/* DHT.h * * An implementation of the DHT as seen in http://wiki.tox.im/index.php/DHT * * Copyright (C) 2013 Tox project All Rights Reserved. * * This file is part of Tox. * * Tox 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, either version 3 of the License, or * (at your option) any later version. * * Tox 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 Tox. If not, see . * */ #ifndef DHT_H #define DHT_H #include "net_crypto.h" /* Size of the client_id in bytes. */ #define CLIENT_ID_SIZE crypto_box_PUBLICKEYBYTES /* Maximum number of clients stored per friend. */ #define MAX_FRIEND_CLIENTS 8 /* A list of the clients mathematically closest to ours. */ #define LCLIENT_LIST 32 /* Maximum newly announced nodes to ping per TIME_TOPING seconds. */ #define MAX_TOPING 16 /* Ping timeout in seconds */ #define PING_TIMEOUT 3 /* Ping interval in seconds for each node in our lists. */ #define PING_INTERVAL 60 /* The number of seconds for a non responsive node to become bad. */ #define PINGS_MISSED_NODE_GOES_BAD 3 #define PING_ROUNDTRIP 2 #define BAD_NODE_TIMEOUT (PING_INTERVAL + PINGS_MISSED_NODE_GOES_BAD * PING_INTERVAL + PING_ROUNDTRIP) /* Redefinitions of variables for safe transfer over wire. */ #define TOX_AF_INET 2 #define TOX_AF_INET6 10 /* Functions to transfer ips safely across wire. */ void to_net_family(IP *ip); void to_host_family(IP *ip); typedef struct { IP_Port ip_port; uint64_t timestamp; } IPPTs; typedef struct { /* Node routes request correctly (true (1) or false/didn't check (0)) */ uint8_t routes_requests_ok; /* Time which we last checked this.*/ uint64_t routes_requests_timestamp; uint8_t routes_requests_pingedid[CLIENT_ID_SIZE]; /* Node sends correct send_node (true (1) or false/didn't check (0)) */ uint8_t send_nodes_ok; /* Time which we last checked this.*/ uint64_t send_nodes_timestamp; uint8_t send_nodes_pingedid[CLIENT_ID_SIZE]; /* Node can be used to test other nodes (true (1) or false/didn't check (0)) */ uint8_t testing_requests; /* Time which we last checked this.*/ uint64_t testing_timestamp; uint8_t testing_pingedid[CLIENT_ID_SIZE]; } Hardening; typedef struct { IP_Port ip_port; uint64_t timestamp; uint64_t last_pinged; Hardening hardening; /* Returned by this node. Either our friend or us. */ IP_Port ret_ip_port; uint64_t ret_timestamp; } IPPTsPng; typedef struct { uint8_t client_id[CLIENT_ID_SIZE]; IPPTsPng assoc4; IPPTsPng assoc6; } Client_data; /*----------------------------------------------------------------------------------*/ typedef struct { /* 1 if currently hole punching, otherwise 0 */ uint8_t hole_punching; uint32_t punching_index; uint64_t punching_timestamp; uint64_t recvNATping_timestamp; uint64_t NATping_id; uint64_t NATping_timestamp; } NAT; typedef struct { uint8_t client_id[CLIENT_ID_SIZE]; Client_data client_list[MAX_FRIEND_CLIENTS]; /* Time at which the last get_nodes request was sent. */ uint64_t lastgetnode; /* Symetric NAT hole punching stuff. */ NAT nat; } DHT_Friend; /* this must be kept even if IP_Port is expanded: wire compatibility */ typedef struct { uint8_t client_id[CLIENT_ID_SIZE]; IP4_Port ip_port; } Node4_format; typedef struct { uint8_t client_id[CLIENT_ID_SIZE]; IP_Port ip_port; } Node_format; /*----------------------------------------------------------------------------------*/ typedef struct { Net_Crypto *c; Client_data close_clientlist[LCLIENT_LIST]; uint64_t close_lastgetnodes; /* Note: this key should not be/is not used to transmit any sensitive materials */ uint8_t secret_symmetric_key[crypto_secretbox_KEYBYTES]; DHT_Friend *friends_list; uint16_t num_friends; struct PING *ping; struct Assoc *assoc; uint64_t last_run; } DHT; /*----------------------------------------------------------------------------------*/ /* Add a new friend to the friends list. * client_id must be CLIENT_ID_SIZE bytes long. * * return 0 if success. * return 1 if failure (friends list is full). */ int DHT_addfriend(DHT *dht, uint8_t *client_id); /* Delete a friend from the friends list. * client_id must be CLIENT_ID_SIZE bytes long. * * return 0 if success. * return 1 if failure (client_id not in friends list). */ int DHT_delfriend(DHT *dht, uint8_t *client_id); /* Get ip of friend. * client_id must be CLIENT_ID_SIZE bytes long. * ip must be 4 bytes long. * port must be 2 bytes long. * * !!! Signature changed !!! * * OLD: IP_Port DHT_getfriendip(DHT *dht, uint8_t *client_id); * * return ip if success. * return ip of 0 if failure (This means the friend is either offline or we have not found him yet). * return ip of 1 if friend is not in list. * * NEW: int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port); * * return -1, -- if client_id does NOT refer to a friend * return 0, -- if client_id refers to a friend and we failed to find the friend (yet) * return 1, ip if client_id refers to a friend and we found him */ int DHT_getfriendip(DHT *dht, uint8_t *client_id, IP_Port *ip_port); /* Compares client_id1 and client_id2 with client_id. * * return 0 if both are same distance. * return 1 if client_id1 is closer. * return 2 if client_id2 is closer. */ int id_closest(uint8_t *id, uint8_t *id1, uint8_t *id2); /* Run this function at least a couple times per second (It's the main loop). */ void do_DHT(DHT *dht); /* * Use these two functions to bootstrap the client. */ /* Sends a "get nodes" request to the given node with ip, port and public_key * to setup connections */ void DHT_bootstrap(DHT *dht, IP_Port ip_port, uint8_t *public_key); /* Resolves address into an IP address. If successful, sends a "get nodes" * request to the given node with ip, port and public_key to setup connections * * address can be a hostname or an IP address (IPv4 or IPv6). * if ipv6enabled is 0 (zero), the resolving sticks STRICTLY to IPv4 addresses * if ipv6enabled is not 0 (zero), the resolving looks for IPv6 addresses first, * then IPv4 addresses. * * returns 1 if the address could be converted into an IP address * returns 0 otherwise */ int DHT_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enabled, uint16_t port, uint8_t *public_key); /* ROUTING FUNCTIONS */ /* Send the given packet to node with client_id. * * return -1 if failure. */ int route_packet(DHT *dht, uint8_t *client_id, uint8_t *packet, uint32_t length); /* Send the following packet to everyone who tells us they are connected to friend_id. * * return number of nodes it sent the packet to. */ int route_tofriend(DHT *dht, uint8_t *friend_id, uint8_t *packet, uint32_t length); /* NAT PUNCHING FUNCTIONS */ /* Puts all the different ips returned by the nodes for a friend_id into array ip_portlist. * ip_portlist must be at least MAX_FRIEND_CLIENTS big. * * returns number of ips returned. * returns -1 if no such friend. */ int friend_ips(DHT *dht, IP_Port *ip_portlist, uint8_t *friend_id); /* SAVE/LOAD functions */ /* Get the size of the DHT (for saving). */ uint32_t DHT_size(DHT *dht); /* Save the DHT in data where data is an array of size DHT_size(). */ void DHT_save(DHT *dht, uint8_t *data); /* Load the DHT from data of size size. * * return -1 if failure. * return 0 if success. */ int DHT_load(DHT *dht, uint8_t *data, uint32_t length); /* Initialize DHT. */ DHT *new_DHT(Net_Crypto *c); void kill_DHT(DHT *dht); /* return 0 if we are not connected to the DHT. * return 1 if we are. */ int DHT_isconnected(DHT *dht); int addto_lists(DHT *dht, IP_Port ip_port, uint8_t *client_id); #endif