/*
* An implementation of the DHT as seen in docs/updates/DHT.md
*/
/*
* Copyright © 2016-2018 The TokTok team.
* Copyright © 2013 Tox project.
*
* This file is part of Tox, the free peer to peer instant messenger.
*
* 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 .
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "DHT.h"
#include "LAN_discovery.h"
#include "logger.h"
#include "mono_time.h"
#include "network.h"
#include "ping.h"
#include "state.h"
#include "util.h"
#include
#include
#include
/* The timeout after which a node is discarded completely. */
#define KILL_NODE_TIMEOUT (BAD_NODE_TIMEOUT + PING_INTERVAL)
/* Ping interval in seconds for each random sending of a get nodes request. */
#define GET_NODE_INTERVAL 20
#define MAX_PUNCHING_PORTS 48
/* Interval in seconds between punching attempts*/
#define PUNCH_INTERVAL 3
/* Time in seconds after which punching parameters will be reset */
#define PUNCH_RESET_TIME 40
#define MAX_NORMAL_PUNCHING_TRIES 5
#define NAT_PING_REQUEST 0
#define NAT_PING_RESPONSE 1
/* Number of get node requests to send to quickly find close nodes. */
#define MAX_BOOTSTRAP_TIMES 5
typedef struct DHT_Friend_Callback {
dht_ip_cb *ip_callback;
void *data;
int32_t number;
} DHT_Friend_Callback;
struct DHT_Friend {
uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE];
Client_data client_list[MAX_FRIEND_CLIENTS];
/* Time at which the last get_nodes request was sent. */
uint64_t lastgetnode;
/* number of times get_node packets were sent. */
uint32_t bootstrap_times;
/* Symetric NAT hole punching stuff. */
NAT nat;
uint16_t lock_count;
DHT_Friend_Callback callbacks[DHT_FRIEND_MAX_LOCKS];
Node_format to_bootstrap[MAX_SENT_NODES];
unsigned int num_to_bootstrap;
};
typedef struct Cryptopacket_Handler {
cryptopacket_handler_cb *function;
void *object;
} Cryptopacket_Handler;
struct DHT {
const Logger *log;
Networking_Core *net;
bool hole_punching_enabled;
Client_data close_clientlist[LCLIENT_LIST];
uint64_t close_lastgetnodes;
uint32_t close_bootstrap_times;
/* DHT keypair */
uint8_t self_public_key[CRYPTO_PUBLIC_KEY_SIZE];
uint8_t self_secret_key[CRYPTO_SECRET_KEY_SIZE];
DHT_Friend *friends_list;
uint16_t num_friends;
Node_format *loaded_nodes_list;
uint32_t loaded_num_nodes;
unsigned int loaded_nodes_index;
Shared_Keys shared_keys_recv;
Shared_Keys shared_keys_sent;
struct Ping *ping;
Ping_Array *dht_ping_array;
Ping_Array *dht_harden_ping_array;
uint64_t last_run;
Cryptopacket_Handler cryptopackethandlers[256];
Node_format to_bootstrap[MAX_CLOSE_TO_BOOTSTRAP_NODES];
unsigned int num_to_bootstrap;
};
const uint8_t *dht_friend_public_key(const DHT_Friend *dht_friend)
{
return dht_friend->public_key;
}
const Client_data *dht_friend_client(const DHT_Friend *dht_friend, size_t index)
{
return &dht_friend->client_list[index];
}
const uint8_t *dht_get_self_public_key(const DHT *dht)
{
return dht->self_public_key;
}
const uint8_t *dht_get_self_secret_key(const DHT *dht)
{
return dht->self_secret_key;
}
void dht_set_self_public_key(DHT *dht, const uint8_t *key)
{
memcpy(dht->self_public_key, key, CRYPTO_PUBLIC_KEY_SIZE);
}
void dht_set_self_secret_key(DHT *dht, const uint8_t *key)
{
memcpy(dht->self_secret_key, key, CRYPTO_SECRET_KEY_SIZE);
}
Networking_Core *dht_get_net(const DHT *dht)
{
return dht->net;
}
struct Ping *dht_get_ping(const DHT *dht)
{
return dht->ping;
}
const Client_data *dht_get_close_clientlist(const DHT *dht)
{
return dht->close_clientlist;
}
const Client_data *dht_get_close_client(const DHT *dht, uint32_t client_num)
{
assert(client_num < sizeof(dht->close_clientlist) / sizeof(dht->close_clientlist[0]));
return &dht->close_clientlist[client_num];
}
uint16_t dht_get_num_friends(const DHT *dht)
{
return dht->num_friends;
}
DHT_Friend *dht_get_friend(DHT *dht, uint32_t friend_num)
{
assert(friend_num < dht->num_friends);
return &dht->friends_list[friend_num];
}
const uint8_t *dht_get_friend_public_key(const DHT *dht, uint32_t friend_num)
{
assert(friend_num < dht->num_friends);
return dht->friends_list[friend_num].public_key;
}
/* Compares pk1 and pk2 with pk.
*
* return 0 if both are same distance.
* return 1 if pk1 is closer.
* return 2 if pk2 is closer.
*/
int id_closest(const uint8_t *pk, const uint8_t *pk1, const uint8_t *pk2)
{
for (size_t i = 0; i < CRYPTO_PUBLIC_KEY_SIZE; ++i) {
const uint8_t distance1 = pk[i] ^ pk1[i];
const uint8_t distance2 = pk[i] ^ pk2[i];
if (distance1 < distance2) {
return 1;
}
if (distance1 > distance2) {
return 2;
}
}
return 0;
}
/* Return index of first unequal bit number.
*/
static unsigned int bit_by_bit_cmp(const uint8_t *pk1, const uint8_t *pk2)
{
unsigned int i;
unsigned int j = 0;
for (i = 0; i < CRYPTO_PUBLIC_KEY_SIZE; ++i) {
if (pk1[i] == pk2[i]) {
continue;
}
for (j = 0; j < 8; ++j) {
const uint8_t mask = 1 << (7 - j);
if ((pk1[i] & mask) != (pk2[i] & mask)) {
break;
}
}
break;
}
return i * 8 + j;
}
/* Shared key generations are costly, it is therefor smart to store commonly used
* ones so that they can re used later without being computed again.
*
* If shared key is already in shared_keys, copy it to shared_key.
* else generate it into shared_key and copy it to shared_keys
*/
void get_shared_key(Shared_Keys *shared_keys, uint8_t *shared_key, const uint8_t *secret_key, const uint8_t *public_key)
{
uint32_t num = ~0;
uint32_t curr = 0;
for (uint32_t i = 0; i < MAX_KEYS_PER_SLOT; ++i) {
const int index = public_key[30] * MAX_KEYS_PER_SLOT + i;
Shared_Key *const key = &shared_keys->keys[index];
if (key->stored) {
if (id_equal(public_key, key->public_key)) {
memcpy(shared_key, key->shared_key, CRYPTO_SHARED_KEY_SIZE);
++key->times_requested;
key->time_last_requested = unix_time();
return;
}
if (num != 0) {
if (is_timeout(key->time_last_requested, KEYS_TIMEOUT)) {
num = 0;
curr = index;
} else if (num > key->times_requested) {
num = key->times_requested;
curr = index;
}
}
} else if (num != 0) {
num = 0;
curr = index;
}
}
encrypt_precompute(public_key, secret_key, shared_key);
if (num != UINT32_MAX) {
Shared_Key *const key = &shared_keys->keys[curr];
key->stored = 1;
key->times_requested = 1;
memcpy(key->public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(key->shared_key, shared_key, CRYPTO_SHARED_KEY_SIZE);
key->time_last_requested = unix_time();
}
}
/* Copy shared_key to encrypt/decrypt DHT packet from public_key into shared_key
* for packets that we receive.
*/
void dht_get_shared_key_recv(DHT *dht, uint8_t *shared_key, const uint8_t *public_key)
{
get_shared_key(&dht->shared_keys_recv, shared_key, dht->self_secret_key, public_key);
}
/* Copy shared_key to encrypt/decrypt DHT packet from public_key into shared_key
* for packets that we send.
*/
void dht_get_shared_key_sent(DHT *dht, uint8_t *shared_key, const uint8_t *public_key)
{
get_shared_key(&dht->shared_keys_sent, shared_key, dht->self_secret_key, public_key);
}
#define CRYPTO_SIZE 1 + CRYPTO_PUBLIC_KEY_SIZE * 2 + CRYPTO_NONCE_SIZE
/* Create a request to peer.
* send_public_key and send_secret_key are the pub/secret keys of the sender.
* recv_public_key is public key of receiver.
* packet must be an array of MAX_CRYPTO_REQUEST_SIZE big.
* Data represents the data we send with the request with length being the length of the data.
* request_id is the id of the request (32 = friend request, 254 = ping request).
*
* return -1 on failure.
* return the length of the created packet on success.
*/
int create_request(const uint8_t *send_public_key, const uint8_t *send_secret_key, uint8_t *packet,
const uint8_t *recv_public_key, const uint8_t *data, uint32_t length, uint8_t request_id)
{
if (!send_public_key || !packet || !recv_public_key || !data) {
return -1;
}
if (MAX_CRYPTO_REQUEST_SIZE < length + CRYPTO_SIZE + 1 + CRYPTO_MAC_SIZE) {
return -1;
}
uint8_t *const nonce = packet + 1 + CRYPTO_PUBLIC_KEY_SIZE * 2;
random_nonce(nonce);
uint8_t temp[MAX_CRYPTO_REQUEST_SIZE];
memcpy(temp + 1, data, length);
temp[0] = request_id;
const int len = encrypt_data(recv_public_key, send_secret_key, nonce, temp, length + 1,
CRYPTO_SIZE + packet);
if (len == -1) {
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return -1;
}
packet[0] = NET_PACKET_CRYPTO;
memcpy(packet + 1, recv_public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, send_public_key, CRYPTO_PUBLIC_KEY_SIZE);
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return len + CRYPTO_SIZE;
}
/* Puts the senders public key in the request in public_key, the data from the request
* in data if a friend or ping request was sent to us and returns the length of the data.
* packet is the request packet and length is its length.
*
* return -1 if not valid request.
*/
int handle_request(const uint8_t *self_public_key, const uint8_t *self_secret_key, uint8_t *public_key, uint8_t *data,
uint8_t *request_id, const uint8_t *packet, uint16_t length)
{
if (!self_public_key || !public_key || !data || !request_id || !packet) {
return -1;
}
if (length <= CRYPTO_SIZE + CRYPTO_MAC_SIZE || length > MAX_CRYPTO_REQUEST_SIZE) {
return -1;
}
if (!id_equal(packet + 1, self_public_key)) {
return -1;
}
memcpy(public_key, packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, CRYPTO_PUBLIC_KEY_SIZE);
const uint8_t *const nonce = packet + 1 + CRYPTO_PUBLIC_KEY_SIZE * 2;
uint8_t temp[MAX_CRYPTO_REQUEST_SIZE];
int len1 = decrypt_data(public_key, self_secret_key, nonce,
packet + CRYPTO_SIZE, length - CRYPTO_SIZE, temp);
if (len1 == -1 || len1 == 0) {
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return -1;
}
request_id[0] = temp[0];
--len1;
memcpy(data, temp + 1, len1);
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return len1;
}
#define PACKED_NODE_SIZE_IP4 (1 + SIZE_IP4 + sizeof(uint16_t) + CRYPTO_PUBLIC_KEY_SIZE)
#define PACKED_NODE_SIZE_IP6 (1 + SIZE_IP6 + sizeof(uint16_t) + CRYPTO_PUBLIC_KEY_SIZE)
/* Return packet size of packed node with ip_family on success.
* Return -1 on failure.
*/
int packed_node_size(Family ip_family)
{
if (net_family_is_ipv4(ip_family) || net_family_is_tcp_ipv4(ip_family)) {
return PACKED_NODE_SIZE_IP4;
}
if (net_family_is_ipv6(ip_family) || net_family_is_tcp_ipv6(ip_family)) {
return PACKED_NODE_SIZE_IP6;
}
return -1;
}
/* Packs an IP_Port structure into data of max size length.
*
* Returns size of packed IP_Port data on success
* Return -1 on failure.
*/
int pack_ip_port(uint8_t *data, uint16_t length, const IP_Port *ip_port)
{
if (data == nullptr) {
return -1;
}
bool is_ipv4;
uint8_t net_family;
if (net_family_is_ipv4(ip_port->ip.family)) {
// TODO(irungentoo): use functions to convert endianness
is_ipv4 = true;
net_family = TOX_AF_INET;
} else if (net_family_is_tcp_ipv4(ip_port->ip.family)) {
is_ipv4 = true;
net_family = TOX_TCP_INET;
} else if (net_family_is_ipv6(ip_port->ip.family)) {
is_ipv4 = false;
net_family = TOX_AF_INET6;
} else if (net_family_is_tcp_ipv6(ip_port->ip.family)) {
is_ipv4 = false;
net_family = TOX_TCP_INET6;
} else {
return -1;
}
if (is_ipv4) {
const uint32_t size = 1 + SIZE_IP4 + sizeof(uint16_t);
if (size > length) {
return -1;
}
data[0] = net_family;
memcpy(data + 1, &ip_port->ip.ip.v4, SIZE_IP4);
memcpy(data + 1 + SIZE_IP4, &ip_port->port, sizeof(uint16_t));
return size;
} else {
const uint32_t size = 1 + SIZE_IP6 + sizeof(uint16_t);
if (size > length) {
return -1;
}
data[0] = net_family;
memcpy(data + 1, &ip_port->ip.ip.v6, SIZE_IP6);
memcpy(data + 1 + SIZE_IP6, &ip_port->port, sizeof(uint16_t));
return size;
}
}
static int dht_create_packet(const uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE],
const uint8_t *shared_key, const uint8_t type, uint8_t *plain, size_t plain_length, uint8_t *packet)
{
VLA(uint8_t, encrypted, plain_length + CRYPTO_MAC_SIZE);
uint8_t nonce[CRYPTO_NONCE_SIZE];
random_nonce(nonce);
const int encrypted_length = encrypt_data_symmetric(shared_key, nonce, plain, plain_length, encrypted);
if (encrypted_length == -1) {
return -1;
}
packet[0] = type;
memcpy(packet + 1, public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(packet + 1 + CRYPTO_PUBLIC_KEY_SIZE, nonce, CRYPTO_NONCE_SIZE);
memcpy(packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE, encrypted, encrypted_length);
return 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + encrypted_length;
}
/* Unpack IP_Port structure from data of max size length into ip_port.
*
* Return size of unpacked ip_port on success.
* Return -1 on failure.
*/
int unpack_ip_port(IP_Port *ip_port, const uint8_t *data, uint16_t length, uint8_t tcp_enabled)
{
if (data == nullptr) {
return -1;
}
bool is_ipv4;
Family host_family;
if (data[0] == TOX_AF_INET) {
is_ipv4 = true;
host_family = net_family_ipv4;
} else if (data[0] == TOX_TCP_INET) {
if (!tcp_enabled) {
return -1;
}
is_ipv4 = true;
host_family = net_family_tcp_ipv4;
} else if (data[0] == TOX_AF_INET6) {
is_ipv4 = false;
host_family = net_family_ipv6;
} else if (data[0] == TOX_TCP_INET6) {
if (!tcp_enabled) {
return -1;
}
is_ipv4 = false;
host_family = net_family_tcp_ipv6;
} else {
return -1;
}
if (is_ipv4) {
const uint32_t size = 1 + SIZE_IP4 + sizeof(uint16_t);
if (size > length) {
return -1;
}
ip_port->ip.family = host_family;
memcpy(&ip_port->ip.ip.v4, data + 1, SIZE_IP4);
memcpy(&ip_port->port, data + 1 + SIZE_IP4, sizeof(uint16_t));
return size;
} else {
const uint32_t size = 1 + SIZE_IP6 + sizeof(uint16_t);
if (size > length) {
return -1;
}
ip_port->ip.family = host_family;
memcpy(&ip_port->ip.ip.v6, data + 1, SIZE_IP6);
memcpy(&ip_port->port, data + 1 + SIZE_IP6, sizeof(uint16_t));
return size;
}
}
/* Pack number of nodes into data of maxlength length.
*
* return length of packed nodes on success.
* return -1 on failure.
*/
int pack_nodes(uint8_t *data, uint16_t length, const Node_format *nodes, uint16_t number)
{
uint32_t packed_length = 0;
for (uint32_t i = 0; i < number && packed_length < length; ++i) {
const int ipp_size = pack_ip_port(data + packed_length, length - packed_length, &nodes[i].ip_port);
if (ipp_size == -1) {
return -1;
}
packed_length += ipp_size;
if (packed_length + CRYPTO_PUBLIC_KEY_SIZE > length) {
return -1;
}
memcpy(data + packed_length, nodes[i].public_key, CRYPTO_PUBLIC_KEY_SIZE);
packed_length += CRYPTO_PUBLIC_KEY_SIZE;
const uint32_t increment = ipp_size + CRYPTO_PUBLIC_KEY_SIZE;
assert(increment == PACKED_NODE_SIZE_IP4 || increment == PACKED_NODE_SIZE_IP6);
}
return packed_length;
}
/* Unpack data of length into nodes of size max_num_nodes.
* Put the length of the data processed in processed_data_len.
* tcp_enabled sets if TCP nodes are expected (true) or not (false).
*
* return number of unpacked nodes on success.
* return -1 on failure.
*/
int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, const uint8_t *data,
uint16_t length, uint8_t tcp_enabled)
{
uint32_t num = 0, len_processed = 0;
while (num < max_num_nodes && len_processed < length) {
const int ipp_size = unpack_ip_port(&nodes[num].ip_port, data + len_processed, length - len_processed, tcp_enabled);
if (ipp_size == -1) {
return -1;
}
len_processed += ipp_size;
if (len_processed + CRYPTO_PUBLIC_KEY_SIZE > length) {
return -1;
}
memcpy(nodes[num].public_key, data + len_processed, CRYPTO_PUBLIC_KEY_SIZE);
len_processed += CRYPTO_PUBLIC_KEY_SIZE;
++num;
const uint32_t increment = ipp_size + CRYPTO_PUBLIC_KEY_SIZE;
assert(increment == PACKED_NODE_SIZE_IP4 || increment == PACKED_NODE_SIZE_IP6);
}
if (processed_data_len) {
*processed_data_len = len_processed;
}
return num;
}
/* Find index of ##type with public_key equal to pk.
*
* return index or UINT32_MAX if not found.
*/
#define INDEX_OF_PK(array, size, pk) \
do { \
for (uint32_t i = 0; i < size; ++i) { \
if (id_equal(array[i].public_key, pk)) { \
return i; \
} \
} \
\
return UINT32_MAX; \
} while (0)
static uint32_t index_of_client_pk(const Client_data *array, uint32_t size, const uint8_t *pk)
{
INDEX_OF_PK(array, size, pk);
}
static uint32_t index_of_friend_pk(const DHT_Friend *array, uint32_t size, const uint8_t *pk)
{
INDEX_OF_PK(array, size, pk);
}
static uint32_t index_of_node_pk(const Node_format *array, uint32_t size, const uint8_t *pk)
{
INDEX_OF_PK(array, size, pk);
}
/* Find index of Client_data with ip_port equal to param ip_port.
*
* return index or UINT32_MAX if not found.
*/
static uint32_t index_of_client_ip_port(const Client_data *array, uint32_t size, const IP_Port *ip_port)
{
for (uint32_t i = 0; i < size; ++i) {
if ((net_family_is_ipv4(ip_port->ip.family) && ipport_equal(&array[i].assoc4.ip_port, ip_port)) ||
(net_family_is_ipv6(ip_port->ip.family) && ipport_equal(&array[i].assoc6.ip_port, ip_port))) {
return i;
}
}
return UINT32_MAX;
}
/* Update ip_port of client if it's needed.
*/
static void update_client(const Logger *log, int index, Client_data *client, IP_Port ip_port)
{
IPPTsPng *assoc;
int ip_version;
if (net_family_is_ipv4(ip_port.ip.family)) {
assoc = &client->assoc4;
ip_version = 4;
} else if (net_family_is_ipv6(ip_port.ip.family)) {
assoc = &client->assoc6;
ip_version = 6;
} else {
return;
}
if (!ipport_equal(&assoc->ip_port, &ip_port)) {
char ip_str[IP_NTOA_LEN];
LOGGER_TRACE(log, "coipil[%u]: switching ipv%d from %s:%u to %s:%u",
index, ip_version,
ip_ntoa(&assoc->ip_port.ip, ip_str, sizeof(ip_str)),
net_ntohs(assoc->ip_port.port),
ip_ntoa(&ip_port.ip, ip_str, sizeof(ip_str)),
net_ntohs(ip_port.port));
}
if (ip_is_lan(assoc->ip_port.ip) != 0 && ip_is_lan(ip_port.ip) == 0) {
return;
}
assoc->ip_port = ip_port;
assoc->timestamp = unix_time();
}
/* Check if client with public_key is already in list of length length.
* If it is then set its corresponding timestamp to current time.
* If the id is already in the list with a different ip_port, update it.
* TODO(irungentoo): Maybe optimize this.
*
* return True(1) or False(0)
*/
static int client_or_ip_port_in_list(const Logger *log, Client_data *list, uint16_t length, const uint8_t *public_key,
IP_Port ip_port)
{
const uint64_t temp_time = unix_time();
uint32_t index = index_of_client_pk(list, length, public_key);
/* if public_key is in list, find it and maybe overwrite ip_port */
if (index != UINT32_MAX) {
update_client(log, index, &list[index], ip_port);
return 1;
}
/* public_key not in list yet: see if we can find an identical ip_port, in
* that case we kill the old public_key by overwriting it with the new one
* TODO(irungentoo): maybe we SHOULDN'T do that if that public_key is in a friend_list
* and the one who is the actual friend's public_key/address set?
* MAYBE: check the other address, if valid, don't nuke? */
index = index_of_client_ip_port(list, length, &ip_port);
if (index == UINT32_MAX) {
return 0;
}
IPPTsPng *assoc;
int ip_version;
if (net_family_is_ipv4(ip_port.ip.family)) {
assoc = &list[index].assoc4;
ip_version = 4;
} else {
assoc = &list[index].assoc6;
ip_version = 6;
}
/* Initialize client timestamp. */
assoc->timestamp = temp_time;
memcpy(list[index].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
LOGGER_DEBUG(log, "coipil[%u]: switching public_key (ipv%d)", index, ip_version);
/* kill the other address, if it was set */
memset(assoc, 0, sizeof(IPPTsPng));
return 1;
}
/* Add node to the node list making sure only the nodes closest to cmp_pk are in the list.
*/
bool add_to_list(Node_format *nodes_list, unsigned int length, const uint8_t *pk, IP_Port ip_port,
const uint8_t *cmp_pk)
{
uint8_t pk_bak[CRYPTO_PUBLIC_KEY_SIZE];
IP_Port ip_port_bak;
for (size_t i = 0; i < length; ++i) {
if (id_closest(cmp_pk, nodes_list[i].public_key, pk) == 2) {
memcpy(pk_bak, nodes_list[i].public_key, CRYPTO_PUBLIC_KEY_SIZE);
ip_port_bak = nodes_list[i].ip_port;
memcpy(nodes_list[i].public_key, pk, CRYPTO_PUBLIC_KEY_SIZE);
nodes_list[i].ip_port = ip_port;
if (i != (length - 1)) {
add_to_list(nodes_list, length, pk_bak, ip_port_bak, cmp_pk);
}
return 1;
}
}
return 0;
}
/* TODO(irungentoo): change this to 7 when done*/
#define HARDENING_ALL_OK 2
/* return 0 if not.
* return 1 if route request are ok
* return 2 if it responds to send node packets correctly
* return 4 if it can test other nodes correctly
* return HARDENING_ALL_OK if all ok.
*/
static uint8_t hardening_correct(const Hardening *h)
{
return h->routes_requests_ok + (h->send_nodes_ok << 1) + (h->testing_requests << 2);
}
/*
* helper for get_close_nodes(). argument list is a monster :D
*/
static void get_close_nodes_inner(const uint8_t *public_key, Node_format *nodes_list,
Family sa_family, const Client_data *client_list, uint32_t client_list_length,
uint32_t *num_nodes_ptr, uint8_t is_LAN, uint8_t want_good)
{
if (!net_family_is_ipv4(sa_family) && !net_family_is_ipv6(sa_family) && !net_family_is_unspec(sa_family)) {
return;
}
uint32_t num_nodes = *num_nodes_ptr;
for (uint32_t i = 0; i < client_list_length; ++i) {
const Client_data *const client = &client_list[i];
/* node already in list? */
if (index_of_node_pk(nodes_list, MAX_SENT_NODES, client->public_key) != UINT32_MAX) {
continue;
}
const IPPTsPng *ipptp = nullptr;
if (net_family_is_ipv4(sa_family)) {
ipptp = &client->assoc4;
} else if (net_family_is_ipv6(sa_family)) {
ipptp = &client->assoc6;
} else if (client->assoc4.timestamp >= client->assoc6.timestamp) {
ipptp = &client->assoc4;
} else {
ipptp = &client->assoc6;
}
/* node not in a good condition? */
if (is_timeout(ipptp->timestamp, BAD_NODE_TIMEOUT)) {
continue;
}
/* don't send LAN ips to non LAN peers */
if (ip_is_lan(ipptp->ip_port.ip) == 0 && !is_LAN) {
continue;
}
if (ip_is_lan(ipptp->ip_port.ip) != 0 && want_good && hardening_correct(&ipptp->hardening) != HARDENING_ALL_OK
&& !id_equal(public_key, client->public_key)) {
continue;
}
if (num_nodes < MAX_SENT_NODES) {
memcpy(nodes_list[num_nodes].public_key, client->public_key, CRYPTO_PUBLIC_KEY_SIZE);
nodes_list[num_nodes].ip_port = ipptp->ip_port;
++num_nodes;
} else {
add_to_list(nodes_list, MAX_SENT_NODES, client->public_key, ipptp->ip_port, public_key);
}
}
*num_nodes_ptr = num_nodes;
}
/* Find MAX_SENT_NODES nodes closest to the public_key for the send nodes request:
* put them in the nodes_list and return how many were found.
*
* TODO(irungentoo): For the love of based make this function cleaner and much more efficient.
*
* want_good : do we want only good nodes as checked with the hardening returned or not?
*/
static int get_somewhat_close_nodes(const DHT *dht, const uint8_t *public_key, Node_format *nodes_list,
Family sa_family, uint8_t is_LAN, uint8_t want_good)
{
uint32_t num_nodes = 0;
get_close_nodes_inner(public_key, nodes_list, sa_family,
dht->close_clientlist, LCLIENT_LIST, &num_nodes, is_LAN, 0);
/* TODO(irungentoo): uncomment this when hardening is added to close friend clients */
#if 0
for (uint32_t i = 0; i < dht->num_friends; ++i) {
get_close_nodes_inner(dht, public_key, nodes_list, sa_family,
dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS,
&num_nodes, is_LAN, want_good);
}
#endif
for (uint32_t i = 0; i < dht->num_friends; ++i) {
get_close_nodes_inner(public_key, nodes_list, sa_family,
dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS,
&num_nodes, is_LAN, 0);
}
return num_nodes;
}
int get_close_nodes(const DHT *dht, const uint8_t *public_key, Node_format *nodes_list, Family sa_family,
uint8_t is_LAN, uint8_t want_good)
{
memset(nodes_list, 0, MAX_SENT_NODES * sizeof(Node_format));
return get_somewhat_close_nodes(dht, public_key, nodes_list, sa_family, is_LAN, want_good);
}
typedef struct DHT_Cmp_data {
const uint8_t *base_public_key;
Client_data entry;
} DHT_Cmp_data;
static bool assoc_timeout(const IPPTsPng *assoc)
{
return is_timeout(assoc->timestamp, BAD_NODE_TIMEOUT);
}
static bool incorrect_hardening(const IPPTsPng *assoc)
{
return hardening_correct(&assoc->hardening) != HARDENING_ALL_OK;
}
static int cmp_dht_entry(const void *a, const void *b)
{
DHT_Cmp_data cmp1, cmp2;
memcpy(&cmp1, a, sizeof(DHT_Cmp_data));
memcpy(&cmp2, b, sizeof(DHT_Cmp_data));
const Client_data entry1 = cmp1.entry;
const Client_data entry2 = cmp2.entry;
const uint8_t *cmp_public_key = cmp1.base_public_key;
bool t1 = assoc_timeout(&entry1.assoc4) && assoc_timeout(&entry1.assoc6);
bool t2 = assoc_timeout(&entry2.assoc4) && assoc_timeout(&entry2.assoc6);
if (t1 && t2) {
return 0;
}
if (t1) {
return -1;
}
if (t2) {
return 1;
}
t1 = incorrect_hardening(&entry1.assoc4) && incorrect_hardening(&entry1.assoc6);
t2 = incorrect_hardening(&entry2.assoc4) && incorrect_hardening(&entry2.assoc6);
if (t1 && !t2) {
return -1;
}
if (!t1 && t2) {
return 1;
}
const int close = id_closest(cmp_public_key, entry1.public_key, entry2.public_key);
if (close == 1) {
return 1;
}
if (close == 2) {
return -1;
}
return 0;
}
/* Is it ok to store node with public_key in client.
*
* return 0 if node can't be stored.
* return 1 if it can.
*/
static unsigned int store_node_ok(const Client_data *client, const uint8_t *public_key, const uint8_t *comp_public_key)
{
return (is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT)
&& is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT))
|| id_closest(comp_public_key, client->public_key, public_key) == 2;
}
static void sort_client_list(Client_data *list, unsigned int length, const uint8_t *comp_public_key)
{
// Pass comp_public_key to qsort with each Client_data entry, so the
// comparison function can use it as the base of comparison.
VLA(DHT_Cmp_data, cmp_list, length);
for (uint32_t i = 0; i < length; ++i) {
cmp_list[i].base_public_key = comp_public_key;
cmp_list[i].entry = list[i];
}
qsort(cmp_list, length, sizeof(DHT_Cmp_data), cmp_dht_entry);
for (uint32_t i = 0; i < length; ++i) {
list[i] = cmp_list[i].entry;
}
}
static void update_client_with_reset(Client_data *client, const IP_Port *ip_port)
{
IPPTsPng *ipptp_write = nullptr;
IPPTsPng *ipptp_clear = nullptr;
if (net_family_is_ipv4(ip_port->ip.family)) {
ipptp_write = &client->assoc4;
ipptp_clear = &client->assoc6;
} else {
ipptp_write = &client->assoc6;
ipptp_clear = &client->assoc4;
}
ipptp_write->ip_port = *ip_port;
ipptp_write->timestamp = unix_time();
ip_reset(&ipptp_write->ret_ip_port.ip);
ipptp_write->ret_ip_port.port = 0;
ipptp_write->ret_timestamp = 0;
/* zero out other address */
memset(ipptp_clear, 0, sizeof(*ipptp_clear));
}
/* Replace a first bad (or empty) node with this one
* or replace a possibly bad node (tests failed or not done yet)
* that is further than any other in the list
* from the comp_public_key
* or replace a good node that is further
* than any other in the list from the comp_public_key
* and further than public_key.
*
* Do not replace any node if the list has no bad or possibly bad nodes
* and all nodes in the list are closer to comp_public_key
* than public_key.
*
* returns true when the item was stored, false otherwise */
static bool replace_all(Client_data *list,
uint16_t length,
const uint8_t *public_key,
IP_Port ip_port,
const uint8_t *comp_public_key)
{
if (!net_family_is_ipv4(ip_port.ip.family) && !net_family_is_ipv6(ip_port.ip.family)) {
return false;
}
if (!store_node_ok(&list[1], public_key, comp_public_key) &&
!store_node_ok(&list[0], public_key, comp_public_key)) {
return false;
}
sort_client_list(list, length, comp_public_key);
Client_data *const client = &list[0];
id_copy(client->public_key, public_key);
update_client_with_reset(client, &ip_port);
return true;
}
/* Add node to close list.
*
* simulate is set to 1 if we want to check if a node can be added to the list without adding it.
*
* return -1 on failure.
* return 0 on success.
*/
static int add_to_close(DHT *dht, const uint8_t *public_key, IP_Port ip_port, bool simulate)
{
unsigned int index = bit_by_bit_cmp(public_key, dht->self_public_key);
if (index >= LCLIENT_LENGTH) {
index = LCLIENT_LENGTH - 1;
}
for (uint32_t i = 0; i < LCLIENT_NODES; ++i) {
/* TODO(iphydf): write bounds checking test to catch the case that
* index is left as >= LCLIENT_LENGTH */
Client_data *const client = &dht->close_clientlist[(index * LCLIENT_NODES) + i];
if (!is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT) ||
!is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT)) {
continue;
}
if (simulate) {
return 0;
}
id_copy(client->public_key, public_key);
update_client_with_reset(client, &ip_port);
return 0;
}
return -1;
}
/* Return 1 if node can be added to close list, 0 if it can't.
*/
bool node_addable_to_close_list(DHT *dht, const uint8_t *public_key, IP_Port ip_port)
{
return add_to_close(dht, public_key, ip_port, 1) == 0;
}
static bool is_pk_in_client_list(const Client_data *list, unsigned int client_list_length, const uint8_t *public_key,
IP_Port ip_port)
{
const uint32_t index = index_of_client_pk(list, client_list_length, public_key);
if (index == UINT32_MAX) {
return 0;
}
const IPPTsPng *assoc = net_family_is_ipv4(ip_port.ip.family)
? &list[index].assoc4
: &list[index].assoc6;
return !is_timeout(assoc->timestamp, BAD_NODE_TIMEOUT);
}
static bool is_pk_in_close_list(DHT *dht, const uint8_t *public_key, IP_Port ip_port)
{
unsigned int index = bit_by_bit_cmp(public_key, dht->self_public_key);
if (index >= LCLIENT_LENGTH) {
index = LCLIENT_LENGTH - 1;
}
return is_pk_in_client_list(dht->close_clientlist + index * LCLIENT_NODES, LCLIENT_NODES, public_key, ip_port);
}
/* Check if the node obtained with a get_nodes with public_key should be pinged.
* NOTE: for best results call it after addto_lists;
*
* return false if the node should not be pinged.
* return true if it should.
*/
static bool ping_node_from_getnodes_ok(DHT *dht, const uint8_t *public_key, IP_Port ip_port)
{
bool ret = false;
if (add_to_close(dht, public_key, ip_port, 1) == 0) {
ret = true;
}
{
unsigned int *const num = &dht->num_to_bootstrap;
const uint32_t index = index_of_node_pk(dht->to_bootstrap, *num, public_key);
const bool in_close_list = is_pk_in_close_list(dht, public_key, ip_port);
if (ret && index == UINT32_MAX && !in_close_list) {
if (*num < MAX_CLOSE_TO_BOOTSTRAP_NODES) {
memcpy(dht->to_bootstrap[*num].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
dht->to_bootstrap[*num].ip_port = ip_port;
++*num;
} else {
// TODO(irungentoo): ipv6 vs v4
add_to_list(dht->to_bootstrap, MAX_CLOSE_TO_BOOTSTRAP_NODES, public_key, ip_port, dht->self_public_key);
}
}
}
for (uint32_t i = 0; i < dht->num_friends; ++i) {
DHT_Friend *dht_friend = &dht->friends_list[i];
bool store_ok = false;
if (store_node_ok(&dht_friend->client_list[1], public_key, dht_friend->public_key)) {
store_ok = true;
}
if (store_node_ok(&dht_friend->client_list[0], public_key, dht_friend->public_key)) {
store_ok = true;
}
unsigned int *const friend_num = &dht_friend->num_to_bootstrap;
const uint32_t index = index_of_node_pk(dht_friend->to_bootstrap, *friend_num, public_key);
const bool pk_in_list = is_pk_in_client_list(dht_friend->client_list, MAX_FRIEND_CLIENTS, public_key, ip_port);
if (store_ok && index == UINT32_MAX && !pk_in_list) {
if (*friend_num < MAX_SENT_NODES) {
Node_format *const format = &dht_friend->to_bootstrap[*friend_num];
memcpy(format->public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
format->ip_port = ip_port;
++*friend_num;
} else {
add_to_list(dht_friend->to_bootstrap, MAX_SENT_NODES, public_key, ip_port, dht_friend->public_key);
}
ret = true;
}
}
return ret;
}
/* Attempt to add client with ip_port and public_key to the friends client list
* and close_clientlist.
*
* returns 1+ if the item is used in any list, 0 else
*/
uint32_t addto_lists(DHT *dht, IP_Port ip_port, const uint8_t *public_key)
{
uint32_t used = 0;
/* convert IPv4-in-IPv6 to IPv4 */
if (net_family_is_ipv6(ip_port.ip.family) && ipv6_ipv4_in_v6(ip_port.ip.ip.v6)) {
ip_port.ip.family = net_family_ipv4;
ip_port.ip.ip.v4.uint32 = ip_port.ip.ip.v6.uint32[3];
}
/* NOTE: Current behavior if there are two clients with the same id is
* to replace the first ip by the second.
*/
const bool in_close_list = client_or_ip_port_in_list(dht->log, dht->close_clientlist,
LCLIENT_LIST, public_key, ip_port);
/* add_to_close should be called only if !in_list (don't extract to variable) */
if (in_close_list || add_to_close(dht, public_key, ip_port, 0)) {
++used;
}
DHT_Friend *friend_foundip = nullptr;
for (uint32_t i = 0; i < dht->num_friends; ++i) {
const bool in_list = client_or_ip_port_in_list(dht->log, dht->friends_list[i].client_list,
MAX_FRIEND_CLIENTS, public_key, ip_port);
/* replace_all should be called only if !in_list (don't extract to variable) */
if (in_list || replace_all(dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS, public_key,
ip_port, dht->friends_list[i].public_key)) {
DHT_Friend *dht_friend = &dht->friends_list[i];
if (id_equal(public_key, dht_friend->public_key)) {
friend_foundip = dht_friend;
}
++used;
}
}
if (!friend_foundip) {
return used;
}
for (uint32_t i = 0; i < friend_foundip->lock_count; ++i) {
if (friend_foundip->callbacks[i].ip_callback) {
friend_foundip->callbacks[i].ip_callback(friend_foundip->callbacks[i].data,
friend_foundip->callbacks[i].number, ip_port);
}
}
return used;
}
static bool update_client_data(Client_data *array, size_t size, IP_Port ip_port, const uint8_t *pk)
{
const uint64_t temp_time = unix_time();
const uint32_t index = index_of_client_pk(array, size, pk);
if (index == UINT32_MAX) {
return false;
}
Client_data *const data = &array[index];
IPPTsPng *assoc;
if (net_family_is_ipv4(ip_port.ip.family)) {
assoc = &data->assoc4;
} else if (net_family_is_ipv6(ip_port.ip.family)) {
assoc = &data->assoc6;
} else {
return true;
}
assoc->ret_ip_port = ip_port;
assoc->ret_timestamp = temp_time;
return true;
}
/* If public_key is a friend or us, update ret_ip_port
* nodepublic_key is the id of the node that sent us this info.
*/
static void returnedip_ports(DHT *dht, IP_Port ip_port, const uint8_t *public_key, const uint8_t *nodepublic_key)
{
/* convert IPv4-in-IPv6 to IPv4 */
if (net_family_is_ipv6(ip_port.ip.family) && ipv6_ipv4_in_v6(ip_port.ip.ip.v6)) {
ip_port.ip.family = net_family_ipv4;
ip_port.ip.ip.v4.uint32 = ip_port.ip.ip.v6.uint32[3];
}
if (id_equal(public_key, dht->self_public_key)) {
update_client_data(dht->close_clientlist, LCLIENT_LIST, ip_port, nodepublic_key);
return;
}
for (uint32_t i = 0; i < dht->num_friends; ++i) {
if (id_equal(public_key, dht->friends_list[i].public_key)) {
Client_data *const client_list = dht->friends_list[i].client_list;
if (update_client_data(client_list, MAX_FRIEND_CLIENTS, ip_port, nodepublic_key)) {
return;
}
}
}
}
/* Send a getnodes request.
sendback_node is the node that it will send back the response to (set to NULL to disable this) */
static int getnodes(DHT *dht, IP_Port ip_port, const uint8_t *public_key, const uint8_t *client_id,
const Node_format *sendback_node)
{
/* Check if packet is going to be sent to ourself. */
if (id_equal(public_key, dht->self_public_key)) {
return -1;
}
uint8_t plain_message[sizeof(Node_format) * 2] = {0};
Node_format receiver;
memcpy(receiver.public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
receiver.ip_port = ip_port;
memcpy(plain_message, &receiver, sizeof(receiver));
uint64_t ping_id = 0;
if (sendback_node != nullptr) {
memcpy(plain_message + sizeof(receiver), sendback_node, sizeof(Node_format));
ping_id = ping_array_add(dht->dht_harden_ping_array, plain_message, sizeof(plain_message));
} else {
ping_id = ping_array_add(dht->dht_ping_array, plain_message, sizeof(receiver));
}
if (ping_id == 0) {
return -1;
}
uint8_t plain[CRYPTO_PUBLIC_KEY_SIZE + sizeof(ping_id)];
uint8_t data[1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + sizeof(plain) + CRYPTO_MAC_SIZE];
memcpy(plain, client_id, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(plain + CRYPTO_PUBLIC_KEY_SIZE, &ping_id, sizeof(ping_id));
uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];
dht_get_shared_key_sent(dht, shared_key, public_key);
const int len = dht_create_packet(dht->self_public_key, shared_key, NET_PACKET_GET_NODES,
plain, sizeof(plain), data);
if (len != sizeof(data)) {
return -1;
}
return sendpacket(dht->net, ip_port, data, len);
}
/* Send a send nodes response: message for IPv6 nodes */
static int sendnodes_ipv6(const DHT *dht, IP_Port ip_port, const uint8_t *public_key, const uint8_t *client_id,
const uint8_t *sendback_data, uint16_t length, const uint8_t *shared_encryption_key)
{
/* Check if packet is going to be sent to ourself. */
if (id_equal(public_key, dht->self_public_key)) {
return -1;
}
if (length != sizeof(uint64_t)) {
return -1;
}
const size_t node_format_size = sizeof(Node_format);
Node_format nodes_list[MAX_SENT_NODES];
const uint32_t num_nodes = get_close_nodes(dht, client_id, nodes_list, net_family_unspec, ip_is_lan(ip_port.ip) == 0,
1);
VLA(uint8_t, plain, 1 + node_format_size * MAX_SENT_NODES + length);
int nodes_length = 0;
if (num_nodes) {
nodes_length = pack_nodes(plain + 1, node_format_size * MAX_SENT_NODES, nodes_list, num_nodes);
if (nodes_length <= 0) {
return -1;
}
}
plain[0] = num_nodes;
memcpy(plain + 1 + nodes_length, sendback_data, length);
const uint32_t crypto_size = 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_MAC_SIZE;
VLA(uint8_t, data, 1 + nodes_length + length + crypto_size);
const int len = dht_create_packet(dht->self_public_key, shared_encryption_key, NET_PACKET_SEND_NODES_IPV6,
plain, 1 + nodes_length + length, data);
if (len != SIZEOF_VLA(data)) {
return -1;
}
return sendpacket(dht->net, ip_port, data, len);
}
#define CRYPTO_NODE_SIZE (CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint64_t))
static int handle_getnodes(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
{
if (length != (CRYPTO_SIZE + CRYPTO_MAC_SIZE + sizeof(uint64_t))) {
return true;
}
DHT *const dht = (DHT *)object;
/* Check if packet is from ourself. */
if (id_equal(packet + 1, dht->self_public_key)) {
return true;
}
uint8_t plain[CRYPTO_NODE_SIZE];
uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];
dht_get_shared_key_recv(dht, shared_key, packet + 1);
const int len = decrypt_data_symmetric(
shared_key,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE,
CRYPTO_NODE_SIZE + CRYPTO_MAC_SIZE,
plain);
if (len != CRYPTO_NODE_SIZE) {
return true;
}
sendnodes_ipv6(dht, source, packet + 1, plain, plain + CRYPTO_PUBLIC_KEY_SIZE, sizeof(uint64_t), shared_key);
ping_add(dht->ping, packet + 1, source);
return false;
}
/* return false if no
return true if yes */
static bool sent_getnode_to_node(DHT *dht, const uint8_t *public_key, IP_Port node_ip_port, uint64_t ping_id,
Node_format *sendback_node)
{
uint8_t data[sizeof(Node_format) * 2];
if (ping_array_check(dht->dht_ping_array, data, sizeof(data), ping_id) == sizeof(Node_format)) {
memset(sendback_node, 0, sizeof(Node_format));
} else if (ping_array_check(dht->dht_harden_ping_array, data, sizeof(data), ping_id) == sizeof(data)) {
memcpy(sendback_node, data + sizeof(Node_format), sizeof(Node_format));
} else {
return false;
}
Node_format test;
memcpy(&test, data, sizeof(Node_format));
if (!ipport_equal(&test.ip_port, &node_ip_port) || !id_equal(test.public_key, public_key)) {
return false;
}
return true;
}
/* Function is needed in following functions. */
static int send_hardening_getnode_res(const DHT *dht, const Node_format *sendto, const uint8_t *queried_client_id,
const uint8_t *nodes_data, uint16_t nodes_data_length);
static int handle_sendnodes_core(void *object, IP_Port source, const uint8_t *packet, uint16_t length,
Node_format *plain_nodes, uint16_t size_plain_nodes, uint32_t *num_nodes_out)
{
DHT *const dht = (DHT *)object;
const uint32_t cid_size = 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + 1 + sizeof(uint64_t) + CRYPTO_MAC_SIZE;
if (length < cid_size) { /* too short */
return 1;
}
const uint32_t data_size = length - cid_size;
if (data_size == 0) {
return 1;
}
if (data_size > sizeof(Node_format) * MAX_SENT_NODES) { /* invalid length */
return 1;
}
VLA(uint8_t, plain, 1 + data_size + sizeof(uint64_t));
uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];
dht_get_shared_key_sent(dht, shared_key, packet + 1);
const int len = decrypt_data_symmetric(
shared_key,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE,
1 + data_size + sizeof(uint64_t) + CRYPTO_MAC_SIZE,
plain);
if ((unsigned int)len != SIZEOF_VLA(plain)) {
return 1;
}
if (plain[0] > size_plain_nodes) {
return 1;
}
Node_format sendback_node;
uint64_t ping_id;
memcpy(&ping_id, plain + 1 + data_size, sizeof(ping_id));
if (!sent_getnode_to_node(dht, packet + 1, source, ping_id, &sendback_node)) {
return 1;
}
uint16_t length_nodes = 0;
const int num_nodes = unpack_nodes(plain_nodes, plain[0], &length_nodes, plain + 1, data_size, 0);
if (length_nodes != data_size) {
return 1;
}
if (num_nodes != plain[0]) {
return 1;
}
if (num_nodes < 0) {
return 1;
}
/* store the address the *request* was sent to */
addto_lists(dht, source, packet + 1);
*num_nodes_out = num_nodes;
send_hardening_getnode_res(dht, &sendback_node, packet + 1, plain + 1, data_size);
return 0;
}
static int handle_sendnodes_ipv6(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
{
DHT *const dht = (DHT *)object;
Node_format plain_nodes[MAX_SENT_NODES];
uint32_t num_nodes;
if (handle_sendnodes_core(object, source, packet, length, plain_nodes, MAX_SENT_NODES, &num_nodes)) {
return 1;
}
if (num_nodes == 0) {
return 0;
}
for (uint32_t i = 0; i < num_nodes; ++i) {
if (ipport_isset(&plain_nodes[i].ip_port)) {
ping_node_from_getnodes_ok(dht, plain_nodes[i].public_key, plain_nodes[i].ip_port);
returnedip_ports(dht, plain_nodes[i].ip_port, plain_nodes[i].public_key, packet + 1);
}
}
return 0;
}
/*----------------------------------------------------------------------------------*/
/*------------------------END of packet handling functions--------------------------*/
int dht_addfriend(DHT *dht, const uint8_t *public_key, dht_ip_cb *ip_callback,
void *data, int32_t number, uint16_t *lock_count)
{
const uint32_t friend_num = index_of_friend_pk(dht->friends_list, dht->num_friends, public_key);
uint16_t lock_num;
if (friend_num != UINT32_MAX) { /* Is friend already in DHT? */
DHT_Friend *const dht_friend = &dht->friends_list[friend_num];
if (dht_friend->lock_count == DHT_FRIEND_MAX_LOCKS) {
return -1;
}
lock_num = dht_friend->lock_count;
++dht_friend->lock_count;
dht_friend->callbacks[lock_num].ip_callback = ip_callback;
dht_friend->callbacks[lock_num].data = data;
dht_friend->callbacks[lock_num].number = number;
if (lock_count) {
*lock_count = lock_num + 1;
}
return 0;
}
DHT_Friend *const temp = (DHT_Friend *)realloc(dht->friends_list, sizeof(DHT_Friend) * (dht->num_friends + 1));
if (temp == nullptr) {
return -1;
}
dht->friends_list = temp;
DHT_Friend *const dht_friend = &dht->friends_list[dht->num_friends];
memset(dht_friend, 0, sizeof(DHT_Friend));
memcpy(dht_friend->public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
dht_friend->nat.nat_ping_id = random_u64();
++dht->num_friends;
lock_num = dht_friend->lock_count;
++dht_friend->lock_count;
dht_friend->callbacks[lock_num].ip_callback = ip_callback;
dht_friend->callbacks[lock_num].data = data;
dht_friend->callbacks[lock_num].number = number;
if (lock_count) {
*lock_count = lock_num + 1;
}
dht_friend->num_to_bootstrap = get_close_nodes(dht, dht_friend->public_key, dht_friend->to_bootstrap, net_family_unspec,
1, 0);
return 0;
}
int dht_delfriend(DHT *dht, const uint8_t *public_key, uint16_t lock_count)
{
const uint32_t friend_num = index_of_friend_pk(dht->friends_list, dht->num_friends, public_key);
if (friend_num == UINT32_MAX) {
return -1;
}
DHT_Friend *const dht_friend = &dht->friends_list[friend_num];
--dht_friend->lock_count;
if (dht_friend->lock_count && lock_count) { /* DHT friend is still in use.*/
--lock_count;
dht_friend->callbacks[lock_count].ip_callback = nullptr;
dht_friend->callbacks[lock_count].data = nullptr;
dht_friend->callbacks[lock_count].number = 0;
return 0;
}
--dht->num_friends;
if (dht->num_friends != friend_num) {
memcpy(&dht->friends_list[friend_num],
&dht->friends_list[dht->num_friends],
sizeof(DHT_Friend));
}
if (dht->num_friends == 0) {
free(dht->friends_list);
dht->friends_list = nullptr;
return 0;
}
DHT_Friend *const temp = (DHT_Friend *)realloc(dht->friends_list, sizeof(DHT_Friend) * (dht->num_friends));
if (temp == nullptr) {
return -1;
}
dht->friends_list = temp;
return 0;
}
/* TODO(irungentoo): Optimize this. */
int dht_getfriendip(const DHT *dht, const uint8_t *public_key, IP_Port *ip_port)
{
ip_reset(&ip_port->ip);
ip_port->port = 0;
const uint32_t friend_index = index_of_friend_pk(dht->friends_list, dht->num_friends, public_key);
if (friend_index == UINT32_MAX) {
return -1;
}
DHT_Friend *const frnd = &dht->friends_list[friend_index];
const uint32_t client_index = index_of_client_pk(frnd->client_list, MAX_FRIEND_CLIENTS, public_key);
if (client_index == -1) {
return 0;
}
const Client_data *const client = &frnd->client_list[client_index];
const IPPTsPng *const assocs[] = { &client->assoc6, &client->assoc4, nullptr };
for (const IPPTsPng * const *it = assocs; *it; ++it) {
const IPPTsPng *const assoc = *it;
if (!is_timeout(assoc->timestamp, BAD_NODE_TIMEOUT)) {
*ip_port = assoc->ip_port;
return 1;
}
}
return -1;
}
/* returns number of nodes not in kill-timeout */
static uint8_t do_ping_and_sendnode_requests(DHT *dht, uint64_t *lastgetnode, const uint8_t *public_key,
Client_data *list, uint32_t list_count, uint32_t *bootstrap_times, bool sortable)
{
uint8_t not_kill = 0;
const uint64_t temp_time = unix_time();
uint32_t num_nodes = 0;
VLA(Client_data *, client_list, list_count * 2);
VLA(IPPTsPng *, assoc_list, list_count * 2);
unsigned int sort = 0;
bool sort_ok = false;
for (uint32_t i = 0; i < list_count; ++i) {
/* If node is not dead. */
Client_data *client = &list[i];
IPPTsPng *const assocs[] = { &client->assoc6, &client->assoc4, nullptr };
uint32_t j = 0;
for (IPPTsPng * const *it = assocs; *it; ++it, ++j) {
IPPTsPng *const assoc = *it;
if (!is_timeout(assoc->timestamp, KILL_NODE_TIMEOUT)) {
sort = 0;
++not_kill;
if (is_timeout(assoc->last_pinged, PING_INTERVAL)) {
getnodes(dht, assoc->ip_port, client->public_key, public_key, nullptr);
assoc->last_pinged = temp_time;
}
/* If node is good. */
if (!is_timeout(assoc->timestamp, BAD_NODE_TIMEOUT)) {
client_list[num_nodes] = client;
assoc_list[num_nodes] = assoc;
++num_nodes;
}
} else {
++sort;
/* Timed out should be at beginning, if they are not, sort the list. */
if (sort > 1 && sort < (((j + 1) * 2) - 1)) {
sort_ok = true;
}
}
}
}
if (sortable && sort_ok) {
sort_client_list(list, list_count, public_key);
}
if ((num_nodes != 0) && (is_timeout(*lastgetnode, GET_NODE_INTERVAL) || *bootstrap_times < MAX_BOOTSTRAP_TIMES)) {
uint32_t rand_node = rand() % num_nodes;
if ((num_nodes - 1) != rand_node) {
rand_node += rand() % (num_nodes - (rand_node + 1));
}
getnodes(dht, assoc_list[rand_node]->ip_port, client_list[rand_node]->public_key, public_key, nullptr);
*lastgetnode = temp_time;
++*bootstrap_times;
}
return not_kill;
}
/* Ping each client in the "friends" list every PING_INTERVAL seconds. Send a get nodes request
* every GET_NODE_INTERVAL seconds to a random good node for each "friend" in our "friends" list.
*/
static void do_dht_friends(DHT *dht)
{
for (size_t i = 0; i < dht->num_friends; ++i) {
DHT_Friend *const dht_friend = &dht->friends_list[i];
for (size_t j = 0; j < dht_friend->num_to_bootstrap; ++j) {
getnodes(dht, dht_friend->to_bootstrap[j].ip_port, dht_friend->to_bootstrap[j].public_key, dht_friend->public_key,
nullptr);
}
dht_friend->num_to_bootstrap = 0;
do_ping_and_sendnode_requests(dht, &dht_friend->lastgetnode, dht_friend->public_key, dht_friend->client_list,
MAX_FRIEND_CLIENTS,
&dht_friend->bootstrap_times, 1);
}
}
/* Ping each client in the close nodes list every PING_INTERVAL seconds.
* Send a get nodes request every GET_NODE_INTERVAL seconds to a random good node in the list.
*/
static void do_Close(DHT *dht)
{
for (size_t i = 0; i < dht->num_to_bootstrap; ++i) {
getnodes(dht, dht->to_bootstrap[i].ip_port, dht->to_bootstrap[i].public_key, dht->self_public_key, nullptr);
}
dht->num_to_bootstrap = 0;
uint8_t not_killed = do_ping_and_sendnode_requests(
dht, &dht->close_lastgetnodes, dht->self_public_key, dht->close_clientlist, LCLIENT_LIST, &dht->close_bootstrap_times,
0);
if (not_killed != 0) {
return;
}
/* all existing nodes are at least KILL_NODE_TIMEOUT,
* which means we are mute, as we only send packets to
* nodes NOT in KILL_NODE_TIMEOUT
*
* so: reset all nodes to be BAD_NODE_TIMEOUT, but not
* KILL_NODE_TIMEOUT, so we at least keep trying pings */
const uint64_t badonly = unix_time() - BAD_NODE_TIMEOUT;
for (size_t i = 0; i < LCLIENT_LIST; ++i) {
Client_data *const client = &dht->close_clientlist[i];
IPPTsPng *const assocs[] = { &client->assoc6, &client->assoc4, nullptr };
for (IPPTsPng * const *it = assocs; *it; ++it) {
IPPTsPng *const assoc = *it;
if (assoc->timestamp) {
assoc->timestamp = badonly;
}
}
}
}
void dht_getnodes(DHT *dht, const IP_Port *from_ipp, const uint8_t *from_id, const uint8_t *which_id)
{
getnodes(dht, *from_ipp, from_id, which_id, nullptr);
}
void dht_bootstrap(DHT *dht, IP_Port ip_port, const uint8_t *public_key)
{
getnodes(dht, ip_port, public_key, dht->self_public_key, nullptr);
}
int dht_bootstrap_from_address(DHT *dht, const char *address, uint8_t ipv6enabled,
uint16_t port, const uint8_t *public_key)
{
IP_Port ip_port_v64;
IP *ip_extra = nullptr;
IP_Port ip_port_v4;
ip_init(&ip_port_v64.ip, ipv6enabled);
if (ipv6enabled) {
/* setup for getting BOTH: an IPv6 AND an IPv4 address */
ip_port_v64.ip.family = net_family_unspec;
ip_reset(&ip_port_v4.ip);
ip_extra = &ip_port_v4.ip;
}
if (addr_resolve_or_parse_ip(address, &ip_port_v64.ip, ip_extra)) {
ip_port_v64.port = port;
dht_bootstrap(dht, ip_port_v64, public_key);
if ((ip_extra != nullptr) && ip_isset(ip_extra)) {
ip_port_v4.port = port;
dht_bootstrap(dht, ip_port_v4, public_key);
}
return 1;
}
return 0;
}
/* Send the given packet to node with public_key
*
* return -1 if failure.
*/
int route_packet(const DHT *dht, const uint8_t *public_key, const uint8_t *packet, uint16_t length)
{
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
if (id_equal(public_key, dht->close_clientlist[i].public_key)) {
const Client_data *const client = &dht->close_clientlist[i];
const IPPTsPng *const assocs[] = { &client->assoc6, &client->assoc4, nullptr };
for (const IPPTsPng * const *it = assocs; *it; ++it) {
const IPPTsPng *const assoc = *it;
if (ip_isset(&assoc->ip_port.ip)) {
return sendpacket(dht->net, assoc->ip_port, packet, length);
}
}
break;
}
}
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.
*
* return the number of ips returned.
* return 0 if we are connected to friend or if no ips were found.
* return -1 if no such friend.
*/
static int friend_iplist(const DHT *dht, IP_Port *ip_portlist, uint16_t friend_num)
{
if (friend_num >= dht->num_friends) {
return -1;
}
const DHT_Friend *const dht_friend = &dht->friends_list[friend_num];
IP_Port ipv4s[MAX_FRIEND_CLIENTS];
int num_ipv4s = 0;
IP_Port ipv6s[MAX_FRIEND_CLIENTS];
int num_ipv6s = 0;
for (size_t i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
const Client_data *const client = &dht_friend->client_list[i];
/* If ip is not zero and node is good. */
if (ip_isset(&client->assoc4.ret_ip_port.ip) && !is_timeout(client->assoc4.ret_timestamp, BAD_NODE_TIMEOUT)) {
ipv4s[num_ipv4s] = client->assoc4.ret_ip_port;
++num_ipv4s;
}
if (ip_isset(&client->assoc6.ret_ip_port.ip) && !is_timeout(client->assoc6.ret_timestamp, BAD_NODE_TIMEOUT)) {
ipv6s[num_ipv6s] = client->assoc6.ret_ip_port;
++num_ipv6s;
}
if (id_equal(client->public_key, dht_friend->public_key)) {
if (!is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT)
|| !is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT)) {
return 0; /* direct connectivity */
}
}
}
#ifdef FRIEND_IPLIST_PAD
memcpy(ip_portlist, ipv6s, num_ipv6s * sizeof(IP_Port));
if (num_ipv6s == MAX_FRIEND_CLIENTS) {
return MAX_FRIEND_CLIENTS;
}
int num_ipv4s_used = MAX_FRIEND_CLIENTS - num_ipv6s;
if (num_ipv4s_used > num_ipv4s) {
num_ipv4s_used = num_ipv4s;
}
memcpy(&ip_portlist[num_ipv6s], ipv4s, num_ipv4s_used * sizeof(IP_Port));
return num_ipv6s + num_ipv4s_used;
#else /* !FRIEND_IPLIST_PAD */
/* there must be some secret reason why we can't pad the longer list
* with the shorter one...
*/
if (num_ipv6s >= num_ipv4s) {
memcpy(ip_portlist, ipv6s, num_ipv6s * sizeof(IP_Port));
return num_ipv6s;
}
memcpy(ip_portlist, ipv4s, num_ipv4s * sizeof(IP_Port));
return num_ipv4s;
#endif /* !FRIEND_IPLIST_PAD */
}
/* Send the following packet to everyone who tells us they are connected to friend_id.
*
* return ip for friend.
* return number of nodes the packet was sent to. (Only works if more than (MAX_FRIEND_CLIENTS / 4).
*/
int route_tofriend(const DHT *dht, const uint8_t *friend_id, const uint8_t *packet, uint16_t length)
{
const uint32_t num = index_of_friend_pk(dht->friends_list, dht->num_friends, friend_id);
if (num == UINT32_MAX) {
return 0;
}
uint32_t sent = 0;
uint8_t friend_sent[MAX_FRIEND_CLIENTS] = {0};
IP_Port ip_list[MAX_FRIEND_CLIENTS];
const int ip_num = friend_iplist(dht, ip_list, num);
if (ip_num < (MAX_FRIEND_CLIENTS / 4)) {
return 0; /* Reason for that? */
}
const DHT_Friend *const dht_friend = &dht->friends_list[num];
/* extra legwork, because having the outside allocating the space for us
* is *usually* good(tm) (bites us in the behind in this case though) */
for (uint32_t i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
if (friend_sent[i]) {/* Send one packet per client.*/
continue;
}
const Client_data *const client = &dht_friend->client_list[i];
const IPPTsPng *const assocs[] = { &client->assoc4, &client->assoc6, nullptr };
for (const IPPTsPng * const *it = assocs; *it; ++it) {
const IPPTsPng *const assoc = *it;
/* If ip is not zero and node is good. */
if (ip_isset(&assoc->ret_ip_port.ip) && !is_timeout(assoc->ret_timestamp, BAD_NODE_TIMEOUT)) {
const int retval = sendpacket(dht->net, assoc->ip_port, packet, length);
if ((unsigned int)retval == length) {
++sent;
friend_sent[i] = 1;
}
}
}
}
return sent;
}
/* Send the following packet to one random person who tells us they are connected to friend_id.
*
* return number of nodes the packet was sent to.
*/
static int routeone_tofriend(DHT *dht, const uint8_t *friend_id, const uint8_t *packet, uint16_t length)
{
const uint32_t num = index_of_friend_pk(dht->friends_list, dht->num_friends, friend_id);
if (num == UINT32_MAX) {
return 0;
}
const DHT_Friend *const dht_friend = &dht->friends_list[num];
IP_Port ip_list[MAX_FRIEND_CLIENTS * 2];
int n = 0;
/* extra legwork, because having the outside allocating the space for us
* is *usually* good(tm) (bites us in the behind in this case though) */
for (uint32_t i = 0; i < MAX_FRIEND_CLIENTS; ++i) {
const Client_data *const client = &dht_friend->client_list[i];
const IPPTsPng *const assocs[] = { &client->assoc4, &client->assoc6, nullptr };
for (const IPPTsPng * const *it = assocs; *it; ++it) {
const IPPTsPng *const assoc = *it;
/* If ip is not zero and node is good. */
if (ip_isset(&assoc->ret_ip_port.ip) && !is_timeout(assoc->ret_timestamp, BAD_NODE_TIMEOUT)) {
ip_list[n] = assoc->ip_port;
++n;
}
}
}
if (n < 1) {
return 0;
}
const int retval = sendpacket(dht->net, ip_list[rand() % n], packet, length);
if ((unsigned int)retval == length) {
return 1;
}
return 0;
}
/*----------------------------------------------------------------------------------*/
/*---------------------BEGINNING OF NAT PUNCHING FUNCTIONS--------------------------*/
static int send_NATping(DHT *dht, const uint8_t *public_key, uint64_t ping_id, uint8_t type)
{
uint8_t data[sizeof(uint64_t) + 1];
uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
int num = 0;
data[0] = type;
memcpy(data + 1, &ping_id, sizeof(uint64_t));
/* 254 is NAT ping request packet id */
const int len = create_request(
dht->self_public_key, dht->self_secret_key, packet, public_key, data,
sizeof(uint64_t) + 1, CRYPTO_PACKET_NAT_PING);
if (len == -1) {
return -1;
}
if (type == 0) { /* If packet is request use many people to route it. */
num = route_tofriend(dht, public_key, packet, len);
} else if (type == 1) { /* If packet is response use only one person to route it */
num = routeone_tofriend(dht, public_key, packet, len);
}
if (num == 0) {
return -1;
}
return num;
}
/* Handle a received ping request for. */
static int handle_NATping(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet,
uint16_t length, void *userdata)
{
if (length != sizeof(uint64_t) + 1) {
return 1;
}
DHT *const dht = (DHT *)object;
uint64_t ping_id;
memcpy(&ping_id, packet + 1, sizeof(uint64_t));
uint32_t friendnumber = index_of_friend_pk(dht->friends_list, dht->num_friends, source_pubkey);
if (friendnumber == UINT32_MAX) {
return 1;
}
DHT_Friend *const dht_friend = &dht->friends_list[friendnumber];
if (packet[0] == NAT_PING_REQUEST) {
/* 1 is reply */
send_NATping(dht, source_pubkey, ping_id, NAT_PING_RESPONSE);
dht_friend->nat.recv_nat_ping_timestamp = unix_time();
return 0;
}
if (packet[0] == NAT_PING_RESPONSE) {
if (dht_friend->nat.nat_ping_id == ping_id) {
dht_friend->nat.nat_ping_id = random_u64();
dht_friend->nat.hole_punching = 1;
return 0;
}
}
return 1;
}
/* 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;
ip_reset(&zero);
if (len > MAX_FRIEND_CLIENTS) {
return zero;
}
uint16_t numbers[MAX_FRIEND_CLIENTS] = {0};
for (uint32_t i = 0; i < len; ++i) {
for (uint32_t j = 0; j < len; ++j) {
if (ip_equal(&ip_portlist[i].ip, &ip_portlist[j].ip)) {
++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.
*
* return 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)
{
uint16_t num = 0;
for (uint32_t i = 0; i < len; ++i) {
if (ip_equal(&ip_portlist[i].ip, &ip)) {
portlist[num] = net_ntohs(ip_portlist[i].port);
++num;
}
}
return num;
}
static void punch_holes(DHT *dht, IP ip, uint16_t *port_list, uint16_t numports, uint16_t friend_num)
{
if (!dht->hole_punching_enabled) {
return;
}
if (numports > MAX_FRIEND_CLIENTS || numports == 0) {
return;
}
const uint16_t first_port = port_list[0];
uint32_t i;
for (i = 0; i < numports; ++i) {
if (first_port != port_list[i]) {
break;
}
}
if (i == numports) { /* If all ports are the same, only try that one port. */
IP_Port pinging;
ip_copy(&pinging.ip, &ip);
pinging.port = net_htons(first_port);
ping_send_request(dht->ping, pinging, dht->friends_list[friend_num].public_key);
} else {
for (i = 0; i < MAX_PUNCHING_PORTS; ++i) {
/* TODO(irungentoo): Improve port guessing algorithm. */
const uint32_t it = i + dht->friends_list[friend_num].nat.punching_index;
const int8_t sign = (it % 2) ? -1 : 1;
const uint32_t delta = sign * (it / (2 * numports));
const uint32_t index = (it / 2) % numports;
const uint16_t port = port_list[index] + delta;
IP_Port pinging;
ip_copy(&pinging.ip, &ip);
pinging.port = net_htons(port);
ping_send_request(dht->ping, pinging, dht->friends_list[friend_num].public_key);
}
dht->friends_list[friend_num].nat.punching_index += i;
}
if (dht->friends_list[friend_num].nat.tries > MAX_NORMAL_PUNCHING_TRIES) {
const uint16_t port = 1024;
IP_Port pinging;
ip_copy(&pinging.ip, &ip);
for (i = 0; i < MAX_PUNCHING_PORTS; ++i) {
uint32_t it = i + dht->friends_list[friend_num].nat.punching_index2;
pinging.port = net_htons(port + it);
ping_send_request(dht->ping, pinging, dht->friends_list[friend_num].public_key);
}
dht->friends_list[friend_num].nat.punching_index2 += i - (MAX_PUNCHING_PORTS / 2);
}
++dht->friends_list[friend_num].nat.tries;
}
static void do_NAT(DHT *dht)
{
const uint64_t temp_time = unix_time();
for (uint32_t i = 0; i < dht->num_friends; ++i) {
IP_Port ip_list[MAX_FRIEND_CLIENTS];
const int num = friend_iplist(dht, ip_list, i);
/* If already connected or friend is not online don't try to hole punch. */
if (num < MAX_FRIEND_CLIENTS / 2) {
continue;
}
if (dht->friends_list[i].nat.nat_ping_timestamp + PUNCH_INTERVAL < temp_time) {
send_NATping(dht, dht->friends_list[i].public_key, dht->friends_list[i].nat.nat_ping_id, NAT_PING_REQUEST);
dht->friends_list[i].nat.nat_ping_timestamp = temp_time;
}
if (dht->friends_list[i].nat.hole_punching == 1 &&
dht->friends_list[i].nat.punching_timestamp + PUNCH_INTERVAL < temp_time &&
dht->friends_list[i].nat.recv_nat_ping_timestamp + PUNCH_INTERVAL * 2 >= temp_time) {
const IP ip = nat_commonip(ip_list, num, MAX_FRIEND_CLIENTS / 2);
if (!ip_isset(&ip)) {
continue;
}
if (dht->friends_list[i].nat.punching_timestamp + PUNCH_RESET_TIME < temp_time) {
dht->friends_list[i].nat.tries = 0;
dht->friends_list[i].nat.punching_index = 0;
dht->friends_list[i].nat.punching_index2 = 0;
}
uint16_t port_list[MAX_FRIEND_CLIENTS];
const uint16_t numports = nat_getports(port_list, ip_list, num, ip);
punch_holes(dht, ip, port_list, numports, i);
dht->friends_list[i].nat.punching_timestamp = temp_time;
dht->friends_list[i].nat.hole_punching = 0;
}
}
}
/*----------------------------------------------------------------------------------*/
/*-----------------------END OF NAT PUNCHING FUNCTIONS------------------------------*/
#define DHT_HARDENING 0
#define HARDREQ_DATA_SIZE 384 // Attempt to prevent amplification/other attacks
typedef enum Check_Type {
CHECK_TYPE_ROUTE_REQ = 0,
CHECK_TYPE_ROUTE_RES = 1,
CHECK_TYPE_GETNODE_REQ = 2,
CHECK_TYPE_GETNODE_RES = 3,
CHECK_TYPE_TEST_REQ = 4,
CHECK_TYPE_TEST_RES = 5,
} Check_Type;
#if DHT_HARDENING
static int send_hardening_req(DHT *dht, Node_format *sendto, uint8_t type, uint8_t *contents, uint16_t length)
{
if (length > HARDREQ_DATA_SIZE - 1) {
return -1;
}
uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
uint8_t data[HARDREQ_DATA_SIZE] = {0};
data[0] = type;
memcpy(data + 1, contents, length);
const int len = create_request(
dht->self_public_key, dht->self_secret_key, packet, sendto->public_key,
data, sizeof(data), CRYPTO_PACKET_HARDENING);
if (len == -1) {
return -1;
}
return sendpacket(dht->net, sendto->ip_port, packet, len);
}
/* Send a get node hardening request */
static int send_hardening_getnode_req(DHT *dht, Node_format *dest, Node_format *node_totest, uint8_t *search_id)
{
uint8_t data[sizeof(Node_format) + CRYPTO_PUBLIC_KEY_SIZE];
memcpy(data, node_totest, sizeof(Node_format));
memcpy(data + sizeof(Node_format), search_id, CRYPTO_PUBLIC_KEY_SIZE);
return send_hardening_req(dht, dest, CHECK_TYPE_GETNODE_REQ, data, sizeof(Node_format) + CRYPTO_PUBLIC_KEY_SIZE);
}
#endif
/* Send a get node hardening response */
static int send_hardening_getnode_res(const DHT *dht, const Node_format *sendto, const uint8_t *queried_client_id,
const uint8_t *nodes_data, uint16_t nodes_data_length)
{
if (!ip_isset(&sendto->ip_port.ip)) {
return -1;
}
uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
VLA(uint8_t, data, 1 + CRYPTO_PUBLIC_KEY_SIZE + nodes_data_length);
data[0] = CHECK_TYPE_GETNODE_RES;
memcpy(data + 1, queried_client_id, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(data + 1 + CRYPTO_PUBLIC_KEY_SIZE, nodes_data, nodes_data_length);
const int len = create_request(
dht->self_public_key, dht->self_secret_key, packet, sendto->public_key,
data, SIZEOF_VLA(data), CRYPTO_PACKET_HARDENING);
if (len == -1) {
return -1;
}
return sendpacket(dht->net, sendto->ip_port, packet, len);
}
/* TODO(irungentoo): improve */
static IPPTsPng *get_closelist_IPPTsPng(DHT *dht, const uint8_t *public_key, Family sa_family)
{
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
if (!id_equal(dht->close_clientlist[i].public_key, public_key)) {
continue;
}
if (net_family_is_ipv4(sa_family)) {
return &dht->close_clientlist[i].assoc4;
}
if (net_family_is_ipv6(sa_family)) {
return &dht->close_clientlist[i].assoc6;
}
}
return nullptr;
}
/*
* check how many nodes in nodes are also present in the closelist.
* TODO(irungentoo): make this function better.
*/
static uint32_t have_nodes_closelist(DHT *dht, Node_format *nodes, uint16_t num)
{
uint32_t counter = 0;
for (uint32_t i = 0; i < num; ++i) {
if (id_equal(nodes[i].public_key, dht->self_public_key)) {
++counter;
continue;
}
const IPPTsPng *const temp = get_closelist_IPPTsPng(dht, nodes[i].public_key, nodes[i].ip_port.ip.family);
if (temp) {
if (!is_timeout(temp->timestamp, BAD_NODE_TIMEOUT)) {
++counter;
}
}
}
return counter;
}
/* Interval in seconds between hardening checks */
#define HARDENING_INTERVAL 120
/* Handle a received hardening packet */
static int handle_hardening(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet,
uint16_t length, void *userdata)
{
DHT *const dht = (DHT *)object;
if (length < 2) {
return 1;
}
switch (packet[0]) {
case CHECK_TYPE_GETNODE_REQ: {
if (length != HARDREQ_DATA_SIZE) {
return 1;
}
Node_format node, tocheck_node;
node.ip_port = source;
memcpy(node.public_key, source_pubkey, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(&tocheck_node, packet + 1, sizeof(Node_format));
if (getnodes(dht, tocheck_node.ip_port, tocheck_node.public_key, packet + 1 + sizeof(Node_format), &node) == -1) {
return 1;
}
return 0;
}
case CHECK_TYPE_GETNODE_RES: {
if (length <= CRYPTO_PUBLIC_KEY_SIZE + 1) {
return 1;
}
if (length > 1 + CRYPTO_PUBLIC_KEY_SIZE + sizeof(Node_format) * MAX_SENT_NODES) {
return 1;
}
uint16_t length_nodes = length - 1 - CRYPTO_PUBLIC_KEY_SIZE;
Node_format nodes[MAX_SENT_NODES];
const int num_nodes = unpack_nodes(nodes, MAX_SENT_NODES, nullptr, packet + 1 + CRYPTO_PUBLIC_KEY_SIZE,
length_nodes, 0);
/* TODO(irungentoo): MAX_SENT_NODES nodes should be returned at all times
(right now we have a small network size so it could cause problems for testing and etc..) */
if (num_nodes <= 0) {
return 1;
}
/* NOTE: This should work for now but should be changed to something better. */
if (have_nodes_closelist(dht, nodes, num_nodes) < (uint32_t)((num_nodes + 2) / 2)) {
return 1;
}
IPPTsPng *const temp = get_closelist_IPPTsPng(dht, packet + 1, nodes[0].ip_port.ip.family);
if (temp == nullptr) {
return 1;
}
if (is_timeout(temp->hardening.send_nodes_timestamp, HARDENING_INTERVAL)) {
return 1;
}
if (!id_equal(temp->hardening.send_nodes_pingedid, source_pubkey)) {
return 1;
}
/* If Nodes look good and the request checks out */
temp->hardening.send_nodes_ok = 1;
return 0;/* success*/
}
}
return 1;
}
#if DHT_HARDENING
#define HARDEN_TIMEOUT 1200
/* Return a random node from all the nodes we are connected to.
* TODO(irungentoo): improve this function.
*/
static Node_format random_node(DHT *dht, Family sa_family)
{
uint8_t id[CRYPTO_PUBLIC_KEY_SIZE];
for (uint32_t i = 0; i < CRYPTO_PUBLIC_KEY_SIZE / 4; ++i) { /* populate the id with pseudorandom bytes.*/
const uint32_t t = rand();
memcpy(id + i * sizeof(t), &t, sizeof(t));
}
Node_format nodes_list[MAX_SENT_NODES];
memset(nodes_list, 0, sizeof(nodes_list));
const uint32_t num_nodes = get_close_nodes(dht, id, nodes_list, sa_family, 1, 0);
if (num_nodes == 0) {
return nodes_list[0];
}
return nodes_list[rand() % num_nodes];
}
#endif
/* Put up to max_num nodes in nodes from the closelist.
*
* return the number of nodes.
*/
static uint16_t list_nodes(Client_data *list, size_t length, Node_format *nodes, uint16_t max_num)
{
if (max_num == 0) {
return 0;
}
uint16_t count = 0;
for (size_t i = length; i != 0; --i) {
const IPPTsPng *assoc = nullptr;
if (!is_timeout(list[i - 1].assoc4.timestamp, BAD_NODE_TIMEOUT)) {
assoc = &list[i - 1].assoc4;
}
if (!is_timeout(list[i - 1].assoc6.timestamp, BAD_NODE_TIMEOUT)) {
if (assoc == nullptr) {
assoc = &list[i - 1].assoc6;
} else if (rand() % 2) {
assoc = &list[i - 1].assoc6;
}
}
if (assoc != nullptr) {
memcpy(nodes[count].public_key, list[i - 1].public_key, CRYPTO_PUBLIC_KEY_SIZE);
nodes[count].ip_port = assoc->ip_port;
++count;
if (count >= max_num) {
return count;
}
}
}
return count;
}
/* Put up to max_num nodes in nodes from the random friends.
*
* return the number of nodes.
*/
uint16_t randfriends_nodes(DHT *dht, Node_format *nodes, uint16_t max_num)
{
if (max_num == 0) {
return 0;
}
uint16_t count = 0;
const unsigned int r = rand();
for (size_t i = 0; i < DHT_FAKE_FRIEND_NUMBER; ++i) {
count += list_nodes(dht->friends_list[(i + r) % DHT_FAKE_FRIEND_NUMBER].client_list, MAX_FRIEND_CLIENTS, nodes + count,
max_num - count);
if (count >= max_num) {
break;
}
}
return count;
}
/* Put up to max_num nodes in nodes from the closelist.
*
* return the number of nodes.
*/
uint16_t closelist_nodes(DHT *dht, Node_format *nodes, uint16_t max_num)
{
return list_nodes(dht->close_clientlist, LCLIENT_LIST, nodes, max_num);
}
#if DHT_HARDENING
static void do_hardening(DHT *dht)
{
for (uint32_t i = 0; i < LCLIENT_LIST * 2; ++i) {
IPPTsPng *cur_iptspng;
Family sa_family;
const uint8_t *const public_key = dht->close_clientlist[i / 2].public_key;
if (i % 2 == 0) {
cur_iptspng = &dht->close_clientlist[i / 2].assoc4;
sa_family = net_family_ipv4;
} else {
cur_iptspng = &dht->close_clientlist[i / 2].assoc6;
sa_family = net_family_ipv6;
}
if (is_timeout(cur_iptspng->timestamp, BAD_NODE_TIMEOUT)) {
continue;
}
if (cur_iptspng->hardening.send_nodes_ok == 0) {
if (is_timeout(cur_iptspng->hardening.send_nodes_timestamp, HARDENING_INTERVAL)) {
Node_format rand_node = random_node(dht, sa_family);
if (!ipport_isset(&rand_node.ip_port)) {
continue;
}
if (id_equal(public_key, rand_node.public_key)) {
continue;
}
Node_format to_test;
to_test.ip_port = cur_iptspng->ip_port;
memcpy(to_test.public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
// TODO(irungentoo): The search id should maybe not be ours?
if (send_hardening_getnode_req(dht, &rand_node, &to_test, dht->self_public_key) > 0) {
memcpy(cur_iptspng->hardening.send_nodes_pingedid, rand_node.public_key, CRYPTO_PUBLIC_KEY_SIZE);
cur_iptspng->hardening.send_nodes_timestamp = unix_time();
}
}
} else {
if (is_timeout(cur_iptspng->hardening.send_nodes_timestamp, HARDEN_TIMEOUT)) {
cur_iptspng->hardening.send_nodes_ok = 0;
}
}
// TODO(irungentoo): add the 2 other testers.
}
}
#endif
/*----------------------------------------------------------------------------------*/
void cryptopacket_registerhandler(DHT *dht, uint8_t byte, cryptopacket_handler_cb *cb, void *object)
{
dht->cryptopackethandlers[byte].function = cb;
dht->cryptopackethandlers[byte].object = object;
}
static int cryptopacket_handle(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
{
DHT *const dht = (DHT *)object;
assert(packet[0] == NET_PACKET_CRYPTO);
if (length <= CRYPTO_PUBLIC_KEY_SIZE * 2 + CRYPTO_NONCE_SIZE + 1 + CRYPTO_MAC_SIZE ||
length > MAX_CRYPTO_REQUEST_SIZE + CRYPTO_MAC_SIZE) {
return 1;
}
// Check if request is for us.
if (id_equal(packet + 1, dht->self_public_key)) {
uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE];
uint8_t data[MAX_CRYPTO_REQUEST_SIZE];
uint8_t number;
const int len = handle_request(dht->self_public_key, dht->self_secret_key, public_key,
data, &number, packet, length);
if (len == -1 || len == 0) {
return 1;
}
if (!dht->cryptopackethandlers[number].function) {
return 1;
}
return dht->cryptopackethandlers[number].function(
dht->cryptopackethandlers[number].object, source, public_key,
data, len, userdata);
}
/* If request is not for us, try routing it. */
const int retval = route_packet(dht, packet + 1, packet, length);
if ((unsigned int)retval == length) {
return 0;
}
return 1;
}
/*----------------------------------------------------------------------------------*/
DHT *new_dht(const Logger *log, Networking_Core *net, bool holepunching_enabled)
{
/* init time */
unix_time_update();
if (net == nullptr) {
return nullptr;
}
DHT *const dht = (DHT *)calloc(1, sizeof(DHT));
if (dht == nullptr) {
return nullptr;
}
dht->log = log;
dht->net = net;
dht->hole_punching_enabled = holepunching_enabled;
dht->ping = ping_new(dht);
if (dht->ping == nullptr) {
kill_dht(dht);
return nullptr;
}
networking_registerhandler(dht->net, NET_PACKET_GET_NODES, &handle_getnodes, dht);
networking_registerhandler(dht->net, NET_PACKET_SEND_NODES_IPV6, &handle_sendnodes_ipv6, dht);
networking_registerhandler(dht->net, NET_PACKET_CRYPTO, &cryptopacket_handle, dht);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_NAT_PING, &handle_NATping, dht);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_HARDENING, &handle_hardening, dht);
crypto_new_keypair(dht->self_public_key, dht->self_secret_key);
dht->dht_ping_array = ping_array_new(DHT_PING_ARRAY_SIZE, PING_TIMEOUT);
dht->dht_harden_ping_array = ping_array_new(DHT_PING_ARRAY_SIZE, PING_TIMEOUT);
for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER; ++i) {
uint8_t random_key_bytes[CRYPTO_PUBLIC_KEY_SIZE];
random_bytes(random_key_bytes, sizeof(random_key_bytes));
if (dht_addfriend(dht, random_key_bytes, nullptr, nullptr, 0, nullptr) != 0) {
kill_dht(dht);
return nullptr;
}
}
return dht;
}
void do_dht(DHT *dht)
{
unix_time_update();
if (dht->last_run == unix_time()) {
return;
}
// Load friends/clients if first call to do_dht
if (dht->loaded_num_nodes) {
dht_connect_after_load(dht);
}
do_Close(dht);
do_dht_friends(dht);
do_NAT(dht);
ping_iterate(dht->ping);
#if DHT_HARDENING
do_hardening(dht);
#endif
dht->last_run = unix_time();
}
void kill_dht(DHT *dht)
{
networking_registerhandler(dht->net, NET_PACKET_GET_NODES, nullptr, nullptr);
networking_registerhandler(dht->net, NET_PACKET_SEND_NODES_IPV6, nullptr, nullptr);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_NAT_PING, nullptr, nullptr);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_HARDENING, nullptr, nullptr);
ping_array_kill(dht->dht_ping_array);
ping_array_kill(dht->dht_harden_ping_array);
ping_kill(dht->ping);
free(dht->friends_list);
free(dht->loaded_nodes_list);
free(dht);
}
/* new DHT format for load/save, more robust and forward compatible */
// TODO(irungentoo): Move this closer to Messenger.
#define DHT_STATE_COOKIE_GLOBAL 0x159000d
#define DHT_STATE_COOKIE_TYPE 0x11ce
#define DHT_STATE_TYPE_NODES 4
#define MAX_SAVED_DHT_NODES (((DHT_FAKE_FRIEND_NUMBER * MAX_FRIEND_CLIENTS) + LCLIENT_LIST) * 2)
/* Get the size of the DHT (for saving). */
uint32_t dht_size(const DHT *dht)
{
uint32_t numv4 = 0;
uint32_t numv6 = 0;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
numv4 += (dht->close_clientlist[i].assoc4.timestamp != 0);
numv6 += (dht->close_clientlist[i].assoc6.timestamp != 0);
}
for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER && i < dht->num_friends; ++i) {
const DHT_Friend *const fr = &dht->friends_list[i];
for (uint32_t j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
numv4 += (fr->client_list[j].assoc4.timestamp != 0);
numv6 += (fr->client_list[j].assoc6.timestamp != 0);
}
}
const uint32_t size32 = sizeof(uint32_t);
const uint32_t sizesubhead = size32 * 2;
return size32 + sizesubhead + packed_node_size(net_family_ipv4) * numv4 + packed_node_size(net_family_ipv6) * numv6;
}
static uint8_t *dht_save_subheader(uint8_t *data, uint32_t len, uint16_t type)
{
host_to_lendian32(data, len);
data += sizeof(uint32_t);
host_to_lendian32(data, (host_tolendian16(DHT_STATE_COOKIE_TYPE) << 16) | host_tolendian16(type));
data += sizeof(uint32_t);
return data;
}
/* Save the DHT in data where data is an array of size dht_size(). */
void dht_save(const DHT *dht, uint8_t *data)
{
host_to_lendian32(data, DHT_STATE_COOKIE_GLOBAL);
data += sizeof(uint32_t);
uint8_t *const old_data = data;
/* get right offset. we write the actual header later. */
data = dht_save_subheader(data, 0, 0);
Node_format clients[MAX_SAVED_DHT_NODES];
uint32_t num = 0;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
if (dht->close_clientlist[i].assoc4.timestamp != 0) {
memcpy(clients[num].public_key, dht->close_clientlist[i].public_key, CRYPTO_PUBLIC_KEY_SIZE);
clients[num].ip_port = dht->close_clientlist[i].assoc4.ip_port;
++num;
}
if (dht->close_clientlist[i].assoc6.timestamp != 0) {
memcpy(clients[num].public_key, dht->close_clientlist[i].public_key, CRYPTO_PUBLIC_KEY_SIZE);
clients[num].ip_port = dht->close_clientlist[i].assoc6.ip_port;
++num;
}
}
for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER && i < dht->num_friends; ++i) {
const DHT_Friend *const fr = &dht->friends_list[i];
for (uint32_t j = 0; j < MAX_FRIEND_CLIENTS; ++j) {
if (fr->client_list[j].assoc4.timestamp != 0) {
memcpy(clients[num].public_key, fr->client_list[j].public_key, CRYPTO_PUBLIC_KEY_SIZE);
clients[num].ip_port = fr->client_list[j].assoc4.ip_port;
++num;
}
if (fr->client_list[j].assoc6.timestamp != 0) {
memcpy(clients[num].public_key, fr->client_list[j].public_key, CRYPTO_PUBLIC_KEY_SIZE);
clients[num].ip_port = fr->client_list[j].assoc6.ip_port;
++num;
}
}
}
dht_save_subheader(old_data, pack_nodes(data, sizeof(Node_format) * num, clients, num), DHT_STATE_TYPE_NODES);
}
/* Bootstrap from this number of nodes every time dht_connect_after_load() is called */
#define SAVE_BOOTSTAP_FREQUENCY 8
/* Start sending packets after DHT loaded_friends_list and loaded_clients_list are set */
int dht_connect_after_load(DHT *dht)
{
if (dht == nullptr) {
return -1;
}
if (!dht->loaded_nodes_list) {
return -1;
}
/* DHT is connected, stop. */
if (dht_non_lan_connected(dht)) {
free(dht->loaded_nodes_list);
dht->loaded_nodes_list = nullptr;
dht->loaded_num_nodes = 0;
return 0;
}
for (uint32_t i = 0; i < dht->loaded_num_nodes && i < SAVE_BOOTSTAP_FREQUENCY; ++i) {
const unsigned int index = dht->loaded_nodes_index % dht->loaded_num_nodes;
dht_bootstrap(dht, dht->loaded_nodes_list[index].ip_port, dht->loaded_nodes_list[index].public_key);
++dht->loaded_nodes_index;
}
return 0;
}
static State_Load_Status dht_load_state_callback(void *outer, const uint8_t *data, uint32_t length, uint16_t type)
{
DHT *dht = (DHT *)outer;
switch (type) {
case DHT_STATE_TYPE_NODES: {
if (length == 0) {
break;
}
free(dht->loaded_nodes_list);
// Copy to loaded_clients_list
dht->loaded_nodes_list = (Node_format *)calloc(MAX_SAVED_DHT_NODES, sizeof(Node_format));
const int num = unpack_nodes(dht->loaded_nodes_list, MAX_SAVED_DHT_NODES, nullptr, data, length, 0);
if (num > 0) {
dht->loaded_num_nodes = num;
} else {
dht->loaded_num_nodes = 0;
}
break;
}
default:
LOGGER_ERROR(dht->log, "Load state (DHT): contains unrecognized part (len %u, type %u)\n",
length, type);
break;
}
return STATE_LOAD_STATUS_CONTINUE;
}
/* Load the DHT from data of size size.
*
* return -1 if failure.
* return 0 if success.
*/
int dht_load(DHT *dht, const uint8_t *data, uint32_t length)
{
const uint32_t cookie_len = sizeof(uint32_t);
if (length > cookie_len) {
uint32_t data32;
lendian_to_host32(&data32, data);
if (data32 == DHT_STATE_COOKIE_GLOBAL) {
return state_load(dht->log, dht_load_state_callback, dht, data + cookie_len,
length - cookie_len, DHT_STATE_COOKIE_TYPE);
}
}
return -1;
}
/* return false if we are not connected to the DHT.
* return true if we are.
*/
bool dht_isconnected(const DHT *dht)
{
unix_time_update();
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = &dht->close_clientlist[i];
if (!is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT) ||
!is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT)) {
return true;
}
}
return false;
}
/* return false if we are not connected or only connected to lan peers with the DHT.
* return true if we are.
*/
bool dht_non_lan_connected(const DHT *dht)
{
unix_time_update();
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = &dht->close_clientlist[i];
if (!is_timeout(client->assoc4.timestamp, BAD_NODE_TIMEOUT) && ip_is_lan(client->assoc4.ip_port.ip) == -1) {
return true;
}
if (!is_timeout(client->assoc6.timestamp, BAD_NODE_TIMEOUT) && ip_is_lan(client->assoc6.ip_port.ip) == -1) {
return true;
}
}
return false;
}