toxcore/DHT.c
Rama master · réplica de lectura del repositorio original.
/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2016-2026 The TokTok team.
* Copyright © 2013 Tox project.
*/
/**
* An implementation of the DHT as seen in docs/updates/DHT.md
*/
#include "DHT.h"
#include <assert.h>
#include <string.h>
#include "LAN_discovery.h"
#include "attributes.h"
#include "bin_pack.h"
#include "ccompat.h"
#include "crypto_core.h"
#include "logger.h"
#include "mem.h"
#include "mono_time.h"
#include "network.h"
#include "ping.h"
#include "ping_array.h"
#include "shared_key_cache.h"
#include "sort.h"
#include "state.h"
/** 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 nodes request. */
#define NODES_REQUEST_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 node requests to send to quickly find close nodes. */
#define MAX_BOOTSTRAP_TIMES 5
// TODO(sudden6): find out why we need multiple callbacks and if we really need 32
#define DHT_FRIEND_MAX_LOCKS 32
/* Settings for the shared key cache */
#define MAX_KEYS_PER_SLOT 4
#define KEYS_TIMEOUT 600
typedef struct NAT {
/* true if currently hole punching */
bool hole_punching;
uint32_t punching_index;
uint32_t tries;
uint32_t punching_index2;
uint64_t punching_timestamp;
uint64_t recv_nat_ping_timestamp;
uint64_t nat_ping_id;
uint64_t nat_ping_timestamp;
} NAT;
typedef struct DHT_Friend_Callback {
dht_ip_cb *_Nullable ip_callback;
void *_Nullable 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 nodes request was sent. */
uint64_t last_nodes_request;
/* number of times nodes request packets were sent. */
uint32_t bootstrap_times;
/* Symmetric NAT hole punching stuff. */
NAT nat;
/* Each set bit represents one installed callback */
uint32_t lock_flags;
DHT_Friend_Callback callbacks[DHT_FRIEND_MAX_LOCKS];
Node_format to_bootstrap[MAX_SENT_NODES];
unsigned int num_to_bootstrap;
};
static const DHT_Friend empty_dht_friend = {{0}};
const Node_format empty_node_format = {{0}};
static_assert(sizeof(empty_dht_friend.lock_flags) * 8 == DHT_FRIEND_MAX_LOCKS, "Bitfield size and number of locks don't match");
typedef struct Cryptopacket_Handler {
cryptopacket_handler_cb *_Nullable function;
void *_Nullable object;
} Cryptopacket_Handler;
struct DHT {
const Logger *_Nonnull log;
const Network *_Nonnull ns;
Mono_Time *_Nonnull mono_time;
const Memory *_Nonnull mem;
const Random *_Nonnull rng;
Networking_Core *_Nonnull net;
bool hole_punching_enabled;
bool lan_discovery_enabled;
Client_data close_clientlist[LCLIENT_LIST];
uint64_t close_last_nodes_request;
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 *_Nullable friends_list;
uint16_t num_friends;
Node_format *_Nullable loaded_nodes_list;
uint32_t loaded_num_nodes;
unsigned int loaded_nodes_index;
Shared_Key_Cache *_Nonnull shared_keys_recv;
Shared_Key_Cache *_Nonnull shared_keys_sent;
struct Ping *_Nonnull ping;
Ping_Array *_Nonnull dht_ping_array;
uint64_t cur_time;
Cryptopacket_Handler cryptopackethandlers[256];
Node_format to_bootstrap[MAX_CLOSE_TO_BOOTSTRAP_NODES];
unsigned int num_to_bootstrap;
dht_nodes_response_cb *_Nullable nodes_response_callback;
};
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);
}
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;
}
static bool assoc_timeout(uint64_t cur_time, const IPPTsPng *_Nonnull assoc)
{
return (assoc->timestamp + BAD_NODE_TIMEOUT) <= cur_time;
}
/** @brief Converts an IPv4-in-IPv6 to IPv4 and returns the new IP_Port.
*
* If the ip_port is already IPv4 this function returns a copy of the original ip_port.
*/
static IP_Port ip_port_normalize(const IP_Port *_Nonnull ip_port)
{
IP_Port res = *ip_port;
if (net_family_is_ipv6(res.ip.family) && ipv6_ipv4_in_v6(&res.ip.ip.v6)) {
res.ip.family = net_family_ipv4();
res.ip.ip.v4.uint32 = res.ip.ip.v6.uint32[3];
}
return res;
}
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 between public keys pk1 and pk2. */
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;
}
/**
* Copy shared_key to encrypt/decrypt DHT packet from public_key into shared_key
* for packets that we receive.
*/
const uint8_t *dht_get_shared_key_recv(DHT *dht, const uint8_t *public_key)
{
return shared_key_cache_lookup(dht->shared_keys_recv, public_key);
}
/**
* Copy shared_key to encrypt/decrypt DHT packet from public_key into shared_key
* for packets that we send.
*/
const uint8_t *dht_get_shared_key_sent(DHT *dht, const uint8_t *public_key)
{
return shared_key_cache_lookup(dht->shared_keys_sent, public_key);
}
#define CRYPTO_SIZE (1 + CRYPTO_PUBLIC_KEY_SIZE * 2 + CRYPTO_NONCE_SIZE)
int create_request(const Memory *mem, const Random *rng, 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 data_length, uint8_t request_id)
{
if (send_public_key == nullptr || packet == nullptr || recv_public_key == nullptr || data == nullptr) {
return -1;
}
if (MAX_CRYPTO_REQUEST_SIZE < data_length + CRYPTO_SIZE + 1 + CRYPTO_MAC_SIZE) {
return -1;
}
uint8_t *const nonce = packet + 1 + CRYPTO_PUBLIC_KEY_SIZE * 2;
random_nonce(rng, nonce);
uint8_t temp[MAX_CRYPTO_REQUEST_SIZE] = {0};
temp[0] = request_id;
memcpy(temp + 1, data, data_length);
const int len = encrypt_data(mem, recv_public_key, send_secret_key, nonce, temp, data_length + 1,
packet + CRYPTO_SIZE);
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;
}
int handle_request(const Memory *mem, 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 packet_length)
{
if (self_public_key == nullptr || public_key == nullptr || data == nullptr || request_id == nullptr
|| packet == nullptr) {
return -1;
}
if (packet_length <= CRYPTO_SIZE + CRYPTO_MAC_SIZE || packet_length > MAX_CRYPTO_REQUEST_SIZE) {
return -1;
}
if (!pk_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];
int32_t len1 = decrypt_data(mem, public_key, self_secret_key, nonce,
packet + CRYPTO_SIZE, packet_length - CRYPTO_SIZE, temp);
if (len1 == -1 || len1 == 0) {
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return -1;
}
assert(len1 == packet_length - CRYPTO_SIZE - CRYPTO_MAC_SIZE);
// Because coverity can't figure out this equation:
assert(len1 <= MAX_CRYPTO_REQUEST_SIZE - CRYPTO_SIZE - CRYPTO_MAC_SIZE);
request_id[0] = temp[0];
--len1;
memcpy(data, temp + 1, len1);
crypto_memzero(temp, MAX_CRYPTO_REQUEST_SIZE);
return len1;
}
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;
}
int dht_create_packet(const Memory *mem, const Random *rng,
const uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE],
const uint8_t *shared_key, const uint8_t type,
const uint8_t *plain, size_t plain_length,
uint8_t *packet, size_t length)
{
uint8_t nonce[CRYPTO_NONCE_SIZE];
uint8_t *encrypted = (uint8_t *)mem_balloc(mem, plain_length + CRYPTO_MAC_SIZE);
if (encrypted == nullptr) {
return -1;
}
random_nonce(rng, nonce);
const int encrypted_length = encrypt_data_symmetric(mem, shared_key, nonce, plain, plain_length, encrypted);
if (encrypted_length < 0) {
mem_delete(mem, encrypted);
return -1;
}
if (length < 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + (size_t)encrypted_length) {
mem_delete(mem, encrypted);
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);
mem_delete(mem, encrypted);
return 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + encrypted_length;
}
/** @brief Pack a single node from a node array.
*
* @retval true on success.
*/
static bool bin_pack_node_handler(const void *_Nonnull arr, uint32_t index, const Logger *_Nonnull logger, Bin_Pack *_Nonnull bp)
{
const Node_format *nodes = (const Node_format *)arr;
return bin_pack_ip_port(bp, logger, &nodes[index].ip_port)
&& bin_pack_bin_b(bp, nodes[index].public_key, CRYPTO_PUBLIC_KEY_SIZE);
}
int pack_nodes(const Logger *logger, uint8_t *data, uint16_t length, const Node_format *nodes, uint16_t number)
{
const uint32_t size = bin_pack_obj_array_b_size(bin_pack_node_handler, nodes, number, logger);
if (!bin_pack_obj_array_b(bin_pack_node_handler, nodes, number, logger, data, length)) {
return -1;
}
return size;
}
int unpack_nodes(Node_format *nodes, uint16_t max_num_nodes, uint16_t *processed_data_len, const uint8_t *data,
uint16_t length, bool tcp_enabled)
{
if (nodes == nullptr && max_num_nodes > 0) {
return -1;
}
uint32_t num = 0;
uint32_t 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) {
break;
}
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;
#ifndef NDEBUG
const uint32_t increment = ipp_size + CRYPTO_PUBLIC_KEY_SIZE;
assert(increment == PACKED_NODE_SIZE_IP4 || increment == PACKED_NODE_SIZE_IP6);
#endif /* NDEBUG */
}
if (num == 0 && max_num_nodes > 0 && length > 0) {
return -1;
}
if (processed_data_len != nullptr) {
*processed_data_len = len_processed;
}
return num;
}
/** @brief Find index in an array with public_key equal to pk.
*
* @return index or UINT32_MAX if not found.
*/
static uint32_t index_of_client_pk(const Client_data *_Nullable array, uint32_t size, const uint8_t *_Nonnull pk)
{
assert(size == 0 || array != nullptr);
for (uint32_t i = 0; i < size; ++i) {
if (pk_equal(array[i].public_key, pk)) {
return i;
}
}
return UINT32_MAX;
}
static uint32_t index_of_friend_pk(const DHT_Friend *_Nullable array, uint32_t size, const uint8_t *_Nonnull pk)
{
assert(size == 0 || array != nullptr);
for (uint32_t i = 0; i < size; ++i) {
if (pk_equal(array[i].public_key, pk)) {
return i;
}
}
return UINT32_MAX;
}
static uint32_t index_of_node_pk(const Node_format *_Nullable array, uint32_t size, const uint8_t *_Nonnull pk)
{
assert(size == 0 || array != nullptr);
for (uint32_t i = 0; i < size; ++i) {
if (pk_equal(array[i].public_key, pk)) {
return i;
}
}
return UINT32_MAX;
}
/** @brief 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 *_Nullable array, uint32_t size, const IP_Port *_Nonnull ip_port)
{
assert(size == 0 || array != nullptr);
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 *_Nonnull log, const Mono_Time *_Nonnull mono_time, int index, Client_data *_Nonnull client, const IP_Port *_Nonnull 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)) {
Ip_Ntoa ip_str_from;
Ip_Ntoa ip_str_to;
LOGGER_TRACE(log, "coipil[%u]: switching ipv%d from %s:%u to %s:%u",
(unsigned int)index, ip_version,
net_ip_ntoa(&assoc->ip_port.ip, &ip_str_from),
net_ntohs(assoc->ip_port.port),
net_ip_ntoa(&ip_port->ip, &ip_str_to),
net_ntohs(ip_port->port));
}
if (!ip_is_lan(&assoc->ip_port.ip) && ip_is_lan(&ip_port->ip)) {
return;
}
assoc->ip_port = *ip_port;
assoc->timestamp = mono_time_get(mono_time);
}
/** @brief 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.
*/
static bool client_or_ip_port_in_list(const Logger *_Nonnull log, const Mono_Time *_Nonnull mono_time, Client_data *_Nonnull list, uint16_t length, const uint8_t *_Nonnull public_key,
const IP_Port *_Nonnull ip_port)
{
const uint64_t temp_time = mono_time_get(mono_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, mono_time, index, &list[index], ip_port);
return true;
}
/* 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 false;
}
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.
* We just updated `assoc` (which is either assoc4 or assoc6) with the new public_key.
* If there was an association for the other IP version, it's now invalid for this new identity.
*/
if (ip_version == 4) {
const IPPTsPng empty_ipptspng = {{{{0}}}};
list[index].assoc6 = empty_ipptspng;
} else {
const IPPTsPng empty_ipptspng = {{{{0}}}};
list[index].assoc4 = empty_ipptspng;
}
return true;
}
bool add_to_list(
Node_format *nodes_list, uint32_t length, const uint8_t pk[CRYPTO_PUBLIC_KEY_SIZE],
const IP_Port *ip_port, const uint8_t cmp_pk[CRYPTO_PUBLIC_KEY_SIZE])
{
uint8_t pk_cur[CRYPTO_PUBLIC_KEY_SIZE];
memcpy(pk_cur, pk, CRYPTO_PUBLIC_KEY_SIZE);
IP_Port ip_port_cur = *ip_port;
bool inserted = false;
for (uint32_t i = 0; i < length; ++i) {
Node_format *node = &nodes_list[i];
if (id_closest(cmp_pk, node->public_key, pk_cur) == 2) {
uint8_t pk_bak[CRYPTO_PUBLIC_KEY_SIZE];
memcpy(pk_bak, node->public_key, CRYPTO_PUBLIC_KEY_SIZE);
const IP_Port ip_port_bak = node->ip_port;
memcpy(node->public_key, pk_cur, CRYPTO_PUBLIC_KEY_SIZE);
node->ip_port = ip_port_cur;
memcpy(pk_cur, pk_bak, CRYPTO_PUBLIC_KEY_SIZE);
ip_port_cur = ip_port_bak;
inserted = true;
}
}
return inserted;
}
/**
* helper for `get_close_nodes()`. argument list is a monster :D
*/
static void get_close_nodes_inner(uint64_t cur_time, const uint8_t *_Nonnull public_key, Node_format *_Nonnull nodes_list, uint32_t *_Nonnull num_nodes_ptr, Family sa_family,
const Client_data *_Nonnull client_list, uint32_t client_list_length, bool is_lan, bool want_announce)
{
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];
const IPPTsPng *ipptp;
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 (assoc_timeout(cur_time, ipptp)) {
continue;
}
/* don't send LAN ips to non LAN peers */
if (ip_is_lan(&ipptp->ip_port.ip) && !is_lan) {
continue;
}
#ifdef CHECK_ANNOUNCE_NODE
if (want_announce && !client->announce_node) {
continue;
}
#endif /* CHECK_ANNOUNCE_NODE */
/* node already in list? */
if (index_of_node_pk(nodes_list, num_nodes, client->public_key) != UINT32_MAX) {
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 {
// TODO(zugz): this could be made significantly more efficient by
// using a version of add_to_list which works with a sorted list.
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 nodes request:
* put them in the nodes_list and return how many were found.
*
* want_announce: return only nodes which implement the dht announcements protocol.
*/
static int get_somewhat_close_nodes(uint64_t cur_time, const uint8_t *_Nonnull public_key, Node_format nodes_list[_Nonnull MAX_SENT_NODES], Family sa_family,
const Client_data *_Nonnull close_clientlist, const DHT_Friend *_Nonnull friends_list, uint16_t friends_list_size, bool is_lan, bool want_announce)
{
for (uint16_t i = 0; i < MAX_SENT_NODES; ++i) {
nodes_list[i] = empty_node_format;
}
uint32_t num_nodes = 0;
get_close_nodes_inner(
cur_time, public_key,
nodes_list, &num_nodes,
sa_family, close_clientlist, LCLIENT_LIST,
is_lan, want_announce);
for (uint16_t i = 0; i < friends_list_size; ++i) {
const DHT_Friend *dht_friend = &friends_list[i];
get_close_nodes_inner(
cur_time, public_key,
nodes_list, &num_nodes,
sa_family, dht_friend->client_list, MAX_FRIEND_CLIENTS,
is_lan, want_announce);
}
return num_nodes;
}
int get_close_nodes(
const DHT *dht, const uint8_t *public_key,
Node_format nodes_list[MAX_SENT_NODES], Family sa_family,
bool is_lan, bool want_announce)
{
return get_somewhat_close_nodes(
dht->cur_time, public_key, nodes_list,
sa_family, dht->close_clientlist,
dht->friends_list, dht->num_friends,
is_lan, want_announce);
}
#ifdef CHECK_ANNOUNCE_NODE
static void set_announce_node_in_list(Client_data *_Nonnull list, uint32_t list_len, const uint8_t *_Nonnull public_key)
{
const uint32_t index = index_of_client_pk(list, list_len, public_key);
if (index != UINT32_MAX) {
list[index].announce_node = true;
}
}
void set_announce_node(DHT *dht, const uint8_t *public_key)
{
unsigned int index = bit_by_bit_cmp(public_key, dht->self_public_key);
if (index >= LCLIENT_LENGTH) {
index = LCLIENT_LENGTH - 1;
}
set_announce_node_in_list(dht->close_clientlist + index * LCLIENT_NODES, LCLIENT_NODES, public_key);
for (int32_t i = 0; i < dht->num_friends; ++i) {
set_announce_node_in_list(dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS, public_key);
}
}
/** @brief Send data search request, searching for a random key. */
static bool send_announce_ping(DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull ip_port)
{
uint8_t plain[CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint64_t)];
uint8_t unused_secret_key[CRYPTO_SECRET_KEY_SIZE];
crypto_new_keypair(dht->rng, plain, unused_secret_key);
const uint64_t ping_id = ping_array_add(dht->dht_ping_array,
dht->mono_time,
dht->rng,
public_key, CRYPTO_PUBLIC_KEY_SIZE);
memcpy(plain + CRYPTO_PUBLIC_KEY_SIZE, &ping_id, sizeof(ping_id));
const uint8_t *shared_key = dht_get_shared_key_sent(dht, public_key);
uint8_t request[1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + sizeof(plain) + CRYPTO_MAC_SIZE];
if (dht_create_packet(dht->mem, dht->rng,
dht->self_public_key, shared_key, NET_PACKET_DATA_SEARCH_REQUEST,
plain, sizeof(plain), request, sizeof(request)) != sizeof(request)) {
return false;
}
return sendpacket(dht->net, ip_port, request, sizeof(request)) == sizeof(request);
}
/** @brief If the response is valid, set the sender as an announce node. */
static int handle_data_search_response(void *_Nonnull object, const IP_Port *_Nonnull source,
const uint8_t *_Nonnull packet, uint16_t length,
void *_Nullable userdata)
{
DHT *dht = (DHT *) object;
const int32_t plain_len = (int32_t)length - (1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_MAC_SIZE);
if (plain_len < (int32_t)(CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint64_t))) {
return 1;
}
VLA(uint8_t, plain, plain_len);
const uint8_t *public_key = packet + 1;
const uint8_t *shared_key = dht_get_shared_key_recv(dht, public_key);
if (decrypt_data_symmetric(dht->mem, shared_key,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE,
packet + 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE,
plain_len + CRYPTO_MAC_SIZE,
plain) != plain_len) {
return 1;
}
uint64_t ping_id;
memcpy(&ping_id, plain + (plain_len - sizeof(uint64_t)), sizeof(ping_id));
uint8_t ping_data[CRYPTO_PUBLIC_KEY_SIZE];
if (ping_array_check(dht->dht_ping_array,
dht->mono_time, ping_data,
sizeof(ping_data), ping_id) != sizeof(ping_data)) {
return 1;
}
if (!pk_equal(ping_data, public_key)) {
return 1;
}
set_announce_node(dht, public_key);
return 0;
}
#endif /* CHECK_ANNOUNCE_NODE */
/** @brief Is it ok to store node with public_key in client.
*
* return false if node can't be stored.
* return true if it can.
*/
static bool store_node_ok(const Client_data *_Nonnull client, uint64_t cur_time, const uint8_t *_Nonnull public_key, const uint8_t *_Nonnull comp_public_key)
{
return (assoc_timeout(cur_time, &client->assoc4)
&& assoc_timeout(cur_time, &client->assoc6))
|| id_closest(comp_public_key, client->public_key, public_key) == 2;
}
typedef struct Client_data_Cmp {
const Memory *_Nonnull mem;
uint64_t cur_time;
const uint8_t *_Nonnull comp_public_key;
} Client_data_Cmp;
static int client_data_cmp(const Client_data_Cmp *_Nonnull cmp, const Client_data *_Nonnull entry1, const Client_data *_Nonnull entry2)
{
const bool t1 = assoc_timeout(cmp->cur_time, &entry1->assoc4) && assoc_timeout(cmp->cur_time, &entry1->assoc6);
const bool t2 = assoc_timeout(cmp->cur_time, &entry2->assoc4) && assoc_timeout(cmp->cur_time, &entry2->assoc6);
if (t1 && t2) {
return 0;
}
if (t1) {
return -1;
}
if (t2) {
return 1;
}
const int closest = id_closest(cmp->comp_public_key, entry1->public_key, entry2->public_key);
if (closest == 1) {
return 1;
}
if (closest == 2) {
return -1;
}
return 0;
}
static bool client_data_less_handler(const void *_Nonnull object, const void *_Nonnull a, const void *_Nonnull b)
{
const Client_data_Cmp *cmp = (const Client_data_Cmp *)object;
const Client_data *entry1 = (const Client_data *)a;
const Client_data *entry2 = (const Client_data *)b;
return client_data_cmp(cmp, entry1, entry2) < 0;
}
static const void *_Nonnull client_data_get_handler(const void *_Nonnull arr, uint32_t index)
{
const Client_data *entries = (const Client_data *)arr;
return &entries[index];
}
static void client_data_set_handler(void *_Nonnull arr, uint32_t index, const void *_Nonnull val)
{
Client_data *entries = (Client_data *)arr;
const Client_data *entry = (const Client_data *)val;
entries[index] = *entry;
}
static void *_Nonnull client_data_subarr_handler(void *_Nonnull arr, uint32_t index, uint32_t size)
{
Client_data *entries = (Client_data *)arr;
return &entries[index];
}
static void *_Nullable client_data_alloc_handler(const void *_Nonnull object, uint32_t size)
{
const Client_data_Cmp *cmp = (const Client_data_Cmp *)object;
Client_data *tmp = (Client_data *)mem_valloc(cmp->mem, size, sizeof(Client_data));
if (tmp == nullptr) {
return nullptr;
}
return tmp;
}
static void client_data_delete_handler(const void *_Nonnull object, void *_Nonnull arr, uint32_t size)
{
const Client_data_Cmp *cmp = (const Client_data_Cmp *)object;
mem_delete(cmp->mem, arr);
}
static const Sort_Funcs client_data_cmp_funcs = {
client_data_less_handler,
client_data_get_handler,
client_data_set_handler,
client_data_subarr_handler,
client_data_alloc_handler,
client_data_delete_handler,
};
static void sort_client_list(const Memory *_Nonnull mem, Client_data *_Nonnull list, uint64_t cur_time, unsigned int length, const uint8_t *_Nonnull comp_public_key)
{
// Pass comp_public_key to merge_sort with each Client_data entry, so the
// comparison function can use it as the base of comparison.
const Client_data_Cmp cmp = {
mem,
cur_time,
comp_public_key,
};
merge_sort(list, length, &cmp, &client_data_cmp_funcs);
}
static void update_client_with_reset(const Mono_Time *_Nonnull mono_time, Client_data *_Nonnull client, const IP_Port *_Nonnull 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 = mono_time_get(mono_time);
ip_reset(&ipptp_write->ret_ip_port.ip);
ipptp_write->ret_ip_port.port = 0;
ipptp_write->ret_timestamp = 0;
ipptp_write->ret_ip_self = false;
/* zero out other address */
const IPPTsPng empty_ipptp = {{{{0}}}};
*ipptp_clear = empty_ipptp;
}
/**
* 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.
*
* @return true when the item was stored, false otherwise
*/
static bool replace_all(const DHT *_Nonnull dht, Client_data *_Nonnull list, uint16_t length, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull ip_port,
const uint8_t *_Nonnull 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], dht->cur_time, public_key, comp_public_key) &&
!store_node_ok(&list[0], dht->cur_time, public_key, comp_public_key)) {
return false;
}
sort_client_list(dht->mem, list, dht->cur_time, length, comp_public_key);
Client_data *const client = &list[0];
pk_copy(client->public_key, public_key);
update_client_with_reset(dht->mono_time, client, ip_port);
return true;
}
/** @brief 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 false on failure.
* return true on success.
*/
static bool add_to_close(DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull 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 (!assoc_timeout(dht->cur_time, &client->assoc4) ||
!assoc_timeout(dht->cur_time, &client->assoc6)) {
continue;
}
if (simulate) {
return true;
}
pk_copy(client->public_key, public_key);
update_client_with_reset(dht->mono_time, client, ip_port);
#ifdef CHECK_ANNOUNCE_NODE
client->announce_node = false;
send_announce_ping(dht, public_key, ip_port);
#endif /* CHECK_ANNOUNCE_NODE */
return true;
}
return false;
}
/** 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, const IP_Port *ip_port)
{
return add_to_close(dht, public_key, ip_port, true);
}
static bool is_pk_in_client_list(const Client_data *_Nonnull list, unsigned int client_list_length, uint64_t cur_time, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull ip_port)
{
const uint32_t index = index_of_client_pk(list, client_list_length, public_key);
if (index == UINT32_MAX) {
return false;
}
const IPPTsPng *assoc = net_family_is_ipv4(ip_port->ip.family)
? &list[index].assoc4
: &list[index].assoc6;
return !assoc_timeout(cur_time, assoc);
}
static bool is_pk_in_close_list(const DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull 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, dht->cur_time, public_key,
ip_port);
}
/** @brief Check if the node obtained from a nodes response 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_nodes_response_ok(DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull ip_port)
{
bool ret = false;
if (add_to_close(dht, public_key, ip_port, true)) {
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], dht->cur_time, public_key, dht_friend->public_key)) {
store_ok = true;
}
if (store_node_ok(&dht_friend->client_list[0], dht->cur_time, 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, dht->cur_time, 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;
}
/** @brief Attempt to add client with ip_port and public_key to the friends client list
* and close_clientlist.
*
* @return 1+ if the item is used in any list, 0 else
*/
uint32_t addto_lists(DHT *dht, const IP_Port *ip_port, const uint8_t *public_key)
{
const IP_Port ipp_copy = ip_port_normalize(ip_port);
uint32_t used = 0;
/* 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->mono_time, dht->close_clientlist, LCLIENT_LIST,
public_key, &ipp_copy);
/* 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, &ipp_copy, false)) {
++used;
}
const 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->mono_time, dht->friends_list[i].client_list,
MAX_FRIEND_CLIENTS, public_key, &ipp_copy);
/* replace_all should be called only if !in_list (don't extract to variable) */
if (in_list
|| replace_all(dht, dht->friends_list[i].client_list, MAX_FRIEND_CLIENTS, public_key, &ipp_copy,
dht->friends_list[i].public_key)) {
const DHT_Friend *dht_friend = &dht->friends_list[i];
if (pk_equal(public_key, dht_friend->public_key)) {
friend_foundip = dht_friend;
}
++used;
}
}
if (friend_foundip == nullptr) {
return used;
}
for (uint32_t i = 0; i < DHT_FRIEND_MAX_LOCKS; ++i) {
const bool has_lock = (friend_foundip->lock_flags & (UINT32_C(1) << i)) > 0;
if (has_lock && friend_foundip->callbacks[i].ip_callback != nullptr) {
friend_foundip->callbacks[i].ip_callback(friend_foundip->callbacks[i].data,
friend_foundip->callbacks[i].number, &ipp_copy);
}
}
return used;
}
static bool update_client_data(const Mono_Time *_Nonnull mono_time, Client_data *_Nonnull array, size_t size, const IP_Port *_Nonnull ip_port, const uint8_t *_Nonnull pk, bool node_is_self)
{
const uint64_t temp_time = mono_time_get(mono_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;
assoc->ret_ip_self = node_is_self;
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 *_Nonnull dht, const IP_Port *_Nonnull ip_port, const uint8_t *_Nonnull public_key, const uint8_t *_Nonnull nodepublic_key)
{
const IP_Port ipp_copy = ip_port_normalize(ip_port);
if (pk_equal(public_key, dht->self_public_key)) {
update_client_data(dht->mono_time, dht->close_clientlist, LCLIENT_LIST, &ipp_copy, nodepublic_key, true);
return;
}
for (uint32_t i = 0; i < dht->num_friends; ++i) {
if (pk_equal(public_key, dht->friends_list[i].public_key)) {
Client_data *const client_list = dht->friends_list[i].client_list;
if (update_client_data(dht->mono_time, client_list, MAX_FRIEND_CLIENTS, &ipp_copy, nodepublic_key, false)) {
return;
}
}
}
}
bool dht_send_nodes_request(DHT *dht, const IP_Port *ip_port, const uint8_t *public_key, const uint8_t *client_id)
{
/* Check if packet is going to be sent to ourself. */
if (pk_equal(public_key, dht->self_public_key)) {
return false;
}
uint8_t plain_message[PACKED_NODE_SIZE_IP6];
Node_format receiver;
memcpy(receiver.public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
receiver.ip_port = *ip_port;
/* Avoid warning message when IPv6 is disabled and node address is IPv6. */
if (!net_socket_family_compatible(dht->net, ip_port, false)) {
return false;
}
const int plain_length = pack_nodes(dht->log, plain_message, sizeof(plain_message), &receiver, 1);
if (plain_length == -1) {
return false;
}
uint64_t ping_id = 0;
ping_id = ping_array_add(dht->dht_ping_array, dht->mono_time, dht->rng, plain_message, plain_length);
if (ping_id == 0) {
LOGGER_ERROR(dht->log, "adding ping id failed");
return false;
}
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));
const uint8_t *shared_key = dht_get_shared_key_sent(dht, public_key);
const int len = dht_create_packet(dht->mem, dht->rng,
dht->self_public_key, shared_key, NET_PACKET_NODES_REQUEST,
plain, sizeof(plain), data, sizeof(data));
if (len != sizeof(data)) {
LOGGER_ERROR(dht->log, "nodes request packet encryption failed");
return false;
}
return sendpacket(dht->net, ip_port, data, len) > 0;
}
/** Send a nodes response */
static int send_nodes_response(const DHT *_Nonnull dht, const IP_Port *_Nonnull ip_port, const uint8_t *_Nonnull public_key, const uint8_t *_Nonnull client_id,
const uint8_t *_Nonnull sendback_data, uint16_t length, const uint8_t *_Nonnull shared_encryption_key)
{
/* Check if packet is going to be sent to ourself. */
if (pk_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), false);
VLA(uint8_t, plain, 1 + node_format_size * MAX_SENT_NODES + length);
int nodes_length = 0;
if (num_nodes > 0) {
nodes_length = pack_nodes(dht->log, 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 uint16_t crypto_size = 1 + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE + CRYPTO_MAC_SIZE;
const uint16_t data_size = 1 + nodes_length + length + crypto_size;
VLA(uint8_t, data, data_size);
const int len = dht_create_packet(dht->mem, dht->rng,
dht->self_public_key, shared_encryption_key, NET_PACKET_NODES_RESPONSE,
plain, 1 + nodes_length + length, data, data_size);
if (len < 0 || (uint32_t)len != data_size) {
return -1;
}
return sendpacket(dht->net, ip_port, data, len);
}
#define CRYPTO_NODE_SIZE (CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint64_t))
static int handle_nodes_request(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, void *_Nonnull userdata)
{
DHT *const dht = (DHT *)object;
if (length != (CRYPTO_SIZE + CRYPTO_MAC_SIZE + sizeof(uint64_t))) {
return 1;
}
/* Check if packet is from ourself. */
if (pk_equal(packet + 1, dht->self_public_key)) {
return 1;
}
uint8_t plain[CRYPTO_NODE_SIZE];
const uint8_t *shared_key = dht_get_shared_key_recv(dht, packet + 1);
const int len = decrypt_data_symmetric(
dht->mem,
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 1;
}
send_nodes_response(dht, source, packet + 1, plain, plain + CRYPTO_PUBLIC_KEY_SIZE, sizeof(uint64_t), shared_key);
ping_add(dht->ping, packet + 1, source);
return 0;
}
/** Return true if we sent a nodes request packet to the peer associated with the supplied info. */
static bool sent_nodes_request_to_node(DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, const IP_Port *_Nonnull node_ip_port, uint64_t ping_id)
{
uint8_t data[PACKED_NODE_SIZE_IP6];
const int32_t length = ping_array_check(dht->dht_ping_array, dht->mono_time, data, sizeof(data), ping_id);
if (length == -1) {
return false;
}
Node_format test;
if (unpack_nodes(&test, 1, nullptr, data, length, false) != 1) {
return false;
}
return ipport_equal(&test.ip_port, node_ip_port) && pk_equal(test.public_key, public_key);
}
static bool handle_nodes_response_core(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, Node_format *_Nonnull plain_nodes,
uint16_t size_plain_nodes, uint32_t *_Nonnull 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 false;
}
const uint32_t data_size = length - cid_size;
if (data_size == 0) {
return false;
}
if (data_size > sizeof(Node_format) * MAX_SENT_NODES) { /* invalid length */
return false;
}
const uint32_t plain_size = 1 + data_size + sizeof(uint64_t);
VLA(uint8_t, plain, plain_size);
const uint8_t *shared_key = dht_get_shared_key_sent(dht, packet + 1);
const int len = decrypt_data_symmetric(
dht->mem,
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 ((uint32_t)len != plain_size) {
return false;
}
if (plain[0] > size_plain_nodes) {
return false;
}
uint64_t ping_id;
memcpy(&ping_id, plain + 1 + data_size, sizeof(ping_id));
if (!sent_nodes_request_to_node(dht, packet + 1, source, ping_id)) {
return false;
}
uint16_t length_nodes = 0;
const int num_nodes = unpack_nodes(plain_nodes, plain[0], &length_nodes, plain + 1, data_size, false);
if (length_nodes != data_size) {
return false;
}
if (num_nodes != plain[0]) {
return false;
}
if (num_nodes < 0) {
return false;
}
/* store the address the *request* was sent to */
addto_lists(dht, source, packet + 1);
*num_nodes_out = num_nodes;
return true;
}
static int handle_nodes_response(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, void *_Nonnull userdata)
{
DHT *const dht = (DHT *)object;
Node_format plain_nodes[MAX_SENT_NODES];
uint32_t num_nodes;
if (!handle_nodes_response_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_nodes_response_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);
if (dht->nodes_response_callback != nullptr) {
dht->nodes_response_callback(dht, &plain_nodes[i], userdata);
}
}
}
return 0;
}
/*----------------------------------------------------------------------------------*/
/*------------------------END of packet handling functions--------------------------*/
static uint32_t dht_friend_lock(DHT_Friend *_Nonnull dht_friend, dht_ip_cb *_Nullable ip_callback,
void *_Nullable data, int32_t number)
{
// find first free slot
uint8_t lock_num;
uint32_t lock_token = 0;
for (lock_num = 0; lock_num < DHT_FRIEND_MAX_LOCKS; ++lock_num) {
lock_token = UINT32_C(1) << lock_num;
if ((dht_friend->lock_flags & lock_token) == 0) {
break;
}
}
// One of the conditions would be enough, but static analyzers don't get that
if (lock_token == 0 || lock_num == DHT_FRIEND_MAX_LOCKS) {
return 0;
}
// Claim that slot
dht_friend->lock_flags |= lock_token;
dht_friend->callbacks[lock_num].ip_callback = ip_callback;
dht_friend->callbacks[lock_num].data = data;
dht_friend->callbacks[lock_num].number = number;
return lock_token;
}
static void dht_friend_unlock(DHT_Friend *_Nonnull dht_friend, uint32_t lock_token)
{
// If this triggers, there was a double free
assert((lock_token & dht_friend->lock_flags) > 0);
// find used slot
uint8_t lock_num;
for (lock_num = 0; lock_num < DHT_FRIEND_MAX_LOCKS; ++lock_num) {
if (((UINT32_C(1) << lock_num) & lock_token) > 0) {
break;
}
}
if (lock_num == DHT_FRIEND_MAX_LOCKS) {
// Gracefully handle double unlock
return;
}
// Clear the slot
dht_friend->lock_flags &= ~lock_token;
dht_friend->callbacks[lock_num].ip_callback = nullptr;
dht_friend->callbacks[lock_num].data = nullptr;
dht_friend->callbacks[lock_num].number = 0;
}
int dht_addfriend(DHT *dht, const uint8_t *public_key, dht_ip_cb *ip_callback,
void *data, int32_t number, uint32_t *lock_token)
{
const uint32_t friend_num = index_of_friend_pk(dht->friends_list, dht->num_friends, public_key);
if (friend_num != UINT32_MAX) { /* Is friend already in DHT? */
DHT_Friend *const dht_friend = &dht->friends_list[friend_num];
const uint32_t tmp_lock_token = dht_friend_lock(dht_friend, ip_callback, data, number);
if (tmp_lock_token == 0) {
return -1;
}
return 0;
}
DHT_Friend *const temp = (DHT_Friend *)mem_vrealloc(dht->mem, dht->friends_list, dht->num_friends + 1, sizeof(DHT_Friend));
if (temp == nullptr) {
return -1;
}
dht->friends_list = temp;
DHT_Friend *const dht_friend = &dht->friends_list[dht->num_friends];
*dht_friend = empty_dht_friend;
memcpy(dht_friend->public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
dht_friend->nat.nat_ping_id = random_u64(dht->rng);
++dht->num_friends;
*lock_token = dht_friend_lock(dht_friend, ip_callback, data, number);
assert(*lock_token != 0); // Friend was newly allocated
dht_friend->num_to_bootstrap = get_close_nodes(dht, dht_friend->public_key, dht_friend->to_bootstrap, net_family_unspec(),
true, false);
return 0;
}
int dht_delfriend(DHT *dht, const uint8_t *public_key, uint32_t lock_token)
{
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_unlock(dht_friend, lock_token);
if (dht_friend->lock_flags > 0) {
/* DHT friend is still in use.*/
return 0;
}
--dht->num_friends;
if (dht->num_friends != friend_num) {
dht->friends_list[friend_num] = dht->friends_list[dht->num_friends];
}
if (dht->num_friends == 0) {
mem_delete(dht->mem, dht->friends_list);
dht->friends_list = nullptr;
return 0;
}
DHT_Friend *const temp = (DHT_Friend *)mem_vrealloc(dht->mem, dht->friends_list, dht->num_friends, sizeof(DHT_Friend));
if (temp != nullptr) {
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;
}
const 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 == UINT32_MAX) {
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 != nullptr; ++it) {
const IPPTsPng *const assoc = *it;
if (!assoc_timeout(dht->cur_time, assoc)) {
*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 *_Nonnull dht, uint64_t *_Nonnull lastgetnode, const uint8_t *_Nonnull public_key, Client_data *_Nonnull list, uint32_t list_count,
uint32_t *_Nonnull bootstrap_times, bool sortable)
{
uint8_t not_kill = 0;
const uint64_t temp_time = mono_time_get(dht->mono_time);
uint32_t num_nodes = 0;
Client_data **client_list = (Client_data **)mem_valloc(dht->mem, list_count * 2, sizeof(Client_data *));
IPPTsPng **assoc_list = (IPPTsPng **)mem_valloc(dht->mem, list_count * 2, sizeof(IPPTsPng *));
unsigned int sort = 0;
bool sort_ok = false;
if (client_list == nullptr || assoc_list == nullptr) {
mem_delete(dht->mem, assoc_list);
mem_delete(dht->mem, client_list);
return 0;
}
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 };
for (uint32_t j = 0; j < sizeof(assocs) / sizeof(assocs[0]); ++j) {
IPPTsPng *const assoc = assocs[j];
if (!mono_time_is_timeout(dht->mono_time, assoc->timestamp, KILL_NODE_TIMEOUT)) {
sort = 0;
++not_kill;
if (mono_time_is_timeout(dht->mono_time, assoc->last_pinged, PING_INTERVAL)) {
const IP_Port *target = &assoc->ip_port;
const uint8_t *target_key = client->public_key;
dht_send_nodes_request(dht, target, target_key, public_key);
assoc->last_pinged = temp_time;
}
/* If node is good. */
if (!assoc_timeout(dht->cur_time, assoc)) {
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(dht->mem, list, dht->cur_time, list_count, public_key);
}
if (num_nodes > 0 && (mono_time_is_timeout(dht->mono_time, *lastgetnode, NODES_REQUEST_INTERVAL)
|| *bootstrap_times < MAX_BOOTSTRAP_TIMES)) {
uint32_t rand_node = random_range_u32(dht->rng, num_nodes);
if ((num_nodes - 1) != rand_node) {
rand_node += random_range_u32(dht->rng, num_nodes - (rand_node + 1));
}
const IP_Port *target = &assoc_list[rand_node]->ip_port;
const uint8_t *target_key = client_list[rand_node]->public_key;
dht_send_nodes_request(dht, target, target_key, public_key);
*lastgetnode = temp_time;
++*bootstrap_times;
}
mem_delete(dht->mem, assoc_list);
mem_delete(dht->mem, client_list);
return not_kill;
}
/** @brief Ping each client in the "friends" list every PING_INTERVAL seconds.
*
* Send a nodes request every NODES_REQUEST_INTERVAL seconds to a random good
* node for each "friend" in our "friends" list.
*/
static void do_dht_friends(DHT *_Nonnull 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) {
dht_send_nodes_request(dht, &dht_friend->to_bootstrap[j].ip_port, dht_friend->to_bootstrap[j].public_key, dht_friend->public_key);
}
dht_friend->num_to_bootstrap = 0;
do_ping_and_sendnode_requests(dht, &dht_friend->last_nodes_request, dht_friend->public_key, dht_friend->client_list,
MAX_FRIEND_CLIENTS, &dht_friend->bootstrap_times, true);
}
}
/** @brief Ping each client in the close nodes list every PING_INTERVAL seconds.
*
* Send a nodes request every NODES_REQUEST_INTERVAL seconds to a random good node in the list.
*/
static void do_close(DHT *_Nonnull dht)
{
for (size_t i = 0; i < dht->num_to_bootstrap; ++i) {
dht_send_nodes_request(dht, &dht->to_bootstrap[i].ip_port, dht->to_bootstrap[i].public_key, dht->self_public_key);
}
dht->num_to_bootstrap = 0;
const uint8_t not_killed = do_ping_and_sendnode_requests(
dht, &dht->close_last_nodes_request, dht->self_public_key, dht->close_clientlist, LCLIENT_LIST, &dht->close_bootstrap_times,
false);
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 = mono_time_get(dht->mono_time) - BAD_NODE_TIMEOUT;
for (size_t i = 0; i < LCLIENT_LIST; ++i) {
Client_data *const client = &dht->close_clientlist[i];
if (client->assoc4.timestamp != 0) {
client->assoc4.timestamp = badonly;
}
if (client->assoc6.timestamp != 0) {
client->assoc6.timestamp = badonly;
}
}
}
bool dht_bootstrap(DHT *dht, const IP_Port *ip_port, const uint8_t *public_key)
{
if (pk_equal(public_key, dht->self_public_key)) {
// Bootstrapping off ourselves is ok (onion paths are still set up).
return true;
}
return dht_send_nodes_request(dht, ip_port, public_key, dht->self_public_key);
}
bool dht_bootstrap_from_address(DHT *dht, const char *address, bool ipv6enabled, bool dns_enabled,
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(dht->ns, dht->mem, address, &ip_port_v64.ip, ip_extra, dns_enabled)) {
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 true;
}
return false;
}
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 (pk_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 != nullptr; ++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;
}
/** @brief Puts all the different ips returned by the nodes for a friend_num into array ip_portlist.
*
* @param ip_portlist must be at least MAX_FRIEND_CLIENTS big.
*
* @return the number of ips returned.
* @retval 0 if we are connected to friend or if no ips were found.
* @retval -1 if no such friend.
*/
static int friend_iplist(const DHT *_Nonnull dht, IP_Port *_Nonnull 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)
&& !mono_time_is_timeout(dht->mono_time, 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)
&& !mono_time_is_timeout(dht->mono_time, client->assoc6.ret_timestamp, BAD_NODE_TIMEOUT)) {
ipv6s[num_ipv6s] = client->assoc6.ret_ip_port;
++num_ipv6s;
}
if (pk_equal(client->public_key, dht_friend->public_key)) {
if (!assoc_timeout(dht->cur_time, &client->assoc6)
|| !assoc_timeout(dht->cur_time, &client->assoc4)) {
return 0; /* direct connectivity */
}
}
}
#ifdef FRIEND_IPLIST_PAD
for (int i = 0; i < num_ipv6s; ++i) {
ip_portlist[i] = ipv6s[i];
}
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;
}
for (int i = 0; i < num_ipv4s_used; ++i) {
ip_portlist[num_ipv6s + i] = ipv4s[i];
}
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) {
for (int i = 0; i < num_ipv6s; ++i) {
ip_portlist[i] = ipv6s[i];
}
return num_ipv6s;
}
for (int i = 0; i < num_ipv4s; ++i) {
ip_portlist[i] = ipv4s[i];
}
return num_ipv4s;
#endif /* !FRIEND_IPLIST_PAD */
}
/**
* Callback invoked for each IP/port of each client of a friend.
*
* For each client, the callback is invoked twice: once for IPv4 and once for
* IPv6. If the callback returns `false` after the IPv4 invocation, it will not
* be invoked for IPv6.
*
* @param dht The main DHT instance.
* @param ip_port The currently processed IP/port.
* @param n A pointer to the number that will be returned from `foreach_ip_port`.
* @param userdata The `userdata` pointer passed to `foreach_ip_port`.
*/
typedef bool foreach_ip_port_cb(const DHT *_Nonnull dht, const IP_Port *_Nonnull ip_port, uint32_t *_Nonnull n, void *_Nonnull userdata);
/**
* Runs a callback on every active connection for a given DHT friend.
*
* This iterates over the client list of a DHT friend and invokes a callback for
* every non-zero IP/port (IPv4 and IPv6) that's not timed out.
*
* @param dht The main DHT instance, passed to the callback.
* @param dht_friend The friend over whose connections we should iterate.
* @param callback The callback to invoke for each IP/port.
* @param userdata Extra pointer passed to the callback.
*/
static uint32_t foreach_ip_port(const DHT *_Nonnull dht, const DHT_Friend *_Nonnull dht_friend, foreach_ip_port_cb *_Nonnull callback, void *_Nonnull userdata)
{
uint32_t 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 != nullptr; ++it) {
const IPPTsPng *const assoc = *it;
/* If ip is not zero and node is good. */
if (!ip_isset(&assoc->ret_ip_port.ip)
|| mono_time_is_timeout(dht->mono_time, assoc->ret_timestamp, BAD_NODE_TIMEOUT)) {
continue;
}
if (!callback(dht, &assoc->ip_port, &n, userdata)) {
/* If the callback is happy with just one of the assocs, we
* don't give it the second one. */
break;
}
}
}
return n;
}
static bool send_packet_to_friend(const DHT *_Nonnull dht, const IP_Port *_Nonnull ip_port, uint32_t *_Nonnull n, void *_Nonnull userdata)
{
const Net_Packet *packet = (const Net_Packet *)userdata;
const int retval = net_send_packet(dht->net, ip_port, *packet);
if ((uint32_t)retval == packet->length) {
++*n;
/* Send one packet per friend: stop the foreach on the first success. */
return false;
}
return true;
}
/**
* Send the following packet to everyone who tells us they are connected to friend_id.
* Only works if more than (MAX_FRIEND_CLIENTS / 4) return an ip for friend.
*
* @return number of nodes the packet was sent to.
*/
uint32_t route_to_friend(const DHT *dht, const uint8_t *friend_id, const Net_Packet *packet)
{
const uint32_t num = index_of_friend_pk(dht->friends_list, dht->num_friends, friend_id);
if (num == UINT32_MAX) {
return 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];
Net_Packet packet_userdata = *packet; // Copy because it needs to be non-const.
return foreach_ip_port(dht, dht_friend, send_packet_to_friend, &packet_userdata);
}
static bool get_ip_port(const DHT *_Nonnull dht, const IP_Port *_Nonnull ip_port, uint32_t *_Nonnull n, void *_Nonnull userdata)
{
IP_Port *ip_list = (IP_Port *)userdata;
ip_list[*n] = *ip_port;
++*n;
return true;
}
/** @brief 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 uint32_t routeone_to_friend(const DHT *_Nonnull dht, const uint8_t *_Nonnull friend_id, const Net_Packet *_Nonnull packet)
{
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];
const int n = foreach_ip_port(dht, dht_friend, get_ip_port, ip_list);
if (n < 1) {
return 0;
}
const uint32_t rand_idx = random_range_u32(dht->rng, n);
const int retval = net_send_packet(dht->net, &ip_list[rand_idx], *packet);
if ((unsigned int)retval == packet->length) {
return 1;
}
return 0;
}
/*----------------------------------------------------------------------------------*/
/*---------------------BEGINNING OF NAT PUNCHING FUNCTIONS--------------------------*/
static int send_nat_ping(const DHT *_Nonnull dht, const uint8_t *_Nonnull public_key, uint64_t ping_id, uint8_t type)
{
uint8_t data[sizeof(uint64_t) + 1];
uint8_t packet_data[MAX_CRYPTO_REQUEST_SIZE];
data[0] = type;
memcpy(data + 1, &ping_id, sizeof(uint64_t));
/* 254 is NAT ping request packet id */
const int len = create_request(
dht->mem, dht->rng, dht->self_public_key, dht->self_secret_key, packet_data, public_key,
data, sizeof(uint64_t) + 1, CRYPTO_PACKET_NAT_PING);
if (len == -1) {
return -1;
}
assert(len <= UINT16_MAX);
uint32_t num = 0;
const Net_Packet packet = {packet_data, (uint16_t)len};
if (type == 0) { /* If packet is request use many people to route it. */
num = route_to_friend(dht, public_key, &packet);
} else if (type == 1) { /* If packet is response use only one person to route it */
num = routeone_to_friend(dht, public_key, &packet);
}
if (num == 0) {
return -1;
}
return num;
}
/** Handle a received ping request for. */
static int handle_nat_ping(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull source_pubkey, const uint8_t *_Nonnull packet, uint16_t length,
void *_Nonnull userdata)
{
DHT *const dht = (DHT *)object;
if (length != sizeof(uint64_t) + 1) {
return 1;
}
uint64_t ping_id;
memcpy(&ping_id, packet + 1, sizeof(uint64_t));
const 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_nat_ping(dht, source_pubkey, ping_id, NAT_PING_RESPONSE);
dht_friend->nat.recv_nat_ping_timestamp = mono_time_get(dht->mono_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->rng);
dht_friend->nat.hole_punching = true;
return 0;
}
}
return 1;
}
/** @brief 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(const IP_Port *_Nonnull 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;
}
/** @brief 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 *_Nonnull portlist, const IP_Port *_Nonnull ip_portlist, uint16_t len, const IP *_Nonnull 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 *_Nonnull dht, const IP *_Nonnull ip, const uint16_t *_Nonnull 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];
uint16_t port_candidate;
for (port_candidate = 0; port_candidate < numports; ++port_candidate) {
if (first_port != port_list[port_candidate]) {
break;
}
}
if (port_candidate == 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 {
uint16_t i;
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 != 0) ? -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) {
IP_Port pinging;
ip_copy(&pinging.ip, ip);
uint16_t i;
for (i = 0; i < MAX_PUNCHING_PORTS; ++i) {
const uint32_t it = i + dht->friends_list[friend_num].nat.punching_index2;
const uint16_t port = 1024;
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 *_Nonnull dht)
{
const uint64_t temp_time = mono_time_get(dht->mono_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_nat_ping(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 &&
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 = false;
}
}
}
/*----------------------------------------------------------------------------------*/
/*-----------------------END OF NAT PUNCHING FUNCTIONS------------------------------*/
/** @brief Put up to max_num nodes in nodes from the closelist.
*
* @return the number of nodes.
*/
static uint16_t list_nodes(const Random *_Nonnull rng, const Client_data *_Nonnull list, size_t length, uint64_t cur_time, Node_format *_Nonnull 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 (!assoc_timeout(cur_time, &list[i - 1].assoc4)) {
assoc = &list[i - 1].assoc4;
}
if (!assoc_timeout(cur_time, &list[i - 1].assoc6)) {
if (assoc == nullptr || (random_u08(rng) % 2) != 0) {
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;
}
/** @brief Put up to max_num nodes in nodes from the random friends.
*
* Important: this function relies on the first two DHT friends *not* being real
* friends to avoid leaking information about real friends into the onion paths.
*
* @return the number of nodes.
*/
uint16_t randfriends_nodes(const DHT *dht, Node_format *nodes, uint16_t max_num)
{
if (max_num == 0) {
return 0;
}
uint16_t count = 0;
const uint32_t r = random_u32(dht->rng);
assert(DHT_FAKE_FRIEND_NUMBER <= dht->num_friends);
// Only gather nodes from the initial 2 fake friends.
for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER; ++i) {
count += list_nodes(dht->rng, dht->friends_list[(i + r) % DHT_FAKE_FRIEND_NUMBER].client_list,
MAX_FRIEND_CLIENTS, dht->cur_time,
nodes + count, max_num - count);
if (count >= max_num) {
break;
}
}
return count;
}
/** @brief Put up to max_num nodes in nodes from the closelist.
*
* @return the number of nodes.
*/
uint16_t closelist_nodes(const DHT *dht, Node_format *nodes, uint16_t max_num)
{
return list_nodes(dht->rng, dht->close_clientlist, LCLIENT_LIST, dht->cur_time, nodes, max_num);
}
/*----------------------------------------------------------------------------------*/
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 *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, void *_Nonnull 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 (pk_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->mem, 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 == nullptr) {
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;
}
void dht_callback_nodes_response(DHT *dht, dht_nodes_response_cb *function)
{
dht->nodes_response_callback = function;
}
static int handle_lan_discovery(void *_Nonnull object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length,
void *_Nullable userdata)
{
DHT *dht = (DHT *)object;
if (!dht->lan_discovery_enabled) {
return 1;
}
if (!ip_is_lan(&source->ip)) {
return 1;
}
if (length != CRYPTO_PUBLIC_KEY_SIZE + 1) {
return 1;
}
dht_bootstrap(dht, source, packet + 1);
return 0;
}
/*----------------------------------------------------------------------------------*/
DHT *new_dht(const Logger *log, const Memory *mem, const Random *rng, const Network *ns,
Mono_Time *mono_time, Networking_Core *net,
bool hole_punching_enabled, bool lan_discovery_enabled)
{
if (net == nullptr) {
return nullptr;
}
DHT *const dht = (DHT *)mem_alloc(mem, sizeof(DHT));
if (dht == nullptr) {
LOGGER_ERROR(log, "failed to allocate DHT struct (%lu bytes)", (unsigned long)sizeof(DHT));
return nullptr;
}
dht->ns = ns;
dht->mono_time = mono_time;
dht->cur_time = mono_time_get(mono_time);
dht->log = log;
dht->net = net;
dht->rng = rng;
dht->mem = mem;
dht->hole_punching_enabled = hole_punching_enabled;
dht->lan_discovery_enabled = lan_discovery_enabled;
struct Ping *temp_ping = ping_new(mem, mono_time, log, rng, dht, net);
if (temp_ping == nullptr) {
LOGGER_ERROR(log, "failed to initialise ping");
kill_dht(dht);
return nullptr;
}
dht->ping = temp_ping;
networking_registerhandler(dht->net, NET_PACKET_NODES_REQUEST, &handle_nodes_request, dht);
networking_registerhandler(dht->net, NET_PACKET_NODES_RESPONSE, &handle_nodes_response, dht);
networking_registerhandler(dht->net, NET_PACKET_CRYPTO, &cryptopacket_handle, dht);
networking_registerhandler(dht->net, NET_PACKET_LAN_DISCOVERY, &handle_lan_discovery, dht);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_NAT_PING, &handle_nat_ping, dht);
#ifdef CHECK_ANNOUNCE_NODE
networking_registerhandler(dht->net, NET_PACKET_DATA_SEARCH_RESPONSE, &handle_data_search_response, dht);
#endif /* CHECK_ANNOUNCE_NODE */
crypto_new_keypair(rng, dht->self_public_key, dht->self_secret_key);
Shared_Key_Cache *const temp_shared_keys_recv = shared_key_cache_new(log, mono_time, mem, dht->self_secret_key, KEYS_TIMEOUT, MAX_KEYS_PER_SLOT);
if (temp_shared_keys_recv == nullptr) {
LOGGER_ERROR(log, "failed to initialise shared key cache");
kill_dht(dht);
return nullptr;
}
dht->shared_keys_recv = temp_shared_keys_recv;
Shared_Key_Cache *const temp_shared_keys_sent = shared_key_cache_new(log, mono_time, mem, dht->self_secret_key, KEYS_TIMEOUT, MAX_KEYS_PER_SLOT);
if (temp_shared_keys_sent == nullptr) {
LOGGER_ERROR(log, "failed to initialise shared key cache");
kill_dht(dht);
return nullptr;
}
dht->shared_keys_sent = temp_shared_keys_sent;
Ping_Array *const temp_ping_array = ping_array_new(mem, DHT_PING_ARRAY_SIZE, PING_TIMEOUT);
if (temp_ping_array == nullptr) {
LOGGER_ERROR(log, "failed to initialise ping array");
kill_dht(dht);
return nullptr;
}
dht->dht_ping_array = temp_ping_array;
for (uint32_t i = 0; i < DHT_FAKE_FRIEND_NUMBER; ++i) {
uint8_t random_public_key_bytes[CRYPTO_PUBLIC_KEY_SIZE];
uint8_t random_secret_key_bytes[CRYPTO_SECRET_KEY_SIZE];
crypto_new_keypair(rng, random_public_key_bytes, random_secret_key_bytes);
uint32_t token; // We don't intend to delete these ever, but need to pass the token
if (dht_addfriend(dht, random_public_key_bytes, nullptr, nullptr, 0, &token) != 0) {
LOGGER_ERROR(log, "failed to add initial random seed DHT friends");
kill_dht(dht);
return nullptr;
}
}
if (dht->num_friends != DHT_FAKE_FRIEND_NUMBER) {
LOGGER_ERROR(log, "the RNG provided seems to be broken: it generated the same keypair twice");
kill_dht(dht);
return nullptr;
}
return dht;
}
void do_dht(DHT *dht)
{
const uint64_t cur_time = mono_time_get(dht->mono_time);
if (dht->cur_time == cur_time) {
return;
}
dht->cur_time = cur_time;
// Load friends/clients if first call to do_dht
if (dht->loaded_num_nodes > 0) {
dht_connect_after_load(dht);
}
do_close(dht);
do_dht_friends(dht);
do_nat(dht);
ping_iterate(dht->ping);
}
void kill_dht(DHT *dht)
{
if (dht == nullptr) {
return;
}
networking_registerhandler(dht->net, NET_PACKET_NODES_REQUEST, nullptr, nullptr);
networking_registerhandler(dht->net, NET_PACKET_NODES_RESPONSE, nullptr, nullptr);
networking_registerhandler(dht->net, NET_PACKET_CRYPTO, nullptr, nullptr);
networking_registerhandler(dht->net, NET_PACKET_LAN_DISCOVERY, nullptr, nullptr);
cryptopacket_registerhandler(dht, CRYPTO_PACKET_NAT_PING, nullptr, nullptr);
shared_key_cache_free(dht->shared_keys_recv);
shared_key_cache_free(dht->shared_keys_sent);
ping_array_kill(dht->dht_ping_array);
ping_kill(dht->mem, dht->ping);
mem_delete(dht->mem, dht->friends_list);
mem_delete(dht->mem, dht->loaded_nodes_list);
crypto_memzero(dht->self_secret_key, sizeof(dht->self_secret_key));
mem_delete(dht->mem, 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
/* equal to our max internal state, times 2 for potentially both ip v4+v6 */
#define MAX_SAVED_DHT_NODES (((DHT_FAKE_FRIEND_NUMBER * MAX_FRIEND_CLIENTS) + LCLIENT_LIST) * 2)
static bool node_in_client_list(const Client_data *_Nonnull list, uint32_t length, const Node_format *_Nonnull node)
{
for (uint32_t i = 0; i < length; ++i) {
if (!pk_equal(list[i].public_key, node->public_key)) {
continue;
}
if (list[i].assoc4.timestamp != 0 && ipport_equal(&list[i].assoc4.ip_port, &node->ip_port)) {
return true;
}
if (list[i].assoc6.timestamp != 0 && ipport_equal(&list[i].assoc6.ip_port, &node->ip_port)) {
return true;
}
}
return false;
}
static bool node_in_list(const Node_format *_Nonnull list, uint32_t length, const Node_format *_Nonnull node)
{
for (uint32_t i = 0; i < length; ++i) {
if (pk_equal(list[i].public_key, node->public_key) &&
ipport_equal(&list[i].ip_port, &node->ip_port)) {
return true;
}
}
return false;
}
typedef void dht_gather_cb(const uint8_t public_key[_Nonnull CRYPTO_PUBLIC_KEY_SIZE], const IP_Port *_Nonnull ipport, void *_Nullable userdata);
/** Calls callback for each entry worth saving */
static void dht_save_gather(const DHT *dht, dht_gather_cb *_Nonnull callback, void *_Nullable userdata)
{
uint32_t entries = 0;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
if (dht->close_clientlist[i].assoc4.timestamp != 0) {
callback(dht->close_clientlist[i].public_key, &dht->close_clientlist[i].assoc4.ip_port, userdata);
++entries;
}
if (dht->close_clientlist[i].assoc6.timestamp != 0) {
callback(dht->close_clientlist[i].public_key, &dht->close_clientlist[i].assoc6.ip_port, userdata);
++entries;
}
}
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) {
callback(fr->client_list[j].public_key, &fr->client_list[j].assoc4.ip_port, userdata);
++entries;
}
if (fr->client_list[j].assoc6.timestamp != 0) {
callback(fr->client_list[j].public_key, &fr->client_list[j].assoc6.ip_port, userdata);
++entries;
}
}
}
for (uint32_t i = 0; i < dht->loaded_num_nodes && entries < MAX_SAVED_DHT_NODES; ++i) {
/* check for duplicate */
if (node_in_client_list(dht->close_clientlist, LCLIENT_LIST, &dht->loaded_nodes_list[i])) {
continue;
}
bool exists = false;
for (uint32_t j = 0; j < DHT_FAKE_FRIEND_NUMBER && j < dht->num_friends; ++j) {
const DHT_Friend *const fr = &dht->friends_list[j];
if (node_in_client_list(fr->client_list, MAX_FRIEND_CLIENTS, &dht->loaded_nodes_list[i])) {
exists = true;
break;
}
}
if (exists) {
continue;
}
/* growing self dedup */
if (node_in_list(dht->loaded_nodes_list, i, &dht->loaded_nodes_list[i])) {
continue;
}
callback(dht->loaded_nodes_list[i].public_key, &dht->loaded_nodes_list[i].ip_port, userdata);
++entries;
}
}
static void cb_dht_save_size_only(const uint8_t public_key[_Nonnull CRYPTO_PUBLIC_KEY_SIZE], const IP_Port *_Nonnull ipport, void *_Nullable userdata)
{
uint32_t *packed_size = (uint32_t *)userdata;
*packed_size += packed_node_size(ipport->ip.family);
}
/** Get the size of the DHT (for saving). */
uint32_t dht_size(const DHT *dht)
{
uint32_t nodes_packed_size = 0;
dht_save_gather(dht, cb_dht_save_size_only, &nodes_packed_size);
const uint32_t size_global_cookie = sizeof(uint32_t);
const uint32_t size_section_header = sizeof(uint32_t) * 2;
return size_global_cookie + size_section_header + nodes_packed_size;
}
struct DHT_Save_Gather_Data {
Node_format *_Nonnull clients;
uint32_t clients_num;
};
static void cb_dht_save(const uint8_t public_key[_Nonnull CRYPTO_PUBLIC_KEY_SIZE], const IP_Port *_Nonnull ipport, void *_Nullable userdata)
{
struct DHT_Save_Gather_Data *cb_ctx = (struct DHT_Save_Gather_Data *)userdata;
memcpy(cb_ctx->clients[cb_ctx->clients_num].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
cb_ctx->clients[cb_ctx->clients_num].ip_port = *ipport;
++cb_ctx->clients_num;
}
/** 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_lendian_bytes32(data, DHT_STATE_COOKIE_GLOBAL);
data += sizeof(uint32_t);
uint8_t *const data_start = data;
/* get right offset. we write the actual header later. */
data = state_write_section_header(data, DHT_STATE_COOKIE_TYPE, 0, 0);
Node_format *clients = (Node_format *)mem_valloc(dht->mem, MAX_SAVED_DHT_NODES, sizeof(Node_format));
if (clients == nullptr) {
LOGGER_ERROR(dht->log, "could not allocate %u nodes", (unsigned int)MAX_SAVED_DHT_NODES);
return;
}
struct DHT_Save_Gather_Data cb_ctx = {clients, 0};
dht_save_gather(dht, cb_dht_save, &cb_ctx);
const int packed_nodes_length = pack_nodes(dht->log, data, sizeof(Node_format) * cb_ctx.clients_num, clients, cb_ctx.clients_num);
state_write_section_header(
data_start, DHT_STATE_COOKIE_TYPE, packed_nodes_length, DHT_STATE_TYPE_NODES);
mem_delete(dht->mem, clients);
}
/** Bootstrap from this number of nodes every time `dht_connect_after_load()` is called */
#define SAVE_BOOTSTAP_FREQUENCY 8
int dht_connect_after_load(DHT *dht)
{
if (dht == nullptr) {
return -1;
}
if (dht->loaded_nodes_list == nullptr) {
return -1;
}
/* DHT is connected, stop. */
if (dht_non_lan_connected(dht)) {
mem_delete(dht->mem, 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 *_Nonnull outer, const uint8_t *_Nonnull data, uint32_t length, uint16_t type)
{
DHT *dht = (DHT *)outer;
switch (type) {
case DHT_STATE_TYPE_NODES: {
if (length == 0) {
break;
}
// TODO(Green-Sky): This allocates 130KiB, might be worth reducing or retrying with smaller, partial allocations.
Node_format *nodes = (Node_format *)mem_valloc(dht->mem, MAX_SAVED_DHT_NODES, sizeof(Node_format));
if (nodes == nullptr) {
LOGGER_ERROR(dht->log, "could not allocate %u nodes", (unsigned int)MAX_SAVED_DHT_NODES);
break;
}
const int num = unpack_nodes(nodes, MAX_SAVED_DHT_NODES, nullptr, data, length, false);
if (num <= 0) {
// Unpack error happened or list was empty, we ignore it.
mem_delete(dht->mem, nodes);
} else {
mem_delete(dht->mem, dht->loaded_nodes_list);
dht->loaded_num_nodes = num;
dht->loaded_nodes_list = nodes;
}
break;
}
default: {
LOGGER_ERROR(dht->log, "Load state (DHT): contains unrecognized part (len %u, type %u)",
length, type);
break;
}
}
return STATE_LOAD_STATUS_CONTINUE;
}
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_bytes_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;
}
/**
* @retval false if we are not connected to the DHT.
* @retval true if we are.
*/
bool dht_isconnected(const DHT *dht)
{
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = &dht->close_clientlist[i];
if (!assoc_timeout(dht->cur_time, &client->assoc4) ||
!assoc_timeout(dht->cur_time, &client->assoc6)) {
return true;
}
}
return false;
}
/**
* @retval false if we are not connected or only connected to lan peers with the DHT.
* @retval true if we are.
*/
bool dht_non_lan_connected(const DHT *dht)
{
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = &dht->close_clientlist[i];
if (!assoc_timeout(dht->cur_time, &client->assoc4)
&& !ip_is_lan(&client->assoc4.ip_port.ip)) {
return true;
}
if (!assoc_timeout(dht->cur_time, &client->assoc6)
&& !ip_is_lan(&client->assoc6.ip_port.ip)) {
return true;
}
}
return false;
}
uint16_t dht_get_num_closelist(const DHT *dht)
{
uint16_t num_valid_close_clients = 0;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = dht_get_close_client(dht, i);
// check if client is valid
if (!(assoc_timeout(dht->cur_time, &client->assoc4) && assoc_timeout(dht->cur_time, &client->assoc6))) {
++num_valid_close_clients;
}
}
return num_valid_close_clients;
}
uint16_t dht_get_num_closelist_announce_capable(const DHT *dht)
{
uint16_t num_valid_close_clients_with_cap = 0;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *const client = dht_get_close_client(dht, i);
// check if client is valid
if (!(assoc_timeout(dht->cur_time, &client->assoc4) && assoc_timeout(dht->cur_time, &client->assoc6)) && client->announce_node) {
++num_valid_close_clients_with_cap;
}
}
return num_valid_close_clients_with_cap;
}
unsigned int ipport_self_copy(const DHT *dht, IP_Port *dest)
{
ipport_reset(dest);
bool is_lan = false;
for (uint32_t i = 0; i < LCLIENT_LIST; ++i) {
const Client_data *client = dht_get_close_client(dht, i);
const IP_Port *ip_port4 = &client->assoc4.ret_ip_port;
if (client->assoc4.ret_ip_self && ipport_isset(ip_port4)) {
ipport_copy(dest, ip_port4);
is_lan = ip_is_lan(&dest->ip);
if (!is_lan) {
break;
}
}
const IP_Port *ip_port6 = &client->assoc6.ret_ip_port;
if (client->assoc6.ret_ip_self && ipport_isset(ip_port6)) {
ipport_copy(dest, ip_port6);
is_lan = ip_is_lan(&dest->ip);
if (!is_lan) {
break;
}
}
}
if (!ipport_isset(dest)) {
return 0;
}
if (is_lan) {
return 2;
}
return 1;
}