/* SPDX-License-Identifier: GPL-3.0-or-later

 * Copyright © 2016-2026 The TokTok team.

 * Copyright © 2013 Tox project.

 */

/**

 * Datatypes, functions and includes for the core networking.

 */

#ifndef C_TOXCORE_TOXCORE_NETWORK_H

#define C_TOXCORE_TOXCORE_NETWORK_H

#include <stdbool.h>    // bool

#include <stddef.h>     // size_t

#include <stdint.h>     // uint*_t

#include "attributes.h"

#include "bin_pack.h"

#include "logger.h"

#include "mem.h"

#include "net.h"

#include "net_profile.h"

#include "os_network.h"

#ifdef __cplusplus

extern "C" {

#endif

#define MAX_UDP_PACKET_SIZE 2048

typedef enum Net_Packet_Type {

    NET_PACKET_PING_REQUEST         = 0x00, /* Ping request packet ID. */

    NET_PACKET_PING_RESPONSE        = 0x01, /* Ping response packet ID. */

    NET_PACKET_NODES_REQUEST        = 0x02, /* Nodes request packet ID. */

    NET_PACKET_NODES_RESPONSE       = 0x04, /* Nodes response packet ID. */

    NET_PACKET_COOKIE_REQUEST       = 0x18, /* Cookie request packet */

    NET_PACKET_COOKIE_RESPONSE      = 0x19, /* Cookie response packet */

    NET_PACKET_CRYPTO_HS            = 0x1a, /* Crypto handshake packet */

    NET_PACKET_CRYPTO_DATA          = 0x1b, /* Crypto data packet */

    NET_PACKET_CRYPTO               = 0x20, /* Encrypted data packet ID. */

    NET_PACKET_LAN_DISCOVERY        = 0x21, /* LAN discovery packet ID. */

    NET_PACKET_GC_HANDSHAKE         = 0x5a, /* Group chat handshake packet ID */

    NET_PACKET_GC_LOSSLESS          = 0x5b, /* Group chat lossless packet ID */

    NET_PACKET_GC_LOSSY             = 0x5c, /* Group chat lossy packet ID */

    /* See: `docs/Prevent_Tracking.txt` and `onion.{c,h}` */

    NET_PACKET_ONION_SEND_INITIAL   = 0x80,

    NET_PACKET_ONION_SEND_1         = 0x81,

    NET_PACKET_ONION_SEND_2         = 0x82,

    NET_PACKET_ANNOUNCE_REQUEST_OLD  = 0x83, /* TODO: DEPRECATE */

    NET_PACKET_ANNOUNCE_RESPONSE_OLD = 0x84, /* TODO: DEPRECATE */

    NET_PACKET_ONION_DATA_REQUEST   = 0x85,

    NET_PACKET_ONION_DATA_RESPONSE  = 0x86,

    NET_PACKET_ANNOUNCE_REQUEST     = 0x87,

    NET_PACKET_ANNOUNCE_RESPONSE    = 0x88,

    NET_PACKET_ONION_RECV_3         = 0x8c,

    NET_PACKET_ONION_RECV_2         = 0x8d,

    NET_PACKET_ONION_RECV_1         = 0x8e,

    NET_PACKET_FORWARD_REQUEST      = 0x90,

    NET_PACKET_FORWARDING           = 0x91,

    NET_PACKET_FORWARD_REPLY        = 0x92,

    NET_PACKET_DATA_SEARCH_REQUEST     = 0x93,

    NET_PACKET_DATA_SEARCH_RESPONSE    = 0x94,

    NET_PACKET_DATA_RETRIEVE_REQUEST   = 0x95,

    NET_PACKET_DATA_RETRIEVE_RESPONSE  = 0x96,

    NET_PACKET_STORE_ANNOUNCE_REQUEST  = 0x97,

    NET_PACKET_STORE_ANNOUNCE_RESPONSE = 0x98,

    BOOTSTRAP_INFO_PACKET_ID        = 0xf0, /* Only used for bootstrap nodes */

    NET_PACKET_MAX                  = 0xff, /* This type must remain within a single uint8. */

} Net_Packet_Type;

#define TOX_PORTRANGE_FROM 33445

#define TOX_PORTRANGE_TO   33545

#define TOX_PORT_DEFAULT   TOX_PORTRANGE_FROM

IP4 get_ip4_loopback(void);

IP4 get_ip4_broadcast(void);

IP6 get_ip6_loopback(void);

IP6 get_ip6_broadcast(void);

Socket net_socket(const Network *_Nonnull ns, Family domain, int type, int protocol);

/**

 * Check if socket is valid.

 *

 * @return true if valid, false otherwise.

 */

bool sock_valid(Socket sock);

/**

 * Calls send(sockfd, buf, len, MSG_NOSIGNAL).

 *

 * @param ns System network object.

 * @param log Logger object.

 * @param sock Socket to send data with.

 * @param buf Data to send.

 * @param len Length of data.

 * @param ip_port IP and port to send data to.

 * @param net_profile Network profile to record the packet.

 */

int net_send(const Network *_Nonnull ns, const Logger *_Nonnull log, Socket sock, const uint8_t *_Nonnull buf, size_t len, const IP_Port *_Nonnull ip_port,

             Net_Profile *_Nullable net_profile);

/**

 * Calls recv(sockfd, buf, len, MSG_NOSIGNAL).

 *

 * @param ns System network object.

 * @param log Logger object.

 * @param sock Socket to receive data with.

 * @param buf Buffer to store received data.

 * @param len Length of buffer.

 * @param ip_port IP and port of the sender.

 */

int net_recv(const Network *_Nonnull ns, const Logger *_Nonnull log, Socket sock, uint8_t *_Nonnull buf, size_t len, const IP_Port *_Nonnull ip_port);

/**

 * Calls listen(sockfd, backlog).

 */

int net_listen(const Network *_Nonnull ns, Socket sock, int backlog);

/**

 * Calls accept(sockfd, nullptr, nullptr).

 */

Socket net_accept(const Network *_Nonnull ns, Socket sock);

/**

 * return the size of data in the tcp recv buffer.

 * return 0 on failure.

 */

uint16_t net_socket_data_recv_buffer(const Network *_Nonnull ns, Socket sock);

/** Does the IP6 struct a contain an IPv4 address in an IPv6 one? */

bool ipv6_ipv4_in_v6(const IP6 *_Nonnull a);

#define TOX_ENABLE_IPV6_DEFAULT true

#define TOX_INET6_ADDRSTRLEN 66

#define TOX_INET_ADDRSTRLEN 22

/** this would be TOX_INET6_ADDRSTRLEN, but it might be too short for the error message */

#define IP_NTOA_LEN 96 // TODO(irungentoo): magic number. Why not INET6_ADDRSTRLEN ?

/** Contains a null terminated string of an IP address. */

typedef struct Ip_Ntoa {

    char     buf[IP_NTOA_LEN];  // a string formatted IP address or an error message.

    uint16_t length;  // the length of the string (not including the null byte).

    bool     ip_is_valid;  // if this is false `buf` will contain an error message.

} Ip_Ntoa;

/** @brief Converts IP into a null terminated string.

 *

 * Writes error message into the buffer on error.

 *

 * @param ip_str contains a buffer of the required size.

 *

 * @return Pointer to the buffer inside `ip_str` containing the IP string.

 */

const char *_Nonnull net_ip_ntoa(const IP *_Nonnull ip, Ip_Ntoa *_Nonnull ip_str);

/**

 * Parses IP structure into an address string.

 *

 * @param ip IP of TOX_AF_INET or TOX_AF_INET6 families.

 * @param length length of the address buffer.

 *   Must be at least TOX_INET_ADDRSTRLEN for TOX_AF_INET

 *   and TOX_INET6_ADDRSTRLEN for TOX_AF_INET6

 *

 * @param address dotted notation (IPv4: quad, IPv6: 16) or colon notation (IPv6).

 *

 * @return true on success, false on failure.

 */

bool ip_parse_addr(const IP *_Nonnull ip, char *_Nonnull address, size_t length);

/**

 * Directly parses the input into an IP structure.

 *

 * Tries IPv4 first, then IPv6.

 *

 * @param address dotted notation (IPv4: quad, IPv6: 16) or colon notation (IPv6).

 * @param to family and the value is set on success.

 *

 * @return true on success, false on failure.

 */

bool addr_parse_ip(const char *_Nonnull address, IP *_Nonnull to);

/**

 * Compares two IP structures.

 *

 * Unset means unequal.

 *

 * @return false when not equal or when uninitialized.

 */

bool ip_equal(const IP *_Nullable a, const IP *_Nullable b);

/**

 * Compares two IP_Port structures.

 *

 * Unset means unequal.

 *

 * @return false when not equal or when uninitialized.

 */

bool ipport_equal(const IP_Port *_Nullable a, const IP_Port *_Nullable b);

/**

 * @brief IP_Port comparison function with `memcmp` signature.

 *

 * Casts the void pointers to `IP_Port *` for comparison.

 *

 * @retval -1 if `a < b`

 * @retval 0 if `a == b`

 * @retval 1 if `a > b`

 */

int ipport_cmp_handler(const void *_Nonnull a, const void *_Nonnull b, size_t size);

/** nulls out ip */

void ip_reset(IP *_Nonnull ip);

/** nulls out ip_port */

void ipport_reset(IP_Port *_Nonnull ipport);

/** nulls out ip, sets family according to flag */

void ip_init(IP *_Nonnull ip, bool ipv6enabled);

/** checks if ip is valid */

bool ip_isset(const IP *_Nonnull ip);

/** checks if ip is valid */

bool ipport_isset(const IP_Port *_Nonnull ipport);

/** copies an ip structure (careful about direction) */

void ip_copy(IP *_Nonnull target, const IP *_Nonnull source);

/** copies an ip_port structure (careful about direction) */

void ipport_copy(IP_Port *_Nonnull target, const IP_Port *_Nonnull source);

/**

 * @brief Resolves string into an IP address.

 *

 * @param[in,out] ns Network object.

 * @param[in] address a hostname (or something parseable to an IP address).

 * @param[in,out] to to.family MUST be initialized, either set to a specific IP version

 *   (TOX_AF_INET/TOX_AF_INET6) or to the unspecified TOX_AF_UNSPEC (0), if both

 *   IP versions are acceptable.

 * @param[out] extra can be NULL and is only set in special circumstances, see returns.

 * @param[in] dns_enabled if false, DNS resolution is skipped.

 *

 * Returns in `*to` a matching address (IPv6 or IPv4).

 * Returns in `*extra`, if not NULL, an IPv4 address, if `to->family` was `TOX_AF_UNSPEC`.

 *

 * @return true on success, false on failure

 */

bool addr_resolve_or_parse_ip(const Network *_Nonnull ns, const Memory *_Nonnull mem, const char *_Nonnull address, IP *_Nonnull to, IP *_Nullable extra, bool dns_enabled);

/** @brief Function to receive data, ip and port of sender is put into ip_port.

 * Packet data is put into data.

 * Packet length is put into length.

 */

typedef int packet_handler_cb(void *_Nullable object, const IP_Port *_Nonnull source, const uint8_t *_Nonnull packet, uint16_t length, void *_Nullable userdata);

typedef struct Networking_Core Networking_Core;

Family net_family(const Networking_Core *_Nonnull net);

uint16_t net_port(const Networking_Core *_Nonnull net);

/** Close the socket. */

void kill_sock(const Network *_Nonnull ns, Socket sock);

/**

 * Set socket as nonblocking

 *

 * @return true on success, false on failure.

 */

bool set_socket_nonblock(const Network *_Nonnull ns, Socket sock);

/**

 * Set socket to not emit SIGPIPE

 *

 * @return true on success, false on failure.

 */

bool set_socket_nosigpipe(const Network *_Nonnull ns, Socket sock);

/**

 * Enable SO_REUSEADDR on socket.

 *

 * @return true on success, false on failure.

 */

bool set_socket_reuseaddr(const Network *_Nonnull ns, Socket sock);

/**

 * Set socket to dual (IPv4 + IPv6 socket)

 *

 * @return true on success, false on failure.

 */

bool set_socket_dualstack(const Network *_Nonnull ns, Socket sock);

/* Basic network functions: */

/**

 * An outgoing network packet.

 *

 * Use `net_send_packet` to send it to an IP/port endpoint.

 */

typedef struct Net_Packet {

    const uint8_t *_Nonnull data;

    uint16_t length;

} Net_Packet;

/**

 * Check for the situation when socket TOX_AF_INET, but target IP is not. And log the error.

 * This function can be used for UDP sockets only.

 *

 * @return true if socket is compatible with address.

 */

bool net_socket_family_compatible(const Networking_Core *_Nonnull net, const IP_Port *_Nonnull ip_port, bool log_warning);

/**

 * Function to send a network packet to a given IP/port.

 */

int net_send_packet(const Networking_Core *_Nonnull net, const IP_Port *_Nonnull ip_port, Net_Packet packet);

/**

 * Function to send packet(data) of length length to ip_port.

 *

 * @deprecated Use net_send_packet instead.

 */

int sendpacket(const Networking_Core *_Nonnull net, const IP_Port *_Nonnull ip_port, const uint8_t *_Nonnull data, uint16_t length);

/** Function to call when packet beginning with byte is received. */

void networking_registerhandler(Networking_Core *_Nonnull net, uint8_t byte, packet_handler_cb *_Nullable cb, void *_Nullable object);

/** Call this several times a second. */

void networking_poll(const Networking_Core *_Nonnull net, void *_Nullable userdata);

typedef enum Net_Err_Connect {

    NET_ERR_CONNECT_OK,

    NET_ERR_CONNECT_INVALID_FAMILY,

    NET_ERR_CONNECT_FAILED,

} Net_Err_Connect;

const char *_Nonnull net_err_connect_to_string(Net_Err_Connect err);

/** @brief Connect a socket to the address specified by the ip_port.

 *

 * @param[out] err Set to NET_ERR_CONNECT_OK on success, otherwise an error code.

 *

 * @retval true on success, false on failure.

 */

bool net_connect(const Network *_Nonnull ns, const Memory *_Nonnull mem, const Logger *_Nonnull log, Socket sock, const IP_Port *_Nonnull ip_port, Net_Err_Connect *_Nonnull err);

/** @brief High-level getaddrinfo implementation.

 *

 * Given node, which identifies an Internet host, `net_getipport()` fills an array

 * with one or more IP_Port structures, each of which contains an Internet

 * address that can be specified by calling `net_connect()`, the port is ignored.

 *

 * Skip all addresses with socktype != type (use type = -1 to get all addresses)

 * To correctly deallocate array memory use `net_freeipport()`.

 *

 * @param ns Network object.

 * @param mem Memory allocator.

 * @param node The node parameter identifies the host or service on which to connect.

 * @param[out] res An array of IP_Port structures will be allocated into this pointer.

 * @param tox_type The type of socket to use (stream or datagram), only relevant for DNS lookups.

 * @param dns_enabled If false, DNS resolution is skipped, when passed a hostname, this function will return an error.

 *

 * @return number of elements in res array.

 * @retval 0 if res array empty.

 * @retval -1 on error.

 */

int32_t net_getipport(const Network *_Nonnull ns, const Memory *_Nonnull mem, const char *_Nonnull node, IP_Port *_Nullable *_Nonnull res, int tox_type, bool dns_enabled);

/** Deallocates memory allocated by net_getipport */

void net_freeipport(const Memory *_Nonnull mem, IP_Port *_Nullable ip_ports);

bool bin_pack_ip_port(Bin_Pack *_Nonnull bp, const Logger *_Nonnull logger, const IP_Port *_Nonnull ip_port);

/** @brief Pack an IP_Port structure into data of max size length.

 *

 * Packed_length is the offset of data currently packed.

 *

 * @return size of packed IP_Port data on success.

 * @retval -1 on failure.

 */

int pack_ip_port(const Logger *_Nonnull logger, uint8_t *_Nonnull data, uint16_t length, const IP_Port *_Nonnull ip_port);

/** @brief Unpack IP_Port structure from data of max size length into ip_port.

 *

 * len_processed is the offset of data currently unpacked.

 *

 * @return size of unpacked ip_port on success.

 * @retval -1 on failure.

 */

int unpack_ip_port(IP_Port *_Nonnull ip_port, const uint8_t *_Nonnull data, uint16_t length, bool tcp_enabled);

/**

 * @return true on success, false on failure.

 */

bool bind_to_port(const Network *_Nonnull ns, Socket sock, Family family, uint16_t port);

/** @brief Initialize networking.

 * Bind to ip and port.

 * ip must be in network order EX: 127.0.0.1 = (7F000001).

 * port is in host byte order (this means don't worry about it).

 *

 * @return Networking_Core object if no problems

 * @retval NULL if there are problems.

 *

 * If error is non NULL it is set to 0 if no issues, 1 if socket related error, 2 if other.

 */

Networking_Core *_Nullable new_networking_ex(

    const Logger *_Nonnull log, const Memory *_Nonnull mem, const Network *_Nonnull ns, const IP *_Nonnull ip,

    uint16_t port_from, uint16_t port_to, unsigned int *_Nullable error);

Networking_Core *_Nullable new_networking_no_udp(const Logger *_Nonnull log, const Memory *_Nonnull mem, const Network *_Nonnull ns);

/** Function to cleanup networking stuff (doesn't do much right now). */

void kill_networking(Networking_Core *_Nullable net);

/** @brief Returns a pointer to the network net_profile object associated with `net`.

 *

 * Returns null if `net` is null.

 */

const Net_Profile *_Nullable net_get_net_profile(const Networking_Core *_Nonnull net);

#ifdef __cplusplus

} /* extern "C" */

#endif

#endif /* C_TOXCORE_TOXCORE_NETWORK_H */