transmission/libtransmission/net.h

253 lines
6.2 KiB
C++

// Copyright © Transmission authors and contributors.
// This file is licensed under the MIT (SPDX: MIT) license,
// A copy of this license can be found in licenses/ .
#pragma once
#ifndef __TRANSMISSION__
#error only libtransmission should #include this header.
#endif
#include <cstddef> // size_t
#include <cstdint> // uint8_t
#include <optional>
#include <string>
#include <string_view>
#include <utility> // std::pair
#ifdef _WIN32
#include <ws2tcpip.h>
#else
#include <errno.h>
#include <sys/socket.h>
#include <netinet/in.h>
#endif
#ifdef _WIN32
using tr_socket_t = SOCKET;
#define TR_BAD_SOCKET INVALID_SOCKET
#undef EADDRINUSE
#define EADDRINUSE WSAEADDRINUSE
#undef ECONNREFUSED
#define ECONNREFUSED WSAECONNREFUSED
#undef ECONNRESET
#define ECONNRESET WSAECONNRESET
#undef EHOSTUNREACH
#define EHOSTUNREACH WSAEHOSTUNREACH
#undef EINPROGRESS
#define EINPROGRESS WSAEINPROGRESS
#undef ENOTCONN
#define ENOTCONN WSAENOTCONN
#undef EWOULDBLOCK
#define EWOULDBLOCK WSAEWOULDBLOCK
#undef EAFNOSUPPORT
#define EAFNOSUPPORT WSAEAFNOSUPPORT
#undef ENETUNREACH
#define ENETUNREACH WSAENETUNREACH
#define sockerrno WSAGetLastError()
#else
/** @brief Platform-specific socket descriptor type. */
using tr_socket_t = int;
/** @brief Platform-specific invalid socket descriptor constant. */
#define TR_BAD_SOCKET (-1)
#define sockerrno errno
#endif
/****
*****
***** tr_address
*****
****/
enum tr_address_type
{
TR_AF_INET,
TR_AF_INET6,
NUM_TR_AF_INET_TYPES
};
struct tr_address;
[[nodiscard]] int tr_address_compare(tr_address const* a, tr_address const* b) noexcept;
/**
* Literally just a port number.
*
* Exists so that you never have to wonder what byte order a port variable is in.
*/
class tr_port
{
public:
tr_port() noexcept = default;
[[nodiscard]] constexpr static tr_port fromHost(uint16_t hport) noexcept
{
return tr_port{ hport };
}
[[nodiscard]] static tr_port fromNetwork(uint16_t nport) noexcept
{
return tr_port{ ntohs(nport) };
}
[[nodiscard]] constexpr uint16_t host() const noexcept
{
return hport_;
}
[[nodiscard]] uint16_t network() const noexcept
{
return htons(hport_);
}
constexpr void setHost(uint16_t hport) noexcept
{
hport_ = hport;
}
void setNetwork(uint16_t nport) noexcept
{
hport_ = ntohs(nport);
}
[[nodiscard]] static std::pair<tr_port, uint8_t const*> fromCompact(uint8_t const* compact) noexcept;
[[nodiscard]] constexpr auto operator<(tr_port const& that) const noexcept
{
return hport_ < that.hport_;
}
[[nodiscard]] constexpr auto operator==(tr_port const& that) const noexcept
{
return hport_ == that.hport_;
}
[[nodiscard]] constexpr auto operator!=(tr_port const& that) const noexcept
{
return hport_ != that.hport_;
}
[[nodiscard]] constexpr auto empty() const noexcept
{
return hport_ == 0;
}
constexpr void clear() noexcept
{
hport_ = 0;
}
private:
constexpr tr_port(uint16_t hport) noexcept
: hport_{ hport }
{
}
uint16_t hport_ = 0;
};
struct tr_address
{
[[nodiscard]] static std::optional<tr_address> fromString(std::string_view str);
[[nodiscard]] static std::pair<tr_address, uint8_t const*> fromCompact4(uint8_t const* compact) noexcept;
[[nodiscard]] static std::pair<tr_address, uint8_t const*> fromCompact6(uint8_t const* compact) noexcept;
// human-readable formatting
template<typename OutputIt>
OutputIt readable(OutputIt out, tr_port port = {}) const;
std::string_view readable(char* out, size_t outlen, tr_port port = {}) const;
[[nodiscard]] std::string readable(tr_port port = {}) const;
[[nodiscard]] constexpr auto isIPv4() const noexcept
{
return type == TR_AF_INET;
}
[[nodiscard]] constexpr auto isIPv6() const noexcept
{
return type == TR_AF_INET6;
}
// comparisons
[[nodiscard]] int compare(tr_address const& that) const noexcept;
[[nodiscard]] bool operator==(tr_address const& that) const noexcept
{
return this->compare(that) == 0;
}
[[nodiscard]] bool operator<(tr_address const& that) const noexcept
{
return this->compare(that) < 0;
}
[[nodiscard]] bool operator>(tr_address const& that) const noexcept
{
return this->compare(that) > 0;
}
tr_address_type type;
union
{
struct in6_addr addr6;
struct in_addr addr4;
} addr;
};
extern tr_address const tr_inaddr_any;
extern tr_address const tr_in6addr_any;
bool tr_address_from_string(tr_address* setme, char const* string);
bool tr_address_from_string(tr_address* dst, std::string_view src);
bool tr_address_from_sockaddr_storage(tr_address* setme, tr_port* port, struct sockaddr_storage const* src);
bool tr_address_is_valid_for_peers(tr_address const* addr, tr_port port);
constexpr bool tr_address_is_valid(tr_address const* a)
{
return a != nullptr && (a->type == TR_AF_INET || a->type == TR_AF_INET6);
}
/***********************************************************************
* Sockets
**********************************************************************/
struct tr_session;
tr_socket_t tr_netBindTCP(tr_address const* addr, tr_port port, bool suppressMsgs);
tr_socket_t tr_netAccept(tr_session* session, tr_socket_t bound, tr_address* setme_addr, tr_port* setme_port);
void tr_netSetCongestionControl(tr_socket_t s, char const* algorithm);
void tr_netClose(tr_session* session, tr_socket_t s);
void tr_netCloseSocket(tr_socket_t fd);
bool tr_net_hasIPv6(tr_port);
/// TOS / DSCP
// get a string of one of <netinet/ip.h>'s IPTOS_ values, e.g. "cs0"
std::string tr_netTosToName(int tos);
// get the number that corresponds to the specified IPTOS_ name, e.g. "cs0" returns 0x00
std::optional<int> tr_netTosFromName(std::string_view name);
// set the IPTOS_ value for the specified socket
void tr_netSetTOS(tr_socket_t sock, int tos, tr_address_type type);
/**
* @brief get a human-representable string representing the network error.
* @param err an errno on Unix/Linux and an WSAError on win32)
*/
std::string tr_net_strerror(int err);
unsigned char const* tr_globalIPv6(tr_session const* session);