toxcore/toxcore/onion_client.c
Tux3 / Mlkj / !Lev.uXFMLA 3044bd8101 Fix CppCheck style errors
#if 0 the content of toxav/msi.c : int stringify_message(MSIMessage
*msg, char *dest)
This function has no effect and does not seem to be used for actively
waiting.

Fix various other style errors, reduce scope when possible, avoid
redundant writes, clarify operator priorities, etc.
2014-06-20 21:43:21 +02:00

1154 lines
38 KiB
C

/*
* onion_client.c -- Implementation of the client part of docs/Prevent_Tracking.txt
* (The part that uses the onion stuff to connect to the friend)
*
* Copyright (C) 2013 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "onion_client.h"
#include "util.h"
#include "LAN_discovery.h"
/* defines for the array size and
timeout for onion announce packets. */
#define ANNOUNCE_ARRAY_SIZE 256
#define ANNOUNCE_TIMEOUT 10
/*
* return -1 if nodes are suitable for creating a new path.
* return path number of already existing similar path if one already exists.
*/
static int is_path_used(Onion_Client_Paths *onion_paths, Node_format *nodes)
{
uint32_t i;
for (i = 0; i < NUMBER_ONION_PATHS; ++i) {
if (is_timeout(onion_paths->last_path_success[i], ONION_PATH_TIMEOUT)) {
continue;
}
if (is_timeout(onion_paths->path_creation_time[i], ONION_PATH_MAX_LIFETIME)) {
continue;
}
if (ipport_equal(&onion_paths->paths[i].ip_port1, &nodes[0].ip_port)) {
return i;
}
}
return -1;
}
/* Create a new path or use an old suitable one (if pathnum is valid)
* or a rondom one from onion_paths.
*
* return -1 on failure
* return 0 on success
*
* TODO: Make this function better, it currently probably is vulnerable to some attacks that
* could de anonimize us.
*/
static int random_path(DHT *dht, Onion_Client_Paths *onion_paths, uint32_t pathnum, Onion_Path *path)
{
if (pathnum >= NUMBER_ONION_PATHS)
pathnum = rand() % NUMBER_ONION_PATHS;
if (is_timeout(onion_paths->last_path_success[pathnum], ONION_PATH_TIMEOUT)
|| is_timeout(onion_paths->path_creation_time[pathnum], ONION_PATH_MAX_LIFETIME)) {
Node_format nodes[3];
if (random_nodes_path(dht, nodes, 3) != 3)
return -1;
int n = is_path_used(onion_paths, nodes);
if (n == -1) {
if (create_onion_path(dht, &onion_paths->paths[pathnum], nodes) == -1)
return -1;
onion_paths->last_path_success[pathnum] = unix_time() + ONION_PATH_FIRST_TIMEOUT - ONION_PATH_TIMEOUT;
onion_paths->path_creation_time[pathnum] = unix_time();
} else {
pathnum = n;
}
}
memcpy(path, &onion_paths->paths[pathnum], sizeof(Onion_Path));
return 0;
}
/* Set path timeouts, return the path number.
*
*/
static uint32_t set_path_timeouts(Onion_Client *onion_c, uint32_t num, IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
Onion_Client_Paths *onion_paths;
if (num == 0) {
onion_paths = &onion_c->onion_paths;
} else {
onion_paths = &onion_c->friends_list[num - 1].onion_paths;
}
uint32_t i;
for (i = 0; i < NUMBER_ONION_PATHS; ++i) {
if (ipport_equal(&onion_paths->paths[i].ip_port1, &source)) {
onion_paths->last_path_success[i] = unix_time();
return i;
}
}
return ~0;
}
/* Function to send onion packet via TCP and UDP.
*
* return -1 on failure.
* return 0 on success.
*/
static int send_onion_packet_tcp_udp(const Onion_Client *onion_c, IP_Port ip_port, uint8_t *data, uint32_t length)
{
if (ip_port.ip.family == AF_INET || ip_port.ip.family == AF_INET6) {
if ((uint32_t)sendpacket(onion_c->net, ip_port, data, length) != length)
return -1;
return 0;
} else {
return -1; //TODO: TCP
}
}
/* Creates a sendback for use in an announce request.
*
* num is 0 if we used our secret public key for the announce
* num is 1 + friendnum if we use a temporary one.
*
* Public key is the key we will be sending it to.
* ip_port is the ip_port of the node we will be sending
* it to.
*
* sendback must be at least ONION_ANNOUNCE_SENDBACK_DATA_LENGTH big
*
* return -1 on failure
* return 0 on success
*
*/
static int new_sendback(Onion_Client *onion_c, uint32_t num, uint8_t *public_key, IP_Port ip_port, uint64_t *sendback)
{
uint8_t data[sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES + sizeof(IP_Port)];
memcpy(data, &num, sizeof(uint32_t));
memcpy(data + sizeof(uint32_t), public_key, crypto_box_PUBLICKEYBYTES);
memcpy(data + sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES, &ip_port, sizeof(IP_Port));
*sendback = ping_array_add(&onion_c->announce_ping_array, data, sizeof(data));
if (*sendback == 0)
return -1;
return 0;
}
/* Checks if the sendback is valid and returns the public key contained in it in ret_pubkey and the
* ip contained in it in ret_ip_port
*
* sendback is the sendback ONION_ANNOUNCE_SENDBACK_DATA_LENGTH big
* ret_pubkey must be at least crypto_box_PUBLICKEYBYTES big
* ret_ip_port must be at least 1 big
*
* return ~0 on failure
* return num (see new_sendback(...)) on success
*/
static uint32_t check_sendback(Onion_Client *onion_c, const uint8_t *sendback, uint8_t *ret_pubkey,
IP_Port *ret_ip_port)
{
uint64_t sback;
memcpy(&sback, sendback, sizeof(uint64_t));
uint8_t data[sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES + sizeof(IP_Port)];
if (ping_array_check(data, sizeof(data), &onion_c->announce_ping_array, sback) != sizeof(data))
return ~0;
memcpy(ret_pubkey, data + sizeof(uint32_t), crypto_box_PUBLICKEYBYTES);
memcpy(ret_ip_port, data + sizeof(uint32_t) + crypto_box_PUBLICKEYBYTES, sizeof(IP_Port));
uint32_t num;
memcpy(&num, data, sizeof(uint32_t));
return num;
}
static int client_send_announce_request(Onion_Client *onion_c, uint32_t num, IP_Port dest, uint8_t *dest_pubkey,
uint8_t *ping_id, uint32_t pathnum)
{
if (num > onion_c->num_friends)
return -1;
uint64_t sendback;
if (new_sendback(onion_c, num, dest_pubkey, dest, &sendback) == -1)
return -1;
uint8_t zero_ping_id[ONION_PING_ID_SIZE] = {0};
if (ping_id == NULL)
ping_id = zero_ping_id;
Onion_Path path;
Node_format dest_node;
dest_node.ip_port = dest;
memcpy(dest_node.client_id, dest_pubkey, crypto_box_PUBLICKEYBYTES);
if (num == 0) {
if (random_path(onion_c->dht, &onion_c->onion_paths, pathnum, &path) == -1)
return -1;
uint8_t packet[ONION_MAX_PACKET_SIZE];
int len = create_announce_request(packet, sizeof(packet), &path, dest_node, onion_c->c->self_public_key,
onion_c->c->self_secret_key, ping_id, onion_c->c->self_public_key, onion_c->temp_public_key, sendback);
if (len == -1) {
return -1;
}
return send_onion_packet_tcp_udp(onion_c, path.ip_port1, packet, len);
} else {
if (random_path(onion_c->dht, &onion_c->friends_list[num - 1].onion_paths, pathnum, &path) == -1)
return -1;
uint8_t packet[ONION_MAX_PACKET_SIZE];
int len = create_announce_request(packet, sizeof(packet), &path, dest_node,
onion_c->friends_list[num - 1].temp_public_key, onion_c->friends_list[num - 1].temp_secret_key, ping_id,
onion_c->friends_list[num - 1].real_client_id, zero_ping_id, sendback);
if (len == -1) {
return -1;
}
return send_onion_packet_tcp_udp(onion_c, path.ip_port1, packet, len);
}
}
static uint8_t cmp_public_key[crypto_box_PUBLICKEYBYTES];
static int cmp_entry(const void *a, const void *b)
{
Onion_Node entry1, entry2;
memcpy(&entry1, a, sizeof(Onion_Node));
memcpy(&entry2, b, sizeof(Onion_Node));
int t1 = is_timeout(entry1.timestamp, ONION_NODE_TIMEOUT);
int t2 = is_timeout(entry2.timestamp, ONION_NODE_TIMEOUT);
if (t1 && t2)
return 0;
if (t1)
return -1;
if (t2)
return 1;
int close = id_closest(cmp_public_key, entry1.client_id, entry2.client_id);
if (close == 1)
return 1;
if (close == 2)
return -1;
return 0;
}
static int client_add_to_list(Onion_Client *onion_c, uint32_t num, uint8_t *public_key, IP_Port ip_port,
uint8_t is_stored, uint8_t *pingid_or_key, IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
Onion_Node *list_nodes = NULL;
uint8_t *reference_id = NULL;
if (num == 0) {
list_nodes = onion_c->clients_announce_list;
reference_id = onion_c->c->self_public_key;
if (is_stored && memcmp(pingid_or_key, onion_c->temp_public_key, crypto_box_PUBLICKEYBYTES) != 0) {
is_stored = 0;
}
} else {
list_nodes = onion_c->friends_list[num - 1].clients_list;
reference_id = onion_c->friends_list[num - 1].real_client_id;
}
memcpy(cmp_public_key, reference_id, crypto_box_PUBLICKEYBYTES);
qsort(list_nodes, MAX_ONION_CLIENTS, sizeof(Onion_Node), cmp_entry);
int index = -1;
uint32_t i;
if (is_timeout(list_nodes[0].timestamp, ONION_NODE_TIMEOUT)
|| id_closest(reference_id, list_nodes[0].client_id, public_key) == 2) {
index = 0;
}
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (memcmp(list_nodes[i].client_id, public_key, crypto_box_PUBLICKEYBYTES) == 0) {
index = i;
break;
}
}
if (index == -1)
return 0;
memcpy(list_nodes[index].client_id, public_key, CLIENT_ID_SIZE);
list_nodes[index].ip_port = ip_port;
if (is_stored) {
memcpy(list_nodes[index].data_public_key, pingid_or_key, crypto_box_PUBLICKEYBYTES);
} else {
memcpy(list_nodes[index].ping_id, pingid_or_key, ONION_PING_ID_SIZE);
}
list_nodes[index].is_stored = is_stored;
list_nodes[index].timestamp = unix_time();
list_nodes[index].last_pinged = 0;
list_nodes[index].path_used = set_path_timeouts(onion_c, num, source);
return 0;
}
static int good_to_ping(Last_Pinged *last_pinged, uint8_t *last_pinged_index, uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < MAX_STORED_PINGED_NODES; ++i) {
if (!is_timeout(last_pinged[i].timestamp, MIN_NODE_PING_TIME))
if (memcmp(last_pinged[i].client_id, client_id, crypto_box_PUBLICKEYBYTES) == 0)
return 0;
}
memcpy(last_pinged[*last_pinged_index % MAX_STORED_PINGED_NODES].client_id, client_id, crypto_box_PUBLICKEYBYTES);
last_pinged[*last_pinged_index % MAX_STORED_PINGED_NODES].timestamp = unix_time();
++*last_pinged_index;
return 1;
}
static int client_ping_nodes(Onion_Client *onion_c, uint32_t num, Node_format *nodes, uint16_t num_nodes,
IP_Port source)
{
if (num > onion_c->num_friends)
return -1;
if (num_nodes == 0)
return 0;
Onion_Node *list_nodes = NULL;
uint8_t *reference_id = NULL;
Last_Pinged *last_pinged = NULL;
uint8_t *last_pinged_index = NULL;
if (num == 0) {
list_nodes = onion_c->clients_announce_list;
reference_id = onion_c->c->self_public_key;
last_pinged = onion_c->last_pinged;
last_pinged_index = &onion_c->last_pinged_index;
} else {
list_nodes = onion_c->friends_list[num - 1].clients_list;
reference_id = onion_c->friends_list[num - 1].real_client_id;
last_pinged = onion_c->friends_list[num - 1].last_pinged;
last_pinged_index = &onion_c->friends_list[num - 1].last_pinged_index;
}
uint32_t i, j;
int lan_ips_accepted = (LAN_ip(source.ip) == 0);
for (i = 0; i < num_nodes; ++i) {
if (!lan_ips_accepted)
if (LAN_ip(nodes[i].ip_port.ip) == 0)
continue;
if (is_timeout(list_nodes[0].timestamp, ONION_NODE_TIMEOUT)
|| id_closest(reference_id, list_nodes[0].client_id, nodes[i].client_id) == 2) {
/* check if node is already in list. */
for (j = 0; j < MAX_ONION_CLIENTS; ++j) {
if (memcmp(list_nodes[j].client_id, nodes[i].client_id, crypto_box_PUBLICKEYBYTES) == 0) {
break;
}
}
if (j == MAX_ONION_CLIENTS && good_to_ping(last_pinged, last_pinged_index, nodes[i].client_id)) {
client_send_announce_request(onion_c, num, nodes[i].ip_port, nodes[i].client_id, NULL, ~0);
}
}
}
return 0;
}
static int handle_announce_response(void *object, IP_Port source, const uint8_t *packet, uint32_t length)
{
Onion_Client *onion_c = object;
if (length < ONION_ANNOUNCE_RESPONSE_MIN_SIZE || length > ONION_ANNOUNCE_RESPONSE_MAX_SIZE)
return 1;
uint16_t len_nodes = length - ONION_ANNOUNCE_RESPONSE_MIN_SIZE;
uint8_t public_key[crypto_box_PUBLICKEYBYTES];
IP_Port ip_port;
uint32_t num = check_sendback(onion_c, packet + 1, public_key, &ip_port);
if (num > onion_c->num_friends)
return 1;
uint8_t plain[1 + ONION_PING_ID_SIZE + len_nodes];
int len = -1;
if (num == 0) {
len = decrypt_data(public_key, onion_c->c->self_secret_key, packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES,
length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES), plain);
} else {
if (onion_c->friends_list[num - 1].status == 0)
return 1;
len = decrypt_data(public_key, onion_c->friends_list[num - 1].temp_secret_key,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH,
packet + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES,
length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + crypto_box_NONCEBYTES), plain);
}
if ((uint32_t)len != sizeof(plain))
return 1;
if (client_add_to_list(onion_c, num, public_key, ip_port, plain[0], plain + 1, source) == -1)
return 1;
if (len_nodes != 0) {
Node_format nodes[MAX_SENT_NODES];
int num_nodes = unpack_nodes(nodes, MAX_SENT_NODES, 0, plain + 1 + ONION_PING_ID_SIZE, len_nodes, 0);
if (num_nodes <= 0)
return 1;
if (client_ping_nodes(onion_c, num, nodes, num_nodes, source) == -1)
return 1;
}
return 0;
}
#define DATA_IN_RESPONSE_MIN_SIZE ONION_DATA_IN_RESPONSE_MIN_SIZE
static int handle_data_response(void *object, IP_Port source, const uint8_t *packet, uint32_t length)
{
Onion_Client *onion_c = object;
if (length <= (ONION_DATA_RESPONSE_MIN_SIZE + DATA_IN_RESPONSE_MIN_SIZE))
return 1;
if (length > MAX_DATA_REQUEST_SIZE)
return 1;
uint8_t temp_plain[length - ONION_DATA_RESPONSE_MIN_SIZE];
int len = decrypt_data(packet + 1 + crypto_box_NONCEBYTES, onion_c->temp_secret_key, packet + 1,
packet + 1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES,
length - (1 + crypto_box_NONCEBYTES + crypto_box_PUBLICKEYBYTES), temp_plain);
if ((uint32_t)len != sizeof(temp_plain))
return 1;
uint8_t plain[sizeof(temp_plain) - DATA_IN_RESPONSE_MIN_SIZE];
len = decrypt_data(temp_plain, onion_c->c->self_secret_key, packet + 1, temp_plain + crypto_box_PUBLICKEYBYTES,
sizeof(temp_plain) - crypto_box_PUBLICKEYBYTES, plain);
if ((uint32_t)len != sizeof(plain))
return 1;
if (!onion_c->Onion_Data_Handlers[plain[0]].function)
return 1;
return onion_c->Onion_Data_Handlers[plain[0]].function(onion_c->Onion_Data_Handlers[plain[0]].object, temp_plain, plain,
sizeof(plain));
}
#define FAKEID_DATA_ID 156
#define FAKEID_DATA_MIN_LENGTH (1 + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES)
#define FAKEID_DATA_MAX_LENGTH (FAKEID_DATA_MIN_LENGTH + sizeof(Node_format)*MAX_SENT_NODES)
static int handle_fakeid_announce(void *object, const uint8_t *source_pubkey, const uint8_t *data, uint32_t length)
{
Onion_Client *onion_c = object;
if (length < FAKEID_DATA_MIN_LENGTH)
return 1;
if (length > FAKEID_DATA_MAX_LENGTH)
return 1;
int friend_num = onion_friend_num(onion_c, source_pubkey);
if (friend_num == -1)
return 1;
uint64_t no_replay;
memcpy(&no_replay, data + 1, sizeof(uint64_t));
net_to_host((uint8_t *) &no_replay, sizeof(no_replay));
if (no_replay <= onion_c->friends_list[friend_num].last_noreplay)
return 1;
onion_c->friends_list[friend_num].last_noreplay = no_replay;
onion_set_friend_DHT_pubkey(onion_c, friend_num, data + 1 + sizeof(uint64_t), current_time_monotonic());
onion_c->friends_list[friend_num].last_seen = unix_time();
uint16_t len_nodes = length - FAKEID_DATA_MIN_LENGTH;
if (len_nodes != 0) {
Node_format nodes[MAX_SENT_NODES];
int num_nodes = unpack_nodes(nodes, MAX_SENT_NODES, 0, data + 1 + sizeof(uint64_t) + crypto_box_PUBLICKEYBYTES,
len_nodes, 1);
if (num_nodes <= 0)
return 1;
int i;
for (i = 0; i < num_nodes; ++i) {
uint8_t family = nodes[i].ip_port.ip.family;
if (family == AF_INET || family == AF_INET6) {
DHT_getnodes(onion_c->dht, &nodes[i].ip_port, nodes[i].client_id, onion_c->friends_list[friend_num].fake_client_id);
} else if (family == TCP_INET || family == TCP_INET6) {
if (onion_c->friends_list[friend_num].tcp_relay_node_callback) {
void *obj = onion_c->friends_list[friend_num].tcp_relay_node_callback_object;
uint32_t number = onion_c->friends_list[friend_num].tcp_relay_node_callback_number;
onion_c->friends_list[friend_num].tcp_relay_node_callback(obj, number, nodes[i].ip_port, nodes[i].client_id);
}
}
}
}
return 0;
}
/* Send data of length length to friendnum.
* This data will be received by the friend using the Onion_Data_Handlers callbacks.
*
* Even if this function succeeds, the friend might not receive any data.
*
* return the number of packets sent on success
* return -1 on failure.
*/
int send_onion_data(const Onion_Client *onion_c, int friend_num, const uint8_t *data, uint32_t length)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (length + DATA_IN_RESPONSE_MIN_SIZE > MAX_DATA_REQUEST_SIZE)
return -1;
if (length == 0)
return -1;
uint8_t nonce[crypto_box_NONCEBYTES];
random_nonce(nonce);
uint8_t packet[DATA_IN_RESPONSE_MIN_SIZE + length];
memcpy(packet, onion_c->c->self_public_key, crypto_box_PUBLICKEYBYTES);
int len = encrypt_data(onion_c->friends_list[friend_num].real_client_id, onion_c->c->self_secret_key, nonce, data,
length, packet + crypto_box_PUBLICKEYBYTES);
if ((uint32_t)len + crypto_box_PUBLICKEYBYTES != sizeof(packet))
return -1;
uint32_t i, good_nodes[MAX_ONION_CLIENTS], num_good = 0, num_nodes = 0;
Onion_Path path[MAX_ONION_CLIENTS];
Onion_Node *list_nodes = onion_c->friends_list[friend_num].clients_list;
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++num_nodes;
if (list_nodes[i].is_stored) {
if (random_path(onion_c->dht, &onion_c->friends_list[friend_num].onion_paths, ~0, &path[num_good]) == -1)
continue;
good_nodes[num_good] = i;
++num_good;
}
}
if (num_good < (num_nodes / 4) + 1)
return -1;
uint32_t good = 0;
for (i = 0; i < num_good; ++i) {
uint8_t o_packet[ONION_MAX_PACKET_SIZE];
len = create_data_request(o_packet, sizeof(o_packet), &path[i], list_nodes[good_nodes[i]].ip_port,
onion_c->friends_list[friend_num].real_client_id, list_nodes[good_nodes[i]].data_public_key, nonce, packet,
sizeof(packet));
if (len == -1)
continue;
if (send_onion_packet_tcp_udp(onion_c, path[i].ip_port1, o_packet, len) == 0)
++good;
}
return good;
}
/* Try to send the fakeid via the DHT instead of onion
*
* Even if this function succeeds, the friend might not receive any data.
*
* return the number of packets sent on success
* return -1 on failure.
*/
static int send_dht_fakeid(Onion_Client *onion_c, int friend_num, uint8_t *data, uint32_t length)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (!onion_c->friends_list[friend_num].is_fake_clientid)
return -1;
uint8_t nonce[crypto_box_NONCEBYTES];
new_nonce(nonce);
uint8_t temp[DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES + length];
memcpy(temp, onion_c->c->self_public_key, crypto_box_PUBLICKEYBYTES);
memcpy(temp + crypto_box_PUBLICKEYBYTES, nonce, crypto_box_NONCEBYTES);
int len = encrypt_data(onion_c->friends_list[friend_num].real_client_id, onion_c->c->self_secret_key, nonce, data,
length, temp + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES);
if ((uint32_t)len + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES != sizeof(temp))
return -1;
uint8_t packet[MAX_CRYPTO_REQUEST_SIZE];
len = create_request(onion_c->dht->self_public_key, onion_c->dht->self_secret_key, packet,
onion_c->friends_list[friend_num].fake_client_id, temp, sizeof(temp), FAKEID_DATA_ID);
if (len == -1)
return -1;
return route_tofriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id, packet, len);
}
static int handle_dht_fakeid(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet,
uint32_t length)
{
Onion_Client *onion_c = object;
if (length < FAKEID_DATA_MIN_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES)
return 1;
if (length > FAKEID_DATA_MAX_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES)
return 1;
uint8_t plain[FAKEID_DATA_MAX_LENGTH];
int len = decrypt_data(packet, onion_c->c->self_secret_key, packet + crypto_box_PUBLICKEYBYTES,
packet + crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES,
length - (crypto_box_PUBLICKEYBYTES + crypto_box_NONCEBYTES), plain);
if ((uint32_t)len != length - (DATA_IN_RESPONSE_MIN_SIZE + crypto_box_NONCEBYTES))
return 1;
if (memcmp(source_pubkey, plain + 1 + sizeof(uint64_t), crypto_box_PUBLICKEYBYTES) != 0)
return 1;
return handle_fakeid_announce(onion_c, packet, plain, len);
}
/* Send the packets to tell our friends what our DHT public key is.
*
* if onion_dht_both is 0, use only the onion to send the packet.
* if it is 1, use only the dht.
* if it is something else, use both.
*
* return the number of packets sent on success
* return -1 on failure.
*/
static int send_fakeid_announce(Onion_Client *onion_c, uint16_t friend_num, uint8_t onion_dht_both)
{
if (friend_num >= onion_c->num_friends)
return -1;
uint8_t data[FAKEID_DATA_MAX_LENGTH];
data[0] = FAKEID_DATA_ID;
uint64_t no_replay = unix_time();
host_to_net((uint8_t *)&no_replay, sizeof(no_replay));
memcpy(data + 1, &no_replay, sizeof(no_replay));
memcpy(data + 1 + sizeof(uint64_t), onion_c->dht->self_public_key, crypto_box_PUBLICKEYBYTES);
Node_format nodes[MAX_SENT_NODES];
uint16_t num_relays = copy_connected_tcp_relays(onion_c->c, nodes, (MAX_SENT_NODES / 2));
uint16_t num_nodes = closelist_nodes(onion_c->dht, &nodes[num_relays], MAX_SENT_NODES - num_relays);
num_nodes += num_relays;
int nodes_len = 0;
if (num_nodes != 0) {
nodes_len = pack_nodes(data + FAKEID_DATA_MIN_LENGTH, FAKEID_DATA_MAX_LENGTH - FAKEID_DATA_MIN_LENGTH, nodes,
num_nodes);
if (nodes_len <= 0)
return -1;
}
int num1 = -1, num2 = -1;
if (onion_dht_both != 1)
num1 = send_onion_data(onion_c, friend_num, data, FAKEID_DATA_MIN_LENGTH + nodes_len);
if (onion_dht_both != 0)
num2 = send_dht_fakeid(onion_c, friend_num, data, FAKEID_DATA_MIN_LENGTH + nodes_len);
if (num1 == -1)
return num2;
if (num2 == -1)
return num1;
return num1 + num2;
}
/* Get the friend_num of a friend.
*
* return -1 on failure.
* return friend number on success.
*/
int onion_friend_num(const Onion_Client *onion_c, const uint8_t *client_id)
{
uint32_t i;
for (i = 0; i < onion_c->num_friends; ++i) {
if (onion_c->friends_list[i].status == 0)
continue;
if (memcmp(client_id, onion_c->friends_list[i].real_client_id, crypto_box_PUBLICKEYBYTES) == 0)
return i;
}
return -1;
}
/* Set the size of the friend list to num.
*
* return -1 if realloc fails.
* return 0 if it succeeds.
*/
static int realloc_onion_friends(Onion_Client *onion_c, uint32_t num)
{
if (num == 0) {
free(onion_c->friends_list);
onion_c->friends_list = NULL;
return 0;
}
Onion_Friend *newonion_friends = realloc(onion_c->friends_list, num * sizeof(Onion_Friend));
if (newonion_friends == NULL)
return -1;
onion_c->friends_list = newonion_friends;
return 0;
}
/* Add a friend who we want to connect to.
*
* return -1 on failure.
* return the friend number on success or if the friend was already added.
*/
int onion_addfriend(Onion_Client *onion_c, const uint8_t *client_id)
{
int num = onion_friend_num(onion_c, client_id);
if (num != -1)
return num;
uint32_t i, index = ~0;
for (i = 0; i < onion_c->num_friends; ++i) {
if (onion_c->friends_list[i].status == 0) {
index = i;
break;
}
}
if (index == (uint32_t)~0) {
if (realloc_onion_friends(onion_c, onion_c->num_friends + 1) == -1)
return -1;
index = onion_c->num_friends;
memset(&(onion_c->friends_list[onion_c->num_friends]), 0, sizeof(Onion_Friend));
++onion_c->num_friends;
}
onion_c->friends_list[index].status = 1;
memcpy(onion_c->friends_list[index].real_client_id, client_id, crypto_box_PUBLICKEYBYTES);
crypto_box_keypair(onion_c->friends_list[index].temp_public_key, onion_c->friends_list[index].temp_secret_key);
return index;
}
/* Delete a friend.
*
* return -1 on failure.
* return the deleted friend number on success.
*/
int onion_delfriend(Onion_Client *onion_c, int friend_num)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (onion_c->friends_list[friend_num].is_fake_clientid)
DHT_delfriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id);
memset(&(onion_c->friends_list[friend_num]), 0, sizeof(Onion_Friend));
uint32_t i;
for (i = onion_c->num_friends; i != 0; --i) {
if (onion_c->friends_list[i].status != 0)
break;
}
if (onion_c->num_friends != i) {
onion_c->num_friends = i;
realloc_onion_friends(onion_c, onion_c->num_friends);
}
return friend_num;
}
/* Set the function for this friend that will be callbacked with object and number
* when that friends gives us one of the TCP relays he is connected to.
*
* object and number will be passed as argument to this function.
*
* return -1 on failure.
* return 0 on success.
*/
int recv_tcp_relay_handler(Onion_Client *onion_c, int friend_num, int (*tcp_relay_node_callback)(void *object,
uint32_t number, IP_Port ip_port, uint8_t *public_key), void *object, uint32_t number)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
onion_c->friends_list[friend_num].tcp_relay_node_callback = tcp_relay_node_callback;
onion_c->friends_list[friend_num].tcp_relay_node_callback_object = object;
onion_c->friends_list[friend_num].tcp_relay_node_callback_number = number;
return 0;
}
/* Set a friends DHT public key.
* timestamp is the time (current_time_monotonic()) at which the key was last confirmed belonging to
* the other peer.
*
* return -1 on failure.
* return 0 on success.
*/
int onion_set_friend_DHT_pubkey(Onion_Client *onion_c, int friend_num, const uint8_t *dht_key, uint64_t timestamp)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (onion_c->friends_list[friend_num].status == 0)
return -1;
if (onion_c->friends_list[friend_num].fake_client_id_timestamp >= timestamp)
return -1;
if (onion_c->friends_list[friend_num].is_fake_clientid) {
if (memcmp(dht_key, onion_c->friends_list[friend_num].fake_client_id, crypto_box_PUBLICKEYBYTES) == 0) {
return -1;
}
DHT_delfriend(onion_c->dht, onion_c->friends_list[friend_num].fake_client_id);
}
if (DHT_addfriend(onion_c->dht, dht_key) == 1) {
return -1;
}
onion_c->friends_list[friend_num].last_seen = unix_time();
onion_c->friends_list[friend_num].is_fake_clientid = 1;
onion_c->friends_list[friend_num].fake_client_id_timestamp = timestamp;
memcpy(onion_c->friends_list[friend_num].fake_client_id, dht_key, crypto_box_PUBLICKEYBYTES);
return 0;
}
/* Copy friends DHT public key into dht_key.
*
* return 0 on failure (no key copied).
* return timestamp on success (key copied).
*/
uint64_t onion_getfriend_DHT_pubkey(Onion_Client *onion_c, int friend_num, uint8_t *dht_key)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return 0;
if (onion_c->friends_list[friend_num].status == 0)
return 0;
if (!onion_c->friends_list[friend_num].is_fake_clientid)
return 0;
memcpy(dht_key, onion_c->friends_list[friend_num].fake_client_id, crypto_box_PUBLICKEYBYTES);
return onion_c->friends_list[friend_num].fake_client_id_timestamp;
}
/* Get the ip of friend friendnum and put it in ip_port
*
* return -1, -- if client_id does NOT refer to a friend
* return 0, -- if client_id refers to a friend and we failed to find the friend (yet)
* return 1, ip if client_id refers to a friend and we found him
*
*/
int onion_getfriendip(Onion_Client *onion_c, int friend_num, IP_Port *ip_port)
{
uint8_t dht_public_key[crypto_box_PUBLICKEYBYTES];
if (onion_getfriend_DHT_pubkey(onion_c, friend_num, dht_public_key) == 0)
return -1;
return DHT_getfriendip(onion_c->dht, dht_public_key, ip_port);
}
/* Set if friend is online or not.
* NOTE: This function is there and should be used so that we don't send useless packets to the friend if he is online.
*
* is_online 1 means friend is online.
* is_online 0 means friend is offline
*
* return -1 on failure.
* return 0 on success.
*/
int onion_set_friend_online(Onion_Client *onion_c, int friend_num, uint8_t is_online)
{
if ((uint32_t)friend_num >= onion_c->num_friends)
return -1;
if (is_online == 0 && onion_c->friends_list[friend_num].is_online == 1)
onion_c->friends_list[friend_num].last_seen = unix_time();
onion_c->friends_list[friend_num].is_online = is_online;
/* This should prevent some clock related issues */
if (!is_online)
onion_c->friends_list[friend_num].last_noreplay = 0;
return 0;
}
#define ANNOUNCE_FRIEND ONION_NODE_PING_INTERVAL
static void do_friend(Onion_Client *onion_c, uint16_t friendnum)
{
if (friendnum >= onion_c->num_friends)
return;
if (onion_c->friends_list[friendnum].status == 0)
return;
uint32_t i, count = 0;
Onion_Node *list_nodes = onion_c->friends_list[friendnum].clients_list;
if (!onion_c->friends_list[friendnum].is_online) {
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++count;
if (list_nodes[i].last_pinged == 0) {
list_nodes[i].last_pinged = unix_time();
continue;
}
if (is_timeout(list_nodes[i].last_pinged, ANNOUNCE_FRIEND)) {
if (client_send_announce_request(onion_c, friendnum + 1, list_nodes[i].ip_port, list_nodes[i].client_id, 0, ~0) == 0) {
list_nodes[i].last_pinged = unix_time();
}
}
}
if (count != MAX_ONION_CLIENTS) {
if (count < (uint32_t)rand() % MAX_ONION_CLIENTS) {
Node_format nodes_list[MAX_SENT_NODES];
uint32_t num_nodes = get_close_nodes(onion_c->dht, onion_c->friends_list[friendnum].real_client_id, nodes_list,
(rand() % 2) ? AF_INET : AF_INET6, 1, 0);
for (i = 0; i < num_nodes; ++i)
client_send_announce_request(onion_c, friendnum + 1, nodes_list[i].ip_port, nodes_list[i].client_id, 0, ~0);
}
}
/* send packets to friend telling them our fake DHT id. */
if (is_timeout(onion_c->friends_list[friendnum].last_fakeid_onion_sent, ONION_FAKEID_INTERVAL))
if (send_fakeid_announce(onion_c, friendnum, 0) >= 1)
onion_c->friends_list[friendnum].last_fakeid_onion_sent = unix_time();
if (is_timeout(onion_c->friends_list[friendnum].last_fakeid_dht_sent, DHT_FAKEID_INTERVAL))
if (send_fakeid_announce(onion_c, friendnum, 1) >= 1)
onion_c->friends_list[friendnum].last_fakeid_dht_sent = unix_time();
}
}
/* Timeout before which a peer is considered dead and removed from the DHT search. */
#define DEAD_ONION_TIMEOUT (10 * 60)
static void cleanup_friend(Onion_Client *onion_c, uint16_t friendnum)
{
if (friendnum >= onion_c->num_friends)
return;
if (onion_c->friends_list[friendnum].status == 0)
return;
if (onion_c->friends_list[friendnum].is_fake_clientid && !onion_c->friends_list[friendnum].is_online
&& is_timeout(onion_c->friends_list[friendnum].last_seen, DEAD_ONION_TIMEOUT)) {
onion_c->friends_list[friendnum].is_fake_clientid = 0;
DHT_delfriend(onion_c->dht, onion_c->friends_list[friendnum].fake_client_id);
}
}
/* Function to call when onion data packet with contents beginning with byte is received. */
void oniondata_registerhandler(Onion_Client *onion_c, uint8_t byte, oniondata_handler_callback cb, void *object)
{
onion_c->Onion_Data_Handlers[byte].function = cb;
onion_c->Onion_Data_Handlers[byte].object = object;
}
#define ANNOUNCE_INTERVAL_NOT_ANNOUNCED 10
#define ANNOUNCE_INTERVAL_ANNOUNCED ONION_NODE_PING_INTERVAL
static void do_announce(Onion_Client *onion_c)
{
uint32_t i, count = 0;
Onion_Node *list_nodes = onion_c->clients_announce_list;
for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
if (is_timeout(list_nodes[i].timestamp, ONION_NODE_TIMEOUT))
continue;
++count;
/* Don't announce ourselves the first time this is run to new peers */
if (list_nodes[i].last_pinged == 0) {
list_nodes[i].last_pinged = 1;
continue;
}
uint32_t interval = ANNOUNCE_INTERVAL_NOT_ANNOUNCED;
if (list_nodes[i].is_stored) {
interval = ANNOUNCE_INTERVAL_ANNOUNCED;
}
if (is_timeout(list_nodes[i].last_pinged, interval)) {
if (client_send_announce_request(onion_c, 0, list_nodes[i].ip_port, list_nodes[i].client_id,
list_nodes[i].ping_id, list_nodes[i].path_used) == 0) {
list_nodes[i].last_pinged = unix_time();
}
}
}
if (count != MAX_ONION_CLIENTS) {
if (count < (uint32_t)rand() % MAX_ONION_CLIENTS) {
Node_format nodes_list[MAX_SENT_NODES];
uint32_t num_nodes = get_close_nodes(onion_c->dht, onion_c->c->self_public_key, nodes_list,
(rand() % 2) ? AF_INET : AF_INET6, 1, 0);
for (i = 0; i < num_nodes; ++i) {
client_send_announce_request(onion_c, 0, nodes_list[i].ip_port, nodes_list[i].client_id, 0, ~0);
}
}
}
}
void do_onion_client(Onion_Client *onion_c)
{
uint32_t i;
if (onion_c->last_run == unix_time())
return;
do_announce(onion_c);
for (i = 0; i < onion_c->num_friends; ++i) {
do_friend(onion_c, i);
cleanup_friend(onion_c, i);
}
onion_c->last_run = unix_time();
}
Onion_Client *new_onion_client(Net_Crypto *c)
{
if (c == NULL)
return NULL;
Onion_Client *onion_c = calloc(1, sizeof(Onion_Client));
if (onion_c == NULL)
return NULL;
if (ping_array_init(&onion_c->announce_ping_array, ANNOUNCE_ARRAY_SIZE, ANNOUNCE_TIMEOUT) != 0) {
free(onion_c);
return NULL;
}
onion_c->dht = c->dht;
onion_c->net = c->dht->net;
onion_c->c = c;
new_symmetric_key(onion_c->secret_symmetric_key);
crypto_box_keypair(onion_c->temp_public_key, onion_c->temp_secret_key);
networking_registerhandler(onion_c->net, NET_PACKET_ANNOUNCE_RESPONSE, &handle_announce_response, onion_c);
networking_registerhandler(onion_c->net, NET_PACKET_ONION_DATA_RESPONSE, &handle_data_response, onion_c);
oniondata_registerhandler(onion_c, FAKEID_DATA_ID, &handle_fakeid_announce, onion_c);
cryptopacket_registerhandler(onion_c->dht, FAKEID_DATA_ID, &handle_dht_fakeid, onion_c);
return onion_c;
}
void kill_onion_client(Onion_Client *onion_c)
{
if (onion_c == NULL)
return;
ping_array_free_all(&onion_c->announce_ping_array);
realloc_onion_friends(onion_c, 0);
networking_registerhandler(onion_c->net, NET_PACKET_ANNOUNCE_RESPONSE, NULL, NULL);
networking_registerhandler(onion_c->net, NET_PACKET_ONION_DATA_RESPONSE, NULL, NULL);
oniondata_registerhandler(onion_c, FAKEID_DATA_ID, NULL, NULL);
cryptopacket_registerhandler(onion_c->dht, FAKEID_DATA_ID, NULL, NULL);
memset(onion_c, 0, sizeof(Onion_Client));
free(onion_c);
}