StarMirror/toxcore
1
0
Fork 0
mirror of https://github.com/irungentoo/toxcore.git synced 2024-03-22 13:30:51 +08:00
Code Issues Projects Releases Wiki Activity
9d860fac79
toxcore/core/DHT.c
SilentSand 1577a1eb61 Minor screwup fixed 
I sure wish it was easier to compile on Windows.
2013-07-26 04:08:39 -04:00

1240 lines
41 KiB
C
Raw Blame History

/* DHT.c
*
* An implementation of the DHT as seen in docs/DHT.txt
*
* 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 <http://www.gnu.org/licenses/>.
*
*/
#include "DHT.h"
typedef struct
{
uint8_t client_id[CLIENT_ID_SIZE];
IP_Port ip_port;
uint32_t timestamp;
uint32_t last_pinged;
IP_Port ret_ip_port;/* The ip_port returned by this node for the friend
(for nodes in friends_list) or us (for nodes in close_clientlist) */
uint32_t ret_timestamp;
}Client_data;
/* maximum number of clients stored per friend. */
#define MAX_FRIEND_CLIENTS 8
typedef struct
{
uint8_t client_id[CLIENT_ID_SIZE];
Client_data client_list[MAX_FRIEND_CLIENTS];
uint32_t lastgetnode; /* time at which the last get_nodes request was sent. */
/*Symetric NAT hole punching stuff*/
uint8_t hole_punching; /*0 if not hole punching, 1 if currently hole punching */
uint32_t punching_index;
uint32_t punching_timestamp;
uint64_t NATping_id;
uint32_t NATping_timestamp;
}Friend;
typedef struct
{
uint8_t client_id[CLIENT_ID_SIZE];
IP_Port ip_port;
}Node_format;
typedef struct
{
IP_Port ip_port;
uint64_t ping_id;
uint32_t timestamp;
}Pinged;
/* Our client id/public key */
uint8_t self_public_key[CLIENT_ID_SIZE];
uint8_t self_secret_key[crypto_box_SECRETKEYBYTES];
/* TODO: Move these out of here and put them into the .c file.
A list of the clients mathematically closest to ours. */
#define LCLIENT_LIST 32
static Client_data close_clientlist[LCLIENT_LIST];
static Friend * friends_list;
static uint16_t num_friends;
/* The list of ip ports along with the ping_id of what we sent them and a timestamp */
#define LPING_ARRAY 256
static Pinged pings[LPING_ARRAY];
#define LSEND_NODES_ARRAY LPING_ARRAY/2
static Pinged send_nodes[LSEND_NODES_ARRAY];
/* 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 * client_id, uint8_t * client_id1, uint8_t * client_id2) /* tested */
{
uint32_t i;
for(i = 0; i < CLIENT_ID_SIZE; ++i) {
if(abs(client_id[i] ^ client_id1[i]) < abs(client_id[i] ^ client_id2[i])) {
return 1;
} else if(abs(client_id[i] ^ client_id1[i]) > abs(client_id[i] ^ client_id2[i])) {
return 2;
}
}
return 0;
}
/* check if client with client_id is already in list of length length.
if it is set it's corresponding timestamp to current time.
if the id is already in the list with a different ip_port, update it.
return True(1) or False(0)
TODO: maybe optimize this. */
int client_in_list(Client_data * list, uint32_t length, uint8_t * client_id, IP_Port ip_port)
{
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < length; ++i) {
/*If ip_port is assigned to a different client_id replace it*/
if(list[i].ip_port.ip.i == ip_port.ip.i &&
list[i].ip_port.port == ip_port.port) {
memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
}
if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
/* Refresh the client timestamp. */
list[i].timestamp = temp_time;
list[i].ip_port.ip.i = ip_port.ip.i;
list[i].ip_port.port = ip_port.port;
return 1;
}
}
return 0;
}
/* check if client with client_id is already in node format list of length length.
return True(1) or False(0) */
int client_in_nodelist(Node_format * list, uint32_t length, uint8_t * client_id)
{
uint32_t i;
for(i = 0; i < length; ++i) {
if(memcmp(list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
return 1;
}
}
return 0;
}
/*Return the friend number from the client_id
Return -1 if failure, number of friend if success*/
static int friend_number(uint8_t * client_id)
{
uint32_t i;
for(i = 0; i < num_friends; ++i) {
if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) /* Equal */
{
return i;
}
}
return -1;
}
/* the number of seconds for a non responsive node to become bad. */
#define BAD_NODE_TIMEOUT 70
/* the max number of nodes to send with send nodes. */
#define MAX_SENT_NODES 8
/* Find MAX_SENT_NODES nodes closest to the client_id for the send nodes request:
put them in the nodes_list and return how many were found.
TODO: Make this function much more efficient. */
int get_close_nodes(uint8_t * client_id, Node_format * nodes_list)
{
uint32_t i, j, k;
int num_nodes=0;
uint32_t temp_time = unix_time();
for(i = 0; i < LCLIENT_LIST; ++i) {
if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time &&
!client_in_nodelist(nodes_list, MAX_SENT_NODES,close_clientlist[i].client_id)) {
/* if node is good and not already in list. */
if(num_nodes < MAX_SENT_NODES) {
memcpy(nodes_list[num_nodes].client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE);
nodes_list[num_nodes].ip_port = close_clientlist[i].ip_port;
num_nodes++;
}
else for(j = 0; j < MAX_SENT_NODES; ++j) {
if(id_closest(client_id, nodes_list[j].client_id, close_clientlist[i].client_id) == 2) {
memcpy(nodes_list[j].client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE);
nodes_list[j].ip_port = close_clientlist[i].ip_port;
break;
}
}
}
}
for(i = 0; i < num_friends; ++i) {
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if(friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time &&
!client_in_nodelist(nodes_list, MAX_SENT_NODES,friends_list[i].client_list[j].client_id)) {
/* if node is good and not already in list. */
if(num_nodes < MAX_SENT_NODES) {
memcpy(nodes_list[num_nodes].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
nodes_list[num_nodes].ip_port = friends_list[i].client_list[j].ip_port;
num_nodes++;
} else for(k = 0; k < MAX_SENT_NODES; ++k) {
if(id_closest(client_id, nodes_list[k].client_id, friends_list[i].client_list[j].client_id) == 2) {
memcpy(nodes_list[k].client_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE);
nodes_list[k].ip_port = friends_list[i].client_list[j].ip_port;
break;
}
}
}
}
}
return num_nodes;
}
/* replace first bad (or empty) node with this one
return 0 if successful
return 1 if not (list contains no bad nodes) */
int replace_bad(Client_data * list, uint32_t length, uint8_t * client_id, IP_Port ip_port) /* tested */
{
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < length; ++i) {
if(list[i].timestamp + BAD_NODE_TIMEOUT < temp_time) /* if node is bad. */ {
memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
list[i].ip_port = ip_port;
list[i].timestamp = temp_time;
list[i].ret_ip_port.ip.i = 0;
list[i].ret_ip_port.port = 0;
list[i].ret_timestamp = 0;
return 0;
}
}
return 1;
}
/* replace the first good node that is further to the comp_client_id than that of the client_id in the list */
int replace_good(Client_data * list, uint32_t length, uint8_t * client_id, IP_Port ip_port, uint8_t * comp_client_id)
{
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < length; ++i) {
if(id_closest(comp_client_id, list[i].client_id, client_id) == 2) {
memcpy(list[i].client_id, client_id, CLIENT_ID_SIZE);
list[i].ip_port = ip_port;
list[i].timestamp = temp_time;
list[i].ret_ip_port.ip.i = 0;
list[i].ret_ip_port.port = 0;
list[i].ret_timestamp = 0;
return 0;
}
}
return 1;
}
/* Attempt to add client with ip_port and client_id to the friends client list and close_clientlist */
void addto_lists(IP_Port ip_port, uint8_t * client_id)
{
uint32_t i;
/* NOTE: current behavior if there are two clients with the same id is to replace the first ip by the second. */
if(!client_in_list(close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
if(replace_bad(close_clientlist, LCLIENT_LIST, client_id, ip_port)) {
/* if we can't replace bad nodes we try replacing good ones */
replace_good(close_clientlist, LCLIENT_LIST, client_id, ip_port, self_public_key);
}
}
for(i = 0; i < num_friends; ++i) {
if(!client_in_list(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port)) {
if(replace_bad(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port)) {
/* if we can't replace bad nodes we try replacing good ones. */
replace_good(friends_list[i].client_list, MAX_FRIEND_CLIENTS, client_id, ip_port, friends_list[i].client_id);
}
}
}
}
/* If client_id is a friend or us, update ret_ip_port
nodeclient_id is the id of the node that sent us this info */
void returnedip_ports(IP_Port ip_port, uint8_t * client_id, uint8_t * nodeclient_id)
{
uint32_t i, j;
uint32_t temp_time = unix_time();
if(memcmp(client_id, self_public_key, CLIENT_ID_SIZE) == 0) {
for(i = 0; i < LCLIENT_LIST; ++i) {
if(memcmp(nodeclient_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0) {
close_clientlist[i].ret_ip_port = ip_port;
close_clientlist[i].ret_timestamp = temp_time;
return;
}
}
}
else
for(i = 0; i < num_friends; ++i) {
if(memcmp(client_id, friends_list[i].client_id, CLIENT_ID_SIZE) == 0) {
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if(memcmp(nodeclient_id, friends_list[i].client_list[j].client_id, CLIENT_ID_SIZE) == 0) {
friends_list[i].client_list[j].ret_ip_port = ip_port;
friends_list[i].client_list[j].ret_timestamp = temp_time;
return;
}
}
}
}
}
/* ping timeout in seconds */
#define PING_TIMEOUT 5
/* check if we are currently pinging an ip_port and/or a ping_id
variables with values of zero will not be checked.
if we are already, return 1
else return 0
TODO: optimize this */
int is_pinging(IP_Port ip_port, uint64_t ping_id)
{
uint32_t i;
uint8_t pinging;
uint32_t temp_time = unix_time();
for(i = 0; i < LPING_ARRAY; ++i ) {
if((pings[i].timestamp + PING_TIMEOUT) > temp_time) {
pinging = 0;
if(ip_port.ip.i != 0) {
if(pings[i].ip_port.ip.i == ip_port.ip.i &&
pings[i].ip_port.port == ip_port.port) {
++pinging;
}
}
if(ping_id != 0) {
if(pings[i].ping_id == ping_id)
{
++pinging;
}
}
if(pinging == (ping_id != 0) + (ip_port.ip.i != 0)) {
return 1;
}
}
}
return 0;
}
/* Same as last function but for get_node requests. */
int is_gettingnodes(IP_Port ip_port, uint64_t ping_id)
{
uint32_t i;
uint8_t pinging;
uint32_t temp_time = unix_time();
for(i = 0; i < LSEND_NODES_ARRAY; ++i ) {
if((send_nodes[i].timestamp + PING_TIMEOUT) > temp_time) {
pinging = 0;
if(ip_port.ip.i != 0) {
if(send_nodes[i].ip_port.ip.i == ip_port.ip.i &&
send_nodes[i].ip_port.port == ip_port.port) {
++pinging;
}
}
if(ping_id != 0) {
if(send_nodes[i].ping_id == ping_id) {
++pinging;
}
}
if(pinging == (ping_id != 0) + (ip_port.ip.i != 0)) {
return 1;
}
}
}
return 0;
}
/* Add a new ping request to the list of ping requests
returns the ping_id to put in the ping request
returns 0 if problem.
TODO: optimize this */
uint64_t add_pinging(IP_Port ip_port)
{
uint32_t i, j;
uint64_t ping_id = ((uint64_t)random_int() << 32) + random_int();
uint32_t temp_time = unix_time();
for(i = 0; i < PING_TIMEOUT; ++i ) {
for(j = 0; j < LPING_ARRAY; ++j ) {
if((pings[j].timestamp + PING_TIMEOUT - i) < temp_time) {
pings[j].timestamp = temp_time;
pings[j].ip_port = ip_port;
pings[j].ping_id = ping_id;
return ping_id;
}
}
}
return 0;
}
/* Same but for get node requests */
uint64_t add_gettingnodes(IP_Port ip_port)
{
uint32_t i, j;
uint64_t ping_id = ((uint64_t)random_int() << 32) + random_int();
uint32_t temp_time = unix_time();
for(i = 0; i < PING_TIMEOUT; ++i ) {
for(j = 0; j < LSEND_NODES_ARRAY; ++j ) {
if((send_nodes[j].timestamp + PING_TIMEOUT - i) < temp_time) {
send_nodes[j].timestamp = temp_time;
send_nodes[j].ip_port = ip_port;
send_nodes[j].ping_id = ping_id;
return ping_id;
}
}
}
return 0;
}
/* send a ping request
Ping request only works if none has been sent to that ip/port in the last 5 seconds. */
static int pingreq(IP_Port ip_port, uint8_t * public_key)
{
if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */ {
return 1;
}
if(is_pinging(ip_port, 0)) {
return 1;
}
uint64_t ping_id = add_pinging(ip_port);
if(ping_id == 0) {
return 1;
}
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING];
uint8_t encrypt[sizeof(ping_id) + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
int len = encrypt_data(public_key, self_secret_key, nonce, (uint8_t *)&ping_id, sizeof(ping_id), encrypt);
if(len != sizeof(ping_id) + ENCRYPTION_PADDING) {
return -1;
}
data[0] = 0;
memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(ip_port, data, sizeof(data));
}
/* send a ping response */
static int pingres(IP_Port ip_port, uint8_t * public_key, uint64_t ping_id)
{
/* check if packet is gonna be sent to ourself */
if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) {
return 1;
}
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING];
uint8_t encrypt[sizeof(ping_id) + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
int len = encrypt_data(public_key, self_secret_key, nonce, (uint8_t *)&ping_id, sizeof(ping_id), encrypt);
if(len != sizeof(ping_id) + ENCRYPTION_PADDING) {
return -1;
}
data[0] = 1;
memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(ip_port, data, sizeof(data));
}
/* send a getnodes request */
static int getnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id)
{
/* check if packet is gonna be sent to ourself */
if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) {
return 1;
}
if(is_gettingnodes(ip_port, 0)) {
return 1;
}
uint64_t ping_id = add_gettingnodes(ip_port);
if(ping_id == 0) {
return 1;
}
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING];
uint8_t plain[sizeof(ping_id) + CLIENT_ID_SIZE];
uint8_t encrypt[sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
memcpy(plain, &ping_id, sizeof(ping_id));
memcpy(plain + sizeof(ping_id), client_id, CLIENT_ID_SIZE);
int len = encrypt_data(public_key, self_secret_key, nonce, plain, sizeof(ping_id) + CLIENT_ID_SIZE, encrypt);
if(len != sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING) {
return -1;
}
data[0] = 2;
memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(ip_port, data, sizeof(data));
}
/* send a send nodes response */
static int sendnodes(IP_Port ip_port, uint8_t * public_key, uint8_t * client_id, uint64_t ping_id)
{
if(memcmp(public_key, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is gonna be sent to ourself */ {
return 1;
}
uint8_t data[1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ sizeof(Node_format) * MAX_SENT_NODES + ENCRYPTION_PADDING];
Node_format nodes_list[MAX_SENT_NODES];
int num_nodes = get_close_nodes(client_id, nodes_list);
if(num_nodes == 0) {
return 0;
}
uint8_t plain[sizeof(ping_id) + sizeof(Node_format) * MAX_SENT_NODES];
uint8_t encrypt[sizeof(ping_id) + sizeof(Node_format) * MAX_SENT_NODES + ENCRYPTION_PADDING];
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
memcpy(plain, &ping_id, sizeof(ping_id));
memcpy(plain + sizeof(ping_id), nodes_list, num_nodes * sizeof(Node_format));
int len = encrypt_data(public_key, self_secret_key, nonce, plain,
sizeof(ping_id) + num_nodes * sizeof(Node_format), encrypt);
if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format) + ENCRYPTION_PADDING) {
return -1;
}
data[0] = 3;
memcpy(data + 1, self_public_key, CLIENT_ID_SIZE);
memcpy(data + 1 + CLIENT_ID_SIZE, nonce, crypto_box_NONCEBYTES);
memcpy(data + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES, encrypt, len);
return sendpacket(ip_port, data, 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + len);
}
/* Packet handling functions
One to handle each types of packets we receive
return 0 if handled correctly, 1 if packet is bad. */
int handle_pingreq(uint8_t * packet, uint32_t length, IP_Port source)
{
uint64_t ping_id;
if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING) {
return 1;
}
/* check if packet is from ourself. */
if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) {
return 1;
}
int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + ENCRYPTION_PADDING, (uint8_t *)&ping_id);
if(len != sizeof(ping_id)) {
return 1;
}
pingres(source, packet + 1, ping_id);
pingreq(source, packet + 1); /* TODO: make this smarter? */
return 0;
}
int handle_pingres(uint8_t * packet, uint32_t length, IP_Port source)
{
uint64_t ping_id;
if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + ENCRYPTION_PADDING) {
return 1;
}
if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) /* check if packet is from ourself. */ {
return 1;
}
int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + ENCRYPTION_PADDING, (uint8_t *)&ping_id);
if(len != sizeof(ping_id)) {
return 1;
}
if(is_pinging(source, ping_id)) {
addto_lists(source, packet + 1);
return 0;
}
return 1;
}
int handle_getnodes(uint8_t * packet, uint32_t length, IP_Port source)
{
uint64_t ping_id;
if(length != 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING) {
return 1;
}
/* check if packet is from ourself. */
if(memcmp(packet + 1, self_public_key, CLIENT_ID_SIZE) == 0) {
return 1;
}
uint8_t plain[sizeof(ping_id) + CLIENT_ID_SIZE];
int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + CLIENT_ID_SIZE + ENCRYPTION_PADDING, plain);
if(len != sizeof(ping_id) + CLIENT_ID_SIZE) {
return 1;
}
memcpy(&ping_id, plain, sizeof(ping_id));
sendnodes(source, packet + 1, plain + sizeof(ping_id), ping_id);
pingreq(source, packet + 1); /* TODO: make this smarter? */
return 0;
}
int handle_sendnodes(uint8_t * packet, uint32_t length, IP_Port source)
{
uint64_t ping_id;
if(length > (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ sizeof(Node_format) * MAX_SENT_NODES + ENCRYPTION_PADDING) ||
(length - (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ ENCRYPTION_PADDING)) % (sizeof(Node_format)) != 0 ||
length < 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES + sizeof(ping_id)
+ sizeof(Node_format) + ENCRYPTION_PADDING) {
return 1;
}
uint32_t num_nodes = (length - (1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES
+ sizeof(ping_id) + ENCRYPTION_PADDING)) / sizeof(Node_format);
uint8_t plain[sizeof(ping_id) + sizeof(Node_format) * MAX_SENT_NODES];
int len = decrypt_data(packet + 1, self_secret_key, packet + 1 + CLIENT_ID_SIZE,
packet + 1 + CLIENT_ID_SIZE + crypto_box_NONCEBYTES,
sizeof(ping_id) + num_nodes * sizeof(Node_format) + ENCRYPTION_PADDING, plain);
if(len != sizeof(ping_id) + num_nodes * sizeof(Node_format)) {
return 1;
}
memcpy(&ping_id, plain, sizeof(ping_id));
if(!is_gettingnodes(source, ping_id)) {
return 1;
}
Node_format nodes_list[MAX_SENT_NODES];
memcpy(nodes_list, plain + sizeof(ping_id), num_nodes * sizeof(Node_format));
addto_lists(source, packet + 1);
uint32_t i;
for(i = 0; i < num_nodes; ++i) {
pingreq(nodes_list[i].ip_port, nodes_list[i].client_id);
returnedip_ports(nodes_list[i].ip_port, nodes_list[i].client_id, packet + 1);
}
return 0;
}
/* END of packet handling functions */
int DHT_addfriend(uint8_t * client_id)
{
Friend * temp;
if(num_friends == 0) {
temp = malloc(sizeof(Friend));
} else {
temp = realloc(friends_list, sizeof(Friend) * (num_friends + 1));
}
if(temp == NULL) {
return 1;
}
friends_list = temp;
memset(&friends_list[num_friends], 0, sizeof(Friend));
memcpy(friends_list[num_friends].client_id, client_id, CLIENT_ID_SIZE);
friends_list[num_friends].NATping_id = ((uint64_t)random_int() << 32) + random_int();
++num_friends;
return 0;
}
int DHT_delfriend(uint8_t * client_id)
{
uint32_t i;
Friend * temp;
for(i = 0; i < num_friends; ++i) {
/* Equal */
if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0){
--num_friends;
if(num_friends != i) {
memcpy(friends_list[i].client_id, friends_list[num_friends].client_id, CLIENT_ID_SIZE);
}
temp = realloc(friends_list, sizeof(Friend) * (num_friends));
if(temp != NULL) {
friends_list = temp;
}
return 0;
}
}
return 1;
}
/* TODO: Optimize this. */
IP_Port DHT_getfriendip(uint8_t * client_id)
{
uint32_t i, j;
IP_Port empty = {{{0}}, 0};
uint32_t temp_time = unix_time();
for(i = 0; i < num_friends; ++i) {
/* Equal */
if(memcmp(friends_list[i].client_id, client_id, CLIENT_ID_SIZE) == 0) {
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if(memcmp(friends_list[i].client_list[j].client_id, client_id, CLIENT_ID_SIZE) == 0 &&
friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time) {
return friends_list[i].client_list[j].ip_port;
}
}
return empty;
}
}
empty.ip.i = 1;
return empty;
}
/* The timeout after which a node is discarded completely. */
#define Kill_NODE_TIMEOUT 300
/* ping interval in seconds for each node in our lists. */
#define PING_INTERVAL 60
/* ping interval in seconds for each random sending of a get nodes request. */
#define GET_NODE_INTERVAL 10
/* Ping each client in the "friends" list every 60 seconds.
Send a get nodes request every 20 seconds to a random good node for each "friend" in our "friends" list. */
void doDHTFriends()
{
uint32_t i, j;
uint32_t temp_time = unix_time();
uint32_t rand_node;
uint32_t index[MAX_FRIEND_CLIENTS];
for(i = 0; i < num_friends; ++i) {
uint32_t num_nodes = 0;
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if(friends_list[i].client_list[j].timestamp + Kill_NODE_TIMEOUT > temp_time) /* if node is not dead. */ {
if((friends_list[i].client_list[j].last_pinged + PING_INTERVAL) <= temp_time) {
pingreq(friends_list[i].client_list[j].ip_port, friends_list[i].client_list[j].client_id);
friends_list[i].client_list[j].last_pinged = temp_time;
}
if(friends_list[i].client_list[j].timestamp + BAD_NODE_TIMEOUT > temp_time) /* if node is good. */ {
index[num_nodes] = j;
++num_nodes;
}
}
}
if(friends_list[i].lastgetnode + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
rand_node = rand() % num_nodes;
getnodes(friends_list[i].client_list[index[rand_node]].ip_port,
friends_list[i].client_list[index[rand_node]].client_id,
friends_list[i].client_id);
friends_list[i].lastgetnode = temp_time;
}
}
}
static uint32_t close_lastgetnodes;
/* Ping each client in the close nodes list every 60 seconds.
Send a get nodes request every 20 seconds to a random good node in the list. */
void doClose() /* tested */
{
uint32_t i;
uint32_t temp_time = unix_time();
uint32_t num_nodes = 0;
uint32_t rand_node;
uint32_t index[LCLIENT_LIST];
for(i = 0; i < LCLIENT_LIST; ++i) {
/* if node is not dead. */
if(close_clientlist[i].timestamp + Kill_NODE_TIMEOUT > temp_time) {
if((close_clientlist[i].last_pinged + PING_INTERVAL) <= temp_time)
{
pingreq(close_clientlist[i].ip_port, close_clientlist[i].client_id);
close_clientlist[i].last_pinged = temp_time;
}
/* if node is good. */
if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time) {
index[num_nodes] = i;
++num_nodes;
}
}
}
if(close_lastgetnodes + GET_NODE_INTERVAL <= temp_time && num_nodes != 0) {
rand_node = rand() % num_nodes;
getnodes(close_clientlist[index[rand_node]].ip_port,
close_clientlist[index[rand_node]].client_id,
self_public_key);
close_lastgetnodes = temp_time;
}
}
void DHT_bootstrap(IP_Port ip_port, uint8_t * public_key)
{
getnodes(ip_port, public_key, self_public_key);
}
/* send the given packet to node with client_id
returns -1 if failure */
int route_packet(uint8_t * client_id, uint8_t * packet, uint32_t length)
{
uint32_t i;
for(i = 0; i < LCLIENT_LIST; ++i) {
if(memcmp(client_id, close_clientlist[i].client_id, CLIENT_ID_SIZE) == 0) {
return sendpacket(close_clientlist[i].ip_port, packet, length);
}
}
return -1;
}
/* Puts all the different ips returned by the nodes for a friend_num into array ip_portlist
ip_portlist must be at least MAX_FRIEND_CLIENTS big
returns the number of ips returned
return 0 if we are connected to friend or if no ips were found.
returns -1 if no such friend*/
static int friend_iplist(IP_Port * ip_portlist, uint16_t friend_num)
{
int num_ips = 0;
uint32_t i;
uint32_t temp_time = unix_time();
if(friend_num >= num_friends) {
return -1;
}
for(i = 0; i < MAX_FRIEND_CLIENTS; ++i)
{
/*If ip is not zero and node is good */
if(friends_list[friend_num].client_list[i].ret_ip_port.ip.i != 0 &&
friends_list[friend_num].client_list[i].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
if(memcmp(friends_list[friend_num].client_list[i].client_id, friends_list[friend_num].client_id, CLIENT_ID_SIZE) == 0 ) {
return 0;
}
ip_portlist[num_ips] = friends_list[friend_num].client_list[i].ret_ip_port;
++num_ips;
}
}
return num_ips;
}
/* Send the following packet to everyone who tells us they are connected to friend_id
returns the number of nodes it sent the packet to */
int route_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
{
uint32_t i, j;
uint32_t sent = 0;
uint32_t temp_time = unix_time();
for(i = 0; i < num_friends; ++i) {
/* Equal */
if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0) {
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
/*If ip is not zero and node is good */
if(friends_list[i].client_list[j].ret_ip_port.ip.i != 0 &&
friends_list[i].client_list[j].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
if(sendpacket(friends_list[i].client_list[j].ip_port, packet, length) == length) {
++sent;
}
}
}
return sent;
}
}
return 0;
}
/* Send the following packet to one random person who tells us they are connected to friend_id
returns the number of nodes it sent the packet to */
int routeone_tofriend(uint8_t * friend_id, uint8_t * packet, uint32_t length)
{
int num = friend_number(friend_id);
if(num == -1) {
return 0;
}
IP_Port ip_list[MAX_FRIEND_CLIENTS];
int n = 0;
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
/*If ip is not zero and node is good */
if(friends_list[num].client_list[i].ret_ip_port.ip.i != 0 &&
friends_list[num].client_list[i].ret_timestamp + BAD_NODE_TIMEOUT > temp_time) {
ip_list[n] = friends_list[num].client_list[i].ip_port;
++n;
}
}
if(n < 1) {
return 0;
}
if(sendpacket(ip_list[rand() % n], packet, length) == length) {
return 1;
}
return 0;
}
/* 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 the number of ips returned
return 0 if we are connected to friend or if no ips were found.
returns -1 if no such friend*/
int friend_ips(IP_Port * ip_portlist, uint8_t * friend_id)
{
uint32_t i;
for(i = 0; i < num_friends; ++i) {
/* Equal */
if(memcmp(friends_list[i].client_id, friend_id, CLIENT_ID_SIZE) == 0) {
return friend_iplist(ip_portlist, i);
}
}
return -1;
}
/*BEGINNING OF NAT PUNCHING FUNCTIONS*/
int send_NATping(uint8_t * public_key, uint64_t ping_id, uint8_t type)
{
uint8_t data[sizeof(uint64_t) + 1];
data[0] = type;
memcpy(data + 1, &ping_id, sizeof(uint64_t));
uint8_t packet[MAX_DATA_SIZE];
int len = create_request(packet, public_key, data, sizeof(uint64_t) + 1, 254); /* 254 is NAT ping request packet id */
if(len == -1) {
return -1;
}
int num = 0;
if(type == 0) {
num = route_tofriend(public_key, packet, len);/*If packet is request use many people to route it*/
}
else if(type == 1) {
num = routeone_tofriend(public_key, packet, len);/*If packet is response use only one person to route it*/
}
if(num == 0) {
return -1;
}
return num;
}
/* Handle a recieved ping request for */
int handle_NATping(uint8_t * packet, uint32_t length, IP_Port source)
{
if(length <= crypto_box_PUBLICKEYBYTES * 2 + crypto_box_NONCEBYTES + 1 + ENCRYPTION_PADDING &&
length > MAX_DATA_SIZE + ENCRYPTION_PADDING) {
return 1;
}
/* check if request is for us. */
if(memcmp(packet + 1, self_public_key, crypto_box_PUBLICKEYBYTES) == 0) {
uint8_t public_key[crypto_box_PUBLICKEYBYTES];
uint8_t data[MAX_DATA_SIZE];
int len = handle_request(public_key, data, packet, length);
if(len != sizeof(uint64_t) + 1) {
return 1;
}
uint64_t ping_id;
memcpy(&ping_id, data + 1, sizeof(uint64_t));
int friendnumber = friend_number(public_key);
if(friendnumber == -1) {
return 1;
}
if(data[0] == 0) {
send_NATping(public_key, ping_id, 1);/*1 is reply*/
return 0;
} else if (data[0] == 1) {
if(friends_list[friendnumber].NATping_id == ping_id)
{
friends_list[friendnumber].NATping_id = ((uint64_t)random_int() << 32) + random_int();
friends_list[friendnumber].hole_punching = 1;
return 0;
}
}
return 1;
}
/* if request is not for us, try routing it. */
else {
if(route_packet(packet + 1, packet, length) == length) {
return 0;
}
}
return 0;
}
/*Get the most common ip in the ip_portlist
Only return ip if it appears in list min_num or more
len must not be bigger than MAX_FRIEND_CLIENTS
return ip of 0 if failure */
static IP NAT_commonip(IP_Port * ip_portlist, uint16_t len, uint16_t min_num)
{
IP zero = {{0}};
if(len > MAX_FRIEND_CLIENTS) {
return zero;
}
uint32_t i, j;
uint16_t numbers[MAX_FRIEND_CLIENTS] = {0};
for(i = 0; i < len; ++i) {
for(j = 0; j < len; ++j) {
if(ip_portlist[i].ip.i == ip_portlist[j].ip.i) {
++numbers[i];
}
}
if(numbers[i] >= min_num) {
return ip_portlist[i].ip;
}
}
return zero;
}
/*Return all the ports for one ip in a list
portlist must be at least len long
where len is the length of ip_portlist
returns the number of ports and puts the list of ports in portlist*/
static uint16_t NAT_getports(uint16_t * portlist, IP_Port * ip_portlist, uint16_t len, IP ip)
{
uint32_t i;
uint16_t num = 0;
for(i = 0; i < len; ++i) {
if(ip_portlist[i].ip.i == ip.i) {
portlist[num] = ntohs(ip_portlist[i].port);
++num;
}
}
return num;
}
#define MAX_PUNCHING_PORTS 32
static void punch_holes(IP ip, uint16_t * port_list, uint16_t numports, uint16_t friend_num)
{
if(numports > MAX_FRIEND_CLIENTS || numports == 0) {
return;
}
uint32_t i;
uint32_t top = friends_list[friend_num].punching_index + MAX_PUNCHING_PORTS;
for(i = friends_list[friend_num].punching_index; i != top; i++) {
/*TODO: improve port guessing algorithm*/
uint16_t port = port_list[(i/2) % numports] + (i/(2*numports))*((i % 2) ? -1 : 1);
IP_Port pinging = {ip, htons(port)};
pingreq(pinging, friends_list[friend_num].client_id);
}
friends_list[friend_num].punching_index = i;
}
/*Interval in seconds between punching attempts*/
#define PUNCH_INTERVAL 10
static void doNAT()
{
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < num_friends; ++i) {
IP_Port ip_list[MAX_FRIEND_CLIENTS];
int num = friend_iplist(ip_list, i);
/*If we are connected to friend or if friend is not online don't try to hole punch with him*/
if(num < MAX_FRIEND_CLIENTS/2) {
continue;
}
if(friends_list[i].hole_punching != 1) {
if(friends_list[i].NATping_timestamp + PUNCH_INTERVAL < temp_time) {
send_NATping(friends_list[i].client_id, friends_list[i].NATping_id, 0); /*0 is request*/
friends_list[i].NATping_timestamp = temp_time;
}
}
else if(friends_list[i].punching_timestamp + PUNCH_INTERVAL < temp_time) {
IP ip = NAT_commonip(ip_list, num, MAX_FRIEND_CLIENTS/2);
if(ip.i == 0) {
continue;
}
uint16_t port_list[MAX_FRIEND_CLIENTS];
uint16_t numports = NAT_getports(port_list, ip_list, num, ip);
punch_holes(ip, port_list, numports, i);
friends_list[i].punching_timestamp = temp_time;
friends_list[i].hole_punching = 0;
}
}
}
/*END OF NAT PUNCHING FUNCTIONS*/
int DHT_handlepacket(uint8_t * packet, uint32_t length, IP_Port source)
{
switch (packet[0]) {
case 0:
return handle_pingreq(packet, length, source);
case 1:
return handle_pingres(packet, length, source);
case 2:
return handle_getnodes(packet, length, source);
case 3:
return handle_sendnodes(packet, length, source);
case 254:
return handle_NATping(packet, length, source);
default:
return 1;
}
return 0;
}
void doDHT()
{
doClose();
doDHTFriends();
doNAT();
}
/* get the size of the DHT (for saving) */
uint32_t DHT_size()
{
return sizeof(close_clientlist) + sizeof(Friend) * num_friends;
}
/* save the DHT in data where data is an array of size DHT_size() */
void DHT_save(uint8_t * data)
{
memcpy(data, close_clientlist, sizeof(close_clientlist));
memcpy(data + sizeof(close_clientlist), friends_list, sizeof(Friend) * num_friends);
}
/* load the DHT from data of size size;
return -1 if failure
return 0 if success */
int DHT_load(uint8_t * data, uint32_t size)
{
if(size < sizeof(close_clientlist)) {
return -1;
}
if((size - sizeof(close_clientlist)) % sizeof(Friend) != 0) {
return -1;
}
uint32_t i, j;
/* uint32_t temp_time = unix_time(); */
uint16_t temp;
temp = (size - sizeof(close_clientlist))/sizeof(Friend);
if(temp != 0) {
Friend * tempfriends_list = (Friend *)(data + sizeof(close_clientlist));
for(i = 0; i < temp; ++i) {
DHT_addfriend(tempfriends_list[i].client_id);
for(j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if(tempfriends_list[i].client_list[j].timestamp != 0) {
getnodes(tempfriends_list[i].client_list[j].ip_port,
tempfriends_list[i].client_list[j].client_id, tempfriends_list[i].client_id);
}
}
}
}
Client_data * tempclose_clientlist = (Client_data *)data;
for(i = 0; i < LCLIENT_LIST; ++i) {
if(tempclose_clientlist[i].timestamp != 0) {
DHT_bootstrap(tempclose_clientlist[i].ip_port, tempclose_clientlist[i].client_id);
}
}
return 0;
}
/* returns 0 if we are not connected to the DHT
returns 1 if we are */
int DHT_isconnected()
{
uint32_t i;
uint32_t temp_time = unix_time();
for(i = 0; i < LCLIENT_LIST; ++i) {
if(close_clientlist[i].timestamp + BAD_NODE_TIMEOUT > temp_time) {
return 1;
}
}
return 0;
}
Reference in New Issue View Git Blame Copy Permalink