allwpilib/wpinet/src/main/native/include/wpi/net/uv/util.hpp

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

#ifndef WPINET_UV_UTIL_H_
#define WPINET_UV_UTIL_H_

#include <uv.h>

#include <cstring>
#include <string_view>

#ifdef _WIN32
#pragma comment(lib, "Ws2_32.lib")
#endif

namespace wpi::uv {

namespace detail {
template <typename T>
concept StringAssignable = requires(T a, const char* p) {
  { a.assign(p, p) };  // NOLINT(readability/braces)
};
}  // namespace detail

/**
 * Convert a binary structure containing an IPv4 address to a string.
 * @param addr Binary structure
 * @param ip Output string (any type that has `assign(char*, char*)`)
 * @param port Output port number
 * @return Error (same as `uv_ip4_name()`).
 */
template <detail::StringAssignable T>
int AddrToName(const sockaddr_in& addr, T* ip, unsigned int* port) {
  char name[128];
  int err = uv_ip4_name(&addr, name, 128);
  if (err == 0) {
    ip->assign(name, name + std::strlen(name));
    *port = ntohs(addr.sin_port);
  } else {
    ip->assign(name, name);
  }
  return err;
}

/**
 * Convert a binary structure containing an IPv6 address to a string.
 * @param addr Binary structure
 * @param ip Output string (any type that has `assign(char*, char*)`)
 * @param port Output port number
 * @return Error (same as `uv_ip6_name()`).
 */
template <detail::StringAssignable T>
int AddrToName(const sockaddr_in6& addr, T* ip, unsigned int* port) {
  char name[128];
  int err = uv_ip6_name(&addr, name, 128);
  if (err == 0) {
    ip->assign(name, name + std::strlen(name));
    *port = ntohs(addr.sin6_port);
  } else {
    ip->assign(name, name);
  }
  return err;
}

/**
 * Convert a binary structure containing an IPv4 or IPv6 address to a string.
 * @param addr Binary structure
 * @param ip Output string (any type that has `assign(char*, char*)`)
 * @param port Output port number
 * @return Error (same as `uv_ip6_name()`).
 */
template <detail::StringAssignable T>
int AddrToName(const sockaddr_storage& addr, T* ip, unsigned int* port) {
  if (addr.ss_family == AF_INET) {
    return AddrToName(reinterpret_cast<const sockaddr_in&>(addr), ip, port);
  }
  if (addr.ss_family == AF_INET6) {
    return AddrToName(reinterpret_cast<const sockaddr_in6&>(addr), ip, port);
  }
  char name[1] = {'\0'};
  ip->assign(name, name);
  return -1;
}

/**
 * Convert a binary IPv4 address to a string.
 * @param addr Binary address
 * @param ip Output string (any type that has `assign(char*, char*)`)
 * @return Error (same as `uv_inet_ntop()`).
 */
template <detail::StringAssignable T>
int AddrToName(const in_addr& addr, T* ip) {
  char name[128];
  int err = uv_inet_ntop(AF_INET, &addr, name, 128);
  if (err == 0) {
    ip->assign(name, name + std::strlen(name));
  } else {
    ip->assign(name, name);
  }
  return err;
}

/**
 * Convert a binary IPv6 address to a string.
 * @param addr Binary address
 * @param ip Output string (any type that has `assign(char*, char*)`)
 * @return Error (same as `uv_inet_ntop()`).
 */
template <detail::StringAssignable T>
int AddrToName(const in6_addr& addr, T* ip) {
  char name[128];
  int err = uv_inet_ntop(AF_INET6, &addr, name, 128);
  if (err == 0) {
    ip->assign(name, name + std::strlen(name));
  } else {
    ip->assign(name, name);
  }
  return err;
}

/**
 * Convert a string containing an IPv4 address to a binary structure.
 * @param ip IPv4 address string
 * @param port Port number
 * @param addr Output binary structure
 * @return Error (same as `uv_ip4_addr()`).
 */
int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in* addr);

/**
 * Convert a string containing an IPv6 address to a binary structure.
 * @param ip IPv6 address string
 * @param port Port number
 * @param addr Output binary structure
 * @return Error (same as `uv_ip6_addr()`).
 */
int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in6* addr);

/**
 * Convert a string containing an IPv4 address to binary format.
 * @param ip IPv4 address string
 * @param addr Output binary
 * @return Error (same as `uv_inet_pton()`).
 */
int NameToAddr(std::string_view ip, in_addr* addr);

/**
 * Convert a string containing an IPv6 address to binary format.
 * @param ip IPv6 address string
 * @param addr Output binary
 * @return Error (same as `uv_inet_pton()`).
 */
int NameToAddr(std::string_view ip, in6_addr* addr);

}  // namespace wpi::uv

#endif  // WPINET_UV_UTIL_H_