/* return 0 if ip is a LAN ip.
* return -1 if it is not.
*/
int ip_is_lan(IP ip)
{
if (ip_is_local(ip)) {
return 0;
}
if (ip.family == TOX_AF_INET) {
IP4 ip4 = ip.ip.v4;
/* 10.0.0.0 to 10.255.255.255 range. */
if (ip4.uint8[0] == 10) {
return 0;
}
/* 172.16.0.0 to 172.31.255.255 range. */
if (ip4.uint8[0] == 172 && ip4.uint8[1] >= 16 && ip4.uint8[1] <= 31) {
return 0;
}
/* 192.168.0.0 to 192.168.255.255 range. */
if (ip4.uint8[0] == 192 && ip4.uint8[1] == 168) {
return 0;
}
/* 169.254.1.0 to 169.254.254.255 range. */
if (ip4.uint8[0] == 169 && ip4.uint8[1] == 254 && ip4.uint8[2] != 0
&& ip4.uint8[2] != 255) {
return 0;
}
/* RFC 6598: 100.64.0.0 to 100.127.255.255 (100.64.0.0/10)
* (shared address space to stack another layer of NAT) */
if ((ip4.uint8[0] == 100) && ((ip4.uint8[1] & 0xC0) == 0x40)) {
return 0;
}
} else if (ip.family == TOX_AF_INET6) {
/* autogenerated for each interface: FE80::* (up to FEBF::*)
FF02::1 is - according to RFC 4291 - multicast all-nodes link-local */
if (((ip.ip.v6.uint8[0] == 0xFF) && (ip.ip.v6.uint8[1] < 3) && (ip.ip.v6.uint8[15] == 1)) ||
((ip.ip.v6.uint8[0] == 0xFE) && ((ip.ip.v6.uint8[1] & 0xC0) == 0x80))) {
return 0;
}
/* embedded IPv4-in-IPv6 */
if (IPV6_IPV4_IN_V6(ip.ip.v6)) {
IP ip4;
ip4.family = TOX_AF_INET;
ip4.ip.v4.uint32 = ip.ip.v6.uint32[3];
return ip_is_lan(ip4);
}
}
return -1;
}
static int handle_LANdiscovery(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
{
DHT *dht = (DHT *)object;
char ip_str[IP_NTOA_LEN] = { 0 };
ip_ntoa(&source.ip, ip_str, sizeof(ip_str));
if (ip_is_lan(source.ip) == -1) {
return 1;
}
if (length != CRYPTO_PUBLIC_KEY_SIZE + 1) {
return 1;
}
DHT_bootstrap(dht, source, packet + 1);
return 0;
}
static int handle_announce_request(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
{
Onion_Announce *onion_a = (Onion_Announce *)object;
if (length != ANNOUNCE_REQUEST_SIZE_RECV) {
return 1;
}
const uint8_t *packet_public_key = packet + 1 + CRYPTO_NONCE_SIZE;
uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];
get_shared_key(onion_a->mono_time, &onion_a->shared_keys_recv, shared_key, dht_get_self_secret_key(onion_a->dht),
packet_public_key);
uint8_t plain[ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE +
ONION_ANNOUNCE_SENDBACK_DATA_LENGTH];
int len = decrypt_data_symmetric(shared_key, packet + 1, packet + 1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE,
ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH +
CRYPTO_MAC_SIZE, plain);
if ((uint32_t)len != sizeof(plain)) {
return 1;
}
uint8_t ping_id1[ONION_PING_ID_SIZE];
generate_ping_id(onion_a, mono_time_get(onion_a->mono_time), packet_public_key, source, ping_id1);
uint8_t ping_id2[ONION_PING_ID_SIZE];
generate_ping_id(onion_a, mono_time_get(onion_a->mono_time) + PING_ID_TIMEOUT, packet_public_key, source, ping_id2);
int index;
uint8_t *data_public_key = plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE;
if (crypto_memcmp(ping_id1, plain, ONION_PING_ID_SIZE) == 0
|| crypto_memcmp(ping_id2, plain, ONION_PING_ID_SIZE) == 0) {
index = add_to_entries(onion_a, source, packet_public_key, data_public_key,
packet + (ANNOUNCE_REQUEST_SIZE_RECV - ONION_RETURN_3));
} else {
index = in_entries(onion_a, plain + ONION_PING_ID_SIZE);
}
/*Respond with a announce response packet*/
Node_format nodes_list[MAX_SENT_NODES];
unsigned int num_nodes =
get_close_nodes(onion_a->dht, plain + ONION_PING_ID_SIZE, nodes_list, net_family_unspec, ip_is_lan(source.ip), 1);
uint8_t nonce[CRYPTO_NONCE_SIZE];
random_nonce(nonce);
uint8_t pl[1 + ONION_PING_ID_SIZE + sizeof(nodes_list)];
if (index == -1) {
pl[0] = 0;
memcpy(pl + 1, ping_id2, ONION_PING_ID_SIZE);
} else {
if (public_key_cmp(onion_a->entries[index].public_key, packet_public_key) == 0) {
if (public_key_cmp(onion_a->entries[index].data_public_key, data_public_key) != 0) {
pl[0] = 0;
memcpy(pl + 1, ping_id2, ONION_PING_ID_SIZE);
} else {
pl[0] = 2;
memcpy(pl + 1, ping_id2, ONION_PING_ID_SIZE);
}
} else {
pl[0] = 1;
memcpy(pl + 1, onion_a->entries[index].data_public_key, CRYPTO_PUBLIC_KEY_SIZE);
}
}
int nodes_length = 0;
if (num_nodes != 0) {
nodes_length = pack_nodes(pl + 1 + ONION_PING_ID_SIZE, sizeof(nodes_list), nodes_list, num_nodes);
if (nodes_length <= 0) {
return 1;
}
}
uint8_t data[ONION_ANNOUNCE_RESPONSE_MAX_SIZE];
len = encrypt_data_symmetric(shared_key, nonce, pl, 1 + ONION_PING_ID_SIZE + nodes_length,
data + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE);
if (len != 1 + ONION_PING_ID_SIZE + nodes_length + CRYPTO_MAC_SIZE) {
return 1;
}
data[0] = NET_PACKET_ANNOUNCE_RESPONSE;
memcpy(data + 1, plain + ONION_PING_ID_SIZE + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_PUBLIC_KEY_SIZE,
ONION_ANNOUNCE_SENDBACK_DATA_LENGTH);
memcpy(data + 1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH, nonce, CRYPTO_NONCE_SIZE);
if (send_onion_response(onion_a->net, source, data,
1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE + len,
packet + (ANNOUNCE_REQUEST_SIZE_RECV - ONION_RETURN_3)) == -1) {
return 1;
}
return 0;
}
