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

/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
 *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
 *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
 *   Copyright (C) 2007 Craig Edwards <craigedwards@brainbox.cc>
 *
 * This file is part of InspIRCd.  InspIRCd is free software: you can
 * redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation, version 2.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */


#pragma once

#include "inspircd.h"

#include "utils.h"

/*
 * 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.
 * Any socket can have one of five states at any one time.
 *
 * CONNECTING:  indicates an outbound socket which is
 *                                                      waiting to be writeable.
 * WAIT_AUTH_1: indicates the socket is outbound and
 *                                                      has successfully connected, but has not
 *                                                      yet sent and received SERVER strings.
 * WAIT_AUTH_2: indicates that the socket is inbound
 *                                                      but has not yet sent and received
 *                                                      SERVER strings.
 * CONNECTED:   represents a fully authorized, fully
 *                                                      connected server.
 * DYING:       represents a server that has had an error.
 */
enum ServerState { CONNECTING, WAIT_AUTH_1, WAIT_AUTH_2, CONNECTED, DYING };

struct CapabData
{
        reference<Link> link;                   /* Link block used for this connection */
        reference<Autoconnect> ac;              /* Autoconnect used to cause this connection, if any */
        std::string ModuleList;                 /* Required module list of other server from CAPAB */
        std::string OptModuleList;              /* Optional module list of other server from CAPAB */
        std::string ChanModes;
        std::string UserModes;
        std::map<std::string,std::string> CapKeys;      /* CAPAB keys from other server */
        std::string ourchallenge;               /* Challenge sent for challenge/response */
        std::string theirchallenge;             /* Challenge recv for challenge/response */
        int capab_phase;                        /* Have sent CAPAB already */
        bool auth_fingerprint;                  /* Did we auth using SSL certificate fingerprint */
        bool auth_challenge;                    /* Did we auth using challenge/response */

        // Data saved from incoming SERVER command, for later use when our credentials have been accepted by the other party
        std::string description;
        std::string sid;
        std::string name;
        bool hidden;
};

/** Every SERVER connection inbound or outbound is represented by an object of
 * type TreeSocket. During setup, the object can be found in Utils->timeoutlist;
 * after setup, MyRoot will have been created as a child of Utils->TreeRoot
 */
class TreeSocket : public BufferedSocket
{
        struct BurstState;

        std::string linkID;                     /* Description for this link */
        ServerState LinkState;                  /* Link state */
        CapabData* capab;                       /* Link setup data (held until burst is sent) */
        TreeServer* MyRoot;                     /* The server we are talking to */
        time_t NextPing;                        /* Time when we are due to ping this server */
        bool LastPingWasGood;                   /* Responded to last ping we sent? */
        int proto_version;                      /* Remote protocol version */
        bool ConnectionFailureShown; /* Set to true if a connection failure message was shown */

        /** True if we've sent our burst.
         * This only changes the behavior of message translation for 1202 protocol servers and it can be
         * removed once 1202 support is dropped.
         */
        bool burstsent;

        /** Checks if the given servername and sid are both free
         */
        bool CheckDuplicate(const std::string& servername, const std::string& sid);

        /** Send all ListModeBase modes set on the channel
         */
        void SendListModes(Channel* chan);

        /** Send all known information about a channel */
        void SyncChannel(Channel* chan, BurstState& bs);

        /** Send all users and their oper state, away state and metadata */
        void SendUsers(BurstState& bs);

        /** Send all additional info about the given server to this server */
        void SendServerInfo(TreeServer* from);

        /** Find the User source of a command given a prefix and a command string.
         * This connection must be fully up when calling this function.
         * @param prefix Prefix string to find the source User object for. Can be a sid, a uuid or a server name.
         * @param command The command whose source to find. This is required because certain commands (like mode
         * changes and kills) must be processed even if their claimed source doesn't exist. If the given command is
         * such a command and the source does not exist, the function returns a valid FakeUser that can be used to
         * to process the command with.
         * @return The command source to use when processing the command or NULL if the source wasn't found.
         * Note that the direction of the returned source is not verified.
         */
        User* FindSource(const std::string& prefix, const std::string& command);

        /** Finish the authentication phase of this connection.
         * Change the state of the connection to CONNECTED, create a TreeServer object for the server on the
         * other end of the connection using the details provided in the parameters, and finally send a burst.
         * @param remotename Name of the remote server
         * @param remotesid SID of the remote server
         * @param remotedesc Description of the remote server
         * @param hidden True if the remote server is hidden according to the configuration
         */
        void FinishAuth(const std::string& remotename, const std::string& remotesid, const std::string& remotedesc, bool hidden);

        /** Authenticate the remote server.
         * Validate the parameters and find the link block that matches the remote server. In case of an error,
         * an appropriate snotice is generated, an ERROR message is sent and the connection is closed.
         * Failing to find a matching link block counts as an error.
         * @param params Parameters they sent in the SERVER command
         * @return Link block for the remote server, or NULL if an error occurred
         */
        Link* AuthRemote(const parameterlist& params);

        /** Write a line on this socket with a new line character appended, skipping all translation for old protocols
         * @param line Line to write without a new line character at the end
         */
        void WriteLineNoCompat(const std::string& line);

 public:
        const time_t age;

        /** Because most of the I/O gubbins are encapsulated within
         * BufferedSocket, we just call the superclass constructor for
         * most of the action, and append a few of our own values
         * to it.
         */
        TreeSocket(Link* link, Autoconnect* myac, const std::string& ipaddr);

        /** 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, ListenSocket* via, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server);

        /** Get link state
         */
        ServerState GetLinkState();

        /** Get challenge set in our CAPAB for challenge/response
         */
        const std::string& GetOurChallenge();

        /** Get challenge set in our CAPAB for challenge/response
         */
        void SetOurChallenge(const std::string &c);

        /** Get challenge set in their CAPAB for challenge/response
         */
        const std::string& GetTheirChallenge();

        /** Get challenge set in their CAPAB for challenge/response
         */
        void SetTheirChallenge(const std::string &c);

        /** Compare two passwords based on authentication scheme
         */
        bool ComparePass(const Link& link, const std::string &theirs);

        /** Clean up information used only during server negotiation
         */
        void CleanNegotiationInfo();

        CullResult cull();
        /** Destructor
         */
        ~TreeSocket();

        /** Construct a password, optionally hashed with the other side's
         * challenge string
         */
        std::string MakePass(const std::string &password, const std::string &challenge);

        /** 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.
         */
        void OnConnected();

        /** Handle socket error event
         */
        void OnError(BufferedSocketError e) CXX11_OVERRIDE;

        /** Sends an error to the remote server, and displays it locally to show
         * that it was sent.
         */
        void SendError(const std::string &errormessage);

        /** 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.
         */
        void SendServers(TreeServer* Current, TreeServer* s);

        /** Returns module list as a string, filtered by filter
         * @param filter a module version bitmask, such as VF_COMMON or VF_OPTCOMMON
         */
        std::string MyModules(int filter);

        /** Send my capabilities to the remote side
         */
        void SendCapabilities(int phase);

        /* Isolate and return the elements that are different between two lists */
        void ListDifference(const std::string &one, const std::string &two, char sep,
                std::string& mleft, std::string& mright);

        bool Capab(const parameterlist &params);

        /** 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(std::string &from, TreeServer* Current, int& num_lost_servers, int& 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, const std::string &reason);

        /** 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(Channel* c);

        /** Send G, Q, Z and E lines */
        void SendXLines();

        /** Send all known information about a channel */
        void SyncChannel(Channel* chan);

        /** 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);

        /** This function is called when we receive data from a remote
         * server.
         */
        void OnDataReady();

        /** Send one or more complete lines down the socket
         */
        void WriteLine(const std::string& line);

        /** Handle ERROR command */
        void Error(parameterlist &params);

        /** (local) -> SERVER
         */
        bool Outbound_Reply_Server(parameterlist &params);

        /** (local) <- SERVER
         */
        bool Inbound_Server(parameterlist &params);

        /** Handle IRC line split
         */
        void Split(const std::string &line, std::string& prefix, std::string& command, parameterlist &params);

        /** Process complete line from buffer
         */
        void ProcessLine(std::string &line);

        void ProcessConnectedLine(std::string& prefix, std::string& command, parameterlist& params);

        /** Handle socket timeout from connect()
         */
        void OnTimeout();
        /** Handle server quit on close
         */
        void Close();

        /** Returns true if this server was introduced to the rest of the network
         */
        bool Introduced();

        /** Fixes messages coming from old servers so the new command handlers understand them
         */
        bool PreProcessOldProtocolMessage(User*& who, std::string& cmd, std::vector<std::string>& params);
};