// Copyright (c) 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/base/net_util_mac.h"

#include <ifaddrs.h>
#include <net/if.h>
#include <netinet/in.h>
#include <set>
#include <sys/types.h>

#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_tokenizer.h"
#include "base/strings/string_util.h"
#include "base/threading/thread_restrictions.h"
#include "net/base/escape.h"
#include "net/base/ip_endpoint.h"
#include "net/base/net_errors.h"
#include "net/base/net_util_posix.h"
#include "url/gurl.h"

#if !defined(OS_IOS)
#include <net/if_media.h>
#include <netinet/in_var.h>
#include <sys/ioctl.h>
#endif  // !OS_IOS

namespace net {

namespace {

#if !defined(OS_IOS)

// MacOSX implementation of IPAttributesGetterMac which calls ioctl on socket to
// retrieve IP attributes.
class IPAttributesGetterMacImpl : public internal::IPAttributesGetterMac {
 public:
  IPAttributesGetterMacImpl();
  ~IPAttributesGetterMacImpl() override;
  bool IsInitialized() const override;
  bool GetIPAttributes(const char* ifname,
                       const sockaddr* sock_addr,
                       int* native_attributes) override;

 private:
  int ioctl_socket_;
};

IPAttributesGetterMacImpl::IPAttributesGetterMacImpl()
    : ioctl_socket_(socket(AF_INET6, SOCK_DGRAM, 0)) {
  DCHECK_GE(ioctl_socket_, 0);
}

bool IPAttributesGetterMacImpl::IsInitialized() const {
  return ioctl_socket_ >= 0;
}

IPAttributesGetterMacImpl::~IPAttributesGetterMacImpl() {
  if (ioctl_socket_ >= 0) {
    close(ioctl_socket_);
  }
}

bool IPAttributesGetterMacImpl::GetIPAttributes(const char* ifname,
                                                const sockaddr* sock_addr,
                                                int* native_attributes) {
  struct in6_ifreq ifr = {};
  strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
  memcpy(&ifr.ifr_ifru.ifru_addr, sock_addr, sock_addr->sa_len);
  int rv = ioctl(ioctl_socket_, SIOCGIFAFLAG_IN6, &ifr);
  if (rv >= 0) {
    *native_attributes = ifr.ifr_ifru.ifru_flags;
  }
  return (rv >= 0);
}

// When returning true, the platform native IPv6 address attributes were
// successfully converted to net IP address attributes. Otherwise, returning
// false and the caller should drop the IP address which can't be used by the
// application layer.
bool TryConvertNativeToNetIPAttributes(int native_attributes,
                                       int* net_attributes) {
  // For MacOSX, we disallow addresses with attributes IN6_IFF_ANYCASE,
  // IN6_IFF_DUPLICATED, IN6_IFF_TENTATIVE, and IN6_IFF_DETACHED as these are
  // still progressing through duplicated address detection (DAD) or are not
  // suitable to be used in an one-to-one communication and shouldn't be used
  // by the application layer.
  if (native_attributes & (IN6_IFF_ANYCAST | IN6_IFF_DUPLICATED |
                           IN6_IFF_TENTATIVE | IN6_IFF_DETACHED)) {
    return false;
  }

  if (native_attributes & IN6_IFF_TEMPORARY) {
    *net_attributes |= IP_ADDRESS_ATTRIBUTE_TEMPORARY;
  }

  if (native_attributes & IN6_IFF_DEPRECATED) {
    *net_attributes |= IP_ADDRESS_ATTRIBUTE_DEPRECATED;
  }

  return true;
}

NetworkChangeNotifier::ConnectionType GetNetworkInterfaceType(
    int addr_family,
    const std::string& interface_name) {
  NetworkChangeNotifier::ConnectionType type =
      NetworkChangeNotifier::CONNECTION_UNKNOWN;

  struct ifmediareq ifmr = {};
  strncpy(ifmr.ifm_name, interface_name.c_str(), sizeof(ifmr.ifm_name) - 1);

  int s = socket(addr_family, SOCK_DGRAM, 0);
  if (s == -1) {
    return type;
  }

  if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1) {
    if (ifmr.ifm_current & IFM_IEEE80211) {
      type = NetworkChangeNotifier::CONNECTION_WIFI;
    } else if (ifmr.ifm_current & IFM_ETHER) {
      type = NetworkChangeNotifier::CONNECTION_ETHERNET;
    }
  }
  close(s);
  return type;
}

#endif  // !OS_IOS
}  // namespace

namespace internal {

bool GetNetworkListImpl(NetworkInterfaceList* networks,
                        int policy,
                        const ifaddrs* interfaces,
                        IPAttributesGetterMac* ip_attributes_getter) {
  // Enumerate the addresses assigned to network interfaces which are up.
  for (const ifaddrs* interface = interfaces; interface != NULL;
       interface = interface->ifa_next) {
    // Skip loopback interfaces, and ones which are down.
    if (!(IFF_RUNNING & interface->ifa_flags))
      continue;
    if (IFF_LOOPBACK & interface->ifa_flags)
      continue;
    // Skip interfaces with no address configured.
    struct sockaddr* addr = interface->ifa_addr;
    if (!addr)
      continue;

    // Skip unspecified addresses (i.e. made of zeroes) and loopback addresses
    // configured on non-loopback interfaces.
    if (IsLoopbackOrUnspecifiedAddress(addr))
      continue;

    const std::string& name = interface->ifa_name;
    // Filter out VMware interfaces, typically named vmnet1 and vmnet8.
    if (ShouldIgnoreInterface(name, policy)) {
      continue;
    }

    NetworkChangeNotifier::ConnectionType connection_type =
        NetworkChangeNotifier::CONNECTION_UNKNOWN;

    int ip_attributes = IP_ADDRESS_ATTRIBUTE_NONE;

#if !defined(OS_IOS)
    // Retrieve native ip attributes and convert to net version if a getter is
    // given.
    if (ip_attributes_getter && ip_attributes_getter->IsInitialized()) {
      int native_attributes = 0;
      if (addr->sa_family == AF_INET6 &&
          ip_attributes_getter->GetIPAttributes(
              interface->ifa_name, interface->ifa_addr, &native_attributes)) {
        if (!TryConvertNativeToNetIPAttributes(native_attributes,
                                               &ip_attributes)) {
          continue;
        }
      }
    }

    connection_type = GetNetworkInterfaceType(addr->sa_family, name);
#endif  // !OS_IOS

    IPEndPoint address;

    int addr_size = 0;
    if (addr->sa_family == AF_INET6) {
      addr_size = sizeof(sockaddr_in6);
    } else if (addr->sa_family == AF_INET) {
      addr_size = sizeof(sockaddr_in);
    }

    if (address.FromSockAddr(addr, addr_size)) {
      uint8 prefix_length = 0;
      if (interface->ifa_netmask) {
        // If not otherwise set, assume the same sa_family as ifa_addr.
        if (interface->ifa_netmask->sa_family == 0) {
          interface->ifa_netmask->sa_family = addr->sa_family;
        }
        IPEndPoint netmask;
        if (netmask.FromSockAddr(interface->ifa_netmask, addr_size)) {
          prefix_length = MaskPrefixLength(netmask.address());
        }
      }
      networks->push_back(NetworkInterface(
          name, name, if_nametoindex(name.c_str()), connection_type,
          address.address(), prefix_length, ip_attributes));
    }
  }

  return true;
}

}  // namespace internal

bool GetNetworkList(NetworkInterfaceList* networks, int policy) {
  if (networks == NULL)
    return false;

  // getifaddrs() may require IO operations.
  base::ThreadRestrictions::AssertIOAllowed();

  ifaddrs* interfaces;
  if (getifaddrs(&interfaces) < 0) {
    PLOG(ERROR) << "getifaddrs";
    return false;
  }

  scoped_ptr<internal::IPAttributesGetterMac> ip_attributes_getter;

#if !defined(OS_IOS)
  ip_attributes_getter.reset(new IPAttributesGetterMacImpl());
#endif

  bool result = internal::GetNetworkListImpl(networks, policy, interfaces,
                                             ip_attributes_getter.get());
  freeifaddrs(interfaces);
  return result;
}

}  // namespace net