//===-- SocketAddress.cpp -------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Note: This file is used on Darwin by debugserver, so it needs to remain as
//       self contained as possible, and devoid of references to LLVM unless 
//       there is compelling reason.
//
//===----------------------------------------------------------------------===//

#if defined(_MSC_VER)
#define _WINSOCK_DEPRECATED_NO_WARNINGS
#endif

#include "lldb/Host/SocketAddress.h"
#include <cstddef>
#include <cstdio>

#if !defined(_WIN32)
#include <arpa/inet.h>
#endif

#include <cassert>
#include <cstring>

#include "lldb/Host/PosixApi.h"

// WindowsXP needs an inet_ntop implementation
#ifdef _WIN32

#ifndef INET6_ADDRSTRLEN // might not be defined in older Windows SDKs
#define INET6_ADDRSTRLEN 46
#endif

// TODO: implement shortened form "::" for runs of zeros
const char *inet_ntop(int af, const void *src, char *dst, socklen_t size) {
  if (size == 0) {
    return nullptr;
  }

  switch (af) {
  case AF_INET: {
    {
      const char *formatted = inet_ntoa(*static_cast<const in_addr *>(src));
      if (formatted && strlen(formatted) < static_cast<size_t>(size)) {
        return ::strcpy(dst, formatted);
      }
    }
    return nullptr;
  case AF_INET6: {
    char tmp[INET6_ADDRSTRLEN] = {0};
    const uint16_t *src16 = static_cast<const uint16_t *>(src);
    int full_size = ::snprintf(
        tmp, sizeof(tmp), "%x:%x:%x:%x:%x:%x:%x:%x", ntohs(src16[0]),
        ntohs(src16[1]), ntohs(src16[2]), ntohs(src16[3]), ntohs(src16[4]),
        ntohs(src16[5]), ntohs(src16[6]), ntohs(src16[7]));
    if (full_size < static_cast<int>(size)) {
      return ::strcpy(dst, tmp);
    }
    return nullptr;
  }
  }
  }
  return nullptr;
}
#endif

using namespace lldb_private;

// SocketAddress constructor
SocketAddress::SocketAddress() { Clear(); }

SocketAddress::SocketAddress(const struct sockaddr &s) { m_socket_addr.sa = s; }

SocketAddress::SocketAddress(const struct sockaddr_in &s) {
  m_socket_addr.sa_ipv4 = s;
}

SocketAddress::SocketAddress(const struct sockaddr_in6 &s) {
  m_socket_addr.sa_ipv6 = s;
}

SocketAddress::SocketAddress(const struct sockaddr_storage &s) {
  m_socket_addr.sa_storage = s;
}

SocketAddress::SocketAddress(const struct addrinfo *addr_info) {
  *this = addr_info;
}

// Destructor
SocketAddress::~SocketAddress() = default;

void SocketAddress::Clear() {
  memset(&m_socket_addr, 0, sizeof(m_socket_addr));
}

bool SocketAddress::IsValid() const { return GetLength() != 0; }

static socklen_t GetFamilyLength(sa_family_t family) {
  switch (family) {
  case AF_INET:
    return sizeof(struct sockaddr_in);
  case AF_INET6:
    return sizeof(struct sockaddr_in6);
  }
  assert(0 && "Unsupported address family");
  return 0;
}

socklen_t SocketAddress::GetLength() const {
#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
  return m_socket_addr.sa.sa_len;
#else
  return GetFamilyLength(GetFamily());
#endif
}

socklen_t SocketAddress::GetMaxLength() { return sizeof(sockaddr_t); }

sa_family_t SocketAddress::GetFamily() const {
  return m_socket_addr.sa.sa_family;
}

void SocketAddress::SetFamily(sa_family_t family) {
  m_socket_addr.sa.sa_family = family;
#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
  m_socket_addr.sa.sa_len = GetFamilyLength(family);
#endif
}

std::string SocketAddress::GetIPAddress() const {
  char str[INET6_ADDRSTRLEN] = {0};
  switch (GetFamily()) {
  case AF_INET:
    if (inet_ntop(GetFamily(), &m_socket_addr.sa_ipv4.sin_addr, str,
                  sizeof(str)))
      return str;
    break;
  case AF_INET6:
    if (inet_ntop(GetFamily(), &m_socket_addr.sa_ipv6.sin6_addr, str,
                  sizeof(str)))
      return str;
    break;
  }
  return "";
}

uint16_t SocketAddress::GetPort() const {
  switch (GetFamily()) {
  case AF_INET:
    return ntohs(m_socket_addr.sa_ipv4.sin_port);
  case AF_INET6:
    return ntohs(m_socket_addr.sa_ipv6.sin6_port);
  }
  return 0;
}

bool SocketAddress::SetPort(uint16_t port) {
  switch (GetFamily()) {
  case AF_INET:
    m_socket_addr.sa_ipv4.sin_port = htons(port);
    return true;

  case AF_INET6:
    m_socket_addr.sa_ipv6.sin6_port = htons(port);
    return true;
  }
  return false;
}

// SocketAddress assignment operator
const SocketAddress &SocketAddress::
operator=(const struct addrinfo *addr_info) {
  Clear();
  if (addr_info && addr_info->ai_addr && addr_info->ai_addrlen > 0 &&
      size_t(addr_info->ai_addrlen) <= sizeof m_socket_addr) {
    ::memcpy(&m_socket_addr, addr_info->ai_addr, addr_info->ai_addrlen);
  }
  return *this;
}

const SocketAddress &SocketAddress::operator=(const struct sockaddr &s) {
  m_socket_addr.sa = s;
  return *this;
}

const SocketAddress &SocketAddress::operator=(const struct sockaddr_in &s) {
  m_socket_addr.sa_ipv4 = s;
  return *this;
}

const SocketAddress &SocketAddress::operator=(const struct sockaddr_in6 &s) {
  m_socket_addr.sa_ipv6 = s;
  return *this;
}

const SocketAddress &SocketAddress::
operator=(const struct sockaddr_storage &s) {
  m_socket_addr.sa_storage = s;
  return *this;
}

bool SocketAddress::getaddrinfo(const char *host, const char *service,
                                int ai_family, int ai_socktype, int ai_protocol,
                                int ai_flags) {
  Clear();

  auto addresses = GetAddressInfo(host, service, ai_family, ai_socktype,
                                  ai_protocol, ai_flags);
  if (!addresses.empty())
    *this = addresses[0];
  return IsValid();
}

std::vector<SocketAddress>
SocketAddress::GetAddressInfo(const char *hostname, const char *servname,
                              int ai_family, int ai_socktype, int ai_protocol,
                              int ai_flags) {
  std::vector<SocketAddress> addr_list;

  struct addrinfo hints;
  memset(&hints, 0, sizeof(hints));
  hints.ai_family = ai_family;
  hints.ai_socktype = ai_socktype;
  hints.ai_protocol = ai_protocol;
  hints.ai_flags = ai_flags;

  struct addrinfo *service_info_list = nullptr;
  int err = ::getaddrinfo(hostname, servname, &hints, &service_info_list);
  if (err == 0 && service_info_list) {
    for (struct addrinfo *service_ptr = service_info_list;
         service_ptr != nullptr; service_ptr = service_ptr->ai_next) {
      addr_list.emplace_back(SocketAddress(service_ptr));
    }
  }

  if (service_info_list)
    ::freeaddrinfo(service_info_list);
  return addr_list;
}

bool SocketAddress::SetToLocalhost(sa_family_t family, uint16_t port) {
  switch (family) {
  case AF_INET:
    SetFamily(AF_INET);
    if (SetPort(port)) {
      m_socket_addr.sa_ipv4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
      return true;
    }
    break;

  case AF_INET6:
    SetFamily(AF_INET6);
    if (SetPort(port)) {
      m_socket_addr.sa_ipv6.sin6_addr = in6addr_loopback;
      return true;
    }
    break;
  }
  Clear();
  return false;
}

bool SocketAddress::SetToAnyAddress(sa_family_t family, uint16_t port) {
  switch (family) {
  case AF_INET:
    SetFamily(AF_INET);
    if (SetPort(port)) {
      m_socket_addr.sa_ipv4.sin_addr.s_addr = htonl(INADDR_ANY);
      return true;
    }
    break;

  case AF_INET6:
    SetFamily(AF_INET6);
    if (SetPort(port)) {
      m_socket_addr.sa_ipv6.sin6_addr = in6addr_any;
      return true;
    }
    break;
  }
  Clear();
  return false;
}

bool SocketAddress::IsAnyAddr() const {
  return (GetFamily() == AF_INET)
             ? m_socket_addr.sa_ipv4.sin_addr.s_addr == htonl(INADDR_ANY)
             : 0 == memcmp(&m_socket_addr.sa_ipv6.sin6_addr, &in6addr_any, 16);
}

bool SocketAddress::IsLocalhost() const {
  return (GetFamily() == AF_INET)
             ? m_socket_addr.sa_ipv4.sin_addr.s_addr == htonl(INADDR_LOOPBACK)
             : 0 == memcmp(&m_socket_addr.sa_ipv6.sin6_addr, &in6addr_loopback,
                           16);
}

bool SocketAddress::operator==(const SocketAddress &rhs) const {
  if (GetFamily() != rhs.GetFamily())
    return false;
  if (GetLength() != rhs.GetLength())
    return false;
  switch (GetFamily()) {
  case AF_INET:
    return m_socket_addr.sa_ipv4.sin_addr.s_addr ==
           rhs.m_socket_addr.sa_ipv4.sin_addr.s_addr;
  case AF_INET6:
    return 0 == memcmp(&m_socket_addr.sa_ipv6.sin6_addr,
                       &rhs.m_socket_addr.sa_ipv6.sin6_addr, 16);
  }
  return false;
}

bool SocketAddress::operator!=(const SocketAddress &rhs) const {
  return !(*this == rhs);
}