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      1 /*
      2  * libjingle
      3  * Copyright 2004--2011, Google Inc.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  *  1. Redistributions of source code must retain the above copyright notice,
      9  *     this list of conditions and the following disclaimer.
     10  *  2. Redistributions in binary form must reproduce the above copyright notice,
     11  *     this list of conditions and the following disclaimer in the documentation
     12  *     and/or other materials provided with the distribution.
     13  *  3. The name of the author may not be used to endorse or promote products
     14  *     derived from this software without specific prior written permission.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
     17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
     19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     26  */
     27 
     28 #ifdef POSIX
     29 #include <sys/types.h>
     30 #include <sys/socket.h>
     31 #include <netinet/in.h>
     32 #ifdef OPENBSD
     33 #include <netinet/in_systm.h>
     34 #endif
     35 #include <netinet/ip.h>
     36 #include <arpa/inet.h>
     37 #include <netdb.h>
     38 #include <unistd.h>
     39 #endif
     40 
     41 #include <stdio.h>
     42 
     43 #include "talk/base/ipaddress.h"
     44 #include "talk/base/byteorder.h"
     45 #include "talk/base/nethelpers.h"
     46 #include "talk/base/logging.h"
     47 #include "talk/base/win32.h"
     48 
     49 namespace talk_base {
     50 
     51 // Prefixes used for categorizing IPv6 addresses.
     52 static const in6_addr kULAPrefix = {{{0xfc, 0}}};
     53 static const in6_addr kV4MappedPrefix = {{{0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     54                                            0xFF, 0xFF, 0}}};
     55 static const in6_addr k6To4Prefix = {{{0x20, 0x02, 0}}};
     56 static const in6_addr kTeredoPrefix = {{{0x20, 0x01, 0x00, 0x00}}};
     57 static const in6_addr kV4CompatibilityPrefix = {{{0}}};
     58 static const in6_addr kSiteLocalPrefix = {{{0xfe, 0xc0, 0}}};
     59 static const in6_addr k6BonePrefix = {{{0x3f, 0xfe, 0}}};
     60 
     61 bool IPAddress::strip_sensitive_ = false;
     62 
     63 static bool IsPrivateV4(uint32 ip);
     64 static in_addr ExtractMappedAddress(const in6_addr& addr);
     65 
     66 uint32 IPAddress::v4AddressAsHostOrderInteger() const {
     67   if (family_ == AF_INET) {
     68     return NetworkToHost32(u_.ip4.s_addr);
     69   } else {
     70     return 0;
     71   }
     72 }
     73 
     74 size_t IPAddress::Size() const {
     75   switch (family_) {
     76     case AF_INET:
     77       return sizeof(in_addr);
     78     case AF_INET6:
     79       return sizeof(in6_addr);
     80   }
     81   return 0;
     82 }
     83 
     84 
     85 bool IPAddress::operator==(const IPAddress &other) const {
     86   if (family_ != other.family_) {
     87     return false;
     88   }
     89   if (family_ == AF_INET) {
     90     return memcmp(&u_.ip4, &other.u_.ip4, sizeof(u_.ip4)) == 0;
     91   }
     92   if (family_ == AF_INET6) {
     93     return memcmp(&u_.ip6, &other.u_.ip6, sizeof(u_.ip6)) == 0;
     94   }
     95   return family_ == AF_UNSPEC;
     96 }
     97 
     98 bool IPAddress::operator!=(const IPAddress &other) const {
     99   return !((*this) == other);
    100 }
    101 
    102 bool IPAddress::operator >(const IPAddress &other) const {
    103   return (*this) != other && !((*this) < other);
    104 }
    105 
    106 bool IPAddress::operator <(const IPAddress &other) const {
    107   // IPv4 is 'less than' IPv6
    108   if (family_ != other.family_) {
    109     if (family_ == AF_UNSPEC) {
    110       return true;
    111     }
    112     if (family_ == AF_INET && other.family_ == AF_INET6) {
    113       return true;
    114     }
    115     return false;
    116   }
    117   // Comparing addresses of the same family.
    118   switch (family_) {
    119     case AF_INET: {
    120       return NetworkToHost32(u_.ip4.s_addr) <
    121           NetworkToHost32(other.u_.ip4.s_addr);
    122     }
    123     case AF_INET6: {
    124       return memcmp(&u_.ip6.s6_addr, &other.u_.ip6.s6_addr, 16) < 0;
    125     }
    126   }
    127   // Catches AF_UNSPEC and invalid addresses.
    128   return false;
    129 }
    130 
    131 std::ostream& operator<<(std::ostream& os, const IPAddress& ip) {
    132   os << ip.ToString();
    133   return os;
    134 }
    135 
    136 in6_addr IPAddress::ipv6_address() const {
    137   return u_.ip6;
    138 }
    139 
    140 in_addr IPAddress::ipv4_address() const {
    141   return u_.ip4;
    142 }
    143 
    144 std::string IPAddress::ToString() const {
    145   if (family_ != AF_INET && family_ != AF_INET6) {
    146     return std::string();
    147   }
    148   char buf[INET6_ADDRSTRLEN] = {0};
    149   const void* src = &u_.ip4;
    150   if (family_ == AF_INET6) {
    151     src = &u_.ip6;
    152   }
    153   if (!talk_base::inet_ntop(family_, src, buf, sizeof(buf))) {
    154     return std::string();
    155   }
    156   return std::string(buf);
    157 }
    158 
    159 std::string IPAddress::ToSensitiveString() const {
    160   if (!strip_sensitive_)
    161     return ToString();
    162 
    163   switch (family_) {
    164     case AF_INET: {
    165       std::string address = ToString();
    166       size_t find_pos = address.rfind('.');
    167       if (find_pos == std::string::npos)
    168         return std::string();
    169       address.resize(find_pos);
    170       address += ".x";
    171       return address;
    172     }
    173     case AF_INET6: {
    174       // TODO(grunell): Return a string of format 1:2:3:x:x:x:x:x or such
    175       // instead of zeroing out.
    176       return TruncateIP(*this, 128 - 80).ToString();
    177     }
    178   }
    179   return std::string();
    180 }
    181 
    182 IPAddress IPAddress::Normalized() const {
    183   if (family_ != AF_INET6) {
    184     return *this;
    185   }
    186   if (!IPIsV4Mapped(*this)) {
    187     return *this;
    188   }
    189   in_addr addr = ExtractMappedAddress(u_.ip6);
    190   return IPAddress(addr);
    191 }
    192 
    193 IPAddress IPAddress::AsIPv6Address() const {
    194   if (family_ != AF_INET) {
    195     return *this;
    196   }
    197   in6_addr v6addr = kV4MappedPrefix;
    198   ::memcpy(&v6addr.s6_addr[12], &u_.ip4.s_addr, sizeof(u_.ip4.s_addr));
    199   return IPAddress(v6addr);
    200 }
    201 
    202 void IPAddress::set_strip_sensitive(bool enable) {
    203   strip_sensitive_ = enable;
    204 }
    205 
    206 
    207 bool IsPrivateV4(uint32 ip_in_host_order) {
    208   return ((ip_in_host_order >> 24) == 127) ||
    209       ((ip_in_host_order >> 24) == 10) ||
    210       ((ip_in_host_order >> 20) == ((172 << 4) | 1)) ||
    211       ((ip_in_host_order >> 16) == ((192 << 8) | 168)) ||
    212       ((ip_in_host_order >> 16) == ((169 << 8) | 254));
    213 }
    214 
    215 in_addr ExtractMappedAddress(const in6_addr& in6) {
    216   in_addr ipv4;
    217   ::memcpy(&ipv4.s_addr, &in6.s6_addr[12], sizeof(ipv4.s_addr));
    218   return ipv4;
    219 }
    220 
    221 bool IPFromAddrInfo(struct addrinfo* info, IPAddress* out) {
    222   if (!info || !info->ai_addr) {
    223     return false;
    224   }
    225   if (info->ai_addr->sa_family == AF_INET) {
    226     sockaddr_in* addr = reinterpret_cast<sockaddr_in*>(info->ai_addr);
    227     *out = IPAddress(addr->sin_addr);
    228     return true;
    229   } else if (info->ai_addr->sa_family == AF_INET6) {
    230     sockaddr_in6* addr = reinterpret_cast<sockaddr_in6*>(info->ai_addr);
    231     *out = IPAddress(addr->sin6_addr);
    232     return true;
    233   }
    234   return false;
    235 }
    236 
    237 bool IPFromString(const std::string& str, IPAddress* out) {
    238   if (!out) {
    239     return false;
    240   }
    241   in_addr addr;
    242   if (talk_base::inet_pton(AF_INET, str.c_str(), &addr) == 0) {
    243     in6_addr addr6;
    244     if (talk_base::inet_pton(AF_INET6, str.c_str(), &addr6) == 0) {
    245       *out = IPAddress();
    246       return false;
    247     }
    248     *out = IPAddress(addr6);
    249   } else {
    250     *out = IPAddress(addr);
    251   }
    252   return true;
    253 }
    254 
    255 bool IPIsAny(const IPAddress& ip) {
    256   switch (ip.family()) {
    257     case AF_INET:
    258       return ip == IPAddress(INADDR_ANY);
    259     case AF_INET6:
    260       return ip == IPAddress(in6addr_any);
    261     case AF_UNSPEC:
    262       return false;
    263   }
    264   return false;
    265 }
    266 
    267 bool IPIsLoopback(const IPAddress& ip) {
    268   switch (ip.family()) {
    269     case AF_INET: {
    270       return ip == IPAddress(INADDR_LOOPBACK);
    271     }
    272     case AF_INET6: {
    273       return ip == IPAddress(in6addr_loopback);
    274     }
    275   }
    276   return false;
    277 }
    278 
    279 bool IPIsPrivate(const IPAddress& ip) {
    280   switch (ip.family()) {
    281     case AF_INET: {
    282       return IsPrivateV4(ip.v4AddressAsHostOrderInteger());
    283     }
    284     case AF_INET6: {
    285       in6_addr v6 = ip.ipv6_address();
    286       return (v6.s6_addr[0] == 0xFE && v6.s6_addr[1] == 0x80) ||
    287           IPIsLoopback(ip);
    288     }
    289   }
    290   return false;
    291 }
    292 
    293 bool IPIsUnspec(const IPAddress& ip) {
    294   return ip.family() == AF_UNSPEC;
    295 }
    296 
    297 size_t HashIP(const IPAddress& ip) {
    298   switch (ip.family()) {
    299     case AF_INET: {
    300       return ip.ipv4_address().s_addr;
    301     }
    302     case AF_INET6: {
    303       in6_addr v6addr = ip.ipv6_address();
    304       const uint32* v6_as_ints =
    305           reinterpret_cast<const uint32*>(&v6addr.s6_addr);
    306       return v6_as_ints[0] ^ v6_as_ints[1] ^ v6_as_ints[2] ^ v6_as_ints[3];
    307     }
    308   }
    309   return 0;
    310 }
    311 
    312 IPAddress TruncateIP(const IPAddress& ip, int length) {
    313   if (length < 0) {
    314     return IPAddress();
    315   }
    316   if (ip.family() == AF_INET) {
    317     if (length > 31) {
    318       return ip;
    319     }
    320     if (length == 0) {
    321       return IPAddress(INADDR_ANY);
    322     }
    323     int mask = (0xFFFFFFFF << (32 - length));
    324     uint32 host_order_ip = NetworkToHost32(ip.ipv4_address().s_addr);
    325     in_addr masked;
    326     masked.s_addr = HostToNetwork32(host_order_ip & mask);
    327     return IPAddress(masked);
    328   } else if (ip.family() == AF_INET6) {
    329     if (length > 127) {
    330       return ip;
    331     }
    332     if (length == 0) {
    333       return IPAddress(in6addr_any);
    334     }
    335     in6_addr v6addr = ip.ipv6_address();
    336     int position = length / 32;
    337     int inner_length = 32 - (length - (position * 32));
    338     // Note: 64bit mask constant needed to allow possible 32-bit left shift.
    339     uint32 inner_mask = 0xFFFFFFFFLL  << inner_length;
    340     uint32* v6_as_ints =
    341         reinterpret_cast<uint32*>(&v6addr.s6_addr);
    342     for (int i = 0; i < 4; ++i) {
    343       if (i == position) {
    344         uint32 host_order_inner = NetworkToHost32(v6_as_ints[i]);
    345         v6_as_ints[i] = HostToNetwork32(host_order_inner & inner_mask);
    346       } else if (i > position) {
    347         v6_as_ints[i] = 0;
    348       }
    349     }
    350     return IPAddress(v6addr);
    351   }
    352   return IPAddress();
    353 }
    354 
    355 int CountIPMaskBits(IPAddress mask) {
    356   uint32 word_to_count = 0;
    357   int bits = 0;
    358   switch (mask.family()) {
    359     case AF_INET: {
    360       word_to_count = NetworkToHost32(mask.ipv4_address().s_addr);
    361       break;
    362     }
    363     case AF_INET6: {
    364       in6_addr v6addr = mask.ipv6_address();
    365       const uint32* v6_as_ints =
    366           reinterpret_cast<const uint32*>(&v6addr.s6_addr);
    367       int i = 0;
    368       for (; i < 4; ++i) {
    369         if (v6_as_ints[i] != 0xFFFFFFFF) {
    370           break;
    371         }
    372       }
    373       if (i < 4) {
    374         word_to_count = NetworkToHost32(v6_as_ints[i]);
    375       }
    376       bits = (i * 32);
    377       break;
    378     }
    379     default: {
    380       return 0;
    381     }
    382   }
    383   if (word_to_count == 0) {
    384     return bits;
    385   }
    386 
    387   // Public domain bit-twiddling hack from:
    388   // http://graphics.stanford.edu/~seander/bithacks.html
    389   // Counts the trailing 0s in the word.
    390   unsigned int zeroes = 32;
    391   word_to_count &= -static_cast<int32>(word_to_count);
    392   if (word_to_count) zeroes--;
    393   if (word_to_count & 0x0000FFFF) zeroes -= 16;
    394   if (word_to_count & 0x00FF00FF) zeroes -= 8;
    395   if (word_to_count & 0x0F0F0F0F) zeroes -= 4;
    396   if (word_to_count & 0x33333333) zeroes -= 2;
    397   if (word_to_count & 0x55555555) zeroes -= 1;
    398 
    399   return bits + (32 - zeroes);
    400 }
    401 
    402 bool IPIsHelper(const IPAddress& ip, const in6_addr& tomatch, int length) {
    403   // Helper method for checking IP prefix matches (but only on whole byte
    404   // lengths). Length is in bits.
    405   in6_addr addr = ip.ipv6_address();
    406   return ::memcmp(&addr, &tomatch, (length >> 3)) == 0;
    407 }
    408 
    409 bool IPIs6Bone(const IPAddress& ip) {
    410   return IPIsHelper(ip, k6BonePrefix, 16);
    411 }
    412 
    413 bool IPIs6To4(const IPAddress& ip) {
    414   return IPIsHelper(ip, k6To4Prefix, 16);
    415 }
    416 
    417 bool IPIsSiteLocal(const IPAddress& ip) {
    418   // Can't use the helper because the prefix is 10 bits.
    419   in6_addr addr = ip.ipv6_address();
    420   return addr.s6_addr[0] == 0xFE && (addr.s6_addr[1] & 0xC0) == 0xC0;
    421 }
    422 
    423 bool IPIsULA(const IPAddress& ip) {
    424   // Can't use the helper because the prefix is 7 bits.
    425   in6_addr addr = ip.ipv6_address();
    426   return (addr.s6_addr[0] & 0xFE) == 0xFC;
    427 }
    428 
    429 bool IPIsTeredo(const IPAddress& ip) {
    430   return IPIsHelper(ip, kTeredoPrefix, 32);
    431 }
    432 
    433 bool IPIsV4Compatibility(const IPAddress& ip) {
    434   return IPIsHelper(ip, kV4CompatibilityPrefix, 96);
    435 }
    436 
    437 bool IPIsV4Mapped(const IPAddress& ip) {
    438   return IPIsHelper(ip, kV4MappedPrefix, 96);
    439 }
    440 
    441 int IPAddressPrecedence(const IPAddress& ip) {
    442   // Precedence values from RFC 3484-bis. Prefers native v4 over 6to4/Teredo.
    443   if (ip.family() == AF_INET) {
    444     return 30;
    445   } else if (ip.family() == AF_INET6) {
    446     if (IPIsLoopback(ip)) {
    447       return 60;
    448     } else if (IPIsULA(ip)) {
    449       return 50;
    450     } else if (IPIsV4Mapped(ip)) {
    451       return 30;
    452     } else if (IPIs6To4(ip)) {
    453       return 20;
    454     } else if (IPIsTeredo(ip)) {
    455       return 10;
    456     } else if (IPIsV4Compatibility(ip) || IPIsSiteLocal(ip) || IPIs6Bone(ip)) {
    457       return 1;
    458     } else {
    459       // A 'normal' IPv6 address.
    460       return 40;
    461     }
    462   }
    463   return 0;
    464 }
    465 
    466 }  // Namespace talk base
    467