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

 * Copyright © 2016-2018 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 "logger.h"

#include "mem.h"

#ifdef __cplusplus

extern "C" {

#endif

/**

 * @brief Wrapper for sockaddr_storage and size.

 */

typedef struct Network_Addr Network_Addr;

typedef int net_close_cb(void *obj, int sock);

typedef int net_accept_cb(void *obj, int sock);

typedef int net_bind_cb(void *obj, int sock, const Network_Addr *addr);

typedef int net_listen_cb(void *obj, int sock, int backlog);

typedef int net_recvbuf_cb(void *obj, int sock);

typedef int net_recv_cb(void *obj, int sock, uint8_t *buf, size_t len);

typedef int net_recvfrom_cb(void *obj, int sock, uint8_t *buf, size_t len, Network_Addr *addr);

typedef int net_send_cb(void *obj, int sock, const uint8_t *buf, size_t len);

typedef int net_sendto_cb(void *obj, int sock, const uint8_t *buf, size_t len, const Network_Addr *addr);

typedef int net_socket_cb(void *obj, int domain, int type, int proto);

typedef int net_socket_nonblock_cb(void *obj, int sock, bool nonblock);

typedef int net_getsockopt_cb(void *obj, int sock, int level, int optname, void *optval, size_t *optlen);

typedef int net_setsockopt_cb(void *obj, int sock, int level, int optname, const void *optval, size_t optlen);

typedef int net_getaddrinfo_cb(void *obj, int family, Network_Addr **addrs);

typedef int net_freeaddrinfo_cb(void *obj, Network_Addr *addrs);

/** @brief Functions wrapping POSIX network functions.

 *

 * Refer to POSIX man pages for documentation of what these functions are

 * expected to do when providing alternative Network implementations.

 */

typedef struct Network_Funcs {

    net_close_cb *close;

    net_accept_cb *accept;

    net_bind_cb *bind;

    net_listen_cb *listen;

    net_recvbuf_cb *recvbuf;

    net_recv_cb *recv;

    net_recvfrom_cb *recvfrom;

    net_send_cb *send;

    net_sendto_cb *sendto;

    net_socket_cb *socket;

    net_socket_nonblock_cb *socket_nonblock;

    net_getsockopt_cb *getsockopt;

    net_setsockopt_cb *setsockopt;

    net_getaddrinfo_cb *getaddrinfo;

    net_freeaddrinfo_cb *freeaddrinfo;

} Network_Funcs;

typedef struct Network {

    const Network_Funcs *funcs;

    void *obj;

} Network;

const Network *os_network(void);

typedef struct Family {

    uint8_t value;

} Family;

bool net_family_is_unspec(Family family);

bool net_family_is_ipv4(Family family);

bool net_family_is_ipv6(Family family);

bool net_family_is_tcp_server(Family family);

bool net_family_is_tcp_client(Family family);

bool net_family_is_tcp_ipv4(Family family);

bool net_family_is_tcp_ipv6(Family family);

bool net_family_is_tox_tcp_ipv4(Family family);

bool net_family_is_tox_tcp_ipv6(Family family);

Family net_family_unspec(void);

Family net_family_ipv4(void);

Family net_family_ipv6(void);

Family net_family_tcp_server(void);

Family net_family_tcp_client(void);

Family net_family_tcp_ipv4(void);

Family net_family_tcp_ipv6(void);

Family net_family_tox_tcp_ipv4(void);

Family net_family_tox_tcp_ipv6(void);

#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_GET_NODES            = 0x02, /* Get nodes request packet ID. */

    NET_PACKET_SEND_NODES_IPV6      = 0x04, /* Send nodes response packet ID for other addresses. */

    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

/** Redefinitions of variables for safe transfer over wire. */

#define TOX_AF_UNSPEC 0

#define TOX_AF_INET 2

#define TOX_AF_INET6 10

#define TOX_TCP_INET 130

#define TOX_TCP_INET6 138

#define TOX_SOCK_STREAM 1

#define TOX_SOCK_DGRAM 2

#define TOX_PROTO_TCP 1

#define TOX_PROTO_UDP 2

/** TCP related */

#define TCP_CLIENT_FAMILY (TOX_AF_INET6 + 1)

#define TCP_INET (TOX_AF_INET6 + 2)

#define TCP_INET6 (TOX_AF_INET6 + 3)

#define TCP_SERVER_FAMILY (TOX_AF_INET6 + 4)

#define SIZE_IP4 4

#define SIZE_IP6 16

#define SIZE_IP (1 + SIZE_IP6)

#define SIZE_PORT 2

#define SIZE_IPPORT (SIZE_IP + SIZE_PORT)

typedef union IP4 {

    uint32_t uint32;

    uint16_t uint16[2];

    uint8_t uint8[4];

} IP4;

IP4 get_ip4_loopback(void);

IP4 get_ip4_broadcast(void);

typedef union IP6 {

    uint8_t uint8[16];

    uint16_t uint16[8];

    uint32_t uint32[4];

    uint64_t uint64[2];

} IP6;

IP6 get_ip6_loopback(void);

IP6 get_ip6_broadcast(void);

typedef union IP_Union {

    IP4 v4;

    IP6 v6;

} IP_Union;

typedef struct IP {

    Family family;

    IP_Union ip;

} IP;

typedef struct IP_Port {

    IP ip;

    uint16_t port;

} IP_Port;

typedef struct Socket {

    int sock;

} Socket;

non_null()

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

/**

 * Check if socket is valid.

 *

 * @return true if valid, false otherwise.

 */

bool sock_valid(Socket sock);

Socket net_invalid_socket(void);

/**

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

 */

non_null()

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

/**

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

 */

non_null()

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

/**

 * Calls listen(sockfd, backlog).

 */

non_null()

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

/**

 * Calls accept(sockfd, nullptr, nullptr).

 */

non_null()

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

/**

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

 * return 0 on failure.

 */

non_null()

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

/** Convert values between host and network byte order. */

uint32_t net_htonl(uint32_t hostlong);

uint16_t net_htons(uint16_t hostshort);

uint32_t net_ntohl(uint32_t hostlong);

uint16_t net_ntohs(uint16_t hostshort);

non_null()

size_t net_pack_bool(uint8_t *bytes, bool v);

non_null()

size_t net_pack_u16(uint8_t *bytes, uint16_t v);

non_null()

size_t net_pack_u32(uint8_t *bytes, uint32_t v);

non_null()

size_t net_pack_u64(uint8_t *bytes, uint64_t v);

non_null()

size_t net_unpack_bool(const uint8_t *bytes, bool *v);

non_null()

size_t net_unpack_u16(const uint8_t *bytes, uint16_t *v);

non_null()

size_t net_unpack_u32(const uint8_t *bytes, uint32_t *v);

non_null()

size_t net_unpack_u64(const uint8_t *bytes, uint64_t *v);

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

non_null()

bool ipv6_ipv4_in_v6(const IP6 *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.

 */

non_null()

const char *net_ip_ntoa(const IP *ip, Ip_Ntoa *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.

 */

non_null()

bool ip_parse_addr(const IP *ip, char *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.

 */

non_null()

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

/**

 * Compares two IPAny structures.

 *

 * Unset means unequal.

 *

 * @return false when not equal or when uninitialized.

 */

nullable(1, 2)

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

/**

 * Compares two IPAny_Port structures.

 *

 * Unset means unequal.

 *

 * @return false when not equal or when uninitialized.

 */

nullable(1, 2)

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

/** nulls out ip */

non_null()

void ip_reset(IP *ip);

/** nulls out ip_port */

non_null()

void ipport_reset(IP_Port *ipport);

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

non_null()

void ip_init(IP *ip, bool ipv6enabled);

/** checks if ip is valid */

non_null()

bool ip_isset(const IP *ip);

/** checks if ip is valid */

non_null()

bool ipport_isset(const IP_Port *ipport);

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

non_null()

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

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

non_null()

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

/**

 * Resolves string into an IP address

 *

 * @param address a hostname (or something parseable to an IP address)

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

 *

 * 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

 */

non_null(1, 2, 3) nullable(4)

bool addr_resolve_or_parse_ip(const Network *ns, const char *address, IP *to, IP *extra);

/** @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 *object, const IP_Port *source, const uint8_t *packet, uint16_t length, void *userdata);

typedef struct Networking_Core Networking_Core;

non_null()

Family net_family(const Networking_Core *net);

non_null()

uint16_t net_port(const Networking_Core *net);

/** Close the socket. */

non_null()

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

/**

 * Set socket as nonblocking

 *

 * @return true on success, false on failure.

 */

non_null()

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

/**

 * Set socket to not emit SIGPIPE

 *

 * @return true on success, false on failure.

 */

non_null()

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

/**

 * Enable SO_REUSEADDR on socket.

 *

 * @return true on success, false on failure.

 */

non_null()

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

/**

 * Set socket to dual (IPv4 + IPv6 socket)

 *

 * @return true on success, false on failure.

 */

non_null()

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

/* Basic network functions: */

/**

 * An outgoing network packet.

 *

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

 */

typedef struct Packet {

    const uint8_t *data;

    uint16_t length;

} Packet;

/**

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

 */

non_null()

int send_packet(const Networking_Core *net, const IP_Port *ip_port, Packet packet);

/**

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

 *

 * @deprecated Use send_packet instead.

 */

non_null()

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

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

non_null(1) nullable(3, 4)

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

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

non_null(1) nullable(2)

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

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

 *

 * Return true on success.

 * Return false on failure.

 */

non_null()

bool net_connect(const Memory *mem, const Logger *log, Socket sock, const IP_Port *ip_port);

/** @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()`

 *

 * @return number of elements in res array.

 * @retval 0 if res array empty.

 * @retval -1 on error.

 */

non_null()

int32_t net_getipport(const Memory *mem, const char *node, IP_Port **res, int tox_type);

/** Deallocates memory allocated by net_getipport */

non_null(1) nullable(2)

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

/**

 * @return true on success, false on failure.

 */

non_null()

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

/** @brief Get the last networking error code.

 *

 * Similar to Unix's errno, but cross-platform, as not all platforms use errno

 * to indicate networking errors.

 *

 * Note that different platforms may return different codes for the same error,

 * so you likely shouldn't be checking the value returned by this function

 * unless you know what you are doing, you likely just want to use it in

 * combination with `net_new_strerror()` to print the error.

 *

 * return platform-dependent network error code, if any.

 */

int net_error(void);

/** @brief Get a text explanation for the error code from `net_error()`.

 *

 * return NULL on failure.

 * return pointer to a NULL-terminated string describing the error code on

 * success. The returned string must be freed using `net_kill_strerror()`.

 */

char *net_new_strerror(int error);

/** @brief Frees the string returned by `net_new_strerror()`.

 * It's valid to pass NULL as the argument, the function does nothing in this

 * case.

 */

nullable(1)

void net_kill_strerror(char *strerror);

/** @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.

 */

non_null(1, 2, 3, 4) nullable(7)

Networking_Core *new_networking_ex(

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

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

non_null()

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

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

nullable(1)

void kill_networking(Networking_Core *net);

#ifdef __cplusplus

} /* extern "C" */

#endif

#endif /* C_TOXCORE_TOXCORE_NETWORK_H */