libtox moved to tox folder instead of libs

1 files changed, 1771 insertions, 0 deletions

diff --git a/protocols/Tox/libtox/src/toxcore/onion_client.c b/protocols/Tox/libtox/src/toxcore/onion_client.c
new file mode 100644
index 0000000000..94e9c91652
--- /dev/null
+++ b/protocols/Tox/libtox/src/toxcore/onion_client.c
@@ -0,0 +1,1771 @@
+/*
+ * Implementation of the client part of docs/Prevent_Tracking.txt (The part that
+ * uses the onion stuff to connect to the friend)
+ */
+
+/*
+ * Copyright © 2016-2017 The TokTok team.
+ * Copyright © 2013 Tox project.
+ *
+ * This file is part of Tox, the free peer to peer instant messenger.
+ *
+ * Tox is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Tox is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Tox.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "onion_client.h"
+
+#include "LAN_discovery.h"
+#include "util.h"
+
+/* defines for the array size and
+   timeout for onion announce packets. */
+#define ANNOUNCE_ARRAY_SIZE 256
+#define ANNOUNCE_TIMEOUT 10
+
+/* Add a node to the path_nodes bootstrap array.
+ *
+ * return -1 on failure
+ * return 0 on success
+ */
+int onion_add_bs_path_node(Onion_Client *onion_c, IP_Port ip_port, const uint8_t *public_key)
+{
+    if (ip_port.ip.family != TOX_AF_INET && ip_port.ip.family != TOX_AF_INET6) {
+        return -1;
+    }
+
+    unsigned int i;
+
+    for (i = 0; i < MAX_PATH_NODES; ++i) {
+        if (public_key_cmp(public_key, onion_c->path_nodes_bs[i].public_key) == 0) {
+            return -1;
+        }
+    }
+
+    onion_c->path_nodes_bs[onion_c->path_nodes_index_bs % MAX_PATH_NODES].ip_port = ip_port;
+    memcpy(onion_c->path_nodes_bs[onion_c->path_nodes_index_bs % MAX_PATH_NODES].public_key, public_key,
+           CRYPTO_PUBLIC_KEY_SIZE);
+
+    uint16_t last = onion_c->path_nodes_index_bs;
+    ++onion_c->path_nodes_index_bs;
+
+    if (onion_c->path_nodes_index_bs < last) {
+        onion_c->path_nodes_index_bs = MAX_PATH_NODES + 1;
+    }
+
+    return 0;
+}
+
+/* Add a node to the path_nodes array.
+ *
+ * return -1 on failure
+ * return 0 on success
+ */
+static int onion_add_path_node(Onion_Client *onion_c, IP_Port ip_port, const uint8_t *public_key)
+{
+    if (ip_port.ip.family != TOX_AF_INET && ip_port.ip.family != TOX_AF_INET6) {
+        return -1;
+    }
+
+    unsigned int i;
+
+    for (i = 0; i < MAX_PATH_NODES; ++i) {
+        if (public_key_cmp(public_key, onion_c->path_nodes[i].public_key) == 0) {
+            return -1;
+        }
+    }
+
+    onion_c->path_nodes[onion_c->path_nodes_index % MAX_PATH_NODES].ip_port = ip_port;
+    memcpy(onion_c->path_nodes[onion_c->path_nodes_index % MAX_PATH_NODES].public_key, public_key,
+           CRYPTO_PUBLIC_KEY_SIZE);
+
+    uint16_t last = onion_c->path_nodes_index;
+    ++onion_c->path_nodes_index;
+
+    if (onion_c->path_nodes_index < last) {
+        onion_c->path_nodes_index = MAX_PATH_NODES + 1;
+    }
+
+    return 0;
+}
+
+/* Put up to max_num nodes in nodes.
+ *
+ * return the number of nodes.
+ */
+uint16_t onion_backup_nodes(const Onion_Client *onion_c, Node_format *nodes, uint16_t max_num)
+{
+    unsigned int i;
+
+    if (!max_num) {
+        return 0;
+    }
+
+    unsigned int num_nodes = (onion_c->path_nodes_index < MAX_PATH_NODES) ? onion_c->path_nodes_index : MAX_PATH_NODES;
+
+    if (num_nodes == 0) {
+        return 0;
+    }
+
+    if (num_nodes < max_num) {
+        max_num = num_nodes;
+    }
+
+    for (i = 0; i < max_num; ++i) {
+        nodes[i] = onion_c->path_nodes[(onion_c->path_nodes_index - (1 + i)) % num_nodes];
+    }
+
+    return max_num;
+}
+
+/* Put up to max_num random nodes in nodes.
+ *
+ * return the number of nodes.
+ */
+static uint16_t random_nodes_path_onion(const Onion_Client *onion_c, Node_format *nodes, uint16_t max_num)
+{
+    unsigned int i;
+
+    if (!max_num) {
+        return 0;
+    }
+
+    unsigned int num_nodes = (onion_c->path_nodes_index < MAX_PATH_NODES) ? onion_c->path_nodes_index : MAX_PATH_NODES;
+
+    //if (DHT_non_lan_connected(onion_c->dht)) {
+    if (DHT_isconnected(onion_c->dht)) {
+        if (num_nodes == 0) {
+            return 0;
+        }
+
+        for (i = 0; i < max_num; ++i) {
+            nodes[i] = onion_c->path_nodes[rand() % num_nodes];
+        }
+    } else {
+        int random_tcp = get_random_tcp_con_number(onion_c->c);
+
+        if (random_tcp == -1) {
+            return 0;
+        }
+
+        if (num_nodes >= 2) {
+            nodes[0].ip_port.ip.family = TCP_FAMILY;
+            nodes[0].ip_port.ip.ip4.uint32 = random_tcp;
+
+            for (i = 1; i < max_num; ++i) {
+                nodes[i] = onion_c->path_nodes[rand() % num_nodes];
+            }
+        } else {
+            unsigned int num_nodes_bs = (onion_c->path_nodes_index_bs < MAX_PATH_NODES) ? onion_c->path_nodes_index_bs :
+                                        MAX_PATH_NODES;
+
+            if (num_nodes_bs == 0) {
+                return 0;
+            }
+
+            nodes[0].ip_port.ip.family = TCP_FAMILY;
+            nodes[0].ip_port.ip.ip4.uint32 = random_tcp;
+
+            for (i = 1; i < max_num; ++i) {
+                nodes[i] = onion_c->path_nodes_bs[rand() % num_nodes_bs];
+            }
+        }
+    }
+
+    return max_num;
+}
+
+/*
+ * 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(const Onion_Client_Paths *onion_paths, const Node_format *nodes)
+{
+    unsigned int 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;
+        }
+
+        // TODO(irungentoo): do we really have to check it with the last node?
+        if (ipport_equal(&onion_paths->paths[i].ip_port1, &nodes[ONION_PATH_LENGTH - 1].ip_port)) {
+            return i;
+        }
+    }
+
+    return -1;
+}
+
+/* is path timed out */
+static bool path_timed_out(Onion_Client_Paths *onion_paths, uint32_t pathnum)
+{
+    pathnum = pathnum % NUMBER_ONION_PATHS;
+
+    bool is_new = onion_paths->last_path_success[pathnum] == onion_paths->path_creation_time[pathnum];
+    uint64_t timeout = is_new ? ONION_PATH_FIRST_TIMEOUT : ONION_PATH_TIMEOUT;
+
+    return ((onion_paths->last_path_used_times[pathnum] >= ONION_PATH_MAX_NO_RESPONSE_USES
+             && is_timeout(onion_paths->last_path_used[pathnum], timeout))
+            || is_timeout(onion_paths->path_creation_time[pathnum], ONION_PATH_MAX_LIFETIME));
+}
+
+/* should node be considered to have timed out */
+static bool onion_node_timed_out(const Onion_Node *node)
+{
+    return (node->timestamp == 0
+            || (node->unsuccessful_pings >= ONION_NODE_MAX_PINGS
+                && is_timeout(node->last_pinged, ONION_NODE_TIMEOUT)));
+}
+
+/* Create a new path or use an old suitable one (if pathnum is valid)
+ * or a random one from onion_paths.
+ *
+ * return -1 on failure
+ * return 0 on success
+ *
+ * TODO(irungentoo): Make this function better, it currently probably is
+ * vulnerable to some attacks that could deanonimize us.
+ */
+static int random_path(const Onion_Client *onion_c, Onion_Client_Paths *onion_paths, uint32_t pathnum, Onion_Path *path)
+{
+    if (pathnum == UINT32_MAX) {
+        pathnum = rand() % NUMBER_ONION_PATHS;
+    } else {
+        pathnum = pathnum % NUMBER_ONION_PATHS;
+    }
+
+    if (path_timed_out(onion_paths, pathnum)) {
+        Node_format nodes[ONION_PATH_LENGTH];
+
+        if (random_nodes_path_onion(onion_c, nodes, ONION_PATH_LENGTH) != ONION_PATH_LENGTH) {
+            return -1;
+        }
+
+        int n = is_path_used(onion_paths, nodes);
+
+        if (n == -1) {
+            if (create_onion_path(onion_c->dht, &onion_paths->paths[pathnum], nodes) == -1) {
+                return -1;
+            }
+
+            onion_paths->path_creation_time[pathnum] = unix_time();
+            onion_paths->last_path_success[pathnum] = onion_paths->path_creation_time[pathnum];
+            onion_paths->last_path_used_times[pathnum] = ONION_PATH_MAX_NO_RESPONSE_USES / 2;
+
+            uint32_t path_num = rand();
+            path_num /= NUMBER_ONION_PATHS;
+            path_num *= NUMBER_ONION_PATHS;
+            path_num += pathnum;
+
+            onion_paths->paths[pathnum].path_num = path_num;
+        } else {
+            pathnum = n;
+        }
+    }
+
+    if (onion_paths->last_path_used_times[pathnum] < ONION_PATH_MAX_NO_RESPONSE_USES) {
+        onion_paths->last_path_used[pathnum] = unix_time();
+    }
+
+    ++onion_paths->last_path_used_times[pathnum];
+    memcpy(path, &onion_paths->paths[pathnum], sizeof(Onion_Path));
+    return 0;
+}
+
+/* Does path with path_num exist. */
+static bool path_exists(Onion_Client_Paths *onion_paths, uint32_t path_num)
+{
+    if (path_timed_out(onion_paths, path_num)) {
+        return 0;
+    }
+
+    return onion_paths->paths[path_num % NUMBER_ONION_PATHS].path_num == path_num;
+}
+
+/* Set path timeouts, return the path number.
+ *
+ */
+static uint32_t set_path_timeouts(Onion_Client *onion_c, uint32_t num, uint32_t path_num)
+{
+    if (num > onion_c->num_friends) {
+        return -1;
+    }
+
+    Onion_Client_Paths *onion_paths;
+
+    if (num == 0) {
+        onion_paths = &onion_c->onion_paths_self;
+    } else {
+        onion_paths = &onion_c->onion_paths_friends;
+    }
+
+    if (onion_paths->paths[path_num % NUMBER_ONION_PATHS].path_num == path_num) {
+        onion_paths->last_path_success[path_num % NUMBER_ONION_PATHS] = unix_time();
+        onion_paths->last_path_used_times[path_num % NUMBER_ONION_PATHS] = 0;
+
+        Node_format nodes[ONION_PATH_LENGTH];
+
+        if (onion_path_to_nodes(nodes, ONION_PATH_LENGTH, &onion_paths->paths[path_num % NUMBER_ONION_PATHS]) == 0) {
+            unsigned int i;
+
+            for (i = 0; i < ONION_PATH_LENGTH; ++i) {
+                onion_add_path_node(onion_c, nodes[i].ip_port, nodes[i].public_key);
+            }
+        }
+
+        return path_num;
+    }
+
+    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, const Onion_Path *path, IP_Port dest,
+                                     const uint8_t *data, uint16_t length)
+{
+    if (path->ip_port1.ip.family == TOX_AF_INET || path->ip_port1.ip.family == TOX_AF_INET6) {
+        uint8_t packet[ONION_MAX_PACKET_SIZE];
+        int len = create_onion_packet(packet, sizeof(packet), path, dest, data, length);
+
+        if (len == -1) {
+            return -1;
+        }
+
+        if (sendpacket(onion_c->net, path->ip_port1, packet, len) != len) {
+            return -1;
+        }
+
+        return 0;
+    }
+
+    if (path->ip_port1.ip.family == TCP_FAMILY) {
+        uint8_t packet[ONION_MAX_PACKET_SIZE];
+        int len = create_onion_packet_tcp(packet, sizeof(packet), path, dest, data, length);
+
+        if (len == -1) {
+            return -1;
+        }
+
+        return send_tcp_onion_request(onion_c->c, path->ip_port1.ip.ip4.uint32, packet, len);
+    }
+
+    return -1;
+}
+
+/* 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, const uint8_t *public_key, IP_Port ip_port,
+                        uint32_t path_num, uint64_t *sendback)
+{
+    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port) + sizeof(uint32_t)];
+    memcpy(data, &num, sizeof(uint32_t));
+    memcpy(data + sizeof(uint32_t), public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    memcpy(data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE, &ip_port, sizeof(IP_Port));
+    memcpy(data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port), &path_num, sizeof(uint32_t));
+    *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_PUBLIC_KEY_SIZE 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, uint32_t *path_num)
+{
+    uint64_t sback;
+    memcpy(&sback, sendback, sizeof(uint64_t));
+    uint8_t data[sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port) + sizeof(uint32_t)];
+
+    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_PUBLIC_KEY_SIZE);
+    memcpy(ret_ip_port, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE, sizeof(IP_Port));
+    memcpy(path_num, data + sizeof(uint32_t) + CRYPTO_PUBLIC_KEY_SIZE + sizeof(IP_Port), sizeof(uint32_t));
+
+    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, const uint8_t *dest_pubkey,
+                                        const uint8_t *ping_id, uint32_t pathnum)
+{
+    if (num > onion_c->num_friends) {
+        return -1;
+    }
+
+    uint64_t sendback;
+    Onion_Path path;
+
+    if (num == 0) {
+        if (random_path(onion_c, &onion_c->onion_paths_self, pathnum, &path) == -1) {
+            return -1;
+        }
+    } else {
+        if (random_path(onion_c, &onion_c->onion_paths_friends, pathnum, &path) == -1) {
+            return -1;
+        }
+    }
+
+    if (new_sendback(onion_c, num, dest_pubkey, dest, path.path_num, &sendback) == -1) {
+        return -1;
+    }
+
+    uint8_t zero_ping_id[ONION_PING_ID_SIZE] = {0};
+
+    if (ping_id == NULL) {
+        ping_id = zero_ping_id;
+    }
+
+    uint8_t request[ONION_ANNOUNCE_REQUEST_SIZE];
+    int len;
+
+    if (num == 0) {
+        len = create_announce_request(request, sizeof(request), dest_pubkey, 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);
+    } else {
+        len = create_announce_request(request, sizeof(request), dest_pubkey, 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_public_key, zero_ping_id,
+                                      sendback);
+    }
+
+    if (len == -1) {
+        return -1;
+    }
+
+    return send_onion_packet_tcp_udp(onion_c, &path, dest, request, len);
+}
+
+typedef struct {
+    const uint8_t *base_public_key;
+    Onion_Node entry;
+} Onion_Client_Cmp_data;
+
+static int onion_client_cmp_entry(const void *a, const void *b)
+{
+    Onion_Client_Cmp_data cmp1, cmp2;
+    memcpy(&cmp1, a, sizeof(Onion_Client_Cmp_data));
+    memcpy(&cmp2, b, sizeof(Onion_Client_Cmp_data));
+    Onion_Node entry1 = cmp1.entry;
+    Onion_Node entry2 = cmp2.entry;
+    const uint8_t *cmp_public_key = cmp1.base_public_key;
+
+    int t1 = onion_node_timed_out(&entry1);
+    int t2 = onion_node_timed_out(&entry2);
+
+    if (t1 && t2) {
+        return 0;
+    }
+
+    if (t1) {
+        return -1;
+    }
+
+    if (t2) {
+        return 1;
+    }
+
+    int close = id_closest(cmp_public_key, entry1.public_key, entry2.public_key);
+
+    if (close == 1) {
+        return 1;
+    }
+
+    if (close == 2) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static void sort_onion_node_list(Onion_Node *list, unsigned int length, const uint8_t *comp_public_key)
+{
+    // Pass comp_public_key to qsort with each Client_data entry, so the
+    // comparison function can use it as the base of comparison.
+    VLA(Onion_Client_Cmp_data, cmp_list, length);
+
+    for (uint32_t i = 0; i < length; i++) {
+        cmp_list[i].base_public_key = comp_public_key;
+        cmp_list[i].entry = list[i];
+    }
+
+    qsort(cmp_list, length, sizeof(Onion_Client_Cmp_data), onion_client_cmp_entry);
+
+    for (uint32_t i = 0; i < length; i++) {
+        list[i] = cmp_list[i].entry;
+    }
+}
+
+static int client_add_to_list(Onion_Client *onion_c, uint32_t num, const uint8_t *public_key, IP_Port ip_port,
+                              uint8_t is_stored, const uint8_t *pingid_or_key, uint32_t path_used)
+{
+    if (num > onion_c->num_friends) {
+        return -1;
+    }
+
+    Onion_Node *list_nodes = NULL;
+    uint8_t *reference_id = NULL;
+    unsigned int list_length;
+
+    if (num == 0) {
+        list_nodes = onion_c->clients_announce_list;
+        reference_id = onion_c->c->self_public_key;
+        list_length = MAX_ONION_CLIENTS_ANNOUNCE;
+
+        if (is_stored == 1 && public_key_cmp(pingid_or_key, onion_c->temp_public_key) != 0) {
+            is_stored = 0;
+        }
+    } else {
+        if (is_stored >= 2) {
+            return -1;
+        }
+
+        if (is_stored == 1) {
+            onion_c->friends_list[num - 1].last_reported_announced = unix_time();
+        }
+
+        list_nodes = onion_c->friends_list[num - 1].clients_list;
+        reference_id = onion_c->friends_list[num - 1].real_public_key;
+        list_length = MAX_ONION_CLIENTS;
+    }
+
+    sort_onion_node_list(list_nodes, list_length, reference_id);
+
+    int index = -1, stored = 0;
+    unsigned int i;
+
+    if (onion_node_timed_out(&list_nodes[0])
+            || id_closest(reference_id, list_nodes[0].public_key, public_key) == 2) {
+        index = 0;
+    }
+
+    for (i = 0; i < list_length; ++i) {
+        if (public_key_cmp(list_nodes[i].public_key, public_key) == 0) {
+            index = i;
+            stored = 1;
+            break;
+        }
+    }
+
+    if (index == -1) {
+        return 0;
+    }
+
+    memcpy(list_nodes[index].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    list_nodes[index].ip_port = ip_port;
+
+    // TODO(irungentoo): remove this and find a better source of nodes to use for paths.
+    onion_add_path_node(onion_c, ip_port, public_key);
+
+    if (is_stored == 1) {
+        memcpy(list_nodes[index].data_public_key, pingid_or_key, CRYPTO_PUBLIC_KEY_SIZE);
+    } 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].unsuccessful_pings = 0;
+
+    if (!stored) {
+        list_nodes[index].last_pinged = 0;
+        list_nodes[index].added_time = unix_time();
+    }
+
+    list_nodes[index].path_used = path_used;
+    return 0;
+}
+
+static int good_to_ping(Last_Pinged *last_pinged, uint8_t *last_pinged_index, const uint8_t *public_key)
+{
+    unsigned int i;
+
+    for (i = 0; i < MAX_STORED_PINGED_NODES; ++i) {
+        if (!is_timeout(last_pinged[i].timestamp, MIN_NODE_PING_TIME)) {
+            if (public_key_cmp(last_pinged[i].public_key, public_key) == 0) {
+                return 0;
+            }
+        }
+    }
+
+    memcpy(last_pinged[*last_pinged_index % MAX_STORED_PINGED_NODES].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    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, const 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;
+    unsigned int list_length;
+
+    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;
+        list_length = MAX_ONION_CLIENTS_ANNOUNCE;
+        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_public_key;
+        list_length = MAX_ONION_CLIENTS;
+        last_pinged = onion_c->friends_list[num - 1].last_pinged;
+        last_pinged_index = &onion_c->friends_list[num - 1].last_pinged_index;
+    }
+
+    unsigned int 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 (onion_node_timed_out(&list_nodes[0])
+                || id_closest(reference_id, list_nodes[0].public_key, nodes[i].public_key) == 2
+                || onion_node_timed_out(&list_nodes[1])
+                || id_closest(reference_id, list_nodes[1].public_key, nodes[i].public_key) == 2) {
+            /* check if node is already in list. */
+            for (j = 0; j < list_length; ++j) {
+                if (public_key_cmp(list_nodes[j].public_key, nodes[i].public_key) == 0) {
+                    break;
+                }
+            }
+
+            if (j == list_length && good_to_ping(last_pinged, last_pinged_index, nodes[i].public_key)) {
+                client_send_announce_request(onion_c, num, nodes[i].ip_port, nodes[i].public_key, NULL, ~0);
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int handle_announce_response(void *object, IP_Port source, const uint8_t *packet, uint16_t length,
+                                    void *userdata)
+{
+    Onion_Client *onion_c = (Onion_Client *)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_PUBLIC_KEY_SIZE];
+    IP_Port ip_port;
+    uint32_t path_num;
+    uint32_t num = check_sendback(onion_c, packet + 1, public_key, &ip_port, &path_num);
+
+    if (num > onion_c->num_friends) {
+        return 1;
+    }
+
+    VLA(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_NONCE_SIZE,
+                           length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE), 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_NONCE_SIZE,
+                           length - (1 + ONION_ANNOUNCE_SENDBACK_DATA_LENGTH + CRYPTO_NONCE_SIZE), plain);
+    }
+
+    if ((uint32_t)len != SIZEOF_VLA(plain)) {
+        return 1;
+    }
+
+    uint32_t path_used = set_path_timeouts(onion_c, num, path_num);
+
+    if (client_add_to_list(onion_c, num, public_key, ip_port, plain[0], plain + 1, path_used) == -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;
+        }
+    }
+
+    // TODO(irungentoo): LAN vs non LAN ips?, if we are connected only to LAN, are we offline?
+    onion_c->last_packet_recv = unix_time();
+    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, uint16_t length, void *userdata)
+{
+    Onion_Client *onion_c = (Onion_Client *)object;
+
+    if (length <= (ONION_DATA_RESPONSE_MIN_SIZE + DATA_IN_RESPONSE_MIN_SIZE)) {
+        return 1;
+    }
+
+    if (length > MAX_DATA_REQUEST_SIZE) {
+        return 1;
+    }
+
+    VLA(uint8_t, temp_plain, length - ONION_DATA_RESPONSE_MIN_SIZE);
+    int len = decrypt_data(packet + 1 + CRYPTO_NONCE_SIZE, onion_c->temp_secret_key, packet + 1,
+                           packet + 1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE,
+                           length - (1 + CRYPTO_NONCE_SIZE + CRYPTO_PUBLIC_KEY_SIZE), temp_plain);
+
+    if ((uint32_t)len != SIZEOF_VLA(temp_plain)) {
+        return 1;
+    }
+
+    VLA(uint8_t, plain, SIZEOF_VLA(temp_plain) - DATA_IN_RESPONSE_MIN_SIZE);
+    len = decrypt_data(temp_plain, onion_c->c->self_secret_key, packet + 1, temp_plain + CRYPTO_PUBLIC_KEY_SIZE,
+                       SIZEOF_VLA(temp_plain) - CRYPTO_PUBLIC_KEY_SIZE, plain);
+
+    if ((uint32_t)len != SIZEOF_VLA(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_VLA(plain), userdata);
+}
+
+#define DHTPK_DATA_MIN_LENGTH (1 + sizeof(uint64_t) + CRYPTO_PUBLIC_KEY_SIZE)
+#define DHTPK_DATA_MAX_LENGTH (DHTPK_DATA_MIN_LENGTH + sizeof(Node_format)*MAX_SENT_NODES)
+static int handle_dhtpk_announce(void *object, const uint8_t *source_pubkey, const uint8_t *data, uint16_t length,
+                                 void *userdata)
+{
+    Onion_Client *onion_c = (Onion_Client *)object;
+
+    if (length < DHTPK_DATA_MIN_LENGTH) {
+        return 1;
+    }
+
+    if (length > DHTPK_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;
+
+    if (onion_c->friends_list[friend_num].dht_pk_callback) {
+        onion_c->friends_list[friend_num].dht_pk_callback(onion_c->friends_list[friend_num].dht_pk_callback_object,
+                onion_c->friends_list[friend_num].dht_pk_callback_number, data + 1 + sizeof(uint64_t), userdata);
+    }
+
+    onion_set_friend_DHT_pubkey(onion_c, friend_num, data + 1 + sizeof(uint64_t));
+    onion_c->friends_list[friend_num].last_seen = unix_time();
+
+    uint16_t len_nodes = length - DHTPK_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_PUBLIC_KEY_SIZE,
+                                     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 == TOX_AF_INET || family == TOX_AF_INET6) {
+                DHT_getnodes(onion_c->dht, &nodes[i].ip_port, nodes[i].public_key, onion_c->friends_list[friend_num].dht_public_key);
+            } 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].public_key);
+                }
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int handle_tcp_onion(void *object, const uint8_t *data, uint16_t length, void *userdata)
+{
+    if (length == 0) {
+        return 1;
+    }
+
+    IP_Port ip_port = {{0}};
+    ip_port.ip.family = TCP_FAMILY;
+
+    if (data[0] == NET_PACKET_ANNOUNCE_RESPONSE) {
+        return handle_announce_response(object, ip_port, data, length, userdata);
+    }
+
+    if (data[0] == NET_PACKET_ONION_DATA_RESPONSE) {
+        return handle_data_response(object, ip_port, data, length, userdata);
+    }
+
+    return 1;
+}
+
+/* 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(Onion_Client *onion_c, int friend_num, const uint8_t *data, uint16_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;
+    }
+
+    unsigned int i, good_nodes[MAX_ONION_CLIENTS], num_good = 0, num_nodes = 0;
+    Onion_Node *list_nodes = onion_c->friends_list[friend_num].clients_list;
+
+    for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
+        if (onion_node_timed_out(&list_nodes[i])) {
+            continue;
+        }
+
+        ++num_nodes;
+
+        if (list_nodes[i].is_stored) {
+            good_nodes[num_good] = i;
+            ++num_good;
+        }
+    }
+
+    if (num_good < (num_nodes - 1) / 4 + 1) {
+        return -1;
+    }
+
+    uint8_t nonce[CRYPTO_NONCE_SIZE];
+    random_nonce(nonce);
+
+    VLA(uint8_t, packet, DATA_IN_RESPONSE_MIN_SIZE + length);
+    memcpy(packet, onion_c->c->self_public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    int len = encrypt_data(onion_c->friends_list[friend_num].real_public_key, onion_c->c->self_secret_key, nonce, data,
+                           length, packet + CRYPTO_PUBLIC_KEY_SIZE);
+
+    if ((uint32_t)len + CRYPTO_PUBLIC_KEY_SIZE != SIZEOF_VLA(packet)) {
+        return -1;
+    }
+
+    unsigned int good = 0;
+
+    for (i = 0; i < num_good; ++i) {
+        Onion_Path path;
+
+        if (random_path(onion_c, &onion_c->onion_paths_friends, ~0, &path) == -1) {
+            continue;
+        }
+
+        uint8_t o_packet[ONION_MAX_PACKET_SIZE];
+        len = create_data_request(o_packet, sizeof(o_packet), onion_c->friends_list[friend_num].real_public_key,
+                                  list_nodes[good_nodes[i]].data_public_key, nonce, packet, SIZEOF_VLA(packet));
+
+        if (len == -1) {
+            continue;
+        }
+
+        if (send_onion_packet_tcp_udp(onion_c, &path, list_nodes[good_nodes[i]].ip_port, o_packet, len) == 0) {
+            ++good;
+        }
+    }
+
+    return good;
+}
+
+/* Try to send the dht public key 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_dhtpk(const Onion_Client *onion_c, int friend_num, const uint8_t *data, uint16_t length)
+{
+    if ((uint32_t)friend_num >= onion_c->num_friends) {
+        return -1;
+    }
+
+    if (!onion_c->friends_list[friend_num].know_dht_public_key) {
+        return -1;
+    }
+
+    uint8_t nonce[CRYPTO_NONCE_SIZE];
+    random_nonce(nonce);
+
+    VLA(uint8_t, temp, DATA_IN_RESPONSE_MIN_SIZE + CRYPTO_NONCE_SIZE + length);
+    memcpy(temp, onion_c->c->self_public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    memcpy(temp + CRYPTO_PUBLIC_KEY_SIZE, nonce, CRYPTO_NONCE_SIZE);
+    int len = encrypt_data(onion_c->friends_list[friend_num].real_public_key, onion_c->c->self_secret_key, nonce, data,
+                           length, temp + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE);
+
+    if ((uint32_t)len + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE != SIZEOF_VLA(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].dht_public_key, temp, SIZEOF_VLA(temp), CRYPTO_PACKET_DHTPK);
+
+    if (len == -1) {
+        return -1;
+    }
+
+    return route_tofriend(onion_c->dht, onion_c->friends_list[friend_num].dht_public_key, packet, len);
+}
+
+static int handle_dht_dhtpk(void *object, IP_Port source, const uint8_t *source_pubkey, const uint8_t *packet,
+                            uint16_t length, void *userdata)
+{
+    Onion_Client *onion_c = (Onion_Client *)object;
+
+    if (length < DHTPK_DATA_MIN_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + CRYPTO_NONCE_SIZE) {
+        return 1;
+    }
+
+    if (length > DHTPK_DATA_MAX_LENGTH + DATA_IN_RESPONSE_MIN_SIZE + CRYPTO_NONCE_SIZE) {
+        return 1;
+    }
+
+    uint8_t plain[DHTPK_DATA_MAX_LENGTH];
+    int len = decrypt_data(packet, onion_c->c->self_secret_key, packet + CRYPTO_PUBLIC_KEY_SIZE,
+                           packet + CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE,
+                           length - (CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE), plain);
+
+    if (len != length - (DATA_IN_RESPONSE_MIN_SIZE + CRYPTO_NONCE_SIZE)) {
+        return 1;
+    }
+
+    if (public_key_cmp(source_pubkey, plain + 1 + sizeof(uint64_t)) != 0) {
+        return 1;
+    }
+
+    return handle_dhtpk_announce(onion_c, packet, plain, len, userdata);
+}
+/* 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_dhtpk_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[DHTPK_DATA_MAX_LENGTH];
+    data[0] = ONION_DATA_DHTPK;
+    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_PUBLIC_KEY_SIZE);
+    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 + DHTPK_DATA_MIN_LENGTH, DHTPK_DATA_MAX_LENGTH - DHTPK_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, DHTPK_DATA_MIN_LENGTH + nodes_len);
+    }
+
+    if (onion_dht_both != 0) {
+        num2 = send_dht_dhtpk(onion_c, friend_num, data, DHTPK_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 *public_key)
+{
+    unsigned int i;
+
+    for (i = 0; i < onion_c->num_friends; ++i) {
+        if (onion_c->friends_list[i].status == 0) {
+            continue;
+        }
+
+        if (public_key_cmp(public_key, onion_c->friends_list[i].real_public_key) == 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 = (Onion_Friend *)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 *public_key)
+{
+    int num = onion_friend_num(onion_c, public_key);
+
+    if (num != -1) {
+        return num;
+    }
+
+    unsigned int 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_public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    crypto_new_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].know_dht_public_key)
+    //    DHT_delfriend(onion_c->dht, onion_c->friends_list[friend_num].dht_public_key, 0);
+
+    crypto_memzero(&(onion_c->friends_list[friend_num]), sizeof(Onion_Friend));
+    unsigned int i;
+
+    for (i = onion_c->num_friends; i != 0; --i) {
+        if (onion_c->friends_list[i - 1].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, const 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 the function for this friend that will be callbacked with object and number
+ * when that friend gives us his DHT temporary public key.
+ *
+ * object and number will be passed as argument to this function.
+ *
+ * return -1 on failure.
+ * return 0 on success.
+ */
+int onion_dht_pk_callback(Onion_Client *onion_c, int friend_num, void (*function)(void *data, int32_t number,
+                          const uint8_t *dht_public_key, void *userdata), void *object, uint32_t number)
+{
+    if ((uint32_t)friend_num >= onion_c->num_friends) {
+        return -1;
+    }
+
+    onion_c->friends_list[friend_num].dht_pk_callback = function;
+    onion_c->friends_list[friend_num].dht_pk_callback_object = object;
+    onion_c->friends_list[friend_num].dht_pk_callback_number = number;
+    return 0;
+}
+
+/* Set a friends DHT public key.
+ *
+ * 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)
+{
+    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].know_dht_public_key) {
+        if (public_key_cmp(dht_key, onion_c->friends_list[friend_num].dht_public_key) == 0) {
+            return -1;
+        }
+
+        onion_c->friends_list[friend_num].know_dht_public_key = 0;
+    }
+
+    onion_c->friends_list[friend_num].last_seen = unix_time();
+    onion_c->friends_list[friend_num].know_dht_public_key = 1;
+    memcpy(onion_c->friends_list[friend_num].dht_public_key, dht_key, CRYPTO_PUBLIC_KEY_SIZE);
+
+    return 0;
+}
+
+/* Copy friends DHT public key into dht_key.
+ *
+ * return 0 on failure (no key copied).
+ * return 1 on success (key copied).
+ */
+unsigned int onion_getfriend_DHT_pubkey(const 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].know_dht_public_key) {
+        return 0;
+    }
+
+    memcpy(dht_key, onion_c->friends_list[friend_num].dht_public_key, CRYPTO_PUBLIC_KEY_SIZE);
+    return 1;
+}
+
+/* Get the ip of friend friendnum and put it in ip_port
+ *
+ *  return -1, -- if public_key does NOT refer to a friend
+ *  return  0, -- if public_key refers to a friend and we failed to find the friend (yet)
+ *  return  1, ip if public_key refers to a friend and we found him
+ *
+ */
+int onion_getfriendip(const Onion_Client *onion_c, int friend_num, IP_Port *ip_port)
+{
+    uint8_t dht_public_key[CRYPTO_PUBLIC_KEY_SIZE];
+
+    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;
+        onion_c->friends_list[friend_num].run_count = 0;
+    }
+
+    return 0;
+}
+
+static void populate_path_nodes(Onion_Client *onion_c)
+{
+    Node_format nodes_list[MAX_FRIEND_CLIENTS];
+
+    unsigned int num_nodes = randfriends_nodes(onion_c->dht, nodes_list, MAX_FRIEND_CLIENTS);
+
+    unsigned int i;
+
+    for (i = 0; i < num_nodes; ++i) {
+        onion_add_path_node(onion_c, nodes_list[i].ip_port, nodes_list[i].public_key);
+    }
+}
+
+static void populate_path_nodes_tcp(Onion_Client *onion_c)
+{
+    Node_format nodes_list[MAX_SENT_NODES];
+
+    unsigned int num_nodes = copy_connected_tcp_relays(onion_c->c, nodes_list, MAX_SENT_NODES);;
+    unsigned int i;
+
+    for (i = 0; i < num_nodes; ++i) {
+        onion_add_bs_path_node(onion_c, nodes_list[i].ip_port, nodes_list[i].public_key);
+    }
+}
+
+#define ANNOUNCE_FRIEND (ONION_NODE_PING_INTERVAL * 6)
+#define ANNOUNCE_FRIEND_BEGINNING 3
+
+#define RUN_COUNT_FRIEND_ANNOUNCE_BEGINNING 17
+
+#define ONION_FRIEND_BACKOFF_FACTOR 4
+#define ONION_FRIEND_MAX_PING_INTERVAL (5*60*MAX_ONION_CLIENTS)
+
+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;
+    }
+
+    unsigned int interval = ANNOUNCE_FRIEND;
+
+    if (onion_c->friends_list[friendnum].run_count < RUN_COUNT_FRIEND_ANNOUNCE_BEGINNING) {
+        interval = ANNOUNCE_FRIEND_BEGINNING;
+    } else {
+        if (onion_c->friends_list[friendnum].last_reported_announced == 0) {
+            onion_c->friends_list[friendnum].last_reported_announced = unix_time();
+        }
+
+        uint64_t backoff_interval = (unix_time() - onion_c->friends_list[friendnum].last_reported_announced)
+                                    / ONION_FRIEND_BACKOFF_FACTOR;
+
+        if (backoff_interval > ONION_FRIEND_MAX_PING_INTERVAL) {
+            backoff_interval = ONION_FRIEND_MAX_PING_INTERVAL;
+        }
+
+        if (interval < backoff_interval) {
+            interval = backoff_interval;
+        }
+    }
+
+    unsigned int i, count = 0;
+    Onion_Node *list_nodes = onion_c->friends_list[friendnum].clients_list;
+
+    if (!onion_c->friends_list[friendnum].is_online) {
+        // ensure we get a response from some node roughly once per
+        // (interval / MAX_ONION_CLIENTS)
+        bool ping_random = true;
+
+        for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
+            if (!(is_timeout(list_nodes[i].timestamp, interval / MAX_ONION_CLIENTS)
+                    && is_timeout(list_nodes[i].last_pinged, ONION_NODE_PING_INTERVAL))) {
+                ping_random = false;
+                break;
+            }
+        }
+
+        for (i = 0; i < MAX_ONION_CLIENTS; ++i) {
+            if (onion_node_timed_out(&list_nodes[i])) {
+                continue;
+            }
+
+            ++count;
+
+
+            if (list_nodes[i].last_pinged == 0) {
+                list_nodes[i].last_pinged = unix_time();
+                continue;
+            }
+
+            if (list_nodes[i].unsuccessful_pings >= ONION_NODE_MAX_PINGS) {
+                continue;
+            }
+
+            if (is_timeout(list_nodes[i].last_pinged, interval)
+                    || (ping_random && rand() % (MAX_ONION_CLIENTS - i) == 0)) {
+                if (client_send_announce_request(onion_c, friendnum + 1, list_nodes[i].ip_port, list_nodes[i].public_key, 0, ~0) == 0) {
+                    list_nodes[i].last_pinged = unix_time();
+                    ++list_nodes[i].unsuccessful_pings;
+                    ping_random = false;
+                }
+            }
+        }
+
+        if (count != MAX_ONION_CLIENTS) {
+            unsigned int num_nodes = (onion_c->path_nodes_index < MAX_PATH_NODES) ? onion_c->path_nodes_index : MAX_PATH_NODES;
+
+            unsigned int n = num_nodes;
+
+            if (num_nodes > (MAX_ONION_CLIENTS / 2)) {
+                n = (MAX_ONION_CLIENTS / 2);
+            }
+
+            if (count <= (uint32_t)rand() % MAX_ONION_CLIENTS) {
+                if (num_nodes != 0) {
+                    unsigned int j;
+
+                    for (j = 0; j < n; ++j) {
+                        unsigned int num = rand() % num_nodes;
+                        client_send_announce_request(onion_c, friendnum + 1, onion_c->path_nodes[num].ip_port,
+                                                     onion_c->path_nodes[num].public_key, 0, ~0);
+                    }
+
+                    ++onion_c->friends_list[friendnum].run_count;
+                }
+            }
+        } else {
+            ++onion_c->friends_list[friendnum].run_count;
+        }
+
+        /* send packets to friend telling them our DHT public key. */
+        if (is_timeout(onion_c->friends_list[friendnum].last_dht_pk_onion_sent, ONION_DHTPK_SEND_INTERVAL)) {
+            if (send_dhtpk_announce(onion_c, friendnum, 0) >= 1) {
+                onion_c->friends_list[friendnum].last_dht_pk_onion_sent = unix_time();
+            }
+        }
+
+        if (is_timeout(onion_c->friends_list[friendnum].last_dht_pk_dht_sent, DHT_DHTPK_SEND_INTERVAL)) {
+            if (send_dhtpk_announce(onion_c, friendnum, 1) >= 1) {
+                onion_c->friends_list[friendnum].last_dht_pk_dht_sent = unix_time();
+            }
+        }
+    }
+}
+
+
+/* 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 3
+#define ANNOUNCE_INTERVAL_ANNOUNCED ONION_NODE_PING_INTERVAL
+
+#define TIME_TO_STABLE (ONION_NODE_PING_INTERVAL * 6)
+#define ANNOUNCE_INTERVAL_STABLE (ONION_NODE_PING_INTERVAL * 8)
+
+static void do_announce(Onion_Client *onion_c)
+{
+    unsigned int i, count = 0;
+    Onion_Node *list_nodes = onion_c->clients_announce_list;
+
+    for (i = 0; i < MAX_ONION_CLIENTS_ANNOUNCE; ++i) {
+        if (onion_node_timed_out(&list_nodes[i])) {
+            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;
+        }
+
+        if (list_nodes[i].unsuccessful_pings >= ONION_NODE_MAX_PINGS) {
+            continue;
+        }
+
+
+        unsigned int interval = ANNOUNCE_INTERVAL_NOT_ANNOUNCED;
+
+        if (list_nodes[i].is_stored && path_exists(&onion_c->onion_paths_self, list_nodes[i].path_used)) {
+            interval = ANNOUNCE_INTERVAL_ANNOUNCED;
+
+            uint32_t pathnum = list_nodes[i].path_used % NUMBER_ONION_PATHS;
+
+            /* A node/path is considered 'stable', and can be pinged less
+             * aggressively, if it has survived for at least TIME_TO_STABLE
+             * and the latest packets sent to it are not timing out.
+             */
+            if (is_timeout(list_nodes[i].added_time, TIME_TO_STABLE)
+                    && !(list_nodes[i].unsuccessful_pings > 0
+                         && is_timeout(list_nodes[i].last_pinged, ONION_NODE_TIMEOUT))
+                    && is_timeout(onion_c->onion_paths_self.path_creation_time[pathnum], TIME_TO_STABLE)
+                    && !(onion_c->onion_paths_self.last_path_used_times[pathnum] > 0
+                         && is_timeout(onion_c->onion_paths_self.last_path_used[pathnum], ONION_PATH_TIMEOUT))) {
+                interval = ANNOUNCE_INTERVAL_STABLE;
+            }
+        }
+
+        if (is_timeout(list_nodes[i].last_pinged, interval)
+                || (is_timeout(onion_c->last_announce, ONION_NODE_PING_INTERVAL)
+                    && rand() % (MAX_ONION_CLIENTS_ANNOUNCE - i) == 0)) {
+            uint32_t path_to_use = list_nodes[i].path_used;
+
+            if (list_nodes[i].unsuccessful_pings == ONION_NODE_MAX_PINGS - 1
+                    && is_timeout(list_nodes[i].added_time, TIME_TO_STABLE)) {
+                /* Last chance for a long-lived node - try a random path */
+                path_to_use = ~0;
+            }
+
+            if (client_send_announce_request(onion_c, 0, list_nodes[i].ip_port, list_nodes[i].public_key,
+                                             list_nodes[i].ping_id, path_to_use) == 0) {
+                list_nodes[i].last_pinged = unix_time();
+                ++list_nodes[i].unsuccessful_pings;
+                onion_c->last_announce = unix_time();
+            }
+        }
+    }
+
+    if (count != MAX_ONION_CLIENTS_ANNOUNCE) {
+        unsigned int num_nodes;
+        Node_format *path_nodes;
+
+        if (rand() % 2 == 0 || onion_c->path_nodes_index == 0) {
+            num_nodes = (onion_c->path_nodes_index_bs < MAX_PATH_NODES) ? onion_c->path_nodes_index_bs : MAX_PATH_NODES;
+            path_nodes = onion_c->path_nodes_bs;
+        } else {
+            num_nodes = (onion_c->path_nodes_index < MAX_PATH_NODES) ? onion_c->path_nodes_index : MAX_PATH_NODES;
+            path_nodes = onion_c->path_nodes;
+        }
+
+        if (count <= (uint32_t)rand() % MAX_ONION_CLIENTS_ANNOUNCE) {
+            if (num_nodes != 0) {
+                for (i = 0; i < (MAX_ONION_CLIENTS_ANNOUNCE / 2); ++i) {
+                    unsigned int num = rand() % num_nodes;
+                    client_send_announce_request(onion_c, 0, path_nodes[num].ip_port, path_nodes[num].public_key, 0, ~0);
+                }
+            }
+        }
+    }
+}
+
+/*  return 0 if we are not connected to the network.
+ *  return 1 if we are.
+ */
+static int onion_isconnected(const Onion_Client *onion_c)
+{
+    unsigned int i, num = 0, announced = 0;
+
+    if (is_timeout(onion_c->last_packet_recv, ONION_OFFLINE_TIMEOUT)) {
+        return 0;
+    }
+
+    if (onion_c->path_nodes_index == 0) {
+        return 0;
+    }
+
+    for (i = 0; i < MAX_ONION_CLIENTS_ANNOUNCE; ++i) {
+        if (!onion_node_timed_out(&onion_c->clients_announce_list[i])) {
+            ++num;
+
+            if (onion_c->clients_announce_list[i].is_stored) {
+                ++announced;
+            }
+        }
+    }
+
+    unsigned int pnodes = onion_c->path_nodes_index;
+
+    if (pnodes > MAX_ONION_CLIENTS_ANNOUNCE) {
+        pnodes = MAX_ONION_CLIENTS_ANNOUNCE;
+    }
+
+    /* Consider ourselves online if we are announced to half or more nodes
+       we are connected to */
+    if (num && announced) {
+        if ((num / 2) <= announced && (pnodes / 2) <= num) {
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+#define ONION_CONNECTION_SECONDS 3
+
+/*  return 0 if we are not connected to the network.
+ *  return 1 if we are connected with TCP only.
+ *  return 2 if we are also connected with UDP.
+ */
+unsigned int onion_connection_status(const Onion_Client *onion_c)
+{
+    if (onion_c->onion_connected >= ONION_CONNECTION_SECONDS) {
+        if (onion_c->UDP_connected) {
+            return 2;
+        }
+
+        return 1;
+    }
+
+    return 0;
+}
+
+void do_onion_client(Onion_Client *onion_c)
+{
+    unsigned int i;
+
+    if (onion_c->last_run == unix_time()) {
+        return;
+    }
+
+    if (is_timeout(onion_c->first_run, ONION_CONNECTION_SECONDS)) {
+        populate_path_nodes(onion_c);
+        do_announce(onion_c);
+    }
+
+    if (onion_isconnected(onion_c)) {
+        if (onion_c->onion_connected < ONION_CONNECTION_SECONDS * 2) {
+            ++onion_c->onion_connected;
+        }
+    } else {
+        populate_path_nodes_tcp(onion_c);
+
+        if (onion_c->onion_connected != 0) {
+            --onion_c->onion_connected;
+        }
+    }
+
+    bool UDP_connected = DHT_non_lan_connected(onion_c->dht);
+
+    if (is_timeout(onion_c->first_run, ONION_CONNECTION_SECONDS * 2)) {
+        set_tcp_onion_status(onion_c->c->tcp_c, !UDP_connected);
+    }
+
+    onion_c->UDP_connected = UDP_connected
+                             || get_random_tcp_onion_conn_number(onion_c->c->tcp_c) == -1; /* Check if connected to any TCP relays. */
+
+    if (onion_connection_status(onion_c)) {
+        for (i = 0; i < onion_c->num_friends; ++i) {
+            do_friend(onion_c, i);
+        }
+    }
+
+    if (onion_c->last_run == 0) {
+        onion_c->first_run = unix_time();
+    }
+
+    onion_c->last_run = unix_time();
+}
+
+Onion_Client *new_onion_client(Net_Crypto *c)
+{
+    if (c == NULL) {
+        return NULL;
+    }
+
+    Onion_Client *onion_c = (Onion_Client *)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_new_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, ONION_DATA_DHTPK, &handle_dhtpk_announce, onion_c);
+    cryptopacket_registerhandler(onion_c->dht, CRYPTO_PACKET_DHTPK, &handle_dht_dhtpk, onion_c);
+    set_onion_packet_tcp_connection_callback(onion_c->c->tcp_c, &handle_tcp_onion, 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, ONION_DATA_DHTPK, NULL, NULL);
+    cryptopacket_registerhandler(onion_c->dht, CRYPTO_PACKET_DHTPK, NULL, NULL);
+    set_onion_packet_tcp_connection_callback(onion_c->c->tcp_c, NULL, NULL);
+    crypto_memzero(onion_c, sizeof(Onion_Client));
+    free(onion_c);
+}
+