s with host %s:%d",L.Name.c_str(),L.IPAddr.c_str(),L.Port);
                }
                else
                {
                        log(DEFAULT,"m_spanningtree: Invalid configuration for server '%s', ignored!",L.Name.c_str());
                }
        }
        delete Conf;
}


class ModuleSpanningTree : public Module
{
        std::vector<TreeSocket*> Bindings;
        int line;
        int NumServers;

 public:

        ModuleSpanningTree(Server* Me)
                : Module::Module(Me)
        {
                Srv = Me;
                Bindings.clear();

                // Create the root of the tree
                TreeRoot = new TreeServer(Srv->GetServerName(),Srv->GetServerDescription());

                ReadConfiguration(true);
        }

        void ShowLinks(TreeServer* Current, userrec* user, int hops)
        {
                std::string Parent = TreeRoot->GetName();
                if (Current->GetParent())
                {
                        Parent = Current->GetParent()->GetName();
                }
                for (unsigned int q = 0; q < Current->ChildCount(); q++)
                {
                        ShowLinks(Current->GetChild(q),user,hops+1);
                }
                WriteServ(user->fd,"364 %s %s %s :%d %s",user->nick,Current->GetName().c_str(),Parent.c_str(),hops,Current->GetDesc().c_str());
        }

        int CountLocalServs()
        {
                return TreeRoot->ChildCount();
        }

        int CountServs()
        {
                return serverlist.size();
        }

        void HandleLinks(char** parameters, int pcnt, userrec* user)
        {
                ShowLinks(TreeRoot,user,0);
                WriteServ(user->fd,"365 %s * :End of /LINKS list.",user->nick);
                return;
        }

        void HandleLusers(char** parameters, int pcnt, userrec* user)
        {
                WriteServ(user->fd,"251 %s :There are %d users and %d invisible on %d servers",user->nick,usercnt()-usercount_invisible(),usercount_invisible(),this->CountServs());
                WriteServ(user->fd,"252 %s %d :operator(s) online",user->nick,usercount_opers());
                WriteServ(user->fd,"253 %s %d :unknown connections",user->nick,usercount_unknown());
                WriteServ(user->fd,"254 %s %d :channels formed",user->nick,chancount());
                WriteServ(user->fd,"254 %s :I have %d clients and %d servers",user->nick,local_count(),this->CountLocalServs());
                return;
        }

        // WARNING: NOT THREAD SAFE - DONT GET ANY SMART IDEAS.

        void ShowMap(TreeServer* Current, userrec* user, int depth, char matrix[128][80])
        {
                if (line < 128)
                {
                        for (int t = 0; t < depth; t++)
                        {
                                matrix[line][t] = ' ';
                        }
                        strlcpy(&matrix[line][depth],Current->GetName().c_str(),80);
                        line++;
                        for (unsigned int q = 0; q < Current->ChildCount(); q++)
                        {
                                ShowMap(Current->GetChild(q),user,depth+2,matrix);
                        }
                }
        }

        // Ok, prepare to be confused.
        // After much mulling over how to approach this, it struck me that
        // the 'usual' way of doing a /MAP isnt the best way. Instead of
        // keeping track of a ton of ascii characters, and line by line
        // under recursion working out where to place them using multiplications
        // and divisons, we instead render the map onto a backplane of characters
        // (a character matrix), then draw the branches as a series of "L" shapes
        // from the nodes. This is not only friendlier on CPU it uses less stack.

        void HandleMap(char** parameters, int pcnt, userrec* user)
        {
                // This array represents a virtual screen which we will
                // "scratch" draw to, as the console device of an irc
                // client does not provide for a proper terminal.
                char matrix[128][80];
                for (unsigned int t = 0; t < 128; t++)
                {
                        matrix[t][0] = '\0';
                }
                line = 0;
                // The only recursive bit is called here.
                ShowMap(TreeRoot,user,0,matrix);
                // Process each line one by one. The algorithm has a limit of
                // 128 servers (which is far more than a spanning tree should have
                // anyway, so we're ok). This limit can be raised simply by making
                // the character matrix deeper, 128 rows taking 10k of memory.
                for (int l = 1; l < line; l++)
                {
                        // scan across the line looking for the start of the
                        // servername (the recursive part of the algorithm has placed
                        // the servers at indented positions depending on what they
                        // are related to)
                        int first_nonspace = 0;
                        while (matrix[l][first_nonspace] == ' ')
                        {
                                first_nonspace++;
                        }
                        first_nonspace--;
                        // Draw the `- (corner) section: this may be overwritten by
                        // another L shape passing along the same vertical pane, becoming
                        // a |- (branch) section instead.
                        matrix[l][first_nonspace] = '-';
                        matrix[l][first_nonspace-1] = '`';
                        int l2 = l - 1;
                        // Draw upwards until we hit the parent server, causing possibly
                        // other corners (`-) to become branches (|-)
                        while ((matrix[l2][first_nonspace-1] == ' ') || (matrix[l2][first_nonspace-1] == '`'))
                        {
                                matrix[l2][first_nonspace-1] = '|';
                                l2--;
                        }
                }
                // dump the whole lot to the user. This is the easy bit, honest.
                for (int t = 0; t < line; t++)
                {
                        WriteServ(user->fd,"006 %s :%s",user->nick,&matrix[t][0]);
                }
                WriteServ(user->fd,"007 %s :End of /MAP",user->nick);
                return;
        }

        int HandleSquit(char** parameters, int pcnt, userrec* user)
        {
                TreeServer* s = FindServerMask(parameters[0]);
                if (s)
                {
                        TreeSocket* sock = s->GetSocket();
                        if (sock)
                        {
                                WriteOpers("*** SQUIT: Server \002%s\002 removed from network by %s",parameters[0],user->nick);
                                sock->Squit(s,"Server quit by "+std::string(user->nick)+"!"+std::string(user->ident)+"@"+std::string(user->host));
                                sock->Close();
                        }
                        else
                        {
                                WriteServ(user->fd,"NOTICE %s :*** SQUIT: The server \002%s\002 is not directly connected.",user->nick,parameters[0]);
                        }
                }
                else
                {
                         WriteServ(user->fd,"NOTICE %s :*** SQUIT: The server \002%s\002 does not exist on the network.",user->nick,parameters[0]);
                }
                return 1;
        }

        int HandleRemoteWhois(char** parameters, int pcnt, userrec* user)
        {
                if ((user->fd > -1) && (pcnt > 1))
                {
                        userrec* remote = Srv->FindNick(parameters[1]);
                        if ((remote) && (remote->fd < 0))
                        {
                                std::deque<std::string> params;
                                params.push_back(parameters[1]);
                                DoOneToOne(user->nick,"IDLE",params,remote->server);
                                return 1;
                        }
                        else if (!remote)
                        {
                                WriteServ(user->fd,"401 %s %s :No such nick/channel",user->nick, parameters[1]);
                                WriteServ(user->fd,"318 %s %s :End of /WHOIS list.",user->nick, parameters[1]);
                                return 1;
                        }
                }
                return 0;
        }

        void DoPingChecks(time_t curtime)
        {
                for (unsigned int j = 0; j < TreeRoot->ChildCount(); j++)
                {
                        TreeServer* serv = TreeRoot->GetChild(j);
                        TreeSocket* sock = serv->GetSocket();
                        if (sock)
                        {
                                if (curtime >= serv->NextPingTime())
                                {
                                        if (serv->AnsweredLastPing())
                                        {
                                                sock->WriteLine(":"+Srv->GetServerName()+" PING "+serv->GetName());
                                                serv->SetNextPingTime(curtime + 60);
                                        }
                                        else
                                        {
                                                // they didnt answer, boot them
                                                WriteOpers("*** Server \002%s\002 pinged out",serv->GetName().c_str());
                                                sock->Squit(serv,"Ping timeout");
                                                sock->Close();
                                                return;
                                        }
                                }
                        }
                }
        }

        void AutoConnectServers(time_t curtime)
        {
                for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                {
                        if ((x->AutoConnect) && (curtime >= x->NextConnectTime))
                        {
                                log(DEBUG,"Auto-Connecting %s",x->Name.c_str());
                                x->NextConnectTime = curtime + x->AutoConnect;
                                TreeServer* CheckDupe = FindServer(x->Name);
                                if (!CheckDupe)
                                {
                                        // an autoconnected server is not connected. Check if its time to connect it
                                        WriteOpers("*** AUTOCONNECT: Auto-connecting server \002%s\002 (%lu seconds until next attempt)",x->Name.c_str(),x->AutoConnect);
                                        TreeSocket* newsocket = new TreeSocket(x->IPAddr,x->Port,false,10,x->Name);
                                        Srv->AddSocket(newsocket);
                                }
                        }
                }
        }

        int HandleVersion(char** parameters, int pcnt, userrec* user)
        {
                // we've already checked if pcnt > 0, so this is safe
                TreeServer* found = FindServerMask(parameters[0]);
                if (found)
                {
                        std::string Version = found->GetVersion();
                        WriteServ(user->fd,"351 %s :%s",user->nick,Version.c_str());
                }
                else
                {
                        WriteServ(user->fd,"402 %s %s :No such server",user->nick,parameters[0]);
                }
                return 1;
        }
        
        int HandleConnect(char** parameters, int pcnt, userrec* user)
        {
                for (std::vector<Link>::iterator x = LinkBlocks.begin(); x < LinkBlocks.end(); x++)
                {
                        if (Srv->MatchText(x->Name.c_str(),parameters[0]))
                        {
                                TreeServer* CheckDupe = FindServer(x->Name);
                                if (!CheckDupe)
                                {
                                        WriteServ(user->fd,"NOTICE %s :*** CONNECT: Connecting to server: \002%s\002 (%s:%d)",user->nick,x->Name.c_str(),x->IPAddr.c_str(),x->Port);
                                        TreeSocket* newsocket = new TreeSocket(x->IPAddr,x->Port,false,10,x->Name);
                                        Srv->AddSocket(newsocket);
                                        return 1;
                                }
                                else
                                {
                                        WriteServ(user->fd,"NOTICE %s :*** CONNECT: Server \002%s\002 already exists on the network and is connected via \002%s\002",user->nick,x->Name.c_str(),CheckDupe->GetParent()->GetName().c_str());
                                        return 1;
                                }
                        }
                }
                WriteServ(user->fd,"NOTICE %s :*** CONNECT: No server matching \002%s\002 could be found in the config file.",user->nick,parameters[0]);
                return 1;
        }

        virtual bool HandleStats(char ** parameters, int pcnt, userrec* user)
        {
                if (*parameters[0] == 'c')
                {
                        for (unsigned int i = 0; i < LinkBlocks.size(); i++)
                        {
                                WriteServ(user->fd,"213 %s C *@%s * %s %d 0 M",user->nick,LinkBlocks[i].IPAddr.c_str(),LinkBlocks[i].Name.c_str(),LinkBlocks[i].Port);
                                WriteServ(user->fd,"244 %s H * * %s",user->nick,LinkBlocks[i].Name.c_str());
                        }
                        WriteServ(user->fd,"219 %s %s :End of /STATS report",user->nick,parameters[0]);
                        WriteOpers("*** Notice: Stats '%s' requested by %s (%s@%s)",parameters[0],user->nick,user->ident,user->host);
                        return true;
                }
                return false;
        }

        virtual int OnPreCommand(std::string command, char **parameters, int pcnt, userrec *user)
        {
                if (command == "CONNECT")
                {
                        return this->HandleConnect(parameters,pcnt,user);
                }
                else if (command == "SQUIT")
                {
                        return this->HandleSquit(parameters,pcnt,user);
                }
                else if (command == "STATS")
                {
                        return this->HandleStats(parameters,pcnt,user);
                }
                else if (command == "MAP")
                {
                        this->HandleMap(parameters,pcnt,user);
                        return 1;
                }
                else if (command == "LUSERS")
                {
                        this->HandleLusers(parameters,pcnt,user);
                        return 1;
                }
                else if (command == "LINKS")
                {
                        this->HandleLinks(parameters,pcnt,user);
                        return 1;
                }
                else if (command == "WHOIS")
                {
                        if (pcnt > 1)
                        {
                                // remote whois
                                return this->HandleRemoteWhois(parameters,pcnt,user);
                        }
                }
                else if ((command == "VERSION") && (pcnt > 0))
                {
                        this->HandleVersion(parameters,pcnt,user);
                        return 1;
                }
                else if (Srv->IsValidModuleCommand(command, pcnt, user))
                {
                        // this bit of code cleverly routes all module commands
                        // to all remote severs *automatically* so that modules
                        // can just handle commands locally, without having
                        // to have any special provision in place for remote
                        // commands and linking protocols.
                        std::deque<std::string> params;
                        params.clear();
                        for (int j = 0; j < pcnt; j++)
                        {
                                if (strchr(parameters[j],' '))
                                {
                                        params.push_back(":" + std::string(parameters[j]));
                                }
                                else
                                {
                                        params.push_back(std::string(parameters[j]));
                                }
                        }
                        DoOneToMany(user->nick,command,params);
                }
                return 0;
        }

        virtual void OnGetServerDescription(std::string servername,std::string &description)
        {
                TreeServer* s = FindServer(servername);
                if (s)
                {
                        description = s->GetDesc();
                }
        }

        virtual void OnUserInvite(userrec* source,userrec* dest,chanrec* channel)
        {
                if (source->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(dest->nick);
                        params.push_back(channel->name);
                        DoOneToMany(source->nick,"INVITE",params);
                }
        }

        virtual void OnPostLocalTopicChange(userrec* user, chanrec* chan, std::string topic)
        {
                std::deque<std::string> params;
                params.push_back(chan->name);
                params.push_back(":"+topic);
                DoOneToMany(user->nick,"TOPIC",params);
        }

        virtual void OnWallops(userrec* user, std::string text)
        {
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(":"+text);
                        DoOneToMany(user->nick,"WALLOPS",params);
                }
        }

        virtual void OnUserNotice(userrec* user, void* dest, int target_type, std::string text)
        {
                if (target_type == TYPE_USER)
                {
                        userrec* d = (userrec*)dest;
                        if ((d->fd < 0) && (user->fd > -1))
                        {
                                std::deque<std::string> params;
                                params.clear();
                                params.push_back(d->nick);
                                params.push_back(":"+text);
                                DoOneToOne(user->nick,"NOTICE",params,d->server);
                        }
                }
                else
                {
                        if (user->fd > -1)
                        {
                                chanrec *c = (chanrec*)dest;
                                std::deque<TreeServer*> list;
                                GetListOfServersForChannel(c,list);
                                unsigned int ucount = list.size();
                                for (unsigned int i = 0; i < ucount; i++)
                                {
                                        TreeSocket* Sock = list[i]->GetSocket();
                                        if (Sock)
                                                Sock->WriteLine(":"+std::string(user->nick)+" NOTICE "+std::string(c->name)+" :"+text);
                                }
                        }
                }
        }

        virtual void OnUserMessage(userrec* user, void* dest, int target_type, std::string text)
        {
                if (target_type == TYPE_USER)
                {
                        // route private messages which are targetted at clients only to the server
                        // which needs to receive them
                        userrec* d = (userrec*)dest;
                        if ((d->fd < 0) && (user->fd > -1))
                        {
                                std::deque<std::string> params;
                                params.clear();
                                params.push_back(d->nick);
                                params.push_back(":"+text);
                                DoOneToOne(user->nick,"PRIVMSG",params,d->server);
                        }
                }
                else
                {
                        if (user->fd > -1)
                        {
                                chanrec *c = (chanrec*)dest;
                                std::deque<TreeServer*> list;
                                GetListOfServersForChannel(c,list);
                                unsigned int ucount = list.size();
                                for (unsigned int i = 0; i < ucount; i++)
                                {
                                        TreeSocket* Sock = list[i]->GetSocket();
                                        if (Sock)
                                                Sock->WriteLine(":"+std::string(user->nick)+" PRIVMSG "+std::string(c->name)+" :"+text);
                                }
                        }
                }
        }

        virtual void OnBackgroundTimer(time_t curtime)
        {
                AutoConnectServers(curtime);
                DoPingChecks(curtime);
        }

        virtual void OnUserJoin(userrec* user, chanrec* channel)
        {
                // Only do this for local users
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        params.clear();
                        params.push_back(channel->name);
                        if (*channel->key)
                        {
                                // if the channel has a key, force the join by emulating the key.
                                params.push_back(channel->key);
                        }
                        if (channel->GetUserCounter() > 1)
                        {
                                // not the first in the channel
                                DoOneToMany(user->nick,"JOIN",params);
                        }
                        else
                        {
                                // first in the channel, set up their permissions
                                // and the channel TS with FJOIN.
                                char ts[24];
                                snprintf(ts,24,"%lu",(unsigned long)channel->age);
                                params.clear();
                                params.push_back(channel->name);
                                params.push_back(ts);
                                params.push_back("@"+std::string(user->nick));
                                DoOneToMany(Srv->GetServerName(),"FJOIN",params);
                        }
                }
        }

        virtual void OnChangeHost(userrec* user, std::string newhost)
        {
                // only occurs for local clients
                if (user->registered != 7)
                        return;
                std::deque<std::string> params;
                params.push_back(newhost);
                DoOneToMany(user->nick,"FHOST",params);
        }

        virtual void OnChangeName(userrec* user, std::string gecos)
        {
                // only occurs for local clients
                if (user->registered != 7)
                        return;
                std::deque<std::string> params;
                params.push_back(gecos);
                DoOneToMany(user->nick,"FNAME",params);
        }

        virtual void OnUserPart(userrec* user, chanrec* channel)
        {
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(channel->name);
                        DoOneToMany(user->nick,"PART",params);
                }
        }

        virtual void OnUserConnect(userrec* user)
        {
                char agestr[MAXBUF];
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        snprintf(agestr,MAXBUF,"%lu",(unsigned long)user->age);
                        params.push_back(agestr);
                        params.push_back(user->nick);
                        params.push_back(user->host);
                        params.push_back(user->dhost);
                        params.push_back(user->ident);
                        params.push_back("+"+std::string(user->modes));
                        params.push_back(user->ip);
                        params.push_back(":"+std::string(user->fullname));
                        DoOneToMany(Srv->GetServerName(),"NICK",params);
                }
        }

        virtual void OnUserQuit(userrec* user, std::string reason)
        {
                if ((user->fd > -1) && (user->registered == 7))
                {
                        std::deque<std::string> params;
                        params.push_back(":"+reason);
                        DoOneToMany(user->nick,"QUIT",params);
                }
        }

        virtual void OnUserPostNick(userrec* user, std::string oldnick)
        {
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(user->nick);
                        DoOneToMany(oldnick,"NICK",params);
                }
        }

        virtual void OnUserKick(userrec* source, userrec* user, chanrec* chan, std::string reason)
        {
                if (source->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(chan->name);
                        params.push_back(user->nick);
                        params.push_back(":"+reason);
                        DoOneToMany(source->nick,"KICK",params);
                }
        }

        virtual void OnRemoteKill(userrec* source, userrec* dest, std::string reason)
        {
                std::deque<std::string> params;
                params.push_back(dest->nick);
                params.push_back(":"+reason);
                DoOneToMany(source->nick,"KILL",params);
        }

        virtual void OnRehash(std::string parameter)
        {
                if (parameter != "")
                {
                        std::deque<std::string> params;
                        params.push_back(parameter);
                        DoOneToMany(Srv->GetServerName(),"REHASH",params);
                        // check for self
                        if (Srv->MatchText(Srv->GetServerName(),parameter))
                        {
                                Srv->SendOpers("*** Remote rehash initiated from server \002"+Srv->GetServerName()+"\002.");
                                Srv->RehashServer();
                        }
                }
                ReadConfiguration(false);
        }

        // note: the protocol does not allow direct umode +o except
        // via NICK with 8 params. sending OPERTYPE infers +o modechange
        // locally.
        virtual void OnOper(userrec* user, std::string opertype)
        {
                if (user->fd > -1)
                {
                        std::deque<std::string> params;
                        params.push_back(opertype);
                        DoOneToMany(user->nick,"OPERTYPE",params);
                }
        }

        void OnLine(userrec* source, std::string host, bool adding, char linetype, long duration, std::string reason)
        {
                if (source->fd > -1)
                {
                        char type[8];
                        snprintf(type,8,"%cLINE",linetype);
                        std::string stype = type;
                        if (adding)
                        {
                                char sduration[MAXBUF];
                                snprintf(sduration,MAXBUF,"%ld",duration);
                                std::deque<std::string> params;
                                params.push_back(host);
                                params.push_back(sduration);
                                params.push_back(":"+reason);
                                DoOneToMany(source->nick,stype,params);
                        }
                        else
                        {
                                std::deque<std::string> params;
                                params.push_back(host);
                                DoOneToMany(source->nick,stype,params);
                        }
                }
        }

        virtual void OnAddGLine(long duration, userrec* source, std::string reason, std::string hostmask)
        {
                OnLine(source,hostmask,true,'G',duration,reason);
        }
        
        virtual void OnAddZLine(long duration, userrec* source, std::string reason, std::string ipmask)
        {
                OnLine(source,ipmask,true,'Z',duration,reason);
        }

        virtual void OnAddQLine(long duration, userrec* source, std::string reason, std::string nickmask)
        {
                OnLine(source,nickmask,true,'Q',duration,reason);
        }

        virtual void OnAddELine(long duration, userrec* source, std::string reason, std::string hostmask)
        {
                OnLine(source,hostmask,true,'E',duration,reason);
        }

        virtual void OnDelGLine(userrec* source, std::string hostmask)
        {
                OnLine(source,hostmask,false,'G',0,"");
        }

        virtual void OnDelZLine(userrec* source, std::string ipmask)
        {
                OnLine(source,ipmask,false,'Z',0,"");
        }

        virtual void OnDelQLine(userrec* source, std::string nickmask)
        {
                OnLine(source,nickmask,false,'Q',0,"");
        }

        virtual void OnDelELine(userrec* source, std::string hostmask)
        {
                OnLine(source,hostmask,false,'E',0,"");
        }

        virtual void OnMode(userrec* user, void* dest, int target_type, std::string text)
        {
                if ((user->fd > -1) && (user->registered == 7))
                {
                        if (target_type == TYPE_USER)
                        {
                                userrec* u = (userrec*)dest;
                                std::deque<std::string> params;
                                params.push_back(u->nick);
                                params.push_back(text);
                                DoOneToMany(user->nick,"MODE",params);
                        }
                        else
                        {
                                chanrec* c = (chanrec*)dest;
                                std::deque<std::string> params;
                                params.push_back(c->name);
                                params.push_back(text);
                                DoOneToMany(user->nick,"MODE",params);
                        }
                }
        }

        virtual void ProtoSendMode(void* opaque, int target_type, void* target, std::string modeline)
        {
                TreeSocket* s = (TreeSocket*)opaque;
                if (target)
                {
                        if (target_type == TYPE_USER)
                        {
                                userrec* u = (userrec*)target;
                                s->WriteLine(":"+Srv->GetServerName()+" FMODE "+u->nick+" "+modeline);
                        }
                        else
                        {
                                chanrec* c = (chanrec*)target;
                                s->WriteLine(":"+Srv->GetServerName()+" FMODE "+c->name+" "+modeline);
                        }
                }
        }

        virtual void ProtoSendMetaData(void* opaque, int target_type, void* target, std::string extname, std::string extdata)
        {
                TreeSocket* s = (TreeSocket*)opaque;
                if (target)
                {
                        if (target_type == TYPE_USER)
                        {
                                userrec* u = (userrec*)target;
                                s->WriteLine(":"+Srv->GetServerName()+" METADATA "+u->nick+" "+extname+" :"+extdata);
                        }
                        else
                        {
                                chanrec* c = (chanrec*)target;
                                s->WriteLine(":"+Srv->GetServerName()+" METADATA "+c->name+" "+extname+" :"+extdata);
                        }
                }
        }

        virtual ~ModuleSpanningTree()
        {
        }

        virtual Version GetVersion()
        {
                return Version(1,0,0,0,VF_STATIC|VF_VENDOR);
        }
};


class ModuleSpanningTreeFactory : public ModuleFactory
{
 public:
        ModuleSpanningTreeFactory()
        {
        }
        
        ~ModuleSpanningTreeFactory()
        {
        }
        
        virtual Module * CreateModule(Server* Me)
        {
                TreeProtocolModule = new ModuleSpanningTree(Me);
                return TreeProtocolModule;
        }
        
};


extern "C" void * init_module( void )
{
        return new ModuleSpanningTreeFactory;
}