text: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
  /* vim: set ts=8 sts=2 et sw=2 tw=80: */
  /* This Source Code Form is subject to the terms of the Mozilla Public
   * License, v. 2.0. If a copy of the MPL was not distributed with this
   * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  
  #ifndef DNS_h_
  #define DNS_h_
  
  #include "nscore.h"
  #include "prio.h"
  #include "prnetdb.h"
  #include "plstr.h"
  #include "mozilla/LinkedList.h"
  #include "mozilla/MemoryReporting.h"
  
  #if !defined(XP_WIN)
  #include <arpa/inet.h>
  #endif
  
  #ifdef XP_WIN
  #include "winsock2.h"
  #endif
  
  #define IPv6ADDR_IS_LOOPBACK(a) \
    (((a)->u32[0] == 0)     &&    \
     ((a)->u32[1] == 0)     &&    \
     ((a)->u32[2] == 0)     &&    \
     ((a)->u8[12] == 0)     &&    \
     ((a)->u8[13] == 0)     &&    \
     ((a)->u8[14] == 0)     &&    \
     ((a)->u8[15] == 0x1U))
  
  #define IPv6ADDR_IS_V4MAPPED(a) \
    (((a)->u32[0] == 0)     &&    \
     ((a)->u32[1] == 0)     &&    \
     ((a)->u8[8] == 0)      &&    \
     ((a)->u8[9] == 0)      &&    \
     ((a)->u8[10] == 0xff)  &&    \
     ((a)->u8[11] == 0xff))
  
  #define IPv6ADDR_V4MAPPED_TO_IPADDR(a) ((a)->u32[3])
  
  #define IPv6ADDR_IS_UNSPECIFIED(a) \
    (((a)->u32[0] == 0)  &&          \
     ((a)->u32[1] == 0)  &&          \
     ((a)->u32[2] == 0)  &&          \
     ((a)->u32[3] == 0))
  
  namespace mozilla {
  namespace net {
  
  // Required buffer size for text form of an IP address.
  // Includes space for null termination. We make our own contants
  // because we don't want higher-level code depending on things
  // like INET6_ADDRSTRLEN and having to include the associated
  // platform-specific headers.
  #ifdef XP_WIN
  // Windows requires longer buffers for some reason.
  const int kIPv4CStrBufSize = 22;
  const int kIPv6CStrBufSize = 65;
  const int kNetAddrMaxCStrBufSize = kIPv6CStrBufSize;
  #else
  const int kIPv4CStrBufSize = 16;
  const int kIPv6CStrBufSize = 46;
  const int kLocalCStrBufSize = 108;
  const int kNetAddrMaxCStrBufSize = kLocalCStrBufSize;
  #endif
  
  // This was all created at a time in which we were using NSPR for host
  // resolution and we were propagating NSPR types like "PRAddrInfo" and
  // "PRNetAddr" all over Gecko. This made it hard to use another host
  // resolver -- we were locked into NSPR. The goal here is to get away
  // from that. We'll translate what we get from NSPR or any other host
  // resolution library into the types below and use them in Gecko.
  
  union IPv6Addr {
    uint8_t  u8[16];
    uint16_t u16[8];
    uint32_t u32[4];
    uint64_t u64[2];
  };
  
  // This struct is similar to operating system structs like "sockaddr", used for
  // things like "connect" and "getsockname". When tempted to cast or do dumb
  // copies of this struct to another struct, bear compiler-computed padding
  // in mind. The size of this struct, and the layout of the data in it, may
  // not be what you expect.
  union NetAddr {
    struct {
      uint16_t family;                /* address family (0x00ff maskable) */
      char data[14];                  /* raw address data */
    } raw;
    struct {
      uint16_t family;                /* address family (AF_INET) */
      uint16_t port;                  /* port number */
      uint32_t ip;                    /* The actual 32 bits of address */
    } inet;
    struct {
      uint16_t family;                /* address family (AF_INET6) */
      uint16_t port;                  /* port number */
      uint32_t flowinfo;              /* routing information */
      IPv6Addr ip;                    /* the actual 128 bits of address */
      uint32_t scope_id;              /* set of interfaces for a scope */
    } inet6;
  #if defined(XP_UNIX)
    struct {                          /* Unix domain socket address */
      uint16_t family;                /* address family (AF_UNIX) */
      char path[104];                 /* null-terminated pathname */
    } local;
  #endif
    // introduced to support nsTArray<NetAddr> (for DNSRequestParent.cpp)
    bool operator == (const NetAddr& other) const;
  };
  
  // This class wraps a NetAddr union to provide C++ linked list
  // capabilities and other methods. It is created from a PRNetAddr,
  // which is converted to a mozilla::dns::NetAddr.
  class NetAddrElement : public LinkedListElement<NetAddrElement> {
  public:
    explicit NetAddrElement(const PRNetAddr *prNetAddr);
    NetAddrElement(const NetAddrElement& netAddr);
    ~NetAddrElement();
  
    NetAddr mAddress;
  };
  
  class AddrInfo {
  public:
    // Creates an AddrInfo object. It calls the AddrInfo(const char*, const char*)
    // to initialize the host and the cname.
    AddrInfo(const char *host, const PRAddrInfo *prAddrInfo, bool disableIPv4,
             bool filterNameCollision, const char *cname);
  
    // Creates a basic AddrInfo object (initialize only the host and the cname).
    AddrInfo(const char *host, const char *cname);
    ~AddrInfo();
  
    void AddAddress(NetAddrElement *address);
  
    size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
  
    char *mHostName;
    char *mCanonicalName;
    uint16_t ttl;
    static const uint16_t NO_TTL_DATA = (uint16_t) -1;
  
    LinkedList<NetAddrElement> mAddresses;
  
  private:
    void Init(const char *host, const char *cname);
  };
  
  // Copies the contents of a PRNetAddr to a NetAddr.
  // Does not do a ptr safety check!
  void PRNetAddrToNetAddr(const PRNetAddr *prAddr, NetAddr *addr);
  
  // Copies the contents of a NetAddr to a PRNetAddr.
  // Does not do a ptr safety check!
  void NetAddrToPRNetAddr(const NetAddr *addr, PRNetAddr *prAddr);
  
  bool NetAddrToString(const NetAddr *addr, char *buf, uint32_t bufSize);
  
  bool IsLoopBackAddress(const NetAddr *addr);
  
  bool IsIPAddrAny(const NetAddr *addr);
  
  bool IsIPAddrV4Mapped(const NetAddr *addr);
  
  bool IsIPAddrLocal(const NetAddr *addr);
  
  nsresult GetPort(const NetAddr *aAddr, uint16_t *aResult);
  
  } // namespace net
  } // namespace mozilla
  
  #endif // DNS_h_
  