text: /* Copyright (c) 2003-2004, Roger Dingledine
   * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   * Copyright (c) 2007-2013, The Tor Project, Inc. */
  /* See LICENSE for licensing information */
  
  /**
   * \file address.h
   * \brief Headers for address.h
   **/
  
  #ifndef TOR_ADDRESS_H
  #define TOR_ADDRESS_H
  
  #include "orconfig.h"
  #include "torint.h"
  #include "compat.h"
  
  /** The number of bits from an address to consider while doing a masked
   * comparison. */
  typedef uint8_t maskbits_t;
  
  struct in_addr;
  /** Holds an IPv4 or IPv6 address.  (Uses less memory than struct
   * sockaddr_storage.) */
  typedef struct tor_addr_t
  {
    sa_family_t family;
    union {
      uint32_t dummy_; /* This field is here so we have something to initialize
                        * with a reliable cross-platform type. */
      struct in_addr in_addr;
      struct in6_addr in6_addr;
    } addr;
  } tor_addr_t;
  
  /** Holds an IP address and a TCP/UDP port.  */
  typedef struct tor_addr_port_t
  {
    tor_addr_t addr;
    uint16_t port;
  } tor_addr_port_t;
  
  #define TOR_ADDR_NULL {AF_UNSPEC, {0}}
  
  static INLINE const struct in6_addr *tor_addr_to_in6(const tor_addr_t *a);
  static INLINE uint32_t tor_addr_to_ipv4n(const tor_addr_t *a);
  static INLINE uint32_t tor_addr_to_ipv4h(const tor_addr_t *a);
  static INLINE uint32_t tor_addr_to_mapped_ipv4h(const tor_addr_t *a);
  static INLINE sa_family_t tor_addr_family(const tor_addr_t *a);
  static INLINE const struct in_addr *tor_addr_to_in(const tor_addr_t *a);
  static INLINE int tor_addr_eq_ipv4h(const tor_addr_t *a, uint32_t u);
  
  socklen_t tor_addr_to_sockaddr(const tor_addr_t *a, uint16_t port,
                                 struct sockaddr *sa_out, socklen_t len);
  int tor_addr_from_sockaddr(tor_addr_t *a, const struct sockaddr *sa,
                             uint16_t *port_out);
  void tor_addr_make_unspec(tor_addr_t *a);
  void tor_addr_make_null(tor_addr_t *a, sa_family_t family);
  char *tor_sockaddr_to_str(const struct sockaddr *sa);
  
  /** Return an in6_addr* equivalent to <b>a</b>, or NULL if <b>a</b> is not
   * an IPv6 address. */
  static INLINE const struct in6_addr *
  tor_addr_to_in6(const tor_addr_t *a)
  {
    return a->family == AF_INET6 ? &a->addr.in6_addr : NULL;
  }
  
  /** Given an IPv6 address <b>x</b>, yield it as an array of uint8_t.
   *
   * Requires that <b>x</b> is actually an IPv6 address.
   */
  #define tor_addr_to_in6_addr8(x) tor_addr_to_in6(x)->s6_addr
  /** Given an IPv6 address <b>x</b>, yield it as an array of uint16_t.
   *
   * Requires that <b>x</b> is actually an IPv6 address.
   */
  #define tor_addr_to_in6_addr16(x) S6_ADDR16(*tor_addr_to_in6(x))
  /** Given an IPv6 address <b>x</b>, yield it as an array of uint32_t.
   *
   * Requires that <b>x</b> is actually an IPv6 address.
   */
  #define tor_addr_to_in6_addr32(x) S6_ADDR32(*tor_addr_to_in6(x))
  
  /** Return an IPv4 address in network order for <b>a</b>, or 0 if
   * <b>a</b> is not an IPv4 address. */
  static INLINE uint32_t
  tor_addr_to_ipv4n(const tor_addr_t *a)
  {
    return a->family == AF_INET ? a->addr.in_addr.s_addr : 0;
  }
  #   define ntohl(x) __bswap_32 (x)
  /** Return an IPv4 address in host order for <b>a</b>, or 0 if
   * <b>a</b> is not an IPv4 address. */
  static INLINE uint32_t
  tor_addr_to_ipv4h(const tor_addr_t *a)
  {
    return ntohl(tor_addr_to_ipv4n(a));
  }
  /** Given an IPv6 address, return its mapped IPv4 address in host order, or
   * 0 if <b>a</b> is not an IPv6 address.
   *
   * (Does not check whether the address is really a mapped address */
  static INLINE uint32_t
  tor_addr_to_mapped_ipv4h(const tor_addr_t *a)
  {
    return a->family == AF_INET6 ? ntohl(tor_addr_to_in6_addr32(a)[3]) : 0;
  }
  /** Return the address family of <b>a</b>.  Possible values are:
   * AF_INET6, AF_INET, AF_UNSPEC. */
  static INLINE sa_family_t
  tor_addr_family(const tor_addr_t *a)
  {
    return a->family;
  }
  /** Return an in_addr* equivalent to <b>a</b>, or NULL if <b>a</b> is not
   * an IPv4 address. */
  static INLINE const struct in_addr *
  tor_addr_to_in(const tor_addr_t *a)
  {
    return a->family == AF_INET ? &a->addr.in_addr : NULL;
  }
  /** Return true iff <b>a</b> is an IPv4 address equal to the host-ordered
   * address in <b>u</b>. */
  static INLINE int
  tor_addr_eq_ipv4h(const tor_addr_t *a, uint32_t u)
  {
    return a->family == AF_INET ? (tor_addr_to_ipv4h(a) == u) : 0;
  }
  
  /** Length of a buffer that you need to allocate to be sure you can encode
   * any tor_addr_t.
   *
   * This allows enough space for
   *   "[ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255]",
   * plus a terminating NUL.
   */
  #define TOR_ADDR_BUF_LEN 48
  
  int tor_addr_lookup(const char *name, uint16_t family, tor_addr_t *addr_out);
  char *tor_dup_addr(const tor_addr_t *addr) ATTR_MALLOC;
  
  /** Wrapper function of fmt_addr_impl(). It does not decorate IPv6
   *  addresses. */
  #define fmt_addr(a) fmt_addr_impl((a), 0)
  /** Wrapper function of fmt_addr_impl(). It decorates IPv6
   *  addresses. */
  #define fmt_and_decorate_addr(a) fmt_addr_impl((a), 1)
  const char *fmt_addr_impl(const tor_addr_t *addr, int decorate);
  const char *fmt_addrport(const tor_addr_t *addr, uint16_t port);
  const char * fmt_addr32(uint32_t addr);
  int get_interface_address6(int severity, sa_family_t family, tor_addr_t *addr);
  
  /** Flag to specify how to do a comparison between addresses.  In an "exact"
   * comparison, addresses are equivalent only if they are in the same family
   * with the same value.  In a "semantic" comparison, IPv4 addresses match all
   * IPv6 encodings of those addresses. */
  typedef enum {
    CMP_EXACT,
    CMP_SEMANTIC,
  } tor_addr_comparison_t;
  
  int tor_addr_compare(const tor_addr_t *addr1, const tor_addr_t *addr2,
                       tor_addr_comparison_t how);
  int tor_addr_compare_masked(const tor_addr_t *addr1, const tor_addr_t *addr2,
                              maskbits_t mask, tor_addr_comparison_t how);
  /** Return true iff a and b are the same address.  The comparison is done
   * "exactly". */
  #define tor_addr_eq(a,b) (0==tor_addr_compare((a),(b),CMP_EXACT))
  
  uint64_t tor_addr_hash(const tor_addr_t *addr);
  int tor_addr_is_v4(const tor_addr_t *addr);
  int tor_addr_is_internal_(const tor_addr_t *ip, int for_listening,
                            const char *filename, int lineno);
  #define tor_addr_is_internal(addr, for_listening) \
    tor_addr_is_internal_((addr), (for_listening), SHORT_FILE__, __LINE__)
  
  /** Longest length that can be required for a reverse lookup name. */
  /* 32 nybbles, 32 dots, 8 characters of "ip6.arpa", 1 NUL: 73 characters. */
  #define REVERSE_LOOKUP_NAME_BUF_LEN 73
  int tor_addr_to_PTR_name(char *out, size_t outlen,
                                      const tor_addr_t *addr);
  int tor_addr_parse_PTR_name(tor_addr_t *result, const char *address,
                                         int family, int accept_regular);
  
  int tor_addr_port_lookup(const char *s, tor_addr_t *addr_out,
                          uint16_t *port_out);
  #define TAPMP_EXTENDED_STAR 1
  int tor_addr_parse_mask_ports(const char *s, unsigned flags,
                                tor_addr_t *addr_out, maskbits_t *mask_out,
                                uint16_t *port_min_out, uint16_t *port_max_out);
  const char * tor_addr_to_str(char *dest, const tor_addr_t *addr, size_t len,
                               int decorate);
  int tor_addr_parse(tor_addr_t *addr, const char *src);
  void tor_addr_copy(tor_addr_t *dest, const tor_addr_t *src);
  void tor_addr_copy_tight(tor_addr_t *dest, const tor_addr_t *src);
  void tor_addr_from_ipv4n(tor_addr_t *dest, uint32_t v4addr);
  /** Set <b>dest</b> to the IPv4 address encoded in <b>v4addr</b> in host
   * order. */
  #define tor_addr_from_ipv4h(dest, v4addr)       \
    tor_addr_from_ipv4n((dest), htonl(v4addr))
  void tor_addr_from_ipv6_bytes(tor_addr_t *dest, const char *bytes);
  /** Set <b>dest</b> to the IPv4 address incoded in <b>in</b>. */
  #define tor_addr_from_in(dest, in) \
    tor_addr_from_ipv4n((dest), (in)->s_addr);
  void tor_addr_from_in6(tor_addr_t *dest, const struct in6_addr *in6);
  int tor_addr_is_null(const tor_addr_t *addr);
  int tor_addr_is_loopback(const tor_addr_t *addr);
  
  int tor_addr_port_split(int severity, const char *addrport,
                          char **address_out, uint16_t *port_out);
  
  int tor_addr_port_parse(int severity, const char *addrport,
                          tor_addr_t *address_out, uint16_t *port_out,
                          int default_port);
  
  int tor_addr_hostname_is_local(const char *name);
  
  /* IPv4 helpers */
  int addr_port_lookup(int severity, const char *addrport, char **address,
                      uint32_t *addr, uint16_t *port_out);
  int parse_port_range(const char *port, uint16_t *port_min_out,
                       uint16_t *port_max_out);
  int addr_mask_get_bits(uint32_t mask);
  /** Length of a buffer to allocate to hold the results of tor_inet_ntoa.*/
  #define INET_NTOA_BUF_LEN 16
  int tor_inet_ntoa(const struct in_addr *in, char *buf, size_t buf_len);
  char *tor_dup_ip(uint32_t addr) ATTR_MALLOC;
  int get_interface_address(int severity, uint32_t *addr);
  
  tor_addr_port_t *tor_addr_port_new(const tor_addr_t *addr, uint16_t port);
  
  #endif
  
  